Primary hemophagocytic lymphohistiocytosis in Iran: report from a single referral center

Hemophagocytic lymphohistiocytosis (HLH) is a rare condition characterized by fever, hepatosplenomegaly, and cytopenia, and widespread accumulation of lymphocytes and histiocytes, sometimes with hemophagocytosis, primarily involving the spleen, lymph nodes, bone marrow, and liver. HLH can either occur sporadically (secondary HLH) or as part of a familial syndrome (primary HLH), including familial HLH and the distinct immunodeficiency syndromes. Herein the authors report 6 Iranian patients with primary HLH and their outcome from a single tertiary-care center.     

A simulation study of nonparametric total deviation index as a measure of agreement based on quantile regression

Total deviation index (TDI) captures a prespecified quantile of the absolute deviation of paired observations from raters, observers, methods, assays, instruments, etc. We compare the performance of TDI using nonparametric quantile regression to the TDI assuming normality (Lin, 2000). This simulation study considers three distributions: normal, Poisson, and uniform at quantile levels of 0.8 and 0.9 for cases with and without contamination. Study endpoints include the bias of TDI estimates (compared with their respective theoretical values), standard error of TDI estimates (compared with their true simulated standard errors), and test size (compared with 0.05), and power. Nonparametric TDI using quantile regression, although it slightly underestimates and delivers slightly less power for data without contamination, works satisfactorily under all simulated cases even for moderate (say, ≥40) sample sizes. The performance of the TDI based on a quantile of 0.8 is in general superior to that of 0.9. The performances of nonparametric and parametric TDI methods are compared with a real data example. Nonparametric TDI can be very useful when the underlying distribution on the difference is not normal, especially when it has a heavy tail.     

Bisegmentectomy 7-8 as alternative to more extensive liver resections

BACKGROUND: Preservation of hepatic parenchyma should be attempted whenever possible in order to reduce the risk of liver failure and increase the chance to re-resect the recurrence. STUDY DESIGN: The presence of a lesion in segments 7-8 infiltrating the right hepatic vein is usually an indication for right hepatectomy. If a thick inferior right hepatic vein is seen, a bisegmentectomy 7-8 can be performed. We review our experience with this uncommon liver resection. RESULTS: In 11 of 332 patients with colorectal liver metastases, a lesion was localized in segments 7-8 infiltrating the right hepatic vein. Six underwent resection of segments 7-8. The mean estimated rate of remnant liver volume (segments 2-4 plus caudate lobe) was 23.7%; 4 patients had neoadjuvant chemotherapy. Intraoperative mean blood loss was 200 mL without transfusions; no patients developed postoperative liver failure, and there was no in-hospital mortality. Surgical margin was negative in all patients. Median survival was 25 months, with 3 patients alive and disease-free. One patient with an intrahepatic recurrence underwent re-resection. CONCLUSIONS: Bisegmentectomy 7-8 is an uncommon but safe procedure that allows curative resections without unnecessary sacrifice of functional parenchyma.     

Optimal designs in stability studies

New optimality criteria for stability studies are proposed, and the related optimal designs are investigated. For each optimality criterion, optimal designs are identified within a class of competing designs. The property of the optimal designs for detecting slope differences is discussed.     

Disruption of growth hormone signaling retards early stages of prostate carcinogenesis in the C3(1)/T antigen mouse

Recent epidemiological studies suggest that elevated serum titers of IGF-I, which are, to a large degree, regulated by GH, are associated with an increase in prostate cancer risk. The purpose of the current study was to develop the first animal models to directly test the hypothesis that a normal, functional GH/IGF-I axis is required for prostate cancer progression. The GH receptor (GHR) gene-disrupted mouse (Ghr(-/-)), which has less than 10% of the plasma IGF-I found in GHR wild-type mice, was crossed with the C3(1)/T antigen (Tag) mouse, which develops prostatic intraepithelial neoplasia driven by the large Tag that progress to invasive prostate carcinoma in a manner similar to the process observed in humans. Progeny of this cross were genotyped and Tag/Ghr(+/+) and Tag/Ghr(-/-) mice were killed at 9 months of age. Seven of eight Tag/Ghr(+/+) mice harbored prostatic intraepithelial neoplasia lesions of various grades. In contrast, only one of the eight Tag/Ghr(-/-) mice exhibited atypia (P < 0.01, Fischer's exact test). Disruption of the GHR gene altered neither prostate androgen receptor expression nor serum testosterone titers. Expression of the Tag oncogene was similar in the prostates of the two mouse strains. Immunohistochemistry revealed a significant decrease in prostate epithelial cell proliferation and an increase in basal apoptotic indices. These results indicate that disruption of GH signaling significantly inhibits prostate carcinogenesis.     

Diagnostic value of frozen section examination in thyroid nodule-surgery at the shariati hospital (1997–2000)

Introduction There is controversy regarding the use and accuracy of frozen section (FS) in managing thyroid nodules. We compared the diagnostic value of FS with that of permanent histopathology examination and fine needle aspiration (FNA). Materials and Methods Permanent, FS, and FNA sample reports were compared in 214 patients between 1997 and 2000. FS, FNA, and permanent pathology (gold standard) results were compared using McNemar's test. Results 160 women and 54 men (mean age: 42.3±5.4 yr) took part in the study; 163 patients (76%) had benign and 51 (24%) malignant lesions; 76% of our thyroid cancer cases were papillary, 13.5% follicular, 6% medullary carcinoma, 4% Hürthle cell carcinoma, and 0.5% anaplastic carcinoma. FNA yielded definite results in 150 patients (sensitivity 72%, specificity 96%, and precision 90%). In 64 patients with equivocal FNA, FS was performed (sensitivity 36%, specificity 73%, and precision 85%). The observed difference between FNA and FS was not statistically significant. Discussion When FNA results are inconclusive, FS does not provide any further information. In suspected cases of papillary, undifferentiated, or medullary carcinomas, FS can confirm FNA findings and guide surgical therapy. An erratum to this article is available at .     

Effects of Electromagnetic Radiation Exposure on Stress-Related Behaviors and Stress Hormones in Male Wistar Rats

Studies have demonstrated that electromagnetic waves, as the one of the most important physical factors, may alter cognitive and non-cognitive behaviors, depending on the frequency and energy. Moreover, non-ionizing radiation of low energy waves e.g. very low frequency waves could alter this phenomenon via alterations in neurotransmitters and neurohormones. In this study, short, medium, and long-term exposure to the extremely low frequency electromagnetic field (ELF-EMF) (1 and 5 Hz radiation) on behavioral, hormonal, and metabolic changes in male Wistar rats (250 g) were studied. In addition, changes in plasma concentrations for two main stress hormones, noradrenaline and adrenocorticotropic hormone (ACTH) were evaluated. ELF-EMF exposure did not alter body weight, and food and water intake. Plasma glucose level was increased and decreased in the groups which exposed to the 5 and 1Hz wave, respectively. Plasma ACTH concentration increased in both using frequencies, whereas nor-adrenaline concentration showed overall reduction. At last, numbers of rearing, sniffing, locomotor activity was increased in group receiving 5 Hz wave over the time. In conclusions, these data showed that the effects of 1 and 5 Hz on the hormonal, metabolic and stress-like behaviors may be different. Moreover, the influence of waves on stress system is depending on time of exposure.     

Survey of Clostridium botulinum toxins in Iranian traditional food products

A total of 131 traditional food product samples (57 cheese, 11 kashk, and 63 salted fish) were examined using a bioassay method for detection of Clostridium botulinum toxin. Standard monovalent antitoxins were used to determine the toxin types. C. botulinum toxins were detected in 4.58% of examined samples (3.51% of cheese samples and 6.36% of salted fish samples). Contamination with this toxin was not observed in kashk samples. C. botulinum types A & E were dominant in cheese and salted fish samples, respectively. The results indicate that some Iranian traditional foods (cheese and salted fish) are contaminated by different types of C. botulinum. Consumption of these traditional foods either raw or cooked may contribute to food-borne toxicity in Iranian populations.