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Biomedical subjects

L Fernando

Publications and source records attributed to L Fernando.

31 records · Page 2Linked to original sources
PubMed1989

Effects of in utero exposure to cyclophosphamide in mice. II. Assessment of immunocompetence of offspring from 5 to 10 weeks of age.

Offspring of mice treated with cyclophosphamide (Cy; 1, 2.5 or 5 mg/kg) during pregnancy (6-18 days of gestation) and tested for immunocompetence from 5 to 10 weeks of age were found to have defective reticuloendothelial clearance. The main effects were: a) increased elimination half time (T 1/2) of 51Cr-labeled SRBC from circulation, b) decreased liver uptake of 51Cr and c) impaired ability of the spleen, mostly affecting the female pups, to compensate for decreased liver uptake. The highest dose group suffered the most pronounced effects. This group was also found to have increased IgG immunoglobulin levels at 7 weeks of age. IgG antibody production in response to specific antigenic stimulation and delayed hypersensitivity reactions to oxazolone did not appear to be affected by Cy treatment.

Aging↗
PubMed1988

An asparaginase of Aspergillus nidulans is subject to oxygen repression in addition to nitrogen metabolite repression.

Of five amidohydrolase activities subject to nitrogen metabolite repression in Aspergillus nidulans, L-asparaginase shows clearest evidence of also being subject to repression by atmospheric oxygen. Such oxygen repressibility is only evident under nitrogen metabolite derepressed conditions. Asparaginase levels are also considerably elevated by areA300, an altered function allele of the positive acting wide domain regulatory gene areA mediating nitrogen metabolite repression and are drastically reduced by loss of function mutations in areA. A. nidulans has two L-asparaginase enzymes and it has been shown by the use of appropriate mutants that these regulatory effects are exerted on the expression of that specified by the ahrA gene but probably not that specified by the apnA gene.

Aerobiosis↗
PubMed1986

Early detection and treatment of spinal epidural metastases: the role of myelography.

Spinal epidural metastases were detected in 75 of 140 cancer patients with back pain who were evaluated prospectively by clinical criteria, spine roentgenography, and bone scan. Fifty-five of the 75 patients with epidural metastases had no evidence of myelopathy when diagnosed. Of the patients diagnosed and treated while still ambulatory, more than 90% remained so. Myelograms were performed in 127 patients to diagnose the 75 with epidural disease. To try to reduce the number of myelograms needed, we attempted to design radiotherapy ports based on clinical symptoms and the plain spine films alone. A port could not be designed for 64 of the 127 patients, either because of diffuse vertebral metastases or a normal plain roentgenogram. A port could be designed for 63 patients, and all epidural disease would have been encompassed in 50 of the 54 patients who had spinal epidural metastases (93%). Most patients with cancer and back pain require myelography for accurate treatment planning. There are, however, situations in which treatment can be determined based on symptoms and plain films alone, with a low risk of missing epidural cancer.

Back Pain↗
PubMed1982

Pasteurella multocida--the major cause of hand infections following domestic animal bites.

Pasteurella multocida is a common cause of infection following bites or scratches caused by dogs and (especially) cats. It is rarely reported, however, and apparently often overlooked as a pathogen. The typical clinical manifestation is a rapidly developing cellulitis at the site of injury. The infection is potentially dangerous and can cause a chronic local infection of deep tissues and osteomyelitis. It responds well to several antimicrobials, with penicillin being drug of choice. Fifty-five patients are reported--72% with cat bites and/or scratches and 28% with dog bites. Ninety-two percent of the wounds went deeply through the skin. All patients presented for treatment 12 to 72 hours after receiving the animal wounds to their hands. Drainage from all wounds was serosanguineous or purulent, and cultures taken were positive for P. multocida. All of the wounds responded to surgical drainage and penicillin. One patient developed osteomyelitis. The acute onset of cellulitis, lymphangitis, and serosanguineous or purulent drainage from hand wounds 12 to 24 hours after cat or dog bites should suggest P. multocida as the predominant etiologic agent. Immediate surgical drainage and penicillin therapy is the treatment of choice.

Adolescent↗
PubMed1981

The antibody-independent cytotoxic activity of normal circulating human leucocytes. I. Lysis of target cells by monocytes and neutrophils in a non-phagocytic pathway.

Normally circulating human leucocytes were found to consistently lyse rabbit erythrocyte (RRBC) target cells within 24 hr in culture. The reaction is referred to as the naturally-occurring cell-mediated cytotoxic, or NOCC, reaction. Characteristics of this cytotoxic reaction are as follows. (i) The cytotoxic reaction described here can be distinguished from the antibody-dependent cellular cytotoxic (ADCC) reaction as conventional Fc receptors do not appear to play a role. Although the cytotoxic reaction occurs optimally in medium fortified with normal human serum to a final concentration of 1%, neither antibodies nor immunoglobulins in general appear to play a role. Agamma human serum or purified human serum albumin without detectable immunoglobulins are as capable of facilitating and sustaining the NOCC cytotoxic reaction as is normal human serum. Furthermore, foetal calf serum, which promotes the ADCC cytotoxic reaction, inhibits the NOCC cytotoxic reaction. (ii) The NOCC reaction is not a phagocytic one as phagocytosis of the RRBC could not be detected during the culture period. (iii) Monocytes and neutrophils, but not lymphocytes, are capable of lysing the target cells in the NOCC reaction. The effector mononuclear cell is a monocyte with receptors for Fc and C'3. (iv) The NOCC cytotoxic reaction is dependent upon direct effector cell--target cell contact and not upon soluble mediators secreted by the effector cells since third-party bystander erythrocytes are not lysed in the presence of rabbit erythrocyte target cells and human mononuclear cells. Supernatants from lysed RRBC target cells could not lyse fresh RRBC. It is concluded that the NOCC cytotoxic reaction utilizing rabbit erythrocytes as target cells permits the identification of cytotoxic subclasses of monocytes and neutrophils.

Antibody-Dependent Cell Cytotoxicity↗
PubMedDate not supplied

Identification of HIV-infected transfusion recipients: the utility of crossreferencing previous donor records with AIDS case reports.

An expanded "look-back" program has been developed, in which patients who may have been exposed to HIV through blood transfusion were identified via three triggers: the blood that they received was donated by persons who 1) have subsequently been reported to local health departments as meeting the diagnostic criteria for AIDS, 2) have donated since the introduction of anti-HIV screening and tested positive, or 3) have been found to be infected during investigation of reported transfusion-associated HIV infections. In comparing triggers, cross-referencing the list of patients reported to have AIDS (AIDS case list) proved to be the most efficient approach for identifying HIV-infected donors and transfusion recipients. Of the 7973 AIDS patients reported in eight Northern California counties as of December 1988, 316 (4.0%) were determined to have donated at Irwin Memorial Blood Centers between 1977 and 1985. Despite the logarithmic increase in reported cases of AIDS in the San Francisco Bay area over the last 5 years, the rate of detection of previous donors from AIDS case lists remained between 3.3 and 5.4 percent. These persons accounted for 69 percent of the identified infected donors, and their identification led to notification of 60 percent of potentially exposed recipients and 51 percent of known infected recipients. The crossreferencing of AIDS case listings with blood bank records was equally efficient for regions with low and high AIDS prevalence. National adoption of AIDS case list crossreferencing is recommended as an effective means of identifying previously unidentified infected recipients in an effort to limit the secondary spread of HIV infection.

Acquired Immunodeficiency Syndrome↗