In vitro experiments of Pediculus humanus capitis (Phthiraptera: Pediculidae) resistance to permethrin and 6-paradol in East Jakarta: Detoxification enzyme activity and electron microscopic changes in lice.

BACKGROUND AND AIM: Pediculus humanus capitis, the human head louse, remains a global health problem. This study evaluated the resistance of head lice to permethrin and 6-paradol mediated by in vitro detoxification enzyme activity experiments and to describe physical changes in the lice using scanning electron microscopy (SEM). MATERIALS AND METHODS: The adult stages of P. h. capitis were collected from patients exposed to 1% permethrin and three different concentrations of 6-paradol (0.00005%, 0.0001%, and 0.00015%) using a filter paper diffusion bioassay. Healthy P. h. capitis adults served as the control. The in vitro bioassays were conducted after 10, 20, 30, and 60 min of exposure. The activities of acetylcholinesterase (AChE), glutathione S-transferase (GST), and oxidase were analyzed. Physical changes in the lice were analyzed using SEM. RESULTS: Permethrin and 6-paradol exhibited low toxicity against the lice. At 60 min, 1% permethrin had killed 36.7% of the lice present, while 6-paradol had killed 66.7-86.7%. Permethrin induced significantly elevated AChE, GST, and oxidase activity; 6-paradol also caused significantly elevated AChE, GST, and oxidase activity. Permethrin did not cause any ultrastructural morphological changes on the lice, while 6-paradol severely damaged the head, thorax, respiratory spiracles, and abdomen of the dead lice. CONCLUSION: This in vitro experimental of P. h. capitis is the first study to report P. h. capitis in East Jakarta shows complete resistance to permethrin and 6-paradol, and to describe the associated increase in AChE, GST, and oxidase activity. It was observed that 6-paradol severely damaged the head, thorax, respiratory spiracles, and abdomen of the dead lice.

Structure of Escherichia coli Grx2 in complex with glutathione: a dual-function hybrid of glutaredoxin and glutathione S-transferase.

The structure of glutaredoxin 2 (Grx2) from Escherichia coli co-crystallized with glutathione (GSH) was solved at 1.60 Šresolution. The structure of a mutant with the active-site residues Cys9 and Cys12 changed to serine crystallized in the absence of glutathione was solved to 2.4 Šresolution. Grx2 has an N-terminal domain characteristic of glutaredoxins, and the overall structure is congruent with the structure of glutathione S-transferases (GSTs). Purified Grx2 exhibited GST activity. Grx2, which is the physiological electron donor for arsenate reduction by E. coli ArsC, was docked with ArsC. The docked structure could be fitted with GSH bridging the active sites of the two proteins. It is proposed that Grx2 is a novel Grx/GST hybrid that functions in two steps of the ArsC catalytic cycle: as a GST it catalyzes glutathionylation of the ArsC-As(V) intermediate and as a glutaredoxin it catalyzes deglutathionylation of the ArsC-As(III)-SG intermediate.

Crystallization and preliminary X-ray crystallographic studies of the ArsI C-As lyase from Thermomonospora curvata.

Arsenic is a ubiquitous and carcinogenic environmental element that enters the biosphere primarily from geochemical sources, but also through anthropogenic activities. Microorganisms play an important role in the arsenic biogeochemical cycle by biotransformation of inorganic arsenic into organic arsenicals and vice versa. ArsI is a microbial nonheme ferrous-dependent dioxygenase that transforms toxic methylarsonous acid to the less toxic inorganic arsenite by C-As bond cleavage. An ArsI ortholog from the thermophilic bacterium Thermomonospora curvata was expressed, purified and crystallized. The crystals diffracted to 1.46 Šresolution and belonged to space group P43212 or its enantiomer P41212, with unit-cell parameters a=b=42.2, c=118.5 Å.

Do heart failure patients understand their diagnosis or want to know their prognosis? Heart failure from a patient's perspective.

The management of heart failure has evolved to become a multidisciplinary affair. Constraints of time and resources limit the amount of counselling that is given to heart failure patients in hospital and, with the advent of community heart failure specialist nurses, there is a trend to move more of these services into the community. Most heart failure patients are elderly and may find the information given to them, at the time of diagnosis and later on at home by heart failure nurses, difficult to grasp. In this study, patients' perspectives of a diagnosis of heart failure, their understanding of the diagnosis as well as what being diagnosed with heart failure means to them were recorded. Patients were questioned on whether the news of the heart failure diagnosis was broken to them in a sympathetic manner and how they felt about the information provided at diagnosis.

Room temperature detection of sub-terahertz radiation in double-grating-gate transistors.

Room temperature photovoltaic non-resonant detection by large area double-grating-gate InGaP/InGaAs/GaAs heterostructures was investigated in sub-THz range (0.24 THz). Semi-quantitative estimation of the characteristic detection length combined with self-consistent calculations of the electric fields excited in the structure by incoming terahertz radiation allowed us to interpret quantitatively the results and conclude that this detection takes place mainly in the regions of strong oscillating electric field excited in depleted portions of the channel.

Confocal microscopy of thick specimens.

Confocal microscopy is an excellent tool to gain structural information from deep within a biological sample. The depth from which information can be extracted as well as the resolution of the detection system are limited by spherical aberrations in the laser pathway. These spherical aberrations of the visible light can be efficiently canceled by optimizing the refractive index of the immersion media. Another way of cancelling spherical aberrations is by changing tube length, or alternatively, by changing the objective from infinite correction to finite correction, or vice versa, depending on which microscope is used. A combination of these two methods allows for confocal imaging at continuous depths. Presently, confocal microscopes typically operate at a maximum depth of 40 microm in the sample, but with the methods presented here, we show that information can easily be gained from depths up to 100 microm. Additionally, the precision of localization of a single fluorophore in the axial direction, limited by spherical aberrations, can be significantly improved, even if the fluorophore is located deep within the sample. In principle, this method can improve the efficiency of any kind of microscopy based on visible light.

Abnormal angiopoietins 1&2, angiopoietin receptor Tie-2 and vascular endothelial growth factor levels in hypertension: relationship to target organ damage [a sub-study of the Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT)].

BACKGROUND: The increased risk of target organ damage (TOD) in hypertension may be related to a prothrombotic or hypercoagulable state, with abnormalities in platelet activation. Altered angiogenesis, possibly related to increased plasma vascular endothelial growth factor (VEGF) is also a feature of hypertension. We hypothesized a link between altered angiogenesis and TOD in hypertension. Accordingly, the angiogenic growth factors VEGF, angiopoietin 1 and 2 (Ang 1 & 2) and soluble angiopoietin receptor Tie-2 in plasma and in platelets were assessed in terms of the presence or absence of hypertensive TOD. METHODS: We studied 199 patients (75% men; mean age 68 years) with hypertension. Of these, 125 had evidence of hypertensive TOD (stroke, previous myocardial infarction, angina, left ventricular hypertrophy and mild renal failure). Patients were compared with 74 healthy normotensive controls (69% men; mean age 68 years). Plasma VEGF, Ang 1 & 2 and Tie-2, and total platelet levels of VEGF and Ang-1 (obtained by lysing a known number of platelets with 0.5% Tween) were measured by an enzyme-linked immunosorbent assay. RESULTS: Hypertensive patients had higher levels of plasma VEGF, Ang-1, Ang-2, Tie-2 and platelet VEGF (all P

Tissue inhibitor of metalloproteinse-1 is a marker of diastolic dysfunction using tissue doppler in patients with type 2 diabetes and hypertension.

BACKGROUND: Tissue inhibitor of metalloproteinase-1 (TIMP-1) is associated with increased fibrosis of the extracellular matrix (ECM). Myocardial stiffness is a feature of diastolic dysfunction. We assessed circulating TIMP-1 as a marker of diastolic dysfunction in patients with type 2 diabetes mellitus (DM) and hypertension, who were compared with healthy controls. METHODS: We recruited 54 patients (43 males; mean age 68 +/- 5 years) with treated type 2 DM (i.e. controlled glycaemia, hypertension, hyperlipidaemia), 35 (30 males; 69 +/- 8 years) treated nondiabetic hypertensives, and 31 healthy controls (18 males; 66 +/- 5 years). Circulating TIMP-1 was measured by ELISA. Using transthoracic echocardiography, the early (E) diastolic mitral inflow velocity was measured with pulse wave Doppler, and the early mitral annular velocity (e'), a recognized index of diastolic relaxation, was measured with tissue Doppler. The E/A ratio was also calculated and isovolumic relaxation time measured. RESULTS: Mean e' levels differed significantly between controls, diabetics and hypertensives (P < 0.0001). Circulating TIMP-1 was significantly different between patients and controls (P = 0.006), but there was no statistically significant difference between the DM and hypertension group. In both groups, only e' was negatively correlated with TIMP-1 levels, with a stronger correlation among the hypertensive patients (Spearman r = -0.544, P = 0.001) when compared with the diabetic group (r = -0.341, P = 0.011). CONCLUSION: Diastolic relaxation is impaired in diabetes and hypertensive patients. The relationship between TIMP-1 and e' may reflect increased myocardial fibrosis and consequent diastolic dysfunction, which may be more prominent in hypertension.

Echocardiographic changes in patients with malignant phase hypertension: the West Birmingham Malignant Hypertension Register.

In order to study the echocardiographic abnormalities in consecutive patients with malignant phase hypertension (MHT), we reviewed echocardiograms of 31 patients (23 male; mean age 52+/-14 years) with MHT who were admitted to our unit. Trans-thoracic echocardiography was carried out in all patients, and echocardiographic measurements were compared with those of 39 patients (30 male; mean age 54+/-10 years) with controlled nonmalignant essential hypertension, and 32 (19 male; mean age 51+/-10 years) healthy normotensive volunteers. Patients with MHT had a significantly higher mean systolic and diastolic blood pressure (P<0.001) compared to the other two groups. MHT patients had significantly greater mean left atrial dimensions (P=0.002), as well as aortic root dimensions (P=0.01) and left ventricular (LV) dimensions (with the exception of the diastolic internal diameter) (P<0.001). MHT patients also had a mean larger LV mass and LV mass index (both P<0.001) when compared to the other two groups. The mean ejection fraction was also lower in the MHT group (P<0.001). In conclusion, patients with MHT have significant cardiac hypertrophy, in association with systolic dysfunction and dilated left atria, irrespective of the duration of known hypertension. These abnormalities may predispose MHT patients to cardiovascular complications including heart failure and cardiac arrhythmias, such as atrial fibrillation.

Plasma and platelet-derived vascular endothelial growth factor and angiopoietin-1 in hypertension: effects of antihypertensive therapy.

BACKGROUND: Platelets carry angiogenic growth factors vascular endothelial growth factor (VEGF) and angiopoietin-1 (Ang-1). Although platelet-derived growth factors are important in the pathogenesis and metastasis of malignancy, their role in the pathogenesis of complications and the response to treatment in hypertension is less known. OBJECTIVE: To test the hypotheses that there are differences in VEGF and Ang-1 in the plasma and within platelets from patients with hypertension, and that levels change with successful treatment. METHODS: We recruited 42 previously untreated patients with hypertension (25 male; mean age 53 years) and 30 age- and sex-matched controls. Plasma VEGF, Ang-1 and soluble P-selectin (sPsel, an index of platelet activation), and total platelet [platelet VEGF (pVEGF) and platelet Ang-1 (pAng-1)] were measured by ELISA. The patients were then treated for 6 months with amlodipine-based antihypertensive therapy, achieving a mean blood pressure below 140/80 mmHg. RESULTS: Patients with hypertension had significantly higher levels of plasma sPsel (P =0.01), VEGF (P < 0.001) and Ang-1 (P = 0.01), as well as pVEGF (P < 0.001) and pAng-1 (P =0.02). The levels of plasma and platelet angiogenic growth factors were significantly reduced after antihypertensive treatment (VEGF, P = 0.01; pVEGF, P < 0.001; Ang-1, P < 0.001; pAng-1, P = 0.04). There were no correlations with blood pressure or the levels of sPsel. CONCLUSION: Levels of plasma and intra-platelet VEGF and Ang-1 are increased in hypertension and are decreased with treatment. Platelet levels of VEGF and Ang-1 may be related to platelet activation but may also involve other mechanisms (for example, the general vascular and haemodynamic changes) that are seen in hypertension.

Case report: gastric carcinoma as a complication of dyskeratosis congenita in an adolescent boy.

Dyskeratosis congenita (DC), or the Zinsser-Engman-Cole syndrome, is a rare X-linked heritable disorder, affecting primarily the ectodermal tissues, with hyperpigmentation of the skin, leukoplakia of the buccal and anal mucosa, and nail dystrophy (1, 2). Aplastic anemia (3) and a variety of neoplasms (4, 5) are some of the extraectodermal manifestation of this disorder, which although X-linked recessive, has also been described in a few females (6, 7). Mental retardation, diarrhea, and gastrointestinal bleeding have been considered to be less frequent features (8). We report an adolescent Indian male who presented with all the ectodermal manifestations, as well as mental retardation, bone marrow aplasia, and gastrointestinal hemorrhage secondary to adenocarcinoma of the stomach.

Variation in the p-H of faeces in disease.

Although it is highly unlikely that a disease can be definitively diagnosed from a study of the pH of the faeces alone, the present study has helped to dispel the past belief that the pH of faeces in acute amoebic dysentery is more likely to be acidic. Culture for other pathogenic organisms has not been done in the present series of cases, but the chances of the coincidence of bacillary dysentery in this group would probably not have been significant. Further, in the past a simple litmus paper test was suggested to differentiate an amoebic dysentery from a bacillary dysentery, a procedure which can no longer hold good.