Effect of interaction between methotrexate and dihydrofolate reductase on DNA synthesis in L1210 cells in vitro. L1210 leukaemia cells were preloaded with [(3)H methotrexate] (MTX) to saturate high-affinity intracellular sites, and were then incubated with [(3)H]MTX to determine the steady-state intracellular MTX concentrations at extracellular concentrations ranging from 10 μM to zero. In addition, incubations to generate incomplete saturation of high-affinity intracellular MTX-binding sites were also carried out. Following determination of the total intracellular MTX, cells were pulsed with deoxyuridine (UdR) and its incorporation into DNA examined to assess the role of exchangeable and bound intracellular MTX on DNA synthesis. Further, cell pellets were disrupted and dihydrofolate reductase (DHFR) activity determined under each experimental condition. Extracellular MTX concentrations in excess of 1 μM depressed UdR incorporation to <2% of control, but incorporation rapidly recovered to 62% of control at the point of MTX-DHFR equivalence, and exceeded control values when all high-affinity sites were not saturated. DHFR activity was undetectable at extracellular MTX concentrations >0.50 μM, and never exceeded 6.09% of control at the "equivalence point" where all high-affinity sites were saturated. When less than 10% of potential inhibitor sites were occupied, enzyme activity increased rapidly, but never reached control. However, 5% of the DHFR activity was sufficient to permit UdR incorporation to continue at 50% of control levels, and UdR incorporation returned to control levels at 20% of the DHFR activity. The relationship between cellular MTX content and DNA synthesis or DHFR activity is sigmoid, suggesting a reversible interaction between enzyme and inhibitor. This lends support to the notion that "free" intracellular MTX is necessary for a maximal antitumour effect, and may explain its role in "high-dose" MTX therapy in man.


Differences in metabolism of vinylidene chloride between mice and rats. The present finding that mice metabolize a greater proportion of an oral dose (50 mg/kg) of vinylidence chloride. (1,1 - dichloroethylene, DCE) than rats implies (a) that the efficiency of DCE metabolism follows the known activity of cytochrome P-450 in the organs of these animals, and (b) that, in accordance with the LD(50) values, the real exposure (expressed as the amount of DCE metabolized) is relatively higher for orally dosed mice than rats, and (c) that DCE carcinogenicity would appear to be more likely in mice than rats.Mice metabolize DCE simiarly to rats (Jones and Hathway, 1977) but there are some differences. Thus, qualitatively, treated mice (but not rats) excrete a small amount of N-acetyl-S-(2carboxymethyl)cysteine. Quantitatively, (i) the relative proportions of the N-acetyl-S-(2-cysteinyl acetyl derivative that are formed in mice and rats parallel the activity of liver glutathione-S-epoxide transferase in these rodents, and (ii) there are marked differences in the proportions of DCE metabolites belonging to the chloroacetic acid branch of the metabolic pathway. Furthermore, the previously assumed β-thionase hydrolysis of thiodiglycollic acid (Jones and Hathway, 1977) is now established in vivo, and the possible biogenesis of the N-acetyl-S-cysteinyl acetyl derivative is verified by another tracer study. The conclusion is drawn that the DCE metabolites, 1,1-dichloroethylene oxide and chloroacetyl chloride, may be important to murine DCE carcinogenicity.


Long-term effects of phenobarbitone-Na on male Fischer rats. Male inbred Fischer rats were fed phenobarbitone-Na at a level of 500 parts/10(6) in the diet for 1 week, followed by 1000 parts 10(6) for 103 weeks at which time the survivors were killed. Thirty-three treated rats survived to 80 weeks. Before 80 weeks, no animals showed hyperplastic lesions. Of the 33 rats surviving 80 weeks and more, 11 had foci of nodular hyperplasia. These foci were usually small, but one animal killed at 102 weeks had a lesion of 0.75 cm diameter, which compressed the surrounding liver. In one case was evidence of local invasion or metastasis found. All the livers had evidence of parenchymal cell damage. No evidence of nodular hyperplasia was found in the controls. It is concluded that there is no evidence to suggest that phenobarbitone-Na induced neoplasm in the liver of male Fischer rats.


Fibrinolytic activity of cultured cells derived during ethylnitrosourea-induced carcinogenesis of rat brain. Using a fibrin-agarose-overlay technique, high levels of plasminogen-dependent fibrinolytic activity have been demonstrated in cell lines derived from an ethylnitrosourea-induced glioma of the rat brain. Cell lines derived from normal adult rat brain showed only low levels of activity. The degree of lysis produced by a cell line was dependent on the average number of cells per colony, and a different pattern of response was observed for tumour and normal cell lines. A good positive correlation existed between the level of fibrinolytic activity, growth in agar and tumourigenicity of a cell line. Fibrinolytic activity was associated with cell lines derived at various times in the latent period, before the appearance of a visible tumour. Many cell lines derived from rat brains at 57-60 (E7), 90-91 (E8) and 111-112 (E6) days after transplacental exposure to ethylnitrosourea showed fibrinolytic activity, and in the latter group the close association with growth in agar and tumourigenicity was also demonstrated. Results from cell lines derived in the E7 and E8 experiments indicated that the possession of fibrinolytic activity preceded the ability of cells to form colonies in agar.


Management of trials in the development of cancer chemotherapy. Potential anti-cancer agents have classically undergone clinical assessment in Phase I, II and III trials. This paper examines the role of these trials and pre-clinical studies in the light of improving cancer chemotherapy. Many patients must now be treated with standard therapy before investigational drugs can be ethically used. The introduction of combined modality trials will require a very prolonged follow-up to demonstrate improved survival and recognize late onset of chronic toxicity.


Pre-cancers and liability to other diseases. Data of 10,556 case-control pairs from the Oxford Survey of Childhood Cancers and related sources have shown that when cancers originate in the reticuloendothelial system (RES neoplasms) they are liable to cause loss of immunological competence before they are clinically recognizable. Since these early effects may have lethal consequences, the true prevalence of RES neoplasms is difficult to identify, especially in infection-sensitive age groups and populations with high death rates from infection. An inevitable consequence of a nuclear holocaust is a high infection death rate. Therefore, a population of A-bomb survivors is a totally unsuitable one for studying the precise nature of the association between ionizing radiation and human cancers.


Biosynthesis and release of prostaglandins by mast cells. Rat mast cells, isolated from peritoneal fluids, were found to release substantial amounts of immunoreactive E-type prostaglandin when stimulated in vitro by foetal calf serum or incubated in the presence of arachidonic acid. Extracellular accumulation of iPGE reflected synthesis, rather than release of preformed material, since it was abolished by indomethacin, a potent and relatively specific inhibitor of prostaglandin synthetase. Hydrocortisone and Compound 48/80, in such experimental conditions, did not affect PGE release.


Myocardial changes after infection with Coxsackie virus B3 in nude mice. Athymic BALB/c-nu/nu (nu/nu) mice were inoculated i.p. with Coxsackie virus B3. The infected nu/nu mice were studied histopathologically, virologically and serologically in comparison with BALB/c-nu/+ (nu/+), BALB/c-+/+(+/+) and conventional ddY/S mice inoculated with the same virus. The virus titre in the hearts of nu/nu mice was roughly similar to that of nu/+ or +/+ and was higher than that of ddY/S. The neutralizing antibody titre in nu/nu mice was slightly lower than that of nu/+ or +/+ mice and somewhat lower than that of ddY/S mice. Histopathologically, there was a lack of mononuclear cells in myocarditis produced by Coxsackie virus B3 in athymic nu/nu mice. In contrast, myocarditis with mononuclear cell infiltrations were found in nu/+, +/+ and ddY/S mice. The lack of mononuclear cell reaction was a distinguishing difference in the myocardial changes of athymic nu/nu mice from those in nu/+, +/+ and ddY/S mice. The incidence in the myocardial lesions of nu/nu mice was about the same as those in nu/+, +/+ and ddY/S mice. However, the intensity of the myocardial changes of nu/nu mice was significantly less than that of other three groups. From the histopathological viewpoint, it is suggested that inflammatory response in the myocardium of mice infected with Coxsackie virus B3 is thymus-dependent.


Specific immunity to influenza virus in ferret organ cultures. Ferret tracheal organ cultures prepared from animals previously infected intranasally with influenza A virus required approximately 130 times more homologous virus (A/PR/8/34(HON1) or A/Port Chalmers/1/73 (H3N2)) to become infected in vitro than similar cultures from normal ferrets. Also, these cultures from convalescent ferrets required 9 times more heterologous virus (A/PR/8/34(HON1) or Sendai) to become infected in vitro than similar cultures from normal animals challenged in vitro with the hererologous virus. We conclude that these tracheal rings are specifically immune. Once tracheal rings are infected, they continue to shed viruses for at least 60 days, the longest period any cultures were kept. Virus sheeding in the intact ferret lasts normally 5-7 days. Thus recovery in the intact ferret seems to be dependent upon factors which are not present, or at least not functional, in the tracheal explant. This is consistent with the hypothesis that recovery is dependent upon systemic rather than local phenomena. Bladder tissue from normal and previously infected ferrets was also cultured and challenged with homologous and heterologous virus. The bladder from previously infected ferrets exhibited specific immunity, although the immunity was more varible.


Quantitative studies on the accumulation of serum albumin and erythrocytes in mouse paw oedema induced by bradykinin or thermal injury. The accumulation of 125I-labelled serum albumin and 51Cr-labelled erythrocytes was measured in mouse paw oedema induced by bradykinin or by heating the paw at 46.5 degrees. The extravasating fluid in bradykinin oedema consistently contained 50% of the albumin concentration of plasma, whereas the extravasating fluid induced by thermal injury initially had a low albumin content, but it progressively increased over a period of 30-40 min to equal albumin levels in plasma. Thermal injury also caused the extravascular accumulation of erythrocytes. Errors involved in attempting to measure the albumin content of the additional extravascular fluid in inflammation are discussed. Adrenaline suppressed bradykinin oedema, but potentiated thermal injury. These results do not support the view that bradykinin is the inflammatory mediator in thermally-induced oedema.


The significance of secondary gram-negative coliform infection of the lungs of mice with influenzal pneumonitis. Influenza-virus-induced pneumonia of mice was consistently shown to be associated with secondary infection with coliform organisms. Treatment with gentamicin effectively sterilized the lungs of these mice but had no effect on either mortality or extent of the pneumonic process. The significance of these findings is discussed.


Metyrapone-induced cardiovascular degenerative changes in non-arteriosclerotic and arteriosclerotic rats. Virgin and breeder, male and female, Sprague-Dawley rats were unilaterally nephrectomized and given 1% saline drinking water. Animals were injected i.p., twice daily, with a 10 mg/100 g body wt dose of the 11-beta hydroxylation inhibitor, Metyrapone. After 7 weeks of treatment, both the previously nonarteriosclerotic virgin rats and the breeder rats with pre-existing arteriosclerosis developed de nove, widely distributed, intimal hyalinization of their peripheral arteries along with myocardial fibrosis and hyalinization of their intramyocardial coronary arteries. The Metyrapone-treated animals developed severe hypertension with greatly elevated serum creatin phosphokinase, glucose, BUN and cholesterol levels. The adrenal glands, hearts, and kidneys were greatly hypertrophied, in keeping with Metyrapone-induced extra ACTH release and the hypertension-induced myocardial and renal histopathology. Uniparous, Metyrapone-treated, female rats manifested an unusually high incidence of saccular aneurysms of the aorta. It is suggested that the hypertension and the intimal hyalinization and other specific morphologic characteristics of the cardiovascular degenerative changes observed were directly related to excess production of mineralocorticoids, e.g., deoxycorticosterone.


Effects of fever on host defense mechanisms after infection in the lizard Dipsosaurus dorsalis. Fever has never been proven beneficial in mammals, although it enhances survival in the lizard D. dorsalis infected with Aeromonas hydrophila. We examined the course of the infection and the function of host defence in febrile (41 degrees) and afebrile (35 degrees or 38 degrees) animals using this model. Infected, febrile lizards had sterile blood cultures, and 1-2 logs fewer bacteria in body tissues 6-12 h after infection. Granulocytes appeared early and in large numbers at the site of inoculation in febrile, but not afebrile, animals. We were unable to demonstrate effects of this small range of temperatures on in vitro growth rates of bacteria, on lizard granulocyte chemotactic or phagocytic functions, or upon serum antibody levels. Our results suggest that fever enhances some aspect of the early inflammatory response, leading to increased leucocyte emigration at the local site and containment of the infection.


Hepatic blood flow studies in the rat before and after portacaval transposition. Portacaval transposition diverts portal blood from the liver and allows systemic venous blood from the caudal inferior vena cava to perfuse the portal bed. Measurement of hepatic tissue blood flow before and after portacaval transposition and its relationship to the liver atrophy seen after portacaval transposition is important. Sequential measurements of hepatic tissue blood flow carried out before and after portacaval transposition have been made using the clearance of the inert radioactive gas 85Krypton after injection into the portal bed. These measurements reveal that hepatic tissue blood flow is not diminished following the operation. The relative liver atrophy seen after portacaval transposition is therefore consequent on portal venous diversion but not on diminished hepatic perfusion.


Cell degeneration and necrosis in experimental gliomas. Cell degeneration and necrosis in ethylnitrosourea-induced gliomas of rats were examined using light and electron microscopy. Two types of cell loss were observed: massive necrosis and individual cell death. Massive necrosis was influenced by the size, malignancy and histological type of the gliomas: it occurred most frequently in large, malignant pleomorphic gliomas and epindymomas. Proliferation of endothelial cells, narrowing of vascular lumina and degenerative changes affecting vessel walls were thought to be the major factors causing necrosis. Individual cell death occurred throughout the neoplasms irrespective of their size. Progressive degenerative changes, involving both the nucleus and cytoplasm, preceded cell death. Macrophages (both microglial and monocytic in origin). reacting astrocytes and, to a lesser extent, neoplastic glial cells engulfed and digested the necrotic cells and their remnants.


A morphological assessment of the stimulatory effect of coumarin on macrophages. In examining the migration of macrophages on to subcutaneously implanted coverslips in rats, it was found that coumarin (5-6 benzo-alpha-pyrone) and a preparation (Venalot) containing the former, very significantly increased the total macrophage number as well as the percentage of stimulation on the skin side of the coverslip. For the muscle side, Venalot increased the total numbers and the percentage stimulated while coumarin alone had no effect compared with the control. It remains to be seen whether these stimulated macrophages are also activated.


Host responses to cryoablation of normal kidney and liver tissue. Following cryoablation of one kidney in Strain-2 guinea-pigs, the viable opposite kidney was assessed by functional, histological and immunopathological techniques for evidence of immunologically mediated damage. The autoantibody content of postoperative sera was also examined. Control operations involved ligation, surgical nephrectomy and the production of hepatic cryolesions. The results indicate that autoantibody production and glomerular deposition of immune complexes can occur and may cause abnormal passage of hippuran through the kidney. There is no evidence for autoallergy against highly tissue-specific determinants; the specificity, strength and time course of the reactions obtained was dependent on the site of the lesion, whether or not freezing was accompanied by ligation.


Cellular fine structure in the invasive nodules of different histogenetic types of malignant melanoma. Ultrastructural studies were carried out on the invasive nodule of forty malignant melanomas. The findings support the concept that the fine structure of lentigo maligna melanoma is often characteristic, and differs from that of superficial spreading and nodular melanoma. The melanosomes in lentigo maligna melanoma are usually ellipsoidal and resemble those of normal melanocytes, whereas the melanosomes in superficial spreading and nodular melanoma are most often spheroidal and abnormal in appearance. Superficial spreading and nodular melanomas cannot be distinguished reliably by their ultrastructure. Melanosomal appearances could not be related to the presence of a pre-existing naevus or the depth of invasion of the tumour nodule.


A quantitative approach to epidermal wound healing: the effect of dexamethasone on regenerating epithelium. The effect of dexamethasone on the regeneration of new epithelium over the base of an excised suction blister has been studied over a period of 9 days. It was found that dexamethasone did not significantly affect the migration of epidermis over the blister base but it did significantly reduce the number of cells in DNA synthesis and post wounding acanthosis of wound edge and regenerating epithelium.


Antiserum to the cell surface of oral epithelial cells: relationship to pemphigus antiserum. Antisera to human oral epithelial cells were produced in rabbits and found to be specific for epithelial type cells of man, guinea-pig and rabbit. Binding of the antisera to human oral epithelial cells was not affected by pre-incubation in concanavalin A, trypsin or neuraminidase, nor by pre-incubation of the antisera with fetuin. The antisera would appear to differ from pemphigus antiserum.


The relationship between immunological parameters and response to therapy in resistant oral candidosis. Eight patients with resistant oral candidal infection have undergone full immunological assessment. In four of these patients no significant abnormality of immune function was observed, and all responded to intensive antifungal therapy with nutritional supplements of iron and folic acids as required. The remaining four patients had abnormalities only of specific candida-related immune function and no detectable abnormality of general immune function. Surgical excision of affected areas of oral mucosa was found to be the most effective therapy in three of these four cases. The immunological findings in these cases are compared with those observed in five patients with chronic mucocutaneous candidosis in whom both specific candida-related and non-specific immune incompetence were present.


Erythropoietic protoporphyria: hepatic cirrhosis. Observations on liver pathology and function were made on 12 patients with erythropoietic protoporphyria (EPP). Needle liver biopsies in 3 of 11 patients showed mild portal or periportal fibrosis without evidence of abnormal liver function. One patient (Case 12), died from hepatic cirrhosis and failure at the age of 11 years, the youngest yet reported. He was not suspected of pending liver disease until 3 months before death. The quantity of protoporphyrin present in his liver was approximately 5.75% of total liver weight. Fatal liver disease in EPP has occurred in 13 patients, 7 male and 6 female, in which the mean age of death was 38 years. The pathology of the liver in EPP is characteristic and is described.


The effects on epidermal DNA synthesis of the butyrate esters of clobetasone and clobetasol, and the propionate ester of clobetasol. An animal model for evaluating the effects of drugs on epidermal DNA synthesis has been used to determine the time of onset, period of maximum activity and duration of effect of two topically applied proprietary glucocorticosteroids, clobetasone butyrate and clobetasol propionate. Both drugs produced maximum inhibition of epidermal DNA synthesis by 24 h after application. Clobetasol propionate exhibited a significantly earlier onset (4 1/2 h) and longer duration (36 h) of activity than clobetasone butyrate (6 and 24 h respectively). A systemic effect was not observed at any time after the application of clobetasone butyrate but was observed for up to 24 h after the application of clobetasol propionate. Clobetasol butyrate was also assayed in this system and was found to be as potent as clobetasol propionate. It is concluded that the alcoholic, as opposed to the ketonic, grouping in the 11 positions of the steroid ring profoundly alters the potentials of this molecule for systemic activity.


Spreading pigmented actinic keratoses.

Spreading pigmented actinic keratoses. The clinical and histological features of ten pigmented keratoses arising on the face are described. They were all greater than 1.5 cm in diameter and had been spreading centrifugally. They were variably pigmented and possessed either a smooth, verrucous or slightly scaly surface. Two lesions had progressed to become pigmented squamous cell carcinomas.


Human malignant melanoma. Melanosomal polymorphism and the ultrastructural dopa reaction. An ultrastructural dopa reaction, with glutaraldehyde--formaldehyde prefixation, was carried out on ten specimens of malignant melanoma showing a wide variation in melanosomal morphology. All tumours, but only a minority of tumour cells, contained reaction product. In all tumours the reaction product was distributed similarly in the Golgi apparatus and Golgi associated endoplasmic reticulum (GERL). However, differences were noted in its deposition in melanosomes. Whereas vacuolar and lamellar profiles sometimes contained reaction product, it was not seen in normal, granular and abortive melanosomes. Tumour cells without melanosomes were also seen to contain reaction product.


Epidermal activity in the involved and uninvolved skin of patients with psoriasis. A simple biochemical technique has been used to study the rate of incorporation of precursor materials in the involved and uninvolved skin of psoriatic subjects. Psoriatic plaques were found to incorporate tritaited thymidine twice as rapidly as skin from control subjects. The uninvolved skin of psoriatics showed a 48% increase in thymidine incorporation. Histidine and proline incorporations were also increased in psoriatic plaques but not in the uninvolved skin of psoriatics.


The role of serum in the epithelial outgrowth of mouse skin explants. An experimental system is described which facilitates the measurement of epithelial outgrowth in vitro. Using this sytem the properties of the serum component supporting epithelial spread have been studied. It has been found that appreciable epithelial outgrowth occurs in concentrations of cow serum greater than 0.5% and that maximal outgrowth occurs at concentrations of 1% or greater. Only minimal outgrowth is apparent during the first day of culture. The lack of epithelial outgrowth in the absence of serum is not due to reduced cell viability since replacing serum after 3 days leads to cellular outgrowth. Though this activity is found in several sera studied (cow, fetal calf, human, horse, mouse and chicken), there are considerable quantitative differences between species. Epithelial cell outgrowth  does not occur in the presence of medium plus bovine fibrin, serum albumin or thrombin. The serum component is heat labile and non-dialysable. It appears to be needed continuously and does not require DNA synthesis for its effect.


Half-and-half cells in lichen planus. A possible clue to the origin and early formation of colloid bodies. In the course of a study of wound healing in four patients with lichen planus, we found transformed keratinocytes with a hitherto undescribed ultrastructure in both wounded and undisturbed papules. We have called these epidermal cells half-and-half cells because they showed changes on the one hand of increased synthetic activity and, on the other hand, of fibrillar transformation closely resembling that seen in fully developed colloid bodies. We suggest that these half-and-half cells may provide a useful clue to the early changes occurring in colloid body formation.


Histocompatibility antigens in granuloma annulare. Comparative study of the generalized and localized types. Thirteen patients with localized granuloma annulare and 19 with the generalized form of the disease were typed for HLA antigens. The control group consisted of 70 matched apparently healthy subjects. No significant difference in the frequencies of the 26 tested antigens was revealed between patients with localized granuloma annulare and controls. Patients with the generalized form of the disease showed a highly significant increase in the frequency of HLA-Bw35 as compared with both controls and patients with the localized form of the disorder (P = 0.001 and 0.01 respectively). The results seem suggestive of a possible different pathogenesis of the two forms of the disease.


Updating the Goeckerman regimen for psoriasis. Various components of the Goeckerman regimen were analysed. Although our findings are preliminary, they indicate several important observations: (1) Irradiation of tar treated patients with UVA compared to UVB showed the most efficacious wavelengths to be in the erythemic range (UVB). (2) A 1% concentration of crude coal tar was as effective as 5 and 25%.(3) Application of tar 2 h prior to irradiation was equivalent to overnight usage. (4) Little difference was noted between hydrophilic ointment and petrolatum as vehicles. (5) A tar gel was less beneficial than crude tar. The benefits of the Goeckerman therapy are derived from the intrinsic antipsoriatic effects of both tar and UVB. For some the combination is additive and necessary for clearing; for others either of the components may have great benefit alone. Our favourable results with UVB alone indicate that its effectiveness has been understated and poorly appreciated. Minimizing the time of tar application without loss of efficacy makes treatment adaptable to outpatient practice.


The decrease of hyaluronate synthesis by anti-inflammatory steroids in vitro. The effect of anti-inflammatory steroids (prednisolone and derivatives of hydrocortisone, dexamethasone and betamethasone) on the synthesis of hyaluronic acid and sulphated glycosaminoglycans in human skin fibroblast culture was studied. The concentrations of steroids varied between 1 x 10(-10)M and 1 x 10(-6)M. All tested steroids decreased the synthesis of hyaluronic acid to the same final level which was about 40--50% of the controls, but the concentrations required varied between different steroids. The relative inhibitory potencies of the steroids were calculated based on concentrations needed to decrease the synthesis of hyaluronate. When the inhibitory potency of hydrocortisone was calculated as one, the values of the other steroids were: prednisolone 5, hydrocortisone 17- butyrate 20, betamethasone alcohol 30, dexamethasone alcohol 38, betamethasone 17-valerate 350--400, dexamethasone monosodium phosphate and betamethasone disodium phosphate over 400. Hydrocortisone sodium succinate was as potent an inhibitor of hyaluronate synthesis as hydrocortisone alcohol. None of the tested steroids affected the synthesis of sulphated glycosaminoglycans at these concentrations. The changes ovbserved in glycosaminoglycans in the medium were in accordance with the changes in the cell layer. The possible significance of hyaluronate synthesis inhibition by anti-inflammatory steroids is discussed.


Immunotherapy of verrucae vulgares with dinitrochlorobenzene. A study using daily topical applications of dinitrochlorobenzene on recalcitrant verrucae vulgares demonstrated this to be of practical value. Complete resolution of lesions occurred in 66% of 35 patients, with a complication rate of 24%. The results of other studies are reviewed and recommendations for use of this medication are given. DNCB therapy should, however, be reserved for use on recalcitrant lesions because of the complications associated with its usage.


Successful treatment with pimozide of delusional parasitosis. An introduction to the concept of delusional parasitosis is presented. The persistent and refractory nature of the condition is emphasized. A case history is described in which a 67-year-old spinster, with classical symptoms of this condition, responded extremely favourably to simply administered pharmacotherapy. The authors allude to five similar patients also treated successfully by the same method. It is suggested that dermatologists might profitably treat this condition without recourse to psychiatric referral, which can often be counter-productive.


Multiple disseminated pyogenic granuloma. A 15-month-old baby girl with extensive skin burns developed within the burned areas multiple lesions with the clinical and histological characteristics of granuloma pyogenicum. These lesions seem to differ from those reported by others as pyogenic granuloma with multiple satellites.


Erythema gyratum repens with pulmonary tuberculosis. A 63-year-old man presented with erythema gyratum repens of 7 months' duration. A cavitating mass at the right lung apex was resected and proved to be tuberculous. Following the resection, the skin lesions cleared within a few days. Erythema gyratum repens has not previously been described in association with non-malignant visceral pathology. The pathogenesis remains obscure but cannot be related specifically to a response to tumour cells or their products in view of the association reported here. The condition bears no resemblance to any known tuberculide.


Pruritus and dermographism due to intrahepatic cholestasis of infancy. A case report of intrahepatic cholestasis of infancy presenting with chronic severe pruritus is described. This presentation is compared with similar cases attending this unit. Intrahepatic cholestasis of infancy and the pathogenesis of puritus associated with cholestasis are briefly discussed.


Thrombin activation of factor VIII. II. A comparison of purified factor VIII and the low molecular weight factor VIII procoagulant. The current experiments examine the reaction between purified human alpha-thrombin and purified human factor VIII and compare this with the reaction between alpha-thrombin and the low molecular weight factor VIII procoagulant activity obtained by high ionic strength dissociation. The reaction patterns of both procoagulants are similar, demonstrating in initial increase in factor VIII activity followed by a decay of procoagulant activity. The extent of activation which is observed in the initial phase decreases with lower temperatures and with lower thrombin concentrations. A pseudo-first order relationship is demonstrated for the activation phase. The labile factor VIII procoagulant activity produced by the initial action of thrombin appears to be intrinsically unstable, since the addition of hirudin or diisopropylfluorophosphate does not prevent the subsequent decay of the procoagulant activity. The similar activation and decay patterns of purified factor VIII and the dissociated low molecular weight factor VIII procoagulant support the concept that the low molecular weight procoagulant itself represents the functional coagulant moiety of the factor VIII complex.


Efficacy of platelets collected by semi-continuous flow centrifugation (Haemonetics Model 30). The viability of both autologous and donor platelets collected by means of a semi-continuous flow centrifuge (Haemonetics Model 30) was measured. Radiochromium labelled pooled platelets harvested from six passes and reinfused into their normal donors showed recoveries and survivals of 58% +/- 8 and 9.6 d +/- 0.8 compared with normal values of 65% and 9.5 d +/- 0.6, respectively. When the viability in aplastic thrombocytopenic recipients of platelets collected from normal donors by the Haemonetics Model 30 was compared with that of platelets collected from the same donors by multiple bag plateletpheresis the results were very similar: recoveries of 82% +/- 18 and 80% +/- 25 and survivals of 3.9 d +/- 2.0 and 3.8 d +/- 1.3, respectively. The in vitro function of the collected platelets in response to aggregating agents was normal when measured within 60 min of collection at pH 7.4. The relationship between bleeding time and post-transfusion platelet count in aplastic, thrombocytopenic patients showed that in vivo function was maintained.


Variations in globin synthesis in delta-beta-thalassaemia. Peripheral blood globin synthesis studies were done in 11 patients with delta beta-thalassaemia trait, Hb S-delta beta-thalassaemia or delta beta/betao-thalassaemia from two black and two Caucasian families. All patients had elevated Hb F and normal or decreased Hb A2 levels and 10 had family studies confirming the diagnosis. In addition, four unrelated non-thalassaemic patients with elevated Hb F levels also had peripheral blood globin synthesis studies. The beta/alpha specific activity globin synthesis ratios in the three blacks with delta beta-thalassaemia trait were 0.60--1.04. In the four Caucasians with delta beta-thalassaemia traint, the beta/alpha ratios were 0.58--1.02. These results demonstrate a wide range of ratios overlapping those of normal controls (0.99 +/- 0.06). The betas/alpha ratios in three blacks with Hb S-delta beta-thalassaemia ranged from 0.66 to 1.00, similar to those of patients with delta beta-thalassaemia trait. In the black patient with delta beta/betao-thalassaemia, the gamma/alpha ratio was 0.67. The beta/alpha peripheral blood ratios in the four non-thalassaemia patients with elevated Hb F ranged from 1.00 to 1.11, similar to those of normal controls. These studies indicate that a decreased beta/alpha ratio is not an invariable finding in delta beta-thalassaemia in blacks or Caucasian patients and that globin synthesis data alone is insufficient to diagnose definitively heterozygotes for delta beta-thalassaemia or to distinguish this trait from non-thalassaemic haematological disorders associated with a normal percentage of Hb A2 and an elevated level of Hb F.


Congenital dyserythropoietic anaemia type III: an electron microscopic study. The morphological features of erythroblasts in congenital dyserthropoietic anaemia (CDA) type III were studied by electron microscopy. Typical findings included clefts and blebs within the nuclear region, autolytic areas within cytoplasm, iron-filled mitochondria and myelin figures. The findings resembled those reported in other dyserythropoietic anaemias particularly in CDA type I; the main morphologic features which distinguished the two types were lack of spongy appearance of the chromatin, lack of cytoplasmic organelles within the nuclear region and intact nuclear envelope in CDA type III.


Autoimmune antibodies in chronic lymphatic leukaemia. In chronic lymphocytic leukaemia a factor in patients' serum enhances the in vitro viability of the abnormal cells and this has been identified as an antibody. The activity of this factor can be removed by interaction with anti-immunoglobulin and by ammonium sulphate precipitation with a degree of saturation in excess of 46%. Cohn fractionation and chromatography with A-50 Sephadex show that the factor is not a complex but an immunoglobulin. No activity is removed after reaction of sera with 2-mercapto-ethanol and di-thiothreitol. The evidence therefore suggests that a gamma-G immunoglobulin is involved. Concentrated washings from the leukaemic cells behave in exactly the same way as patients' sera and activity is retained in the same fraction during precipitation and purification procedure. The extensive cross-reactivity of the sera suggests a common chronic lymphatic leukaemic antibody and it is considered that an active autoimmune response may be an integral part of the disease.


Identification of the hairy cells of leukaemic reticuloendotheliosis by an esterase method. A distinctive pattern of alpha-naphthyl butyrate esterase positivity was observed in all of a series of 14 patients with HCL. This pattern was not observed in a range of other haematological malignancies including nine cases of CLL, two cases of Sézary's syndrome, six cases of null cell ALL, two cases of Schilling-type monocytic leukaemia and one case of lymphosarcoma cell leukaemia. The potential diagnostic value of this simple cytochemical test is discussed in relation to existing methods.


High resolution autoradiographic studies of RNA, protein and DNA synthesis during human eosinophil granulocytopoiesis: evidence for the presence of RNA on or within eosinophil granules. Human bone marrow cells which had been incubated with [3H]uridine or [3H]leucine for I h were studied using the technique of electron microscope-autoradiography. The autoradiographs revealed the presence of newly-synthesized RNA and protein molecules within or on a proportion of (I) the primary and secondary granules in all classes of eosinophil precursors and (2) the secondary granules in eosinophil granulocytes. It is suggested that the granule-associated RNA molecules may be concerned with the synthesis of at least some of the new protein molecules which were incorporated into the limiting membrane or substance of eosinophil granules long after the immature primary granule stage. Studies of eosinophil precursors which had been incubated with [3H]thymidine for I h showed that the eosinophil granules do not label with this DNA precursor.


Non-tropical 'idiopathic splenomegaly': a follow-up study of ten patients described in 1969. The later history is described of four of 10 patients who were reported in 1969 as suffering from non-tropical 'idiopathic splenomegaly'. Two of the four  patients developed malignant lymphomas 6 years and 2 years, respectively, after splenectomy but the two other patients have lived for 17 and 15 years, respectively, without developing any signs of a malignant tumour. Thus, four of the original 10 patients have developed malignant's lymphomas. The histology of the patients' spleens has been reviewed in the light of their clinical history, but no criteria have been found which are of clear prognostic value. However, with hindsight it was possible to recognize some cytological abnormality in the spleens in three out of the four patients who developed malignant lymphomas, and it appears that unless the cell population in both the red and white pulp is strictly normal, the patient is likely to develop a malignant lymphoma. The tumours which subsequently developed showed no special or characteristic features. The title 'idiopathic splenomegaly' is clearly unsatisfactory but the alternative 'chronic lymphocytic lymphoma with hypersplenism', although appropriate for the illness of the patients who developed malignant lymphomas, is inappropriate for those in which the pathological process seems not to be neoplastic.


The identification of the products of folate catabolism in the rat. Further analysis of rat urine containing labelled catabolites derived from administered 3H- or 14C-labelled folic acid is described. The results support previously described studies, and show that folate catabolism in the rat takes place by cleavage of the C9-N10 bond, and not by excretion of inactive forms of the vitamin which still contain the intact folate skeleton.


Evidence that endotoxins enhance the factor X activator activity of washed human platelets. The in vitro effect of several bacterial endotoxins on human platelets was determined. Nine different endotoxins failed to induce aggregation in platelet-rich plasma (PRP) or of platelets washed by two different methods; four of them which we studied further failed to induce [14C]serotonin release in PRP. In contrast, using recently described test systems for platelet coagulant activity, all the endotoxins shortened the latent period occurring before aggregation of a mixture of washed platelets, normal serum, and CaCl2, and the clotting time of this mixture upon addition of fibrinogen. Washed platelets obtained from PRP preincubated with endotoxin had a higher platelet coagulant activity than platelets obtained from PRP preincubated with buffer. Washed platelets contribute to thrombin generation by providing factor V, a factor X activator and possibly phospholipid. Since the endotoxins did not influence the factor V activity of platelets or the platelet factor 3 activity, either in PRP or using platelets washed by albumin density gradient centrifugation, it is suggested that they enhance the factor-X activator activity of human platelets.


Subunits A and S inheritance in four families with congenital factor XIII deficiency. Previous studies of the inheritance of the two molecular subunits of fibrin stablizing factor (factor XIII) refer to isolated cases. The present work investigates the hereditary mode of transmission of subunits A and S, measured by the Laurell technique, in seven homozygotes and in 29 heterozygotes belonging to four families with factor XIII deficiency. The results indicate that the homozygotes were devoid of immunologically identifiable A subunit, whereas the heterozygotes could be identified by measuring this protein. The subunit S has been found to be decreased both in homozygous and in heterozygous patients, so that it seems that the two subunits, even if their synthesis is controlled by different genes, are genetically related. The mode of transmission of this disorder, supported by quantitative determinations of plasma subunit A, is autosomal recessive.


Differential blood cell separation using a high gradient magnetic field. A technique for the separation of erythrocytes from whole blood is described which exploits the magnetic property of haemoglobin in the reduced state. The technique is characterized by the use of a filter consisting of a cylinder, containing stainless steel wire mesh, placed between the jaws of an electro magnet. When activated, the electromagnet induces a magnetic field gradient in the vicinity of each of the constituent wires, sufficient to attract and trap erythrocytes in suspension. The number of erythrocytes captured varies with the applied field (0-1.4 Tesla in these experiments) and flow rate (1.9-12.9 x 10(-4) m s-1). The capture process does not cause haemolysis or observable surface damage to the erythrocytes and neither leucocytes nor platelets are retained by the filter.


The measurement of total and unsaturated iron-binding capacity in serum. An inter-laboratory investigation into the assay of serum iron binding capacity by the magnesium carbonate adsorption method was undertaken. The source of MgCO3, storage temperature of whole serum, lyophilization and storage temperature of lyophilized serum were identified as sources of inter-laboratory variation. Protocols for the clinical assay of UIBC and TIBC are given which have achieved satisfactory inter-laboratory precision.


Recommendations for measurement of serum iron in human blood. The following method has been approved by the International Committee for Standardization in Haematology (ICSH) Board for publication as an ICSH standard (EP7/1978).


Immunologic characterization and quantification of haemoglobin A1c. Sheep antiserum developed against the human glycohaemoglobin, Hb A1c, distinguishes this fraction from the major component Hb A0. Partial cross reactivity is observed with Hb A1a and Hb A1b, as well as with analogous glycohaemoglobins from mouse and dog haemolysates. The reactivity of the haemoglobins with this specific antiserum is abolished by the reduction of the keto group of the sugar ligand. The immunological specificity displayed provides the basis of a quantitative assay for Hb A1c, suitable for studies of clinical and experimental diabetes.


Fetal haemoglobin in early malignant osteopetrosis. The characteristics of the fetal haemoglobin (HbF) in two children with osteopetrosis and high levels of HbF have been studied. The structural analysis of the gamma chains demonstrated a fetal Ggamma/Agamma ratio. HbF was distributed inside only 30% of the peripheral red blood cells. In vitro globin chain synthesis studies showed that there was balanced globin chain production, despite the increased level of HbF.


Capacity of ringed sideroblasts to synthesize nucleic acids and protein in patients with primary acquired sideroblastic anaemia. Bone marrow cells from two patients with primary acquired sideroblastic anaemia were studied using the technique of electron microscope autoradiography. Whereas a significant proportion of erythroblasts containing small to moderate quantities of intramitochondrial deposits incorporated [3H]thymidine into DNA, the majority of cells containing large quantities of intramitochondrial deposits did not. These results are consistent with the idea that several of the early polychromatic cells with large quantities of deposits become arrested in their progress through the cell cycle. The data also revealed that the accumulation of increasing quantities of iron-containing material within the mitochondria of an erythroblast was frequently (but not invariably) associated with and was possibly responsible for (I) a depression of RNA synthesis and (2) a more marked depression of protein synthesis. A small proportion of the erythroblasts showing a depression of protein synthesis also displayed various non-specific ultrastructural abnormalities indicative of cellular injury such as the presence of intranuclear clefts, nuclear membrane-associated myelin figures and lipid-laden intracytoplasmic vacuoles.


Folate-dependent serine synthesis in lymphocytes from controls and patients with megaloblastic anaemia: the effect of therapy. The utilization of [14C]formate for serine synthesis by lymphocytes was impaired in all the patients with pernicious anaemia and in 70% of other patients with megaloblastic anaemia. In pernicious anaemia this was corrected by vitamin B12 therapy in 48 h but not by folate therapy although patients given folate showed a satisfactory haematological response.


A modified sedimentation method for counting platelets in blood. A sedimentation method for counting human blood platelets is proposed which uses a fluid of sp.gr. i.057 at an osmolarity of 320 milliosmols. The fluid is a mixture of Lymphoprep and Isoton II. After centrifugation at about 200 platelets are counted on an electronic particle counter.


A study of plasma progesterone, oestradiol-17beta, prolactin and LH levels, and of the luteal phase appearance of the ovaries in patients with endometriosis and infertility. Thirty-four infertile patients with regular cycles and endometriosis were studied and compared to a control group of 28 women. The endometriosis was classified as mild (n = 16), moderate (n = 9) and severe (n = 9) according to Acosta et al (1973). The interval between the LH peak and the onset of subsequent menstruation was shorter (P = 0.024) in patients with endometriosis than in the control group. In mild endometriosis, oestradiol-17beta levels fell on the day after the LH peak, but this was not the case in moderate and severe endometriosis. In mild, moderate and severe endometriosis the plasma progesterone concentration did not rise on the first day following the LH peak, and at laparoscopy significantly (P less than 0.005) less ovulation stigmata were present. We conclude that endometriosis is associated with luteinization in situ and that this may explain the associated infertility.


The treatment of mild adrenal hyperplasia and associated infertility with prednisone. Thirty patients with mild post-pubertal adrenal hyperplasia, characterized by raised urinary 17-oxosteroid levels and variable combinations of irregular menses, hirsuties, infertility, and spontaneous abortion, were treated with 2.5 to 10 mg of prednisone per day and all conceived (55 pregnancies). With this treatment, regular, ovulatory cycles occurred immediately in 25 patients, and after two to six months, in the rest. Treatment reduced raised 17-oxosteroid levels to normal and brought about some improvement in hirsuties and acne. Forty-seven pregnancies ended in the birth of liveborn infants; one of these died of prematurity and another had congenital emphysema. One pregnancy was terminated, two were of unknown outcome and five (9.4%) ended in abortion. Before treatment, 20 out of 22 pregnancies (91%) had ended in abortion.


Water relations of early embryogenesis.

Water relations of early embryogenesis. Attention is drawn to the changes in maternal serum osmolality that accompany ovulation, fertilization and early embryogenesis, and the possible significance of those changes is discussed in relation to the sequence of development. From these considerations it is tentatively concluded that maternal hydration influences all stages of early development, and that transient derangement of maternal body fluid regulation could, therefore, be a significant factor in the aetiology of fetal malformations.


Dyspnoea during normal pregnancy.

Dyspnoea during normal pregnancy. The incidence, severity and time-course of dyspnoea were assessed in 62 women on eight occasions throughout a normal pregnancy. Fifteen per cent of subjects noticed an increase in dyspnoea in the first trimester compared with the nonpregnant state and in almost half of them dyspnoea was experienced before 19 weeks gestation; 76% complained of this symptom by 31 weeks gestation. After this time, few subjects noticed any increase in their symptoms.


Amoebiasis in pregnancy and the puerperium. The overall incidence and mortality of amoebiasis in the Kilimanjaro Region of Tanzania is briefly reviewed and seven patients with fatal amoebic colitis occurring during pregnancy and the puerperium are described. The possible causes of the fulminating course of the disease in pregnancy are considered and the management is discussed.


The relevance of antenatal and intrapartum fetal heart rate patterns to fetal outcome. Antenatal fetal heart rate (FHR) as an indicator of fetal status was evaluated in two separate studies. The first attempted to determine, in 30 minutes of continuous recording from each of 50 antenatal patients, relationships between spontaneous FHR changes and fetal condition before and after birth. No significant association was found between observed FHR patterns and antenatal or neonatal fetal status. The second study used induction of labour as a stress test, because similar conditions to that required for oxytocin stress testing were present and there was the advantage of direct FHR recording. In 150 induced and monitored labours, FHR changes associated with the first six suitable contractions seldom related to Apgar scores at birth or development of fetal distress in active labour. Fetuses showing no response to contractions tended to have better Apgar scores than those which showed FHR decelerations. Results from these studies do not substantiate reports that FHR changes arising spontaneously, or in response to induced contractions, reflect satisfactorily the existing or subsequent fetal status.


Nitrous oxide transfer across the placenta and condition of the newborn at delivery. Nitrous oxide transfer to the fetus was measured in 14 consecutive patients having a Caesarean section near term. Better babies, as assessed by birth weight and Apgar score at five minutes, were associated with better transfer of nitrous oxide. The correlation was probably attributable to differences in placental blood flow, although it is not possible to prove this.


Cord blood hypertriglyceridaemia as an index of fetal stress: use of a simple screening test and results of further biochemical analysis. In this preliminary study, 120 cord blood samples were subjected to a simple on-the-ward triglyceride screening procedure and 15 were designated as being high and another 15 randomly selected as controls. All the samples were then subjected to detailed biochemical analysis for fatty acid profiles and/or concentrations of free fatty acids, triglycerides (TG), phospholipids, cholesterol esters and glycerol. Eleven of the samples designated 'high' were associated with one or more of the following clinical conditions: family history of ischaemic heart disease, maternal starvation, fetal distress, light-for-dates babies and excessive weight gain during pregnancy. There was an association between high TG levels and high glycerol levels. The fatty acid pattern of the TG was altered when at abnormally high concentration, in particular oleic acid was increased relative to the others, and this was associated with an increase in cholesterol ester oleic acid. The possible mechanisms resulting in cord hypertriglyceridaemia are discussed.


Pregnancy and childbirth in a true hermaphrodite following reconstructive surgery. An 18-year-old Tanzanian true hermaphrodite became pregnant one month after reconstructive vaginal surgery. Chromosomal analysis of the mother showed a 46 XX constitution; a chromosome 21 carried a large short arm which might have contained Y chromosome material.


Ocular antigens VIII: assay of delayed hypersensitivity to corneal epithelium in the rabbit. Rabbits were sensitised with complete bovine corneal epithelium. The lymphocyte stimulation test was performed with the lymphocytes of these rabbits using the soluble and sonicated insoluble fraction of the corneal epithelium as the antigens. A striking difference existed in the optimal test conditions for these antigen fractions. By comparing the results of the lymphocyte stimulation test with other immunological parameters, namely, skin test reaction, antibody titre, and phytohaemagglutinin stimulation of the lymphocytes, we concluded that both antigen fractions stimulate predominantly the T-lymphocyte system, although boosting augmented the humoral immune response. Stimulation of the cultured lymphocytes by both the separate and mixed antigen fractions is evidence for the existence of crossreacting antigens between the soluble and insoluble epithelial fractions.


Visual fields in metastatic choroidal carcinoma. A large choroidal metastasis was diagnosed in the right eye of a 44-year-old man referred for admission to hospital because of 'retinal detachment.' At the same time in the second, symptomless, eye a very small metastasis was observed. Close follow-up during the next month showed an extremely rapid deterioration of visual acuity and visual field in this eye. This is thought to be characteristic of such metastatic tumours in contrast to the slower progress of choroidal malignant melanoma. The application of local radiotherapy to the same eye led to an impressive improvement in the visual acuity and visual field. The source of these bilateral choroidal metastases, which was found only after the patient's death, proved to a bronchial carcinoma.


Corneal toxicity from vinblastine solution. The case is reported of a male physician who accidentally sprayed some vinblastine solution into his eyes. The resulting lesions are described.


Effects of ultrasound on the corneal endothelium: I. The acute lesion. The ultrasonic radiation utilised in phacoemulsification procedures for the removal of cataractous lenses results in the widespread production of discrete lesions in the corneal endothelium. The morphology of this induced damage has been examined in rabbit and man using both scanning and transmission electron microscopy. The illustrated results are related to both the duration of the ultrasonic exposure and to the mechanisms of damage.


Effects of ultrasound on the corneal endothelium: II. The endothelial repair process. The responses of corneal endothelium to a 2-minute exposure of ultrasound from a clinical phacoemulsification device have been studied by specular microscopy and both scanning and transmission electron microscope. Healing of lesions occurred in two ways, and these were related to lesion size. Small lesions healed by a process of rosette formation, and large lesions were repaired by a process of endothelial dedifferentiation and migration. All damaged areas were re-covered with endothelial cells within 24 hours of exposure, and at this time corneal thickness had returned to control levels. The implications are discussed in relation to the phacoemulsification procedure.


Intracorneal and sclerocorneal cysts.

Intracorneal and sclerocorneal cysts. Two cases of corneal cysts are reported, one sclerocorneal and the other intracorneal. The two conditions differ in pathogenesis, appearance, course, and management.


Clinical aspects of corneal trachoma.

Clinical aspects of corneal trachoma. Classification of trachoma by site rather than density of opacities is better related to visual prognosis and helps in selection for graft surgery. The cases are divided into 3 groups: peripheral corneal opacities, central corneal opacities, and diffuse corneal opacities (ground-glass cornea). A central lesion has the poorest prognosis, especially in children.


Refractive errors of retinitis pigmentosa patients. A retinitis pigmentosa (RP) population (268 eyes) had predominantly myopic refractive errors. Whereas 12% of a normal population have myopic refractions, myopia was found in 75% of 268 eyes of RP patients and in 95% of 41 eyes of X-linked RP patients. The spherical errors describe a single-peaked, skewed distribution, with a mean of -1.86 dioptres that is significantly (P less than 0.001) more myopic, by -2.93 D, than that of a normal population. The X-linked genetic group has a spherical mean of -5.51 D that is significantly (P less than 0.01) more myopic than the non-X-linked RP population. This X-linked spherical error distribution may be composed of two separate subdistributions. Astigmatic refractive errors greater than 0.5 D are found in 47% of this RP population, considerably in excess of the 19% of a normal population with such astigmatic errors.


Copper metabolism in American retinitis pigmentosa patients. Serum copper, serum caeruloplasmin, and urinary copper excretion were measured in 38 American patients (and 15 family members) with recessive, dominant, and X-linked forms of retinitis pigmentosa. No abnormalities were found, in contrast to the findings of a recent study on Indian patients. Our data argue against a role for copper metabolism in ordinary retinitis pigmentosa.


The incidence of HLA-SD antigens in recessive retinitis pigmentosa. Eighteen patients with recessive retinitis pigmentosa were tissue typed for HLA-SD antigens. There was no evidence that a particular HLA-SD antigen was associated with autosomal recessive retinitis pigmentosa.


Retinitis pigmentosa and retinal oedema. Twenty-five patients with retinitis pigmentosa and retinal leakage were investigated. Oedema was present in dominant and X-linked inherited disease and is likely to be present in recessive disease as well. We suggest that this might be a general response seen in many types of tapeto-retinal degeneration to actively degenerating photoreceptors or pigment epithelium.


Immunological studies in retinitis pigmentosa associated with retinal vascular leakage. Seventeen patients with retinitis pigmentosa and vascular leakage were studied for humoral immunological abnormalities. Apart from raised levels of IgM in 5 patients no other abnormalities were found.


Total body water in malnutrition: the possible role of energy intake. 1. Total body water (TBW) was measured using tritiated water in sixty-five children. The measurements were distributed throughout rehabilitation in order to define the effect of changing energy intakes. 2. Oedematous children had a high TBW which decreased to the normal range during loss of oedema providing they were not receiving more than maintenance amounts of energy during this period. 3. Marasmic children who had not received greater than maintenance amounts of energy had a normal TBW. 4. Treatment with a high-energy diet was associated with an initial increase in TBW. 5. The possible mechanisms for this phenomenon are discussed.


Amino acid requirements of the breeding sow: the dietary lysine requirement during pregnancy. 1. Four pregnant sows were used to study lysine requirements by means of the interpretation of values for plasma amino acid and blood urea. Diets containing graded levels of dietary lysine were fed at the rate of 1.82 kg/d. 2. Plasma lysine remained at a low level up to 6.4 g dietary lysine/kg (dry matter basis) and then increased sharply with further increases in lysine intake. 3. Blood urea levels decreased when the dietary lysine content was increased to 6.4 g/kg and then increased at higher dietary lysine concentrations. 4. Both criteria of response indicated that the lysine requirement of the pregnant sow given 1.82 kg diet/d during the later stages of pregnancy does not exceed 10.00 g/d.


Effects of liquid feeding of concentrate from a pail on growth and on the digestibility of the diet in young calves. 1. Studies were done on the effects of giving calves two types of concentrate diet, both in a liquid form from an open pail or in a dry pelleted form, on the closure of oesophageal groove, body-weight gains and the digestibility of rations. 2. Twenty-four Holstein calves were used in an experiment by dividing into two groups of twelve calves each. The 'dry-fed' group (DFG) was given a pelleted concentrate, F1, from 25 to 42 d of age, and then given another type of pelleted concentrate, F2, from 43 to 87 d of age, and again given F1 from 88 to 112 d of age. The 'liquid-fed' group (LFG) was given from a pail a liquid suspension of the equivalent amount of the same concentrates as those fed to DFG calves, for the same periods. F1 contained skim milk and glucose with lower levels of maize and soya-bean meal than F2 which did not contain skim milk or glucose; F1 and F2 were both supplemented with 10 g methionine/kg and also supplemented with lysine at 5 and 10 g/kg respectively. All calves were allowed free access to roughage, and digestibilities were measured at 12 and 16 weeks of age. 3. Wet weights of reticulo-rumen and abomasal tissues (% whole stomach weight) were respectively 69.8 and 17.6 in DFG, and 59.0 and 26.4 in LFG at 42 d of age; at 87 d of age, the corresponding values were 68.0 and 16.3 in DFG, and 52.8 and 36.6 in LFG, and further, LFG had significantly more developed caecums and large intestines as well as significantly less developed reticulo-rumens and omasums than DFG. 4. Free amino acid patterns in plasma did not vary in DFG, but varied in LFG in response to the change in diet from F1 to F2 and to the difference between diets in lysine supplementation. 5. Feeding F1 in a liquid form and F2 in a dry form significantly improved calf gains. The intake of roughage in DFG exceeded that in LFG especially when F2 was fed. 6. The digestibility of diethyl ether extracts did not vary with feeding procedures, but that of crude protein (nitrogen x 6.25) was significantly higher in DFG independent of the type of diet. Digestibilities of dry matter and N-free extracts were significantly higher in LFG for F1, while higher in DFG for F2. The digestibility of acid-detergent fibre did not differ significantly between groups at 12 weeks of age, but was significantly higher in LFG at 16 weeks of age, suggesting a possible compensatory contribution of the large intestine to the digestion of fibre in LFG. 7. The efficiency of liquid feeding of a concentrate diet to ruminants compared with that of dry feeding is discussed.


Studies in iron supplementation of preschool children. 1. The effect of daily supplements of 20-30 mg inorganic iron as ferrous sulphate on the growth, activity and haematological status of preschool children was studied for 3.5, 7 and 12 months and compared to that of children who served as controls. All children were given their daily requirements of energy and protein. In addition, they received 5 microgram cyanocobalamin and 200 microgram folic acid. 2. Fe supplementation increased the haemoglobin, serum Fe and percentage saturation of transferrin and reduced the unsaturated Fe-binding capacity significantly compared to corresponding values for the controls. 3. Height and activity were unaffected by Fe supplements. 4. Of the children 45% had haemoglobin values below 110 g/l at the end of 7-12 months of Fe supplementation.


Effects of vitamin B12 deficiency on lipid metabolism of the rat liver and nervous system. 1. Rats bred from vitamin B12-depleted dams were fed on a vitamin B12-deficient diet for 12-15 months and developed a severe vitamin B12 deficiency, as judged from methylmalonic acid excretion and tissue vitamin B12 levels at slaughter. Control rats were supplemented with vitamin B12 in the drinking-water. 2. Neurological signs were recorded after 7 months but the motor nerve conduction velocities remained normal. Neuropathological examination revealed mild changes in the peripheral nerves but no changes in the central nervous system. 3. The amounts of total lipids and phospholipids were normal, but in all examined tissues the proportions of pentadecanoate (C15 fatty acid) and heptadecanoate (C17 fatty acid) were considerably increased in vitamin B12 deficiency. 4. 3H2O was incorporated to the same extent into the fatty acids of nervous tissue from vitamin B12-deficient and control rats after 48 h. Less 3H was found in the liver fatty acids of the vitamin B12-deficient rats. 5. Neurological dysfunction can be demonstrated in the vitamin B12-deficient rat; the relation of the biochemical and neuropathological changes to the neurological signs needs further study.


Studies on digestion and absorption in the intestines of growing pigs. 2. Measurements of the flow of dry matter, ash and water. 1. Digesta were collected from twenty-three pigs, initially of 30 kg live weight, and fitted with single Ash re-entrant cannulas in either the duodenum, jejunum or ileum. A further twenty-four pigs were used in a conventional digestibility trial. 2. The diets contained: barley, fine wheat offal, white fish meal, minerals and vitamins (diet BWF); starch, sucrose, maize oil, cellulose, minerals, vitamins and either groundnut (diet SSG) or casein (diet SSC). 3. The flow-rates of dry matter (DM), ash and water were measured hourly in the duodenum and jejunum, and every 6 h in the ileum during 24 h collection periods. Faeces were collected during 5 d periods. 4. Marked increases in the flow rates of each of the digesta components after feeding each diet were observed in the duodenum and jejunum, but not in the ileum. The total flow in 24 h periods was much lower in the ileum than at the other sites. 5. Values for the ratio, DM output: intake for DM outputs from the duodenal, jejunal or ileal cannulas, and in faeces, in 24 h periods were respectively 0.94, 0.81, 0.28 and 0.22 for diet BWF; 0.96, 0.76, 0.20 and 0.15 for diet SSG; 0.96, 0.73, 0.08 and 0.04 for diet SSC. The corresponding values for ash were: 1.47, 1.65, 0.74 and 0.53 for diet BWF; 1.28, 1.34, 0.59 and 0.51 for diet SSG; 1.63, 1.35, 0.50 and 0.26 for diet SSC. The corresponding values for water were: 3.49, 3.41, 0.88 and 0.18 for diet BWF, 2.75, 2.80, 0.80 and 0.08 for diet SSG and 2.61, 1.87, 0.23 and 0.01 for diet SSC.


Studies on digestion and absorption in the intestines of growing pigs. 3. Net movements of mineral nutrients in the digestive tract. 1. Pigs growing from 20 to 60 kg live weight were given diets based on barley, weatings and fish meal, or starch, sucrose and groundnut meal or starch, sucrose and casein. Seventeen pigs were fitted with single re-entrant cannulas in the duodenum (posterior to entry of bile and pancreatic ducts), jejunum or terminal ileum and twenty-four non-cannulated pigs were used in a conventional digestibility trial. 2. The amounts of calcium, phosphorus, magnesium, sodium and potassium passing through the re-entrant cannulas and amounts excreted in the faeces were measured. These values were used to calculate the direction and extent of net movements of the five elements through the walls of the four parts of the digestive tract anterior to the collection sites. 3. The small intestine was the principal site of Ca and P absorption but there were differences between the diets in the relative importance of the regions anterior and posterior to the mid-jejunum. 4. Secretion of small amounts of Mg occurred in the anterior small intestine; the ileum and large intestine were the principal sites of net absorption. 5. There was a large net secretion of Na anterior to the duodenal cannulas and further secretion into the anterior small intestine with each diet. There were marked differences between diets in the amounts secreted but the ileal Na concentration was the same in each instance. Absorption occurred in the ileum and large intestine. 6. Secretion of small amounts of K was evident anterior to the duodenal cannulas and net absorption occurred in both parts of the small intestine with each diet.


Studies on digestion and absorption in the intestines of growing pigs. 4. Effects of dietary cellulose and sodium levels on mineral absorption. 1. Seven pigs of 30 kg initial live weight were fitted with re-entrant cannulas in the terminal ileum. Each was fed, in succession, four purified diets having cellulose and sodium levels (g/kg) of 30 and 2.7, 30 and 0.9, 90 and 2.7 or 90 and 0.9, respectively. Collections of digesta (24 h) and 3 or 4 d collections of faeces were made. 2. There was a greater throughput of ileal digesta with the high-cellulose diets than with the low-cellulose diets, mainly due to increased water content, and there was a concomitant reduction in the net absorption of Na from the small intestine. The immediate response to reduced Na intake was increased secretion of Na into the gut lumen anterior to the terminal ileum; this was more pronounced with the high-cellulose diet. Na concentrations in ileal digesta were very similar for all four diets. 3. The apparent absorptions of calcium, phosphorus, magnesium, potassium and zinc were reduced by the high-cellulose diets. In each instance this was due to reduced absorption posterior to the terminal ileum.


Blood pyruvate carboxylase (EC 6.4.1.1) activity as a criterion of biotin status in chickens and turkeys. 1. Blood pyruvate carboxylase (pyruvate-CO2 ligase (ADP-forming); EC 6.4.1.1; PC) activities in young chickens and turkeys given low-biotin diets supplemented with biotin at graded levels were studied in three experiments. 2. In both species PC activity was related positively to the supplemental biotin level. The relationship was sigmoid and maximum activity was attained with supplemental levels above those required to give maximal growth response. 3. Enzyme activity decreased between 2 and 4 weeks of age but remained almost constant thereafter. 4. Activity in chicks was not affected by alterations in the fat or protein content of the diet. 5. Changing poults from high to low and from low to high supplemental biotin levels resulted in reversals in the levels of enzyme activity. 6. It is concluded that blood PC activity is a promising new criterion for assessing the biotin status of young chickens and turkeys.


A human calorimeter for the direct and indirect measurement of 24 h energy expenditure. 1. A calorimeter for the continuous measurement of heat production and heat loss in the human subject, for at least 24 h, is described. The calorimeter operated on the heat-sink principle for direct calorimetry and an open-circuit system for indirect calorimetry. 2. Sensible heat loss was measured using a water-cooled heat exchanger, and the temperature of water entering the heat exchanger was controlled to maintain a mean temperature gradient of zero across the chamber walls. 3. Evaporative heat loss was determined from ingoing and outgoing wet-and-dry bulb temperatures and air flow-rates. 4. Problems associated with the calculation of evapoative heat loss and the estimation of the volume of incoming air in open-circuit systems are considered. 5. The calibration, limits of accuracy, sources of error and experiments with subjects are discussed.


On supplementing the selenium intake of New Zealanders. 1. Short experiments with large doses of selenite or selenomethionine. 1. Urinary and faecal excretion of single oral doses of 1 mg selenium or 0.1 mg Se as selenomethionine (Semet-Se) in solution were studied in two women. Most of the Se was absorbed and little was eliminated in the urine (0.05-0.22 dose). 2. The results have been compared with those from an earlier study (Thomson, 1974) on the same two women after similarly sized doses of sodium selenite (selenite-Se) in solution. Although selenite-Se was almost as well absorbed as Semet-Se more was excreted in the urine (0.41-0.85 dose). 3. Repeated dosing with 1 mg selenite-Se on five consecutive days in one of the women indicated that 1.1 mg had been retained. 4. Twenty patients with muscular complaints from Tapanui (South Otago, New Zealand), a low-Se soil area, ingested 0.5 mg selenite-Se daily for 20 d. Blood Se increased rapidly to almost twice the initial concentration but reached a plateau well below most values reported for residents outside New Zealand. No difference in blood Se concentration was found between those who did or did not report improvement. 5. Spasmodic medication with selenite-Se by some residents near Lincoln (Christchurch, New Zealand) for periods of up to 10 years or more had increased the blood Se somewhat.


A study of the protein and amino acid requirements of the growing New Zealand White rabbit with emphasis on lysine and the sulphur-containing amino acids. 1. New Zealand White (NZW) rabbits were given, between 4 and 8 weeks of age, a range of diets, based on oats and fish meal, containing from 104 to 255 g crude protein (nitrogen x 6.25; CP)/kg to establish the level of CP below which growth was retarded. 2. In three experiments each diet was fed to four animals and food intake, growth and N balance were measured over 4 weeks. Body analysis was also carried out after two of the experiments. 3. The rates of food intake and growth of animals increased with dietary CP concentration until a CP concentration of approximately 150 g/kg diet had been reached. Beyond this there was little further improvement. N balance studies showed that once this dietary concentration of CP had been reached, there was a reduced rate of N retention. 4. Good agreement was found between N retention measured by balance methods and by body analysis: body composition showed a tendency towards an increase 5. Microbial protein produced in the caecum and eaten during coprophagy, was found to supplement the dietary protein by approximately 2 g CP/d, or by only 0.1 of a normal dietary intake of CP. 6. In the second part of the study NZW rabbits were offered, between 5 and 8 weeks of age, diets based on oats containing 150 g CP/kg. The protein supplied by oats was supplemented with maize gluten, gelatin, groundnut meal, casein, soya-bean meal or fish meal. 7. Rabbits offered diets containing casein, soya-bean meal and fish meal gained 40-50 g/d similar, to animals given a well-balanced control diet, while those given diets containing maize gluten, gelatin or groundnut meal gained approximately 30 g/d. This indicated that amino acid balance in dietary protein was important to the growing rabbit. 8. In later experiments, diets based on cereals and groundnut meal supplemented with varying amounts of lysine and methionine were offered during a 3-week-post-weaning period in order to assess requirements for those limiting amino acids. 9. The addition of both lysine and methionine improved growth rates. The minimum requirements for normal growth were found to be 6.2 g methionine+cystine and 9.4 g lysine/kg diet.


Necessity of vitamin B12 for growth of rats fed on an odd- or even-carbon-number fat. 1. The effect of vitamin B12 on growth was studied in young male and female rats fed on diets sufficient (+B12) or deficient (-B12) in vitamin B12 containing 30% of the dietary energy as fat, either maize oil (CO) or triundecanoin (TUD). 2. Vitamin B12 deficiency severely depressed growth. After 6 weeks the weight gain of CO(-B12) rats was only 72% of that of CO(+B12) rats and the gain of TUD(-B12) rats was only 47% of TUD(+B12) rats. 3. After fasting 24 or 96 h TUD-fed rats, both +B12 and -B12, had greater glycogen reserves and higher plasma glucose levels than CO-fed rats. 4. It is concluded that vitamin B12 is required for the metabolism and utilization of both an odd-carbon-number medium-chain fat, TUD, and an even-C-number long-chain fat, CO, during growth in rats.


The effect of iron status of Nigerien mothers on that of their infants at birth and 6 months, and on the concentration of Fe in breast milk. 1. Within the limits of this study, neither maternal iron deficiency nor Fe-overload as measured at term appeared to affect the complement of Fe received by the foetus. 2. Infants feeding entirely on breast milk appeared to have normal Fe status 6 months postpartum regardless of the Fe status of the mother. 3. No relationship could be demonstrated between the Fe content of breast milk and the Fe status of the mother.


Iron availability from meat.

Iron availability from meat. 1. The distribution of radioactive iron in 59Fe-labelled rat muscle extract was determined using gel filtration. This showed that most (approximately 70%) of the radioactivity was associated with the heamatin compounds; myoglobin and haemoglobin. 2. Raw beef and freeze-dried rat muscle were digested in vitro, under simulated physiological conditions, and after centrifugation the supernatants fractionated by gel filtration. The soluble products were haematin Fe complexes of molecular weight above 10,000 and non-haematin Fe compounds of molecular weight below 6000, the major products being the non-haematin Fe complexes. The soluble compounds were also separated by dialysis and, in rat muscle, it was found that the low-molecular-weight non-haematin compounds accounted for more than 80% of the total soluble iron. 3. In vivo absorption studies with rats showed the Fe in a digested muscle dialysate to be more readily absorbed than that from an aqueous muscle extract which itself was more readily absorbed than the Fe from whole blood. 4. It may not, therefore, be the haemoproteins per se which are responsible for the high availability of Fe in meat, but rather the nature of their degradation products, formed by digestion within the meat environment.


Copper, manganese, zinc, nickel, cadmium and lead in human foetal tissues. 1. Concentrations of copper, manganese, zinc, nickel, cadmium and lead were measured in samples of liver, kidney, brain, heart, lung, skeletal muscle and vertebral bone from forty foetuses of 23-43 weeks gestation. 2. Cu concentrations in the liver were up to 100 times those in other tissues, but only those in the brain showed a significant increase with gestational age. 3. Mn concentrations were similar in all tissues; the over-all range was 0.35-9.27 microgram/g dry matter (DM). 4. Concentrations of Zn in the liver were much higher than in other tissues and decreased with gestational age, whereas levels in skeletal muscle increased. 5. In all tissues Ni concentrations were within the range 0.04-2.8 microgram/g DM and levels in kidney and muscle decreased significantly with age. 6. Cd was detected in most of the tissue samples and concentrations were within the range 0.01-0.58 microgram/g DM. 7. Concentrations of Pb, where it was detected, varied from 0.1 to 2.4 microgram/g DM in the soft tissues and from 0.4 to 4.3 microgram/g DM in the bone samples.


Comparison of the chemical and biochemical composition of thirteen muscles of the rat after dietary protein restriction. 1. The objective of this study was to determine whether the chemical and biochemical changes induced by muscle wasting caused by dietary protein restriction are different in various skeletal muscles. 2. Rats were fasted for 3 d and then fed on a 10 g protein/kg diet for 21 d. Thirteen muscles from the trunk, forelimb, and hind-limb regions were analysed for muscle weight, and the content of water, fat, cellular and extracellular protein, DNA and RNA. Results were compared to values for an 'initial' control group killed at the start of the experiment. 3. Weight loss was greatest in trunk muscles and least in the distal forelimb muscles. Water content decreased in most muscles, but increased in three forelimb muscles. A significant loss of lipid was found in the gastrocnemius, while the biceps brachii gained lipid. Changes in lipid content of the muscles did not form a distinctive pattern. 4. All muscles except the distal forelimb muscles lost a significant amount of cellular protein, while all muscles except the diaphragm gained extracellular protein. 5. DNA content was unchanged in all muscles. The value for cellular protein:DNA was significantly reduced in the rectus abdominis and the diaphragm. A significant loss of RNA was found in all muscles; the percentage change was greatest in trunk muscles and least in the distal forelimb muscles. The values for RNA:protein and RNA:DNA were significantly lower in all muscles except two distal forelimb muscles. 6. With the exception of the water and lipid content of the muscles, the directions of the changes in the experimental animals were the same for all muscles. The results suggested, however, that the magnitude of changes in certain chemical and biochemical indices of composition may depend to some extent on the anatomical location of the muscle: trunk muscles tended to show the greatest percentage change, while the distal forelimbs changed the least.


The effect of simulated altitude on the heat increment of feed in sheep. 1. Sheep given constant feed were exposed to environments in which the oxygen concentration in air was either 200 or 150 ml/l. There were no differences in daily heat production, methane production, urinary energy or faecal energy losses measured over periods of 4 d. 2. When the sheep were fasted there were no differences in heat production to be ascribed to the O2 concentration in air. The thermic response to feed was unaffected by the O2 concentration in the air.


Mono ferrous acid citrate (FeC6O7H2O) as an iron fortificant. 1. Iron absorption from ferrous citrate (monoferrous acid citrate, FeC6H6O7H2O) was studied in normal healthy male and female volunteers using ferrous citrate labelled with radioactive Fe and whole-body counting. Ferrous citrate was either given alone or with a rice-based meal. 2. Fe absorption from ferrous citrate was satisfactory and was comparable to that from ferrous sulphate. 3. Fortification of crude cooking salt with ferrous citrate was not satisfactory due to colour development on storage. Ferrous citrate can, however, serve as an effective Fe fortificant with sugar or wheat flour.


Competition between the 735 nm fluorescence and the photochemistry of Photosystem I in chloroplasts at low temperature. Fluorescence emission spectra of chloroplasts, initially frozen to--196 degrees C, were measured at various temperatures as the sample was allowed to warm. The 735 nm emission band attributed to fluorescence from Photosystem I was approx. 10-fold greater at--196 degrees C than at--78 degrees C. The initial rate of photooxidation of P-700 was also measured at--196 degrees C and--78 degrees C and was found to be approximately twice as large at the higher temperature. It is proposed that the 735 nm emission band is fluorescence from a long wavelength form of chlorophyll, C-705, which acts as a trap for excitation energy in the antenna chlorophyl system of Photosystem I. Furthermore, it is proposed that C-705 only forms on cooling to low temperatures and that the temperature dependence of the 735 nm emission is the temperature dependence for the formation of C-705. C-705 and P-700 compete to trap the excitation energy in Photosystem I. It is estimated from the data that at--78 degrees C P-700 traps approx. 20 times more energy than C-705 while, at--196 degrees C, the two traps are approximately equally effective. By analogy, the 695 nm fluorescence which also appears on cooling to--196 degrees C is attributed to traps in Photosystem II which form only on cooling to temperatures near--196 degrees C.


Preparation and characterization of phospholipid-depleted chloroplasts. Spinach class II chloroplasts were treated with snake venom phospholipase A2 in the presence of bovine serum albumin, and separated by sucrose-density centrifugation. The treatment yielded phospholipid-depleted chloroplasts which had lost 82.6% of the original phospholipids. About 20% of the phospholipids of chloroplasts were resistant to enzyme attack. These results suggest that phospholipids exist in two states in chloroplast membranes. In spite of considerable phospholipid depletion, the chloroplast preparations retained a large portion of their photoactivities, i.e. light-induced electron transport, light-induced H+ uptake, and light-induced shrinkage. However, cyclic photophosphorylation was significantly affected with the phospholipid removal.


Duroquinol as an electron donor for chloroplast electron transfer reactions. Duroquinol (tetramethylhydroquinone) was found to function as an electron donor in chloroplasts. Non-cyclic electron transfer from duroquinol to electron acceptors such as oxygen proceeded at high rates, was insensitive to 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) but was sensitive to the plastoquinone antagonist 2,5-dibromo-3-methyl-6-isopropyl-1,4-benzoquinone (DBMIB). The electron transport from duroquinol was coupled to the synthesis of ATP. Spectroscopic studies of chloroplast electron carriers in the dark indicated the high-potential "Rieske" iron-sulfur center, cytochrome f, plastocyanin and P-700 were all reduced by duroquinol. The dark reduction of the "Rieske" iron-sulfur center and cytochrome f were inhibited by DBMIB but not by DCMU. These results have been interpreted in terms of a linear sequence of electron carriers in the non-cyclic electron transport chain which includes plastoquinone, the "Rieske" iron-sulfur center, cytochrome f, plastocyanin and P-700.


Heat-induced changes of chlorophyll fluorescence in isolated chloroplasts and related heat-damage at the pigment level. The heat-induced changes of chlorophyll fluorescence excitation and emission properties were studied in isolated chloroplasts of Larrea divaricata Cav. An analysis of the temperature dependency of fluorescence, under Fo and Fmax conditions, of temperature-jump fluorescence induction kinetics, and of 77 degrees K emission spectra of preheated chloroplasts revealed two major components in the heat-induced fluorescence changes: (1) a fluorescence rise, reflecting the block of Photosystem II reaction centers; and (2) a fluorescence decrease, caused by the functional separation of light-harvesting pigment protein complex from the rest of the pigment system. Preferential excitation of chlorophyll a around 420 nm, produced a predominant fluorescence rise. Preferential excitation of chlorophyll b, at 480 nm, gives a predominant fluorescence decrease. It is proposed that the overlapping of the fluorescence decrease on the somewhat faster fluorescence rise, results in the biphasic fluorescence rise kinetics observed in isolated chloroplasts. Both the rise component and the decay component are affected by the thermal stability of the chloroplasts, acquired during growth of the plants in different thermal environments. Mg2+ enhances the stability against heat-damage expressed in the decrease component, but has no effect on the rise component. Heat pretreatment leads to a decrease of the variable fluorescence in the light-induced 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) rise curve, but no change in half-rise time is observed. It is concluded that the block of Photosystem II reaction centers precedes the loss of the light-harvesting pigment protein complex. However, the approximately antiparallel heat-induced Fmax decrease and Fo increase suggest a common cause for the two events. A heat-induced perturbation of the thylakoid membrane is discussed.


The effects of coenzyme A and carnitine on steady-state ATP/ADP ratios and the rate of long-chain free fatty acid oxidation in liver mitochondria. 1. Conditions for the optimal coupled oxidation by rat liver mitochondria of long-chain free fatty acids were defined. The fatty acids studied were in the omega9 series: oleic (18 : 1), gondoic (20 : 1) and erucic (22 : 1) acids. Carnitine (about 0.1 mM) maximally stimulated State 3 respiration due to oleic and gondoic acids about three-fold (coenzyme A present), and coenzyme A (10--20 micrometer) stimulated about two-fold (carnitine present). When neither coenzyme A nor carnitine was added, respiration was very slow. 2. When respiration was limited by ADP, concentrations of added CoA only slightly in excess of that required for fatty acid oxidation very significantly decreased the ATP/ADP ratio maintained at a given rate of respiration imposed by externally added ATPase, and increased the level of membrane-associated acyl-CoA. This effect was most pronounced with oleic acid, and least with erucic acid. When excess ADP was present, higher concentrations of added coenzyme A (50--200 micrometer) inhibited to oxidation of oleic acid in a concentration-dependent manner, whereas the oxidation of substrates other than fatty acids was essentially unaffected. 3. It is concluded that, in addition to its requirement for fatty acid oxidation, coenzyme A exerts two independent effects on mitochondrial metabolism as here determined in vitro: (a) under conditions mimicking those in the intact cell with respect to phosphorylation-dependent respiration (ADP limiting), acyl-CoA formed from added coenzyme A and fatty acid inhibits the adenine nucleotide translocase, resulting in a lowering in the extramitochondrial ATP/ADP ratio obtained at any given rate of phosphorylation-limited respiration, and (b) under State 3 conditions (ADP in excess) coenzyme A ( less than 50--200 micrometer) specifically suppresses oxidation of long-chain fatty acids by limiting the rate of formation of intramitochondrial acyl-CoA.


Isolation and characterization of a rubredoxin and an (8Fe-8S) ferredoxin from Desulfuromonas acetoxidans. A two cluster (4Fe-4S) ferredoxin and a rubredoxin have been isolated from the sulfur-reducing bacterium Desulfuromonas acetoxidans. Their amino acid compositions are reported and compared to those of other iron-sulfur proteins. The ferredoxin contains 8 cysteine residues, 8 atoms of iron and 8 atoms of labile sulfur per molecule; its minimum molecular weight is 6163. The protein exhibits an abosrbance ratio of A385/A283 = 0.74. Storage results in a bleaching of the chromophore; the denatured ferredoxin is reconstitutable with iron and sulfide. The instability temperature is 52 degrees C. The rubredoxin does not differ markedly from rubredoxins from other anaerobic bacteria.


The effects of cotyledon senescence on the composition and physical properties of membrane lipid. The phospholipid content of rough and smooth microsomal fractions from cotyledons of germinating bean declines as the tissue becomes senescent. Both types of membrane contain comparable proportions of three major phospholipids, phosphatidylcholine, phosphatidylethanolamine and phosphatidylinositol, which collectively comprise about 90% of the total. This proportionality does not change appreciably during senescence. Only small quantities of lysophosphatides were noted at all stages of senescence. The unsaturated:saturated fatty acid ratio for total extracted lipid declined only slightly in both membrane systems, but pronounced differences in this ratio were observed among the major phospholipids of the membranes. The most striking alteration in lipid composition with advancing senescence was an increase in the sterol:phospholipid ratio; this rose by about 50% for rough microsomes and 400% for smooth microsomes. For both types of membrane the patterns of change in this ratio correlated with previously reported changes in bulk lipid transition temperature, suggesting that the increase in sterol level may contribute to changes in phase behaviour of the membranes during senescence. Arrhenius plots of rotational correlation times for the electron spin label 2,2-dimethyl-5-dodecyl-5-methyloxazolidine-N-oxide (2N14) partitioned into the membrane lipid showed an increase in viscosity with advancing senescence and a corresponding increase in activation energy for both types of membrane. These changes in activation energy and viscosity correlated closely with the increase in sterol:phospholipid ratio. However, no phase transitions were detectable between temperatures of 2 and 55 degrees C despite the fact that transitions from a lipid-crystalline to gel state are detectable within this temperature range by wide angle X-ray diffraction.


Effect of concanavalin A and its succinylated derivative on the oxidative metabolism of guinea pig peritoneal macrophages. The effect of concanavalin A and its succinylated derivative on the metabolic regulation of guinea pig peritoneal macrophages was observed. The binding of tetravalent concanavalin A to the surface glycoproteins of macrophages caused a marked increase in the rate of oxygen consumption due to the activation of the hexose monophosphate shunt. Divalent succinylated concanavalin A, also induced a similar change in the rate of oxygen metabolism. The metabolic change induced by these two types of lectin was reversibly inhibited by alpha-methyl-D-glucoside, a haptenic inhibitor of these lectins, and was temperature dependent (observed at above 15 degrees C). It is suggested that the binding of these lectins to the surface glycoproteins, and not their cross-linking into caps, is required for the activation of oxygen metabolism of macrophages, and that highly fluid state of the plasma membrane seems to be an essential requirement for the transduction of glycoprotein perturbation on the macrophage surface into cellular interior via transmembrane control mechanism.


Potassium transport in dispersed mucosal cells from guinea pig stomach. Dispersed mucosal cells (approx. 70% parietal cells) prepared from guinea pig stomach maintained their cellular concentration of potassium (65--80 nmol potassium/10(6) cells) for at least 5 h in vitro. Uptake of 42K by dispersed gastric mucosal cells depended on temperature, H+ concentration and oxidative metabolism. Carbachol and, in some instances, gastrin caused a 40--50% increase in cellular uptake of 42K as a consequence of the ability of these agents to increase 42K influx. Ouabain reduced uptake of 42K by 70% but did not alter the effect of carbachol. Cellular uptake of 42K was not altered by histamine, prostaglandin, E1, glucagon, secretin, vasoactive intestinal peptide or C-terminal octapeptide of cholecystokinin. Uptake of 42K was also increased by dibutyryl cyclic AMP or dibutyryl cyclic GMP but not by cyclic AMP, cyclic GMP or their 8-bromo derivatives. Theophylline caused a small (10--15%) increase in 42K uptake and potentiated the increase caused by submaximal concentrations of carbachol. The increase in 42K uptake caused by either dibutyryl cyclic nucleotide and carbachol was additive.


Identification of the Cl- transport site of human red blood cells by a kinetic analysis of the inhibitory effects of a chemical probe. H2DIDS, the dihydro analog of DIDS (4,4'-diisothiocyanostilbene-2,2'-disulfonic acid) can interact covalently with membrane sites, resulting in an irreversible inhibition of anion exchange. At low temperatures (0 degrees C) and for relatively short times, however, its interaction is largely reversible, so that a kinetic analysis of the nature of its inhibitory effect on Cl- self exchange can be performed. The effects of variations in the chloride concentration on the inhibitory potency of H2DIDS are consistent with the concept that Cl- and H2DIDS compete for the transport site of the anion exchange system. The value of Ki for H2DIDS is 0.046 micrometer, indicating that H2DIDS has a higher affinity for the transport system than any other inhibitor so far examined. If, as seems probable, the covalent labelling of H2DIDS occurs at the same site as the reversible binding, H2DIDS can be used as a covalent label for the transport site. The specific localization of H2DIDS in the band-3 protein thus indicates that this protein participates directly in anion exchange.


The acidic amino acid transport system of the baby hamster kidney cell line BHK21-C13. The uptake of L-glutamate into BHK21-C13 cells in culture has been studied. This amino acid appears to be transported via a relatively high affinity, low capacity, Na+-dependent transport system capable of the rapid accumulation of substrate amino acids. Kinetic studies of the inhibition of L-glutamate uptake has provided information as to the substrate and the molecular configuration required for transport via the glutamate transport system. This system exhibited marked substrate specificity and was only capable of transporting L-glutamate and aspartate and certain closely related acidic amino acid analogues.