Quinolone scaffolds as potential drug candidates against infectious microbes: a review

Prevalence of microbial infections and new rising pathogens are signified as causative agent for variety of serious and lethal health crisis in past years. Despite medical advances, bacterial and fungal infections continue to be a rising problem in the health care system. As more bacteria develop resistance to antibiotics used in therapy, and as more invasive microbial species develop resistance to conventional antimicrobial drugs. Relevant published publications from the last two decades, up to 2024, were systematically retrieved from the MEDLINE/PubMed, SCOPUS, EMBASE, and WOS databases using keywords such as quinolones, anti-infective, antibacterial, antimicrobial resistance and patents on quinolone derivatives. With an approach of considerable interest towards novel heterocyclic derivatives as novel anti-infective agents, researchers have explored these as essential tools in vistas of drug design and development. Among heterocycles, quinolones have been regarded extremely essential for the development of novel derivatives, even able to tackle the associated resistance issues. The quinolone scaffold with its bicyclic structure and specific functional groups such as the carbonyl and acidic groups, is indeed considered a valuable functionalities for further lead generation and optimization in drug discovery. Besides, the substitution at N-1, C-3 and C-7 positions also subjected to be having a significant role in anti-infective potential. In this article, we intend to highlight recent quinolone derivatives based on the SAR approach and anti-infective potential such as antibacterial, antifungal, antimalarial, antitubercular, antitrypanosomal and antiviral activities. Moreover, some recent patents granted on quinolone-containing derivatives as anti-infective agents have also been highlighted in tabular form. Due consideration of this, future research in this scaffold is expected to be useful for aspiring scientists to get pharmacologically significant leads.

Occurrence, speciation, and controls on arsenic mobilization in the alluvial aquifer system of the Ghaghara basin, India

High concentrations of arsenic (As) in groundwater are among the long-standing environmental problems on the planet. Due to adverse impacts on the human and aquatic system, characterization and quantification of individual inorganic As species are crucial in understanding the occurrence, environmental fate, behaviour, and toxicity in natural waters. This study presents As concentration and its speciation As(III) and As(V) data, including the interrelationship with other major and trace aqueous solutes from parts of the Ghaghara basin, India. More than half (57%) of the groundwater samples exhibited elevated As concentrations (> 10 μg/L), whereas 67.4% of samples have higher As(III) values relative to As(V), signifying a potential risk of As(III) toxicity. The elevated concentration of As was associated with higher Fe, Mn, and HCO3-, especially in samples from shallow well depth. PHREEQC modeling demonstrates the presence of mineral phases such as hematite, goethite, rhodochrosite, etc. Therefore, it is inferred that the release of As from sediment particles into pore water via microbially mediated Fe/Mn oxyhydroxides, and As(V) reduction processes mainly control high As concentrations. The heavy metal pollution indices (HPI) and (HEI) values revealed heavy metal pollution in low-lying areas deposited by relatively younger sediments along the Ghaghara River. Large-scale agricultural practices, overexploitation of groundwater, and indiscriminate sewage disposal, in addition to geogenic factors, cannot be ruled out as potential contributors to As mobilization in the region. This study recommends conducting seasonal hydrogeochemical monitoring and investigating regional natural background levels of As, to precisely understand the controlling mechanistic pathways of As release.

Association Between Candida albicans and COVID-19 in Complete Denture Wearers: An Observational Study

Introduction The phenomenon of coronavirus disease 2019 (COVID-19)-related candidiasis is gaining increased attention and acknowledgment as an integral component of the severe consequences of COVID-19. The aim of the present study was to assess the association between Candida albicans and COVID-19 in complete denture wearers. Materials and methods An observational study was conducted on 45 complete denture wearers, who were divided into three groups as follows: Group 1, 15 subjects with mild to moderate COVID-19 infection; Group 2, 15 subjects with severe COVID-19 infection; and Group 3, 15 subjects without COVID-19 infection. Mean colony forming units (CFU) were observed on agar plates containing Sabouraud dextrose in the salivary samples of the participants. Analysis of variance, followed by post-hoc analysis by Tukey's test, was used to compare CFU between the groups. Pearson's correlation coefficient was used to study the correlation between variables. Results The highest average colony-forming units of Candida albicans were observed in Group 2, followed by Group 1, compared to the control group, and a significant (p<0.001) difference was found. A weak positive correlation was found between the age of the patients and the duration of denture usage, as well as between age and the counts of Candida albicans in Groups 1 and 3. This correlation was more pronounced in Group 3. A strong positive correlation was observed in all groups between the Candida albicans count and the duration of denture usage by the patients. Conclusion The association between Candida albicans and denture wear was compounded by the presence of COVID-19. Consequently, the timely identification of Candida albicans infection in patients with COVID-19 is important to establish more efficacious approaches for antifungal treatment and prophylactic interventions.

Distribution, geochemical behavior, and risk assessment of arsenic in different floodplain aquifers of middle Gangetic basin, India

The present study interprets the distribution and geochemical behavior of As in groundwaters of different regions along the floodplains of Ganga river (Varanasi, Ghazipur, Ballia), Ghaghara river (Lakhimpur Kheri, Gonda, Basti), and Rapti river (Balrampur, Shrawasti) in the middle Gangetic basin, India for risk assessment (non-carcinogenic and carcinogenic). The concentration of As in groundwaters of these floodplains ranged from 0.12 to 348 μg/L (mean 24 μg/L), with around ~ 37% of groundwater samples exceeding the WHO limit of 10 μg/L in drinking water. Highest As concentration (348 μg/L) was recorded in groundwater samples from Ballia (Ganga Floodplains), where 50% of the samples had As > 10 μg/L in groundwater. In the study area, a relatively higher mean concentration was recorded in deep wells (28.5 μg/L) compared to shallow wells (20 μg/L). Most of the high As-groundwaters were associated with the high Fe, bicarbonate and low nitrate and sulfate concentrations indicating the release of As via reductive dissolution of Fe oxyhydroxides. The saturation index values of the Fe minerals such as goethite, hematite, ferrihydrite, and siderite showed the oversaturation to near equilibrium in groundwater, suggesting that these mineral phases may act as source/sink of As in the aquifers of the study area. The health risk assessment results revealed that a large number of people in the study area were prone to carcinogenic and non-carcinogenic health risks due to daily consumption of As-polluted groundwater. The highest risks were estimated for the aquifers of Ganga floodplains, as indicated by their mean HQ (41.47) and CR (0.0142) values.

FLAIR MRI biomarkers of the normal appearing brain matter are related to cognition

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Normal appearing brain matter (NABM) biomarkers in FLAIR MRI are related to cognition.

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NABM texture in FLAIR MRI is correlated to mean diffusivity (MD) in dMRI.

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Analysis conducted on large multicentre FLAIR MRI dataset: 1400 subjects, 87 centers.

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NABM biomarkers vary differently across age and MoCA categories.

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Biomarkers showed differences in patients with AD dementia and vascular disease.

A novel biomarker panel was proposed to quantify macro and microstructural biomarkers from the normal-appearing brain matter (NABM) in multicentre fluid-attenuation inversion recovery (FLAIR) MRI. The NABM is composed of the white and gray matter regions of the brain, with the lesions and cerebrospinal fluid removed. The primary hypothesis was that NABM biomarkers from FLAIR MRI are related to cognitive outcome as determined by MoCA score. There were three groups of features designed for this task based on 1) texture: microstructural integrity (MII), macrostructural damage (MAD), microstructural damage (MID), 2) intensity: median, skewness, kurtosis and 3) volume: NABM to ICV volume ratio. Biomarkers were extracted from over 1400 imaging volumes from more than 87 centres and unadjusted ANOVA analysis revealed significant differences in means of the MII, MAD, and NABM volume biomarkers across all cognitive groups. In an adjusted ANCOVA model, a significant relationship between MoCA categories was found that was dependent on subject age for MII, MAD, intensity, kurtosis and NABM volume biomarkers. These results demonstrate that structural brain changes in the NABM are related to cognitive outcome (with different relationships depending on the age of the subjects). Therefore these biomarkers have high potential for clinical translation. As a secondary hypothesis, we investigated whether texture features from FLAIR MRI can quantify microstructural changes related to how “structured” or “damaged” the tissue is. Based on correlation analysis with diffusion weighted MRI (dMRI), it was shown that FLAIR MRI texture biomarkers (MII and MAD) had strong correlations to mean diffusivity (MD) which is related to tissue degeneration in the GM and WM regions. As FLAIR MRI is routinely collected for clinical neurological examinations, novel biomarkers from FLAIR MRI could be used to supplement current clinical biomarkers and for monitoring disease progression. Biomarkers could also be used to stratify patients into homogeneous disease subgroups for clinical trials, or to learn more about mechanistic development of dementia disease.

An in-silico analysis of ivermectin interaction with potential SARS-CoV-2 targets and host nuclear importin α

Ivermectin (IVM) is a broad-spectrum antiparasitic agent, having inhibitory potential against wide range of viral infections. It has also been found to hamper SARS-CoV-2 replication in vitro, and its precise mechanism of action against SARS-CoV-2 is yet to be understood. IVM is known to interact with host importin (IMP)α directly and averts interaction with IMPβ1, leading to the prevention of nuclear localization signal (NLS) recognition. Therefore, the current study seeks to employ molecular docking, molecular mechanics generalized Born surface area (MM-GBSA) analysis and molecular dynamics simulation studies for decrypting the binding mode, key interacting residues as well as mechanistic insights on IVM interaction with 15 potential drug targets associated with COVID-19 as well as IMPα. Among all COVID-19 targets, the non-structural protein 9 (Nsp9) exhibited the strongest affinity to IVM showing -5.30 kcal/mol and -84.85 kcal/mol binding energies estimated by AutoDock Vina and MM-GBSA, respectively. However, moderate affinity was accounted for IMPα amounting -6.9 kcal/mol and -66.04 kcal/mol. Stability of the protein-ligand complexes of Nsp9-IVM and IMPα-IVM was ascertained by 100 ns trajectory of all-atom molecular dynamics simulation. Structural conformation of protein in complex with docked IVM exhibited stable root mean square deviation while root mean square fluctuations were also found to be consistent. In silico exploration of the potential targets and their interaction profile with IVM can assist experimental studies as well as designing of COVID-19 drugs.

Calendula officinalis ameliorates l-arginine-induced acute necrotizing pancreatitis in rats

CONTEXT

Calendula officinalis L. (Asteraceae) has been traditionally used in treating inflammation of internal organs, gastrointestinal tract ulcers and wound healing.

OBJECTIVE

The present study investigates the effect of ethanol extract (95%) of Calendula officinalis flowers in l-arginine induced acute necrotizing pancreatitis in rats.

MATERIALS AND METHODS

Rats were divided into four groups: normal control, l-arginine control, Calendula officinalis extract (COE) treated and melatonin treated (positive control), which were further divided into subgroups (24 h, day 3 and 14) according to time points. Two injections of l-arginine 2 g/kg i.p. at 1 h intervals were administered in l-arginine control, COE and melatonin-treated groups to produce acute necrotizing pancreatitis. Biochemical parameters [serum amylase, lipase, pancreatic amylase, nucleic acid content, total proteins, transforming growth factor-β1 (TGF-β1), collagen content, lipid peroxidation, reduced glutathione and nitrite/nitrate] and histopathological studies were carried out.

RESULTS

COE treatment (400 mg/kg p.o.) was found to be beneficial. This was evidenced by significantly lowered histopathological scores (2 at day 14). Nucleic acid content (DNA 21.1 and RNA 5.44 mg/g pancreas), total proteins (0.66 mg/mL pancreas) and pancreatic amylase (1031.3 100 SU/g pancreas) were significantly improved. Marked reduction in pancreatic oxidative and nitrosative stress; collagen (122 μmoles/100 mg pancreas) and TGF-β1 (118.56 pg/mL) levels were noted. Results obtained were comparable to those of positive control.

DISCUSSION AND CONCLUSION

The beneficial effect of COE may be attributed to its antioxidant, antinitrosative and antifibrotic actions. Hence, the study concludes that COE promotes spontaneous repair and regeneration of the pancreas.

Placenta accreta and anesthesia: A multidisciplinary approach

Placenta accreta (an abnormally adherent placenta) is one of the two leading causes of peripartum hemorrhage and the most common indication for peripartum hysterectomy. Placenta accreta may be associated with significant maternal hemorrhage at delivery owing to the incomplete placental separation. When placenta accreta is diagnosed before delivery, a multidisciplinary approach may improve patient outcome.

Anesthetic consideration in dystrophic epidermolysis bullosa

Epidermolysis bullosa is a group of inherited rare skin disease, characterized by bullae formation in the skin or mucous membranes. The fundamental abnormality is collagen degeneration leads to splitting of various epidermal layers. Dystrophic epidermolysis bullosa (DEB) is one of the major forms of epidermolysis bullosa. These patients often admitted to the hospital for corrective surgeries, change of dressing, contracture release, and skin grafting. Anesthetic management of these cases is always a challenge. We are reporting a case of 5-year-old boy diagnosed as a case of DEB scheduled for upper lip contracture release, skin grafting and debridement of nonhealing scars under anesthesia. In this case, we have focused mainly on the anesthetic management, preparation of the monitoring, transportation, difficulties in establishing the venous accesses, and airway management.

Hepatoprotective effect of trans-Chalcone on experimentally induced hepatic injury in rats: inhibition of hepatic inflammation and fibrosis

The current study investigated the hepatoprotective effect of trans-Chalcone in carbon tetrachloride (CCl4) and paracetamol (PCM) induced liver damage in rats. Administration of CCl4 and PCM (1 mL/kg, i.p., 3 days, and 2 g/kg, p.o., single dose, respectively) produced hepatic injury. Ponderal changes (percent change in body mass and relative liver mass) and biochemical parameters (serum ALT, AST, ALP, bilirubin) were estimated. The markers of oxidative and nitrosative stress (TBARS, reduced GSH, nitrite and nitrate), hepatic fibrosis (TGF-β1, collagen content), hepatic inflammation (TNF-α), and histopathological study were evaluated. trans-Chalcone (5, 10, and 20 mg/kg, i.p.) was found to be beneficial as demonstrated by significant reversal of liver histology by perceptible reduction of inflammatory cell infiltration with regenerative changes in hepatocytes. Improvement in percent change in body mass and significant reduction in relative liver mass were observed. Marked reduction in serum levels of ALT, AST, ALP, and bilirubin were noted. Decreases in TBARS and nitrites and nitrates and increases in reduced GSH levels were noted. Hepatic fibrosis and inflammation were significantly decreased. The findings indicate a novel hepatoprotective role for trans-Chalcone by improving hepatic injury by possible actions such as anti-oxidant, anti-nitrosative, anti-fibrotic, and anti-inflammatory. Hence, it can be used as promising hepatoprotective agent.

Protective role of fibrates in cardiac ischemia/reperfusion

Prevention of myocardial injury has been considered as the most important therapeutic challenge of today. Fibrates, the agonists of the peroxisome proliferator-activated receptor (PPAR)-a receptor, have been regarded as potent therapeutic agents in this context. Hence, the present study has been designed to investigate the effect of fibrates, i.e., Clofibrate and Fenofibrate, the potent agonists PPAR-a, on ischemia-reperfusion (I/R)-induced myocardial injury. The isolated Langendorff-perfused rat hearts were subjected to global ischemia for 30 minutes followed by reperfusion for 120 minutes. Myocardial infarct size and the release of lactate dehydrogenase (LDH) and creatine kinase (CK) in coronary effluent have been conducted to assess the degree of cardiac injury. Moreover, the oxidative stress in the heart was assessed by measuring lipid peroxidation, superoxide anion generation, and reduced glutathione. Clofibrate and Fenofibrate showed cardioprotection against I/R-induced myocardial injury in rat hearts as assessed in terms of reductions in myocardial infarct size, LDH, and CK levels in coronary effluent along with reduction in I/R-induced oxidative stress. It may be concluded that the observed cardioprotective potential of Clofibrate and Fenofibrate against I/R-induced myocardial injury was due to the reductions in infarct size and oxidative stress.

Cardioprotective potential of simvastatin in the hyperhomocysteinemic rat heart

The present study investigated the probable role of simvastatin, 3-hydroxymethyl-glutaryl coenzyme A (HMG-CoA) reductase inhibitor, in abrogated cardioprotection in hyperhomocysteinemic (Hhcy) rat hearts. Isolated Langendorff's perfused normal and Hhcy rat hearts were subjected to 30-min global ischemia (I) followed by 120-min reperfusion (R). Assessment of myocardial damage was done by measuring infarct size and analyzing the release of lactate dehydrogenase (LDH) and creatine kinase (CK-MB) in coronary effluent. In addition, the oxidative stress in the heart was assessed by measuring lipid peroxidation and superoxide anion generation. I/R produced myocardial injury in normal and Hhcy rat hearts by increasing myocardial infarct size, LDH and CK in coronary effluent and oxidative stress. Hhcy rat hearts showed enhanced myocardial injury and high oxidative stress as compared to normal hearts. Treatment with Simvastatin (10 μMol) afforded cardioprotection against I/R-induced myocardial injury in normal and hyperhomocysteinemic rat hearts as assessed in terms of reductions in myocardial infarct size, LDH and CK levels in coronary effluent and oxidative stress. The reductions in the high degree of oxidative stress may be responsible for the observed cardioprotection afforded by simvastatin against I/R-induced myocardial injury in normal and hyperhomocysteinemic rat hearts.

Effect of angiotensin-converting enzyme inhibitor on response of plasma renin activity and aldosterone to tilting in man

1 The effect of an angiotensin-converting enzyme inhibitor (SQ 20,881; 0.5 mg/kg) on the response to tilting of plasma renin activity (PRA), plasma aldosterone and cortisol was studied in five normal subjects. 2 PRA rose significantly in both the supine and upright positions following administration of SQ 20,881; no significant effect on aldosterone or cortisol was observed.

Clinical indications for Gallium-68 positron emission tomography imaging

BACKGROUND

(68)Ga-PET imaging is showing slow but steady progress when compared to (18)F-FDG PET. The advantage of in-house preparation of (68)Ga without necessity of a cyclotron, and the new generator configuration with future possibility of freeze-dried kits would make it a promising PET agent for the future.

METHODS

An exhaustive literature exploration was performed using the search engines High-Wire Press, Pubmed, Embase and library databases. Recent reviews on the subject and up-to-date studies on the topic were found that described the role of (68)Ga-PET imaging. Clinical experiences, including our own are described.

RESULTS

Recent resurgence in development of peptides labelled with radiometals, for diagnostic and therapeutic purposes, resulted in a new beginning for (68)Ga-PET imaging. Pre-clinical experience employing animal models and investigation of tracer kinetics/tumour uptake measurements using dynamic (68)Ga-PET have provided data regarding identification of Somatostatin receptors subtypes on many tumours. Present published experiences including our own support these and highlight current clinical utility of (68)Ga-PET imaging. (68)Ga-DOTATOC and (68)Ga-DOTANOC are the most prominent radiopharmaceuticals used nowadays.

CONCLUSION

(68)Ga-PET is employed in the management of neuroendocrine tumours and neural crest tumours (phaeochromocytoma and paraganglioma) with diagnostic and therapeutic implications where it compliments present radiologic and scintigraphic procedures. Diagnosis and radiotherapy treatment planning for meningiomas in pertinent clinical setting is another potential use of (68)Ga-PET. Limited studies have shown its utility in prostate cancer but further studies are contemplated. Therefore, current experience tends to open a new horizon for the clinical utility of (68)Ga-PET imaging in future.

Radioiodinated metaiodobenzylguanidine in the diagnosis and therapy of carcinoid tumors

Carcinoid tumors account for less than 1% of all malignancies and the majority arises in the gastrointestinal system. These tumors are slow-growing compared with adenocarcinomas and they differ from the other neuroendocrine malignancies by their protean clinical presentation. Carcinoid tumors were previously considered indolent, but they can manifest malignant characteristics with metastatic spread which often results in a poor prognosis. Although there have been advances in diagnostic and treatment modalities, carcinoid tumors are still frequently diagnosed late, often when the tumor has metastasized and patients have developed carcinoid syndrome. Diagnosis, prognosis and treatment options are based on biochemical markers and imaging investigations. High concentration of urinary 5-HIAA, elevated plasma serotonin and chromogranin A levels help to establish the initial diagnosis of carcinoid tumors. In addition to the computed tomography and magnetic resonance imaging, molecular imaging modalities such as OctreoScan, metaiodobenzylguanidine (MIBG) imaging and more recently PET imaging are used in detecting the primary malignancy and metastatic involvement. Surgery is the mainstay of treatment of non-metastatic carcinoid tumors. Cytotoxic chemotherapy has limited role because of the chemoresistant nature of these tumors. Because carcinoid tumors express somatostatin receptors, somatostatin analogues, which inhibit release of serotonin and other neuroendocrine peptides, are often used, but their use is limited to symptom control. Treatment using high doses of radionuclides, such as radiolabeled somatostatin analogues and MIBG, is a more recent option, which offers a definite advantage in management. In this article, we review the current state of the art in the diagnosis and treatment of carcinoid tumors as well as the role of MIBG in their diagnosis and management.

An audit of perioperative cardiac arrests in a Southeast Asian university teaching hospital over 15 years

An audit of the incidence, causes and outcome of perioperative cardiac arrest was conducted in a university hospital in Pakistan. All perioperative cardiac arrests from induction of anaesthesia to post anaesthesia care unit discharge or intensive care unit admission during noncardiac surgery, from January 1992 to December 2006 were included. Patients' demographic information, physical status and type of surgery and anaesthesia were noted. Outcome variables were noted as immediate survival and survival to discharge. Anaesthesia-related cardiac arrests were identified and their causes analysed. Forty-two cardiac arrests occurred among 140,384 patients. Overall frequency was 2.99 per 10,000 (95% confidence interval: 2.90 to 3.08). Twenty-four (3.77/10,000) were females. Thirty-four (13.59/10,000) patients were ASA physical status III to V, 10 (4.95/10,000) were children and 14 (4.28/10,000) above 60 years. Sixteen patients (6.48/10,000) were undergoing emergency surgery. Anaesthesia was deemed primarily responsible in nine cases (0.64/10,000). The causes of anaesthesia-related arrests were medication related (4), airway related (3), massive air embolism (1) and under-replacement of fluids (1). The event was considered to be avoidable in 26 cases. Seventeen patients died during the arrest, 15 survived more than one hour and 10 were discharged home. The number of perioperative cardiac arrests and their mortality was higher in patients with poor physical status and in emergency surgery. The number was also higher in infants, patients above 60 and females. The majority of the cases were considered avoidable, indicating the importance of prevention strategies.

Life-threatening hyperkalaemia developing following excessive ingestion of orange juice in a patient with baseline normal renal function

Hyperkalaemia is a less-recognised life-threatening cause of paralysis. We describe a 51-year-old African-American man, who suffered from muscle weakness progressing to ascending symmetric paralysis, and inability to masticate. Physical examination revealed flaccid paralysis with areflexia of the four limbs. Computed tomography of the brain and cervical spine did not demonstrate any organic lesions. Laboratory investigations revealed serum potassium 9.0 mEq/L (not haemolysed), blood urea nitrogen 34 mg/dL, and serum creatinine 2.0 mg/dL. Electrocardiography showed typical features of hyperkalaemia. After emergent treatment for hyperkalaemia was initiated, serum potassium was rapidly-normalised to 5 mEq/L and all neuromuscular symptoms reversed within one hour. Upon reviewing his food and medication history, he admitted drinking 2.5 litres of orange juice (which contains about 450 mg of potassium in 1,000 ml) per day for the past three weeks to quench his thirst. Hyperkalaemia should be borne in mind in the differential diagnosis of acute paralysis. Hidden sources of potassium intake, such as orange juice, should not be overlooked, even in patients with baseline normal renal function.

The role of phosphatidylcholine in fatty acid exchange and desaturation in Brassica napus L. leaves

The role of phosphatidylcholine (PC) in fatty acid exchange and desaturation was examined and compared with that of monogalactosyldiacylglycerol (MGDG) in Brassica napus leaves using (14)C-labelling in vivo. Data are presented which indicate that in the chloroplast newly formed saturated (palmitic acid, 16:0) and monounsaturated (oleic acid, 18:1) fatty acid is incorporated into MGDG and desaturated in situ. In the non-plastidic compartments, however, newly formed fatty acid is exchanged with polyunsaturated fatty acid in PC, the probable major site of subsequent desaturation. The unsaturated fatty acid is released to the acyl-CoA pool, which is then used to synthesize diacylglycerol (DAG) containing a high level of unsaturated fatty acid. This highly unsaturated DAG may be the source for the biosynthesis of other cellular glycerolipids. The generally accepted pathway in which PC is synthesized from molecular species of DAG containing 16:0 and 18:1 followed by desaturation of the 18:1 to linoleic (18:2) and linolenic (18:3) acids is questioned.

Photosynthetic acclimation of the filamentous cyanobacterium, Plectonema boryanum UTEX 485, to temperature and light

Photosynthetic acclimation to temperature and irradiance was studied in the filamentous, non-heterocystous cyanobacterium Plectonema boryanum UTEX 485. Growth rates of this cyanobacterium measured at ambient CO2 were primarily influenced by temperature with minimal effects of irradiance. Both growth temperature and irradiance affected linolenic (18:3) and linoleic acid (18:2) levels in the four major lipid classes in an independent but additive manner. In contrast, photosynthetic acclimation was not due to either growth temperature or irradiance per se, but rather, due to the interaction of these environmental factors. P. boryanum grown at low temperature and moderate irradiance mimicked cells grown at high light. Compared to cells grown at either 29 degrees C/150 micromol m(-2) s(-1) (29/150) or 15/10, P. boryanum grown at either 15/150 or 29/750 exhibited: (1) reduced cellular levels of Chl a and phycobilisomes (PBS), and concomitantly higher content of an orange-red carotenoid, myxoxanthophyll; (2) higher light saturated rates (Pmax) when expressed on a Chl a basis but lower apparent quantum yields of oxygen evolution and (3) enhanced resistance to high light stress. P. boryanum grown at 15/150 regained normal blue-green pigmentation within 16 h after a temperature shift to 29 degrees C at a constant irradiance of 150 micromol m(-2) s(-1). DBMIB and KCN but not DCMU and atrazine partially inhibited the change in myxoxanthophyll/Chl a ratio following the shift from 15 to 29 degrees C. We conclude that P. boryanum responds to either varying growth temperature or varying growth irradiance by adjusting the ability to absorb light through decreasing the cellular contents of Chl a and light-harvesting pigments and screening of excessive light by myxoxanthophyll predominantly localized in the cell wall/cell membrane to protect PSII from over-excitation. The possible role of redox sensing/signalling for photosynthetic acclimation of cyanobacteria to either temperature or irradiance is discussed.

Role of social factors in the prevalence of diarrhoeal diseases in under-five Saudi children

Social factors influencing diarrhoea prevalence rates, in Saudi communities, were studied during 1991 taking statistically representative samples from the whole population. The factors included mother's age, child's age, birth order, parent's education, feeding pattern, and urban, rural, and regional residences. This study was a part of the National Maternal and Child Health Survey which involved interviewing of 6308 women with 8292 children under 5 years. The social factors and diarrhoea occurring in children during the preceding 14 days prior to the date of survey were inquired into and recorded in the pre-coded and field-tested questionnaire forms. There were 3.8 episodes of diarrhoea per year per child under 5 or 15 per cent per 2 weeks. This was higher than previously reported. The factors associated with higher prevalence rate were the children of youngest (15-19-years-old) mothers (28 per cent), the last children (18 per cent), and the children aged 6-17 months (24-31 per cent). Additionally, by birth order, the last (third) child on the average had highest rate (18 per cent) than the second (9 per cent) and the second had higher rate than the first (6 per cent) child. The rate in those who lived in rural setting was higher (15 per cent) than in those who lived in urban setting (14 per cent). The rates were almost identical between the areas of the country (13-17 per cent) except having higher rate in the northern area (17 per cent).(ABSTRACT TRUNCATED AT 250 WORDS)

Antenatal care, attitudes, and practices

This paper discusses attitudes and practices of antenatal care in Saudi Arabia, based on the results of the maternal and child health survey of 1991. The survey covered a cluster random sample of 6306 households, with 6294 ever-married Saudi women 15-49 years of age out of whom 1050 were pregnant. The interview questionnaire included maternal care data on current pregnancies and births in the sample, totaling 4777 children less than 5 years old. Coverage of antenatal care and frequency of visits among pregnancies identified, by whom and where, and reasons for not attending antenatal services by age, urban-rural, geographical, and educational differentials. Proportions pregnant at the time of the survey were 17 per cent; antenatal care attendance for the whole sample reached 86 per cent; frequencies of one or two visits were 37 per cent; and three or four visits 25 per cent; those checked by a physician were 85 per cent, while 88 per cent attended governmental facilities. Those with timely attendance were 85 per cent. However, almost one-third of non-attenders (30 per cent) believed they did not need antenatal care. Though utilization of antenatal care services is already high, it has to be further increased through health education and publicity, emphasizing the couples role.

ORS use in diarrhoea in Saudi children: is it adequate?

The prevalence of diarrhoea and especially the pattern of diarrhoea therapy in Saudi children under 5 years were studied as a part of the Maternal and Child Health Survey during 1991. A statistically representative sample of over 6300 mothers, from all over the country was interviewed by trained nurses. There were 3.8 episodes of diarrhoea per child under 5 per year. For treating diarrhoea, ORS, salt-sugar solution (SSS), other available solutions, intravenous fluid and various drugs were the therapeutic agents. In 73 per cent of cases ORS, nearly 3 per cent SSS, 33 per cent other solutions and in over 4 per cent intravenous fluid were used. Anti-diarrhoeal drugs and antibiotics were used in over 40 per cent of cases. Over 9 per cent of cases did not use any treatment. Young mothers used ORS at a higher rate (84 per cent) for their children compared to the average for all (73 per cent). Children of illiterate parents used ORS at a higher rate than children of literate parents. In urban area, the use-rate was lower (68 per cent) than in rural area (80 per cent). The regional use-rates were almost similar excepting a higher rate in the northern area. In over 87 per cent of cases, advice on diarrhoea therapy was obtained from government health centres (physicians/nurses), while only 3 per cent of the diarrhoea cases acquired information from national media. The overall use-rate of ORS was thus better than many other countries and there was a 25 per cent increase over the previous Saudi findings in 1987.(ABSTRACT TRUNCATED AT 250 WORDS)

Changing marriage age and consanguineous marriage in Saudi females

Current marital age and consanguinity are not precisely known in Saudi Arabia. Saudi National Child Health Survey data were used to examine marital age, consanguinity, status and outcome of marriage of Saudi females. The survey (1987-88) involved interviewing 8482 ever-married urban and rural females by 120 female nurses. The results showed that 16% of young females and about 1% of young males were married before age 20. The rate of first marriage of females under 15 years of age decreased from 33% 20 years earlier to only 3.6% recently. The highest of 90% of females (35 to 39 years) and 98% of males (50 to 54 years) were currently married. Widowhood increased from 8% in the age group 40 to 44 to nearly 54% in those 70 over. Over all, nearly 0.5% of males and 3.4% of females remained widowed and 0.2% of males and 1.2% of females divorced. Thirty-four percent of all marriages were to first cousins in urban areas and 41% in rural areas. Thirty percent of marriages among literate groups and 39% in illiterate groups were consanguineous. Further research is needed to examine the causes and effects of (1) intercousin and (2) delayed marriage of females and (3) the welfare status of widowed and divorced females and their children.

A simple technique for the analysis of positional distribution of fatty acids on di- and triacylglycerols using lipase and phospholipase A2

A simple technique is described for the analysis of positional distribution of fatty acids on di- and triacylglycerols using lipase and phospholipase A2 that de-esterify fatty acids from specific sn positions. The technique makes use of the fact that methanolic-NaOH methylates only fatty acids esterified to glycerol, while methanolic-HCl methylates both free and esterified fatty acids. After lipase action it is possible to determine the fatty acid released by lipase activity by comparing the fatty acid contents of the two methylation reactions. A computer program has been written to calculate enzyme activity and positional distribution from the results. The new technique is easier to use as it eliminates thin-layer chromatography used in the standard technique and can be performed on smaller samples using less lipase.

Does hilly ecology prevent childhood diarrhoea?

Incidence of reported diarrhoeal diseases in hilly children are not precisely known. The pattern of diarrhoeal diseases in the hilly areas of Abha and Khamis Moshayet mountainous regions of Saudi Arabia has been studied. These areas are situated at 2,000 to 3,200 meters above the sea level and are devoid of river, canal or lake. The temperature ranges from 5 degrees C to 30 degrees C and humidity 30% to 60% usually. Diarrhoeal patients treated in the six health centres were recorded and analyzed for the years 1987-88 and 1989-90. Dysentery affected 2.37% of the children giving 0.023 episodes per head per year. It was almost uniformly distributed in all age groups but was higher in males 10 years and over than in females. Diarrhoea affected 8.00% of the whole population and 27.44% children giving 0.27 episodes per child per year. In all age groups, incidences in male were higher than in female. Incidences of both were higher during July to October and lower during March to April. The rate was highest in Umme Sarrar PHC area. Overall, 10.35% of the whole population and 30% of the children contracted diarrhoeal diseases. The episode of reported cases per child (0.30) per year was one-seventh of the Saudi national door-to-door survey findings (2.07) and one-fourth of the US hospital reported diarrhoea cases. This extremely low incidence in the hilly children may be due to hilly ecology, under reporting, low rate in the country or a combination of all. Further studies are needed in hilly areas of Bangladesh.

Low temperature-induced fatty acid desaturation in Brassica napus: thermal deactivation and reactivation of the process

When Brassica napus plants are grown at low temperatures (e.g., 5 degrees C) the rate of desaturation in leaves of newly formed fatty acids in both chloroplastic (MGDG) and cytosolic (PC) diacylglycerols is higher or more rapid than in plants grown at higher temperatures (e.g., 30 degrees C). This low temperature-induced increase in the rate of desaturation is lost within hours if plants are transferred to higher temperatures. However, if plants are then returned to low temperatures they regain the ability to rapidly desaturate fatty acids. This process is restored relatively slowly (over days) in contrast to the more rapid loss at high temperatures. This has important physiological consequences on the level of unsaturated fatty acids in plant membranes and the process of temperature control of the fatty acid composition of membrane lipids.

The Role of Acyl Lipids in Reconstitution of Lipid-Depleted Light-Harvesting Complex II from Cold-Hardened and Nonhardened Rye

The role of acyl lipids in the in vitro stabilization of the oligomeric form of light-harvesting complex II of winter rye (Secale cereale L. cv Muskateer) grown at 5 or 20 degrees C was investigated. Purified light-harvesting complex II was enzymically delipidated to various extents by treatment with the following lipolytic enzymes: phospholipase C, phospholipase A(2), and galactolipase. Complete removal of phosphatidylcholine had no effect on the stability of the oligomeric form, whereas the removal of phosphatidylcholine plus phosphatidylglycerol caused a decrease in the ratio of oligomeric:monomeric forms from 1.86 +/- 0.17 to 0.85 +/- 0.17 and 3.51 +/- 0.82 to 0.81 +/- 0.29 for purified cold-hardened and nonhardened light-harvesting complex II, respectively, with no change in free pigment content. Incubation of delipidated cold-hardened or nonhardened light-harvesting complex with purified thylakoid phosphatidylglycerol containing trans-Delta(3)-hexadecenoic acid resulted in 48% reconstitution of the oligomeric form on a total chlorophyll basis with an oligomer:monomer of about 1.90. Incubation in the presence of di- 16:0 or di- 18:1 phosphatidylglycerol, phosphatidylcholine, monogalactosyldiacylglyceride, or digalactosyldiacylglyceride caused no oligomerization, but rather a further destabilization of the monomeric form. These lipid-dependent structural changes were correlated with significant changes in the 77K fluorescence emission spectra for purified light-harvesting complex II. We conclude that the stabilization of the supramolecular organization of light-harvesting complex II from rye is specifically dependent upon molecular species of phosphatidylglycerol containing trans-Delta(3)-hexadecenoic acid.

Low temperature-induced fatty acid desaturation in Brassica napus: thermal lability of the process

The leaves of Brassica napus plants grown at 5 degrees C have a higher rate of fatty acid desaturation in both the cytosolic and chloroplastic pathways of diacylglycerol biosynthesis than plants grown at higher (up to 30 degrees C) temperatures. This physiological response to low growth temperature results in higher levels of unsaturated fatty acids in the leaf membrane lipids. These data suggest that this low temperature-induced desaturation process is thermolabile and can be inactivated by placing the leaves at temperatures of 30 degrees C for 4-8 h. Our evidence suggests that it is an additional rapid process to the normal 'basal' desaturation which occurs at a relatively slower rate. The data also show that the C16 and C18 fatty acids in the cytosol are desaturated at different rates and react differently to the high temperature treatment, suggesting that they are separate processes and are controlled independently.

Pattern of diarrhoeal deaths during 1966-1987 in a demographic surveillance area in rural Bangladesh

Death pattern was analysed in relation to age, sex, seasonality and yearly variation during 1966-1987 in Matlab upazila of Chandpur district, Bangladesh. The overall death rate due to diarrhoeal diseases and other causes fluctuated during the period. Diarrhoeal death rate varied between 2.0 and 4.0 per 1,000 population except during the war and famine periods of 1971 and 1974-1975 respectively when it was two times higher over the preceding period of five years' average. On an average, more than 20% of all deaths appeared to be related to diarrhoea. The relative importance of diarrhoea as the cause of death did not diminish over time. Persistent diarrhoea caused more deaths than acute diarrhoea. At all times the highest diarrhoeal mortality rate was shown in children aged 1-4 years, specially in girls. Women aged under 20 years had a higher rate of diarrhoeal deaths than the men of similar age. November was the peak month of diarrhoeal deaths in this rural area. Introduction of the Maternity, Child Health-Family Planning (MCH-FP) services had significant impact of reducing diarrhoeal deaths as well as deaths from other causes.

Impact of acute diarrhoea on parasite loads

Parasites and diarrhoea are more frequent in poor populations. Parasite prevalence rates in post-diarrhoeal patients of the International Centre for Diarrhoeal Disease Research (ICDDRB) and in non-diarrhoeal populations of two Dhaka poor socioeconomic communities have been compared to explore if there is any effect of acute diarrhoea on parasite prevalence rates. Stool of a 4% systemic randomly selected sample of diarrhoeal patients and the whole population of two local poor communities have been examined. The results showed that the prevalence of parasites in a post-diarrhoeal population is significantly lower than in a non-diarrhoeal population. These reductions (E. hist. 10.2% vs. 2.03%, G. lamb. 9.7% vs. 3.5%, hookworm 37.4% vs. 4.7% and Ascaris lumbricoides 81% vs. 20.6%) may be attributed mainly to the flushing effect of diarrhoea.

Teething pattern and prevalence of dental caries

A cross-sectional study was conducted on the children of 146 randomly selected families in Abha, Saudi Arabia. Counting of teeth and examination for caries teeth of children under 12 years of age were done by family visits. The results showed that no child developed teeth before 5 months. By 12 months there were on an average 3.3 teeth erupted per child, and by three years 18.8 teeth. At 12 years of age there were 24.4 teeth per child as compared to 28 in other countries. The DMF (decayed, missing and filled) index of children increased from 1.8 at the age of 4 to 5.1 at 7 and 5.2 at 10 years of age. The rate of caries teeth was higher than that in Australia, Great Britain, USA, India, China and Sudan. Further investigations on causes of high rate of caries teeth are recommended.

Factors influencing development of caries teeth

A cross sectional study was conducted on the children of 146 randomly selected urban families of Abha, Saudi Arabia, to find out the common factors associated with caries teeth. The factors considered for association were per capita monthly income, sources of drinking water, consumption of soft drinks, daily brushing of teeth, daily consumption of candy, and the education levels of mothers. All children up to 12 years of age were examined by visiting their families. The results showed that the per capita monthly income, sources of drinking water and habit of drinking soft drinks had no significant relation with the prevalence rates of caries teeth in children. But the habit of nonbrushing of teeth daily, daily consumption of candies, and low or no education of mothers had significant association with the presence of caries teeth. Adequate health education of children about the ill effects of these practices and raising the educational levels of mothers and prospective mothers may contribute towards achieving dental health by the year 2000 as targetted by the World Health Organization.

Oral cholera vaccines containing B-subunit-killed whole cells and killed whole cells only. II. Field evaluation of cross-protection against other members of the Vibrionaceae family

Because of demonstrable cross-reactivity of cellular antigens contained in B subunit-killed whole-cell (BS-WC) and killed whole-cell-only (WC) oral cholera vaccines with antigens of various non-cholera species of the family Vibrionaceae (NCV), the protection conferred by the vaccines against diarrhoea associated with NCV was evaluated during a randomized, double-blind field trial in Bangladesh. Children aged 2-15 years and women aged greater than 15 years (62,285 in number) received three doses of BS-WC vaccine, WC-only vaccine, or a placebo consisting of Escherichia coli K12 strain (K12). During 1 year of follow-up, the incidence of treated episodes of diarrhoea associated with non-cholera vibrios known to be enteric pathogens (non-01 Vibrio cholerae, V. fluvialis, V. parahaemolyticus, V. mimicus) in the placebo group was low (1.9 cases per 10,000 recipients) and identical to that for the two vaccine groups combined. The incidence (per 10,000 recipients) of treated diarrhoeal episodes associated with Aeromonas species was considerably higher, but nearly identical in the three groups (26.1 cases for BS-WC, 26.0 cases for WC; 25.9 cases for K12). Pleisiomonas shigelloides was not isolated from any participant. It is concluded that NCV other than Aeromonas were rarely isolated from diarrhoeal patients in our study population and that killed oral vaccines which were effective against cholera exhibited no detectable cross-protection against diarrhoea associated with NCV organisms.

Cross-protection by B subunit-whole cell cholera vaccine against diarrhea associated with heat-labile toxin-producing enterotoxigenic Escherichia coli: results of a large-scale field trial

The B subunit (BS) of cholera toxin and that of the heat-labile enterotoxin (LT) of enterotoxigenic Escherichia coli (ETEC) are antigenically similar. We therefore assessed whether a combined cholera toxin BS/whole-cell (BS-WC) oral vaccine against cholera conferred cross-protection against LT-producing ETEC (LT-ETEC) diarrhea in a randomized, double-blind field trial among rural Bangladeshi children and women. The 24,770 persons who ingested two or more doses of BS-WC vaccine were compared with 24,842 controls who took two or more doses of killed whole-cell (WC) oral cholera vaccine. Sixty-seven percent fewer episodes of LT-ETEC diarrhea were noted in the BS-WC group than in the WC group during short-term (three-month) follow-up (P less than .01), but no reduction was evident during the ensuing nine months. Short-term protection was particularly notable against LT-ETEC diarrhea causing life-threatening dehydration (protective efficacy, 86%; P less than .05).

The Effect of Temperature on the Level and Biosynthesis of Unsaturated Fatty Acids in Diacylglycerols of Brassica napus Leaves

Experiments on the effects of temperature on the levels of unsaturated fatty acids and their rates of desaturation in Brassica napus leaf lipids have shown that significant differences occur in the composition of all diacylglycerols in the leaf between plants grown at high and low temperatures. In the major thylakoid diacylglycerols, monogalactosyl-diacylglycerol and digalactosyldiacylglycerol, not only is there an increase in the level of unsaturation at low temperatures, but there is a change in the balance between molecular species of chloroplastic origin (16/18C) and cytosolic origin (18/18C). Radioactivity tracer data indicate that at low temperatures there are two distinct phases of desaturation in the fatty acids of the major diacylglycerols of these leaves. A rapid phase, which appears in plants grown at low temperatures and results in the desaturation of palmitic acid to hexadecadienoic acid and oleic acid to linoleic acid may explain the high levels of unsaturated fatty acids found in the leaf diacylglycerols from plants grown at low temperatures. The appearance of this rapid phase is controlled by the temperature at which the plant is grown and is not subject to rapid variations in environmental temperature.

Field trial of oral cholera vaccines in Bangladesh: results of one year of follow-up

We assessed the protective efficacy (PE) of three doses of B subunit-killed whole cell (BS-WC) and killed whole cell-only (WC) oral cholera vaccines in a randomized, double-blind trial among 62,285 children and women residing in rural Bangladesh. After one complete year of surveillance, 110 cases of cholera were detected in the placebo group, 52 in the WC group (PE, 53%; P less than .0001), and 41 in the BS-WC group (PE, 62%; P less than .0001). Protection was greater for BS-WC recipients than for WC recipients only during the initial eight months of observation. Both vaccines conferred equivalent protection against cholera associated with life-threatening dehydration and against less severe cholera. High-grade, sustained protection was observed in persons vaccinated when older than five years; in younger persons protection was transient. We conclude that BS-WC and WC vaccines confer significant protection against cholera, particularly in persons vaccinated when older than five years.

Cholera, rotavirus and ETEC diarrhoea: some clinico-epidemiological features

This paper analyses a few selected features from the history and clinical examination of 1258 patients with acute diarrhoea and a single laboratory diagnosis of either cholera, rotavirus, or enterotoxigenic (ETEC) Escherichia coli infection. Age distribution and seasonality in Bangladesh were also studied. The duration of illness before admission was not significantly different in the 3 groups. Cholera occurred especially in the spring and early winter. Most cholera patients were between 3 and 10 years of age. Over 37% of the patients developed severe dehydration. In about 90% of cholera cases, the stools were alkaline (pH greater than 7). ETEC infections were seen mostly in April-May and September-October. Infants were frequently affected but from age 25 onwards the age distribution closely followed that of cholera. Severe dehydration occurred in 8.3% of patients and was more frequent than in rotavirus cases. Stool pH was as frequently acidic as basic. Rotavirus cases were concentrated during the winter in patients under 2 years of age. They had marked vomiting, yet severe dehydration was almost absent. Cough was present in half of them. The stools were usually acidic. In spite of considerable overlap of signs and symptoms between the 3 aetiological groups, a presumptive diagnosis of cholera could be made in patients past infancy and early childhood who showed very severe dehydration. However, age-specific prevalence was strikingly different and seasonal variations considerable.

Vibriocidal titre in cholera cases and contacts: its value in assessing endemicity of or susceptibility to cholera

Vibriocidal antibody titre in excess of 1:40 occurred within two weeks of cholera infection, both in severe hospitalized cases, contact cases and in asymptomatic infected contacts. These levels, considered to be indicative of protection, persisted for six months or longer in more than half of the subjects irrespective of presence and severity of symptoms. Approximately 40% of infected family contacts had similar titres implying recent infection and subsequent protection. The use of antibiotics to treat acute cases, and whether infection was due to antibiotic resistant or sensitive Vibrio cholerae had no effect on the response of vibriocidal titre. Endemicity of cholera was higher than previously observed in Dhaka. Screening populations to obtain positive titre rates permits retrospective assessment of cholera infection and provides an indicator of future susceptibility.

B subunit-whole cell and whole cell-only oral vaccines against cholera: studies on reactogenicity and immunogenicity

We conducted a randomized trial among persons in rural Bangladesh to evaluate the side effects and immunogenicity of orally administered B subunit-killed whole cell (BS-WC) and killed whole cell-only (WC) cholera vaccines and a killed Escherichia coli strain K12 placebo proposed for field testing. Three doses of BS-WC, WC, E. coli, or a control agent were given with antacid to 1,257 women (aged greater than 15 years) and children (aged to to 15 years). The four groups exhibited no statistically significant differences in occurrence of symptoms after each dose, and rises in titers of vibriocidal (VC) antibodies to Inaba and Ogawa were twofold higher for vaccinees than for controls (P less than .001). Half of the persons with fourfold or greater VC responses to WC responded after the first dose; many additional patients, particularly young children, responded after subsequent doses. In contrast, 89% of persons who responded to BS-WC with twofold or greater rises in titer of IgG antibodies to cholera toxin did so after the first dose. After the third dose, vaccinees exhibited a fivefold higher rise in titer than did controls (P less than .001); a dose-to-dose booster effect was most evident in young children.

Limitation of communal latrines in changing the prevalence of parasites and diarrhoeal attack rate in Dhaka Peri-urban slums

A study of the effects of communal latrines on diarrhoeal incidence and parasite prevalence rates was conducted in 1983 at Tongi, which had five communal Oxfam latrines with a manual flushing system for 924 people; and at Kalsi, which had 39 open fit latrines for 823 people. Inhabitants' stool samples were tested initially and also after twelve months to see the reinfection rates. All inhabitants were dewormed with pyrantel, and were visited weekly to obtain diarrhoea histories. In both communities, there were high prevalence rates of roundworm, hookworm, Trichuris trichiura, Entamoeba histolytica, Giardia lambia and Strongyloides stercoralis. Following the dewormings, the prevalence rates of roundworm, hookworm and Trichuris infection came down significantly, in both areas. The prevalence or reinfection rates remained identical in both communities. There was also no difference in diarrhoea incidence rate for the two areas. It is found that keeping all other variables unchanged, use of communal latrines, without strict disposal of everyone's excreta, does not affect parasite prevalence and diarrhoea rates. People must be educated about the use of communal latrines and the safe disposal of all excreta, including that of children.

Field trial of oral cholera vaccines in Bangladesh

The protective efficacy of oral B subunit killed whole-cell (BS-WC) and killed whole-cell (WC) cholera vaccines was assessed in 63 498 Bangladeshi children aged 2-15 years and women aged over 15 years. Each received three doses of BS-WC, WC, or placebo in a randomised, double-blinded fashion. Surveillance for cases seeking medical care up to six months after the third dose revealed 26 cases of confirmed cholera in the placebo group, 4 cases in the BS-WC group (protective efficacy 85%; p less than 0.0001), and 11 cases in the WC group (protective efficacy 58%; p less than 0.01). For each vaccine protective efficacy was consistent in different age-groups (2-10 years versus greater than 10 years) and for different severities of cholera.