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Biomedical subjects

T B Smith

Publications and source records attributed to T B Smith.

At least 37 records · Page 2Linked to original sources

Effects of subliminal stimuli on unconscious processing of anxiety: an examination of implicit perception.

Researchers in cognitive psychology generally accept that information, including emotions, may be processed outside of awareness. Some have postulated that anxiety may be induced by stimuli presented below the level of detection, a process called implicit perception; however, conflicting findings as to the validity of subliminal stimuli in influencing anxiety have been reported over the past decade. In the present study, 39 subjects were exposed to either positive, negative, or neutral subliminal stimuli, and half the subjects were informed as to the type of stimuli they received. All subjects were monitored for frontalis muscle tension, a physiological indicator of anxiety, on an electromyograph (EMG). No significant effects of the exposure upon EMG recordings were noted. Awareness of the type of stimuli presented had a small but insignificant effect. These results, although tentative, when replicated would question the validity of subliminal visual presentation in altering emotive states.

Adult↗

Depressive symptomatology and interaction behaviors of mothers having a child with disabilities.

Previous research has indicated that parents who raise children having disabilities report greater emotional distress than other parents. To investigate the association between symptoms of depression and maternal behaviors, interactions between 48 mothers and children having disabilities were rated. Measures of maternal depression and child functioning were also administered. Analyses indicated that mothers reported a relatively large number of symptoms often associated with depression. However, reports of depressive symptomatology were not meaningfully related to the children's developmental status or parent-child interaction behaviors.

Adult↗

A prospective evaluation of a simplified captopril test for the detection of renovascular hypertension.

Renovascular hypertension is potentially curable but of low prevalence. A previous retrospective study has demonstrated the use of a potentiated increase in plasma renin activity after captopril administration as a diagnostic test for renovascular hypertension; this requires two blood samples for plasma renin activity determination and three inclusive criteria for a positive test result. We applied this test prospectively to screen 100 hypertensive patients for renovascular hypertension. We evaluated 29 patients with renovascular hypertension; the remainder were diagnosed as having essential hypertension. In our patient population, a postcaptopril plasma renin activity of 5.7 ng of angiotensin per milliliter per hour (ngAl.mL-1.h-1) or greater had a 100% sensitivity and an 80% specificity for renovascular hypertension. An absolute increase in plasma renin activity with captopril of 4.7 ngAl.mL-1.h-1 or greater had a lower sensitivity of 90% and a specificity of 87%, whereas a fractional increase in plasma renin activity after captopril of 150% or higher had the lowest sensitivity of 69% and a specificity of 86%. A subgroup analysis of 38 patients who were receiving diuretic therapy demonstrated that the test sensitivity was unchanged but the specificity was reduced. In conclusion, a single postcaptopril plasma renin activity value of 5.7 ngAl.mL-1.h-1 or greater is a simplified screening test for renovascular hypertension, with excellent sensitivity and acceptable specificity. This test is well tolerated, inexpensive, and easy to perform.

Captopril↗

The captopril glomerular filtration rate renogram in renovascular hypertension.

Administration of captopril to animals with two-kidney, one clip, renovascular hypertension (RH) lowers the glomerular filtration rate (GFR) in the clipped kidney. The authors therefore tested the hypothesis that a decrease in GFR after captopril administration would identify patients with RH. Total GFR was measured by the plasma disappearance of Tc-99m-diethylenetriaminepentaacetic acid (DTPA) after bolus injection and single-kidney GFR from renal uptake of DTPA assessed by renography. The authors studied six patients with arteriosclerotic RH who had strongly lateralizing renal vein renin levels and greater than 80% stenosis of the renal artery to that kidney. Results were contrasted with those of six patients with essential hypertension (EH) with a similar mean arterial blood pressure (MABP). Captopril (50 mg orally) increased total GFR (ml/min) in all patients with EH (102 +/- 8 to 120 +/- 12, P less than 0.005). However, GFR decreased in patients with RH (73 +/- 8 to 61 +/- 9, P less than 0.05) after captopril. Although the single-kidney GFR of patients with RH decreased in all six stenotic kidneys (27 +/- 4 to 21 +/- 5, P less than 0.02), it did not change consistently in the contralateral kidneys (45 +/- 8 to 40 +/- 6, N.S.). Clonidine (0.3 mg) also lowered MABP in patients with RH but, unlike captopril, it did not reduce total kidney GFR (75 +/- 10 to 79 +/- 11, N.S.). In conclusion, short-term captopril administration increases GFR in patients with EH, but decreases it in those with RH. This action is unrelated to its depressor response.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Diagnostic uses of angiotensin-converting enzyme inhibitors in renovascular hypertension.

The response to angiotensin-converting enzyme inhibitors (ACEIs) can be of considerable help in the diagnosis of human renovascular hypertension (RVH) in three settings. First, a particularly dramatic antihypertensive response or a decline in glomerular filtration rate (GFR), as indexed by a rise in serum creatinine or blood urea nitrogen concentrations, are useful clues to the presence of renovascular hypertension. Second, an exaggerated rise in plasma renin activity (PRA) after short-term captopril administration is a very promising screening test for this condition. Third, ACEI-induced changes in single-kidney hemodynamics (assessed by renography) may be helpful in confirming the diagnosis and offers the prospect of localizing the ischemic kidney.

Angiotensin-Converting Enzyme Inhibitors↗

Blood parasites of birds in Cameroon.

Birds from south-central Cameroon, western Africa, were surveyed for blood parasites from August to October 1986. Of 331 birds examined, representing 65 species of 15 families and 6 orders (mostly passerines), 55 (17%) were found to be infected with 1 or more genera of hemotropic parasites. These included: Haemoproteus spp. (11% prevalence), Leucocytozoon spp. (3%), Plasmodium spp. (2%), Trypanosoma spp. (1%), and microfilariae of filariid nematodes (1%). Several new host-parasite associations were identified.

Animals↗

Clinical evaluation of three urine screening tests.

Evaluations of screening tests for bacteriuria have traditionally compared the test results with those of quantitative urine cultures. However, many patients with symptomatic urinary tract infections can have less than 10(5) CFU/ml in their urine. Therefore, the results of urine culture and three screening tests (Bac-T-Screen, Chemstrip LN [which tests for leukocyte esterase and nitrate reductase], and Gram stain) were correlated with the clinical classification of urinary tract infection. The Bac-T-Screen test detected 98, 93, and 100% of the infections classified as probable, possible, and asymptomatic, respectively. In contrast, the Gram stain, leukocyte esterase, and nitrate reductase tests were all insensitive screening tests for infection. Additionally, only 45% of the patients with probable infections had greater than or equal to 10(5) CFU/ml. Thus, the majority of infected patients would not have been detected if quantitative urine cultures were used alone.

Bacteria↗

Hearing loss in pediatric meningitis.

Bacterial meningitis is the leading cause of acquired sensorineural hearing loss in children. Acquired hearing loss can have a devastating effect on a child's speech, language and eventual intellectual development, especially when the hearing loss occurs before the child learns to talk. If an immediate referral for audiologic testing is not made, valuable time is lost in obtaining hearing aids and habilitative/rehabilitative services for children during the critical period of language development.

Audiometry, Evoked Response↗

Health insurance coverage of the unemployed.

Of 1,332 unemployed individuals in the Detroit area interviewed in late 1983, 51% did not have health insurance. Lack of insurance was directly related to length of unemployment. Of those unemployed 3 months or less, 31% had no insurance, as compared with 56% of those unemployed more than 3 years. For the most part, these were not the chronically uninsured: 78% of them were insured when they were employed. Three fourths of those without insurance were not covered by Medicaid either. These findings suggest that during the latest economic recession, the problem of health insurance loss due to losing one's job was more severe than had been assumed by most policymakers.

Adult↗

Clinical application of immunofluorescence. 3. Identification of Lancefield group B streptococci.

The identification of Lancefield group B streptococci with immunofluorescence was studied after significant differences between the precipitin and immunofluorescent results were noted. It was found that strains of group B streptococci, unlike groups A, C, and G streptococci, do not reliably react with a fluorescein isothiocyanate-labeled conjugate that contains antibodies mainly against C polysaccharide. It was assumed that the difficulty probably resulted from a blocking of the antigen-antibody reaction between the group antigen and its antibody by the S antigen located in the capsule. On the basis of this assumption, a conjugate was prepared that contained antibodies against the various S antigens of group B and it was found to be effective.

Animals↗