[An experimental study on the pathogenesis of osteoarthritis--histological and biochemical changes of proteoglycan in the osteoarthritic cartilage of rabbit in the early stage-- (author's transl)]. Osteoarthritis is generally a slowly progressive destructive disease of joints. As the disease is asymptomatic in its initial phases, it was detectable only at the later stage when radiological changes and clinical symptom had developed. The biochemical and cellular changes that had been recorded were those of the later clinically recognizable stage of the disease. Because the time of onset in not known, the initial events which might be the most important to investigate the pathogenesis of osteoarthritis, are virtually impossible to investigate except in experimentally induced models of osteoarthritis. For the purpose of investigating the pathogenesis of degenerative osteoarthritis, experimental osteoarthritic model was prepared. Section of the medial collateral and both cruciate ligaments combined with resection of the medial meniscus in adult rabbit knees showed progressive histological changes similar to those in human osteoarthritis. Therefore, qualitative and progressive alteration of the cartilage matrix proteoglycan in experimental osteoarthritis of the early stages were investigated with time. Biochemical analysis of the cartilage from experimental osteoarthritic model demonstrated a decrease in the content of glycosaminoglycan and increase in the rate of the synthesis of glycosaminoglycan as compared to the normals. The analysis of disaccharide chain revealed a decrease in the concentration of kelatan sulfate and chondroitin-6 sulfate, along with an increase in the concentration of chondroitin-4 sulfate. These findings, which were quite consistent with those in human osteoarthritis and were contrary to those in aging, indicate the attempts of cells to compensate for the proteoglycan deficiency in osteoarthritic cartilage by synthesizing large quantities of glycosaminoglycans of immature pattern. On the other hand, synthesized aggregated proteoglycans in arthritic cartilage had shown a polydispersive pattern in CsCl density gradient compared to that of normal one, which had shown a single curved pattern. Further, newly synthesized proteoglycan in osteoarthritic cartilage seemed to be polydispersive compared with control proteoglycan in molecular sizes on Sepharose 2B gel chromatography under non-aggregated dissociative condition. Large molecular size proteoglycan composed of small molecular size glycosaminoglycan on its polysaccharide chain and small molecular size proteoglycan composed of large molecular size glycosaminoglycan. This might represent the expression of repair mechanism in the damaged cartilage, or phenotypic transformation of extracellular macromolecule in osteoarthritis.


Functional anatomy of the elbow joint and three-dimensional quantitative motion analysis of the elbow joint. This work consists of two parts. Part One is a three-dimensional study of the passive motion of the elbow joint and revealed that the elbow joint was not a true hinge joint. Part Two is a three-dimensional quantitative motion analysis which was undertaken to compare shoulder and trunk motion in normal subjects with those with contracted elbows. This analysis revealed that shoulder rotation, shoulder abduction, trunk flexion and trunk rotation compensates for a contracted elbow.


Radiation-induced fibrosarcoma of the mandible following treatment for bilateral retinoblastoma. A case of fibrosarcoma of the mandible following radiotherapy for bilateral retinoblastoma and occurring in an 11-year-old female child is described. After a clinical description of the case, reported with histological documentation, problems connected with the pathogenesis of the malignancies are dealt with. Besides irradiation, genetic mutation as a carcinogenetic co-factor is taken into consideration.


True carcinosarcoma of the larynx: a case report. A case of true carcinosarcoma of the larynx occurring in a 55-year-old male is reported. The two components of this very rare tumour are pleomorphic rhabdomyosarcoma and squamous cell carcinoma. A review of the literature has revealed only two authentic cases of true carcinosarcomas.


Chondrosarcoma of the larynx.

Chondrosarcoma of the larynx. A chondrosarcoma arising in the posterior cricoid plate is presented. The tumour gave rise to increasing inspiratory stridor: laryngectomy was performed. The tumour consisted of loose cartilaginous tissue with great predominance of highly differentiated cartilage cells and only small areas with nuclear polymorphism. This complicated the differential diagnosis between chondroma and highly differentiated chondrosarcoma. From the fact that the patient died from massive pulmonary metastases 3 1/2 years later, it is evident that the degree of malignancy of cartilaginous tumours should be determined even on small polymorphic foci. The DNA histogram for the foci of the laryngeal tumour with atypia differed distinctly from those for benign chondroma and normal cartilage, but resembled those of the pulmonary and splenic metastases and of a nasal chondrosarcoma. Photometric examination may provide an aid in the difficult differential diagnosis between chondroma and highly differentiated chondrosarcoma.


The effects of vascular occlusion on the human inner ear. Occlusion of the anterior vestibular artery has resulted in severe degeneration and new bone formation limited to the utricle, saccule, and superior and lateral semicircular canals. Depriving the inner ear of its main blood supply, i.e. the internal auditory artery, has resulted in severe degeneration and ossification of the entire membranous labyrinth, except the endolymphatic duct and sac. A more severe cochlear sclerosis was seen when both arterial and venous blood supplies to the cochlea were occluded. The implications of these findings on the etiology and management of inner ear disorders are emphasized.


Use of middle ear ventilation tubes in recurrent acute otitis media. A method of treatment of recurrent acute otitis media with polythene middle ear ventilation tubes in young children is presented. 56 ears in which infection had persisted for one to six months despite antibiotic therapy and multiple myringotomies were included in the study. The tubes were inserted under topical anaesthesia and cure within one week was obtained in 73 per cent of ears. In another 9 per cent the otorrhoea stopped within 3 weeks, but in 18 per cent reinsertion of the tube became necessary and in this latter group 11 per cent resolved in two weeks following adenoidectomy as well. In 7 per cent the problem remained unresolved. Therefore with this regimen a total of 93 per cent of recurrent infections settled. It is emphasized that the ventilation tube should remain 'in situ' for over 3 months.


Domestic pets and perennial nasal allergy in children. Domestic pets form an important etiological factor in the occurrence of perennial allergic rhinitis. In their management, patients responded well to animal exclusion and hyposensitization, with good amelioration of all their symptoms; these measures form an effective treatment for this type of disease.


Hearing loss in perforations of the tympanic membrane. 70 patients with dry central perforations have been studied to assess the hearing loss. The hearing loss is greater at the lower frequencies and increases with the size of the perforation. Malleolar perforations cause more hearing loss than the non-malleolar unless the perforation involves less than 10 per cent of the tympanic membrane surface area. Perforations of the postero-inferior quadrant cause more hearing loss than those in the antero-inferior quadrant.


Sequential audiometric evaluations of cats with regrowing tympanic membranes. Audiometric evaluations were made for cats which were undergoing TM regeneration. For a one month period of regrowth and testing, there was an improvement in thresholds over the range of frequencies which were tested and the final evaluations (complete TM regrown) indicated greater auditory deficits in the high frequencies. The greater high frequency losses started at 1 to 2 kHz. and increased with frequency. The pattern of greater high frequency loss is thought to result from the fact that the regrown TMs did not adhere to the manubrium, but rather grew straight from the fibrous annulus and formed a flat rather than conical membrane.


Ameloblastoma of the maxilla. Report of three cases. Three cases of ameloblastoma of the maxilla are presented. Symptoms, diagnostic procedures and therapy are discussed in relation to these cases. It is stressed that surgery of a maxillary ameloblastoma must be radical from the beginning. Otherwise the tumour may spread to the pterygopalatine fossa, temporal fossa or base of skull. Such tumour extensions are not resectable. The tumour is slowly-growing and a careful follow-up is mandatory.


Nasal metastasis from primary cancer of the kidney. A case of nasal metastasis, indicating primary cancer of the kidney, and occurring in a 67-year-old man, is described. Differential diagnosis and pathogenesis are discussed. In particular, stress is laid on the problems concerning diagnosis when the nasal metastasis is the first clinical symptom. A clinicosemeiologic study of the patient is mandatory, as histology alone is not always sufficient to settle all doubts, even with the support of ample histochemical investigations.


The radioallergosorbent test (RAST) in nasal polyposis. The incidence of atopy among 64 adults undergoing polypectomy was 25 per cent. Among these atopic patients it was usual for the polyp IgE level to exceed that in the serum. Similarly, D. pteronyssinus-specific IgE was more commonly identified in polyp fluid by the RAST technique than in serum. However, this was not so for grass pollen-specific IgE, where serum and polyp fluid were equally positive. We conclude that there are atopic and non-atopic polyps.


Lennert's lymphoma (lympho-epithelioid cellular lymphoma). The authors describe a case of Lennert's lymphoma occurring in a 64-year-old male patient. After a comprehensive examination of the world literature on the disease, clinical and pathologic problems, as well as differential diagnoses from other malignant lymphoid proliferations, are discussed. This is the first observation to be reported in the otorhinolaryngologie literature.


Sjögren's syndrome involving the larynx: report of a case. Sjögren's syndrome is a presumably autoimmune disease with pathologic findings of lymphocytic infiltration of the involved structures. Although the salivary and lacrimal glands are the most commonly involved sites, extraglandular lymphoproliferation also occurs. Upper and lower respiratory tract lymphoproliferation is known, but only one case of Sjögren's disease of the larynx has been previously reported. We present a case of laryngeal involvement in which the gross pathologic appearance is different from that in the earlier case report. The otolaryngologist should consider Sjögren's disease in the differential diagnosis of diffuse laryngeal lesions.


A contemporary view of the ventricular gradient of Wilson. We have derived quantitative expressions for QRS, T, and QRST areas of the scalar electrocardiogram. The QRST area, or ventricular gradient, is seen to be essentially independent of the activation sequence and to reflect recovery properties of the tissue as weighted by the vector lead field of a given lead. The results are derived for uniform isotropic conditions and under the assumption that the temporal waveforms everywhere are identical except for possible variations in the duration of the plateau. However, it is noted that the results are, probably, valid under anisotropic conditions as well. The examination of ventricular gradients from epicardial and intramural leads should reflect local recovery properties and be a useful tool in study of the physiology of recovery, as well as the study of arrhythmias.


An approach to direct detection of sinus nodal activity in man. We are reporting a series of 13 out of a total of 16 patients in whom sinus nodal activity was recorded with the use of intra-atrial electrodes, during diagnostic His-bundle electrocardiography investigations. The protocol consisted of the simultaneous monitoring of the following intra-atrial points: high right atrium, low lateral right atrium, left atrium and the His-bundle electrogram (HBE), which accompanied the detecting sonde placed as a loop in the superior vena cava, with the electrodes facing the sinus nodal area. This permitted an adequate assessment of the sequence of the depolarizing activity. All patients showed sinus nodal potentials preceding the initiation of the P-wave in the surface-EKG or the atrial potential in the high right atrial lead, respectively, in the range of 60 to 270 msec depending upon the functional status of the sinus node in each patient. Such waves were clearly separated from the initiation of the atrial potential by an isoelectric line and showed functional traits compatible with the S-A nodal functions, as many authors have previously reported in experimental animal models. The text contains a review of the relevant literature and discussion upon the diagnostic significance of this method in the assessment of sinus nodal disease.


Effects of dobutamine on electrophysiological properties of the specialized conduction system in man. The electrophysiological effects of Dobutamine, a new beta adrenergic drug, were investigated using intracardiac electrograms and the extrastimulus method, in 19 patients with 1:1 AV conduction and in 10 other patients, five with second and five with third degree AV block. The electrophysiological effects were studied at three concentrations of the drug: 5, 10 and 15 micrograms/Kg/m'. Dobutamine induces: 1) an enhancement of SA node automaticity, showed by a decrease of the sinus cycle length (P less than 0.001 at the first concentration) and by a decrease in the corrected sinus node recovery time (P less than 0.001 at the second concentration); 2) a decrease in the effective atrial refractory period (P less than 0.001 at the first concentration); 3) an improvement of AV conduction, showed by a decrease in AH interval (P less than 0.001 at the first concentration) and by a shortening of functional and effective refractory periods (P less than 0.001 at the first concentration); 4) no change in the HV interval; 5) an improvement of conduction in patients with second degree AV block proximal to the His bundle; and 6) a minimal increase in the heart rate in patients with complete AV block distal to His bundle.


Carotid sinus massage induced elimination of rate related bundle branch block during paroxysmal atrial tachycardia: a simple method of proving bypass tract participation in the tachycardia. Four cases of paroxysmal atrial tachycardia are described in whom rate related left bundle branch block (LBBB) was often present which persisted indefintely and showed no signs of spontaneous disappearance. Transient slowing of the tachycardia by carotid sinus massage in each case eliminated LBBB and this led to tachycardia acceleration. The tachycardia acceleration was traceable to a shortening in ventriculoatrial conduction. These observations proved the participation of a left sided bypass tract in the tachycardia circuit in each of these cases.


Spectral analysis of the normal electrocardiogram in children and adults. We performed spectral analysis of the X-lead Frank VCG from six normal adults (Group A) and eight normal children (Group B) using a Fast Fourier Transform. The Group A magnitudes were consistently and significantly lower than Group B in the 20--90 Hz region. Similarly, the -40 dB point was 75 Hz for Group A and 107 Hz for Group B. The P waves of the two groups had similar spectra, as did their T waves. When the entire cardiac cycle was analyzed, there was again a consistent and significant difference in the frequencies from 25--80 Hz. Despite the significant differences in the Group A and B spectra, the vast majority of the information contained in the ECG signal was confined to frequencies below 100 Hz. Therefore, a bandwidth of 100 Hz is probably adequate for accurate recording of the ECG signal from children, as well as from adults.


The normal values of spatial velocity in the second part of QRS (a cooperative study of 229 healthy individuals). The Spatial Velocity (SV) represents the inscription velocity from spatial vectors of the QRS loop. According to Sano, this parameter has revealed a diagnostic capacity for some well defined pathologies. Using Hellerstein and Hamlin's formula, the SV has been determined from the orthogonal Frank leads in a 250 mm/sec recording. Using Simonson's criteria, 229 normal individuals, arranged in seven groups according to age and sex, were used in an attempt to get normal values for the second half of the QRS loop. SV was determined in six time intervals of 2.5 msec from the 25 msec vector before the end of QRS. We found significant difference between the values obtained from each time interval, except in the 35--37.5 msec and 37.5--40 msec vectors. On the other hand, no significant differences were found among the normal individual groups. The 96th percentile distribution was used to get the normal extreme values in the entire group of individuals.


Experimental evaluation of the mean electrical equivalent generator of the isolated rabbit heart. Previous data have documented that the instantaneous cardiac equivalent generator is inadequately modeled as a single dipole. The properties of the mean equivalent generator during the QRS, ST-T and QRST intervals were determined in 22 isolated rabbit heart preparations suspended within a spherical volume conductor and perfused with an electrolyte solution. ECG potentials recorded from 32 surface electrodes were processed to compute instantaneous equivalent generator properties at 0.4 to 2.0 msec intervals during QRS and ST-T. QRS and ST-T areas of each electrode waveform were determined and processed to compute the parameters of the mean generator during QRS, ST-T and QRST intervals. A centric dipole fit 77.96, 71.73 and 67.48 percent of the recorded summed square (SSQ) area during these three intervals. Corresponding values for a single moving dipole model were 86.14%, 87.17% and 86.11%. A four element centric multipole series, in contrast, fit over 98% of SSQ area during each interval. Isoarea maps demonstrated multiple maxima and/or minima in 48% of the studied cases. Thus, mean cardiac forces during activation and recovery, as well as the instantaneous counterparts, are inadequately represented as single dipolar generator sources.


A sequential angular lead presentation.

A sequential angular lead presentation. The presentation of the frontal leads was altered so that they could be displayed in sequential angular order. This was achieved by insertion of an inverting switch at the output stage of an electrocardiograph, so that the presented sequence of leads would be I, -aVR, II, aVF, III, and -aVL, corresponding to frontal plane vectors of 0 degree, 30 degrees, 60 degrees, 90 degrees, 120 degrees and 150 degrees. This form of presentation was made in normals, patients with myocardial infarction, hemiblock, and switched leads. A smooth flow of ECG information results, the extent of the disease is more easily evaluated, and the QRS, T, and P axis is more easily evaluated. The usefulness of neglected leads in diagnosis may be increased.


Torso mounted electrocardiographic electrodes for routine clinical electrocardiography. An easily applicable lead system similar to that proposed by Mason and Likar in 1966 for stress electrocardiography provides quantitative and qualitative electrocardiographic information and diagnoses similar to those derived from the "standard" lead system using only torso placement of ten electrodes.


The precordial ECG belt for obtaining rapid reproducible precordial leads. A new, stretchable precordial ECC belt is described. It represents an excellent method for obtaining reproducible, accurate precordial ECGs and is especially useful in women and individuals with abnormal chest configurations.


A grid for calculating vectorcardiographic loop areas. A graph consisting of small squares of equal size preprinted on a transparent plastic chart can be used for a quick and accurate calculation of the VCG loop area in each quadrant of the three conventional planes.


Ventricular parasystole in a newborn infant. A case of ventricular parasystole is presented which appeared in an otherwise healthy newborn infant. The dysrhythmia persisted until 10 months of age. In contrast to its occurrence in adults, this rare dysrhythmia appears not to be associated with primary cardiac disease in children.


Dependence of testicular germ cells on hormones: a quantitative study in hypophysectomized testosterone-treated rats. Quantitative analysis of spermatogenesis was used to investigate the dependence of testicular germ cells on hormones in Sprague-Dawley rats. Adult hypophysectomized rats were given daily injections of testosterone propionate (TP) for 30 days. Intact and hypophysectomized control rats received vehicle only. Spermatogonia were classified as undifferentiated or differentiated, using established criteria suitable for morphological identification on periodic acid-Schiff's-haematoxylin stained sections of testis. Data on cell counts showed that the undifferentiated spermatogonia may be partially dependent on TP and/or pituitary hormones. The group of differentiated spermatogonia were dependent on pituitary hormones, and TP only partially restored their number by partially protecting them from spontaneous degeneration in stages XIV to II (A3-to-Intermediate). The maturation and division of B type spermatogonia and maturation of preleptotene spermatocytes to the zygotene stage appeared to be independent of hormones. Maturation of pachytene spermatocytes was hormone dependent, and TP completely supported their development, meiotic division and spermiogenesis in the complete absence of pituitary hormones.


Progestin binding in vitro by the brain cell nuclei of ovariectomized oestrogen-primed rats. The uptake and binding of 17 alpha, 21-dimethyl-19-nor-4,9-pregnadiene-3,20-dione, a synthetic progestin, by the hypothalamus and cerebral cortex of ovariectomized oestrogen-primed rats was examined in vitro. Uptake of this steroid by the medial basal hypothalamus was higher than that by the remaining hypothalamus and cerebral cortex. The component in the cytosol from whole hypothalami which bound the radioactive progestin sedimented in the 7S region when centrifuged in a sucrose density gradient. The tritiated progestin was displaced by incubation with non-radioactive progestin or progesterone but not by oestradiol-17 beta, corticosterone or 5 alpha-dihydrotestosterone (1 mumol/l). No 7S binding component was detected in a similar preparation from the cerebral cortex. The nuclear fraction from whole hypothalami extracted by KCl (0.4 mol/l) contained a progestin-binding complex which sedimented at 9S and which was heat-labile and protein in nature. It was concluded that the hypothalamus of ovariectomized oestrogen-primed rats contains progestin-binding material in the cytoplasm and progestin, bound to such material, is transported from the cytoplasm to the nucleus.


Circadian phase-dependent prolactin mechanisms in hepatic lipogenesis of a teleost. In the teleost, Fundulus grandis, injections of prolactin early in the light phase cause an immediate 50% depression in the rate of hepatic lipogenesis ([14C]acetate incorporation); 10 h later, that rate has returned to levels not different from controls. Injections of prolactin late in the light phase cause an even more dramatic immediate depression of lipogenesis (79%) followed by a gradual increase in lipogenic rate which is 2.6 times higher than the control rate after 24 h. The stimulation of lipogenesis by prolactin is blocked by simultaneous treatment with indomethacin, an inhibitor of prostaglandin synthesis. These circadian phase-dependent effects of prolactin on hepatic lipogenesis are discussed with reference to possible mechanisms of action exerted by endogenous prolactin rhythms.


Development of a radioimmunoassay for adrenal specific protein: its measurement in biological fluids and tissues. A radioimmunoassay for a new human adrenal specific protein (ASP) is described. The assay has a lower limit of detection of approximately 50 micrograms/l. The ASP extracted and purified from adrenal glands was used for standardization, radio-iodination and immunization of rabbits. Adrenal specific protein can be detected in normal human serum and plasma (240 +/- 80 and 190 +/- 60 micrograms/ml (means +/- S.D.) respectively), tissue levels were found in extracts of adrenal medulla, with appreciable amounts in the adrenal cortex, pituitary gland, seminal vesicle and testis, and low levels in all other tissues examined. The highest concentrations in biological fluids were found in seminal plasma and to a lesser extent in milk and menstrual fluid.


Reduction of androstenedione by skin in vitro and serum levels of gonadotrophins and androgens in men with hypospadias. The reduction of 4-[1,2-3H]androstene-3,17-dione (androstenedione) in vitro by scrotal skin was measured in samples from nine men (16--34 years old) with hypospadias and from ten male control subjects. The reduction of androstenedione was also studied in axillary and upper arm skin of seven control subjects. Androstenedione was reduced to material with chromatographic characteristics of 5 alpha-androstane-3,17-dione and to 3 alpha- and 3 beta-hydroxy-5 alpha-androstan-17-one. No difference in 5 alpha-reductase activity (defined as the sum of these three metabolites formed) was found in scrotal skin from hypospadic and control men. The mean concentration of 5 alpha-dihydrotestosterone in serum from men with hypospadias was lower than that in serum from control subjects (P less than 0.01). The mean ratio of the serum concentrations of testosterone and 5 alpha-dihydrotestosterone was higher in hypospadic men than in control subjects (P less than 0.05). No differences between the two groups were found in the mean serum concentrations of LH, FSH, prolactin, dehydroepiandrosterone, androstenedione, testosterone or testosterone-binding globulin.


Secretion rate and metabolic clearance rate of prolactin in the rat during mid- and late lactation. The prolactin concentration in the plasma of lactating rats rose less rapidly and attained a significantly lower plateau level in response to suckling on day 20--21 of lactation than it did on day 13--14 of lactation. Neither differences in suckling stimulation of the older pups nor a higher metabolic clearance rate (MCR) of prolactin were implicated in the reduced prolactin concentration seen in the late-lactating rats. The MCR was, in fact, slightly reduced in both conscious and late-lactating rats anaesthetized with urethane when compared with those in mid-lactation. The MCR of prolactin was not significantly altered by urethane anaesthesia in rats on either day of lactation. However, the secretion rate of prolactin, computed from the MCR multiplied by the equilibrium concentration of prolactin during suckling, was considerably reduced (665 to 392 ng/min) from mid- to late lactation. We conclude from these data that the reduced plasma concentration of prolactin in response to suckling in late lactation is the result of an impairment within the prolactin secretory mechanism.


Steroid and prostaglandin secretion by the corpus luteum, endometrium and embryos of cyclic and pregnant pigs. Prostaglandin F2 alpha (PGF2 alpha) secreted by the reproductive tissues of the pig in vitro was measured and it was found that the levels secreted by the corpus luteum and endometrium of early pregnant sows were significantly lower than those secreted by tissues during the late stage of the oestrous cycle. They were, however, comparable to levels secreted by tissues from the mid-stage of the oestrous cycle. Embryos also secreted significant amounts of PGF2 alpha. Secretion of progesterone and oestradiol by the corpora lutea of both cyclic and pregnant pigs fell within accepted limits but embryos were also found to secrete significant amounts of oestradiol. The results suggest that luteal maintenance in the early pregnant pig is unlikely to be directly due to reduced synthesis of PGF2 alpha.


Determination of the tumorigenic potential of methylene-bis-orthochloroaniline. Methylene-bis-orthochloroaniline (MOCA) induced a wide spectrum of neoplasms in male rats fed either a protein-adequate (27 percent casein) or a protein-deficient (8 percent casein) diet. The concentrations of MOCA used were 125, 250, 500 and 1000 ppm. Increasing doses of MOCA in either diet resulted in decreased survival times. MOCA induced pulmonary adenomas, adenocarcinomas, mammary gland adenocarcinomas, Zymbal gland carcinomas, hepatocellular carcinomas, and hemangiosarcomas. In both diet groups the lungs were the most sensitive organs to the induction of neoplasms by MOCA. The incidence of primary pulmonary neoplasms in the lowest dose tested (125 ppm) was 6 percent (p less than or equal to 0.01), while in the highest dose (1000 ppm) it was 70 percent (p less than or equal to 0.01). The hepatocellular carcinoma incidence in rats fed a protein-deficient diet with 500 ppm MOCA was 18 percent, whereas in rats fed a protein-adequate diet with the same MOCA concentration this incidence was only 4 percent. The mean urinary concentration of MOCA in the group of rats fed the lowest dose (125 ppm-PD) was 0.63 ppm, a concentration comparable to that measured in the urine of workers exposed to MOCA.


Toxicity of low concentration long-term exposure to an airborne mixture of nitrous oxide and halothane. To evaluate experimentally the questions of reproductive, teratological, cytogenetic, and tumorigenic sequelae of long-term exposures to escape levels of halothane plus nitrous oxide (N2O), male and female rats were exposed either to air, to 1 ppm halothane plus 50 ppm N2O, or to 10 ppm halothane plus 500 ppm N2O for 7 hr/day, 5 days/wk for appropriate periods of time. In one experiment, young adult female rats were exposed for 60 days, then mated and reexposed either staring with Day 1 or Day 6 of gestation until Day 15. The former were permitted to deliver naturally while the latter were delivered by C-section on Day 20. The young adult males used in breeding were also exposed for 60 days prior to mating and then for a total of 52 weeks thereafter. At termination, bone marrow cell and spermatogonial metaphase preparations were made and assessed for cytogenetic abnormalities. The mated females were evaluated for ovulation, pre- and post-implantation loss, fetal growth, fetal abnormalities, and early post-natal development, as appropriate. In a parallel experiment, 50 male and 50 female weanling rats in each group were exposed for 104 weeks to the same levels and then evaluated for tumor development with emphasis on the reticuloendothelial system. The results indicated a significant reduction in ovulation and implantation efficiency from exposure to the higher levels and slightly retarded fetal development at both levels. No teratological or abortifacient effects were noted. No tumorogenic effects were observed. However, cytogenetic damage to both bone marrow and spermatogonial cells was seen at both levels.


The use of helium-oxygen spirometry in occupational lung disease. One of the major problems in the study and management of occupational lung disease is to detect early impairment so that corrective measures can be taken before irreversible or more severe damage occurs. Unfortunately standard spirometric tests are not sensitive to functional impairment in small airways where the earliest abnormalities in many pulmonary diseases are thought to occur. A a result, several new tests have been devised in the last decade to study this so-called silent zone. Helium-oxygen spirometry, one such test, is safe, convenient, and can eaily be added to conventional air spirometry apparatus. Two studies using helium-oxygen and air spirometry done by the Appalachian Laboratory are presented. In the first, non-exposed controls were compared to flax workers with either low or high dust exposure. Both air and helium-oxygen flow volume curves showed decreased flow rates after a work-shift in the high exposure group but no change in controls. In the low-dust exposure group, only helium-oxygen spirometry detected decreased post-shift flow rates suggesting small airways disease. Coal miners were compared to controls in the second study. Subgroups of younger subjects, smokers, non-smokers, bronchitics, and non-bronchitics were also analyzed. In no case did helium-oxygen spirometry detect differences which were not present on routine air spirometry. It is concluded that further studies in this area are needed. At present, random screening with helium-oxygen spirometry for early occupational disease is not warranted, and this test remains an investigative tool.


Subchronic inhalation toxicity of nitromethane and 2-nitropropane. Nitromethane (NM) and 2-nitropropane (2-NP) and versatile compounds employed in a wide variety of industrial applications, thus providing ample opportunity for occupational exposure. The purpose of this study was to determine the subchronic inhalation toxicity of NM and 2-NP in order to recommend acceptable exposure levels in the workplace. Fifty male rats and 15 male rabbits were exposed to either 98 ppm or 745 ppm of NM or 27 or 207 ppm of 2-NP 7 hours/day, 5 days/week, for periods up to 24 weeks. Fifty rats and 15 rabbits were exposed to filtered air for similar lengths of time and served as controls. Ten rats from each exposure and control group were sacrificed following 2 days, 10 days, 1 month, 3 months, and 6 months of exposure. Five rabbits from each exposure or control group were sacrificed at 1, 3, and 6 months of exposure. Effects relatable to exposure to NM were decreased body weight gain in rats following 8 weeks of exposure to 745 ppm, and a thyroid effect evidenced by an increased thyroid weight and decreased serum thyroxin levels, most notable in rabbits. Liver weights were significantly elevated in rats exposed to 207 ppm of 2-NP for 1, 3, and 6 months. No exposure-related gross or microscopic alterations were seen in any of the tissues examined for rats and rabbits exposed to 745 and 98 ppm of NM and 27 ppm of 2-NP or in tissues of rabbits exposed to 207 ppm of 2-NP. Liver neoplasms were seen in all 10 rats killed following 6 months of exposure to 207 ppm of 2-NP, indicating that 2-NP is a potent carcinogen in the rat.


Frequency of sickness absence and worksite clinic visits among nurses as a function of shift. The records of 1219 nurses on permanent day, afternoon, night and rotating shifts were examined to assess the effects of shift schedule on sick leave and frequency of worksite clinic visits. Relative to nurses on permanent shifts, rotators exhibited a significantly higher rate of clinic visits and took more sick days for serious illnesses.


A preliminary report of mortality patterns among foundry workers. A proportional mortality study was conducted utilizing the death records maintained from 1971 to 1975 by the International Molders and Allied Workers Union as part of a death benefits program. Death certificates were obtained on 3,013 members of the study group and classified according to the 8th Revision of the ICA by a trained nosologist. The ate- and race-specific cause distribution of all deaths among males in the United States for 1973 were used as a standard from which expected deaths were calculated. The statistical significance of differences between observed and expected numbers of deaths was determined by a chi-square test. The most statistically significant finding in this study was an excess lung cancer mortality (208 observed vs. 142 expected) and an excess mortality due to pneumoconiosis (29 observed vs. 5 expected). A discussion is included of the potential agents found in the foundry environment that may be responsible for the increased lung cancer risk.


Engineering control technology in polyvinyl chloride polymerization plants. The National Institute for Occupational Safety and Health, Division of Physical Sciences and Engineering has initiated a research program in control technology. The objective of this program is to facilitate the implementation of effective preventative measures in order to prevent occupational illness. The plastics and resins industry control technology assessment has recently been completed. The objectives of this study were to document and evaluate effective control technology for plastics and resins polymerization plants. Particular emphasis was given to PVC polymerization processes, since the relatively recent lowering in the personal exposure limit for vinyl chloride monomer (VCM) to an 8-hour 1-ppm time-weighted average has required the application of state-of-the-art controls. The present paper contains a summary of the control technology that was found to be effective in controlling VCM in processes manufacturing PVC by suspension, bulk, and dispersion polymerization. Controls necessary for VCM include process and equipment modification, isolation, local and general ventilation, work practices, personal protective equipment, workplace monitoring systems, employee/employer education, and on-going effort by both workers and management. All of these components must function together as an integrated coordinated system in order to assure worker protection under normal operating conditions or under conditions of process upset or maintenance.


Recent developments in fibrous aerosol measurements. Asbestos and other fibrous aerosols have been shown to cause respiratory disease. There has been a continuing search for improved monitoring methods to evaluate workers exposure to fibrous aerosols, especially asbestos. Work is continuing in several areas on the use of light scattering from fibers for their detection. A contract with GCA/Technology, which was completed in FY 77, resulted in a portable survey instrument. We have investigated the capabilities of this instrument and it looks very promising. The basic behavior and characteristics of the detection system for this instrument is the subject of a current NIOSH grant to the John B. Pierce Foundation. In-house work in FY 76 indicated that the use of light scattering for the detection of fibers directly on filter samples was promising A current contract at leeds and Northrup will result in an instrument based on this work and should provide some relief in the future for people who are involved in manual counting of asbestos.


Schedule-induced drinking: rate of food delivery and Herrnstein's equation. Schedule-induced drinking was measured in four rats exposed to fixed-time schedules of food ranging from 30 to 480 seconds. Herrnstein's (1970, 1974) equation relating rate of a single response as a hyperbolic function of reinforcement rate provided a good fit to three measures of drinking: lick rate, ingestion rate, and relative time spent drinking. The functions relating the three measures of drinking to reinforcement rate were of similar form. Herrnstein's equation also provided a good description of some already published data on schedule-induced drinking. The fit both to the present data and to the already published data was improved somewhat by computing the measures by subtracting from the time base a latency constant representing the minimal time required to consume the food pellet and travel to the water source. The data from this study provide two correspondences between operant behavior and schedule-induced behavior: (a) conformity to Herrnstein's equation and (b) equivalence of rate and relative time measures.


Comparison of yes-no and latency measures of auditory intensity discrimination. Rats discriminated auditory intensity differences of sinusoids at 3.0 kilohertz in a go/no-go signal detection procedure. Responses to the signal (hits) were reinforced with electrical brain stimulation, and misses produced a brief timeout. On intermixed noise trials, withholding of responses (correct rejections) was reinforced, and false alarms produced the time-out. In two test conditions, the signal was either the louder (100 decibels) or softer (90, 93, 96, or 99 decibels) of the pair of intensities presented within a set of trials. Each animal was first trained with signal value louder or softer, and reversed for the second condition so that the former noise value served as signal. Hits showed shorter latencies than false alarms, regardless of the relative intensity of signal and noise, and the magnitude of differentiation was proportional to signal-noise separation. Both hits and false alarms showed longer latencies as the discrimination became more difficult. Isosensitivity contours derived from the latencies showed close similarity across conditions; in comparison, the yes-no measure of detectability, d', showed greater variability. The similarity of latency differentiation across louder and softer signal conditions supports a detection model in which the observer's judgment is controlled by the distance of sensory effect from criterion on each trial, as opposed to the loudness of the tones per se.


Immunological studies of grain dust.

Immunological studies of grain dust. Epidemiological investigations of grain workers have suggested the presence of biological hazards in terminal grain elevators. Immunological assessments of the involved individuals, however, have produced inconclusive results. We have recently demonstrated in vitro a potential biological mechanism which could occur in vivo upon inhaling airborne graon dust, thereby constituting a potential inflammatory insult to the respiratory tracts of grain workers. Airborne dusts of similar size distributions generated by transporting grain in terminal grain elevators have been shown to activate the alternative pathway of complement in precipitin-negative pooled normal human serum. These dusts consumed hemolytic complement in a dose-response manner as quantified by both CH100 immunodiffusion and CH50 tube methods. The proactivator of C3 was converted to the activator form in the presence of the chelator EGTA, but conversion was prevented by EDTA. Likewise, serum from guinea pigs genetically deficient in C4, thereby lacking a functional classical complement pathway, showed complement consumption by grain dusts via the alternative pathway. Relative CH50 toxicity ranking of the various dusts was found to be unrelated to the amount of endotoxin present. Of interest, aged settled dust (20-30 years) remained relatively active against the alternative complement pathway as did 15 min aqueous extracts of ground whole rye.


Signal probability, reinforcement and signal detection. Five pigeons were trained to detect differences in light intensity. Two stimuli, S1 and S2, differing in intensity, were arranged on the center key of a three-key chamber according to set probabilities. A peck on the center key turned on the two side keys. When S1 was presented on the center key, a peck on the left key was "correct" and when S2 was presented, a peck on the right key was "correct." Correct responses produced reinforcement and incorrect responses produced 3-second blackout. Detection performance was measured under three procedures. The first was a standard signal-detection design in which the probability of S1 was varied and the number of reinforcements obtained for correct responses to S1 was allowed to covary. In the second procedure, the probability of S1 was again varied but the distribution of reinforcements between the two choices was kept equal. In the third procedure, probability of S1 was held constant while the distribution of reinforcements was varied between the two choices. Changes in response bias were a function of variations in the relative reinforcement ratio for the choice responses and not a function of variations in the probability of stimulus presentation. Discriminability remained constant across the three procedures.


Shock as a signal for shock or no-shock: a feature-negative effect in conditioned suppression. Rats were trained in conditioned suppression discriminations where shock at the beginning of a trial signaled either shock or no-shock at the end of the trial. In the shock-positive condition, shock at the beginning of a presentation of white noise signaled that noise would end with shock; noise that did not begin with shock did not end with shock. In the shock-negative discrimination, shock at the beginning of noise signaled that noise would not end with shock; presentations of noise that did not begin with shock ended with shock. In shock-random training, shock at the beginning of noise did not reliably signal whether the noise presentation would or would not end with shock. Most subjects in shock-negative training quickly developed a differential pattern of suppression on positive (shock reinforced) trials and no suppression on negative (nonreinforced) trials. The shock-positive discrimination was much more difficult to establish and was not acquired by the majority of the rats. This "feature-negative" effect is a clear exception to the general superiority of feature-positive learning commonly observed in discriminations based on a single distinguishing feature. The results are discussed in terms of Pavlovian stimulus-shock contingencies in the shock-positive and shock-negative paradigms, which appear to favor rapid development of the shock-negative discrimination.


A comparative study of the effects of carbon monoxide and methylene chloride on human performance. The purpose of this investigation was to determine whether similar carboxyhemoglobin (COHb) values obtained from inhaling carbon monoxide or methylene chloride have the same behavioral effects. The effects were assessed by the performance of 12 humans on a visual-manual, dual-task, and an auditory vigilance task. The results indicated that both substances in concentrations sufficient to produce 5-percent COHb significantly impaired human performance under difficult or demanding task conditions. The conclusion was that carbon monoxide, the main metabolite of methylene chloride, was responsible for the observed performance decrements.


Choice for signaled over unsignaled shock as a function of signal length. Subjects chose between signaled and unsignaled shock conditions while signal length was varied between .5 and 2.0 seconds in steps of .5 seconds in both ascending and descending series. Preference for the signaled condition failed to develop initially for five of six subjects when signals were .5 or 1.0 seconds but became strong for all subjects when signals were 2.0 seconds (ascending series). Preference declined when signals were shortened, but for most subjects this decline was small (descending series). Since discriminable shock-free periods were present in the signaled condition at all signal lengths, these results suggest that safety may not be a sufficient condition for preference to develop for signaled shock.


Effects of d-amphetamine and caffeine on schedule-controlled and schedule-induced responding. The effects of d-amphetamine and caffeine were studied on rates and patterns of lever pressing and schedule-induced licking under fixed-interval schedules of food pellet presentation. In addition, the effects of caffeine were studied on lever pressing and licking under a multiple fixed-ratio fixed-interval schedule. Caffeine reduced mean overall rates of licking at lower doses than it reduced mean overall rates of pressing under the fixed-interval schedules, but the effects of caffeine on both licking and lever pressing depended largely on the control rate of responding. d-Amphetamine reduced mean overall rates of lever pressing and licking at about the same dose, but the effects of d-amphetamine also were a function of the control rate of responding.


Mortality of steelworkers employed in hot jobs. This paper investigates possible relationships between heat stress of steelworkers and cause-specific mortality patterns. Prior to field investigation, jobs were identified which appeared to involve heat stress exposure. A selected sample of these jobs was surveyed for assessing the workers' environmental and metabolic heat load. These data were utilized to form different categories of heat stress. Mortality patterns of workers in jobs falling in each of the heat stress categories were analyzed by length of exposure for those workers from a cohort of 59,000 steelworkers who held one of the surveyed jobs. The comparison group consisted of workers who never worked in any of the work areas in which job were surveyed but were members of the same cohort. Findings of interest are: a deficit in mortality from cardiovascular disease for workers in jobs involving higher levels of environmental heat exposure; a high risk of death from cardiovascular disease for workers with less than 6 months of exposure and a downward trend in mortality for workers who remained on the job, indicating a possible relationship between inability to work in jobs involving heat stress and health; and, increased risks of digestive disease mortality among workers exposed to higher levels of environmental heat.


Synaptic and hormonal modulation of a neuronal oscillator: a search for molecular mechanisms. 1. The central ganglia of a number of gastropod molluscs (including the marine snail Aplysia californica and the terrestrial snail Helix pomatia) contain neurones which exhibit endogenous patterns of oscillatory activity. 2. This oscillatory activity can be modulated for long periods of time by synaptic and hormonal stimulation. 3. Stimulation of appropriate pre-synaptic nerves causes long-lasting hyperpolarization in these neurones, with complete abolition of oscillatory activity. This synaptic response is mediated by an increase in K+ conductance, together with a decrease in inward (Na+/Ca2+) conductance. The ionic conductances affected by synaptic stimulation are those responsible for producing the rhythmic oscillations. 4. The oscillatory activity can also be modulated by the vertebrate neurohyophyseal peptides, vasopressin and oxytocin, and by an endogenous peptide-containing extract of molluscan ganglia. In contrast to synaptic stimulation, these agents cause an increase in oscillatory activity. 5. The endogenous molluscan factor which produces an increase in oscillatory activity can be purified by affinity chromatography on bovine neurophysin linked to Sepharose. This indicates that the molluscan nervous system may contain a neurohypophyseal-like peptide. 6. Oscillatory activity can be modulated by manipulation of cyclic nucleotide metabolism in these neurones. Increases in cAMP alone are associated with abolition of oscillatory activity; this mimics long-lasting synaptic hyperpolarization. Increases in cAMP and cGMP together are associated with an increase in oscillatory activity and mimic the effects of the vertebrate and molluscan peptides. Thus, it is possible that cyclic nucleotides play a role in these physiological responses.


Oscillatory contraction activity in Physarum. The plasmodia of Physarum polycephalum show different oscillatory phenomena (time period approximately 1.3 min) in their contraction behaviour and their protoplasmic flow. The force generating system for these phenomena is cytoplasmic actomyosin. The biochemical nature and location(s) of the oscillator(s), i.e. the clock governing these phenomena are unknown. The following locations are discussed as possible sites of the oscillator: (1) cytoplasmic actomyosin, (2) the energy supply system, (3) inner Ca2+ stores, and (4) the plasmalemma, which must be involved at least in modulating the force generated by the contractile machinery during a chemotactic response. The following oscillatory phenomena were used to assess the effects of externally and internally applied substances (e.g. calcium antagonistic drugs, caffeine, D2O) on oscillating force output: (1) persistance of longitudinal contractile activity of veins (for external application of test substances), (2) persistance of radial activity of veins (for internal application of the test substances), (3) de novo generation of contractile activity in protoplasmic drops (external application). The data seem to exclude rhythmical Ca2+, Na+ or K+ transport across the plasmalemma as a triggering function for the oscillation. Contractile activity seems to represent a spontaneous, endogeneous oscillation which can be modulated via the plasmalemma during chemotaxis.


On exploring the basis for slow potential oscillations in the mammalian stomach and intestine. The basic driving unit of oscillatory electrical activity in stomach and intestine is the slow wave, a propagating depolarization of myogenic origin. The slow wave controls contractile activity in the intestine by triggering action potential bursts, while in the stomach there is both action potential and spike-free slow wave activation. This review attempts to summarize recent characterizations of the slow wave and to explore in detail the evidence, which suggests that the mechanisms which generate the electrical oscillations are quite closely coupled to metabolic processes.


Cellular and subcellular mechanisms of cardiac pacemaker oscillations. Rhythmic oscillations in the membrane potential of heart cells are important in normal cardiac pacemaker activity as well as cardiac arrhythmias. Two fundamentally different mechanisms of oscillatory activity can be distinguished at the cellular and subcellular level. The first mechanism, referred to as a surface membrane oscillator, can be represented by a control loop in which membrane potential changes evoke delayed conductance changes and vice versa. Since the surface membrane potential is a key variable within the control loop, the oscillation can be interrupted at any time by holding the membrane potential constant with a voltage clamp. This mode of oscillation seems to describe spontaneous pacemaker activity in the primary cardiac pacemaker (sinoatrial node) as well as other regions (Purkinje fibre, atrial or ventricular muscle). In all tissues studied so far, the pacemaker depolarization is dominated by the slow shutting-off of an outward current, largely carried by potassium ions. The second mechanism can be called an internal oscillator since it depends upon a subcellular rhythm generator which is largely independent from the surface membrane. Under voltage clamp, the existence of the internal oscillation is revealed by the presence of oscillations in membrane conductance or contractile force which occur even though the membrane potential is held fixed. The two oscillatory mechanisms are not mutually exclusive; the subcellular mechanism can be preferentially enhanced in any given cardiac cell by conditions which elevate intracellular calcium. Such conditions include digitalis intoxication, high Cao, low Nao, low or high Ko, cooling, or rapid stimulation. Several lines of evidence suggest that the subcellular mechanism involves oscillatory variations in myoplasmic calcium, probably due to cycles of Ca uptake and release by the sarcoplasmic reticulum. The detailed nature of the Cai oscillator and its interaction with the surface membrane await further investigation.


Oscillatory membrane potential changes in cells of mesenchymal origin: the role of an intracellular calcium regulating system. A number of mesenchymal cells (fibroblasts, macrophages and megakaryocytes) respond to a variety of stimuli with large hyperpolarizations lasting several seconds (the H.A. response). The H.A. responses can occur as repetitive trains or oscillations. These hyperpolarizations are due to an increase of the surface membrane permeability to potassium ions which is probably mediated by an increase in the cytoplasmic free calcium ion concentration. Evidence is discussed which suggests that the source of this increased calcium, is least in part, an intracellular sequestering system, probably the endoplasmic reticulum. A model capable of producing oscillatory changes in membrane potential is proposed based on such an intracellular calcium sequestering and releasing system.


Rapid acetylcholine and adenosine triphosphate oscillations triggered by stimulation of the Torpedo electric organ. 1. When the electric organ of Torpedo is stimulated a large number of synchronized cholinergic synapses are activated. This permits the measurement of changes in the tissue level of ACh associated with the release process, usually recorded as an electric discharge. 2. At 5 Hz stimulation the output per impulse and the amount of cytoplasmic (free ACh) declines for about 30 s. The output then remains constant while ACh is synthesized for about 90 s. Finally, the output and cytoplasmic ACh are exhausted after 120 s. These 'slow wave' changes in ACh represent about 50% of the total. 3. Superimposed on the 'slow wave' are rapid oscillations of 5 s period, which represent about 30% of the total ACh. 4. The amount of ATP oscillates in phase with ACh. These oscillations might result from regulation of enzymes involved in the synthesis of transmitter. 5. The amplitude of electrical discharge does not normally oscillate. Transmitter output is therefore not directly related to ACh concentration changes. The mechanism releasing ACh is a saturable process.


Production of monoclonal antibodies specific for two distinct steric portions of the glycolipid ganglio-N-triosylceramide (asialo GM2). Two hybrid cell lines were prepared by the fusion of mouse myeloma cells with the spleen cells of BALB/c mice that had been immunized with the glycolipid ganglio-N-triosylceramide (asialo GM2). The specificity of the monoclonal antibodies produced by these hybridomas, one an IgM and the other an IgG3, has been defined by hemagglutination inhibition, complement fixation, and lysis of glycolipid liposomes by antibody and complement. A major determinant recognized by the IgM antibody is the nonreducing terminal N-acetylgalactosamine including the C6 primary hydroxyl group, but excluding the C2-acetamide group of N-acetylgalactosamine, because oxidation with galactose oxidase produced a structure showing only minimal cross-reaction with the IgM but replacement of the N-acetyl group with an N-n-butyryl group produced a glycolipid that reacts with IgM antibody to the same extent as with the unmodified glycoplipd. A major determinant recognized by the IgG3 antibody is the terminal N-acetylgalactosamine including the C2-acetamido group, but excluding the C6 primary hydroxyl group of N-acetylgalactosamine, because replacement of the N-acetyl group with an N-n-butyryl group produced a glycolipid that did not react with the IgG3 antibody; in striking contrast the IgG3 antibody reacted with the C6-oxidized glycolipid as well as with the native glycolipid. Neither antibody reacted significantly with any other natural glycolipids tested including several that are structurally related to asialo GM2 such as ganglioside GM2, ganglio-N-tetraosylceramide (asialo GM1), or ceramide dihexoside. These results indicated that in addition to the fine structure specificity described above both antibodies recognize the nonreducing terminal GalNAc beta 1 leads to 4Gal structure. The strict antigenic specificity of these monoclonal anti-glycolipid antibodies indicates their great potential as specific probes for cell surface studies.


H-Y antigen. Cell surface mapping and testosterone-induced supramolecular repatterning. Previous work with the antibody-blocking technique showed that the map of surface components for thymocytes prefixed with paraformaldehyde is the same as the map for unfixed thymocytes, with the following exception: after exposure to anti-TL or anti-Db, TL and H-2Db occupy adjacent positions on unfixed cells but not on fixed cells. This was interpreted as an indication that activation of particular components of the surface phenotype initiates ordered changes in the display of cell-surface molecules, approximation of TL and Db in this instance. These studies have now been extended to the H-Y component on the surface of male cells. On fixed male mouse thymocytes, H-Y lies adjacent to TL and relatively distant from H-2Db, H-2Kb, H-2Lb, Lyt-1.2, and Lyt-2.2. However, on unfixed male mouse thymocytes, similarly exposed to H-Y antibody, H-Y and H-2Db are adjacent. Presumably, this engagement of H-Y sites by H-Y antibody brings H-Y and H-2Db together. Evidence that this change in pattern may be physiologically relevant comes from the finding that testosterone, but not estradiol, caused the same selective approximation of H-Y and H-2Db.


Diacylglycerol metabolism in mast cells: a potential role in membrane fusion and arachidonic acid release. Purified rat peritoneal mast cells stimulated with the polycationic histamine-releasing agent compound 48/80 demonstrated a two- to four-fold increase in cellular levels of 1,2-diacylglycerol (DAG) within 1 min as detected by radioactive labeling and direct quantitation experiments. When 2-[1-14C]arachidonoyl-DAG was incubated in the presence of mast-cell homogenates, a rapid conversion to free arachidonate, and to a lesser extent, to monoacylglycerol, triglyceride, and phospholipid was observed. The release of arachidonate was proportional to the amount of broken-cell preparation added and the time of incubation, was prevented by preheating mast-cell preparations, and did not occur when 1-[1-14C]arachidonoyl-phosphatidylcholine was used as substrate, suggesting that the degradation was mediated by an enzyme with Dag-lipase activity. Although much work remains to be done to clarify the precise role of DAG in mast cells, DAG metabolism may be involved in secretion by generating substances which may faciliate membrane fusion and also in arachidonic acid-derived mediator formation by liberating esterified arachidonic acid from mast-cell lipids. Taken together, these studies indicate that the formation of DAG may play a central role in mast-cell function.


Recognition among mice. Evidence from the use of a Y-maze differentially scented by congenic mice of different major histocompatibility types. Previous studies of mating preference signified that mice can sense one another's major histocompatibility complex (MHC) types, probably by olfaction. This conclusion has now been substantiated by the use of a Y-maze whose two arms were differentially scented with currents of air conducted through boxes occupied by B6 (H-2b) males and by B6-H-2k congenic males. Four B6 mice, two males and two females, were successfully trained, by water deprivation and reward, to enter the arm scented by B6 or B6-H-2k males. One of the males and one of the females were trained to select the B6-scented arm; the other male and female were trained to select the B6-H-2k-scented arm. Untrained mice showed no MHC discrimination in the maze. The performance of the trained mice in distinguishing between MHC congenic homozygous F2 segregants derived from a cross of B6-H-2k with B6 was as good as their performance in distinguishing the respective inbred strains, thus essentially eliminating alternative and significant additional explanations of MHC-associated sensory discrimination. The data further indicate that chemosensory discrimination of MHC types can be entirely dissociated from sex differences and from the circumstances of mating.


Multicellular origin of fibrosarcomas in mice induced by the chemical carcinogen 3-methylcholanthrene. The cellular origin of tumors induced by the chemical carcinogen 3-methylcholanthrene (MCA) was studied in mice with X-chromosome inactivation mosaicism. Because only one of the two X-chromosomes is active in XX somatic cells, a female heterozygous at the X-linked phosphoglycerate kinase (PGK-1) locus for the usual Pgk-1b gene and the variant Pgk-1a has two populations of cells, in the cells of one population, Pgk-1b is active and B-type enzyme is synthesized, whereas in cells of the other population, A-type enzyme is produced. Both enzyme types are found in normal tissues from these mosaic mice. A tumor developing from a single cell exhibits only one of the two PGK enzyme types, whereas a tumor with a multicellular origin expresses both enzymes (i.e., it has a double-enzyme phenotype). Five fibrosarcomas developing at the site of injection of 0.2 or 2.0 mg of MCA were analyzed. 36 of 38 fragments from the five tumors had double-enzyme PGK phenotypes. One piece from each of two tumors showed a single-enzyme phenotype. Histological, cell culture, and cloning studies indicate that the double-enzyme phenotypes reflect the presence of both types of malignant cells and not admixture of normal with neoplastic elements in the specimens tested for PGK. The results suggest strongly that these fibrosarcomas have a multicellular origin.


Association of alkaline-phosphatase-positive reticulum cells in bone marrow with granulocytic precursors. In the bone marrow, an elaborate stroma forms the structural basis of the hemopoietic microenvironment. In this study, two different types of stromal cells were identified with certainty on tissue sections of intact bone marrow of rats and mice using light and electron microscopic histochemistry: (a) a fibroblast-type of reticulum cell which is characterized by having alkaline phosphatase associated with its plasma membrane. We refer to this cell as the alkaline-phosphatase-positive reticulum cell (Al-RC). It is closely associated with granulocytic precursors, particularly myeloblasts and neutrophilic promyelocytes. These reticulum cells may be found throughout the marrow but are concentrated near the endosteum. (b) a macrophage-type of reticulum cell which is characterized by its abundance of lysosomal acid phosphatase and is mainly associated with erythroid precursors (as observed by others). In contrast to the above-mentioned cell type, this latter cell was found to be distributed uniformly throughout the marrow. We speculate that the Al-RC are mesenchymal stromal cells necessary for granulocytic differentiation in bone marrow.


Macrophage oxygen-dependent antimicrobial activity. II. The role of oxygen intermediates. The capacity of three populations of mouse peritoneal macrophages to generate oxidative metabolites (as judged by extracellular release of H2O2) was compared to their ability to influence the intracellular fate of virulent Toxoplasma gondii. Macrophages from normal mice released little H2O2 and allowed unrestricted multiplication of intracellular toxoplasmas. Cells from chronically infected, immune (IM) mice released 4 times more H2O2 and displayed microbistatic activity. In contrast, macrophages from immune-boosted (IB) mice released 25 times more H2O2 than normal cells and rapidly killed the bulk of ingested toxoplasmas within 1 h. When macrophage monolayers were exposed to scavengers of O2-, H2O2, OH., and 1O2, both the inhibition of intracellular toxoplasma multiplication by IM macrophages and the killing of toxoplasmas by IB macrophages were reversed. Depriving cells of glucose, which markedly reduced H2O2 release, resulted in similar reversal of IM and IB macrophage anti-toxoplasma activity. As judged by the effect of the individual oxygen intermediate scavengers, O2- and H2O2 appeared to serve as precursors for the key toxic agents which may include OH. and 1O2. Providing normal macrophages with an exogenous source of oxidative metabolites generated by xanthine and xanthine oxidase, but not glucose and glucose oxidase, resulted in inhibition of intracellular toxoplasma growth. These findings suggest the presence of an oxygen-dependent antimicrobial system in mononuclear phagocytes beyond the production of O2- and H2O2, and indicate an important role for oxygen intermediates in macrophage resistance to the intracellular pathogen T. gondii.


A new class of cell surface antigens. Quantitative absorption studies defining cell-lineage-specific antigens on hemopoietic cells. A new class of cell surface antigens are described which are expressed on cells within a particular differentiation pathway. These antigens, termed cell-lineage-specific antigens, are shown to be distinct from differentiation antigens and from histocompatibility antigens. The presence of these antigens was demonstrated by raising antisera against terminally differentiated hemopoietic cells such as platelets, thymocytes, and macrophages and showing cross-reaction with the pluripotent stem cells from which these cells were derived. Quantitative absorption studies of each antiserum showed the antigens to be largely cell-lineage-specific. For example, the anti-stem cell activity in anti-platelet serum was not absorbed out with thymocytes or macrophages from the same mouse strain but was removed by absorption with platelets. Absorption of each antiserum with nonhemopoietic mouse tissues such as brain, kidney, liver, and testis did not reduce anti-stem cell activity. Thus, each antiserum was shown to be tissue specific and species specific. Hemopoietic cells from mouse strains other than CBA absorbed out most of the anti-stem cell activity indicating cell-lineage-specific antigens to be common to the mouse strains tested.


Integration of a virus membrane protein into the lipid bilayer of target cells as a prerequisite for immune cytolysis. Specific cytolysis after virosome-target cell fusion. Structural requirements for membrane antigens on target cells to mediate immune cytolysis were studied in a model system with purified membrane proteins from Semliki Forest virus (SFV). These SFV spike proteins were isolated in the form of detergent- and lipid-free protein micelles (29S complexes) or, after reconstitution into lipid vesicles, in the form of virosomes. Both the 29S complexes and the virosomes were found to bind well to murine tumor cells (P815 or Eb). When these cells, however, were used as target cells in complement-dependent lysis or in antibody-dependent cell- mediated cytotoxicity assays in the presence of anti-SFV serum, they were not lysed, although they effectively bound the antibody and consumed complement. The same tumor cells infected with SFV served as positive controls in both assays. Different results were obtained when inactivated Sendai virus was added as a fusion reagent to the cells coated with either virosomes or 29S complexes. Under these conditions the virosome-coated cells became susceptible to SFV- specific lysis, whereas the 29S complex-coated cells remained resistant. Evidence that the susceptibility to lysis ofvirosome-coated cells was dependent on active fusion and, therefore, integration of the viral antigens into the lipid bilayer of the target cells was derived from control experiments with enzyme-treated Sendai virus preparations. The 29S complexes and the virosomes partially and selectively blocked the target cell lysis by anti-H-2 sera but not by anti-non-H-2 sera confirming our previous finding that major histocompatibility antigens serve as receptors for SFV. The general significance of these findings for mechanisms of immune cytolysis is dicussed.


Identification of secretory component as an IgA receptor on rat hepatocytes. Secretory component (SC) was found to be synthesized by isolated rat hepatocytes. SC was detected by radioimmunoassay and cultured hepatocytes were found to synthesize 0.078 microgram SC/10(6) hepatocytes in a 48-h period. SC was also present on the surface of hepatocytes as detected by the specific binding of radiolabeled anti-SC antibodies as well as by the detection of specific membrane staining in indirect immunofluorescence tests using specifically purified anti-SC antibodies. Rat SC was detected on hepatocytes and intestinal epithelial cells but not on peripheral blood lymphocytes, unfractionated spleen cells, or erythrocytes. Specific binding of radiolabeled rat dimeric IgA to rat hepatocytes was also observed and evidence was obtained to indicate that such binding was mediated by SC. Thus, prior incubation of hepatocytes with anti-SC prevented binding of radiolabeled IgA. Moreover, prior incubation of radiolabeled IgA with rat SC prevented binding of the IgA to isolated hepatocytes. Cells treated with 0.25% trypsin lost their ability to bind to radiolabeled dimeric IgA.


Secretory component as the receptor for polymeric IgA on rat hepatocytes. Rat hepatocytes in short-term monolayer cultures bound radiolabeled polymeric rat IgA but not IgG. The binding of 125I-IgA was inhibited equally well by unlabeled polymeric IgA and by antiserum to rat secretory component (SC). The antibody to SC, after specific purification and radiolabeling, was bound to hepatocytes as effectively as the IgA. These results indicate that SC acts as the receptor for polymeric IgA on rat hepatocytes as it does on human gut epithelia, and that the transport of IgA from blood to bile in rats across the liver is analogous to that of IgA across human enterocytes.


An ultrastructural study of epididymal mouse spermatozoa binding to zonae pellucidae in vitro: sequential relationship to the acrosome reaction. Mouse sperm bind to the zona pellucida of the egg prior to penetration of the zona and entry into the perivitelline space. The question then arises: when does the acrosome reaction occur relative to these processes? An ultrastructural study of mouse epididymal sperm bound to the surface of the zona and in the privitelline space was undertaken to clarify this point. Cumulus-free mouse eggs were inseminated in either a complete defined culture medium capable of supporting in vitro fertilization or in Tris/NaCl buffer containing Ca+2. Both media support sperm binding to the zona to the same extent; binding is complete in 15 minutes. Unbound sperm were removed by a step gradient density centrifugation to yield a preparation of eggs with sperm firmly bound. All sperm in the perivitelline space had undergone the acrosome reaction. Sperm bound at the surface of the zonae pellucidae of eggs recovered at ten minutes after insemination all had intact acrosomes. At 40 minutes after insemination, half of the sperm were intact; the other half were in the initial stages of the acrosome reaction. At 90 minutes after insemination, 12% of the sperm had undergone the full acrosome reaction and were starting to penetrate the zona; of the balance, half were in various stages of the acrosome reaction, while half were still intact. These findings support the hypothesis that the sequence of the early reactions leading to fertilization in the mouse is: intact sperm binding to zona; acrosome reaction at the zona surface; penetration of the zona.


Germinal vesicle configurations and patterns of polypeptide synthesis of procine oocytes from antral follicles of different size, as related to their competency for spontaneous maturation. The cytogenetic configurations of germinal vesicle (gv) chromatin were analyzed for pools of porcine oocytes harvested from small (1.0-2.0 mm), medium (3.0-5.0 mm), and large (6.0-10.0 mm) antral follicles. Groups of oocytes from these follicular classes also were examined by high-resolution, two-dimensional, polyacrylamide gel electrophoresis to compare their patterns of polypeptide synthesis. The results show a high incidence of gross and cytogenetic degeneration among oocytes from small antral follicles as compared with those from medium or lage follicles. Pools of oocytes could be separated, on the basis of gross morphology and integrity of adherent granulosa cells, into two classes: "Type A" which appeared normal, and "type B" which appeared to be atretic. Among selected "type A" oocytes a particular chromatin configuration, termed "fibrous" characterizes the gv of oocytes from small follicles; whereas a different configuration, termed "diffuse," characterizes the gv of oocytes from large follicles. The patterns of polypeptide synthesis were markedly different for samples of "type A" oocytes of the three follicular classes; and the patterns for oocytes from medium and large follicles were more similar to each other than to patterns for oocytes from slall follicles. The incidences of maturational development beyond the gv stage in vitro were similar for "type A" oocytes from the three follicular classes (i.e., 66% to 82% maturation); although "type B" oocytes underwent maturation beyond the gv at a significantly reduced incidence (i.e., 20% to 29% maturation). "Type A" oocytes from large follicles completed maturation in vitro (i.e., underwent the first meiotic division) at a significantly higher incidence (55%) than did oocytes from small (11% to 20%) or medium (16%) follicles. Our findings are consistent with the hypotheses that a high proportion of oocytes from small antral follicles are atretic, and that a developmental program controls the molecular and cytogenetic changes occurring in porcine oocytes during follicular growth. These changes appear to be highly correlated with the acquisition of competency to complete maturation in vitro, and possibly also are required for normal fertilization and embryogenesis.


Electrophoretic analyses of lactate dehydrogenase C4 in testes and vesicular glands of normal and male sterile translocation mice. Lactate dehydrogenase (LDH) C, activity was observed in testis extracts from normal mice but was progressively reduced in mice carrying the male-sterile translocations T31H, T32H, T37H, T38H, T40H and T42H, with no detectable activity being observed in the last two mice. None of the vesicular gland extracts from these male-steriles showed LDH-C4 activity, unlike normal mice. The differential LDH-C4 activity in male-sterile testes is interpreted as reflecting the varying stages of the spermatogenic defect during meiosis. In general, early meiotic defects exhibited no LDH-C4 activity whereas late stage (usually after metaphase-1 stage) defect animals exhibited some activity. The results also provide evidence for contaminating sperm being the source of normal vesicular gland LDH-C4 activity.


Relationships between eye factors and lens-forming transformations in the cornea and pericorneal epidermis of larval Xenopus laevis. Larval Xenopus laevis at stage 56 (Nieuwkoop and Faber, '56) were subjected to various types of lentectomy: (1) simple lentectomy, from the pupillary space after incision of outer and inner cornea; (2) lentectomy from the dorsal region of the eye; (3) lentectomy from the dorsal region of the eye and simultaneous incision of the outer cornea; (4) lentectomy from the dorsal region of the eye and simultaneous incision of the outer and inner cornea. The results obtained show that the outer cornea underwent lens-forming transformations only when the inner cornea had been incised, thus permitting outer cornea (Experiments I-IV). No lens regeneration occurred when the inner cornea was left intact (Experiments II, III). It was concluded that the factor(s) allowing the lens-forming transformations of the outer cornea is not an aspecific nutritional factor(s) but a more specific factor(s) that cannot reach the outer cornea when the inner cornea is intact. Therefore, the absence of the lens and sufficient nutrient available to the outer cornea are not enough to allow lens regeneration from the outer cornea. When lens removal was carried out through the dorsal part of the eye (Experiments III-IV) the lens regenerated from the pericorneal epidermis of this region in a large number of cases.


The interaction of nerves of opposite regenerating polarity in fused newt forelimbs. Previous studies involving nerve interactions and limb regenerative processes were carried out on adult newts after their forelimbs were amputated through the distal radius and ulna and fused end-to-end. On the basis of limb regeneration results at the junction of the fused limbs, it was postulated that regenerating nerves from each limb (i.e., nerves of opposite polarity) would not invade the foreign territory of the contralateral limb if it were already normally innervated. A direct study of this nerve interaction, however, was not made in this earlier study. The present investigation was designed to obtain direct histological and electrophysiological evidence for the interaction of nerves of opposite regenerating polarity in fused newt forelimbs. The primary objective was to determine how the regenerating nerves would interact in the establishment of innervation territories-first, at the fusion zone, which represents the junction of the normal innervation territories of the nerves of each limb; and secondly, half way up one of the limbs, where interaction would occur in a territory normally innervated by only one of the regenerating nerves. The results showed that when nerves of opposite regenerating polarity approached one another at the junction of the fused limbs a discontinuation of axonal growth occurred; no indication of overlap of nerves into foreign territory was seen. When the nerves were allowed to interact within one of the fused limbs, however, an overlap of nerve fibers and a functional "double innervation" of that limb was demonstrated. These results are discussed in terms of possible mechanisms for the establishment of innervation territories in salamander limbs. The question of nerve-muscle reinnervation specificity is also raised.


A comparison between oocyte growth in coculture with granulosa cells and oocytes with granulosa cell-oocyte junctional contact maintained in vitro. Evidence is presented that strongly supports the hypothesis that the junctional association between oocytes and granulosa cells must be maintained to promote oocyte growth and development in vitro and that the coculture of oocytes with granulosa cells is not a sufficient condition for oocyte development. Furthermore, it is shown that incorporation of uridine and leucine by oocytes into TCA-insoluble material is significantly greater in granulosa cell-enclosed oocytes than in cocultured oocytes.


Determination of sex by discriminant function analysis of postcranial skeletal measurements. Thieme and Schull [16] took measurements of seven postcranial traits from black skeletons of known sex to devise a method for accurately sexing human remains. With a linear discriminant function analysis of the data they obtained a 98.5% accuracy. The research reported here was designed to assess the accuracy of their method in the hands of other investigators using a sample of the same black population and its applicability to other populations of the same and different races. None of the samples used in this study were sexed with the same rate of accuracy either achieved or predicted by Thieme and Schull. However, two samples did reach 91% or better. Such results suggest that the methods employed have considerable value if used with appropriate precautions. Our multiple discriminant function analysis strongly indicates that neither side nor observer techniques affected the results. Sex accounts for a predominant fraction of the total variation among samples and race accounts for most of that remaining.


Some difficulties in the Gustafson dental age estimations. The Gustafson technique was a significant contribution to forensic identification. Unfortunately, many statistical errors were present in the published articles. It now seems clear that greater precision can be achieved through modification of the original technique. One of the authors (W. R. M.) will report soon on multiple regression formulae that offer both increased precision and technical simplicity.


Identification of mass disaster victims: the Swiss identification system. A new, simple, and reliable forensic identification system has been described. It permits the rapid and positive identification of victims of catastrophies such as airplane accidents, battles, floods, and fires. An electronic microprocessing unit directs a mechanical engraver to encode up to 13 alphanumeric characters on a small gold disk 0.25 mm thick and 2.0 mm in diameter. The identification chip is sealed in a 0.8-mm deep cavity prepared with a specially designed diamond burr in the lingual enamel of a molar tooth. The sealant is a stained composite material shown experimentally to be leakage proof, fire resistant, and readily detectable in teeth exposed to high temperatures. At the identification center the gold disk can easily be recovered and the victim positively identified without recourse to time-consuming comparison of dental records. Minimal training is required for the forensic personnel.


Dissecting coronary artery aneurysm: a report of two cases. Two cases of sudden, unexpected death resulting from coronary artery dissection have been reported. Since sudden and unexpected death falls within medical examiners' jurisdiction, the systematic autopsy examination of such cases offers an opportunity to evaluate this entity as well as other rare causes of natural death. A review of the literature concerning the subject has been presented.


Verifying identification of military remains: a case study. The processing and reprocessing of repatriated remains of military personnel in the U.S. Army Central Identification Laboratory, Thailand, were a complex set of laboratory and administrative procedures. These procedures had been standardized and systematized to comply with the requirements of the case papers generated for each set of remains examined. Supplementary osteological data, obtained during laboratory examination but not requested by the standard forms, revealed additional information that suggested that the history of the remains was somewhat different from the accounts reported in the accompanying records or in the accounts related by the former inmates of the prison camps in North Vietnam.


Further alleles of phosphoglucomutase in human semen detected by isoelectric focusing. A technique for identifying further alleles of PGM1 in human semen detected by isoelectric focusing has been described. A survey of 100 semen samples has shown that there was close agreement between the observed and expected gene frequencies of these new alleles on the basis that there were four common alleles determined by the PGM1 locus and not two as originally proposed [1,2]. The use of these new genetic variatns of PGM will considerably enhance the investigation of semen stains in forensic science.


A stability study of the esterase D isoenzymes. A study of the changes in electrophoretic patterns of EsD 1 and 2--1 phenotypes in progressively aging bloodstains was carried out and resulted in the establishment of criteria for the proper interpretation of such patterns. With these criteria, the EsD isoenzymes in dried bloodstains were found to have a maximum stability of four weeks. While degradation of the isoenzyme in fluid blood at 37 degrees C was complete by the third day, instability was not detected until the sixth week in fluid samples stored at 3 degrees C; the presence or type of anticoagulant had no observable effect on the 3 degrees C samples. When fluid blood was stored at room temperature, the presence of anticoagulant and preservative did not enhance the stabilityof EsD. Critrate-fluoride did not produce any observable effect; heparin, oxalate, and EDTA increased the rate of degradation, with EDTA being the most detrimental, reducing the stable period to three days.


Factors influencing gastric emptying.

Factors influencing gastric emptying. Gastric emptying time may be of investigative value and evidentiary significance in estimating the time of death. However, in order to express an expert opinion with a degree of certainty, the time, volume, and character of the last meal must be known, and other factors considered. The maximum normal emptying time for the healthy intact stomach is 6 h. Factors accelerating or delaying gastric emptying include fear and apprehension, acute and chronic diseases, trauma, drugs, and the stomach that has undergone surgery. Recognition of these influences supports the conclusions that the forensic pathologist draws regarding the interval between the last meal and death.


Sudden coronary deaths associated with sexual activity. Two cases of sudden coronary deaths occurring in circumstances of unusual sexual activity are reported. Previous recorded cases are reviewed and the subject is discussed as regards the magnitude of the problem, its circumstances, the mechanisms involved, and the preventive measures to be adopted.


Enuresis, firesetting, and cruelty to animals: the significance of two thirds of this triad. The full childhood triad of enuresis, firesetting, and cruelty to animals is seldom reported by patients in acute care psychiatric facilities. Two of the three elements have been reported with greater frequency and constitute useful diagnostic information. Literature on the triad has been reviewed and data from three studies have been presented. The authors concluded that a history of two thirds of the triad is significantly associated with aggressive behaviours directed against people.


Human plague in New Mexico: report of three autopsied cases. Plague is a deadly disease of obvious concern to individuals, communities, and public health officials. The rapid recognition of plague victims is of paramount importance in saving the lives of the victims and in the protection of contacts. Three autopsied plague cases have been presented and the pathological features have been discussed.


A new approach to upper cervical injuries. Severe injuries to the upper cervical region can be the cause of death. Standard autopsy techniques are inadequate for examination of this area. Therefore a technique has been developed that gives excellent visualization and allows removal of the brain and spinal cord in one piece. With the body prone a midline incision is made from the top of the head to the sacrum. The skull is sawed in a circle from one side of the foramen magnum around the top of the skull to the other side of the foramen magnum. The lamina of the neural arches of the vertebral column are sawed. With the removal of the piece of skull and the posterior portions of the neural arches, the posterior half of the cerebral cortex, cerebellum, and entire spinal cord are exposed. The entire brain and spinal cord can be removed as a unit. Cases are selected by history, X-ray examination, or floppy head. Four cases in which this approach has been helpful are briefly mentioned.


The screening and quantitation of diazepam, flurazepam, chloridazepoxide, and their metabolites in blood and plasma by electron-capture gas chromatography and high pressure liquid chromatography. A combined GLC-ECD and HPLC procedure has been developed for the analysis of the most commonly encountered benzodiazepine drugs and has been applied to both plasma and postmortem blood samples. There is no doubt that since their introduction the use of these sensitive analytical methods have resulted in an increase in the incidence of detection of these drugs in both clinical and forensic toxicology cases.


Determination at the nanogram range of rilatinic acid in urine after ion-pair extraction. Ion-pair extraction and extractive alkylation of urine allows a simple, rapid, and very sensitive detection by TLC as well as EC-GLC tecnhiques, of rilatinic acid in small urine samples after the oral intake of therapeutic doses of methylphenidate.


Fatal intoxication from 3,4-methylenedioxyamphetamine. The symptoms of MDA intoxication exhibited by the decedent prior to death closely mimic those of acute amphetamine poisoning: profuse sweating, violent and irrational behavior, and stereotypically compulsive behavior. Therefore, if amphetamines are not detected in specimens from a person displaying classic symptoms of amphetamine poisoning, hallucinogenic amphetamine derivatives may be considered. In the case described, a divided dose of 850 mg of MDA ingested within 2 h and 15 min was sufficient to cause the death of a 24-year-old male, 4 h after the final dose. While the methaqualone may have contributed to the demise of the decedent, the authors think that the MDA itself was sufficient to cause death. Results of limited recovery studies of MDA extraction from blood and elution from TLC plates supported the observations of Cimbura [13]. Approximately 85% of MDA is extracted by the method described and its elution from TLC plates is quantitative. This case points out once again the dangers of false advertising in the illicit market. The decedent, himself a dealer in the illicit drug market, and all present at the party believed the ingested white powder to be a mixture of morphine, LSD, and amphetamine, hence MDA. They were totally unfamiliar with 3,4-methylenedioxyamphetamine, MDA.


Correlates of outcome following acute glutethimide overdosage. Potential predictors of outcome following acute glutethimide overdosage were assessed in 63 patients hospitalized with this diagnosis at a large urban medical center between 1962 and 1975. Their mean age was 34 years (range, 15 to 84 years) and 62% were female. Assisted ventilation was required in 59% of cases, and 32% developed hypotension. Six patients died, including all three aged 60 years or older. Multiple regression analysis confirmed that age was the major identifiable determinant of survival, regardless of other factors. Among identifiable determinants of coma grade, glutethimide dose, glutethimide plasma concentration, and coingestion of barbiturates were the most important. An ingested dose of 10 g or more, or a plasma concentration exceeding 30 microgram/ml, was almost always associated with deep coma. However, a relatively small ingested dose or a low plasma level by no means ruled out development of serious intoxication, particularly in those patients who also ingested barbiturates. Thus elderly individuals are at high risk for fatal outcome following glutethimide overdosage and should receive priority for intensive care and monitoring. Glutethimide dose, plasma concentration, and history of coingestion of barbiturates are of value in predicting development of deep coma. These items of information should be obtained on admission whenever possible.


Modification of a voltage-gated K+ channel from sarcoplasmic reticulum by a pronase-derived specific endopeptidase. AK+ -selective membrane conductance channel from rabbit sarcoplasmic reticulum (SR) is studied in an artificial planar phospholipid bilayer. Membranes containing many such channels display voltage-dependent conductance, which is well described by a two-state conformational equilibrium with a free energy term linearly dependent on applied voltage. Pronase-derived alkaline proteinase b (APb), when added to the side of the membrane opposite to the SR vesicles (trans side), reduces the voltage dependence of the K+ conductance. Single-channel fluctuation experiments show that after APb treatment, the channel is still able to undergo transitions between its open and closed states, but that the probability of forming the open state is only slightly voltage-dependent. In terms of the conformational model, the enzyme's primary effect is to reduce the effective gating charge of the opening process by over 80%; a second effect of APb is to reduce the internal free energy of opening from +1.2 to +0.4 kcal/mol. The kinetics of APb action are strongly voltage-dependent, so as to indicate that the enzyme can react only with the channel's open state. The results imply that the channel contains a highly charged polypeptide region which moves in the direction perpendicular to the membrane plane when transitions between the open and closed states occur. A lysine or arginine residue in this region becomes exposed to the trans aqueous solution when the channel is in its open conformation.


Inotropic effects and changes in sodium and calcium contents associated with inhibition of monovalent cation active transport by ouabain in cultured myocardial cells. Cultured monolayers of spontaneously contracting chick embryo ventricular cells were perfused with culture medium containing ouabain. Contractile state was monitored by an optical-video system recording amplitude and velocity of cell wall motion. Positive inotropic effects of 2.5 x 10(-7) to 10(-6) M ouabain were manifest within 1.5-2 min, and reached a stable plateau within 5-6 min. The inotropic effect was fully reversed within 5 min after washout of ouabain. Inhibition of uptake of 42K+ (or the K+ analog 86Rb+) and efflux of 24Na+ occurred 1.5-2 min after exposure to ouabain. The degree of inhibition of transport was closely related to the magnitude of the positive inotropic effect throughout the ouabain concentration range 10(-7) to 10(-6) M. After washout of ouabain from monolayers, the monovalent cation active transport rate returned to normal within 1 min. Thus, both the onset and offset of inotropic action of ouabain were closely related temporally to inhibition of the sodium pump. Exposure to ouabain caused significant increases in exchangeable Na and Ca contents that appeared to be developed within 5 min. These data support the hypothesis that inhibition of monovalent cation active transport by ouabain is causally related to the development of positive inotropy and are consistent with modulation of Ca content by intracellular Na+ via the Na+-Ca2+ exchange carrier mechanism.


Selective hepatic uptake of synthetic glycoproteins: mannosaminated ribonuclease A dimer and serum albumin. The influence of mannose-containing oligosaccharides on the tissue uptake of glycoproteins has been examined with synthetic glycoconjugates. Oligosaccharides obtained from the acetolysis of bakers' yeast mannan have been coupled to the lysine residues of the cross-linked dimer of bovine pancreatic ribonuclease A and of human serum albumin by reductive amination with cyanoborohydride. 14C-labeled derivatives of the two proteins containing two to four mannopyranose residues per 10,000 mol wt were administered intravenously to rats. There was selective (70-80%) uptake of these derivatives by the liver within 10-15 min after injection. A minor site of uptake was the spleen. The extent of hepatic uptake was a function of the number and size of the mannooligosaccharide residues coupled. With the nonglycosaminated derivatives the liver uptake was less than 5%. Related studies have shown that mannose-containing glycoproteins are taken up by both the endothelial and Kupffer cells of the liver; thus, reductive mannosamination may provide a means of directing to these cells proteins of potential therapeutic interest.