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Biomedical subjects

A Chernoff

Publications and source records attributed to A Chernoff.

13 recordsLinked to original sources
PubMed1997

Periurethral collagen injection for the treatment of urinary incontinence in children.

PURPOSE: We assessed the efficacy and safety of periurethral collagen injection for urinary incontinence in children with neurogenic bladder dysfunction. MATERIALS AND METHODS: We treated 11 children (mean age 10.6 years) who had incontinence and neurogenic bladder dysfunction with periurethral injections of glutaraldehyde cross-linked collagen. All patients were on anticholinergics and all but 1 were on clean intermittent catheterization preoperatively. Four patients had previously undergone augmentation cystoplasty. All patients were assessed before and after injection with a subjective continence scale and multichannel urodynamics. Followup ranged from 4 to 20 months from the last injection. RESULTS: Mean group Valsalva leak point pressure was 34.5 cm. water. Four of the 11 patients had an identifiable detrusor leak point pressure. Overall success rate was 55% with 4 patients dry and 2 improved. Success correlated with a minimum increase in Valsalva leak point pressure of 20 to 25 cm. water to greater than 60 cm. water. Three patients had no demonstrable Valsalva leak point pressure after injection. All 5 patients in whom treatment failed had no change in Valsalva leak point pressure, including 2 with small capacity, poorly compliant bladders preoperatively. Because they had a component of sphincteric insufficiency, they underwent injection in the hope of increasing capacity with increased continence. In 3 patients Valsalva leak point pressure was greater than 50 cm. water. Detrusor leak point pressure developed in 3 patients postoperatively, including 1 with significantly increased Valsalva leak point pressure. One patient with significantly increased Valsalva leak point pressure had urethral hypermobility postoperatively. Of the 3 patients who subsequently underwent augmentation cystoplasty 1 is now dry, 1 is wet and 1 died of complications unrelated to urological disease. Patients underwent 1 to 4 procedures (mean 2.5). CONCLUSIONS: Periurethral collagen injection may be effective for urinary incontinence in patients who have adequate capacity with good compliance and low Valsalva leak point pressure. When there is no response to repeat injections or a transient response, one should consider the possibility of bladder decompensation.

Adolescent↗
PubMed1992

Blood donation and transfusion practices: the 1990 American Association of Blood Banks Institutional Membership Questionnaire.

Responses to the 1990 American Association of Blood Banks (AABB) Institutional Membership Questionnaire were submitted by 2126 regional blood centers, hospital-based blood banks, and transfusion facilities. Data from 2117 of these facilities were considered to be valid. The questionnaire included information on blood donor demographics, number of units collected, and collection procedures; services performed; usage of blood components; and transfusion-transmitted diseases reported during 1989. Institutional members collected 7.4 million whole blood units, of which 90.8 percent were donated for allogeneic use, 6.0 percent were donated for autologous use, and 3.2 percent were donated for directed use. Approximately 630,546 allogeneic and directed-use blood donors were deferred, most often for low hemoglobin or hematocrit values. Approximately 225,205 full allogeneic and directed-donor units were discarded, primarily for elevated alanine aminotransferase levels or the presence of hepatitis B core antibody. The 14.3 million transfused components included 56.7 percent red cell-containing components, 27.4 percent platelets, 11 percent fresh-frozen plasma, and 4.8 percent cryoprecipitate. Institutional members reported 1397 cases of transfusion-associated hepatitis. In this group, 921 patients were tested for hepatitis B surface antigen after the transfusion; 339 (36.8%) were found to be hepatitis B surface antigen positive. The AABB Institutional Questionnaire results provide recent data on blood donor and transfusion-related activities that are vital to the evaluation of current transfusion medicine practices.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Endobronchial lymphocytic infiltration. Unusual manifestation of chronic lymphocytic leukemia.

This report describes a patient with chronic lymphocytic leukemia followed over a 15-year period. The distinctive feature of her course was the infiltration of the bronchial wall by malignant lymphocytes, which produced endobronchial obstruction, atelectasis, and infection. Symptomatic improvement occurred following local irradiation and steroid therapy. A review of the literature establishes that the development of endobronchial infiltration during the course of chronic lymphocytic leukemia and other lymphoproliferative disorders is distinctly uncommon.

Biopsy↗
PubMed1980

Origin of platelet-derived growth factor in megakaryocytes in guinea pigs.

Growth factor activity, as determined by the stimulation of [3H]thymidine incorporation into the DNA of quiescent 3T3 cells in culture, was found in lysates of guinea pig platelets and megakaryocytes. Quantitative dilution studies demonstrated that, of the cells present in the guinea pig bone marrow, only the megakaryocyte possessed quantitatively significant growth factor activity. The amount of activity present in one megakaryocyte was equivalent to that present in 1,000-5,000 platelets, a value approximately comparable to the number of platelets shed from a single megakaryocyte. It is suggested that guinea pig platelet-derived growth factor has its origin in the megakaryocyte.

Animals↗
PubMed1979

Release of platelet-derived growth factor from human platelets by arachidonic acid.

Platelet alpha-granules contain a factor that stimulates the proliferation of arterial smooth muscle cells and may play a role in atherogenesis. We have studied the role of arachidonic acid in mediating the release of the platelet-derived growth factor (PDGF) from human platelets. PDGF was assayed by stimulating of [(3)H]thymidine incorporation into DNA of mouse 3T3 cells. Platelet aggregation and the release of platelet factor 4,beta-thromboglobulin, and serotonin were also studied. A biphasic response pattern was observed when gel-filtered platelets were incubated with arachidonate over the concentration range 0.01-0.4 mM. At low arachidonate levels (approximately 0.025-0.1 mM), specific concentration-dependent aggregation and release of PDGF and of the other components were observed. This effect was not seen with any of five other fatty acids tested and was suppressed by indomethacin (25 muM). At higher arachidonate concentrations (approximately 0.15-0.35 mM), a concentration-dependent turn-off of both aggregation and release occurred. At these concentrations the platelets remained functional, and no release of lactate dehydrogenase was observed. A similar biphasic pattern of arachidonate-induced aggregation and release was observed with platelet-rich plasma, over a similar range of arachidonate to albumin mole ratios. These studies demonstrate that PDGF and other alpha-granule constituents can be released from platelets specifically by arachidonate via an indomethacin-sensitive pathway, most probably involving the platelet cyclooxygenase and conversion of arachidonate to prostaglandin metabolities. The mechanisms responsible for the turn-off of the specific arachidonate-mediated responses at higher arachidonate concentrations remain to be defined.

Arachidonic Acids↗