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Biomedical subjects

M Stein

Publications and source records attributed to M Stein.

504 records · Page 28Linked to original sources
PubMedDate not supplied

Increased CCR5 expression with decreased beta chemokine secretion in Ethiopians: relevance to AIDS in Africa.

OBJECTIVE: This study was undertaken to determine the contribution of HIV co-receptors and beta chemokine secretion to the increased susceptibility for human immunodeficiency virus (HIV) infection of peripheral blood mononuclear cells (PBMC) obtained from HIV-seronegative Ethiopian immigrants in Israel (ETH). STUDY DESIGN: Immune activation markers and HIV co-receptor expression on lymphocytes and monocytes, and beta chemokine secretion by CD8+ cells, were compared between ETH and non-Ethiopian Israeli (IS) HIV-negative individuals. RESULTS: The percentage of lymphocytes and monocytes expressing CCR5 was 1.6 and 3.0 times higher in ETH (n = 83) than in IS (n = 45), respectively (P < .001), whereas RANTES and MIP-1alpha secretion was 0.5 and 0.7 times lower (P < .01 and P < .05). The percentage of CCR5-expressing cells and RANTES secretion were inversely correlated (r = -0.7; P < .002). No differences were found in the proportion of CXCR4-expressing cells. No correlation between CCR5 expression and cell activation profile in the whole ETH population was found. However, in highly activated individuals (HLA-DR/CD3 > 7%), a significant decrease in CCR5 expression was observed. CONCLUSIONS: An increased proportion of CCR5-expressing cells with decreased beta chemokine secretion observed in ETH may account for the increased susceptibility to HIV infection of cells obtained from this group. These findings may partly explain the higher susceptibility for HIV infection in Africa and thus the rapid spread of acquired immunodeficiency syndrome (AIDS) in that continent.

Chemokine CCL3↗
PubMedDate not supplied

MHC-class I antigen expression on micrometastases in bone marrow of patients with head and neck squamous cell cancer.

Although squamous cell carcinoma of the head and neck region very rarely metastasize to the skeleton, epithelial cells have been found in bone marrow aspirates of these patients. This observation reflects the general spread of the disease, indicating a poor clinical prognosis with a much higher risk of developing local or distant recurrences. In a first attempt to characterize the phenotypic properties, the expression of the major histo-compatibility complex (MHC) class I antigens on bone marrow micrometastases was assessed. It has been shown that the down-regulation of these molecules is a potential mechanism to escape from HLA class I restricted lysis by cytotoxic T-cells. The significance of reduced MHC class I expression might be relevant for the survival of residual metastatic cells in the bone marrow of patients with squamous cell carcinoma of the head and neck region. Bone marrow aspirates were screened for individual disseminated epithelial cells using the immunoalkaline phosphatase technique with monoclonal antibodies to the epithelial differentiation marker cytokeratin 19 (CK19), as described previously. Specimens containing CK19-positive cells were colabelled with the monoclonal antibody W6/32. The loss of MHC expression is not related to the tumor stage but clearly to the degree of differentiation: 6 out of 7 patients with low-grade SCCHN, but only 3 out of 13 patients with medium-grade SCCHN showed a complete loss of MHC class I molecules. This finding could indicate the reduced prognosis of undifferentiated SCCHN. The lack of MHC class I expression could encourage the survival of residual tumor cells in the bone marrow of patients with SCCHN that evade immunosurveillance.

Antibodies, Monoclonal↗
PubMedDate not supplied

Predictors of surgical outcome in patients undergoing aortobifemoral bypass reconstruction.

We report a prospective study with 2 years of follow-up including 105 consecutive symptomatic patients (58.1% claudication and 41.9% severe ischemia) undergoing aortobifemoral bypass surgery (ABF/BP). Proportional-hazards, stepwise regression, and life-table analyses were used to determine predictors of the following outcome criteria: graft patency, amputation, mortality, symptomatic recurrence, and palliation. The operative mortality was 5.7% and the 2-year cumulative mortality was 15.5%. Most deaths (61.5%) were cardiac-related. There were 3 predictors of mortality: the presence of more than 1 surgical risk factor (relative risk [RR] 6.2; p less than 0.001), advanced age (RR 2.9; p = 0.03) and the presence of ischemic heart disease (RR 1.5; p = 0.045). No patient required amputation. Early graft patency rate was 94.3% and the 2-year cumulative patency was 92.8%. The only predictor of graft failure was preoperative ankle/brachial index (ABI) of less than 0.4 (RR 6.1; p = 0.003). Early symptomatic relief was 98.1% and at 2 years it was 77.3%. There were 2 predictors of symptomatic recurrence: postoperative smoking (RR 2.4; p less than 0.001) and impaired runoff (RR 2.5; p = 0.017). Cumulative palliation was 87.6% at 1 month and 66.5% at 2 years postoperatively. There were 2 predictors of palliation: the presence of more than 1 surgical risk-factor (RR 1.8; p = 0.001) and postoperative transcutaneous oximetry (PtcO2) of less than 35 mmHg (RR 3.1; p = 0.04). We conclude that the best predictors of outcome in patients undergoing ABF/BP surgery were the number of preoperative risk factors, age, ischemic heart disease, ABI, PtcO2, postoperative smoking, and angiographic runoff.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Effects of cigarette smoking on outcome of femoral popliteal bypass for limb salvage.

A retrospective 5-year follow-up study of 83 femoral-popliteal bypass operations for severe ischemia (79 patients) is presented. There were no operative deaths. At one month, cumulative patency rates (CPR) and limb salvage rates (LSR) were 86.8% and 96.4% respectively. At 5 years, CPR, LSR and cumulative survival were 50%, 79.4% and 71.6% respectively. Post-operative smoking habits were strongly related to CPR and LSR. Smoking more than 5 cigarettes per day adversely affected CPR's. At 5 years, CPR of non-smokers and smokers of up to 5 cigarettes per day (47 patients) was 67.7% and for smokers of more than 5 cigarettes per day (32 patients) it was 44.7% (P less than 0.045). Smoking more than 15 cigarettes per day had an adverse effect on LSR's. Smokers of more than 15 cigarettes per day (17 patients) had a 5-year LSR of 58.5% compared with 89% for non-smokers and smokers of up to 15 cigarettes per day (62 patients) (P = 0.009). For 20 limbs requiring thrombectomy LSR was 100% at 1 year and 57.5% at 5 years. CPR's and LSR's were not significantly influenced by pre-operative smoking, diabetes, run off or level of distal anastomosis relative to the knee joint. Based on zero operative mortality and 96.4% limb salvage at 1 year, it is concluded that an aggressive approach toward revascularization for limb salvage is well justified in most patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Status asthmaticus.

Explore the source record for details and available documents.

Adult↗
PubMedDate not supplied

Unusual distribution and onset of stress fractures in soldiers.

Ninety-four stress fractures were detected in 64 soldiers by scintigraphy during the first 11 weeks of basic training. Unlike past military studies that showed large numbers of stress fractures of the feet, only 2% were in the metatarsals and none were in the calcaneus. Most fractures were in the tibia (71%) and femoral shaft (25%). Contrary to previous reports in the literature, the fractures occurred later in training, with 67% occurring during the fifth to eighth weeks of basic training and 12 percent during the ninth to eleventh weeks. This unusual distribution and onset has possible explanations in (1) new training concepts to fit modern warfare, with more emphasis on runs and marches; (2) new apparel and equipment carried by the soldiers; (3) changes in prearmy lifestyle; and (4) the extensive use of bone scan for diagnosis.

Adolescent↗
PubMedDate not supplied

Multiple stress fractures. A longitudinal study of a soldier with 13 lesions.

A highly motivated 18-year-old man continued vigorous military training in spite of the presence of 11 stress fractures and subsequently developed two additional stress fractures. Scintigraphy over 27 weeks illustrated simultaneous regression and progression in his individual multiple foci. When stress fracture foci were not in anatomic locations prone to evolve to gross fractures, healing occurred despite vigorous activities and pain.

Adolescent↗
PubMedDate not supplied

[Parasite nematodes from Dusycion griseus (Gray, 1837), D. culpaeus (Molina, 1782) and Conepatus chinga (Molina, 1782) (Mammalia:Carnivora) in Neuquén, Argentina. Systematics and ecology].

Four nematode species (Physaloptera clausa Rudolphi, 1819; Ph. maxillaris Molin, 1860; Protospirura numidica criceticola Quentin, Karimi and Rodrigues De Almeida, 1968; Toxascaris leonina (Von Linstow, 1902) were collected from D. griseus, D. culpaeus and C. chinga in Neuquen Province, Argentina. These hosts were captured from April to August in 1990 and 1991. Ph. clausa and Ph. maxillaris ar redescribed. The systematic position of Ph. clausa is discussed and the authors conclude that this species could be considered the type species of the genus. The possibility that D. griseus and D. culpaeus could be the accidental hosts for P. n. criceticola is discussed. Prevalence, mean intensity and frequency of each species are given. These parameters were related with the diets of the hosts and the parasite life cycles. There was no relationship between parasitic burden of each host and their nutritional condition (Kendall Tau Test). Significant differences exist among the diet of each host and among prevalence values of each parasite species (Homogeneity Test SYSTAT Program).

Animals↗
PubMedDate not supplied

Fatal neutropenic colitis complicating successful chemotherapy for small cell lung cancer: a case report.

Neutropenic colitis, a severe necrotizing enteropathy, is being recognized with increasing frequency as a life-threatening complication of aggressive chemotherapy mainly for lymphoproliferative and hematologic malignancies. It is often under-recognized clinically, despite its potentially lethal outcome. Both medical and surgical approaches to management are possible. We describe a case of neutropenic colitis involving predominantly the transverse colon in a patient successfully treated for limited-disease small cell lung cancer. This is only the second reported case of neutropenic colitis complicating chemotherapy for small cell lung cancer. A brief review of the diagnosis, clinical features, and management is presented.

Antineoplastic Combined Chemotherapy Protocols↗
PubMedDate not supplied

HIV infection and Salmonella septic arthritis.

Human immunodeficiency virus (HIV) infection predisposes to bacterial infection at may sites but septic arthritis is notably uncommon. An HIV seropositive patient who presented with oligoarticular septic arthritis due to Salmonella enteritidis and who responded poorly to antibiotic therapy and repeated aspiration of involved joints is described. Unusual features included the clinical presentation of septic arthritis in more than one joint, a protracted clinical course with radiological destruction of the hip, bone marrow suppression induced by cotrimoxazole, and death thought to be due to a gastropathy induced by non-steroidal anti-inflammatory therapy at a time when the septic arthritis appeared to have responded to treatment. Cure of Salmonella septic arthritis in HIV infected patients may be difficult and require aggressive prolonged treatment. Septic arthritis should be considered in the differential diagnosis in a patient with HIV infection and arthritis.

AIDS-Related Opportunistic Infections↗
PubMedDate not supplied

A literature review: oral irrigation therapy. The adjunctive roles for home and professional use.

It is now recognized that there are several different types of periodontal infections. As we learn more about the cause of these diseases, it becomes obvious that we have treatment options. A successful choice of procedures for each individual depends on an accurate diagnosis based on comprehensive data collection of clinical and microbiological findings. Treatment choices include a non-surgical phase which consists of plaque removal, plaque control, scaling, root planing, and the use of chemical agents. For complete debridement of deep pockets, furcations or areas with root surface irregularities, surgical access may be necessary. When considering drug therapy, it must be noted that systemic antibiotics may be necessary to suppress those subgingival periodontal pathogens which have the ability to invade the tissue and resist other methods of eradication. Removal or alteration of pathogenic flora is mandatory to improve a patient's periodontal health. The extensive use of supragingival irrigation as an adjunct for treating gingivitis has led to the interest in subgingival irrigation as a possible adjunct for treatment of periodontal diseases. Targeted lavage and subgingival delivery of effective antimicrobial agents show potential as supplemental office procedures or as a component of a home oral hygiene regime. Additional research is needed to develop more efficacious chemotherapeutic substances than are currently available and to further define the optimum application of each. Substantive medicaments that react specifically against periodontopathic organisms are essential. Exact frequency and duration of professionally-applied and self-administered subgingival irrigation need to be determined for maximum results. Further investigation is required to establish the potential role of adjunctive irrigation and antimicrobial therapy in the treatment of periodontitis. Yet, another important application of irrigation has been recognized. Recently, the American Heart Association revised its guidelines for the prevention of bacterial endocarditis. The amendments to the dentistry sections have been approved by the Council on Dental Therapeutics of the American Dental Association. Included in this text is the recommendation that as an adjunct to antibiotic prophylaxis, sulcular irrigation with chlorhexidine may be useful for those patients considered high risk and/or have poor oral hygiene. Irrigation therapy is undergoing extensive scrutiny in the scientific research community. Presently, considerable conclusive evidence exists to suggest that adjunctive irrigation may play an important role in controlling gingivitis and periodontitis. The overwhelming challenge for any and all successful periodontal therapy will always remain dependent on patient compliance to regular professional and home care.

Anti-Bacterial Agents↗