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Biomedical subjects

H Williams

Publications and source records attributed to H Williams.

At least 163 records · Page 9Linked to original sources
PubMed1991

Clinical and microbiological investigations of anorexia nervosa.

Several studies have examined the relationship between anorexia nervosa and oral status. However, none has used control subjects. Furthermore, none has examined bacteriological data in these subjects to determine whether dietary restrictions, particularly of carbohydrates, change the levels of Streptococcus mutans and Lactobacillus species. Fifteen female subjects recently hospitalized for anorexia were studied along with fifteen age- and sex-matched control subjects. The parameters examined included salivary pH and flow rate, levels of S. mutans and Lactobacillus spp., DMFT scores, facial and palatal plaque scores, periodontal pocketing, gingival recession and bleeding following gentle probing. Compared with control subjects, anorexics had significantly lower salivary pH (7.1 +/- 0.4 vs 7.6 +/- 0.3, p less than 0.01), more facial and lingual surfaces with plaque scores of 1 (facial plaque 38 per cent vs 18 per cent, p less than 0.01, lingual plaque 47 per cent vs 29 per cent, p less than 0.01), more surfaces with gingival recession (1 mm-7.9 per cent vs 1.8 per cent, p less than 0.001; 2 mm-1.7 per cent vs 0.2 per cent, p less than 0.001; greater than 2 mm-0.6 per cent vs 0.0 per cent, p less than 0.001), more surfaces with bleeding on probing (16.9 per cent vs 6.5 per cent, p less than 0.001) and fewer sextants with CPITN scores of 0 (1.9 +/- 1.5 vs 3.2 +/- 1.0, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Anterior and combined anteroposterior fusion for lumbar disc pain. A preliminary study.

This article reports on a study of 51 consecutive patients (83 lumbar discs) with back pain who underwent anterior interbody lumbar fusion or combined anterior and posterior fusion at the same operation during a 2-year period. All patients met the criteria for diagnosis of a painful internal disc disruption and/or failed back syndrome and have had a lengthy trial of conservative treatment consisting of rest, physical therapy, back support, nonsteroidal anti-inflammatory drug therapy, and guarded activity; this treatment was often supplemented by epidural cortisone injections, pain management, and functional rehabilitation. Patients with prolonged back pain who failed with conservative care after a minimum of 12 months of severely disabling symptoms were selected for surgery on the basis of a positive dynamic discogram reproducing their exact pain and demonstrating a morphologically degenerative disc (internal disc disruption). For the purpose of this study, patients were categorized into three groups and followed up for 15-36 months after the operation. There were no deaths or major complications, and the overall success in achieving measurable diminution of preoperative pain was 80%. This article discusses preliminary conclusions on the efficacy and safety on anterior and anteroposterior fusion for lumbar disc pain.

Adult↗
PubMed1991

Determinants of acceptance of routine voluntary human immunodeficiency virus testing in an inner-city prenatal population.

Routine voluntary prenatal human immunodeficiency virus (HIV) counseling and testing offer the opportunity to encourage reduction of high-risk behaviors among uninfected women and to identify those women with asymptomatic HIV infection. To characterize the determinants of acceptance of routinely offered and encouraged HIV testing in inner-city parturients in Atlanta, we identified two groups of women, one that declined HIV testing and another that accepted testing. Each group was asked to complete a questionnaire designed to assess the effectiveness of pre-test counseling. During the 7-month study period, 4731 women registered for prenatal care and 4574 (97%) consented to HIV testing. Nearly all women stated that they were not pressured into having HIV testing performed. Women who accepted HIV testing were more likely to be young, black, and single (P less than .001) and less likely to have received education beyond high school (P less than .05). More accepters than decliners thought the HIV counseling session was valuable (97 versus 91%; P = .04); 55% of accepters agreed to antibody testing because of concern about the risk of transmitting HIV infection to their fetus or infant. More accepters than decliners indicated a willingness to have HIV testing in a future pregnancy (74 versus 33%; P less than .001). These data suggest that most inner-city parturients in our institution view routine voluntary HIV counseling as a valuable component of their prenatal care.

Adolescent↗
PubMed1990

Song learning in birds: the relation between perception and production.

The vocal control system of oscine songbirds has some perplexing properties--e.g. laterality, adult neurogenesis, neuronal replacement--that are not predicted by common views of how vocal learning takes place. Similarly, we do not understand the relation between the direct pathway for the control of learned song and the recursive pathway necessary for song learning. Some of the paradoxes of the vocal system of birds may disappear once the relation between the perception and production of learned vocalizations is better understood. To some extent, perception and production may be two closely related states of a same system.

Animals↗
PubMed1990

Risk behaviour for HIV transmission in attenders on methadone maintenance.

Sixty-nine opiate addicts on methadone maintenance programmes at the Drug Treatment Centre were interviewed, all meet DSM. 3 criteria for opioid dependency. Most were young, poorly educated, unemployed and had involvement with both police and prison. Drug abuse started at a young age, all had injected drugs, heroin being the most widely abused opiate. Forty-eight (70%) were HIV (Human Immunodeficiency Virus) positive. Since diagnosis these individuals had made significant changes in their injecting practices and sexual behaviour. However, despite this positive change, there remained a high level of at risk behaviour for further HIV transmission.

Adolescent↗
PubMed1990

Hyperproduction of TEM-1 beta-lactamase in clinical isolates of Escherichia coli serotype O15.

During an outbreak of infection with ampicillin-resistant, TEM-1 beta-lactamase-producing Escherichia coli serotype O15, some strains were noted to differ from the majority in that they showed reduced susceptibility to amoxycillin/clavulanic acid (Augmentin), ureidopenicillins and first generation cephalosporins and produced increased amounts of beta-lactamase. The plasmid from one such isolate was compared with that from an isolate that produced normal amounts of beta-lactamase. Restriction analysis with EcoRI revealed extra fragments in the plasmid from the beta-lactamase hyperproducer and use of DNA-DNA hybridisation with a biotinylated TEM-1 probe showed genetic rearrangement in the beta-lactamase hyperproducer so that the TEM gene appeared to be present in larger amounts and was located on a smaller fragment than for the plasmid from the strain that produced normal amounts of beta-lactamase.

DNA, Bacterial↗
PubMed1990

Timbre discrimination in zebra finch (Taeniopygia guttata) song syllables.

Zebra finch (Taeniopygia guttata) songs include syllables of a fundamental frequency and harmonics. Individual harmonics in 1 syllable can be more or less emphasized. The functional role of this variability is unknown. These experiments provide evidence of how the phenomenon is perceived. We trained 12 male and female zebra finches on a go-no-go operant procedure to discriminate between 2 song syllables that varied only in the absence of the 2nd or 5th harmonic. Training involved many thousands of trials. Both sexes used the presence or absence of the 2nd harmonic as the sole discriminative cue. Females had more difficulty learning to perform the task when the presence of the 2nd harmonic was the go stimulus, which indicates that their use of the information was biased by stimulus-response contingencies. The results are discussed in terms of a broad strategy to understand how animals perceive sounds used in communication.

Animals↗
PubMed1990

Is hydrochlorothiazide-induced hypocalciuria due to inhibition of prostaglandin E2 synthesis?

1. Since prostaglandin E2 could play a role in idiopathic hypercalciuria, and considering the well-established hypocalciuric action of hydrochlorothiazide, we have evaluated the effect of 15 days' treatment with hydrochlorothiazide in 10 hypercalciuric male stoneformers on urinary Ca2+ and prostaglandin E2, as well as on plasma bicyclo-prostaglandin E2, 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D and parathyroid hormone. 2. In addition to lowering urinary Ca2+ (P less than 0.001), hydrochlorothiazide also promoted a significant fall in urinary prostaglandin E2 (P less than 0.001), plasma bicyclo-prostaglandin E2 (P less than 0.001) and 1,25-dihydroxyvitamin D (P less than 0.01), and an increase in plasma parathyroid hormone (P less than 0.025), whereas plasma 25-hydroxyvitamin D was unchanged. 3. A positive correlation between urinary Ca2+ and prostaglandin E2 was present before (P less than 0.00005), but not after, hydrochlorothiazide. Plasma bicyclo-prostaglandin E2 and plasma 1,25-dihydroxyvitamin D were positively correlated both before (P less than 0.005) and after (P less than 0.005) hydrochlorothiazide, as was also the percentage change in each induced by the drug (P less than 0.05). Furthermore, the changes in plasma 25-hydroxyvitamin D and plasma 1,25-dihydroxyvitamin D after hydrochlorothiazide were negatively correlated (P less than 0.05). 4. It is suggested that a block of prostaglandin E2 synthesis plays a role in the effect of hydrochlorothiazide on Ca2+ metabolism, most probably through an inhibition of 1 alpha-hydroxylase activity.

Adult↗
PubMed1990

X linked neonatal centronuclear/myotubular myopathy: evidence for linkage to Xq28 DNA marker loci.

We have studied the inheritance of several polymorphic Xq27/28 DNA marker loci in two three generation families with the X linked neonatal lethal form of centronuclear/myotubular myopathy (XL MTM). We found complete linkage of XLMTM to all four informative Xq28 markers analysed, with GCP/RCP (Z = 3.876, theta = 0.00), with DXS15 (Z = 3.737, theta = 0.00), with DXS52 (Z = 2.709, theta = 0.00), and with F8C (Z = 1.020, theta = 0.00). In the absence of any observable recombination, we are unable to sublocalise the XLMTM locus further within the Xq28 region. This evidence for an Xq28 localisation may allow us to carry out useful genetic counselling within such families.

Cell Nucleus↗
PubMed1990

Drug control strategies of United States law enforcement.

The American approach to drug control is conditioned by several national characteristics, including fragmentation of the law enforcement system, a 12,000-mile international boundary and a legal system that restricts police authority to search, arrest, detain, eavesdrop and maintain intelligence files. Drug problems in the United States, though, are by all accounts greater than in any other country. Enforcement has traditionally emphasized street-level arrests, investigation of distribution networks, crop eradication and smuggling interdiction. These practices can be shown to produce arrests and seizures, but there is little evidence to show that they reduce drug supply or drug abuse. More contemporary and promising approaches include community policing, problem-oriented policing, financially oriented investigations, increased international co-operation and a renewed emphasis on drug demand reduction. The most pressing needs in law enforcement are (a) improved intelligence-gathering and analysis and (b) research on the illicit drug industry and on the effectiveness of drug control strategies.

Drug and Narcotic Control↗
PubMed1990

Problems with clinical trials in general practice--a double-blind comparison of cream containing miconazole and hydrocortisone with hydrocortisone alone in the treatment of intertrigo.

A double-blind comparative study between 1% hydrocortisone cream and a combination of 1% hydrocortisone cream and 2% miconazole cream has highlighted some of the problems with this type of research in general practice. The collection of adequate patient numbers within a predefined time scale proved a major problem. However, the study demonstrated the safety and efficacy of both these preparations in the treatment of intertrigo.

Double-Blind Method↗