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Biomedical subjects

W J Hall

Publications and source records attributed to W J Hall.

At least 73 records · Page 4Linked to original sources
PubMed1988

Testing for the teratogenicity of pulsed ultrasound in mice.

Our replicate of a study by Takabayashi et al. (1981) Effects of pulse-wave ultrasonic irradiation on mouse embryo. Cho-Onpa Igaku (Supersonic Medicine) 8, 286-288 failed to show any effects of exposure in utero of mice to spatial average, temporal maximum intensities of 60 W/cm2. Fetuses were exposed at 8 days post fertilization and assessed at 18 days for fetal weight, resorptions, premature deaths, and malformations. Carrier frequency in the pulse was 2 MHz. Pulse lengths of 10 microseconds and pulse repetition frequencies of 1000 and 200 Hz yielded spatial average, temporal average intensities of 0.6 and 0.1 W/cm2. Total exposure time was 5 min. Our results provide no basis to conclude that conditions relevant to human fetal monitoring will cause developmental, externally visible anomalies in mice exposed as 8-day fetuses.

Animals↗
PubMed1987

How does the team approach to outpatient geriatric evaluation compare with traditional care: a report of a randomized controlled trial.

Although team-oriented geriatric assessment clinics are growing throughout the country, little documentation exists regarding their clinical efficacy, cost-effectiveness, or impact on patient functioning and well-being. This report describes a randomized controlled clinical trial to evaluate the effectiveness of a team-oriented geriatric assessment approach compared to traditional care. One hundred-seventeen subjects 65 years of age and over, meeting eligibility criteria to target frail older persons with changing medical and social needs, were randomly assigned to receive a comprehensive geriatric assessment by a multidisciplinary team (treatment) or by one of a panel of community internists who were reimbursed according to their usual and customary fee (controls). Extensive analysis of baseline information failed to identify any significant differences between groups. Over the 1-year follow-up period, treatment participants experienced 26 hospital admissions and used 670 hospital days compared with 23 admissions and 1113 days for controls (a 39.8% difference). Annual hospital costs averaged $4297 for treatment subjects and $7018 for controls. Overall institutional costs including hospital and nursing home care revealed an average saving of $2189 per person for treatment subjects compared with controls, a 25% reduction. A small proportion of subjects accounted for this difference. No significant differences were noted in patient or caregiver satisfaction with the evaluation process, functional ability, or health status. These findings suggest that team-oriented outpatient geriatric assessment provides a promising way to deliver high-quality, satisfying care to older persons without increasing (and possibly decreasing) health care costs.

Aged↗
PubMed1987

Multiple sclerosis and the workplace: report of an industry-based cluster.

Eleven cases of MS occurred within a 10-year period in a zinc-related manufacturing plant. The observed disease incidence was greater than expected from population data, using multiple approaches to statistical analysis (p less than or equal to 0.01). A case-control study, performed to examine several zinc parameters in blood, failed to indicate specific abnormalities among the MS patients, but all subjects (both MS and controls) working in the plant demonstrated higher serum zinc levels than all subjects (MS and controls) not working there.

Age Factors↗
PubMed1986

Plasma expansion does not precipitate the fall in plasma vasopressin in humans drinking isotonic fluids.

In a group of healthy humans, plasma vasopressin (AVP) levels fell on drinking either Tyrode or mannitol solutions isosmotic with plasma. Both the timing and magnitude of the fall were appropriate to account for the transient diuresis which followed the drinking. Although plasma expansion follows drinking Tyrode solution it occurred too late to account for the fall in plasma AVP. It was also too small to inhibit AVP secretion. Even though plasma volume tended to contract on drinking isosmotic mannitol solution a fall in plasma AVP and a diuresis occurred, similar to those found after drinking Tyrode solution. These findings appear to eliminate plasma volume expansion as the stimulus for the fall in plasma AVP and the associated diuresis on drinking isotonic fluids. In a further group of human subjects, bypassing the oropharynx by intragastric infusion resulted in a slower onset of diuresis after a water load. We suggest that receptors, as yet undefined, in the upper gastrointestinal tract contribute to the early stages of a water diuresis and account for the apparently inappropriate transient diuresis which follows the drinking of isotonic fluids.

Adult↗
PubMed1985

Normal pulmonary function measurements and airway reactivity in childhood after mild bronchiolitis.

Concern about the long-term sequelae of bronchiolitis has been raised through studies of children hospitalized for bronchiolitis, but the long-term sequelae of mild bronchiolitis have not been studied. We assessed the hypothesis that 25 children with mild bronchiolitis (index subjects) were at greater risk for abnormalities of pulmonary function or airway reactivity to cold air between the ages of 8 and 12 years than were randomly selected, matched controls. There were no consistent differences in pulmonary function or airway reactivity between index and control groups. Airway hyperreactivity was found in five control subjects and three index subjects, and all children with symptomatic asthma were identified by cold air challenge. Our data suggest that children with a history of mild bronchiolitis are not at increased risk between ages 8 and 12 years for airway hyperreactivity or for abnormalities in pulmonary function.

Adult↗
PubMed1985

A vasopressin-mediated diminution of potassium excretion in water-loaded man.

Intravenous vasopressin (1-3 mu-units min-1 kg-1) had an antidiuretic effect on water-loaded man and also diminished potassium excretion. As noted by others, aspirin (2.4 g) enhanced the antidiuretic effect of vasopressin, but the fall in potassium excretion was not modified by prior administration of aspirin, which makes it unlikely that the fall was due to the release of endogenous prostaglandins. After terminating the infusion of vasopressin, the fall in potassium output persisted longer than the antidiuresis, which makes it unlikely that the antikaliuretic effect of vasopressin is secondary to its effect on urine flow. The unchanged antikaliuretic effect of vasopressin after aspirin treatment, together with its persistence after terminating the infusion, suggest the possible existence of vasopressin-mediated potassium absorption in the distal nephron in certain circumstances. Aspirin administration had specific effects of its own in water-loaded man. It decreased both the water diuresis and sodium excretion but did not alter potassium excretion or urine osmolality.

Adult↗
PubMed1985

Signals from the oropharynx may contribute to the diuresis which occurs in man to drinking isotonic fluids.

The drinking of a variety of isotonic salt solutions provoked a short load-dependent diuretic response in man, similar in latency to that of a water diuresis and reaching its maximum 40-60 min from the start of drinking. Subjects differed in the threshold load at which the response became evident, and also in the magnitude of their responses. Changes in free water clearance matched the increases in urinary minute volume, with no significant change in either urinary sodium or potassium excretion. Changes in urinary pH and in ammonium excretion were similar to those described for a water diuresis. Drinking an isotonic solution of mannitol provoked a diuresis similar to that of the salt solutions. All subjects had diarrhoea after drinking the mannitol. Signals arising from the oropharynx might be partly responsible for eliciting the diuresis. The significantly smaller urinary responses to infusions of isotonic salt solutions directly into the stomach support this view. The absence of a significant response to 'sham drinking' appears inconsistent with this, but oropharyngeal signals may only have a priming role in man and interact with other signals to give the full response.

Adult↗
PubMed1984

Long-term prospective study in children after respiratory syncytial virus infection.

We have prospectively evaluated for the past 8 years 29 children who were hospitalized during infancy with acute lower respiratory tract illness caused by respiratory syncytial virus (RSV). No differences in the prevalence of a family history of atopy or breast-feeding in these infants compared with controls were noted. However, a history of parental smoking was significantly associated with hospital admission for RSV lower respiratory tract disease. Evidence of atopy, as defined by serum IgE levels and radioallergosorbent testing, have developed in only three (10%) of 29 children. Six children (21%) continue to have recurrent lower respiratory tract disease. Fifty-five percent of these children had abnormally low oxyhemoglobin levels (SaO2) measured by ear oximetry for the first 3 to 4 years after the acute illness. Twenty-one percent have persistently low SaO2 levels during the eighth year of follow-up. Spirometric values indicate evidence of peripheral airway obstruction. These studies suggest that an association between RSV lower respiratory tract infections and chronic abnormalities of pulmonary function may be detected sequentially through the first 8 years of life. These abnormalities are not limited to those children developing an atopic state during that same time period.

Breast Feeding↗
PubMed1984

Sensitivity, specificity, and predictive values of closed pleural biopsy.

To determine the clinical value of a nonspecific pleural biopsy specimen and fluid in malignant neoplasm and tuberculosis, we retrospectively reviewed records of all patients with pleural effusions undergoing the procedure at three community hospitals over six years. Two hundred eleven patients underwent biopsies. Adequate tissue was obtained in 207. The results were compared with the ultimate clinical and pathologic outcome by follow-up for 12 to 72 months. The initial procedure was diagnostic of malignant neoplasm in 54 patients and granulomatous disease in ten. A nonspecific or normal result was found in 143 (68%). Malignant neoplasms or tuberculosis was eventually established in 30 and excluded in 101 of the 143 patients. In 12 patients, no diagnosis was made. The procedure's sensitivities were 65% (malignant neoplasm) and 90% (tuberculosis). One false-positive result occurred in a patient with nontuberculous granulomatous pleuritis. The specificity and positive predictive value were 99% and 98%, respectively. The negative predictive value was 77%. Closed pleural biopsy with simultaneous fluid analysis is a valuable diagnostic procedure in community hospital patients, but a nonspecific result does not exclude malignant disease.

Adolescent↗
PubMed1983

Aerosolized ribavirin treatment of infants with respiratory syncytial viral infection. A randomized double-blind study.

We evaluated a new antiviral agent, ribavirin, in the treatment of infants hospitalized with lower-respiratory-tract disease from respiratory syncytial virus. Ribavirin or placebo was administered to 33 infants in a double-blind manner by continuous aerosol for three to six days. Seventeen infants were treated with placebo, and 16 with ribavirin. By the end of treatment, infants receiving ribavirin had significantly greater improvement in their overall score for severity of illness, in lower-respiratory-tract signs, and in arterial oxygen saturation. Viral shedding was also diminished in the treated groups as compared with the placebo group. No side effects or toxicity were associated with the aerosol therapy. Isolates of respiratory syncytial virus obtained from the infants over the course of therapy showed no change in sensitivity to ribavirin.

Aerosols↗
PubMed1983

Ribavirin treatment of experimental respiratory syncytial viral infection. A controlled double-blind study in young adults.

The effect of ribavirin aerosol on experimental respiratory syncytial virus (RSV) infection was evaluated in a double-blind controlled study of 16 young adult volunteers. Two days after intranasal inoculation with RSV, half of the subjects were treated with a small-particle aerosol of ribavirin and half with placebo for a total of 12 hours each day for three days. Seven of eight placebo-treated and six of eight ribavirin-treated subjects became infected. Viral shedding was diminished in the ribavirin-treated group. The proportion of infected volunteers still shedding virus on days 6 through 9 was significantly less than in the placebo-treated group. Ribavirin appeared to have no effect on minor upper respiratory tract signs, but systemic complaints and fever occurred significantly less often in the ribavirin-treated group. Ribavirin aerosol therapy was well tolerated and produced no significant changes in pulmonary function test results or signs of toxicity. This suggests that such therapy might be further evaluated in infants with RSV lower respiratory tract disease.

Adult↗
PubMed1982

Transseptal repair of unilateral choanal atresia.

Unilateral choanal atresia is a congenital problem initially observed by the otolaryngologist as unilateral nasal obstruction. Elective surgical correction can be done using the transnasal, transpalatal, transantral, or transseptal techniques. Two patients underwent this procedure with the transseptal technique. We believe this is a safe, uncomplicated, and reliable technique for the correction of unilateral choanal atresia.

Child↗
PubMed1982

Chronic cough: bronchoscopy or pulmonary function testing?

To determine how frequently bronchoscopic examination and pulmonary function testing are useful in establishing a diagnosis in patients with chronic cough as an isolated clinical symptom, we reviewed the records of all patients referred to pulmonary specialists at 3 community hospitals for evaluation of cough over a 6-yr period. There were 109 patients with the isolated symptom of chronic cough and a normal or stable chest roentgenogram. Bronchoscopy was performed in 51. All patients but 1 were followed until the cough disappeared or for a minimum of 1 yr. Carcinoma was established as the cause for cough in 1 patient. Spirometry and/or bronchial inhalation challenge was performed in 87 patients. Previously undiagnosed asthma was discovered in 39 patients by these means. Pulmonary function testing has diagnostic value in this population, but bronchoscopy is of limited value in determining the cause of isolated chronic cough.

Adolescent↗
PubMed1980

Analysis of swimming pool accidents resulting in spinal cord injury.

This paper is a summary of a study of 72 cases of swimming-pool accidents resulting in serious injuries with the potential of permanent disability. Sixty-four of the 72 cases resulted in spinal cord injuries, 57 of which involved quadriplegic lesions. The authors observed that the majority of these injuries resulted from a lack of good judgement and common sense rather than from intoxication or pool structural deficiencies. Also of note was the lack of appropriate first-aid and extrication rendered, as well as the absence of uniform treatment and care received by the majority of the patients.

Accidents↗
PubMed1980

Therapeutic effects of aerosolized amantadine in naturally acquired infection due to influenza A virus.

The effect of small-particle aerosol therapy with amantadine was assessed in a randomized, double-blind study of 20 patients with naturally acquired influenza A virus infection. Aerosol treatments of 20 min with either distilled water or with amantadine hydrochloride (1.0 g/100 ml of distilled water) were given three times a day for four days. The amantadine-treated patients experienced a significantly more rapid resolution of clinical signs and symptoms when compared with placebo-treated patients. The resolution of fever was similar for both groups. Aerosol delivery of amantadine did not affect the frequency of viral isolation from upper respiratory tract secretions but was associated with a trend toward reduced quantity of viral shedding. Serial pulmonary function tests found no important differences between the groups. Amantadine-treated patients experienced a greater frequency of mild local side effects (rhinorrhea, nasal irritation) during aerosol exposures, but aerosol treatments did not cause any apparent decline in pulmonary function.

Adult↗