Clinical and laboratory evaluation of cured and non-cured patients with cutaneous leishmaniasis treated by Glucantime

BACKGROUND & OBJECTIVES

Insufficient treatment of cutaneous leishmaniasis (CL) by conventional drugs is a major barrier in control strategies. This study was aimed to evaluate Glucantime efficacy and the susceptibility of Glucantime unresponsive and responsive CL isolates in the field and laboratory.

METHODS

Chi-square test (x^[2]) was used to determine the significance of difference between proportions in Glucantime-treated patients. The inhibitory activity of various concentrations of Glucantime against Leishmenia tropica stages was evaluated by a colorimetric cell viability MTT and macrophage assays. Mixed model, t-test and ANOVA were performed to determine the significance of difference between various concentrations of Glucantime unresponsive or responsive isolates and untreated control group and p <0.05 was defined as significant level. Altogether, 89.8% of the patients were cured by Glucantime, whilst 10.2% remained non-cured.

RESULTS

The overall Glucantime efficacy in different age groups and genders was similar. The IC₅₀ values of promastigotes and amastigotes for Glucanime unresponsive isolates were 2.1 and 2.6 times higher than the equivalent rates obtained for responsive cases, respectively. The overall mean number of amastigotes within macrophages in unresponsive isolates was significantly higher (32.68 ± 1.24) than that in responsive ones (18.68 ± 1.52, p <0.001). Glucantime unresponsive and responsive field isolates of anthroponotic CL (ACL) caused by L. tropica strongly correlated to in vitro assays.

INTERPRETATION & CONCLUSION

Monitoring of Glucantime unresponsiveness by the health surveillance system is extremely important, where anthroponotic transmission occurs in humans. Hence, physicians should be aware of such clinical unresponsive presentations with ACL for antimonial therapeutic failure to improve management of disease in endemic regions.

Changes in gastrocnemii activation at mid-to-late stance markedly affects the intact and anterior cruciate ligament deficient knee biomechanics and stability in gait

INTRODUCTION

We aimed to quantify the sensitivity in biomechanical response and stability of the intact and anterior cruciate ligament deficient (ACL-D) joints at mid-to-late stance periods of gait to the alterations in activation of gastrocnemii (Gas) muscles.

METHODS

A validated kinematics-driven musculoskeletal finite-element model of the lower extremity is used to compute knee joint response and stability under reported kinetics-kinematics of healthy subjects. Activation in Gas is altered under prescribed gait data at the mid-to-late stance of gait and associated changes in remaining muscle forces/contact forces/areas/ACL force and joint stability are computed in both intact and ACL-D joints.

RESULTS

In the intact joint, the anterior-tibial-translation (ATT) as well as ACL and joint contact forces follow variations in Gas forces. Both the stability and ATT of an ACL-D joint are restored to the near-intact levels when the activity in Gas is reduced. Knee joint instability, excessive ATT as well as larger peak articular contact stresses with a posterior shift in contact areas are estimated under greater Gas forces.

CONCLUSIONS

ACL-D joint is unstable with ATT > 10 mm under larger activities in Gas. Gas is an ACL-antagonist while hamstrings and soleus are ACL-agonists. The near-intact joint stability and ATT of an ACL-D joint can be restored at a lower activation in Gas; or in other words, when activation in ACL-antagonist muscles drops compared with that in ACL-agonist muscles. Results could help analyze the gait of ACL-D copers and non-copers and provide better understanding towards improved preventive, diagnostic, and treatment approaches.

Knee flexion angle and muscle activations control the stability of an anterior cruciate ligament deficient joint in gait

Anterior cruciate ligament (ACL) is a primary structure and a commonly injured ligament of the knee joint. Some patients with ACL deficiency (ACLD) experience joint instability and require a reconstructive surgery to return to daily routines, some can adapt by limiting their activities while others, called copers, can return to high-level activities with no instability. We investigated the effects of alterations in the knee flexion angle (KFA) and muscle force activations on the stability and biomechanics of ACLD joints at 25, 50, and 75% periods of gait stance. ACLD joint stability is controlled by variations in both KFA and knee muscle forces. For the latter, a parameter called activity index is defined as the ratio of forces in ACL antagonists (quadriceps and gastrocnemii) to those in ACL agonists (hamstrings). Under a greater KFA (2-6° beyond the mean of reported values in healthy subjects), an ACLD joint regains its pre-injury stability levels. The ACLD joint stability also markedly improves at smaller quadriceps and larger hamstrings forces (activity indices of 2.0-3.6 at 25%) at the first half of stance and smaller gastrocnemii and larger hamstrings forces (activity indices of 0.1-1.1 at 50% and 0.1-1.2 at 75%) at the second half of stance. Activity index and KFA are both crucial when assessing the dynamic stability of an ACLD joint. These results are helpful in our understanding of the biomechanics and stability of ACLD joints towards improved prevention and treatment strategies.

Uncertainty in and around biophysical modelling: insights from interdisciplinary research on agricultural digitalization

Agricultural digitalization is providing growing amounts of real-time digital data. Biophysical simulation models can help interpret these data. However, these models are subject to complex uncertainties, which has prompted calls for interdisciplinary research to better understand and communicate modelling uncertainties and their impact on decision-making. This article develops two corresponding insights from an interdisciplinary project in a New Zealand agricultural research organization. First, we expand on a recent Royal Society Open Science journal article (van der Bles et al. 2019 Royal Society Open Science 6, 181870 (doi:10.1098/rsos.181870)) and suggest a threefold conceptual framework to describe direct, indirect and contextual uncertainties associated with biophysical models. Second, we reflect on the process of developing this framework to highlight challenges to successful collaboration and the importance of a deeper engagement with interdisciplinarity. This includes resolving often unequal disciplinary standings and the need for early collaborative problem framing. We propose that both insights are complementary and informative to researchers and practitioners in the field of modelling uncertainty as well as to those interested in interdisciplinary environmental research generally. The article concludes by outlining limitations of interdisciplinary research and a shift towards transdisciplinarity that also includes non-scientists. Such a shift is crucial to holistically address uncertainties associated with biophysical modelling and to realize the full potential of agricultural digitalization.

Going beyond audit and feedback: towards behaviour-based interventions to change physician laboratory test ordering behaviour

Studies indicate there are a variety of contributing factors affecting physician test ordering behaviour. Identifying these behaviours allows development of behaviour-based interventions. Methods Through a pilot study, the list of contributing factors in laboratory tests ordering, and the most ordered tests, were identified, and given to 50 medical students, interns, residents and paediatricians in questionnaire form. The results showed routine tests and peer or supervisor pressure as the most influential factors affecting physician ordering behaviour. An audit and feedback mechanism was selected as an appropriate intervention to improve physician ordering behaviour. The intervention was carried out at two intervals over a three-month period. Findings There was a large reduction in the number of laboratory tests ordered; from 908 before intervention to 389 and 361 after first and second intervention, respectively. There was a significant relationship between audit and feedback and the meaningful reduction of 7 out of 15 laboratory tests including complete blood count (p = 0.002), erythrocyte sedimentation rate (p = 0.01), C-reactive protein (p = 0.01), venous blood gas (p = 0.016), urine analysis (p = 0.005), blood culture (p = 0.045) and stool examination (p = 0.001). Conclusion The audit and feedback intervention, even in short duration, affects physician ordering behaviour. It should be designed in terms of behaviour-based intervention and diagnosis of the contributing factors in physicians' behaviour. Further studies are required to substantiate the effectiveness of such behaviour-based intervention strategies in changing physician behaviour.

Effects of nitrate supplementation and forage level on gas production, nitrogen balance and dry-matter degradation in sheep

The present study was conducted to evaluate the effect of nitrate supplementation on dry-matter (DM) degradation and ruminal fermentation parameters by using in vitro gas production and in situ technique. In vitro gas production and in situ DM degradation in the presence or absence of nitrate were recorded at all incubation times. At all incubation times, diets incubated with nitrate gave a significantly lower gas production than did the other diets, except at 2-h incubation. Ruminal DM degradation did not differ among the experimental treatments. Furthermore, at most incubation times, total volatile fatty acids in diets containing nitrate were lower than those in the other treatments. Nitrate supplementation considerably increased gas production from the insoluble fraction, whereas it decreased gas production from the quickly soluble fraction, and potential gas production. Moreover, in all incubations, there were significant correlations between gas production and in situ DM-degradation parameters. The control diet had the greatest retained nitrogen content, but the diets containing nitrate had the greatest faecal nitrogen. The results showed that nitrate addition resulted in a lower gas production and volatile fatty acid production in in vitro assay. It was concluded that considering the strong posetive relationship between the two methodologies, the degradability parameters can be predicted from obtained gas production.

Molecular modeling and molecular dynamics simulation study of archaeal leucyl-tRNA synthetase in complex with different mischarged tRNA in editing conformation

Aminoacyl-tRNA synthetases (aaRSs) play important roles in maintaining the accuracy of protein synthesis. Some aaRSs accomplish this via editing mechanisms, among which leucyl-tRNA synthetase (LeuRS) edits non-cognate amino acid norvaline mainly by post-transfer editing. However, the molecular basis for this pathway for eukaryotic and archaeal LeuRS remain unclear. In this study, a complex of archaeal P. horikoshii LeuRS (PhLeuRS) with misacylated tRNA^Leu was modeled wherever tRNA's acceptor stem was oriented directly into the editing site. To understand the distinctive features of organization we reconstructed a complex of PhLeuRS with tRNA and visualize post-transfer editing interactions mode by performing molecular dynamics (MD) simulation studies. To study molecular basis for substrate selectivity by PhLeuRS's editing site we utilized MD simulation of the entire LeuRS complexes using a diverse charged form of tRNAs, namely norvalyl-tRNA^Leu and isoleucyl-tRNA^Leu. In general, the editing site organization of LeuRS from P.horikoshii has much in common with bacterial LeuRS. The MD simulation results revealed that the post-transfer editing substrate norvalyl-A76, binds more strongly than isoleucyl-A76. Moreover, the branched side chain of isoleucine prevents water molecules from being closer and hence the hydrolysis reaction slows significantly. To investigate a possible mechanism of the post-transfer editing reaction, by PhLeuRS we have determined that two water molecules (the attacking and assisting water molecules) are localized near the carbonyl group of the amino acid to be cleaved off. These water molecules approach the substrate from the opposite side to that observed for Thermus thermophilus LeuRS (TtLeuRS). Based on the results obtained, it was suggested that the post-transfer editing mechanism of PhLeuRS differs from that of prokaryotic TtLeuRS.

The effect of grapeseed oil on performance, rumen fermentation, antioxidant status and subcutaneous adipose fatty acid profile in lambs

This experiment was carried out to examine the effect of grapeseed oil (GSO) on performance, rumen fermentation, antioxidant status and subcutaneous adipose fatty acid (FA) profile in lambs. Eighteen Baluchi lambs, 196 ± 14 days of age and 39.8 ± 1.7 kg body weight, were randomly assigned to three experimental diets: (i) diet without GSO (control), (ii) diet containing 2% of GSO (GSO2) and (iii) diet containing 4% of GSO (GSO4) for 42 days. Results showed that the experimental diets had no significant effect on dry matter intake and performance (p > 0.05). The supplemented diets with GSO had no effect on pH and NH₃ -N of rumen fluid (p > 0.05), but GSO4 increased (p = 0.003) the concentration of propionic acid and reduced (p = 0.002) the concentration of acetate acid compared to the control. Inclusion 4% of GSO to the diet increased total antioxidant activity and decreased malondialdehyde in serum and muscle (p < 0.001). The level of blood glutathione peroxidase in diets containing GSO was higher than control diet (p = 0.02), but diets had no effect on superoxide dismutase in blood and muscle tissues (p > 0.05). The concentration of vaccenic acid, rumenic acid and linoleic acid and thus polyunsaturated fatty acid in subcutaneous fat was affected by experimental diets (p < 0.001), as control had the lowest amount of these FAs and GSO4 had the highest amount of them. Therefore, it can be concluded that the use of GSO up to 4% improves the antioxidant status and adipose fatty acid profile in lambs without effects on performance.

Fate and transport modeling of phthalate esters from biosolid amended soil under corn cultivation

Phthalate esters (PAEs) are prevalent in the environment due to the broad range of industrial, agriculture and domestic applications. The ubiquitous use of PAEs has resulted in their potential to reach groundwater sources through application of agri-chemicals and municipal biosolids. A study was conducted to monitor the fate and transport of seven commonly detected PAEs in the environment including: dimethyl phthalate (DMP), diethyl phthalate (DEP), benzyl butyl phthalate (BBP), bis(di-ethyl hexyl) phthalate (DEHP), di-n-octyl phthalate (DnOP), dipentyl phthalate (DPP), and di-n-butyl phthalate (DnBP). Biosolids sourced from the Halifax Regional Municipality were applied at three rates on field-based lysimeter cells which were cropped to corn (Zea mays) for one growing season. In the present study, breakthrough curves (BTCs) were established for phthalates leaching from a corn-cultivated agricultural soil profile. The HYDRUS-1D model and a two-site sorption model were applied to predict transport parameters of PAEs using an inverse solution approach. Results of our research revealed that higher PAE adsorption was observed based on increasing carbon chain number. In addition, higher values of F (i.e. the fraction of type-1 sorption sites assumed to be in equilibrium with the solution phase) and lower values of D (i.e. dispersion coefficient) were observed for PAEs with large carbon chains which was validated both through the empirical dataset and the model simulations.

Prevalence of childhood obesity in the state of Kuwait

BACKGROUND

Overweight and obesity have reached an epidemic in Kuwait, with the highest rate of adult obesity in the region. National estimates of childhood obesity in Kuwait are scarce. The purpose of this study is to evaluate the prevalence of overweight and obesity among school children in Kuwait.

METHODS

This is a cross-sectional study of a representative sample of 6-18 years old school children, randomly selected from 244 schools in Kuwait. Anthropometric data was measured from 6574 students in September 2012-June 2013. Overweight and obesity have been defined in accordance with the Centres for Disease Control and Prevention (CDC), International Obesity Task Force (IOTF) and World Health Organization (WHO) 2007 criteria.

RESULTS

The prevalence estimate overweight was based on the three different systems (CDC = 17.7%, IOTF = 23.3%, WHO = 21.6%). The prevalence of obesity was (CDC = 33.9%, IOTF = 28.2%, WHO = 30.5%). Boys had a higher percentage of obesity regardless of the classification system used.

CONCLUSIONS

The prevalence of childhood obesity is alarmingly high in the State of Kuwait and exceeds the prevalence rates reported from neighbouring countries and from North America.

3D structure prediction of histone acetyltransferase proteins of the MYST family and their interactome in Arabidopsis thaliana

Histone lysine acetylation is a reversible post-translational modification that does not involve changes in DNA sequences. Enzymes play an important role in developmental processes and their deregulation has been linked to the progression of diverse disorders. The HAT enzyme family fulfills an important role in various developmental processes mediated by the state of chromatin, and have been attributed to its deregulation. To understand acetylation mechanisms and their role in cell signaling, transcriptional regulation, and apoptosis, it is crucial to identify and analyze acetylation sites. Bioinformatics methods can be used to generate relatively precise predictions. Here we applied classical bioinformatics methods-sequence alignment, homology modeling, and docking-to compare approved and predicted lysine acetylation processes in different organisms. HAM1 and HAM2 are analogs of KAT8 and KAT7 (MYST1 and MYST2), members of the MYST histone acetyltransferase family, and our results show that HAM1 and HAM2 have much in common with other representatives of MYST families from various organisms. One function of acetyl-CoA binding was predicted with a high level of probability by computational methods. Based on our data, we conclude that, despite huge genetic distances and some structural differences between animal and plant species, a closer look at acetylation mechanism shows that they have much in common.

Locked nucleic acid anti-miR-21 inhibits cell growth and invasive behaviors of a colorectal adenocarcinoma cell line: LNA-anti-miR as a novel approach

Colorectal cancer (CRC) is the third leading cause of cancer-related death and has an extremely poor prognosis. Dysregulation of microRNAs (miRNAs) has been shown to be involved in the pathogenesis and progression of many malignancies. Recent data suggest that microRNA-21 (miR-21) is significantly elevated in different types of cancer, especially colon adenocarcinoma. Against this background, locked nucleic acid (LNA)-modified oligonucleotides have recently been suggested as a novel approach for targeting miRNAs as antisense-based gene silencing. The aim of the current study was to explore the functional role of LNA-anti-miR-21 in a colon adenocarcinoma LS174T cell line. LS174T cells were transfected with LNA-anti-miR-21 for 24, 48 and 72 h. Quantitative real-time reverse transcriptase-PCR (qRT-PCR) was performed to assess miR-21 expression by LNA-anti-miR-21. The viability of the cells was evaluated by MTT (3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide) assay and Annexin V/propidium iodide staining assay was used to detect apoptosis. Moreover, invasive behavior of the cells was evaluated before and after therapy by transwell assay. LNA-anti-miR-21 was successfully transfected in human LS174T cells and suppressed the endogenous miR-21. LNA-anti-miR-21 inhibited the cells' growth followed by induction of apoptosis. LNA-anti-miR-21 (50 pmol/μl) reduced the invasive behaviors of LS174T cells after 24 h, compared with untreated cells and scrambled LNA-transfected cells. However, this effect was more pronounced after 72 h. Our findings suggest the therapeutic potential of LNA-anti-miR-21 in a colon adenocarcinoma for targeting miR-21 expression. Further studies are warranted to investigate the molecular mechanisms underlying this novel inhibitor in colorectal cancer to establish its potential value for treatment of CRC patients with high miR-21 expression.

Evaluation of miR-146a expression level in macrophages exposed to Candida glabrata

Background and Purpose:

MicroRNAs are small non-coding RNAs with 19-24 nucleotides in length. Up- or down-regulation of many miRNAs has been shown by stimulation of Toll-like receptors (TLRs) in the innate immune system. Up-regulation of miR-146a has been reported by both TLR and heat-killed Candida albicans. In this study, we aimed to evaluate the expression of miR-146a in cultured monocyte-derived macrophages (MDMs) infected by Candida glabrata at 12, 24, and 48 hours.

Materials and Methods:

miR-146a expression was evaluated by qRT-real time polymerase chain reaction (PCR) at three time points in C. glabrata-infected MDMs. The data was analyzed using repeated measures ANOVA.

Results:

miR-146a expression was down-regulated in infected MDMs compared to the control group (P<0.018). The expression of miR-146a was at its highest level at 48 h, as compared to 12 and 24 h (P<0.018) .The differences between the experimental group compared to the control group were statistically significant (P<0.018).

Conclusion:

These results suggest that miR-146a can be involved in regulating macrophage function following TLR stimulation in C. glabrata-infected MDMs.

Locked nucleic acid inhibits miR-92a-3p in human colorectal cancer, induces apoptosis and inhibits cell proliferation

MicroRNAs (miRNAs) are a type of small noncoding RNAs that have a vital role in basic biological processes such as cellular growth, division and apoptosis. A change in the expression of miRNAs can induce many diseases. Recently, the role of miRNA in some of the cancers as a tumor suppressor and oncogene has been recognized. Several studies have proved that miR-92a-3p acts as an oncogene in colorectal cancer (CRC). We studied CRC by inhibiting miR-92a-3p in SW48 cells (human colorectal cancer cell line) that were transfected with locked nucleic acid (LNA). At different times, the expression level of miR-92a-3p, cell vitality, apoptosis and necrosis were studied by qRT-PCR, MTT, Annexin-V and propidiumiodide. Our results showed that the expression of miR-92a-3p and proliferation of SW48 cells were decreased, and also a high percentage of SW48 cells were exposed to apoptosis and necrosis (P⩽0.005). Our study showed that the inhibition of miR-92a-3p with LNA inhibited cell proliferation and induced apoptosis and necrosis in CRC.

Changes in the chemical properties and swelling coefficient of alfalfa root cell walls in the presence of toluene as a toxic agent

The influence of toluene pollution on the chemical properties and swelling coefficient of root cell walls in alfalfa (Medicago sativa L.) was investigated. Two sets of alfalfa seedlings were selected and one set was treated with 450 mg L(-1) toluene in the nutrient solution under hydroponic culture. Thirty days after treatment with toluene, alfalfa plants were harvested and the root cell walls were isolated. Fourier-transform infrared (FTIR) spectroscopy was carried out for the characterization of the root cell walls composition. The cation exchange capacity (CEC) and the swelling coefficient of the root cell walls (Kcw) were estimated at various pH values. The toluene contamination significantly reduced the mass of the cell wall material in the alfalfa roots. According to the FTIR spectra, the toluene pollution can change the alfalfa root cell wall properties by reducing the cell wall functional groups. These functional groups are probably related to the proteins and polysaccharides in the cell wall. Also, toluene pollution strongly reduced CEC and Kcw of the root cell walls. The results show that the decrease in the active sites of adsorption on the root cell walls as a response to toluene pollution can affect the water flow rate and the mineral nutrients uptake by roots.

Cardiovascular disease risk factors in the South Asian population living in Kuwait: a cross-sectional study

BACKGROUND

High rates of diabetes and cardiovascular disease have been reported in South Asian immigrants in many countries. However, the prevalence and characteristics of cardiovascular disease risk factors among a South Asian population living in Kuwait have not yet been investigated. This study was therefore designed to estimate the prevalence of cardiovascular disease risk factors and determine whether they are independently associated with diabetes in such a population.

METHODS

A population-based cross-sectional study was conducted on 1094 South Asians (781 men and 313 women), mainly Indian and Pakistani (≥ 18 years of age), of whom 75.1% were Indians. Interviews were carried out, during which socio-demographic and anthropometric data were collected, followed by a physical examination and collection of fasting blood samples for laboratory investigations. Diabetes was defined by fasting plasma glucose ≥ 7 mmol/l, or being on treatment, and/or self-reported previously diagnosed Type 2 diabetes.

RESULTS

The prevalence of diabetes was 21.1%, with 3.4% of that percentage of people being newly diagnosed. Using BMI measurements, 24.0% of those who participated in the study were obese and 46.1% were overweight. Dyslipidaemia was found in 77.6% and hypertension in 44.8%. Advancing age (≥ 40 years), male gender, high LDL, high total cholesterol, hypertension and positive family history of diabetes were significantly associated with increased risk of diabetes.

CONCLUSION

Our study shows that the prevalence of cardiovascular disease risk factors in South Asian expatriates in Kuwait exceeds prevalence rates reported in their homeland and other countries. This may suggest the added stress of environmental factors on the development of cardiovascular disease risk factors in such populations. Specialized prevention programmes targeting such high-risk ethnic populations are paramount and need to be implemented.

Diabetes and associated cardiovascular risk factors in the State of Kuwait: the first national survey

BACKGROUND

Cardiovascular diseases (CVD) are the leading cause of mortality worldwide as well as in Kuwait. People with diabetes have two to five times greater risk of developing CVD as compared with non-diabetic individuals. To date, little information exists on the prevalence and characteristics of cardiovascular risk factors in Kuwait. The objective of this survey was to address the growing burden of diabetes and related cardiovascular risk factors, and to estimate, for the first time, the prevalence of cardiovascular risk factors in the State of Kuwait.

METHODS

The study was carried out using the World Health Organization (WHO) STEPwise approach for surveillance of non-communicable disease risk factors. This study represents a national survey for Kuwaiti nationals aged between 20 and 65 years. All participants were involved in an interview for gathering sociodemographic information, underwent focused physical examination and donated a blood sample for the study-specific laboratory investigations.

RESULTS

A total of 1970 subjects, with a mean age of 48.9 ± 10.5, were screened. The prevalence of cardiovascular risk factors was as follows: diabetes 17.9%, dyslipidaemia 70.3%, hypertension 25.3% and obesity 48.2%. Over 62% had a sedentary lifestyle, and 17.8% were smokers. The prevalence of diabetes and dyslipidaemia increased with age and body mass index. Diabetes was also significantly associated with age above 40 years (OR = 10.5), family history of diabetes (OR = 2.79), hypertension (OR = 2.22), obesity (OR = 2.87) and lower literacy (OR = 4.23).

CONCLUSIONS

This study found that advancing age (≥ 40 years), diabetes mellitus, obesity, positive family history of diabetes, hypertension and dyslipidaemia are significant risk factors for developing CVD in Kuwait as in other parts of the world. Understanding these factors allows for preventive measures to be taken for Kuwaiti population.

Median aperture of the fourth ventricle revisited

BACKGROUND

The median aperture of Magendie is the largest of three openings of the fourth ventricle and thus it forms the main path for the outflow of the cerebrospinal fluid from the ventricle. The Magendie aperture connects the fourth ventricle with the cisterna magna and makes a natural corridor for neurosurgical approach and inspection of the ventricle and its floor. The purpose of this study was to give a contemporary anatomical view of this structure in the context of historical data.

MATERIAL AND METHODS

The Magendie foramen was studied in 30 fixed specimens of human brainstems with cerebella. The microdissection technique was used. Measurements were taken with a microscope ocular ruler.

RESULTS

The aperture is limited by the following structures: obex and gracile tubercles inferiorly, and tela choroidea with choroid plexus superolaterally. Obex tubercles usually have the form of a piece of neural tissue bridging two halves of the brainstem above the entrance to the central canal. Gracile tubercles together are 8.15 mm wide and the maximal width of the foramen is 6.53 mm. Tela choroidea attaches laterally at both sides to the inferior medullary velum. In most cases the right and left choroid plexus are connected to each other with a triangular membrane of tela choroidea, which protrudes through the median foramen and attaches to the vermis at a highly variable level.

CONCLUSIONS

We hope that the presented description of anatomical relations around the Magendie aperture, with its new measurements, will be helpful for those operating in the area and will explain some of the inaccuracies found in literature.

A comparison between the results of fissurectomy and lateral internal sphincterotomy in the surgical management of chronic anal fissure

BACKGROUND

We compare lateral internal sphincterotomy as an effective treatment of chronic fissure in ano to fissurectomy, which is as an alternative surgical treatment.

METHODS

Sixty two consecutive patients were divided into two groups through sequential sampling. Thirty patients underwent fissurectomy and 32 underwent lateral internal sphincterotomy. After a median follow-up of 22 months, we compared the results of the two procedures. In addition to frequent visits on a predetermined basis, a telephone inquiry into fissure recurrence and continence status was made.

RESULTS

All patients in both groups were pain-free and without bleeding within 1 week. In both groups, urinary retention was noted in one patient. Incontinence to flatus was noted in the fissurectomy (F) group in two (6.2%) patients, but no incontinence was noted in the lateral internal sphincterotomy (LIS) group. There was one patient (3.1%) with fissure recurrence in the F group but none in the LIS group. No patient in either group was afflicted with anal stenosis or perianal infections. All wounds healed within 8 weeks. Twenty nine patients (96.6%) in the LIS group and 28 (87.5%) in the F group reported satisfactory results with their procedure.

CONCLUSION

In the surgical treatment of chronic anal fissure not responding to conservative management, LIS may be the better treatment and, perhaps, the preferable surgical technique with fewer total complications (P < 0.005).

Reductions in the tobacco specific nitrosamine (TSNA) content of tobaccos taken from commercial Canadian cigarettes and corresponding reductions in TSNA deliveries in mainstream smoke from such cigarettes

Tobacco specific nitrosamines (TSNAs) are suspected to cause smoking-related neoplastic diseases. The change from direct-fired to indirect-fired barns (aka kilns) for curing bright (aka Virginia, flue-cured) tobaccos was made to reduce the TSNA concentrations. The effectiveness of such processes in reducing the deliveries of TSNAs to the users of the products should be monitored. However, it is difficult to assess the effects of this reduction on the TSNA levels in mainstream smoke when cigarette blends contain burley tobaccos and other blend components that can increase smoke TSNA concentrations. Canadian cigarettes made prior to and in the few years just after the conversion to indirect-fired curing should not be subject to such interferences. Thus, the TSNA content of tobaccos and mainstream smoke from six brands of Canadian cigarettes produced in 2003, 2004, and 2005 were determined. Reductions in NNK [4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone], the most important TSNA in flue-cured tobaccos, levels in the tobacco blends ranged from 60% to 85%. The corresponding reductions in mainstream smoke TSNA levels ranged from 59% to 72% (ISO smoking conditions) and 58-76% (Health Canada Intensive smoking conditions). These results show that other factors (microorganisms, nitrite levels) may be negating the TSNA reductions achieved by indirect-fired curing.

Experimental and Theoretical Investigation of High-Power Laser Ionization and Dissociation of Methane

The main purpose of this paper is to report the high-power laser ionization-dissociation of CH(4) at various femtosecond (fs) laser intensities (from 1 x 10(14) W/cm(2) to 2 x 10(15) W/cm(2)) with a laser pulse duration of 48 fs. The generalized molecular Keldysh theory has been applied to calculate the ionization yields for CH(4)+ and CH(4)++. Outside the influence of the fs intense laser, we propose to calculate the mass spectra due to the decomposition of CH(4)+ and CH(4)++, using the Rice-Ramsperger-Kassel-Marcus (RRKM) theory. The agreement between the experimental mass spectra and calculated mass spectra seems to be reasonable.

Platelet nitric oxide synthase is activated by tyrosine dephosphorylation: possible role for SHP-1 phosphatase

BACKGROUND

Endothelial nitric oxide synthase (eNOS) activity in endothelial cells is regulated by post-translational phosphorylation of critical serine, threonine and tyrosine residues in response to a variety of stimuli. However, the post-translational regulation of eNOS in platelets is poorly defined.

OBJECTIVES

We investigated the role of tyrosine phosphorylation in the regulation of platelet eNOS activity.

METHODS

Tyrosine phosphorylation of eNOS and interaction with the tyrosine phosphatase SHP-1 were investigated by coimmunoprecipitation and immunoblotting. An in vitro immunoassay was used to determine eNOS activity together with the contribution of protein tyrosine phosphorylation.

RESULTS

We found platelet eNOS was tyrosine phosphorylated under basal conditions. Thrombin induced a dose- and time-dependent increase in eNOS activity without altering overall level of tyrosine phosphorylation, although we did observe evidence of minor tyrosine dephosphorylation. In vitro tyrosine dephosphorylation of platelet eNOS using a recombinant protein tyrosine phosphatase enhanced thrombin-induced activity compared to thrombin alone, but had no effect on endothelial eNOS activity either at basal or after stimulation with bradykinin. Having shown that dephosphorylation could modulate platelet eNOS activity we examined the role of potential protein phosphatases important for platelet eNOS activity. We found SHP-1 protein tyrosine phosphatase, co-associated with platelet eNOS in resting platelets, but does not associate with eNOS in endothelial cells. Stimulation of platelets with thrombin increased SHP-1 association with eNOS, while inhibition of SHP-1 abolished the ability of thrombin to induce elevated eNOS activity.

CONCLUSIONS

Our data suggest a novel role for tyrosine dephosphorylation in platelet eNOS activation, which may be mediated by SHP-1.

The occurrence, variations and diameter of the human condylar canal in relation to the jugular foramen

In medical practice, especially in analysis of radiograms and computed tomography scans, it is very important to be familiar with the anatomy of the skull base, not only the normal and typical anatomical structures but also the variations and anomalies. One of the important venous foramina of the human skull is the condylar canal. This structure is described as the most stable and permanent venous emissary, with a prevalence of up to 100%. In our study, based on 100 human macerated skulls, this canal was encountered in 81% of cases. In several it was double. We have not encountered any information on this in the available literature. We found that the condylar canal in humans could be double and that the size of the external opening of this canal is not crucial in relation to the size of the jugular foramen. There was no significant correlation between the jugular foramen and the condylar canal in our specimens.

Coronary angioplasty and stenting in orthotopic heart transplants: a fruitful act or a futile attempt?

Accelerated allograft coronary artery disease remains the major cause of mortality after the first year of transplantation. Despite the extensive use of stents and angioplasty in coronary artery disease, there is a paucity of data about the efficacy of such interventions in orthotopic heart transplants. The authors herein report the outcome of those patients in their institution who had undergone percutaneous coronary artery angioplasty and stenting at a late stage of their transplantation. Within a 12-year period, 106 adult patients underwent orthotopic heart transplantation at their institution. Eight of these patients with 17 lesions underwent deployment of nine stents and eight angioplasties 8.1 +/- 3.2 years posttransplantation. There were 15 denovo and two restenotic lesions. The indications for intervention were presence of symptoms in five patients and severity of lesions in three asymptomatic patients detected on their follow-up angiogram. All patients had angiographic worsening of lesions at their follow-up angiogram. The initial procedural success for both stented and angioplastied lesions was 100%. Within a mean angiographic follow-up of 261 days, all balloon angioplastied lesions had developed restenosis, whereas within a mean period of 67 days, 50% of stented lesions had developed restenosis. On the follow-up angiogram, deterioration of the nontreated segments were noted throughout the coronary arterial tree; however, the immediate proximal and distal parts of the target segments demonstrated an exaggerated hyperproliferative response as compared to other sites. The overall median time to the detection of restenosis for both stented and angioplastied lesions was 5.2 months (inner quartile 2.5-6.2 months). The authors conclude that angioplasty and stenting late in the course of transplantation is associated with a significant restenosis rate and in such patients earlier or alternative catheter-based interventions must be considered.

Simulation of ion trajectories in a quadrupole ion trap: a comparison of three simulation programs

An attempt has been made to compare the performance, design and operation of three simulators, ISIS, ITSIM and SIMION-3D, when applied to the calculation of ion trajectories in a quadrupole ion trap. For the simulation of the trajectory of a single ion in a collision-free system, the calculated spatial trajectory components, kinetic energies and secular frequencies from the three simulators were virtually identical. It is concluded that, despite the various approaches to electrode design, calculation of fields, integration methods and ion generation tactics, there is a remarkable degree of consistency among the products of the simulators when dealing with collision-free conditions. The results of the ion injection simulations under collisional conditions were indicative of the complexity that can be introduced into the simulations with little effort. Random effects such as collisions of ions with He buffer gas and accumulated calculation errors together with the different collision model settings and the different approaches to field calculation are thought to have contributed to the somewhat minor differences in trapping efficiency. SIMION is the simulator of choice for the simulation of ion trajectories in hybrid instruments and in custom-designed assemblies of electrodes; and ITSIM would appear to be the best choice on the basis of computational speed for running multiparticle simulations and user friendliness. Both ISIS and ITSIM are adept at providing detailed information of collision events. Copyright 1999 John Wiley & Sons, Ltd.