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Biomedical subjects

A Abramovici

Publications and source records attributed to A Abramovici.

At least 37 records · Page 2Linked to original sources
PubMed1991

Immunocytochemistry of epithelial markers in citral-induced prostate hyperplasia in rats.

Immunocytochemical characterization of several epithelial markers using the PAP technique was analyzed during different stages of induced prostatic hyperplasia in rats. Intact adolescent rats (42 days old) were treated with citral (3,7 dimethyl-2,6 octadienal) for 10, 30 and 100 days and their ventral prostate compared to untreated, matched-age animals. Among the epithelial markers studied the prostatic specific acid phosphatase was present in hyperplastic prostates of rats. The immunoreaction showed a fair correlation with the severity of lesion and duration of treatment. The prostatic specific antigen showed equally immunoreactive in both control and treated rats. The hyperplastic and normal rat prostates did not show immunoreactivity towards the other epithelial cell markers such as epithelial membrane antigen, carcinoembrionic antingen and alpha-fetoprotein antisera. It is concluded that prostatic specific acid phosphatase, and to a lesser extent prostatic specific antigen, might represent valuable markers for comparative studies of prostatic hyperplasia in rodents.

Acyclic Monoterpenes↗
PubMed1991

The distribution of peptide-containing nerves in the synovia of the cat knee joint.

Synovial capsule in cats is extensively innervated by a network with axonal diameter ranging from 0.6-3 microns according to its position and neuropeptide content. Nerve markers such as Neuron Specific Enolase (NSE) and Neurofilament triplet protein (NF) could be observed only when the axonal fibre attained a critical diameter of over the 3 microns limit. The relatively thick fibres (1-3 microns) show positive immunoreactivity for Substance P (SP), 5-hydroxytryptamine (5-HT), and Vasoactive Intestinal Peptide (VIP), and seldom coreact with NSE and NF, whereas, the thinnest fibres (0.6-0.8 microns) characterized to contain either Methionine or Leucine Enkephalin (M-Enk, L-Enk) did not coreact positively with axonal markers. We found that different anesthetics may effect variably the immunoreactivity of some neuropeptides (SP, L-Enk, 5-HT) while others (VIP, M-Enk) remained unaffected. Based on our data and the few reported ones in the pertinent literature, it is judged that urethane is the anesthetic of choice in experimental studies of neuropeptides. Our findings of isolated positive immunoreactive cell bodies to enkephalin in synovia might suggest the presence of intrinsic relay system, where the enkephalin acts as suppressor of SP and VIP release from the sunovium nerve terminals. Such a local inter-relationship between different neuropeptide systems might have a practical role on the understanding of the pathogenesis of different arthritic processes as well as therapeutic strategy in the future.

Animals↗
PubMed1990

Clinical and pathological findings in prostates following intravesical bacillus Calmette-Guerin instillations.

The prostates of 36 patients who were treated with intravesical bacillus Calmette-Guerin were evaluated by digital rectal examination and transrectal ultrasonography. When abnormal palpatory and/or ultrasonographic findings were detected, core needle biopsies from the suspicious areas were performed. Of the 36 patients 20 underwent biopsies of the prostate. Pathological findings revealed typical granulomas in 8 patients (3 caseating and 5 noncaseating multifocal granulomas). Nonspecific chronic prostatitis was noted in 4 patients and benign prostatic hyperplasia was noted in 8. The number of bacillus Calmette-Guerin instillations ranged from 6 to 19. The interval from initiation of therapy to biopsy ranged from 1.5 to 14.5 months. Caseating granulomas were found during the early course of bacillus Calmette-Guerin instillations (1.5 to 3.0 months), whereas noncaseating granulomas were detected at later stages (4 to 14.5 months). These findings present a high incidence of granuloma formation in patients treated with intravesical bacillus Calmette-Guerin. The duration of therapy is a determinant factor in the induction of granuloma type.

Administration, Intravesical↗
PubMed1990

Ontogeny of mast cells in the ventral prostate of the rat.

The ontogenic evolution of mast cells in the rat ventral prostate was studied using the Grimelius silver impregnation method. The mast cell density was highest during the pubertal period and later, it declined significantly with age. Most mast cells were identified in the fibrovascular stroma in close proximity to nerve fibers and blood vessels. The total number of mast cells seems to be constant when correlated with prostatic weight.

Age Factors↗
PubMed1989

Lectin histochemistry of brains from a murine mutant carrying a storage disorder.

A strain of Balb/c mice with neurovisceral storage disorder exhibits metabolic and phenotypic manifestations similar to those found in Niemann-Pick type C and D patients. The storage material in the brain reacted positively with periodate-Schiff reagent. To identify the chemical nature of the storage material we applied lectin histochemistry on paraffin-embedded and frozen sections, using biotinylated lectins and avidin-biotin-peroxidase complex. Major abnormalities were noted in the neurons and glia cells. Swollen neurons were stained heavily by Con A and S-WGA, whereas glia cells, mainly astrocytes, which were abundant both in the cerebrum and cerebellum, were positive to RCA-I, GS-I, PNA, S-WGA and WGA. The myelin tracts reacted with PNA, SBA and RCA-I but to a lesser extent in affected animals when compared to normals. Frozen brain sections stained positively only after extraction with chloroform methanol prior to the lectin treatment and revealed a lectin binding pattern similar to that of the paraffin-embedded preparations. The data presented here show that the stored glucoconjugates in the neurons are of a different chemical composition than those found in glia cells. Since only paraffin embedded sections or lipid extracted frozen sections reacted with the lectins, we suggest that the stored glucoconjugates are glycoproteins or oligosaccharides rather than glycolipids.

Animals↗
PubMed1989

Simultaneous occurrence of a congenital lateral upper lip sinus and congenital gingival cyst: a case report and discussion of pathogenesis.

The simultaneous occurrence of a congenital lateral sinus of the upper lip and of a congenital gingival cyst in a newborn boy is reported. The sinus extended to a depth of 10 mm and was lined by a parakeratinized squamous epithelium. The gingival cyst appeared as a 1 cm palatal enlargement lingual to the maxillary alveolar ridge and demonstrated a thin epithelial lining with localized plaquelike thickenings and occasional clear cells with vacuolated cytoplasm. There was no familial history of congenital deformities, and no additional abnormalities were noted. These two epithelium-lined structures show a clear topographic and morphologic relationship, and they may share a common embryologic origin. It is suggested that they derive from epithelium remaining subsequent to the union of the maxillary process and medial nasal process mesoderms.

Child↗
PubMed1989

The safety evaluation of Dunaliella bardawil as a potential food supplement.

The safety of the alga Dunaliella bardawil for food use, was evaluated in a multigeneration study with rats. Four generations were raised on diets containing 0, 5 or 10% dehydrated D. bardawil. Each experimental group comprised ten males and 20 females. No significant differences were observed between the rats consuming algae and the controls, of any generation, in general appearance, behaviour, growth, reproductive performance or gross pathology. The blood chemistry and haematology of the first generation animals, after 1 yr on the diets, showed no appreciable differences between the experimental and control animals. The only differences in histopathology observed were a decrease in some chronic inflammations and an increased frequency of focal bronchopneumonia in rats fed 10% algae compared with the controls. The latter effect may be attributed to the powdery nature of the algal diet. Considering the large amount of algae consumed by the experimental rats, and the absence of adverse effects in these animals, this multigeneration feeding study may be indicative of the safety of D. bardawil for human consumption.

Animal Feed↗
PubMed1989

The protracted effect of o,p'-DDD in Cushing's disease and its impact on adrenal morphogenesis of young human embryo.

We hereby present a patient with Cushing's disease who became pregnant while being treated with o,p'-DDD and underwent a therapeutic abortion in view of the known embryotoxicity and placental transfer of this drug. Biopsy of adipose tissue in this patient showed it to be the storage site of considerable quantities of o,p'-DDD. Serum levels of o,p'-DDD determined in this patient initially four months after withdrawal of treatment and in another similar case three months after withdrawal were about 20 times higher than those found in untreated patients and reached control values only about 20 months later. Repeated evaluation of plasma and urinary free cortisol failed to reveal any correlation with the serum levels of o,p'-DDD, suggesting that the drug blood values cannot be used as a reliable indicator of the therapeutic effect on the adrenal gland. The histopathological examination of the embryo, aged about 42 days, revealed a dysmorphogenic event in the cortical primordia characterized by pycnotic sympathoblasts. It is suggested that such a toxic effect of o,p'-DDD on the embryonic cortical cells may act indirectly, affecting the viability of the migrating sympathoblasts.

Abortion, Therapeutic↗
PubMed1988

The use of carbon dioxide fiberoptic laser catheter for atrial septostomy.

The development of optical fibers capable of transmitting laser energy has encouraged the experimental use of laser irradiation for the treatment of acquired cardiovascular disorders. One of the key questions is which combination of laser source, energy parameters, and transmitting fiberoptic would be best suited for intravascular use. In most experiments argon, neodymium-YAG, and excimer lasers, coupled to suitable optical fibers, have been used. We now describe the use of a carbon dioxide fiberoptic laser catheter for the creation of an atrial septal defect. Silver halide infrared transmitting fibers were inserted into standard 6 French cardiovascular catheters. This laser catheter system, capable of transmitting several watts of pulsed CO2 laser energy, was initially used to create atrial septal defects in isolated dog hearts to determine the best energy parameters. Atrial septostomy was later performed successfully in four of five anesthetized dogs. The thermal damage extended 50 to 60 micron beyond the "holes" created by the laser irradiation in the interatrial septum. Thus, pulsed CO2 laser irradiation, delivered through optical fibers, can create an atrial septal defect.

Animals↗
PubMed1988

Sebaceous gland hyperplasia following topical application of citral. An ultrastructural study.

Topical application of citral on male rat skin induces hyperplasia of the sebaceous glands. Ultrastructural study showed that this hyperplasia is manifested by an increase in number of the partially differentiated cells of the gland. Citral was found in fat droplets of the mature differentiated and partially differentiated cells. Because citral causes an increase in testosterone level, we conclude that the sebaceous gland hyperplasia is related to androgen activity.

Acyclic Monoterpenes↗
PubMed1987

Dysmyelination in NCTR-Balb/C mouse mutant with a lysosomal storage disorder. Morphological survey.

A morphological survey of the central nervous system of a NCTR-Balb/C mouse afflicted by neurovisceral storage disease was performed. It has been demonstrated that this mutant is characterized by primary dysmyelination, which is evident as early as 12 days of age. The failure of myelin formation in the CNS was shown by histochemical and ultrastructural methods. Inasmuch as neither lipid-containing macrophages nor infiltrating mononuclear cells were apparent, secondary demyelination could be excluded. The multiform ultrastructural appearance of the storage material in the various CNS cell types suggested heterogeneity of the accumulated substances. The storage materials which reacted positively with periodate-Schiff reagent, but not with other histochemical stains, are most likely the accumulated gangliosides and neutral glycosphingolipids identified previously in this mutant's brain. Considering the probable role of cholesterol ester in the early phases of myelinogenesis, in conjunction with the fact that the NCTR-Balb/C mouse carries a defect in the esterification of exogenously derived cholesterol, it is possible that the later metabolite is relevant to the impaired myelin formation.

Animals↗
PubMed1987

Further studies of a transplantable rat pheochromocytoma.

Additional histopathological and immunocytological studies were completed on the serially transplanted Warren rat pheochromocytoma. Special efforts were made to characterize features of the primary tumor common to pheochromocytomas, as well as features of the primary tumor commonly found in neuroblastoma. In summary this study found evidence for a composite primary tumor exhibiting a dual differentiative expression of both pheochromocytoma and neuroblastoma. We feel this reflects a possibility that this primary tumor arose from a common progenitor cell in the neural crest.

Animals↗
PubMed1987

Transcutaneous electrical nerve stimulation in experimental acute arthritis.

Transcutaneous electrical nerve stimulation (TENS) is applied for the relief of various types of pain, including rheumatoid arthritis and osteoarthritis. This study evaluated the influence of TENS on intraarticular (IA) temperature and pressure and synovial tissue of inflamed rabbit joints. Four hours after induction of acute bilateral hind joint arthritis by single intraarticular injection of urate crystals, the knees of 14 anesthetized rabbits were fixed at 90 degrees between femur and tibia. TENS was supplied from an electrical stimulator to the left knee joint while the other joint was unstimulated as a control. A microprobe needle for temperature measurement was inserted into the knee joint. Intraarticular pressure was recorded by polygraph connected to an IA needle. Readings were carried out at 10-min intervals three times before and four times after 5 min of TENS. A significant increase in IA temperature from mean 36.2C to 36.6C and significant reduction of IA pressure (mean decrease of 0.8 mmHg, from 2.5 mmHg to 1.7 mmHg) were found in the stimulated joints, which also showed a reduction of synovial fluid volume and total leukocyte count in comparison to the controls. While the nonstimulated synovial membrane showed massive leukocytic infiltration with neutrophilic exudate and fibrin clot in the intraarticular cavity, the stimulated synovial membrane demonstrated moderate homogeneous leukocytic infiltration through all layers, with absence of inflammatory exudate in the intraarticular cavity. These results suggested that the analgesic effect of TENS on arthritis may be partially attributed to decrease in IA synovial fluid pressure, volume, and leukocyte count. Therefore, TENS may be useful for reducing pain from inflammatory arthritis.

Animals↗
PubMed1987

Use of cultured embryonal chick epiphyseal chondrocytes as grafts for defects in chick articular cartilage.

Full-thickness defects in articular cartilage were repaired with cultured homologous embryonic chick epiphyseal chondrocytes embedded in a biological resorbable immobilization vehicle (BRIV). This graft was successfully transplanted in mechanically induced defects in the surface of condylar articular cartilage of the tibiotarsal joint of four-month-old roosters. Healing of the defects was observed macroscopically, histologically, and histochemically and with the use of biochemical analyses for six months. Chondrocyte proliferation was seen 48 hours after implantation, and a hyaline cartilage matrix surrounding the cells was present two weeks later. Within eight weeks, the defects were completely filled with hyaline cartilage, which integrated smoothly with the neighboring cartilage without the formation of fibrous tissue at the interface. The cell content and rate of proteoglycan synthesis remained high for four months, then declined slowly to the level of the surrounding cartilage. Six months after transplantation, the cartilaginous tissue in the wound at levels below the ossification front showed penetration by vascular elements and young bone trabeculae at the margins of the reparative tissue. No signs of immunogenic rejection of the implants were observed. These results may be related to the employment of a capable source of cells, i.e., cultured chondrocytes characterized by a high mitotic rate and an early stage of development. The transplanted cells grew well and maintained their initial rate of proliferation, with definite maturation and transformation. The resulting cartilage was structurally reorganized according to the host pattern and under the influence of multitudinous environmental conditions. The articular zone preserved its cartilaginous phenotype, whereas the subchondral regions were transformed into bone.

Animals↗