Dose perturbation effects by metal hip prosthesis in gynaecological 192Ir HDR brachytherapy

The present study was conducted to elucidate the effects of hip prostheses in ¹⁹²Ir HDR brachytherapy and determine dose uncertainties introduced by the treatment planning. A gynaecological phantom irradiated using Nucletron ¹⁹²Ir microSelectron HDR source was modeled using MCNP5 code. Three hip materials considered in this study were water, bone, and metal prosthesis. According to the obtained results, a dose perturbation was observed within the medium with a higher atomic number, which reduced the dose to the nearby region.

Functional papaya beverage increases healthy gut microbiota in Streptozotocininduced diabetic Sprague Dawley rats

Diabetes mellitus is a silent killer illness, characterized by hyperglycaemia effect and can cause many health complications. A new functional papaya beverage was produced via selected pure symbiotic culture of bacteria and yeast (SCOBY) which offers an alternative food therapy in regulating blood glucose and its efficacy was evaluated using Streptozotocin (STZ)-induced diabetic Sprague Dawley rats for one month treatment. Under moderate diabetes condition, SCOBY papaya beverage was shown able to reduce high blood glucose in diabetic rats to normal level, comparably effective with commercial drug, Metformin. Not only that, it also helped restore body weight of diabetic rats to a healthier state with a gradual increment of body weight observed weekly. In contrast, untreated diabetic rats experienced a sharp rise in blood glucose with stunted body weight. Nutrigenomic studies were conducted to identify the mechanisms that support the effectiveness of SCOBY papaya beverage as an anti-diabetic therapy. Evidence from quantitative polymerase chain reaction (qPCR) analysis disclosed significant higher expression on gene markers related to insulin receptor substrate 1 (Irs1), glucose transporter (Slc2a8) and glutathione S-transferase mu 1 (Gstm1), but lower expression of gene markers indicative of diabetes complications and inflammation e.g., tissue inhibitors of metalloproteinase 1 (Timp1), nuclear factor kappa B subunit 1 (Nfkb1) and nitric oxide 2 (NOS2) in diabetic rats treated with SCOBY papaya beverage and Metformin (p<0.05). SCOBY papaya treated diabetic rats showed an increment of short chain fatty acids content and gut microbiota enriched with some beneficial microbes particularly for Alloprevotella, Ruminococcus 1, Lachnospiraceae NK4A136, Prevotellaceae UCG-001 and Prevotellaceae NK3B31 compared to untreated diabetic rats. These data support the effectiveness of SCOBY papaya as a functional beverage in improving intestinal health by changing the environment of the microbiome of diabetic rats, in turn offering costeffective food therapies in blood glucose regulation.

The characterization of the bioactive compounds in fermented papaya pulp and leaves: providing new insights on the anti-ageing potential

Nowadays, fermented food and beverages derived from plants have become popular choices for consuming functional foods as they provide enormous advantages to human health. Fermented food and beverage might offer more therapeutic benefits than natural nutrition. Papaya contains high antioxidant, antitumor, and immune regulatory effects due to its valuable phytochemical properties. Despite all the advantages, papaya leaves were underutilised as they have an astringent and bitter taste. During this study, papaya pulp and leaves underwent fermentation to enhance their functional properties and improve their taste and flavour. Both papaya pulp and leaves were fermented using mixed cultures of Komagataiebacter sp. bacteria and Dekkera sp. yeast and incubated under a controlled fermentation process. The supernatant extracted from both fermented papaya pulp and leaves was collected and its inhibitory effect towards the elastase, tyrosinase and acetylcholinesterase was analysed. Elastase and tyrosinase were employed for anti-ageing as increasing in dermal enzymatic activities will cause skin disorders. Meanwhile, acetylcholinesterase will affect the cholinergic crisis in the brain. Thus, inhibiting these enzymes is important for preventing hyperpigmentation, skin ageing and improving cognitive function. In comparison to non-fermented papaya pulp and leaves, the fermented papaya extracts demonstrated significant differences (P<0.05) in the inhibition effect against elastase, tyrosinase and acetylcholinesterase with an inhibitory value above 80%. Most of the flavonoids obtained in fermented papaya pulp and leaves were higher than non-fermented pulp and leaves. Protocatechuic acid was the highest compound in fermented papaya pulp (1.22±0.11 µg/mL), while vitexin (113.20±1.18 µg/mL), rutin (10.56±0.52 µg/mL), and ellagic acid (8.76±0.40 µg/mL) highly contained in fermented papaya leaves. The highest organic acids obtained from fermented papaya pulp and leaves acetic acid (13495.42±308.99 µg/mL and 18572.48±78.45 µg/mL), followed by quinic acid (2148.71±63.31 µg/mL and 984.40±2.29 µg/mL) and citric acid (802.57±17.68 µg/ mL and 151.83±6.50 µg/mL), respectively. The findings described the potential of fermented papaya pulp and leaves extracts as potential bio-ingredients to slow down ageing development

The effects of organic materials on the growth of Boesenbergia rotunda

Boesenbergia rotunda (L.) Mansf. commonly known as temu kunci is a perennial herb which is botanically described as a small herbaceous plant. Temu kunci has a short, fleshy or slender rhizome shape. The rhizomes of B. rotunda have been widely used as spices due to their aromatic flavour, which promotes appetite. This herbal plant is also used as flavouring agents, dyes and traditional medicine to cure various kinds of illnesses. Organic materials have been widely used in agriculture development to improve soil quality, increase crop yield, and plant growth performance, and reduce chemical fertilizer usage. The adverse impact of excessive use of chemical fertilizers in conventional agricultural practices is well documented. A field study was conducted to identify the effects of organic materials on the growth of B. rotunda. A completely randomized design (CRD) was used which involve seven treatments and four replication including control, chemical fertilizer alone, and 10% additional materials in 5 kg of soil. The organic materials used in this study are biochar, vermicompost, food waste compost, empty fruit bunch compost and lignohumate. In this study, the vermicompost gave a significant increase and highest reading of plant height, number of leaves, rhizome and finger roots fresh and dry weight compared to other treatments. In conclusion, organic materials can give positive effects on the growth of B. rotunda and at the same time can reduce the dependencies on chemical fertilizer.

Development of the rural Palliative Care Services by the Kuala Lipis District Hospital

In recognising the palliative care (PC) needs globally and in Malaysia, services were developed to serve the rural area of Kuala Lipis, Pahang. This communication describes the initial a Strengths, Weaknesses, Opportunities, and Threats (SWOT) analysis, stages of development towards achieving a successful implementation. PC services were led by Kuala Lipis district hospital include inpatient referrals, outpatient and community care through home visits. These services involve multi-disciplinary team inclusive of representatives from health clinics and allied health. Referrals and opioid usage have demonstrated an increasing trend since its implementation in October 2018. Implementation of rural PC services is feasible; however, long-term sustainability needs to addressed.

Fermented jackfruit leaf beverage offers new affordable and effective diabetes therapy

Diabetes mellitus is complicated multifactorial disorders characterised by hyperglycemia or glucose intolerance. Globally, the number of people suffering from diabetes has increased steadily. Jackfruit leaf, a rich source of phytochemicals offers the opportunity for the development of value-added products. A fermented jackfruit leaf beverage product was developed using symbiotic culture of bacteria and yeast (SCOBY) as cost-effective beneficial treatment for mankind in the management of diabetes. The effectiveness of this fermented jackfruit leaf beverage as an anti-diabetic therapy agent was evaluated using Streptozotocin-induced Sprague Dawley rats model for 4 weeks. The findings depict that, there was a remarkable reduction of blood glucose level in fermented jackfruit leaf-treated diabetic rats as opposed to non-treated diabetic rats, comparable with metformin-treated diabetic rats. The body weight and various relative organ weights of diabetic rats treated with fermented jackfruit leaf beverage showed a healthy recovery sign from diabetes symptoms. The blood haematology profile, liver and kidney function analysis revealed no toxic effect of prolong fermented jackfruit leaf beverage consumption. These results indicated that fermented jackfruit leaf beverage has similar anti-diabetic properties with commercial anti-diabetic drugs with no adverse side effect. Promisingly, it offers a cheaper source to alleviate the diabetes epidemic in a natural way.

Evidence of potent antibacterial effect of fermented papaya leaf against opportunistic skin pathogenic microbes

The papaya leaf juice has been long practised as a traditional remedy to cure ailments due to its medicinal properties. The objective of this research is to study the effectiveness of fermented papaya leaf to inhibit the growth of pathogenic bacteria and yeast: Staphylococcus aureus, Pseudomonas aeruginosa, Propionibacterium acnes and Candida albicans. The efficacy of fermented papaya leaf against selected pathogenic microbes was evaluated using agar well diffusion assay, broth microdilution assay and time-kill test. Evidence from data collected confirmed that fermented papaya leaf supernatant showed more pronounced antibacterial and antifungal effect than papaya leaf alone. Generally, fermented papaya leaf supernatant demonstrated potent antimicrobial effect against all bacterial pathogens tested particularly P. aeruginosa followed by P. acne and S. aureus. However, it was found that fermented papaya leaf was less effective against Candida albicans. It needs 4- to 7-folds higher concentration to inhibit 50% C. albicans growth than the bacteria. The antibacterial compounds produced in the supernatant appeared to have some bactericidal effect against P. aeruginosa, P. acne and S. aureus with the minimum inhibitory concentration (MIC>99) of 16%, 50% and 60%, respectively. Particularly, the fermented papaya leaf supernatant at 60% concentration showed 100% inhibition rate within 30 mins against P. aeruginosa. However, it needs a longer time to show the same inhibition effect against S. aureus and P. acne, which was about 2-6 h. The potent killing effect of fermented papaya leaf showed a potential use in skincare application to control pathogenic microbe infection

Geospatial Distribution and Predictors of Mortality in Hospitalized Patients With COVID-19: A Cohort Study

BACKGROUND

The global coronavirus disease 2019 (COVID-19) pandemic offers the opportunity to assess how hospitals manage the care of hospitalized patients with varying demographics and clinical presentations. The goal of this study was to demonstrate the impact of densely populated residential areas on hospitalization and to identify predictors of length of stay and mortality in hospitalized patients with COVID-19 in one of the hardest hit counties internationally.

METHODS

This was a single-center cohort study of 1325 sequentially hospitalized patients with COVID-19 in New York between March 2, 2020, to May 11, 2020. Geospatial distribution of study patients' residences relative to population density in the region were mapped, and data analysis included hospital length of stay, need and duration of invasive mechanical ventilation (IMV), and mortality. Logistic regression models were constructed to predict discharge dispositions in the remaining active study patients.

RESULTS

The median age of the study cohort (interquartile range [IQR]) was 62 (49-75) years, and more than half were male (57%) with history of hypertension (60%), obesity (41%), and diabetes (42%). Geographic residence of the study patients was disproportionately associated with areas of higher population density (r s = 0.235; P = .004), with noted "hot spots" in the region. Study patients were predominantly hypertensive (MAP > 90 mmHg; 670, 51%) on presentation with lymphopenia (590, 55%), hyponatremia (411, 31%), and kidney dysfunction (estimated glomerular filtration rate < 60 mL/min/1.73 m2; 381, 29%). Of the patients with a disposition (1188/1325), 15% (182/1188) required IMV and 21% (250/1188) developed acute kidney injury. In patients on IMV, the median (IQR) hospital length of stay in survivors (22 [16.5-29.5] days) was significantly longer than that of nonsurvivors (15 [10-23.75] days), but this was not due to prolonged time on the ventilator. The overall mortality in all hospitalized patients was 15%, and in patients receiving IMV it was 48%, which is predicted to minimally rise from 48% to 49% based on logistic regression models constructed to project disposition in the remaining patients on ventilators. Acute kidney injury during hospitalization (odds ratioE, 3.23) was the strongest predictor of mortality in patients requiring IMV.

CONCLUSIONS

This is the first study to collectively utilize the demographics, clinical characteristics, and hospital course of COVID-19 patients to identify predictors of poor outcomes that can be used for resource allocation in future waves of the pandemic.

P2545Long-term use of anabolic-androgenic steroids in male weightlifters is associated with left ventricular systolic dysfunction

Background

Illicit use of anabolic-androgenic steroids (AAS) is widespread and has adverse psychological and cardiovascular effects. Few well-powered studies have explored the effect of long-term AAS-use on left ventricular systolic function.

Purpose

To explore the relationship between long-term use of AAS and left ventricular mass and systolic function.

Methods

We included male weightlifters with a history of >1 year of cumulative AAS-use and male weightlifters unexposed to AAS. We performed echocardiography in all and assessed left ventricular mass using 2D echocardiographic linear measurements and Cube formula, left ventricular ejection fraction (EF) ad modum Simpson, and left ventricular global longitudinal strain (GLS) by speckle-tracking echocardiography.

Results

We recruited 100 male weightlifters, 58 of whom were previous or current AAS-users with mean±SD AAS-use of 10.4±7.0 years, and 42 unexposed weightlifters. There were no difference in age (35.5±9.2 vs. 35.3±7.5 years, p=0.8) nor body mass index (BMI) (BMI 31.4±5.0 vs. 30.1±3.5, p=0.6) between AAS-exposed and unexposed weightlifters. Compared with unexposed weightlifters, AAS-exposed weightlifters demonstrated thicker interventricular septum (11.2±2.4 vs. 9.2±1.3 mm, p<0.001), thicker left ventricular posterior wall dimension (10.1±2.1 vs. 8.9±1.3 mm, p<0.001), and higher left ventricular mass index (99.7±25.4 vs. 78.4±12.1 g/m2, p<0.001). Both left ventricular EF and left ventricular GLS were decreased in AAS-exposed weightlifters compared with unexposed weightlifters (49±9 vs. 53±6%, p=0.02, and −15.6±2.6 vs. −18.3±2.1%, p<0.001) (Figure).

Conclusion

AAS use in male weightlifters was associated with increased left ventricular mass and impaired left ventricular systolic function. Our results suggest considerable adverse cardiac effects of AAS use, but the results need confirmation in prospective observational trials.

Encapsulation of Bacillus salmalaya 139SI using double coating biopolymer technique

Sustainable crop production for a rapidly growing human population is one of the current challenges faced by the agricultural sector. However, many of the chemical agents used in agriculture can be hazardous to humans, non-targeted organism and environment. Plant growth promoting rhizobacteria have demonstrated a role in promoting plant growth and health under various stress conditions including disease. Unfortunately, bacterial viability degrades due to temperature and other environmental factors (Bashan et al., Plant Soil 378: 1-33, 2014). Encapsulation of bacteria into core-shell biopolymers is one of the promising techniques to overcome the problem. This study deals with the encapsulation of Bacillus salmalaya 139SI using simple double coating biopolymer technique which consist of brown rice protein/alginate and 0·5% low molecular weight chitosan of pH 4 and 6. The influence of biopolymer to bacteria mass ratio and the chitosan pH on the encapsulation process, physic-chemical, morphology and bioactivity properties of encapsulated B. salmalaya 139SI have been studied systematically. Based on the analysis of physico-chemical, morphology and bioactivity properties, B. salmalaya 139S1 encapsulated using double coating encapsulation technology has promising viability pre- and postfreeze-drying with excellent encapsulation yields of 99·7 and 89·3% respectively. SIGNIFICANCE AND IMPACT OF THE STUDY: The need of a simple yet effective way of encapsulating plant growth promoting rhizobacteria is crucial to further improve their benefits to global sustainable agriculture practice. Effective encapsulation allows for protection, controlled release and function of the micro-organism, as well as providing a longer shelf life for the product. This research report offers an innovative yet simple way of encapsulating using double coating technology with environmentally friendly biopolymers that could degrade and provide nutrients when in soil. Importantly, the bioactivity of the bacteria is maintained upon encapsulation.

Lung cancer tissue diagnosis in poor lung function: addressing the ongoing percutaneous lung biopsy FEV1 paradox using Heimlich valve

Many centres continue to decline percutaneous lung biopsy (PLB) in patients with poor lung function (particularly FEV1 <1 L) due to the theoretically increased risk of pneumothorax. This practice limits access to novel lung cancer therapies and minimally invasive surgical techniques. Our retrospective single-centre analysis of 212 patients undergoing PLB, all performed prospectively and blinded to lung function, demonstrates that using ambulatory Heimlich valve chest drain (HVCD) to treat significant postbiopsy pneumothorax facilitates safe, diagnostic, early discharge lung biopsy irrespective of lung function with neither FEV1 <1 L nor transfer coefficient for carbon monoxide (TLCO) <40% predicted shown to be independent predictors of HVCD insertion or pneumothorax outcomes. Incorporating ambulatory HVCD into standard PLB practice thereby elegantly bridges the gap that currently exists between tissue diagnosis in patients with poor lung function and the advanced therapeutic options available for this cohort.

Monte Carlo dose calculation in dental amalgam phantom

It has become a great challenge in the modern radiation treatment to ensure the accuracy of treatment delivery in electron beam therapy. Tissue inhomogeneity has become one of the factors for accurate dose calculation, and this requires complex algorithm calculation like Monte Carlo (MC). On the other hand, computed tomography (CT) images used in treatment planning system need to be trustful as they are the input in radiotherapy treatment. However, with the presence of metal amalgam in treatment volume, the CT images input showed prominent streak artefact, thus, contributed sources of error. Hence, metal amalgam phantom often creates streak artifacts, which cause an error in the dose calculation. Thus, a streak artifact reduction technique was applied to correct the images, and as a result, better images were observed in terms of structure delineation and density assigning. Furthermore, the amalgam density data were corrected to provide amalgam voxel with accurate density value. As for the errors of dose uncertainties due to metal amalgam, they were reduced from 46% to as low as 2% at d₈₀ (depth of the 80% dose beyond Z_max) using the presented strategies. Considering the number of vital and radiosensitive organs in the head and the neck regions, this correction strategy is suggested in reducing calculation uncertainties through MC calculation.

Human System Modeling Technique for Semiconductor Assembly and Test

Global competitions are putting pressure on the manufacturing companies to produce products cheaper and faster. Thus, manufacturing operations are urgently exploring methods to reduce cost through improved efficiency in managing the resources. In recent years, there has been growing interest to study human system due to the lack of focus as compared to other resources such as equipment and material. This paper presents the overview and evaluation of the various human issues affecting manufacturing system dynamics and performance. Furthermore, the gap in the current models will be discussed before presenting the development of a proposed model to study human system in semiconductor assembly and test.

Characterization and stability of nanostructured lipid carriers as drug delivery system

Recently more focus has been put to the development of innovative drug-delivery systems that includes polymer nanoparticles, emulsions and liposomes and solid lipid nanoparticles (SLNs). The SLNs have been proposed to be an alternative colloidal drug delivery system. The aim of this study was preparation and characterization of solid lipid nanoparticle (SLN) using varieties of emulsifier for encapsulation of the drug with poor water solubility. In these study four types of solid lipid nanoparticles were prepared based on different compositions of palm oil (S154) and lecithin (Lipoid 100) using the high pressure homogenization method. The SLN formulation had the following (palm oil+lecithin) compositions: SLN-01 (90 + 10%, respectively), SLN-02 (80 + 20%, respectively), SLN-03 (70 + 30%, respectively) and SLN-04 (60 + 40%, respectively). The SLNs were characterized and the optimum stability factors for one year storage determined. The parameters used to characterize the SLNs were particle size and polydispersity index (particle sizer), zeta potential (zetasizer), crystallinity (differential scanning calorimetry and wide angle X-ray diffraction), ultrastructure (transmission electron microscopy). Varying the palm oil and lecithin compositions resulted in SLNs of variable sizes and zeta potentials. The particle sizes of SLN-01, SLN-02, SLN-03 and SLN-04 were 298.40 +/- 11.80, 255.40 +/- 3.20, 145.00 +/- 3.39 and 273.00 +/- 86.50 nm, respectively, while the zeta potentials were -19.44 +/- 60.00, -19.50 +/- 1.80, -17.83 +/- 10.00 and -13.33 +/- 2.30 mV, respectively. Thermoanalysis and X-ray diffraction analysis showed that the SLNs had lower crystallinity than bulk lipid. The SLNs were generally round and uniform in shape under transmission electron microscopy. The SLN dimensional data suggested they had high quality physicochemical characteristics, which are conducive for the loading of poor water solubility drugs.

Developing a nutrition education package for Malaysian hemodialysis patients

OBJECTIVE

To develop an education package with uniform nutrition messages appropriate for Malaysian patients undergoing hemodialysis.

METHODS

Nutritional problems and socioeconomic, ethnic, cultural, and religious factors influencing food habits of HD patients were considered in planning the package. The package comprised a Flipchart and 55 food Fotocards. The Flipchart used a modular format to target nutrition education in stages. The food Fotocards were designed to help the patient plan a daily menu and enjoy greater food variety. Photographs related to common food servings carried symbols for significant nutrient sources of energy, protein, fat, sodium, potassium, and phosphate. A traffic-light color system quantified potassium and phosphate content. The package was evaluated by 25 respondents, composed of nephrologists, nurses, dietitians, and patients.

RESULTS

Eighty percent of evaluators rated the Flipchart as good and 20% rated it as excellent, whereas 28% rated the Food Fotocards as good and 72% rated them as as excellent.

CONCLUSION

This package is a useful nutrition education tool for both health educators and dietitians to present first-line nutrition advice to patients undergoing hemodialysis.

Air quality in Malaysia: impacts, management issues and future challenges

OBJECTIVE

Observations have been made on the long-term trends of major air pollutants in Malaysia including nitrogen dioxide, carbon monoxide, the ozone and total suspended particulate matter (particularly PM10), and sulfur dioxide, emitted from industrial and urban areas from early 1970s until late 1998.

METHODOLOGY

The data show that the status of atmospheric environment in Malaysia, in particular in highly industrialized areas such as Klang Valley, was determined both by local and transboundary emissions and could be described as haze and non-haze periods.

RESULTS

During the non-haze periods, vehicular emissions accounted for more than 70% of the total emissions in the urban areas and have demonstrated two peaks in the diurnal variations of the aforementioned air pollutants, except ozone. The morning 'rush-hour' peak was mainly due to vehicle emissions, while the late evening peak was mainly attributed to meteorological conditions, particularly atmospheric stability and wind speed. Total suspended particulate matter was the main pollutant with its concentrations at few sites often exceeding the Recommended Malaysia Air Quality Guidelines. The levels of other pollutants were generally within the guidelines. Since 1980, six major haze episodes were officially reported in Malaysia: April 1983, August 1990, June 1991, October 1991, August to October 1994, and July to October 1997. The 1997 haze episode was the worst ever experienced by the country. Short-term observations using continuous monitoring systems during the haze episodes during these periods clearly showed that suspended particulate matter (PM10) was the main cause of haze and was transboundary in nature. Large forest fires in parts of Sumatra and Kalimantan during the haze period, clearly evident in satellite images, were identified as the probable key sources of the widespread heavy haze that extended across Southeast Asia from Indonesia to Singapore, Malaysia and Brunei. The results of several studies have also provided strong evidence that biomass burning is the dominating source of particulate matter. The severity and extent of 1997's haze pollution was unprecedented, affecting some 300 million people across the region. The amount of economic costs suffered by Southeast Asian countries during this environmental disaster was enormous and is yet to be fully determined. Among the important sectors severely affected were air and land transport, shipping, construction, tourism and agro-based industries. The economic cost of the haze-related damage to Malaysia presented in this study include short-term health costs, production losses, tourism-related losses and the cost of avertive action. Although the cost reported here is likely to be underestimated, they are nevertheless significant (roughly RM1 billion).

CONCLUSIONS

The general air quality of Malaysia since 1970 has deteriorated. Studies have shown that should no effective countermeasures be introduced, the emissions of sulfur dioxide, nitrogen oxides, particulate matter, hydrocarbons and carbon monoxide in the year 2005 would increase by 1.4, 2.12, 1.47 and 2.27 times, respectively, from the 1992 levels.

Characteristics of glutathione-capped ZnS nanocrystallites

The titration of increasing equivalents of inorganic sulfide into preformed Zn-glutathione led to the appearance of UV/VIS spectral features attributable to ZnS nanocrystallites. Glutathione-ZnS complexes upon irradiation caused reduction of methylviologen confirming their semiconductor properties. Size-fractionation of glutathione-ZnS samples on a gel filtration column showed the formation of a range of complexes whose spectral properties were correlated with the sulfide content. The stoichiometry of Zn:glutathione increased from 1:2 to a maximum of about 7:1 as the sulfide/Zn ratios increase from 0 to approximately 1.0 in Zn-glutathione complex indicating up to 14-fold increase in the Zn-binding capacity of glutathione upon sulfide incorporation. Spectral characteristics of GSH-capped ZnS nanocrystallites were significantly influenced by pH and by the stoichiometry of Zn, sulfide and glutathione in the complex. Samples containing least glutathione and highest sulfide showed maximal luminescence at pH 6, whereas those with higher glutathione and lower sulfide content showed maximal luminescence at pH 11.

Linkage and physical mapping of X-linked lissencephaly/SBH (XLIS): a gene causing neuronal migration defects in human brain

While disorders of neuronal migration are associated with as much as 25% of recurrent childhood seizures, few of the genes required to establish neuronal position in cerebral cortex are known. Subcortical band heterotopia (SBH) and lissencephaly (LIS), two distinct neuronal migration disorders producing epilepsy and variable cognitive impairment, can be inherited alone or together in a single pedigree. Here we report a new genetic locus, XLIS, mapped by linkage analysis of five families and physical mapping of a balanced X;2 translocation in a girl with LIS. Linkage places the critical region in Xq21-q24, containing the breakpoint that maps to Xq22.3-q23 by high-resolution chromosome analysis. Markers used for somatic cell hybrid and fluorescence in situ hybridization analyses place the XLIS region within a 1 cM interval. These data suggest that SBH and X-linked lissencephaly are caused by mutation of a single gene, XLIS, that the milder SBH phenotype in females results from random X-inactivation (Lyonization), and that cloning of genes from the breakpoint region on X will yield XLIS.

Optical spectroscopic and reverse-phase HPLC analyses of Hg(II) binding to phytochelatins

Optical spectroscopy and reverse-phase HPLC were used to investigate the binding of Hg(II) to plant metal-binding peptides (phytochelatins) with the structure (gammaGlu-Cys)2Gly, (gammaGlu-Cys)3Gly and (gammaGlu-Cys)4Gly. Glutathione-mediated transfer of Hg(II) into phytochelatins and the transfer of the metal ion from one phytochelatin to another was also studied using reverse-phase HPLC. The saturation of Hg(II)-induced bands in the UV/visible and CD spectra of (gammaGlu-Cys)2Gly suggested the formation of a single Hg(II)-binding species of this peptide with a stoichiometry of one metal ion per peptide molecule. The separation of apo-(gammaGlu-Cys)2Gly from its Hg(II) derivative on a C18 reverse-phase column also indicated the same metal-binding stoichiometry. The UV/visible spectra of both (gammaGlu-Cys)3Gly and (gammaGlu-Cys)4Gly at pH 7.4 showed distinct shoulders in the ligand-to-metal charge-transfer region at 280-290 mm. Two distinct Hg(II)-binding species, occurring at metal-binding stoichiometries of around 1.25 and 2.0 Hg(II) ions per peptide molecule, were observed for (gammaGlu-Cys)3Gly. These species exhibited specific spectral features in the charge-transfer region and were separable by HPLC. Similarly, two main Hg(II)-binding species of (gammaGlu-Cys)4Gly were observed by UV/visible and CD spectroscopy at metal-binding stoichiometries of around 1.25 and 2.5 respectively. Only a single peak of Hg(II)-(gammaGlu-Cys)4Gly complexes was resolved under the conditions used for HPLC. The overall Hg(II)-binding stoichiometries of phytochelatins were similar at pH 2.0 and at pH 7.4, indicating that pH did not influence the final Hg(II)-binding capacity of these peptides. The reverse-phase HPLC assays indicated a rapid transfer of Hg(II) from glutathione to phytochelatins. These assays also demonstrated a facile transfer of the metal ion from shorter- to longer-chain phytochelatins. The strength of Hg(II) binding to glutathione and phytochelatins followed the order: gammaGlu-Cys-Gly<(gammaGlu-Cys)2Gly<(gammaGlu-Cy s)3Gly<(gamma Glu-Cys)4Gly.

Chain length-dependent Pb(II)-coordination in phytochelatins

UV/visible and circular dichroism (CD) spectroscopy have been used to study the binding of Pb(II) to plant metal-sequestering peptides, phytochelatins (PCs), with the structure (gamma Glu-Cys)2Gly, (gamma Glu-Cys)3Gly and (gamma Glu-Cys)4Gly. Saturation of the Pb(II)-induced charge-transfer bands indicated that both (gamma Glu-Cys)2Gly and (gamma Glu-Cys)3Gly bound one metal ion per peptide molecule. However, (gamma Glu-Cys)4Gly formed two distinct species with stoichiometries of one and two Pb(II) ions per peptide molecule, respectively. The optical spectra of Pb(II)1-(gamma Glu-Cys)4Gly were similar to those of Pb(II)1-(gamma Glu-Cys)3Gly, whereas the spectra of Pb(II)2-(gamma Glu-Cys)4Gly were similar to those of Pb(II)1-(gamma Glu-Cys)2Gly. Since cysteinyl thiolates are the likely ligands for Pb(II) in PCs, Pb(II) appears to form two-, three- and four-coordinate complexes with PCs depending on their chain length. Furthermore, Pb(II) may exhibit multiple coordination in longer chain PCs as indicated by the formation of two Pb(II)-binding species of (gamma Glu-Cys)4Gly. The transfer of Pb(II) from glutathione to PCs and from shorter chain to longer chain PCs is also demonstrated.

Hemostatic abnormalities in nephrotic syndrome

Nephrotic syndrome is often associated with a hypercoagulable state and thrombotic complications. Thrombosis may be due to a number of abnormalities in blood, including AT III deficiency, increased concentrations of fibrinogen, factors V and VIII, and platelet hyperaggregability. The therapeutic approach to thrombosis in nephrotic syndrome is the use of anticoagulants as a preventive measure or an attempt at thrombolysis with streptokinase, urokinase, or stanozolol.

Pneumococcal infection in hospitalized patients: a four-year study in Malaysia

A total of 90 cases of pneumococcal infections were identified at a major referral hospital in Kuala Lumpur, Malaysia during a study period of four years. Pneumonia was the most common clinical presentation (41 cases) followed by meningitis (19 cases). Of 48 patients who were followed-up during the microbiology consultation round, 11 died, 9 were children below two years old. Capsular typing was carried out on 57 strains of Streptococcus pneumoniae isolated from blood and body fluids of 43 children and 14 adults. 38 strains isolated from pharyngeal specimens were also typed. Types 6A (11 strains), 6B (7 strains), 14 (8 strains) and 19A (8 strains) predominated in children. The strains from older patients comprised 3 isolates from cerebrospinal fluid (types 18B, 6B and 14), five from blood (4 strains, type 1 and 1 strain, type 4) and six from pus (1 strain, type 14, 3 strains type 23F and 2 strains type 34). The isolates from pharyngeal specimens belonged to capsular type similar to those implicated in infections. 90% of the types reported in this study are included in the 23 valent pneumococcal vaccines. Minimum inhibitory concentrations of penicillin, cefuroxime, chloramphenicol and rifampicin were determined for selected strains. 4.1% of isolates were resistant to penicillin (3/74), 4.5% to cefuroxime (2/44), 6.5% to chloramphenicol (3/46) and 14.6% to rifampicin (6/41).

Responses of thyroid activity to feed restriction in the goat

A study of the effect of restriction of feed intake on the deiodination, faecal excretion, distribution and secretion of thyroid hormones was carried out in a group of eight young male goats. In the control goats fed ad libitum no changes in the concentration of circulating thyroxine were observed with increasing age or body weight during the experimental period; however, an increase in thyroxine secretion rate per animal was apparent with increasing age or body weight of the goats. In feed-restricted goats, no changes in the peripheral deiodination of [125I]thyroxine were observed, though significantly reduced faecal excretion of [125I]thyroxine was seen in goats restricted to 50 or 20% of their ad libitum feed intake. Both thyroxine turnover rate and thyroxine distribution volume were reduced by feed restriction. The secretion rate of thyroxine was reduced to 45% of the rate in ad libitum fed animals when feed intake was restricted to 20%. Calculation of thyroxine secretion rate per kilogram 0-75 body weight showed a highly significant correlation with feed intake. It was concluded that the marked reduction in thyroid activity occurring when feed restriction was imposed would be expected to cause a physiologically significant reduction in metabolic activity.