Search PubMedSearch

Biomedical subjects

A Stark

Publications and source records attributed to A Stark.

At least 19 recordsLinked to original sources

Risk of congenital malformations associated with proximity to hazardous waste sites.

Concern about environmental pollutants has increased; however, it remains unclear whether chronic exposures to toxic chemicals in the environment occur at doses sufficient to produce adverse health effects in humans. To date, community studies have not adequately addressed this question. In this study, the authors linked two existing data bases of the New York State Department of Health to evaluate the relation between congenital malformations and residential proximity to hazardous waste sites in New York State. A total of 9,313 newborns with congenital malformations and 17,802 healthy controls living in proximity to 590 hazardous waste sites in 1983 and 1984 were evaluated. After the authors controlled for several possible confounding factors, results indicated that maternal proximity to hazardous waste sites may carry a small additional risk of bearing children with congenital malformations (odds ratio (OR) = 1.12, 95% confidence interval (Cl) 1.06-1.18). Higher malformation rates were associated with both a higher exposure risk (no exposure risk: OR = 1.00; low exposure risk: OR = 1.09, 95% Cl 1.04-1.15; high exposure risk: OR = 1.63, 95% Cl 1.34-1.99) and documentation of off-site chemical leaks (not exposed: OR = 1.00; exposed, but no leaks at site: OR = 1.08, 95% Cl 1.02-1.15; exposed, and leaks found at site: OR = 1.17, 95% Cl 1.08-1.27). The increased rates detected may be important in terms of their public health implications. Further research is necessary to strengthen causal inferences regarding the teratogenicity, of waste site exposure.

Adolescent

A prospective randomized study of the use of sliding hip screws and Ender nails for trochanteric fractures of the femur.

The functional outcome of trochanteric hip fractures was investigated prospectively in a group of 92 patients treated at random with either Ender nails or a sliding hip screw. Apart from clinical variables, the walking ability of the patients was assessed by gait analysis performed on an electronic walkway. No perioperative complications were noted. The patients in the Ender group had significantly less blood loss and a shorter operation time than the patients treated with the sliding hip screw, indicating that the former method is more gentle as a primary intervention. However, over time there were more reoperations in the Ender group and the functional outcome, including gait analysis after 6 months, showed more favourable results for fractures treated with the sliding hip screw. We therefore recommend the sliding hip screw for an optimal functional result.

Aged

Clinical features and walking ability in the early postoperative period after treatment of trochanteric hip fractures. Results with special reference to fracture type and surgical treatment.

The purpose of this study was to analyze the functional outcome during the early postoperative period (six weeks) in patients with trochanteric fractures. A consecutive series of 149 patients were randomized to treatment with either the DHS or Ender operative technique. 120 patients were available at review six weeks after surgery. Groups were comparable with respect to age (mean 77 years), sex ratio (73% women), type of fracture (59% and 55% unstable), experience level of the surgeon, prefracture health condition and ambulatory status. During follow-up eight patients died and there were 19 complications of neurologic and cardiovascular types equally spread among the two groups. All four infections were found in the DHS group. Orthopaedic hospital stay averaged 19 days and more patients in the Ender group could return to their previous home at time of discharge. At the six week visit 14% in the Ender group compared to 33% in the DHS group had not recovered functional walking distance (less than 15 m). All patients in the Ender group managed to walk, but 11% of the patients in the DHS group could not walk. Walking ability was most impaired for unstable fractures. It is concluded that the Ender technique will involve less operative trauma (shorter operations with less blood loss) and in the early postoperative period it can provide better conditions for walking and less need for further hospitalization than the DHS technique.

Aged

Functional restitution after lower leg fractures. A long-term follow-up.

Twenty-five patients with fractures of the lower leg treated by closed reduction and plaster fixation were examined an average of 7 years and 8 months after trauma. The end result was assessed according to the following: (1) The patient's own opinion; (2) clinical examination including comparing range of motion in knee and ankle in the fractured and non-fractured leg, leg length discrepancy, malrotation of the injured extremity and muscle force analysis; (3) radiological examination. All fractures had healed after a mean of 13.4 weeks. Twelve of the 25 patients had no complaints. Subjective and objective assessment of the end results were in good correlation. Only eight patients had remaining radiological displacement, in only one of which it was severe. The slight remaining malpositionings did not influence the final functional result. The muscle force analysis showed that fractures caused by high-energy trauma also brought permanent reduction of muscular strength to the fractured extremity.

Adolescent

Vertebral resection and fusion for paralytic kyphosis. 9 patients followed up for 6 (2-14) years.

Nine patients with a thoracolumbar, progressing, paralytic kyphosis, pressure sores from gibbus, an inability to lie on the back, and deterioration of the sitting balance were operated on with resection of two to three vertebrae and a thoracolumbar fusion. One child died from intracranial bleeding caused by a halo screw. There were no implant loosenings or non-unions. Pressure sores healed, sitting improved, and lying on the back became possible. A mild scoliosis above the fusion level developed in 2 patients, but neither of them needed any treatment.

Adolescent

The identification of occupational lung disease from hospital discharge data.

The Bureau of Labor Statistics-State Health Department Select Committee on Occupational Illnesses and Injuries conducted a study of hospital discharge records to determine their usefulness for identifying cases of occupational disease. Four states searched the diagnosis fields on computerized hospital discharge records for selected occupational lung diseases; pneumoconiosis, extrinsic allergic alveolitis, and respiratory conditions due to chemical fumes and vapors. The hospital discharge data identified more cases of pneumoconiosis than did the BLS data systems. Numerous cases of extrinsic allergic alveolitis and respiratory conditions due to chemical fumes and vapors were also identified. Patterns evidenced in the data were generally consistent with current knowledge of the diseases. The inclusion of industry and occupation on the hospital discharge record, further study of the quality of diagnosis coding, and the use of these data by additional states will enhance the usefulness of these data for occupational disease surveillance.

Alveolitis, Extrinsic Allergic

[Operative aspects of prosthesis change in the hip joint after fracture of the prosthesis shaft].

Between 1983 and 1988 revision arthroplasty was performed in 45 patients with broken femoral stems, an average of 11 years after primary total hip replacement. There were 25 men and 20 women, with an average age of 70 years at revision. The primary endoprostheses were all cemented and of the following types: Buchholz A1 (41) Charnley-Müller (2), Weber-Huggler (1), Charnley (1). In 8 cases the femoral stem only was changed, while in 37 both components had to be replaced. The posterior approach with the patient in the lateral position gave excellent exposure of both the acetabulum and the femur. This approach gave ready access to a dorsal window, through which the broken femoral stem could be removed with a punch. To achieve stability of the femur permitting immediate full weight-bearing, the femoral defect was always made good by a revision stem with at least twice the femoral diameter. In order to stabilize large acetabular defects a combination of homologous bone graft and an acetabular support ring was used. The implanted prostheses were of the revision type, cemented and individually selected in each case. It was possible to implant an adequate revision prosthesis in all cases. The following complications were noted during surgery: fracture of the femur (1) defects of the femur (5), and haemorrhages that were difficult to manage (2). It was necessary to reoperate in 2 patients, in 1 because of a stitched-up drain and in 1 because of postoperative haematoma. Postoperatively, 21 patients had cardiopulmonary complications, which were successfully treated in the intensive care unit in all cases but 1.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged

Human cytochrome P450IIA3: cDNA sequence, role of the enzyme in the metabolic activation of promutagens, comparison to nitrosamine activation by human cytochrome P450IIE1.

We report that, in a human cell line, human cytochrome P450IIA3 is capable of metabolizing aflatoxin B1, benzo[a]-pyrene, N-nitrosodimethylamine (NDMA) and N-nitrosodiethylamine (NDEA) to cytotoxic and mutagenic species. Cytochrome P450IIA3-mediated activation of NDMA and NDEA was compared with human cytochrome P450IIE1-mediated activation in the same cell system. P450IIE1 was more effective at activating NDMA than P450IIA3, while P450IIA3 was more effective at activating NDEA than P450IIE1. Whole cells and microsomal fractions obtained from control cells and from cells expressing the P450IIA3 cDNA were characterized for expression of P450IIA3. Microsomal coumarin 7-hydroxylase activity was some 40 times greater in the transfected cells than in the control cells and was catalyzed by a protein that was immunochemically related to the rat liver cytochrome P450IIA gene family. Immunoblot analysis demonstrated that this protein was readily detectable in transfected cells but barely detectable in control cells. We also report the DNA and deduced amino acid sequence of the P450IIA3 cDNA isolate used in this study. Our isolate encodes a protein 489 amino acids that is five amino acids shorter at the N terminus but otherwise identical to a previously reported human P450IIA3 cDNA sequence.

Aflatoxin B1

Postoperative improvement of walking capacity in patients with trochanteric hip fracture: a prospective analysis 3 and 6 months after surgery.

Between 1982-1985, 149 patients with trochanteric fractures were randomly selected for treatment with either Ender nails or a sliding nail plate. Ninety-two patients were able to perform walkway tests on an electronic walkway and were considered the best prospects for rehabilitation. Thirty-seven patients' fractures were stabilized with Ender nails and 55 with a sliding nail plate. Gait analyses were made at 3 and 6 months after surgery. Change in walking capacity based on four parameters (walking aids, walking distance, maximal vertical force, and single limb support) was compared to changes in clinical and radiographic parameters at 3 and 6 months after surgery. In all, less than half of the patients had achieved their preoperative status 3 months after surgery. Between 3 and 6 months postoperatively, 42 patients experienced less pain, 23 improved in range of hip motion, and 12 improved in strength. According to multivariate regression analysis, the significant factors associated with improvement in walking capacity during this period were an unstable fracture type (p = 0.003), improvement of hip strength (p = 0.006), and improvement of pain (p = 0.03). In conclusion, rehabilitation of patients with trochanteric fractures, particularly in those patients with unstable fractures, should be continued for more than 3 months after surgery.

Adult

The age of osteosarcoma patients is increasing. An epidemiological study of osteosarcoma in Sweden 1971 to 1984.

We conducted an epidemiological study of osteosarcoma in Sweden from 1971 to 1984 to investigate whether the typical features of the disease had changed. Of 294 osteosarcoma patients reviewed, 249 had primary skeletal tumours, and for these the mean annual incidence was 2.1 per million, without any clear trend over time. The mean male/female ratio for the period was 1.6 again with no consistent pattern over time; nor was there any significant change in the distribution of tumours according to location. The only feature which showed a significant change over the 14-year period was the mean age of the patients, being at its lowest (19 years) in 1972 and at its highest (40 years) in 1981. Excluding the 22 patients with craniofacial tumours, the remaining 227 also showed a significant increase in mean age. Analysis of the annual age distribution disclosed an increasing fraction of patients older than those in the classical age peak between 10 and 29 years. A large number of trials have shown improved survival in osteosarcoma over the last 15 years, which has been attributed mainly to adjuvant chemotherapy. The change we have observed in age distribution should also be taken into account in the evaluation of the results of treatment; it may be that older patients have a better prognosis.

Adolescent

Acute compartment syndrome in forearm fractures.

Sixteen patients were reexamined 2 to 5 years after surgical treatment of acute compartment syndrome in forearm fractures. High-energy trauma was the casual factor in 11 cases, in 5 of which there was an open fracture with skin defect. Fracture stabilization and fasciotomy of forearm and carpal compartments were performed as emergency procedures. The time for fracture healing averaged 8 weeks. Median nerve function was impaired in all the patients, and the ulnar nerve function in 8. The median nerve recovered completely in 15 patients, but ulnar nerve function was still impaired in 2 patients, 1 of whom had a nerve tissue defect. Eight patients could resume their occupation within a year.

Acute Disease

Improvement of platelet counts in steroid-unresponsive idiopathic immune thrombocytopenic purpura after short-course therapy with recombinant alpha 2b interferon.

In 13 patients with severe steroid-refractory idiopathic immune thrombocytopenia (ITP), a short course of recombinant alpha 2b interferon (IFN), given at a dose of 3 MU for 12 doses, caused a significant increase in platelet count in 11 patients. The rise in platelet count occurred following completion of the short course of IFN in 10 patients and occurred during therapy in one patient. Three patients showed an increase to normal platelet counts within 14 days of discontinuing the drug, eight showed a partial response, with a platelet count increase from 30 to 100 x 10(9)/L, and two patients showed minimal response. One complete responder relapsed at 5 months from initial response, and a further course of alpha 2b IFN caused a second prompt response with a rise of platelet count to supranormal levels. Short-course alpha 2b IFN can be recommended as a therapy for severe ITP. Responses are seen in splenectomized and nonsplenectomized subjects, and thrombocytopenia is not exacerbated during treatment.

Autoimmune Diseases

Surgical treatment of scaphoid nonunion. Review of the literature and recommendations for treatment.

The management of scaphoid pseudarthrosis is still controversial. The numerous methods that have been proposed can be roughly classified according to their aim - relief of pain or healing of bone. Following a review of the literature, and guided by personal experience with the Matti-Russe technique and McLaughlin internal fixation, the authors present recommendations for treatment according to clinical presentation of the condition.

Carpal Bones

Human osteogenic sarcoma: fine structural localization of adenosine triphosphatase.

The localization of ATPases in 7 osteogenic sarcomas of osteoblastic, chondroblastic and fibroblastic type was investigated at the fine structural level using two types of substrates: one with lead as capturing ion and one with strontium (the latter presumed to reveal sites of Na+-K+-dependent transport ATPase). Reaction product with the lead-ATP medium was located on the plasma membrane and the membranes bordering subjacent vesicles and vacuoles in all the various types of osteoblastlike and fibroblastlike cells and also in types 1 and 3 chondroblastlike cells, and multinucleated giant cells believed to be neoplastic. Furthermore, deposits of reaction product were demonstrated in lysosomelike organelles in all the aforementioned cells. Except in the case of chondroblastlike cells, precipitates marking the localization of enzyme were confined to areas of the plasma membrane where adjacent cells were closely applied (the free surface lacked precipitates). In chondroblastlike cells the reaction product was usually deposited along the whole plasma membrane. Presence of L-Homoarginine or L-Tetramisole in the incubation medium in concentrations that have been shown to completely abolish alkaline phosphatase activity did not affect the occurrence of the reaction product with ATP as substrate indicating that the enzyme hydrolysing ATP was substrate-specific. Reaction product marking sites of Na+-K+-dependent ATPase was confined to plasma membranes and lysosomes of cells in vessel walls. The observations strengthen the notion obtained in studies on the localization of alkaline phosphatase, namely that osteoblastlike, chondroblastlike, and fibroblastlike cells in osteogenic sarcomas are histogenetically related to one another and to those multinucleated giant cells that presumably are of a neoplastic nature.

Adenosine Triphosphatases

Bronchopulmonary dysplasia: possible relationship to pulmonary edema.

The pathogenesis of bronchopulmonary dysplasia is controversial. Oxygen toxicity, mechanical trauma to the lung secondary to respirator therapy, and congestive heart failure with a left to right shunt through a patent ductus arteriosus have all been implicated. Our data suggest that in addition to these three conditions, all of which are edemagenic, infants with bronchopulmonary dysplasia have a significantly greater mean fluid intake in the first five days of life when compared with infants with respiratory distress syndrome or patent ductus arteriosus alone. We suggest that the addition of a fluid load may potentiate the effects of other factors and increase the risk of bronchopulmonary dysplasia in infants with respiratory distress syndrome who require respiratory support.

Bronchial Diseases