A prospective cross-sectional study on hypocalcemia after total thyroidectomy in patients with Graves' disease: insights on secondary hyperparathyroidism.

PURPOSE: To investigate the parathyroid function and calcium (Ca) levels in the secondary hyperparathyroidism (SHPT) state in patients with Graves' disease. METHODS: We examined 31 consecutive patients with Graves' disease without chronic kidney disease, who were treated with total thyroidectomy. The patients were divided into a normal parathyroid hormone (PTH) group (NPTH group; n = 19) with a PTH level ≤ 65 pg/mL, and a secondary hyperparathyroidism group (SHPT group; n = 12), with a PTH level > 65 pg/mL. The PTH and Ca-related parameters were examined and the risk factors for postoperative hypocalcemia were analyzed. RESULTS: The preoperative Ca level was significantly lower (2.24 ± 0.06 vs. 2.31 ± 0.07 mmol/L, p < 0.05) in the SHPT group than in the NPTH group. The reduction in PTH, 1,25-dihydroxyvitamin D (1,25(OH)2D), and Ca levels from the preoperative day to the next morning was significantly greater in the SHPT group than in the NPTH group (p < 0.05). When intraoperative factors were included, the decrease in the PTH level alone was significant. SHPT was a significant factor in determining the extent of PTH reduction. CONCLUSIONS: Hyperfunctioning parathyroid glands in the SHPT state were more susceptible to postoperative PTH reduction, which, combined with low preoperative Ca levels, increased the risk of postoperative hypocalcemia in patients with Graves' disease.

Development and evaluation of an original phantom model of ultrasonography-guided thyroid gland biopsy for the training of surgical residents and students.

PURPOSES: Fine-needle aspiration cytology (FNAC) is a specific and important test used for the diagnosis of thyroid gland cancer. We developed a thyroid gland phantom using original manufacturing techniques and direct three-dimensional (3D) printing. The aim of this study was to confirm the effectiveness of this phantom by collecting data to evaluate puncture training. METHODS: Data from 45 ultrasonography-guided thyroid nodule FNAC procedures performed on our thyroid phantom were evaluated in our department. The first group comprised qualified physicians who specialized in thyroid gland treatment (group A; n = 10). The second and third groups comprised senior and junior residents (group B; n = 8 and group C; n = 12; respectively). The fourth group comprised students (group D; n = 15). We measured the times taken by these groups to complete each task. RESULTS: The skills of all participants in groups B, C, and D improved after using this phantom involving the major (parallel)- (0.47 ± 0.07) and short (orthogonal)-axes (0.52 ± 0.07) methods (P < 0.001). The number of erroneous punctures decreased from 53 to 3. CONCLUSIONS: Our original phantom improved the puncture skills of students and junior doctors and was suitable as a tailored training model for practicing thyroid gland transfixion.

Usefulness of preoperative ice cream consumption and novel postoperative drainage management in patients undergoing left-sided neck dissection for thyroid cancer: a nonrandomized prospective study.

PURPOSE: This study investigated the effects of ice cream consumption on chyle leakage after left lateral neck dissection in patients with thyroid cancer. METHODS: A total of 491 patients with thyroid cancer underwent left lateral neck dissection with identification of the thoracic duct following ice cream consumption. Before closing the wound, the anesthesiologist increased the intrathoracic pressure to observe chyle leakage. If chyle leakage occurred postoperatively, the drain was removed using the drain negative pressure release test. RESULTS: Postoperative chyle leakage was observed in 18 of the 491 patients who underwent left lateral neck dissection. We treated 17 patients conservatively and 1 patient surgically. Drains were removed within five days in all patients. After the drain negative pressure release test had been performed in eight patients, the drainage volume significantly decreased from an average of 175 ml to 31 ml per day. The average number of days until the removal of the drainage tube was 3.2 days. No perioperative complications were associated with ice cream consumption. CONCLUSIONS: In left lateral neck dissection for thyroid cancer, performing surgery following ice cream consumption does not completely prevent chyle leakage; however, early drain removal is possible because there is only mild leakage.

Position paper from the Japan Thyroid Association task force on the management of low-risk papillary thyroid microcarcinoma (T1aN0M0) in adults.

The incidence of thyroid carcinoma has been increasing worldwide. This is interpreted as an increase in the incidental detection of papillary thyroid microcarcinomas (PTMCs). However, mortality has not changed, suggesting overdiagnosis and overtreatment. Prospective clinical trials of active surveillance for low-risk PTMC (T1aN0M0) have been conducted in two Japanese institutions since the 1990s. Based on the favorable outcomes of these trials, active surveillance has been gradually adopted worldwide. A task force on the management of PTMC in adults organized by the Japan Thyroid Association therefore conducted a systematic review and has produced the present position paper based on the scientific evidence concerning active surveillance. This paper indicates evidence for the increased incidence of PTMC, favorable surgical outcomes for low-risk PTMC, recommended criteria for diagnosis using fine needle aspiration cytology, and evaluation of lymph node metastasis (LNM), extrathyroidal extension (ETE) and distant metastasis. Active surveillance has also been reported with a low incidence of disease progression and no subsequent recurrence or adverse events on survival if conversion surgery was performed at a slightly advanced stage. Active surveillance is a safe and valid strategy for PTMC, because it might preserve physical quality of life and reduce 10-year medical costs. However, some points should be noted when performing active surveillance. Immediate surgery is needed for PTMC showing high-risk features, such as clinical LNM, ETE or distant metastasis. Active surveillance should be performed under an appropriate medical team and should be continued for life.

Significant role of 1,25-dihydroxyvitamin D on serum calcium levels after total thyroidectomy: a prospective cohort study.

Introduction: Although active vitamin D (VD) has been used both preoperatively and postoperatively to prevent hypocalcemia risk in patients undergoing total thyroidectomy, the role of 1,25-dihydroxyvitamin D (1,25(OH)2D) has not been examined. This study comprehensively investigated the effects of 1,25(OH)2D on calcium (Ca) concentrations after total thyroidectomy. Methods: Serum Ca, parathyroid hormone (PTH), and 1,25(OH)2D levels were measured in 82 patients with thyroid disease before and after surgery. Results: Serum Ca, PTH, and 1,25(OH)2D levels decreased significantly on the morning of the first postoperative day. Notably, the decrease in 1,25(OH)2D concentration was significantly lower than that of PTH concentration (10.5 ± 33.4% vs. 52.1 ± 30.1%, p<0.0001), with 28% of patients showing increases in 1,25(OH)2D. The only factor predicting a postoperative 1,25(OH)2D decrease was a high preoperative 1,25(OH)2D concentration. Postoperative 1,25(OH)2D concentrations, as well as the magnitude and rate of decrease from preoperative levels, showed strong positive correlations with preoperative 1,25(OH)2D concentrations (p<0.0001 for all three variables) but not with PTH concentrations. These findings suggest that 1,25(OH)2D concentrations after thyroidectomy were more strongly dependent on preoperative concentrations than on the effect of PTH decrease and were relatively preserved, possibly preventing sudden severe postoperative hypocalcemia. A high 1,25(OH)2D level was the most important preoperative factor for hypocalcemia (<2 mmol/L; p<0.05) on the first postoperative day; however, only PTH decrease was statistically significant (p<0.001) when intraoperative factors were added. In the PTH >10 pg/mL group, the decrease in 1,25(OH)2D levels was significantly associated with postoperative hypocalcemia (p<0.05). Similarly, in the PTH levels >15 pg/mL group, a decrease in 1,25(OH)2D concentration was a significant factor, and the amount of PTH decrease was no longer significant. Conclusion: 1,25(OH)2D plays an important role in preventing sudden, severe hypocalcemia due to decreased PTH levels after total thyroidectomy, whereas high preoperative 1,25(OH)2D levels are a significant risk factor for postoperative hypocalcemia. Optimizing preoperative protocols to adjust Ca, PTH, and 1,25(OH)2D levels to improve the management of patients undergoing total thyroidectomy and to prevent extreme intraoperative PTH decreases may reduce the risk of hypocalcemia.

Intraoperative parathyroid hormone measurement pitfalls: parathyroid hormone spikes with carboxyl-terminal parathyroid hormone fragments in primary hyperparathyroidism-a case report.

BACKGROUND: Intraoperative parathyroid hormone (IOPTH) monitoring is a critical surgical adjunct for determining the extent of surgery for primary hyperparathyroidism (PHPT), with reported false-positive and false-negative rates of up to 10%. Surgeons must understand the parathyroid hormone (PTH) dynamics and select the appropriate IOPTH protocol and interpretation criteria for curative surgery. CASE PRESENTATION: We present the case of a 64-year-old woman with a large cystic parathyroid tumor and PHPT who experienced a significant delay in IOPTH decrease but was cured without additional surgery. The patient's basal intact PTH was 96.2 pg/mL, which decreased to 93.3 pg/mL at 25 min and 72.4 pg/mL at 55 min after removal of the parathyroid tumor. In an attempt to elucidate its pathophysiology, 1-84 PTH levels were measured in stored serum. These results can also be attributed to the relatively low basal PTH levels, intact PTH spike, and high ratio of large carboxyl-terminal PTH fragments present. The patient had normal intact PTH and calcium levels at the 9-month postoperative visit. CONCLUSIONS: As detailed reports on these phenomena are scarce, we discuss the causes of false-negative IOPTH results in terms of PTH production, secretion, metabolism, and differences in measurement methods to avoid unnecessary surgery.

Interferon regulatory factor-4 activates IL-2 and IL-4 promoters in cooperation with c-Rel.

Interferon regulatory factor (IRF)-4 is a member of the IRF transcription factor family, whose expression is primarily restricted to lymphoid and myeloid cells. In T-cells, IRF-4 expression is induced by T-cell receptor (TCR) cross-linking or treatment with phorbol-12-myristate-13-acetate (PMA)/Ionomycin, and IRF-4 is thought to be a critical factor for various functions of T-cells. To elucidate the IRF-4 functions in human adult T-cell leukemia virus type 1 (HTLV-1)-infected T-cells, which constitutively express IRF-4, we isolated IRF-4-binding proteins from T-cells, using a tandem affinity purification (TAP)-mass spectrometry strategy. Fourteen proteins were identified in the IRF-4-binding complex, including endogenous IRF-4 and the nuclear factor-kappaB (NF-κB) family member, c-Rel. The specific association of IRF-4 with c-Rel was confirmed by immunoprecipitation experiments, and IRF-4 was shown to enhance the c-Rel-dependent binding and activation of the interleukin-4 (IL-4) promoter region. We also demonstrated that IL-2 production was also enhanced by exogenously-expressed IRF-4 and c-Rel in the presence of P/I, in T-cells, and that the optimal IL-2 and IL-4 productions in vivo was IRF-4-dependent using IRF-4-/- mice. These data provide molecular evidence to support the clinical observation that elevated expression of c-Rel and IRF-4 is associated with the prognosis in adult T-cell leukemia/lymphoma (ATLL) patients, and present possible targets for future gene therapy.

Additional Tissue Sampling Trials Did Not Change Our Thyroid Practice.

This study aimed to determine whether additional tissue sampling of encapsulated thyroid nodules would increase the frequency of follicular thyroid carcinoma (FTC) diagnoses. We examined thyroid tissue specimens from 86 patients suspected of FTC (84.9% female; mean age, 49.0 ± 17.8 years). The number of tissue blocks created for pathological assessments ranged from 3 to 20 (mean, 9.1 ± 4.1); the numbers in the previous method recommended by the Japanese General Rules for the Description of Thyroid Cancer and additional blocks ranged from 1 to 12 (mean, 6.0 ± 2.8) and from 1 to 8 (mean, 3.1 ± 2.0), respectively. The additional blocks were subsequently examined to determine whether any diagnoses changed from those based on the previous method. Five patients were diagnosed with FTC using the previous method; however, additional tissue blocks led to the diagnosis of FTC in 6 patients, as 1 diagnosis was revised from follicular adenoma to FTC. It has been reported that increasing the number of tissue blocks used for pathological assessments can increase the frequency of FTC diagnoses; however, this was not clinically significant in thyroid carcinoma, which requires completion thyroidectomy and radioactive iodine treatment. It resulted in no benefits to the patient because all minimally invasive FTCs, follicular tumors of uncertain malignant potential (FT-UMP), and follicular adenomas are treated with lobectomy alone in Japan. Additional tissue sampling only had a slight impact on our thyroid practice; therefore, we decided to cease it.

Indications and Strategy for Active Surveillance of Adult Low-Risk Papillary Thyroid Microcarcinoma: Consensus Statements from the Japan Association of Endocrine Surgery Task Force on Management for Papillary Thyroid Microcarcinoma.

Background: The question of how to manage patients with low-risk papillary thyroid microcarcinoma (PTMC; T1aN0M0) has recently become an important clinical issue. Two Japanese centers have conducted prospective clinical trials of active surveillance (AS) for low-risk PTMC since the 1990s, reporting favorable outcomes. This policy has thus seen gradual adoption worldwide to avoid overtreatment. Not all PTMCs are suitable for AS, however, and many physicians still hesitate to apply the management policy in daily clinical practice. A task force on management for PTMC created by the Japan Association of Endocrine Surgery collected and analyzed bibliographic evidence and has produced the present consensus statements regarding indications and concrete strategies for AS to facilitate the management of adult patients diagnosed with low-risk PTMC. Summary: These statements provide indications for AS in adult patients with T1aN0M0 low-risk PTMC. PTMCs with clinical lymph node metastasis, distant metastasis, recurrent laryngeal nerve (RLN) paralysis due to carcinoma invasion, or protrusion into the tracheal lumen warrant immediate surgery. Tumors suspected of aggressive subtypes on cytology are recommended for immediate surgery. Immediate surgery is also recommended for tumors adherent to the trachea or located along the course of the RLN. Practical strategies include diagnosis, decision-making, follow-up, and monitoring related to the implementation of AS. The rate of low-risk PTMC progression is lower in older patients. However, we recommend continuing AS as long as circumstances permit. Future tasks in optimizing management for low-risk PTMC are also described, including molecular markers and patient-reported outcomes. Conclusions: An appropriate multidisciplinary team is necessary to accurately evaluate primary tumors and lymph nodes at the beginning of and during AS, and to adequately reach a shared-decision with individual patients. If appropriately applied, AS of low-risk PTMC is a safe management strategy offering favorable outcomes and preserves quality of life at low cost.

[A case of cardiac tamponade induced by gastric cancer responding to S-1].

A 56-year-old man was admitted to our hospital for gastric cancer. He had dyspnea before admission. Chest CT scan showed massive pericardial and pleural effusion. He was treated by cardiac drainage, and cytology of the effusion showed class V. We injected mitomycin C 10 mg into the pericardiac cavity, and also administered S-1 100 mg per day. His dyspnea improved and he was discharged. Afterward the dyspnea re-appeared, and he died 9 months after the diagnosis. We report this rare case of cardiac tamponade induced by gastric cancer responding to S-1 with a review of the literature.

Comparative study of anastomosis in pancreaticogastrostomy and pancreaticojejunostomy after pancreaticoduodenectomy.

BACKGROUND/AIMS: The relative advantages of pancreaticojejunostomy and pancreaticogastrostomy after pancreaticoduodenectomy remain to be established. To clarify differences between the two procedures, we examined 66 patients who underwent PD and compared clinical and histological parameters, surgical records and patient outcomes. METHODOLOGY: In this retrospective study, subjects were divided into a pancreaticojejunostomy group (n=48) and a pancreaticogastrostomy group (n=18). Pancreaticogastrostomy and pancreaticojejunostomy were performed using invagination technique and end-to-side anastomosis, respectively. RESULTS: There were no significant differences in patient demographics and surgical records between the two groups. Increases in serum amylase concentrations after operation were significantly greater in the pancreaticogastrostomy group (902 +/- 915 IU/L) than in the pancreaticojejunostomy group (326 +/- 761 IU/L) (p = 0.025). However, there were no significant differences in other postoperative laboratory data or complications between the two groups. CONCLUSIONS: In our study, the clinical and safety data associated with pancreaticojejunostomy and pancreaticogastrostomy procedures for anastomosis after pancreaticoduodenectomy were almost similar. Therefore, the anastomotic procedure used should depend on the surgeon's choice or the distance between the remnant stomach and pancreas.

Advantages of thoracoabdominal approach by oblique incision for right-side hepatectomy.

BACKGROUND/AIMS: Thoracoabdominal approach might be safe and facilitate hepatic resection for tumors located in the right lobe. To evaluate the clinical usefulness of the thoracoabdominal approach using oblique incision for the right-side hepatectomy, we compared the perioperative data with those of the abdominal approach. METHODOLOGY: The oblique incision for the thoracoabdominal approach was placed along the intercostal space (Oblique group, n=13). The J-shape incision for abdominal approach consisted of an upper median incision and transverse incision (J-shape group, n=13). RESULTS: Patient demographics were similar in the two groups. Operation time was significantly shorter in the oblique group (292 +/- 122 min) than in the J-shape group (450 +/- 137 min, p < 0.01). The difference was noted regardless of the extent of hepatic resection. Clamping time and blood loss were similar in the two groups. The postoperative period of use of analgesia tended to be shorter in the oblique group (9 +/- 3 days) than in the J-shape group (15 +/- 11 days) but not significant (p = 0.08). Postoperative liver function tests, complications and clinical outcome were not significantly different between the two groups. CONCLUSIONS: Thoracoabdominal approach using oblique incision was useful for resection of liver tumors located in the hepatic dome and posterior segment.

Thoracoscopy-assisted radiofrequency ablation liver cancer. Report of three cases.

To achieve complete ablation of liver cancer in the hepatic dome, thoracoscopy-assisted radiofrequency ablation was attempted in three patients. Under general anesthesia and left lateral position, a thoracoport site was placed in the 6th intercostal space and a small thoracotomy was placed in the 7th intercostal space. In all three cases, the liver cancer was located in the hepatic dome of segment 7/8 and the tumor could not be fully observed on the lung echogram. In Case 1, saline was infused into the thoracic cavity under thoracoscopic observation and percutaneous ablation was safely performed. In Cases 2 and 3, the right diaphragm was opened, guided by ultrasonography, and the electrode was inserted into this working space via the thoracotomy site. At day 7, complete ablation was confirmed by computed tomography. All patients recovered and were discharged after a short hospital stay without severe complications. Tumor recurrence has not been observed in any patient at this stage. For liver cancer located in the right subphrenic dome of the liver, thoracoscopy-assisted ablation is a safe and useful option particularly in patients with poor hepatic function.

Development of a Tailored Thyroid Gland Phantom for Fine-Needle Aspiration Cytology by Three-Dimensional Printing.

BACKGROUND: Fine-needle aspiration cytology (FNAC) is a challenging and risky procedure for inexperienced clinicians to perform because of the proximity of the thyroid to the jugular veins, carotid arteries, and trachea. A phantom model for transfixion practice would help train clinicians in FNAC. OBJECTIVE: To fabricate a tailored phantom with consideration for authenticity of size, touch, feel, and ultrasonographic (US) characteristics. METHODS: A three-dimensional (3D) digital model of the human neck was reconstructed from computed tomography data of a subject. This model was used to create 3D-printed templates for various organs that require US visualization. The templates were injected with polymers that provided similar degrees of ultrasound permeability as the corresponding organs. For fabrication of each organ, the respective molds of organs, blood vessels, thyroid gland, and tumor were injected with the material. The fabricated components were then removed from the templates and colored. Individual components were then positioned in the neck mold, and agar gel was poured in. The complete phantom was then removed from the mold. Thereafter, 45 medical doctors and students performed ultrasound-guided FNAC using the phantom, following which they were queried regarding the value of the phantom. RESULTS: The structure, US characteristics, and elasticity of the phantom were similar to those of the human subject. In the survey, all 45 participants replied that they found the phantom useful for FNAC training, and 30 medical students professed increased interest in thyroid diseases after using the phantom. CONCLUSIONS: We successfully fabricated a tailored thyroid gland phantom for transfixion practice. As most of the phantom parts are injected in molds fabricated using a 3D printer, they can be easily reproduced once the molds are fabricated. This phantom is expected to serve as an effective and fully tailored training model for practicing thyroid gland transfixion.

Papillary thyroid microcarcinoma might progress during pregnancy.

BACKGROUND: Papillary thyroid cancer occasionally occurs in women of childbearing age. As papillary thyroid microcarcinoma (PTMC) rarely grows or becomes clinically apparent, observation without surgery is an appropriate strategy for patients with low-risk PTMC. Human chorionic gonadotropin possesses weak thyroid-stimulating activity. The aim of this study was to assess the effect of pregnancy on PTMC. METHODS: We studied 9 patients with PTMC who became pregnant between 2005 and 2011. Twenty-seven age-matched nonpregnant female PTMC patients from a database we used in our previous report served as controls. Tumor enlargement was defined as an increase in the diameter of the tumor of 3 mm or more. RESULTS: PTMC enlargement occurred in 44.4% (4/9 patients) of the pregnant subjects, whereas it occurred only in 11.1% (3/27 patients) of the controls (p=0.0497). Three of the pregnant patients who exhibited tumor enlargement underwent surgery after delivery. No relationship was detected between the changes in the serum thyroglobulin level, the serum thyrotropin level, and tumor size during pregnancy. Immunohistochemical examinations did not detect the estrogen receptor in the tumors of the three patients who underwent surgery. CONCLUSIONS: This study is an initial report indicating that the risk of PTMC enlargement might increase during pregnancy. PTMC should be carefully followed-up for possible disease aggravation during pregnancy. Even if a PTMC enlarges during pregnancy, the patient's prognosis will probably not worsen.

Ki-67 labeling index is a predictor of postoperative persistent disease and cancer growth and a prognostic indicator in papillary thyroid carcinoma.

BACKGROUND: We previously reported that the Ki-67 labeling index (LI) in primary tumors and the thyroglobulin (Tg)-doubling time (DT) were potent prognostic indicators in patients with papillary thyroid carcinoma (PTC). OBJECTIVES: To elucidate the relationship between these two factors. METHODS: A total of 390 patients with PTC who underwent total thyroidectomy between 1998 and 2004 and in whom the Tg-DT was calculated were enrolled. We determined the Ki-67 LI in primary tumors and compared these values with the patients' clinicopathological factors, postoperative Tg status, Tg-DT, and prognosis. Tg status was categorized by postoperative serum Tg values: biochemically persistent disease (BPD), equivocal state, and biochemical remission. RESULTS: The Ki-67 LI was ≤5% in 312 patients (80%), 5%-10% in 48 patients (12%), and >10% in 30 patients (8%). Ki-67 LI was significantly associated with BPD (p < 0.0001). The proportion of BPD patients increased with the higher Ki-67 LI category: 24, 67, and 87%, respectively. The Ki-67 LI had a significant inverse correlation with the Tg-DT (Spearman's ρ = -0.5267, p < 0.0001). Of the 378 patients without distant metastasis at surgery, 68 patients had recurrence, and 6 of the 390 patients died of PTC during the follow-up (mean 88 months). On multivariate analyses, the Ki-67 LI remained an independent predictor of disease-free survival and disease-specific survival when Tg-DT and Tg status were excluded from the analyses. CONCLUSIONS: Evaluation of the Ki-67 LI in primary tumors may allow the prediction of the postoperative Tg status, Tg-DT and prognosis of patients with PTC. Published by S. Karger AG, Basel.

Evaluation of cytologically benign solitary thyroid nodules by ultrasonography: a retrospective analysis of 1877 cases.

OBJECTIVE: The purpose of this study is to evaluate the role of ultrasonography (US) in the management of thyroid nodules when the cytology is benign tumor on fine needle aspiration biopsy (FNAB). METHODS: Between 2006 and 2011, we investigated 13,972 patients who had solitary thyroid nodule with cytological findings of benign. Surgery was performed according to our criteria for surgical indication. Of these patients, 1877 (13%) patients who underwent surgery were enrolled in this study. We compared the results of clinical findings including US classification and final histopathological diagnosis. RESULTS: One hundred seven (6%) after surgery were diagnosed as malignancy pathologically. Large nodule or high serum thyroglobulin level were not associated with an increased risk of malignancy. Ultrasonographic evaluation as malignancy was directly linked to pathological diagnosis as thyroid carcinoma (p<0.001). CONCLUSION: US may help to play a role in deciding whether surgical treatment is necessary for cytologically benign thyroid nodules.

New insulin sensitivity index from the oral glucose tolerance test.

A new insulin sensitivity index was devised on the basis of an autoregressive model and its validity was investigated. Using data from the 75-g oral glucose tolerance test (OGTT), 115 subjects were divided into 3 groups: 40 with normal glucose tolerance, 34 with impaired glucose tolerance, and 41 with type 2 diabetes mellitus. The new insulin sensitivity index: oral glucose insulin sensitivity index (GSI) was calculated from five sets of plasma glucose and insulin levels obtained at 0, 30, 60, 90 and 120 min during OGTT using a formula based on an autoregressive model. Forty-three of the 115 subjects were examined for insulin sensitivity index (ISI) by euglycemic hyperinsulinemic clamp. GSI decreased in the order of normal glucose tolerance group>impaired glucose tolerance group>diabetic group. There was a significant correlation between GSI and the ISI derived from euglycemic hyperinsulinemic clamp study data in all 43 subjects who underwent both tests (r=0.72; P<0.0001). The ISI calculated by previous methods poorly correlated with the ISIs obtained by euglycemic hyperinsulinemic clamp study. In conclusion, this new insulin sensitivity index based on the data obtained from OGTT using an autoregressive model is comparable to an insulin sensitivity index by euglycemic hyperinsulinemic clamp technique and may be superior to previous indexes that have been devised to determine insulin sensitivity from OGTT data.

Induction of epithelial cell apoptosis in the uterus by a mouse uterine ischemia-reperfusion model: possible involvement of tumor necrosis factor-alpha.

Menstruation in primates is preceded by a period of intense vasoconstriction, with resultant ischemia-reperfusion. Although apoptosis is involved in endometrial breakdown, the relationship between ischemia-reperfusion and apoptosis in the female genital tract has not been determined. To investigate the relationship between ischemia-reperfusion and apoptosis in the uterus, we analyzed a uterine ischemia-reperfusion model using BDF1 and C57BL/6 mice. Ischemia was induced by clamping the uterine horn and uterine artery for 5 to 30 min, followed by 6, 12, 24, or 48 h of reperfusion (n = 4 for each group). The number of TUNEL-positive endometrial cells increased with the duration of ischemia and reached a maximum at 24 h of reperfusion, but then tended to decrease at 48 h. Transmission electron micrographs of endometrial cells revealed a typical nuclear condensation, confirming the occurrence of apoptosis. The mRNA expression level of the proinflammatory cytokine tumor necrosis factor-alpha (TNFalpha) in the uterus increased after reperfusion. Ischemia-reperfusion-induced endometrial apoptosis was markedly decreased in TNF-R p55-deficient mice, confirming the essential role of TNFalpha in the induction of apoptosis by ischemia-reperfusion (n = 4). Our results suggest that ischemia-reperfusion and subsequent TNFalpha expression may be critical factors in inducing endometrial cell apoptosis. Our mouse model could be suitable for investigating ischemia-related uterine injury in humans, particularly in menstruation.