Wolfram Syndrome-2, a Cause of Severe Gastrointestinal Bleeding: A Case Series and a Literature Review

Background

There are very few reports of Wolfram syndrome-2 (WFS2) in the literature, and understanding of involvement of the gastrointestinal (GI) tract in the syndrome is limited. Objectives: This study aims to describe the clinical presentations of a large number of WFS2 patients with specific focus on their GI manifestations.

Methods

This is a retrospective case series study. Patients who were homozygous for the CISD2 gene mutation were identified through the genetic department of Al-Makassed hospital. Their medical records were reviewed, and biometric data have been obtained. The data were collected and arranged on a data sheet, and descriptive analysis was done using SPSS.

Results

Thirteen patients from 9 families were identified; diabetes mellitus was present in 6 of them, optic atrophy in 5, diabetes insipidus (DI) in 5, and deafness in 2. All of the patients had GI manifestations with abnormal findings on upper endoscopy. Dysmorphic facial features and abnormal findings on brain MRI were present in 3 of our patients. The GI manifestations including GI bleeding and severe ulcerations were the first to appear in 9 of them, while anemia in the remaining 4.

Conclusion

This is the largest study to date describing patients with WFS2. This study's evidence shows the prominent presence of GI involvement, and the severe findings on endoscopy, including duodenal, gastric, and esophageal ulcerations and strictures. Unlike in the Jordanian report, some of the patients in our report also have DI.

Strategic response to COVID-19 in Ethiopia

COVID-19, the novel coronavirus, has posed a major threat to low- and middle-income countries (LMICs) due to inadequate health infrastructure and human resources. Ethiopia, a low-income country with the second largest population in Africa, has coordinated a strategic response, leveraging existing infrastructure and health systems and mobilizing public health professionals and specialist expert physicians for a multifaceted, unified government approach and adaptive response. Resource limitations, particularly in critical care, have still posed challenges, but the public health and clinical interventions thus far have prevented the catastrophic toll that many predicted. As the pandemic continues, Ethiopia expects to use a triple care model integrated at all levels, consisting of COVID-19 care, isolation care for suspected cases, and essential health services, and urges intensified non-pharmaceutical interventions alongside equitable global vaccine distribution as the ultimate answers to pandemic control. This paper draws on existing data, national planning and guidelines, and expertise from health leadership to describe this response in hopes of providing an example of how future large-scale health challenges might be faced in LMICs, using Ethiopia's successes and challenges in facing the pandemic.

RIPK1 mutations causing infantile-onset IBD with inflammatory and fistulizing features

PURPOSE

Receptor-interacting serine/threonine-protein kinase 1 (RIPK1) is an important regulator of necroptosis and inflammatory responses. We present the clinical features, genetic analysis and immune work-up of two patients with infantile-onset inflammatory bowel disease (IBD) resulting from RIPK1 mutations.

METHODS

Whole exome and Sanger sequencing was performed in two IBD patients. Mass cytometry time of flight (CyTOF) was conducted for in-depth immunophenotyping on one of the patient's peripheral blood mononuclear cells, and compared to control subjects and patients with Crohn's disease.

RESULTS

The patients presented with severe colitis and perianal fistulas in the first months of life, without severe/atypical infections. Genetic studies identified pathogenic genetic variants in RIPK1 (Patient 1, A c.1934C>T missense mutation in Exon 11; Patient 2, c.580G>A missense mutation residing in Exon 4). Protein modeling demonstrated that the mutation in Patient 1 displaces a water molecule, potentially disrupting the local environment, and the mutation in Patient 2 may lead to disruption of the packing and conformation of the kinase domain. Immunofluorescence RIPK1 staining in rectal biopsies demonstrated no expression for Patient 1 and minimal expression for Patient 2, compared to controls and patients with active Crohn's disease. Using CyTOF unbiased clustering analysis, we identified peripheral immune dysregulation in one of these patients, characterized by an increase in IFNγ CD8+ T cells along with a decrease in monocytes, dendritic cells and B cells. Moreover, RIPK1-deficient patient's immune cells exhibited decreased IL-6 production in response to lipopolysaccharide (LPS) across multiple cell types including T cells, B cells and innate immune cells.

CONCLUSIONS

Mutations in RIPK1 should be considered in very young patients presenting with colitis and perianal fistulas. Given RIPK1's role in inflammasome activation, but also in epithelial cells, it is unclear whether IL1 blockade or allogeneic hematopoietic stem cell transplantation can suppress or cure the hyper-inflammatory response in these patients. Additional studies in humans are required to better define the role of RIPK1 in regulating intestinal immune responses, and how treatment can be optimized for patients with RIPK1 deficiency.

Reduced pulmonary functions and respiratory muscle strength in Type 2 diabetes mellitus and its association with glycemic control

OBJECTIVE

Diabetes mellitus is one of the main devastating causes of mortality and morbidity due to its detrimental complications. We aimed to evaluate the pulmonary functions and respiratory muscle strength in relationship with glycemic control and gender in type 2 Diabetes Mellitus (T2DM).

MATERIALS AND METHODS

This cross-sectional study was performed at King Saud University and King Khalid University Hospital, Riyadh, Kingdom of Saudi Arabia from June 2107 to June 2019. We evaluated pulmonary functions, respiratory muscle strength, body composition and glycemic control in T2DM (n=110) and control group (n=119). Gender differences were also evaluated in T2DM.

RESULTS

Subjects with T2DM have significantly decreased forced vital capacity (FVC) (3.6±0.7 vs 3.3±0.9, p = 0.012), forced expiratory volume in first second (FEV1) (3.3±2.2 vs 2.7±0.6, p = 0.019), peak expiratory flow (PEF) (127.4±210.9 vs. 49.2±133.6, p = 0.003), FEF25-75 (3.6±1.3 vs. 3.1±1.1, p-value = 0.025), and maximum inspiratory pressure (MIP) (99.3±26.9 vs. 87.4±19.3, p=0.001). However, no significant difference between control and diabetes was found in maximum expiratory pressure (MEP) (132.5±34.9 vs 126.2±30.0, p = 0.202). Significant reduction in FVC (male=3.7±0.8 vs female = 3.0±0.7 p = 0.000), FEV1 (3.3±1.9 vs 2.6±0.5 p = 0.000), FEF25-75 (3.6 ± 1.3 vs 2.9 ± 1.0 with p-value = 0.000), MIP (96.9±23.1 vs 87.5±27.1 with p = 0.017), and MEP (134.0±32.2 vs. 120.1±33.5 with p = .011) were observed in females compared to males in T2DM subjects.

CONCLUSIONS

Decline in the pulmonary function and inspiratory muscle strength are associated with poor glycemic control in T2DM. Moreover, there are significant differences between male and female in lung parameters and inspiratory as well as expiratory muscles strength. The exact pathophysiological mechanism to explain this association requires further investigations.

Estimating treatment effect of tafamidis on hospitalisation in NYHA class III ATTR-CM patients in the presence of death using principal stratification

Background

Hospitalisation has been widely used as a measure of morbidity in clinical trials for chronic heart failure. As previously reported in the Transthyretin Amyloidosis Cardiomyopathy Clinical Trial (ATTR-ACT), the observed frequency of cardiovascular (CV)-related hospitalisations favoured tafamidis over placebo in all analyses except in the NYHA Class III baseline subgroup with a relative risk of 1.41 [95% CI: 1.05, 1.90]1. However, the evaluation of the causal effect of treatment on hospitalisation is complicated in the presence of death as death precludes further hospitalisation and thus limits the evaluation of hospitalisation rates between groups. This confounding effect of death is particularly relevant in NYHA Class III participants who had higher mortality rates compared to Class I or II participants.

Purpose

This aim of this study was to assess the impact of the confounding effect of death on CV-related hospitalisation.

Methods

The effect of tafamidis treatment on CV-related hospitalisations was defined and compared in the subset of participants from either treatment arm who were alive at the end of the study (ie, Month 30); however the subset of participants who survive on the tafamidis arm would be expected to have different characteristics from the subset of participants who survive on the control arm and thus these analyses do not estimate the causal effect.

To address this possible survivor bias, we additionally conducted a post hoc principal stratification analysis. Principal stratification is a statistical method to adjust for post treatment events, in this case mortality, by classifying participants according to their potential to survive under each treatment arm. Specifically, we sought to estimate the principal strata effect on CV-related hospitalisations in NYHA Class III participants who would survive irrespective of treatment assignment. Sensitivity analyses were performed to assess the model assumptions.

Results

The analysis within the subset of participants who survived at Month 30 demonstrated a relative risk of 1.1 (95% CI: 0.56, 2.16) between tafamidis and placebo. The principal stratification analyses of subjects who would survive to 30 months irrespective of treatment estimated a 0.75 (95% CI: 0.44, 1.23) relative risk between tafamidis and placebo, suggesting a 25% reduction in frequency of CV-related hospitalisations in the tafamidis arm.

Conclusion

The initial data reported in ATTR-ACT likely underestimated the true effect of tafamidis on CV-related hospitalisations due to the confounding effect of death. The analysis of treatment group among observed survivors estimated a smaller relative risk for NYHA Class III; however, this analysis does not fully address the possible survivor bias. The survivor average causal effect, which adjusts for the survival bias demonstrated a reduction in the frequency of CV-related hospitalisation in the tafamidis treated arm for NYHA Class III participants.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Pfizer

Homozygous variant in MADD, encoding a Rab guanine nucleotide exchange factor, results in pleiotropic effects and a multisystemic disorder

Rab proteins coordinate inter-organellar vesicle-mediated transport, facilitating intracellular communication, protein recycling, and signaling processes. Dysfunction of Rab proteins or their direct interactors leads to a wide range of diseases with diverse manifestations. We describe seven individuals from four consanguineous Arab Muslim families with an infantile-lethal syndrome, including failure to thrive (FTT), chronic diarrhea, neonatal respiratory distress, variable pituitary dysfunction, and distal arthrogryposis. Exome sequencing analysis in the independent families, followed by an internal gene-matching process using a local exome database, identified a homozygous splice-site variant in MADD (c.2816 + 1 G > A) on a common haplotype. The variant segregated with the disease in all available family members. Determination of cDNA sequence verified single exon skipping, resulting in an out-of-frame deletion. MADD encodes a Rab guanine nucleotide exchange factor (GEF), which activates RAB3 and RAB27A/27B and is thus a crucial regulator of neuromuscular junctions and endocrine secretory granule release. Moreover, MADD protects cells from caspase-mediated TNF-α-induced apoptosis. The combined roles of MADD and its downstream effectors correlate with the phenotypic spectrum of disease, and call for additional studies to confirm the pathogenic mechanism and to investigate possible therapeutic avenues through modulation of TNF-α signaling.

A hybrid achromatic metalens

Metalenses, ultra-thin optical elements that focus light using subwavelength structures, have been the subject of a number of recent investigations. Compared to their refractive counterparts, metalenses offer reduced size and weight, and new functionality such as polarization control. However, metalenses that correct chromatic aberration also suffer from markedly reduced focusing efficiency. Here we introduce a Hybrid Achromatic Metalens (HAML) that overcomes this trade-off and offers improved focusing efficiency over a broad wavelength range from 1000–1800 nm. HAMLs can be designed by combining recursive ray-tracing and simulated phase libraries rather than computationally intensive global search algorithms. Moreover, HAMLs can be fabricated in low-refractive index materials using multi-photon lithography for customization or using molding for mass production. HAMLs demonstrated diffraction limited performance for numerical apertures of 0.27, 0.11, and 0.06, with average focusing efficiencies greater than 60% and maximum efficiencies up to 80%. A more complex design, the air-spaced HAML, introduces a gap between elements to enable even larger diameters and numerical apertures.

Metalenses that correct chromatic aberration also suffer from reduced focusing efficiency. Here, the authors introduce a Hybrid Achromatic Metalens which merges a metalens and phase plate to offer improved focusing efficiency over a broad wavelength range and diffraction limited imaging performance.

Organic solute transporter-β (SLC51B) deficiency in two brothers with congenital diarrhea and features of cholestasis

Primary bile acid malabsorption is associated with congenital diarrhea, steatorrhea, and a block in the intestinal return of bile acids in the enterohepatic circulation. Mutations in the ileal apical sodium-dependent bile acid transporter (ASBT; SLC10A2) can cause primary bile acid malabsorption but do not appear to account for most familial cases. Another major transporter involved in the intestinal reclamation of bile acids is the heteromeric organic solute transporter alpha-beta (OSTα-OSTβ; SLC51A-SLC51B), which exports bile acid across the basolateral membrane. Here we report the first patients with OSTβ deficiency, clinically characterized by chronic diarrhea, severe fat soluble vitamin deficiency, and features of cholestatic liver disease including elevated serum gamma-glutamyltransferase activity. Whole exome sequencing revealed a homozygous single nucleotide deletion in codon 27 of SLC51B, resulting in a frameshift and premature termination at codon 50. Functional studies in transfected cells showed that the SLC51B mutation resulted in markedly reduced taurocholic acid uptake activity and reduced expression of the OSTα partner protein.

CONCLUSION

The findings identify OSTβ deficiency as a cause of congenital chronic diarrhea with features of cholestatic liver disease. These studies underscore OSTα-OSTβ's key role in the enterohepatic circulation of bile acids in humans. (Hepatology 2017).

Severe persistent unremitting dermatitis, chronic diarrhea and hypoalbuminemia in a child; Hartnup disease in setting of celiac disease

Background

Celiac disease (CD) is a complex autoimmune disorder that can lead to an inflammatory small intestinal villous atrophy and malabsorption.

Hartnup disease is an autosomal recessive disorder caused by increased urinary excretion of neutral amino acids. Co-occurrence of Hartnup disease and CD is extremely rare with only a single case reported.

Case presentation

We report a 3-year girl with chronic diarrhea, Hypoalbuminemia and exfoliative erythema. She was diagnosed with celiac disease, which did not improve on gluten free diet. Hartnup disease was suspected and was confirmed by neutral aminoaciduria. Niacin was started and followed by dramatic improvement.

Conclusion

Presence of Celiac and Hartnup disease in single individual is very rare. Complete nutritional assessment of refractory celiac patient can reveal underlying nutritional deficiency.

Calprotectin in cystic fibrosis

BACKGROUND

There is increasing evidence that intestinal inflammation plays a major role in gastrointestinal symptoms in cystic fibrosis (CF). Fecal calprotectin is a marker that is elevated in several gastrointestinal inflammatory diseases, but little is known about its value in CF. We aimed to look for associations of elevated fecal calprotectin among CF patients and whether its level correlates with the clinical manifestations of CF.

METHODS

A single stool specimen was collected from 62 patients with CF. Fecal calprotectin was measured using the commercially available ELISA kits (PhiCal™ test). Clinical data were collected from patients' records and CF registry.

RESULTS

There were no significant differences between CF patients with normal and abnormal fecal calprotectin levels. However, patients who were not receiving inhaled antibiotics had higher fecal calprotectin levels than those who were.

CONCLUSION

Elevated fecal calprotectin may not accurately predict intestinal inflammation in CF. However, the fact that it was elevated in both pancreatic sufficient and insufficient groups supports the concept of "cystic fibrosis enteropathy" regardless of the pancreatic status.

Early mid-term results of the first 103 cases of multilayer flow modulator stent done under indication for use in the management of thoracoabdominal aortic pathology from the independent global MFM registry

AIM

We report mid-term results from the Global Independent multilayer flow modulator (MFM) registry using a uni-modular multilayer flow modulator stent technology.

METHODS

We present the first 103 cases out of the 380 cases implanted in Europe under indications for use. All were done on a compassionate basis, in 12 countries, and were fully analyzed through the MFM registry. Primary endpoints were: one-year freedom from rupture and aneurysm-related death, one year all cause mortality, patency of visceral branches at one year, and one year incidence of stroke and paraplegia. Primary technical endpoints were aneurysm sac volume modulation at one year. Secondary technical endpoints were technical success and one-year freedom from reintervention. Mean age of 69.2 years (16-93 years), mean aneurysm diameter was 6.4±1.66 cm and mean length was 12.96 cm. They were 75 Crawford thoracoabdominal aortic aneurysms (TAAA) (11 Type I, 14 Type II, 26 Type III, and 24 Type IV), 7 arch aneurysms, 15 suprarenal aortic aneurysms and 6 type B dissections. The mean number of side branches covered for a total number of 378 branches is 3.7 side branches per case. Total numbers of stents used was 176 with a mean of 1.71 MFM stents per case; 77.77 were ASA IV E, 72.7% had previous thoracic endovascular aortic repair or open TAAA repair.

RESULTS

Thirty-day morbidity was 5.4% with zero mortality. Aneurysm related survival was 91.7% at one year. No rupture occurred. Four cases of consumptive coagulopathy were observed, two of which resulted in death from hemorrhagic cerebrovascular stroke and one of which resulted in death from a gastrointestinal bleed. Technical success was 97.3%. One-year all-cause survival was 86.8%. At 12 months 95.1% of all visceral branches were patent. There were no stent fractures. One-year intervention free survival was 89.4%. At six months the mean rate of sac volume increase was 0.57%% per month, resulting in a mean volume increase of 2.56%. At 12 months the rate of increase had slowed to 0.33% per month, resulting in a total average increase in sac volume of 5.07%. Mean base line thrombus volume was 297.54 cm3. At one year the mean thrombus volume was 361.38 cm3 with mean volume change of 63.45 cm3. However, mean base line total volume was 332.79 cm3. At one year the mean total volume was 355.4 cm3 with a mean total volume change of 22.61 cm3. The mean base line maximum diameter was 6.27 cm. At one year mean maximum diameter was 7.06 cm with mean total change of 0.79 cm3. The mean baseline residual flow volume was 71.75 cm3. At one year, mean residual flow volume had decreased to 63.3cm3 with mean volume change of 8.4 cm3.

CONCLUSION

Increasing sac volume, thrombus or diameter size was not associated with rupture. MFM implantation instigates a process of aortic remodeling involving initial thrombus deposition, which slows between six and twelve months. This Global MFM Registry data has demonstrated the proof of concept of this disruptive technology.

Fournier’s gangrene: outcome analysis of 62 consecutive cases

Objectives:

The objective of this article is to study the outcome of management of 62 consecutive cases of Fournier’s gangrene (FG).

Patients and methods:

We conducted an observational study of all cases of FG admitted to the Urology and General Surgery departments of Farwaniya Hospital, Kuwait, between 2004 and 2013. We recorded the laboratory and clinical findings on admission. Operative and postoperative data were also recorded.

Results:

Our study included 62 cases of FG. Patients were divided into two groups: Group A (survival) consisted of 55 cases and Group B (mortality) of seven cases. The mean duration of symptoms before admission was significantly longer in the mortality group (3.86 days versus 1.96 days in survival group) ( p < 0.05). The mean duration of symptoms until time of first debridement was also significantly longer in the mortality group (4.39 days versus 2.35 days in survival group) ( p < 0.05). There was also a statistically significant difference between the two groups regarding the percentage of the affected area in relation to total body surface area (4.6% in Group A versus 8% in Group B) ( p < 0.05). The Fournier Gangrene Severity Index score (FGSI) was significantly higher in Group B (10.26) in comparison to Group A (6) ( p < 0.01). The mean duration of hospital stay was significantly higher in the survival group (22.24 days versus 14.28 days) ( p < 0.01). Diabetes and renal failure were significantly higher in the mortality group (100% and 57.1% in Group B versus 54.5% and 9.1% in Group A, respectively) ( p < 0.05). The number of patients presenting with severe sepsis was higher in the mortality group (71.4% in Group B versus 12.7% in Group A) ( p < 0.05).

Conclusion:

We concluded that FG is a serious, potentially fatal disease. Higher mortality is related to severe sepsis on admission, renal failure, diabetes, extensive disease involving extra-genital areas and late presentation. A multidisciplinary approach in diagnosis and management of the disease can achieve good outcome with low mortality rate.

Induction of heme oxygenase-1 protects mouse liver from apoptotic ischemia/reperfusion injury

Ischemia/reperfusion (I/R) injury is the main cause of primary graft dysfunction of liver allografts. Cobalt-protoporphyrin (CoPP)-dependent induction of heme oxygenase (HO)-1 has been shown to protect the liver from I/R injury. This study analyzes the apoptotic mechanisms of HO-1-mediated cytoprotection in mouse liver exposed to I/R injury. HO-1 induction was achieved by the administration of CoPP (1.5 mg/kg body weight i.p.). Mice were studied in in vivo model of hepatic segmental (70 %) ischemia for 60 min and reperfusion injury. Mice were randomly allocated to four main experimental groups (n = 10 each): (1) A control group undergoing sham operation. (2) Similar to group 1 but with the administration of CoPP 72 h before the operation. (3) Mice undergoing in vivo hepatic I/R. (4) Similar to group 3 but with the administration of CoPP 72 h before ischemia induction. When compared with the I/R mice group, in the I/R+CoPP mice group, the increased hepatic expression of HO-1 was associated with a significant reduction in liver enzyme levels, fewer apoptotic hepatocytes cells were identified by morphological criteria and by immunohistochemistry for caspase-3, there was a decreased mean number of proliferating cells (positively stained for Ki67), and a reduced hepatic expression of: C/EBP homologous protein (an index of endoplasmic reticulum stress), the NF-κB's regulated genes (CIAP2, MCP-1 and IL-6), and increased hepatic expression of IκBa (the inhibitory protein of NF-κB). HO-1 over-expression plays a pivotal role in reducing the hepatic apoptotic IR injury. HO-1 may serve as a potential target for therapeutic intervention in hepatic I/R injury during liver transplantation.

Eosinophilic annular erythema is a peculiar subtype in the spectrum of Wells syndrome: a multicentre long-term follow-up study

BACKGROUND/OBJECTIVE

Eosinophilic annular erythema (EAE) was proposed to describe annular skin lesions associated with tissue eosinophilia, however, its relation to Well's syndrome (WS) remains a source of controversy. We studied a series of patients to increase awareness of this entity and to clarify its relation to WS.

METHODS

A multicentre study in which the clinical records, histological findings, laboratory results, therapeutic responses and follow-up of 10 patients were demonstrated.

RESULTS

The study included seven women and three men with age ranging from 31 to 54 years. The duration of the disease ranged from 3 to 28 months. All patients showed involvement of trunk and extremities. Early lesions were manifested as erythematous plaques, which progressed to well-developed figurate lesions and ended as large annular lesions with pigmented centre and elevated border. Flame figures were only observed in well-developed and long-standing lesions. Blood eosinophilia was found in all patients with different grades. Associated disorders included chronic gastritis, diabetes mellitus, chronic hepatitis-C virus infection and chronic kidney disease. The disease showed chronic course with high relapse rate and resistance to various therapeutic modalities including systemic steroid alone and in combination with hydroxychloroquine and cyclosporine.

CONCLUSION

We believe that EAE is a peculiar clinical variant in the spectrum of WS, which is characterized by a chronic course, resistance to treatment and high relapse rate. The diagnosis and evaluation of this condition need a close monitoring with repeated clinical, histological and laboratory assessment.

Subjective global nutritional assessment in critically ill children

BACKGROUND

Underweight children admitted to the pediatric intensive care unit (PICU) have a higher risk of mortality than normal-weight children. The authors hypothesized that subjective global nutrition assessment (SGNA) could identify malnutrition in the PICU and predict nutrition-associated morbidities.

METHODS

The authors prospectively evaluated the nutrition status of 150 children (aged 31 days to 5 years) admitted to the PICU with the use of SGNA and commonly used objective anthropometric and laboratory measurements. Each child was administered the SGNA by a dietitian while anthropometric measurements were performed by an independent assessor. To test interrater reproducibility, 76 children had SGNA performed by another dietitian. Occurrence of nutrition-associated complications was documented for 30 days after admission.

RESULTS

SGNA ratings of well nourished, moderately malnourished, or severely malnourished demonstrated moderate to strong correlation with several standard anthropometric measurements (P < .05). The laboratory markers did not demonstrate any correlation with SGNA. Interrater agreement showed moderate reliability (κ = 0.671). Length of stay, pediatric logistic organ dysfunction, and Pediatric Risk of Mortality III were not significantly different across the groups and did not correlate with SGNA.

Neutron transmutation doping conceptual design

This paper describes and investigates upgrading of the silicon doping facility at the ETRR-2 research reactor to accommodate larger size silicon ingots in the two positions available for irradiation in the thermal column of the reactor. Two methods of irradiation are proposed. Both are based on irradiating two ingots simultaneously in one position. After a certain irradiation time, the silicon ingots are reshuffled inside the irradiation channel. The results obtained show that the proposed irradiation strategies of doping silicon ingots are simple to handle and result in acceptable values of resistivity variation.

Tricho-hepato-enteric syndrome: a case of hemochromatosis with intractable diarrhea, dysmorphic features, and hair abnormality

We report on a female infant with congenital iron storage disease, facial dysmorphism, intractable diarrhea, and hair abnormalities. The intractable diarrhea failed to resolve despite total parenteral nutrition and complete bowel rest for more than 3 weeks. The patient also had elevated liver enzymes and failure to thrive. Histopathologic examination of the liver revealed marked iron deposits in hepatocytes with portal edema, fibrosis, and septal formation. No metabolic abnormalities could be detected. She died at the age of 10 months. We suggest that this case could have a specific iron storage syndrome that is similar to the two sibs reported by Stankler et al. [1982; Arch Dis Child 57:212-216] and Verloes et al. [1997; Am J Med Genet 68:391-395]. The condition was called the tricho-hepato-enteric (THE) syndrome.

Spectrofluorometric determination of montelukast in dosage forms and spiked human plasma

The native fluorescence of montelukast has been studied under different experimental conditions. The highest fluorescence intensity was obtained in methanol at 390 nm using 340 nm for excitation. Surfactants and sensitizers had either a negative or a slightly positive effect on its fluorescence intensity. The fluorescence intensity-concentration plot was rectilinear over the range 0.125 to 5 microg/ml with a lower detection limit of 0.02 microg/ml (3.4 x 10(-8) M). Interference likely to be introduced from co-formulated drugs (such as loratadine) or co-administered drugs (such as verapamil, carbazepam, propranolol) or other common drugs, was studied. The method was successfully applied to the determination of the drug in tablets (pediatric tablets, chewable tablets and adult tablets). The mean % recoveries were in agreement with those provided by the manufacturer. The method was further applied to the in vitro determination of montelukast in spiked human plasma, the mean % recovery (n = 5) was 100.08 +/- 1.40.

Voltammetric study of danazol and its determination in capsules and spiked biological fluids

The voltammetric behaviour of danazol DZ (antigonadotropin) was studied using cyclic voltammetry, direct current, differential pulse polarography (DPP) and alternating current polarography. Danazol exhibited irreversible cathodic waves over the pH range of 1-5 in Britton Robinson buffers. At pH 1 (the analytical pH), a well-defined wave with E1/2 of -1.04 V versus Ag/AgCl reference electrode was obtained. The diffusion current constant (Id) was 4.8+/-0.14 microA.L.m mole(-1) and the current-concentration plot was rectilinear over the range from 5 x 10(-6) to 1 x 10(-4) M with correlation coefficient (n = 11) of 0.995. The calculated detection limit was 1 x 10(-6) M using the DPP mode. The wave was characterized as being irreversible, diffusion-controlled although adsorption phenomenon played a limited role in the electrode process. The proposed method was applied to commercial capsules and the average percentage recovery was in agreement with that obtained by the official USP method. The method was extended to the in vitro determination of DZ in spiked human urine and plasma samples, the percentage recoveries were 96+/-4 and 97+/-5, respectively. A proposal of the electrode reaction was postulated.

Binary tree-structured vector quantization approach to clustering and visualizing microarray data

MOTIVATION

With the increasing number of gene expression databases, the need for more powerful analysis and visualization tools is growing. Many techniques have successfully been applied to unravel latent similarities among genes and/or experiments. Most of the current systems for microarray data analysis use statistical methods, hierarchical clustering, self-organizing maps, support vector machines, or k-means clustering to organize genes or experiments into 'meaningful' groups. Without prior explicit bias almost all of these clustering methods applied to gene expression data not only produce different results, but may also produce clusters with little or no biological relevance. Of these methods, agglomerative hierarchical clustering has been the most widely applied, although many limitations have been identified.

RESULTS

Starting with a systematic comparison of the underlying theories behind clustering approaches, we have devised a technique that combines tree-structured vector quantization and partitive k-means clustering (BTSVQ). This hybrid technique has revealed clinically relevant clusters in three large publicly available data sets. In contrast to existing systems, our approach is less sensitive to data preprocessing and data normalization. In addition, the clustering results produced by the technique have strong similarities to those of self-organizing maps (SOMs). We discuss the advantages and the mathematical reasoning behind our approach.

High Performance Liquid Chromatoqraphic Method for the Simultaneous Determination of Labetalol and Hydrochlorothiazide in Tablets and Spiked Human Plasma

A reversed-phase HPLC method with spectrophotometric detection was developed for the simultaneous determination of labetalol (LBT) and hydrochloro-thiazide (HCD). The chromatographic separation was performed using a Microbondapak C18 column (4.6 i.d. x 250 nm) and paracetamol as internal standard. A mobile phase consisting of 0.05 M phosphate buffer/acetonitrile of pH 4 (7:3) at a flow rate of 0.7 ml/min was used. The detection was affected spectrophotornetrically at 302 nm. The working concentration range was 0.3–10 µg/ml with detection limits of 0.05 µg/ml for both drugs. The lower quantitation limit was 0.25 µg/ml in the two cases. The method was successfully applied to tablets, the % recoveries were 99.45 ± 0.68 for LBT and 99.79 ± 0.75 for HCD. The method was extended to the in-vitro determination in spiked human plasma. The % recoveries were 91.12 ± 0.33 for LBT and 91.37 ± 0.40 for HCD. The interday and intraday precision and accuracy were evaluated in plasma by calculating the % RSD (n=5) and the % error and were found to be in the ranges of 1.18–4.1% and 0.38–0.36% for both drugs, respectively.

Spectrophotometric determination of acyclovir in some pharmaceutical formulations

A simple and reliable spectrophotometric method has been developed for the determination of acyclovir in pharmaceutical formulations. The method is based on its oxidative coupling reaction with 3-methylbenzothiazolin-2-one hydrazone (MBTH) in the presence of FeCl3 as an oxidant to produce deep-green colored species measurable at 616 nm. The absorbance-concentration plot is linear over the range 20-200 microg ml(-1) with minimum detectability of 1.06 microg ml(-1) (4.71 x 10(-6) M). The molar absorptivity was 9.41 x 10(2) l mol(-1) cm(-1) with correlation coefficient (n = 7) of 0.9998. The different experimental parameters affecting the development and stability of the color were studied carefully and optimized. The proposed method was applied successfully to the determination of acyclovir in its dosage forms. The percentage recoveries +/-SD (n = 9) were 98.63 +/- 0.34, 99.61 +/- 0.58, 99.35 +/- 0.58 and 99.72 +/- 0.86 for tablets, ophthalmic ointment and cream, respectively. A proposal of the reaction pathway was presented.

Women's empowerment and reproductive choices

The authors use data from the 1990-1991 Pakistan Demographic and Health Survey to examine some variables indicating women's empowerment and to analyze the impact of such variables on reproductive choices. They conclude that "most Pakistani women are unaccustomed to the idea of planning children; for them, having children is a phenomenon as simple and common as most other issues of life. Among others who desire a specific number of children, the majority end up having more. It is because socio-cultural influences lead women to have a large family size. Our analysis also denotes similar results, and hence most of the empowerment variables used in this analysis do not explain the variation in the dependent variable as was expected." A comment by Khaleda Manzoor (pp.1,148-50) is included.

Reconstructive surgery of the pelvis after surgery for rectal cancer

The role of the reconstructive surgeon has increased with an increasingly aggressive surgical approach to locally advanced rectal carcinoma. Multiple options exist for pelvic floor reconstruction. Muscle and myocutaneous flaps for pelvic-floor reconstruction provide well vascularized tissues which may also serve as a biologic spacer. Flaps help to prevent post-radiation fistulae, small bowel obstruction, and pelvic sidewall adherence; flaps also may serve as a barrier to radiation injury. Often a more stable perineal wound closure is achieved. In cases that involve vaginal resection, flaps make neo-vaginal reconstruction possible. Pre-operative consultation with the reconstructive surgeon allows planning of complex, multi-disciplinary procedures, and facilitates patient understanding of the proposed procedure.

Idiotypic regulation in Schistosomiasis mansoni

The role of anti-idiotype Ab2 in regulation of the immune response in schistosomiasis was studied. Positive Ab2 could be detected among the newborns of infected mothers and experimentally S. mansoni- infected mice. Negative anti-idiotypic antibodies were observed among children above 3 years and control mice. Increasing levels of anti-idiotypic antibodies were detected among S. mansoni infected children and adults. Higher mean anti-idiotype A2 levels were found among patients with hepatosplenomegaly than those with intestinal manifestations. The kinetics of anti-idiotype Ab2 among the S. mansoni- infected mice started from the end of the first week after infection up to 8 weeks. It was continuous, but with undulating levels. Moreover, the anti-idiotype antibody was able to stimulate lymphocyte proliferation at 8 weeks post infection.