Molecular docking as a tool for the discovery of novel insight about the role of acid sphingomyelinase inhibitors in SARS- CoV-2 infectivity

Recently, COVID-19, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its variants, caused > 6 million deaths. Symptoms included respiratory strain and complications, leading to severe pneumonia. SARS-CoV-2 attaches to the ACE-2 receptor of the host cell membrane to enter. Targeting the SARS-CoV-2 entry may effectively inhibit infection. Acid sphingomyelinase (ASMase) is a lysosomal protein that catalyzes the conversion of sphingolipid (sphingomyelin) to ceramide. Ceramide molecules aggregate/assemble on the plasma membrane to form "platforms" that facilitate the viral intake into the cell. Impairing the ASMase activity will eventually disrupt viral entry into the cell. In this review, we identified the metabolism of sphingolipids, sphingolipids' role in cell signal transduction cascades, and viral infection mechanisms. Also, we outlined ASMase structure and underlying mechanisms inhibiting viral entry 40 with the aid of inhibitors of acid sphingomyelinase (FIASMAs). In silico molecular docking analyses of FIASMAs with inhibitors revealed that dilazep (S = - 12.58 kcal/mol), emetine (S = - 11.65 kcal/mol), pimozide (S = - 11.29 kcal/mol), carvedilol (S = - 11.28 kcal/mol), mebeverine (S = - 11.14 kcal/mol), cepharanthine (S = - 11.06 kcal/mol), hydroxyzin (S = - 10.96 kcal/mol), astemizole (S = - 10.81 kcal/mol), sertindole (S = - 10.55 kcal/mol), and bepridil (S = - 10.47 kcal/mol) have higher inhibition activity than the candidate drug amiodarone (S = - 10.43 kcal/mol), making them better options for inhibition.

Outcomes of traumatic brain injury in the patient of 60 years and above: a single centre retrospective study

INTRODUCTION

The elderly is at risk for traumatic brain injury (TBI), but local data on their morbidity and mortality outcomes was lacking. This study aims to assess the outcome in mortality and functional outcome, Glasgow Outcome Scale (GOS) and factors associated with poor outcomes in patients with TBI more than 60 years old.

MATERIALS AND METHODS

This single centre retrospective cohort study was carried out involving patients age 60 years old and above with TBI between June 2018 to May 2021. The mortality and GOS at hospital discharge, 30th day, and 90th day of trauma were analysed. The simple logistic regression (SLR) and multiple logistic regression (MLR) were performed to determine factors associated with poor outcomes and mortality.

RESULTS

A total of 248 patients were analysed. The mean age was 67.5 ± 6.31 years. 156 (62.9%), 26 (10.5%), and 66 (26.6%) had mild, moderate, and severe TBI, respectively. The overall mortality rate was 9.7% and the median(IQR) GOS score were 4(2); p<0.001 at hospital discharge, 30th day and 90th day. There was significant difference in GOS outcomes after 90 days χ2(2) = 136.76 p<0.001. Upon MLR, there was a significant association of polytrauma, Adj. OR 11.04 (2.503-48.711); p < 0.002 and TBI severity: moderate TBI, Adj. OR 71.44(13.028-391.782); p < 0.001 and severe TBI, Adj OR 2533.51 (213.050-30127.644); p<0.001 towards poor outcome. However, only severity of TBI: moderate TBI, Adj. OR 19.48 (1.899-199.094); p=0.012 and severe TBI, Adj OR 26.42 (2.864-243.722); p=0.004 is associated with mortality.

CONCLUSION

Polytrauma and moderate-severe head injury are associated with poor outcomes and moderate-severe head injury is associated with high mortality.

Thiamine deficiency and oxidative stress induced by prolonged metronidazole therapy can explain its side effects of neurotoxicity and infertility in experimental animals: Effect of grapefruit co-therapy

We aimed to explore the possible neurotoxicity and infertility mechanisms of prolonged metronidazole (MTZ) use and the effects of antioxidant grapefruit (GP) co-therapy on MTZ-induced complications. Sixty male albino Wistar rats were divided into four groups (n = 15 each). Group I (control group) received 1% dimethyl sulfoxide (27 ml/ kg/day), group II (MTZ group) received MTZ (400 mg/kg/day), group III (MTZ + GP) received MTZ (400 mg/kg/ day) plus GP juice (27 ml/kg/ day) and group IV (GP group) received GP juice (27 ml/kg) for 60 days. Semen analyses were performed. Free testosterone, gonadotrophin (follicle-stimulating hormone (FSH) and luteinizing hormone) and thiamine levels were measured. Samples of cerebellar, testicular and epididymal tissues were used for both colorimetric assays of oxidative stress markers and histopathological examinations. Significant decreases in the sperm count, percent total sperm motility, serum thiamine levels, free testosterone levels and FSH levels were observed in the MTZ and MTZ + GP groups (p < 0.05 for all parameters). Significantly higher oxidative stress levels (p < 0.05) were observed in the cerebellar and testicular tissue homogenates of these groups than in those of the control group, and associated disruptions in the cerebellar, testicular and epididymal structures were apparent compared to those of the control group. Although the GP group showed a significantly higher sperm count and significantly lower oxidative stress than the control group (p < 0.05), with histological similarity to the control group, the GP group exhibited significantly higher prolactin levels and lower free testosterone and FSH levels than the control group (p < 0.05). Oxidative stress and decreased thiamine levels could explain the MTZ-induced neurotoxicity and infertility side effects that aggravated by GP co-administration.

MCNP5 evaluation of photoneutron production from the Alexandria University 15 MV Elekta Precise medical LINAC

Photoneutron production, and the dose equivalent, in the head assembly of the 15 MV Elekta Precise medical linac; operating in the faculty of Medicine at Alexandria University were estimated with the MCNP5 code. Photoneutron spectra were calculated in air and inside a water phantom to different depths as a function of the radiation field sizes. The maximum neutron fluence is 3.346×10^-9 n/cm²-e for a 30×30 cm² field size to 2-4 cm-depth in the phantom. The dose equivalent due to fast neutron increases as the field size increases, being a maximum of 0.912 ± 0.05 mSv/Gy at depth between 2 and 4 cm in the water phantom for 40×40 cm² field size. Photoneutron fluence and dose equivalent are larger to 100 cm from the isocenter than to 35 cm from the treatment room wall.

Design, synthesis and biological evaluation studies of novel quinazoline derivatives as cytotoxic agents

Some novel quinazoline derivatives 6a-h were designed, synthesized and evaluated for their in vitro cytotoxic activity against lymphoma cell line compared to etoposide as a reference drug. Compounds (S)-2-(6,8-diiodo-2-phenylquinazolin-4-ylamino)-3-phenylpropanoic acid (6 f), (S)-2-(6,8-diiodo-2-phenylquinazolin-4-ylamino)-3-(1H-imidazol-4-yl)propanoic acid (6 g) and (S)-2-(6,8-diiodo-2-phenylquinazolin-4-ylamino)-3-(1H-indol-3-yl) propanoic acid (6 h) had comparable higher cytotoxic activity than the reference drug. Compound 6 f, the most active compound, had IC50=13.2 µM. In an attempt to interpret such anti-cancer activity of these derivatives, their anti-inflammatory action was examined using the carrageenan induced rat paw edema method. The most active compounds showed moderate anti-inflammatory activity compared to the reference drug. In order to identify the most relevant physicochemical features important for high antitumor activity of the target compounds, specific 2D descriptors were calculated and correlated with the antileukemic activity.

Treatment of hepatitis C virus infection in patients on maintenance hemodialysis: a single United Arab Emirates center experience

BACKGROUND

Hepatitis C is prevalent among hemodialysis patients. In patients with normal kidney function, treatment with pegylated interferon and ribavirin can lead to eradication of HCV (hepatitis C virus). But the treatment is more problematic in patients with impaired kidney function, in part due to the altered pharmacokinetics of these medications. Despite recent guidelines, the optimal strategy in this group of patients is not well defined.

METHOD

In a retrospective study, we reviewed all patients with chronic hepatitis C on hemodialysis treated at Sheikh Khalifa Medical City, in the United Arab Emirates between 2003 and 2009. The aim of our study was to determine the rate of sustained viral response (SVR) and to establish the safety and rate of dropouts in the different treatment regimens used (patients treated with peginterferon only and patients treated with peginterferon and low dose ribavirin).

RESULTS

22 patients were treated during this period. 5 patients received monotherapy with a reduced dose of peginterferon alfa 2b s.c. once weekly while 17 patients were treated with a combination of reduced dose of peginterferon alfa 2a or 2b s.c. once weekly and a low dose ribavirin (200mg/day). A SVR was achieved in 73% (16/22 patients) of the total patient population and in 76% (13/17 patients) in the sub-group of patients treated with a combination therapy. The tolerability was high. No patients had to discontinue their treatment. The use of ESA (erythropoietin stimulating agents) and G-CSF was common in the combination therapy (94% and 53% respectively).

CONCLUSION

In our study of patients on hemodialysis with chronic hepatitis C, the use of peginterferon or a combination of peginterferon with a low daily dose of ribavirin achieved a high rate of SVR and the rate of dropout was low after pursuing an aggressive management of side effects.

Towards non-surgical therapy for uterine fibroids: catechol-O-methyl transferase inhibitor shrinks uterine fibroid lesions in the Eker rat model

BACKGROUND

Uterine leiomyomas (fibroids) are the most common pelvic tumors in women. We assessed the potential therapeutic utility of Ro 41-0960, a synthetic catechol-O-methyl transferase inhibitor (COMTI), in the Eker rat.

METHODS

We randomized uterine fibroid-bearing Eker rats for treatment with Ro 41-0960 (150 mg/kg/12 h) versus vehicle for 2 and 4 weeks. The fibroids were measured by caliper and subjected to histological evaluation. Urinary levels of 2-hydroxy estrogen (E(2)), 16-hydroxy E2 and DPD (osteoporosis marker) and serum liver enzymes were evaluated. Expressions of Cyclin D1, proliferating cell nuclear antigen (PCNA), Poly [ADP-ribose] polymerase1 (PARP1), tumor suppressor gene (P53) and transforming growth factor (TGFβ3) were assessed in fibroids using immunohistochemical analysis or RT-PCR. Apoptosis was confirmed using terminal deoxynucleotidyltransferase-mediated dUTP nick-end labeling (TUNEL).

RESULTS

Ro 41-0960-treated rats exhibited fibroid volumes of 86 ± 7% and 105 ± 12% of initial burden, at 2 and 4 weeks post-treatment, respectively, significantly lower than control group (240 ± 15% and 300 ± 18%; P< 0.01). Ro 41-0960 increased the urinary 2-hydroxy E2/16-hydroxy E(2) ratio, level of p53 mRNA and TUNEL positivity (P< 0.05) and decreased PARP1, PCNA and cyclin D1 proteins and TGFβ3 mRNA (P< 0.05). Ro 41-0960 did not change normal tissue histology, liver functions or urinary DPD level.

CONCLUSIONS

Ro 41-0960 (COMTI) arrested growth/shrunk uterine fibroids in Eker rats. This result may be related to modulation of estrogen-dependent genes involved in apoptosis, proliferation and extracellular matrix deposition via accumulation of 2-hydroxy estrogen. The efficacy and safety of Ro 41-0960 in rats suggest its candidacy for treatment of uterine fibroids.

CMOS Conductometric System for Growth Monitoring and Sensing of Bacteria

We present the design and implementation of a prototype complementary metal-oxide semiconductor (CMOS) conductometric integrated circuit (IC) for colony growth monitoring and specific sensing of Escherichia coli (E. coli) bacteria. The detection of E. coli is done by employing T4 bacteriophages as receptor organisms. The conductometric system operates by measuring the resistance of the test sample between the electrodes of a two-electrode electrochemical system (reference electrode and working electrode). The CMOS IC is fabricated in a TSMC 0.35-μm process and uses a current-to-frequency (I to F) conversion circuit to convert the test sample resistance into a digital output modulated in frequency. Pulsewidth control (one-shot circuit) is implemented on-chip to control the pulsewidth of the output digital signal. The novelty in the current work lies in the ability of the CMOS sensor system to monitor very low initial concentrations of bacteria (4×10(2) to 4×10(4) colony forming unit (CFU)/mL). The CMOS system is also used to record the interaction between E. coli and its specific receptor T4 bacteriophage. The prototype CMOS IC consumes an average power of 1.85 mW with a 3.3-V dc power supply.

Toward gene therapy of uterine fibroids: targeting modified adenovirus to human leiomyoma cells

BACKGROUND

To circumvent the paucity of the primary adenovirus (Ad5) receptor and the non-specific Ad5 tropism in the context of uterine leiomyoma cells, Ad5 modification strategies would be beneficial.

METHODS

We screened several modified adenoviruses to identify the most efficient and selective virus toward human leiomyoma cells to be used as candidate for delivering therapeutic genes. We propagated: wild-type Ad5-luc, fiber-modified viruses: ad5 RGD-luc, Ad5-Sigma-luc, Ad5/3-luc and Ad5-CAV2-luc, as well as transcriptional targeted viruses: ad5 survivin-luc, Ad5-heparanase-luc, Ad5-MSLN-CRAD-luc and Ad5-SLPI-luc, on 293 cells and purified them by double CsCL density centrifugation. Then we transfected primary cultures of human leiomyoma cells derived from fibroids of four different patients, telomerase-immortalized human leiomyoma cell line (huLM), telomerase-immortalized normal human myometrial cell line (HM9) and immortalized normal human liver cells (THLE3) with the viruses at 5, 10 and 50 plaque-forming units (PFU)/cell. After 48 h, luciferase activities were measured and normalized to the total cellular protein content.

RESULTS

Ad5-RGD-luc and Ad5-CAV2-luc, Ad5-SLPI-luc and Ad5-MSLN-CRAD-luc at 5, 10 and 50 pfu/cell showed significantly higher expression levels of luciferase activity in both primary and immortalized human leiomyoma cells when compared with Ad5-Luc. Additionally, these modified viruses demonstrated selectivity toward leiomyoma cells, compared with myometrial cells and exhibited lower liver cell transduction, compared with Ad5-luc, at the same dose levels.

CONCLUSIONS

Ad5-CAV2-luc, Ad5-RGD-luc, Ad5-SLPI-luc and Ad5-MSLN-CRAD-luc are promising delivery vehicles in the context of leiomyoma gene therapy.

The use of cyclohexanone as a "derivatizing" reagent for the GC-MS detection of amphetamines and ephedrines in seizures and the urine

A GC-MS method has been developed for the detection of amphetamine, methamphetamine, and the ephedrines, in seizures and the urine, based on on-GC condensation (derivatization) with cyclohexanone. The method is simple: the dried seizure material or the urine extract was mixed with cyclohexanone and injected into the GC-MS. The method was found to be superior to the methods based on acyl and trimethylsilyl (TMS) derivatization. Unlike for the acyl and TMS derivatives, the molecular and fragment ions of the cyclohexanone condensation products (cyclohexanone derivatives) were of substantial abundance, a useful property in unambiguous compound characterization. Furthermore, the high stability of the "derivatizing" reagent, cyclohexanone, compared with acyl and TMS derivatizing reagents, is a useful property in method development. The present method has proved selective and, tentatively, sensitive enough in the following areas (where methods based on acyl and TMS derivatization, as tested in this laboratory, have failed): (a) detection of amphetamine as a metabolite of methamphetamine; (b) detection of norpseudoephedrine as a metabolite of pseudoephedrine; (c) detection of amphetamine as an impurity of methamphetamine; (d) detection of cathine (norephedrine) as a constituent of Khat leaves; and (e) differentiation of Khat use from phenylpropanolamine use.

Predictors of treatment failure among tuberculosis patients under DOTS strategy in Egypt

Treatment failure is a serious problem facing some national tuberculosis (TB) control programmes. Irregularity of treatment is a factor that can lead to treatment failure. A case-control study was carried out in TB centres in Egypt during April 2001-December 2002 aimed at investigating the predictors of treatment failure. We interviewed 119 people with treatment failure and an equal number of cured cases (controls) and their families regarding sociodemographic characteristics, information about TB, information about drugs, treatment compliance, family support and patient-family interaction. Significant risk factors for treatment failure were non-compliance to treatment, deficient health education to the patient, poor patient knowledge regarding the disease and diabetes mellitus as co-morbid condition.

Investigation into some aspects of EMIT d.a.u., TLC, and GC-MS urinalysis of bromazepam

Among the different 1,4-benzodiazepine urinary metabolites, those of bromazepam possess distinctive chemical features that may be used in their selective isolation and detection. The detection of bromazepam metabolites in urine was carried out using EMIT d.a.u., thin-layer chromatography (TLC), and gas chromatography-mass spectrometry (GC-MS). The positive EMIT d.a.u. benzodiazepine assay for bromazepam was found to be due to the 3-hydroxybromazepam (3HOB) metabolite. The detection by TLC and GC-MS was carried out after enzyme or acid hydrolysis of the glucuronide conjugates. Both the 2-amino-3-hydroxy5-bromobenzoylpyridine (AHBBP) metabolite and the acid hydrolysis product of 3-HOB, 2-amino-5-bromobenzoylpyridine (ABBP), were selectively detected by TLC. The bromazepam metabolites in urine could be both isolated and detected selectively by GC-MS in the presence of the metabolites of other 1,4-benzodiazepines that were sometimes used in combination with bromazepam. Both 3-HOB and AHBBP were detected by GC-MS only after trimethylsilyl (TMS) derivatization and not as the free compounds or the acetyl derivatives. Only ABBP was detected in three forms: ABBP, the TMS derivative, and the acetyl derivative. Evidence has been obtained from the enzyme hydrolysis and the TLC studies for the formation of the glucuronide conjugate of AHBBP at the 3-OH group rather than at the 2-NH2 group. All the results have been validated using reference 3-HOB and AHBBP.

A GC-MS method for the detection of toluene and ethylbenzene in volatile substance abuse

The interference of some substances with the gas chromatography-flame ionization detection and gas chromatography-Fourier transform infrared detection of toluene and ethylbenzene in volatile substance abuse poses problems. A gas chromatography-mass spectrometry (GC-MS) method that will overcome such interference has been developed for the detection of toluene and/or ethylbenzene in the headspace of preparations and products containing these substances and in the headspace of blood samples in the cases of volatile substance abuse. The method is based on converting toluene to benzoic acid via the formation of benzotrichloride. The latter compound was obtained upon the reaction of toluene with chlorine gas under direct sunlight conditions. In the presence of water, benzotrichloride was converted to benzoic acid. Ethylbenzene was converted to benzoic acid and two phenylethanols via the formation of side chain chloro-substituted phenylethanes followed by reaction with water. The chloro-substituted phenylethanes were obtained by the reaction of ethylbenzene with chlorine under direct sunlight conditions. The benzoic acid resulting from toluene and/or ethylbenzene and the two phenylethanols resulting from ethylbenzene were detected by GC-MS as their trimethylsilyl (TMS) derivatives. For the method to be viable for the detection of volatile substance abuse, the chlorination reactions were effected in the gaseous state.

Parasitic infections and maternal awareness of preschool children in Karmouz district, Alexandria

Intestinal parasitic infections are widespread especially among preschool children living in poor areas. Also pediculosis has been perceived as a public health nuisance for decades. A cross-sectional study was conducted on 256 children and their mothers in a poor urban district to assess mothers' knowledge and practices as regards parasitic infections and infestations that may be present in her preschool child, and to correlate the presence of these infections with her awareness. A pre-designed questionnaire that included socio-demographic data, items to assess mothers' knowledge of sources and preventive measures of parasitic infections and infestations and her practices was completed. A stool sample was collected from children and examined using formol-ether technique and Sellotape technique was used to detect Enterobius vermicularis. Pediculus capitis was diagnosed by inspection of the scalp and was found to be the most prevalent parasite found in 58.9% of those children followed by Enterobius vermicularis in 46%. A strong positive association between pediculosis and enterobiasis was detected (phi coefficient = 0.956, p < 0.001). Socioeconomic level affected both knowledge and practices scores where one point change in knowledge score or socioeconomic score caused an increase in practice score of 0.279 and 0.071, respectively. Also higher risk of pediculosis was found to be significantly associated with female sex and low socioeconomic level. An increase of one point in practice score showed a decrease in the log likelihood ratio of enterobiasis of 14.3%. The majority of mothers (77.3%) were found to be aware that their children had a parasitic infection, which was significantly associated with results of stool analysis. This indicates that awareness building is not enough to be of practical benefit. Appropriate and detailed control methods of parasitic infections and pediculosis must be taught and applied by parents and community. Socio-economic development, organized health programs and motivation should be undertaken to help today's children.

The GC/MS analysis of some commonly used non-steriodal anti-inflammatory drugs (NSAIDs) in pharmaceutical dosage forms and in urine

All the commonly used non-steriodal anti-inflammatory drugs (NSAIDs), except mefenamic acid, when extracted from the pharmaceutical dosage forms or the urines of users, and derivatized by silylation and then analysed by GC/MS, gave the mono- or the di-trimethylsilyl derivatives (depending on the number of derivatized groups in the drug) as the sole products. Mefenamic acid gave a mixture of products. When extracted from pharmaceutical dosage froms or from the urines of users, and analysed by GC/MS without derivatization, some of the NSAIDs were separated and detected as the unchanged molecules as the sole products, while others were separated and detected in altered forms as sole products or mixtures, depending on: (a) the solvent in which the extract was dissolved for injection into GC/MS, (b) the chemical structure of the drug, and (c) specifically for diflunisal, the presence or absence of potential methylating and/or acetylating agents on the GC column and/or septum. The main thermally-induced reactions of the underivatized NSAIDs included (i) methyl ester formation at the COOH group when the extract was dissolved in methanol, (ii) decarboxylation (i.e., loss of CO2), (iii) dehydration (i.e., loss of H2O) when the chemical structure permitted, such as for diclofenac, and (iv) cleavage at a carbon-heterocyclic nitrogen bond when one is present in an NSAID. Heating the urine in approximately 2 M HCl at 100 degrees C for 30 min, has been found to be a satisfactory means for effecting hydrolysis of the NSAIDs glucuronide conjugates. No metabolites, resulting from aromatic-ring hydroxylation, have been detected in urine for any of the NSAIDs studied.

Association of IgA nephropathy with Clostridium difficile colitis

Immunoglobulin A (IgA) nephropathy, the most common cause of glomerulonephritis worldwide, is usually idiopathic in origin and renal limited. Secondary IgA nephropathy has been associated with systemic disease, including such gastrointestinal tract disturbances as celiac sprue and inflammatory bowel disease. We describe gross hematuria and reversible acute renal failure from IgA nephropathy in a patient with cephalosporin-induced Clostridium difficile colitis. In addition to mesangial IgA and C3 deposition, renal histological examination showed glomerular bleeding, intratubular red blood cell casts, and acute tubular necrosis. To the best of our knowledge, this is the first report of an association between IgA nephropathy and C difficile colitis.

Association of IgA nephropathy with Clostridium difficile colitis

Immunoglobulin A (IgA) nephropathy, the most common cause of glomerulonephritis worldwide, is usually idiopathic in origin and renal limited. Secondary IgA nephropathy has been associated with systemic disease, including such gastrointestinal tract disturbances as celiac sprue and inflammatory bowel disease. We describe gross hematuria and reversible acute renal failure from IgA nephropathy in a patient with cephalosporin-induced Clostridium difficile colitis. In addition to mesangial IgA and C3 deposition, renal histological examination showed glomerular bleeding, intratubular red blood cell casts, and acute tubular necrosis. To the best of our knowledge, this is the first report of an association between IgA nephropathy and C difficile colitis.

Chronic lymphocytic leukaemia in Egyptian farm workers exposed to pesticides

We aimed to explore the relationship between chronic lymphocytic leukaemia and pesticide exposure among farm workers. Blood samples were obtained from 932 male Egyptian farm workers exposed to pesticides and from a control group of 932 males of similar age and socioeconomic status who were not involved in farming and did not normally deal with pesticides. The farm workers had significantly higher lymphocyte, white blood corpuscle and platelet counts. About 5% of the farm workers over 40 years had immature cells. Two of the farm workers and none of the control group had chronic lymphocytic leukaemia, giving an undefined relative risk and an attributable risk of 2.1 per 1000, which was not statistically significant.

Prevalence of asthma, rhinitis and eczema among schoolchildren in Kelantan, Malaysia

The prevalence and severity of asthma, rhinitis and eczema in Kelantanese schoolchildren were determined as part of an international study of the epidemiology of asthma and allergic diseases. The international study of asthma and allergies in childhood (ISAAC) written questionnaire was administered to 7055 schoolchildren from February 1995 to August 1995. The respondents were parents or guardians of 5- to 7-year-old children (n = 3939), and schoolchildren aged 12-14 years (n = 3116). The ISAAC video questionnaire (AVQ3.0) was shown to children aged 12-14 years after the written questionnaire. The overall prevalences of 'ever wheezed' and 'wheezing in last 12 months' were 9.4 and 6.0% respectively. The prevalence of 'ever diagnosed with asthma' was 9.4%. Both 'ever wheezed' and 'wheezing in the last 12 months' were significantly higher in 12- to 14-year-old children than in 5- to 7-year-old children, with P values of 0.0006 and 0.014 respectively. No gender differences in the prevalences were observed. For the complete study group, 4.7% of children had sleep disturbed by wheezing but only 1.1% had a severe attack limiting speech in the preceding 12 months. Sleep disturbance was more common in the 12- to 14-year-old children than in 5- to 7-year-old children (P = 0.006). There was no difference between the age groups for severe attacks limiting speech. The overall prevalence of rhinitis and eczema symptoms were 27 and 12%, respectively. The prevalence of rhinitis in the 12-14 year age group (38.2%) was significantly higher (P < 0.0001) than in the 5-7 year age group (18.2%). The prevalence of eczema in the 5-7 year age group (13.7%) was significantly higher (P = < 0.0001) than in the 12-14 year age group (9.9%). These prevalence data are comparable with previous reports in Malaysian children, but are considerably lower than those reported for most developed countries.

Evaluation of house-to-house versus fixed-site oral poliovirus vaccine delivery strategies in a mass immunization campaign in Egypt

Among poliomyelitis eradication activities recommended by WHO are national immunization days. Most campaigns have delivered oral poliovirus vaccine (OPV) from fixed sites, reaching 80-90% of target populations. Although house-to-house vaccination provides nearly universal coverage, countries have been reluctant to use this approach because it is considered more costly and logistically difficult. To quantify the cost-effectiveness of both these strategies, we compared the vaccine coverage and vaccination costs per child for house-to-house and fixed-site delivery (38% and 13% higher, respectively), the costs per child vaccinated were similar. This was due primarily to the high coverage levels achieved in house-to-house delivery (100% versus 86%) and the reduced vaccine wastage. Vaccinating children at highest risk of infection was only 25-50% as expensive on a per child basis using house-to-house delivery, since such children were less likely to visit fixed sites. These findings may not be generalizable to other countries where labour costs are higher and the population density lower; however, house-to-house delivery may prove to be the most cost-effective eradication strategy by ensuring universal access to immunization.

Usage of personal protective devices among Egyptian industrial workers

A systematic random sample of 405 workers from metal, asbestos cement pipes, textile, and viscose rayon industries were interviewed using a prepared and tested questionnaire. Personal Protective Devices (PPDs), namely goggles, gloves, respirators, and ear defenders, had been distributed to all workers on the payroll and were used by 31.4%. Usage of PPDs was associated with the educational level, duration of occupation, awareness of the work hazards, and knowledge about the purpose of PPDs. Marked association was found between nonusage of PPDs and discomfort, interference with job performance, and the psychological feeling of lowering the person's prestige by the wearing of PPDs. Nonusage was also associated with lack of maintenance of the device and absence of supervision of its usage. Users were more numerous among married workers and workers with urban residence than among unmarried workers and those with rural residence, respectively. No association could be found between the rate of usage and the worker's age except for ear plugs, for which nonusage was proportional to the worker's age. The most important factors were those related to the role of the safety staff and the discomfort of the devices. Recommendations for occupational health authorities on the basis of the above evaluation are suggested.

[Determination of the binding of 3,5-bis(acetamido)-2,4,6-triiodobenzoic acid and some of its salts to human serum albumin using the ultrafiltration flat chamber method]

Using the ultrafiltration flat chamber method the binding of N-methylglucamine, meglumine amido trizoate, lysine amido trizoate, diatrizoic acid and L-lysine to human serum albumin (HSA) was investigated. It was demonstrated that the affinity to HSA decreases in the above mentioned order. Binding was characterised by determination of K1 (total binding constant), k+ (apparent binding constant), n (number of binding sites per molecule of albumin) and delta F degrees (free reaction energy).