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Biomedical subjects

G Genkins

Publications and source records attributed to G Genkins.

At least 19 recordsLinked to original sources
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

The prognostic significance of peripheral lymphocyte counts in patients with breast carcinoma.

A retrospective study evaluating five-year survival rates in relation to pretreatment lymphocyte counts was undertaken in 453 patients with breast carcinoma. Patients with early tumor stages had higher pretreatment lymphocyte counts than those with advanced tumors: five-year survival in patients with pretreatment counts above 2000 per mm3 was 87% in Stage I, 67% in Stage II, and 57% in Stage III, while the comparable figures in patients with lower counts were 82%, 51%, and 29%. The differences in five-year survival rates for Stage II and III were significant: z equals 1.6955, p equals 0.046 and z equals 1.8841, p equals 0.03. Similar differences were noted in the disease-free, five-year survival rates. The corresponding figures in the three tumor stages for patients with counts above 2000/mm3 were 80%, 63%, and 53%, while those for patients with lower counts were 74%, 44%, and 18%. The differences in Stage II and III were also statistically significant: z equals 1.8430, p equals 0.33 and z equals 2.592, p equals 0.005 respectively. The possibility that the presence of suppressant factors related to the thymus may influence levels of lymphocytes was evaluated. Comparison of pre-thymectomy and postthymectomy lymphocyte counts in a control group of patients who had thymectomy for myasthenia gravis revealed a gradual increase of lymphocytes following thymectomy. The increase was significant at the second year following thymectomy. These observations indicate that lymphocyte counts may serve as prognostic indicators in patients with breast cancer. Low lymphocyte counts may be related to the presence of suppressor substances.

Adult↗
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: early thymectomy. Electrophysiologic and pathologic correlations.

Indications for thymectomy in myasthenia gravis have been recently expanded to include all cases with extraocular symptoms as a result of the minimal morbidity and negligible mortality of the transcervical approach. As increasing numbers of patients with myasthenia gravis, covering the entire spectrum of generalized disease, have been added to the thymectomy population, a more accurate evaluation of the effects of the operation is possible. Our experience with 353 patients who have undergone thymectomy indicates that early thymectomy, particularly in patients who do not have germinal centers, is followed by early remission of the disease. Delayed remission after thymectomy is related to the duration and severity of the disease, and to presence of thymic germinal centers. Germinal centers were found more frequently in patients with long duration of the disease and in patients in whom the disease had progressed to respiratory involvement. Marked improvement in electromyographic findings immediately after thymectomy was observed in the majority of patients who had had the disease for 1 year of less and where germinal centers were absent. The percentage of malignant thymomas was higher in patients who underwent thymectomy 1 year or more after the onset of symptoms of myasthenia gravis. These data indicate the importance of early thymectomy while the disease is still in the mild stages. Transcervical thymectomy is the treatment of choice as it is followed by a higher percentage of remissions and by less morbidity than other forms of treatment.

Adolescent↗
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↗