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Biomedical subjects

R Long

Publications and source records attributed to R Long.

At least 19 recordsLinked to original sources
PubMed1992

Structure of bis(2-chloroethyl)ammonium hexachlorostannate.

[(ClCH2CH2)2NH2]2SnCl6, M(r) = 617.48, monoclinic, C2/c, a = 15.67 (2), b = 13.54 (2), c = 13.24 (2) A, beta = 127.9 (2) degrees, V = 2217 A3, Z = 4, D chi = 1.85 g cm-3, lambda(Mo K alpha) = 0.71073 A, mu = 23.70 cm-1, F(000) = 1208, T = 295 K, R = 0.058, wR = 0.071 for 1231 unique reflections. The structure consists of discrete (ClCH2CH2)2NH2+ cations and octahedral SnCl6(2-) anions with the Sn sitting on the twofold axis.

Chemical Phenomena↗
PubMed1992

The influence of urinary diversion on experimental gastrocystoplasty.

Gastrocystoplasty is used to augment the bladder of patients with decreased renal function to prevent development or worsening of metabolic acidosis. We recently observed a perforated peptic ulcer in the gastric portion of a defunctionalized gastrocystoplasty. We postulated that the lack of buffering action of urine precipitated peptic ulcer disease in the gastrocystoplasty. To explore this possibility further, we conducted an experiment. In 12 adult female mongrel dogs (weight 15 to 26 kg.) the bladder was divided into right and left segments. One kidney was removed and both hemibladders were capped with a vascularized segment of gastric body. Thus, 1 side (wet) remained exposed to urine, while the other side (dry) was drained to the abdominal wall with a cystostomy tube. The animals were divided into 2 groups: 9 in group 1 received no drugs to modify gastric secretion and 3 in group 2 received a hydrogen (H2) blocker. Three animals in group 1 had perforation of the vesical part of the dry gastrocystoplasty 2 to 3 weeks postoperatively and were sacrificed. The others were sacrificed 3 to 6 weeks postoperatively. Serum gastrin levels remained normal in all animals. Gross and histological examinations of the augmented bladders in group 1 revealed ulcerations of the bladder segment of the wet and dry gastrocystoplasties but the lesions were more numerous and prominent on the dry side in all animals, particularly those in which the perforations occurred. A peptic ulcer was noted in the gastric portion of the dry gastrocystoplasty in 1 animal. The bladder epithelium of the dry gastrocystoplasty showed glandular metaplasia in several animals in this group. In group 2 the wet gastrocystoplasty showed normal histology except in 1 dog that had mild inflammation and focal superficial ulceration in the vesical portion. On the other hand, the dry gastrocystoplasty showed severe inflammation and ulcerations in 2 animals, and mild inflammation of the vesical portion in 1. There were no perforations in this group. This experiment demonstrates that gastrocystoplasty produces cystitis but that these changes are more prominent in the absence of urine, as indicated by the severity of the lesions, perforations and metaplasia. Peptic ulcer disease occurred in the gastric portion of the dry gastrocystoplasty in 1 animal. The use of H2 blockers decreases the incidence of ulceration in wet gastrocystoplasty but it seems to have less influence on the ulceration of dry gastrocystoplasty. Clinicians must be alerted to the risk of perforation of dry gastrocystoplasty.

Animals↗
PubMed1992

Paediatric outpatient utilisation in a district general hospital.

Paediatric outpatient utilisation in a district general hospital was studied for 20 general practices that covered a population of 26,433 children. The actions taken by paediatric staff were analysed for 487 new referrals and 2784 review attendances (the latter in 1630 children) over an eight month period. New referral rates from different general practices varied between 3.7 per thousand children 0 to 15 years and 29.6 with a mean of 13.7, equivalent to 19 per thousand per year. (The national mean based on health district populations is 21.2 per year.) A total of 63% of new referrals and 49% of review patients were aged under 5 years. Over the study period 2.2% of children under 5 years in the population were referred as a new patient, equivalent to 3.1% per year, and 1.3% of children aged 0 to 15 years were referred, equivalent to 1.8% per year. Review attendances on one or more occasion occurred in 6.5% of children under 5 years over the study period, equivalent to 9.2% per year, and for age 0 to 15 years, 4.8% attended once or more times over the study period, equivalent to 6.7% per year. The review attendance rate per thousand child population per practice varied between 59 and 160 with a mean of 81.9. New patients formed 14.8% of the total attendances (the national mean is 18.3%). Review attendance rates were significantly lower when the general practice was large. Socioeconomic factors suggested by a high proportion of children in the general practice list were associated with a high review attendance rate. Altogether 27.0% of new referrals were seen once only and 32.8% had no tests done. The most common reason for attendance was asthma (11% of new and 19% of review patients). The second commonest was for fits (8.4% of new referrals and 4.7% of review patient attendances).

Adolescent↗
PubMed1992

[Partial purification and analysis of allergenicity, immunogenicity of Ginkgo biloba L. pollen].

Pollens of Ginkgo biloba L. (G.b.l.p) have been found to be a kind of important allergen which causes pollinosis in Chengdu. The goal of this study is to purify G.b.l.p and to determine the allergenicity and immunogenicity of various fractions. Crude extract was purified by gel filtration with Sephadex G25, then G75. Two elution peaks were observed. On SDS-PAGE, the molecular weights of protein of the 1st peak and the valley were 30-42 kd and 13-18kd, respectively, and that of the 2nd peak was less than 13 kd. 40 patients with allergic rhinitis and/or asthma underwent the skin test with crude extract and various fractions of gel filtration; it revealed that the strongest allergenic activity existed in the 1st peak and there was mild allergenic activity in the 2nd peak. The in vitro allergenic activity and immunogenic activity of various fractions were examined by ELISA inhibition test. It was further confirmed that the allergenic activity and immunogenic activity of the 1st peak were the strongest, and those of the 2nd peak were the lowest. It is suggested that diagnosing reagents can be made satisfactorily by partial purification, i.e. discarding the inactive fractions, since allergenicity exists in various fragments. But fractions of allergen with high IgG immunogenicity should be selected to produce immunotherapy agents so as to enhance the production of blocking antibody and thus improve the therapeutic effect.

Allergens↗
PubMed1991

Major problems with paediatric bed usage statistics?

This study was carried out on the way in which children's beds were used by the specialty of paediatrics in a district general hospital. Five differing ways were found of interpreting the present Department of Health guidelines on health services information (Körner recommendations). These gave bed occupancy figures varying between 73% and 106%; throughput figures varying between 23.8 and 34.7 discharges per bed; and turnover interval varying between -0.17 and 1.1 days for the same group of paediatric admissions. For comparisons of efficiency and costs between hospitals, which are based upon bed utilisation statistics, it is essential that there is standardisation of method of analysis.

Bed Occupancy↗
PubMed1991

Impact of human immunodeficiency virus type 1 on tuberculosis in rural Haiti.

We conducted a case-control study to determine the relative and attributable risk of HIV seropositivity for bacillary-positive (smear and/or culture) pulmonary tuberculosis in Haiti. There were 274 patients with tuberculosis and an equal number of control subjects. Antibodies to HIV were present in 67 (24%) patients and eight (3%) control subjects. Odds ratios suggested that the risk of pulmonary tuberculosis was 15.7 times as great (95% confidence interval, 4.8 to 5.0; p less than 0.05) in patients 20 to 39 yr of age who were HIV-seropositive than in HIV-seronegative patients. In contrast, the relative risk in those 40 to 59 yr of age was elevated (3.0 times), though not significantly (lower 95% confidence interval, 0.8). In the 20- to 39-yr age group, 31% of tuberculosis was attributable to HIV infection (95% confidence interval between 23 and 39%). HIV-seropositive and HIV-seronegative patients did not differ with respect to sputum smear positivity. HIV-seronegative patients were twice as likely to be infected with resistant organisms, though this was not significant. We conclude that HIV infection is a major risk factor for pulmonary tuberculosis in young adult residents of Haiti. This, together with the fact that similar proportions of HIV-seropositive and HIV-seronegative patients were potentially infectious, suggests that without vigorous counteraction tuberculosis will become a greater problem for Haiti.

Acquired Immunodeficiency Syndrome↗
PubMed1991

The chest roentgenogram in pulmonary tuberculosis patients seropositive for human immunodeficiency virus type 1.

To determine the impact that co-infection with HIV has on the radiographic presentation of pulmonary tuberculosis, we examined the chest roentgenograms obtained before treatment in 225 HIV-tested adult Haitians with bacillary (smear or culture or both) positive pulmonary tuberculosis. There were 67 HIV-seropositive and 158 HIV-seronegative patients. Intrathoracic adenopathy alone was more common and parenchymal infiltrates less common in HIV-seropositive patients (p less than 0.05). Although a parenchymal infiltrate was less likely to be cavitating in the HIV-seropositive group (p less than 0.05) when cavitary parenchymal disease was present, HIV seropositivity did not affect the number of cavities (single or multiple) or the size of the largest cavity. Patients with AIDS were significantly more likely to have a chest radiographic pattern consistent with primary tuberculosis (80 percent) than HIV-seropositive patients without AIDS (30 percent), and the latter were significantly more likely to have such a pattern than HIV-seronegative patients (11 percent) (p less than 0.05). The HIV-seropositive patients were equally infectious, regardless of the pattern of disease (primary vs postprimary). Even though pulmonary tuberculosis in an HIV-seropositive adult probably results from reactivation of dormant foci or reinfection, the pattern on the chest roentgenogram often suggests primary disease, especially if the patient has AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1991

The impact of HIV on the usefulness of sputum smears for the diagnosis of tuberculosis.

In a developing country, 289 patients were examined for active pulmonary mycobacterial disease (sputum smear and culture) and HIV infection (serology) to compare the sensitivity and positive predictive value of sputum smears for diagnosing pulmonary tuberculosis in patients with and without antibodies to HIV. Seventy-nine percent of HIV-seronegative vs 66% of HIV-seropositive patients with positive cultures for Mycobacterium tuberculosis were smear positive (P less than .05), and a positive sputum smear predicted the presence of M. tuberculosis in 90% of HIV seronegative vs 80% of HIV seropositive patients (P less than .05). In our opinion, HIV did not significantly compromise the diagnostic utility of the sputum smear.

Adolescent↗
PubMed1991

Subchronic oral toxicity of pyridostigmine bromide in rats.

This study evaluated the oral toxicity of pyridostigmine bromide in Sprague-Dawley rats when administered for 13 weeks by daily gavage. Groups of 10 rats/sex received doses of 0, 5, 15, 30, or 60 mg/kg/day. Toxicity was limited to exaggerated cholinergic stimulation at doses of 15 mg/kg/day or greater. Significant findings included tremors and inhibition of RBC acetylcholinesterase. Thus, 5 mg/kg/day of pyridostigmine bromide appears to be the no observed toxic effect level under the conditions of the present investigation.

Administration, Oral↗
PubMed1991

Pulmonary tuberculosis, human immunodeficiency virus type-1 and malnutrition.

In rural Haiti we measured and compared the muscle protein and calorie reserves (anthropometrics) as well as the visceral protein reserves (serum albumin, tuberculin sensitivity) in 56 HIV (human immunodeficiency virus type-1) seropositive and 108 HIV seronegative pulmonary tuberculosis patients. Results in patients were also compared to the results of the same measurements made in 160 age, sex and residence matched HIV seronegative controls without tuberculosis. Tuberculosis patients, regardless of HIV status, had significantly reduced muscle protein and calorie reserves compared to controls. The serum albumin was significantly lower in HIV seropositive tuberculosis patients (21.0 g/l) compared to HIV seronegative tuberculosis patients (26.9 g/l) and the serum albumin in both tuberculosis groups was significantly lower than in controls (41.3 g/l). The lower the serum albumin in the tuberculosis patients the greater the likelihood of a negative tuberculin test. HIV seropositive tuberculosis patients were significantly more likely to be tuberculin negative than HIV seronegative tuberculosis patients. Tuberculosis is associated with significant malnutrition. Worse malnutrition in tuberculosis patients co-infected with HIV suggests that the effect of the two pathogens on nutrition is additive or, alternatively, that tuberculosis patients who are particularly malnourished are at increased risk for HIV.

Adult↗