Search PubMed⌕ Search

Biomedical subjects

D Jenkins

Publications and source records attributed to D Jenkins.

At least 55 records · Page 3Linked to original sources
PubMed2002

Total daily energy expenditure and incidence of upper respiratory tract infection symptoms in young females.

UNLABELLED: A group of 31 young females, tennis players and non-athletes, aged 16 +/- 2 years (range: 14 - 21 years), with a wide range of physical activity levels was used to investigate the relationship between total daily energy expenditure and the incidence of upper respiratory tract infection symptoms. METHODS: During a 12 week winter period, habitual daily activity (excluding training) was evaluated using a 3-day physical activity record. Tennis training was quantified using a validated method of estimating energy expenditure during play. Total daily energy expenditure was calculated from the sum of daily training plus mean habitual daily activity energy expenditures. The total group of subjects was divided in quartiles for total daily energy expenditure. A validated symptom checklist was used to assess the incidence and severity of upper respiratory tract infections, on a daily basis. RESULTS: The girls in the highest quartile of total daily energy expenditure (> or = 17,322 kJ/day) and in the lowest quartile (< or = 10,047 kJ/day) had the greatest incidence of URTI symptomatology, although the moderately active girls in quartile three (12,290 - 16,410 kJ/day) presented the lowest incidence. Significant differences in number of upper respiratory tract infection episodes, sickness days and symptomatology index were found between quartiles three and one (p < 0.05) and quartiles three and four (p < 0.01). Peak severity of symptoms was significantly lower in quartile three compared with all other quartiles (p < 0.05).

Adolescent↗
PubMed2002

High prevalence of undetected ulcerative colitis: data from the Nottingham fecal occult blood screening trial.

OBJECTIVES: Inflammatory bowel disease (IBD) is usually diagnosed as a result of symptoms but occasionally is found during investigation for other conditions. An earlier report from Nottingham had found a high prevalence of previously undetected "asymptomatic" IBD detected as a result of colorectal cancer screening, and the aim of this study was to reassess the prevalence, symptoms, and outcome in these patients. METHODS: We investigated subjects found to be fecal occult blood (FOB) positive in a randomized trial of FOB screening for colorectal cancer. All FOB-positive subjects were investigated by colonoscopy or flexible sigmoidoscopy and barium enema. Subjects with IBD were referred back to their general practitioner for any further investigation and treatment. RESULTS: Seventy-five thousand two hundred fifty-three subjects (aged 45-74) were sent FOB tests and 44,838 (60%) completed a series of tests on one or more occasions. Of 133,000 test series, 1.5% were positive. During investigation 53 cases of previously undetected IBD (52 of ulcerative colitis) were found; 52% (27/52) had proctosigmoiditis only, whereas 25% (13/52) had pancolitis. Only 17% (9/52) were completely asymptomatic, with a half or more reporting some rectal bleeding (54%) or diarrhea (50%). The overall prevalence of undetected ulcerative colitis was 69/10(5) (95% CI = 50-88/10(5)) in people offered screening and 116/10(5) (95% CI = 85-147/10(5)) in people accepting screening and was higher in men. Of 32 subjects followed up 2-12 yr after diagnosis, 91% (29) continued to have few or no symptoms, with only 12 currently receiving any treatment for their colitis. CONCLUSIONS: In comparison with detected disease, undetected ulcerative colitis is relatively common but does usually cause some symptoms. It generally appears to follow a benign course, but a significant proportion have extensive colitis and may therefore be at an increased risk of colorectal cancer.

Age Distribution↗
PubMed2002

Impact of acid secretion, gastritis, and mucus thickness on gastric transfer of antibiotics in rats.

BACKGROUND AND AIMS: The success of Helicobacter pylori eradication regimens depends on gastric pH, inflammation, and mucus thickness. Our aim was to investigate the effects of acid secretion, inflammation, and mucolysis on gastric antibiotic transfer. SUBJECTS AND METHODS: A total of 134 anaesthetised rats were given metronidazole, amoxicillin, or clarithromycin intravenously and gastric contents were aspirated via an indwelling cannula. Acid secretion was controlled by either omeprazole or pentagastrin while gastritis was induced by infection with H pylori or dosing with iodoacetamide. Mucolysis was achieved by instilling pronase into the gastric lumen. RESULTS: Metronidazole transfer increased with acid secretion and fell with omeprazole, independently of gastric pH. Clarithromycin was also transferred with acid but was then rapidly degraded. Omeprazole prevented this degradation, raising gastric luminal concentrations. Omeprazole did not alter amoxicillin transfer. Gastritis induced by H pylori did not alter gastric transfer of metronidazole and amoxicillin but that of clarithromycin was increased by 23%. However, gastritis induced by iodoacetamide reduced clarithromycin transfer without any effect on metronidazole or amoxicillin transfer. Pronase treatment increased amoxicillin transfer fourfold and metronidazole by 66% but reduced clarithromycin transfer by 35%. CONCLUSIONS: Metronidazole and clarithromycin are predominantly transferred with gastric acid rather than by an acid trapping mechanism. Pronase increases the appearance of amoxicillin and metronidazole in gastric secretions.

Amoxicillin↗
PubMed2002

How could pathologists improve the initial diagnosis of colitis? Evidence from an international workshop.

BACKGROUND: The taking of multiple colorectal biopsies is in widespread use although there is little research into their benefit for the pathological diagnosis of inflammatory bowel disease. There is also still debate about appropriate morphological criteria for interpreting these biopsies. AIMS: To determine the effect of single versus multiple biopsies on the accuracy of diagnosis and to study the accuracy and reproducibility of the different criteria used in the diagnosis of multiple biopsies by expert and non-expert pathologists. METHOD: Thirteen expert and 12 non-expert international diagnostic histopathologists attended a workshop. Sixty cases with full follow up were viewed, blinded, in two rounds. Diagnoses were made on rectal biopsies and then full colonoscopic series. RESULTS: Experts correctly identified 24% of Crohn's disease cases (non-experts, 12%) from the rectal biopsies. This improved to 64% (non-experts, 60%) with the full series. The accuracy of the diagnosis of ulcerative colitis also improved slightly with the full series from 64% to 74% overall. Experts had a similar (moderate) level of agreement and accuracy to non-experts. For Crohn's disease, the likelihood ratios (LR) for the most important individual features were 12.4 for granulomas and 3.3 for focal or patchy inflammation. Features favouring ulcerative colitis were diffuse crypt architectural irregularity (LR, 3.4), general crypt epithelial polymorphs (LR, 3.7), and reduced crypt numbers (LR, 2.9). CONCLUSIONS: A full colonoscopic series gave more accurate diagnosis than a rectal biopsy. Accurate pathologists used the same evidence based criteria for multiple biopsies as for single biopsies.

Biopsy↗
PubMed2002

Polyphosphate kinase genes from activated sludge carrying out enhanced biological phosphorus removal.

The community structure and metabolic function of activated sludge carrying out enhanced biological phosphorus removal have been investigated. Laboratory-scale sequencing batch reactors were operated at several influent COD/P ratios to obtain sludges with a range of phosphorus contents. Molecular microbiological techniques based on small subunit ribosomal RNA were used to characterize the structure of these sludges. The dominant polyphosphate accumulating organism was a close relative of Rhodocyclus tenuis, a member of the beta subclass of the Proteobacteria. Fragments of genes coding for polyphosphate kinase (PPK), thought to be responsible for polyphosphate accumulation, were retrieved from one of the sludges. The relative abundance of PPK gene copies in genomic DNA extracted from sludges was determined to confirm that at least one of the PPK gene sequences was derived from the dominant polyphosphate accumulating organism.

DNA Primers↗
PubMed2002

Effects of pH on enhanced biological phosphorus removal metabolisms.

Laboratory-scale sequencing batch reactors exhibiting enhanced biological phosphorus removal were analyzed for pH effects on anaerobic phosphorus (P) release, glycogen degradation, and acetate uptake. Samples with non-soluble P/total suspended solids values of either 0.13-0.14 mg/mg (HP) or 0.065-0.075 mg/mg (LP) were analyzed in anaerobic batch tests with excess acetate addition at pH values ranging from 5.2 to 9.5. A polyphosphate-accumulating metabolism (PAM) had a competitive advantage over a glycogen-accumulating metabolism (GAM) at pH > 7.0. Maximum acetate uptake rates by the HP and LP samples occurred at pH values 8.0 and 6.9, respectively. Anaerobic P release/acetate uptake increased with increasing pH at rates similar to previously reported values. Glycogen degradation/acetate uptake decreased with increasing pH above pH 7, which disagreed with previous reports that glycogen degradation/acetate increased or was unaffected by increasing pH. The results suggested that the acetate uptake mechanisms of GAM and PAM may be different.

Acetates↗
PubMed2002

Removal of fecal coliforms by thermophilic anaerobic digestion processes.

Recent U.S. EPA regulations (40 CFR Section 503) specify maximum concentrations of pathogens and metals for Class A wastewater treatment plant sludges. The most common sludge process is mesophilic (35 degrees C) digestion which stabilizes the solids, produces a combustible gas but does not create an effluent that meets the 503 Class A pathogen requirements. This investigation was conducted to determine whether anaerobic digestion processes incorporating a thermophilic stage could achieve 503 Class A pathogen levels. The research reported here was a bench-scale screening study meant to identify the most promising process alternatives for further investigation. Fecal Coliform (FC) concentrations were used to assess disinfection efficiency. Digesters were 30 L capacity fed semi-continuously in draw-fill mode. Digester startup was rapid to produce true thermophiles. Temperature staging and pH were assessed in 3 sets of experiments: Set 1 were one stage ("acid phase"), Set 2 were one stage ("acid + methane phases") and Set 3 were two stage ("acid phase" then "methanogenic phase"). Feed was a 1:1 mixture of Thickened Waste Activated Sludge and Primary Sludge. The following anaerobic digestion configurations and operating parameters allowed the production of digested sludge with a mean FC concentration statistically less than 10(3) (the regulatory value for Class A sludge): thermophilic single stage acid phase at 52 and 62 degrees C; thermophilic single stage acid + methane phase at 48 degrees C, 52 degrees C and 62 degrees C; two-stage mesophilic acid phase followed by mesophilic methane phase; two stage mesophilic acid phase followed by thermophilic methane phase at 48 degrees C, 52 degrees C and 62 degrees C. If the maximum digested FC concentration must be below 10(3) MPN/g TS then the following digester configurations and operating conditions will be compliant: two stage mesophilic acid phase followed by thermophilic methane phase at 52 degrees C and 62 degrees C.

Bacteria, Anaerobic↗
PubMed2002

Multi-vessel off-pump coronary artery bypass grafting can be taught to trainee surgeons.

BACKGROUND: Although, Off-Pump Coronary Artery Bypass (OPCAB) surgery is being increasingly explored and practised in many cardiac units worldwide, there have been only few reports documenting the training of surgeons in this new technique. The purpose of this study was to address the reproducibility of the OPCAB in a unit where this technique is used extensively. METHODS: Registry data, notes and charts of 64 patients who were operated on by four trainee cardiac surgeons over a period of thirteen months at Harefield Hospital, were reviewed retrospectively. These trainees were part of an accredited training programme for cardiothoracic training and were trained by a single consultant trainer in a cardiac unit after it has had an established recent experience in performing non-selective OPCAB for all coming-in patients. Five (7.8%) patients (with 17 distal anastomoses) consented and underwent early postoperative angiography to check the quality of the grafts and anastomoses. RESULTS: The mean age of the study patients was 65.6 and the mean Parsonnet score was 9.4. There was a mean of 2.9 grafts per patient and circumflex territory anastomoses were performed in 48 (75%) patients. No operation required conversion to Cardiopulmonary Bypass (CPB). Angiography of the five patients revealed satisfactory seventeen (100%) distal anastomoses. CONCLUSION: With appropriate training, it is possible for trainees to learn OPCAB and perform multi-vessel revascularization in relatively high-risk patients with good results.

Adult↗
PubMed2001

Alignment delays in the N = Z nuclei (72)Kr, (76)Sr, and (80)Zr.

The ground state rotational bands of the N = Z nuclei (72)Kr, (76)Sr, and (80)Zr have been extended into the angular momentum region where rotation alignment of particles is normally expected. By measuring the moments of inertia of these bands we have observed a consistent increase in the rotational frequency required to start pair breaking, when compared to neighboring nuclei. (72)Kr shows the most marked effect. It has been widely suggested that these "delayed alignments" arise from np-pairing correlations. However, alignment frequencies are very sensitive to shape degrees of freedom and normal pairing, so the new experimental observations are still open to interpretation.

Journal Article↗
PubMed2001

Activation of mammalian Chk1 during DNA replication arrest: a role for Chk1 in the intra-S phase checkpoint monitoring replication origin firing.

Checkpoints maintain order and fidelity in the cell cycle by blocking late-occurring events when earlier events are improperly executed. Here we describe evidence for the participation of Chk1 in an intra-S phase checkpoint in mammalian cells. We show that both Chk1 and Chk2 are phosphorylated and activated in a caffeine-sensitive signaling pathway during S phase, but only in response to replication blocks, not during normal S phase progression. Replication block-induced activation of Chk1 and Chk2 occurs normally in ataxia telangiectasia (AT) cells, which are deficient in the S phase response to ionizing radiation (IR). Resumption of synthesis after removal of replication blocks correlates with the inactivation of Chk1 but not Chk2. Using a selective small molecule inhibitor, cells lacking Chk1 function show a progressive change in the global pattern of replication origin firing in the absence of any DNA replication. Thus, Chk1 is apparently necessary for an intra-S phase checkpoint, ensuring that activation of late replication origins is blocked and arrested replication fork integrity is maintained when DNA synthesis is inhibited.

Alkaloids↗
PubMed2001

Relationship of Campylobacter toxigenicity in vitro to the development of postinfectious irritable bowel syndrome.

Campylobacter enteritis is associated with a significant risk of developing irritable bowel syndrome, but the mechanism is unknown. This study ascertained bowel symptoms in 93 patients 3 months after Campylobacter jejuni enteritis infection. The infecting organisms were cultured, and the effects of culture supernatants on toxin-sensitive epithelial cell monolayers (HEp-2, Green monkey kidney epithelial [Vero], and CHO-K1) were investigated. In all, 50, 43, and 41 of the isolates showed toxigenic effects on HEp-2, CHO-K1, and Vero cells, respectively. Persistently changed bowel habit was reported by 9 of 50 persons with HEp-2 toxin-positive infections but by only 2 of 43 with isolates negative for toxin (chi2=4.0; P<.05). Toxicity to HEp-2 and Vero cells was associated with significantly increased numbers of days with loose stools 6 months after C. jejuni enteritis infection (both, P<.05). Thus, long-term symptoms that occur Campylobacter infection are significantly associated with bacterial toxicity.

Adolescent↗
PubMed2001

The ep -->e'p eta reaction at and above the S11(1535) baryon resonance.

New cross sections for the reaction e p-->e p eta are reported for total center of mass energy W = 1.5--1.86 GeV and invariant momentum transfer Q2 = 0.25--1.5 (GeV/c)(2). This large kinematic range allows extraction of important new information about response functions, photocouplings, and eta N coupling strengths of baryon resonances. Newly observed structure at W approximately 1.65 GeV is shown to come from interference between S and P waves and can be interpreted with known resonances. Improved values are derived for the photon coupling amplitude for the S11(1535) resonance.

Journal Article↗
PubMed2001

Quantitative analysis of IL-10 and IFN-gamma mRNA levels in normal cervix and human papillomavirus type 16 associated cervical precancer.

Human papillomavirus type 16 is a major factor in cervical carcinogenesis. Inappropriate cytokine synthesis may direct the local immune response away from a type-1 (cellular) pattern and may subsequently contribute to the development and progression of precancer. Quantitative reverse transcription-polymerase chain reaction (RT-PCR) using a competitive mimic was carried out to determine type-1 (interferon gamma (IFN-gamma)) and type-2 (interleukin-10 (IL-10)) cytokine mRNA levels in whole cervical specimens (without microdissection) from seven normal and nine HPV-16 positive CIN formalin-fixed paraffin-embedded tissues. Microdissection was used to measure separately the epithelial and sub-epithelial levels of IFN-gamma and IL-10 mRNAs in 11 specimens of normal cervix and 25 HPV-16 positive CIN (nine CIN 1, seven CIN 2 and nine CIN 3). IFN-gamma mRNA was lower in CIN than normal (p=0.04). IL-10 mRNA level in CIN was significantly higher (p=0.005) than in normal cervix (before microdissection). Epithelial IFN-gamma mRNA showed a significant decrease in all grades of CIN (median=3.58) compared with normal (7.74) (p<0.05), but there was no significant difference between the grades. A significant decrease in sub-epithelial IFN-gamma mRNA was found in CIN 1(9.81), CIN 2 (3.82) and CIN 3 (4.62) compared with normal cervix (27.35) (p<0.05). Also, sub-epithelial IFN-gamma mRNA was significantly lower in CIN 2 and CIN 3 than in CIN 1 (p=0.005 and 0.0005, respectively). IL-10 was detected in the epithelium of only one of 11 normal and one of 25 CIN, but sub-epithelial IL-10 was significantly higher in CIN 2 (0.08) and CIN 3 (0.26) than in normal (0.00) (p=0.036 and 0.0032, respectively). There was no significant difference in the sub-epithelial level of IL-10 between normal and CIN 1 (0.00) (p=0.96). Our results suggest that reduced epithelial and sub-epithelial IFN-gamma, as well as increased sub-epithelial IL-10 synthesis may play a role in the development and progression of HPV-16 associated cervical precancer.

Cervix Uteri↗
PubMed2001

Altered HLA-G transcription in pre-eclampsia is associated with allele specific inheritance: possible role of the HLA-G gene in susceptibility to the disease.

Pre-eclampsia is a disorder of human pregnancy occurring in 5-10% of all births, and represents the leading cause of infant morbidity and mortality and maternal death. In pre-eclampsia, invasion of fetal trophoblasts into maternal arteries during early pregnancy is shallow or absent. Here we examined the hypothesis that HLA-G, a non-classical class I HLA expressed in cytotrophoblasts, may act as a key gene in pre-eclampsia. We analysed HLA-G at the level of transcription and genotyped a silent CAC-CAT polymorphism in exon 3 and a 14-bp insertion/deletion in the 3' untranslated region. A deficit in levels of the HLA-G3 transcript was observed in mild pre-eclampsia compared to normal placentas. The distribution of HLA-G polymorphisms was different between normal and pre-eclampsia samples. A correlation between the alteration in transcription of the HLA-G gene and certain HLA-G genotypes was also observed. Thus we provide the first evidence for a possible role of HLA-G in genetic susceptibility to, and pathogenesis of pre-eclampsia.

Alleles↗
PubMed2001

HLA alleles and IDDM in children in Hungary: a comparison with Finland.

It has been postulated that variation in the distribution of human leukocyte antigen (HLA)-encoded susceptibility alleles for insulin-dependent diabetes mellitus (IDDM) is the genetic basis for variation in the incidence of the disease between populations. The aim of this study was to characterize HLA-encoded susceptibility to IDDM in Hungary and to identify whether HLA-DRB1/DQ-encoded susceptibility could account for the five times lower incidence of disease in Hungary compared with Finland. The haplotypes DRB1*03-DQA1*05-DQB1*02 (DRB1*03-DQ2) and DRB1*04-DQA1*0301-DQB1*0302 (DRB1*04-DQ8) were significantly associated with disease in both populations. Three genotypes incorporating either or both of these haplotypes accounted for over 70% of the diabetic population in both races. The combined background frequency and the degree of risk as measured by odds ratios of these HLA-DRB1-DQ genotypes were not significantly different in the two countries. Comparison of the DRB1*0401-DQ8 haplotype between the two races suggested a role for HLA-B alleles in susceptibility. These data indicate that the susceptibility associated with high risk DRB1-DQ genotypes alone is insufficient to account for the fivefold variation in incidence of IDDM between Hungary and Finland. Other genetic and/or environmental influences must be involved.

Alleles↗
PubMed2001

Measurement of energy expenditure of daily tasks among mothers of young children.

There is currently some debate about whether the energy expenditure of domestic tasks is sufficient to confer health benefits. The aim of this study was therefore to measure the energy cost of five activities commonly undertaken by mothers of young children. Seven women with at least one child younger than five years of age spent 15 minutes in each of the following activities: sitting quietly, vacuum cleaning, washing windows, walking at moderate pace (approx 5km/hour), walking with a stroller and grocery shopping in a supermarket. Each of the six 'trials' was completed on the same day, in random order. A carefully calibrated portable gas analyser was used to measure oxygen uptake during each activity, and data were converted to units of energy expenditure (METS). Vacuum cleaning, washing windows and walking with and without a stroller were found to be 'moderate intensity activities' (3 to 6 METs), but supermarket shopping did not reach this criterion. The MET values for these activities were similar to those reported in the Compendium of Physical Activities (Ainsworth et al., 2000). However, the energy expenditures of walking, both with and without a stroller, were higher than those reported in the Compendium. The findings suggest that some of the tasks associated with domestic caring duties are conducted at an intensity which is sufficient to confer some health benefit. Such benefits will only accrue however if the daily duration of these activities is sufficient to meet current guidelines.

Activities of Daily Living↗
PubMed2001

Isolated human papillomavirus 18-positive extragenital bowenoid papulosis and idiopathic CD4+ lymphocytopenia.

We report a case of isolated extragenital bowenoid papulosis (BP) in a young man with an idiopathic low CD4 count. The lesions occurred on the dorsal aspect of his left middle finger and were not associated with genital involvement. Polymerase chain reaction studies of a biopsy demonstrated human papillomavirus 18. As far as we are aware, this is the first documented case of BP (genital or extragenital) associated with idiopathic CD4 lymphocytopenia.

Adult↗