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Biomedical subjects

C Brown

Publications and source records attributed to C Brown.

At least 307 records · Page 17Linked to original sources
PubMed1994

Case report: intestinal perforation--an unusual complication of endoscopic biliary stenting.

The endoscopic placement of stents to decompress biliary obstruction is accepted practice in the management of malignant biliary strictures. In our patient, a 73-year-old man with a presumed malignant common hepatic duct stricture, palliation of his obstructive jaundice has been achieved. However, his clinical course was complicated by a colonic perforation--a previously unreported complication of distal stent migration.

Aged↗
PubMed1994

The ecology of human performance: a framework for considering the effect of context.

In theory and in practice, context (as an area of concern to occupational therapists) has not received the same attention as performance components and performance areas. The Ecology of Human Performance serves as a framework for considering the effect of context. Context is described as a lens from which persons view their world. The interrelationship of person and context determines which tasks fall within the person's performance range. The Ecology of Human Performance framework provides guidelines for encompassing context in occupational therapy theory, practice, and research.

Activities of Daily Living↗
PubMed1994

An evaluation of a smoking cessation training program for medical residents in an inner-city hospital.

Thirty-four medical residents at a hospital serving a predominantly black inner-city area were trained to counsel their patients to quit smoking. They were tested before the training session and again 4 months later with questionnaires assessing smoking knowledge, attitude, and clinical practice. The training consisted of two 1-hour lectures, printed materials, and a 1.5-hour Objective Simulated Clinical Exam. Most of the residents were males (88.2%), in internal medicine (87.5%), under the age of 35 (79.4%), and foreign-born (76.5%). Asians (44.1%) comprised the largest racial group, followed by whites (29.4%) and blacks (20.6%). The impact of the training was assessed by comparing the pre- and posttests using paired Student's t tests. Overall score increased from 69.3 to 89.1 (P = .0001) out of a maximum of 131. Scores increased significantly for attitudes and beliefs (38 to 52; P = .0001), knowledge (5.3 to 6.6; P = .0001), and usual practices with smoking patients (25 to 30; P = .002). These data provide evidence that training increased the confidence, motivation, and reported practice of these residents in intervening with their patients, the majority of whom are black. This has special significance because physicians are least likely to advise black patients and those in lower socioeconomic groups to quit smoking. The demographic profile of our residents is characteristic of many inner-city hospitals.

Adult↗
PubMed1994

Lack of association between anti-V3 loop antibody and perinatal HIV-1 transmission in Kinshasa, Zaire, despite use of assays based on local HIV-1 strains.

Maternal antibodies against the V3 loop principal neutralizing domain (PND) have been reported to protect against perinatal HIV-1 transmission. To study this association in an African city with a long-standing HIV epidemic and no established "consensus sequence" for the V3 loop region of gp120, we determined the DNA sequence for the V3 region of HIV-1 from 13 HIV-1-infected residents of Kinshasa, Zaire, and developed peptide enzyme immunoassays (EIAs) reflecting the V3 loop PND for those HIV-1 strains. Using the most broadly reactive locally derived V3 loop peptide in a limited-antigen EIA, there was no significant difference in the perinatal HIV-1 transmission risk between 64 women with anti-V3 loop antibody (transmission risk, 30%) and 104 women without anti-V3 loop antibody (transmission risk, 25%; p = 0.5); this finding was unchanged after we controlled for maternal AIDS and low birth weight. Although we used assays for V3 loop antibody based on local HIV-1 strains and evaluated a large number of mother-child pairs, we found no evidence that maternal anti-V3 loop PND antibody protects against perinatal HIV-1 transmission.

Amino Acid Sequence↗
PubMed1993

A prospective study of diarrhea and HIV-1 infection among 429 Zairian infants.

BACKGROUND: Persistent diarrhea is a prominent feature of the acquired immunodeficiency syndrome in adults, but its cause and its effect on children with human immunodeficiency virus (HIV) infection are largely unknown, particularly in Africa. METHODS: We studied a birth cohort of 429 infants born to HIV-positive or HIV-negative mothers in Zaire to determine the incidence of acute, recurrent (> or = 2 episodes), and persistent (> or = 14 days) diarrhea; outcome; and risk factors. RESULTS: Of the 238 infants whose mothers were HIV-positive, 53 were infected, 139 were uninfected, and the HIV status of 46 could not be determined. As compared with uninfected infants, infected infants had higher incidence rates for acute diarrhea (170 vs. 100 episodes per 100 child-years, P = 0.003), recurrent diarrhea (21 vs. 11, P = 0.12), and persistent diarrhea (19 vs. 4, P < 0.003). Persistent diarrhea developed in 11 HIV-infected infants; all but 1 died. It also developed in 19 uninfected infants; all but 1 survived. The prevalence of stool pathogens was similar in the two groups. In a multivariate model, persistent diarrhea in an infant was independently associated with symptomatic HIV type 1 infection in the mother (relative hazard, 1.5; P = 0.08). The incidence of persistent diarrhea in the uninfected infants of seropositive mothers was nearly double that in the uninfected infants of seronegative mothers (4.9 vs. 2.7 episodes per 100 child-years), and the risk increased if the mother died (relative hazard, 10.4). Significant growth impairment and severe immunosuppression occurred in the six to eight weeks before the onset of persistent diarrhea. CONCLUSIONS: In Zaire, infants with HIV infection have an 11-fold increased risk of death from diarrhea, largely persistent diarrhea, which is often preceded by recurrent episodes of acute diarrhea, malnutrition, or immunosuppression. Illness and death of the mother increase that risk, even among her uninfected infants.

Acute Disease↗
PubMed1993

A new restriction endonuclease, TspEI, from the genus Thermus that generates cohesive termini compatible with those of EcoRI.

The detection, isolation and properties of the restriction endonuclease TspEI are described. The canonical recognition sequence (AATT) is the same as the 4-bp core of the 6-bp sequence (GAATTC) of EcoRI. Hydrolysis occurs 5' to the palindromic tetramer so that TspEI produces the same cohesive termini as EcoRI. TspEI therefore has an obvious application in producing partial digests of DNA for ligation to EcoRI-digested cloning vectors.

Base Sequence↗
PubMed1993

Spectrum of immunodeficiency in HIV-1-infected patients with pulmonary tuberculosis in Zaire.

Tuberculosis (TB) is the most common opportunistic infection in African patients who die from AIDS, yet the stage of immunodeficiency at which TB develops is uncertain. We studied the immune status of HIV-infected outpatients with pulmonary TB in relation to their clinical presentation in a cross-sectional study of 216 HIV-seropositive and 146 HIV-seronegative ambulatory incident cases of smear-positive and culture-positive pulmonary TB in Kinshasa, Zaire. HIV-seropositive and seronegative patients had median CD4 lymphocyte counts of 316.5/microL and 830.5/microL, respectively. Of the HIV-seropositive patients, 32.9% had less than 200 CD4 lymphocytes/microL, 37% between 200 and 499, and 30.1% 500 or more. Clinical AIDS, as defined by the WHO clinical case-definition or a modified version, was of similar limited use as a predictor of immunodeficiency. Among HIV-seropositive patients, oral candidosis, lymphopenia, a negative tuberculin purified protein derivative test, and cutaneous anergy were strongly associated with CD4 counts of less than 200/microL, and seemed to be better markers of immune dysfunction. We conclude that pulmonary TB develops across a broad spectrum of HIV-induced immunodeficiency and that a diagnosis of pulmonary TB is of limited use as a marker of stage of HIV disease in African HIV-infected outpatients.

AIDS-Related Opportunistic Infections↗
PubMed1993

Risk for perinatal HIV-1 transmission according to maternal immunologic, virologic, and placental factors.

OBJECTIVE: To evaluate how maternal and obstetric factors interact to influence mother-to-child human immunodeficiency virus type 1 (HIV-1) transmission. DESIGN: Prospective, observational cohort study of children born to HIV-infected women to determine child's HIV infection status. The analysis then compared peripartum maternal, placental, and obstetric variables between HIV-1 transmitter and nontransmitter women. SETTING: Two large maternity wards in Kinshasa, Zaire. PARTICIPANTS: Consecutive sample of 324 HIV-1-infected women at delivery, with 254 HIV-seronegative women followed up as control subjects. PRINCIPAL OUTCOME MEASURES: HIV infection status of children, to classify each woman as an HIV-1 transmitter or nontransmitter. RESULTS: The highest transmission risk (TR) was associated with maternal p24 antigenemia (TR, 71%; relative risk [RR], 3.0; 95% confidence interval [CI], 1.7 to 5.2) and maternal CD8+ lymphocyte counts of at least 1.80 x 10(9)/L (1800/microL) (TR, 50%; RR, 2.2; 95% CI, 1.2 to 4.2). Among women with CD8+ lymphocyte counts of less than 1.80 x 10(9)/L, CD4+ lymphocyte counts of less than 0.60 x 10(9)/L were a risk factor (TR, 29%; RR, 2.2; 95% CI, 1.2 to 4.2). In women with neither high CD8+ nor low CD4+ lymphocyte counts, placental membrane inflammation was associated with perinatal transmission (TR, 40%; RR, 4.2; 95% CI, 1.3 to 13.7). In women with neither p24 antigenemia, high CD8+ or low CD4+ lymphocyte counts, nor placental membrane inflammation, the transmission risk was only 7%. Additional correlates of transmission included maternal anemia and fever, but not maternal sexually transmitted diseases. CONCLUSIONS: Identifiable subgroups of HIV-1-infected women based on maternal and placental characteristics had between a 7% and 71% risk of perinatal HIV-1 transmission. Not only the overall rate of transmission but the impact of different risk factors for transmission appear to vary over the course of HIV infection.

AIDS Serodiagnosis↗
PubMed1993

Protection of goats against peste des petits ruminants with a vaccinia virus double recombinant expressing the F and H genes of rinderpest virus.

Peste des petits ruminants (PPR) is a viral disease of goats and sheep characterized by necrotizing and erosive stomatitis, enteritis and pneumonia. The causative agent, PPRV, is a member of the family Paramyxoviridae and the genus Morbillivirus. Other members of the genus include rinderpest (RPV), measles, canine distemper and phocid distemper viruses. PPR has a very high rate of morbidity and mortality, and effective control of this disease is of economic importance in Africa, Asia and the Middle East. Currently, there is no safe and effective vaccine available against the disease. The tissue culture rinderpest vaccine (TCRV) protects small ruminants against severe disease; there are, however, clinical problems associated with vaccination. This laboratory has recently developed several effective vaccinia virus recombinant vaccines for rinderpest. These vaccines are easy to administer, inexpensive to produce and heat-stable. Goats were vaccinated with a vaccinia virus double recombinant expressing the haemagglutinin and fusion genes of RPV. Although vaccinated animals developed antibodies (neutralizing and ELISA) to RPV, and not to PPRV, they were completely protected against challenge inoculation with virulent PPRV. This would indicate that protection is most probably due to cell-mediated immunity. Use of the rinderpest double recombinant vaccinia virus in areas of the world where PPRV is endemic would aid in the control and eradication of PPR.

Animals↗
PubMed1993

Genetic diversity of human immunodeficiency virus type 1 strains in Kinshasa, Zaire.

The envelope (env) gene of human immunodeficiency virus type 1 (HIV-1) was amplified by polymerase chain reaction (PCR) from the peripheral blood mononuclear cells (PBMCs) of 14 HIV-1-infected women from Kinshasa, Zaire. Amplified DNA was directly sequenced with a primer specific for the HIV-1 env C2 region. The predicted amino acid sequences for the C2-V3 region for the 14 specimens are presented. The tetrapeptide sequence, GPGQ, located at the crown of the V3 loop, is conserved in all specimens. The same tetrapeptide sequence is present in the Zairian isolate MAL, but not in other published Zairian isolates (Z6, ELI, Z321, JY1, and NDK). Sequence comparison of the env C2-V3 region among the 14 specimens from Kinshasa revealed a 9-25% range of nucleotide divergence, with an average of 16%. Divergence between the 14 specimens and the Zairian isolates MAL, Z6, ELI, Z321, JY1, and NDK ranged from 13 to 31%. A range of 18-28% nucleotide sequence divergence was demonstrated between the 14 Kinshasa specimens and the North American isolate MN. These results demonstrate the importance of examining HIV-1 samples from diverse geographic origins in the development of effective HIV-1 vaccines.

Amino Acid Sequence↗
PubMed1993

Immunogenicity of high-titer Edmonston-Zagreb measles vaccine in human immunodeficiency virus-infected children in Kinshasa, Zaire.

The response to Edmonston-Zagreb vaccine (titer, 5.4 log10 pfu) was evaluated among children in a study of perinatal transmission of human immunodeficiency virus (HIV) in Kinshasa. Acute postvaccination adverse events were monitored for 49 HIV-infected and 376 non-HIV-infected infants, and measles antibody responses were assessed by ELISA for 34 HIV-infected and 255 non-HIV-infected infants. There was no increase in the incidence of common symptoms 7-10 days after vaccination. HIV-infected infants were more likely to have detectable prevaccination measles antibody, and seroconversion after vaccination was somewhat lower in HIV-infected (76.5%) than non-HIV-infected infants (85.5%). Seroconversion rates did not differ among children with or without rhinitis or fever at vaccination. High-titer Edmonston-Zagreb vaccine given at 6 months of age has the potential to provide earlier protection against measles; however, this vaccine is no longer recommended for routine use, and two doses of standard-titer vaccines remains the preferred option for measles vaccination of HIV-infected infants.

Child↗
PubMed1993

Periurethral Teflon for stress urinary incontinence: medium-term results.

Medium-term results are presented for the periurethral injection of Teflon in the treatment of stress urinary incontinence. Follow-up data were obtained on 36 women by means of case note review and the completion of a postal questionnaire. Mean follow-up was 5.1 years. Subjective results showed 12 patients to be dry or much improved while the remaining 24 patients did not obtain significant benefit from the procedure. Repeat injections in 12 women resulted in only 3 obtaining useful improvement, while a subgroup of patients who had undergone previous procedures showed a better response. No significant complications were observed. Periurethral Teflon injection is a minor surgical procedure which can produce worthwhile improvement, although an initially good result may not be sustained with longer follow-up. This method may be advocated as treatment for poor risk patients who are unsuitable for surgery, particularly when previous attempts at formal surgical correction have been unsuccessful.

Adult↗
PubMed1993

Diversion colitis and involution of the defunctioned anorectum.

To measure the effects of defunction in the anorectum, 12 patients (seven men and five women aged 59 (44-81) years) were studied after the Hartmann operation. The operation was for septic complications of diverticular disease in nine and sigmoid carcinoma in three patients. Physiology studies were undertaken 1 and 3 months after surgery, and diversion colitis was assessed endoscopically and by mucosal biopsy at 3 months. There was no change in anal sphincter function by three months. Proctometrogram studies, however, showed an appreciable decrease in rectal volume in all cases, by a mean of 35% of the 1 month volume. The maximum tolerable volume at 1 month was 157 (111-210) ml and at 3 months 87 (71-145) ml; p < 0.01. There was no change in rectal sensation or compliance. Erythema and granularity without gross erosions or ulceration were found at endoscopy. Histology showed abnormalities in all cases by 3 months. The characteristic features were of a chronic inflammatory cell infiltrate with surface exudate, microscopic erosions, and lymphoid follicular hyperplasia. Crypt abscesses were not a feature at this stage and there was no distortion of crypt architecture. After defunction the previously normal rectum is affected by diversion colitis which, at 3 months, is mild but has characteristics that distinguish the changes from those of inflammatory bowel disease. It is associated with progressive rectal stump involution.

Adult↗
PubMed1993

Helicobacter pylori eradication: efficacy and side effect profile of a combination of omeprazole, amoxycillin and metronidazole compared with four alternative regimens.

We evaluated eradication of Helicobacter pylori infection in 263 patients by a new 14-day regimen of omeprazole 40 mg mane (a gastric secretory inhibitor) plus two antibiotics: amoxycillin 500 mg three-times daily (tds) plus metronidazole 400 mg tds. The comparative groups included updated results of our previous work with a 14-day course of either standard triple therapy (STT, colloidal bismuth subcitrate 120 mg four times daily (qds) plus tetracycline 500 mg qds and metronidazole 400 mg tds), omeprazole 40 mg once daily plus amoxycillin 500 mg tds (OA), or two modified triple therapy: either Borody's (BTT) of all three components (colloidal bismuth subcitrate 120 mg, tetracycline 500 mg, metronidazole 200 mg) qds instead of tds, or Logan's (LTT) seven-day therapeutic regimen of colloidal bismuth subcitrate 120 mg qds, amoxycillin 500 mg qds and, for the last three days, metronidazole 400 mg five times daily. Omeprazole/amoxycillin/metronidazole (OAM) therapy was better tolerated than STT (course completion 98.1% vs. 81.4%, p < 0.001). H. pylori was eradicated by OAM therapy in 53/55 (96.4%) patients with metronidazole-sensitive organisms and in 54/72 (75.0%) with metronidazole-resistant isolates (p < 0.01). The respective corresponding rates for STT and OA therapy were 20/22 (90.9%) and 14/29 (48.3%), (metronidazole-sensitive organisms) and 7/21 (33.3%) and 15/31 (48.4%) (infections resistant to metronidazole). BTT and LTT were also better tolerated than STT. The eradication rate for BTT was 23/26 (88.5%) but that for LTT, the best tolerated of the five treatment regimens, was only 19/28 (67.9%) when pretreatment isolates were metronidazole-sensitive.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗