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T Colton

Publications and source records attributed to T Colton.

70 records · Page 4Linked to original sources

The distribution of intraocular pressures in the general population.

A variety of studies are reviewed in which intraocular pressure (IOP) was determined in defined, general populations. The studies exhibit a remarkably consistent pattern for the frequency distribution of IOP. The distribution conforms well to a normal curve for pressures up to 21 mm Hg, after which a distinct skewness to the right begins to appear. When the data are grouped by age and sex, the degree of right skewness intensifies with age. Mean IOP increases with age. Some studies also show higher mean levels for women than men, but not all do. The arbitrary nature of specifying upper limits of normality is stressed. In addition, the literature is reviewed concerning the arguments for a mixture of two overlapping normal (or lognormal) curves vs a continuum for the distribution of IOP.

Adult

Seizures in bacterial meningitis: prevalence, patterns, pathogenesis, and prognosis.

Of 207 patients with acute bacterial meningitis previously reported by Dodge and Swartz, seizures occurred in 56 (27%). Most seizures began on the first or second day, and most stopped within two days. Seizures occurred most often at the extremes of life. Age-adjusted seizure frequency was greater with Hemophilus influenzae meningitis than with Streptococcus pneumoniae or Neisseria meningitidis. When seizures complicated bacterial meningitis, age-corrected mortality increased from 24% to 38%. Though seizures after recovery were infrequent (2.7% of cases), recurrences were five times more frequent in patients who convulsed acutely than in those who did not. When focal seizures accompanied focal pathology (extracranial or intracranial), the seizures were usually not lateralized to the opposite side of the body. Of factors of potential importance in causation of seizures, fever was the most important risk factor regardless of patient age.

Adolescent

Randomized trials of aminoglycoside antibiotics: quantitative overview.

Individual randomized trials comparing aminoglycosides have usually involved a sample size inadequate for reliable detection of small to moderate differences. In a search for overall effects that might not be apparent from any single trial, a quantitative overview of all randomized studies comparing amikacin, gentamicin, netilmicin, sisomicin, and tobramycin was performed. These aminoglycosides appeared equally efficacious, except that tobramycin seemed less effective than sisomicin. Patients given gentamicin or sisomicin seemed to run a higher risk of nephrotoxicity than those given amikacin; the risk for patients receiving tobramycin was lower than that for patients given gentamicin but higher than that for those given netilmicin. The only statistically significant difference with regard to auditory toxicity was a lower risk among patients receiving netilmicin than among those given amikacin or tobramycin. Meaningful differences in toxicity may exist for individual aminoglycosides given in efficacious doses. Future trials must include sample sizes sufficient to detect differences of the magnitudes observed in this overview. In the absence of such data, the overview may guide clinicians in determining the risk-to-benefit ratio for a particular aminoglycoside, especially for patients at high risk of toxicity.

Aminoglycosides

Unmedicated blood pressure levels and quality of life in elderly hypertensive women.

We examined the associations between unmedicated systolic and diastolic blood pressure (BP) levels and measures of quality of life (QOL). Women (N = 315) ranging in age from 60 to 80 with diagnoses of mild to moderate hypertension were removed from antihypertensive medications and placed on placebo medication in the context of a clinical drug trial. Unmedicated BP levels were measured at the QOL interview, which followed a 4- to 8-week placebo run-in period, and at the preceding visit 1 week earlier. Indices representing five QOL dimensions were obtained in the QOL interview. The QOL dimensions assessed were: 1) sense of general well-being; 2) cognitive functioning; 3) affective status; 4) physical health status; and 5) level and enjoyment of social activity. QOL indices were regressed on unmedicated systolic and diastolic BP levels and on duration of hypertension in separate models. Each regression model included age, education, cigarette smoking, alcohol intake, and body mass index as covariables. We found that unmedicated BP levels were inversely related to QOL measures of cognitive functioning and social activity level. Although duration of hypertension was not related to cognitive functioning or social activity level, duration was associated with indices representing other dimensions of QOL. Specifically, duration of hypertension was inversely related to sense of general well-being and positively related to measures of physical health status, i.e., physical symptom incidence and sleep dysfunction.

Activities of Daily Living

Pre-anesthetic cimetidine alteration of gastric fluid volume and pH.

Gastric volume and pH were studied immediately after induction of anesthesia and endotracheal intubation in 101 elective surgical patients. Of 44 patients not given cimetidine, 82% had a gastric pH less than 2.5 with a mean pH of 1.6; 45% of these patients had a gastric aspirate pH less than 2.5 associated with a volume exceeding 25 ml. In 57 patients premedicated with intravenous cimetidine at variable intervals (15 to 60 minutes) prior to induction of anesthesia, a significant time-dependent increase was noted in gastric pH (p less than 0.001) together with a decline in gastric volume (p less than 0.001). Of the patients given intravenous cimetidine (mean 4.5 mg/kg) 45 minutes prior to induction of anesthesia, 90% had a gastric pH greater than 2.5. The increase in gastric pH after cimetidine administration would result in a reduced chemical pulmonary reaction should aspiration occur during induction of anesthesia.

Adolescent

Quantitative relationships between perceived and objective need for health care--dentistry as a model.

To elaborate and refine a previously devised method for quantifying the relationship between perceived and objectively determined dental disease, data on a random sample of 588 patients in two towns in England were analyzed. The data included the number of decayed (D), missing (M), and filled (F) teeth, composite DMF scores, and patients' self-assessments of the state of their teeth and the need for treatment. The study method was a combination of bioassay and psychophysical techniques. Categorical self-assessments of the state of teeth and the need for treatment were dichotomized to yield proportions, which, when transformed into logits, resulted in a linear relation to increments of dental disease. A 50% point for each of the component D, M, and F scores was derived from the intercept of the line of best fit. The D50 for both the state of teeth and the need for treatment was found to be closest to the objective measure (Dx), with the smallest standard error. Although males had a significantly lower D50 (0.5) than females (D50=2.1) for need for treatment, with no differences in D50 for state of teeth, the females actually had a significantly lower Dx. These data indicate that males as a group had a lower threshold for perception of the need for treatment. This finding contrasts with the observation in other studies that males actually use dental services less than females.

Adolescent