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Biomedical subjects

B Walsh

Publications and source records attributed to B Walsh.

At least 55 records · Page 3Linked to original sources
PubMed1996

Preharvest food safety.

Preharvest food safety is essential for the protection of our food supply. The production and transport of livestock and poultry play an integral part in the safety of these food products. The goals of this safety assurance include freedom from pathogenic microorganisms, disease, and parasites, and from potentially harmful residues and physical hazards. Its functions should be based on hazard analysis and critical control points from producer to slaughter plant with emphasis on prevention of identifiable hazards rather than on removal of contaminated products. The production goal is to minimize infection and insure freedom from potentially harmful residues and physical hazards. The marketing goal is control of exposure to pathogens and stress. Both groups should have functional hazard analysis and critical control points management programs which include personnel training and certification of producers. These programs must cover production procedures, chemical usage, feeding, treatment practices, drug usage, assembly and transportation, and animal identification. Plans must use risk assessment principles, and the procedures must be defined. Other elements would include preslaughter certification, environmental protection, control of chemical hazards, live-animal drug-testing procedures, and identification of physical hazards.

Abattoirs↗
PubMed1995

Arterial closing pressure correlates with diastolic pseudohypertension in the elderly.

BACKGROUND: Pseudohypertension has frequently been reported in the elderly population, with the diastolic measurement being the most frequent source of error. There is no satisfactory noninvasive method of calculating the error in the blood pressure reading. We investigated the role of arterial closing pressure in the diagnosis of diastolic pseudohypertension. METHODS: Indirect and direct blood pressure were measured in 24 elderly patients. Brachial artery closure was visualized by ultrasound in all subjects. Arterial closing pressure (ACP) was recorded as zero if the vessel was seen to close spontaneously when it was isolated from central arterial pressure. If the vessel did not close spontaneously, a water cuff was applied externally over the artery and the additional pressure required to close it was recorded. RESULTS: Diastolic pseudohypertension was noted in 8 subjects. Spontaneous closure of the brachial artery occurred in the 16 without pseudohypertension; i.e., ACP = 0. Additional pressure of the water cuff (range: 30-158 mm Hg) was required to collapse the artery (ACP) in those with diastolic pseudohypertension. ACP correlated with the extent of diastolic pseudohypertension (range: 5-17 mm Hg); r = .85, p < .001). CONCLUSION: We propose that ACP may be used to diagnose the presence and extent of pseudohypertension.

Aged↗
PubMed1994

Metabolic impact of adding medroxyprogesterone acetate to conjugated estrogen therapy in postmenopausal women. The Menopause Study Group.

OBJECTIVE: To evaluate the impact of different dosages of medroxyprogesterone acetate (MPA) on metabolism and hemostasis in postmenopausal women treated with conjugated estrogens. METHODS: In this prospective, double-blind study, 525 women were randomized to five treatment groups at 26 sites in the United States and Europe. All participants received 0.625 mg conjugated estrogens daily for up to 13 cycles; four groups also received MPA, either 2.5 or 5.0 mg/day continuously or 5.0 or 10.0 mg/day for the last 14 days of each cycle. Effects on lipid and carbohydrate metabolism and coagulation were evaluated. RESULTS: Beneficial changes in plasma lipid levels occurred in all groups, but were greatest with conjugated estrogens alone (P < or = .05). Fasting glucose and insulin levels were significantly lower and the insulin response to glucose challenge was significantly blunted in all groups (P < or = .05). No major changes of clinical significance occurred in hemostatic levels. CONCLUSIONS: Metabolic levels were not affected adversely by the addition of MPA to conjugated estrogens, but some beneficial changes were greater with conjugated estrogens alone. Hemostatic levels were not affected.

Aged↗
PubMed1993

The relationship of Chlamydia trachomatis infection and male infertility.

OBJECTIVES: Infertility affects at least 2 million couples in the United States. One third of infertility is attributed to male causes, but the etiology of most male infertility remains obscure. This study was designed to investigate the relationship between Chlamydia trachomatis and unexplained infertility in men. METHODS: Questionnaires and serum were collected prospectively from 52 case subjects (men from couples with explicitly defined idiopathic infertility) and 79 control subjects (first-time expectant fathers). RESULTS: Case subjects were significantly more likely than control subjects to be seropositive for antibody to C trachomatis at a titer of 1:64 or higher. By test of trend, higher titers were associated with higher odds ratios. Adjustment for age of either partner at initiation of pregnancy attempt, race, income, previous genitourinary symptoms or diagnoses, number of previous sexual partners, and barrier contraceptive use had no significant effect on the estimate of the odds ratio. One half of the men who were antibody positive had no history of genitourinary symptoms. CONCLUSIONS: Our results suggest an association between infection with C trachomatis in men and unexplained infertility and imply that infection is frequently asymptomatic.

Adult↗
PubMed1992

Restoring antibody activity of a monoclonal anti-RNP antibody by dissociative HPLC. Demonstration of blocking antibody binding sites with antigen released from effete hybridoma cells.

In biomedical research, monoclonal anti-nuclear antibodies have a number of advantages over polyclonal antibodies in terms of both specificity and reproducibility. However, there are some potential problems in the preparation of monoclonal antibodies. A well characterized mouse monoclonal anti-ribonucleoprotein antibody (anti-RNP antibody, 2.73) known to function in Western blotting was found to lose this activity when produced in vitro from long term hybridoma cell culture. Whilst it could no longer detect RNP antigen by Western blotting, it could still function effectively in affinity purification of RNP antigen. Further studies suggested that this was due to blocking of antibody binding sites by RNP antigen released from effete hybridoma cells in culture. The activity of the antibody in affinity purification was retained because the antigen was stripped away by repeated elutions with 6 M urea. HPLC gel filtration in the presence of 6 M guanidine was able to restore the antibody activity of the protein A purified monoclonal antibody. This finding has important general consequences for the preparation of monoclonal antibodies against antigens present in hybridoma cell culture media.

Animals↗
PubMed1991

Decreased incidence of urinary tract infections in patients with spinal cord injury: effect of methenamine.

This study was designed to determine the effect of methenamine on the frequency of urinary tract infections (UTI) in hospitalized patients after spinal cord injury. The study included 56 patients with neurogenic bladder dysfunction treated with intermittent catheterization. A group of 34 patients was treated with methenamine, 1g twice daily; the other group of 22 patients was the control group receiving no antimicrobial therapy. On a weekly basis urine samples from all patients were obtained for urinalysis and culture. A total of 500 urine samples were analyzed. The patients treated with methenamine had 23.4% positive urine cultures which was significantly lower than 57.5% in the untreated control group (p less than 0.001). Our data suggest that methenamine therapy is an effective prevention of UTI in paralyzed patients with neurogenic bladder dysfunction during the rehabilitation in hospital.

Bacteriuria↗
PubMed1991

Antibacterial activity of lomefloxacin.

Lomefloxacin has marked activity against Gram-negative bacilli including Enterobacteriaceae, non-fermenting strains and Haemophilus influenzae with 98% of all isolates tested having MICs of 0.25 mg/l or less. Sixty-eight per cent of Pseudomonas aeruginosa strains were sensitive to 1 mg/l with a few strains resistant to 8 or 16 mg/l. Gram-positive cocci were more resistant, particularly streptococci, where the MICs vary between 1 and 8 mg/l. Bactericidal activity was similar to inhibitory activity and the effect of increasing serum concentrations and bacterial inocula was minimal. The MIC and MBC were increased in the presence of urine, particularly at an acid pH 5. Comparative MICs showed that lomefloxacin was more active than ofloxacin and pefloxacin, similar to norfloxacin but less active than ciprofloxacin for Gram-negative bacteria but not for Gram-positive cocci. Comparative studies with sensitivity disc concentrations showed that a 5 micrograms disc was more satisfactory than the 10 micrograms disc as the zone sizes were more suitable for routine testing. Solutions of lomefloxacin showed instability in bright sunlight when 52% of activity was lost in 1 h. Similar instability was shown in impregnated discs which lost up to 40% activity in 6 h exposure. Lomefloxacin showed a wide range of activity against Gram-negative bacteria including multiresistant strains and Pseudomonas spp. Gram-positive bacteria were less susceptible, with streptococci more resistant than staphylococci. Lomefloxacin is well absorbed after oral administration giving high blood and urine concentrations and its prolonged half-life means once daily dosing in the treatment of many types of bacterial infection may be possible.

4-Quinolones↗
PubMed1991

Pharmacokinetic study of lomefloxacin and its effect on the faecal flora of volunteers.

In a volunteer pharmacokinetic study mean peak serum concentrations of lomefloxacin of 7.19 mg/l were obtained 1.5 h after an oral dose of 400 mg. Women had higher concentrations than men. Urinary excretion was 34% in 6 h and 63% in 24 h and the mean peak concentration was 699 mg/l. Saliva concentrations were 37% of those in serum. Lomefloxacin was detectable in the faeces up to seven days after the last dose. The major effect of lomefloxacin on the faecal flora of volunteers following a four day course of 400 mg once daily was the elimination of strains of Enterobacteriaceae and an increase in the numbers of Gram-positive cocci, mainly streptococci. There was no effect on anaerobic bacteria or yeasts. Lomefloxacin was well tolerated and no side effects were recorded. No bacterial resistance was detected after treatment.

4-Quinolones↗
PubMed1991

Wheat dust-associated respiratory disease in a farming community.

Sixty-six volunteers who considered themselves to have wheat dust-related respiratory disease, were reviewed from a farming community. A spectrum of disease was described ranging from a mild allergic rhinitis limited to periods of wheat dust exposure through to perennial asthma in which wheat dust was but one of several precipitating factors. Approximately half of those with asthma had symptoms limited to times of wheat dust exposure. Results of a limited survey of farmers showed patterns of symptoms similar to those in the volunteer group. Most subjects were atopic with elevated IgE levels, and had positive skin prick tests to environmental allergens. All but one of 65 subjects tested had a positive RAST test to wheat dust antigen. It is concluded that wheat dust associated respiratory tract disease is a significant problem in Australian farming communities, that a particular pattern of asthma can be described, and that IgE mediated reactions contribute to this disease pattern.

Adolescent↗
PubMed1991

Isolated fallopian tube torsion presenting in labor. A case report.

Isolated torsion of the fallopian tube was discovered during labor. Tubal torsion may occur in the absence of adnexal disease. Diagnosing this disorder is especially difficult in labor, when other causes, such as disruption of a prior uterine scar, may be considered.

Adult↗