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Biomedical subjects

M Sohn

Publications and source records attributed to M Sohn.

At least 37 records · Page 2Linked to original sources
PubMed1995

Venous stenosis and occlusion in hemodialysis shunts: follow-up results of stent placement in 65 patients.

PURPOSE: To provide follow-up data on the use of self-expanding stents in hemodialysis fistulas to improve the technical success of balloon angioplasty. MATERIALS AND METHODS: Ninety-two self-expanding vascular stents were placed in 65 patients (29 men and 36 women 25-79 years of age; mean, 57.6 years) with failing hemodialysis fistulas or shunts. RESULTS: Stent placement was successful in all patients, but rethrombosis of the shunt occurred in six patients (10%) within 1 week. There were 96 episodes of reobstruction. In 87 cases, percutaneous or combined surgical and percutaneous repeat intervention was performed. The cumulative shunt function rate was 88% after 6 months, 86% after 1 year, and 77% after 2 years. CONCLUSION: Stent placement in hemodialysis fistulas helps treat lesions that cannot be adequately treated with percutaneous transluminal angioplasty (PTA) alone but has a follow-up patency rate similar to that of PTA. Standard central venous stents have a better patency rate than after PTA.

Adult↗
PubMed1995

Cross-specialty linkage and extrapolation of resource-based relative value scales.

This article describes methods used to produce a RBRVS (resource-based relative value scales), a common scale from two specialties (internal medicine and general surgery) and explains the newly developed extrapolation process within each specialty. To produce a common scale, we selected six 'same' services as linking services common to both specialties. Then we used the bi-weighted least squares method to locate all the same services on a single, common scale. By using the same method, we tried to extrapolate all the services within each specialty, not by the method of Kelly et al, dividing all the services within the specialty into families (small homogeneous groups of services) to apply charge-based ratios. To compare both methods, we extrapolated all the services of general surgery according to each method. With the correlation analysis to compare both results to American RVUs, we found that general surgery's RVUs from our own extrapolation method turned out to be more highly correlated with American RVUs than from Kelly's extrapolation method. Consequently, extrapolation with bi-weighted least squares method gave reasonable results.

General Surgery↗
PubMed1995

[Preoperative autologous blood donation and its effects on pulmonary lobectomy].

It was the aim of the underlying study to determine the value of preoperative autologous blood donation and its importance with regard to pulmonal lobectomies. Over the course of three years and a total number of 220 operations, autologous blood was preoperatively deposited in 74 cases. 21 patients did not meet the criteria for autologous blood donation and hence, were omitted from the study. It was found that only 5.4% of the patients who had donated autologous blood required a homologous blood transfusion versus 27.2% in the non-donor group. This would imply, that the necessity for homologous blood transfusion is reduced by approximately 80% in patients depositing autologous blood prior to surgery. Observing a similar haemoglobin in both groups at admission, it was found that autologous blood donors went into surgery with an hb 1.5 g/dl lower than non donors; the levels however adjusting themselves immediately postoperatively. No increased complication rate was found as a result of preoperative autologous blood donation. The data indicate that only 30% of patients undergoing pulmonal lobectomy require homologous blood transfusions. 80% of these patients could profit from preoperative autologous blood donation. For 70% of all patients the procedure would be of no benefit. Bearing in mind the immunosuppressive effect of homologous blood transfusions, which may result in a higher rate of tumor recurrence, we find preoperative autologous blood donation a justifiable procedure even under these circumstances. It would however be beneficial if studies were conducted hereby investigating to what extent similar results could be achieved by preoperative acute isovolemic hemodilution.

Blood Loss, Surgical↗
PubMed1994

[Differed autologous blood transfusion and its effects during pulmonary lobectomy].

The aim of our study was to determine the value of preoperative autologous blood donation and its importance with regard to pulmonary lobectomies. Over the course of three years and a total number of 220 operations, autologous blood was preoperatively deposited in 74 cases. 21 patients did not meet the criteria for autologous blood donation and were excluded from the study. It was found that only 6.8% of the patients who had donated autologous blood required a homologous blood transfusion versus 27.2% in the non-donor group. This would imply, that the necessity for homologous blood transfusion is reduced by approximately 75% in patients depositing autologous blood prior to surgery. While we observed similar haemoglobin levels in both groups at admission, it was found that autologous blood donors went into surgery with an Hb 1.5 g% lower than non donors; the levels however adjusted themselves immediately postoperatively. No increased complication rate was found as a result of preoperative autologous blood donation. The data indicate that only 30% of patients undergoing pulmonary lobectomy require homologous blood transfusions. 80% of these patients could benefit from preoperative autologous blood donation. For 70% of all patients the procedure would be of no benefit. Bearing in mind the immunosuppressive effect of homologous blood transfusions, which may result in a higher rate of tumor recurrence, we find preoperative autologous blood donation a justifiable procedure even under these circumstances. It would however be beneficial if studies were conducted to investigate to what extent similar results could be achieved by preoperative acute isovolemic hemodilution.

Blood Transfusion, Autologous↗
PubMed1994

[Therapy of primary testicular chondrosarcoma].

We describe the clinical course in a patient with a primary testicular chondrosarcoma. The way of metastasizing and cytogenetic analysis proved the germ cell origin of this tumour. After unilateral orchiectomy four cycles of chemotherapy with cisplatin, etoposide and bleomycin and one cycle of vinblastine, ifophosphamide and cisplatin were given. Even though the retroperitoneal metastases continued to grow, a radical retroperitoneal lymph node dissection was performed. Five years after surgery the patient is still in remission.

Adult↗
PubMed1994

[Immunoassays for determination of glycoprotein specificity, serum quantitation and determination of binding sites of granulocyte antibodies].

For the characterization of granulocyte antibodies an antigen capture assay and a method based upon quantitative determination of eluted IgG were developed. These assays allowed the quantitation of granulocyte antibodies in sera, the determination of their binding sites and their glycoprotein specificity, and the identification of NA-specific antibodies in sera containing mixtures of granulocyte antibodies.

Antibodies, Monoclonal↗
PubMed1993

Bone marrow immunoscintigraphy compared with conventional bone scintigraphy for the detection of bone metastases.

Immunoscintigraphy of haematopoetic bone marrow was compared to conventional bone scanning in 141 patients with malignant disease. Forty patients had breast cancer, 25 prostatic carcinoma, 14 kidney or bladder cancer, 13 bronchial carcinoma, 39 malignant lymphoma and 10 multiple myeloma. A total of 18,800 skeletal regions were evaluated. Marrow scans showed more metastatic lesions than bone scanning in all patient subgroups. Computerized tomography was concordant with bone marrow scintigraphy in 83.3% of 323 skeletal sites. Bone marrow scans in 30 control patients with fever of unknown origin were abnormal only in 3 patients and in only 7 out of 2,135 skeletal regions examined. In patients with malignant lymphoma, bone marrow histology or aspiration cytology was concordantly positive in 14 and concordantly negative in 17 patients. We conclude that immunoscintigraphy of haematopoetic bone marrow provides a reliable, sensitive and safe novel approach for non-invasive detection of metastatic spread to the skeleton.

Aged↗
PubMed1993

Current transition of the physician's professionalism and doctor-patient relationship.

In recent years, the physician's professionalism seemed to be facing or experiencing a phase of change. To investigate this phenomenon, social perception and attitude toward physicians were surveyed and analyzed. The subjects consisted of three types of sample group, namely, the general public, physicians, and medical students. Data were collected through interviews, mailing, and self-administered questionnaire surveys to each sample, respectively. The results of analysis showed us that social evaluation of physicians in Korean society exhibited ambivalent perceptions toward physicians. The physician's occupational status was generally evaluated by the three samples as being in a higher stratum in the social structure. But there were great gaps between their perceptions of the change in the physician's occupational status. While the general public perceived that the physician's status might improve in the future, physicians and medical students predicted an absolute declination of the status. Although the general public sympathized with the physician's characteristics as a professional group, an apparent tendency to assume the attitude of a fairly equal relationship toward physicians has increased. The transitional change in the physician's professionalism could be observed through the ubiquity in the perception of the patient's rights in doctor-patient relationships. Such phenomena are believed to have caused physicians to think that not only has their status declined in recent years but also that this declination of social status would continue in the future.

Attitude↗
PubMed1993

[Detection of bone involvement in malignant diseases by immunoscintigraphy of the bone marrow].

The results of immunoscintigraphy of haematopoetic bone marrow were compared with those of conventional bone scanning in 141 patients with malignant diseases. Marrow scans showed more metastatic lesions than bone scanning in all patient subgroups, resulting in a significantly more extended skeletal involvement. CT was concordant in 83.3% of 323 skeletal regions with bone marrow scanning. Bone marrow scans of 30 control patients with benign disease were abnormal only in 7 of 2135 skeletal regions in 3 patients. In malignant lymphoma, bone marrow histology or aspiration cytology was concordantly positive in 14 or negative in 17 patients. Immunoscintigraphy of haematopoetic bone marrow provides a reliable, sensitive and safe novel approach towards the non-invasive evaluation of metastatic spread to the skeleton.

Aged↗
PubMed1993

Intracavernosal kinetics of eicosanoids and endothelin during erection. Data from human and animal studies on intrapenile and systemic prostaglandins.

The release of mediator substances of the arachidonic acid cascade is closely related to the functional state of the endothelium. A significant lower prostacyclin/thromboxane A2 ratio in penile plasma of organogenic impotent patients in comparison to patients with psychogenic erectile dysfunction has been described in the literature. We observed the time-related liberation of prostacyclin, thromboxane A2 and the vasoactive peptide endothelin for 16 minutes of a drug-induced erection. We compared kinetics of patients with penile deviation and transsexualism, to patients suffering from severe organogenic impotence. We assessed the usefulness of the prostacyclin-to-thromboxane A2 ratio as a possible indicator of corporal degeneration. An animal model has been created to observe differences between rabbits under 100 days of standard diet alimentation, rabbits under cholesterol enriched diet and rabbits with hereditary hyperlipidemia type II A. Hyperlipidemia is suspected to be one possible factor causing organogenic impotence. Enzyme-immuno-assays were used for the determination of all substances. The systemic prostacyclin-to-thromboxane A2 ratio differed significantly between control rabbits and rabbits with hyperlipidemia. Prostacyclin, thromboxane A2 and endothelin in corpus cavernosum plasma showed a typical profile during spontaneous and drug-induced erection. A significant difference between groups of patients suffering from organogenic or psychogenic impotence could not be found. The value of the determination of the studied substances in differential diagnosis seems to be dubious.

Alprostadil↗
PubMed1992

Quantitation of granulocyte antibodies in sera and determination of their binding sites.

An enzyme immunoassay using eluates was developed for the quantitation of granulocyte antibodies in sera. Incubation of donor granulocytes with sera containing granulocyte alloantibodies (NA1, NA2, NB1, 5b, HLA) or autoantibodies resulted in a significantly higher amount of immunoglobulin G (IgG) per cell than did incubation with control sera. Ultracentrifugation of the sera prior to testing reduced unspecific binding of IgG to granulocytes. In eight of 10 assessed sera from patients with Felty's syndrome eluted IgG decreased from elevated to normal levels. Ultracentrifugation further allowed determination of the binding sites of granulocyte-reactive alloantibodies. Using sera containing NA1- and NA2-specific alloantibodies 173,000-188,000 binding sites on homozygous and 84,000-110,000 on heterozygous cells were determined. A similar number was found using a Fc gamma receptor III (FcRIII)-specific monoclonal antibody. Granulocytes from patients with paroxysmal nocturnal haemoglobinuria showed greatly reduced binding sites for NA-specific alloantibodies. The binding sites for the human alloantibody NB1 ranged from 36,000 to 318,000 and for the 5b alloantibody from 44,000 to 65,000. Mean values of 139,000 binding sites for HLA antigens and 27,000 binding sites for the FcRII were determined using monoclonal antibodies.

Autoantibodies↗
PubMed1992

Network analysis of Korean health insurance policy-making process.

This study examines how the decision-making process evolved in Korea during the initial phases of introduction and implementation of National Health Insurance. This study analyses the official documents and interviews views made with government officials and related personnel. We used the method of network analysis and multidimensional scaling in order to demonstrate how the major participants in the decision-making process developed and changed under the contemporary political situations. In the pre-implementation stage around 1976, major concerns were concentrated around the issues of financial support for social insurance, the fee schedule and who ought to be covered first. The total number of participants of the health or health-related organization was 61, which included the President, the Minister of Health and Social Affairs, representatives of special interest groups, etc. In the actual implementation period of 1982, different issues were brought up by the major participants. The number of participants in this period declined to 44 with the deletion of 19 and with the addition of two newly formed health insurance organizations. By 1988, as the implementation reached its final decision period, disagreements were centered on progressive premium rating and the administration of National Health Insurance. The number of participants increased to 60 after the addition of 16 participants. The analysis of this paper may provide some insight for other countries which wish to establish National Health Insurance; as reference to the policy-making process, it may provide some suggestions for when to initiate and how to formulate National Health Insurance policies.

Humans↗
PubMed1992

[Late pulmonary changes following bleomycin administration in computed tomography. Nodular fibrosis mimicking a seminoma metastasis].

This is a case report of a patient with multiple metastases to the lung due to a seminoma, treated with a chemotherapeutic regimen containing bleomycin. The typical subpleural fibrosis of the lung related to bleomycin damage disappeared 6 months after the start of chemotherapy. 4 weeks later, a solitary nodule at a prior unchanged site of the lung appeared, mimicking recurrent metastasis. Explorative thoracotomy revealed a nodular fibrosis of the lung, representing a late reaction of the lung to chemotherapy damage.

Adult↗
PubMed1991

[Angiography of the a. pudenda and its branches in erectile dysfunction. A modified angiographic technic and optimized use of vasodilator substances].

A new simplified technique for evaluating the internal pudendal artery and the penile vessels is described using a new catheter configuration with a very short 90 degrees-angled tip. In 30 consecutive patients, a superselective catheterisation of the internal pudendal artery was achieved in 93%. To improve visualisation of the penile arteries, the selective intraarterial application of 0.2 mg nitroglycerin in addition to the mandatory intracavernous injection of papaverin or prostaglandin E1 has proved to be of value. Examination of the blood blow velocity in the dorsal penile artery with Doppler ultrasound 2 minutes after intra-arterial application of 0.2 mg nitroclyerin showed a mean elevation of the Doppler amplitude by the factor 2.4 (range 0.4-9). With regard to the maximal increase of the blood velocity (range 1-6 minutes), a high interindividual difference was observed.

Arteries↗
PubMed1991

Induction of unilateral pulmonary fibrosis in the rat by cadmium chloride.

Intralobar instillation of cadmium chloride (CdCl2) into the left lungs of rats initiated a sequence of events that culminated in massive unilateral intraluminal fibrosis. Early events (days 1 and 2) after CdCl2 administration included infiltration of the treated lung with polymorphonuclear leukocytes, an increase in the number of alveolar macrophages, activation of the macrophages as assessed by the induction of cathepsin L mRNA, and the induction in liver of mRNA for the acute-phase response protein, alpha 1-acid glycoprotein. By days 5 to 7 in the treated lungs, mRNA for procollagen alpha 1(I) increased 20- to 60-fold, and mRNA for procollagen alpha 1(III) increased 4- to 14-fold. These increases were correlated with the almost complete filling of the alveolar spaces with fibroblasts and collagen. The contralateral lung exhibited no significant change in histology but showed a similar induction of collagen gene expression. These increases were tissue-specific, as the livers of these animals showed no change from the control levels of collagen gene expression. Procollagen messages in the treated and contralateral lungs were equally competent for translation into pro-alpha 1(I) and pro-alpha 2(I) polypeptides. Both the treated and contralateral lungs increased hydroxyproline content about 1.5- to 2-fold over 14 days. The contralateral lung, but not the treated lung, showed a 2-fold increase in lung volume. As a result, the collagen density (mg collagen/ml lung volume) doubled in the treated lung but remained constant in the contralateral lung. These data indicate that CdCl2 caused a rapid induction of pulmonary fibrosis in the treated lungs of rats and stimulated histologically normal growth of the contralateral lung.

Actins↗
PubMed1991

Disseminated Pneumocystis carinii infection with hepatic involvement in a patient with the acquired immune deficiency syndrome.

Extrapulmonary infection with Pneumocystis carinii (P. carinii) in AIDS patients is uncommon, and is often described only at postmortem examination. Although most antemortem cases involve spread to the bone marrow or spleen, P. carinii involvement of other organs has only recently been described. Despite the frequency of liver enzyme abnormalities in AIDS patients with a history of P. carinii pneumonia, P. carinii has been observed only rarely in the liver. We present a well-documented case of P. carinii involving the liver in an AIDS patient with P. carinii pneumonia and progressive liver enzyme abnormalities. We suggest that P. carinii infection should be considered in the differential diagnosis of AIDS-related liver disease.

Acquired Immunodeficiency Syndrome↗