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Biomedical subjects

J A Reid

Publications and source records attributed to J A Reid.

At least 37 records · Page 2Linked to original sources
PubMed1993

Radiation exposures around a panoramic dental x-ray unit.

To evaluate the radiation hazard in the vicinity of a panoramic x-ray unit, Ektaspeed periapical films were placed in an array behind and to the side of the unit. They were left in place for 7 months, during which 1414 examinations were carried out. The maximum exposure at 80 cm from the patient was determined to be about 1 mGy in 7 months with a heavy workload. This shows clearly that no special environmental shielding barriers are necessary around this unit.

Dental Staff↗
PubMed1993

Medical audit of community screening for undescended testes in Halton District.

OBJECTIVES: To evaluate the quality of screening in the community for undescended testis and to determine the percentage of boys referred for surgery before their second birthday. DESIGN: Population-based retrospective study of hospital and community clinic records of boys resident in Halton Health District who underwent surgery for undescended testicle during 1987-89. SETTING: Community Child Health Clinics. Medical Records Department of referral hospitals surrounding Halton district. RESULTS: During 1987-89, 76 boys from Halton district underwent surgery for undescended testis in the neighbouring hospitals: 64 (84%) of these boys had attended at least one screening examination in the community clinics; 12 (16%) did not attend any. Among the 64 who attended 18 (28%) were not considered to have undescended testis. Of the 30 boys diagnosed to have undescended testis after school entry, six were diagnosed incidentally in hospital and 24 were detected by general practitioners and School Medical Service. The age range for surgical referral varied from six months to 12.5 years. The percentage of boys referred for surgery before their second birthday was only 13%. CONCLUSION: Many cryptorchid boys were not picked up in community screening and many of these did not receive early surgery. This audit report suggested the following recommendations: (a) increased awareness of the condition amongst doctors and health visitors performing screening examination; (b) early surgical referral. These recommendations have been implemented in the district. Our further plan is to repeat the audit in three years to assess changes.

Child, Preschool↗
PubMed1993

CDC WONDER: a comprehensive on-line public health information system of the Centers for Disease Control and Prevention.

OBJECTIVES: CDC WONDER, a comprehensive on-line public health information system of the Centers for Disease Control and Prevention (CDC), was developed to place timely, action-oriented information in the hands of public health professionals. METHODS: A unified system was developed de novo to be used for and to evolve along with public health. All data are stored and updated on the CDC mainframe. RESULTS: CDC WONDER provides menu-driven access to 24 databases with information on mortality, hospital discharges, cancer incidence, notifiable diseases, acquired immunodeficiency syndrome, the Morbidity and Mortality Weekly Report, etc.; each database has on-line documentation. Results can be tabulated and graphed, and there is full-text searching of textual databases. Non-CDC staff have access via telephone connection. From August 1991 through June 1992, system databases were accessed 10,698 times, and there were 842 users (mean of 97 new users per month). CONCLUSIONS: CDC WONDER has shown that it is possible to build a large, on-line database of scientific data for public health professionals. CDC WONDER provides a common foundation from which to build information-based public health plans and policy and could help strengthen the public health system.

Centers for Disease Control and Prevention, U.S.↗
PubMed1992

Weyers' ulnar ray/oligodactyly syndrome and the association of midline malformations with ulnar ray defects.

We describe a two generation family with variable ulnar and radial ray reduction and midline craniofacial abnormalities. The features suggest a diagnosis of Weyers' ulnar ray/oligodactyly syndrome originally described in two isolated cases. Syndromes of ulnar ray reduction are briefly reviewed and the relationship between limb bud and midline development discussed.

Abnormalities, Multiple↗
PubMed1991

Effect of adrenaline on extradural anaesthesia, plasma lignocaine concentrations and the feto-placental unit during elective caesarean section.

Extradural anaesthesia was induced with either 2% lignocaine or 2% lignocaine with adrenaline 1:200,000 in 20 patients undergoing elective Caesarean section. With the adrenaline-containing solution, a smaller dose of lignocaine was required to produce an adequate block and the lignocaine concentrations in both mother and neonate were significantly smaller compared with the plain solution. Arterial pressures were less in the adrenaline group, but there was no difference in umbilical flow velocity waveform, fetal heart rate or fetal outcome. Neither feto-placental circulation nor fetal outcome were affected adversely by episodes of hypotension or the ephedrine used for treatment.

Adolescent↗
PubMed1991

Single-dose trospectomycin for chlamydial urethritis in men.

Trospectomycin is an aminocyclitol analog of spectinomycin with significant in vitro activity against Chlamydia trachomatis. A single 1-g intramuscular dose was administered to 10 men with symptomatic, culture-positive chlamydial urethritis. Trospectomycin was well tolerated but failed to eradicate chlamydial infection, as determined by cultures obtained approximately 1 week after treatment.

Adolescent↗
PubMed1991

Development and testing of artificial low-frequency speech codes.

In a new approach to the frequency-lowering of speech, artificial codes were developed for 24 consonants (C) and 15 vowels (V) for two values of lowpass cutoff frequency F (300 and 500 Hz). Each individual phoneme was coded by a unique, nonvarying acoustic signal confined to frequencies less than or equal to F. Stimuli were created through variations in spectral content, amplitude, and duration of tonal complexes or bandpass noise. For example, plosive and fricative sounds were constructed by specifying the duration and relative amplitude of bandpass noise with various center frequencies and bandwidths, while vowels were generated through variations in the spectral shape and duration of a ten-tone harmonic complex. The ability of normal-hearing listeners to identify coded Cs and Vs in fixed-context syllables was compared to their performance on single-token sets of natural speech utterances lowpass filtered to equivalent values of F. For a set of 24 consonants in C-/a/ context, asymptotic performance on coded sounds averaged 90 percent correct for F = 500 Hz and 65 percent for F = 300 Hz, compared to 75 percent and 40 percent for lowpass filtered speech. For a set of 15 vowels in /b/-V-/t/ context, asymptotic performance on coded sounds averaged 85 percent correct for F = 500 Hz and 65 percent for F = 300 Hz, compared to 85 percent and 50 percent for lowpass filtered speech. Identification of coded signals for F = 500 Hz was also examined in CV syllables where C was selected at random from the set of 24 Cs and V was selected at random from the set of 15 Vs. Asymptotic performance of roughly 67 percent correct and 71 percent correct was obtained for C and V identification, respectively. These scores are somewhat lower than those obtained in the fixed-context experiments. Finally, results were obtained concerning the effect of token variability on the identification of lowpass filtered speech. These results indicate a systematic decrease in percent-correct score as the number of tokens representing each phoneme in the identification tests increased from one to nine.

Evaluation Studies as Topic↗
PubMed1990

Infection of staff during an outbreak of viral gastroenteritis in an elderly persons' home.

An outbreak of viral gastroenteritis in an elderly persons' residence is reported. Seventeen of 37 (47%) residents and 22 of 50 (44%) staff developed illness. Adenovirus was seen by direct electron microscopy in two vomitus and two faeces specimens. It is suggested that the most likely mode of transmission was environmental contamination by vomitus.

Adenoviridae Infections↗
PubMed1990

9,11-epoxy-9-homoprosta-5-enoic acid analogues as thromboxane A2 receptor antagonists.

A novel bicyclic prostaglandin analogue, (1S)-[1 alpha, 2 alpha(Z),3 alpha(1E,3S*,4R*),4 alpha]-7-[3-(3-hydroxy-4-phenyl-1-pentenyl)-7- oxabicyclo[2.2.1]hept-2-yl]-5-heptenoic acid (4), was found to be a potent and selective thromboxane A2 (TxA2) receptor antagonist. Alcohol 4 was the only member in a series of allylic alcohols which did not display direct contractile activity in the rat stomach strip model. Alcohol 4 was effective in the inhibition of (a) arachidonic acid induced platelet aggregation of human platelet-rich plasma (I50 = 0.65 +/- 0.1 microM); (b) 11,9-epoxymethano-PGH2 induced contraction of guinea pig trachea (pA2 = 8.0 +/- 0.2) or rat aorta (pA2 = 8.1 +/- 0.2); and (c) arachidonic acid induced bronchoconstriction in the anesthetized guinea pig (1 mg/kg iv). A radioiodinated analogue of 4 bound in a specific and saturable manner to human platelet membranes with a Kd = 2.3 +/- 0.9 nM. Modification of the alpha-chain, in an attempt to minimize in vivo metabolism, resulted in TxA2 receptor antagonists of reduced in vitro potency.

Animals↗
PubMed1990

7-Oxabicyclo[2.2.1]heptyl carboxylic acids as thromboxane A2 antagonists: aza omega-chain analogues.

A novel bicyclic prostaglandin analogue, [1S-[1 alpha, 2 alpha (Z), 3 alpha, 4 alpha]]-7-[3-[[[[(1- Oxoheptyl)amino]acetyl]amino]-methyl]-7-oxabicyclo[2.2.1]hept-2- yl]-5-heptenoic acid [-)-7) was found to be a potent and selective thromboxane A2 (TxA2) receptor antagonist. Unlike the related series of omega-chain allylic alcohols, amide 7 and its congeners were uniformly free of direct contractile activity in vitro (bovine coronary) and in vivo (anesthetized guinea pig). Amide 7 was effective in the inhibition of (a) arachidonic acid induced platelet aggregation of human platelet-rich plasma (I50 = 0.18 +/- 0.006 microM), (b) 11,9-epoxymethano-PGH2 induced platelet aggregation of human platelet-rich plasma (I50 = 0.24 microM), (c) 11,9-epoxymethano-PGH2 induced contraction of guinea pig trachea (Kb = 3.0 +/- 0.3 nM) or rat aorta (Kb = 8.8 +/- 1.1 nM), and (d) arachidonic acid induced bronchoconstriction in the anesthetized guinea pig (0.1-1.0 mg/kg iv). Amide 7 inhibited the binding of [5,6-3H2]-[1S- (1 alpha, 2 alpha (Z), 3 alpha, 4 alpha)]-7-[3-[[2-[(Phenyl- amino)carbonyl]hydrazino]methyl]-7-oxabicyclo[2.2.1]hept-2-yl]-5- heptenoic acid to human platelet membranes in a specific and saturable manner with a Kd = 49.6 +/- 1.4 nM.

Animals↗
PubMed1989

The unerupted or impacted third molar--a critical appraisal of its pathologic potential.

The prophylactic removal of asymptomatic unerupted or impacted third molars constitutes a major proportion of all oral surgical procedures. Patients are advised to have this preventive surgery on the basis that such teeth, if retained, are likely to cause certain pathologic lesions. The evidence in the scientific literature on the prevalence of dentigerous cysts, mural ameloblastoma, epidermoid carcinoma and root resorption indicates that this concern is exaggerated. The retrospective data on the reasons for extractions of third molars confirm this conclusion. Until there are prospective studies which demonstrate a significant patient benefit from surgery exceeding the risks of retention, the practice should be discontinued. Third molars should be removed only where there is a defined pathologic indication.

Dentigerous Cyst↗
PubMed1989

Vaccination viewpoints.

Liverpool is an area of lower than average immunisation uptake. A survey of health visitors, school nurses and clinical medical officers suggests that professional disagreements and lack of belief are contributory factors.

Attitude of Health Personnel↗
PubMed1988

Role of infected food handler in hotel outbreak of Norwalk-like viral gastroenteritis: implications for control.

Investigation of an outbreak of viral (Norwalk-like) gastroenteritis amongst staff (40 cases), resident guests (over 70 cases), and persons attending functions (54 cases) at one hotel over 8 days suggested that the main vehicle of infection was cold foods prepared by a food handler during and after a mild gastrointestinal illness. He was excreting Norwalk-like virus particles 48 hours after the illness. In addition, ill kitchen staff vomited in the kitchen area and may have contaminated surfaces and stored foods. It is recommended that food handlers should be regarded as potentially infectious until at least 48 hours after clinical recovery from viral gastroenteritis. Stored foods that may have been contaminated should be immediately discarded and areas of the work place which may have been affected should be identified and decontaminated.

Food Handling↗