Transcervical thymectomy for myasthenia gravis achieves results comparable to thymectomy by sternotomy

BACKGROUND: It remains controversial whether transcervical thymectomy offers results equivalent to thymectomy by way of a median sternotomy in the treatment of myasthenia gravis. Furthermore, preoperative prognostic factors have not been clearly defined. METHODS: This study is a retrospective chart review and interview of 78 patients completing transcervical thymectomy for myasthenia gravis between 1992 and 1999. RESULTS: There were 24 men and 54 women. Mean age was 40 years (range, 13 to 78 years). Twelve patients were in Osserman class 1, 25 in class 2, 30 in class 3, and 11 in class 4 (mean, 2.5). There was no perioperative mortality and 6 (7.7%) morbidities. Mean length of stay was 1.5 days and mean follow-up, 54.6 months. The crude cumulative complete remission (asymptomatic off medications for 6 months) rate was 39.7% (n = 31). Only 8 patients (10.3%) failed to improve after transcervical thymectomy. Kaplan-Meier estimates of complete remission were 31% and 43% at 2 and 5 years, respectively. Eight patients with thymoma had a 5-year estimated complete remission rate of 75% in contrast to 43% in 38 patients with thymic hyperplasia and 36% in 32 patients with neither thymoma nor hyperplasia (p = 0.01). Twelve patients with ocular myasthenia had a 5-year estimated complete remission rate of 57%, whereas patients with mild-to-moderate (n = 55) or severe (n = 11) generalized symptoms had 5-year complete remission rates of 43% and 30%, respectively (p = 0.21). CONCLUSIONS: Overall, extended transcervical thymectomy offers results that are comparable to those published for the transsternal procedure. Patients with milder disease (including isolated ocular disease) and taking no preoperative immunosuppressive agents appear to experience higher remission rates. In contrast to previous studies, we also find that small thymomas predict better responses to thymectomy.     

Radiochemical and biological characteristics of 99mTc-UBI 29-41 for imaging of bacterial infections

A technetium-99m-labeled peptide derived from ubiquicidine, further referred to as 99mTc-UBI 29-41, targets bacterial and fungal infections, but not sterile inflammatory processes, in experimental animals. This paper reports on the radiochemical and biological features of this radioactive agent and the importance of the amino acid sequence of UBI 29-41 for imaging of infections.Radiochemical analyses of 99mTc-UBI 29-41 and a radiolabeled scrambled version of this peptide, i.e. 99mTc-Sc-UBI 29-41, revealed that both peptides were labeled rapidly (within 10 min) and effectively with little colloid formation (less than 5% of the total radioactivity) and very little free pertechnetate (or radioactive intermediates) in the preparations containing radiolabeled peptide. Furthermore, association of the peptides with bacteria could be competed with excess unlabeled peptide and this association proved to be temperature-dependent. Based on this in vitro data we concluded that labeling of peptides with 99mTc by this direct method is rapid, efficient, and safe.Scintigraphy demonstrated that radioactivity is rapidly removed from the circulation (half-lifes of UBI 29-41 and Sc-UBI 29-41 were 16 and 21 min, respectively) mainly by renal clearance. Analysis of murine blood revealed that only a small proportion of the intravenously injected 99mTc-peptides is associated with blood cells. Although both radiolabeled peptides accumulated rapidly at sites of infection, the values for 99mTc-UBI 29-41 were higher (P < 0.05) than for 99mTc-Sc-UBI 29-41. Moreover, injection of excess unlabeled UBI 29-41, but not Sc-UBI 29-41, into Staphylococcus aureus-infected mice prior to injection of 99mTc-UBI 29-41 significantly (P < 0.05) reduced the accumulation of this radiopharmaceutical at the site of infection. In addition, we observed significantly (P < 0.01) higher amounts of 99mTc-UBI 29-41 at the site of infection in mice using a carrier-free radiolabeled UBI 29-41 as compared with unpurified preparations containing radiolabeled UBI 29-41. This in vivo data indicates that the amino acid sequence of 99mTc-UBI 29-41 contributes to its accumulation at the site of infection.     

Does frozen section have a role in the intraoperative management of thyroid nodules?

Background: Frozen section in thyroid surgery is used to make an intraoperative pathological diagnosis of malignancy in a thyroid nodule at the time of hemithyroidectomy. A positive diagnosis allows completion of thyroidectomy, thus avoiding reoperation. However, the use of fine needle aspiration cytology in making a preoperative diagnosis of cancer has resulted in the lack of a defined role for frozen section. We examined the role of frozen section as an adjunct to fine needle aspiration cytology in determining which cytological subset will benefit from frozen section. Methods: All patients who underwent thyroidectomy between 1992 and 2000 by a single endocrine surgeon were reviewed. Results: Two hundred and nine frozen sections were performed, of which 144 underwent preoperative fine needle aspiration cytology. Frozen sections reported 135 benign nodules, 59 follicular neoplasms, five specimens with suspicious histology and 10 cancers. Ten out of 20 thyroid cancers were correctly identified by frozen section (sensitivity: 50%; specificity: 100%), eight cancers were reported on frozen section as indeterminate and two benign. Of 144 fine needle aspiration cytological procedures, frozen section on seven suspicious aspirates identified two cancers, and frozen section on 70 follicular aspirates identified four cancers, allowing intraoperative conversions to total thyroidectomy. Frozen section on seven malignant aspirates confirmed four cancers but resulted in reoperation for three because of the indeterminate frozen section reports. There were no cancers found on 135 benign aspirates. Conclusions: Frozen section on benign aspirates is unhelpful in the management of thyroid nodules. It need not be performed for cytologically proven malignant thyroid nodules. Selective use of frozen section complements fine needle aspiration cytology findings of suspicious or follicular lesions, especially in the subset with papillary cancer, allowing one-stage total thyroidectomy.     

Local recurrence in head and neck cancer: relationship to radiation resistance and signal transduction.

PURPOSE: Locoregional recurrence is the dominant form of treatment failure in head and neck (H&N) cancer. The epidermal growth factor receptor (EGFR) is frequently amplified in this disease (相似文献   

Hyponatremia secondary to reset osmostat in a child with a central nervous system midline defect and a chromosomal abnormality

A newborn with a CNS midline defect and persistent hyponatremia was diagnosed with a "reset" osmostat using a 3% hypertonic saline test. The diagnosis was established by measuring urinary arginine vasopressin (UAVP) and plasma osmolality (P(Osmoil)). In this infant a chromosome abnormality with the karyotype 46, X, -X, +der(X) t(X;13) (p22.1;q22) was associated with the midline defect and a reset osmostat.     

Farnesyltransferase inhibitor effects on prostate tumor micro-environment and radiation survival

BACKGROUND: Ras activation by mutation, overexpression, or receptor signaling can increase tumor cell survival after irradiation. METHODS: We examined whether inhibiting Ras activity with farnesyltransferase inhibitors (FTI) altered the radiosensitivity and tumor micro-environment in prostate tumors. RESULTS: Treatment with FTIs L-744,832 or FTI-277 reduced clonogenic survival of prostate tumor cells expressing oncogenic H-ras after irradiation. PI3-kinase/Akt and MAPK signaling pathways were downregulated by FTIs in these cells. FTI treatment reduced tumor hypoxia and also reduced MMP-9 expression in tumors with activated mutant H-ras. FTI treatment did not, however, increase apoptosis in irradiated intestine, demonstrating that acute radiation injury of this normal tissue was not enhanced by FTIs. CONCLUSIONS: FTIs can enhance the killing of prostate tumors with activated H-Ras. Together with the absence of increased acute toxicity to normal bowel, these results imply that FTI treatment should be further studied as a possible adjuvant to radiotherapy in the treatment of abdominal cancers with activated Ras signaling.