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Biomedical subjects

C A Johnson

Publications and source records attributed to C A Johnson.

At least 235 records · Page 13Linked to original sources
PubMed1992

Cryptorchidism and monorchism in cats: 25 cases (1980-1989).

Of 1,345 cats admitted for orchiectomy during a 10-year period, 23 (1.7%) were cryptorchid and 2 (0.1%) were monorchid. Persian cats were over-represented in the cryptorchid population (P = 0.01). Cats were more likely to be unilaterally than bilaterally cryptorchid (P = 0.01). A predisposition for location of undescended testes (abdominal vs inguinal or right vs left side) was not identified in unilateral cryptorchids. All bilateral cryptorchids had abdominally located testes. The most common surgical approaches used for orchiectomy of cryptorchid cats were a caudal ventral midline incision for inguinal testes and a caudal ventral midline celiotomy for abdominal testes.

Animals↗
PubMed1992

Retinoscopic measurement of the refractive state of the rat.

Using retinoscopy, we measured the refractive state of 96 eyes of three different strains of rats: albino Sprague-Dawley, Royal College of Surgeons (RCS) with and without inherited retinal dystrophy, and lean and obese varieties of Zucker rats. Contrary to previous reports, we do not find consistent high hyperopia in the rat, but rather refractions that range from near emmetropia (-0.12 D) to extreme hyperopia (+18.95 D). This range of refractive errors suggests a poorly developed emmetropization mechanism in the rat, and that individual refractions should be performed on animals utilized in experiments where refractive state is critical.

Albinism, Ocular↗
PubMed1992

National TV smoking cessation program and contest in Finland.

BACKGROUND: In the fall of 1986 the North Karelia Project in cooperation with Finnish TV 2 arranged an eight-part nationwide smoking cessation TV program. The Project, also arranged a smoking cessation contest coinciding with the TV program in cooperation with four major voluntary public health organizations and the national health service. The TV program featured two studio groups of local volunteers: one from Turku (southwestern Finland) and the other from North Karelia, where there was more intensive community support for the activity. RESULTS: Based on a national survey of a representative population sample, the reported viewing rates (at least one part) of the working-age population (15-64 years, smokers and nonsmokers) were 64% in North Karelia, 45% in Turku, and 46% nationally (P less than 0.001). Among smokers who had watched at least one session of the TV program, 7.7% reported to have tried to quit smoking in North Karelia, 4.1% in Turku, and 7.5% nationally. Altogether, 16,089 smokers participated in the contest; again the highest participation rate was in North Karelia. The 6-month success rate among the smokers who participated in the contest was 22% in North Karelia, 18% in Turku, and 17% nationally (P less than 0.05). Men were more likely to succeed in quitting: among men the 6-month success rate was 22% and among women 15% (P less than 0.001). CONCLUSIONS: The results and experiences indicate high viewing and participation and a beneficial cost-effect ratio. They also stress the importance of community support activities in enhancing the effects of a media-based health promotion program.

Adolescent↗
PubMed1992

Reactivity to alcohol-relevant beverage and imaginal cues in alcoholics.

This study was designed to explore three primary facets of reactivity to alcohol-relevant stimuli among alcoholics: (a) comparison of exposure to an alcohol-containing beverage vs. an appropriate, standardized control beverage; (b) efficacy of imaginally presented cues to elicit reactivity, alone and in combination with beverage cues; and (c) examination of the recovery process. Forty-eight male veterans attending an inpatient alcohol treatment program served as participants and were randomly assigned to one of four groups in a 2 (Alcohol vs. Lemonade Beverage) X 2 (High-Risk vs. Low-Risk Imagery) design. Heart rate reactivity to Beverage cues was consistent with previous research. An interaction of Beverage and Imagery manipulations during recovery revealed both experimental manipulations influenced heart rate, although the Alcohol/High-Risk Imagery exposure group did not demonstrate enhanced effects. Both manipulations also had an impact on ratings of desire to consume alcohol. These findings provide further support for the reliability of cue reactivity effects, and suggest the utility of imaginal exposure procedures as a component of a comprehensive cue reactivity assessment.

Adult↗
PubMed1992

Single-dose pharmacokinetics of piperacillin and tazobactam in patients with renal disease.

Tazobactam is an irreversible inhibitor of many beta-lactamases. In combination with piperacillin, tazobactam exhibits synergy against many beta-lactamase-producing bacteria. The pharmacokinetics of piperacillin and tazobactam were evaluated in eight normal volunteers and in 52 patients with renal dysfunction. Plasma and urine were obtained for up to 30 hours after an infusion of piperacillin and tazobactam (3 and 0.375 gm, respectively). Dialysate samples were collected from patients undergoing dialysis. Piperacillin and tazobactam concentrations were determined by high-performance liquid chromatography. Noncompartmental methods were used for pharmacokinetic analysis. Piperacillin and tazobactam total body clearance, area under the curve, and terminal elimination rate correlated with renal function. Hemodialysis removed 31% and 39% of piperacillin and tazobactam, respectively. During continuous ambulatory peritoneal dialysis, 5.5% of the piperacillin and 10.7% of the tazobactam was recovered in the dialysate over 28 hours. Peak plasma concentrations of both drugs increased minimally with decreasing creatinine clearance. Dosage alterations for creatinine clearance values less than 40 ml/min are recommended.

Adult↗
PubMed1992

Comparison of postoperative analgesic effects of intraarticular bupivacaine and morphine following arthroscopic knee surgery.

Recent studies have shown that, in the presence of inflammation, the local administration of opioids results in analgesia. The analgesic efficacy of local anesthetics and morphine administered intraarticularly was compared in patients undergoing arthroscopic knee surgery under epidural anesthesia. We compared postoperative pain scores (VAS) and opioid requirements among 47 patients receiving, in a randomized, double-blinded fashion, one of three intraarticular medications (20 ml): normal saline with 100 micrograms epinephrine (group 1, n = 16); 0.25% bupivacaine with 100 micrograms epinephrine (group 2, n = 15); and 3 mg morphine sulfate and 100 micrograms epinephrine in normal saline (group 3, n = 16). VAS scores were similar in the groups preoperatively and on arrival in the recovery room. At the end of the first postoperative hour, the residual sensory blockade was minimal in all three groups (mean = 3.8-4.1 segments) and almost total recovery occurred in all three groups before the second postoperative hour. The VAS in group 3 was not significantly different than group 1 at any time interval. Intraarticular bupivacaine (group 2) provided significantly better analgesia than did saline or morphine (group 1 or 3) in the first 2 postoperative hours (ANOVA, P < .05). Subsequent VAS scores were not significantly different in the three groups. While no patient in group 2 requested analgesics during the first postoperative hour, nine patients in group 3 required systemic analgesics (P < .01). We conclude that no evidence for a peripheral opiate-receptor mediated analgesia could be demonstrated in patients undergoing arthroscopic knee surgery under epidural anesthesia.

Adult↗
PubMed1992

The relationship of ovarian steroids, headache activity and menstrual distress: a pilot study with female migraineurs.

Fourteen female volunteers who met diagnostic criteria for migraine headache monitored their headache activity and menstrual distress symptoms for one menstrual cycle. Serum estradiol and progesterone levels, and menstrual distress measures were collected at four points of the menstrual cycle: menstrual, ovulatory, luteal and premenstrual. Results indicated that one patient (7.1%) had menstrual migraine, 10 patients (71.4%) had menstrually-related headache and 3 (21.4%) had migraine headache unrelated to their menstrual cycle: subsequent analyses were conducted with the first two groups. Headache activity for the sample was highest during the premenstrual phase. Headache activity during the luteal and premenstrual phases was related to luteal phase progesterone levels. Menstrual distress was highest during the menstrual and premenstrual phases of the cycle, and these symptoms were related to higher estradiol levels, higher estradiol/progesterone ratios, and increased headache activity. These results indicated that for women with menstrual migraine or menstrually-related migraine, luteal progesterone and estradiol and the estradiol/progesterone ratio may be significantly related to menstrual distress during the premenstrual phase of the cycle. The estradiol/progesterone ratio was not more related to headache or menstrual distress than either of these ovarian hormones alone. Suggestions for future research in this area are offered.

Adult↗
PubMed1992

Comparison of commercially available media for detection and isolation of Ureaplasma urealyticum and Mycoplasma hominis.

The Mycotrim Triphasic flask system (Irvine Scientific, Irvine, Calif.) was compared with a system composed of Mycotrim GU broth (Irvine Scientific) and A7 or A8 agar (Remel, Lenexa, Kans.) for the ability to detect Ureaplasma urealyticum and Mycoplasma hominis from 129 genital specimens. Of the 64 specimens positive for U. urealyticum, 25, 98, and 100% were detected on Mycotrim Triphasic agar and A7 and A8 agars, respectively. All 18 specimens that grew M. hominis were detected by A7 and A8 agars, and 94% grew on Mycotrim Triphasic agar. Mycotrim GU broth detected all of the positive specimens, and Mycotrim Triphasic broth detected all but one. Mycotrim GU broth inoculated simultaneously with either A7 or A8 agar was found to be more sensitive and cost-effective than the Mycotrim Triphasic flask system.

Culture Media↗
PubMed1992

Postpartum hemolytic uremic syndrome associated with antiphospholipid antibodies. A case report and review of the literature.

Postpartum hemolytic uremic syndrome (HUS) is described in a woman with a history of spontaneous abortions and both circulating lupus anticoagulant and anticardiolipin antibody (ACA). After termination of her pregnancy because of severe preeclampsia, ACA blood levels increased simultaneously with the onset of a microangiopathic process associated with severe hypertension and renal failure. Plasma exchange resulted in a rapid decline in ACA levels and immediate improvement in her clinical condition. This case strongly suggests an important causal relationship between ACA and postpartum HUS. The possible mechanisms of ACA-related postpartum HUS and the potential role of plasmapheresis in its treatment are reviewed and discussed.

Adult↗
PubMed1992

A prospective open-label study evaluating the efficacy and adverse reactions of the use of Niferex-150 in ESRD patients receiving EPOGEN.

Iron supplementation is usually required in patients receiving epoetin alfa. Ferrous sulfate is commonly prescribed, however many patients experience adverse gastrointestinal effects. Adverse effects may limit the amount of iron that can be prescribed, and may lead to noncompliance. Polysaccharide-iron complex (PIC) is an iron supplement containing greater amounts of elemental iron, and may produce fewer adverse effects. This study compared the efficacy and adverse effects of PIC to a historical period of treatment with ferrous iron salts to 38 dialysis patients receiving epoetin alfa. All patients were switched to PIC, and were followed for six months. The following laboratory information was recorded: hematocrit, serum iron concentration, percent transferrin saturation, total iron-binding capacity, serum ferritin concentration. Patients were given an adverse experience questionnaire at four and six months of PIC treatment. No differences in laboratory values were noted between treatments. The amount of prescribed elemental iron increased, while iron dextran use decreased during PIC therapy. Epoetin alfa doses were unchanged. Patients reported fewer gastrointestinal adverse effects at four months, however differences at six months were less striking. PIC is as effective as ferrous sulfate in sustaining erythropoiesis in patients receiving epoetin alfa. It may produce fewer adverse effects.

Administration, Oral↗
PubMed1992

Teaching family-centered perinatal care in family medicine, Part 2.

Pregnancy, childbirth, postpartum, and infant care are a continuum in the family life cycle for which the family physician is especially qualified to provide primary, comprehensive care. The purpose of this paper is to document and share the controversies, wisdom, and knowledge about caring for women and their families before, during, and after pregnancy. Family physicians can be leaders in developing an appropriate perinatal care system for the community. The level of care the family physician chooses to provide is discretionary. However, the family physician should be invested in ensuring that all families receive the greatest benefit from pregnancy, birth, and the newborn experience. Interest in perinatal care in family medicine is increasing, as reflected by the growing numbers participating in the Society of Teachers of Family Medicine Working Group on Family-Centered Perinatal Care. The authors of this article, who are active in this working group, hope that this information is useful in designing a balanced curriculum and delivery system for perinatal care in family medicine training programs.

Anesthesia, Obstetrical↗
PubMed1992

Properties of staircase procedures for estimating thresholds in automated perimetry.

The properties of the staircase procedure as applied in automated perimetry were examined. Two computer simulation models were used to vary different test- and patient-related parameters in clinical perimetry. One model was based on the KRAKEN computer simulation program; the other computer simulation was based on stimulus-response data sets from 11 normal subjects. The results were analyzed in terms of efficiency and accuracy. It was found that: (1) in general, there was an efficiency-accuracy trade-off; (2) increases in response fluctuation produced substantially greater errors in threshold estimates; (3) little or no improvements in accuracy were achieved by increasing the number of reversals; (4) the starting position of the staircase relative to the threshold influenced the efficiency of threshold determinations but not their accuracy; (5) a single-response error reduced the efficiency of staircases; (6) the position of a single-response error in a staircase sequence influenced the accuracy and efficiency of the threshold determination; and (7) more than one response error during a staircase sequence always resulted in a marked reduction in accuracy and/or efficiency. Current perimetric strategies appear to be at or near optimal levels, and therefore, strategies in the future may need to depart from a staircase-style procedure to achieve a significant increase in both accuracy and efficiency. Computer simulation studies can provide an effective means of evaluating perimetric test procedures and defining optimum strategies, which then can be verified clinically by subsequent testing in patient populations.

Adolescent↗
PubMed1992

Cost-effectiveness of epoetin alfa therapy for anemia of end-stage renal disease.

The cost-effectiveness of epoetin alfa therapy for anemia in 20 patients with end-stage renal disease was retrospectively studied. Ten patients on continuous ambulatory peritoneal dialysis (CAPD) were given subcutaneous epoetin alfa as part of a multicenter, protocol-controlled study of the efficacy of epoetin alfa. Ten patients on in-center hemodialysis were given intravenous epoetin alfa as part of their routine clinical care. Change in hematocrit was used as the measure of effectiveness of epoetin alfa. Medication, laboratory, and transfusion costs were monitored for the six months preceding the initiation of epoetin alfa and the first six months of treatment. The cost of therapy increased for all patients by an average of $2722 +/- 1118; transfusion costs decreased, whereas medication and laboratory costs increased. Laboratory costs were significantly greater in CAPD patients than in hemodialysis patients during epoetin alfa therapy; no significant differences in medication costs or transfusion costs were noted between the groups. The mean increase in hematocrit for all patients was 7.4 volume percent. Following the initial change in hematocrit, further therapeutic response did not appear to be determined by increasing expenditures. Epoetin alfa was shown to be effective in treating anemia in patients with end-stage renal disease, but it was associated with higher costs of therapy.

Adult↗
PubMed1991

Delay in the diagnosis of cutaneous malignant melanoma. A prospective study in 250 patients.

The extent and consequence of patient and professional delay in the diagnosis and treatment of 250 consecutive patients with primary cutaneous malignant melanoma was investigated. Mean total delay from the onset of observed change in a melanoma to appropriate therapy was 11.1 months. The major component of delay (9.8 months) was patient related. Seventy-nine (31.6%) patients waited more than 6 months before seeking medical attention. Few patients recognized early melanoma, and 46% responded only to late features (i.e., ulceration or bleeding). Inappropriate professional delay (misdiagnosis or observation without specific action) occurred in 30 consultations (12.4%) and resulted in a further 1.3-month mean delay in treatment. No correlation (r = 0.027) was found between delay in diagnosis and thickness of melanoma for the study population overall. A significant relationship (r = 0.2087; P less than 0.05) was found between longer lag time and advanced disease in 92 patients with nodular melanoma. Asymptomatic melanomas incidentally diagnosed during routine skin surveillance were significantly more favorable (mean depth, 0.89 mm) than symptomatic melanoma (1.76 mm; P less than 0.01). These data suggest that future public education campaigns should emphasize early signs of melanoma and that professional programs should stress routine skin surveillance and prompt referral of suspicious lesions for diagnostic biopsy.

Adolescent↗