A comparative evaluation of dengue diagnostic tests based on single-acute serum samples for laboratory confirmation of acute dengue

A prospective study was carried out to evaluate the sensitivity of dengue NS1 antigen-capture ELISA in comparison with dengue virus isolation, conventional RT-PCR and real-time RT-PCR for laboratory confirmation of acute dengue based on single-acute serum samples. Four primary healthcare centres were involved to recruit patients with clinical diagnosis of dengue illness. Patient's demographic, epidemiological and clinical information were collected on a standardized data entry form and 5 ml of venous blood was collected upon consent. In the laboratory, six types of laboratory tests were performed on each of the collected acute serum sample. Of the 558 acute serum samples collected from 558 patients with clinical diagnosis of dengue from mid-August 2006 to March 2009, 174 serum samples were tested positive by the dengue NS1 antigen-capture ELISA, 77 by virus isolation, 92 by RT-PCR and 112 by real-time RT-PCR. A total of 190 serum samples were tested positive by either one or a combination of the four methods whereas, only 59 serum samples were tested positive by all four methods. Thus, based on single-acute serum samples, 190 of the 558 patients (34.1%) were laboratory-confirmed acute dengue. The overall test sensitivity was 91.6%, 40.5%, 48.4% and 58.9% for dengue NS1 antigen-capture ELISA, virus isolation, conventional RT-PCR and real-time RT-PCR respectively. Statistically, dengue NS1 antigen-capture ELISA was the most sensitive and virus isolation was the least sensitive test for the laboratory confirmation of acute dengue based on single-acute serum specimens. Real-time RT-PCR was significantly more sensitive than the conventional RT-PCR.     

Protective role of propolis in chlorpyrifos-induced changes in the haematological parameters and the oxidative/antioxidative status of Cyprinus carpio carpio

The protective effect of propolis on haematological parameters and antioxidant status were evaluated in the blood and various tissues of carp exposed to chlorpyrifos (CPF). The fish were exposed to sublethal concentrations of CPF (0.040 and 0.080 mg/L) for 10 days, and propolis (10 mg per kg of fish weight) was simultaneously administered. Samples of the blood and tissue (liver, kidney, and gill) were collected at the end of the experiment and analysed for their oxidant–antioxidant status, including the malondialdehyde (MDA) levels, and the superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activity. The samples were also measured for changes in the haematological parameters, such as the red blood cell (RBC) and white blood cell (WBC) counts, the haemoglobin concentration (Hb), the haematocrit (Ht) level, and the erythrocyte indices: the mean corpuscular volume (MCV), the mean corpuscular haemoglobin (MCH) and the mean corpuscular haemoglobin concentration (MCHC). The findings of this study demonstrated that CPF had a negative effect on the haematological parameters and the antioxidant enzyme activities of the fish; this toxic effect was neutralised by the administration of propolis. The present results suggest that propolis can be effective in the protection of CPF-induced toxicity in fish.     

Cellular immune responses in mice induced by M. tuberculosis PE35-DNA vaccine construct

The PE35 (Rv3872) gene of Mycobacterium tuberculosis is present in the region of difference (RD) one that is deleted in all vaccine strains of Mycobacterium bovis bacillus Calmette Guerin. The aim of this study was to clone PE35 DNA into a DNA vaccine plasmid with CMV promoter and interleukin‐2 secretory signal and evaluate the recombinant plasmid for induction of antigen‐specific cellular responses in mice. DNA corresponding to PE35 was PCR amplified from the genomic DNA of M. tuberculosis H₃₇Rv, cloned into pGEMT‐Easy vector and sub‐cloned into the DNA vaccine vector pUMVC6. BALB/c mice were immunized with recombinant pUMVC6/PE35 and spleen cells were tested for T‐helper (Th)1‐type (antigen‐induced proliferation and secretion of IFN‐γ) and Th2‐type (IL‐5), and anti‐inflammatory (IL‐10) cytokine responses to pure recombinant PE35 protein and its synthetic peptides. Mice immunized with the recombinant plasmid DNA (pUMVC6/PE35) showed positive Th1‐type cellular responses to pure PE35, but not to an irrelevant antigen, i.e. PPE68 (Rv3873). However, the vaccine construct did not induce antigen‐specific Th2‐type (IL‐5) or anti‐inflammatory (IL‐10) reactivity to PE35. Testing with synthetic peptides showed that Th1‐type cells recognizing various epitopes of PE35 were induced in mice immunized with pUMVC6/PE35 DNA. These results suggest that pUMVC6/PE35 may be useful as a safer vaccine candidate against TB.     

Hyperthermia up-regulates matrix metalloproteinases and accelerates basement membrane degradation in experimental stroke

We investigated the effects of balance difficulty on contingent negative variation (CNV) and postural preparation against perturbation. Thirteen subjects were perturbed by a backward floor translation (S2) after an auditory warning stimulus. To alter balance difficulty, subjects maintained standing posture from four initial positions before perturbation. The position of the center of pressure in the anteroposterior direction (CoPy) was expressed as a percentage distance of foot length (%FL) from the heel: 10%FL anterior to extreme backward leaning; quiet standing (QS); and 20%FL and 10%FL posterior to extreme forward leaning. CNV, CoPy, and electromyography (EMG) of the lower leg muscles were analyzed. Balance difficulty was represented by the relative distance of the forward peak position of CoPy after S2 from the QS position. Balance difficulty was higher with a more anterior initial position. The late CNV peaked just before S2 (latency: -76 to -306 ms), then started becoming small. CNV peak was earlier and larger with increasing balance difficulty. CoPy backward shift and a continuous EMG increase were observed as the strategy for postural preparation, and were significantly earlier (61 ms and 42 ms, respectively) than the CNV peak. CNV peak time correlated closely with onset times of CoPy backward shift (r=0.78) and continuous EMG increase (r=0.71). These findings suggest that as balance difficulty increases, attentional allocation to sensory information and/or postural preparation starts earlier just before the perturbation.     

Enhanced pain perception prior to smoking cessation is associated with early relapse

Accumulated evidence suggests that nicotine induces analgesia, and endogenous pain regulatory mechanisms may be altered by chronic smoking. The extent to which individual differences in pain perception are related to smokers’ ability to abstain from smoking has not been directly examined. Seventy-one smokers who were interested in quitting completed a pre-cessation laboratory session which included the cold pressor test (CPT). Pain ratings were collected during and after CPT. Also, mood changes, cardiovascular measures, and salivary cortisol samples were evaluated prior to, during, and after CPT. Participants attended 4 weekly follow-up assessment sessions after their quit day. Cox regression analysis revealed that higher pain ratings during and after CPT predicted greater risk for smoking relapse. These results remained significant after affective and physiological responses to CPT were controlled, suggesting that pain ratings prior to smoking cessation are potentially useful in identifying smokers who are at greater risk of early smoking relapse and may reflect underlying putative risk for nicotine dependence and relapse.     

Diffuse infiltration of Aspergillus hyphae in the thyroid gland with multinodular goiter

A 35-year-old woman presented with a thyroid mass, weakness and shortness of breath of 3 years duration. On physical examination, she had a diffusely enlarged thyroid gland with multiple nodules. There were no signs to suggest immune suppression. The patient farmed and raised livestock. Biochemical tests and hemogram were normal. She underwent surgery, and a histological examination of the surgical specimen revealed nodular hyperplasia. Microscopically, silver methenamine (PASM) stain-positive hyphae that divided into branches at 45° and conidia were detected beside the thyroid capsule, with conidia in the cystic nodule. Moreover, ischemic changes of the thyroid tissue were observed closer to the capsule. We report a case of Aspergillosis of the thyroid of a patient who underwent surgery for a multinodular goiter.     

Nitric oxide synthase inhibitors protect cerebellar Purkinje cells from zinc-induced cell loss in adult rat

Zinc is an important trace element in biological systems; however, excessive extracellular zinc could lead to neuronal cell death following ischemia, seizures, and brain trauma. In this study, we investigated whether the intracortical injection of zinc sulphate (200 μg/kg, i.c.) changes total number of Purkinje cells in the cerebellum and whether different types nitric oxide synthase inhibitors, N-(G)-nitro-L-arginine methyl ester (L-NAME), N(omega)-nitro-L-arginine (L-NNA), aminoguanidine and 7-nitroindazole (7-NI), have protective effects against zinc neurotoxicity in Wistar albino rats. Animals were divided into 6 groups: control, zinc, zinc+L-NAME (100 mg/kg, i.p.), zinc+L-NNA (100 mg/kg, i.p.), zinc+7-NI (100 mg/kg, i.p.) and zinc+aminoguanidine (100 mg/kg, i.p.) groups. Total number of Purkinje cells in the cerebellum was estimated using unbiased stereological technique as 318,947 ± 20,549, 123,483 ± 23,762, 206,537 ± 43,128, 178,135 ± 26,635, 193,148 ± 46,104 and 212,910 ± 26,399 in the control, zinc, zinc+L-NAME, zinc+L-NNA, zinc+7-NI and zinc+aminoguanidine groups, respectively (mean ± SD). The number of Purkinje cells in zinc group was significantly lower than that of the other groups (P<0.001). It was found that the nitric oxide synthase inhibitors have neuroprotective effect against zinc neurotoxicity on Purkinje cells. These data show that the inhibition of the nitric oxide synthase could prevent some of the deleterious effects of zinc on Purkinje cells.     

The presence of Epstein-Barr virus (EBV) in diffuse large B-cell lymphomas (DLBCLs) in Turkey: special emphasis on 'EBV-positive DLBCL of the elderly'

Accumulated evidence has shown the importance of Epstein-Barr virus in the pathogenesis of various lymphomas. This study aimed to determine the prevalence of Epstein-Barr virus expression and its effect on survival amongst diffuse large B-cell lymphoma (DLBCL) cases from two large tertiary care centres in Turkey with a particular interest in identifying cases of 'Epstein-Barr virus-positive DLBCL of the elderly'. Diffuse large B-cell lymphoma cases diagnosed between 1999 and 2009 were retrieved and 340 cases were used to construct tissue microarrays. The presence of Epstein-Barr virus small ribonucleic acids was examined by in situ hybridization using Epstein-Barr virus (EBV)-encoded small RNA (EBER) oligonucleotides. A total of 18 cases (5.3%) showed Epstein-Barr virus expression. Twelve cases were classified as Epstein-Barr virus-positive DLBCL of the elderly. Epstein-Barr virus-positive DLBCL cases showed a significantly inferior overall survival as compared with Epstein-Barr virus-negative cases (p < 0.001). In our study group Epstein-Barr virus expression is not prevalent in DLBCLs. Epstein-Barr virus-positive DLBCL of the elderly is also rare in the Turkish population. The presence of Epstein-Barr virus, however, is associated with poor prognosis.     

Patterns of motor branching of the musculocutaneous nerve in human fetuses and clinical significance

The purpose of this morphologic study is to investigate the course and the branching pattern of motor branches of musculocutaneous nerve (MCN) in human fetuses. Twenty upper limbs (10 right, 10 left) of spontaneously aborted formalin-fixed fetuses were dissected under a stereomicroscope to determine motor branches for the biceps brachii and brachialis and the communicating branches between the MCN and median nerve (MN). The MCN entered the proximal and middle part of coracobrachialis in 13/20 and 5/20 of arms, respectively, and the remaining 2/20 did not pierce coracobrachialis. The communication between MCN and MN was observed in 5/20 of the arms and detected only in the distal part of the coracobrachialis. The most frequently observed innervation is the type wherein a single branch to biceps brachii, which bifurcated for supplying the short and long heads (12/20). For the innervation of brachialis, the most frequent type was a single branch from the main trunk of the MCN (15/20). During the dissections, the distance between the acromion and the emerging point of the motor branches was measured. The mean distance between the acromion and the emerging point of the all motor branches for biceps brachii in all types of specimens was 33.8 ± 6.1% of acromion-lateral epicondyle length and for brachialis was 50.6 ± 11.5% of acromion-lateral epicondyle length. The data of the MCN variations in the human fetus may be useful for the clinicians and pediatric surgery.     

Discovering the "anatomy" in students' mind through metaphors

Purpose  

This study aims to obtain clues about the beliefs of medical students on learning anatomy through metaphor analysis which has not been used in this field before.