Muscle-specific knockout of PKC-lambda impairs glucose transport and induces metabolic and diabetic syndromes

Obesity, the metabolic syndrome, and type 2 diabetes mellitus (T2DM) are major global health problems. Insulin resistance is frequently present in these disorders, but the causes and effects of such resistance are unknown. Here, we generated mice with muscle-specific knockout of the major murine atypical PKC (aPKC), PKC-lambda, a postulated mediator for insulin-stimulated glucose transport. Glucose transport and translocation of glucose transporter 4 (GLUT4) to the plasma membrane were diminished in muscles of both homozygous and heterozygous PKC-lambda knockout mice and were accompanied by systemic insulin resistance; impaired glucose tolerance or diabetes; islet beta cell hyperplasia; abdominal adiposity; hepatosteatosis; elevated serum triglycerides, FFAs, and LDL-cholesterol; and diminished HDL-cholesterol. In contrast to the defective activation of muscle aPKC, insulin signaling and actions were intact in muscle, liver, and adipocytes. These findings demonstrate the importance of aPKC in insulin-stimulated glucose transport in muscles of intact mice and show that insulin resistance and resultant hyperinsulinemia owing to a specific defect in muscle aPKC is sufficient to induce abdominal obesity and other lipid abnormalities of the metabolic syndrome and T2DM. These findings are particularly relevant because humans who have obesity, impaired glucose tolerance, and T2DM reportedly have defective activation and/or diminished levels of muscle aPKC.

[Experimental study on Ruxian Pill I in treating mammary gland hyperplasia rabbits]

OBJECTIVE

To observe the effect of Ruxian Pill I (RXP I) on mammary gland hyperplasia (MGH) in rabbits and to explore its mechanism.

METHODS

Sixty rabbits were divided into the high, medium and low dose of RXP I groups, the Xiaoyao Pill (XYP) group, the model group and the normal control group with 10 in each group. The former 5 groups were injected with diethylstilbestrol and progesterone intramuscularly for one month to induce the MGH model and then given respective medicines via gastrogavage for 3 months. The changes in morphology of mammary gland were observed using light and electronic microscope, the levels of estradiol (E2) and progestogen (P) were measured by radioimmunoassay, and the expression of estradiol receptor (ER) and progestogen receptor (PR) were detected with immunohistochemistry before, at the end of and 3 months after the treatment.

RESULTS

Compared with those before treatment and those in the model group, in the high and midium dose of RXP I groups after treatment, obvious decrease of acini number in hyper-plastic lobuli mammae, connective tissues and blood capillaries, layers of glandular epithelium cells and organellers were seen with partial of hyperplastic cell apoptosis in them. Besides, the serum E2 level decreased obviously (P < 0.05), while the serum P level increased, and the ER expression down-regulated significantly (P < 0.05), but no obvious changes of PR expression was found. Three months later, all the above indexes maintained stable without rebound.

CONCLUSION

RXP I treatment could alleviate the hyperplasia of mammary glands, reduce E2 level, and down-regulate ER expression in rabbits with MGH, showing a significant therapeutical effect.

Adrenocorticotropin concentration following administration of thyrotropin-releasing hormone in healthy horses and those with pituitary pars intermedia dysfunction and pituitary gland hyperplasia

OBJECTIVE

To compare the effect of thyrotropin-releasing hormone (TRH) administration on endogenous ACTH concentrations in healthy horses and those with pituitary pars inter-media hyperplasia and compare the test with the dexamethasone suppression test (DST).

DESIGN

Prospective case series.

ANIMALS

15 horses with clinical signs of pituitary pars intermedia dysfunction (PPID), 4 horses with equivocal signs of PPID, and 29 horses without signs of PPID.

PROCEDURES

ACTH concentrations prior to and after administration of TRH were measured 61 times in 48 horses. Results of the DST (cortisol response) were compared with those of the TRH test in 29 horses. Thirty-three horses (24 with no clinical signs of PPID, 5 with clinical signs of PPID, and 4 with equivocal clinical signs of PPID) were euthanized and necropsied and their pituitary glands evaluated.

RESULTS

ACTH concentrations increased in all horses, but magnitude and duration of increase were significantly higher in horses with PPID. Endogenous ACTH concentrations were influenced by season. The ACTH baseline concentrations and response to TRH were not correlated with results of the DST. Results of DST were abnormal only in clinically abnormal horses or those with pars intermedia hyperplasia, but were within reference range in 17 of 26 tests in these horses.

CONCLUSIONS AND CLINICAL RELEVANCE

The ACTH response to TRH is a useful test for diagnosis of pituitary gland hyperplasia, particularly in horses in which baseline ACTH concentrations are within reference range. The DST was specific but not sensitive and was inconsistent for individuals, and results often did not agree with the TRH test response.

Male gonadal function, prolactin secretion and lactotroph population in an experimental model of cirrhosis

Liver cirrhosis, a highly prevalent chronic disease, is frequently associated with endocrine dysfunctions, notably in the gonadal axis. We evaluated lactotroph population by immunohistochemistry, gonadotropins and prolactin by immunoradiometric assay and testosterone and estradiol by radioimmunoassay in adult male Wistar rats with cirrhosis induced by carbon tetrachloride. No significant difference in mean +/- SEM percentages of lactotrophs was found between cirrhotic animals and controls (N = 12, mean 18.95 +/- 1.29%). Although there was no significant difference between groups in mean serum levels of prolactin (control: 19.2 +/- 4 ng/mL), luteinizing hormone (control: 1.58 +/- 0.43 ng/mL), follicle-stimulating hormone (control: 19.11 +/- 2.28 ng/mL), estradiol (control: 14.65 +/- 3.22 pg/mL), and total testosterone (control: 138.41 +/- 20.07 ng/dL), 5 of the cirrhotic animals presented a hormonal profile consistent with hypogonadism, all of them pointing to a central origin of this dysfunction. Four of these animals presented high levels of estradiol and/or prolactin, with a significant correlation between these two hormones in both groups (r = 0.54; P = 0.013). It was possible to detect the presence of central hypogonadism in this model of cirrhotic animals. The hyperestrogenemia and hyperprolactinemia found in some hypogonadal animals suggest a role in the genesis of hypogonadism, and in the present study they were not associated with lactotroph hyperplasia.

Effectiveness of parathyroid-hormone measurement in detecting patients with multiple gland disease causing primary hyperparathyroidism

BACKGROUND AND AIM

Intraoperative parathyroid hormone measurement (iPTH) has strengthened the successful use of minimal-invasive approaches in surgery of primary hyperparathyroidism (pHPT). The aim of the study was to evaluate the efficacy of iPTH monitoring in treating pHPT resulting from multiple gland disease.

MATERIALS AND METHODS

In this retrospective study, 58 patients with pHPT underwent surgery (minimally invasive or open exploration) between January 2003 and July 2005. iPTH levels were routinely measured at the start of anesthesia, in any case before skin incision, and 10 as well as 15 min after removal of abnormal gland(s). A drop in iPTH >50% after 10 min and >60% after 15 min was considered adequate to prove the success of the removal of the abnormal gland(s). The removed tissue was examined histologically by immediate frozen section.

RESULTS

A single gland disease was found in 51 (88%) cases, a multiple gland disease (double adenoma or hyperplasia) in 7 (12%) cases. In all cases of single adenoma, an adequate drop of iPTH was seen after removal of the pathologic gland. In contrast, in all cases with a second adenoma, an adequate drop in iPTH was detected only after removal of both adenoma/hyperplasia. Immediate sectioning was only helpful for identification of removed tissue, but was no help in deciding whether to search for an additional gland. The follow-up showed no late disease recurrence.

CONCLUSION

The measurement of iPTH is an effective and safe means in treating single gland disease as well as multiple gland disease (adenoma/hyperplasia) causing pHPT and also allows a successful limited dissection via minimally invasive parathyroidectomy.

Basic and clinical aspects of parathyroid hyperplasia in chronic kidney disease

Marked parathyroid hyperplasia develops in patients with chronic kidney disease, especially those with long dialysis vintage. Although progression of hyperplasia is associated with downregulation of vitamin D receptor and calcium-sensing receptor, initial abnormality that triggers and maintains parathyroid cell proliferation, as well the critical abnormality for the progression of diffuse hyperplasia to nodular hyperplasia, still remains to be elucidated. It is quite important for the optimal management of renal osteodystrophy to recognize the development of nodular hyperplasia, because the cells in nodular hyperplasia are usually resistant to medical therapy and further treatment of such patients often leads to vascular calcification. For this purpose, size and blood supply of enlarged parathyroid glands have been used as good clinical markers. Furthermore, we have recently shown that the serum fibroblast growth factor 23 level can be used for predicting refractory hyperparathyroidism. Once nodular hyperplasia develops in any of the enlarged parathyroid glands, such patients need to be treated by parathyroid intervention including percutaneous ethanol injection therapy. In addition, as direct vitamin D injection therapy has been shown to induce regression of hyperplasia, it may become possible to reverse or normalize established nodular hyperplasia if we can develop new agents with such effects in the near future.

A case of ACTH-independent bilateral macronodular adrenal hyperplasia and severe congestive heart failure

Cortisol secretion in ACTH independent bilateral macronodular adrenal hyperplasia (AIMAH) can be regulated by aberrant adrenal receptors. We describe a patient with Cushing's syndrome (CS) due to AIMAH and concomitant Class IV congestive heart failure (CHF). Clinical testing for the presence of aberrant receptors revealed a pronounced serum cortisol (257%) and aldosterone response (212%) to the administration of ACTH and a partial serum cortisol (35%) and aldosterone (106%) response to upright posture. This suggested the possible presence of aberrant hormone receptors for ACTH [melanocortin 2 receptor (MC2-R)], vasopressin, catecholamines or angiotensin II (AT-II) on the patient's adrenal glands. Adrenal tissue from the patient demonstrated an eight-fold increased expression of MC2-R compared to normal adrenal tissue. This increased expression was consistent with the increase in cortisol and aldosterone seen in response to exogenous ACTH. We propose that the severe CHF resulted in activation of the renin-angiotensin system, with an increased production of AT-II. The elevated circulating levels of AT-II may have led to increased expression of MC2-R on the patient's adrenal glands and increased responsiveness to ACTH. This unusual case of CS may elucidate a heretofore unknown mechanism for the development of AIMAH.

Direct injection of calcitriol or its analog into hyperplastic parathyroid glands induces apoptosis of parathyroid cells

Hyperplasia of the parathyroid gland (PTG) is associated not only with excessive secretion of parathyroid hormone (PTH) but also with changes in the parathyroid cell (PTC) characteristics (i.e. hyperproliferative activity, and low contents of vitamin D and calcium-sensing receptors). Control of PTG hyperplasia is most important in the management of secondary hyperparathyroidism, but the advanced stage of hyperplasia is considered irreversible. In the present study, dialysis patients with PTG hyperplasia underwent direct injection of calcitriol or maxacalcitol (OCT) into the PTG. Ultrasonography showed that this treatment had significantly reduced PTG volume and tissue analysis using the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) method and DNA electrophoresis indicated that cellular apoptosis had been induced. The mechanism of apoptosis was evaluated in detail in uremic rats fed a high-phosphate diet. OCT or its vehicle was directly injected into the rats' PTGs. In the PTGs treated by OCT, there was a significantly increased number of TUNEL-positive PTCs and DNA electrophoresis revealed the characteristic ladder pattern of DNA fragmentation, both findings indicative of apoptosis. There was also a significant upregulation of both vitamin D and Ca-sensing receptors in the PTCs and a clear shift of the Ca-PTH response curve to the left and downward. None of these findings was observed in the PTGs treated by vehicle. This novel treatment is successful in causing regression of PTG hyperplasia. Thus, it is expected to significantly reduce the PTH level and ameliorate the abnormal bone turnover and mineral metabolism.

Insulin stimulates arterial neointima formation in normal rats after balloon injury

AIM

Insulin resistance in patients is associated with increased atherosclerosis and arterial restenosis. It is thought that the concomitant hyperinsulinaemia exacerbates vascular disease because resistance to insulin-induced glucose disposal is associated with resistance to certain effects of insulin which inhibit, but with no resistance to other effects which promote, neointimal hyperplasia. We sought to determine the net effect of hyperinsulinaemia on neointimal hyperplasia in normal animals.

METHODS

Rats were infused with or without insulin for 16 days and the carotid artery injured by balloon catheter on day 2.

RESULTS

Steady-state serum insulin concentrations were 0.56 +/- 0.04 and 1.25 +/- 0.05 nm for control and hyperinsulinaemic rats respectively (p < 0.01). Systolic blood pressures, weights and serum glucose levels were not affected by hyperinsulinaemia. Fourteen days after injury, the neointima-to-media area ratio was 0.72 +/- 0.07 and 1.39 +/- 0.15 for control and hyperinsulinaemic rats respectively (p < 0.05). Media area was unaffected by hyperinsulinaemia.

CONCLUSIONS

The effects of hyperinsulinaemia which promote neointimal hyperplasia after balloon injury of rat carotid artery predominate over the effects which inhibit it even in normal animals.

Rat thymectomy effects on leptin receptor and T-bet: erythroid hyperplasia with maturation arrest and suppressed T-cell-mediated hepatotoxicity

Thymectomy is an inevitable therapy for thymoma. Therefore, determining hemato-immune changes post-thymectomy is important. Twenty-six normal LEW/Sea rats thymectomized (Tx) at the ages of 38 +/- 5 days were followed without any treatment for 4 months (experiments [Exp] A and B). In addition, 16 LEW/Sea rats Tx at the age of 42 days (Exp C and D) and 10 non-Tx control LEW/Sea rats (Exp E) were immunized with syngeneic male liver cells 2 to 3 times and followed 2.7 months after the first immunization. Flow cytometric (FCM) analysis of mesenteric lymph nodes (MLN) and peripheral blood (PB) showed as follows: among the 26 Tx rats (Exp A and B), MLN lymphocyte population at 4 months postthymectomy was characterized by decreased numbers of CD4+ cells (22%-36%) or alphabeta T-cell receptor (TCR)-positive cells (16%-54%) and increased numbers of interleukin 2 receptors (IL-2R) (>90%). In the 16 Tx-immunized rats (Exp C and D), both alphabeta TCR (MLN) and CD45R (PB) expression on lymphocytes was suppressed with rather high numbers of CD4. Bone marrow (BM) and PB hematological studies of the partially and totally Tx rats indicated the following: 8 BM of the 10 totally Tx males (Exp A) and the 7/10 male spleen showed erythroid hyperplasia with maturation arrest at the stage of basophilic erythroblasts and reticulocytopenia in the PB. One of the 10 males, which had both BM myeloid to erythroid (M/E) ratio of 4.3 and spleen myeopoiesis, was in a more advanced stage, a prestage of pure red cell aplasia (PRCA) with 22% of CD4+ MLN cells. Syngeneic liver cell immunization resulted in the Tx rats as follows: hepatotoxicity based on the immunization was weaker in the 16 Tx rats (Exp C and D) than in the 10 non-Tx rats (Exp E). Polymerase chain reaction (PCR) of PB and MLN showed compensatory activated leptin receptor (LR) and T-bet DNA in 19 Tx rats (Exp A and B) with abnormal FCM findings. The ineffective erythropoiesis at 4 months after thymectomy was explained by the erythroblast LR/erythropoietin receptor (EPOR) dysfunction. The low grade hepatotoxicity in the Tx rats (Exp C and D) was explained by the disturbed Th1 reactions (or the disturbed T-bet gene transcription) at postthymectomy.

Role of FNA in the medical management of minimally enlarged thyroid

Fine-needle aspiration (FNA) of thyroid is a cost-effective and simple diagnostic tool in the initial screening of patients with thyroid nodules. But, its role in a clinically normal thyroid or a minimally enlarged thyroid in a symptomatic patient suspected of having thyroid dysfunction is unknown. With our 2-yr experience in a setup of a tertiary health care hospital in a developing country, we have aimed to implement a management protocol using FNA thyroid done without ultrasound guidance and TSH estimation done during the same visit in symptomatic patients suspected of having thyroid pathology but presenting with no goiter or having minimally enlarged thyroid with no palpable nodules. The thyroid enlargement in 172 cases were graded with the criteria endorsed by WHO, Pan American Health Organization, and International Council for Control of Iodine Deficiency Disorders into grade 0, 1, and 2. The cases were evaluated cytologically and correlated with TSH values according to the algorithm formulated by the authors. FNA was diagnostic in 86.6, 98, and 100% in grade 0, 1, and 2 goiters, respectively. 52.3% (n = 90), 19.8% (n = 34), 16.9% (n = 29) of cases were diagnosed as Hashimoto's thyroiditis (HT), colloid goiter (CG), and lymphocytic thyroiditis (LT). Sixteen had a combination of LT and CG (n = 6), HT and CG (n = 6), papillary carcinoma (n = 2), and diffuse hyperplasia (n = 2). No statistically significant difference (P = 0.4586) was noted between the groups of patients with grade 0 and grade 1-2 goiter, who underwent FNAC. 38.95% of patients (n = 67) with TSH values greater than 10 microIU/ml and considered hypothyroid showed features of HT/LT at FNA. 23.83% (n = 41) having TSH values between 5 and 10 microIU/ml (subclinical hypothyroidism) also showed features of HT/LT at FNA. Both groups were treated with thyroxine. 35.46% (n = 61) of cases with TSH values within normal range (0.5-5.1 microIU/ml) and considered euthyroid showed a spectrum of lesions at cytology other than HT and LT. They are being followed up to detect them at an early stage of subclinical hypothyroidism. Only 13 cases (7.5%) who were serologically euthyroid showed HT/LT and are being followed-up. Thus, the authors advocate FNA of the thyroid as a single simple cost-effective office procedure in the medical management of all nonpalpable/minimally enlarged thyroid in patients suspected of having thyroid pathology and/or in combination with TSH values. FNA helps in early detection of subclinical hypothyroidism, which is of utmost importance in pregnant women and further makes possible availability of baseline values for future reference. With the implementation of this protocol of FNA thyroid without imaging, we affirm that the practice of cytology which differs in different geographic areas and from country to country depending on economy and availability of infrastructure can be made more user-friendly.

Serum Concentrations of Estrogens, Sex Hormone Binding Globulin, and Androgens and Risk of Breast Hyperplasia in Postmenopausal Women

OBJECTIVE

We sought to determine whether serum concentrations of estrogens, androgens, and sex hormone binding globulin in postmenopausal women were related to the presence of mammary hyperplasia, an established breast cancer risk factor.

METHODS

Study participants provided serum before breast biopsy or mastectomy in three hospitals in Grand Rapids, Michigan, between 1977 and 1987. A total of 179 subjects with breast hyperplasia were compared with 152 subjects with nonproliferative breast changes that are not associated with increased breast cancer risk.

RESULTS

The odds ratios (OR) associated with the three upper quartiles of estradiol in comparison with the lowest quartile were 2.2 [95% confidence interval (95% CI) 1.1-4.6], 2.5 (95% CI, 1.1-5.3), and 4.1 (95% CI, 2.0-8.5; Ptrend = 0.007). The corresponding ORs for bioavailable estradiol, estrone, and estrone sulfate were of generally similar magnitude (Ptrend = 0.003 for bioavailable estradiol, 0.0004 for estrone, and 0.0009 for estrone sulfate). Relative to women concurrently in the lowest tertile for serum estradiol, estrone, and estrone sulfate, women concurrently in the highest tertile for all three hormones had an OR of 5.8 (95% CI, 2.2-15.2). Serum concentrations of sex hormone binding globulin, testosterone, dehydroepiandrosterone, androstenedione, and androstenediol were not associated with risk of hyperplasia.

CONCLUSIONS

Serum concentrations of estrogens, but not of androgens or sex hormone binding globulin, were strongly and significantly associated with risk of breast hyperplasia in postmenopausal women, suggesting that estrogens are important early in the pathologic process towards breast cancer.

Effects of 5 years of treatment with rabeprazole or omeprazole on the gastric mucosa

BACKGROUND

Prolonged gastric acid suppression leads to hypergastrinaemia, which promotes hyperplasia of the enterochromaffin-like (ECL) cells of the oxyntic mucosa. The objective was to determine the effects of 5 years of treatment with rabeprazole or omeprazole on the gastric mucosa.

METHODS

Two hundred and forty-three patients received rabeprazole (20 mg or 10 mg) or omeprazole (20 mg) once daily for up to 5 years, for gastro-oesophageal reflux disease and 51% completed the whole 5 year period. Gastric biopsy specimens were taken and examined for gastritis, Helicobacter pylori infection, and ECL cell status.

FINDINGS

H. pylori infection in the gastric corpus was more common than in the antrum, and remained constant, whereas antral H. pylori infection became less common as the study progressed. H. pylori infection was a highly significant predictor of higher gastritis scores, which were similar among the three treatment groups. ECL cell hyperplasia occurred in a minority of patients, and was associated with serum gastrin concentrations. No ECL cell dysplasia or tumours were observed. There were no significant differences among the treatment groups in gastritis or ECL cell hyperplasia grades.

INTERPRETATION

This study has confirmed the link between ECL cell hyperplasia and elevated serum gastrin concentrations, but has found no evidence that this progresses to high grades of hyperplasia during 5 years of treatment with rabeprazole or omeprazole.

Selective arterial calcium stimulation and hepatic venous sampling in the evaluation of hyperinsulinemic hypoglycemia: potential and limitations

PURPOSE

To describe the potential and limitations of selective arterial calcium stimulation and hepatic venous sampling (ASVS) in the evaluation of patients with hyperinsulinemic hypoglycemia.

MATERIALS AND METHODS

Twenty-seven consecutive adult patients with documented hyperinsulinemic hypoglycemia undergoing an ASVS test and histologically confirmed diagnosis were included.

RESULTS

By histology, 24 patients were found to have an insulinoma, two had islet cell hyperplasia, and one had insulin-secreting neuroendocrine carcinoma of the liver. ASVS correctly predicted the source of excessive insulin secretion in 26 of 27 (sensitivity, 96%) patients. In two patients with an insulinoma, ASVS had to be repeated for correct diagnosis; in one patient with a glucose-sensitive insulinoma, ASVS was falsely negative. In one patient, a falsely negative ASVS test was caused by diazoxide treatment; in another patient a falsely negative ASVS test occurred because of extraordinarily high baseline insulin levels when the calcium stimulation was performed. CT and/or MR imaging correctly predicted the source of excessive insulin secretion in 59% of patients, the sensitivity of the intraoperative exploration was 88%.

CONCLUSIONS

In the authors' experience, the ASVS test is superior to CT/MR imaging and even the intraoperative exploration in identifying the source of excessive insulin secretion in patients with hyperinsulinemic hypoglycemia. To prevent false negative ASVS tests, medications with an influence on insulin secretion have to be discontinued prior to ASVS and two baseline blood samples should be obtained before the calcium stimulation is performed.

Essential Role of Vascular Endothelial Growth Factor and Flt-1 Signals in Neointimal Formation After Periadventitial Injury

Objective— Vascular endothelial growth factor (VEGF) is upregulated after arterial injury. Its role in the pathogenesis of neointimal formation after periadventitial injury, however, has not been addressed.

Methods and Results— Expression of VEGF and its receptors but not that of placental growth factor markedly increased with the development of neointimal formation in hypercholesterolemic mice after cuff-induced periarterial injury. Transfection with the murine soluble Flt-1 (sFlt-1) gene to block VEGF in vivo in mice inhibited early inflammation and later neointimal formation. The sFlt-1 gene transfer did not affect plasma lipid levels but attenuated increased expression of VEGF, Flt-1, Flk-1, monocyte chemoattractant protein-1, and other inflammation-promoting factors. Mice with Flt-1 kinase deficiency also displayed reduced neointimal formation.

Conclusions— Inflammatory changes mediated by VEGF and Flt-1 signals play an important role in the pathogenesis of neointimal formation after cuff-induced periadventitial injury. VEGF might promote neointimal formation by acting as a proinflammatory cytokine.

Comparison of Sequential versus Simultaneous Methods of Adrenal Venous Sampling

PURPOSE

To compare two methods of adrenal venous sampling (AVS) in preoperative localization of adrenal lesions in primary hyperaldosteronism.

MATERIALS AND METHODS

Twenty-one patients (13 men, eight women) underwent selective adrenal venous sampling between July 2001 and May 2003. One of the 21 patients underwent repeat AVS, for a total of 22 procedures. In half the procedures (n = 11), simultaneous bilateral adrenal venous catheterization and sampling was performed before and after intraprocedural adrenocorticotropic hormone (ACTH) administration; in the remaining half (n = 11), sequential catheterization of the left and right adrenal veins was performed during continuous ACTH infusion 1 hour before and throughout AVS. Chart review provided procedural data, including sampling intervals and aldosterone/cortisol ratios. Patient records provided clinical data, including blood pressure, serum aldosterone levels, and computed tomography and magnetic resonance imaging findings. Surgical pathology reports confirmed unilateral disease but were not applicable to bilateral disease.

RESULTS

Selective AVS was completed successfully in 21 of 22 procedures (95%); the unsuccessful sampling was repeated successfully. Disease lateralized in 13 of 22 cases. Simultaneous bilateral AVS localized unilateral disease in seven of eight cases (88%) and was nondiagnostic in one case (13%), with cases confirmed by surgical pathology reports. Sequential bilateral AVS localized unilateral disease in four of four cases (100%) confirmed by surgical pathology reports, with one lost to follow-up. Bilateral disease was diagnosed in six of 22 cases: two of 11 by simultaneous AVS and four of 11 by sequential AVS. Three of 22 cases demonstrated borderline hormone levels that failed to meet the diagnostic threshold for recommended adrenalectomy. Mean elapsed time between acquisition of right and left samples did not differ between simultaneous and sequential AVS (P = .09). Baseline (prestimulation) sampling did not contribute unique diagnostic information in any case and provided contradictory or confounding information in three of 11 simultaneous AVS procedures (27%).

CONCLUSIONS

Sequential bilateral catheterization does not compromise the reliability of time-sensitive AVS. Both simultaneous and sequential AVS are adequate studies; however, obtaining baseline prestimulation samples during simultaneous AVS is unnecessary and increases the cost of the procedure.

Elevated soluble epidermal growth factor receptor level in pituitary adenoma and carcinoma

OBJECTIVE

To investigate effect of the soluble epidermal growth factor receptor (sEGFR/sErbB1) level in the peripheral blood in development, invasiveness, apoplexy of each type of pituitary tumor.

METHODS

The sEGFR level was determined in peripheral serum from 190 patients with pituitary diseases by enzyme linked immunosorbent assay. The sEGFR levels were measured in 10 pituitary Rathke's pouch, 18 pituitary hyperplasia, 161 pituitary adenomas including 30 microadenomas, 83 large adenomas, 48 giant adenomas, 1 pituitary carcinoma, and 28 healthy controls.

RESULTS

In the patients with pituitary hyperplasia, microadenoma, large adenoma, giant adenoma, and pituitary carcinoma, the sEGFR level was 188.92 +/- 32.62, 209.83 +/- 19.01, 333.20 +/- 69.33, 405.85 +/- 37.38, and 617.45 fmol/mL independently. They were all significantly higher than patients with pituitary Rathke's pouch (156.78 +/- 18.24 fmol/mL, P < 0.001) and healthy control group (159.11 +/- 40.50 fmol/mL, P < 0.05). The sEGFR level in pituitary carcinoma was higher than pituitary adenoma. In patients with pituitary adenoma, the sEGFR level was positive correlated to the size of pituitary adenomas (r=0.998), the significant difference was observed for the sEGFR level in each group of the patients with pituitary adenomas (P < 0.001). Furthermore, in patients with pituitary ACTH-secreting microadenomas, the serum sEGFR levels in invasiveness (295.00 +/- 77.80 fmol/mL) was higher than that in non-invasiveness (210.60 +/- 16.4 fmol/mL, P < 0.05). In patients with pituitary ACTH-secreting, PRL-secreting, GH-secreting, and non-functioning large adenomas, the serum sEGFR levels in invasiveness (407.86 +/- 28.50, 399.25 +/- 30.10, 386.00 +/- 13.08, and 369.25 +/- 36.70 fmol/mL) was higher than that in non-invasiveness (335.25 +/- 63.49, 300.64 +/- 47.57, 297.00 +/- 61.93, and 269.30 +/- 25.68 fmol/mL) respectively (P < 0.05). In patients with invasive pituitary PRL-secreting, GH-secreting, and non-functioning giant adenomas, the serum sEGFR levels not significantly different in between invasiveness (417.50 +/- 35.94, 409.50 +/- 69.14, and 417.50 +/- 44.13 fmol/mL) and non-invasiveness (386.00 +/- 49.64, 417.50 +/- 44.03, and 409.51 +/- 35.17 fmol/mL) (P > 0.05). In patients with pituitary large adenomas, the sEGFR levels in pituitary apoplexy (377.48 +/- 39.18 fmol/mL) was higher than that in non-pituitary apoplexy (343.18 +/- 68.17 fmol/mL, P > 0.05).

CONCLUSIONS

The increased level of peripheral serum sEGFR is concomitant with development, proliferous size of the adenomas in patients with pituitary adenomas. In addition, the elevated levels of serum sEGFR occur in pituitary apoplexy as clinical active tumors, and the non-invasive ACTH secreting adenomas. The sEGFR levels could be differentiated helpfully between pituitary adenomas and non-pituitary adenomas. These data suggest that serum sEGFR could be as a referable marker of the size and activation of proliferation in pituitary adenoma.

Effects of Preinjury Administration of Corticosteroids on Pseudointimal Hyperplasia and Cytokine Response in a Rat Model of Balloon Aortic Injury

Restenosis occurs in approximately one-third of patients with coronary or peripheral vascular disease who undergo balloon angioplasty or a surgical bypass procedure primarily because of the development of pseudointimal hyperplasia (PIH). Corticosteroids were effective in suppressing PIH in several experimental studies, but no clinical studies have been reported. To resolve this discrepancy, we studied the effects of preinjury administration of several doses of methylprednisolone (MP) at targeted times in a rat model of balloon aortic injury. Rats were given either no treatment or an intravenous injection of MP (0.5, 5.0, 50, or 500 mg/kg) 2 hours before aortic injury. Four hours later interleukin-6 (IL-6), IL-10, and macrophage migration inhibitory factor (MIF) concentrations in serum and tissue of injured aortas were assessed. Two weeks after injury, damaged aortas were harvested and studied histopathologically. Compared with results in controls, MP at a dose of 5 mg/kg significantly inhibited increases in plasma and tissue levels of IL-6 and significantly reduced the pseudointimal area, pseudointimal/medial area ratio, and proliferating cell nuclear antigen index in injured vessels. Administration of MP had no significant effect on the IL-10 or MIF level. Thus in a rat model of balloon aortic injury, preinjury administration of MP 5 mg/kg mitigated the development of PIH and cell proliferation and suppressed the postinjury increase in serum and tissue IL-6 concentrations. These results suggest that there is an appropriate dosage as well as appropriate timing for MP administration to suppress PIH.

[Expressive level of vascular endothelial growth factor in peripheral blood in patients with pituitary adenomas]

OBJECTIVE

To discuss whether vascular endothelial growth factor (VEGF) in the peripheral blood can reflect the biological activities of pituitary adenomas.

METHODS

The concentrations of VEGF in peripheral blood were measured with ELISA in 203 patients with pituitary adenomas, 22 patients with pituitary hyperplasia, 7 patients with pituitary Rathke' pouch and 3 patients with pituitary abscess.

RESULTS

The serum VEGF levels were (366.8 +/- 211.1) pg/ml and (286.8 +/- 107.6) pg/ml in patients with pituitary adenomas and pituitary hyperhasia, respectively, which were higher than those in patients with pituitary Rathke' pouch [(180.5 +/- 61.7) pg/ml], patients with pituitary abscess [(147.5 +/- 46.3) pg/ml] and the health control [(180.8 +/- 56.2) pg/ml] (P < 0.05). In patients with pituitary adenomas, the VEGF levels were (380.0 +/- 234.5) pg/ml in macroadenomas and (380.1 +/- 2870.3) pg/ml in giant adenomas, higher than those in microadenomas [(294.6 +/- 111.6) pg/ml] and in pituitary hyperhasia respectively (P < 0.05). The serum VEGF levels were not significantly different in pituitary adenoma in terms of invasive growth, apoplexy, cyst and hormone secretory functions (P > 0.05).

CONCLUSIONS

The upregulation of serum VEGF expression may reflect the biological activities of pituitary adenoma. However, it may not be associated with pituitary Rathke' pouch, pituitary abscess, adenoma with invasiveness, apoplexy, cyst and hormone secretory function. The serum VEGF levels could be helpful in differentiating pituitary adenoma from pituitary Rathke' pouch and pituitary abscess.

Ovarian stromal hyperplasia and ovarian vein steroid levels in relation to endometrioid endometrial cancer

OBJECTIVE

To study the relationship between the presence of endometrioid endometrial cancer, the degree of ovarian stromal hyperplasia and ovarian steroid production in postmenopausal women.

DESIGN

Retrospective and prospective study, respectively.

SETTING

Medical Centre Leeuwarden and the University Hospital Groningen, The Netherlands. Postmenopausal women with or without endometrial cancer, undergoing a hysterectomy with bilateral salpingo-oophorectomy.

METHODS

In 112 women with endometrioid endometrial cancer, 47 women with a benign gynaecological condition and 10 women with non-endometrioid endometrial cancer, the degree of ovarian stromal hyperplasia was scored retrospectively on a semi-quantitative scale (atrophy, slight, marked). All women were postmenopausal and had undergone a hysterectomy with bilateral salpingo-oophorectomy. Prospectively, blood sampling from the ovarian veins was performed in a further 60 women. Steroid levels (oestrone, oestradiol, androstenedione, testosterone) were determined and related to the degree of ovarian stromal hyperplasia and the presence (n = 52) or absence (n = 8) of endometrioid endometrial cancer.

MAIN OUTCOME MEASURES

Degree of ovarian stromal hyperplasia and steroid levels in the utero-ovarian circulation.

RESULTS

In the retrospective study, the degree of ovarian stromal hyperplasia was higher in the presence of endometrioid endometrial cancer (P = 0.0001). The prospective study showed that an increasing degree of ovarian stromal hyperplasia was related to higher ovarian levels of both testosterone and androstenedione (P < 0.05 and P < 0.005, respectively), but not to oestrone or oestradiol. A non-significant increase in mean ovarian vein levels of both testosterone and androstenedione was seen in patients with endometrial cancer as compared with patients with benign conditions.

CONCLUSION

In endometrioid endometrial cancer, higher degrees of ovarian stromal hyperplasia were found and with increasing degrees of ovarian stromal hyperplasia, levels of ovarian vein androgens were higher. A causal relationship in the origin of hormone-dependent endometrial pathology may exist between ovarian stromal hyperplasia, ovarian vein androgen levels and endometrioid endometrial carcinoma.

Intraoperative parathormone measurement in patients with primary hyperparathyroidism: a prospective clinical study

BACKGROUND

The objective of this pilot study was to evaluate the use of intraoperative iPTH measurement in combination with bilateral neck exploration in patients with primary hyperparathyroidism.

METHODS

A prospective study was conducted in a single centre university hospital in Switzerland comprising 33 patients with primary hyperparathyroidism undergoing neck surgery. No routine preoperative localisation studies were conducted. Intraoperative iPTH measurement was performed at defined times. Exploration was discontinued when iPTH fell below 15% of baseline.

RESULTS

For all patients with adenoma the median serum iPTH decreased to 11.9% (standard deviation 5.5%) of baseline concentrations. All patients with hyperplasia achieved normocalcaemia. At median follow-up of 17.7 weeks neither recurrent nor persistent hypercalcaemia was observed. Eleven patients were explored unilaterally.

CONCLUSION

Measurement of intraoperative serum iPTH is a helpful tool in the differentiation of single adenoma from hyperplastic glands. When we call for a strict 78% decrease in serum iPTH from base levels after 10 minutes, measurement of this marker protein even allows differentiation of single- from multi-glandular disease.