Biomedical subjects

A White

Publications and source records attributed to A White.

At least 595 records · Page 33Linked to original sources

PubMedDate not supplied

Selection of high-affinity and high-specificity monoclonal antibodies for 1 alpha,25-dihydroxyvitamin D.

The preparation of high-affinity and high-specificity monoclonal antibodies to 1 alpha,25-dihydroxyvitamin D is described. Monoclonal antibodies were derived from Balb-c mice immunised with either 1 alpha-hydroxy-25,26,27-trinor-24-cholecalcioic acid or with 1 alpha-hydroxy-26,27-dinor-cholecalciferol-25-oxime, and spleen cells were hybridised with mouse myeloma cells. From six fusions nine monoclonal antibodies (MAb's) were selected from 676 antibody-secreting hybrids. Antibodies varied widely in their ability to bind 1 alpha,25-dihydroxyvitamin D3 (50% displacement of radioligand ranged from 25 - 900 pg); two had particularly useful characteristics for 1 alpha,25-dihydroxyvitamin D assay. MAb 5F2 has high affinity (Ka = 1.39 X 10(10) M-1) and does not discriminate between 1 alpha,25-dihydroxyvitamin D2 and D3, thus enabling the two forms to be measured together. MAb 1G7 is highly specific, having no cross-reactivity with 25-hydroxy-, 24,25-dihydroxy- or 25,26-dihydroxyvitamin D at concentrations found in normal human serum; this MAb has the potential to eliminate the lengthy extraction procedures involved in currently available assays for 1 alpha,25-dihydroxyvitamin D.

Animals↗

PubMedDate not supplied

Cerebrospinal fluid levels of beta endorphin in painful and painless diabetic polyneuropathy.

beta endorphin (beta-EP) is an important modulator of central pain pathways. To examine whether changes in central production of beta-EP contribute to the pathogenesis of diabetic neuropathic pain, we compared the cerebrospinal fluid (CSF) levels of beta-EP and its precursor proopiomelanocortin (POMC) between 15 diabetic patients with chronic painful diabetic polyneuropathy, eight patients with severe painless diabetic neuropathy, and ten nondiabetic controls. Both peptides were measured by specific monoclonal antibody-based two-site immunoradiometric assays (IRMAs). In the diabetic patients with painful neuropathy, mean +/- SD CSF beta-EP concentrations (5.7 +/- 2.2 pmol/L) were comparable to those of the diabetic patients with painless neuropathy (6.0 +/- 2.3 pmol/L) and did not correlate with the severity of neuropathic pain. CSF beta-EP, but not POMC, concentrations were lower in the diabetic neuropathic patients overall (5.8 +/- 1.9 pmol/L) compared to the control subjects (7.6 +/- 2.2 pmol/L) (p < 0.05). CSF POMC showed no intergroup differences. However, POMC levels were 80-fold higher than those of beta-EP and should always be considered when interpreting immunoreactive beta-EP or other derivative peptide levels in CSF. We conclude that CSF beta-EP levels appear to be reduced in diabetic polyneuropathy but they do not relate to the presence of neuropathic pain. This might explain why opioid analgesics are of little, if any, help in alleviating diabetic neuropathic pain.

Cohort Studies↗

PubMedDate not supplied

The complexities of nursing research with men.

There has been a proliferation of nursing and other research on women's health over the last thirty years but a similar interest in men's health has not materialised. Within this paper we seek to explore the issues that need to be taken into consideration when conducting research with (or on) men. It outlines the current thinking on men and masculinity and the social development of stereotypes of men. The position of men with regard to the development of feminist thinking is also explored. The paper develops the argument by an examination of the different stages of the research process in nursing. The effect of gender on the setting of the research question; the choice of methodology; obtaining the data; analysis; discussion and dissemination of the findings of research conducted upon men are considered. We suggest that there is a requirement to consider the gender of both researched and researcher during the research process.

Data Collection↗

PubMedDate not supplied

Long-term costs of treatment for depression: impact of drug selection and guideline adherence.

OBJECTIVES: This paper examines three processes: SSRI antidepressant choice, adherence to treatment guidelines, and long-term health care expenditures associated with antidepressant treatment for patients with a diagnosis of depression. METHODS: Patient records were abstracted from a medical claims database covering employer-provided health care plans. Treatment episodes required a 6-month antidepressant-free prior period; initial treatment with sertraline, paroxetine or fluoxetine; and data on direct medical costs over the 24 months following the initial prescription. The multivariate model of drug selection, patient adherence to antidepressant use guidelines, and cost was subjected to specification testing to rule out the possibility that nonrandom initial antidepressant selection might lead to sample selection bias. Further tests indicated that the results were free of bias due to a possible correlation between antidepressant selection and use of the medication, or because of the endogeneity of use patterns in the process driving cost. However, there was evidence of unobserved variables correlated with both achieving guideline adherent use and expenditures, which might have led to sample selection bias. RESULTS: Subjects who met the study criteria included 796 initiating therapy with sertraline, 352 with paroxetine, and 882 with fluoxetine. Fluoxetine patients were significantly more likely than sertraline or paroxetine patients to achieve a use pattern that was consistent with guidelines for treating depressive disorder (p < .05). There were no statistically significant differences between the three treatment cohorts in total direct health care expenditures over the 2-year period (p < .05), and depression-related expenditures, other mental health expenditures, and non-mental health care expenditures did not show significant differences across the treatments (p < .05). Natural logged values of antidepressant drug expenditures were predicted to be highest for fluoxetine, followed by sertraline, then paroxetine (p < .01). Predicted log values of mental health expenditures were lower for sertraline relative to fluoxetine. CONCLUSIONS: Fluoxetine patients had the highest likelihood of using antidepressant medication according to treatment guidelines that were developed to assure quality care. This benefit was achieved without incurring greater total health care expenditures.

Adult↗

PubMedDate not supplied

The Middlesex University rehabilitation robot.

This paper describes the development of an electrically powered wheelchair-mounted manipulator for use by severely disabled persons. A detailed review is given explaining the specification. It describes the construction of the device and its control architecture. The prototype robot used several gesture recognition and other input systems. The system has been tested on disabled and non-disabled users. They observed that it was easy to use but about 50% slower than comparable systems before design modifications were incorporated. The robot has a payload of greater than 1 kg with a maximum reach of 0.7-0.9 m.

Computer Systems↗

PubMedDate not supplied

Long-term studies of the effect of rifampin on nasal carriage of coagulase-positive staphylococci.

Eighty healthy men with nasal carriage of coagulase-positive staphylococci were given cloxacillin, rifampin, cloxacillin plus rifampin, or no drug. Treatment with rifampin alone or with rifampin plus cloxacillin eradicated the original strain from 80% of the men for 12 weeks after treatment; 15%-20% of the 80 subjects acquired a strain of a different phage type. Treatment with cloxacillin alone did not significantly alter the rate of carriage. Only one of 40 men receiving rifampin (either alone or with cloxacillin) acquired rifampin-resistant, coagulase-positive staphylococci; seven of the 40 acquired rifampin-resistant, coagulase-negative staphylococci. Rifampin-resistant organisms did not persist in repeat nasal cultures five months after treatment. Of the 40 subjects given rifampin alone or rifampin plus cloxacillin, 60% had repeat nasal cultures done one year later. Only 50% were found to be carriers of coagulase-positive staphylococci. In another study, coagulase-positive staphylococci were eradicated from 70% of 20 carriers undergoing renal dialysis who received rifampin plus cloxacillin.

Carrier State↗

PubMedDate not supplied

Serological reactions to Nocardia antigens.

Sera from 23 patients with nocardiosis were tested for the presence of precipitating antibodies against an extract of Nocardia asteroides. Sera from nine of 20 patients infected with Nocardia asteroides and one of three sera from patients with Nocardia brasiliensis produced one to three precipitin lines with the antigen. Sera from eight of 55 patients with tuberculosis and 11 of 13 patients with leprosy also contained Nocardia precipitins. None of 33 sera from patients with cryptococcosis, blastomycosis, actinomycosis, histoplasmosis, coccidioidomycosis, mucormycosis or candidiasis contained Norcardia antibodies. None of the sera from ten patients infected with Staphylococcus aureus, ten patients infected with Pseudomonas, or 16 sera from uninfected patients contained Nocardia precipitins.

Actinomycosis↗

PubMedDate not supplied

Infections or neoplasm as causes of prolonged fever in cancer patients.

Thirty-six consecutive patients with cancer who met the classical criteria for fever of unexplained origin (FUO) were identified. A total of 18 patients had infections including all 12 with leukemia, four of 12 with Hodgkin's disease, and two with solid tumors. Fungal infections were found in nine: histoplasmosis, three; candidiasis, three; and aspergillosis, systemic sporotrichosis, or cryptococcal meningitis, one each. Six patients had unresolved pyogenic infections and one had tuberculous pericarditis. Two others had viral etiologies. Granulocytopenia was significantly more common in the FUO patients with documented infections. Clinical or laboratory abnormalities suggesting involvement of a specific organ or organ system provided important clues indicating infections. Morphological examination of biopsy specimens, with cultures, was the best method for diagnosis. In 18 patients, 12 with lymphomas and 6 with solid tumors, only the neoplasm appeared responsible for the fever. In these patients there was a paucity of abnormalities indicating organ system involvement with infection. Regardless, physicians' diagnostic efforts should not be deterred in such patients. Repeated thorough evaluations for infection are warranted.

Adolescent↗

PubMedDate not supplied

A serologic response in human infection with Enterobacteriaceae.

Sera from patients infected with Escherichia coli, Proteus, Klebsiella, and Serratia were studied for precipitins to ultrasonic extracts of these organisms in gel-diffusion plates. Sera from 66 per cent of these patients contained precipitins when initially tested. Twenty-four per cent of sera tested in the first week after onset of infection contained precipitins, but this rose to 78 per cent by the third week. Cross-reactions of sera with Pseudomonas antigens were unusual, but were common with other enterobacterial antigen extracts. However, higher titers were usually present to homologous as compared to heterologus antigens. Sera from seven patients contained precipitins to a common enterobacterial antigen. Precipitins to E. coli, Proteus, Klebsiella, and Serratia were detected in only a small proportion of control sera.

Antibodies, Bacterial↗

PubMedDate not supplied

Detection of IgG candida antibodies by solid-phase radioimmunoassay and comparison with agar-gel diffusion.

Comparison of solid-phase radioimmunoassay (S-PRIA) and agar-gel diffusion for detecting antibodies to candida organisms was undertaken in patients with systemic candidiasis, candida colonization, noncandida febrile illnesses, and in healthy controls. Radioimmunoassay results were highly reproducible when the same sera were tested on three different days. Sera from all three groups of patients had higher counts per minute (CPM) by S-PRIA then sera from control subjects. Although positive precipitins and high CPM occurred frequently in patients with systemic candidiasis, both precipitins and high CPM were detected in some sera from patients with colonization without system disease.

Adrenal Cortex Hormones↗

PubMedDate not supplied

Multiple recurrences of nocardial pneumonia.

A 47-year-old patient without underlying disease was first treated for nocardial pneumonia in 1970. She has had three relapses of nocardial pneumonia despite treatment with sulfasoxazole and tetracycline for nine, 15, and 12 months for the first three episodes. Therapy was continued two, 12, and nine months after chest roentgenograms returned to normal. The recurrences occurred two, 39, and 11 months after therapy was discontinued.

Female↗

PubMedDate not supplied

Radioimmunoassay for detection of IgG antibodies against enterobacterial antigens.

The rough mutant of Salmonella minnesota (Re 595) contains several broad reacting antigens including a core LPS common to many aerobic gram-negative bacteria without sugars that confer serotype specificity to most gram-negative bacteria. Therefore, antibodies against this organism can be evoked by a large number of gram-negative bacteria. Using radioimmunoassay methods, sera from 59 patients with bacteremia due to enterobacteriaceae had higher concentrations of IgG antibodies against the rough mutant of Salmonella minnesota (Re 595) than control subjects. There was a significant correlation between concentrations of antibodies against Salmonella minnesota and concentrations of antibodies against a single strain of E coli. Sera from patients with bacteremia due to E coli or Klebsiella were tested against one strain of E coli and one strain of Klebsiella. The concentrations of antibodies against the homologous antigen were not higher than the concentrations of antibodies against the heterologous antigen. Sera from patients infected with S aureus or Pseudomonas aeruginosa did not have high concentrations of antibodies against S minnesota. Antibodies against common antigen(s) in Salmonella minnesota (Re 595) are useful in diagnosis of enterobacterial infections.

Antigens, Bacterial↗

PubMedDate not supplied

The causal role for genital ulcer disease as a risk factor for transmission of human immunodeficiency virus. An application of the Bradford Hill criteria.

BACKGROUND AND OBJECTIVES: Genital ulcer disease (GUD) has been reported to increase the risk for the acquisition of human immunodeficiency virus (HIV). Although many investigators have reported an increased risk for HIV infection in persons with concurrent or previous GUD, not all studies have been designed to determine whether GUD causes an increased risk for HIV infection or acts only as a risk marker for infection. The evidence from the literature is discussed, and the criteria for causal inference proposed by Sir Austin Bradford Hill are applied. GOAL: To evaluate the strength of the association between GUD and infection by HIV. STUDY DESIGN: Case-control, cross-sectional, and cohort studies that examined the association between HIV seroconversion and GUD were chosen from the literature. Twenty-seven epidemiologic studies were selected for analysis, many of which reported separate analyses of the association between HIV infection and herpes simplex virus infection, syphilis, or nonspecified GUD. The studies were analyzed to investigate the magnitude of association between GUD and HIV, and the evidence evaluated using Hill's criteria. RESULTS: Approximately two thirds of the analyses reported a statistically significant association between GUD and HIV infection. Fourteen studies reported 29 separate analyses using a case-control design, 18 of which reported a statistically significant association between GUD (GUD, herpes, and syphilis) and HIV infection, four analyses were of varying significance depending on the analytical technique used, and seven were nonsignificant. Thirteen studies reported 23 separate longitudinal analyses that used a nested case-control or cohort design: 11 reported a significant association, 11 had nonsignificant findings, and results of one study varied. No study reported a statistically significant negative association. When applying the literature to Hill's criteria, all nine criteria for causal inference were met, providing additional evidence that genital ulcers are associated with an increased risk for the development of HIV infection. CONCLUSIONS: The published evidence suggests that GUD increases the risk for HIV acquisition. Few studies, however, have examined carefully the temporal association between preexisting GUD and subsequent HIV acquisition. The analyses that simultaneously controlled for additional risks for HIV infection, such as lifetime sex partners or history of injection drug use, report a generally lower risk for HIV associated with GUD. It is likely that studies that adequately control for risk factors will find a lower risk associated with GUD than was reported in the literature earlier in the HIV epidemic. Future research needs and the problems associated with conducting these types of studies are discussed.

Case-Control Studies↗

PubMedDate not supplied

Diagnostic efficacy of optical coherence tomography in the management of preinvasive and invasive cancer of uterine cervix and vulva.

The purpose of this study was to understand the capabilities and utility of optical coherence tomography (OCT) in characterizing tissue in patients with precancer and cancer of the uterine cervix and vulva. OCT is an optical technique that uses low-coherence interferometer to develop a two-dimensional image of optical scattering from internal tissue microstructure. This study was designed to develop diagnostic criteria. Women undergoing colposcopic evaluation secondary to an abnormal Papanicolaou smear or visualized grossly abnormal vulvar lesion comprised the study population. Under colposcopic visualization, the OCT device was applied to normal regions in all patients and abnormal areas when present, and images were captured. Each subject then underwent multiple directed biopsies. Images were then reviewed and compared with matched histology. A total of 50 women were recruited for the study. Of the 50 patients evaluated, 18 had cervical intraepithelial neoplasia (CIN) II,III, 14 had CIN I, 13 had metaplasia/inflammation, two had invasive squamous cell carcinoma of the cervix, and three had a diagnosis of Paget's disease of the vulva. Analysis of the OCT images showed a repetitive pattern that represented normal squamous epithelium of the cervix in 100% of the normal biopsies. Images of the 18 patients with histologically proven CIN II,III showed an unstructured homogeneous highly backscattering region with fast attenuation of the signal in 16 (89%) of the patients. OCT is a new approach for the early identification of cervix and vulvar malignancies. Using information inherent to the returning photon signals from tissue, early morphological and light-scattering changes can be detected during tumorigenesis. It has the potential to be a true optical biopsy. If diagnostically comparable to a biopsy, then clearly the ability of OCT to provide a point of service diagnosis would serve a significant advantage.

Carcinoma, Squamous Cell↗

PubMedDate not supplied

Intravenous procaine as a supplement to general anesthesia for carbon dioxide laser resection for carbon dioxide laser resection of laryngeal papillomas in children.

Procaine suppresses the cough reflex, decreases laryngeal irritability, and has general anesthetic properties. For these reasons, 14 pediatric patients undergoing CO2 laser resection of laryngeal papillomas were studied in which an intravenous infusion of procaine (1 mg/kg/min) was added to N2O-O2 halothane/enflurane general anesthesia immediately following endotracheal intubation. These patients were compared to nine patients receiving the same anesthesia without procaine. The mean age of both groups was 11 years. There was no difference between the groups in duration of anesthesia or surgery. Emergence, however, averaged 15 minutes in study patients compared to 36 minutes in the control group (p less than 0.01). There was no difference in anesthetic concentrations required to maintain satisfactory operative conditions in the two groups. Muscle relaxants were required intraoperatively in seven control patients but in none of the study patients. The surgeon ranked the operative conditions excellent in all study patients but poor in seven of the nine control patients. Five of the latter required postoperative treatment of laryngeal complications, including reintubation in three. Only one of the study patients had postoperative stridor. No evidence of procaine toxicity was noted in the study patients with total doses ranging from 500--3600 mg. Intravenous procaine is useful in pediatric patients having endoscopic laryngeal operations.

Anesthesia, Inhalation↗

PubMedDate not supplied

Pharmacology for nursing practice.

Nurses must have sufficient understanding of pharmacology to ensure that they are able to comply with the UKCC's standards for the administration of medicines. The depth of understanding required for these purposes needs to be established. More emphasis needs to be given to the biological sciences when planning nursing curricula.

Clinical Competence↗

PubMedDate not supplied

Surgical treatment of angina pectoris in the elderly.

We collected hospital and follow-up data for a consecutive series of 35 patients aged 65 years and over who underwent coronary artery bypass grafting for the relief of severe angina pectoris between January, 1974, and June, 1979. The inhospital mortality was 2.8% (one patient). Three patients (9%) suffered perioperative myocardial infaction, three (9%) were reoperated upon for early postoperative bleeding, and four (11%) had significant cerebrovascular complications. Only the latter rate differs significantly (P = 0.05) from the rate of complications reported in published series which include patients of all ages. Late mortality at a mean of 24.3 months follow-up was 12% (four late deaths). Relief of angina in survivors was excellent, with 20 of the 30 survivors (67%) free of chest pain at the time of follow-up. Twenty-five of the 30 survivors (82%) reported no limitation of their activities. Results in the elderly group were compared with those obtained for 322 consecutive patients of all ages, tha latter group having an operative mortality of 3.4%, a late mortality (at a mean of 15 months follow-up) of 12%, complete relief of angina in 62% and complete freedom from physical incapacity in 61% of survivors. Good short-term and long-term results can be obtained from coronary artery bypass grafting in symptomatic elderly patients, but with an increased risk of cerebrovascular complications.

Aged↗

PubMedDate not supplied

Alveolar proteinosis treated with a single bronchial lavage.

An acute febrile illness with respiratory failure and pulmonary infiltrates is a recognized accompaniment of many infective and inflammatory diseases. We report a case of pulmonary alveolar proteinosis, with secondary bacterial infection, that responded to a single pulmonary lavage and the elimination of occupational exposure to dust. In contrast to other interstitial lung diseases, therapy with corticosteroid or antibiotic agents alone was not appropriate. This report underlines the need for early, active intervention in diffuse lung diseases, and emphasizes the importance of obtaining a specific diagnosis in directing subsequent therapy.

Adult↗