The contribution of smoking and smokeless tobacco to oesophageal squamous cell carcinoma risk in the African oesophageal cancer corridor: Results from the ESCCAPE multicentre case-control studies

Tobacco use is a well-established risk factor for oesophageal squamous cell carcinoma (ESCC) but the extent of its contribution to the disease burden in the African oesophageal cancer corridor has not been comprehensively elucidated, including by type of tobacco use. We investigated the contribution of tobacco use (smoking and smokeless) to ESCC in Tanzania, Malawi and Kenya. Hospital-based ESCC case-control studies were conducted in the three countries. Incident cases and controls were interviewed using a comprehensive questionnaire which included questions on tobacco smoking and smokeless tobacco use. Logistic regression models were used to estimate odds ratios (OR) and their 95% confidence intervals (CI) of ESCC associated with tobacco, adjusted for age, sex, alcohol use, religion, education and area of residence. One thousand two hundred seventy-nine cases and 1345 controls were recruited between August 5, 2013, and May 24, 2020. Ever-tobacco use was associated with increased ESCC risk in all countries: Tanzania (OR 3.09, 95%CI 1.83-5.23), and in Malawi (OR 2.45, 95%CI 1.80-3.33) and lesser in Kenya (OR 1.37, 95%CI 0.94-2.00). Exclusive smokeless tobacco use was positively associated with ESCC risk, in Tanzania, Malawi and Kenya combined (OR 1.92, 95%CI 1.26-2.92). ESCC risk increased with tobacco smoking intensity and duration of smoking. Tobacco use is an important risk factor of ESCC in Tanzania, Malawi and Kenya. Our study provides evidence that smoking and smokeless tobacco cessation are imperative in reducing ESCC risk.

A very-hot food and beverage thermal exposure index and esophageal cancer risk in Malawi and Tanzania: findings from the ESCCAPE case-control studies

BACKGROUND

Consumption of very-hot beverages/food is a probable carcinogen. In East Africa, we investigated esophageal squamous cell carcinoma (ESCC) risk in relation to four thermal exposure metrics separately and in a combined score.

METHODS

From the ESCCAPE case-control studies in Blantyre, Malawi (2017-20) and Kilimanjaro, Tanzania (2015-19), we used logistic regression models adjusted for country, age, sex, alcohol and tobacco, to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for self-reported thermal exposures whilst consuming tea, coffee and/or porridge.

RESULTS

The study included 849 cases and 906 controls. All metrics were positively associated with ESCC: temperature of drink/food (OR 1.92 (95% CI: 1.50, 2.46) for 'very hot' vs 'hot'), waiting time before drinking/eating (1.76 (1.37, 2.26) for <2 vs 2-5 minutes), consumption speed (2.23 (1.78, 2.79) for 'normal' vs 'slow') and mouth burning (1.90 (1.19, 3.01) for ≥6 burns per month vs none). Amongst consumers, the composite score ranged from 1 to 12, and ESCC risk increased with higher scores, reaching an OR of 4.6 (2.1, 10.0) for scores of ≥9 vs 3.

CONCLUSIONS

Thermal exposure metrics were strongly associated with ESCC risk. Avoidance of very-hot food/beverage consumption may contribute to the prevention of ESCC in East Africa.

A clinical and molecular epidemiological survey of hepatitis C in Blantyre, Malawi, suggests a historic mechanism of transmission

Hepatitis C virus (HCV) is a leading cause of liver disease worldwide. There are no previous representative community HCV prevalence studies from Southern Africa, and limited genotypic data. Epidemiological data are required to inform an effective public health response. We conducted a household census-based random sampling serological survey, and a prospective hospital-based study of patients with cirrhosis and hepatocellular carcinoma (HCC) in Blantyre, Malawi. We tested participants with an HCV antigen/antibody ELISA (Monolisa, Bio-Rad), confirmed with PCR (GeneXpert, Cepheid) and used line immunoassay (Inno-LIA, Fujiribio) for RNA-negative participants. We did target-enrichment whole-genome HCV sequencing (NextSeq, Illumina). Among 96,386 censused individuals, we randomly selected 1661 people aged ≥16 years. Population-standardized HCV RNA prevalence was 0.2% (95% CI 0.1-0.5). Among 236 patients with cirrhosis and HCC, HCV RNA prevalence was 1.9% and 5.0%, respectively. Mapping showed that HCV RNA+ patients were from peri-urban areas surrounding Blantyre. Community and hospital HCV RNA+ participants were older than comparator HCV RNA-negative populations (median 53 vs 30 years for community, p = 0.01 and 68 vs 40 years for cirrhosis/HCC, p < 0.001). Endemic HCV genotypes (n = 10) were 4v (50%), 4r (30%) and 4w (10%). In this first census-based community serological study in Southern Africa, HCV was uncommon in the general population, was centred on peri-urban regions and was attributable for <5% of liver disease. HCV infection was observed only among older people, suggesting a historic mechanism of transmission. Genotype 4r, which has been associated with treatment failure with ledipasvir and daclatasvir, is endemic.

Alcohol consumption and oesophageal squamous cell cancer risk in east Africa: findings from the large multicentre ESCCAPE case-control study in Kenya, Tanzania, and Malawi

BACKGROUND

The contribution of alcohol to the large burden of oesophageal squamous cell carcinoma (ESCC) in east Africa remains uncertain and difficult to assess owing to complex consumption patterns of traditional and commercial drinks. We aimed to assess whether alcohol drinking, overall and at specific intake levels, contributes to ESCC risk in east Africa.

METHODS

We did a hospital-based case-control study in Kenya, Tanzania, and Malawi, which included comprehensive assessment of a variety of locally consumed alcohol that we used to classify drinkers as exclusively low alcohol-by-volume (ABV; <30% ABV) drinkers or drinkers of some high-ABV drinks, as well as the number of drinks consumed, average weekly ethanol intake, and the contribution of each drink type to overall ethanol consumption. Cases were patients aged 18 years and older with incident primary ESCC, confirmed histologically for the majority of cases, and a clinical diagnosis for the remainder. Controls were frequency-matched on age and sex in a 1:1 ratio with cases. The controls were recruited from the same hospitals as cases and included outpatients, inpatients, and hospital visitors who did not have cancer or any other digestive disease. Consenting participants took part in face-to-face interviews in which they were asked whether they had ever consumed alcohol (the primary exposure variable); those who had were asked follow-up questions about their consumption habits for different alcoholic drinks.

FINDINGS

1279 cases and 1346 controls were recruited between Aug 5, 2013, and May 24, 2020, including 430 cases and 440 controls from Kenya, 310 cases and 313 controls from Tanzania, and 539 cases and 593 controls from Malawi. 65 (4·8%) of 1344 cases were excluded. Consistent positive associations with ESCC risk were found for ever having consumed alcohol in Kenyan men and Tanzanian men, and for daily number of drinks and estimated ethanol intake in Kenya, Tanzania (both sexes) and Malawian women. Corresponding population-attributable fractions of ESCC for those reporting ever drinking alcohol (vs never drinking) were 65% (95% CI 52-78) in Kenyan men and 23% (<1-45) in Kenyan women, and 56% (95% CI 36-76) in Tanzanian men and 5% (0-42) in Tanzanian women. Increased risk and population-attributable fractions were almost entirely due to risks in high-ABV drinkers.

INTERPRETATION

Alcohol appears to be a substantial contributor to ESCC risk in east Africa, particularly among men, and a large fraction of ESCC could be prevented by cessation or reduction of alcohol consumption. Future studies should consider independent ascertainment of alcohol intake to assess the potential of under-reporting in Malawi.

FUNDING

US National Cancer Institute, Wereld Kanker Onderzoek Fonds, and the IARC Environment and Lifestyle Epidemiology Branch.

TRANSLATIONS

For the Swahili and Chichewa translations of the abstract see Supplementary Materials section.

Geophagia and risk of squamous cell esophageal cancer in the African esophageal cancer corridor: Findings from the ESCCAPE multicountry case-control studies

Geophagia, the intentional practice of consuming soil, occurs across the African esophageal cancer corridor, particularly during pregnancy. We investigated whether this practice is linked to endemic esophageal squamous cell carcinoma (ESCC) in this region. We conducted ESCC case-control studies in Tanzania, Malawi and Kenya. Cases were patients with incident histologically/clinically confirmed ESCC and controls were hospital patients/visitors without digestive diseases. Participants were asked if they had ever eaten soil (never/regularly/pregnancy-only). Odds ratios (OR) are adjusted for sex, age, tobacco, alcohol, country, religion and marital status. Overall, 934 cases (Malawi 535, Tanzania 304 and Kenya females 95) and 995 controls provided geophagia information. Among controls, ever-geophagia was common in women (Malawi 49%, Kenya 43% and Tanzania 29%) but not in men (10% Malawi, <1% Tanzania). In women, ESCC ORs were 1.25 (95% CI: 0.70, 2.22) for regular versus never geophagia and 0.88 (95% CI: 0.64, 1.22) for pregnancy-only versus never. Findings were stronger based on comparisons of cases with hospital visitor controls and were null using hospital patients as controls. In conclusion, geophagia is too rare to contribute to the male ESCC burden in Africa. In women, the practice is common but we did not find consistent evidence of a link to ESCC. The study cannot rule out selection bias masking modest effects. Physical effects of geophagia do not appear to have a large impact on overall ESCC risk. Research with improved constituent-based geophagia exposure assessment is needed.

Early onset myasthenia gravis in a Malawian woman: Challenges in managing myasthenia gravis in a low-resource setting

Myasthenia gravis is a rare autoimmune disease, which presents with ocular or generalised symptoms. Few publications describe its prevalence in African populations. We describe a young woman who was diagnosed with myasthenia gravis in a Malawian public hospital and outline the challenges encountered in managing this condition in a low-resource setting.

Systematic review: the etiology of esophageal squamous cell carcinoma in low-income settings

Esophageal carcinoma causes over 380 000 deaths per year, ranking sixth worldwide in mortality amongst all malignancies. Globally, the squamous cell subtype is most common and accounts for 80% of esophageal cancers. Nonetheless, esophageal squamous cell carcinoma is much more poorly understood than esophageal adenocarcinoma, including what is driving such high prevalences, why it often presents in young patients, and shows such marked geographical delineations Areas covered: The current literature was searched for articles focusing on aetiopathogenesis of squamous cell esophageal carcinoma via a systematic review, particularly in low-resource settings. This was supplemented by papers of interest known to the authors. Expert commentary: Current putative mechanisms include polycyclic aromatic hydrocarbons, nitrosamines, acetaldehyde, cyclo-oxygenase-2 pathways, androgen and their receptor levels, as well as smoking & alcohol, micronutrient deficiencies and diet, mycotoxins, thermal damage, oral hygiene and microbiotal factors, inhaled smoke, viral infections such as HPV, and chronic irritative states. Etiology is likely multifactorial and varies geographically. Though smoking and alcohol play a predominant role in high-income settings, there is strong evidence that mycotoxins, diet and temperature effects may play an under-recognized role in low and middle-income settings.

Intra-abdominal fat: Comparison of computed tomography fat segmentation and bioimpedance spectroscopy

Background

Intra-abdominal fat is an important factor in determining the metabolic syndrome/insulin resistance, and thus the risk of diabetes and ischaemic heart disease. Computed Tomography (CT) fat segmentation represents a defined method of quantifying intra-abdominal fat, with attendant radiation risks. Bioimpedance spectroscopy may offer a method of assessment without any risks to the patients. A comparison is made of these two methods.

Methods

This was a preliminary study of the utility of multifrequency bioimpedance spectroscopy of the mid abdomen as a measure of intra-abdominal fat, by comparison with fat segmentation of an abdominal CT scan in the −30 to −190 HU range.

Results

There was a significant (P < 0.01) correlation between intra-abdominal fat and mid-upper arm circumference, as well as the bioimpedance parameter, the R/S ratio. Multivariate analysis showed that these were the only independant variables and allowed the derivation of a formula to estimate intra-abdominal fat: IAF = 0.02 × MAC − 0.757 × R/S + 0.036.

Conclusions

Circumabdominal bioimpedance spectroscopy may prove a useful method of assessing intra-abdominal fat, and may be suitable for use in studies to enhance other measures of body composition, such as mid-upper arm circumference.

Induced topological phases at the boundary of 3D topological superconductors

We present tight-binding models of 3D topological superconductors in class DIII that support a variety of winding numbers. We show that gapless Majorana surface states emerge at their boundary in agreement with the bulk-boundary correspondence. At the presence of a Zeeman field, the surface states become gapped and the boundary behaves as a 2D superconductor in class D. Importantly, the 2D and 3D winding numbers are in agreement, signifying that the topological phase of the boundary is induced by the phase of the 3D bulk. Hence, the boundary of a 3D topological superconductor in class DIII can be used for the robust realization of localized Majorana zero modes.

Painless electrodiagnostic current perception threshold and pain tolerance threshold values in CRPS subjects and healthy controls: a multicenter study

The purpose of this study is to evaluate both painless and painful sensory transmission in patients with Complex Regional Pain Syndrome (CRPS) using the automated electrodiagnostic sensory Nerve Conduction Threshold (sNCT) test. This test generates reliable, painless Current Perception Threshold (CPT) and atraumatic Pain Tolerance Threshold (PTT) measures. Standardized CPT and PTT measures using constant alternating current sinusoid waveform stimulus at 3 different frequencies 5 Hz, 250 Hz, and 2 kHz (Neurometer CPT/C Neurotron, Inc. Baltimore, MD) were obtained from CRPS subjects at a distal phalange of the affected extremity and at an ipsilateral asymptomatic control site. Matched sites were tested on healthy subjects. Detection sensitivities for an abnormal PTT and CPT test were calculated based on specificity of 90% as determined from data obtained from healthy controls. A Spearman rank correlation was used to test for a significant association between presence of allodynia and an abnormal PTT or CPT at any frequency tested. Thirty-six CRPS subjects and 57 healthy controls were tested. The highest detection sensitivity of the PTT test from symptomatic test sites was 63% for the finger and 71% for the toe. PTT abnormalities were also detected, to a lesser degree, at the asymptomatic control site (41% finger control site, 16% toe control site). The highest CPT detection sensitivity at the symptomatic site was 37% for the finger site and 53% for the toe site. CPT abnormalities were also detected at the asymptomatic control site (29% finger control site, 37% toe control site). Eighty-six percent of the CRPS subjects had either a PTT or CPT abnormality at any frequency at the symptomatic site. There was a significant correlation between presence of allodynia and presence of an abnormal CPT and PTT, respectively (P < .01). The correlation coefficient was lower for CPT than for PTT, ie, 0.34 versus 0.6 for the finger and 0.48 versus 0.67 for the toe, respectively. In studied CRPS patients an abnormal PTT was detected with higher sensitivity than an abnormal CPT. Assessing PTT may become a useful electrodiagnostic quantitative sensory test for diagnosing and following the course of neuropathic pain conditions.

The changing motivation of massage therapy students

PURPOSE

The study was conducted in order to determine whether the level of motivation related to intrinsic (people-oriented) and extrinsic (external reward) value complexes in a class of massage therapy students changed during their professional education.

METHODS

The research was a quasi-experimental within-subject design, in which survey data was collected from students on their first day in the massage therapy program and again towards the end of their final term. The data were collated and summarized, and the differences in motivation scores were assessed using Fisher's Least Significant Difference procedure.

RESULTS

The results support the hypothesis that massage therapy students are motivated more strongly by intrinsic than extrinsic rewards both at the commencement of their studies and as they approach entry to practice. Also evident from the data is the fact that the students' motivation changed during their professional studies. This change involved a significant decrease in the level of intrinsic motivation and significant increase in the level of extrinsic motivation. Thus, although intrinsic motivation reduced while extrinsic motivation increased, the former remained the more powerful influence.

CONCLUSION

Professional programs should consider the balance between intrinsic and extrinsic student motivation and attempt to control influences that might shift this such that the humanistic / altruistic mission of health care is undermined.

Applying the Slevin-Pinto Project Implementation Profile to an Information Systems Project

This paper describes and evaluates the application of the project implementation profile (PIP) methodology to a recent information systems (IS) project within a global company. The methodology was developed by Slevin and Pinto in an attempt to assess which aspects of a project determine its success or failure. Potential weaknesses of the methodology are highlighted. Areas in which the methodology is unable to fully assist in determining critical factors for the successful implementation of an IS project are identified. Recommendations for future research are made.

Intra-ureteric capsaicin in loin pain haematuria syndrome: efficacy and complications

OBJECTIVE

To evaluate the safety and efficacy of intra-ureteric capsaicin for loin pain haematuria syndrome (LPHS).

PATIENTS AND METHODS

In an open prospective pilot study, four middle-aged patients (three women and one man) with LPHS resistant to therapies such as splanchnic nerve block, psychological treatment or renal autotransplantation (one) were assessed. An intra-ureteric infusion of capsaicin (30 mg/100 mL of 30% alcohol in saline) for 30 min with bladder irrigation was administered under general anaesthesia, with a subsequent intravenous patient-controlled narcotic analgesic pump for pain control. Double-concentration capsaicin was used for second infusions, if necessary when the response to the earlier infusion was inadequate or incomplete.

RESULTS

The first patient had experienced reduced pain levels for the first 3 months only, with no benefit from the subsequent treatments with higher doses of capsaicin (60 mg). The second patient with recurrent pain in an autotransplanted kidney had no benefit from either a 30 or 60 mg capsaicin infusion a month apart, but developed a fibrotic stricture at the transplant pelvi-ureteric junction, requiring pyelocystoplasty. The third patient with concurrent depression had no benefit from a 30-mg infusion of capsaicin. The fourth patient experienced no pain relief from a 30 mg infusion of capsaicin but developed proteinuria secondary to mesangial proliferative glomerulonephritis, ureteric inflammation needing stenting within 7 days of treatment and subsequently nephrectomy for a nonfunctioning kidney at 3 months.

CONCLUSION

Intra-ureteric capsaicin was neither effective nor safe in LPHS; the contribution of the alcohol diluent cannot be excluded.

Expression of TA1, a rat oncofetal cDNA with homology to transport-associated genes, in carbon-tetrachloride-induced liver injury

TA1, a novel rat oncofetal cDNA, is the predicted homolog of the human lymphocyte activation gene E16. The encoded peptides share high homology with transport-associated and uncharacterized sequences in distant species, suggesting an important and conserved function in cellular homeostasis. Moderate steady-state levels of TA1 RNA were induced following acute and chronic CCl4-mediated liver injury. TA1 expression was either greatly reduced or absent in livers of animals receiving injury-protective doses of vitamin E in conjunction with CCl4. In contrast to the in vivo data, acute in vitro exposure of hepatocytes to CCl4 did not induce TA1 RNA. Our results indicate that TA1 is spatially and temporally associated with liver injury in vivo and may play an adaptive role in the hepatic response to environmental toxicants.

Differential neuronal and astrocytic expression of transforming growth factor beta isoforms in rat hippocampus following transient forebrain ischemia

Although transforming growth factor-beta (TGF-beta) is known to be multifunctional in many physiological systems, its role in the brain is undergoing elucidation. The situation is made more complex by the presence of multiple isoforms, which may be differentially regulated and have various activities in each particular cell type. Because neurons are dependent on neurotrophic factors for survival, we utilized a rat model of transient forebrain ischemia (TFI) to test the hypothesis that TGF-beta isoforms are important in the hippocampal response to injury. Northern blot analysis demonstrated a differential and temporal alteration in TGF-beta isoform expression following TFI. In-situ hybridization experiments revealed that at day 1 following TFI, there was a strong neuronal increase in the TGF beta-1 transcript but a reciprocal decrease in TGF-beta 2 and -beta 3 transcript levels. Immunohistochemical analysis of all three TGF-beta s demonstrated at day 1 following TFI a loss of the immunoreactive proteins in the vulnerable CA-1 hippocampal neurons, but protein preservation in the CA-2-4 neurons which are more resistant to the ischemic insult. At 3-5 days following TFI, significant extraneuronal changes in TGF-beta isoform expression were also detected. Double-staining experiments with antibody to glial fibrillary acidic protein (GFAP) as a marker for astrocytes, and lectin isolectin B4 Griffonia simplicifolia for microglia, demonstrated increased expression of all TGF-beta isoforms in astrocytes but not microglia. Taken together, these results suggest that the TGF-beta peptides in neurons and astrocytes are important endogenous mediators in the CNS response to ischemic injury.

Recurrent graft pain following renal autotransplantation for loin pain haematuria syndrome

OBJECTIVE

To review retrospectively the Perth experience of autotransplantation for loin pain haematuria syndrome and identify possible factors associated with its failure.

PATIENTS AND METHODS

The medical records of 11 women patients (median age 42 years, range 29-48) who had 12 autotransplantations were reviewed. All patients were then interviewed and asked whether they considered the operation a success.

RESULTS

All patients initially had complete relief of symptoms. Three patients who had four transplants are still symptom-free with a follow-up of 24-46 months. Five patients have had partial relief with marked variability in their patterns of recurrent pain. Three patient have symptoms as severe as those before operation. One kidney was lost because of acute thrombosis and another developed a urinoma. No patient had deterioration in renal function.

CONCLUSION

Renal autotransplantation is a treatment option of last resort, with acceptable morbidity in patients with intractable, functionally disabling renal pain, but three-quarters of these patients may develop recurrent pain in the transplant site. A current or past history of depression or absence of haematuria may represent risk factors for a poor post-operative prognosis. Treatment failure is predictable by a poor response to sympathetic neurolytic block.

TA1, a highly conserved oncofetal complementary DNA from rat hepatoma, encodes an integral membrane protein associated with liver development, carcinogenesis, and cell activation

Hepatocellular carcinoma is characterized by changes in gene expression associated with cell growth and differentiation. Cell surface antigenic changes have also been described based on differential antibody reactivity between normal and neoplastic liver. We obtained a novel tumor-associated cDNA designated TA1 on the basis of its differential expression between hepatoma cells and normal liver. Sequence analysis predicted a 723-base pair open reading frame with the deduced amino acid sequence encoding an integral membrane protein containing multiple hydrophobic transmembrane domains. Database searches revealed TA1 as the likely rat homologue of E16, a recently cloned human cDNA associated with lymphocyte activation. Although noncoding sequences diverged significantly, the 95% conservation of the predicted proteins between species strongly suggests an important, although as yet undefined, function in normal cells. TA1 transcripts were detected in normal adult rat tissues including testes, brain, ovary, spleen, mammary gland, and uterus with the highest steady-state expression in placenta. Although no expression was detected in normal liver, all rat hepatomas examined expressed an abundant 3.2-kilobase transcript. TA1 expression was closely associated with progression in this tumor model and suggests this molecule, originally linked to cell activation, also plays a role in the malignant phenotype.

Acute injury of the neck: anatomical and pathological basis of pain

Headache, upper torso and upper limb pain can all originate in lesions of the cervical spine. The pain distribution is similar whether the cause is traumatic or degenerative. Nociceptive fibres are present in many cervical spine structures including the disc annulus, facet joint capsules, muscles, meninges, arteries, nerve roots and dorsal root ganglia. Such nerves are not present in the disc nucleus, facet articular cartilages and the ligamentum flavum. Central nervous connections between the trigeminal nucleus and upper cervical sensory input provide an explanation for some forms of headache and facial pain. This paper focuses on neck sprain from road traffic accidents as a cause of pain. Similar lesions are seen in the cervical spines of those who die immediately and survivors who die some years after a neck injury, from unrelated causes. Both discs and facet joints are injured. The common disc injury is a "rim lesion" or transverse tear near the anterior vertebral rim. It is caused by distraction and shearing in sudden extension. Both the posterior disc and the facets are compressed, causing disc contusion or herniation, facet haemarthroses, bruising around the C2 nerve, or fractures of articular processes. Suboccipital vascular congestion and annulus calcification are also seen in the "survivors". Chronic pain develops in 20-40% of the "survivors". The reasons include altered spinal mechanics, neural damage and vascular changes. Management must always start with an accurate diagnosis based on a history and physical examination. Simple investigations such as extension X-rays may reveal vacuum clefts in the same anatomical position as rim lesions. Nuclear scans detect increased uptake at damaged end plates or facet fractures.(ABSTRACT TRUNCATED AT 250 WORDS)

Determination of the structures of cystocarpic carrageenans from Gigartina skottsbergii by methylation analysis and NMR spectroscopy

The combined use of methylation analysis and high-field 1H and 13C NMR spectroscopy allows the determination of the fine structure of the carrageenans produced by the cystocarpic stage of Gigartina skottsbergii.

Antimutagens from Momordica charantia

The antimutagenic principle of the green fruits of Momordica charantia was shown by the micronucleus test to be an intractable mixture of novel acylglucosylsterols. The antimutagens were extracted from the green fruits with ethanol and isolated from the bioactive petroleum ether and carbon tetrachloride extracts by repeated and sequential flash column chromatography. The major component of the mixture is 3-O-[6'-O-palmitoyl-beta-D-glucosyl-stigmasta-5,25(27)-dien and the minor component is the stearyl derivative (Guevara, 1989). At a dosage range in mice of 50-12.5 micrograms extract/g, the mixture reduced by about 80% the number of micronucleated polychromatic erythrocytes induced by the well-known mutagen mitomycin C. Structure-activity correlation studies suggested that the antimutagenic activity may reside in the peculiar lipid-like structure of the acylglucosylsterols. Ingestion of these compounds may result in their absorption in the plasma membrane lipid bilayer which could adversely affect the membrane permeability towards mitomycin C and disrupt the cellular activity of the latter.

Structure of a mutagen from roasted seeds of Moringa oleifera

A mutagenic compound was isolated from roasted seeds of Moringa oleifera Lam. Its structure has been elucidated by spectral analysis as 4(alpha-L-rhamnosyloxy)phenylacetonitrile. The results of the Micronucleus Test, an in vivo method, showed that the number of micronucleated polychromatic erythrocytes (PCE)/1000 PCE for this compound is higher than that of the solvent control, dimethylsulfoxide, and approximates that of the positive control, tetracycline. This indicates that 4(alpha-L-rhamnosyloxy)phenylacetonitrile is a genotoxic compound.

Stereoselective O-glycosylation of trans-4-hydroxy-L-proline derivatives promoted by silver zeolite

Trans-4-hydroxy-L-proline has been converted to four imino- and carboxyl-blocked derivatives which are suitable for the synthesis of 4-O-glycosyl conjugates. Reaction of these derivatives with 2,3,5-tri-O-benzyl-alpha-L-arabinofuranosyl chloride in the presence of a silver zeolite promoter yielded the blocked beta-furanosyl amino-acid conjugates. Deprotection gave trans-4-(beta-L-arabinofuranosyloxy)-L-proline which was characterised as its crystalline isopropyl ester. 13C-NMR Data are presented for the compounds described.

Plastic endobronchial tubes in the management of life-threatening hemoptysis

Plastic double-lumen endobronchial tube was used to maintain the airway in a patient with massive hemoptysis and nonresectable lung cancer. This tube is superior to the previously used Carlens tube, as it can be inserted in emergency situations and does not require surgical setting. In addition, the larger internal diameter of these tubes allows better airway clearance and passage of a flexible bronchoscope. The double-lumen tube may be considered as an alternative to selective main-stem intubation.

Reappraisal of empyema thoracis. Surgical intervention when the duration of illness is unknown

The timing of surgical treatment of empyema remains controversial. Traditionally, thoracotomy is performed either within three weeks of diagnosis or delayed until presumed pleurodesis occurs. Often, these patients are moribund and the duration of illness impossible to determine. We report our surgical results in seven patients with a deteriorating clinical course and multiple loculations which persisted after tube thoracostomy and would not have responded to multiple thoracostomies. Five patients required decortication. One required lobectomy for an abscess which developed on the contralateral side six weeks after discharge. There were no deaths or recurrences of empyema. Average times from surgery to tube removal and to discharge were six to 12 days, respectively. We conclude that one can safely and cost-effectively treat these patients surgically even when the duration of illness and presence of pleurodesis are unknown, and that the postoperative course will be uncomplicated.

Cystadenoma of the pancreas--an unusual presentation

Cystadenoma is a rare lesion of the pancreas. A case is reported in which the tumour was initially misdiagnosed as a pseudocyst and inappropriate surgery performed. The patient subsequently presented with gastro-intestinal haemorrhage and the tumour was resected. The diagnosis and management of cystic lesions of the pancreas are discussed, stressing the need for complete pre-operative investigation in order that incorrect treatment is avoided.

Nucleotide sequence of the regulatory region of the uvrD gene of Escherichia coli

We have sequenced the control region of the Escherichia coli uvrD gene and demonstrated the presence of a nucleotide sequence which is a perfect match for the consensus LexA protein binding site [Little and Mount, Cell 29 (1982) 11-22]. Upstream of this presumed LexA binding site is a promoter sequence, uvrD P1 which would be under LexA control while farther downstream is another possible promoter, uvrD P2, which would be independent of LexA control. Downstream of the LexA binding site is a potential transcription terminator in the form of a stem-loop structure followed by a series of T residues. On the basis of this sequence analysis, expression of the uvrD gene would be expected to increase after DNA damage or replication inhibition as part of the SOS response, as is reported in the preceding paper [Arthur and Eastlake, Gene 25 (1983) 309-316].

The substrate specificity of yeast hexokinase: reaction with D-arabinose oxime

By chromatography, electrophoresis, n.m.r. spectroscopy, and spectrophotometric assay, it has been shown that D-arabinose oxime acts as a weak substrate for yeast hexokinase. The enzyme-catalysed phosphorylation of the oxime, which exists as a mixture of E (80%) and Z (20%) acyclic forms in solution at equilibrium, is proposed to proceed via the transient formation of a furanoid species. Weak substrate-activity was also observed with 4-deoxy-D-xylo-hexose, but not with 5-deoxy-D-xylohexose. The relation of these and previous results concerning the carbohydrate-substrate specificity of yeast hexokinase in solution to X-ray crystallographic studies is discussed.

The role of hospital medical teams at a major accident

Despite an apparently adequate major accident plan which has been used successfully on two previous occasions, considerable difficulties were experienced by the mobile medical teams at the scene of the Moorgate tube train accident. The authors have attempted to describe the role and organisation of mobile medical teams placing particular emphasis on a simple and flexible plan.