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Biomedical subjects

R L Watson

Publications and source records attributed to R L Watson.

At least 37 records · Page 2Linked to original sources
PubMed1990

Potassium and calcium intake, excretion, and homeostasis in blacks, and their relation to blood pressure.

Blacks in the United States have higher blood pressures than whites. They ingest and excrete less calcium and potassium. There is some evidence that blacks have a difference in vitamin D metabolism that might increase any problem caused by low calcium intake. Some studies can be interpreted to suggest that calcium or potassium therapy has greater hypotensive effects in blacks than in whites. Decreased intake of calcium and potassium may be major causes of the greater prevalence of hypertension in blacks than in whites.

Black People↗
PubMed1989

Medical and financial implications of discontinuing a statewide free insulin program involving 3,720 people.

In 1981 a statewide program supplying free insulin to 3,720 patients of state health clinics was discontinued. We attempted to assess whether this action had an adverse effect medically and financially on those concerned. A computer randomized sample of 351 patients (9%) was studied by personal interview and questionnaire. Information obtained focused on certain events that occurred 18 months before and after the program ceased. Measurements used to determine medical impact were number of hospitalizations, emergency room and physician visits, changes in weight and glucose levels, and episodes of ketoacidosis. Financial impact was measured by cost of hospitalization and physician visits. Our results revealed no significant changes in any of the medical parameters studied except for fasting serum glucose levels above 300 mg/dl, which occurred less frequently after the free insulin program was discontinued. There were fewer hospitalizations, more visits to physicians, and no change in number of emergency room visits after discontinuance of the free program. The overall cost saving was estimated to be +883,558 for the 18-month study period, in addition to the +550,000 the plan had been costing the state.

Blood Glucose↗
PubMed1983

The effects of morphine, nalbuphine, and butorphanol on adrenergic function in canine saphenous veins.

Saphenous vein rings mounted in organ chambers containing Krebs-Ringer solution were used to determine if the venodilator effects of morphine, nalbuphine, and butorphanol are the result of interference with adrenergic neurotransmission or are caused by direct depressant actions on venous smooth muscle cells. Morphine (5 X 10(-5) M and 2 X 10(-4) M) caused a dose-dependent depression of the contractile response to transmural electrical stimulation. H1- and H2- histamine antagonists did not attenuate the inhibitory effect of morphine. Concentrations of morphine and nalbuphine lower than 5 X 10(-5) M had no effect, whereas 5 X 10(-6) M butorphanol significantly depressed the evoked tension response to electrical stimulation. The contractile responses of the veins to exogenous norepinephrine (NE) were not altered by morphine, indicating a presynaptic site of action rather than a direct action on the venous smooth muscle. Transmural electrical stimulation was used to evoke release of endogenous NE. Morphine (5 X 10(-5) M and 2 X 10(-4) M), nalbuphine (2 X 10(-4) M), and butorphanol (4 X 10(-6) M) significantly decreased release of NE. Naloxone did not alter NE release and did not attenuate the inhibition of NE release observed with the opiates, indicating that the effect of morphine on this neuroeffector junction is not mediated by a naloxone-sensitive opiate receptor. Blockade of presynaptic alpha receptors by phenoxybenzamine or phentolamine augments NE release caused by transmural electrical stimulation; morphine inhibited this augmentation. The results of these experiments indicate that high concentrations of morphine may decrease NE release, an effect that may contribute to the venodilation and hypotension observed following administration of high doses of morphine in humans. In the usual analgesic doses, the venodilatory effects of morphine cannot be explained by local action on either NE release or venous smooth muscle contractility.

Adrenergic alpha-Antagonists↗
PubMed1982

Determination of morphine in cerebrospinal fluid and plasma by high-performance liquid chromatography with electrochemical detection.

Two methods for the extraction of morphine from cerebrospinal fluid or plasma with quantitation by high-performance liquid chromatography with electrochemical detection were compared for accuracy, precision and ease of preparation. One procedure was a standard extraction procedure and the other utilized a commercially available liquid-liquid extraction column. Both methods produced linear calibration curves over the concentration range of 1-200 ng/ml with coefficients of correlation of 0.999. Since the electrochemical detector is capable of detecting 20 pg of morphine, biological samples as small as 0.1 to 0.4 ml can be quantified with an average relative precision of 4.1 +/- 3.9% over the concentration range 1-200 ng/ml. The potential clinical importance of the assay is demonstrated using a time course distribution study of morphine in the cerbrospinal fluid and plasma of a Rhesus monkey.

Animals↗
PubMed1982

Weight, urinary electrolytes and blood pressure--results of several community based studies.

One hundred and seventy-nine Negro females, originally seen in high school in 1965, were visited at home during the summers of 1968 or 1969, and were revisited at home during 1978 or 1979. Weight, blood pressure, and urinary electrolyte excretion rates were obtained during the 1968-1969 studies. This report relates the previous measurements to the current (follow-up) blood pressure levels. 52 of the 179 have been told by a physician that they have high blood pressure, and 16 are now taking antihypertensive medication. The group now on medication were 27 lbs heavier and had higher blood pressures, 123/76 vs 114/70 in 1968-1969 than the remainder of the cohort, and their 24-hr urinary sodium excretion rate was greater, 5.9 vs 4.4 mEq/hr (p = 0.06). Among the groups now on therapy, the overnight K rate and Na/Ca ratio were inversely related to the 1968-1969 diastolic BP and the 24-hr Na rate and Na/K ratio were positively correlated with the 1968-1969 blood pressure, both systolic and diastolic. These associations were diminished when partial correlation coefficients adjusted for weight were calculated. Similar associations were not observed among the remainder of the cohort, suggesting that among persons who have the propensity to become hypertensive, the influence of factors which may produce hypertension such as sodium and/or obesity is more easily discernible.

Adolescent↗
PubMed1982

A case-comparison study of hypertension and hyperparathyroidism.

The frequency of hypertension in patients with primary hyperparathyroidism has been compared with that found in cases matched for conditions of comparable surgical magnitude, age, race, sex, and days in the hospital. The mean blood pressure of the patients was 143/89 mm Hg, significantly higher than that of controls, which was 130/81 mm Hg (P less than 0.001 for systolic and diastolic pressures). The difference was especially notable in view of the fact that the mean weight of the controls was 169 lb compared to 153.9 lb for the patients. Actual hypertension, defined as a diastolic blood pressure of 90 mm Hg or more and or treatment with hypertensive therapy was much more frequent in the patients (90 of 124; 73%) than in the controls (53 of 124; 43%; P less than 0.001). Serum creatinine was 1.3 mm/dl in patients and 1.1 mm/dl in controls. The blood pressure difference between patients and controls persisted when patients with creatinine levels of 2.0 mm/dl or less were omitted. The blood pressure difference between patients and controls had disappeared by the end of hospitalization. We conclude that primary hyperparathyroidism is associated with modest blood pressure elevation, that renal damage is probably not the mechanism, and that surgical cure perhaps may lower blood pressure. The mean effect of primary hyperparathyroidism is to shift the blood pressure distribution curve to the right by approximately 15/10 mm Hg.

Age Factors↗
PubMed1981

Epidural morphine following epidural local anesthesia: effect on ventilatory and airway occlusion pressure responses to CO2.

The authors measured the minute inspired ventilation (VI) and airway occlusion pressure (P 100) responses to CO2 during rebreathing in ten patients who were given epidural morphine for analgesia following lower extremity or lower abdominal surgery. All patients were studied and blood samples for morphine analysis were obtained at four different times: preoperatively, postoperatively premorphine, and one and six hours after a single 10-mg epidural dose of preservative-free morphine in 10 ml of saline. All patients reported effective analgesia with a duration ranging from 8-25.5 h. There were no differences between the pre- and postoperative VI vs. PCO2 and P100 vs. PCO2 response slopes, indicating that the epidural local anesthetic alone had no effect on respiratory drive. Administration of 10 mg morphine epidurally caused a significant 22 per cent decrease in the average VI vs. PCO2 slope and a 33 per cent decrease in the average P100 vs. PCO2 slope one hour postmorphine when compared to the postoperative slopes. The average decrease in VI vs. PCO2 at 6 h postmorphine was not significant. The average P100 vs. PCO2 response slope was decreased significantly at 6 h postmorphine by 27 per cent. There was no significant correlation between serum morphine concentration and the ventilatory responses. The authors conclude that morphine administered by the epidural route produces decreased respiratory drive and that there is a high degree of individual variability in the magnitude and time course of this effect.

Adult↗
PubMed1980

Humidity in children and adults using the controlled partial rebreathing anesthesia method.

The authors examined inspired humidity using a controlled partial rebreathing anesthesia method (CPRAM) and a circle system in 16 healthy adults and five healthy children. The patients were divided into five study groups (A-E). All patients except those in Group E were anesthetized with fentanyl, pancuronium, nitrous oxide-oxygen, 66-33 per cent, and their lungs were mechanically ventilated; patients in Group E received halothane and nitrous oxide-oxygen, 66-33 per cent, with spontaneous ventilation. Group A (five children) had inspired hummidity measured within a modified coaxial (Bain) anesthesia circuit using CPRAM. Groups B and C (five adults each) had humidity measured within the modified coaxial circuit and at the end of a non-modified coaxial circuit using CPRAM. Groups D and E (three adults each) had humidity measured in the semi-closed and closed circle systems, respectively. Initial, mid-, and end-inspired humidity were measured in all groups for two hours by interrupting the controlled ventilation at 30-min intervals, except in patients of Group E, who had humidity measured at similar intervals for two hours during spontaneous ventilation. No significant difference was found among initial, mid-, or end-inspired humidity, nor was there a significant difference between inspired humidities in children and in adults using CPRAM. The humidity measured in adults within the circuit near the endotracheal tube was not significantly different from that measured distal to the fresh gas flow. The humidities in all CPRAM patients exceeded those of both the semiclosed and closed circle systems, stabilizing within 30 min and remaining constant between 24 and 26 mg H2O/1.

Adult↗
PubMed1979

Spontaneous-ventilation general anesthesia for outpatients using enflurane.

We have described our technique for general anesthesia for outpatients using a mixture of nitrous oxide, oxygen, and enflurane with spontaneous ventilation through a Bain anesthetic circuit. In our experience, surgical excision of impacted teeth, multiple extractions and alveoloplasty, enucleation of simple cysts, excision of benign tumors, and other similar operations have been done efficiently with these anesthetic techniques. More than 500 such cases have been managed without significant complication. The concepts of selection and preparation of patients, airway security and protection during surgery performed in the upper airway on an unconscious patient who is breathing spontaneously, continuous monitoring of vital functions, and rapid induction and recovery all combine to make this technique consistent with standards for excellence in anesthesia.

Ambulatory Care↗
PubMed1978

An evaluation of enflurane as an amnesic agent for outpatient oral surgery.

An alternative to general anesthesia for outpatient oral surgery that creates a state of cooperative amnesia without eliminating the patient's protective reflexes has been developed. Enflurane, 1.5%, administered via a nasal mask produced a high incidence of amnesia with all patients remaining cooperative, with protective reflexes intact.

Adolescent↗