Citations

AbstractPrimary aldosteronism affects 5–13% of patients with hypertension. Patients with hypertension and hypokalemia and most patients with treatment-resistant hypertension should undergo screening for primary aldosteronism with a plasma aldosterone concentration to plasma renin activity ratio. A high plasma aldosterone concentration to plasma renin activity ratio is a positive screening test result, a finding that warrants confirmatory testing. For those patients that want to pursue a surgical cure, the accurate distinction between the subtypes (unilateral vs. bilateral adrenal disease) of primary aldosteronism is a critical step. The subtype evaluation may require one or more tests, the first of which is imaging the adrenal glands with computed tomography, followed by selective use of adrenal venous sampling. Because of the deleterious cardiovascular effects of aldosterone, normalization of circulating aldosterone or aldosterone receptor blockade should be part of the management plan for all patients with primary aldosteronism. Unilateral laparoscopic adrenalectomy is an excellent treatment option for patients with unilateral aldosterone-producing adenoma. Bilateral idiopathic hyperaldosteronism should be treated medically. In addition, aldosterone-producing adenoma patients may be treated medically if the medical treatment includes mineralocorticoid receptor blockade.

The objective of this study was to define the workforce needs for the specialty of endocrinology, diabetes, and metabolism in the United States between 1999 and 2020. An interactive model of factors likely to influence the balance between the supply and demand of endocrinologists during the next 20 yr was constructed. The model used data from a wide range of sources and was developed under the guidance of a panel of experts derived from sponsoring organizations of endocrinologists. We determined current and projected numbers and demographics of endocrinologists in the United States workforce and the anticipated balance between supply and demand from 1999 to 2020. There were 3,623 adult endocrinologists in the workforce in 1999, of which 2,389 (66%) were in office-based practice. Their median age was 49 yr. Both total office visits and services performed by endocrinologists (particularly for diabetes) increased substantially during the 1990s. Waiting time for an initial appointment is presently longer for endocrinologists than for other physicians. Compared with a balanced, largely closed-staff health maintenance organization, the current national supply of endocrinologists is estimated to be 12% lower than demand. The number of endocrinologists entering the market has continuously fallen over the previous 5 yr, from 200 in 1995 to 171 in 1999. Even if this downward trend were abruptly stopped, the model predicts that demand will exceed supply from now until 2020. Whereas this gap narrows from 2000 to 2008 due to projected growth of managed care, it widens thereafter due to the aging of both the population and the endocrine workforce. Inclusion of other factors such as projected real income growth and increased prevalence of age-related endocrine disorders (e.g. diabetes and osteoporosis) further accentuates the deficit. If the number of endocrinologists entering the workforce remains at 1999 levels, demand will continue to exceed supply from now through 2020 for adult endocrinologists, and the gap will widen progressively from 2010 onward. The present analysis indicates that the number of endocrinologists entering the workforce will not be sufficient to meet future demand. These data suggest that steps should be taken to stop the ongoing decline in the number of endocrinologists in training and consideration should be given to actions designed to increase the number of endocrinologists in practice in the years ahead.

AbstractWe reported recently the induction of androgen-dependent iodide uptake activity in the human prostatic adenocarcinoma cell line LNCaP using a prostate-specific antigen (PSA) promoter-directed expression of the sodium iodide symporter (NIS) gene. This offers the potential to treat prostate cancer with radioiodine. In the current study, we examined the regulation of PSA promoter-directed NIS expression and therapeutic effectiveness of 131I in LNCaP cells by all-trans-retinoic acid (atRA). For this purpose, NIS mRNA and protein expression levels in the NIS-transfected LNCaP cell line NP-1 were examined by Northern and Western blot analysis following incubation with atRA (10 −9 to 10−6m) in the presence of 10−9m mibolerone (mib). In addition, NIS functional activity was measured by iodide uptake assay, and in vitro cytotoxicity of 131I was examined by in vitro clonogenic assay. Following incubation with atRA, NIS mRNA levels in NP-1 cells were stimulated 3-fold in a concentration-dependent manner, whereas NIS protein levels increased 2.3-fold and iodide accumulation was stimulated 1.45-fold. This stimulatory effect of atRA, which has been shown to be retinoic acid receptor mediated, was completely blocked by the pure androgen receptor antagonist casodex (10−6m), indicating that it is androgen receptor dependent. The selective killing effect of 131I in NP-1 cells was 50% in NP-1 cells incubated with 10−9m mib. This was increased to 90% in NP-1 cells treated with atRA (10−7m) plus 10−9m mib. In conclusion, treatment with atRA increases NIS expression levels and selective killing effect of 131I in prostate cancer cells stably expressing NIS under the control of the PSA promoter. Therefore atRA may be used to enhance the therapeutic response to radioiodine in prostate cancer cells following PSA promoter-directed NIS gene delivery.

Abstract Background Primary sarcomas of the liver are extremely rare in adults. Optimal therapeutic approaches remain unclear. Methods Twenty consecutive adult patients who had surgical treatment for primary hepatic sarcomas were reviewed. Patient age ranged from 23 to 80 years. Other than one patient with primary hepatic angiosarcoma who had a history of thorium dioxide colloid (Thorotrast) exposure 23 years before diagnosis, no predisposing causes were apparent. Nineteen patients had hepatic resection and one patient had an orthotopic liver transplant. No patient received neoadjuvant chemotherapy or radiotherapy but radiotherapy was delivered intraoperatively in one patient. Results Leiomyosarcoma was the most common histological type of sarcoma diagnosed (five of 20 patients), followed by malignant solitary fibrous tumour (four) and epithelioid haemangioendothelioma (three). Fourteen tumours were high-grade sarcomas and six were low grade malignancies. Thirteen patients developed a recurrence. Distant metastases (ten patients) and intrahepatic recurrence (six) were the predominant sites of initial treatment failure. Six patients received salvage chemotherapy. Histological grade was the only factor significantly associated with overall patient survival (P = 0·03). With complete resection, patients with high-grade tumours had a 5-year survival rate of 18 (95 per cent confidence interval 5–62) per cent compared with 80 (52–100) per cent for patients with low-grade tumours. The 5-year survival rate for all 20 patients was 37 (20–60) per cent. Conclusion Surgical resection is the only effective therapy for primary hepatic sarcomas at present. Better adjuvant therapy is necessary, especially for high-grade malignancies, owing to the high failure rate with operation alone.

The lack of diagnostic certainty in some patients makes it difficult to distinguish between primary and secondary forms of thrombocytosis. To augment current diagnostic studies for thrombocytosis, we retrospectively evaluated clinical records and bone marrow trephine specimens of 183 patients with thrombocytosis—164 with essential thrombocythemia (ET), 19 with reactive thrombocytosis (RT)—for bone marrow angiogenesis, bone marrow megakaryocyte c-Mpl staining, and morphologic evidence of megakaryocyte proliferation. Angiogenesis was increased in patients with ET compared with healthy controls (P < .0001) and patients with RT (P = .006). In addition, an increase in angiogenesis was associated with certain disease features such as splenomegaly (P = .004) and reticulin fibrosis (P = .005). Decreased megakaryocyte c-Mpl staining was observed in a heterogeneous pattern in ET compared with healthy controls (P < .0001) and RT (P < .0001). Histologic stratifying criteria incorporating increased angiogenesis, decreased megakaryocyte c-Mpl expression, and marked megakaryocyte proliferation in the bone marrow was highly sensitive (97%) and specific (95%) for distinguishing ET from RT (P < .0001). However, with the current duration of follow-up available on the patients, none of the histologic features evaluated have yet demonstrated prognostic value for subsequent clinical course, vascular events, or survival.

Background: Interstitial cells of Cajal (ICC) are required for normal intestinal motility. ICC are found throughout the human colon and are decreased in the sigmoid colon of patients with slow transit constipation. Aims: The aims of this study were to determine the normal distribution of ICC within the human colon and to determine if ICC are decreased throughout the colon in slow transit constipation. Patients: The caecum, ascending, transverse, and sigmoid colons from six patients with slow transit constipation and colonic tissue from patients with resected colon cancer were used for this study. Methods: ICC cells were identified with a polyclonal antibody to c-Kit, serial 0.5 μm sections were obtained by confocal microscopy, and three dimensional software was employed to reconstruct the entire thickness of the colonic muscularis propria and submucosa. Results: ICC were located within both the longitudinal and circular muscle layers. Two networks of ICC were identified, one in the myenteric plexus region and another, less defined network, in the submucosal border. Caecum, ascending colon, transverse colon, and sigmoid colon displayed similar ICC volumes. ICC volume was significantly lower in the slow transit constipation patients across all colonic regions. Conclusions: The data suggest that ICC distribution is relatively uniform throughout the human colon and that decreased ICC volume is pan-colonic in idiopathic slow transit constipation.

AbstractThis prospective randomized study examined the acute‐phase response and wound healing, comparing laparoscopic (LA) and open posterior (PA) adrenalectomy in a cushingoid porcine model. Repository corticotropin gel was given to 40 pigs for 21 days. Biochemical and tissue parameters of Cushing syndrome were confirmed. The pigs were randomized to undergo LA or PA. In addition to operating time and morbidity, the acute‐phase response was compared by measuring the postoperative white blood cell count, fasting glucose, C‐reactive protein, and nitrogen balance. Wound healing was assessed by (1) scored (1–4) gross appearance at 48 hours and 1 and 2 weeks; (2) histologic examination; and (3) tensile strength. There was no difference in operating time (mean ± SD) (36 ± 9 minutes open vs. 37 ± 7 minutes laparoscopic), perioperative mortality, degree of leukocytosis, fasting glucose, or C‐reactive protein (p > 0.05). Nitrogen balance, wound scores, and tensile strength at 24 hours and 1 week were more favorable in the LA group than in the PA group (p < 0.05). In the cushingoid porcine model, laparoscopic adrenalectomy was less catabolic and was associated with fewer wound complications than the open posterior adrenalectomy. These findings provide support for continued pursuit of laparoscopic methods for adrenalectomy in the clinical setting.

AbstractFunctioning extraadrenal paragangliomas represent more than 10% of all pheochromocytomas, occur at diverse anatomic locations, and are said to have a higher malignancy rate than intraadrenal pheochromocytomas. Sixty‐six patients had surgery for catecholamine‐producing paragangliomas between 1952 and 1992. Median follow‐up was 8.8 years. Median age was 40 years (11–67 years); the male/female ratio was 29:37. Familial disease occurred in 9 patients (13.6%), and 10 patients (15.2%) also developed adrenal pheochromocytoma. Solitary paragangliomas occurred in 52 patients: 46 abdominal, 4 thoracic, and 2 head and neck. Fifty‐three tumors developed in 14 patients with multiple paragangliomas: 38 abdominal and 15 thoracic. Of 28 patients with solitary tumors undergoing localization studies over the past 10 years accurate localization was achieved in 27. There was one operative death; 15 patients had persistent disease; and 50 were cured postoperatively. Of those cured, nine developed recurrence, disease‐free survival being 86%, 80%, and 80% at 5, 10, and 20 years. Metastatic disease was found in 14 patients (21%), 7 of whom have died. An additional 10 patients (15%) had locally invasive disease, of whom 4 have died. Cause‐specific survivals at 5, 10, and 20 years were 90%, 83%, and 72%. Risk factors for death from pheochromocytoma were tumor size > 5 cm (p= 0.0002), metastatic disease (p= 0.001), and tumor invasion (p= 0.0023). Cause‐specific survival for patients with tumors > 5 cm was 59% at 15 years compared to 100% among patients with tumors ≤ 5 cm (p= 0.0003). Functional paragangliomas are frequently malignant and are associated with a high incidence of persistent or recurrent disease. Tumor size > 5 cm and the occurrence of invasive or metastatic disease are strong predictors of outcome. Most tumors are abdominal, and imaging is highly successful for localization.

AbstractAnagrelide is a novel platelet-lowering agent that has recently been approved for use in essential thrombocythemia (ET) and related disorders. Short-term drug efficacy and toxicity data have previously been presented. The purpose of this study was to obtain additional information regarding long-term anagrelide use. This is a retrospective series of 35 young patients (17 to 48 years) with ET who received anagrelide treatment before 1992. Initial drug dosage ranged between 1 and 10 mg/d, and the median maintenance dosage was 2.5 mg/d. The overall initial response rate of 94% included 74% complete remissions and 20% partial remissions. Of the 33 responding patients, 27 (82%) remained on anagrelide therapy for a median of 10.8 years (range, 7 to 15.5). Of these, 66% maintained a complete and 34% a partial remission over the study period. In general, the reporting of somatic side effects decreased over time, and anemia was the only new side effect that emerged after long-term therapy. Eight patients (24%) experienced a more than 3 g/dL decrease in hemoglobin level. Despite active therapy, 20% of the patients experienced a total of 10 thrombotic episodes, and a similar proportion experienced major hemorrhagic events. All thrombohemorrhagic complications occurred at a platelet count of more than 400 × 109/L. It is concluded that long-term treatment of ET with anagrelide is associated with decreased reporting of initial side effects and the development of mild-to-moderate anemia. Complete normalization of platelet counts may be needed to minimize residual thrombohemorrhagic risk during therapy.