PubMed Health⌕ Search

Biomedical subjects

M Behar

Publications and source records attributed to M Behar.

At least 19 recordsLinked to original sources

Giant Barkas effect observed for light ions channeling in Si.

Measurements of the electronic energy loss are presented for (4)He and (7)Li ions channeling along the Si main axial directions at intermediate to high projectile energies. The Barkas effect, an energy-loss enhancement proportional to the third power of the projectile charge at high energies, is clearly separated from other processes. It reaches about 50% for Li ions channeling along the Si [110] direction. The observed Barkas contribution from the valence-electron gas is in fair agreement with the Lindhard model.

Journal Article↗

Continuous esophageal pH monitoring during laparoscopic cholecystectomy.

Gastro-esophageal regurgitation (GER) and eventual aspiration is considered a major risk during general anesthesia. High intraperitoneal pressure produced during laparoscopic cholecystectomy (LC) is a possible source of increased GER. We investigated the incidence of GER using continuous esophageal pH monitoring in 14 patients undergoing elective LC. Only two brief episodes of acid reflux (pH < 4) occurred during LC. Apparently the high intraperitoneal pressure during LC carries no increased risk of regurgitation and aspiration.

Adult↗

Airway obstruction in neonates and children: surgical treatment.

OBJECTIVE: This review of 54 infants and children with airway obstruction who were treated surgically emphasizes the importance of the surgical indications with respect to various anomalies causing airway obstruction and the surgical approach to their management. PATIENTS: There were 4 etiologic groups of airway obstruction. Group A comprised 12 infants with subglottic stenosis; Group B--20 infants with tracheomalacia; 21 patients (Group C) with anatomic narrowing of the trachea; and 1 infant (Group D) with laceration of a main bronchus. METHODS: The surgical procedures performed included anterior laryngotracheal decompression in 12 infants, aortopexy in 19; 1 pulmonary arteriopexy; tracheal stenting with an autologous rib graft in 3 and with Marlex mesh in 1. Tracheal widening, using a free tibia autologous graft, was performed in 3 patients; transbronchoscopic excision in 12; anterior tracheal wedge resection in 4, and segmental tracheal resection and anastomosis in 1 patient. The lacerated bronchus was repaired with fine Dexon sutures. RESULTS: There were no operative deaths. With respect to the original indications for surgery, there were 3 failures--2 in Group A and 1 in Group C. Two patients died from causes unrelated to the procedures--one 10 days postoperatively, and the other 3 months after surgery. CONCLUSIONS: The surgical approach to tracheal obstruction in infants and children offers effective treatment, with no operative mortality, a low complication rate, and good long term survival.

Age Factors↗

Acute toxicity and effects on hepatic oxidative drug metabolism of mopyridone.

Mopyridone (CAS 82822-14-8) is a new chemotherapeutic with a strong antiviral effect (vs. influenza- and toga viruses) and certain advantages over the chemotherapeutics known so far. Toxicological studies reveal its low oral and intraperitoneal toxicity in mice and rats. The 5- and 14-day administration of mopyridone (37.5 mg/kg b.w., orally) to male rats established a growing tendency to the shortening of hexobarbital sleeping time, associated with moderate changes in the hepatic oxidase activity on the 15th day, most pronounced for amidopyrine N-demethylase (by 37%) and less for benzphetamine N-demethylase (by 17%). Aniline hydroxylase activity was slightly diminished (by 18% and 16%, resp.). No significant changes in the components of the electron-transport chain of cytochrome P-450 were established--the content of cytochrome P-450, cytochrome b-5 and cytochrome C reductase, both after 5- and 14-day mopyridone administration.

Animals↗

Acetic acid visualization of the cervix to detect cervical dysplasia.

OBJECTIVE: To determine whether acetic acid visualization of the cervix can identify cervical dysplasia and improve detection of lesions missed by Papanicolaou test screening. METHODS: During a 2-year period, patients attending family planning clinics for regular gynecologic examinations had acetic acid applied to the cervix, followed by gross visualization without magnification. Patients with suspicious acetowhite lesions and normal Papanicolaou tests were referred for colposcopic evaluation. Findings from these examinations and corresponding biopsy results were analyzed retrospectively. RESULTS: Eighty-five women were referred for colposcopy because of abnormal acetowhite areas on the cervix. Thirteen patients (15%) had cervical intraepithelial neoplasia (CIN) (nine CIN I, four CIN II), 22 (26%) had koilocytosis, and 16 (19%) had benign histologic findings. In total, 51 patients had suspicious lesions at colposcopy for which biopsies were performed, and 34 (40%) had normal colposcopic examinations. CONCLUSIONS: Acetic acid visualization of the cervix can detect dysplasia otherwise missed by Papanicolaou test screening. However, further refinements in technique are required to decrease false-positive findings and unnecessary referrals for colposcopy.

Acetates↗

HIV roundtable. Strategies to enhance professional awareness and involvement. Part II.

Despite extensive public attention to the social and medical problems associated with HIV infection and AIDS, many clinicians remain largely uninvolved in public health and patient counseling programs aimed at preventing infection and getting patients into treatment. Suggestions to enhance professional involvement include improved schooling and continuing medical education; increased liaison and exchange of information among the various groups working with AIDS patients and at-risk populations; and programs to help clinicians confront their own feelings and concerns relating to AIDS.

Community-Institutional Relations↗

HIV roundtable. Professional perspectives.

As the HIV epidemic escalates, concern is mounting over the implications of infection among health care workers. Should all medical professionals be tested? Should supervisors and/or patients be notified if the results are positive? Should the infected PA continue to practice? What about performing surgery? Should he or she be considered impaired? And what about the long-term stress of working with HIV patients? Experts discuss the AAPA's latest recommendations, and share suggestions on prevention and patient care with the audience.

Cross Infection↗

HIV roundtable. Strategies to enhance professional awareness and involvement, Part I.

Despite extensive public attention to the social and medical problems associated with HIV infection and AIDS, many clinicians remain largely uninvolved in public health and patient counseling programs aimed at preventing infection and getting patients into treatment. Suggestions to enhance professional involvement include improved schooling and continuing medical education; increased liaison and exchange of information among the various groups working with AIDS patients and at-risk populations; and programs to help clinicians confront their own feelings and concerns relating to AIDS.

Acquired Immunodeficiency Syndrome↗

Carotid endarterectomy under local anesthesia supplemented with neuroleptic analgesia.

Surgical treatment of the carotid artery is being performed increasingly under local rather than general anesthesia. The advantage of local anesthesia is that neurologic function can be continuously assessed while the carotid arteries are cross-clamped, and unnecessary shunting can, thus, be avoided, with resulting sedation, analgesia, alpha blockade and blood pressure stability. The main objection to the use of local anesthesia is the anxiety of the patient. We overcame this difficulty in a series of 42 patients by supplementing the local anesthetic with neuroleptic analgesia. The possible disadvantages of neuroleptic administration are apnea and prolonged sedation. Only one of the patients we studied required an intraluminal shunt. One patient died of cardiac disease and one suffered an early postoperative stroke, which subsequently resolved. We believe that local anesthesia, supplemented by neuroleptic sedation and analgesia to overcome patient anxiety, should be more widely used for carotid endarterectomy.

Aged↗

A rat hybridoma model of Heymann nephritis: production of a monoclonal anti GP330 from a nephritic rat.

Autologous (Heymann) nephritis was induced by immunizing Sprague-Dawley rats with a crude membrane extract (Fx1A) prepared from renal cortical tubules. Urine protein excretion was monitored to determine the onset of nephritis and then the spleens of nephritic rats were fused with a non-secretor rat myeloma cell line. Supernatants from hybridoma cultures were first screened for production of anti-brush border membrane (BBM) antibody by immunodot blotting of highly purified rat BBM on nitrocellulose. Positive hybrids were then tested by indirect immunofluorescence for the presence of IgG, which binds to the brush border of rat renal proximal tubules. Those hybrids which were positive by both screening assays were subcloned twice. Two monoclonal antibodies (C5, D11) were studied in some detail. Both C5 and D11 immunoprecipitated a single polypeptide from BBM, labelled with 125I by the lactoperoxidase method. Radioautography of gradient 4-11% slab sodium dodecyl sulphate polyacrylamide gels revealed that the polypeptide against which C5 and D11 were directed co-migrated with the polypeptide immunoprecipitated by (i) IgG eluted from the renal cortex of nephritic rats, and by (ii) a mouse anti-rat monoclonal against gp 330 [a BBM constituent with proven pathogenicity [9]]. Supernatants which tested positive by immunodot blotting but negative by indirect immunofluorescence showed no detectable immunoprecipitate after reaction with BBM. Immunocytochemical staining by immunoperoxidase and immunogold methods localized C5 and D11 to the BBM of the renal proximal tubule and to the urine face of the glomerular epithelium.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PAs and HIV-antibody testing. The need for guidelines when the practitioner is at risk. Discussion.

The PA profession should establish guidelines for PAs at risk for infection with the human immunodeficiency virus (HIV) who wish to be tested for HIV antibody. Confidentiality and anonymity are critical factors, along with the employer's established policies. PAs working in emergency and surgical settings may be at greater professional risk of exposure to HIV; those with personal risk factors may consider being tested if their work exposes them to opportunistic infections. A clearinghouse for information should be established through the American Academy of Physician Assistants and state chapters.

Acquired Immunodeficiency Syndrome↗

PA impairment due to HIV infection. Part II: Building a professional support network. Forum.

Several members of the AAPA's Lesbian and Gay Physician Assistants Caucus who participated in the roundtable PAs and HIV-Antibody Testing: The Need for Guidelines When the Practitioner Is at Risk (1989;13[5]:146-158) met with members of the 12-Step/Caduceus Caucus to begin developing a cooperative effort to assist PAs who test positive for antibodies to the human immunodeficiency virus, and to explore other HIV-associated impairment issues. Part II focuses on concerns of the provider who is HIV-antibody positive as well as ways PA groups can cooperate to raise the profession's conciousness further and recommend guidelines and policy.

HIV Infections↗

Immunocytochemical characterization of cells in rat glomerular culture.

Identification and characterization of cells in glomerular tissue culture has been an ongoing concern of experimental renal biologists. We examined the immunocytochemical staining profiles of primary and passaged rat glomerular cultures using a battery of commercially available antisera. In all culture systems examined, two distinct cell populations could be distinguished. One cell type stained positively for desmin and had ultrastructurally smooth muscle features typical of contractile mesangial cells. The second cell type proliferated in a manner classically described for "epithelial" cells but, intriguingly, did not express any of the numerous epithelial markers tested. The second cell population may represent an undifferentiated reserve cell type. Immunocytochemical methods offer an independent modality to the evaluation of cells which proliferate in glomerular cell culture.

Animals↗