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Biomedical subjects

J Mathews

Publications and source records attributed to J Mathews.

At least 55 records · Page 3Linked to original sources
PubMed1991

Daily administration of the progesterone antagonist RU 486 prevents implantation in the cycling guinea pig.

Since progesterone is required to prepare the endometrium for implantation of an embryo, a progesterone antagonist may inhibit nidation and thus prevent pregnancy. We addressed this possibility in the guinea pig, the small laboratory animal whose reproductive physiology most resembles that of women. Daily administration of the antiprogestin RU 486 (0, 1, 2, or 3 mg/kg, subcutaneously) for 9 days after mating inhibited implantation in a dose-dependent fashion. When this compound was given daily throughout the estrous cycle, cyclic vaginal changes, ovulation, and mating were suppressed in up to 17%, 28%, and 55% of animals, respectively. Two of seven mated female animals receiving RU 486, 1 mg/kg/day, had implantation sites. Nidation was completely blocked at higher doses. Thus daily antiprogestin administration prevented pregnancy in sexually active, normally cycling guinea pigs. A similar strategy using a daily antinidatory dose of an antiprogestin may offer a novel approach to human fertility control.

Animals↗
PubMed1990

Sodium-22 influx into erythrocytes from diabetic hypertensive patients on maintenance hemodialysis.

We have studied the percentage of 22Na+ uptake in cell suspensions; 0.4 to 2.0 x 10(9) erythrocytes/mL from diabetic uremic patients with secondary hypertension and from normal subjects. Suspensions from diabetic uremic patients with secondary hypertension 0.42 +/- 0.06 to 2.05 +/- 0.28; normal subjects showed a percentage uptake of 22Na+ of 0.27 +/- 0.05 to 1.28 +/- 0.22. The uptake of 22Na+ in 2.0 x 10(9) cells/mL was 60% more (P less than .05) in diabetic uremic patients than in the controls. These studies indicate that 22Na+ influx determinations may be used to distinguish secondary hypertensive patients from normal subjects.

Adult↗
PubMed1989

A follow-up report of occupational stress in urban EMT-paramedics.

A survey completed by 280 nonvolunteer, urban emergency medicine technician (EMT)-paramedics revealed high levels of occupational stress. We used a four-component model of occupational stress in medical environments to show indications that much variation in the manifestation of stress was accounted for by the rank and job description of the EMT-paramedic, the district served by the EMT-paramedic, and the patient population served by the EMT-paramedic. Stress exhibited by field EMT-paramedics tended to manifest in more negative attitudes toward patients, whereas administrative-level paramedics exhibited more organizational stress. We noted that the age of the EMT-paramedic and the length of time employed as an EMT-paramedic correlated with the level of occupational stress (P less than .05). The recent occurrence of significant life events also was significantly related to the level of stress (P less than .05). An EMT-paramedic's gender, marital status, and number of calls per shift had no significant correlation to the level of occupational stress. Based on these results, we recommend tailoring occupational stress programs to meet the needs of individual EMT-paramedics. Special attempts should be made to identify and counsel EMT-paramedics who are undergoing stressful life events. Finally, we suggest that rotating EMT-paramedics through various districts on a regular basis may help alleviate the negative impact on patient care in areas that have been identified as particularly stressful. Further studies are needed to verify our hypothesis.

Administrative Personnel↗
PubMed1988

A simpler procedure to study sodium-22 uptake (ouabain insensitive) in human erythrocytes.

We report a modification of the technique of Mahoney et al. (Blood 1982; 59: 439) for the determination of sodium-22 (22Na+) uptake in human erythrocytes. This modification facilitates the separation of 22Na+ taken up by erythrocytes from the free 22Na+ in the buffer by the addition of dibutyl phthalate, which forms an immiscible layer between the two. To further improve the sensitivity of 22Na+ uptake, we incubated a range of known numbers of erythrocytes with 22Na+ as opposed to the single cell suspension of known hematocrit used in Mahoney's et al. procedure (1). Erythrocytes are incubated in KCI buffer containing 2627 Bq (0.071 microCi) 22Na+ in a total volume of 0.5 mL for 0.5 h at 37 degrees C. Incubation is terminated by placing the tubes in ice for 10 min and the amount of 22Na+ taken up by the erythrocytes determined. We observe a linear relationship between erythrocyte concentrations (0.5 to 2.5 X 10(9) cells/mL) and percent uptake of 22Na+ (0.37 +/- 0.06 (1 SD) to 1.85 +/- 0.27 (1 SD) of the total 22Na+, respectively). The procedure is simple and sensitive, and can be used in clinical laboratories for the routine evaluation of 22Na+ uptake in erythrocytes.

Black People↗
PubMed1988

The use of epinephrine in the treatment of older adult asthmatics.

Three subcutaneous doses of 0.3 mL 1:1,000 epinephrine were given 20 minutes apart to 95 adult asthmatics 15 to 96 years old during 108 asthma exacerbations. Patients with a history of recent myocardial infarction or of angina were excluded from our study. Heart rhythm and rate, blood pressure, respiratory rate, and clinical response were prospectively evaluated before, during, and after the administration of epinephrine. There was no significant difference in the occurrence of ventricular arrhythmias between patients less than 40 and more than 40 years old. The mean systolic and diastolic blood pressures, mean heart rate, and mean respiratory rate decreased with treatment in the older population. Our results suggest that epinephrine is safe to use in acute asthmatics of any age.

Acute Disease↗
PubMed1988

Formulary of commonly used ophthalmologic medications.

This brief article presents in table form the most commonly used ophthalmologic agents. Other information pertinent to these agents is included, such as how the medication is supplied, what are the adverse effects, the usual dosages, and the most probable use for each agent.

Administration, Topical↗
PubMed1987

Lithium in the treatment of aggression in mentally handicapped patients. A double-blind trial.

In a double-blind trial lasting 4 months in 42 mentally handicapped patients, the effect of lithium on aggression was assessed in comparison with placebo. In the lithium-treated group, 73% of patients showed a reduction in aggression during treatment. There were significant differences in mean weekly aggression scores and in the frequency of aggressive episodes between the lithium and placebo groups. Side-effects were noted in 36% of the lithium group (and 20% of the placebo group), but were mainly transitory. There were no episodes of toxicity, and no patients had to be withdrawn from the trial. Lithium appears to be worth a 2-month trial in such patients, where repeated aggression has not been relieved by more appropriate placement, occupation or company.

Adult↗
PubMed1986

Technetium-99m MDP demonstration of neoplastic lesions involving bone and adjacent soft tissue.

Four patients are presented with malignant tumors involving both bone and adjacent soft tissue. In each of these neoplasms (two representing adenocarcinoma of the prostate, and one each of squamous cell carcinoma of lung and chondrosarcoma), the lesions were detected by accumulation of Tc-99m MDP. Involvement of both bone and soft tissue was confirmed by CT examination or surgery. It is probable that the lesions originated in bone and then extended to soft tissue.

Adolescent↗
PubMed1986

Bone imaging in the diagnosis of fractures of the femur and pelvis in the sixth to tenth decades.

A review was made of the records of 24 consecutive trauma patients (aged 55-94 years) who had under gone radiographic examinations and a positive bone image of the femur or pelvis. There was considerable discordance between the radiographs and the bone images. Initially, 25% of the radiographs were interpreted as positive. Even after additional radiographs and retrospective. review, only 38% of the x-ray studies were positive. Bone imaging was a useful adjunct in these patients, both to confirm or exclude suspected fractures and to detect occult fractures. The necessity of delaying bone imaging for several days after the trauma was discussed.

Aged↗
PubMed1986

Splenectomy for splenic metastasis from carcinoma of colon.

An 81-year-old woman with carcinoma of the colon had a normal liver-spleen radiocolloid image at the time of surgery. Two years later, a defect was noted in the spleen on a follow-up radiocolloid study. A repeat examination showed that the mass was increasing in size. An abdominal CT examination also revealed an intrasplenic mass with spring of the liver. After splenectomy for a metastatic carcinoma of the colon, the patient has survived for over a year without symptoms referable to tumor spread. Mention is made of the apparent splenic "immunity" from metastases.

Adenocarcinoma↗
PubMed1986

Australian National Health and Medical Research Council dietary salt study in mild hypertension.

Two-hundred-and-twelve untreated subjects (mean age 52.3 +/- 0.8 years; 181 males and 31 females) with a diastolic blood pressure between 90 and 100 mmHg were recruited to the study. Subjects were seen fortnightly and, after 4 pre-diet visits, were randomized into a normal diet group (A, 55 subjects), a high-potassium diet group (B, 52 subjects receiving greater than 100 mmol K+/day) a reduced-sodium diet group (C, 52 subjects receiving 50-75 mmol Na+/day) or a high-potassium and low-sodium diet group (D, 53 subjects receiving same Na+ and K+ as groups B and C). Two-hundred subjects completed the diet phase of 12 weeks. Urine sodium fell to 86 +/- 7 mmol/day in group C and 73 +/- 6 mmol/day in group D, while daily potassium excretion rose to 96 +/- 5 mmol in group B and 87 +/- 4 mmol in group C. Systolic and diastolic blood pressure fell by 3.8 +/- 1.0 and 1.6 +/- 0.6 mmHg respectively in the normal diet group. The falls in systolic and diastolic blood pressures (mmHg) in the diet phase were 7.7 +/- 1.1 and 4.7 +/- 0.7 (B), 8.9 +/- 1.0 and 5.8 +/- 0.6 (C) and 7.9 +/- 0.9 and 4.2 +/- 0.7 (D). These falls were all greater than those in the control group on an intention-to-treat analysis (P less than 0.005) but did not differ from each other. Factorial analysis confirmed that the falls in pressure attributable to the low-sodium diet and high-potassium diet were not additive.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗
PubMed1986

Liver function tests. A study in patients with imaging-demonstrated metastases.

Thirty-eight consecutive patients with liver scan evidence of hepatic metastases (and confirmation by other modalities) had blood levels of lactate dehydrogenase and alkaline phosphatase performed within two weeks. In 38% of the patients with small liver metastases, both alkaline phosphatase and lactate dehydrogenase were in the normal range. Even with large metastases present (one or more lesions over 2.5 cm in diameter), 19% of the patients had both enzyme tests within the normal range. Despite the lower cost of these enzyme assays, they failed to detect hepatic metastases in an appreciable portion of our patients.

Alkaline Phosphatase↗
PubMed1985

Rapid response of intrasplenic lesions to steroids in non-Hodgkin's lymphoma.

A 70 year old woman had a [99mTc]sulfur colloid liver/spleen scan that showed splenomegaly and multiple intrasplenic defects. The lesions failed to concentrate radiogallium. Thirteen days later, after being on steroid therapy, the spleen had decreased in size and the lesions were only barely apparent. The intrasplenic process, due to non-Hodgkin's lymphoma, was thus markedly sensitive to steroids. It is uncertain if such rapid regression can be employed as a prognostic indicator in non-Hodgkin's lymphoma and suggests the need for further monitoring. The differential diagnosis of the rapid response of intrasplenic lesions to steroids is a limited one, and likely includes sarcoidosis.

Aged↗
PubMed1985

Pulmonary ventilation/perfusion and reverse mismatches in an infant.

A male infant, with bronchopulmonary dysplasia and ventilator dependence, had lung ventilation (Xe-133 gas) and perfusion (Tc-99m MAA) imaging performed. The examination revealed a region that was ventilated but not perfused (mismatch) and a separate area that was perfused but not ventilated (reverse mismatch). The basis of both abnormalities is suspected to be related to bronchopulmonary dysplasia, atelectasis and/or mechanical ventilation. Ventilation/perfusion mismatches and reverse mismatches can occur in the same patient.

Bronchopulmonary Dysplasia↗