Identification and engraftment of new bacterial strains by shotgun metagenomic sequence analysis in patients with recurrent Clostridioides difficile infection before and after fecal microbiota transplantation and in healthy human subjects

Background

Recurrent Clostridioides diffícile infection (RCDI) is associated with major bacterial dysbiosis and colitis. Fecal microbiota transplantation (FMT) is a highly effective therapeutic modality for RCDI. While several studies have identified bacterial species associated with resolution of symptoms in patients, characterization of the fecal microbiome at the bacterial strain level in RCDI patients before and after FMT and healthy donors, has been lacking. The aim of this study was to examine the ability of bacterial strains from healthy donors to engraft in the gastrointestinal tract of patients with RCDI following FMT.

Methods

Fecal samples were collected from 22 patients with RCDI before and after FMT and their corresponding healthy donors. Total DNA was extracted from each sample and analyzed by shotgun metagenomic sequencing. The Cosmos-ID analysis platform was used for taxonomic assignment of sequences and calculation of the relative abundance (RA) of bacterial species and strains. From these data, the total number of bacterial strains (BSI), Shannon diversity index, dysbiosis index (DI), and bacterial engraftment factor, were calculated for each strain.

Findings

A marked reduction (p<0·0001) in the RA of total and specific bacterial strains, especially from phylum Firmicutes, was observed in RCDI patients prior to FMT. This change was associated with an increase in the DI (p<0·0001) and in pathobiont bacterial strains from phylum Proteobacteria, such as Escherichia coli O157:H7 and Klebsiella pneumoniae UCI 34. BSI was significantly lower in this group of patients as compared to healthy donors and correlated with the Shannon Index. (p<0·0001). Identification and engraftment of bacterial strains from healthy donors revealed a greater diversity and higher relative abundance of short-chain fatty acid (SCFA)-producing bacterial strains, including Lachnospiraceae bacterium 5_1_63FAA_u_t, Dorea formicigenerans ATCC 27755, Anaerostipes hadrusand others, in RCDI patients after FMT.

Interpretation

These observations identify a group of SCFA-producing bacterial strains from healthy donors that engraft well in patients with RCDI following FMT and are associated with complete resolution of clinical symptoms and bacterial dysbiosis.

Head to head comparison between neurology residents and a mobile medical application for diagnostic accuracy in cognitive neurology

BACKGROUND

A novel Mobile Medical Application (App) App was created on iOS platform (Neurology Dx®) to deduce Differential Diagnoses (DDx) from a set of user selected Symptoms, Signs, Imaging data and Lab findings. The DDx generated by the App was compared for diagnostic accuracy with differentials reasoned by participating neurology residents when presented with same clinical vignettes.

METHODS

Hundred neurology residents in seven leading Neurology centers across India participated in this study. A panel of experts created 60 clinical vignettes of varying levels of difficulty related to Cognitive neurology. Each neurology resident was instructed to formulate DDx from a set of 15 cognitive neurology vignettes. Experts in Cognitive Neurology made the gold standard DDx answers to all 60 clinical vignettes. The differentials generated by the App and neurology residents were then compared with the Gold standard.

RESULTS

Sixty clinical vignettes were tested on 100 neurology residents (15 vignettes each) and also on the App (60 vignettes). The frequency of gold standard high likely answers accurately documented by the residents was 25% compared with 65% by the App (95% CI 33.1-46.3), P < 0.0001. Residents correctly identified the first high likely gold standard answer as their first high likely answer in 35% (95% CI 30.7-36.6) compared with 62% (95% CI 14.1-38.5), P < 0.0001.

CONCLUSION

An App with adequate knowledge-base and appropriate algorithm can augment and complement human diagnostic reasoning in drawing a comprehensive list of DDx in the field of Cognitive Neurology (CTRI/2017/06/008838).

Parkinson's Disease: The Emerging Role of Gut Dysbiosis, Antibiotics, Probiotics, and Fecal Microbiota Transplantation

The role of the microbiome in health and human disease has emerged at the forefront of medicine in the 21st century. Over the last 2 decades evidence has emerged to suggest that inflammation-derived oxidative damage and cytokine induced toxicity may play a significant role in the neuronal damage associated with Parkinson’s disease (PD). Presence of pro-inflammatory cytokines and T cell infiltration has been observed in the brain parenchyma of patients with PD. Furthermore, evidence for inflammatory changes has been reported in the enteric nervous system, the vagus nerve branches and glial cells. The presence of α-synuclein deposits in the post-mortem brain biopsy in patients with PD has further substantiated the role of inflammation in PD. It has been suggested that the α-synuclein misfolding might begin in the gut and spread “prion like” via the vagus nerve into lower brainstem and ultimately to the midbrain; this is known as the Braak hypothesis. It is noteworthy that the presence of gastrointestinal symptoms (constipation, dysphagia, and hypersalivation), altered gut microbiota and leaky gut have been observed in PD patients several years prior to the clinical onset of the disease. These clinical observations have been supported by in vitro studies in mice as well, demonstrating the role of genetic (α-synuclein overexpression) and environmental (gut dysbiosis) factors in the pathogenesis of PD. The restoration of the gut microbiome in patients with PD may alter the clinical progression of PD and this alteration can be accomplished by carefully designed studies using customized probiotics and fecal microbiota transplantation.

Barrett's esophagus and β-carotene therapy: symptomatic improvement in GERD and enhanced HSP70 expression in esophageal mucosa

INTRODUCTION

Epidemiological studies suggest a protective role for β-carotene with several malignancies. Esophageal adenocarcinoma frequently arises from Barrett's esophagus (BE). We postulated that β-carotene therapy maybe protective in BE.

MATERIALS AND METHOD

We conducted a prospective study in which 25 mg of β-carotene was administered daily for six-months to six patients. Each patient underwent upper endoscopy before and after therapy and multiple mucosal biopsies were obtained. Additionally, patients completed a gastroesophageal reflux disease (GERD) symptoms questionnaire before and after therapy and severity score was calculated. To study the effect of β-carotene at molecular level, tissue extracts of the esophageal mucosal biopsy were subjected to assessment of heat-shock protein 70 (HSP70).

RESULTS

A significant (p<0.05) reduction in mean GERD symptoms severity score from 7.0±2.4 to 2.7±1.7 following β-carotene therapy was noted. Measurement of Barrett's segment also revealed a significant reduction in mean length after therapy. In fact, two patients had complete disappearance of intestinal metaplasia. Furthermore, marked enhancement of HSP70 expression was demonstrated in biopsy specimens from Barrett's epithelium in four cases that were tested.

CONCLUSIONS

Long- term β-carotene therapy realizes amelioration of GERD symptoms along with restitution of the histological and molecular changes in esophageal mucosa of patients with BE, associated with concurrent increase in mucosal HSP70 expression.

Serum HSP70: a novel biomarker for early detection of pancreatic cancer

OBJECTIVES

Heat shock protein 70 (HSP70) is overexpressed in human pancreatic cancer cell lines. To determine if serum HSP70 levels are elevated in patients with pancreatic cancer and can function as a biomarker for early detection of pancreatic cancer.

METHODS

Study subjects were divided into 3 groups: histologically proven pancreatic cancer (PC; n = 23), chronic pancreatitis (CP; n = 12), and matched normal control subjects (C; n = 10). Serum HSP70 levels were determined using a novel immunoelectrophoresis method developed and validated by the authors. Significance of difference between the groups was analyzed with analysis of variance (ANOVA). Receiver operating characteristic (ROC) curve analysis was performed to discriminate patients with pancreatic cancer from normal controls.

RESULTS

The mean ± SE serum HSP70 levels in the PC, CP, and C groups were 1.68 ± 0.083 ng/mL, 0.40 ± 0.057 ng/mL, and 0.04 ng/mL, respectively. Serum HSP70 levels in the PC group were significantly higher compared with either the CP or C groups (P < 0.01). The sensitivity and specificity of elevated serum HSP70 in the PC group was 74% and 90%, respectively.

CONCLUSIONS

Serum HSP70 levels are significantly increased in patients with pancreatic cancer and may be useful as an additional biomarker for the detection of pancreatic cancer.

Status epilepticus: why, what, and how

Status epilepticus (SE) is an important neurological emergency with high mortality and morbidity. The first official definition of SE was the product of 10 th Marseilles colloquium held in 1962 which was accepted by International League Against Epilepsy in 1964. There are as many types of SE as of seizures. SE is supposed to result from failure of normal mechanisms that terminate an isolated seizure. In half of the cases, there is no history of epilepsy and SE is precipitated by some intercurrent infection. In children, it is often infection, whereas in adults, the major causes are stroke, hypoxia, metabolic derangements, and alcohol intoxication or drug withdrawal. The treatment of SE aims at termination of SE, prevention of seizure recurrence, management of precipitating causes, and the management of complications. The extent of investigations done should be based on the clinical picture and cost benefit analysis. The first line antiepileptic drugs (AED) for SE include benzodiazepines, phenytoin, phosphenytoin, and sodium valproate. Mortality of SE ranges between 7 and 39% and depends on underlying cause and response to AEDs.

Markers of Inflammation and Lineage on Exfoliated Colonic Cells In Pediatric Inflammatory Bowel Disease

OBJECTIVES

The diagnosis (endoscopy, and biopsy) and continued clinical management of Inflammatory Bowel Disease (IBD), remain highly invasive, expensive, and inconvenient for the pediatric patient. The objective of this study was to see if colonocytes obtained from stools of subjects with IBD and normal controls would demonstrate higher levels of inflammatory markers (Cox 2 in CD45+ and CD45- cells) and if the inflammatory process and treatment effects would be reflected in an altered cytokine expression in the subjects compared to controls.

SETTING

Outpatient hospital based pediatric gastroenterology clinic.

METHODS AND MAIN OUTCOME MEASURES

Stool samples (~ 1 gm), were obtained from 18 children between the ages of 4 and 18 diagnosed with IBD, and from a normal first degree relative. Colonocytes were isolated using the Somatic Cell Sampling Recovery (SCSR) system and assessed for the expression of COX-2, CD-45, IgA, IgG, IL6, IL18, TGF β, TNF, and IL16β using flow cytometry. In addition, levels of COX-2 and cytokeratin 19 transcripts were measured by microwell plate hybridization assay.

RESULTS

Expression of COX-2 and co-expression of IgA and IgG were significantly higher in the IBD cases compared to the controls. In ulcerative colitis, the expression of COX-2 and co-expression of COX-2 and CD45 were greater than that in patients with Crohn's disease. In contrast, cells expressing IgA and IgG were higher in Crohn's. Subjects on immunosuppressants and/or anti-inflammatory medications, expressed significantly lower levels of COX-2 and IL-18 compared to those who were not on treatment.

CONCLUSIONS

This study indicates that the use of disease markers on exfoliated colonic cells can be used for non-invasive assessment of disease status, for follow-up of response to treatment and for forecasting flare-up of disease before its symptomatic manifestations.

Studies on bile acids: The microquantitative separation of cellular bile acids by gas-liquid chromatography

1. A method is described for the quantitative isolation of bile acids from cellular material. Homogenates of rat liver are freeze-dried and extracted exhaustively with 95% (v/v) ethanol containing 0.1% (v/v) of aq. ammonia (sp.gr. 0.88) and purified by anion-exchange chromatography on Amberlyst A-26. 2. The extracted bile acid conjugates are subjected to either of two hydrolytic procedures, one involving chemical and the other enzymic agents. A unique feature in this study is the introduction of an enzyme, a clostridial peptide-bond hydrolase, for the rapid cleavage of bile acid conjugates, replacing the classical drastic chemical hydrolysis with strong alkali. 3. After hydrolysis, free bile acids are methylated and converted into their trifluoroacetates for final determination by gas-liquid chromatography on a triple component column, FS-1265-SE30-NGS. 4. For the purpose of identification of peaks, bile acid methyl esters are converted into their trimethylsilyl ethers by allowing the methyl esters to react with a new and potent silyl donor, bis(trimethylsilyl)acetamide. 5. The technique affords us a means of studying the metabolism of bile acids at the cellular and subcellular levels in tissues.

A clinical, radiological and outcome study of status epilepticus from India

The objective of this study is to evaluate the clinical and radiological characteristics and the outcome of status epilepticus (SE). 117 consecutive patients with SE were evaluated including their demographics, history of epilepsy, antiepileptic drug (AED) default, comorbidities, SE type and duration. The study included 22 children, 77 adults and 18 elderly patients with SE. Blood counts, serum chemistry, ECG, cranial MRI, cerebrospinal fluid and EEG were done. Patients were treated with IV phenytoin, valproate, lorazepam or diazepam as per a fixed protocol and responses to first and second drugs were noted. Death during hospital was recorded. The etiology of SE was infection in 53.8%, drug default in 7.9%, metabolic in 14.5%, stroke in 12.8% and miscellaneous in 11% of patients. 92.3% of patients had convulsive and 7.7% nonconvulsive SE. Cranial MRI was abnormal in 62%. Infection as an etiology was more common in children, drug default and metabolic causes in adults and stroke in adults and elderly. Following first AED, SE was controlled in 50%. 30% of patients remained refractory to second AED which was related to duration of SE and mortality. 29% patients died and death was higher in elderly (44%) compared to children (14%). Acute symptomatic SE is more common in developing countries. Refractory SE is associated with SE duration and mortality.

Status epilepticus in encephalitis: a study of clinical findings, magnetic resonance imaging, and response to antiepileptic drugs

This study evaluates clinical findings, magnetic resonance imaging (MRI), and response to antiepileptic drugs (AEDs) in encephalitis patients with status epilepticus (SE). Encephalitis patients with SE were included and they were grouped into herpes (HSE), Japanese (JE), dengue, and nonspecific encephalitis on the basis of virological studies. The demographic and clinical details, including SE type and duration, were noted. Cranial MRI and cerebrospinal fluid (CSF) were carried out. Response to first, second, and third AEDs were noted and the patients not responding to the second AED were considered refractory SE. The relationships of the mortality and the refractoriness of SE with various clinical findings, MRI, CSF, and the type of encephalitis were evaluated. Thirty SE patients with encephalitis aged 1 to 64 years were included. Nine patients had JE, 4 HSE, 1 dengue, and 16 nonspecific encephalitis. Generalized convulsive SE was present in 26 and nonconvulsive SE in 4 patients. The mean duration of SE was 21 (0.83 to 72) h. MRI was abnormal in 20 patients. A 46.7% of patients responded to the first AED and 36.7% remained refractory to the second AED. In 26.7% patients, the seizure continued even after the third AED. The response to AED was not related to the clinical, MRI, and laboratory variables. Nine patients died and the mortality was related to gender and Glasgow Coma Scale (GCS) score. In encephalitis with SE, 46.7% patients responded to the fist AED and 36.7% remained refractory to the second AED. One third of patients of died, which was related to the depth of coma.

Traditional journal club: a continuing problem

OBJECTIVE

To evaluate the pattern, motivation and facilities for choosing journal club topics by residents in two medical institutions in India.

METHOD

A self-appraisal questionnaire was used to compare motivation for choice of topics, availability of infrastructure, sites and type of articles accessed and formal training in computer based literature search in two medical institutions- a postgraduate institute (PGI) and medical college (MC) which provided mainly specialty and superspecialty training respectively.

RESULTS

One hundred and fifty five out of two hundred and fifty five residents responded to the questionnaire. Super-specialty training was pursued by 58 and specialty training by 97 residents. The residents in PGI more frequently selected journal articles which they considered good and in MC, faculty guidance determined the choice of journal club topics. The super-specialty residents, however, more frequently selected patient management related topics compared to specialty residents. MEDLINE and MD Consult were more frequently accessed by PGI residents where infrastructure and training in literature search were superior to MC.

CONCLUSION

In both the institutions surveyed, journal clubs were of traditional type. Better infrastructure and training at PGI were not reflected in quality of journal club. Successful journal club should focus on current, real patient's problem of most interest to the group.

Studies on the bioavailability of the provitamin A carotenoid, β-carotene, using human exfoliated colonic epithelial cells

The possibility of using exfoliated colonic epithelial cells for assessing the bioavailability of β-carotene was examined. Analysis of exfoliated colonic epithelial cells showed the presence of β-carotene and vitamin A. The β-carotene content was significantly lower in cells from stool samples of subjects on a β-carotene-poor diet than those receiving a single dose of a β-carotene supplement. Colonic epithelial cells isolated from stool samples collected daily during a wash-out period while the subjects were on a β-carotene-poor diet showed a steady decrease in β-carotene content, reaching the lowest value on day 7. Kinetic analysis showed that a single dose of a β-carotene supplement in the form of spirulina (Spirulina platensis) or agathi (Sesbania grandiflora) after the wash-out period caused an increase in the β-carotene content after a lag period of 5–7 d, but the vitamin A levels during these periods were not significantly affected. Analysis of plasma β-carotene concentration also showed similar changes, which correlated with those of exfoliated colonic cells. A relationship between the β-carotene content of the diet and that of the colonic epithelial cells suggests that analysis of the β-carotene content in exfoliated human colonic epithelial cells is a useful non-invasive method to assess the bioavailability of provitamin A β-carotene.

Exfoliated colonic epithelial cells: surrogate targets for evaluation of bioactive food components in cancer prevention

There is significant evidence supporting the hypotheses that lifestyle, diet, and bioactive components in foods are important modifiers of cancer risk. However, our ability to assess host response noninvasively is limited. To overcome this, we have developed a technology to isolate several million viable exfoliated somatic colonic cells from a small sample of stool (0.5-1.0 g) by a procedure known as somatic cell sampling and recovery (SCSR). Orally administered carotenoids appear in these cells several days after consuming the supplement, usually showing a peak concentration between 5-7 d after their ingestion. The time lag observed for the appearance of orally administered carotenoids in SCSR cells corresponds to the turnover rate of the colonic mucosa. This is an example of how changes in cell turnover rates can be carefully assessed using the SCSR system. The specific mechanisms by which individual constituents of diet affect the cancer process are not fully understood. However, host response to dietary constituents may be investigated, noninvasively, by following the modulation of tumor-associated molecular markers in these exfoliated SCSR cells. We have demonstrated the feasibility of using SCSR cells to detect the expression of carcinoembryonic antigen, CD44, and its splice variants, c-myc, c-erbb2, and mutations in the p53 gene. In this regard, SCSR cells are a readily available surrogate cellular target that may serve to monitor changes in cell turnover, differentiation, and expression of cancer-associated biomarkers that are likely to be modulated by bioactive food components.

Global outlook on nutrition and the environment: meeting the challenges of the next millennium

As we enter the new millennium, nearly 800 million of the World's population will remain chronically malnourished. Nearly 200 million children are moderately to severely underweight, while 70 million are severely malnourished. And those who are yet to be born will be faced with the same set of circumstances that predispose them to malnutrition and its consequences. Eradication of nutritional deficiencies among women and children on a global scale are needed to ensure improved quality of life for the next generation of citizens. Primary deficiencies in vitamin A, iron, iodine, calcium, folic acid and trace elements such as zinc are compounded by pollutants caused by human activity. Environmental lead, arsenic, mercury, and other heavy metals that enter the food chain can seriously deplete body stores of iron, vitamin C and other essential nutrients leading to decreased immune defenses, intrauterine growth retardation, impaired psycho-social faculties and other disabilities associated with malnutrition. Increased susceptibilities to communicable diseases, and those provoked by water or insect borne vectors are additional risks encountered by malnourished individuals. Migration of populations from rural to urban centers and the expansion of major metropolitan areas have had a significant and adverse impact on the quality of life of these citizens. In the next 20 years most of the growth in urban populations will be in Asia and Latin America. Urbanization and the resultant burden on limited national resources is a major contributory factor to malnutrition. There are many other lifestyle-associated disabilities such as use of tobacco (cancer) and alcoholism that require active intervention. Within the family unit, socioeconomic factors and the status of women (literacy, economic independence) are major determinants of the quality of life. In the coming century, the World will have to meet these challenges by careful planning and international cooperation.

The induction of SOS function in Escherichia coli K-12/PQ37 by 4-nitroquinoline oxide (4-NQO) and fecapentaenes-12 and -14 is bile salt sensitive: implications for colon carcinogenesis

The response of Escherichia coli to genotoxic agents involves the triggering of a complex system of genes known as the SOS response. In E. coli PQ37, a test organism used for the assessment of genotoxicity, lacZ, the beta-galactosidase gene is placed under the control of sfiA, one of the SOS genes through an operon fusion. The induction of beta-galactosidase activity, when the organism is exposed to genotoxic agents, is an indirect measure of the genotoxic activity of the test compound. Incubation of E. coli PQ37 with either 4-nitroquinoline oxide (4-NQO) or one of the fecal mutagens, fecapentaene-12 or -14 (F-12 or F-14) in the presence of sodium taurocholate or sodium deoxycholate resulted in a significant enhancement of induction of beta-galactosidase activity. The molecular mechanisms of 4-NQO-induced mutagenesis in E. coli are similar to those of the effects of UV light in which both replication-dependent and repair-dependent pathways of mutagenesis exist. Since E. coli PQ37 is excision-repair-deficient, alternate pathways are involved in this system. Bile salts by themselves do not trigger the SOS response, and hence their role in enhancing the SOS-inducing potency of mutagens may involve the potentiation of the cleavage-inactivation of lexA (repressor of SOS) by the protein product of the SOS-controlled gene, recA. The potentiating effect of bile salts on the fecal mutagens, F-12 and F-14, has implications in their suspected role in colon carcinogenesis associated with high-fat, low-fiber diets.

Lupus vulgaris of nose - a case report

Lupus vulgaris which is a mucocutaneous form of Tuberculosis is not an uncommon condi-tion. But the disease resulting in excessive destruction is rare today. We report a case of lupus vulgaris which almost completely destroyed the nose.

Lectin binding to human colonocytes is predictive of colonic neoplasia

OBJECTIVE

The aim of this study was to determine whether lectin binding to exfoliated human colonocytes could be used as a noninvasive test for colorectal polyps or cancer.

METHODS

Colonocytes were harvested from 31 patients (10 controls, 10 with adenomatous polyps, and 11 with cancer), incubated with a panel of fluorescent-labeled lectins, and assayed by flow cytometry.

RESULTS

The lectins jacalin (JAC) and wheat germ agglutinin (WGA) were useful in predicting the presence of a colorectal neoplasm (p = 0.0018 for JAC and p = 0.0099 for WGA). For JAC, sensitivity reached 81% with a specificity of 80%, and for WGA the sensitivity and specificity were both 75%.

CONCLUSIONS

Lectin binding to human colonocytes can predict the presence of malignant and premalignant lesions of the colon, and has potential as a noninvasive screening tool for colorectal neoplasms.

Peripheral ameloblastoma involving tongue-a rare case

Peripheral ameloblastoma is a rare tumour of oral cavity. It presents as a mass without bony continuity. Here we report a unique case of peripheral ameloblastoma involving tongue, with review of relevant literature.

Tumor proliferative fraction in infiltrating duct carcinoma

Deregulated cell proliferation is a key factor in malignancy and therefore may be of prognostic significance. Both Proliferating Cell Nuclear Antigen (PCNA) and silver binding Argyrophilic Nucleolar Organizer Regions (AgNORs) have been established as a valuable reflection of the tissue proliferative compartment and hence could be of value in studying the biologic behavior of malignant cells. In the present study, we evaluated the proliferative activity of 120 infiltrating duct carcinomas by analysing for PCNA and AgNOR expression in relation to pathologic variables. The AgNOR scores were significantly greater in the malignant tissue than in benign lesions. Expression of PCNA was also found to be increased in malignant breast tumors, when compared to controls. A strong positive correlation between PCNA immunoreactivity and AgNORs was evident. There was also a positive correlation between histologic grading and AgNOR score in breast cancer (r = 0.92, p = 0.000). Tumor with elevated AgNOR counts were often poorly differentiated. It is therefore apparent that evaluation of AgNORs and PCNA may help in the elaboration of histopathologic grading of infiltrating duct carcinoma and may be of prognostic significance.

p53 tumor suppressor protein and tissue proliferative fraction in infiltrating duct carcinoma

BACKGROUND AND OBJECTIVES

Breast cancer continues to frustrate oncologists worldwide. In India, it is the second most common neoplasm among women and is increasing in incidence. Several molecular markers have been associated with a poor prognosis in patients with breast cancer, and the presence of these markers is often thought to provide information on the biological behavior of the malignant breast tumor. Much attention has recently been focused on the tumor suppressor gene p53. Mutation or alteration in this gene leads to the loss of negative growth regulation and hence to rapid cell proliferation. The present study was designed to evaluate the connection between expression of the p53 protein and its relation to the tissue proliferative compartment as measured by expression of the proliferating cell nuclear antigen (PCNA).

METHODS

Expression of p53 and PCNA were detected by immunocytochemistry in paraffin-embedded sections of infiltrating duct carcinoma and control breast tissue (normal tissue and adenoma).

RESULTS

A significant correlation was observed between expression of p53 and PCNA. A significant correlation was also observed between expression of p53 and grade of tumor and stage of disease.

CONCLUSIONS

Our results support the hypothesis that accumulation of p53 is associated with a high tumor proliferation rate an association that might be expected in view of the role of wild p53 as a negative regulator of cell proliferation.

Chemoprevention of oral leukoplakia with vitamin A and beta carotene: an assessment

We conducted a double-blind placebo-controlled trial to evaluate the chemopreventive potential of either vitamin A alone or beta carotene alone in subjects with oral leukoplakia in Kerala, India. We randomised 160 fishermen and women with oral precancerous lesions to receive oral vitamin A (retinyl acetate 300,000 IU/week x 12 months, n = 50), or beta carotene (360 mg/week x 12 months, n = 55), or placebo (n = 55). Blood, saliva and urine samples were collected at baseline and at exit to study serum micronutrients and mutagenicity assays. Biopsies of the mucosal lesions at entry were performed for histopathological exclusion of malignancy. The subjects were examined once every 2 months to establish clinical response of lesions and toxicity, if any. The results are based on 43 complaint subjects on placebo, 42 on vitamin A and 46 on beta carotene. The complete regression rates were: 10% in the placebo arm, 52% with vitamin A and 33% with beta carotene (P < 0.0001). Homogeneous leukoplakias and smaller lesions responded better than non-homogeneous and larger lesions. No major toxicities were observed. Half of the responders with beta carotene and two thirds with vitamin A relapsed after stopping supplementation. Serum beta carotene concentration increased substantially with beta carotene administration while with vitamin A supplementation there was no change in serum retinol levels. In the vitamin A treated group there was a significant decrease in serum alpha tocopherol. Vitamin A administration resulted in a significant remission of oral leukoplakia without any side effects of prolonged vitamin A supplementation. The results of this study, as well as those from previous studies, appear to provide strong supporting evidence to justify long term trials with vitamin A in subjects with high-risk leukoplakias with oral cancer as an endpoint.

Expression of the antiapoptotic protein bcl-2 is not dependent on the tumor suppressor p53 protein in Indian breast carcinoma

Tissue homeostasis and the maintenance of cell populations depend on a delicate balance between the rates of cell proliferation and cell death. Programmed cell death or apoptosis is believed to play a major role in physiological processes which, when defective, could contribute to the pathogenesis and progression of tumors. A role for altered programmed cell death in cancer stems from the description of alterations on tumor-associated genes involved in the regulation of apoptosis such as p53 and bcl-2. The p53 gene promotes apoptosis in cells with genetic damage, while bcl-2 is an antiapoptotic gene. It is therefore possible that the balance between p53 and bcl-2 may have significant implications for the pathobiology of breast cancer. This study was therefore undertaken to evaluate the expression of these two proteins with opposite functions and their relation to the total growth fraction of the tumor as measured by PCNA immunoreactivity. A significant correlation was observed between expression of p53 and PCNA. In contrast, bcl-2 expression did not correlate with the expression of p53. There was also no correlation observed between expression of bcl-2 and PCNA. A significant correlation was observed between expression of p53 and the grade of the tumor and stage of the disease. Our results thus support the hypothesis that accumulation of p53 is associated with a high tumor proliferation rate, an association that might be expected in view of the role of wild-type p53 as a negative regulator of cell proliferation. Another important observation was the lack of relationship between bcl-2 expression and PCNA immunoreactivity, supporting the hypothesis that bcl-2 is not a major regulator of proliferation.

Effects of dietary fat and fiber on plasma and urine androgens and estrogens in men: a controlled feeding study

We conducted a controlled feeding study to evaluate the effects of fat and fiber consumption on plasma and urine sex hormones in men. The study had a crossover design and included 43 healthy men aged 19-56 y. Men were initially randomly assigned to either a low-fat, high-fiber or high-fat, low-fiber diet for 10 wk and after a 2-wk washout period crossed over to the other diet. The energy content of diets was varied to maintain constant body weight but averaged approximately 13.3 MJ (3170 kcal)/d on both diets. The low-fat diet provided 18.8% of energy from fat with a ratio of polyunsaturated to saturated fat (P:S) of 1.3, whereas the high-fat diet provided 41.0% of energy from fat with a P:S of 0.6. Total dietary fiber consumption from the low- and high-fat diets averaged 4.6 and 2.0 g.MJ-1.d-1, respectively. Mean plasma concentrations of total and sex-hormone-binding-globulin (SHBG)-bound testosterone were 13% and 15% higher, respectively, on the high-fat, low-fiber diet and the difference from the low-fat, high-fiber diet was significant for the SHBG-bound fraction (P = 0.04). Men's daily urinary excretion of testosterone also was 13% higher with the high-fat, low-fiber diet than with the low-fat, high-fiber diet (P = 0.01). Conversely, their urinary excretion of estradiol and estrone and their 2-hydroxy metabolites were 12-28% lower with the high-fat, low-fiber diet (P < or = 0.01). Results of this study suggest that diet may alter endogenous sex hormone metabolism in men.

Uptake and distribution of carotenoids, retinol, and tocopherols in human colonic epithelial cells in vivo

Studies suggest that micronutrients such as the tocopherols, retinol, and the carotenoids have a chemopreventive action against colonic carcinogenesis and that they may be essential for the functioning and structural integrity of the gastrointestinal epithelium. In this study, we have determined the concentrations of tocopherols, retinol, and the carotenoids in human colonic epithelial cells using a noninvasive procedure developed in this laboratory (G.P. Albaugh et al., Int. J. Cancer, 52: 347-350, 1992). In subjects on a normal diet, almost all of these micronutrients were restricted to cells in the density range of rho 1.065-1.090 and rho 1.090-1.110. The lighter fraction (rho 1.033-1.064), representing the most senescent subpopulation, retained these micronutrients only when the subjects were on diets rich in vegetables. Cells isolated from subjects on their usual diets gave the following values expressed as ng/10(7) cells: alpha-tocopherol, 93-151; gamma-tocopherol, 152-280; retinol, 12-20; lutein, 4-18; cryptoxanthin, not detected; lycopene, 0-17; alpha-carotene, 3-7; and beta-carotene, 6-9. Peak responses in specific micronutrients following 5 days on a high carotenoid diet showed a lag period of at least 5 days, corresponding to the turnover rates of the epithelium itself. The evidence suggests that uptake of these micronutrients by the colonic mucosa occurs in the deep cryptal zone where the actively proliferating cells extract the nutrients from the systemic circulation.

Selective responses of hormones involved in carbohydrate and lipid metabolism and properties of erythrocyte membranes during the menstrual cycle in premenopausal women consuming moderate amounts of alcohol

The effects of chronic consumption of moderate amounts of alcohol on hormones associated with lipid and carbohydrate metabolism, plasma concentrations of triacylglycerol and cholesterol, insulin receptors on erythrocyte membranes, and erythrocyte membrane fluidity were studied during three phases of the menstrual cycle in 37 premenopausal women. Subjects were given either 30 g ethanol or an equienergetic fruit juice for three menstrual cycles in a crossover design. Blood samples were analyzed during the luteal, midcycle, and follicular phases. Administration of alcohol induced a significant rise in plasma glucagon and cortisol uniformly across the entire menstrual cycle. A similar rise in plasma growth hormone was observed at midcycle during the period when subjects consumed alcohol. A marginal effect was observed on cholesterol and somatomedin C concentrations. Insulin binding to erythrocyte ghosts was not affected by either alcohol or menstrual-cycle phase. Erythrocyte membranes were more fluid during the follicular phase than during the luteal phase of the menstrual cycle when the women were consuming the alcohol. There were no perceptible interactions between alcohol and phases of the menstrual cycle for the indexes studied, except membrane fluidity.

Flow cytometric identification of cell surface markers on cultured human colonic cell lines using monoclonal antibodies

BACKGROUND

The expression of tumor-associated cell surface antigens is a reflection of the state of cell differentiation of tumor cells in culture.

METHOD

Monoclonal antibodies (MoAbs) against the tumor-associated antigens carcinoembryonic antigen (CEA) and CA19-9 and the extracellular matrix protein CD44 were used to label the cell surface of human colonic cells in culture. The binding of each antibody to its respective antigen was measured by fluorescence-activated flow cytometry and expressed as a percentage of positive cells.

RESULTS

The human colon adenocarcinoma cell (HCAC) line, LS-180, showed strong binding with CEA (81%), CA 19-9 (87%), and CD44 (83%). LS-174t cells, a trypsinized variant of LS-180 cells, showed less binding with CEA (66%) and CA 19-9 (49%), but no binding with CD44. With cells from HCAC line HT-29, antigen expression was highly variable for CEA (13% +/- 18) and CD44 (31% +/- 35) but was consistently positive for CA19-9 (33% +/- 13). The expression of CEA in the Caco-2 cell line was weak (24%), whereas there was no expression of CA19-9 and CD44. Normal human colon fibroblast cells (CCD-18Co) did not recognize the monoclonal antibodies to CEA or CA 19-9, but were strongly positive with the CD44 antibody (97%).

CONCLUSIONS

These results support the concept that the expression of the tumor associated markers CEA and CA19-9 and the cell surface marker CD44 on human colonic cell lines varies with the degree of cellular differentiation. Carcinoembryonic antigen and/or CA19-9 were expressed in all four human colon adenocarcinoma cell lines, but not in the normal colon fibroblast cells (CCD-18Co). Using these two MoAbs appeared to be a more reliable measure of the state of differentiation of human colon adenocarcinoma cells.

Evaluation of chemoprevention of oral cancer with Spirulina fusiformis

The blue-green microalgae Spirulina, used in daily diets of natives in Africa and America, have been found to be a rich natural source of proteins, carotenoids, and other micronutrients. Experimental studies in animal models have demonstrated an inhibitory effect of Spirulina algae on oral carcinogenesis. Studies among preschool children in India have demonstrated Spirulina fusiformis (SF) to be an effective source of dietary vitamin A. We evaluated the chemopreventive activity of SF (1 g/day for 12 mos) in reversing oral leukoplakia in pan tobacco chewers in Kerala, India. Complete regression of lesions was observed in 20 of 44 (45%) evaluable subjects supplemented with SF, as opposed to 3 of 43 (7%) in the placebo arm (p < 0.0001). When stratified by type of leukoplakia, the response was more pronounced in homogeneous lesions: complete regression was seen in 16 of 28 (57%) subjects with homogeneous leukoplakia, 2 of 8 with erythroplakia, 2 of 4 with verrucous leukoplakia, and 0 of 4 with ulcerated and nodular lesions. Within one year of discontinuing supplements, 9 of 20 (45%) complete responders with SF developed recurrent lesions. Supplementation with SF did not result in increased serum concentration of retinol or beta-carotene, nor was it associated with toxicity. This is the first human study evaluating the chemopreventive potential of SF. More studies in different settings and different populations are needed for further evaluation.

Relative genotoxic activities of pesticides evaluated by a modified SOS microplate assay

The genotoxic activities of 47 pesticides were determined using a modified SOS microplate assay in which the induction of beta-galactosidase in E. coli PQ37 was used as a quantitative measure of genotoxic activity. The results were compared with those obtained with anethole, curcumin, and capsaicin, a few examples of naturally occurring compounds present in foods. The assays were conducted with pesticides dissolved either in a suitable solvent, such as 10% DMSO in physiological saline or dispersed in sodium taurocholate micelles, to simulate conditions in the small intestine from where these substances are normally absorbed from the diet. 4-Nitroquinoline oxide (4-NQO) served as the reference standard of a direct acting mutagen. In micellar form, 4-NQO and 25 of the 47 pesticides tested showed significantly higher genotoxic activities than when they were tested in an organic solvent. In micellar form the SOS inducing potency of 4-NQO was almost twice as high as in 10% DMSO in physiological saline. In taurocholate micelles, the five most active compounds had activities in the range of 1,234-3,765 units/mumol and in the order of decreasing activities they were ranked as follows: malathion > dichlorvos > lindane > chlordane > endrin. They were significantly less active than 4-NQO (less than 40%). In micellar solution the naturally occurring compounds, anethole, curcumin, and capsaicin gave activities of 4,594, 928, and 809 units/mumol, respectively. These studies show that genotoxicity may depend upon the environment in which cells are exposed to these potential genotoxins. It appears that testing of the more hydrophobic compounds, both synthetic and naturally occurring, are needed.

Isolation and HPLC of N-epsilon-lithocholyl lysine as its fluorescamine and dimethylaminoazobenzene isothiocyanate derivatives

N-epsilon-lithocholyl lysine (NELL) is a component of tissue-bound lithocholic acid (TBL). The isolation of NELL from native protein sources was simulated by hydrolysis of lithocholyl-bovine serum albumin (BSA) (synthesized by coupling lithocholyl-N-hydroxysuccinimide to fatty acid-free BSA) by digestion with a mixture of 6N HCl-propionic acid at 70 C for 3 h under partial vacuum. NELL was isolated on a reversed phase Sep-Pak C18 column and converted to either a fluorophor with fluorescamine or to a chromophor with dimethylaminoazobenzene isothiocyanate for subsequent HPLC using appropriate fluorescence or UV/visible absorption detectors. The procedure described here is quantitative, highly sensitive, and not dependent upon the use of Clostridial cholanoylamino acid hydrolase, the activity of which is sometimes blocked by steric hindrance on the substrate. Using this procedure we have demonstrated the presence of TBL in native histones.

Quantitative assessment of groundwater quality using a biological indicator: some preliminary observations

The genotoxicity of groundwater was evaluated, using a novel application of the SOS microplate assay (SOSMA). Organic residues were extracted from groundwater samples from Maryland, Pennsylvania, and Delaware by using C-18 bonded silica solid phase extraction tubes. Total organic carbon content (TOC) of water samples was also determined. The genotoxicity of the extracts was determined by the SOSMA. Relative activity (RA) as determined by the SOSMA is a quantitative measure of genotoxicity based on a comparison to the activity of the mutagen, 4-nitroquinoline oxide. Low levels of RA (about 2x background) were detected in waters from sites within these states. There was considerable temporal and spatial variation in the observed RA, but no definite patterns were observed in the variation. Between sampling sites there was a positive correlation between RA and TOC; however, this relationship appeared to be reversed occasionally within a sampling site. The extraction and bioassay methods provide an easy and relatively inexpensive means of determining water quality.

Fecal bile acids and neutral sterols in the cotton-top tamarin (Saguinus oedipus)

1. The cotton-top tamarin (Saguinus oedipus), a small New World primate susceptible to spontaneous development of colon cancer, was studied for its fecal neutral sterol and bile salt composition. 2. Standardization procedures to establish the effect of exposure of the stool to room temperature air for various time-periods showed no significant effects on the neutral sterol and bile salt composition of the samples. 3. Microbial degradation of cholesterol and bile acids to secondary metabolites showed a progressive rise during the first year of life after which some degree of homeostasis was observed. 4. The proportion of cholesterol that remained unmetabolized by colonic microflora was in excess of 50%, an amount that was significantly higher than in man and other higher primates. 5. Ursodeoxycholic acid was identified as a significant (12%) component of fecal bile acids in this species. 6. Secondary bile acids formed by the action of enteric microflora were also significantly lower than levels found in man and other animals.

Dietary fish oil-induced changes in the distribution of alpha-tocopherol, retinol, and beta-carotene in plasma, red blood cells, and platelets: modulation by vitamin E

Healthy men (ages 24-57 y) were fed a controlled basal diet supplemented with 15 g/d of placebo oil (PO) for 10 wk followed by 15 g/d of fish-oil concentrate (FO) (fortified with 15 mg all-rac-tocopherol) for 10 wk without additional alpha-tocopherol and the last 8 wk with 200 mg alpha-tocopherol/d (FO+E). Compared with PO, FO raised plasma malondialdehyde; lowered alpha-tocopherol in plasma, red blood cells, and platelets; and raised plasma and platelet beta-carotene. Supplementation with additional alpha-tocopherol (FO+E) not only restored tocopherol concentrations but also reversed the rise in beta-carotene. The response in retinol, particularly in platelets, showed an inverse relationship to beta-carotene, alpha-tocopherol exhibiting a modulating effect on these changes. From these observations it is postulated that platelets may be a significant extraintestinal site of retinol formation from beta-carotene.

Effects of alcohol consumption on plasma and urinary hormone concentrations in premenopausal women

BACKGROUND

Most epidemiologic studies of the relationship between alcohol consumption and breast cancer risk over the past decade have shown that persons who consume a moderate amount of alcohol are at 40%-100% greater risk of breast cancer than those who do not consume alcohol. Dose-response effects have been observed, but no causal relationship has been established.

PURPOSE

This study examines the hypothesis that alcohol consumption affects levels of reproductive hormones.

METHODS

A controlled-diet study lasting for six consecutive menstrual cycles was conducted. Participants were randomly assigned to two groups, and a crossover design was used. During the last three menstrual cycles, alcohol consumption of the two groups was reversed. Thirty-four premenopausal women, aged 21-40 years, with a history of regular menstrual cycles, consumed 30 g of ethanol (equivalent to approximately two average drinks) per day for three menstrual cycles and no alcohol for the other three. All food and alcohol consumed were provided by the study. Caloric intake was monitored to ensure that each woman would maintain body weight at approximately the baseline level. Hormone assays were performed on pooled plasma or 24-hour urine specimens collected during the follicular (days 5-7), peri-ovulatory (days 12-15), and mid-luteal (days 21-23) phases of the third menstrual cycle for subjects on each diet.

RESULTS

Alcohol consumption was associated with statistically significant increases in levels of several hormones. Plasma dehydroepiandrosterone sulfate levels were 7.0% higher in the follicular phase (P = .05). In the peri-ovulatory phase, there were increases of 21.2% (P = .01) in plasma estrone levels, 27.5% (P = .01) in plasma estradiol levels, and 31.9% (P = .009) in urinary estradiol levels. In the luteal phase, urinary estrone levels rose 15.2% (P = .05), estradiol levels increased 21.6% (P = .02), and estriol levels rose 29.1% (P = .03). No changes were found in the percent of bioavailable estradiol, defined by the sum of percent free estradiol and percent albumin-bound estradiol. However, increased total estradiol levels in the peri-ovulatory phase suggest elevated absolute amounts of bioavailable estradiol.

CONCLUSION

This study has shown increases in total estrogen levels and amount of bioavailable estrogens in association with alcohol consumption in premenopausal women.

IMPLICATION

This possible explanatory mechanism for a positive association between alcohol consumption and breast cancer risk merits further investigation.

Ingestion of marine oil reduces excretion of 11-dehydrothromboxane B2, an index of intravascular production of thromboxane A2

We evaluated the effect of anchovy oil supplementation on the endogenous production of thromboxane A2 by measuring the excretion of its stable metabolite, 11-dehydrothromboxane B2 (11-DTXB2), in 24-h urine. In a longitudinal study, 35 male volunteers consumed a controlled basal diet for two experimental periods lasting a total of 20 weeks. During period 1 (10 weeks) the diet was supplemented with placebo (PO) capsules (15 x 1 g/d) consisting of a blend of fats approaching the fatty acid profile of the basal diet. During period 2 the subjects received 15 x 1 g/d capsules of fish oil concentrate (FOC). PO and FOC capsules contained 1 mg alpha-tocopherol per gram of fat as antioxidant. A 38% reduction of 11-DTXB2 excretion was observed after 10 weeks of FOC supplementation (period 2, n-6/n-3 PUFA ratio = 2.3), compared to an identical period of PO supplementation (period 1, n-6/n-3 = 12.5), p = 0.0001. The 11-DTXB2 excretion reduction (delta) fits the quadratic equation delta = 136.0038-0.3178(tx1)-0.0002(tx1)2, (R2 = 0.8944), where tx1 is the excretion rate at the end of period 1. This finding supports the hypothesis that the antithrombotic effect of marine oil is mediated, at least in part, by diet-induced shifts in the eicosanoid system.

Effects of dietary fibre on faecal steroid measurements in baboons (Papio cynocephalus cynocephalus)

A study was conducted in captive baboons to determine (i) the impact of cereal dietary fibre on faecal progestogen excretion, and (ii) whether means of controlling dietary effects could be identified. Blood was collected on 3 days per week and faeces on 5 days per week from four unanesthetized cyclic female baboons, consecutively fed three diets of 5, 10 and 20% fibre for 90 days per diet. A 2 day lag time was detected before progesterone in the blood appeared in the faeces, regardless of diet (mean correlation was 0.62, P = 0.002). Increased dietary fibre had a negative effect on progestogen excretion (P < 0.004). Correspondence between blood and faecal progestogens was consistently greatest and the effect of dietary fibre least when faecal progestogens were expressed g-1 dry faeces. Several means of indexing faecal steroid excretion rates were examined including dehydroepiandrosterone (DHEA) and a number of byproducts of cholesterol metabolism. The cholesterol metabolite, cholestanone, was positively correlated with dietary fibre (r = 0.27; P < 0.04). Multiplying faecal progestogen concentration by the cholestanone g-1 dry faeces concentration increased the correlation between serum and cholestanone-indexed faecal progestogens (r = 0.78, P = 0.0001) compared with nonindexed progestogens (r = 0.71, P = 0.0001). We conclude that expressing faecal progestogens g-1 dry faeces may be sufficient and the most cost-effective method for controlling for most dietary effects when the objective is monitoring longitudinal endocrine status in baboons. However, it may be appropriate to express faecal progestogens by cholestanone concentrations when increased precision is needed to overcome the effects of profound variations in dietary fibre.

Isolation of exfoliated colonic epithelial cells, a novel, non-invasive approach to the study of cellular markers

Human stool is a heterogeneous mixture of non-digestible food residues, bacteria, cells exfoliated from the gastrointestinal mucosa and other secretory products. We have demonstrated that fresh human stools dispersed in a buffered saline solution can be fractionated over Percoll/BSA gradients to yield 9 discrete bands of cells in the density range of rho 1.033 to 1.139 and which could be further purified over Histopaque 1077. Enzyme-linked immunoassays (ELISA) for colon-specific antigen (CSA) and cytokeratins (CK) were positive. Western blot analysis showed the presence of 3 cytokeratin bands in the 40-kDa to 60-kDa range suggestive of cytokeratins 8, 18, and 19. Fluorescence flow-cytometric analysis of these cells using antibodies against CSA, CK, the blood-group antigens, carcinoembryonic antigen (CEA), non-mucus-secreting columnar-epithelium-specific MAb PR1A3, and to mucus-secreting colonic-epithelium-specific MAb PR5D5 showed varying degrees of reactivity. Expression of the blood-group phenotype suggests that cells from the proximal half of the colon had survived the transit, since in the adult expression of this marker is limited to cells from the proximal region of the colon. In this report we demonstrate the feasibility of studying, non-invasively, cell-specific markers on exfoliated cells isolated from stools. The evidence strongly suggests that almost all the cells are of colonic origin.

Effect of lithocholic acid feeding on plasma lipoproteins and binding of radioiodinated human lipoproteins to hepatic membranes in rats

1. Male Sprague-Dawley rats fed diets containing 0.25% lithocholic acid for 6 weeks exhibited elevated serum cholesterol. 2. The rats were fed diets containing 5 or 20% fat with and without the lithocholate and/or oxytetracycline-HCl. 3. The cholesterol elevation was associated with high density lipoprotein (HDL) and not very low density lipoprotein (VLDL) or low density lipoprotein (LDL). 4. Specific binding of human [125I]HDL to hepatic membranes was lowered in lithocholate-fed rats, but binding of human [125I]LDL to these membranes was not affected.

Effect of dietary fat on length of the follicular phase of the menstrual cycle in a controlled diet setting

The length of the follicular phase of the menstrual cycle (defined as the time from the first day of menses until the day of urinary LH peak, inclusive) was examined in 30 healthy, premenopausal women. The women consumed defined, weight maintaining diets, with a ratio of polyunsaturated to saturated fatty acids (P/S ratio) of either 0.3 or 1.0. Both P/S groups consumed a high fat diet (40% energy from fat) for 4 menstrual cycles, followed by 4 menstrual cycles of a low fat diet (20% energy from fat). There was a significant increase (P less than 0.006) in the length of the follicular phase of the menstrual cycle during consumption of the low fat diet. Two thirds of the women showed increases in follicular phase length with an average increase of 1.9 days.

Increased vitamin E intake restores fish-oil-induced suppressed blastogenesis of mitogen-stimulated T lymphocytes

We sought to determine whether fish-oil supplementation would suppress blastogenesis in vitro of concanavalin A (ConA)-stimulated peripheral blood mononuclear cells (PBMCs) and, if so, whether it could be reversed with increased intake of vitamin E. Healthy males ate a controlled basal diet providing a total of 40% of energy from fat when fed in conjunction with 15 g/d of either placebo oil (PO) or fish-oil concentrate (FOC) fortified with 15 mg alpha-tocopherol/d for three periods. The subjects were supplemented with PO for 10 wk (PO), with FOC for 10 wk (FOC), and with FOC plus an additional 200 mg alpha-tocopherol/d for 8 wk (FOC+E). During FOC supplementation mitogenic responsiveness of PBMCs to ConA was suppressed, but this effect was reversed by concurrent supplementation with all-rac-alpha-tocopherol (FOC+E). There was a significant positive relationship (P less than 0.001) between plasma alpha-tocopherol concentrations and responsiveness of T lymphocytes to ConA.

Effects of omega 3 fatty acids and vitamin E on hormones involved in carbohydrate and lipid metabolism in men

Forty healthy men were fed diets providing 40% of energy from fat and a minimum of 25 mg vitamin E for 28 wk. During the first 10 wk diets were supplemented with placebo, 15 g mixed fat/d. During the second 10 wk placebo was replaced by 15 g fish-oil concentrate/d. During the last 8 wk 200 mg vitamin E/d was added to fish oil. Compared with placebo, fish-oil feeding significantly increased plasma glucose and decreased triacylglycerol, insulin, glucagon, growth hormone, and somatomedin C. The changes in plasma cholesterol, cortisol, and dehydroepiandrosterone sulphate (DHEA-S) were not significant. Fish oil plus vitamin E further decreased insulin, growth hormone, and DHEA-S and reversed the effect of fish-oil on somatomedin C. The changes in glucose, glucagon, growth hormone, and cortisol were not significant. Thus, changes in plasma glucose and lipids caused by dietary fish oil alone and with fish oil plus vitamin E appear to be due to alterations in hormones involved in carbohydrate and lipid metabolism.

Human stools as a source of viable colonic epithelial cells

Human stools consist of a mixture of undigested food residues, colonic microflora, and cellular components shed from the walls of the gastrointestinal tract. The cellular components are made up mostly of terminally differentiated colonic epithelial cells. Using a combination of Percoll density gradient centrifugation and countercurrent centrifugal elutriation, it is now possible to recover these cells as an enriched fraction from fresh human stools. Cells can be visualized on heat-fixed smears of the enriched fractions stained with modified Wright's stain. The enrichment process is optimized by following the segregation of eukaryotic cells as determined by an ELISA technique using monoclonal antibodies against human double-stranded DNA. This work, demonstrating the feasibility of isolating intact colonic cells from stools, has important applications as a noninvasive approach to the biology of exfoliated cells from the gastrointestinal tract.