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Biomedical subjects

H Adam

Publications and source records attributed to H Adam.

At least 37 records · Page 2Linked to original sources
PubMed1989

[Phospholipid content of subcellular structures in skeletal muscles after halothane loading in Landrace swine in relation to mating variants and genotype].

Membraneous phospholipids of subcellular structures were determined from the musculature of German Landrace pigs of the GDR, following exposure to halothane. Mating variants A (H+ male X H+ female), B (H+ male X H- female), and C (H- male X H+ female) were used for positive responders (MHS), while variants B, C, and D (H- male X H- female) were used for negative responders (MHN). Four phospholipid fractions were recorded from the muscle samples for mitochondria and microsomes (according to SR section). Differences between the MHS and MHN groups for the above fractions and without consideration of mating variants and genotype were not observed, although unambiguous responses were exhibited by all animals, either positive or negative to halothan. Significant differences with regard to the above phospholipid fractions were recordable only for variant A (MHS group) as compared to D (MHN), in other words, for the homozygous genotypes, once the above results had been rearranged within MHS and MHN along with different mating variants and genotypes. However, no unambiguous results were obtainable for the heterozygous genotypes of mating variants B and C. Possible underlying reasons are discussed in some detail. The results obtained from mating variants A and D are likely to confirm earlier findings and seem to suggest that the sarcoplasmic reticulum is the primary site of origin of susceptibility to halothane or malignant hyperthermia.

Animals↗
PubMed1989

Comparison of two methods for evaluation of the length of collagen molecules.

Two microscopical methods for the evaluation of molecular length--the measurement of SLS aggregates and the rotary shadowing technique--are compared. Two types of collagen were used for the comparison: type I collagen, isolated by acid extraction from calf skin, and type IX, isolated from chicken cartilage. An average length of 303 nm was obtained for type I collagen (by measurement of SLS aggregates 247 nm). Type IX collagen forms three different types of SLS crystallites corresponding to molecular lengths of 61, 95 and 206 nm; with the rotary shadowing technique, lengths of 84, 116 and 197 nm were measured.

Animals↗
PubMed1988

[Malignant lymphomas in HIV-infected patients].

Eleven patients with non-Hodgkin's lymphoma and three patients with Hodgkin's disease were observed among 876 anti-HIV-positive subjects attending the AIDS clinic at the University Hospital, Zurich, Switzerland. Compared to the general population this represents a 50-fold (95% confidence limits: 25-90) increased risk of non-Hodgkin's lymphoma and an 11.4-fold (2.3-33) increased risk for Hodgkin's disease in anti-HIV-positive men. High malignancy, advanced stage of disease at the time of diagnosis, and extranodal localization are characteristic of non-Hodgkin's lymphoma in AIDS patients, which carries a poor prognosis. However, remissions and prolonged disease-free survival are possible in individual cases. Only one opportunistic infection was observed during 92 months of treatment and observation using a mild chemotherapeutic regimen (m-BACOD). Less myelosuppressive chemotherapeutic schedules appear to be more beneficial than aggressive regimens in anti-HIV-positive patients due to the lower incidence of opportunistic infections.

Acquired Immunodeficiency Syndrome↗
PubMed1988

The effect of gossypol acetic acid on the different stages of the spermatogenic cycle in the rat.

The reversibility of the effect of gossypol on testicular histology and fertility was studied in rats. Adult males of proven fertility were treated orally with gossypol acetic acid (15 mg/kg) for 9 or 16 weeks (groups 1 and 2, respectively). Another groups of animals (group 3) was given gossypol (15 mg/kg) for 16 weeks and killed 6 weeks after the end of treatment. Control animals (group 4) were given the vehicle only by oral intubation. In the mating studies, although only 33% of the animals in group 1 were infertile, 100% infertility was observed following 16 weeks of gossypol treatment (group 2). All animals in group 3 regained their fertility 6 weeks after cessation of drug treatment. Damage was observed to 15.7% of the seminiferous tubules after 9 weeks of drug treatment, and to 78% after 16 weeks of treatment. Extensive vacuolization, increased numbers of lipid droplets, degeneration of germ cells, loosening of the epithelium, and a significant decrease in the number of pachytene spermatocytes (stages VII-X) and spermatids (steps 7-10 at stages VII-X) were observed after gossypol treatment. There was a decrease in the diameter of only stage VIII seminiferous tubules after 9 weeks of treatment, whereas a reduction was observed in the tubules of all stages after 16 weeks of gossypol treatment. In the recovery phase, the diameter of seminiferous tubules was similar to that of controls, except for tubules at stage VIII. No change in the area of the lumen of the seminiferous tubules and lipid bodies was observed after 9 weeks of drug treatment, but a marked reduction in the area of the lumen (stages II-X) and an increase in lipid bodies (all stages) was observed after 16 weeks of gossypol treatment. Six weeks after cessation of treatment, the area of the lumen and the number of lipid bodies were comparable to values in controls. A reduction in the area of the epithelium was restricted to just a few stages (VIII-XIV) in treated animals at 9 weeks, whereas after 16 weeks the area of the epithelium was decreased in all tubules. In the recovery phase, except for tubules at stage VIII, the area of the seminiferous epithelium was comparable to that in controls.

Animals↗
PubMed1988

Vascularization of male gonads in Blennius pavo (Teleostei, Blenniidae) as revealed by scanning electron microscopy of vascular corrosion casts.

The vascular architecture of male gonads of Blennius pavo is studied by scanning electron microscopy of vascular corrosion casts. Arterial supply to the gonads is by a branch of the first ventral segmental artery of the tail. From the surface of the gonads, this vessel gives rise to branches which supply testes, spermatic ducts, testicular glands, blind pouches, urogenital sinus and urogenital papilla. The testis has a rope-ladder-like capillary network around the seminiferous tubules, while in the testicular gland the capillary network is irregular in form. The spermatic ducts are found to have an exterior capillary network located in the compact connective tissue layer and an interior one, lying subepithelially. Urogenital sinus and urogenital papilla show a multilayered capillary network. Angioarchitecture in mature and immature gonads does not differ.

Animals↗
PubMed1987

Serological prevalence of leptospiral infection in domestic animals in West Malaysia.

A cross-sectional serological survey of domestic animals in West Malaysia revealed that 25.5% of the animals examined had agglutinating antibodies to one or more antigens belonging to Leptospira interrogans. Significant prevalence of infection was observed in cattle (40.5%), buffaloes (31%) and pigs (16%). The Sejroe serogroup was shown to be the principal one involved in cattle and buffaloes, and to a lesser extent the Tarassovi and Pomona serogroups. Evidence of infection in domestic animals by strains bearing the other seven antigens appeared insignificant and was indicative of sporadic infection. A majority of the large (semi-intensive) cattle and buffalo farms demonstrated a high prevalence of leptospiral infection. In both species of domestic animals mentioned above, the prevalence of infection was significantly higher (P = 0.01) in the semi-intensive farms than in the smallholdings. Amongst cattle, the droughtmasters had the highest prevalence whilst the Kedah-Kelantan (an indigenous breed) had the lowest prevalence of leptospiral infection. In general, the temperate breeds of cattle had a significantly (P = 0.01) higher prevalence of infection than local breeds. Leptospiral infection in goats and sheep was shown to be sporadic, and the Pomona serogroup was the principal leptospiral serogroup involved in these small ruminants. The prevalence of infection in pigs was observed to decline during the study period, and it is suspected that pigs in West Malaysia are the maintenance host for serovar pomona whilst cattle are the maintenance host for serovar hardjo. Overall, it appears that domestic animals in Malaysia will play a bigger role in the epidemiology of leptospiral infection with the advent of sophisticated farming.

Agglutination Tests↗
PubMed1987

[Coronary surgery in females].

In the last three years, of a total of 617 patients undergoing surgery for ischemic heart disease, 53 were women (8.6%). With one exception, all were in or shortly before the menopause. As compared with men, the women were found to have a preponderance of risk factors. The most unfavorable combination, that of hypertension and hypercholesterolemia, was present in one-third of the patients. Hospital mortality for isolated revascularization was higher in women at 4.9% than in men at 1.5%. The one-year survival rates, however, of 94.4% and 95%, respectively, did not differ between the two sexes. In women, the number of grafts per patient was 2.1 as compared with 2.9 in men. Complete revascularization was achieved less frequently in women than in men; similarly graft patency rate at one year of 66% in women was less than the 84% observed in men. The more marked coronary sclerosis as well as morphologic characteristics of coronary arteries in women construe a special challenge to the surgeon and prerequisite a high degree of technical skill.

Adult↗
PubMed1986

The angioarchitecture of the choroid plexus of the lateral ventricle of the rabbit. A scanning electron microscopic study of vascular corrosion casts.

The vascularization of the choroid plexus of the rabbit's lateral ventricle has been studied by scanning electron microscopy of vascular corrosion casts. Based on the vascular patterns discerned, the plexus was subdivided into 6 different parts: the inferior, lateral, central and superior parts, the free margin and the lingula. These differ in structure and localization. While the arterial supply of the inferior part is via the anterior choroidal artery, the central and superior part are supplied by the posterior choroidal arteries. Three main veins leave the plexus and drain to the basilar vein from the inferior part and to the internal cerebral vein from the inferior, central and superior part. Capillary diameters were typically 10-15 micron. Regular nodular thickenings up to 24 micron in diameter were seen in the free margin and the superior, lateral and inferior parts. 'Garland' shaped capillary configurations sheathing arteries as well as veins were found all over the plexus. It is suggested that these 6 different parts of the plexus described here may reflect functionally different areas.

Animals↗
PubMed1986

Skin peptides in Xenopus laevis: morphological requirements for precursor processing in developing and regenerating granular skin glands.

The biosynthesis of the peptides caerulein and PGLa in granular skin glands of Xenopus laevis proceeds through a pathway that involves discrete morphological rearrangements of the entire secretory compartment. Immunocytochemical localization of these peptides during gland development indicates that biosynthetic precursors are synthesized in intact secretory cells, whereas posttranslational processing requires morphological reorganization to a vacuolated stage. The bulk of the processed secretory material is then stored in vacuolae-derived storage granules. In the mature gland, storage granules are still formed at a low level. However, in this case processing takes place in a distinct cytoplasmic structure, the multicored body, which we suggest to be functionally equivalent to vacuolae. When granular glands regenerate after having lost all their storage granules upon strong stimuli, another morphological pathway is used. 2 wk after gland depletion, secretory cells become arranged in a monolayer that covers the luminal surface of the gland. Storage granules are formed continuously within these intact secretory cells. Here, precursor processing does not require a vacuolated stage as in newly generated glands but occurs in multicored bodies. Most storage granules seem to be formed in the third week of regeneration. The high biosynthetic activity is also reflected by the high activity of the putative processing enzyme dipeptidyl aminopeptidase during this period of regeneration.

Animals↗
PubMed1985

Hypothalamo-neurohypophysial system in hagfish: localization of neurophysin-, arg-vasopressin- and oxytocin-like immunoreactivity.

Serial paraffin sections of hagfish brain (Eptatretus burgeri) were immunocytochemically examined for porcine neurophysin (NEU), arg-vasopressin (AVP) and oxytocin (OT). A big number of NEU-immunoreactive nerve cells were visible in the frontal part of the ventromedial hypothalamus in close vicinity of the third ventricle. These cells were bipolar in most cases and sometimes additionally stained for AVP but not for OT. NEU-reactive neurons extended axons to the median eminence and the posterior lobe of the pituitary which also contained AVP or OT-like immunoreactivity. Immunostaining outside the hypothalamus could not be observed. It is likely that there exists a mammalian-like oxytocinergic and a vasopressinergic hypothalamo-neurohypophysial system in hagfish, despite the large differences in levels of organization.

Animals↗
PubMed1985

Distribution of aminergic neurons in the brain of the sterlet, Acipenser ruthenus (Chondrostei, Actinopterygii).

Aminergic nuclear areas were identified in the brain of Acipenser ruthenus using formaldehyde-induced fluorescence (FIF). One group of scattered, green fluorescent cerebrospinal-fluid (CSF)-contacting neurons is located rostral to the commissura anterior. A second very prominent field of green fluorescent neurons is situated within the recessus preopticus, the recessus preopticus organ (RPO). Caudal to the latter there is a group of green and yellow fluorescent CSF-contacting neurons, the anterior part of the paraventricular organ (PVO). Further caudally, towards the dorsorostral entrance to the recessus lateralis the latter group is continuous with the main part of the PVO, which consists of large green and yellow, fluorescent CSF-contacting neurons in a stratified arrangement. The PVO is caudally continuous with small, green fluorescent CSF-contacting neurons situated within the roof of the recessus lateralis. The nucleus recessus posterior is made up of green and yellow fluorescent CSF-contacting neurons, which cover not only the walls of the recessus posteriores, but also line the lateral, dorsal and caudal aspects of the caudal hypothalamus. Small groups of green and yellow fluorescent CSF-contacting neurons can be found also in other areas of the hypothalamic ventricular walls, especially dorsal to the PVO and within the hypothalamic floor. Three large groups of aminergic neurons are present within the brain stem: One, yellow-fluorescent raphe-system and two green fluorescent groups. The floor of the canalis centralis is lined by green fluorescent CSF-contacting neurons. There is a very low density of aminergic terminals within the brain of Acipenser. A prominent fibre tract connects the PVO and the nucleus recessus posterior.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Comparative scanning electron microscopy of the ventricular surface in four actinopterygian fishes: Acipenser ruthenus, Salmo gairdneri, Tinca tinca and Blennius sanquinolentus (Pisces).

The ventricular surface structure of the brains of actinopterygian fishes representing four distinct evolutionary levels was investigated by scanning electron microscopy (SEM). In the chondrostean Acipenser ruthenus ventricular spaces are wide and the ependymal surface is for the greater part densely covered with cilia; apart from macrophages supraependymal cells (SE) are very scarce. In the teleosts Salmo gairdneri, Tinca tinca and Blennius sanquinolentus the ventricles are slit-like, the densely ciliated areas decrease in size. The following regions carry a variety of supraependymal (SE) cells and fibres: the rostral recessus supraopticus, the hypothalamic walls, especially the infundibulum and the dorsal walls of the rhombencephalic ventricle. There is no tight correlation between areas devoid of cilia and the circumventricular organs in teleosts. The long evolutionary history, independent of other vertebrate lines has caused a series of peculiarities in the brain of actinopterygian fishes, including a peculiar ventricular topography. Observations indicate that the rich spectrum of SE cells found in teleosts reflects a parallel evolution rather than a common heredity of teleostean fishes and higher vertebrates.

Animals↗