Prevalence of Rifampicin resistance tuberculosis among presumptive tuberculosis patients in Egypt-2021: a national health facility-based survey

BACKGROUND

The magnitude of MDR-TB cases was noticeable in Egypt. However, the last national survey was 11-years ago. The current survey was conducted to determine the prevalence of rifampicin resistance among sputum smear-positive pulmonary tuberculosis patients in Egypt.

METHODS

A national health facility-based cross-sectional study was conducted in 14 randomly selected governorates in Egypt between August 2020 and September 2021. All presumptive TB cases, either new or previously treated according to WHO definitions, with no gender, age, or nationality limitations, and provided informed consent were included in the study. Each patient completed a case report form (CRF). The CRF included socio-demographic and clinical data. Sputum samples were collected according to standard techniques and cultured on Lowenstein-Jensen (L-J) medium. Gene X-pert test was carried out first on the samples for simultaneous identification of MTB and rifampicin resistance. The prevalence of RR was calculated using crude, cluster, and weighted methods. Factors associated with RR were analyzed by bivariate and multivariate techniques.

RESULTS

Among the total 849 presumptive TB patients enrolled in the study, 710 (83.6%) patients were subjected to Gene X-pert testing (MTB/RIF). The crude prevalence of RR was 3.32% (95% CI: 1.89-4.76%) among the new cases and 9.46% (95% CI: 2.63-16.29%) among the retreated cases with an overall estimate of 3.99%; (95% CI: 2.51-5.47%). By cluster analysis the overall prevalence of RR was 5.01% (95% CI: 2.90-7.13). Factors associated with the prevalence of RR were co-morbidity with bronchial asthma, drug abuse and history of contact with a family member with TB.

CONCLUSION

The prevalence of RR among either new or retreated cases TB patients was lower than the previous Egyptian rates in 2010-2012. The strongest predictor associated with RR was comorbidity with bronchial asthma.

Effectiveness and Safety of Inactivated SARS-CoV-2 Vaccine (BBIBP-CorV) among Healthcare Workers: A Seven-Month Follow-Up Study at Fifteen Central Hospitals

BACKGROUND

During a pandemic, healthcare workers are at high risk of contracting COVID-19. To protect these important individuals, it is highly recommended that they receive the COVID-19 vaccine. Our study focused on evaluating the safety and efficacy of Egypt's first approved vaccine, the Sinopharm vaccine (BBIBP-CorV), and comparing these findings with other vaccines.

METHODS

An observational study was conducted in fifteen triage and isolation hospitals, from the 1st of March until the end of September 2021. The study included fully vaccinated and unvaccinated participants, and we measured vaccine effectiveness (using 1-aHR), the incidence rate of severely to critically ill hospitalized cases, COVID-19-related work absenteeism, and the safety of the vaccine as outcomes.

RESULTS

Of the 1364 healthcare workers who were interviewed, 1228 agreed to participate. After taking the hazard ratio into account, the vaccine effectiveness was found to be 67% (95% CI, 80-43%) for symptomatic PCR-confirmed cases. The incidence rate ratio for hospitalization was 0.45 (95% CI, 0.15-1.31) in the vaccinated group compared to the unvaccinated group, and there was a significant reduction in absenteeism among the vaccinated group (p < 0.007). Most adverse events were mild and well tolerated. Vaccinated pregnant and lactating mothers did not experience any sentinel adverse events.

CONCLUSION

Our study found that the BBIBP-CorV vaccine was effective in protecting healthcare workers from COVID-19.

Household catastrophic total cost due to tuberculosis in Egypt: incidence, cost drivers and policy implication

Background: Tuberculosis (TB) is a disease that disproportionately affects the poor. The World Health Organization lists economic factors as one of main barriers to tuberculosis management. Aims: This study aimed to estimate the household total catastrophic cost of TB and its determinants among newly diagnosed Egyptian tuberculous patients. Methods: This was a cohort prospective study covering 257 TB patients registered in 2019. The patients were followed up bi-monthly till the end of the treatment regimen (4 visits). A standardized questionnaire published by the poverty sub-working group of the Stop TB Partnership; was used after minor modification. The following costs were measured: pre-diagnosis, direct and indirect, guardian and coping, as well as annual household income. Catastrophic cost (direct plus indirect) is considered if the total cost of TB treatment exceeds 20% of the household’s annual income. Sensitivity analyses were analysed using different thresholds. Results: The incidence of household total catastrophic cost was 24.1%. The mean total cost of TB treatment was US$ 198. Over 50% of the total direct cost was incurred during the pre-diagnosis period. After adjustment for other determinant variables using multivariable logistic regression, we found that age < 30 years, living in a house with crowding index > 2, poverty and coping were more likely to incur higher total catastrophic cost. Conclusions: Catastrophic cost was experienced by 1 out of every 4 new TB patients.

Clinical Efficacy of Early Administration of Convalescent Plasma among COVID-19 Cases in Egypt

Background: The rapid worldwide spread of the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) or COVID-19 pandemic from its epicentre; Wuhan has led to an epidemiological breakdown. Egypt reported its first COVID-19 case on Feb 14, 20202,3. Thereafter, Egypt scaled-up preventive measures, with a partial lockdown starting on March 25. Several therapeutic agents along with Convalescent Plasma Transfusion are under investigation and data from Convalescent Plasma Transfusions (CPT) have been receiving a lot of attention, after Emergency approvals from the Food and Drug Administration (FDA) suggesting that it may provide a clinical effect in the treatment of SARS-COV-2 Importance: Early and effective treatment of COVID-19 is vital for control of SARS-CoV-2 infection Methods: -Designs: An interventional, single-arm, non-randomized clinical trial conducted in Egypt from April 15 to July 21, 2020.   -Settings: This was a multi-centre study conducted in 3 hospitals in Egypt.   -Participants: a total of 94 COVID-19 laboratory-confirmed patients using qRT-PCR were enrolled in the study.   -Intervention: All patients were administered with two plasma units (each unit is 200cc). The volume of donated plasma was 800cc.   -Main Outcome and Measures: Primary measure was the degree of clinical improvement among the COVID-19 patients who received CPT within seven days   Results: A total of 94 patients were enrolled who received CPT either within seven days or after seven days of hospitalization. 82 were severely ill, 12 were critically ill. The average age remained 58 years (±SD 15.1 years). Male were 69% and 49% patients got cured while 51% died with CFR 51%. 75% deaths were above 45years of age. The symptoms were dyspnoea (55%), fever (52%), cough (46%), and loss of taste and smell (21%), and cyanosis (15%). The most common co-morbidities among the <40 years remained Diabetes Mellitus (21%) and Asthma (14%). Among 40-60 years Hypertension (56%), Diabetes Mellitus (39%) and among >60 years age group Hypertension (57%) and Chronic Heart Disease (24%) were reported. CPT within seven days remained significant as compared with the  CPT after seven days with the number of days to cure (p=0.007) and ICU stay (P=0.008) among severely ill cured cases.   Conclusions: Among patients with COVID-19 and severe or critical illness, the use of CPT along with routine standard therapy resulted in a statistically significant improvement when administered within seven days of hospital admission. However, plasma transfusion, irrespective of days to transfusion may not help treat critically ill patients. The overall mean time to cure in severely ill patients was 15 days if CPT provided within seven days with 65% cure rate.   Trial Registration: Clinical Intervention identifier: MOHP_COVID-19_Ver1.1 registered April 2020 Keywords: Covid 19 pandemic, Convalescent plasma, SARS-CoV-2,

Clinical evaluation of pregnant women with SARS-COV2 pneumonia: a real-life study from Egypt

BACKGROUND

Knowledge about the outcome of COVID-19 on pregnant women is so important. The published literature on the outcomes of pregnant women with COVID-19 is confusing. The aim of this study was to report our clinical experience about the effect of COVID-19 on pregnant women and to determine whether it was associated with increased mortality or an increase in the need for mechanical ventilation in this special category of patients.

METHODS

This was a cohort study from some isolation hospitals of the Ministry of Health and Population, in eleven governorates, Egypt. The clinical data from the first 64 pregnant women with COVID-19 whose care was managed at some of the Egyptian hospitals from 14 March to 14 June 2020 as well as 114 non-pregnant women with COVID-19 was reviewed.

RESULTS

The two groups did not show any significant difference regarding the main outcomes of the disease. Two cases in each group needed mechanical ventilation (p 0.617). Three cases (4.7%) died among the pregnant women and two (1.8%) died among the non-pregnant women (p 0.352).

CONCLUSIONS

The main clinical outcomes of COVID-19 were not different between pregnant and non-pregnant women with COVID-19. Based on our findings, pregnancy did not exacerbate the course or mortality of COVID-19 pneumonia.

Assessment of Interferon Gamma-Induced Protein 10 mRNA Release Assay for Detection of Latent Tuberculosis Infection in Egyptian Pediatric Household Contacts

OBJECTIVES

Current diagnostic tests for tuberculosis (TB) in children living in low-endemic countries are limited by low specificity and the inability of the current tests to differentiate between active TB and latent TB infection (LTBI). This study aimed to evaluate the blood IP-10 mRNA expression level to detect LTBI in Egyptian pediatric household contacts (PHC).

METHODS

TB-specific IP-10 and IFN-γ mRNA levels were assessed by real-time quantitative PCR (RT-qPCR) in 72 Egyptian PHC of active pulmonary TB cases. All study participants were also assessed by Tuberculin Skin Test (TST) and Quantiferon gold in tube (QFN-GIT) assay.

RESULTS

IP-10 and IFN-γ mRNA expression levels were significantly higher in PHC with active TB or LTBI than TB negative (p < 0.0001). The level of IP-10 mRNA expression was significantly higher in PHC with active TB than LTBI (p = 0.0008). In contrast, there was no significant differences in the IFN-γ mRNA expression between PHC with active TB compared to LTBI (p = 0.49). The sensitivity and specificity of the IP-10 RT-qPCR were 94.2% and 95.2%, respectively, in PHC with active TB compared to 85.7% and 81.8% in PHC with LTBI. The negative and positive predictive values and accuracy of IP-10 RT-qPCR for distinguishing active TB from LTBI were 85.2%, 58.3%, and 72.6% respectively.

CONCLUSION

Blood IP-10 mRNA expression level may be a potential diagnostic marker to help distinguish active TB from LTBI in PHC.

Attitudes, beliefs and practice of Egyptian healthcare workers towards seasonal influenza vaccination

Background

Seasonal influenza vaccination is highly recommended for healthcare workers (HCWs) every year to protect them and reduce the risk of disease transmission at workplaces. Relatively few studies addressed influenza vaccination in the Eastern Mediterranean Region.

Objectives

The main objective of this study was to explore the attitudes, beliefs and practice of Egyptian HCWs towards seasonal influenza vaccine.

Methods

This is a nationwide cross‐sectional study. Data were collected through self‐administered structured questionnaire. A sample of 3534 HCWs (physicians and nurses) was collected from different levels of healthcare facilities.

Results

The proportion of seasonal influenza vaccine uptake during the last season was 30.7% while the percentage of ever vaccinated was 46.8%. The most identified reason for non‐compliance was lack of trust about vaccine efficacy and its adverse events. Around 80% of participants expressed positive attitude towards influenza vaccine and the vast majority (98%) agreed to uptake the vaccine during pandemic. There was significant positive association between attitude score and influenza vaccine uptake. Raising awareness about vaccine and ensuring vaccine availability were the main suggestions by HCWs to improve vaccine uptake.

Conclusions

Although there was positive attitude towards influenza vaccine, yet vaccination coverage was suboptimal particularly among those working in university hospitals. Educational messages and operational strategies addressing motivators and barriers that emerged from this study are needed to optimize vaccine uptake.

Utility of Lung Ultrasound in Decision making to prioritize hospital admission for COVID-19 patients: A Developing Country Perspective

BACKGROUND & AIMS

In healthcare settings with limited resources, it is crucial to make a plan to prioritize hospital admission for patients affected by COVID-19. So, we tried to develop a novel approach for triaging COVID-19 patients and deciding the priority for hospital admission using Lung Ultrasound. In this study, we aimed to evaluate the efficacy of lung ultrasound in triaging suspected COVID-19 patients and assessment of the severity of COVID-19 pneumonia and its comparison with CT chest as the gold standard.

METHOD

This was a multicenter cross-sectional study enrolled on 243 COVID-19 confirmed patients presented to the emergency department in three major University hospitals in Egypt. Lung ultrasound was done by an experienced emergency physician or chest physician according to the local protocol of each hospital. Demographic, clinical, and laboratory data were collected from each patient. Each patient was subjected to CT chest and lung ultrasound.

RESULTS

A total of 243 confirmed COVID-19 patients were enrolled in this study, with a mean age of 46.7+10.4 years. Ground glass opacity (GGO), subpleural consolidation, trans-lobar consolidation, and crazy paving were reported in chest CT scans of 54.3%, 15.2%, 11.1%, and 8.6% of patients, respectively. B-line artifacts were found in 81.1% of COVID-19 patients, which was of confluent pattern in 18.9% of patients. The lung ultrasound findings of 197 patients (81.1%) were completely coincident with those of CT with a Kappa agreement value of 0.77, and this offered a diagnostic sensitivity of 74 %, a diagnostic specificity of 97.9 %, positive predictive value (PPV) of 90.2% and negative predictive value (NPV) of 93.6 % for lung ultrasound in triaging COVID-19 patients. Adding O2 saturation to the findings of lung imaging, the accuracy of evaluation of lung ultrasound to differentiate between severe and non-severe lung diseases showed that ultrasound had 100% sensitivity and specificity.

CONCLUSION

Lung Ultrasound with Oxygen saturation is a very efficient tool for decision-making to prioritize hospital admission for patients affected by COVID-19 in healthcare settings with limited resources.

A living WHO guideline on drugs to prevent covid-19

CLINICAL QUESTION

What is the role of drugs in preventing covid-19? WHY DOES THIS MATTER?: There is widespread interest in whether drug interventions can be used for the prevention of covid-19, but there is uncertainty about which drugs, if any, are effective. The first version of this living guideline focuses on the evidence for hydroxychloroquine. Subsequent updates will cover other drugs being investigated for their role in the prevention of covid-19.

RECOMMENDATION

The guideline development panel made a strong recommendation against the use of hydroxychloroquine for individuals who do not have covid-19 (high certainty).

HOW THIS GUIDELINE WAS CREATED

This living guideline is from the World Health Organization (WHO) and provides up to date covid-19 guidance to inform policy and practice worldwide. Magic Evidence Ecosystem Foundation (MAGIC) provided methodological support. A living systematic review with network analysis informed the recommendations. An international guideline development panel of content experts, clinicians, patients, an ethicist and methodologists produced recommendations following standards for trustworthy guideline development using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

UNDERSTANDING THE NEW RECOMMENDATION

The linked systematic review and network meta-analysis (6 trials and 6059 participants) found that hydroxychloroquine had a small or no effect on mortality and admission to hospital (high certainty evidence). There was a small or no effect on laboratory confirmed SARS-CoV-2 infection (moderate certainty evidence) but probably increased adverse events leading to discontinuation (moderate certainty evidence). The panel judged that almost all people would not consider this drug worthwhile. In addition, the panel decided that contextual factors such as resources, feasibility, acceptability, and equity for countries and healthcare systems were unlikely to alter the recommendation. The panel considers that this drug is no longer a research priority and that resources should rather be oriented to evaluate other more promising drugs to prevent covid-19.

UPDATES

This is a living guideline. New recommendations will be published in this article and signposted by update notices to this guideline.

READERS NOTE

This is the first version of the living guideline for drugs to prevent covid-19. It complements the WHO living guideline on drugs to treat covid-19. When citing this article, please consider adding the update number and date of access for clarity.

Supramolecular Solvent Extraction-Gas Chromatography-Tandem Mass Spectrometry for Detection of Benzodiazepines in Urines

Objective To establish a method using supramolecular solvent and gas chromatography-tandem mass spectrometry （GC-MS/MS） to analyze 9 benzodiazepines in urines. Methods Urine samples containing 9 benzodiazepines reference substance were subjected to liquid-liquid extractions with supramolecular solvent, which consisted of tetrahydrofuran and 1-hexanol. The solvent layer was evaporated to dryness by stream of nitrogen. The residue was reconstituted with methanol, and GC-MS/MS analysis was performed on it. The way of data collection was multiple reaction monitoring （MRM） mode; internal standard method was employed for quantification. Results In urine samples, when the range of mass concentration was 1-100 ng/mL for diazepam, midazolam, flunitrazepam and clozapine, 5-100 ng/mL for lorazepam and alprazolam, 2-100 ng/mL for nitrazepam and clonazepam, and 0.2-100 ng/mL for estazolam, respectively, good linearities were obtained, correlation coefficients were 0.999 1-0.999 9, the lower limits of the quantifications ranged from 0.2 to 5 ng/mL, the extraction recovery rates were 81.12%-99.52%. The intra-day precision ［relative standard deviation （RSD）］ and accuracy （bias） were lower than 9.86% and 9.51%, respectively; the inter-day precision （RSD） and accuracy （bias） were lower than 8.74% and 9.98%, respectively. Nine drugs in urine samples showed good stability at ambient temperature and -20 ℃ within 15 days. The mass concentrations of alprazolam in urine samples obtained from 8 volunteers who took alprazolam tablets orally within 8-72 h after ingestions ranged from 6.54 to 88.28 ng/mL. Conclusion The supramolecular solvent extraction GC-MS/MS method for analysis of 9 benzodiazepines in urines provided by this study is simple, fast, accurate and sensitive, which can provide technical support for monitoring of poisoning by benzodiazepines for clinical treatment and judicial identification.

COVID-19 in Egyptian Children: A Multicenter Study

Objective The novel coronavirus disease 2019 (COVID-19) has made its worldwide spread since its outbreak in December 2019. Limited information is available about the epidemiology and clinical characteristics of COVID-19, especially in Africa and Egypt.

Methods We aimed to study the clinical and epidemiological characteristics of COVID-19 in Egyptian children. This is an observational retrospective cohort study performed at two specialized COVID-19 isolation hospitals in Egypt. All admitted COVID-19 pediatric patients between March 20, 2020, and May 1, 2020, were included in the study.

Discussion This study included 40 COVID-19 confirmed cases (mean age, 9.4 years), 67.5% were male, 85% were asymptomatic, and 15% had mild symptoms. There were no confirmed severe or critically ill cases among the patients.

Conclusion COVID-19 runs in a benign course in Egyptian children with no mortality and no significant morbidity.

A living WHO guideline on drugs for covid-19

Updates

This is the fourteenth version (thirteenth update) of the living guideline, replacing earlier versions (available as data supplements). New recommendations will be published as updates to this guideline.

Clinical question

What is the role of drugs in the treatment of patients with covid-19?

Context

The evidence base for therapeutics for covid-19 is evolving with numerous randomised controlled trials (RCTs) recently completed and underway. Emerging SARS-CoV-2 variants and subvariants are changing the role of therapeutics.

What is new?

The guideline development group (GDG) defined 1.5% as a new threshold for an important reduction in risk of hospitalisation in patients with non-severe covid-19. Combined with updated baseline risk estimates, this resulted in stratification into patients at low, moderate, and high risk for hospitalisation. New recommendations were added for moderate risk of hospitalisation for nirmatrelvir/ritonavir, and for moderate and low risk of hospitalisation for molnupiravir and remdesivir. New pharmacokinetic evidence was included for nirmatrelvir/ritonavir and molnupiravir, supporting existing recommendations for patients at high risk of hospitalisation. The recommendation for ivermectin in patients with non-severe illness was updated in light of additional trial evidence which reduced the high degree of uncertainty informing previous guidance. A new recommendation was made against the antiviral agent VV116 for patients with non-severe and with severe or critical illness outside of randomised clinical trials based on one RCT comparing the drug with nirmatrelvir/ritonavir. The structure of the guideline publication has also been changed; recommendations are now ordered by severity of covid-19.

About this guideline

This living guideline from the World Health Organization (WHO) incorporates new evidence to dynamically update recommendations for covid-19 therapeutics. The GDG typically evaluates a therapy when the WHO judges sufficient evidence is available to make a recommendation. While the GDG takes an individual patient perspective in making recommendations, it also considers resource implications, acceptability, feasibility, equity, and human rights. This guideline was developed according to standards and methods for trustworthy guidelines, making use of an innovative process to achieve efficiency in dynamic updating of recommendations. The methods are aligned with the WHO Handbook for Guideline Development and according to a pre-approved protocol (planning proposal) by the Guideline Review Committee (GRC). A box at the end of the article outlines key methodological aspects of the guideline process. MAGIC Evidence Ecosystem Foundation provides methodological support, including the coordination of living systematic reviews with network meta-analyses to inform the recommendations. The full version of the guideline is available online in MAGICapp and in PDF on the WHO website, with a summary version here in The BMJ. These formats should facilitate adaptation, which is strongly encouraged by WHO to contextualise recommendations in a healthcare system to maximise impact.

Future recommendations

Recommendations on anticoagulation are planned for the next update to this guideline. Updated data regarding systemic corticosteroids, azithromycin, favipiravir and umefenovir for non-severe illness, and convalescent plasma and statin therapy for severe or critical illness, are planned for review in upcoming guideline iterations.

A budget impact analysis of budesonide/formoterol in patients with mild asthma in Egypt

Background: The aim of this study is to estimate the budget impact of budesonide/formoterol fixed dose combination (FDC) vs salbutamol, both used as needed, in mild asthma patients, from the perspective of the Health Insurance Organization (HIO). Methods: A static budget impact model was developed to assess the impact of budesonide/formoterol FDC entry on HIO budget over a 3-year period in Egyptian settings. Direct medical costs, including the costs of asthma medications, exacerbations, and management of side-effects, were obtained from HIO cost data. Population data were obtained from the World Bank and supplemented with local studies, and the rates of exacerbations, adverse effects, and number of sick leave days were elicited from the SYGMA 1 trial. Scenario analyses from a societal perspective and deterministic sensitivity analyses were conducted. Results: The total costs (drug and non-drug costs) for managing mild asthma patients from the HIO perspective were estimated to be EGP8.563 billion before budesonide/formoterol entry compared to EGP5.525 billion post-entry, leading to a total budget savings of EGP3.038 billion after 3 years. This total budget saving included an increase in drug costs (EGP104 million) and a decrease in non-drug costs (EGP3.143 billion). Drug costs were higher in the budesonide/formoterol group than in the salbutamol group, but this cost was offset by reductions in non-drug costs, resulting in a reduction in the total costs of healthcare resources. At the societal level, the total budget savings after including the indirect costs was expected to be EGP5.976 billion after 3 years of budesonide/formoterol entry. Conclusion: Budesonide/formoterol in mild asthma instead of salbutamol produces better patient outcomes and decreases total costs, with increases in drug cost offset by reductions in non-drug costs due to fewer exacerbations. Budesonide/formoterol is a budget saving option for guideline-directed treatment, from the economic perspective of the payer and the health perspective of the patient.

Screening for diabetes among tuberculosis patients: a nationwide population-based study in Egypt

Background

The prevalence of type 2 diabetes mellitus (DM) is increasing rapidly in Egypt and considered one of the major health problems in the Eastern Mediterranean region.

Objectives

To measure the prevalence of diabetes and detect the undiagnosed cases of diabetes mellitus among patient with tuberculosis.

Methods

Study Design: Nationwide population-based study. To diagnose DM among TB patients, we used a fasting blood sugar level of ≥ 126 mg/dl and a post-prandial blood glucose test result of ≥ 200 mg/dl.

Results

Screening for DM among 1435 TB patients' with no history of DM detected 30 new cases of DM, with a case detection rate of 2.09%. The highest screening yields were among TB patients aged ≥ 40 years, females and those with pulmonary TB. The number needed to screen (NNS) TB patients for detecting one new case of DM was 48 while the lowest values were for older age (NNS=27) and females (NNS=29).

Conclusion

Older age and being females and those with pulmonary type of TB were more prone to the double burden of TB and DM. Identifying cases with double burden of diseases will improve the proper management of both diseases and prevent complications.

Coinheritance of two rare genodermatoses (Papillon-Lefèvre syndrome and oculocutaneous albinism type 1) in two families: a genetic study

The co-occurrence of two rare recessive genetic conditions in apparently unrelated individuals or families is extremely rare. Two geographically distant and apparently unrelated families were identified in which individuals were simultaneously affected by two rare recessive mendelian syndromes, Papillon-Lefevre syndrome and type 1 oculocutaneous albinism. The families were tested for mutations in the causative genes, cathepsin C (CTSC) and tyrosinase (TYR), respectively, by direct sequencing. To assess the relationship of the two families, both families were tested for polymorphisms at eight microsatellite markers spanning both CTSC and TYR loci. Independent mutations (c.318-1G-->A and c.817G-->C/p.W272C) were identified in CTSC and TYR, respectively, that were shared by the affected individuals in both families. The two affected genes lie close together on chromosome bands 11q14.2-14.3, and studies with linked genetic markers suggested that the families shared a small chromosomal segment carrying both mutations that had been transmitted intact from a remote common ancestor. The co-occurrence of the two rare diseases in multiple families depends on their shared chromosomal location, but not on any shared pathogenic mechanism.

Regulation of NCAM by growth factors in serum-free myotube cultures

Regulation of the neural cell adhesion molecule (NCAM) was examined in primary cultures of chick skeletal muscle grown in serum-free defined medium. Relative levels of NCAM (per microgram protein) increased 20-30% in myotubes grown on Matrigel, a reconstituted basement membrane preparation, compared to those grown on collagen; total NCAM levels on Matrigel were increased 40-55% due to the additional increase in total protein. A dose dependent increase in relative NCAM levels in myotubes grown on Matrigel in defined medium was observed with the addition of adsorbed horse serum, while relative NCAM levels in myotubes grown on collagen were unaffected by altering the serum concentration. Thus, extracellular matrix molecules and soluble factors exert trophic effects on myotube NCAM expression. Similar developmental changes in the expression of the different molecular size forms of NCAM occurred in myotubes grown on collagen and Matrigel: levels of 150K and 135K Mr forms decreased during development, while 125K remained prominent in older myotubes. Relative NCAM levels were specifically enhanced 11-26% by several factors: nerve growth factor, thyroxine, insulin-like growth factor II, dibutyryl cyclic AMP, veratridine (a sodium ion channel agonist), and nisoldipine (a calcium ion channel agonist). Total protein and overall myotube development in serum-free cultures were enhanced by fetuin, insulin-like growth factor II, acidic fibroblast growth factor, calcitonin gene-related peptide, dibutyryl cyclic AMP, and veratridine. Thus, changes in extracellular matrix, intracellular calcium, and sodium ions, as well as extracellular trophic factors, such as nerve growth factor, thyroxine, and insulin-like growth factor II, may regulate muscle NCAM expression during embryonic development.

Matrigel enhances myotube development in a serum-free defined medium

Previously reported serum-free defined media for muscle cell culture require supplementation with hormones, purified growth factors or attachment factors. This report describes a culture system that enhances embryonic chick, skeletal muscle cell growth and differentiation in a serum-free defined medium, without added specialized trophic factors. Myoblasts adhered more to and proliferated more rapidly on a reconstituted basement membrane substrate, Matrigel, than on rat-tail collagen. Matrigel contains several basement membrane attachment molecules which apparently obviate the need for added purified attachment factors. Matrigel also appeared to play a trophic role in subsequent development by enabling the serum-free growth of myotubes which suggests that Matrigel mediates the cellular interaction of growth or attachment factors. Collagen, on the other hand, did not support serum-free myotube growth. Supplementation of defined medium with increasing levels of horse serum enhanced total protein in myotubes grown on both substrates; protein was higher in Matrigel cultures for each medium tested. The serum-free defined medium supported complete morphological differentiation of myotubes grown on Matrigel and maintained myotube cultures up to 22 days. Fibroblast proliferation was higher in cultures on collagen in defined medium with high serum levels, but was virtually eliminated in cultures on Matrigel in serum-free defined medium. The culture system described supports the differentiation of embryonic muscle cells in a simple, serum-free defined medium, thus providing an in vitro model of developing myotubes which should be particularly useful for studies of regulation mediated by extracellular factors.

Plasminogen activator secretion by established lines of human ovarian carcinoma cells in vitro

Ten human ovarian carcinoma cell lines (A121, A121[as], Caov-3, Caov-4, NIH:OVCAR-3, OVCA 420, OVCA 429, OVCA 432, OVCA 433, and SK-OV-3) were examined for secretion of plasminogen activators (PAs) using a chromogenic PA assay and SDS-PAGE zymography. PA activity was detected in conditioned media from all 10 cell lines. PA levels secreted by the 10 individual lines in a 24-hr period spanned a large range, with the extremes being 8 and 5244 milliPloug units (mPU)/10(6) cells for SK-OV-3 and OVCA 420 cells, respectively. Secreted PAs were identified as urokinase (UK)-like or tissue plasminogen activator (tPA)-like using dual criteria of comigration with UK or tPA standards on SDS-PAGE zymography and fibrin-dependence characteristics. Using both criteria, all 10 cell types produced UK-like activity, while tPA-like activity was produced by only 5 of the lines: A121[as], Caov-3, NIH:OVCAR-3, OVCA 429, and OVCA 433. Two additional cell lines produced PA activities that were tPA-like if judged by only one of the two criteria. Thus, Caov-4 cells produced a PA which comigrated with tPA, yet displayed no fibrin-dependent characteristics. Conversely, SK-OV-3 cells produced a fibrin-dependent PA, yet a band comigrating with tPA was not seen on SDS-PAGE zymography. Two lines derived from primary and ascitic sites from the same patient (A121 and A121[as], respectively) produced PAs with markedly different characteristics. Thus, PA produced by A121 cells was 100% UK-like, while that produced by A121[as] cells was greater than 90% tPA-like. Also, the total PA activity secreted by A121 cells was four times that secreted by A121[as] cells. In addition to bands comigrating with UK or tPA, all of the cell lines except Caov-3 and NIH:OVCAR-3 displayed higher molecular weight PA activities suggestive of the SDS-stable complexes between PAs and PA inhibitors reported in other cell types. While our results indicate that PA production may be a general characteristic of ovarian carcinoma cells in culture, individual patterns of UK and tPA production appear to be complex and vary from cell line to cell line. The precise characteristics of PA production in a given cell line may therefore depend on currently unidentified characteristics of the original tumor.

Hormonal regulation of CA125 tumor marker expression in human ovarian carcinoma cells: inhibition by glucocorticoids

The CA125 tumor marker is an antigenic determinant present on a high-molecular-weight glycoprotein expressed by more than 80% of newly diagnosed nonmucinous epithelial ovarian cancers. OVCA 433 human ovarian carcinoma cells express the CA125 marker at the cell surface and release large quantities of this antigen into culture medium. Here we show that release of CA125 by OVCA 433 cells is 90 to 95% inhibited by treatment with 1 x 10(-7) M dexamethasone, as determined using a biotin-based enzyme-linked immunosorbent assay utilizing OC125 monoclonal antibodies to CA125. The relative cell surface density of CA125 is also decreased following dexamethasone treatment as determined by immunofluorescence techniques using OC125 monoclonal antibodies. Inhibition of CA125 expression is specific for glucocorticoids, such as cortisol and dexamethasone, and does not occur with estrogens, progestins, androgens, or mineralocorticoids. CA125 inhibition is also dependent on the concentration of steroid used, with half-maximal and maximal inhibition by dexamethasone occurring at about 3 x 10(-9) M and 1 x 10(-7) M, respectively. Previous work has shown that OVCA 433 cells are growth inhibited by glucocorticoids and contain 14,000 glucocorticoid receptors per cell with an affinity for dexamethasone (Kd = 6.6 x 10(-9) M) which corresponds well with the concentration required for half-maximal CA125 inhibition. This correspondence, together with the specificity of CA125 inhibition for glucocorticoids, suggests that this effect is mediated by glucocorticoid receptors and is a specific biological effect of glucocorticoids on this cell type. Our results demonstrate glucocorticoid inhibition of CA125 expression by ovarian carcinoma cells and suggest that endogenous or therapeutically administered glucocorticoids can influence CA125 production by tumors in vivo.

Glucocorticoid sensitivity of OVCA 433 human ovarian carcinoma cells: inhibition of plasminogen activators, cell growth, and morphological alterations

OVCA 433 human ovarian carcinoma cells secrete large amounts of plasminogen activator (PA), which consists of immunologically identifiable urokinase (UK) and tissue-type PA (tPA). Total extracellular PA activity is 95% inhibited by treatment of cells with 1 X 10(-7) M dexamethasone (Dex) for 3 days. This inhibition is both time and concentration dependent, with half-maximal inhibition occurring after 1.5 days with 1 X 10(-7) M Dex, or with 1 X 10(-9) M Dex for 3 days, respectively. Interestingly, the loss of UK activity precedes the loss of tPA activity, such that half-maximal inhibition of the two PA types occurs at 1 and 2 days, respectively. Dex treatment leads to approximately 50% inhibition of cell growth and pronounced morphological alterations, including marked enlargement, flattening, and multinucleation. Treatment of the cells with other classes of steroid hormones, i.e., estrogens, progestins, androgens, and mineralocorticoids, is without effect on UK and tPA activities, cell growth, or morphology. OVCA 433 cells contain about 14,000 nuclear glucocorticoid receptors (GR) per cell (measured at 37 degrees C), with an average affinity (Kd) for [3H]Dex of 6.6 X 10(-9) M. Only active glucocorticoids compete with [3H]Dex for nuclear GR binding sites. Our results demonstrate steroid-specific glucocorticoid responsiveness of ovarian carcinoma cells, a tumor cell type not usually considered hormonally responsive. Since almost 90% of ovarian carcinoma tumor biopsies contain GR (M. C. Galli, et al., Cancer (Phila.), 47: 1297-1302, 1981), it is possible that glucocorticoid sensitivity could be exploited clinically, particularly following the almost universal development of resistance to the chemotherapeutic drugs commonly used in this disease.

Occupational chronic exposure to metals. I. Chromium exposure of stainless steel welders--biological monitoring

External and internal chromate exposure of 103 stainless steel welders who were using manual metal are welding (MMA), metal inert gas welding (MIG) and both methods, were measured by ambient and biological monitoring. At the working places the maximum chromium trioxide concentrations were 80 micrograms/m3. The median values were 4 micrograms/m3 (MMA) and 10 micrograms/m3 (MIG). The median chromium concentrations in erythrocytes, plasma and urine of all welders were less than 0.60, 9.00 and 32.50 micrograms/l. For biological monitoring purposes, chromium levels in erythrocytes and simultaneously in plasma seem to be suitable parameters. According to our results, chromium levels in plasma and urine in the order of 10 and 40 micrograms/l seem to correspond to an external exposure of 100 micrograms chromium trioxide per cubic metre, the technical guiding concentration (TRK-value). Chromium concentrations in erythrocytes greater than 0.60 micrograms/l indicate an external chromate exposure greater than the TRK-value.