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Biomedical subjects

J Steinberg

Publications and source records attributed to J Steinberg.

At least 55 records · Page 3Linked to original sources
PubMed1993

Effect of one hyperbaric oxygen-induced convulsion on cortical polyamine content in two strains of mice.

In rat striatum, after one hyperbaric oxygen (HBO)-induced convulsion, polyamine changes are found that could promote N-methyl-D-aspartate (NMDA) activation. In the HBO-sensitive CD1 mouse, unlike in the common C57 strain, there is some support for NMDA activation after the HBO seizure. We measured PA cortical content before and after the first HBO-induced convulsion (about 608 kPa O2) in CD1 and C57 strains. Putrescine, spermidine and spermine were dansyl derived and analysed by HPLC. Exposure to HBO significantly increased putrescine content only in CD1 though a similar trend was observed in C57. No further increase was observed after convulsion whatever the strain. There were no significant changes in spermidine or spermine to support NMDA activation. Therefore, putrescine increase in CD1 cortex could reflect the free radical formation that is known to be greater in CD1 than in C57 mouse. Attempts to increase putrescine levels before HBO exposure hastened HBO-induced convulsion, less than spermidine or spermine. Because of physiological polyamine interconversion, additional experiments with indirect manipulation of putrescine levels and study of their time-course would precise these preliminary reports on putrescine and HBO.

Animals↗
PubMed1993

Comparison of vasovasostomy techniques in rats utilizing conventional microsurgical suture, carbon dioxide laser, and fibrin tissue adhesives.

An evaluation of vas reanastomoses in rats comparing suture only, carbon dioxide (CO2) laser-assisted, and fibrin-based tissue adhesive was performed in our laboratory. A cohort of 60 known fertile male Sprague Dawley rats initially underwent lower midline abdominal exploration and transection of their vas deferens bilaterally, followed by immediate microsurgical vasovasostomy by one of the three experimental methods. All groups initially had the severed vasa ends coapted by two or three transmural (mucosa through serosa) sutures of 10-0 nylon under an operating microscope. The conventionally sutured group had an additional four to six nylon 10-0 sutures placed externally in the serosa only to complete the anastomosis. The CO2 laser-assisted group underwent laser welding with denaturation of the serosa to seal the anastomosis. A fibrin-based tissue adhesive, produced by combining human cryoprecipitate and thrombin, was placed topically over the coapted vas ends to seal the anastomosis in the third group. Postoperative evaluation revealed similarities among the three surgical groups with the fibrin-based tissue adhesive group resulting in the highest patency rate (89%) and pregnancy rate (85%) as well as the lowest granulation rate (18%) and shortest operative time (27 minutes). The laser-assisted group resulted in the lowest pregnancy rate (68%), while the sewn anastomosis group had the lowest patency rate (76%). Both laser-assisted and conventionally sewn vasectomy reversals required significantly longer operative time (39 and 46 minutes, respectively) compared with the fibrin-based tissue adhesive-assisted procedures (p < 0.01). This study provides evidence that alternative microsurgical techniques may be utilized to perform uncomplicated, expeditious, and successful vasectomy reversals.

Animals↗
PubMed1993

Desipramine does not alter plasma GABA in patients with major depression.

Low plasma GABA is a biological marker for depression in a subset of patients tested. Plasma GABA has been shown to reflect brain GABA activity. This marker has many characteristics of a trait marker for depression, including stability with time, and lack of influence by coincident factors such as gender, season, time, activity or diet. We here report that plasma GABA remained stable after 4 weeks of treatment with desipramine in patients with major depression. Since the levels of plasma GABA did not change with time, nor with clinical improvement, plasma GABA is not a state marker of depression.

Adult↗
PubMed1993

Evaluation and treatment of post-traumatic stress disorder.

Post-traumatic stress disorder (PTSD) is a common anxiety disorder seen by general practice physicians as well as by specialists. The authors review current assessment criteria, psychotherapy procedures, and psychopharmacological management of PTSD patients.

Antidepressive Agents↗
PubMed1992

Prognostic factors in patients with metastatic colorectal cancer receiving 5-fluorouracil and folinic acid.

We have reported that 5-fluorouracil (5-FU) and folinic acid increased response rate and survival in patients with metastatic colorectal cancer. Now we have analysed prognostic factors for response, toxicity, survival and time to progression. The variables used for survival and response were treatment centre, treatment, age, sex, Eastern Cooperative Oncology Group (ECOG) performance status (PS), site of disease, previous radiotherapy, site of primary, disease-free interval, initial alkaline phosphatase (AP), albumin (A), lactate dehydrogenase (LDH) and aspartate aminotransferase (SGOT). The significant independent variables for survival were PS of 2 or more, initial albumin and SGOT, and treatment received, in order of importance. The relative risk of death when patients received 5-FU/folinic acid was 60% of that of patients receiving 5-FU alone. The variables predictive of response were treatment and PS. The variables used for analysis of toxicity were age, treatment centre, treatment, sex, tumour response, PS, number of courses, SGOT, AP and albumin. Treatment was found to be predictive of toxicity. Thus, baseline albumin and SGOT, and 5-FU/folinic acid treatment are significant determinants of survival, 5-FU/folinic acid and PS of 2 or more are major determinants of response and no clinical parameter could be identified as a predictor of toxicity.

Adult↗
PubMed1992

Effect of diabetes on in vivo and in vitro hypothalamic somatostatin release.

In order to better understand the mechanisms underlying the reduction in growth hormone (GH) secretion in diabetic rats, we studied hypothalamic somatostatin secretion both in vivo (into hypophysial portal blood) and in vitro (from hypothalamic fragments) 5, 9 and 30 days after induction of diabetes. Experimental diabetes was induced by an intraperitoneal injection of streptozotocin (STZ) at a dose of 65 mg/kg. Basal plasma GH was significantly reduced in diabetic rats at all stages. Somatostatin levels in hypophysial portal blood was unaffected in 5-day STZ-diabetic rats and significantly increased 9 days after STZ administration. Chronic insulin replacement therapy in diabetic animals partly normalized somatostatin levels as well as plasma GH and glucose levels. A good correlation was observed between in vivo and in vitro experiments. Indeed, somatostatin release from hypothalamic fragments did not change 5 days after STZ-induced diabetes and significantly increased 9 and 30 days after STZ administration. The in vitro increase in hypothalamic somatostatin secretion was observed in 10 as well as in 33 mM glucose concentration in the incubation medium. In the same experiment, the in vitro hypothalamic corticotropin-releasing factor secretion was lowered 5 and 9 days after diabetes induction. We conclude that hypothalamic somatostatin release increases in diabetic rats. These changes may contribute to the reduction in GH secretion in these animals. However, since these changes occur after the onset of plasma GH decrease, a factor(s) other(s) than somatostatin may play a causal role in the reduction in GH secretion.

Animals↗
PubMed1992

Cardiosynchronous limb compression: effects on noninvasive vascular tests and clinical course of the ischemic limb.

Some patients with chronic arterial obstruction of the limbs may still suffer the consequences of advanced tissue ischemia, including ulceration and rest pain, and face threatened limb loss in spite of available surgical, pharmacologic, and other treatments. Additional therapeutic modalities were thus sought to accomplish limb salvage. A literature review indicated that most reports on R-wave-triggered circumferential limb compression (cardiosynchronous limb compression [CSC]) demonstrate its ability to augment limb arterial blood flow and improve ischemic limbs. To determine the device's efficacy and safety, and possibly confirm earlier positive reports, a systematic study was undertaken, using older, as well as newer, more electronically reliable CSC devices. The present study was designed to determine the following: 1. objectively, by noninvasive vascular tests, changes in limb blood flow, if any, by CSC; 2. clinical effects of CSC, if any, on the ischemic limb; 3. duration of CSC-induced limb improvements, if any; 4. side effects or safety of CSC. The study demonstrated that CSC treatments: 1. caused increased limb blood flow as determined by increased ankle/arm indices and hallux photoplethysmograph waveform amplitudes during treatments; 2. led, in most cases, to improvement in or resolution of the presenting ischemic problem (eg, ulcer, cellulitis, rest pain); 3. induced limb improvements that persist for up to seven years 4. caused no adverse side effects.

Aged↗
PubMed1992

AIDS prevention is thicker than blood. Zimbabwe.

Usually, giving blood is generous. Sometimes, however, it is lethal. In countries such as the US, India and Brazil, where blood donors can get paid by the pint, drug addicts, street dwellers and others who have little to sell except their bodies flock to for-profit blood centers. Many of these people carry the AIDS virus. A survey in the Indian state of Maharashtra revealed that 27% of blood donors tested positive for AIDS antibodies--a slightly higher rate than the same survey found among prostitutes. If 1 private blood bank tests for AIDS antibodies and turns HIV-positive volunteers away--forget about treating them--those poor and desperate enough can often find another, less scrupulous clinic. Or a clinic that doesn't do the testing properly. Although the 1988 Brazilian constitution banned the sale of blood, private clinics continue to flourish and nobody knows whose veins the blood is flowing from. The inevitable result is a frightening rate of contamination. An estimated 85% of Brazilian hemophiliacs have become infected with the HIV virus by contaminated blood or blood products. Even in countries that eschew blood sales and rely on donated supplies, the danger of HIV contamination is still present. HIV infection often does not generate antibodies for weeks; sometimes months or even years. In many 3rd World communities without adequate equipment, blood storage is impossible. The cost of testing emergency donations is so high that the choice may be narrowed--either go without testing or do without blood. Despite all these obstacles, Zimbabwe has shown that a 3rd World country where public health care takes precedence over private profit can make the blood supply network a force for reducing the spread of AIDS rather than increasing it. All blood donations in Zimbabwe were voluntary even before AIDS became an issue. When AIDS was accorded recognition as a serious issue, the country had no clinic for HIV testing. Concerned with the rapid spread of AIDS among the general population, the National Blood Transfusion Service (NBTS) began testing in 1985. Zimbabwe was the 3rd country in the world to begin routine testing. The NBTS is a nonprofit organization headed by representatives from the ministry of health, the Red Cross, and private donors. Because the NBTS was the only group in the country testing blood, many people who suspected they might be infected volunteered to donate blood just so they could have the test. Unfortunately, their suspicions were often justified. The service has found that regular donors now have a far lower incidence of HIV-positive since 1989, when alternative testing services were opened. Analysts believe much of the credit goes to the AIDS counseling given before each blood donation. Each individual is interviewed by a nurse who takes a comprehensive medical history. The education session also includes how AIDS might be contracted. The NBTS quickly discovered that the incidence of HIV antibodies was far lower among students aged 17-19. Since then, the service has thrown much of its resources into school blood campaigns. The service has also opened 5 new collection branches, 1 in each province. Samples from each donation are sent to 1 of the 2 national centers for testing. AIDS is still spreading in Zimbabwe, but thanks to the efforts of NBTS, hospital patients can feel secure.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Alcohol and breast cancer risk--putting the current controversy into perspective.

The potential association of alcohol intake with breast cancer risk is currently being debated in the literature and a clear consensus of opinion has not emerged. Clarification of the issues surrounding this controversy would be helpful in developing recommendations for the general public regarding alcohol use. A review of the available evidence regarding the association of alcohol with breast cancer is presented followed by an application of the Bradford Hill criteria for causal inference to this data to examine the existence and nature of the association of alcohol with breast cancer risk. Results of published studies demonstrated a weak association of alcohol with breast cancer risk that was consistent only for relatively high levels of intake (more than 1 or 2 drinks daily). Increasing daily intake was associated with increased risk, but the association was not linear. Criteria relating to temporality and analogy to other causal associations were satisfied while inconsistent evidence was available for those relating to epidemiologic and biologic sense. The criterion for specificity was not satisfied and no experimental evidence was available. It is concluded that insufficient evidence exists to support a causal association of alcohol consumption with breast cancer risk. Further research is recommended to resolve conflicting evidence and to provide additional evidence where needed. In the meantime, recommendations that women should reduce their consumption of alcohol beyond existing guidelines to modify breast cancer risk are probably premature.

Alcohol Drinking↗
PubMed1991

Acute urinary retention secondary to Herpes simplex meningitis.

We report a case of acute urinary retention in a 24-year-old man with Herpes simplex meningitis without genital lesions. Since the differential diagnosis in young patients who present with acute urinary retention also includes multiple sclerosis, lumbosacral disk herniation, rheumatological disorders and drug intoxication, a thorough history and careful neurological examination are of paramount importance in distinguishing these syndromes. As part of a directed neurological evaluation prompt performance of lumbar puncture is indicated; a lymphocytic pleocytosis is suggestive of herpetic meningitis. Culture of Herpes simplex virus from the cerebrospinal fluid should be attempted. We recommend conservative management only, typically with intermittent catheterization, since bladder function usually normalizes within 10 to 14 days.

Acute Disease↗
PubMed1990

Use of thermography in the differential diagnosis of phylloides tumour.

Thermography can be used as a method of diagnosing breast masses. We report our results of its use in the differential diagnosis of fibroadenoma from phylloides tumours (n = 47 and 20 respectively). Thermographic resolution (Th) and the difference in temperature between the tumour and a similar zone in the contralateral breast (delta 2) were compared. Thermograms were class Th1 (with a similar thermal pattern in both breasts without hypervascularization or hot points) and Th2 (with hypervascularization or a hot area with a thermal difference with the same area in the opposite breast (delta 2) of less than 2 degrees C) in most (95.7 per cent) of the patients with fibroadenoma and were class Th5 (having one or more pathological sign) in 85 per cent of the patients with phylloides tumours. Patients with phylloides tumours had a mean delta 2 of 2.99 degrees C whereas most of the patients with a fibroadenoma showed no difference in temperature. Their mean delta 2 was 0.2 degrees C (P less than 0.0005). We conclude that thermography helps in differential diagnosis between a fibroadenoma and a phylloides tumour.

Adenofibroma↗
PubMed1990

Cognition and metacognition at extreme altitudes on Mount Everest.

The FACTRETRIEVAL2 test battery, which assesses both retrieval of general information from memory and metacognition about that retrieval, was administered to people before and after a recent expedition to Mount Everest and at extreme altitudes above 6,400 m (higher than any mountain in North America or Europe). The major findings were as follows: First, the same extreme altitudes already known to impair learning did not affect either accuracy or latency of retrieval, and this robustness of retrieval occurred for both recall and forced-choice recognition. Second, extreme altitude did affect metacognition: The climbers showed a decline in their feeling of knowing both while at extreme altitude and after returning to Kathmandu (i.e., both an effect and an aftereffect of extreme altitude). Third, extreme altitude had different effects than alcohol intoxication (previously assessed by Nelson. McSpadden, Fromme, & Marlatt, 1986). Alcohol intoxication affected retrieval without affecting metacognition, whereas extreme altitude affected metacognition without affecting retrieval; this different pattern for extreme altitude versus alcohol intoxication implies that (a) hypoxia does not always yield the same outcome as alcohol intoxication and (b) neither retrieval nor metacognition is strictly more sensitive than the other for detecting changes in independent variables.

Adult↗
PubMed1990

A double-blind, placebo-controlled trial of thymostimulin in symptomatic HIV-infected patients.

The potential therapeutic efficacy of the thymic hormone preparation, thymostimulin (TP1), in HIV infection has been studied in a multi-institutional, randomized, double-blind, placebo-controlled trial. Fifty evaluable patients with advanced AIDS-related complex (ARC) were injected with TP1 or placebo twice weekly for 6 months after 2 weeks of daily injections. The primary endpoint, progression to AIDS, was reached in nine TP1- and 11 placebo-treated subjects after 1 year. CD4 cell numbers were not affected by administration of the study drug. No toxicity was associated with TP1 treatment. We conclude that TP1 is ineffective in altering the progress of HIV disease in patients with advanced ARC.

AIDS-Related Complex↗
PubMed1990

The use of collagen membrane barriers in conjunction with combined demineralized bone-collagen gel implants in human infrabony defects.

The present study evaluated the clinical efficacy of a combined graft of autolysed antigen-extracted allogeneic (AAA) bone and microfibrillar collagen (Zyderm) covered with a resorbable collagen membrane in human infrabony defects. The results were compared at 1 year with debrided controls, AAA bone grafts alone, combined AAA bone-collagen grafts (without membrane), and debrided defects covered only with collagen membranes. Ten adult patients having moderate periodontitis and one or more radiographically detectable angular defects probing 6 mm to 7 mm in each quadrant were included. Preoperative measurements of clinical attachment, probing depth, and recession were taken and compared at 1 year following surgery. Measurements at the time of surgery and at 1 year re-entry evaluated osseous defect fill and crestal changes. Each patient received the 5 treatment modalities. Treatment results per patient were used for a series of 2-way analyses of variance. When a significant difference was found, a Student-Newman-Keuls multiple range test was used to determine which treatments were statistically different (0.05 probability level) from each other. All treatment modalities showed improvement over the debrided controls. Similar advantages to using bone-collagen grafts with and without membranes were found in reducing probing depths and gaining new attachment. Significant differences were found when comparing the multifaceted bone graft collagen-membrane technique to all others in achieving superior defect fill. Ninety three percent of all defects treated resulted in 50% or greater fill.

Adult↗
PubMed1989

Bacterial tracheitis in children.

We examined the records of 14 patients aged 7 months to 10 1/4 years who were treated for bacterial tracheitis from May 1982 to December 1987; the management protocol for 13 of the patients included the use of nasotracheal intubation. The infection was caused by Staphylococcus aureus in seven, Haemophilus influenzae in three, Branhamella catarrhalis in one and Streptococcus pneumoniae in one. Both H. influenzae and B. catarrhalis were isolated in another patient, and no organism was found in the remaining patient. In addition to the bacteria, viruses were cultured from the tracheal secretions of two patients. The mean duration of intubation was 7.6 days and of hospital stay 9.2 days. Twelve of the cases occurred during the cold months of the year (October to March). Of the three deaths only one occurred in the pediatric intensive care unit and was due to severe bronchospasm and an air leak that caused bilateral pneumothorax and pneumomediastinum. In one patient subglottic stenosis developed that necessitated tracheostomy. Healing began 5 to 9 days after the onset of symptoms, as demonstrated with the use of repeated fibreoptic bronchoscopy. We found that the airway could be safely managed with the use of a nasotracheal tube. Bronchoscopy helped to confirm the diagnosis, to remove adherent secretions and to monitor the course of the disease. The ventilation tube can be removed after the patient's temperature returns to normal, if there is an air leak around the tube, if the quantity and viscosity of the secretions decrease and if healing is observed at bronchoscopy.

Airway Obstruction↗