[Protein digestability and amino acid absorption in various segments of the digestive tract of pigs. 1. Methods of animal experimentation, protein content and amino acid patterns of the digesta in the small intestine and in feces after feeding different feeds].

Re-entrance cannulae were applied by way of operations at the end of the small intestine of a larger number of growing pigs. After a post-operative phase these animals were fed with various rations (N-free diet, fattening feed for pigs, rations with dried skim milk resp. wheat gluten + lysine and wheat + wheat gluten + lysine). During the main experiment periods the ileum digesta (24 hour-periods of collecting) and the feces were quantitatively registered. The protein and amino acid content ascertained in the feed rations, the digesta and feces samples are reported, comparatively evaluated and discussed. The amount of amino acids (in mg per kg intake of dry matter) contained in the ileum digesta after N-free feeding were statistically calculated with regard to differences occuring between the animals and days. For most amino acids a significant decrease in the ileum digesta could be detected during the course of the N-free feeding period. Moreover, the amount of amino acids in the ileum digesta was compared with the metabolic fecal amino acids, from which conclusions could be drawn concerning the disappearance rate of the individual amino acids in large intestine.


Preliminary investigation on the nutritive value of krill meal in the feed of broiler chickens and laying hens.

Krill meal was used as a protein feed in rations for broiler chickens and laying hens and its nutritional effectiveness was studied in comparison with conventional feed-stuffs of animal origin. In experiments with 650 broiler chickens from 1 to 28 and from 29 to 56 days to fattening krill meal was added to the standard feedmixture in lieu of fish meal, and dried skim-milk, and at higher levels also in lieu of soyabean oilmeal. In the experiment with 22 layer hens kept in individual cages 3% of the fish meal were substituted by 3% of krill meal. The performance of chickens fed on diets with krill meal was lower in comparison with analogical groups fed on fish meal. Higher levels of krill meal, exceeding 15 and 11% in the first and second period of feeding respectively, reduced the weight gains and feed intake of chickens. The fatty acid C14, C18 and C18:1 content of internal body fat was changed in chickens fed on higher levels of krill meal. In the experiment with hens krill meal decreased the feed efficiency, the pigmentation of egg yolks, however, was more intensive and the vitamin A content of yolks was increased in comparison with the control group. The results show that krill meal can be used as a partial substitute of fish meal in the feed of broilers and hens.


[Formation of the microcirculatory bed of the muscle coat of the wall of the sigmoid colon during human fetal development].

During intrauterine life microcirculatory bed of the muscular coat is forming and developing in accordance with its differentiation, growth and functional changes at various steps of its ontogenesis. This step-like differentiation in the parts composing the microcirculatory bed and the whole microcirculatory network of longitudinal and circulatory layers of the muscular coat is genetically connected with differentiation taking place in the wall of the sigmoid colon during the developmental period studied and, in the end, reflects morphological maturation of the sigmoid colon at different stages of its individual ontogenesis.


[State of the rat thyroid gland in coarctation of the abdominal aorta].

In order to study connections between blood vessels and follicular thyrocytes, the method of modulation (a purposeful change of state in one element with registration of states in other elements of the system) was used. In rats chronic increase of blood stream was produced in the thyroid gland; in 15 days it was 54% as high as in the control. The volume of the vascular bed increased by 28% and that of follicles by 26%. Volumetric ratio between the thyroid epithelium and colloid did not changed. Follicular thyrocytes grew high and the nuclear volumes of these cells increased. Thyrocytes greately varied in their height. The number of mast cells in the thyroid gland remained the same. Iodine absorption by the thyroid gland increased as it is dependent on the volume of the vascular bed of the organism (+0.82). The data obtained demonstrate a significant connection existing between the follicular thyrocytes and blood vessels.


[Ultrastructural organization of the brush alveocytes of normal and hypertrophic rat lungs].

In non-inbred male rats, 140-200 g of body weight, the left lung was removed. In the right lung of the experimental and intact animals, brush alveolocytes were revealed electron microscopically and their structural organization was stated 1, 3, 7, 30 and 274 days after the operation. It was stated that during the process of compensatory hypertrophy in the lung, the occurrence rate of these cells increased considerably. In controls only 3 such cells were revealed, while in the experiment, the number of the brush alveolocytes was 20. In the experiment, most of the cells had signs of hyperfunction: increased amount of pinocytic vesicles in the apical part of the cell, dilated canaliculi in granular cytoplasmic network, formation of "laminar" structures from the membranes of the canaliculi of the granular cytoplasmic network. The brush alveolocytes were especially active during the period of acute alveolar hypertrophy (5-7 days after the operation) and correlated with the state of alveolar surfactant. The data obtained supported the hypothesis on chemoreceptor nature of the cells in question and demonstrated their participation in regulation of alveolar surface tension.


[Effect of orotic acid on reparative processes in the lungs following pneumonectomy].

The effect of orotic acid on pulmonary regeneration has been studied in mature rats after left-sided pneumonectomy. A complex morphometric analysis of the pulmonary parenchyma during the process of compensatory-hypertrophic rearrangement has been carried out; mitotic activity of cells in the interalveolar septae, peculiarities of DNA synthesis and those of enzymatic status in lymphocytes of the peripheral blood have been determined. As the investigations have demonstrated, the administration of orotic acid during the postoperative period contributes to a more complete regeneration of the lung volume, alveolar surface, results in formation of new alveoli, prevents the development of morphologic long-term decompensation following pneumonectomy. Activation of the alveolar cells proliferation and increased DNA synthesis are the main stimulating effects of orotic acid. Certain correlative connections are revealed between the course of pulmonary regenerative processes and the enzymic status of circulating lymphocytes.


[Changes in rabbit thymus lymphoid tissue after administration of pyrogenal and hydrocortisone].

After a single administration of pyrogenal (0.2 and 5 mkg/kg) and hydrocortisone (100 mg/kg) histological changes in the rabbit thymus have been studied and compared with the level of 11-oxycorticosteroids (11-OCS) in blood of the animals under investigation. Hydrocortisone, while producing a considerable rise in the level of 11-OCS, increases the number of degenerating cells, inhibits mitotic activity and decreases the amount of lymphocytes per stipulated area unit in the cortical substance. Changes produced in the thymus after pyrogenal administration are similar to those produced by hydrocortisone administration but are pronounce much weaker, that is connected with concentration of corticosteroids circulating in blood.


[Functional interrelationships of the sympathetic nervous system and the hypothalamo-hypophyseo-adrenal complex].

Adrenal and hypothalamic structure has been studied in mice at functional inhibition of the sympathetic region of the vegetative nerve system by means of antibodies against the nerve growth factor. Routine histological, histochemical, morphometric, electron microscopic and radioautographic methods have been applied. In the experiment the hypothalamic region is in the state of a continuous functional stress which is evident from enlargement of neurons and their nuclei in the macrocellular neurosecretory nuclei of the hypothalamus. The method of radioautography proves increasing activity in synthetic processes taking place in supraoptic, paraventricular and ventromedial nuclei of the hypothalamus and in the medial habenular nucleus of the epithalamus. In 30-day-old mice certain structural changes have been revealed in the adrenals demonstrating an increasing activity in their cortex: blood vessels are dilated, cholesterine, lipid and ascorbic acid granules are not evenly distributed, enzymatic activity in cytoplasm of adrenocorticocytes is increased. Ultramicroscopic destructive and regenerative alterations have no definite zonal specificity, nevertheless they are more pronounced in the fascicular zone. Radioautographic and morphometric investigations demonstrate an increasing functional activity in glomerular and fascicular adrenal zones. Taking into account morphologic demonstration of functional stress in hypophysial adenocytes in the same animals (Molostov O. K., 1974), it is possible to conclude that lesions in the sympathetic system center result in adaptive reaction of the hypothalamo-hypophysial system which, in its turn, produces reactions in the adrenals and in the vascular complex. This interconnection is accompanied by the reaction depending on breaking off direct sympathetic effects in the adrenals and vessels.


[Quantitative analysis of the structure of the varicose dilatations in the nerve fibers of the rabbit coronary artery (according to the results of three-dimensional reconstruction)].

Axoplasmic vesicles and microtubes in varicosities of axonal plexus in the external sheath of the rabbit coronary artery have been studied. Comparing serial sections and examining three-dimensional reconstruction of small nerve plexus, it was demonstrated that various varicosities differed only in their correlation of the amount of small (30-80 nm) and large (80-180 nm) vesicles. Average diameters in profiles of small and large vesicles are 56.3 nm and 115.6 nm, respectively. There are varicosities containing about 250 or more than 1,000 vesicles. Evenly distributed vesicles throughout the volume of varicosities and lack of specialized structures on the axolemma are supposed to demonstrate the absence of special areas for the mediator removal in the axons studied. The microtubes in the varicosities are peripherally arranged, next to the axolemma and form 1-1.5 wide coils. A suggestion is made that the varicosities in neighbouring axons of the same nerve plexus, with specific structural organization, are special functional units and appear to be peculiar not only for nerve plexus of the coronary artery, but also for other parts of the peripheral vegetative nerve system.


[Quantitative characteristics of components of the placental barrier of women with uncomplicated full-term pregnancies].

Placentas from four healthy women have been studied electron microscopically after urgent spontaneous deliveries. In every placenta 130-200 resorptive villi of the chorion were photographed. The results on morphometric analysis of 1,205 electronograms of the placental barrier are presented. At full-term uncomplicated pregnancies all components of the placental barrier (syncytium, cytotrophoblast, basal membrane of the trophoblast, stromal connective-tissue layer, basal membrane and endothelium of fetal capillaries) have been stated to demonstrate rather stable quantitative characteristics (see Table in the text). The quantitative data obtained can serve for electron microscopic investigation of placenta at different pathologic states of the mother and the fetus, make it possible to differentiate more precisely physiological and pathological changes in placental ultrastructure.


[Coelomic gonadal epithelia during the period of human embryonic morphologic sex differentiation].

The course of divergent differentiation of coelomic epithelium in the indifferent gonad has been traced up to the stage when morphological sex signs are distinctly seen. Eleven human embryos fixed in Carnoy and Bouin's fluid have been studied from 6 to 10 weeks of gestation. Paraffin sections were stained with hematoxylin, ferric hematoxylin after Heidenhain. Basal membrane fibres were revealed by silver impregnation after Karupu. PAS-reaction after McManus and additional staining with hematoxylin and light green were applied, as well as the reaction for total proteins with bromphenol blue after Miguel--Calvo. Sex differentiation of coelomic epithelium in the gonad developing according to the male type begins a little later than in the ovary. In the epithelium of the forming testis a great amount of mitotic figures is observed that might be connected with the presence of Y-chromosome stimulating cells for extra mitotic cycles. The increasing presence of Y-chromosome stimulating cells for extra mitotic cycles. The increasing number of mitotic figures in the epithelium should be considered as a sign demonstrating that differentiation according to the male type has started. Superficial epithelium of the embryonic ovary has a peculiar false pseudostratified structure. This secures cellular reserve for the ovarian cortex formation from the external epithelium. The apical surface of the cells in the external epithelium has a border which is evidently formed by microvilli and revealed by PAS-reaction and bromphenol blue. Ovarian follicular cells and Sertoli's cells (sustentocytes) in testis have the common origin in the human fetus--from coelomic epithelium of the gonad germ.


[Skeletal muscle ultrastructure of untrained humans and animals after physical loading].

In non-trained mice subjected to a single and repeated swimming up to complete wearness, fibres in the skeletal muscles demonstrated certain ultrastructural alterations in their nuclei. Twenty-four and 48 h after a single swimming many muscular nuclei have only non-condensed chromatin. After repeated swimming large clumps of condensed chromatin appear in most of the muscular fibre nuclei. These nuclear changes are accompanied by segregation of separate fibrillar areas containing nuclei. Similar phenomena are also noticed in muscular fibres of non-trained people after a single physical loading. Ultrastructural changes in skeletal muscular fibres of volunteers, nonsportsmen are of individual character and depend on the degree of wearness resulting from the loading. In people subjected to the experiment and having severe fatigue (disability to work) significant shifts in submicroscopical structure of the fibrillar components were observed: in mitochondria, sarcoplasmic reticulum, T-system, contractile apparatus, etc. In this case, matrix becomes clear, lysis in mitochondrial crysts, dilatation of terminal cysterns of the sarcoplasmic reticulum and T-system tubes, destructive and regenerative processes in the contractile apparatus are observed. The data obtained demonstrate varied changes in ultrastructure of different components composing skeletal muscles of the non-trained organism subjected to physical loading.


[Histological classification of stomach cancer and its prognostic value].

The morphology of stomach carcinoma was analysed in relation to the longevity of the patients after a radical operation for 1958--1967 (513 observations). The highest prognostic importance was found to belong to such factors as the presence of metastases in the perigastral lymph nodes, the depth of the tumour outgrowth through the stomach wall, the pattern of the tumour growth in relation to the surrounding tissue (pushing back or infiltrating), mucus formation in the tumour, the reaction of the tumour stroma and the surrounding tissue in the form of infiltration with lymphoid or plasma cells. The histological form of the tumour by itself as well as the degree of its structural differentiation are of little value for the prognosis. From the foregoing, a histological classification of stomach carcinoma is suggested including the two main histological forms of stomach carcinoma: adenocarcinoma and carcinoma simplex, and reflecting most prognostically important features of the tumour.


[Benign non-epithelial tumors of the stomach].

Six cases of mature non-epithelial tumours of the stomach are described; epithelioid leiomyoma, leiomyoma, lipoma, two fibromata and angiofibrolipoma. Noteworthy is the extremely rarely occurring epithelioid leiomyoma. In one case, lipoma and chronic peptic ulcer coexisted. All the stomach tumours under study were mature benign ones, but some of them presented a clinical course with signs of malignancy probably due to the endogastric growth of the tumour, its dimensions, and its localization near the stomach outlet, as well as to the breach of integrity of the mucous membrane above the tumour.


[Morphology of experimental tumors of the sympathetic nervous system].

Morphology of experimental tumours of the sympathetic nervous system in rabbits and hamsters induced by administration of nitrose compounds and the use of modifying factors was studied. The tumours were localized in the mediastinum, retroperitoneal space, adrenals and kidneys. The predominant involvement of the female animals was observed. Histological, histochemical and electron microscopic study of 33 tumours of the sympathetic nervous system was carried out. The tumours were classified as ganglioneuromas, ganglioneuroblastomas and sympathoblastomas by their degree of maturity. The experimental tumours by their structure were similar to the analogous neoplasias of man.


[Correlation analysis of the organometric heart parameters under normal and pathological conditions].

An organometric study of 27 heart parameters normally, in hypertension, chronic nonspecific pulmonary diseases and ischemic heart disease was carried out. Significant differences in the heart weight values under normal and pathological conditions were found. A correlation analysis of the heart parameters normally and pathologically was performed revealing specific associations for each group of pathology. Increased associations were observed between heart weight values and its parts and the linear-planimetric parameters in the groups of ischemic heart disease and chronic nonspecific pulmonary diseases.


[Morphological characteristics of acute viral hepatitis].

From the literature and their own observations the authors present morphological criteria of acute viral hepatitis which may be used for differential diagnosis from hepatites of other etiology (toxic, drug). Examinations of liver biopsies from patients with viral hepatitis permit to establish the stage of the disease and to predict its possible outcomes.


[Use of morphometry in pathological anatomy].

The paper describes the main principles of morphometry and its concepts and characterizes the potentials of the morphometric methods. Statistical sampling and conditions of preserving its representative character are dealt with. The implications of some concepts of variation statistics are analysed: mean values, variability indices, confidence intervals, thresholds of confidence probability, criteria of significance, regularities of the distribution of frequencies of sampling elements. The main rules of the factor, correlation, regression, dispersion, and information analysis are described. Attention is drawn to the insufficient use of morphometry potentials. It is stated that morphometric description should not overshadow the specific features of the structures under study.


[2 cases of  hemangioendothelioma of the liver and the spleen].

Hemangioendothelioma of the liver and spleen with similar affection of the organs resembling a bloody sponge was diagnosed histologically in men of 35 and 59 years. Microscopically, the structure of the tumour presented a picture of multiple ugly vascular fissures and cavities lined with atypical polymorphous endothelial cells not infrequently transformed into giant cells with hyperchronic nuclei. Impregnation of the sections with silver nitrate according to Gomori revealed an irregular vascular network and facilitated the recognition of the true nature of the disease.


[Malignant carcinoid tumor of the bladder].

One of the first observations of malignant carcinoid of the urinary bladder in a man of 42 is described. Histologically the tumour resembled solid-alveolar transitional cell carcinoma. The carcinoid was verified by finding in the tumour cells electron dense endocrine granules and helix-like rough endoplasmic reticulum. Possible sources of urothelium carcinoid development are discussed.


[Oleogranulomatosis of the lung as a late complication of oleothorax in a patient with pulmonary tuberculosis].

An observation of total oleogranulomatosis of the lung developing in a patient as a rare complication of extrapleural oleothorax used for treatment of infiltrative pulmonary tuberculosis is described.


[Generalized sarcoidosis with the involvement of the brain].

A rare case of generalized sarcoidosis with the involvement of the brain is presented. Death occurred as a result of the sarcoid affection of the central nervous system, granulomatous vasculitis of the brain meninges and substance.


[Insecticide poisoning. Microdissection of nerves and muscle histochemistry in 10 cases].

A sural nerve and a muscle biopsy study of patients with chronic insecticides poisoning, with teased fiber preparations, routine pathologic studies of nerves and histochemistry of muscle is reported. The sural nerves of ten patients were studied and a teased fiber preparation was done in nine. The tenth patient had only fibrosis and no myelin was found. The sural nerves were abnormal in all patients and the teased fiber preparation resulted in preponderance of type C, D and large amount of G type fibers, according to Dyck's classification. These fibers had enlargement of the axon and myelin sheath, also seen in routine sections. The muscle biopsy with routine and histochemistry methods was done in 8 cases; in 6 there was found signs of denervation; the remaining cases were normal, but these were proximal muscles. The authors conclude that the process primarily interfere with the functions of the axons, with distal axonal degeneration and a dying back phenomen.


[Involvement of the central nervous system in cysticercosis].

The involvement of the central nervous system in cysticercosis was demonstrate as an incidental finding in a frequence of 0,3% in 4000 autopsied cases. Most of the 12 patients came from rural areas of the State of Bahia. The low frequence compared to other sites reported in Brasil shows that the neurcysticercosis does not represent an important problem in Bahia. The host tissue response observed was represented by a chronic fibrosing inflammatory type of reaction. This study points out the importance of the methenamine silver stain (Grocott) in the identification of the degenerated embryo inside the fibrous and/or calcified lesions.


[Prophylactic antibiotics in neurosurgery].

The post-operative infection-rate in neurosurgical patients who received prophylactic antibiotics was compared to the infection-rate of patients who received no antibiotics. None of the 73 studied patients had pre-operative infection. Infections occured in 26,4% of the patients in the first group and in none of the second group (p less than 0,2); 27,5% of the patients with intracranial lesions and 9% of the patients with spinal lesions in the frist group had post-operative infections, and none in the second group (p less than 0,05 and 0.05 less than p less than 0.1). 67% of all the patients had severe neurological lesions; 27% of these had post-operative infections; only 4% of the patients with mild lesions had infections (p less than 0.05). Post-operative infections were severe and fatal in most of these cases. Prophylactic broad-spectrum antibiotics were of no value in preventing post-operative infections in these neurosurgical patients and those who received no antibiotics had a significantly lower rate of infections.


[Adult form of Niemann-Pick disease associated with Osler-Rendu-Weber syndrome. Report of a case].

The case of a 28-year-old female with an adult form of Niemann-Pick disease is described. The illness started at the age of 22 years. The characteristics actually established in the adult form of this lipidosis were discussed. Vision was impaired but there was no clinical evidence of importnat visual involvement. Neurologic and psychiatric examinations were always normal. The bone marrow contained foam cells. A cherry red spot was present in the macula. An uncommon association with Osler-Rendu-Weber disease was described. The patient maintained normal clinical and neurological conditions, that is, she continues to show an extraordinarily benign course with poor cerebral participation represented by a moderate localized cortical atrophy seen at the pneumoencephalogram.


[Transverse myelopathy and systemic lupus erythematosus. Report of a case and review of the literature].

A case of transverse myelopathy in systemic lupus erythematosus with subacute onset and fatal course is reported. A review of the literature is done and clinical, laboratorial, therapeutics and pathological aspects are discussed. The authors call attention to the poor results of therapy and discuss the participation of immunological factors leaving to demyelination which are, aside the classical vascular involvement, the probable mechanisms in the neurological manifestations of systemic lupus erythematosus. The authors believe that, in their case, such a demyelinative mechanism was responsible for the clinical picture, although a necroscopic examination was not allowed.


[Diabetes insipidus after myelography. Report of a case].

The case of a 28 year-old man in whom diabetes insipidus appeared 24 hours after Pantopaque myelography is reported. This unusual complication, not previously reported, probably was caused by a hypersensitivity reaction or mechanical-irritative effect on the hypothalamic-hipophyseal area produced by suprasellar Pantopaque droplets, demonstrated by skull x-rays. The patient improved after being treated with steroids. Some serious complications of myelography can be prevented by avoiding supratentorial spillage of Pantopaque.


Optic disc parameters and onset of glaucomatous field loss. I. Methods and progressive changes in disc morphology.

Serial stereoscopic fundus photographs taken in known relationship to the onset of glaucomatous visual field loss on 12 eyes were intermixed with those from 206 age- and race-matched controls and analyzed in randomized masked fashion. Progressive changes in the size, shape, or contour of the disc, and a newly described parameter, thickness of the nerve fiber layer as it crosses the disc rim, were readily apparent by the time of onset of glaucomatous field loss in all but two abnormal eyes (one case). In the latter instance, direct comparison of stereophotos indicated progressive pallor of the remaining disc tissue. Serial stereophotographs appear superior to fundus drawings for anticipating glaucomatous field loss.


Optic disc parameters and onset of glaucomatous field loss. II. Static screening criteria.

Stereoscopic fundus photographs of 17 abnormal eyes, taken in known temporal relationship to the onset of glaucomatous visual field loss, and 206 eyes of age- and race-matched controls were examined in randomized masked fashion. Width of the narrowest remaining disc rim, size of the vertical and horizontal physical cups, contour of the temporal and nasal slopes (vertical ovalness), and a newly described parameter, thickness of the nerve fiber layer as it crosses the disc rim, were all useful for distinguishing patients with impending or established visual field loss. None, however, was as effective as defects in the nerve fiber layer, the only parameter displaying sufficient promise as a clinical screening tool to warrant initiation of large-scale prospective evaluation.


Multivariate analysis of the risk of glaucomatous visual field loss.

In a retrospective study, 92 patients with ocular hypertension, ie, intraocular pressure of 21 mm Hg or higher, and no evidence of glaucomatous visual field defects, were observed for five years. Visual field defects developed in one or both eyes of 33 patients during the five-year follow-up period, while none were detected in the remaining 59. Values for suspected risk factors, determined at the outset of the follow-up period, were subjected to a multivariate analysis with use of linear discriminant analysis and a multiple logistic function. Models of risk providing maximum separation of the two patient groups (visual field loss vs no visual field loss) found that the risk factors having the greatest significance for prediction of visual field loss included vertical estimates of cup/disc ratio, mean IOP during the period of observation, a positive family history of glaucoma, and age. Factors having the lowest predictive values included IOP response to topical dexamethasone, plasma cortisol suppression, and a history of systemic hypertension.


Optic nerve decompression. Presumed postoperative development of medullated nerve fibers.

A child had an inoperable arterial venous malformation with chronic papilledema first noticed at age 7 months. Bilateral optic nerve decompressions were performed with satisfactory results. What appeared to be medullated nerve fibers developed in the retina of one eye 5 1/2 months after surgery.


Comparison of photo slit lamp and fundus camera photography of the optic disc.

The photo slit lamp has characteristics that may be important in optic disc photography for measuring glaucomatous cupping. This finding led to the question of whether disc photographs with the slit lamp showed less detail than fundus camera photographs. Tests were conducted on in-air resolution and of each instrument's ability to record fine vessel detail in normal human optic discs. The results showed that the instruments performed comparably in each test.


Ultrasonographic features of choroidal malignant melanomas.

In a 12-month period 26 eyes were enucleated after an ultrasonographic diagnosis was made of malignant melanoma of the choroid. Histologic features of the tumors were reviewed. The ultrasonographic diagnosis was correct in 100% (26/26) of enucleated eyes. Spontaneous vascular movement (SVM) was identified by standardized A-scan echography in 69% (18/26) of the tumors. Contact B-scan ultrasonography demonstrated choroidal excavation in 65% (17/26) of the melanomas. During the 12-month study period, choroidal excavation was also demonstrated in cases of metastatic choroidal tumors, hemangiomas of the choroid, and long-standing choroidal nevi. The standardized A-scan finding of SVM is a compelling sign in the diagnosis of choroidal malignant melanoma. In contrast, the B-scan finding of choroidal excavation is a less useful sign since it may also be seen in various other ocular lesions.


Use of air to decrease endothelial cell loss during intraocular lens implantation.

We performed 26 consecutive intracapsular cataract extractions with lens implantation. The last 17 implantations were performed with air instilled in the anterior chamber, whereas the first nine operations were performed without air. The central corneal endothelium of each eye operated on was photographed before and within five days after lens implantation. A computer analysis of the endothelial photographs showed that, on the average, 32% of the central corneal endothelial cells were lost during lens implantation without the use of air and 15% were lost when the lens was implanted with air. Increased endothelial cell loss was significantly correlated with the failure to implant the lens with use of air, with increased operative endothelial trauma, and with higher postoperative intraocular pressures. A significantly larger increase in corneal thickness on the first postoperative day occurred in patients with larger or more varied cell sizes preoperatively.


Posterior scleritis. A cause of diagnostic confusion.

The referring diagnoses in seven women with posterior scleritis included intraocular neoplasm, retrobulbar tumor, choroiditis, and idiopathic central serous choroidopathy. In all cases, a localized area of intense posterior scleritis was responsible for the misdiagnosed ocular findings. Features that helped to correctly identify posterior scleritis were as follows: female sex; a history of anterior scleritis; a fundus mass the same color as normal adjacent pigment epithelium; choroidal folds; serous retinal detachment with cloudy fluid; early pinpoint leaking spots from fluorescein angiography; and thickening of the posterior coats of the eye, retrobulbar edema, and high internal reflectivity on ultrasonography. Corticosteroids given for retrobulbar or systemic effect provided effective treatment.


Müller's muscle excision and levator recession in retracted upper lid. Treatment of thyroid-related retraction.

The results of excision of Müller's muscle with or without recession of the levator palpebrae superioris aponeurosis were examined in 61 upper eyelids of 40 patients. The cosmetic results were acceptable in 35 patients (56 upper eyelids). Another five patients had a subsequent unilateral partial (nasal) or total ptosis, which was successfully treated with additional surgery. Overcorrections (ptosis) have ceased to be a problem since modifications to the original technique have been used. Only one undercorrection was encountered, and it was treated successfully with a simple surgical procedure. We believe that the described procedure is desirable for the treatment of thyroid-related upper eyelid retraction because it is simple, is based on anatomic and physiologic principles, is tailored to the individual patient intraoperatively and yields consistently good results.


Vitamin E in kitten oxygen-induced retinopathy. II. Blockage of vitreal neovascularization.

The effect of vitamin E (tocopherol) on oxygen-induced retinopathy was studied in the kitten after a quantitative scoring system was developed for their India ink injected retinal flat preparations. In 75 previously described kittens exposed to two or three days of oxygen from day 3, treatment from day 1 with vitamin E or placebo disclosed that kittens treated with vitamin E had less retinopathy. Theories of the mechanism of action of vitamin E would predict that, if given only after the oxygen exposure, vitamin E should be ineffective. This was tested in 37 kittens with placebo or drug begun only after withdrawal from oxygen. Unexpectedly, significantly less intravitreal neovascularization was found in kittens treated with vitamin E after oxygen exposure.


Extratemporal facial nerve grafting and radiotherapy.

Nineteen patients with extratemporal facial nerve grafting procedures and 13 patients with facial hypoglossal anastomosis were followed up with serial photographs for at least one year. The photographic analysis of the results demonstrates that radiotherapy had a detrimental influence on the return of facial movements after extratemporal facial nerve grafting.


Prospective tympanometry in 3-year-old children. A study of the spontaneous course of tympanometry types in a nonselected population.

For six months we observed all 3-year-old children showing type B or C tympanograms at a prevalence study in a geographically limited area (372 ears or 37.2% of the screened total) to study the spontaneous course of middle ear effusions. A considerable test-retest stability was found only for type B. In type C, such stability was equally rare whether the middle ear pressure was highly or only slightly negative. Conversion to type A was observed in about 70% of cases. Ears having a middle ear pressure from -100 to -199 mm H2O almost always returned to normal. The tendency for a negative middle ear pressure or middle ear effusion to develop was the same for both sexes. Conversely, the prognosis of an effusion, once formed, differed significantly, with only girls showing a brief course. Accordingly, a sex-differentiated evaluation appears to be needed in preschool tympanometric screening, and should be included in all clinical considerations when middle ear effusion is demonstrated in young children.


Effects of pentobaribtal and ketamine on brain stem auditory potentials. Latency and amplitude intensity functions after intraperitoneal administration.

Latency and amplitude intensity functions of two short latency (less than 5 ms) components (I and IV) of the brain stem auditory potentials were recorded from scalp electrodes in 18 paralyzed, hooded rats breathing with the assistance of artificial respirators. Averaged responses were obtained in three groups of rats before and 30 minutes after intraperitoneal injections of saline, ketamine hydrochloride (Ketalar), and pentobarbital sodium. Although both ketamine and pentobarbital significantly decreased heart rate and altered the gross EEG, they did not significantly change the latency or amplitude intensity functions of the two evoked-potential components.


Management of advanced and recurrent facial carcinoma.

I report five cases of advanced and recurrent facial carcinoma to illustrate the extent to which such disease can develop and yet be compatible with life. Radical treatment approaches are used so as to maximize the chances for tumor ablation and survival as well as for restoration of function and cosmetics.


Electrocochleography of ears with mumps deafness.

Electrocochleography was performed on 16 affected ears of 15 deaf patients whose deafness had resulted from the mumps. Although pure-tone audiometry showed no response in each case, the cases of mumps deafness can be classified into the following three types of cochlear impairment according to the cochlear microphonic (CM) response: (1) no action potential (AP) response but a well-developed CM response, with impairment at the neural level and probable functioning of Corti's organ; (2) absence of both the AP CM responses, with severe impairment of both the neural regions and Corti's organ; (3) no AP response but a decreased CM response, with severe impairment of the neural regions and partial impairment of Corti's organ.


Squamous cell carcinoma of the tonsil and tongue-base region.

From 1969 through 1975, 145 patients were treated for squamous cell carcinoma of the tonsil and tongue-base region; 119 received initial treatment, and salvage operations were done in 26. The overall five-year survival rate was 42%. Cervical metastasis was the most important determinant of survival. Pathologic stage I or II disease was controlled by surgical treatment. In patients with stage III or IV disease, operation alone controlled the primary lesion better than radiation alone or combined preoperative radiation and surgical treatment. With operation alone, however the rate of neck recurrence was higher than with the other two methods of treatment. In advanced disease, surgical treatment combined with postoperative radiation should be considered. Mandibular osteotomy and excision of the primary lesion are as effective in local tumor control as composite resection. In patients with a tumor-free margin, osteotomy can be used to preserve the mandible.


Vestibular sensory epithelium in Meniere's disease.

Utricle and horizontal semicircular canal ampulla removed during labyrinthectomy from 11 patients with advanced Meniere's disease were studied under light and electron microscope. In light microscopy the epithelium of both sensory areas appeared fairly normal. Many sensory cells revealed fluid-filled crescents at the nucleus and many cells were extensively vacuolated. Ultrastructurally, a part of the observations were apparently artifacts due to specimen handling; some were normal, age-related findings. Some changes were considered secondary to dilation of the endolymphatic space. True signs of degeneration, seldom seen in these specimens were intraepithelial cysts, necrotic cells, and dark homogeneous masses in the sensory epithelium and dilated nerve fibers in the subepithelial tissue. No general degeneration of the utricular macula or ampullar crista seems to occur in Meniere's disease.


Ophthalmoplethysmography in head and neck surgery.

Ophthalmoplethysmography (OPG) is a simple, noninvasive diagnostic test in which the cerebral hemispheric blood flow can be indirectly measured. Its use in head and neck surgery is invaluable because it enables the surgeon to predict preoperatively whether a patient will survive carotid artery resection. In a three-year period, nine patients have survived carotid resection on the basis of favorable OPGs, without a death or permanent neurologic complication. A comparison of the results of OPG testing with intraoperative measurement of internal carotid artery pressure showed close correlation in 14 of 20 patients who were tested. Lack of correlation in four patients can be explained by the circumstances of the intraoperative test. This study's findings demonstrate that this test has high clinical reliability.


Home or hospital?

That life begins at home is the desire of most women, and the fear of most obstetricians. The following article attempts  to look at some facets of the problem.


Study of the hearing losses of industrial workers with occupational noise exposure, using statistical methods for the analysis of qualitative data.

The application of a polychotomous generalization of the linear probabilistic model of Cox is described, which allows the investigation of the effects of different noise levels with various durations of exposure on hearing. If the model assumptions are not rejected, it is possible to separate the effect of noise exposure from the effect of age. The results will thus show to what extent the hearing losses of an industrial worker are due to presbyacusis or to noise exposure. An empirical investigation was based on the evaluation of hearing losses at the audiometric frequencies 1, 2 and 3 kHz in 35 212 industrial workers of both sexes. It was attempted to predict the distribution of hearing losses in the left and the right ear as an additive function of the effect of noise exposure, age and sex. The parameters describing the effect of age increased linearly. Noise levels equal to and above 85 dB(A) have a noxious influence on hearing. Furthermore, hearing loss does not increase continuously with duration of exposure; from 15 years onwards, no essential increase in hearing loss appears which can be attributed to noise at work.


Induction and enhancement of labour.

The present trend to "natural childbirth" has prompted a critical review of induction of labour, with special reference to physiological and pharmacological aspects as well as indications, contraindications, complications and techniques for induction of labour. Enhancement of labour is also discussed.


Prolonged labour.

Although prolonged labour may be a decreasing obstetrical problem, the importance of its implications should not be overlooked. This article discusses the causes of arrested labour, its complications and their management.


Critical bandwidth in Menière's disease.

The critical bandwidth in loudness summation was estimated in 20 patients with typical Menière's disease using noise bands centered around 1 kHz. A reduction of the normal loudness difference between broad-band noise and narrow-band noise was present at all except the highest levels. Judged individually, 7 of the 20 patients appeared to have a widened critical band, but in the pooled data the size of the critical band was normal. This was the case in patients with a hearing loss less than 50 dB HL as well as in patients with a hearing loss greater than or equal to 50 dB HL. Expressed in terms of the critical band mechanism as an internal filter system, the single filter appears to have normal bandwidth but the interaction between adjacent filters is defective. The anatomical localisation of this interaction is discussed.


The Leboyer method.

The method described is the reception of the newborn on the assumption that the baby is a sensitive, feeling being. The reasons for Leboyer's concept are discussed and the benefits to the parent-child bond are emphasized.


Consonant discrimination as a function of presentation level.

This study examined the effect of presentation level (seven levels ranging from 0 to 60 dB re the subject's SRT) on the discrimination of 20 consonants spoken in CV syllables. The subjects were 10 young adults with normal hearing. It was determined that the performance-intensity functions for individual consonants varied widely. Some sounds were not identified correctly 100% of the time even at the highest level tested, whereas other sounds were consistently identified at 10 dB SL. The data were considered with respect to stimulus and response bias and also were subjected to a feature analysis using features of voice, manner and place.


The technique of episiotomy.

Episiotomy is frequently performed, with an incidence of 70-80 per cent in someunits, but is still often poorly executed and repaired with  little thought as to the importance of a supple pain-free scar.


Effects of room reverberation upon hearing aid quality judgments.

Hearing-aid-processed speech recorded in reverberant and nonreverberant environments was ranked utilizing quality judgment and speech discrimination tasks. 21 normally hearing and 20 hearing-impaired listeners ranked the hearing-aid-processed speech. Quality judgments in reverberant environments may yield important information with respect to hearing aid selection. In contrast, speech discrimination rankings in a nonreverberant environment appeared to be similar to the speech discrimination rankings obtained in the reverberant condition.


Adolescent pregnancy in Australia. A hazard of early sexual intercourse.

The incidence in Australia of pregnancy in women under the age of twenty years is increasing, and constitutes a major medical and social problem. The outcome of these pregnancies has changed greatly during the past decade: more unmarried teenaged mothers are keeping their babies, fewer young women are marrying because of pregnancy, and the number of adolescents undergoing induced abortion continues to rise. Some suggestions for the prevention of adolescent pregnancy are discussed in this paper.


Attitides towards peer review.

The Australian Commonwealth Minister for Health called on the Australian Medical standards in Australia. Among the initial responses of the AMA was the organization of a National Seminar of Peer Review. Participants were asked to identify questions they would like to have answered about peer review and about aspects of a peer review system which they would perceive as necessary for its acceptability. Responses to these questions are analyzed and discussed. Implications for the introduction of peer review in Australia are examined, and strategies for gaining the commitment of the profession to the implementation of peer review are suggested.


General practitioners in the Sydney metropolitan health regions.

In a comprehensive survey of the number of general practitioners in the four metropolitan health regions of Sydney, 2,328 general practitioners were identified--the equivalent of 2,225 full time practitioners. This resulted in a ratio of one general practitioner to every 1,393 of the Sydney population.


Amniocentesis in the early second trimester of pregnancy and maternal anxiety.

Anxiety state and trait were measured before and after amniocentesis early in the second trimester of pregnancy, in a group of 28 women who were at risk of bearing an abnormal foetus. A significant decrease in maternal anxiety occurred in the majority of women after receiving the results of the amniocentesis. It is concluded that amniocentesis for intrauterine diagnosis of foetal abnormalities makes a significant contribution to the psychological wellbeing of those pregnant women who are at greater risk of having an abnormal baby.


Mammography--use or abuse.

Excluding the question of cost, at the present time the benefit of mammography associated with physical examination over the age of 50 appears proven as an intervention measure. With recent advances in radiological techniques, women under 50 appear to be advantaged by the performance of mammography but the benefit through the use of screening has yet to be proven by clinical trial. Screening might be restricted to the high risk group of patients with previous or present breast disorders and a family history of breast cancer in close relatives. Promotion of BSE and screening needs continuing education of the public, particularly concerning the value of early detection to successful treatment, and requires agreement on the methods and indications for screening (and subsequent treatment) by those advocating the programmes in order to keep the public's confidence. Overenthusiasm and polarity of views are to be avoided, so that health educators may be allowed to give the same message for credibility's sake.


Breast reconstruction after mastectomy.

Breast reconstruction is being performed with increased frequency, encouraged largely by the positive reaction of satisfied patients, and enabled by more recent advances in plastic surgery. Many of the disadvantages of external prosthesis (discomfort, insecurity, lack of permanence, absent cleavage) are overcome by surgical reconstruction, allowing the patient's greater confidence and more normal life style.


Anthelmintic efficiency of oxfendazole, fenbendazole and levamisole against naturally acquired infections of Ostertagia ostertagi and Trichostrongylus axei in cattle.

The anthelmintic efficiencies of oxfendazole, fenbendazole and levamisole, each at 4 dose rates spanning the manufacturers' recommended dosages were compared in beef cattle with naturally acquired infections of Ostertagia ostertagi and Trichostrongylus axei. In 8 of the 9 cases tested there was no significant increase in anthelmintic efficiency due to increased dose rates of any of the drugs. Percentage efficiencies and their standard errors, calculated from mean worm counts of pooled data for adult worms, developing 4th stage and early 4th stage larvae of O. ostertagi, were respectively, 86.9+/-4.2, 77.4+/-6.1, 74.5+/-7.3 for oxfendazole, 93.7+/-2.0. 80.7+/-6.8, 59.6+/-13.9 for fenbendazole and 69.7+/-6.9, 39.4+/-14.8, 31.2+/-22.6 for levamisole. Counts of O. ostertagi from cattle treated with oxfendazole and fenbendazole were not significantly different, but both were significantly lower than those from cattle given levamisole. Efficiency against T. axei exceeded 99% for all drugs. Practical implications for therapy and preventative control of ostertagiasis are discussed.


Thiabendazole resistance in field populations of Haemonchus contortus.

Six populations of H. contortus were selected for a study of thiabendazole resistance from a collection of 40 populations made during a survey of the efficiency of thiabendazole on the Northern Tablelands of New South Wales. Based on survey results, 3 of these populations were considered susceptible and the remaining 3 were considered resistant. However, when these populations were compared with a known susceptible strain on the ability of their eggs to hatch in a solution containing thiabendazole and 0.1% NaCl all 6 had significantly greater LC50's. The resistance ratios of the LC50 for each of the 6 populations to that of the known susceptible strain were 5.1, 4.3, 3.2, 3.1, 2.3, and 1.6 respectively. Following dosing of their host with 44 mg/kg thiabendazole the resistance ratios of the survivors increased to 5.4, 5.1, 4.7, 4.4, 3.1 and 2.4. Eggs produced by the F1 generation of the worms surviving 44 mg/kg thiabendazole did not revert back to the lower  LC50's of the unselected parents. Rather the LC50 remained at a level near that of a known highly resistant strain of H. contortus.


Effect of birth weight on efficiency of beef production.

The large 'lean beef' breeds are vulnerable to calving difficulties and losses. Dystocia is related to high birth weight. Data recorded from evaluation experiments show that the birth weight of the 'lean beef' taurus crossbreeds was high (39+/-2.1 kg). Indicus beef genotypes were selected with the birth weight (29+/-1.9 kg) significantly lower (P is less than 0.01) without a depression in the final yield of beef. To increase efficiency of beef production the lower birth weight factor needs be incorporated into genotypes for high viability and growth. Profitability depends on output per dam, in relation to inputs, on a herd basis. Hence, progress may depend on the application of such changes of genotype.


Toxicity of Crotalaria Goreensis for chickens.

Ground Crotalaria goreensis seed fed to day-old cockerel chickens at 3 different rates in a commercial ration of chick starter mash depressed growth rates. Moist faeces were common. Lesions consistently found included ulceration of the proximal large intestine and a dark grey discolouration of the glandular portion of the proventriculus. C. goreensis should be excluded from all poultry rations.


Renal failure, hyperparathyroidism and hypercalcaemia in a dog.

A 4-year Basset bitch with a 9-week history of depression, lethargy, inappetence and weight loss was found to have azotaemia, hypercalcaemia and hyperphosphataemia. Laparotomy and kidney biopsy revealed end-stage renal disease and the dog was killed. Hyperplasia of all 4 parathyroid glands was found at autopsy. The presumptive diagnosis was idiopathic renal failure with resulting tertiary hyperparathyroidism.


Renal cortical hypoplasia in a dog.

A case of renal cortical hypoplasia in a Cocker Spaniel bitch is presented. The dog, under clinical observation between the ages of 15 to 26 months, was found to have advancing chronic renal insufficiency. Necropsy examination revealed a markedly hypoplastic renal cortex with a reduced number of glomeruli, some dilated Bowman's capsules, small glomerular tufts, and early interstitial nephritis and fibrosis characteristic of renal cortical hypoplasia.


Ascending urinary tract infection in ponies.

Two young ponies had the prescrotal portion of their penises accidentally amputated during castration. They both developed ascending urinary tract infections over the next 4 weeks. One pony had a necrotising cystitis and pyelonephritis, the other improved markedly after a urethrostomy had been performed but was destroyed several months later.


Dynamic factors influencing the production of lung injury in rabbits subjected to blunt chest wall impact.

Anesthetized rabbits were exposed to blunt impact on the right chest wall. The controlled impact was delivered with a special machine equipped with a captive piston driven by a freely falling weight. Chest wall deflections were recorded in order to study the effects of magnitude and rate of deformation of the thorax on the resulting lung injury. The ranges of magnitude and rate of deformation corresponded to an inward deflection of the chest wall of about 5-60% of the lateral diameter of the chest, and to a velocity of the chest wall of about 2-20 m/s. Impulses delivered to the chest and intrathoracic pressures were also studied. Severe hemorrhages in the lungs were produced at velocities of the chest wall exceeding about 10 m/s. For velocities of the chest wall below about 5 m/s, lethal injuries were produced without severe hemorrhages in the lungs.


Biodynamic effects of canopy loss in the TF-15 aircraft.

In-flight canopy loss in high-speed fighter or trainer aircraft poses serious aeromedical problems for the crew-members. To assess these problems in the TF-15, a series of canopy-off tests were conducted. Preliminary phases of the test consisted of a taxi and a flight test up to 485 knots with pilot in the front seat and an instrumented dummy in the back seat. Upon evaluation of these results, a taxi phase and a flight phase were conducted with a pilot in the front seat and a live subject in the back seat. Maximum air-speed attained was 410 knots. The front crewmember experienced no serious control or medical problems during all phases. The back crewmember did experience problems such as loss of communications, loss of vision, helmet lift, high frequency head buffet, and exhalation difficulties. Airspeed, seat height, and body position had the greatest effect on the severity of the windblast. Angle of bank, angle of attack, and acceleration had little effect. The aft crewmember was able to significantly decrease windblast effects by leaning forward and pulling his head and helmet forward and down with his hand.


Plasma electrolytes in relation to altitude tolerance in rats.

Plasma concentration of Na+, K+ and Cl- ions did not change significantly whereas that of HCO3- dropped to one-third of its initial value in rats during their 15 min of gasping at a simulated altitude of 10,000 m at 33 degrees C, which was their survival threshold. Administration of methamphetamine (2 mg/kg), imipramine (2 mg/kg) and adrenaline (7 mg/kg) i.p. were ineffective in prolonging the survival time of rats, whereas acetazolamide (40 mg/kg), furosemide (2 mg/kg) and caffeine citrate (10 mg/kg) significantly increased their survival under hypoxia, (p less than 0.001, less than 0.01, and less than 0.05, respectively).


Changes in apparent body orientation and sensory localization induced by vibration of postural muscles: vibratory myesthetic illusions.

Illusions of continuous body tilt and rotation can be elicited by vibrating postural muscles of subjects standing in the dark. During such illusory motion, the apparent pivot point of the body can be influenced systematically by touch and pressure cues. Strong apparent movement is sometimes accompained by nystagmus of compensatory sign. If a small target light is visible during vibration, visual motion of like direction and velocity will accompany the illusory body motion. We have designated this pattern of apparent body and visual motion the "propriogyral illusion". Full room illumination abolishes both components of the propiogyral illusion. When the propriogyral illusion is being experienced, there is a dissociation between apparent displacement and apparent velocity; the extent of displacement is always less than would be expected on the basis of apparent velocity. The illusions of continuous body motion and the propriogyral illusion represent elements of a general set of vibratory myesthetic illusions that influence apparent posture, sensory, localization, and position sense of the body. These illusions demonstrate an important contribution of muscle afferent and touch-pressure information to the central mechanisms that determine apparent spatial orientation and visual localization. They also provide evidence that somatosensory information about orientation can influence oculomotor control.


Effects of phase manipulation on speech intelligibility through communication headsets.

A masking level difference (MLD) paradigm was established by rewiring the earphones of a communications headset out-of-phase. Essentially no release from masking could be measured, however, on a crew of listeners in the cabin of light aircraft. The experiment was replicated in the laboratory so that the exact phase of the aircraft noise masker could be controlled. The substantial MLD obtained in this environment led to the conclusion that the noise reaching the ear in the cockpit was of random phase, which almost eliminates the MLD. Therefore, rewiring headsets out-of-phase provides no advantage in intelligibility.


Tissue gas and blood analyses of human subjects breathing 80% argon and 20% oxygen.

Eight human volunteers, individually studied in a hyperbaric chamber, breathed: 1) air at 1 ATA; 2) 80% argon and 20% oxygen and 1 ATA for 30 min; 3) air at 1 ATA for 30 min; 4) 100% 02 at 1 ATA for 30 min; 5) air at 1 ATA for 30 min; 6) 100% O2 at 2 ATA for 60 min; and 7) 80% argon and 20% oxygen at 1 ATA for 30 min. Oxygen, carbon dioxide, nitrogen, and argon tensions were measured in muscle and subcutaneous tissue by mass spectroscopic analyses. Venous blood obtained at regular intervals was analyzed for coagulation and fibrinolytic factors. Inert gas narcosis was not observed. After breathing argon for 30 min, muscle argon tensions were almost three times subcutaneous tensions. Argon wash-in mirrored nitrogen wash-out. Argon wash-in and wash-out had no effect on tissue Po2 or Pco2. Coagulation and fibrinolytic changes usually associated with vascular bubbles were absent.


Mechanical vs. ischemic mechanisms for decompression sickness.

We used 20 kangaroo rats to investigate the effect of exposure to low oxygen levels (0.11 Atm 02 inspired partial pressure) prior to decompression from a steady-state condition. This hypoxia was found to afford significant protection against limb bends as simulated in those animals by tail biting. Yet, it potentiated neurologic symptoms compared with a control exposure on air with the same level of nitrogen supersaturation. However the incidence of simulated limb bends in the same animals was the same with hypoxia as with another control exposure at a pressure estimated to give extravascular bubbles of the same size upon decompression. The results are, therefore, consistent with a simple mechanical basis for limb bends, but are difficult to explain by any ischemic mechanism since a general hypoxia exacerbates any pain produced by oxygen deficiency in the tissues. However, the reverse may be true for some forms of neurologic decompression sickness and the two such cases reported here are consistent with that view, although not statistically significant.


Responses of high altitude natives a standard cold test at sea level.

Studies have been conducted to evaluate the thermoregulatory, calorigenic, and peripheral vascular responses to cold of high altitude (HA) natives on their descent to sea level. Two groups of subjects (18 each), one representing high altitude (3500 m) natives and the other lowlanders, were exposed to a standard cold test at 10 degrees C wearing only shorts for 2 h. Their heart rate (HR), blood pressure (BP), oxygen consumption (VO2), oral temperature (Tor), mean weighted skin temperature (Ts) and shivering activity were recorded initially in a thermoneutral room, and 30 min intervals during the cold exposure. Afterwards, their cold-induced vasodilatation (CIVD) response was studied and the peripheral blood flow during local cold stress was calculated. The responses were statistically compared. The highlanders maintained significantly higher Tor, Tb (mean body temperature), Ts and peripheral Ts during cold stress, and they shivered much less and showed higher CIVD response and peripheral blood flow than the other group. The rise in VO2 on cold stress was identical. The observations showed better cold tolerance for high altitude natives compared to lowlanders, even at sea level.


Measurement and scaling of workload in complex performance.

Two groups of paid male volunteers (Groups I, N = 51, tested with identical schedules on two successive days; Group II, N = 43, tested on one day only) performed over nine intervals on various combinations of the six tasks of the CAMI Multiple Task Performance Battery. Two of the tasks involved monitoring static (lights) and dynamic (meters) processes, and four more-active tasks involved mental arithmetic, elementary problem solving, pattern identification, two-dimensional compensatory tracking. Five of the nine intervals provided different complex tasks consisting of concurrent monitoring tasks and two of the active tasks. Other trials provided data on the single active tasks as well as the combined monitoring tasks. The results indicated that all performance measures--a total of 12 for the six tasks--varied significantly as a function of the different task-combination conditions. A standard psychological scaling technique (Thurstone Case V) was applied to the monitoring data (response times for green and red lights, and for meter monitoring) to develop an index of workload for the five complex task combinations. Since better performance was presumed to indicate a lower workload, workload was inferred to increase as performance declined across conditions. The best performances, which were assigned scale values of 0, were found to be associated with single-task performances, as expected. Scale values for the complex task-combination conditions were found to be consistent between groups and between the two days of testing of Group I (r's of 0.947 to 0.993). Although the scale values are specific to the task and task-combination conditions employed, the scaling-procedure application shows promise for cases in which quantitative measures of performance can be acquired with moderately large samples of subjects (N's greater than 50).


Oculogravic illusion in response to straight-ahead acceleration of CF-104 aircraft.

Experimental subjects wore goggles that restricted monocular vision to a luminous line fixed relative to the head, and they were exposed on one occasion to a straight-ahead acceleration of an aircraft and on another occasion to a tilting chair. The magnitude of change of direction of the resultant accleration was the same on both occasions, but the perceived movement of the luminous line from the two stimuli was very different. In response to the aircraft stimulus, the oculogravic illusion was experienced and the luminous line was perceived as tilting relative to the subject, in response to the tilting chair stimulus, the line was perceived as remaining fixed relative to the subject. It was concluded that the oculogravic illusion, as experienced in the aircraft (and previously in centrifuges), is a true illusion and not merely a fact of physics.


Cardiac response to whole-body heating.

Changes in ventricular function, as described by systolic time interval analysis, have been studied during heat stress and the time course of these changes, as well as changes in heart rate, have been investigated. Seven male and female subjects, 22-35 years of age, immersed their lower legs in water 42-44 degrees C for 30 min; their trunks and upper legs were enclosed in nonpermeable plastic to prevent evaporative heat loss. Total beat interval (R-R), left ventricular ejection time (LVET), pre-ejection period (PEP), arterial blood pressure, and oral temperature were monitored periodically during heating and recovery (post-hearing) periods. The stress induced significant (p less than 0.05) decreases in R-R and LVET by 5 min of heating which continued decreasing throughout the 30-min heating period. Heart rate accelerated from 72 up to 97 beats/min. LVET's during heat stress were shorter than those at similar resting heart rates. R-R and LVET were increased significantly by 1-min recovery but had not returned to preheating levels at 15 min. PEP, on the other hand, was not reduced until 15 min of heating, and did not start to recover until 3 min post-heating, after which it reached values exceeding control. A small increase in systolic blood pressure was maintained throughout heating and remained at 15 min recovery. Oral temperature increased approximately 1 degree C during the heating procedure; 50% of this was dissipated by 15 min recovery. Results are consistent with a two-stage cardiac response to heat-vagal withdrawal followed by a strong sympathetic outflow to the heart affecting both inotropic and chronotropic characteristics.


Rotation at 30 RPM about the A axis after 6 hours in the 10 degree head-down position: effect on susceptibility to motion sickness.

Intraindividual differences in susceptibility to motion sickness were measured in 14 subjects for two conditions of rotation at 30 rpm in the 10 degree head-down position. In one condition, subjects were in the 10 degree head-down position for 6 h prior to the onset of rotation; in the other condition, the delay was only 15 min. In both conditions, there were changes in vital capacity, indicating a redistribution of movable body fluids. Subjects tended to be less susceptible to motion sickness when they were recumbent for 6 h prior to rotation. These results are countervidence for the hypothesis that shifts of body fluid are responsible in large part for the motion sickness elicited in orbital space flight.


Saccadic velocity characteristics: intrinsic variability and fatigue.

Saccadic eye movements exhibit a characteristic peak velocity vs. amplitude relationship. As with all quantifications of biological function, there exists and associated intra- and intersubject variability of this relationship. This paper documents this variability and demonstrates both the absence of a predictable short-term "muscle fatigue" effect and the presence of a generalized "mental fatigue" (i.e. tiredness) effect.


A study of the health status of radar workers.

The health status was examined of 322 radar workers with a history of occupational exposure in a microwave field from 5-10 years. The clinical findings were compared with a control group of 220 persons. There were no statistically significant differences in clinical and laboratory findings between exposed and control group. Only some subjective complaints were found more frequently in the exposed group than in the control. The authors' feeling is that subjective complaints in radar workers could not be ascribed only to the influence of microwaves because they could be due to other nonspecific harmful occupational factors. On the basis of the results of this work, the authors concluded that it is unlikely to expect marked harmful effects from microwaves in radar workers in normal working conditions.


Cerebral accident subsequent to G-force loading: a case report.

A case review of a CVA in a 57-year-old general officer due to positive G-force loading is presented, which is apparently the first such documented episode recorded in the literature. This case reflects the concern about high G-force loading seen in newer high-performance aircraft and has significance in the assignment of older individuals to high G-force environments.


Survey on eye comfort in aircraft: I. Flight attendants.

Extensive research in aviation medicine has been devoted to various aspects of vision, but there has been little attention to the eye problems of flight attendants. Flight attendants, especially contact lens wearers, have complained about eye discomfort in aircraft. The purpose of this study was to evaluate some of the conditions in aircraft that might influence their eye comfort. A questionnaire on eye comfort was developed in conjunction with the Air Safety Department of the Association of Flight Attendants and distributed through its Flightlog magazine. Of the 774 respondents, 95% reported some eye discomfort in aircraft. It is significant that both those who did and who did wear contact lenses reported similar eye problems. The most common eye problems reported were conjunctival redness and dried eyes. Smoking was indicated by the respondents to be the most noticeable factor causing eye symptoms. Aircraft cabin conditions are discussed, including relative humidity, atmospheric oxygen, and ozone concentration. Since air passengers are exposed to the same aircraft conditions as the attendants, they probably would manifest similar eye problems.


The nursing explosion-technology, knowledge, and practice: its implications for leadership in aerospace nursing.

Authorities agree that we are experiencing a tremendous upheavel in numerous fields of endeaveor, health care in particular, resulting from the rapid growth of human information and capabilities since the 1950s. This upgrowth has touched nursing. This nursing explosion, in terms of technological advancement, increased knowledge, and expanded practice, demands the leadership of aerospace nursing to reexamine it posture and direction. A fresh look at its past and present successes and failures is essential to meet the challenges of the future. For "not to decide is to decide". There are two basic assumptions which underlie this challenge for leadership caused by the nursing explosion. First, as a self-directing profession, nursing can define its philosophical base, determine its goals, and identify the means for attaining those goals. Second, as the largest of the health professions, nursing has the right and responsibility to respond to the quantity and quality of global health care delivery systems. The analysis of this challenge for leadership shall be attempted in the light of three perspectives--organizationally, socio-politically, and professionally. The nursing explosion has dramatized the realization that nursing has the knowledge, power, resources in numbers, and dedication to service to move health care systems in the direction necessary. As Prof. Bell of Harvard has noted, the current revolution of rising entitlement to health care will have a marked influence on the nursing effort and vice versa. The call to leadership "a loud call and a clear call and it cannot be denied."


Space osteoporosis: an electromagnetic hypothesis.

Loss of body calcium during spaceflight is a potential problem in long voyages. This loss does not appear to be caused by a deficiency in diet or exercise. The idea is advanced that the altered electromagnetic environment experienced in space may be at least partially responsible. We show that the electric field induced inside astronauts because of their motion in the geomagnetic field is greater than that which has produced a wide variety of biological effects in earth-bound experiments.


The global energy system.

A global energy system is conceptualized and analyzed, the energy distributor sub-system of the worldwide supranational system. Its many interconnections are examined and traced back to their source to determine the major elements of this global energy system. Long-term trends are emphasized. The analysis begins with a discussion of the local systems that resulted from the deployment of technology in the mid-nineteenth century, continues with a description of the global system based on oil that has existed for the past two decades, and ends with a scenario implying that an energy transition will occur in the future in which use of coal, nuclear, and solar energy will predominate. A major problem for the future will be the management of this energy transition. The optimal use of global resources and the efficient management of this transition will require a stable and persistent global order.


An evaluation of salivary scintigraphy in Sjögren's syndrome.

Sequential salivary scintigraphy, labial salivary gland biopsy, and measurement of stimulated parotid flow rate were performed in 50 patients suspected of having Sjögren's syndrome. The value of these tests in the diagnosis of this disease was compared. Salivary scintigraphy and labial salivary gland biopsy can be used together to diagnose the oral component of Sjögren's syndrome. Abnormal salivary scintigraphy correlated with both of the other tests and may be considered optional in the diagnostic evaluation.


The clinical significance of Raynaud's phenomenon in systemic lupus erythematosus.

In a prospective study of 226 patients with systemic lupus erythematosus (SLE), 91 patients (40%) had Raynaud's phenomenon. These patients were compared to 135 patients without Raynaud's phenomenon. Patients with Raynaud's phenomenon had a greater incidence of arthritis (P less than 0.02), malar rash (P less than 0.003), and photosensitivity (P less than 0.03), and a lesser incidence of severe renal disease as manifested by serum creatinine over 3.0 mg/dl (P less than 0.007) or creatinine clearance below 60 ml/minute. Patients with Raynaud's phenomenon were less likely to have severe, life threatening disease and received a lower average monthly (P less than 0.01) and a lower peak daily corticosteroid dose (P less than 0.01). Fourteen patients (16%) with Raynaud's phenomenon died, compared to 41 without (30%) (P less than 0.03). Raynaud's phenomenon in patients with SLE is associated with milder disease and may be regarded as a favorable prognostic sign.


Pharmacokinetic monitoring of salicylate therapy in children with juvenile rheumatoid arthritis.

Free and total (sum of free and protein bound) salicylate concentrations in serum were determined in 17 children (age: 4-17 years) with definite juvenile rheumatoid arthritis. These measurements were carried out immediately before and 2, 4, and 8 hours after the morning dose during a strict 8 hourly aspirin treatment regimen (regular tablets) started 5 days earlier. The ratio of the 0 to 8 hour total salicylate concentrations was 0.95 +/- 0.10 (mean +/- SD), indicating that steady state had been attained. The ratio of the maximum to minimum concentrations during the dosing interval ranged from 1.05 to 2.26 and decreased with increasing average concentration. The concentration ratio was less than 1.3 at average salicylate concentrations above 20 mg/100 ml. It is concluded that the timing of a blood sample is not critical for monitoring steady state serum salicylate concentrations in the usual therapeutic range if the dosing interval is 8 hours or less. Free salicylate concentrations increased more than proportionately with increasing total concentrations due to the concentration dependent protein binding of the drug in serum.


Ophthalmologic safety of long-term hydroxychloroquine treatment.

Ocular toxicity of long-term hydroxychloroquine treatment was assessed by regular ophthalmologic examinations in 99 patients. No patient developed significant loss of vision or visual field constriction to a white test object. Three patients had evidence of toxicity, but the medication had to be permanently discontinued in only one who subsequently had regression of all abnormalities except visual field constriction to a red test object. Neither duration of treatment nor the diagnosis of systemic lupus erythematosus predisposed patients to toxicity.


Quantitative sacroiliac joint scintigraphy. A critical assessment.

With quantitative sacroiliac joint scintigraphy (QSS), sacroiliac joint-to-sacrum (SIS) ratios greater than or equal to 1.40 are abnormal for our method. High SIS ratios are associated with roentgenographically appreciated sacroiliitis and with early clinically evident sacroiliitis. Although highly sensitive, QSS abnormalities are not specific for inflammatory sacroiliac (SI) joint disease. High SIS ratios are also seen in rheumatoid arthritis, degenerative abnormalities of the lumbosacral spine, and metabolic bone disorder. Other disorders with roentgenographic SI joint abnormalities must be studied scintigraphically before QSS can be employed as a useful diagnostic test.


Deposition of antibodies to a soluble cytoplasmic antigen in the kidneys of patients with systemic lupus erythematosus.

Two patients with systemic lupus erythematosus were studied whose sera contained precipitating antibodies to a soluble cytoplasmic antigen, termed Ro. A reduction in the amount of these antibodies in each case was accompanied by a deterioration in the clinical status with the development of nephritis leading to death. Acid elution of gamma globulin was performed from homogenates of the renal cortex, and in both instances antibodies to Ro were demonstrated in the eluates by double immunodiffusion. The titer of these antibodies was measured in both sera and eluates, and specific enrichment of anti-Ro in the eluates was demonstrated in both patients. This strongly suggests the direct participation of Ro-anti-Ro immune complexes in the progressive renal disease and may underlie the association seen here between the decreasing serum titers of antibodies to Ro and the clinical deterioration in these two cases.


Simultaneous immunologic studies of skin and kidney in systemic lupus erythematosus clinicopathologic correlations.

Thirty-two biopsies of kidneys and of normal skin were performed simultaneously on patients with systemic lupus erythematosus (SLE) to determine whether the deposition of immune reactants in skin was correlated with the severity of renal injury or with several serologic measures of systemic disease activity. Immunofluorescent deposits at the dermal-epidermal junction (lupus band test) did not correlate with any clinical or histologic measures of glomerulonephritis or with serologic abnormalities. Immune deposits in dermal venules were found in 56% of the skin biopsies and were correlated with hypocomplementemia and higher levels of immune complexes in serum, and possibly with glomerular subendothelial electron dense deposits. Azathioprine therapy was correlated with absence of both sub-epidermal and vascular immune deposits. Immuno-fluorescent findings on serial skin biopsies on 13 patients were highly inconsistent. It is concluded that the lupus band test is clinically useful only as a diagnostic aid but not helpful in assessing renal or serologic activity of lupus, and that dermal vascular deposits of immunoglobulin or complement are more frequent than previoulsy recognized and correlate with measures of circulating immune complexes.


Glycosaminoglycan synthesis and glucose uptake by rheumatoid and nonrheumatoid fibroblastic cells in culture. The effect of nutritional factors.

Glycosaminoglycan (GAG) synthesis and glucose uptake by rheumatoid (R) and nonrheumatoid (NR) synovial cells were studied at the second subculture during four different sets of nutritional conditions and at sequential, defined intervals of the growth cycle. Synovial fibroblastic cells in monolayer cultures secrete both hyaluronic acid and sulfated GAGs in a ratio of about 8 : 1. With increasing cell density the ability to sulfate GAGs appears to decrease. No significant differences in GAG synthesis between rheumatoid and nonrheumatoid lines on a per cell basis could be detected during any interval in the growth cycle. Similarly, no significant differences of glucose uptake per cell could be demonstrated between rheumatoid and nonrheumatoid lines under the various protocols applied throughout the growth cycle. The most important factor determining glucose uptake per cell is the availability of glucose in the medium which is in turn closely correlated with cell number.


Hyperlipoproteinemia induced by a transplantable pituitary tumor in the rat.

The MtT-F4 tumor, a transplantable pituitary tumor of rats, induces significant hyperlipidemia in male Fisher 344 rats. The increasive hypercholesterolemia was accompanied by hypertriglyceridemia only in the first month of tumor implantation. Clofibrate feeding inhibited the development of hypercholesterolemia and maintained normal serum triglyceride levels. In contrast to the changes in lipoprotein cholesterol distribution and profile found in experimental hyperlipidemia induced by high fat and cholesterol feeding, the hypercholesterolemic tumor-bearing rats showed no accumulation of cholesterol in the very low density and intermediate density lipoproteins, and no appearance of a new class of lipoprotein, B-VLDL. An HDLc-like lipoprotein appeared as hypercholesterolemia developed. Increased amounts of cholesterol were deposited in the aorta. The effects are attributed to the lipolytic hormones secreted by the tumor and antagonism to their action by clofibrate.


Cathepsin D activity of venous and polyester vascular grafts implanted in the abdominal aorta of the dog.

Autogenous veins and polyester prostheses were implanted in the abdominal aorta of dogs. The venous or polyester grafts were removed together with sections of the normal arteries and veins 1 month, 4 months, and 3 years after the operation. This material was then dissected into the intimal, medial, and adventitial layers, and homogenized after which their cathepsin D activity was determined. It was found that the cathepsin D activity was far higher in all the layers of the venous grafts, particularly in the polyester grafts, than in the corresponding layers of the normal arteries and veins.


Effect of clofibrate and gemfibrozil on the activities of mitochondrial carnitine acyltransferases in rat liver. Dose--response relations.

The effects of different doses of clofibrate and gemfibrozil on liver size, serum triglyceride concentration and the activities of hepatic mitochondrial alpha-glycerophosphate dehydrogenase (alpha-GPD) and carnitine acyltransferases were studied in male rats. Both clofibrate and gemfibrozil treatment effectively decreased the fructose-induced hypertriglyceridaemia and increased the liver to body weight ratio. Clofibrate treatment also induced an increase of many times in the activities of mitochondrial alpha-GPD and carnitine acyltransferases, the effect increasing with the dose used. The effect of gemfibrozil on the activities of the enzymes was significantly smaller. There was no correlation between the decrease in serum triglyceride concentration and the changes in the activities of the enzymes. Only clofibrate increased the rate of fatty acylcarnitine oxidation in isolated mitochondria. It is concluded that both drugs increased the size of the rat liver, but that only clofibrate influenced the mitochondrial enzyme activities of mitochondrial carnitine acyltransferases and the accelerated mitochondrial oxidation of fatty acids are not the mechanisms by which these drugs lower serum lipid levels.


Distribution and movement of anionic cell surface sites in cultured human vascular endothelial cells.

Cell surface anionic sites on primary and transformed cultures of human vascular endothelium were studied using cationized ferritin (CF) as an ultrastructural marker. The native distribution of anionic sites on the upper (free) surfaces of cells, fixed in situ with glutaraldehyde, was uniform. Binding of the polycationic ligand, CF, in unfixed cells induced redistribution of anionic sites. Rapid formation of discrete patches of CF particles was followed by reappearance of binding between patches, movement of surface-bound CF into intercellular clefts, and endocytosis, over the next 30 min. Aldehyde-fixed cells, detached from the culture surface, bound CF on both upper and lower surfaces. The distribution and mobility of negatively charged membrane components in vascular endothelium may have relevance for thrombosis, atherogenesis, and vascular permeability.


Effect of enhancement of cholesterol degradation during neonatal life of guinea pig on its subsequent response to dietary cholesterol.

The effect of feeding cholestyramine to neonatal guinea pigs on their subsequent plasma cholesterol levels and response to dietary cholesterol were studied. Male neonatal guinea pigs were suckled for 6 days. One group was maintained on a 1.1% cholestyramine diet for 6 weeks and the control group weaned normally. Both groups of guinea pigs were then fed a standard diet of Guinea Pig Chow for 6 weeks. During the standard diet period bile acid and neutral sterol excretion rates were significantly higher in the group previously treated with cholestyramine than the control group despite the similarity in plasma cholesterol levels. When both groups of guinea pigs were subjected to a 0.5% cholesterol diet for 4 weeks, plasma cholesterol levels were significantly lower in the group previously treated with cholestyramine than the control group. The plasma cholesterol levels continued to be significantly lower in the group previously treated with cholestyramine after an additional four weeks on standard diet. These results suggest that stimulation of cholesterol catabolism in the neonatal period can influence the subsequent response to dietary cholesterol.


The effect of a putative anti-atherosclerotic agent (S 1204) on lipid metabolism in rabbit aorta.

The effects of the novel fenfluramine derivative, S 1204 (meta-trifluoromethyl phenyl-1 [beta(sulfamyl-3'-chloro-4'-benzoyloxyethyl)]amino-2-propane) were studied on lipid metabolism in rabbit aorta and other tissues. Pretreatment of rabbits with S 1204 (50 mg/kg orally) for 10 days strongly inhibited the aortic incorporation of an intravenous 20 muCi tracer-dose of [4-(14)C]-cholesterol given 24 h earlier. However, incorporation of such cholesterol radioactivity into the liver, intestine, lung or plasma was not affected, in comparison with control animals. One hour after i.v. injection of a 100 muCi tracer-dose of [2-(14)C]acetate, S 1204 significantly reduced the radioactivity of total lipids in the aorta and liver. Such inhibition of acetate incorporation into arterial lipids was observed with all lipid fractions (that is, free fatty acids, esterified cholesterol, especially phospholipids, glycerides and free cholesterol). Incorporation of acetate into intestinal triglyceride fractions was also significantly decreased. The results indicate that S 1204 may have anti-atherogenic properties, which could be valuable in the clinical treatment of atherosclerosis.


Effect of CCL4-induced cirrhosis on the pathophysiologic course of acute myocardial infarction in nonarteriosclerotic vs arteriosclerotic male rats.

Arteriosclerotic and nonarteriosclerotic rats were treated with carbon tetrachloride (CCL4) to induce cirrhosis of the liver. Massive myocardial infarction was then induced in intact and CCL4-treated animals. During acute necrosis (Days 1 thru 3), animals were killed at 4, 8, 12 and 24 h on Days 1 and 2, and during myocardial repair on Days 4, 5 and 8. During the induction of cirrhosis, animals developed polydypsia, polyuria, and hyperglycemia; during myocardial infarction, the arteriosclerotic + cirrhotic animals developed severe and persistent congestive heart failure, i.e., hydrothorax. Adrenal and thymus gland weights and corticosterone levels indicated that cirrhosis per se increased pituitary--adrenal activity, particularly in arteriosclerotic animals. Enzyme levels of SGOT and SGPT demonstrated severe hepatic damage due to cirrhosis and acute myocardial infarction. Blood triglycerides and cholesterol responded abnormally in cirrhotic animals during acute myocardial ischemia due to their entrapment within hepatic cells. The cirrhotic animals manifested poor myocardial repair with persistent foci of necrosis, calcification, and a high incidence of large, occlusive, atrial thrombi. It is suggested that cirrhosis interferes with lipid metabolism and adrenal steroid conjugation leading to abnormal levels of mineralocorticoids which favor congestive heart failure, poor myocardial repair, and atrial thrombosis.


Reduction of blood viscosity following plasma exchange.

The effect of plasma exchange with plasma protein fraction on blood viscosity was determined in seven hyperlipoproteinaemic patients with coronary or peripheral vascular disease. This resulted in decreases in whole blood viscosity of 83% and 30% respectively at the lowest and highest shear rates studied, and decreases of 21% and 59% in plasma viscosity and fibrinogen. Serum cholesterol and triglyceride were reduced by 66% and 48% respectively. Sequential studies in two patients showed that blood viscosity returned to near-basal values by the 6th day. These findings suggest that plasma exchange may result in short-term enhancement of blood flow in vessels where low shear rates predominate.


Effect of milk constituents on hepatic cholesterol-genesis.

Two preparations active in reducing hepatic cholesterol biosynthesis were isolated from bovine skim milk. One of the inhibitors was in the dialysate and was identified as orotic acid (OA). The other inhibitor, present in the retentate, was not identified. Orotic acid appears to act by inhibiting cholesterol biosynthesis before the formation of mevalonate, whereas the retentate inhibitor exerts its effect beyond the formation of mevalonate in the biosynthetic pathway. Human milk also inhibited the incorporation of both labeled acetate and mevalonate into cholesterol by rat liver. Orotic acid was not detectable in human milk samples employed in this study. Administration of [6-14C]orotate to rats revealed its conversion to uracil in the liver. Subsequent work demonstrated that uracil had inhibitory activity on hepatic cholesterol biosynthesis similar to that of orotate when incubated with rat liver slices.


Biosynthesis of aortic collagen and glycosaminoglycan following immunological injury.

The effect of immunological injury upon the early in vivo changes in aortic connective tissue metabolism was studied. It was found that a single antigen (bovine serum albumin), when administered in multiple doses, activated collagen synthesis and increased the rate of lgycosaminoglycan synthesis in the arterial wall. The degree of stimulation of both connective tissue components was higher in animals receiving a higher dose of antigen.


Seasonal variations in the biophysical properties of rabbit aorta and its susceptibility to arteriosclerosis.

The physiological variations in the mechanical properties of rabbit aortae in relation to the periods of hair shedding were studied. The load-strain curves of the eight proximal thoracic segment in 15 shedding and 15 non-shedding male albino rabbits were analysed. The slope of the curves (tangent of the angle between the linear region of the load-strain curve and the strain axis) was decreased in the shedding animals compared to that of the non-shedding animals and the toe of the load-strain curves was significantly lower towards the x-axis in the shedding animals. The observations indicate a lower stiffness, that is increased elasticity, of the aortae of rabbits during hair shedding. The increased elasticity during hair shedding may explain the previously reported resistance to experimental arteriosclerosis caused by the hemodynamic strain elicited by exposure to systemic hypoxia. A decrease in the aortic content of collagen and of sulfated glycosaminoglycans, and an increase in the content of hyaluronic acid, may be of importance in the alterations of the mechanical properties of rabbit aorta  during hair shedding.


The arterial wall in malignant disease.

The intimal thickening of arteries present in 95 resected specimens of carcinoma of the colon was studied, using sections from the tumour area and from adjacent normal bowel. Arteries from the tumour area showed a very significant increase in intimal thickening as compared with the controls. It is suggested that the local factor associated with the tumour area is an impaired drainage of macromolecules from the intimal compartment of the arteries due to obstruction of the lymphatic channels of the surrounding interstitial tissue by tumour cells and fibrosis.


Platelet aggregation in relationship to plasma catecholamines in patients with hypertension.

Plasma catecholamine concentration and platelet aggregation were studied in 22 patients with uncomplicated primary hypertension and 13 age-matched normotensive, healthy subjects at rest and in some during isometric handgrip exercise. The effect of norepinephrine (NE) infusion upon platelet aggregation was also examined. Plasma catecholamine concentration was slightly higher in the hypertensive than the normotensive group, but the difference was not significant. However, platelet aggregation to ADP was significantly greater in the hypertensive than the normotensive subjects. Exercise increased significantly both catecholamines and aggregation in both groups. Platelet aggregation was correlated with age (r = 0.62, P less than 0.01) and plasma NE (r = -0.34, P less than 0.05 for the total group of subjects). The infusion of NE increased significantly plasma NE and platelet aggregation and there was an inverse correlation between NE increase and threshold decrease (r = -0.69, P less than 0.05). Thus, plasma catecholamines and important determinants of platelet aggregation. However, in our study, uncomplicated primary hypertension was not associated with abnormal plasma catecholamine concentration. It is likely that the observed abnormal platelet aggregability to ADP represents a secondary phenomenon, possibly related to more advanced atherosclerotic vascular changes in hypertensive than normotensive subjects.


Elastin--lipid interaction action in the arterial wall. Part 1. Extraction of elastin from human aortic intima.

Elastin was extracted from human aortic plaque and adjacent grossly normal intima by the following methods: (1) 0.1 N NaOH at 100 degrees C, (2) hot NaOH and 0.2 M EDTA, (3) 5 M guanidine--HCl and collagenase, (4) guanidine--collagenase and dithioerythritol--urea--sodium dodecyl sulfate, (5) guanidine--collagenase and EDTA, (6) 10% NaCl and collagenase, and (7) NaCl--collagenase and EDTA. All elastin samples contained small amounts of carbohydrate and hydroxyproline. The lipid content of non-plaque intimal elastin samples was small (2--3%), whereas it increased to 4--6% in plaque intima. The lipid composition of elastin preparations varied significantly with the extraction procedure. Elastin from plaque intima contained significantly more cholesterol (50--60%) and less triglyceride and phospholipid than elastin of non-plaque intima (30--50% cholesterol). The contents of free and esterified cholesterol were comparable in all preparations. The main phospholipid in all samples was sphingomyelin, which comprised between 50 and 80% of the total phospholipid. Compared with NaOH-purified elastin, the other elastin samples were characterized by an increased phosphatidyl--choline content, while they all contained an almost equal amount of phosphatidylethanolamine. In elastin samples from plaque intima, the polar amino acids were increased, whereas cross-linking amino acids were decreased. The polarity and hydroxyproline content of elastin samples were slightly decreased after treatment with EDTA or dithioerythritol--urea--sodium dodecyl sulfate.