Search PubMed⌕ Search

Biomedical subjects

T A Smith

Publications and source records attributed to T A Smith.

At least 109 records · Page 6Linked to original sources
PubMed1991

Relationships between growth and acute lower-respiratory infections in children aged less than 5 y in a highland population of Papua New Guinea.

One hundred fifty-six children in the highlands of Papua New Guinea aged less than 5 y, studied for a total of 7019 child-weeks, had an incidence of 1.3 episodes per child-year of acute lower-respiratory-tract infections (ALRIs). There was a marked age trend with an incidence of almost three times this average for children aged less than 6 mo. Those with low weight-for-age or low height-for-age had a higher ALRI incidence rate, with no evidence of cutoffs above which nutritional status had no effect; there was no association between low weight-for-height and increased risk of ALRI. A slow weight gain was not a significant risk factor in the short term but weight gain was reduced during episodes of ALRI.

Aging↗
PubMed1991

Repair of DNA single-strand breaks in lymphocytes from Alzheimer's disease patients.

We have studied DNA single-strand breaks (SSB) and their repair, after gamma-irradiation, in lymphocytes from patients with Alzheimer's disease (AD) and from normal, age-matched individuals, using alkaline sucrose gradient centrifugation. We have found that values for AD patients and normals are similar in each of the following: level of breaks in unirradiated cells, level in cells irradiated with 150 Gy and rate of repair. Also, preliminary results for young and old normal individuals showed no significant difference between their SSB levels in unirradiated cells, nor between levels in irradiated cells nor in repair rate. In all cases, post-irradiation repair appeared to be almost complete after 50 min incubation. We conclude that gamma-irradiation produces no gross difference in the initial number of SSB between lymphocytes from AD patients, old normals and young normals, and that their repair is equally proficient.

Aged↗
PubMed1991

Chemical peritonitis associated with intraperitoneal vancomycin.

A case of chemical peritonitis associated with intraperitoneal vancomycin is reported. A 23-year-old woman presented with signs and symptoms consistent with a chronic ambulatory peritoneal dialysis catheter exit-site infection. Intraperitoneal vancomycin (Vancoled) 1 g was given, followed by 25 mg/L into each subsequent exchange. On day 4 the patient developed abdominal pain and cloudy dialysis effluent. The vancomycin was discontinued, and the dialysate cleared by day 8. Fluid cultures were negative, and Staphylococcus aureus was isolated from the exit site. Subsequent intravenous vancomycin, and smaller intraperitoneal doses, failed to repeat the event. Fluid and serum white blood cell count, serum immunoglobulins and complement, culture results, and the temporal relationship are strongly suggestive of a vancomycin-induced chemical peritonitis.

Adult↗
PubMed1991

Treatment of snakebite poisoning.

The epidemiology, mechanics, prevention, pharmacology, clinical manifestations, and treatment of snakebites are reviewed. Poisonous snakes bite approximately 8000 persons annually in the United States, causing approximately 12-15 deaths per year. Pit vipers (rattlesnakes, copperheads, cottonmouths, and massasaugas) are responsible for 99% of all snakebite poisonings; coral snakes and other foreign exotic species are responsible for the additional 1%. Envenomation is characterized by pain, edema, and ecchymoses at or near the site of venom injection, followed by cardiac, hematologic, neurologic, renal, and pulmonary toxicity. The major clinical finding in most snakebite poisonings is local tissue necrosis. Immediate treatment for snakebite includes limiting movement and placing a constriction band proximal to the site of venom injection. If medical care is more than 30 minutes away, the wound may be incised and suctioned. Antivenin therapy is the mainstay of medical treatment of snakebite, along with administration of plasma expanders, pain medication, diazepam, tetanus toxoid, antiseptics, and antibiotics. Patients who have pain, swelling, ecchymoses, systemic symptoms, or abnormal laboratory findings within 30 minutes to one hour of a bite are probable candidates to receive antivenin therapy. Before receiving antivenin therapy, the patient must be tested for hypersensitivity to the antivenin. Antivenin therapy is most effective when given within four hours of the snakebite. Pharmacists--especially those serving rural areas--should be familiar with current snakebite treatments, both local and systemic, and should be prepared to provide important information and dispel any myths about snakebite poisoning.

Animals↗
PubMed1991

Erythrocyte-reactive T-cell lines and clones from normal mice recognize serum-derived antigens.

T-cell clones and cell lines which apparently respond to autologous (syngeneic) erythrocytes have been generated from the spleens of normal mice. The response showed considerable cross-reactivity with red blood cells (RBC) from other species, including chicken, and was 'heteroclitic' in that reactivity against some species of RBC, notably rat and monkey, was greater than to mouse. The clones were Thy-1+ L3T4+ Lyt-2- and recognized antigen in association with I-Ak or I-Ek. At least three specificities were identified on the basis of reactivity to crude lysates of mouse and rat RBC. One of the putative clones, M0.5/1/D2, showed a change in reactivity during culture, proliferating strongly against antigen-presenting cells (APC) without added erythrocytes. Analysis of the clones and lines using an I-Ak I-Ek expressing hybridoma, HB-98, has indicated that only one, M5/1/F5, was likely to be erythrocyte-specific; the remainder were responding to antigens present in foetal calf serum (FCS). The data demonstrate that apparent erythrocyte specificity can be a result of serum components being presented to T lymphocytes via red blood cells.

Animals↗
PubMed1991

A review of measles admissions and deaths in the paediatric ward of Goroka Base Hospital during 1989.

We reviewed all measles cases admitted to the paediatric ward of Goroka Base Hospital in 1989, and also interviewed a sample of measles patients attending the paediatric outpatient department. Measles accounted for 11% of all paediatric admissions and 32% of deaths. The case fatality rate for measles was 17%. Children with nosocomial infections and children with low birthweight were more likely to die. The most common complications of measles were pneumonia and diarrhoea, pneumonia being the most common cause of death. Twelve cases of subacute sclerosing panencephalitis were admitted during the year (0.5% of paediatric admissions). Measles was underreported because it was frequently omitted from the discharge diagnosis, the emphasis being placed on the complications. The majority of children with measles admitted to the ward and seen in outpatients had not been vaccinated. Nosocomial infections could have been reduced if all paediatric admissions aged 6-35 months had been vaccinated on admission. We strongly endorse the policy of vaccinating children in Papua New Guinea against measles from the age of 6 months.

Age Factors↗
PubMed1990

Comparison of 5-fluorouracil pharmacokinetics following intraperitoneal and intravenous administration using in vivo 19F magnetic resonance spectroscopy.

Intrahepatic pharmacokinetic studies of 5-Fluorouracil (5 FU) metabolism following intravenous and intraperitoneal administration have been undertaken in four patients using in vivo 19F nuclear magnetic resonance spectroscopy. Following intravenous administration, 5 FU decayed with "half times" ranging from 5 to 17 min. There was considerable variation of 5 FU pharmacokinetics between patients following intraperitoneal administration. Peritoneal contamination by infused 5 FU was considered to be a significant problem in one patient. A technique for providing superficial signal suppression was therefore investigated and its efficacy for excluding signal from the peritoneal space has been demonstrated. Owing to the potential for contamination from peritoneal 5 FU, the accumulation of fluoro-beta-alanine (FBAL) is a more reliable indicator of drug catabolism than the measurement of unlocalized "hepatic" 5 FU. Rapid intrahepatic catabolism of 5 FU to FBAL was demonstrated in all patients. However, there was greater pharmacokinetic variation following intraperitoneal administration than following intravenous administration. Therapeutic implications of intravenous compared with intraperitoneal administration of 5 FU are discussed.

Fluorouracil↗
PubMed1990

Evaluating a behavioral method to manage dental fear: a 2-year study of dental practices.

Eleven private general practices and a university clinic formed a network to treat dental fear. The practices located in four states learned a method of treating dental fear using dental staff members and audiovisual materials. This study is an evaluation of the network's effectiveness. In 15 months, 111 patients were treated by the network. The dentists reported providing substantial dental treatment to 77% (n = 86) of the patients. The study showed that private general practices can effectively treat strong dental fear.

Adolescent↗
PubMed1990

The detection of group specific component (Gc) in the general population of West Virginia.

An isoelectric focusing method is described for the detection of group specific component (Gc) in forensic casework. Gc can be subtyped in one day using this reliable and reproducible method. The gene frequency data collected indicate that the occurrence of Gc phenotypes in the population of West Virginia is consistent with established frequencies for the system.

Blood Stains↗
PubMed1989

Induction of experimental autoimmune thyroiditis in B cell-depleted mice.

The effect of B cell depletion on the induction and severity of murine experimental autoimmune thyroiditis was investigated. Thirteen CBA mice were given repeated intraperitoneal doses of 700 micrograms purified rabbit anti-mouse Ig antibody from 24 hours to 8 weeks after birth. Controls were given normal rabbit IgG (14 mice) or were left uninjected (10 mice). At six weeks all mice received two doses of 70 micrograms murine thyroid extract in complete Freund's adjuvant. Only 2/13 of the anti-Ig treated mice were fully B cell-deficient as determined by serum IgM, spleen cell immunofluorescence and responsiveness to LPS; however, the levels of anti-thyroglobulin autoantibodies were very low in 7/13 mice. The results demonstrate that thyroiditis can be actively induced in the absence of B cells and autoantibodies but that B cells may play a role in increasing disease severity.

Animals↗
PubMed1989

A close relationship between microvilli and metabolic cooperation deficiency in embryonal carcinoma cells.

A revertant clone has been isolated from the metabolic cooperation-deficient embryonal carcinoma clone PT2md1. In PT2md1, its cooperation-competent parent, and its cooperation-competent revertant an inverse correlation has been demonstrated between cooperation competence and the incidence of microvilli. This demonstration, together with a similar correlation previously reported in an independently isolated series of cell lines, establishes a close causal relationship between the incidence of microvilli and communication deficiency.

Animals↗
PubMed1989

Radiosensitivity of lymphocytes from patients with Alzheimer's disease.

The response after gamma-irradiation of lymphocytes from 8 patients with Alzheimer's disease (AD), 3 patients with Huntington's disease and 13 normal subjects to stimulation by phytohaemagglutinin (PHA) was assayed by incorporation of [3H]thymidine. The response of non-irradiated cells was found to be significantly lower in AD cells than in age-matched normals but not significantly lower in old normals than in young normals. However, the response of irradiated cells to PHA, expressed as a percentage of that in non-irradiated cells, was found to be similar in AD patients, young and old normals and in HD patients.

Adult↗
PubMed1989

Characteristics of lymphocyte chromatin from Alzheimer's disease patients and from young and old normal individuals.

We have examined chromatin in lymphocytes from patients with Alzheimer's disease (AD) and from normal individuals of a range of ages. We have found that the neucleosome repeat length does not vary with age for normal individuals over the range 24-78 years and that there is no difference between the value for AD cells (mean and standard deviation, 202 +/- 7 base pairs, bp) and for normals (207 +/- 5 bp). The rate of digestion of chromatin in lymphocyte nuclei by micrococcal nuclease does not appear to differ significantly between old and young normals and AD patients.

Adult↗
PubMed1989

Population data of casework in West Virginia on six genetic marker systems.

Blood specimens and stains submitted from all geographic regions of West Virginia were analyzed for six genetic markers: International ABO, phosphoglucomutase (PGM), esterase D (ESD), erythrocyte acid phosphatase (EAP), adenylate kinase (AK), and adenosine deaminase (ADA). The four-year study indicates that markers identified were distributed in Hardy-Weinberg equilibrium and are consistent with population data previously reported.

ABO Blood-Group System↗
PubMed1988

Respiratory and allergic symptoms in wool textile workers.

An epidemiological study of 2153 workers in 15 West Yorkshire wool textile mills was conducted to determine relations between respiratory symptoms and exposure to inspirable wool mill dust. A questionnaire designed to elicit all the common respiratory symptoms was developed and tested, and administered to all workers willing to participate (85%). It was translated and administered in Urdu for the 385 workers from Pakistan whose English was not fluent. Symptoms investigated included cough and phlegm, wheezing and chest tightness, breathlessness and its variability, rhinitis, conjunctivitis, chills, nosebleeds, and chest illnesses. Additional questions were asked, where appropriate, about the times of day, days of the week, seasons, and places that the symptoms were worse or better than normal. An environmental survey was carried out at each mill, which included 629 measurements of inspirable dust, enabling estimates to be made of the airborne concentrations of inspirable dust usually experienced by each member of the workforce under current conditions. Overall symptom prevalences were: persistent cough and phlegm, 9%; wheeze, 31%; breathlessness on walking with others on level ground, 10%; persistent rhinitis, 18%; persistent conjunctivitis, 10%; persistent chills, 2%; ten or more nosebleeds a year, 2%; and three or more chest illnesses in past three years, 5%. After allowing for the effects of age, sex, smoking habit, and ethnic group, cough and phlegm, wheeze, breathlessness, rhinitis, conjunctivitis, and nosebleeds were found to be more frequent in those exposed to higher than to lower concentrations of dust. In some experiencing high concentrations (blenders and carpet yarn backwinders) cough and phlegm, wheeze, rhinitis, and conjunctivitis were related to the years worked in such jobs. Relative risks of each symptom in relation to inspirable dust concentrations were calculated by means of a logistic regression analysis. At concentrations of 10 mg/m3, the current United Kingdom standard for nuisance dusts, the risk of cough and phlegm relative to that of an unexposed worker was 1.37, that of wheeze 1.40, breathlessness 1.48, rhinitis 1.24, and conjunctivitis 1.70. Since some of these symptoms may be associated with functional impairment of the lungs, further studies of selected workers are being carried out to estimate the functional effects of exposure to dust in wool textile mills.

Adolescent↗