Isomeric composition of retinal chromophore in dark-adapted bacteriorhodopsin.

1. Retinal isomers extracted from the acid-hydrolysate of cetyltrimethylammonium bromide-treated dark-adapted bacteriorhodopsin (bRD) were analyzed in a high performance liquid chromatograph (HPLC) system. The extract from bRD contains almost equal molar amounts of both 13-cis retinal and all-trans retinal isomers. The extent of isomerization and the yield of both isomers during the isolation process were investigated by the application of the same extraction procedure to artificial bacteriorhodopsin reconstituted with 13-cis retinal isomer (13-cis bacteriorhodopsin) and also to light-adapted bacteriorhodopsin (bRL) which has been shown to contain only the all-trans isomer (all-trans bacteriorhodopsin). 2. A reconstituted bacteriorhodopsin, which had been prepared from apo-bacteriorhodopsin and an equimolar mixture of both 13-cis retinal and all-trans retinal isomers, showed an absorption spectrum having the same maximum wavelength as that of bRD even at the beginning of the reconstitution process. 3. Analysis of the photosteady states of bRD at -190 degrees C revealed that it was composed of two different species, one having 13-cis retinal and the other having all-trans retinal isomers in approximately equal molar amounts. These two also gave their respective photoproducts. 4. From these results it can be concluded that bRD contains both 13-cis retinal and all-trans retinal isomers in nearly equal molar amounts as its chromophore.


DNA polymerase-beta from the nuclear fraction of sea urchin embryos: characterization of the purified enzyme.

Approximately 2,500-fold purifications of DNA polymerase-beta from the nuclear fraction of blastulae of the sea urchin, Hemicentrotus pulcherrimus, was performed. The enzyme preparation, which was devoid of DNase and terminal deoxynucleotidyl transferase as contaminants, showed a sedimentation constant of 3.0 S in a sucrose density gradient, a molecular weight of 50,000 by gel filtration, and an isoelectric point of pH 8.1. The enzyme activity was resistant to sulfhydryl group inhibitors. Its optimal pH was 9.0-9.5 in Tris-maleate buffer and 10.0 in glycine buffer. The optimal NaCl concentration for the activity was 30-60 mM and about half of the activity remained at 0.4 M NaCl. As a template-primer, the enzyme preferred synthetic homopolymers to activated DNA. The order of this preference was as follows; poly (dA)-oligo (dT)12-18 greater than poly (rA)-oligo (dT)12-18 greater than activated DNA. The above results indicate that the enzyme corresponds to DNA polymerase-beta from vertebrate cells.


Chemical ionization and electron impact mass spectra of oligosaccharides derived from sphingoglycolipids.

Chemical ionization (CI) mass spectra with isobutane and ammonia for the oligosaccharides obtained from sphingoglycolipids were compared with their electron impact (EI) mass spectra. The oligosaccahride moieties were liberated from the parent glycolipids and were further reduced with sodium borohydride. They were analyzed as their permethyl peracetyl and pertrimethylsilyl derivatives. In the CI spectra, peaks corresponding to QM+ and/or [M-59]+ were observed in all of the peracetylated oligosaccharides examined. In CI with ammonia as the reagent, H+ was transferred to nitrogen-containing saccharides to produce [MH]+ and NH4 was transferred to nitrogen-free saccharides to yield [M+NH4]+ as QM+. Non-reducing ends yielded very intense peaks in CI spectra. On the other hand, the reduced end, glucitol, produced rather prominent peaks in EI spectra. Fragment ions due to cleavage of glycosidic bonds were major ones under the CI conditions, and they could be used for elucidating the sugar sequence in the oligosaccharides. An additional characteristic feature in the CI spectra was that ions due to scission of hexosaminyl glycosidic linkages were observed with very high intensities.


Effect of calcium on the endogenous phosphorylation of mouse brain microsomes in vitro.

1. The endogenous phosphorylation of mouse brain microsomes was studied using the technique of acrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS). 2. It was found that specific proteins and lipids in brain microsomes were phosphorylated by the terminal phosphate of ATP under appropriate conditions. Six peaks of radioactivity were observed on SDS-polyacrylamide gel electrophoresis of 32Pi-labelled brain microsomes. The peaks were designated as P-I, P-II, P-III, P-IV, P-V, and P-VI. The peaks from P-I to P-V, which consist of phosphoproteins, underwent rapid dephosphorylation. On the other hand, P-VI, which consists of phospholipids, remained unaffected even after the complete hydrolysis of added ATP. 3. With the addition of 100 muM CaCl2 to the assay medium, the phosphorylation of brain microsomal proteins was stimulated; in the regions of P-I, P-II, and P-III, the amounts of 32Pi incorporation were approximately twice the 32Pi incorporation in the absence of Ca2+. On the other hand, 32Pi incorporation into P-VI was unaffected irrespective of the presence or absence of 100 muM CaCl2. In the presence of higher concentrations of Ca2+ (1-10 mM), the phosphorylation of all components was inhibited.


Luminescence and respiratory activities of Photobacterium phosphoreum. II. Control by monovalent cations.

Luminescent activity of spheroplasts of the cells of Photobacterium phosphoreum was stimulated by Rb+ and K+ and inhibited by Na+ in the medium. Opposite effects of these ions were observed on the rate of O2 consumption of the spheroplasts through the cytochrome and luciferase electron transfer systems. In vitro activities of NADH-FMN reductase and luciferase were only slightly stimulated by Rb+, K+, and Na+, while Na+ exhibited significant activation of the NADH-oxidizing activity of the cells. The redox level of cytochrome b in the spheroplasts during steady-state respiration in an Na+ medium was more reduced, while that of NAD(P) was more oxidized, than those in an Rb+ or K+ medium. Na+ activates the cytochrome electron transfer system at a point between NADH and cytochrome b, and thus has a stimulative effect on cellular O2 consumption. Rb+ and K+ do not show similar activation, but the cellular NAD(P) was brought to a more reduced level, so that in vivo luminescence is stimulated in an Rb+ or K+ medium.


A fluorescence study of egg white riboflavin-binding protein.

1. Denaturation of riboflavin-binding protein (RBP) by guanidine hydrochloride (Gu-HCl) was investigated by measruing the fluorescence of the protein. The denaturation-renaturation processes of RBP by Gu-HCl were fully reversible. The apo-RBP fluorescence had an emission maximum at 343 nm in the absence of Gu-HCl, and at 350 nm in the presence of 4M Gu-HCl, which completely denatured the protein. The relative fluorescence yield of apo-RBP in the presence of 4 M Gu-HCl was about 170% of that in the absence of Gu-HCl. The affinity of native apo-RBP for riboflavin was very strong, while riboflavin was not bound to the denatured form. The equilibrium system of apo-RBP and riboflavin in solutions containing Gu-HCl at various concentrations was analyzed by measuring riboflavin fluorescence. 2. The quenching of apo-RBP fluorescence, probably the fluorescence of tryptophanyl residues, by iodide anions and cesium cations was measured. The fluorescence of apo-RBP in the presence of 4 M Gu-HCl was quenched considerably by iodide and cesium, and Stern-Volmer plots were linear. However, the fluorescence of native apo-RBP was scarcely quenched by iodide or cesium. This suggested that tryptophanyl residues buried inside apo-RBP were responsible for most of the tryptophanyl fluorescence of native apo-RBP.


Subunit structure of hemoglobins from erythrocytes of the blood clam, Anadara broughtonii.

Intracellular hemoglobins of the sea blood clam Anadara broughtonii consist of HbI dimer (33%) and HbII tetramer (60%). The molecular weights of globins of HbI and HbII were determined by sodium dodecyl sulfate (SDS)-gel electrophoresis to be 15,500 and 16,500, respectively. The existence of two dissimilar chains, alpha and beta, in globin from HbII tetramer was confirmed electrophoretically and the chains were separated by CM-cellulose chromatography in 8 M urea. In contrast, globin from HbI dimer showed a single band on two types of electrophoresis. The NH2-terminus and the COOH-terminus of HbI were determined to be proline and leucine, respectively. From the results of finger-printing, the alpha and beta chains from HbII were considered to have a rather similar profile, whereas globin from HbI was very different. The results obtained by amino acid analysis of each chain also supported the above findings. It was thus shown that HbII has an alpha2beta2 subunit structure, which is rare among invertebrate hemoglobins. On the other hand, HbI seems to have two identical subunits, designated as "gamma", and to exist as a "gamma2" dimer structure. Both Anadara Hb's appear to have no functional groups relating to the Bohr effect and to be unable to form a binding site for organic phosphates.


Purification and characterization of choline oxidase from Arthrobacter globiformis.

Choline oxidase was purified from the cells of Arthrobacter globiformis by fractionations with acetone and ammonium sulfate, and column chromatographies on DEAE-cellulose and on Sephadex G-200. The purified enzyme preparation appeared homogeneous on disc gel electrophoresis. The enzyme was a flavoprotein having a molecular weight of approx. 83,000 (gel filtration) or approx. 71,000 (sodium dodecyl sulfate--polyacrylamide disc gel electrophoresis) and an isoelectric point (pI) around pH 4.5. Identification of the reaction products showed that the enzyme catalyzed the following reactions: choline + O2 leads to betaine aldehyde + H2O2, betaine aldehyde + O2 + H2O leads to betaine + H2O2. The enzyme was highly specific for choline and betaine aldehyde (relative reaction velocities: choline, 100%; betaine aldehyde, 46%; N,N-dimethylaminoethanol, 5.2%; triethanolamine, 2.6%; diethanolamine, 0.8%; monoethanolamine, N-methylaminoethanol, methanol, ethanol, propanol, formaldehyde, acetaldehyde, and propionaldehyde, 0%). Its Km values were 1.2 mM for choline and 8.7 mM for betaine aldehyde. The optimum pH for the enzymic reaction was around pH 7.5.


Regulation of the fatty acid composition of alkyl ether phospholipid in Ehrlich ascites tumor cells. The substrate specificities of 1-O-alkylglycerol 3-phosphate and 1-O-alkylglycero-3-phosphocholine acyltransferases.

Activity for the acylation of 1-O-alkyl-GP was found in the microsomes of Ehrlich ascites tumor cells. The reaction product was shown to be 1-O-alkyl-2-acyl-GP by identifying the acetolysis product as 1-O-alkyl-2-acyl-3-acetylglycerol. The acyl transfer activity to 1-O-alkyl-GP was significantly lower than that to 1-acyl-GP. The substrate specificity of 1-O-alkyl-GP acyltransferase was rather broad as regards thiol esters. Similar specificity was observed with 1-acyl-GP acyltransferase. In contrast to these acyltransferase systems, the 1-acyl- and 1-O-alkyl-GPC acyltransferases were specific for polyunsaturated fatty acyl-CoA's. Since a high percentage of polyunsaturated fatty acid and a little palmitic acid were located at the 2-position of 1-O-alkyl-2-acyl-GPC(E), the observed specificities for acyl-COA's of these acyltransferase systems can be considered in relation to the fatty acid composition at the 2-position of 1-O-alkyl-2-acyl-GPC(E) in the cells.


A convenient method for the isolation of 3'-sialyllactose from normal human urine.

A simple method for the preparation of 3'-sialyllactose from normal human urine is described. The method for the collection of sialooligosaccharides is based on adsorption on charcoal followed by elution with a mixture of ethanol, pyridine, and water. The sialooligosaccharide mixture is then fractionated by means of gel filtration on Sephadex G-25 and the low molecular weight fraction is further fractionated on Dowex 1 (eluted with pyridinium acetate) to give five fractions. The last fraction contains almost pure 3'-sialyllactose.


Carotid cross-over bypass. Cerebral revascularization after ligation of common carotid artery.

A rationale is presented for extra-anatomic carotid cross-over bypass to maintain or restore blood flow to the internal carotid artery distal to sites of disruption and ligation of a common carotid artery. Anatomic evidence indicates that the attachment of the carotid sheath to the hyoid bone is a barrier to spread of infection cephalad to that level. A patient with infected and disrupted right common carotid artery associated with an esophageal fistula was treated by double ligation of the artery. Contralateral hemiplegia 48 hours later forced consideration of cerebral revascularization. Left carotid angiography demonstrated patent cerebral vessels on the right, with retrograde filling of the right internal carotid artery to the bifurcation. These findings were interpreted as consistent with technical feasibility of external carotid to external carotid cross-over vein bypass in a suprahyoid location, avoiding reconstruction in an infected area and resulting in prompt recovery of function.


Infections in vascular surgery.

The frequency of postoperative wound infections after 304 vascular surgical procedures was studied. Mean age of the patients was 67 years and the male-female ratio was 5:1. Seventyfive per cent of the operations were of elective type. Wound infections occurred in 12% and was in the majority of cases caused by staphylococcus aureus. Wound infection caused prolongation of hospital stay from 11.9 to 31.3 days. A higher frequency of postoperative wound infections was found in diabetics, in patients with manifest gangrene, in patients with long preoperative hospital stay and after operations with inadequate hemostasis. Infections are potentially dangerous and in this series they caused loss of limb and life in one patient and loss of limb in one.


Factors influenced on prognosis of reconstructive surgery for peripheral arterial occlusion: comparative study between arteriosclerosis obliterans and thromboangiitis obliterans.

Reconstructive surgery was carried out in 93 patients of ASO and TAO. Factors influenced on prognosis were studied being compared with ASO and TAO. Cumulative 5-year patency was 60% in ASO and 25% in TAO. Distal patency was shown by total score given in each site of arteriogram. Patency rate was well correlated with combinated factors such as total score of arteriogram and back flow at site of surgery. Period from onset of symptom to surgery and site of operation also correlated with patency statistically, though total serum cholesterol, ischemic time at reconstructive surgery, and amount of bleeding at operation did not relate to prognosis. Causes of early failure and special problems of late failure in TAO were studied.


Isolated mitral valve replacement with the Björk-Shiley prosthesis in 100 consecutive patients. Short- and long-term results.

Single mitral valve replacement with the Björk-Shiley tilting disc prosthesis was performed in 100 consecutive patients between March 1971 and December 1973. The hospital mortality was 13% and the late mortality was 6%. 74 of the patients were followed for periods ranging between 12 and 46 months (mean follow-up: 24 months): clinical improvement was noted in 92%. The incidence of postoperative embolism, including 1 case of prosthesis thrombosis, was 6.7%, and all cases occurred within the first 9 months after surgery. 6 patients required reoperation because of prosthesis dysfunction due to thrombosis (1 patient), leakage (3), and late disc entrapment (2).


Tissue economics of hydra: regulation of cell cycle, animal size and development by controlled feeding rates.

Epithelial cell production and epithelial cell loss in 6 different size classes of Hydra attenuata were examined to understand the relationships between growth and morphogenesis. The sizes of adult hydra, the sizes of their buds, and their budding rates are all nearly proportional to the amount of food the hydra eat. Hydra fed at high rates (4-25 Artemia nauplii per day) all have the same epithelial cell cycle time (about 4 days). Budding accounts for most of their cell loss. Hydra fed 4-12 Artemia per day maintain a steady state condition in which tissue loss balances tissue growth. Animals fed 25 Artemia per day are not in a steady state growth condition and change in size. At the lowest feeding rates (0-1 Artemia per day), the epithelial cell cycle time is lengthened to about 16 days. Cell loss from the tentacles accounts for most of the cell loss, and this loss is not completely balanced by growth. As a consequence these animals cease budding and shrink in size.


Radical repair of total anomalous pulmonary venous drainage with atrial and ventricular septal defects.

An eleven year old patient with TAPVD, ASD and VSD with left to right shunt who underwent successful total correction is presented. Diagnosis, operative technique and the pertinent literature are briefly discussed.


Failure of a Björk-Shiley mitral valve prosthesis to open: clinical recognition.

Failure of a Björk-Shiley mitral valve prosthesis to open was recognized early in the postoperative period and required immediate replacement. The clinical finding was sudden, intermittent, severe hypotension associated with absent poppet sounds and simultaneous elevation in left atrial pressure. This unique and unusual hemodynamic picture was duplicated in four animal experiments. Routine monitoring of left atrial pressure is a useful postoperative adjunct that can provide early documentation of obstruction to left atrial outflow. Early recognition of the problem and immediate operative correction are mandatory.


Studies of anionic sites on the cell surface of the amoeba Naegleria gruberi using cationized ferritin.

Interaction of cationized ferritin with the anionic groups on the cell surface of Naegleria was studied using transmission electron microscopy in conjunction with fluorescence microscopy. Most of the experiments involved the use of fluorescein-labelled cationized ferritin (FITC-CF) incubated with living amoebae. Initially the FITC-CF was located over the posterior two-thirds of the amoebae but the label was rapidly redistributed to form a cap at the posterior end in the region of the uroid; frequently this cap was shed. Pinosomes containing FITC-CF were clearly visible within the amoebae. Amoebae prefixed in glutaraldehyde were uniformly stained and did not show redistribution of the label. Exposure of live amoebae, previously incubated with cationized ferritin and allowed to cap, to fresh FITC-CF failed to produce fluorescent staining of the general cell surface, i.e. depletion of binding sites had occurred. The binding of the FITC-CF was not affected by pretreatment of the amoebae with neuraminidase or pronase. The possible nature of the anionic sites on the membrane is discussed.


Studies of membrane fusion. I. Paramyxovirus-induced cell fusion, a scanning electron-microscope study.

Fusion of erythrocytes and HeLa cells with Sendai and Newcastle disease viruses has been studied by scanning electron microscopy. Most virus particles are spherical but vary in diameter from approximately 200 to approximately 600 nm. At 4 degrees C virus particles bind randomly to the cell surface and at high cell densities cross-linking of adjacent cells by virus particles results in cell agglutination. Cell-cell fusion takes place when the agglutinated cell suspension is warmed to 37 degrees C. Fusion is initiated at sites of cell-cell contact and is accompanied in all cases by cell swelling. In the case of suspension HeLa cells, virally mediated cell swelling involves an 'unfolding' of cell surface microvilli and results in the formation of smooth-surfaced single or fused cells. With erythrocytes, swelling results in haemolysis. There is a dramatic reduction in the numbers of virus particles bound to cells following fusion.


Anomalous origin of the left coronary artery from the pulmonary artery. Surgical repair of an unusual form.

The authors present a case of a 24-year-old woman with anomalous left coronary artery originating from the pulmonary artery. Surgical correction was performed by the direct transposition of the anomalous left coronary artery from the pulmonary artery to the ascending aorta, without interposed graft. Pre- and postoperative evaluations, including angiograms and cycloergometer stress test are presented. The advantages of this technique are discussed, emphasizing the creation of a two-coronary system without the use of prosthetic, arterial or venous grafts. In the present case the left coronary artery originated from the right posterior sinus of the pulmonary artery. The patient is doing well 23 months after operation.


Surgical treatment of aortic valve insufficiency due to annulo-aortic ectasia.

Five cases of annulo-aortic ectasia are described: etiology was cystic medial necrosis in three, syphylitic aortitis in one and giant-cell aorto-arteritis in another. Apart from the latter patient, in whom the ascending aorta was not truly aneurysmal and aortic valve replacement and aneurysmorraphy were considered adequate, total replacement of the ascending aorta and valve was employed in every case. All patients survived without any complication related to the technique, and are completely asymptomatic 14 to 26 months after the operation. The available techniques for managing annulo-aortic ectasia are reviewed, and their merits and drawbacks discussed.


Endotoxin-induced platelet aggregation and secretion. II. Changes in plasma membrane proteins.

Responses of blood platelets to bacterial endotoxin lipopolysaccharide (LPS) have been correlated with changes in the molecular organization and composition of the platelet plasma membrane proteins. Binding of LPS, which occurred in the absence of Ca2+, was distinguished from platelet aggregation and degranulation, which required Ca2+ and plasma proteins. Changes in membrane organization were detected by double-labelling with [125I] and [131I] iodide, mediated by lactoperoxidase and hydrogen peroxide. Changes in total membrane composition were detected by gel electrophoresis of isolated membranes. Binding of LPS was associated with increased accessibility of a protein of mol. wt. 80000 to iodination. After aggregation and degranulation there was, in addition, increased accessibility of proteins of mol. wt. 68000 and 48000. Isolated membranes from LPS-stimulated platelets contained more of a protein of mol. wt. 200000 and less of a protein of mol. wt. 220000 than control membranes prepared from unstimulated platelets in the presence of cAMP and aminophylline. The relationship of the modified plasma membrane proteins to the contractile proteins of the platelet and their possible redistribution in the cell during aggregation and secretion is discussed.


Partial perfusion in awake neonatal lambs: a comparison of three methods.

A comparison of the effects of extended partial perfusion of conscious lambs was made between the use of a silicone-tube membrane oxygenator and a bubble oxygenator (Infant Temptrol). The survival time of the lambs was markedly shortened with the bubble oxygenator, although much longer than had been anticipated. A serious problem was uncontrollable bleeding from the cannulation wounds with a rapidly declining PCV. In a third group of experiments the suitability of Ancrod (Arvin-extract of the venom from the Malayan Pit Viper) as an anticoagulant for extended perfusion with a membrane oxygenator was assessed. In our hands bleeding from the cannulation wounds was marked and difficult to control. The fall in the haematocrit which accompanied the bubble and the arvin series was rapid and appeared to be greater than may have been expected from the loss alone. The decline in several of the plasma components appeared to be due largely to the fall in the haematocrit. Successful perfusion of conscious lambs for up to 96 hours was possible with a silicone-tube membrane oxygenator with Heparin anticoagulation.


Suppression of myoblast fusion by concanavalin A: possible involvement of membrane fluidity.

Experimental evidence is presented which is consistent with the involvement of membrane fluidity during myoblast fusion. Treatment of pretrypsinized myoblasts with tetrameric Con A, but not with the dimeric succinyl derivate, inhibits fusion. Inhibition is reversed by treatment with alpha-methyl-D-mannoside or subsequent trypsinization. No inhibition is observed when the lectin is incubated with cells at 4 degrees C unless the incubation is followed by treatment with glycogen, a multivalent Con A cross-linking agent. This effect of glycogen is reversed by subsequent treatment with alpha-amylase. Direct observation of Con A-binding site topography by transmission electron microscopy of membrane replicas of cells labelled with Con A and haemocyanin reveals that inhibition of fusion correlates with a clustered distribution of Con A-binding sites, whereas normal fusion correlates with a dispersed distribution.


Association of membrane cisternae and macrotubules in vinblastine-treated histiocytes.

Resting histiocytes within the dermis and epidermis of the cichlid fish Pterophyllum scalare exhibit an unusual association between stacks of lamellar cisternae and tubular structures greater in diameter than ordinary microtubules (macrotubules) after treatment with 2 x 10(-4) M vinblastine. Macrotubules are found in the intercisternal spaces in a regular side-by-side orientation and extend the entire length of the cisternae. The lamellae seem to be formed as a result of increased membrane proliferation of the outer nuclear membrane; in some instances, cisternae have been observed to be continuous with the nuclear envelope. Since blebbing of the outer nuclear membrane is also observed in untreated histiocytes, lamellae formation is envisaged as hypertrophy of a normally occurring process. The association of lamellae with macrotubules possibly indicates a relationship between membranes and microtubule proteins.


Effects of ultraviolet light on synchronized Chinese hamster ovary cells; potentiation by hydroxyurea.

We have examined the effects of hydroxyurea on u.v.-irradiated Chinese hamster CHO-KI cells. Ultraviolet irradiation followed by incubation with hydroxyurea causes only slight disruption of DNA and chromosome structure in CHO-KI cells compared with HeLa cells. There is, however, a clear potentiation by hydroxyurea of the u.v. killing of CHO-KI cells, which is most pronounced at those points in the cycle which are reported to have small DNA precursor pools. This potentiation is reduced when DNA precursors are provided together with hydroxyurea. These data are discussed in terms of an uncoupling of excision and repair DNA synthesis.


The abdominal epidermis of the blowfly Calliphora erythrocephala. II. Imaginal histoblasts during larval life.

Abdominal histoblasts in Calliphora (Diptera) are situated within the larval epidermis, and secrete larval cuticle throughout the 3 larval instars. An optical and electron-microscopic study of histoblasts and epidermal sensilla suggests that the latter have been previously confused with histoblast Anlagen in the first instar. A steady rate of division until the mid-third instar leads to Anlagen growth, which is not seen in larval Drosophila. After a relatively quiescent period, division begins again, at a higher rate, at the time of pupariation (at the time when division first begins in Drosophila). During prepuparial larval life, the ventral, dorsal, and postero-dorsal Anlagen increase from approximately 6, 8 and 4 cells to about 350, 500 and 150 cells respectively. At the time of the second (puparial) mitotic phase there is also extensive reorganization of cellular fine structure in which large secondary lysosomes play an important part. The endoplasmic reticulum and Golgi subsequently present a different profile. At the same time numerous chromatic droplets appear in the rapidly dividing histoblast Anlagen. This division and the appearance of chromatic droplets are shown (and the subcellular reorganization is suggested) to depend upon the hormonal factors which are responsible for pupariation.


Transcriptional reactivation of isolated Xenopus erythrocyte nuclei: patterns of RNA synthesis.

Nuclei isolated from Xenopus erythrocytes can be transcriptionally reactivated by exposure to certain cytoplasmic proteins. The types of RNA synthesized during this reactivation have been studied and compared with those present in, or synthesized by, isolated nuclei not so reactivated or in entire Xenopus erythrocytes. In all cases, the pattern of transcription indicates the synthesis of a broad range of low molecular weight RNAs. Competitive hybridization demonstrates that the reactivated nuclei synthesize some transcripts not normally produced by the isolated nuclei and we have shown that a proportion of these possess amino acid-accepting activity. The significance of these results is discussed in relation to the control of gene activity in these cells.


Autoradiographic evidence for the effects of light on RNA and DNA synthesis during chloroplast replication in spores of Polytrichum.

Light stimulates the incorporation of [3H]uridine and [3H]thymidine in addition to plastid replication in germinating Polytrichum spores. Significant amounts of [3H]uridine and [3H]thymidine are incorporated in darkness but not to the same level as in light. Plastids continue to produce nucleic acids when their capacity to multiply is suspended due to the absence of light. However, a higher amount of DNA synthesis in the light is correlated with the result that chloroplast replication begins again in the light after prolonged dark incubation. An imperfect association of plastid replication and nucleic acid synthesis is suggested by the lack of stimulation of DNA synthesis by light during plastid replication in the first 8 h of incubation. A temporal separation can be demonstrated for chloroplast and nuclear DNA synthesis at the beginning of germination in Polytrichum spores, with DNA synthesis in the chloroplasts preceding that in the nucleus. The mitotic S phase is longer than 16 h for at least half of the nuclei.


Kaposi's sarcoma: histopathological study of 159 cases from Malawi.

The histological features of 168 lesions of Kaposi's sarcoma from 159 patients in Malawi, where the disease is commoner than elsewhere, were characteristic. All showed well-developed areas of tumour and could be grouped fairly readily into those with a mixed pattern, a predominantly spindle cell pattern, and an anaplastic group, though intermediate patterns were seen. Hyaline bodies were present in nearly all tumours of skin. The cell of origin of Kaposi's sarcoma is uncertain and possibly has multipotential capabilities. Differential diagnosis may be difficult. Clinically the lesion may be confused with granuloma pyogenicum and may also be like it histologically. The presence of hyaline bodies and deposits of haemosiderin indicate Kaposi's sarcoma. The spindle cell predominant type may be confused with leiomyoma, leiomyosarcoma, or fibrosarcoma. The presence of hyaline bodies and the formation of vascular channels between spindle cells point to a diagnosis of Kaposi's sarcoma.


Application of a screening test for antibody the hepatitis B core antigen.

Hepatitis B core antigen (HBcAg) was prepared from human liver tissue and used in an immunoelectro-osmophoresis screening test to detect antibody to HBcAg (anti-HBc) in patients with evidence of liver disease and in blood donors. With the exception of two immunosuppressed HBsAg carriers, anti-HBc was found in all cases of hepatitis B infection even when HBsAg was detectable only by radioimmunoassay. Non-specific reactions were observed in 'non-B' hepatitis but, in spite of this problem, antib-HBc screening was considered a useful addition to routine tests in the clinical hepatitis laboratory.


e Antigen and antibody in outbreaks of hepatitis B in two renal dialysis units.

In two renal dialysis units which had outbreaks of hepatitis B, patients were studied for the presence of e antigen and antibody. In one unit, in which the illness was mild and most of the patients (78%) became carriers of HBsAg, all but one patient had e antigen. Most of the HBsAg carriers had persisting e antigen and most of the transient patients had also transient e antigen. In the other unit, in which the illness was more severe, none of the patients became a carrier. Only 30% had e antigen during the acute phase of illness and 40% developed anti-e just before clearing HBsAg. It seems possible that the difference between these two units may reflect strain differences in the infectivity of hepatitis B virus.


Cerebrospinal fluid immunoglobulins and complement in meningococcal meningitis.

Cerebrospinal fluid (CSF) immunoglobulins (IgA, IgG, IgM) were measured in 107 patients with meningococcal meningitis. Levels were correlated significantly with CSF total protein, and both CSF immunoglobulin and protein increased with age. C3 was measured in the CSF of 38 patients and was also closely correlated with the CSF protein level. C3 breakdown products were found in all six CSFs tested. The CSF immunoglobulin and complement were thought to have leaked from the plasma due to inflammation of the meninges and had little value in diagnosis or prognosis.


Serum IgM antibody and influenza A infection.

Sucrose density gradient ultracentrifugation followed by haemagglutination inhibition for demonstrating specific influenza IgM was evaluated as a means of confirming recent infection with influenza A viruses. Specific IgM antibodies were found in at least one serum obtained from 83% of patients with proven recent infection with influenza A viruses but in none of the sera from 21 individuals without evidence of infection. Influenza IgM antibodies persisted for up to 112 days after infection. The relative merits of detecting specific IgM and complement fixing antibodies for diagnostic purposes are discussed.


Stool microscopy in screening for steatorrhoea.

A prospective study is described comparing microscopy of random faecal specimens for the presence of neutral and split fat by a relatively simple, cheap, and rapid methods with standard chemical estimation of faecal fat. The method of microscopy was found to be reliable in excluding steatorrhoea in children over the age of 3 months.


Modified semiautomated method for free fatty acids in serum.

Modifications have been made to the reagent system of the semiautomated method for the determination of plasma free fatty acids by Baird et al. (1967), and results are reported of investigations into parameters affecting sensitivity and analytical range.


Cryopreservation of human granulocytes in liquid nitrogen.

Human granulocytes (PMNL) were successfully cryopreserved for up to 14 months. The PMNL (1-2 X 10(7)/ml) were stored in 2-ml ampoules in the gas phase of liquid nitrogen at a temperature between -160 degrees C and -196 degrees C using dimethylsulphoxide (DMSO 10%) as cryoprotectant. Morphology and phagocytic and bactericidal capacity were best preserved by adding fetal calf serum to the freezing mixture, by using an interrupted cooling process, by washing the thawed PMNL in fresh freeze-dried plasma, and centrifuging at 600 g for no more than two minutes. Careful post-thaw handling of the cells was an important factor in preserving function. These preliminary studies indicate that useful numbers of PMNL can be recovered in a functional state after storage for long periods in liquid nitrogen.


Serial plasmapheresis in a haemophiliac with antibodies to FVIII.

Serial plasmaphereses were performed on a 23-year-old haemophiliac, with antibodies to factor VIII (FVIII), in order to reduce the antibody level before multiple dental extractions. Eight phereses were carried out in which approximately 1.5 litres plasma was exchanged with isotonic saline. By the ninth exchange, which was carried out immediately before the extraction, the antibody level had fallen from 4 u/ml to 0.8 u/ml. On this occasion fresh frozen plasma and FVIII concentrate were infused immediately after the pheresis. A normal post-infusion level of FVIII was achieved with a normal half disappearance time of the infused FVIII.


Comparison of anticoagulants for the preservation of prothrombin time specimens.

The value of different anticoagulants as preservatives of specimens for prothrombin time ratios is evaluated and discussed. An increase in the ratio was demonstrated with all anti-coagulants after 24 hours and this was significant when coagulometer error was taken into account. Both solid and liquid sodium citrate were superior to sodium oxalate as preservatives at 24 hours after taking off samples, but differences were slight and were not significant when coagulometer error was considered. It was concluded that for routine clinical practice, where a range of the prothrombin time ratio of 1.8/1 to 2.5/1 is allowable, there would be no significant advantage in any of the anticoagulants considered.


Practolol therapy associated with a systemic lupus erythematosus-like syndrome and an inhibitor to factor XIII.

A patient is described who had an inhibitor to coagulation factor XIII associated with serum autoantibodies to certain tissues. The relationship of these abnormal findings to practolol therapy suggests that this was practolol-induced lupus erythematosus. Further investigations delineating the site of action of the inhibitor to factor XIII are reported.


Methylphenidate, amygdalectomy, and active avoidance performance in the rat.

Amygdalectomized and control rats were given 400 active avoidance training trials in a shuttle box. Control animals received 0, 4, 8, or 16 mg/kg of methylphenidate throughout acquisition. Amygdalectomized animals were given the first 200 trials without drug, followed by 200 trials with drug. The administration of methylphenidate produced an abrupt and large improvement in performance in the amygdalectomized animals. One month after acquisition under the drug, retraining without drug revealed a significant retention effect for the three amygdaloid-drug groups relative to the nondrug-amygdaloid group. These results indicate that although amygdalectomy impairs the performance of avoidance responses, it does not prevent the learning or retention of such responses. Since methylphenidate appears to act primarily on dopaminergic mechanisms, the possible influence of amygdalectomy on such mechanisms is discussed.


The renin-angiotensin system and thirst: a reevaluation. II. Drinking elicited in rats by caval ligation or isoproterenol.

Ligation of the inferior vena cava and administration of isoproterenol have been shown to stimulate renin secretion and to augment water intake in rats. However, the present experiments suggested that the plasma renin activities produced by these treatments do not account for more than 20% of the observed drinking behavior. Direct measurements of arterial blood pressure further indicated that nephrectomized rats go into hypotensive shock after caval ligation or isoproterenol treatment. Drinking was elicited in these hypotensive animals by systemic injection of hypertonic NaCl solution, renin, or Pitressin, or by intracranial injection of angiotensin, but in each case a rapid increase in blood pressure also was observed. Thus, it appears that nephrectomy reduces water intake in these animals by undermining their general capacity to behave rather than by removing a specific dipsogenic stimulus. These and other results suggested that drinking elicited in rats by caval ligation or isoproterenol is not mediated by the renin-angiotensin system.


Body weight and gastric acid secretion in rats with subdiaphragmatic vagotomy and lateral hypothalamic lesions.

In an experiment to investigate the role of the vagus in the lateral hypothalamic (LH) syndrome of body weight loss, male albino rats were divided into four groups: (a) animals with bilateral LH lesions that were subsequently given a bilateral subdiaphragmatic vagotomy, (b) LH animals that received a control vagotomy operation, (c) nonlesion animals that were given a subdiaphragmatic vagotomy operation, (c) nonlesion animals that were given a subdiaphragmatic vagotomy, and (d) nonlesion animals that received a control vagotomy operation. Both LH lesions and vagotomy reduced body weight levels, though the effects differed in terms of the length of time required to reach initial maximal loss, the time required to reach chronic levels of maintenance, and the severity of body weight reduction. Fasting gastric acid secretion was lowered by LH lesions, and the extent of this reduction was positively correlated with the reduction in body weight. Finally, gastric contents after a 24-hr fast were greater in vagotomized rats than in nonvagotomized animals. These data are discussed in relation to the changes in gastric functioning after LH lesions and vagotomy.


Central and peripheral cholinergic involvement in the habituation of investigatory head poking in rats.

The effects of some centrally and peripherally acting cholinergic agonists and antagonists on locomotor exploration and investigatory head poking were studied in rats. An apparent disruption of within-trials habituation of locomotion and head-poke frequency was demonstrated for arecoline, nicotine, carbachol, scopolamine, and methylscopolamine. It is suggested that the effect may be a consequence of a drug-induced depression of initial activity. When this factor was eliminated, both scopolamine and methylscopolamine showed some slight attenuation of habituation. The increase in head-poke duration over time in controls was blocked by scopolamine; although peripheral factors were involved, the scopolamine effect had a singinficant central component. The results are discussed in relation to hypothetical links between the cholinergic system and habituation.


Central progesterone induces female sexual behavior in estrogen-primed intact males rats.

Progesterone induced high levels of female lordotic behavior in 10 of 17 intact, estrogen-primed male rats when it was applied directly to the medial preoptic-anterior hypothalamic area. All 17 males previously had shown lordosis when the serotonergic antagonist methysergide was applied to the same central sites. Few males responded to systemic progesterone and none to intracralial cholesterol. Intradiencephalic Metycaine, a local anesthetic, induced lordosis in eight male that previously had responded to central progesterone. These data indicate that estrogen and progesterone act synergistically to induce lordosis in male rats when progesterone is administered directly to sensitive brain sites.


Sexual dimorphism in ultrasonic vocalizations of mice (Mus musculus): gonadal hormone regulation.

Male mice (Mus musculus), during courtship and sexual behavior, vocalize substantially more 70-kHz ultrasounds than do females. Four experiments demonstrated that testosterone propionate (TP) substantially increased ultrasonic emissions and mounting by ovariectomized females and the long-term gonadectomized males and females increased their amount of ultrasound production in response to TP to approximately the same levels. From these results it is suggested that the sexual dimorphism normally seen in ultrasonic vocalizations can be accounted for by the activational effects of androgen in adulthood.


Effects of feeding protected tallow on composition of milk and milk fat.

Official methods were used to analyze composite samples of milk collected during the first 15 wk of lactation from 21 Holstein cows fed a milled ration containing 0 (basal), 15% (medium, or 30% (high) protected-tallow supplement (seven cows per treatment). Protein fractions and amino acid composition of the total proteins were determined from samples of individual milking. Melting characteristics of pooled samples were determined by nuclear magnetic resonance. Milk yield was similar for the three treatments, but percent fat and fat yield were higher for cows fed protected tallow. Percentages and yields of protein and solids-not-fat were decreased on the protected tallow treatments, especially for high tallow. The decrease in protein was in the casein fraction. Amino acid composition of the total proteins was similar for the three treatments. Feeding protected tallow caused decreases in all fatty acids except 4:0, 16:1, 18:0, and 18:1 which increased. Nuclear magnetic resonance indicated that butter from the basal group would be harder than that from cows fed protected tallow.


Influences of barley and oat silages for beef cows on occurrence of myopathy in their calves.

Sixteen pregnant Shorthorn cows were winter-fed either oat or barley silage, both of which were low in selenium (less than .1 ppm). Two months before calving, as well as at calving and a month later, four cows on each diet were given intramuscularly a preparation containing 1360 IU of vitamin E and 30 mg selenium as sodium selenite. Barley silage lipids contained higher linoleic (33.2 versus 22.3%) and palmitic acids (32.3 versus 23.1%), and lower oleic (6.3 versus 22.1%) and linolenic acids (20.9 versus 30.9%) than oat silage. Three calves born from the untreated dams on barley silage died from nutritional muscular dystrophy by 50 days of age whereas none of the calves either from the untreated cows on oat silage or from any of the selenium/vitamin E treated cows. Milk from untreated cows fed barley silage contained a higher proportion of linoleic acid than that from treated cows or from those on oat silage. The incidence of nutritional muscular dystrophy was associated closely with ingestion by the calves of an increased amount of dietary dienoic acid. It appears an advantage to include oat silage in winter feeding programs for beef cows to reduce the risk of development of nutritional muscular dystrophy in the offspring.


Efficacy and safety of 1alpha-hydroxyvitamin D3 for prevention of parturient paresis.

Four trials involved intravenous or intramuscular injections of 1alpha-hydroxyvitavin D3 to test efficacy in preventing parturient paresis. Use of .1 mg intravenously afforded total protection compared with an incidence of 33% (2/6) in controls. Intramuscular injections of .1 mg in 2 ml propylene glycol and .3, .5, and 1.0 mg in 5 ml corn oil resulted in 0, 15.7, 20, and 0% incidence of parturient paresis compared with 33, 16.7, 37.5, and 37.5% incidence of parturient paresis in the controls. There was a rapid increase in serum calcium (12 to 24 h) in response to intravenous treatment, whereas the response to intramuscular injections was gradual but was maintained longer. To evaluate the safety of 1alpha-hydroxyvitamin D3, eight cows, two per treatment, were given intramuscular doses of .5, 1.0, 1.5, or 3.0 mg (three 1.0 mg injections) in 5 ml corn oil. No clinical or pathological evidence of hypervitaminosis C or soft tissue calcification was found. Tissue taken from the injection site 15 days after last injection contained 3 to 38 IU vitamin D activity per 100 g wet tissue compared with control of 8 to 15 IU per 100 g. Total vitamin D activity of milk taken the 11th milking postpartum from cows receiving .5 or 1.0 mg had a mean of 13.4 and 22.6 IU vitamin D activity per liter compared to 19 IU per liter for control milk. Milk from the 5th milking postpartum in the cows receiving .5 mg had a mean activity of 14.5 IU per liter. Milk from animals slaughtered for retention studies had a mean activity of 22 IU per liter.


Effect of tris (hydroxymethyl) aminomethane salt of prostaglandin F2alpha on post-thaw motility of bovine spermatozoa.

The effect of the tris (hydroxymethyl) aminomethane salt of prostaglandin F2alpha on the post-thaw motility of bovine spermatozoa was evaluated for two ejaculates from each of five bulls. This salt of prostaglandin F2alpha was added to the glycerol fraction of the extender to provide 37.5, 112.5, or 337.5 microgram of active prostaglandin F2alpha per .5-ml straw. Post-thaw progressive motility was depressed by the addition of the salt of prostaglandin F2alpha. Motilities averaged over both 0 and 2 h of post-thaw incubation were 19.3, 17.8, 13.6, and 5.8% for 0, 37.5, 112.5, and 337.5 microgram.


Detection of estrus by three methods.

Estrus was detected by three methods in 88 postpartum Holstein cows housed in tie-stalls and allowed free activity 1 to 2 h daily in separate exercise lots. Cows in each of three groups were observed visually for standing estrus by herdsmen. Cows (31) in Group I were observed only visually and served as controls, cows (33) in Group II were fitted with MateMaster rump-mounted detectors, and cows (24) in Group III were exposed to a testosterone-treated marking heifer. Cows with less than 1 ng/mg progesterone in serum on the day of detection and greater than 1 ng/ml 10 days later were designated as accurately detected in estrus. Accuracies of detections for cows in Groups I, II, and III were 68, 66, and 79%. Efficiencies of detections were the total observed estrous periods divided by the total expected estrous periods and were 51, 51, and 52%. In addition, overall accuracy, a mathematical product of individual accuracy and efficiency, represented the best measure of a detection method. Overall accuracies in Groups I, II, and III were 35, 34, and 41%.


The role of accommodation in increasing the luminance of the fundus reflex during cognitive processing.

The phenomena observed during book retinoscopy include changes in the brightness of the reflex in response to changes in cognition. This experiment shows that the increase in luminance of the relfex that results from increased cognitive demand is mediated by accommodation. The luminance of the fundus reflex was monitored while subjects either read or added a series of two-digit numbers. During the addition task the luminance of the reflex increased in all cases. However, under cycloplegia the increase in luminance could not be predicted.


Conjoint therapy: a cooperative psychotherapeutic-optometric approach to therapy.

Optometrists often see patients who have psychological problems as well as visual problems. These patients are often referred to other disciplines for appropriate care. Although it is recognized that visual problems and emotional problems affect each other, after the appropriate referral very little interdisciplinary interaction occurs. The authors believe that this interaction--Conjoint Therapy--is frequently crucial for the successful remediation of the patient's emotional problem as well as his visual problem. They present in this report, just such a case with an anecdotal abstract from the psychological as well as the visual therapy reports.


The ocular manifestations of multiple sclerosis.

Multiple sclerosis is a disease of the central nervous system whose clinical manifestations include animportant group of ocular pathologies, e.g., unilateral retrobulbar neuritis, uveitis, decreased visual function, nystagmus, internuclear ophthalmoplegia, diplopia, optic papillitis and Marcus Gunn pupil. Additionally, it is not generally appreciated that bitemporal hemianopia, usually associated with tumors of the optic chiasm, may also result from multiple sclerosis. Since most of a patient's life is spent in the remission phase of the disease, it is important for the practitioner to recognize the ocular findings present during this period. Additionally, studies have shown that such patients lead longer and more productive lives than most practitioners realize, and often have prolonged periods of remission. While the onset of the disease may present with ocular symptoms, such as loss of vision or diplopia, the patients tend to recover and retain relatively good function for many years.


The unwanted ocular effects from topical ophthalmic drugs. Their occurrence, avoidance and reversal.

Unwanted effects may occur when drugs are applied topically on the eye or when they are administered by other routes. The unwanted effects may be ocular, systemic or both. This paper discusses unwanted ocular effects which may arise when certain optometric drugs are applied directly on the eye. Among the effects described are allergic reactions, infections, pigmentary changes, and the production of aqueous "floaters." Changes in intraocular pressure and appropriate first aid measures to counter an acute rise in IOP are also discussed. Not discussed are the adverse ocular effects which are associated with topical application of the potent anticholinesterases nor those which can arise when certain drugs e.g. corticosteroids are applied to the eye for therapeutic purposes.


The value of observation as adjunct to the objective-subjective examination.

A new approach is presented to the refractive procedure by adding observation, both surreptitious and direct, as an adjunct, an aid and a supplement to differential diagnosis in a refractive examination and in visual analysis.


Research in orthokeratology. Part VII: examination of techniques, procedures and control.

Since contact lenses are responsible for producing corneal change it is essential to rigorously examine for variables involved. The need to control corneal change further dictates that fitting procedures or techniques should also be critically evaluated. Given in this first of a two part series is a background discussion of contact lens prescribing characteristics and resultant data collected during an orthokeratology study. Specifically examined were the effects of the base curve-cornea relationship, lens position and temporal factors. Though each was noticed to be involved in the results obtained, their failure to account for all changes observed suggest that other mechanisms need be considered.


Treatment of decompensating strabismic who had diplopia and vertex headaches.

A 26-year-old female was referred for treatment who presented possible retrobulbar optic atrophy, reduced visual acuity, an LXT, a diplopia, and vertex headaches. Fresnel prisms, the simplest and most logical treatment choice were used to relieve the complaints of diplopia and vertex headaches.


Avlox--a new atraumatic method of skin closure: a preliminary report.

The Avlox system, a recently introduced atraumatic method of closing skin, can be used on any surface in which skin edges can be approximated without undue pressure. Although the method has many advantages over conventional suture methods, the authors do not recommend use of the clips on weight-bearing surfaces or above bony prominences.


The metatarsal osteotomy: a 10-year follow-up on the second, third and fourth metatarsal osteotomies and a new approach to the fifth metatarsal osteotomy.

The metatarsal osteotomy, a relatively simple procedure, provides a great amount of correction and relief with a limited amount of bone resection. Postoperative pain and edema are minimal, and disability and loss of time from employment are eliminated as patients are able to walk immediately in a surgical shoe. If biomechanical management is not adequate in relieving discomfort, then a 10-year study of more than 1000 cases indicates that the osteotomy is the procedure of choice.


A new surgical technique for metatarsus primus varus correction with radical bunionectomy: a preliminary report.

Dr. Panacos has developed a new surgical technique for correction of metatarsus primus varus. His technique, which is indicated in moderate to severe metatarsus primus varus (when the intermetatarsal angle exceeds 15 degrees), makes use of a stabilizing implant at the first metatarsal-cuneiform joint. Although the procedure has been performed on a limited number of patients, the author believes it to be superior to the osteotomy for metatarsus primus varus correction.


Nematospiroides dubius: stimulation of acquired immunity in inbred strains of mice.

The development of immunity to Nematospiroides dubius was studied in three strains of inbred mice (BALB/c, C3H and NIH). Although a primary infection in NIH mice persisted for two months without evidence of a reduction in worm numbers, female mice of this strain readily developed resistance to reinfection. The degree of resistance was enhanced when an immunizing infection of 600 larvae was administered as 6 separate doses of 100 larvae given between days 0 and 11, and the worms removed by anthelmintic treatment given on days 15, 21, 28 and 35. Immunity in mice immunized in this way was manifest both as a reduction in worm recoveries on days 9-14 after challenge and also as an expulsion of established worms from the intestine. BALB/c mice were initially less resistant, but expelled most of the worms which became established; C3H mice showed no evidence of expulsion. The finding that inbred NIH and BALB/c mice acquire resistance to N. dubius offers possibilites for the systematic analysis of lymphoid cell activity in initiating and expressing immunity to this parasite.


The occurrence of Sphaerostoma bramae (Digenea: Allocreadiidae) in the roach from the Worcester-Birmingham canal.

Two hundred roach (Rutilus rutilus) were examined over a twelve-month period to provide information concerning the occurrence of Sphaerostoma bramae. Infection levels were high during the autumn and winter and at this time of year the parasite population was composed almost exclusively of immature parasites. Maturation was rapid in the spring but was accompanied by a decrease in the infection level. In late summer, after egg-laying, losses due to the death of spent parasites began to be replaced by the recruitment of immature parasites and this recruitment reached its peak in the autumn and winter. The annual cycle of occurrence and maturation is discussed in relation to fluctuating environmental variables and the feeding behavior of the roach.


The site preferences of two digeneans, Asymphylodora kubanicum and Sphaerostoma bramae, in the intestine of the roach.

The digeneans Asymphylodora kubanicum and Sphaerostoma bramae showed distinct and different site preferences in the roach intestine, the majority of A. kubanicum being found in the first limb and the majority of S. bramae occurring in the second and third limbs. A. kubanicum excysts and establishes itself in the first limb and this is considered to be the basis of the observed distribution of the parasite in the host's intestine. The site preference of S. bramae is discussed in relation to the physiology of the parasite and the host and to possible competitive interactions with A. kubanicum.


Mesocoelium malayanum sp. n. (Digenea: Brachycoeliidae) in a frog, Rana macrodon Dumeril and Bibron 1941, from Malaysia.

Mesocoelium malayanum sp. n. is described from the frog Rana macrodon, in Malaysia. Elongate body, broader anteriorly, measuring 1.900 (1.679-2.070) mm long by 0.404 (0.380-0.437) wide, tegument aspinose oral sucker 0.212 (0.200-0.228) by 0.202 (9.191-0.205), acetabulum 0.141 (0.132-0.150) by 0.139 (0.123-0.146), prepharynx present, oesophagus 0.115 (0.096-0.137), caeca reaching posterior 1/3 of body, anterior testis 0.097 (0.087-0.110) by 0.091 (0.087-0.100) dorsal to acetabulum, posterior testis 0.094 (0.087-0.101) by 0.092 (0.091-0.100), cirrus pouch 0.121 (0.111-0.130) by 0.047 (0.041-0.055), genital pore at left of midline of oesophagus just anterior to intestinal bifurcation, ovary 0.110 (0.091-0.127) by 0.089 (0.085-0.096) on left of body and posterior to acetabulum, vitelline glands with single follicles extending from intestinal bifurcation to ends of caeca, excretory vesicle I-shaped and eggs 0.040 (0.037-0.046) by 0.023 (0.022-0.024). Although morphologically related to M. maroccanum and M. meggitti, M. malayanum is considered to be a new species.


The fate of Fasciola hepatica metacercariae following challenge infection of immune rats.

Groups of rats, infected 7 weeks previously with Fasciola hepatica, together with appropriate control groups, were challenged either orally or intraperitoneally with 30 metacercariae. The mean worm recovery from the previously infected, orally challenged rats was significantly lower than from their respective controls (2.2 +/- 1.1 worms as opposed to 9.0 +/- 2.6). There was no significant difference in mean worm recovery from the previously infected, intraperitoneally challenged rats and their respective controls (5.3 +/- 3.2 worms as opposed to 6.2 +/- 1.9). Livers of the orally challenged group appeared to be largely free from secondary damage but considerable damage was evident in rats which received an intraperitioneal challenge. This evidence supports the view that the gut acts as an important barrier to metacercariae of a challenge infection. In a further experiment, young flukes were recovered from the gut, abdominal cavity and liver of immune and control rats 9, 18, 27, 36 and 45 h after oral challenge. It was found that fewer flukes successfully penetrated the guts of immune rats (3%) than those of uninfected controls (13%), again pointing to the gut as a barrier to metacercariae of a challenge infection. Protective mechanisms that may operate at the level of the gut are discussed.


Paragonimus westermani in Malaysian Felidae and Viverridae: probable modes of transmission in relation to host feeding habits.

Examination of naturally infected felids and viverrids in Malaysia confirmed previously published records which indicated that P. westermani occurred only in felid cats. Felis planiceps and F. temnickli were reported as new host records. Analysis of stomach contents revealed no crab remains in either family of cats, but confirmed that felids were strictly carnivorous while viverrids were often omnivorous. In feeding experiments, only viverrids ate the host crabs Potomiscus johorensis and Parathelphusa maculata. The probable transmission of P. westermani to felids via paratenic hosts was discussed.


Strongyloides ratti: 1. parasitological observations on primary and secondary infections in the small intestine of rats.

Adult Strongyloides ratti were expelled from the small intestine of rats starting 14-18 days after a primary infection. In a secondary infection very few adult worms developed and most of these were expelled before day 14. At the time of expulsion the worms migrated posteriorly in the intestine and their size decreased.


The response of nematodes in vivo and in vitro to some anthelmintics.

Dietary feeding of drugs for 5 days to mice infected with Nematospiroides dubius and Hymenolepis nana detected all modern anthelmintics examined except stilbazium. A simple test using eggs of Nematodirus spathiger and adult Nippostrongylus brasillensis to detect anthelmintics in vitro is reported.


Further observations on the relationship and distribution of Schistosoma margrebowiei and S. leiperi in central southern Africa.

A further survey in East Caprivi, Chobe National Park, Okavango swamps and Kavango was undertaken in June 1976. No evidence of lechwe schistosomes was found in droppings of African buffalo (Syncerus caffer) nor baboons (Papio ursinus) living in lechwe habitats. It was thought that they were not capable of spreading or maintaining these parasites outside the confines of the known distribution of Kobus sp. The role of goats was equivocal but probably they too are poor hosts. Kavango, an endemic area of S. haematobium and S. mansoni, was thought to be free of all animal schistosomes, thus confirming the hypotheses that (1) cattle and goats are poor hosts of the lechwe schistosomes and (2) S. mattheei was blocked from entering the territory by the presence of lechwe schistosomes in the surrounding areas. Evidence of schistosomes was not found in cattle and goats at Maun for the same reasons. The prevalence of S. mansoni at Maun has increased alarmingly over the past 20 years with a simultaneous disappearance of lechwe from the area. S. margrebowiei and S. leiperi eggs were found in lechwe and tsessebe droppings some 80 km north of Maun. A high proportion of children with negative excreta from "non-endemic" areas in East Caprivi had positive CFT and/or skin tests, suggestive of exposure to lechwe schistosomes resulting in a possible immunity to S. mansoni and S. haematobium.


Modification of the pathogenicity of Schistosoma mattheei for sheep by passage of the parasite in hamsters.

Border Leicester X Suffolk sheep infected with a strain of S. mattheei maintained in hamsters do not develop the same pathological changes as Romney Marsh sheep infected with the same strain of parasite before hamster passage. To determine the cause of this reduced pathogenicity, five Romney Marsh sheep were each infected with 10 000 cercariae of the hamster-passaged parasite and five with 10 000 cercariae of a S. mattheei strain from Onderstepoort, South Africa, passaged exclusively through sheep. Striking pathological and parasitological differences were found between the two strains. Infection with the "sheep" strain was lethal, whereas infection with the "hamster" strain produced little evidence of clinical disease. By 13 weeks post-infection the mean body weight of the sheep infected with the sheep strain had declined by 15% compared with both the uninfected controls and the sheep infected with the hamster strain, and the mean PCV was lowered to 20% in the sheep strain infected animals. Egg production began at seven weeks with the sheep strain, faecal counts rising to more than 300 e.p.g., whereas only two of the sheep infected with the hamster strain passed eggs in the faeces (at nine weeks) and the maximum egg count was 50 e.p.g. Twice as many adult worms of the sheep strain were recovered, and, although the number of eggs found in the tissues "per worm pair" was not significantly different, overall egg production was higher for the sheep strain; also more of the sheep strain eggs were deposited in the intestines. Similar parasite differences were seen in a supplementary study in mice and it seemed that "attenuation" of the parasite had occurred, presumably due to its maintenance in hamsters. Histopathological observations and faecal egg counts both indicated an inability of hamster strain eggs to penetrate the intestinal lumen; this was probably important in reducing the pathogenicity of the hamster strain.


Immunization of sheep against a virulent strain of Schistosoma mattheei using a strain of S. mattheei attenuated by hamster passage.

We have previously described the characteristics of a relatively non-pathogenic laboratory strain of S. mattheei, attenuation of which was apparently caused by passage in hamsters. We now show that chronic infection with this avirulent strain largely protects sheep from the manifestations of acute schistosomiasis when challenged with a virulent strain of S. mattheei. Four sheep were each infected with 10 000 cercariae of the avirulent strain and, together with four wormfree sheep, challenged 63 weeks later with 10 000 S. mattheei cercariae of a pathogenic strain. Four more sheep acted as uninfected controls. Following challenge, the animals were weighed and bled weekly for PCV and serum protein determinations, and egg counts were carried out fortnightly on faeces taken from the rectum. Red cell and albumin turnover were monitored for two weeks immediately before challenge and for a similar period before necropsy, when the adult worms were recovered by perfusion and tissues sampled for histopathology and egg counting. The unvaccinated sheep developed severe disease 6-12 weeks after exposure characterised by marked anaemia, hypoalbuminaemia and hyper-gamma globulinaemia coinciding with the passage of blood-stained faeces and progressive inappetence. In the vaccinated sheep, there was an even earlier rise in gamma globulins, but the other clinico-pathological changes were generally slower to devleop and much milder in severity. The parasitological data showed that although this was partly due to a reduction in the establishment of the challenge worm population the main factor was probably a reduction in the fecundity of these worms.


Alkali denaturation of oxyhaemoglobins of some digenetic trematodes and their hosts.

Oxyhaemoglobins of six digenetic trematodes,--Srivastavaia indica, Gastrothylax crumenifer, Gigantocotyle explanatum, Fasciolopsis buski, Gastrodiscoides hominis, Isoparorchis hypselobagri, and of their 3 vertebrate hosts, Bubalus bubalis, Sus scrofa, Wallago attu, were subjected to alkali denaturation at a pH of 12.4. All oxyhaemoglobins from trematodes and their hosts differ from each other in the rate and extent of alkali denaturation which may be explained due to variations in the amino acid sequences of a particular haem protein in addition to other factors.


Characterization of human heteroploid cell line J-111: Reverse banding patterns of marker chromosomes.

The karyotype of the human cell line, J-111, has been studied employing R-banding by fluorescence using acridine orange technique (RFA).  The model chromosome number of this line was 112. All human chromosomes except the Y were present in each metaphase. Twenty-one marker chromosomes were distinguished and their possible origins were investigated. Of these, twelve were consistently present in all cells. Nine markers were highly variable. Four typical marker chromosomes of HeLa cells were found and their origins were identified, indicating that the line is a HeLa contaminant. The reverse banding patterns of all marker chromosomes are presented and the value of the RFA technique is discussed.


Genetic variation of amylases in deer mice.

The inheritance of salivary amylase variants in the deer mouse, Peromyscus maniculatus, is controlled by codominant alleles, Amy-1a, Amy-1b, and Amy-1c, at a single autosomal locus. Pancreatic amylases were invariant and unaffected by salivary amylase genotypes. Salivary amylase zymograms of five myomorphic rodents are compared and evolutionary implications are discussed.


Myelin deficient, a new neurological mutant in the mouse.

A new autosomal recessive gene in mice is described that produces deficiencies in central nervous system myelin and quaking or trembling of the hindquarters during locomotion. Although both behavioral and central nervous system abnormalities resembled those produced by qk, the new mutation was not an allele of qk. We propose that the new mutation should be labeled myelin deficient (symbol, mld).


Immunoglobulin haplotypes of two population groups in Iran.

Genetic markers of IgG and IgA were investigated in two population groups from Iran. The Gm-Am haplotypes found were mainly those prevalent in Caucasians, with a low frequency of Asiatic haplotypes. Twenty samples had phenotypes that led to the assumption of rare haplotypes. The main ones were: Gm(z;n;b)a2m(1) and Gm(za;n;g)A2m(2). The first haplotype differs from the common haplotypes because G1m(z) is present instead of G1m(f), and the second because it has G2m(n) and A2m(2) in combination with G1m(za) and G3m(g).


Genetic analysis of natural populations of Poeciliopsis monacha: Allozyme inheritance and pattern of mating.

The genetic bases of seven polymorphic enzymes in Poeciliopsis monacha have been demonstrated through the analysis of allelic segregation in presumed heterozygotes captured in natural populations. Tests of linkage among loci revealed a significant association between two loci, Ldh-1 and Idh-2. Evidence for multiple insemination was detected in 23 percent of the females examined. Considering the limited number of markers available in the present study, it is probably that the actual frequency of multiple insemination is much higher.


Linkage studies with C6.

The common structural variants of C6 have been used to study the linkage relations of the locus in human pedigrees. Linkage between C6 and RH, Fy, ACP1, MNSS, Jk, HLA, ABO, ESD, Hp, ADA, GPT, Gc, Pi, Gm and Km has been excluded at recombination fractions at least as great as 0-1 in the male.


The time course of the electroretinogram of compound eyes in insects and its dependence on special recording conditions.

Electroretinograms recorded from slowly moving insects like the mealworm beetle Tenebrio molitor and the stick insect Carausius morosus are shown to be distorted by the use of electrodes of stainless steel and silver/silver chloride wires, unless they are used in conjunction with amplifiers having extremely high input resistance. Undistorted electroretinograms can also be recorded using micropipettes filled with a suitable electrolyte. The undistorted ERG of Tenebrio molitor is monophasic, as described by Autrum (1950) for Dixippus, and as expected from his rule.


Estimation of shunting, systemic and pulmonary output of the heart, and regional blood flow distribution in unanaesthetized lizards (Varanus exanthematicus) by injection of radioactively labelled microspheres.

Circulatory parameters in a lizard (Varanus exanthematicus) were determined using the microsphere method. Microspheres (MS) (slightly larger than the erythrocytes and labelled with different gamma-emitting isotopes) were injected into a pulmonary vein or the left atrium for determination of the left-to-right (L-R) shunt and the regional distribution of the ventricular systemic output. Injections were also made into the sinus venosus for determination of the right-to-left (R-L) shunt. The relative blood flow was obtained as the ratio of the MS activity found in the various tissues over the total activity injected. Absolute calibration of the method was performed by introduction of an 'artificial organ' into the circulatory system (Hales, 1973). Ventricular systemic output (VSO), in five animals, averaged 121 ml/ (min.kg) and ventricular pulmonary output 119 ml/(min. kg). The value of VSO was significantly higher than those observed in other lizard species. In all experimental animals both R-L as well as L-R shunting of various extent occurred. The reliability of the microsphere method as applied in lizards is discussed and is considered to be relatively accurate even under conditions of incomplete mixing of shunted and unshunted blood in systemic heart output.


The neuronal control of dragonfly flight. I. Anatomy.

The mechanical action and innervation of the major flight muscles of dragonflies are described. All flight muscles investigated are innervated by at least 3 motor neurones and one by as many as 15. Cell bodies of motor neurones that innervate the same muscle are clustered together and have similar, widespread dendritic branching patterns. Motor neurones of leg muscles have greater variety in cell body size and position than the major flight motor neurones. Striking similarities between the positions of cell bodies of motor neurones in dragonflies and the positions of homologous motor neurones in other insects raise interesting questions about the evolution of insect nervous systems.


Asymmetric waveforms in echinoderm sperm flagella.

1.Dark-field, multiple-exposure photographs of live spermatozoa of a number of echinoderms were analysed. 2. Bends develop at the base in pairs, as they do in flagella with symmetrical waveforms. However, the angles of these bends do not cancel, so that microtubular sliding-of up to over 50% of that associated with bend propagation-is transferred distally. This sliding implies that (a) microtubules are not rigidly cross-linked within straight regions, and (b) bends can propagate normally in spite of appreciable extrinsic microtubular sliding. 3. Both the sperm head and the asymmetry of the waveform appear to affect the swim path of a spermatozoon.


The effect of different dissolved oxygen tensions on growth and enzyme activities of Campylobacter sputorum subspecies bubulus.

Campylobacter sputorum subspecies bubulus was grown in batch cultures in which the dissolved oxygen tension (d.o.t) was maintained at various constant levels. At a range of d.o.t. from 0.002 to 0.05 atm, which allowed good growth (mean generation time approximately 1.5 h), L-lactate was preferentially consumed before D-lactate. L-lactate oxidation was accompanied by equimolar acetate production during exponential growth. A value for YL-lactate (g dry weight bacteria per mol L-lactate) of 54 was determined. Net acetate production stopped when C. sputorum started to use D-lactate after consumption of L-lactate. When a culture growing exponentially at the expense of L-lactate was shifted from a d.o.t. of 0.02 atm to a d.o.t. of 0.15 atm, growth was impaired, and L-lactate consumption and corresponding acetate production diminished. This decrease correlated with a loss of lactate dehydrogenase activity after the shift. Campylobacter sputorum appeared to possess cytochromes of the b- and c-type and a carbon monoxide-binding pigment. Evidence is given that the principal site of oxygen damage is lactate dehydrogenase rather than the cytochrome chain.


Membrane-bound enterotoxin of Vibrio cholerae.

The mode of transport of the complex toxin molecule of Vibrio cholerae (which has a mol. wt of 84000 and consists of several subunits) across the inner and outer membranes of V. cholerae is not known. In this study we found two peptides in the outer and inner membranes of V. cholerae which may be the form in which the toxin subunits are transported across the membrane. We examined two growth conditions: aerobic growth at 37 degrees C, when most of the synthesized toxin is membrane-bound; and anaerobic growth at 37 degrees C, when little toxin remains membrane-bound, the toxin being released into the growth medium. When V. cholerae was grown aerobically at 37 degrees C, the outer and the inner membranes contained two peptides with mol. wts of approximately 22000 and 6000 which were not found in the outer or the inner membrane of anaerobically grown cells. Sodium deoxycholate, which releases membrane-bound toxin, released several peptides including the 22000 and the 6000 mol. wt peptides. Trypsin also released the 22000 and 6000 mol. wt peptides. Purified cholera toxin had three kinds of peptides, of mol. wt 21000 (A1 peptide), 11000 (B subunit) and 5000 (A2 peptide). We postulate that the membrane peptides may be precursors of the A subunit of the toxin molecule.


[Hereditary adenocarcinomatosis in 4 generations of a Valais family].

An account is given of a family from the Canton of Valais, suffering from hereditary adenocarcinomatosis. The pedigree extends over four generations; the first three comprise 47 individuals (28 males, 19 females), of whom 21 (16 males and 5 females), i.e. 44.6%, are affected with malignant tumours. Of the 32 people in the fourth generation, only one individual is affected to date (a girl aged 21, IV/14). There were 27 tumours in all: 16 adenocarcinomas of the colon, two gastric adenocarcinomas, one duodenal adenocarcinoma, one rectal adenocarcinoma, one papillary carcinoma of the ovary, one osseous sarcoma, one cutaneous fibrosarcoma, a multiform glioblastoma of the basal nuclei of the brain, a basocellular epithelioma, also a cerebral metastasis from an adenocarcinoma, the origin of which has not been established, and a tumour invading the biliary tract. Three members of the family suffered from multiple tumours. In three of the patients, the colonic adenocarcinoma was accompanied by one or two polyps. The average age at the onset for all the tumours was 45 years. It was definitely lower in the third than the second generation (anticipation). The transmission was autosomal dominant, with predilection for the male sex (57.1% male and 26.3% female patients). The penetrance was about 80%. The author finally discusses the diagnostic criteria for hereditary adenocarcinoma and reviews the different familial forms of cancer.


[Study of fingerprints in 12 cases of hereditary brachydactyly type C and E (author's transl)].

The authors studied 7 patients with type C brachydactyly and 5 patients with type E brachydactyly. 1. In the C type cases the findings were as follows: a) frequency of anomalies of the digital folds (a fold of the digital flexion); b) frequency of single transverse palmar fold; c) the almost persistent presence of axial t triradius in the intermediate or distal position. 2. In the type E cases there was a predominance, at the digital pulp level, of cubital loops and whorls.


Inherited pericentric inversion of chromosome no. 2 with Robertsonian translocation (13q 14q) resulting in trisomy for chromosome 13q.

This report includes a patient with an inherited pericentric inversion of chromosome No. 2 in addition to a Robertsonian translocation resulting in trisomy for chromosome 13q. The chromosomal constitution of the proband was 46,XX,inv(2) (pter leads to p11 : : q14 leads to p11 : : q14 leads to qter); t(13,14) (13qter leads to 13p11 : : 14q11 leads to 14qter). Sequential QFQ, RFA and GTG banding techniques were employed on the chromosomes of all family members. The chromosomal constitutions of the father and his first child were normal while the mother had an inversion of chromosome No. 2 [46,XX,inv(2) (pter leads to p11 : : q14 leads to p11 : : q14 leads to qter)]. The proband inherited this abnormal chromosome. In addition, she had a de novo Robertsonian translocation involving chromosomes 13q and 14q resulting in trisomy of chromosome 13q.


Physiological properties of the penis retractor muscle of Aplysia.

The properties of the penis retractor muscle of Aplysia have been studied using intracellular, sucrose gap and tension recording. The fibers are of the invertebrate smooth muscle type and exhibit slow contractions which occur spontaneously or in response to stretch in isolated preparations. Individual muscle fibers are innervated by excitatory and inhibitory axons. A variety of sizes of excitatory and inhibitory junctional potentials can be recorded from them. The innervation is probably diffuse and functionally polyneuronal. The fibers are electrically coupled, permeable to potassium and chloride at rest, and exhibit no overshooting active responses. The muscle shows graded responses of depolarization and contraction proportional to strength of nerve stimulation. Facilitation and depression of junctional potentials are seen with various frequencies of nerve stimulation. Post-tetanic potentiation occurs with nerve stimulation at frequencies from 2 to 50 Hz and is suppressed in the presence of increased extracellular calcium concentrations.


Penis-retractor muscle of Aplysia: excitatory motor neurons.

Cobalt axonal iontophoresis and intracellular recordings were used to identify a cluster of several motor neurons innervating the penis-retractor muscle of Aplysia. Intracellularly recorded motor neuron action potentials elicited direct, one-for-one, constant latency excitatory junctional potentials (ejps) in individual muscle fibers. The axons of motor neurons could be recorded extracellularly in the penis-retractor nerve and stimulation of the nerve backfired the motor neurons. Perfusion of the ganglion, the muscle, or both with solutions of either increased Mg++/decreased Ca++ or increased Ca++ sea water indicated that the presumed motor neuron impaled was not a sensory cell and that interneurons were not intercalated in the pathway. Innervation of muscle fibers was found to be functionally polyneuronal and diffuse. The ejps were found to undergo marked facilitation with repetitive motor-neuron stimulation. The motor neurons were isolated in a distinct cluster in the right pedal ganglion. Their electrical activity was characterized by spontaneous irregular action potentials and a moderate input of postsynaptic potentials.


Retinal haemorrhage as a complication of gas encephalography and gas myelography. Prospective study using oxgen gas with a discussion of pathogenetic mechanisms.

Seventy patients, submitted to oxygen encephalography and oxygen myelography, were examined by retinal funduscopy to establish the incidence of intraocular haemorrhages, a complication reported to be frequent by other investigators. We did not discover any retinal haemorrhages. Pathogenetic factors influencing intracranial or intraocular venous pressure or both are discussed, particularly the effect due to different technical procedures during the examination, and the type of anaesthesia used.


Acetylcholinesterase activity and menstrual remissions in myasthenia gravis.

Menstrually related temporary remissions of myasthenic symptoms are reported to occur in 25 to 50% of female patients. Even though this has been attributed to hormonal changes associated with the menstrual cycle the underlying mechanism of this hormonal influence has remained elusive. The present study demonstrated a cyclical variation in the activity of red cell acetylcholinesterase (EC 3.1.1.7) enzyme (AChE) with a marked reduction at the time of menstrual remission of symptoms of myasthenia. These cyclical changes were abolished by thymectomy. It appears, therefore, that menstrual remission in myasthenia is at least partly due to hormone-induced changes in AChE activity. This process seems to be under the control of the thymus gland.


Effect of differential nerve block on inhibition of the monosynaptic reflex by vibration in man.

The differential nerve block produced by ischaemia has been used in an attempt to identify the afferent nerve fibres responsible for vibratory inhibition of the monosynaptic reflex in man. It is concluded that the inhibition arises mainly from receptors in the lower leg and is carried by myelinated afferent fibres larger than A-delta.


Nerve biopsy and conduction studies in diabetic neuropathy.

Morphological findings in sural nerves were related to nerve conduction in 12 patients with diabetic neuropathy, five with mainly sensory involvement, four with severe, symmetrical sensory-motor polyneuropathy, and three with multiple mononeuropathy. All had loss of large and small myelinated and of unmyelinated fibres, even early in the disease; segmental remyelination was the most prominent myelin alteration in teased fibres, segmental demyelination was found in only a few fibres. Axonal degeneration and Schwann cell damage seem to proceed independently of each other. The relation between recorded conduction velocity and that expected from the diameter of the largest fibres indicated that slowing of 20 to 30% was due to causes other than fibre loss; a grossly diminished conduction velocity was caused mainly by fibre loss. Electrophysiological findings in the sural nerve were largely representative of findings in other nerves, though abnormalities were less marked in the median nerve. In half the endoneurial vessels from diabetic neuropathy the perivascular space was thickened or contained more layers of basal laminae than normal. The same abnormalities were found in one-quarter of the endoneurial vessels from other acquired neuropathies.


Effect of body temperature on visual evoked potential delay and visual perception in multiple sclerosis.

Seven multiple sclerosis patients were cooled and four heated, but evoked potential delay changed in only five out 11 experiments. Control limits were set by cooling eight and heating four control subjects. One patient gave anomalous results in that although heating degraded perceptual delay and visual acuity, and depressed the sine wave grating MTF, double-flash resolution was improved. An explanation is proposed in terms of the pattern of axonal demyelination. The medium frequency flicker evoked potential test seems to be a less reliable means of monitoring the progress of demyelination in multiple sclerosis patients than is double-flash campimetry or perceptual delay campimetry, although in some situations the objectivity of the evoked potential test would be advantageous.


An unusual cause of apparent epilepsy: ECG and EEG findings in a case of Jervell Lange-Neilson syndrome.

A case is presented of apparent epilepsy which proved to be due to recurrent ventricular tachyarrhythmias (torsade de pointe). The relationship between the cardiac arrhythmia and changes in the electroencephalograph is recorded and analysed. This is probably an example of the 'Jervell Lange-Neilson' syndrome of cardiac arrhythmias which may produce ictal episodes, prolongation of the QTc interval of the ECG, and sensori-neural deafness. The features of the syndrome, its pathology and treatment, and its relevance to the mangement of epilepsy are discussed.


Relapsing neurological disorder associated with rubella virus infection in two sisters.

A disseminated relapsing neurological disorder presented simultaneously in two sisters. Encephalitic features were present in one case. The illness was associated with a significant increase in rubella specific IgM in both sisters. Despite the absence of a rubella rash, this increase would be compatible with a recent infection by the rubella virus as a basis for the illness, and the persistent elevation, with active antigenic stimulation. It is suggested that both patients might represent the clinical manifestations of perivenous demyelination caused by the rubella virus, which, in view of the relapsing nature of the illness, has progressed to plaque formation.


Spinal cord compression in thalassaemia.

Two cases of spinal cord compression resulting from extramedullary haemopoiesis in patients with thalassaemia of intermediate clinical severity are reported. The association between mild thalassaemia with long survival and the risk of spinal cord compression from extramedullary haemopoietic deposits is emphasised.


Systemic vascular responses to increased intracranial pressure. 1. Effects of progressive epidural ballon expansion on intracranial pressure: and systemic circulation.

This paper details the results of experimental studies, on 16 dogs with artificially-induced intracranial space-occupying lesions, of the systemic vascular responses and the intracranial pressure changes (both in the supratentorial and infratentorial compartments) induced by increasing intracranial pressure. The changes produced were divided into two phases such that phase 1 detailed the alterations observed from the start of the balloon inflation up to the initiation of the systemic pressor response. Phase 2 recorded those alterations which occurred during, and immediately after, the period of systemic hypertension (see Fitch et al., 1977). The changes observed during phase 1, and presented in this communication, were those of increasing intracranial pressures and decreasing mean arterial pressure and heart rate. These alterations were associated with decreases in supratentorial perfusion pressure and increases in transtentorial pressure gradient and arrhythmia index.


Multiple progressive intracranial arterial occlusions ('moyamoya' disease).

Four adult female patients with moyamoya vessels are described. Hypertension and hyperlipidaemia were discovered in three patients. Vessels similar to moyamoya vessels were seen in the orbital and cortical collateral vessels as well as in the basal ganglia region. Attention should now be paid to the aetiological rather than the descriptive aspects of the disorder. An empirical trial of corticosteroids is worth while. Risk factors such as hypertension, hyperlipidaemia, and smoking should be eliminated.


Syndrome of agitated delirium and visual impairment: a manifestation of medial temporo-occipital infarction.

Three patients presented with sudden visual impairment followed by agitated delirium one to three days later. Examination revealed marked agitation, dementia, and loss of vision. Computerised axial tomography demonstrated temporo-occipital infarctions. All recovered from the agitated state in four days to two months, but their visual impairment and dementia persisted one to four years later.


Antimyelin antibody in multiple sclerosis: no change during immunosuppression.

We studied retrospectively levels of antimyelin antibody in a group of 13 multiple sclerosis patients who underwent a clinical trial of long-term, high dose (2.0-4.5 mg/kg/day) azathiaprine therapy. In apparent contrast with collagen vascular disease associated with antitissue antibody, azathiaprine therapy was not associated with significant change in titres of antimyelin antibody. Variation of titre of antimyelin antibody in apparent association with disease activity continued during therapy. No significant changes occurred in levels of serum immunoglobulins.


Epidemiological studies on patients with a persistent vegetative state.

Persistent vegetative state after severe brain damage was studied epidemiologically in 110 cases from 1973 to 1976. The causes of brain damage were varied. More than one-third of the cases were due to trauma, and about one-fifth were the result of vascular accidents. Three year observation revealed that 65% of the patients died during this period. Mean survival time for dead patients was 38 months. Reactivity, clinical signs, EEG findings, methods of management, and results of various trials of treatment were investigated in connection with the patient's prognosis.


Neuroectodermal tumours in the cerebellum in two sisters.

Two sisters, one 5 years and the other 2 years old, with intrinsic tumours of the cerebellum are reported. One of the tumours was interpreted as being a ganglioneuroma with neuroblastomatous change. The other was a desmoplastic medulloblastoma.


Phenytoin intoxication during concurrent diazepam therapy.

Phenytoin elimination is a saturable process obeying Michaelis-Menten kinetics. Plasma phenytoin levels are not related linearly to dose, and small changes in enzyme activity produced by concurrent drug therapy could alter plasma levels. Two cases of phenytoin intoxication associated with simultaneous administration of diazepam are reported. Intravenous phenytoin infusions were given and the apparent K(m) and V(max) computed from the resulting plasma phenytoin levels. In one case `K(m)' and `V(max)' were 0.8 μmol/1 and 1.3 μmol/1/hour respectively during concurrent diazepam administration, and 50.3 μmol/1 and 4.4 μmol/1/hour after discontinuation of diazepam. In the second case phenytoin infusion with diazepam gave `K(m)' and `V(max)' values of 0.012 μmol/1 and 0.95 μmol/1/hour. Without diazepam these were 28.8 μmol/1 and 0.92 μmol/1/hour respectively.


Cerebrospinal fluid enzymes in acute brain injury. 3. Effect of hypotension on increase of CSF enzyme activity after cold injury in cats.

The influence of trimetaphan-induced hypotension was studied on the increase in the activities of various enzymes in the cerebrospinal fluid after cold injuries of the brain in cats. Hypotension was induced immediately after freezing, and in a second series after a delay of 45 minutes. It was shown that induction of hypotension may inhibit the appearance of enzymes in the CSF after cold injuries in the first seven hours after freezing. Histological studies revealed less pronounced oedema in the hypotensive animals. The results suggest that hypotension retards the transport of enzymes released from necrotic areas through the extracellular fluid towards the CSF.


Effects of extensor and flexor group I afferent volleys on the excitability of individual soleus motoneurones in man.

The contour of the postsynaptic potential (PSP) produced in a neurone by an afferent volley can be derived from the contour of the post-stimulus time histogram (PSTH) of that neurone when it is discharging rhythmically. In the present study the PSTH of the firing of individual soleus motor units after stimulation of the popliteal or peroneal nerve was used to explore the effects of extensor and flexor group I afferent volleys on the excitability of single soleus motoneurones in man. Extensor group I volleys resulted in an early peak of increased impulse density in the PSTH of 75% of soleus motoneurones. The latency suggests an analogy with the Ia EPSP. The mean duration of the peak of increased impulse density, equivalent to the rise time of the EPSP, was 3.6 ms. Flexor group I volleys result in a period of reduced impulse density in the PSTH of five out of nine soleus motoneurones. The latency suggests an analogy with the Ia IPSP. We conclude that this method could be used to explore the afferent connections to single motoneurones in man and to derive some of the characteristics of the postsynaptic potentials from a variety of afferent nerve fibres in single human motoneurones.


Subarachnoid haemorrhage of unknown aetiology. A clinical and radiological study of 51 cases.

A detailed clinical and radiological study of 51 patients presenting with a subarachnoid haemorrhage, for which no cause could be found, has been described. Although selection for full investigation has favoured the inclusion of younger and fitter patients, analysis of the information obtained suggests that haemorrhage could be due to: (a) aneurysms undergoing thrombosis at the time of haemorrhage, in which subsequent recanalisation will produce a low incidence of further bleeding; (b) minute (2 mm) aneurysms, destroyed at the time of haemorrhage and posing no subsequent threat.


Mesial temporal haemorrhage, consequence of status epilepticus.

A 52 year old woman developed a severe encephalopathy with status epilepticus of six days duration in the terminal course of an acute hepatitis associated with hyperammonaemia and hyperventilation. Acute haemorrhagic lesions were observed in the brain, involving symmetrically both amygdala and cornu Ammonis. The sequential occurrence of these lesions with status epilepticus are discussed in the light of data from the literature.


An anatomical basis for the resistance and capacitance in series with excitable membrane of the squid giant axon.

To correlate periaxonal tissue layer resistance with Schwann cell layer anatomy, cross and longitudinal sections of giant axons of Loligo pealei were examined by transmission electron microscopy. Measurements were made of the width and frequency of mesaxonal clefts entering the Schwann cell layer from the periaxonal space and leaving the cell layer adjacent to the basal lamina. The average mesaxonal cleft width is 10.5 nm. One cm2 of the giant axon surface is enclosed by a single cell layer containing about 690 000 Schwann cells. One cm2 of axon surface has a sheath mesaxonal area of 0.002 cm2 at the periaxonal surface and 0.016 cm2 at the basal lamina, the mesaxons branching frequently as they cross the sheath. The volume of the Schwann cell layer extracellular space was estimated to be roughly 1% of the Schwann cell layer volume. Several models were used to predict the resistance R, across the Schwann cell layer. Assuming the mesaxonal clefts contain seawater, and can be lumped into volume conductors having simple geometries, then (normalized for one cm2 of axon surface) R was estimated to be between 0.4 and 0.9 omega cm2. This compares favourably with electrophysiological estimates of the periaxonal tissue resistance (current clamp value = 0.9 omega cm2 and the voltage clamp value = 1.4 omega cm2) as these electrically measured values include the resistance across the outer connective tissue layer as well as the Schwann cell layer. The value of the Schwann cell membrane capacity was estimated to be approximately 0.7 muF/cm2.