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Biomedical subjects

J Little

Publications and source records attributed to J Little.

At least 37 records · Page 2Linked to original sources
PubMed2001

APACC, a French prospective study on aspirin efficacy in reducing colorectal adenoma recurrence: design and baseline findings.

UNLABELLED: Colorectal cancer is the second most frequent cause of death from cancer in western countries. Many lines of evidence suggest that non-steroidal anti-inflammatory drugs (NSAIDs) may offer chemoprevention against colorectal cancer. A multicentre, double-blind, randomized, controlled trial is underway to determine the efficacy of regular aspirin intake (160 or 300 mg/day) in reducing colorectal adenoma recurrence. We now report the baseline characteristics of subjects enrolled into the trial. RESULTS: A total of 618 polyps were excised from 274 patients at the baseline colonoscopy. Men had on average (+/-SD) 2.5 +/- 1.8 polyps per subject and women had 1.7 +/- 1.2. Ninety-one (33.7%) had three or more adenomas and 183 (67.8%) had more than one adenoma measuring 10 mm or more in diameter. The mean (+/-SD) age of the subjects was 57.7 (+/- 9.4) years. Sixty-seven (24.9%) reported that they had previously had adenoma(s), 95 (35.2%) reported a family history of colorectal cancer and 41 (15.2%) a family history of colorectal adenomas. PERSPECTIVE: All subjects will undergo a one-year clearance colonoscopy by February 2001. Clinical, molecular biological and dietary data will enable us to investigate other factors influencing the recurrence of adenomas in this group of high-risk subjects.

Adenoma↗
PubMed2000

N-acetyltransferase polymorphisms and colorectal cancer: a HuGE review.

The two expressed genes coding for N-acetyltransferase (NAT) activity, NAT1 and NAT2, are located on chromosome 8 at 8p21.3-23.1 and are polymorphic. Both enzymes are capable of N-acetylation, O-acetylation, and N,O-acetylation and are implicated in the activation and detoxification of known carcinogens. Single base-pair substitutions in NAT2 tend to occur in combination with other substitutions within the gene. As yet, less work has been done to characterize NAT1 allelic variants. Various methods for the detection of the reported polymorphisms exist. It is important to select a method that is appropriate to the population being studied. The functional significance of many NAT allelic variants has not been determined. Geographic and ethnic variation in the frequency of NAT2 genotypes associated with fast or intermediate acetylation has been observed. Insufficient data for NAT1 genotypes are available to reveal a clear geographic pattern. No consistent association has been found between acetylator phenotype or genotype and colorectal cancer. The lack of consistency can in part be accounted for by methodological factors, including limited statistical power. Possible interactions between the NAT genes and either environmental exposures or other polymorphic genes encoding xenobiotic metabolizing enzymes have been investigated in only a minority of these studies, and these studies have lacked statistical power to detect interactions.

Acetyltransferases↗
PubMed2000

Glutathione S-transferase polymorphisms and colorectal cancer: a HuGE review.

The genes glutathione S-transferase M1 (GSTM1) (chromosome 1p13.3) and glutathione S-transferase T1 (GSTT1) (22q11.2) code for cytosolic enzymes glutathione S-transferase (GST)-mu and GST-theta, respectively, which are involved in phase 2 metabolism. Both genes may be deleted. There is geographic and ethnic variation in genotype frequencies for both genes. In developed countries, colorectal cancer is the second most common cancer. Colorectal cancer has been inconsistently associated with polycyclic aromatic hydrocarbons in diet and tobacco. Because GST enzymes are involved in polycyclic aromatic hydrocarbon metabolism, it has been postulated that genotype may modify colorectal cancer risk associated with polycyclic aromatic hydrocarbon exposure. No consistent associations between GSTM1 or GSTT1 genotype and colorectal cancer have been observed. However, most studies have methodological limitations. Few have investigated gene-environment interactions. No interactions between GSTM1 or GSTT1 genotype and smoking and colorectal cancer risk have been reported. One polyp study suggests an interaction between GSTM1 genotype and smoking. Two studies suggest increased disease risk in subjects with high meat intake and GST nonnull genotype, contrary to the underlying hypothesis. One study suggests a strong inverse relation between colorectal adenomas and broccoli consumption, particularly in subjects who are GSTM1 null. These finding require confirmation. Methods for determining GSTM1 and GSTT1 genotype are well established. Population testing is not currently justified.

Chromosomes, Human, Pair 1↗
PubMed2000

Systematic review of epidemiological studies on meat, dairy products and egg consumption and risk of colorectal adenomas.

In view of the direct contact between food residues and metabolites and the large bowel mucosa, it might be expected that food consumption patterns would affect the risk of colorectal carcinogenesis. Many lines of evidence support the adenoma-carcinoma sequence as the major mechanism of colorectal carcinogenesis. The present study aimed to investigate the role of foods of animal origin such as meat, dairy products and eggs in the early stages of colorectal carcinogenesis. Eleven case-control and two cohort studies on colorectal polyps and meat, dairy products and eggs were identified. A quantitative review of these studies and a meta-analysis were carried out. The combined odds ratios suggest a positive association between the risk of colorectal polyps and beef consumption and a negative association with fish or combined poultry/fish consumption. An increase in the ratio of the consumption of red meat to consumption of fish/chicken was associated with an increase in the colorectal polyp risk. Neither dairy product nor egg consumption had a substantial effect on the development of colorectal polyps. These results suggest that dietary factors associated with polyp development may be not the same as those associated with cancer.

Adenoma↗
PubMed1999

Risk factors for meningioma in adults: a case-control study in northeast China.

A hospital case-control study of meningioma was conducted in Heilongjiang Province in northeast China between September 1989 and December 1996. It included 183 cases of newly diagnosed primary meningioma and 366 individually matched hospital controls with non-neoplastic and non-neurological disease selected from six major hospitals. Cases and controls were matched by sex, age and area of residence and interviewed in the hospital wards to obtain information on medical history, occupation and lifestyle. No association with liquor or beer consumption was apparent. Cigarette smoking was positively associated with meningioma risk in women but not in men. In women, compared with non-smokers, the adjusted OR for pack-years of smoking above the median (124) was 6.2 (CI 2.04-18.87). Both of these observations contrast with the results of a study of glioma in the same population, using similar methods. The risk of meningioma was positively associated with reported occupational exposure to lead, tin, cadmium and ionising radiation in both genders.

Adult↗
PubMed1999

Role of medical history in brain tumour development. Results from the international adult brain tumour study.

In an international population-based case-control study carried out in 8 centres in 6 countries, we investigated the role of specific medical conditions in the aetiology of brain tumours in adults. Recruited were 1,178 glioma and 331 meningioma cases and 2,493 age- and gender-matched population controls. Only medical conditions occurring at least 2 years before brain tumour diagnosis were considered. Relative risks (RRs) and 95% confidence intervals (CIs) were estimated using a conditional logistic regression model. Heterogeneity between centres was tested. No association between meningioma and previous medical conditions was observed. For glioma, there was an increased risk associated with epilepsy (RR = 6.55, 95% CI 3.40-12.63), but this was considerably weaker for epilepsy of more than 20 years duration. The risk remained elevated after adjustment for use of anti-epileptic drugs. There was a statistically significant inverse association between glioma and all allergic diseases combined (RR = 0.59, 95% CI 0.49-0.71); this was also observed for specific allergic conditions, namely, asthma and eczema. Subjects who reported a history of infectious diseases (e.g., colds, flu) showed a 30% reduction in risk (RR = 0.72, 95% CI 0.61-0.85). The decreased risks for glioma in subjects reporting a history of allergic conditions or infectious diseases may indicate an influence of immunological factors on the development of glioma. The association between glioma and epilepsy has to be interpreted cautiously and needs further investigation.

Adult↗
PubMed1999

Hypobaric ocular trauma from a Popper.

We have observed 3 cases of ocular trauma in children that were caused by an atypical, hypobaric mechanism induced by a toy called a Popper. When we initially notified the United States Consumer Product Safety Commission in 1990, Poppers disappeared from store shelves. We are concerned that this potentially harmful toy is making a comeback in 1998 (Smilemakers Inc, Spartanburg, SC; June-July 1998 catalog, p. 57). In 1990, packaged poppers cautioned against applying to face or skin; we are not sure that such warnings accompany current Poppers.

Barotrauma↗
PubMed1999

Bronchial hyperresponsiveness and adult onset wheeze: the influence of atopy.

The commonly held belief that adult onset wheezing illness is primarily nonatopic in nature suggests that the role of atopy in the pathophysiology of bronchial hyperresponsiveness (BHR) in adult onset wheeze may be minimal. This study examined risk factors for BHR (BHR: provocative dose causing a 20% fall in forced expiratory volume in one second PD20 < or =16.38 micromol methacholine) among 82 subjects with adult onset wheeze and among 191 subjects who had never wheezed. Subjects were identified from a cohort of subjects aged 39-45 yrs who were known to have had no childhood wheeze and who were involved in a 30 yr follow-up survey. Risk factors for BHR were examined among all subjects with BHR and among subjects with BHR stratified according to whether or not they had ever wheezed. The prevalence of BHR was 40% (33/82) among the subjects with adult onset wheeze and 11% (21/191) among the subjects who had never wheezed. Lower baseline lung function (odds ratio (OR) = 0.94; 95% confidence interval (CI) = 0.92-0.97 per unit forced expiratory volume (FEV1)% predicted) and atopy (OR = 7.23; CI = 2.53-20.64 for all three measures of atopic compared to nonatopic) were associated with BHR, while smoking and family history showed no statistically significant relation to BHR. This pattern was also apparent in analyses stratified by symptom status. A family history of atopy increased the risk that BHR was accompanied by wheezing symptoms (OR = 4.75; CI = 1.53-14.72 for more than one affected relative compared to no affected relatives). These findings suggest that atopy is associated with bronchial hyperresponsiveness in adults known to have had no childhood wheeze. A familial factor reflecting genetic influences and/or shared environmental factors may influence whether bronchial hyperresponsiveness is associated with symptoms.

Adolescent↗
PubMed1999

Systematic review of cancer treatment programmes in remote and rural areas.

In an attempt to ensure high quality cancer treatment for all patients in the UK, care is being centralized in specialist centres and units. For patients in outlying areas, however, access problems may adversely affect treatment. In an attempt to assess alternative methods of delivering cancer care, this paper reviews published evidence about programmes that have set out to provide oncology services in remote and rural areas in order to identify evidence of effectiveness and problems. Keyword and textword searches of on-line databases (MEDLINE, EMBASE, HEALTHSTAR and CINAHL) from 1978 to 1997 and manual searches of references were conducted. Fifteen papers reported evaluations of oncology outreach programmes, tele-oncology programmes and rural hospital initiatives. All studies were small and only two were controlled, so evidence was suggestive rather than conclusive. There were some indications that shared outreach care was safe and could make specialist care more accessible to outlying patients. Tele-oncology, by which some consultations are conducted using televideo, may be an acceptable adjunct. Larger and more methodologically robust studies are justified and should be conducted.

Humans↗
PubMed1999

Post-traumatic syringomyelia.

Post-traumatic syringomyelia is estimated to develop in more than 20% of individuals with traumatic spinal cord injury (SCI). The development can give rise to clinical symptoms 6 months to 26 years after the injury, and presentation 40 years post-injury has been seen by one of the authors.1234 We present an unusual case for comments and discussion.

Adult↗
PubMed1999

SEARCH international case-control study of childhood brain tumours: role of index pregnancy and birth, and mother's reproductive history.

A series of co-ordinated population-based case-control studies of childhood brain tumours (CBT) was undertaken under the auspices of the Surveillance of Environmental Aspects Related to Cancer in Humans (SEARCH) programme of the International Agency for Research on Cancer (IARC) to evaluate, inter alia, the risk in relation to characteristics of the index pregnancy and birth, and maternal reproductive history. Subjects comprised 1218 cases aged 0-19 years and 2223 controls. Risk estimates were calculated by unconditional logistic regression, adjusted for age, sex, centre and mother's years of schooling, for all types of CBT combined as well as for four groups defined by histopathology (astrologlial tumours, primitive neuroectodermal tumours of the brain, 'other glial' tumours and 'other histological types') and for five age groups (0-1, 0-4, 5-9, 10-14, 15-19 years). Use of anaesthetic 'gas' was associated with an increased risk of CBT (OR = 1.5, 95% CI [1.1, 2.0]), apparent in children aged 0-4 years (OR = 2.4, 95% CI [1.4, 4.1]) and for astroglial tumours (OR = 1.6, 95% CI [1.1, 2.2]) with non-significantly increased relative risks for each of the other histological groups. However, not all centre-specific relative risks were elevated. No other aspect of the index pregnancy, delivery and early neonatal period or of the mother's previous reproductive history was associated with risk for CBT.

Adolescent↗
PubMed1999

A patient-based voucher system of brief hospitalisation.

OBJECTIVE: The aim of this study was to demonstrate the clinical use of a patient-based voucher system for brief hospitalisation. CLINICAL PICTURE: A 31-year-old male, chronically disabled, with schizophrenia, polysubstance, and borderline personality disorders presented concerns for the treating team. TREATMENT: Management was community based except for a single admission in which the patient chose the timing and duration via a predetermined set of vouchers. OUTCOME: In contrast to previous admissions, a patient-chosen, voucher-based admission was single, brief and uneventful. CONCLUSIONS: Novel approaches to chronically disabled patients with psychiatric illness enable change from therapeutic pessimism. A patient-based voucher system seemed to be of use in one patient.

Adult↗