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Biomedical subjects

A Schindler

Publications and source records attributed to A Schindler.

At least 55 records · Page 3Linked to original sources
PubMed1988

An oral zinc loading test in psoriasis.

Changes of zinc in body fluids were evaluated in 12 patients with extensive psoriasis and compared with those of 11 healthy volunteers, using an oral zinc loading test. Plasma zinc levels and urinary zinc excretion were measured by atomic absorption spectrophotometry. No significant difference was found between plasma zinc levels and urinary zinc excretion following an overnight fast. Both groups showed extensive increases in urinary zinc excretion following the loading test. The peak levels of plasma zinc were significantly lower in the psoriatic patients two and four hours after zinc ingestion (P less than .01 and P less than .02, respectively).

Administration, Oral↗
PubMed1985

The intracellular degradation of poly(epsilon-caprolactone).

Poly(epsilon-caprolactone) [PEC], a biodegradable aliphatic polyester, undergoes a two-stage degradation process: The first lengthy phase involves nonenzymatic hydrolytic cleavage of ester groups, the second phase beginning when the polymer is more highly crystalline, and of low molecular weight. The cellular events of the second phase were examined by implanting gelatin capsules containing 25 mg of low molecular weight (Mn 3000) PEC powders, 106 to 500 micron, in rats. PEC fragments ultimately were degraded in phagosomes of macrophages and giant cells, the process requiring less than 13 days for completion at some sites. PEC was also identified within fibroblasts. These studies support the intracellular degradation of PEC as the principal pathway of degradation once the molecular weight of the aged polymer is reduced to 3000 or less.

Animals↗
PubMed1982

Progesterone therapy in pregnancy induced hypertension therapeutic value and hormonal profile.

The study was carried on 25 primigravidae with severe pre-eclamptic toxaemia (PET) and 19 normal pregnancies as a control group. 15 cases of PET were treated by 600 mg. progesterone daily for variable duration between one and six weeks. Daily blood samples were assayed for progesterone, dihydroprogesterone, estriol, estradiol, placental lactogen and prolactin. Under progesterone therapy there was a significant decrease in both systolic and diastolic blood pressure, significant increase in urinary output, amelioration of the edema, slight reduction in weight gain, but no change in the proteinuria. Prolactin was the only hormone that showed significant rise in the group of PET when compared with normal pregnancy.

Adolescent↗
PubMed1981

Aliphatic polyesters II. The degradation of poly (DL-lactide), poly (epsilon-caprolactone), and their copolymers in vivo.

The mechanisms of biodegradation of poly (DL-lactide), poly (epsilon-caprolactone), and copolymers of epsilon-caprolactone with DL-dilactide, delta-valerolactone, and DL-epsilon-decalactone in rabbit were shown to be qualitatively similar. However, the rate of the first stage of the degradation process, non-enzymatic random hydrolytic chain scission, varied by an order of magnitude and was dependent on morphological as well as chemical effects. Weight loss was generally not observed until the molecular weight had decreased to 15,000 or less. Poly (DL-lactide) differed from the other polyesters studied, the rate of chain scission increasing after the commencement of weight loss. The rate of weight loss was greater and the period prior to weight loss was shorter when the comonomer content of copolymers of epsilon-caprolactone was sufficient to reduce the melting point of epsilon-caproate sequences to body temperature.

Animals↗
PubMed1981

Biodegradable drug delivery systems based on aliphatic polyesters: application to contraceptives and narcotic antagonists.

The classes of polymer which form the basis of different types of drug delivery systems are discussed, and the relationships between the chemical structure of the polymer and its permeability, morphology, biodegradability, and mechanical properties are considered, using polyesters as specific examples. Studies of the permeability and biodegradability of poly epsilon-caprolactone), poly(DL-lactic acid), and various copolymers are described and used to illustrate how these properties may be varied by the choice of polymer structure. An induction period prior to bioerosion of these polymers, coupled with high permeability, permits their use as reservoir devices (capsules) which exhibit constant, diffusion-controlled drug release rates and which erode after the drug is exhausted. The applications of this approach to the long term delivery (1 year) of levonorgestrel, a contraceptive agent, and the short term delivery (1-2 months) of naltrexone, a narcotic antagonist, are described.

Animals↗
PubMed1979

Sustained drug delivery systems. I. The permeability of poly(epsilon-caprolactone), poly(DL-lactic acid), and their copolymers.

The maximum steady state flux, diffusion coefficients, and solubilities of five contraceptive steroids in homopolymers and copolymers of epsilon-caprolactone and DL-lactic acid were determined. The permeabilities of polymers of epsilon-caprolactone were comparable to silicone rubber and, by inference, are suitable for the construction of drug delivery devices. Poly(DL-lactic acid) was 10(4) times less permeable, although its permeability was significantly enhanced by additives.

Delayed-Action Preparations↗
PubMed1979

Sustained drug delivery systems II: Factors affecting release rates from poly(epsilon-caprolactone) and related biodegradable polyesters.

The release rates of several steroids from films and capsules of homopolymers and copolymer of epsilon-caprolactone, DL-lactic acid, and glycolic acid were measured in vitro and in vivo for up to 200 days. Relatively constant release rates from capsules (reservoir devices) were observed only under certain conditions. Factors that influence the drug release kinetics were evaluated. Release from poly(epsilon-caprolactone) and poly(epsilon-caprolactone-co-DL-lactic acid) was diffusion controlled. Release from poly(DL-lactic acid-co-glycolic acid) was associated with polymer degradation. Release from poly(DL-lactic acid) was very slow when diffusion controlled.

Crystallization↗
PubMedDate not supplied

[Validity of operationalized psychodynamic diagnostics].

The paper describes results of "operationalized psychodynamic diagnostics" (OPD) with 54 adolescent and young adult drug addicts prior to outpatient family therapy. Focus of investigation is the prognostic and factorial validity of the OPD-system. Furthermore, relationships between conflicts and psychic structure are investigated. The use of the OPD-system allows a clinical description of the patient sample. Thus, adolescent drug addicts are characterized by autonomy versus dependence and self-esteem conflicts. A neurotic or sometimes borderline level is found on the structure axis. Low scores on the structure axis are significantly correlated with self-esteem conflicts. There is some evidence for the prognostic validity of the OPD I axis. However, prognostic validity of the structure and conflict axes require further research.

Adolescent↗
PubMedDate not supplied

Occult fracture of the calcaneus in toddlers.

Five children 14-33 months of age were treated for calcaneal fractures. All had a history of trauma with limping or refusal to walk. Physical examination could not localize the fracture. Initial radiographs were negative. There were no signs of systemic illness. They were treated with long-leg casts. Radiographs after 2 weeks revealed an arc of sclerosis across the tuberosity of the calcaneus. In no case was a bone scan instrumental in making the diagnosis. Awareness of calcaneal fractures in the child younger than 36 months can prevent the routine use of bone scans to make the diagnosis.

Calcaneus↗
PubMedDate not supplied

Estimation of the lumbar curve magnitude with correction of the right thoracic curve in idiopathic scoliosis.

A simple formula was proposed to estimate the magnitude of the postoperative uninstrumented lumbar curve with correction of the right thoracic curve in idiopathic scoliosis. This formula is as follows: PLC < or = LC - 0.5(TC - BTC) (PLC, predicted postoperative standing lumbar Cobb angle; LC, preoperative standing lumbar Cobb angle; TC, preoperative standing thoracic Cobb angle; BTC, preoperative supine lateral bending thoracic Cobb angle). Sixty-five patients' preoperative and postoperative radiographic measurements were taken, and of these 45 had measurements taken after > or = 12 months of follow-up. Multiple regression (R) value for the proposed formula postoperatively was 0.8048 and at > or = 1 year follow-up was 0.6869.

Adolescent↗
PubMedDate not supplied

Diagnostic and therapeutic arthroscopy of the hip in children and adolescents: evaluation of results.

Twenty-four arthroscopies of the hip performed at the Alfred I. duPont Institute, Wilmington, Delaware, in 21 patients between 1981 and 1991 were retrospectively studied. The average age of patients at the time of arthroscopy was 16 years (range, 11-21 years). The arthroscopies were diagnostic if the procedure was performed to visualize the hip or to perform a synovial biopsy and therapeutic if the procedure was performed to treat a suspected intra-articular abnormality. There were eight diagnostic arthroscopies and 16 therapeutic arthroscopies. The arthroscopy correlated with the presumptive causes of symptoms in 13 hips (54%) and failed to correlate in 11 hips (46%). Two patients had complications of transient pudendal nerve dysesthesia with full recovery. There were no infections or residual hip stiffness. A diagnostic arthroscopy is not helpful as a confirming diagnostic procedure. Arthroscopy of the hip is helpful in obtaining synovial biopsies and allows loose body removal, thus obviating the need for open surgery and intraoperative dislocation of the hip.

Adolescent↗
PubMedDate not supplied

Distal transfer of the greater trochanter revisited: long-term follow-up of nine hips.

Seven female patients (nine hip joints) with avascular necrosis and functional coxa vara secondary to developmental dysplasia of the hip joint (DDH) were treated by distal transfer of the greater trochanter (DTT). A 5-year follow-up showed good results in 89% of the hip joints. We reviewed the patients again 12 years later using the Mayo Clinic hip score. Improvement of gait was maintained in the majority of the patients (71%), but the hip score was low in 67% of the patients because of the development of osteoarthritis. Two patients underwent a total hip arthroplasty, and a third is awaiting this operation. Distal transfer of the trochanter is beneficial in improvement of gait but may enhance the development of osteoarthritis.

Adolescent↗
PubMedDate not supplied

Hemichondrodiastasis for the treatment of genu varum deformity associated with bone dysplasias.

Hemichondrodiastasis has been reported for treatment of angular deformities in children close to skeletal maturity. The use of distraction through the physis in younger children was not recommended. The authors report three children 3 to 7 years of age who underwent bilateral proximal tibial hemichondrodiastasis for correction of genu varum due to bone dysplasia. Ilizarov external fixators were applied in all cases. The patients underwent gradual angular correction at a rate of 0.5 mm/d. Distraction was continued until a normal mechanical axis was achieved. Normal alignment was achieved in two patients and slight overcorrection in the third. The patients were followed for 3 to 11 years, and no adverse affects on the physis were identified. This is the first report of physeal distraction in patients this young. Our results are good, and we believe that hemichondrodiastasis can be safely used for correction of angular deformities in young children.

Bone Diseases, Developmental↗
PubMedDate not supplied

[Hearing disability in relation to audiometric threshold values: hypothesis on the determination of the onset of hearing loss].

BACKGROUND: The term auditory disability (AD) means the presence of auditory symptoms due to hearing loss. Until now the audiometric threshold cut-off between the presence or absence of AD was not clear. OBJECTIVES: In this study we attempted to define the value of audiometric threshold that could be considered as the limit between the presence or absence of weakness of auditory function, considered as the threshold as the 95th percentile of subjects that did not report AD. METHODS: The study group consisted of 1641 males, 891 normally hearing and 750 affected by noise-induced hearing loss (NIHL) Each subject was submitted to a questionnaire specifically created in order to determine the presence of AD. RESULTS: Statistical analysis confirmed the reliability of answers to items. AD was present in 577 subjects, not all affected by NIHL. Audiometric threshold and age correlated significatively with the degree of AD. CONCLUSIONS: The results obtained allowed the audiometric threshold values to be determined at the 95th percentile of subjects who did not report AD, in relation to the average of frequencies normally used in hearing loss evaluation.

Adolescent↗