C/EBPβ mediates RNA polymerase III-driven transcription of oncomiR-138 in malignant gliomas

MicroRNA-138 (miR-138) is a pro-survival oncomiR for glioma stem cells. In malignant gliomas, dysregulated expression of microRNAs, such as miR-138, promotes Tumour initiation and progression. Here, we identify the ancillary role of the CCAAT/enhancer binding protein β (C/EBPβ) as a transcriptional activator of miR-138. We demonstrate that a short 158 bp DNA sequence encoding the precursor of miR-138-2 is essential and sufficient for transcription of miR-138. This short sequence includes the A-box and B-box elements characteristic of RNA Polymerase III (Pol III) promoters, and is also directly bound by C/EBPβ via an embedded 'C/EBPβ responsive element' (CRE). CRE and the Pol III B-box element overlap, suggesting that C/EBPβ and transcription factor 3C (TFIIIC) interact at the miR-138-2 locus. We propose that this interaction is essential for the recruitment of the RNA Pol III initiation complex and associated transcription of the oncomiR, miR-138 in malignant gliomas.

EGF hijacks miR-198/FSTL1 wound-healing switch and steers a two-pronged pathway toward metastasis

Exploring the parallels between wound healing and epithelial cancers, Sundaram et al. elucidate the mechanism by which cancer cells hijack the wound healing switch to enhance invasion and metastasis in head and neck squamous cell carcinoma.

Epithelial carcinomas are well known to activate a prolonged wound-healing program that promotes malignant transformation. Wound closure requires the activation of keratinocyte migration via a dual-state molecular switch. This switch involves production of either the anti-migratory microRNA miR-198 or the pro-migratory follistatin-like 1 (FSTL1) protein from a single transcript; miR-198 expression in healthy skin is down-regulated in favor of FSTL1 upon wounding, which enhances keratinocyte migration and promotes re-epithelialization. Here, we reveal a defective molecular switch in head and neck squamous cell carcinoma (HNSCC). This defect shuts off miR-198 expression in favor of sustained FSTL1 translation, driving metastasis through dual parallel pathways involving DIAPH1 and FSTL1. DIAPH1, a miR-198 target, enhances directional migration through sequestration of Arpin, a competitive inhibitor of Arp2/3 complex. FSTL1 blocks Wnt7a-mediated repression of extracellular signal–regulated kinase phosphorylation, enabling production of MMP9, which degrades the extracellular matrix and facilitates metastasis. The prognostic significance of the FSTL1-DIAPH1 gene pair makes it an attractive target for therapeutic intervention.

Fast-track rapid warfarin reversal for elective surgery: extending the efficacy profile to high-risk patients with cancer

Periprocedural management of patients on long-term warfarin therapy remains a common and important clinical issue, with little high-quality data to guide this complex process. The current accepted practice is cessation of warfarin five days preoperatively, but this is not without risk and can be complicated, particularly if bridging is required. An alternative method utilising low-dose intravenous vitamin K the day before surgery has been shown previously to be efficacious, safe and convenient in an elective surgical population receiving chronic warfarin therapy. The efficacy and utility of this 'fast-track' warfarin reversal protocol in surgical patients with cancer, who were at high risk of both thromboembolism and bleeding was investigated in a prospective, single-arm study at a dedicated cancer centre. Seventy-one patients underwent 82 episodes of fast-track warfarin reversal (3 mg intravenous vitamin K 18 to 24 hours before surgery). No patient suffered an adverse reaction to intravenous vitamin K, all but one achieved an International Normalized Ratio =1.5 on the day of surgery, and no surgery was deferred. Assays of vitamin K-dependent factor levels pre- and post-vitamin K demonstrated restoration of functional activity to within an acceptable range for surgical haemostasis. While this alternative method requires further validation in a larger prospective randomised study, we have now extended our use of fast-track warfarin reversal using vitamin K to patients with cancer, on the basis of our experience of its safety, convenience, reliability and efficacy.

First test effect in intravenous glucose tolerance testing

AIMS

Intravenous glucose tolerance testing (IVGTT) is a common test of β-cell function in which a glucose load is administered and insulin and/or C-peptide responses are monitored. Since the first IVGTT may be more stressful and stress may alter β-cell secretion or hepatic insulin extraction, we asked whether there was a first test effect.

METHODS

Insulin and C-peptide responses were compared from two sequential IVGTTs performed within 6 months during staging for the Diabetes Prevention Trial-Type 1 (DPT-1) in 368 people at high risk for type 1 diabetes. Insulin data (1+3 min) were used because the first phase insulin response (and peak insulin concentration) occurs within this time frame. Areas under the curve (AUC) calculations represent early insulin or C-peptide responses from 0 through 10 min post-glucose challenge.

RESULTS

More than half of all subjects were found to have first test values lower than the second. This was true for all measures of both insulin and C-peptide but the frequency was significantly different only for insulin measures corrected for basal and for insulin AUC (p < 0.05). However, for subjects (n = 99) whose 1+3 min insulin response was <10th percentile on the first test, there was a significant increase on the second test (p < 0.05). The C-peptide: insulin ratio did not change significantly between tests, indicating that differences are due to changes in β-cell secretion rather than hepatic insulin uptake.

CONCLUSIONS

A statistically significant first test effect occurs during the IVGTT attributable to variations in insulin secretion rather than hepatic uptake.

Inhibition of iPLA2 β and of stretch-activated channels by doxorubicin alters dystrophic muscle function

BACKGROUND AND PURPOSE

Chronic elevation in intracellular Ca(2+) concentration participates in death of skeletal muscle from mdx mice, a model for Duchenne muscular dystrophy (DMD). Candidate pathways mediating this Ca(2+) overload involve store-operated channels (SOCs) and stretch-activated channels (SACs), which are modulated by the Ca(2+) -independent form of PL A2 (iPLA2 ). We investigated the effect of doxorubicin (Dox), a chemotherapeutic agent reported to inhibit iPLA2 in other systems, on the activity of this enzyme and on the consequences on Ca(2+) handling and muscle function in mdx mice.

EXPERIMENTAL APPROACH

Effects of Dox on iPLA2 activity, reactive oxygen species production and on Ca(2+) influx were investigated in C2C12 and mdx myotubes. The mechanism of Dox-mediated iPLA2 inhibition was evaluated using purified 6x histidine-tagged enzyme. Aequorin technology was used to assess Ca(2+) concentrations underneath the plasma membrane. Isolated muscles were exposed to fatigue protocols and eccentric contractions to evaluate the effects of Dox on muscle function.

KEY RESULTS

Dox at 1-30 μM inhibited iPLA2 activity in cells and in the purified enzyme. Dox also inhibited SAC- but not SOC-mediated Ca(2+) influx in myotubes. Stimulated elevations of Ca(2+) concentrations below the plasmalemma were also blocked. Exposure of excised muscle to Dox was not deleterious to force production and promoted recovery from eccentric contractions.

CONCLUSIONS AND IMPLICATIONS

Dox showed efficacy against targets known to play a role in the pathology of DMD, namely iPLA2 and SAC. The potent SAC inhibitory effect of Dox is a novel finding that can explain partly the cardiomyopathy seen in chronic anthracycline treatment.

Prevalence and risk factors for spousal violence among women attending health care centres in Alexandria, Egypt

We conducted a cross-sectional survey to determine the prevalence of, and factors affecting, spousal violence among 3271 ever-married women attending 12 randomly selected family health centres in Alexandria Governorate. More than three-quarters of the participants (77%) reported experiencing spousal violence during their marital life. Emotional violence was the most common type reported (71.0%), followed by physical (50.3%), economic (40.8%) and sexual (37.1%) violence. The study confirms the high prevalence of spousal violence across all socioeconomic strata. Logistic regression analysis indicated large family size, divorce or separation, low educational attainment of husband, smoking habit and drug use in husband, husband's psychological status and history of exposure to physical violence during adolescence were associated with spousal violence. This high rate of spousal violence highlights the urgent need for government and civil society to address the issue, which hinders progress toward Egypt's development goals.

Views of undergraduate students on objective structured clinical examination in neurology: a preliminary report

OBJECTIVE

Obtain the undergraduate medical students' evaluation of an objective structured clinical examination (OSCE) formed by two stations in neurology.

METHODS

The fifth-year medical students taking the neurology course at King Faisal University during the first rotation of academic year 1420-1421H (2000-2001G) made the evaluation. The time for each station was seven minutes. After finishing the examination, each student completed a six-item questionnaire on coverage, question clarity, time, patients, educational usefulness and organization of the examination with yes, no or don't know responses.

RESULTS

A total of 48 students (30 males and 18 females) took the examination. The average time to complete the examination for a group of 16 students was 2 hours. The responses were positive for clarity of questions and organization of the examination 41(85%), and allotted time 36(75%). Thirty-two students (67%) found the structured examination a useful educational experience. About half the students expressed their concern about the coverage of taught material and the number of patients seen in the examination as representative of those seen during the course, and 11 students (23%) requested more time.

CONCLUSIONS

The students' response to the use of the structured clinical examination as an objective tool for evaluation of clinical skills in neurology was favorable and comparable to reports from other parts of the world. Improvement is required in the number of patients, coverage and allotted time to optimize outcome by improving content validity and reducing stress on participating patients.

Clinical pattern of newly-diagnosed seizures in Saudi Arabia: a prospective study of 263 children

The clinical patterns, including history, examination, and electroencephalographic (EEG) and computed tomography (CT) findings were examined prospectively in 263 children (153 boys, 110 girls) with newly diagnosed recurrent seizures. The overall mean age was 4. 2 years, with a range of 0.05-13 years. The age of onset was within the first year of life in 128 (48.7%) of the patients. Hypoxic-ischemic encephalopathy (14.8%), febrile seizures (9.1%) and developmental delay (4.6%) were the predominant signs in this age group. Consanguinity of the parents was present in 29.7% cases. The main EEG abnormalities were epileptiform activity, which was generalized in 133 (50.6%) and focal in 80 (30.4%). Other abnormalities included slow wave activity in 41 (15.6%) and hypsarrhythmia in 3 (1.1%). The main seizure types were generalized in 60.4% and partial in 32.7%. The types of epileptic syndromes included localization-related (28.1%), generalized (23.2%), undetermined (37.4%) and (special) syndromes 11.4%. The cranial CT findings were normal in 60.5%, and the predominant abnormality was cerebral atrophy in 25.3%. The pattern of seizure types and the peak presentation in early childhood are comparable to those in western reports.

A rapid supercritical fluid extraction method for the qualitative detection of 2-alkylcyclobutanones in gamma-irradiated fresh and sea water fish

2-Alkylcyclobutanones are routinely used as chemical markers for irradiated foods containing lipids. However, current extraction procedures (soxhlet-Florisil chromatography) for the isolation of these markers involve a long and tedious clean-up regime prior to GC-MS identification. A simple and rapid method for the isolation of these markers using carbon dioxide as a super critical fluid is described for low lipid content fish samples (fresh and sea water) irradiated up to 8kGy. The presence of 2-dodecylcyclobutanone (2-DCB), a radiolytic marker, was confirmed in all irradiated fish samples at all doses. This was a clear indication that the fish samples had been irradiated and that both methods of isolation (florisil and supercritical fluid extraction) were capable of qualitatively extracting this marker. Supercritical fluid extraction is proposed as an alternative extraction procedure to the florisil chromatography method currently in use and has the added advantage of a considerably shorter extraction time.

Iodine deficiency disorders among school children in upper Egypt: an epidemiologic study

Iodine deficiency disorders (IDD) are the world's single most significant cause of preventable brain damage and mental retardation. Data regarding IDD in upper Egypt are scarce and even lacking. The aim of the present work was to study the prevalence of IDD and some potential risk factors in upper Egypt. Using a two-stage cluster sampling technique, 6750 school children aged 8-10 years were screened for IDD through clinical examination of the thyroid gland and determination of urinary iodine, from three governorates in upper Egypt, namely Al-Minya (population of 3.3 million), Assyut (population of 2.9 million), and Suhag (population of 3.1 million). Iodine was determined in samples of soil and drinking water. Overall, the prevalence rate of goitre was 34.6 per cent. The median urinary iodine level for children with goitre was 5.04 micrograms/dl compared to 14.81 micrograms/dl among children free of goitre. Multiple logistic regression analysis showed that certain groups of school children were much more likely to develop goitre. They included females (OR = 3.07, 95 per cent CI = 2.78-3.39), children in households where drinking water had an iodine content of less than 0.5 microgram/100 ml (OR = 3.44, 95 per cent CI = 3.09-3.89), and children living in places where soil content of iodine was less than 0.2 microgram/100 g (OR = 2.67, 95 per cent CI = 2.30-3.10). We conclude that IDD is a severe public health problem in upper Egypt. The present situation in upper Egypt necessitates an urgent intervention programme.

The effect of intermittent heating on some chemical parameters of refined oils used in Egypt. A public health nutrition concern

As part of a public health campaign in Egypt, various chemical parameters of oil which are considered good indices in assessing the degree of thermal abuse, oxidation and overall quality (acid values, iodine values, peroxide values, etc.) were studied with respect to different frying oils. Ingestion of decomposition products formed as a results of thermal abuse and oxidation of frying oils are known to lead to a variety of symptoms and diseases (allergies, atherosclerosis, coronary heart disease). Results show that the oil most commonly used by street vendors in Egypt (blend of cotton seed and sunflower oil) is the least suitable for frying, while palm oil on the basis of the various chemical parameters studied, is the ideal choice. However, from the nutritional and public health stand point, the use of saturated oils is to be discouraged. Corn oil is therefore the next best choice from both the chemical and nutritional stand point, and is recommended for public use in a country in which deep-fried vegetable patties ('fallafel') forms the staple food item in the diet.

Pattern of electroencephalographic abnormalities in children with hydrocephalus: a study of 68 patients

The pattern of electroencephalographic (EEG) abnormalities was studied in 68 patients (41 male, 27 female, age range 1 month to 17 years) with hydrocephalus. They all had standardized EEG recordings, which were read by the same electroencephalographer. In 48 children the EEG was performed after ventriculo-peritoneal shunting. The EEG abnormalities in the shunted group included slow waves in 26 patients [focal 2 (4.2%), generalized asynchronous 22 (45.8%), generalized synchronous 2 (4.2%)]; amplitude abnormalities in 2 (focal 1, generalized 1); epileptiform activity in 26 [partial 11 (22.9%), generalized 15 (31.3%)] and hypsarrhythmia in 4 (8.3%). Only 4 (8.3%) traces were normal, giving an overall percentage abnormality of 92%. In the unshunted group generalized asynchronous slow waves were found in 12 patients (60%), generalized amplitude abnormality in 1, focal epileptiform activity in 3 (15%), and generalized epileptiform activity in 6 (30%); 2 tracings in this group were normal, giving an overall percentage abnormality of 90%. Hydrocephalus in children, regardless of the cause, may be associated with generalized or focal EEG abnormalities. This may reflect the heterogeneity of the neural generator in the underlying disease process.

Surface Reactivity of Iron Oxide Pigmentary Powders toward Atmospheric Components: XPS, FESEM, and Gravimetry of CO and CO2 Adsorption

The adsorption of carbon monoxide and carbon dioxide (CO and CO2) on a number of specially prepared alpha-Fe2O3 samples was measured gravimetrically at 25&deg;C. The samples were prepared from a steel-pickling waste (97 wt% FeSO4&middot;7H2O) by roasting the original material at 700&deg;C for 5 h in air, oxygen, and nitrogen. Estimated surface coverages by the adsorbed CO and CO2 were made on the basis of nitrogen-adsorption-based surface areas, while the nature of the sample surfaces was investigated by both X-ray photoelectron spectroscopy (XPS) and field emission SEM (FESEM) techniques. In addition a depth profiling study utilizing a sputtering argon beam and XPS was undertaken. Morphological studies using FESEM showed that neither CO nor CO2 caused any significant structural changes. The nature of the resultant alpha-Fe2O3 sample surfaces differed, with the degree of oxygenation decreasing in the order of preparatory gases: oxygen, (wet) air, nitrogen [IP(O), IP(A), and IP(N)]. The amounts of both CO and CO2 adsorbed decreased in the sample order IP(A) > IP(O) > IP(N), though in the case of CO adsorption, the amounts adsorbed on IP(A) and IP(O) were not greatly different. In all cases the amounts adsorbed represented only fractional coverage. Adsorption of the more acidic CO2 is thought to be favored more by basic Ox-2 than by O2- sites on both IP(O) and IP(A), but with surface hydroxyl groups also playing a role (particularly on IP(A)). The CO2 adsorption should result in the formation of mono-, di-, and polydentate carbonate and bicarbonate species, with increasing degassing temperatures favoring the polydentate species and the decomposition of the bicarbonate and carbonate to form undissociated CO2. The adsorption of CO (a weak base) is postulated to take place on strong Lewis acid, highly coordinated, metal sites to form metal carbonyl species, on strong base sites (O2-) to form carbonite, oxalate, and ketenic species, and, to a lesser degree, on surface hydroxyl groups to form formyl and formate species. Copyright 1997 Academic Press. Copyright 1997Academic Press

Electrophysiological findings in newly diagnosed non-insulin-dependent diabetics: A prospective study

This study reports the electrophysiological findings in patients with newly diagnosed non-insulin-dependent diabetes mellitus (NIDDM) studied in the Neurodiagnostic Laboratory of the King Fahd Hospital of the University (KFHU), Al-Khobar, Saudi Arabia. Twenty-nine patients (22 males, 7 females, mean ages 47 and 37 years, respectively) were studied within four weeks of establishing the diagnosis. They were all given nerve conduction studies by the same examiner. Comparison was made with data from a group of 64 normal control subjects. In the study patients, the mean distal sensory peak latency in milliseconds (ms) +/- standard deviation (SD) was 3.5 +/- 0.41 ms in 35 median nerves, 3.2 +/- 0.72 ms in 35 ulnar nerves, 1.9 +/- 0.34 ms in 23 superficial radial nerves and 3.5 7plusmn; 0.61 in 36 sural nerves. The mean distal motor latency +/- SD was 4.6 +/- 0.95 ms in 39 median nerves, 3.5 +/- 0.58 ms in 38 ulnar nerves, 4.8 +/- 1.02 ms in 44 tibial nerves and 6.0 +/- 1.08 ms in 36 peroneal nerves. The electromyogram examination was performed on 24 patients and showed evidence of denervation and/or chronic reinnervation in seven (29%). The frequency of abnormalities in the studied peripheral nerves was 60% for median, 63% ulnar, 33% peroneal, 16% tibial and 8% sural.

Surface Reactivity of Iron Oxide Pigmentary Powders toward Atmospheric Components: XPS and Gravimetry of Oxygen and Water Vapor Adsorption

The adsorption of oxygen and water vapor on a number of specially prepared alpha-Fe2O3 samples was measured gravimetrically at 25&deg;C. The samples themselves were prepared from a steel-pickling chemical waste (97 wt% FeSO4&middot;7H2O) by roasting the original material at 700&deg;C for 5 h in air, oxygen, and nitrogen. Estimated surface coverages by the adsorbed oxygen and water vapor were made on the basis of nitrogen-adsorption-based surface areas, while the nature of the sample surfaces was investigated by both X-ray photoelectron spectroscopy (XPS) and field emission SEM (FESEM) techniques. In addition a depth profiling study utilizing a sputtering argon beam and XPS was undertaken. Morphological studies using FESEM showed that, while the surface areas were essentially the same (27-29 m2/g) for all three samples, the sample prepared in nitrogen had a significantly larger particle size than the other two. These studies also indicated that neither oxygen nor water vapor adsorption caused any significant structural changes. The differing sample preparations resulted in differing oxygenated surfaces for the alpha-Fe2O3 samples, with the degree of oxygenation decreasing in the order of preparatory gases: oxygen, (wet) air, nitrogen. The amounts of both oxygen and water vapor adsorbed were in inverse proportion to the original degree of surface oxygenation, though the amounts of both represented fractional coverage at best. While the water vapor adsorption was always greater than that of oxygen, the former was more weakly adsorbed, as was indicated by the ease of desorption. Depth profiling failed to indicate any bulk diffusion of oxygen but could not be considered reliable since even the attenuated argon beam used here still brought about reduction of surface iron. Both oxygen and dissociative water adsorption are thought to involve surface sites of high coordination unsaturation. Oxygen is postulated to adsorb on such poorly oxygenated sites primarily as O-2; however, O2- and possibly O- or Fe = O are also thought to play a role.

Acute exacerbations of chronic bronchitis. Preventing treatment failures and early reinfection

Although antimicrobial agents from a number of classes have been used with a good degree of clinical success for acute bacterial exacerbations of chronic bronchitis, the incidence of resistance by beta-lactamase-producing strains to certain penicillins and cephalosporins continues to increase and represents a growing clinical problem. There also have been reports of significant resistance by Streptococcus pneumoniae to tetracyclines and of treatment failures caused by this organism among patients receiving fluoroquinolones. The emergence of penicillin-resistant pneumococci in North America also is of concern. Although first-generation cephalosporins are no longer regarded as first-line therapy or optimal alternatives for acute exacerbations of chronic bronchitis, more recently developed agents of this class have better activity against the primary pathogens, and their efficacy and safety have been demonstrated in a number of clinical trials. Newer macrolide agents probably should be reserved for infections caused by atypical organisms.

The hemiplegic arm after stroke: measurement and recovery

Seven clinical tests have been used to study the recovery of arm function in 92 patients over 2 years following their stroke. These tests are simple and quick, and can be used by any interested observer. They form a hierarchical scale that measures recovery. Statistically significant improvement is only seen in the first 3 months. Fifty-six patients initially had non-functional arms; eight made a "complete recovery" and 14 a partial recovery. The tests described are inadequate on their own because they are not sufficiently sensitive at the upper range of ability. While recovery of lost function does relate to the degree of initial neurological loss in the arm, it seems to be largely independent of the overall severity of the stroke.

Isometric contractions of normal and spastic human skeletal muscle

Isometric contractile properties of human elbow flexor muscles were examined in 27 normal subjects (7 females and 20 males). Contractions of elbow flexors were elicited by application of electrical pulses to the biceps motor points. The tension development was recorded at the wrist with the elbow angle fixed at 90 degrees--100 degrees. The data for the time to peak and time to half relaxation of the twitch, the twitch tension-to-tetanus tension ratio, and the posttetanic twitch potentiation are reported. The contractile properties of spastic elbow flexor muscles from 7 subjects who had been hemiparetic for periods ranging from 4 months to 60 months were found to be similar to those of muscles in normal subjects and unaffected muscles in hemiparetic subjects.

Energy expenditure and physiological performance of Sudanese cane cutters

The thermal and exercise tolerances of 165 Sudanese cane cutters were measured in the laboratory and related to work performance and productivity in the cane fields. The results showed that the amount of cane cut per minute in the field was significantly correlated with changes in body weight (r = +0-53) during the third hour of work, aerobic energy expenditure (r = + 0-43), and cardiac frequency during work. These variables in turn were associated with predicted maximal power output (VO2 max) measured in the laboratory. The average energy expenditure during cane cutting was 1-66 +/- 0-33 1/min-1 (34-9 kJ/min-1) which represents approximately 60% of the workers predicted VO2 max. This rate of energy expenditure was sustained in the cane fields for at least three hours without significant pauses for rest. The sweat losses measured in 32 cane cutters during the two and three hours of work averaged 637 +/- 221 and 770 +/- 282 g/h-1 respectively, while the mean urine temperature immediately on cessation of effort was 37-74 +/- 0-46 degrees C. Despite the additional environmental heat load of the tropics, it would seem that cane cutters performing a self-paced task demanding heavy physical effort, are able to sustain work levels well in excess of those recommended for most European factory workers without obvious signs of fatigue or heat stress.

Physiological performance and work capacity of Sudanese cane cutters with Schistosoma mansoni infection

Physiological tests of work performance and measurement of field productivity were made in 194 Sudanese cane cutters in order to study the effect of Schistosoma mansoni infection. The cane cutters were selected from two age ranges (16-24 and 25-45 years) and subdivided into three clinical groups: not infected, infected with, and infected without clinical signs of hepatosplenomegaly. Men infected with Schistosoma haemotobium, malaria (blood film), or with hemoglobin levels less than 10 g/100 ml were excluded. There was a statistically significant (P less than 0.002) higher mean hemoglobin concentration in those not infected but the mean difference was less than 1 g/100 ml. Submaximal responses to exercise on a stationary bicycle ergometer, oxygen intake, ventilation, tidal volume, cardiac frequency and estimated maximal aerobic power output calculated both in absolute terms and relative to lean body mass and leg volume were similar in the six groups of cane cutters. No significant differences were found in physique, body composition or in thermoregulatory function tests. The cane cutters were found to have little natural acclimatization to heat in terms of sweating capacity when compared with a group of fully acclimatized Sudanese soldiers. The mean productivity (mean daily weight of cane cut per man) was significantly correlated with the individual's estimated maximum aerobic capacity determined in the laboratory, but not with the degree of S. mansoni infection. The noninfected group was less "efficient" (mean productivity:oxygen intake) during cutting than the infected groups but a larger proportion of the noninfected were in their first season of cutting. There was a positive correlation between the number of seasons' cutting experience and the individual's age, degree of infection and mean productivity. Cane cutters studied in this investigation were a relatively fit, active population from whom the more seriously ill were excluded. These results do not, therefore necessarily reflect the effects of S. mansoni on physiological work capacity and productivity of more static populations in areas of high endemicity.