Infection control measures at diagnostic imaging departments in governmental hospitals, Gaza-Strip.

INTRODUCTION: Infection prevention and control (IPC) is crucial in safeguarding patient safety and minimizing the risk of healthcare-associated infections. AIM: The study investigated infection prevention and control measures for diagnostic imaging departments at governmental hospitals in the Gaza Strip, Palestine. METHODS: The study design was a cross-sectional analytical study. The sample included all radiographers (81) and radiologists (40) working at Al Shifa Medical Complex and European Gaza Hospital (EGH). Data was collected using an interview questionnaire (121) and an observation checklist. Data analysis was conducted using SPSS 26, and the result was significant (P < 0.05). RESULTS: Only 27.3 % of the participants revealed the availability of training courses for IPC. More than half of the participants received their last training sessions one year ago, and most of them attended five basic in-service training sessions related to IPC. Radiologists' and medical radiographers' knowledge and practice scores regarding IPC measures were 85.3 % and 61.7 %, respectively, and there were statistically significant differences between the participants' practice domain and their years of experience (p-value .014). There is inadequate hand hygiene among radiographers in the radiology department, and only 29 % of the staff washed their hands immediately upon arrival at the unit. The total score of the Hand Hygiene Self-Assessment Framework domains is almost equal at the two hospitals (280/500). The total score of the eight domains of the IPC Assessment Framework is 568.5/800 for Al Shifa Hospital and 516/800 for EGH, which indicates an intermediate IPC level. CONCLUSION: Efforts are needed to enhance the scope and quality of implementation and to concentrate on creating long-term plans to sustain and promote the existing IPC program activities. IMPLICATIONS FOR PRACTICE: Regular assessments should be conducted to monitor progress, identify gaps, and guide quality improvement efforts. Assessment feedback should be used to develop targeted interventions and continuously enhance IPC measures.

Enhancing nursing student presentation competences using Facilitatory Pecha kucha presentation pedagogy: a quasi-experimental study protocol in Tanzania.

INTRODUCTION: With an increasing number of nursing students in higher education institutions in Tanzania, traditional student presentation pedagogies are insufficient to enhance effective learning. Pecha Kucha presentation is a new promising approach that can improve students' speaking skills, learning process, creativity, and students' engagement in learning. It involves the use of 20 slides where each covers 20 s, thus making a total of 6 min and 40 s. The current study will assess the effect of Pecha Kucha's presentation on presentation knowledge, skills, and learning satisfaction among nursing students in Tanzania. OBJECTIVES: The objectives of this study aimed to determine the baseline and end-line of Pecha Kucha Presentation knowledge, skills, and learning satisfaction among nursing students. METHODS: This study protocol proposes to employ an uncontrolled quasi-experimental study design with a quantitative approach among 230 university nursing students in Dodoma Region using simple and stratified sampling techniques. It proposes to employ the researcher-administered questionnaire to assess study variables that arise as students use the Pecha Kucha presentation format to prepare and present their assignments. The study will involve training of research assistants, pre-assessment of study variables, and training, and demonstration of Pecha Kucha presentations format among study participants. It will also involve assigning topics to study participants, submission and evaluation of the prepared assignments, participants' presentations in the classroom, post-intervention assessment, data analysis, reporting and dissemination of the study findings. CONCLUSION: This study will address and complement the global need to invest in nursing in an attempt to prepare competent nurses who are capable of solving complex health challenges through critical thinking, analysis, collaboration, and effective communication. The study will inform policymakers, health training institutions, and educators about a new engaging, and innovative nursing student presentation approach that enhances students' creativity, critical thinking skills, and meaningful learning. The referred nursing students' presentation approach intends to equip the students with survival and life skills in the 21st century in an attempt to meet the global economy and job opportunities. TRIAL REGISTRATION: It is not applicable as this is not a trial.

Auditing the readiness of healthcare facilities for referral and management of pre-eclampsia cases in Zanzibar- a study protocol.

Hypertensive disorders of pregnancy are reported as the second leading root of maternal morbidity and mortality in Zanzibar. Evidence shows that the majority of pregnant women in Zanzibar are referred late from lower-level healthcare facilities, and majority develop complications of eclampsia. This study's goal is to determine if all public healthcare facilities in Zanzibar are prepared to manage pre-eclampsia cases and if lower-levels public healthcare facilities are ready to refer pre-eclampsia cases. This will be a descriptive cross-sectional study that will involve a total of 54 healthcare facilities and 176 health care providers working in antenatal clinics. All public health care facilities will be stratified into tertiary, secondary, and primary strata. A simple random sampling will be used to select 46 healthcare facilities in the primary stratum while all healthcare facilities within the tertiary and secondary strata will be selected. In each healthcare facility, a physical observation will be performed to assess the availability of equipment and supplies, medications, and lab tests, while a self-administered questionnaire will be used to assess the knowledge level and skills of healthcare providers for the management of pre-eclampsia and eclampsia. Patient's case files in the tertiary and secondary strata will be reviewed to assess the quality of management of pre-eclampsia while the service records of the primary stratum will be assessed for compliance status with referral guidelines. Data will be analyzed using SPSS version 25. Descriptive statistics will be used to describe the frequency distribution of the study variables, and results will be presented in terms of frequency and percentage. The Chi-square test will be used to describe the relationship between variables, and a p-value of < 0.05 will be regarded as a statistically significant difference.

The Influence of Fear During Pregnancy, Labour and Delivery on Birth Outcome Among Post-Delivery Women: A Case Control Study in Zanzibar.

Background: Assessing the influence of fear during pregnancy, labour, and delivery on birth outcomes among women is very important. Normally, women experience happiness during pregnancy, but some may develop fear which may cause maternal and neonatal complications. The aim of this study was to determine the influence of fear during pregnancy, labour and delivery on birth outcome among post-delivery women in Zanzibar. Methodology: This was a matched case-control study involving 204 post-delivery women who were randomly selected from 4 hospitals in Zanzibar. Cases (n=68) were those who experienced a negative birth outcome, whether maternal, fetal, or both. The control group (n=136) had normal birth outcomes. A self-administered questionnaire was used to collect data and was analyzed using SPSS whereby percentages, chi-square test, and odds ratio results were reported. Results: Among cases, 27(39.7%) had high level of fear during pregnancy compared to the control group, 75(40.4%). During labour, 29(42.6%) of cases had high level of fear, and in control, 55(42.4%). And during delivery 35(51.4%) of cases had highest level of fear, while only 47(34.5%) of control had high level of fear. The chi-square test showed only fear during delivery was significantly associated with undesirable birth outcomes. Women who experienced a high level of fear during delivery were 2 times more likely to have undesirable birth outcomes (AOR=1.941, p=.051) after adjusting for other variables. Conclusion: This study established that most women experience high level of fear during pregnancy, labour and delivery. A high level of fear during delivery is associated with having negative birth outcomes, but not during pregnancy and labour. The findings are of clinical importance as they highlight the need to integrate a universal screening intervention into antenatal care services for early management.

Clinical manifestations, complications, and outcomes of patients with COVID-19 in Sudan: a multicenter observational study.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is a pandemic caused by a newly discovered coronavirus. Although clinical manifestations of COVID-19 are mainly pulmonary, some patients have other systemic manifestations. This study aimed to describe the clinical finding and outcomes in Sudanese patients diagnosed with COVID-19. METHODS: This retrospective observational study is based on documented files that included patients diagnosed with COVID-19 in seven selected hospitals inside Khartoum. Clinical manifestations, complications and outcomes were extracted from patients' records using an extraction form designed for this study. RESULTS: Data of 243 patients diagnosed with COVID-19 were analyzed. The mean (SD) age in years was 55.8 (18.4). Out of 116 participants, 27 of them (23.3%) had severe disease, 15 (12.9%) were critically ill. 67.5% of patients were admitted to the hospital within 7 days from onset of symptoms; most of them were admitted to the wards (n = 140,72.5%). Fever (83.2%), cough (70.7%), and shortness of breath (69.2%) were the most commonly recorded clinical manifestations. Sepsis (9.8%) and acidosis (7.8%) were the most frequently reported complications. Death was the final outcome in 21.4% (56/243). Older age and presence of diabetes were found significantly associated with in-hospital death. The laboratory results showed high CRP in 85.6% (119/139), high ferritin in 88.9% (24/27), lactate dehydrogenase had a median of 409.0 (359-760), D-dimer had a median of 3.3 (1.2-16. 6), and 53/105 (50.5%) had low albumin. CONCLUSIONS: Fever was the most mentioned sign among the participants, followed by fatigue. Cough and shortness of breath were the most commonly recorded pulmonary symptoms manifested. Our study showed multiple variables were associated with in-hospital death. The mortality rate was high among severe and critically ill patients diagnosed with COVID-19.

Genetic Subtypes and Natural Resistance Mutations in HCV Genotype 4 Infected Saudi Arabian Patients.

This study aimed to characterize the HCV genetic subtypes variability and the presence of natural occurring resistance-associated substitutions (RASs) in Saudi Arabia patients. A total of 17 GT patients were analyzed. Sequence analysis of NS3, NS5A, and NS5B regions was performed by direct sequencing, and phylogenetic analyses were used to determine genetic subtypes, RAS, and polymorphisms. Nine patients were infected by GT 4a, two with GT 4o and three with GT 4d. Two patients were infected with apparent recombinant virus (4a/4o/4a in NS3/NS5A/NS5B), and one patient was infected with a previously unknown, unclassifiable, virus of GT 4. Natural RASs were found in six patients (35%), including three infected by GT 4a, two by GT 4a/GT 4o/GT 4a, and one patient infected by an unknown, unclassifiable, virus of GT 4. In particular, NS3-RAS V170I was demonstrated in three patients, while NS5A-RASs (L28M, L30R, L28M + M31L) were detected in the remaining three patients. All patients were treated with sofosbuvir plus daclatasvir; three patients were lost to follow-up, whereas 14 patients completed the treatment. A sustained virological response (SVR) was obtained in all but one patient carrying NS3-RAS V170I who later relapsed. GT 4a is the most common subtype in this small cohort of Saudi Arabia patients infected with hepatitis C infection. Natural RASs were observed in about one-third of patients, but only one of them showed a treatment failure.

Multistep thermodesorption coupled with molecular analyses as a quick, easy and environmentally friendly way to measure PAH availability in contaminated soils.

Whether it is for risk assessment or for remediation purpose, contaminant availability in polluted soils is a key parameter to determine. Two methods were recently standardized for the estimation of the environmental available fraction of non-polar organics but, in some cases, their application on real historically contaminated soils does not provide satisfactory results. The present study aimed at proposing an alternative method for the estimation of PAH availability in soils, based on analytical thermal desorption and molecular analyses with the hypothesis that the binding strength between PAH and the solid matrix is linked to the desorption temperature. This hypothesis was validated by comparing the thermodesorption molecular distribution of different contaminated soils and of their respective extractable organic matter. Then, comparing the thermodesorption profiles of each studied PAH to the efficiency of biological and chemical remediation treatments through principal component analysis allowed obtaining the desorption temperature corresponding to PAH fractions available towards both treatments. This method was proven to effectively estimate the PAH fraction available towards biological (microbial incubation) and chemical (KMnO4 oxidation) treatments and present multiple advantages such as being fast, easy to execute and solvent free.

Poor level of knowledge on elderly care despite positive attitude among nursing students in Zanzibar Island: findings from a cross-sectional study.

BACKGROUND: It is estimated by the year 2050, 80% of the global elderly population will be from the low-and middle income countries. Elderly care requires health workers with skills associated with an understanding of the biological, psychological, social and cultural theories related to aging. Nurses with better knowledge, skills and positive attitudes towards elderly care are highly needed and critically important for better healthcare and wellbeing of the elderly population. Therefore the objective of this study was to assess the level of knowledge and attitude of nursing students towards elderly care in Zanzibar Island. METHODS: A cross-sectional study was conducted in Zanzibar involving three out of five nursing training institutions. Participants were selected by systematic random sampling. Facts on Aging Quiz 2 and Kogan's Attitudes Toward Old People scale were used to assess the level of knowledge and attitude towards elderly care among the students respectively. Simple and multivariable logistic regressions were applied to determine the predictors of knowledge and attitude among the participants. RESULTS: A total of 393 students participated in this study. Only 17% (69) of the participants had good level of knowledge and about 67.9% (267) had positive attitude towards elderly care. Living in an extended family and with an elderly person at home were both associated with good level of knowledge and positive attitude towards elderly care. Furthermore, living in a rural area (adjusted odds ratio = 2.23; 95% confidence interval: 1.22, 4.10) and studying at public institution (adjusted odds ratio = 2.59; 95% confidence interval: 1.41, 4.63) were associated with positive attitude towards elderly care. CONCLUSION: This study has shown that the majority of nursing students in Zanzibar have positive attitude but poor level of knowledge towards elderly care. The current findings have demonstrated that past experience with an elderly person can help in influencing good knowledge and shaping positive attitudes towards elderly care. Low level of knowledge shown in the study suggests for further research on adequacy of nursing curriculum and/or its implementation.

Heat acclimation mediated cardioprotection is controlled by mitochondrial metabolic remodeling involving HIF-1α.

Heat acclimation (HA) induces metabolic plasticity to resist the effects of environmental heat with cross-tolerance to novel stressors such as oxygen supply perturbations, exercise, and alike. Our previous results indicated that hypoxia inducible transcription factor (HIF-1α) contributes to this adaptive process. In the present study, we link functional studies in isolated cardiomyocytes, with molecular and biochemical studies of cardiac mitochondria and demonstrate that HA remodels mitochondrial metabolism and performance. We observed the significant role that HIF-1α plays in the HA heart, as HA reduces oxidative stress during ischemia by shifting mitochondrial substrate preference towards pyruvate, with elevated level and activity of mitochondrial LDH (LDHb), acting a pivotal role. Increased antioxidative capacity to encounter hazards is implicated. These results deepen our understanding of heat acclimation-mediated cross tolerance (HACT), in which adaptive bioenergetic-mechanisms counteract the hazards of oxidative stress.

Sexual and reproductive health communication intervention for caretakers of adolescents: a quasi-experimental study in Unguja- Zanzibar.

BACKGROUND: Caretakers/parents or parents figure need to be trained to promote effective communication about sexual and reproductive health to their adolescents. This study assessed the effect of an intervention aiming to improve caretaker-adolescent communication on sexual and reproductive health matters through improving information, motivation, and behavioral skills related to sexual health communication. The study also evaluated the relationship of information, motivation, and behavioral skills model-constructs with communication practice. Information-Motivation-Behavioural skills model was used as a framework to guide the intervention implementation and evaluation process. METHOD: This is a quasi-experimental non-randomized controlled pre- and post-test study which involved one thousand caretakers of adolescents in all the six districts of Unguja-Zanzibar. All participants completed interviewer-administered structured pre-test questionnaire. The experimental group then received sexual health communication intervention addressing the information, motivation, and behavioral skills related to sexual health communication, while the control group received the sexual health information only. All participants were then reassessed for their information, motivation, behavioral skills and their sexual health communication after 1 month, 6 months and at 1 year following the intervention. To evaluate the effect of intervention at the post-test measures, Univariate Analyses of Covariance was performed whereby the pre-test score and variables on which the groups differed were considered as covariates. Standardized mean difference statistics of Cohen's d was used to calculate the effect size, and the cut-off point for the level of significance was set at two-sided, p-value < 0.05. RESULTS: Results shows that the immediate post-test sexual health communication, motivation and behavioral skills scores were statistically significantly higher in the experimental group compared to control group (p < 0.05). Moreover, sexual health communication score after 6 months and at 1 year were statistically significantly higher in the experimental group compared to control group (p < 0.05). Information construct however did not differ between groups in post-test measures. Furthermore, results revealed that communication practice is statistically significantly associated with information, motivation and behavioural skills in post-test measures. CONCLUSION: The findings provided preliminary evidence for the effectiveness of SRH communication intervention and supported the significance of IMB model-constructs to inform the SRH-communication intervention and to guide the intervention evaluation.

Anesthetic considerations for a patient with myasthenia gravis undergoing deep sedation in an outpatient oral surgery setting

Myasthenia gravis (MG) is a neuromuscular autoimmune disorder which clinically presents as muscular weakness and fatigue due to autoantibody formation against acetylcholine receptors (AChR), leading to their subsequent destruction. Due to the neuromuscular implications of MG, certain considerations must be taken into account when providing anesthesia to MG patients. In the following case report, we have outlined procedural considerations for the anesthetic management of a patient with MG undergoing deep sedation for an elective oral surgery in an outpatient setting, as well as a discussion of relevant literature.

Is the aging human ovary still ticking?: Expression of clock-genes in luteinized granulosa cells of young and older women.

BACKGROUND: It has been shown - mostly in animal models - that circadian clock genes are expressed in granulosa cells and in corpora luteum and might be essential for the ovulatory process and steroidogenesis. OBJECTIVE: We sought to investigate which circadian clock genes exist in human granulosa cells and whether their expression and activity decrease during aging of the ovary. STUDY DESIGN: Human luteinized granulosa cells were isolated from young (age 18-33) and older (age 39-45) patients who underwent in-vitro fertilization treatment. Levels of clock genes expression were measured in these cells 36 h after human chorionic gonadotropin stimulation. METHODS: Human luteinized granulosa cells were isolated from follicular fluid during oocyte retrieval. The mRNA expression levels of the circadian genes CRY1, CRY2, PER1, PER2, CLOCK, ARNTL, ARNTL2, and NPAS2 were analyzed by quantitative polymerase chain reaction. RESULTS: We found that the circadian genes CRY1, CRY2, PER1, PER2, CLOCK, ARNTL, ARNTL2, and NPAS2, are expressed in cultured human luteinized granulosa cells. Among these genes, there was a general trend of decreased expression in cells from older women but it reached statistical significance only for PER1 and CLOCK genes (fold change of 0.27 ± 0.14; p = 0.03 and 0.29 ± 0.16; p = 0.05, respectively). CONCLUSIONS: This preliminary report indicates that molecular circadian clock genes exist in human luteinized granulosa cells. There is a decreased expression of some of these genes in older women. This decline may partially explain the decreased fertility and steroidogenesis of reproductive aging.

Caretaker-adolescent communication on sexual and reproductive health: a cross-sectional study in Unguja-Tanzania Zanzibar.

BACKGROUND: Caretakers/parents/caregivers/guardians play important roles in improving Sexual and Reproductive Health (SRH) of adolescents. Caretaker-adolescent sexual communication suggested to influence young people's sexual behaviours. Despite this significance, the communication is believed to be low in Unguja due to the increase of risky sexual behaviours among adolescents. This study assessed the pattern of such communication using IMB model as a framework. METHODS: This is a cross-sectional study targeted caretakers of adolescents aged 15-19. One thousand caretakers of adolescents were interviewed using structured questionnaire. Comparison between male and female caretakers on discussing different SRH topics to both sexes of adolescents was made. The mean-score difference of overall communication was examined using Univariate analysis of variance (ANOVA). Bivariate correlation and simple path analysis via regression was conducted to determine the association of IMB variables in relation to communication practice. RESULTS: This study finds 40.7% of caretakers had ever communicated with their adolescents on SRH matters and 9.2% reported to have had communicated in the past 30 days. The weighted topic measure revealed only 26.5% of caretakers communicated with their adolescents. Both caretakers communicated more with their female adolescents. The communication was more common between same sex and between caretakers and their biological adolescents (p < 0.000). Both male and female caretakers mostly discussed sexual abstinence to female adolescents while to male adolescents, HIV/STIs was mostly discussed by female caretakers and pregnancy by male caretakers. The least discussed topics to both sexes are safer sex and other contraceptives use. The bivariate correlations suggested that IMB constructs were inter-related and associated with communication practice. CONCLUSION: Caretakers-adolescents communication on SRH in Unguja is low and it is not comprehensive. Caretakers fail to communicate with their adolescents on sensitive issues but do so on less sensitive ones. The pattern of communication found to vary across gender of caretaker and that of adolescent and depends on the nature of relationship between caretaker and adolescent. There is gender differences in selecting SRH topics of discussion. Interventions programmes have to include strategies that enhance caretaker's information, motivation and skills so as to improve SRH communication between caretakers and adolescent.

Fast method to quantify PAHs in contaminated soils by direct thermodesorption using analytical pyrolysis.

A method for polycyclic aromatic hydrocarbon (PAH) quantification, based on pyrolysis at 450°C combined with gas chromatography coupled with mass spectrometry and flame ionization detection (Py-GC-MS/FID), was developed and compared to a conventional PAH quantification method using accelerated solvent extraction and GC-MS analyses. The PAH contents of three coking plant soils, one gas plant soil, two wood-treating facility soils and one certified reference material (CRM - BCR 524) were determined using both methods. The results obtained with both methods showed a good match, especially in the case of the CRM. The other soil samples presented higher variability which was greatly reduced by crushing the samples to lower particle size (from <500 to <100µm). Higher contents of low molecular weight (LMW) PAHs were quantified with the Py-GC-MS/FID than with the conventional method, probably because of a slight cracking phenomenon occurring during the pyrolysis and/or a loss of the LMW compounds during the sample concentration required for the conventional method. Because of the limited sample preparation and the fact that no solvent was used, the pyrolysis-based method was proven to be a faster, less expensive and more environmentally friendly than the classical methods for PAH quantification in contaminated soils.

Mitochondrial epileptic encephalopathy, 3-methylglutaconic aciduria and variable complex V deficiency associated with TIMM50 mutations.

Mitochondrial encephalopathies are a heterogeneous group of disorders that, usually carry grave prognosis. Recently a homozygous mutation, Gly372Ser, in the TIMM50 gene, was reported in an abstract form, in three sibs who suffered from intractable epilepsy and developmental delay accompanied by 3-methylglutaconic aciduria. We now report on four patients from two unrelated families who presented with severe intellectual disability and seizure disorder, accompanied by slightly elevated lactate level, 3-methylglutaconic aciduria and variable deficiency of mitochondrial complex V. Using exome analysis we identified two homozygous missense mutations, Arg217Trp and Thr252Met, in the TIMM50 gene. The TIMM50 protein is a subunit of TIM23 complex, the mitochondrial import machinery. It serves as the major receptor in the intermembrane space, binding to proteins which cross the mitochondrial inner membrane on their way to the matrix. The mutations, which affected evolutionary conserved residues and segregated with the disease in the families, were neither present in large cohorts of control exome analyses nor in our ethnic specific exome cohort. Given the phenotypic similarity, we conclude that missense mutations in TIMM50 are likely manifesting by severe intellectual disability and epilepsy accompanied by 3-methylglutaconic aciduria and variable mitochondrial complex V deficiency. 3-methylglutaconic aciduria is emerging as an important biomarker for mitochondrial dysfunction, in particular for mitochondrial membrane defects.

Retreatment of failed regenerative endodontic of orthodontically treated immature permanent maxillary central incisor: a case report

A revascularization procedure was shown to be the best alternative therapy for immature teeth with necrotic pulp and apical infection. A 12 year old female with a history of trauma to her upper central incisor and a sinus tract was referred for endodontic treatment. She was an active orthodontic patient and had undergone regenerative endodontic treatment for the past 2 years. Clinical examination revealed no response to sensibility, percussion, and palpation tests. The preoperative radiograph showed an open apex and apical rarefaction. The case was diagnosed as previously treated tooth with asymptomatic apical periodontitis. Regenerative endodontic retreatment was performed, and the case was followed for 3 years. Clinical, radiographic, and cone-beam computed tomography follow-up examination revealed an asymptomatic tooth, with evidence of periapical healing and root maturation.

Antenatal mitochondrial disease caused by mitochondrial ribosomal protein (MRPS22) mutation.

Three patients born to the same set of consanguineous parents presented with antenatal skin oedema, hypotonia, cardiomyopathy and tubulopathy. The enzymatic activities of multiple mitochondrial respiratory chain complexes were reduced in muscle. Marked reduction of 12s rRNA, the core of the mitochondrial small ribosomal subunit, was found in fibroblasts. Homozygosity mapping led to the identification of a mutation in the MRPS22 gene, which encodes a mitochondrial ribosomal protein. Transfection of the patient cells with wild-type MRPS22 cDNA increased the 12s rRNA content and normalised the enzymatic activities. Quantification of mitochondrial transcripts is advisable in patients with multiple defects of the mitochondrial respiratory chain.

Severe infantile type of carnitine palmitoyltransferase II (CPT II) deficiency due to homozygous R503C mutation.

We report a patient with severe infantile carnitine palmitoyltransferase II (CPT II) deficiency who died at the age of 3 months. Genetic analysis of the CPT2 gene revealed that the patient was homozygous, and her parents were heterozygous, for a R503C missense mutation. Heterozygosity for R503C, without a second mutation, has previously been reported in symptomatic patients from two families, one with the mild adult myopathic form and one with malignant hyperthermia. In contrast, the R503C heterozygous parents of the patient were entirely asymptomatic, suggesting that additional genetic and/or environmental factors must have contributed to the occurrence of symptoms in previously reported carriers. Our findings indicate that the mutation R503C should be added to the handful of mutations associated with the severe phenotype when present in the homozygous state or combined with another severe mutation.

Fulminant neurological deterioration in a neonate with Leigh syndrome due to a maternally transmitted missense mutation in the mitochondrial ND3 gene.

Leigh syndrome can result from both nuclear and mitochondrial DNA defects. Mutations in complex V genes of the respiratory chain were considered until recently as the most frequent cause for mitochondrial inherited Leigh syndrome, while gene defects in complex I were related to recessive Leigh syndrome. Recently few reports of mutations in the mitochondrial-encoded complex I subunit genes causing Leigh syndrome have been reported. We describe a 1-month-old baby who acutely deteriorated, with abrupt onset of brainstem dysfunction, due to basal ganglia lesions extending to the brainstem. A muscle biopsy demonstrated complex I deficiency. Subsequent analysis of the mitochondrial genome revealed a homoplastic T10191C mutation in the ND3 gene (in blood and muscle), resulting in a substitution of serine to proline. Hair root analysis revealed a 50% mutant load, reflecting heteroplasmy in early embryonic stages. The mutation was also detected in his mother (5%). Western blot analysis revealed a decrease of the 20 kDa subunit (likely ND6) and of the 30 kDa subunit (NDUFA9), which is probably due to instability attributed to the inability to form subcomplexes with ND3. This is the first description of infantile Leigh syndrome due to a maternally transmitted T10191C substitution in ND3 and not due to a de novo mutation. This mutation is age and tissue dependent and therefore may not be amenable to prenatal testing.

Adsorption of arsenic (V) on kaolinite and on kaolinite-humic acid complexes. Role of humic acid nitrogen groups.

In order to investigate the influence of organic matter on arsenic retention, we used batch experiments at pH 7 to determine the adsorption of As(V) on three different solids: a crude, purified, Ca-exchanged kaolinite and two kaolinites coated with humic acids (HAs) having different nitrogen contents. We first examined the adsorption of each HA onto kaolinite, and then used the HA-kaolinite complexes to study As(V) adsorption. The results clearly show an influence of the HA coating on As adsorption. For example, with low initial As concentrations the solid/liquid partition coefficient (R(d)) for both HA complexes is greater than that for the crude kaolinite. We found that increasing the initial As concentrations decreased the R(d) values of the HA-coated kaolinites until finally they were the same as the crude kaolinite R(d) values. This suggests that adsorption occurs first on the HA sites and then, once the HA sites are saturated, on the remaining kaolinite sites. We also noted that the more reactive HA-kaolinite complex was the one with the highest N/C ratio. Comparing the amount of amine groups in the HA-kaolinite complexes with the total amount of adsorbed As indicates that the HA amine groups, due to their positive charge at pH 7, play a key role in the adsorption of As onto organic matter.