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Biomedical subjects

P Kornfeld

Publications and source records attributed to P Kornfeld.

At least 19 recordsLinked to original sources
PubMed1992

Ten years experience with therapeutic apheresis in a community hospital.

A retrospective study was carried out on 2,500 therapeutic hemapheresis procedures performed at a community teaching hospital from 1980 to 1990. Seventy-six percent of the procedures consisted of plasmapheresis (PE). The most frequently treated conditions were myasthenia gravis (MG), Guillain-Barré syndrome (GB), hyperviscosity (HV), and thrombotic thrombocytopenia purpura (TTP). Therapeutic results and clinical implications for these four conditions are discussed.

Adult↗
PubMed1987

Clinical experience in more than 2000 patients with myasthenia gravis.

The vast strides in terms of pathophysiologic understanding which have been made in the past 25 years of research in myasthenia gravis are remarkable. This period of time has also seen the evolution of many applicable technological advances to better our care of these patients. Myasthenia's place in the autoimmune family of diseases has been demonstrated. No clear-cut strategy resulting from these discoveries has, however, been more than one of temporary relief or clinical improvement. In our center over these years the performance of early thymectomy in all cases of generalized myasthenia seems to be the one demonstrably reliable technique available. The effect of this procedure on coexisting neoplasia and other autoimmune disease suggests continuing avenues of investigation.

Adrenocorticotropic Hormone↗
PubMed1978

Thymomas in patients with myasthenia gravis.

The records of 141 patients with myasthenia gravis who had thymomas were reviewed. In this series there were 69 noninvasive tumors and 52 invasive tumors. The five year survival for all patients was 60%, with the invasive group demonstrating a poorer prognosis than the noninvasive. The remission rates for the whole group (both invasive and noninvasive) of myasthenics was quite low (7%). Although the overall survival of this series of patients was relatively high, it is felt that by earlier diagnosis and a more aggressive surgical approach their prognosis will be even better.

Adolescent↗
PubMed1978

Thymectomy in patients more than forty years of age with myasthenia gravis.

Until recently, thymectomy has been reserved for patients with myasthenia gravis in the younger age groups. The use of transcervical thymectomy, with its reduction in morbidity and mortality, has allowed us to study the effects of thymectomy in the older age group. The records of 525 patients who underwent thymectomy were reviewed and divided into two groups: those less than and those more than 40 years of age. The incidence of thymomas was greatest in the older than 40 year group. This age group without thymoma was also noted to have a high incidence of absent germinal centers. The postoperative remission rates as well as the electromyographic improvement rates were comparable for both age groups. The evidence presented indicates that thymectomy improves the clinical course of myasthenia gravis in all age groups studied. We recommend transcervical thymectomy for all patients with generalized myasthenia gravis, regardless of age.

Adult↗
PubMed1977

Thymus and breast cancer--plasma androgens, thymic pathology, and peripheral lymphocytes in myasthenia gravis.

Plasma androgen sulfates were measured in 92 patients with myasthenia gravis. Plasma androgen sulfates were strongly associated with thymic pathology. The presence of germinal centers was associated with decreased androgen levels. A weak but significant positive correlation existed between androgen sulfates and lymphocyte counts. Low lymphocyte counts in patients with germinal centers were associated with subnormal androgen concentrations. Plasma androgen sulfate levels decreased immediately after thymectomy, but overall no significant differences were found between prethymectomy and post thymectomy levels. A trend toward higher concentrations of plasma androgens was noted 5 or more years post thymectomy. Plasma androgen sulfate levels in myasthenia gravis patients with breast cancer were markedly depressed. The lowest androgen sulfate levels were observed in patients who had previous bilateral breast cancer and those who, subsequent to the determination of the steroid sulfates, developed a second primary lesion of the breast.

Adult↗
PubMed1976

Detection of anti-acetylcholine receptor factors in serum and thymus from patients with myasthenia gravis.

Since the blood and thymus of patients with myasthenia gravis may contain inhibitors of neuromuscular transmission that affect acetylcholine receptors of striated muscle, we used denervated rat muscle to test for inhibitors in 43 serums and 18 thymus glands from such patients. Seven per cent of serums inhibited the binding of 125l alpha-bungarotoxin to triton-solubilized receptors; 65 per cent interfered with binding of toxin-labeled receptors to concanavalin-A coupled to Sepharose gel, and 85 per cent formed IgG-receptor complexes detectable by immunoprecipitation. Serum inhibitory activity varied widely among patients with similar clinical manifestations and was not correlated with duration of myasthenia gravis or thymectomy. Among thymus extracts, 44 per cent were inhibitory in the concanavalin-A binding assay, whereas 72 per cent contained anti-receptor IgG. Thus, serums from patients with myasthenia gravis contain more than one anti-receptor factor.

Acetylcholine↗
PubMed1976

Electrophysiologic diagnosis of myasthenia gravis and the regional curare test.

Two hundred and fifty consecutive patients were evaluated for myasthenia gravis with repetitive supramaximal stimulation of peripheral nerves and regional curare administration when necessary. Among patients with definite generalized myasthenia gravis, 72 percent had abnormal responses to repetitive supramaximal stimulation alone and another 17 percent had abnormal responses after regional curare administration. Among those with possible generalized myasthenia gravis, 15 percent had abnormal responses to repetitive supramaximal stimulation and another 12 percent had abnormal responses after regional curare administration. Of those with only ocular symptoms, 46 percent had abnormal responses to repetitive supramaximal stimulation before or after regional curare administration, suggesting generalized involvement. Myasthenia gravis has not developed subsequently in any of the equivocal patients with negative electric tests. We have found these electric procedures to be simple, safe, and at least as effective as other methods in diagnosing myasthenia gravis.

Curare↗
PubMed1976

Electrophysiologic evaluations of thymectomy in myasthenia gravis. Preliminary findings.

Electric testing was performed in 106 myasthenia gravis patients before and after transcervical thymectomy. Twenty-nine were followed for 3 to 24 months. Results were correlated with thymic pathology, duration of disease, age at operation, and follow-up clinical status. Electric improvement was significantly greater in patients without thymic germinal centers or with only rare to occasional germinal centers, in patients operated on within 1 year after onset of symptoms, and in patients under age 30. Electric improvement immediately after thymectomy heralded later clinical improvement in those patients without germinal centers or with rare to occasional germinal centers. Electric-clinical correlations were excellent in patients with longer follow-up. Serial electric testing provides an objective evaluation of the patients' clinical status post-thymectomy.

Adult↗
PubMed1975

Regional curare test in evaluation of ocular myasthenia.

In 7 of 14 patients with clinically restricted ocular myasthenia gravis, the regional curare test showed latent peripheral involvement. The test consisted of the intravenous administration of 0.2 mg d-tubocurarine into an ischemic arm followed by repetitive supramaximal percutaneous electrical stimulation of the median or ulnar nerves. This produced a decrease in the amplitude of the initial evoked potential and a decrement of greater than 10% in the amplitude of the succeeding three to five potentials at rates of 3, 5, or 15 stimuli/sec. Three patients underwent transcervical thymectomy with subsequent improvement in both electrical and clinical findings. Evaluation of all patients with ocular myasthenia gravis should include regional curare testing of clinically uninvolved peripheral nerves. Thymectomy should be considered for patients with abnormal results.

Adult↗
PubMed1975

Studies in myasthenia gravis. Pyridostigmine-C14 metabolism after thymectomy.

Pyridostigmine-carbon 14 (P-C14) excretion studies in myasthenia gravis patients who had had thymectomies failed to produce any significant difference from results observed in myasthenic patients who had not had thymectomies. Thus, change in P-C14 metabolism cannot help explain decreased anticholinesterase requirements and electromyographic changes observed in some patients following thymectomy.

Adult↗
PubMed1975

Transcervical thymectomy in myasthenia gravis.

Since 1967, transcervical thymectomy has been the procedure of choice for all patients with nonthymomatous myasthenia gravis and a selected group of patients with thymomatous myasthenia gravis operated upon at the Mount Sinai Hospital. A total of 180 transcervical thymectomies have been performed. In 12 patients, a pre-existing tracheostomy was present. Morbidity was minimal, limited to three instances of bleeding, five of pneumothorax, one of self-limited chylothorax, and one wound infection. One postoperative death from an unrelated cause occurred in 1967. The postoperative course has been smoother and the management of the myasthenia gravis considerably easier than those following transthoracic approaches. Consequently, routine elective tracheostomy at the time of thymectomy has been abandoned. The average period of hospitalization does not exceed one week. As a result of the minimal risk involved, indications for thymectomy now include all patients with generalized myasthenia gravis, and the procedure is performed earlier in the course of disease. Postoperative electromyographic findings show immediate improvement in the majority of patients operated upon during the first year in which symptoms occur. Transcervical thymectomy arrests the progress of the disease, decreases the mortality rate, and has long term results equal to those of transthoracic approaches. Earlier remissions, fewer germinal centers, and a smaller number of thymomas were noted in patients operated upon early in the course of the disease. A decrease in neoplasms outside the thymus gland and in neonatal myasthenia gravis was also noted following thymectomy.

Breast Neoplasms↗
PubMed1975

The association of carcinoembryonic antigen and peripheral lymphocytes.

A significant association between carcinoembryonic antigen (CEA) assay titers and peripheral lymphocyte counts was observed in 148 simultaneous determinations. The association was present in a high cancer risk study group of patients with myasthenia gravis and in a control group of patients with granulomatous disease of the bowel, ulcerative colitis, and colonic neoplasms. A highly significant difference in the percentage of positive CEA assays in relation to lymphocyte counts was noted both in the study and control groups. In the study group CEA was positive in seven of 41 patients (17 percent) with counts above 2,000 per cubic millimeter, and in 26 of 56 (43 percent) of those with lower counts (X2 = 9.06, p smaller than 0.005). The corresponding percentages in the control group were 20 and 61 percent (X2 = 5.60, p smaller than 0.025). A significant difference between the means of lymphocytes in groups with different CEA titers also was found (F = 6.77, p smaller than 0.05). The finding of lower peripheral lymphocytes and/or higher titers of CEA in groups with increased risk of cancer, i.e., severe myasthenia gravis, patients with thymomas and patients with long history of granulomatous disease of the bowel, suggests on association between the results of the two tests and cancer risk. The observations indicate that the yield of CEA assay in cancer detection may be higher in patients with lwo lymphocytes, and that these determinations used in conjunction may serve better as diagnostic and prognostic aids in patients with known neoplasms or in high cancer risk groups.

Adolescent↗