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Biomedical subjects

L Klein

Publications and source records attributed to L Klein.

At least 145 records · Page 8Linked to original sources
PubMed1989

[Experimental studies of the precision of lamellar corneal sections].

Using an automatic rotating microkeratome for lamellar corneal grafting, 200 porcine corneal specimens were subjected to lamellar dissection. The aim of the study was to define the factors influencing the optimal thickness of the corneal lamella. The factors investigated were: the rotation speed of the trephine blade; the speed of blade advancement; the influence of lubrication fluids; intraocular pressure; geometry of the rotating blade. Ultrasound pachymetry was performed on non-fixed tissue in 13 defined positions. The optimal conditions for lamellar dissection with the rotating microkeratome were found to be a speed of 0.5 mm/s blade advancement, an intraocular pressure of 40 mmHg, lubrication of the cut area with a 0.05% Healon/BSS +/- solution. Under these conditions the thickness of the lenticule showed an inhomogenity of 2.5% total thickness, which was located in the direction of blade advancement and blade rotation speed.

Animals↗
PubMed1989

[Development of new fixing mechanisms and forms for the preparation of refractive corneal sections].

A method was developed for lathing corneal tissue without freezing. As a cutting instrument we used the rotating lamellar keratome, which was integrated in a mechanically adjustable microsurgical work bench. A set of refractive lathing forms was designed for a lenticule diameter of up to 9.5 mm. For fixation of the tissue, different kinds of suction holes were investigated. A mechanical fixation ring was not required, as the shearing force from the rotating blade does not loosen the lenticule even at a low suction setting. Different surface properties were compared. We found a rough surface to be the most suitable for retaining tissue. With our optimized molding form, the lenticule can be safely retained at a suction of 2.5 m H2O.

Animals↗
PubMed1989

[The brachial flap in reconstructive surgery].

Radical treatment of tumours in the region of the shoulder joint is a problem. For reconstruction we can use local shifts, microsurgical methods and free skin transplants, unless the surgical operation involves resection of the skeleton. Less frequently a brachial flap is used, calling for amputation of the upper extremity to use the soft tissues of the arm. In the described patient a radical approach to a tumour in the area of the left shoulder with the use of a total brachial flap was involved. The authors draw attention to the importance of the surgical decision to apply this mutilating operation where it is necessary to take into account the clinical finding, subjective complaints as well as possibilities of reconstructive surgery.

Adult↗
PubMed1989

The relationship of one abnormal glucose tolerance test value and pregnancy complications.

While an abnormal oral glucose tolerance test (GTT) is known to be associated with an increased risk of pregnancy complications, the impact of one abnormal value is not clear. In 1986 we screened 4618 pregnant women for gestational diabetes at 24-28 weeks' gestation. Eighty-seven percent had normal results; of the 13% with abnormal screening tests, 139 had one abnormal value on the subsequent 3-hour oral GTT. These women were then compared with 725 randomly selected patients with a normal screening test. The frequency of chronic hypertension, cesarean section, 5-minute Apgar score below 7, preterm delivery, shoulder dystocia, congenital malformations, and perinatal mortality did not differ significantly between the groups. The incidence of macrosomia (birth weight above 4000 g) was significantly greater in the study group (18.0%) than in the control group (6.6%) (odds ratio 2.18; 95% confidence interval 1.77-5.37), a relationship that persisted after controlling for confounding risk factors by logistic regression modeling (odds ratio 2.55; 95% confidence interval 1.44-4.52). The incidence of preeclampsia/eclampsia was significantly greater in the study group (7.9%) than in the control group (3.3%) (odds ratio 2.51; 95% confidence interval 1.14-5.52), which also persisted after controlling for confounding risk factors using logistic regression modeling (odds ratio 2.81; 95% confidence interval 1.26-6.28). Our results suggest that patients with one abnormal value on an oral GTT during pregnancy are at risk for delivering macrosomic infants and developing preeclampsia/eclampsia.

Adult↗
PubMed1988

The kinetics of generation of influenza-specific cytotoxic T-lymphocyte precursor cells.

A dramatic increase in the number of restimulatable (memory) cytolytic T-cell precursors (CTLps) has been demonstrated to occur 2 to 4 days postimmunization. By 4 or at the latest 6 days following in vivo priming, the frequency of restimulatable influenza-specific CTLps has reached that characteristic of a memory response. This indicates that the proliferative events which give rise to memory CTLps occur earlier than might have been expected and in fact are completed prior to the cessation of othe primary CTL response. Such information may have important significance to future immunomodulatory efforts aimed at perturbing the establishment of T-cell memory in vivo.

Animals↗
PubMed1988

Computerized telephone assessment of the "concrete" needs of chemotherapy outpatients: a feasibility study.

The feasibility of using a computer-automated telephone outreach system to routinely assess the needs of chemotherapy outpatients was evaluated. The automated intervention was designed as a cost-efficient strategy for assessing patients' needs on a periodic basis so that emerging needs could be identified in a timely way. Ninety-seven chemotherapy outpatients were surveyed at least once over the telephone by a computer in a high-quality, digitally stored voice asking 12 questions regarding the patients' "concrete" needs. Early results of this larger ongoing study, in which patients are scheduled to be called every 4 to 6 weeks for approximately four months, indicated that computer-automated surveys had broad-based acceptance among our outpatients and that patients were able to comply accurately with the survey's instructions. Furthermore, the speech recognition system was found to be reliable, and patients' response patterns to the automated surveys valid. Nonparticipation in this study (28.0%) was not substantially higher than in our previous research within this patient population and neither nonparticipation nor attrition appeared significantly attributable to the automation itself. This method offers the potential for cost-efficient, universal, and ongoing assessment of patient needs, facilitating timely intervention, and efficient use of professional staff.

Ambulatory Care↗
PubMed1988

Cardiopulmonary effects of restraint in dorsal recumbency on awake cattle.

The cardiopulmonary effects of dorsal recumbency were studied in awake cows restrained for surgical correction of left displaced abomasum. During the recumbent period, PaO2, PaCO2, arterial pH, and base excess values were significantly decreased. Heart rate, respiratory rate, blood hemoglobin concentrations, and rectal temperature increased significantly.

Abomasum↗
PubMed1988

Comparison of long bones and vertebrae in growing male rats: rate of growth, mineralization, and uptake of 3H-tetracycline at the organ level.

Two vertebral and two long bones of the growing male rat were separated as an intact anatomical unit (at the organ level) and analyzed for mass of dry weight, calcium, and collagen. The rate of growth (mass) and mineralization (uptake of 3H-tetracycline) was determined in rats from 3 to 36 weeks of age. Groups of rats age 3, 6, 8, 10, 14, 20, and 36 weeks were given a single dose of 3H-tetracycline 4 days before sacrifice. Whole bones were assayed for calcium, collagen, and 3H-tetracycline radioactivity. Growth of vertebrae and long bones is similar from 3 to 6 weeks of age. From age 6 to 20 weeks vertebrae grow at a faster rate than long bones. While long bones reach a peak dry mass at 20 weeks of age, the dry mass of vertebrae continues to increase. At ages 3 and 4 weeks, mineralization is significantly higher in vertebrae than in long bones. Peak calcification occurs at 8 weeks for long bones and at 10 weeks for vertebrae. These differences appear to be associated with the difference in age at which closing of growth plates occur as well as differences in formation rates between vertebrae and long bones.

Animals↗
PubMed1987

Anxiety and depression in a primary care clinic. Comparison of Diagnostic Interview Schedule, General Health Questionnaire, and practitioner assessments.

Over one half of all persons seen in a primary care clinic were identified as having anxiety or depressive disorder by the primary care provider, the General Health Questionnaire (GHQ), or the Diagnostic Interview Schedule (DIS). In only about 5% of all patients were findings positive on all three assessments concurrently. Both the GHQ and the practitioners identified over 30% of all patients as having a disorder, while about 8% had one or more of five DIS anxiety or depressive disorders (major depression, dysthymia, panic disorder, generalized anxiety disorder, or obsessive-compulsive disorder). Of the patients with DIS disorders 83% had positive GHQ scores, and 73% were identified by the practitioner as having a mental disorder.

Adolescent↗
PubMed1987

Coordinated teamwork in California industrial rehabilitation.

This article describes a case study of an industrially produced hand injury that exemplifies the coordination and teamwork involved in vocational rehabilitation in the California Workers' Compensation system. This patient required multiple tendon and nerve transplant operations done with microsurgical techniques, hand therapy for functional and sensory retraining, job analysis, vocational evaluation, labor market survey, work-hardening experience, and an on-the-job training program to effect a successful outcome. An overview of the current status of the California Workers' Compensation system and current insurance perspectives are discussed.

Accidents, Occupational↗
PubMed1987

Plasma and amniotic fluid prostacyclin and thromboxane in mild pregnancy-induced hypertension.

To study the involvement of 6 keto prostaglandin F1 alpha (6 keto PGF1 alpha) and thromboxane B2 (TxB2) in mild pregnancy-induced hypertension (PIH), we measured amniotic fluid and plasma concentration of these prostanoids by radioimmunoassay in PIH subjects and normotensive pregnant controls. The results suggest no difference in plasma or amniotic fluid 6 keto PGF1 alpha or plasma TxB2 in PIH and control subjects. The concentration of TxB2 (mean +/- SE) in amniotic fluid, however, were 189.5 +/- 27.7 for PIH and 107.4 +/- 9.7 for controls (P less than 0.05). This increase in vasoconstrictor TxB2 over vasodilator 6 keto PGF1 alpha may have implications in the hypertensive vascular response of mild PIH.

6-Ketoprostaglandin F1 alpha↗
PubMed1987

Abnormal glucose screening tests in pregnancy: a risk factor for fetal macrosomia.

Of 2276 patients who underwent screening for gestational diabetes mellitus, 1854 (81.5%) had normal glucose screening tests after a 50-g carbohydrate load (serum glucose below 135 mg/dL). Three hundred fifty-seven patients (15.7%) had abnormal glucose screening tests and went on to complete three-hour glucose tolerance tests, of whom 176 (48.7%) were shown to be nondiabetic when further tested using a carbohydrate-loaded, 100-g glucose, three-hour glucose tolerance test. The 176 women with abnormal glucose screens but normal glucose tolerance tests were compared with the 1854 who had normal screening values. The frequency of infants weighing more than 4000 g (greater than 95th percentile at our institution) was 11.9% in the study group and 6.4% in the control group (P = .0086). When the data were corrected for other macrosomia risk factors (advanced age, high parity, obesity, white race, and prolonged gestation), there was still a significantly higher frequency of macrosomia in the study group; this fact suggests that patients with minor abnormalities of carbohydrate metabolism during pregnancy are at risk for delivering a macrosomic infant.

Adult↗