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Biomedical subjects

A Cohen

Publications and source records attributed to A Cohen.

At least 307 records · Page 17Linked to original sources
PubMed1997

Epidural analgesia, intrapartum fever, and neonatal sepsis evaluation.

OBJECTIVE: Although several studies have documented an increase in maternal temperature associated with use of epidural analgesia during labor, none have investigated the impact of epidural use on the rate of intrapartum fever or the consequences for the fetus and newborn of this elevated maternal temperature. This study evaluates the impact of epidural analgesia use during labor on the rate of intrapartum fever and the performance of neonatal sepsis evaluations and treatment with antibiotics. METHODS: We studied 1657 nulliparous women with term pregnancies and singleton vertex fetuses who were afebrile at admission for delivery. The rates of maternal intrapartum fever >100.4 degrees F, neonatal sepsis evaluation, and neonatal antibiotic treatment according to use of epidural analgesia during labor were determined. Rate ratios and 95% confidence intervals (CI) were calculated. Multiple logistic regression was used to examine associations while controlling for confounding factors. RESULTS: Intrapartum fever >100.4 degrees F occurred in 14.5% of women receiving an epidural but only 1.0% of women not receiving an epidural (adjusted odds ratio (OR) = 14.5, 95% CI = 6.3, 33.2). Without epidural, the rate of fever remained low regardless of length of labor; with epidural, the rate of fever increased from 7% for labors < or = 6 hours to 36% for labors >18 hours. Neonates whose mothers received epidurals were more often evaluated for sepsis (34.0% vs 9.8%; adjusted OR = 4.3, 95% CI = 3.2, 5.9) and treated with antibiotics (15.4% vs 3.8%; adjusted OR = 3.9, 95% CI = 2.1, 6.1). Although 63% of women received epidurals, 96.2% of intrapartum fevers, 85.6% of neonatal sepsis evaluations, and 87.5% of neonatal antibiotic treatment occurred in the epidural group. CONCLUSIONS: Use of epidural analgesia during labor is strongly associated with the occurrence of maternal intrapartum fever, neonatal sepsis evaluations, and neonatal antibiotic treatment.

Analgesia, Epidural↗
PubMed1997

TNF-alpha-induced insulin resistance in vivo and its prevention by troglitazone.

Tumor necrosis factor (TNF)-alpha may play a role in the insulin resistance of obesity and NIDDM. Troglitazone is a new orally active hypoglycemic agent that has been shown to ameliorate insulin resistance and hyperinsulinemia in both diabetic animal models and NIDDM subjects. To determine whether this drug could prevent the development of TNF-alpha-induced insulin resistance, glucose turnover was assessed in rats infused with cytokine and pretreated with troglitazone. Normal male Sprague-Dawley rats were fed normal powdered food with or without troglitazone as a food admixture (0.2%). After approximately 10 days, rats were infused with TNF-alpha for 4-5 days, producing a plasma concentration of 632 +/- 30 pg/ml. In vivo insulin action was measured by the euglycemic-hyperinsulinemic clamp technique at a submaximal (24 micromol x kg[-1] x min[-1]) and maximal insulin infusion rate (240 micromol x kg[-1] x min[-1]). TNF-alpha infusion resulted in a pronounced reduction in submaximal insulin-stimulated glucose disposal rate (GDR) (97 +/- 10 vs. 141 +/- 4 micromol x kg[-1] x min[-1], P < 0.05), maximal GDR (175 +/- 8 vs. 267 +/- 6 micromol x kg[-1] x min[-1], P < 0.01), and in insulin receptor-tyrosine kinase activity (IR-TKA) (248 +/- 39 vs. 406 +/- 32 fmol ATP/fmol IR, P < 0.05). It also led to a marked increase in basal insulin (90 +/- 24 vs. 48 +/- 6 micromol/l, P < 0.05) and free fatty acid (FFA) concentration (2.56 +/- 0.76 vs. 0.87 +/- 0.13 mmol/l, P < 0.01). Troglitazone treatment completely prevented the TNF-alpha-induced decline in submaximal GDR (133 +/- 16 vs. 141 +/- 4 micromol x kg[-1] x min[-1], NS) and maximal GDR (271 +/- 19 vs. 267 +/- 6 micromol x kg[-1] x min[-1], NS). The hyperlipidemia was partially corrected by troglitazone (1.53 +/- 0.28 vs. 0.87 +/- 0.13 mmol/l, P < 0.05), while IR-TKA and insulin concentration remained unaffected by the drug. Troglitazone restores insulin action possibly by lowering the FFA concentration of the blood and/or by stimulating glucose uptake at an intracellular point distal to insulin receptor autophosphorylation in muscle. If TNF-alpha plays a role in the development of the obesity/NIDDM syndrome, troglitazone may prove useful in its treatment.

Adenosine Triphosphate↗
PubMed1997

Home hospitalization in the spectrum of community geriatric care.

The Home Hospitalization Programme was initiated in Jerusalem in 1991 to provide intensive medical care at home in order to prevent or shorten hospitalizations. The programme was based upon regular home visits by physicians, and nursing assessment to determine the need for regular nursing care. Primary-care physicians and nurses were renumerated by a global monthly fee, and were on 24-h call in addition to their periodic visits. Patients were recruited by senior geriatric physicians from acute hospital wards, as well as from the community, at the family doctor's request. Ancillary services available to the home hospitalization team included laboratory and electrocardiographic testing, specialty consultations, physical occupational or speech therapy, social work and home help up to 3 h daily. Monthly visits by a senior physician provided oversight and further consultation. Home hospitalization grew out of the continuing care division of the Clalit Sick Fund, a health maintenance organization providing umbrella medical insurance and ambulatory care. The programme grew synergistically with the other facilities of continuing care to encompass a network of comprehensive services to acute, subacute and chronic patients both at home and in institutional settings. In 4 years this network succeeded in establishing the focus of subacute intensive care in the community, achieving high levels of patient and family satisfaction, as well as striking economic advantages. In its first 2 years of operation home hospitalization saved S4 million due to reduced hospital utilization, and preliminary data for the subsequent 2 years indicated that this trend continued. Home hospitalization became the hub of a far-reaching system of supportive, intensive and humane care in the community.

Aged↗
PubMed1997

A substance abuse consultation service. Enhancing the care of hospitalized substance abusers and providing training in addiction psychiatry.

The authors review the literature on the high prevalence but underrecognition of substance abuse among hospitalized patients and the general unavailability of hospital-based substance abuse consultation services. They describe the development, clinical operations, staffing, and teaching activities of a large substance abuse consultation service in one urban academic medical center and detail the service's growth and changing utilization patterns over an 8-year period, reporting the clinical characteristics of 1,819 patients seen over a 1-year period. Differences in patient demographics, patterns of substance use, and diagnoses were highly significant from one referring service to another. The authors discuss the implications of such a service for patient care and teaching.

Adult↗
PubMed1997

Clinical and epizootiological study of a leptospirosis outbreak due to Leptospira canicola in a feedlot.

This report describes the epizootiology, clinical presentation, diagnosis and treatment of an outbreak of leptospirosis caused by Leptospira canicola in feedlot calves. The infection appeared to be of high morbidity with a cumulative clinical incidence of 15.6%, cumulative subclinical incidence of 39% and high mortality (8.3%). Clinical disease was diagnosed in 4-8-month-old calves, while subclinical infection occurred in 9-12-month-old calves. Subclinical infection was based on serological evidence only. The zoonotic aspects of the infection are emphasised.

Animal Feed↗
PubMed1997

[Clinical, echocardiographic and Doppler outcome in ischemic right ventricular dysfunction associated with inferior wall infarction].

Right ventricular involvement during inferior wall myocardial infarction does not seem to alter long-term clinical prognosis but its specific outcome has not been clearly studied. We have previously demonstrated that pulmonary regurgitant (PR) flow tracings doppler analysis allows the accurate diagnosis of RV involvement, especially when the pressure half-time of PR was < or = 150 ms and the ratio of the minimal velocity to the maximal velocity was < or = 0.5. We studied 40 patients with acute inferior wall myocardial infarction and with PR flow. Doppler echocardiography was obtained during the first day, before discharge (early control) and between 12 and 24 months follow-up (late control). Among 22 patients with RV involvement defined with PR-derived doppler parameters (RVIPR). 8 had right ventricular enlargement and/or wall motion abnormalities, observed in 6 cases at early control and in 4 at late control. Doppler analysis showed remnant RVIPR parameters in 9 patients at early control and 8 among these at late contorl, with no relation with pulmonary artery pressure or other echocardiographic parameters. No clinical, angiographic or therapeutic data predicted these distinct echocardiographic and doppler patterns and the long-term prognosis was not different. At late control, among 12 RVIPR patients which PR-derived doppler parameters were normal at early control, two patients had still RVIPR pattern at late control and described ischemic recurrence. PR flow doppler analysis is a useful tool for diagnosis and outcome evaluation of RV involvement and shows a remnant diastolic dysfunction in half of the patients with acute RV involvement.

Aged↗
PubMed1997

Strategies to protect bone mass in the older patient with epilepsy.

The annual incidence of epileptic seizures rises dramatically after the age of 60. Risk factors associated with late-onset epilepsy include cerebrovascular disease, dementia, infection, trauma, and alcoholism. The dominant cause of seizures in older patients is a previous stroke, whereas a significant percentage of cases are attributed to the presence of a tumor. Normal aging is associated with an increased risk for fractures from trauma and osteoporosis. Antiepileptic medications may exacerbate this problem by adversely affecting bone metabolism and increasing the risk of falls related to drug toxicity. The patient work-up, careful prescribing, and monitoring for drug toxicity can help preserve bone integrity in patients receiving antiepileptic drug therapy.

Age Factors↗
PubMed1997

[Evaluation of aortic atherosclerosis by transesophageal echocardiography. Prognostic implications].

A recent anatomical study has reported a relationship between the presence of ulcerated atheromatous plaque of the aortic arch and cerebral infarction. Several studies using transoesophageal echocardiography have established that atherothrombosis of the ascending and proximal is a potential source of systemic embolism. We have shown that aortic plaques > or = 4 mm in thickness increase the risk of cerebral infarction by 9. Several studies have shown that this localisation of atherosclerosis was also a powerful marker of general vascular risk. In the multicenter FAPS (French Study of Aortic Plaque in Stroke) trial, the authors followed up 331 patients who had suffered cerebral infarction, aged over 60 years, for a mean duration of 2.4 years. The occurrence rate of cerebral infarction and the incidence of cardiovascular complications (death, myocardial infarction, cerebral infarction, systemic embolism) was respectively 11.9% and 26% per year. The presence of plaques with thickness greater or equal to 4 mm was associated with an adjusted relative risk of 3.8 (95% confidence interval, 1.8 to 7.8) and 3.5 (95% confidence interval, 3.1 to 5.9) respectively. The influence of plaque morphology (thrombus, irregularity, absence of calcification), independently of its thickness, also seems to affect the prognosis. In this study, as in those reported by other groups, the influence of anti-thrombotic therapy was not specifically addressed. The definition of high risk plaques (thickness, irregularity, thrombus) could be useful in the evaluation of therapy which affects the atherosclerotic process (antiplatelet agents, anticoagulants, statins). We conclude that atherosclerosis of the ascending aorta and aortic arch is a potential source of systemic embolism and a powerful marker of overall vascular risk.

Aged↗
PubMed1997

Adjuvant therapy of colorectal cancer.

Approximately 141,000 patients will develop colorectal cancer each year and 45% will have positive lymph nodes, one of the most significant predictors of survival. Now there is evidence that systemic chemotherapy with fluorouracil (FU) and leucovorin, levamisole, or FU and leucovorin with decrease recurrence and increase survival for patients with Dukes' C colon cancer. In patients with Dukes' B or C rectal cancer, combined radiation and FU increase survival and decrease local and distal recurrence.

Adjuvants, Immunologic↗
PubMed1997

Splenectomy for haematological diseases--a single institution experience.

OBJECTIVES: To evaluate our experience with splenectomy for haematological disease over 15 years, focusing on the diseases and indications requiring surgery, the complications and the haematological results. DESIGN: A single institution retrospective analysis. SETTING: Departments of Surgery, Internal Medicine and Haematology, Rabin Medical Center, Hasharon Hospital, Petah-Tikva, Israel. PATIENTS: Sixty-nine patients undergoing splenectomy for haematological diseases between 1980 and 1994. PARAMETERS STUDIED: (1) the patient characteristics; (2) the haematological disorders and the indications for splenectomy; (3) the splenic size; (4) perioperative complications; (5) the haematological and other results of surgery. RESULTS: The common disease requiring splenectomy in our patient population was immune thrombocytopenic purpura (ITP). Eighteen patients (26%) suffered from ITP, 12 (17.4%) had lymphoproliferative (LP) disorders, including 11 patients with non-Hodgkin's lymphoma (NHL), 9 (13%) immune haemolytic anaemia (IHA), 8 (11.6%) Hodgkin's disease (HD), and 8 patients with myeloproliferative diseases (MPD). Fifty-two patients (75.4%) underwent surgery for therapeutic purposes while 25 patients (36.2%) underwent diagnostic surgery. Eight patients were operated on for both indications. Patients with HD and ITP were younger (mean age in the 30th year) as opposed to patients with congestive splenomegaly and LP (mean age in the 60th year). Most patients with ITP, NHL and IHA were female. Patients with HD and ITP had a small spleen (< 300 g), in contrast with HCL and MPD (> 2400 g). No perioperative mortality was observed. Twenty-one patients (30.4%) experienced perioperative complications, including bleeding in 9 patients (13%) and infection in 10 patients (14.5%). Of the 34 patients evaluable for platelet response to splenectomy, 26 (76.5%) achieved complete response (CR), including 15 of 18 patients with ITP. Eleven of the 17 (64.7%) anaemic patients evaluable for haemoglobin (Hb) response achieved CR. Eight of the 9 leucopenic patients obtained CR. In 15 patients, splenectomy established the diagnosis, including 8 patients with NHL. In 2 others, surgery confirmed the tentative diagnosis. In 2 of the 8 HD patients the spleen was found to be involved. CONCLUSIONS: From both therapeutic and diagnostic standpoints splenectomy is a relatively safe and effective procedure. However, no long-term follow-up data are provided to allow conclusions regarding the long-term prognosis of diseases such as myelo- or lymphoproliferative disorders.

Adolescent↗
PubMed1997

[Dobutamine stress echocardiography; a monocentric experience on 600 consecutive patients. Effect of age].

The increasing indications of dobutamine stress echo in the investigation of myocardial ischaemia, viability and evaluation of the prognosis of coronary artery disease has made this technique a tool of everyday clinical practice. The authors reviewed the results of 600 investigations in consecutive unselected including patients aged over 75. No significant difference was observed with respect to the causes of interruption of the test between patients aged less than 75 (521 patients) and those older than 75 (79 patients). Attaining the target theoretical maximal heart rate was the commonest reason for stopping the test (47 and 48% respectively). Ventricular arrhythmias were not more common (12 and 10% respectively). Twelve cases of ventricular tachycardia were observed, 8 of which were non-sustained; 9 led to interruption of the test. No cases of ventricular fibrillation were observed. A previous history of cardiac arrhythmias was not associated with a higher frequency of arrhythmia during the test (8% in those with a previous history, 4% in those patients without). Supraventricular arrhythmias were significantly more common in patients over 75 years of age (15 versus 8%, p = 0.046). Dobutamine stress echocardiography' is feasible in a population of unselected patients, including those over 75. Therefore, age does not represent a limitation to the extension of this investigation.

Adult↗
PubMed1996

Identification of a mutation in a GATA binding site of the platelet glycoprotein Ibbeta promoter resulting in the Bernard-Soulier syndrome.

Bernard-Soulier Syndrome (BSS) is a rare congenital bleeding disorder due to absent or decreased expression of the glycoprotein Ib-IX-V (GpIb-IX-V) receptor complex on the platelet surface. To date, only mutations in GpIbalpha or GpIX have been reported in patients with BSS. GpIbbeta differs from the other proteins in this receptor in that the gene is more complex, and an alternative form is expressed in cells of non-megakaryocytic lineage, including endothelial cells. It appears that the megakaryocytic and endothelial cell mRNA species are transcribed from different start sites and have different proximal promoter regions. We have identified a patient with BSS who has a deletion on one chromosome 22, resulting in velocardiofacial syndrome. The GpIbbeta gene has been mapped to this deleted (22q11.2) region of chromosome 22. The patient has greatly reduced levels of GpIbbeta mRNA and no detectable platelet GpIbbeta protein, suggesting that his BSS results from a mutation in his remaining GpIbbeta allele. Sequence analysis revealed that the coding region of GpIbbeta is normal, but the 5'-upstream region contains a C to G transversion at base -133 from the transcription start site used in megakaryocytes. The mutation changes a GATA consensus binding site, disrupts GATA-1 binding to the mutated site, and decreases promoter activity by 84%. Thus, in this patient, Bernard-Soulier syndrome results from a deletion of one copy of GpIbbeta and a mutated GATA binding site in the promoter of the remaining allele, resulting in decreased promoter function and GpIbbeta gene transcription.

Alleles↗
PubMed1996

Atherosclerotic disease of the aortic arch as a risk factor for recurrent ischemic stroke.

BACKGROUND: Atherosclerotic disease of the aortic arch is found in 60 percent of patients 60 years of age or older who have had brain infarction. The aim of this study was to determine whether atherosclerotic plaques in the aortic arch are a risk factor for recurrent brain infarction and for vascular events in general (i.e., brain infarction, myocardial infarction, peripheral embolism, and death from vascular causes). METHODS: For a period of two to four years, we followed a cohort of 331 patients 60 years of age or older who were consecutively admitted to the hospital with brain infarction (a total of 788 person-years of follow up). All patients underwent transesophageal echocardiography to determine whether atherosclerotic plaques were present in the aortic arch proximal to the ostium of the left subclavian artery. The patients were divided into three groups according to the thickness of the wall of the aortic arch ( < 1 mm, 1 to 3.9 mm, and > or = 4 mm). RESULTS: The incidence of recurrent brain infarction was 11.9 per 100 person-years in patients with an aortic-wall thickness of > or = 4 mm, as compared with 3.5 per 100 person-years in patients with a wall thickness of 1 to 3.9 mm and 2.8 per 100 person-years in patients with a wall thickness of < 1 mm (P < 0.001). The overall incidence of vascular events was 26.0, 9.1, and 5.9 per 100 person-years of follow-up in the respective groups (P < 0.001). After adjustment for the presence of carotid stenosis, atrial fibrillation, peripheral arterial disease, and other risk factors, aortic plaques > or = 4 mm thick (including the thickness of the aortic wall) were found to be independent predictors of recurrent brain infarction (relative risk, 3.8; 95 percent confidence interval, 1.8 to 7.8; P = 0.0012) and of all vascular events (relative risk, 3.5; 95 percent confidence interval, 2.1 to 5.9; P < 0.001). CONCLUSIONS: Atherosclerotic plaques > or = 4 mm thick in the aortic arch are significant predictors of recurrent brain infarction and other vascular events.

Aged↗
PubMed1996

Inhibition of acute lymphoblastic leukaemia by a Jak-2 inhibitor.

Acute lymphoblastic leukaemia (ALL) is the most common cancer of childhood. Despite the progress achieved in its treatment, 20% of cases relapse and no longer respond to chemotherapy. The most common phenotype of ALL cells share surface antigens with very early precursors of B cells and are therefore believed to originate from this lineage. Characterization of the growth requirement of ALL cells indicated that they were dependent on various cytokines, suggesting paracrine and/or autocrine growth regulation. Because many cytokines induce tyrosine phosphorylation in lymphoid progenitor cells, and constitutive tyrosine phosphorylation is commonly observed in B-lineage leukaemias, attempts have been made to develop protein tyrosine kinase (PTK) blockers of leukaemia cell growth. Here we show that leukaemic cells from patients in relapse have constitutively activated Jak-2 PTK. Inhibition of Jak-2 activity by a specific tyrosine kinase blocker, AG-490, selectively blocks leukaemic cell growth in vitro and in vivo by inducing programmed cell death, with no deleterious effect on normal haematopoiesis.

Animals↗
PubMed1996

CD8/CD4 lineage commitment occurs by an instructional/default process followed by positive selection.

In the present study, we investigated the developmental potential of purified populations of transitional CD4inCD8hi and CD4hiCD8in thymocytes that were further defined according to their differentiation stage by their levels of T cell receptor (TCR) expression into TCRlo, TCRin and TCRhi subpopulations. The differentiation potential of each of these subsets was tested in vitro in a single-cell suspension culture assay that showed that CD4inCD8hiTCRhi are precursors of CD8 single-positive cells, whereas CD4hiCD8inTCRin/hi are precursors of both CD4 and CD8 single-positive thymocytes. The analysis of transitional subsets in mutant mice for either beta 2-microglobulin or major histocompatibility complex (MHC) class II further revealed that lineage commitment to the CD8 lineage requires a TCR-MHC class I engagement, presumably at the immature double-positive stage of thymic development, while CD4 commitment does not require an MHC class II-mediated signal, but rather occurs by default. Using the addition of MHC class I- or class II-expressing cells or the addition of total thymocytes to purified sorted transitional precursors for the duration of the cultures in vitro, we identified an additional stage of differentiation for both CD4 and CD8 lineages that requires a positive selection signal. Examination of protein tyrosine phosphorylation of transitional precursors revealed that CD4inCD8hi transitional cells contain a high level of a 70-kDa phosphorylated protein consistent with a role for ZAP70 in the signal transduction during the positive selection of CD8+ cells.

Animals↗