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Biomedical subjects

J M Manson

Publications and source records attributed to J M Manson.

At least 19 recordsLinked to original sources
PubMed2007

Immunohistochemical study of nuclear factor-kappaB activity and interleukin-8 abundance in oesophageal adenocarcinoma; a useful strategy for monitoring these biomarkers.

AIMS: To determine if immunohistochemistry (IHC) could be used to monitor nuclear factor-kappaB (NF-kappaB) activity in oesophageal adenocarcinoma and pre-malignant (Barrett's) oesophageal tissues, relative to normal oesophageal mucosa. The pro-inflammatory cytokine interleukin-8 (IL-8), a transcriptional target of NF-kappaB, was also studied to better understand NF-kappaB functionality; its RNA and protein levels were assessed in oesophageal tissues. METHODS: IHC was employed using an antibody against the nuclear localisation sequence (NLS) of the p65 subunit as well as an antibody against IL-8. To assess NF-kappaB function, changes in gene expression of NF-kappaB controlled genes (IL-8 and I-kappaB) were also assessed in the histological sequence using real-time PCR. More global expression changes were also studied using membrane arrays. RESULTS: IHC was effective at monitoring overall NF-kappaB activity and IL-8 abundance. This method also allowed NF-kappaB activity and IL-8 abundance to be pinpointed in specific cell types. There were significant increases in nuclear NF-kappaB activity and IL-8 abundance across the histological series. Gene expression analysis also showed consistent up-regulation of IL-8, confirming the IHC data and showing enhanced transcriptional NF-kappaB activity. I-kappaB (another NF-kappaB target) showed down-regulation in dysplastic and adenocarcinoma tissues. Down-regulation of I-kappaB gene expression may partly explain increased NF-kappaB activity. CONCLUSION: IHC, using antibodies against the NLS of p65, may be useful in monitoring overall NF-kappaB activity in oesophageal tissues. As IHC is amenable to high-throughput screening (whereas traditional electrophoretic mobility shift assay methods are not), this may lead to the development of a better screening tool for early cancer risk.

Adenocarcinoma↗
PubMed2001

Use of an automated database to evaluate markers for early detection of pregnancy.

The objective of this study was to develop and validate algorithms to detect pregnancies from the time of first clinical recognition by using Kaiser Permanente automated databases from Portland, Oregon. In 1993--1994, the authors evaluated these databases retrospectively to identify markers indicative of initial clinical detection of pregnancy and pregnancy outcomes. Pregnancy markers were found for 99% of the women for whom pregnancy outcomes were included in the automated databases, and pregnancy outcomes were identified for 77% of the women for whom there were pregnancy markers. The earliest marker most predictive of a pregnancy outcome was a positive human chorionic gonadotropin test; least predictive was an obstetric outpatient visit. Medical record review indicated that in a sample of women with pregnancy markers in the database, an estimated 6% of pregnancy outcomes (primarily early fetal deaths and elective terminations) were lost. Pregnancies were first captured in automated databases 6--8 weeks after the last menstrual period, and a combination of a positive human chorionic gonadotropin test and an outpatient obstetric visit was the most sensitive and specific early marker of pregnancy. When combined with automated pharmacy records, these databases may be valuable tools for evaluating prescription drug effects on all major outcomes of clinically recognized pregnancies.

Abortion, Legal↗
PubMed2001

Racial differences in sex hormone levels in women approaching the transition to menopause.

OBJECTIVE: Evaluate racial differences in reproducibility of hormone levels over time (estradiol, DHEAS, FSH, and testosterone) while adjusting for covariates previously identified as relevant in the study population. DESIGN: Longitudinal cohort study. SETTING: Healthy, late-reproductive-age women in a community-based sample. PATIENT(S): African American and Caucasian women identified by random digit dialing. INTERVENTION(S): Hormone levels measured in the early follicular phase of the menstrual cycle four times over 9 months. A multivariate, linear mixed model estimated effects on hormone levels of race, age at enrollment, age at menarche, number of pregnancies, current smoking, alcohol consumption, body mass index (BMI), waist/hip ratio (WHR), and menstrual cycle length. MAIN OUTCOME MEASURE(S): Follicular plasma levels of estradiol, FSH, DHEAS, and testosterone. RESULT(S): African American but not Caucasian women had significantly lower levels of estradiol and DHEAS with increasing age. African American but not Caucasian women had significantly decreased levels of estradiol and significantly increased levels of DHEAS with increasing BMI. No racial differences in reproducibility of hormone measures were found. CONCLUSION(S): There are racial differences in associations of hormone levels with age and BMI in late reproductive age women. Further study is needed to replicate these findings and to determine the relationships of these hormonal associations with menopausal symptoms.

Adult↗
PubMed2001

Experience with laparoscopic ultrasonography for defining tumour resectability in carcinoma of the pancreatic head and periampullary region.

BACKGROUND: Computed tomography (CT) is currently the most widely available staging investigation for pancreatic tumours. However, the accuracy of CT for determining tumour resectability is variable and can be poor. Laparoscopic ultrasonography (LUS) is potentially a more accurate method for disease staging. The authors' experience of LUS for staging carcinoma of the pancreatic head and periampullary region is described. METHODS: Fifty-one patients with potentially resectable pancreatic tumours defined at CT underwent further investigation with LUS. Twenty-seven patients subsequently had an open laparotomy. The evaluations of tumour resectability at CT and LUS were compared with the operative findings. RESULTS: At LUS, 24 patients were considered to have resectable tumours, 21 non-resectable tumours and six patients were shown to have no pancreatic tumour mass. Twenty-two patients deemed to have a resectable tumour at LUS underwent surgery. Twenty patients were confirmed to have resectable disease and two patients had non-resectable disease. A further five patients underwent surgery. In all five the ultrasonographic diagnosis was confirmed at surgery (four patients with non-resectable disease and no pancreatic tumour in one patient). LUS prevented unnecessary extensive surgery in 53 per cent of patients. For the 22 patients who underwent surgery for potentially resectable disease, the positive predictive value of LUS for defining tumour resectability was 91 per cent. CONCLUSION: LUS is an accurate additional investigation for defining tumour resectability and directing management in patients with potentially resectable carcinoma of the pancreatic head or periampullary region.

Adult↗
PubMed2000

Insertion of self-expanding metal stents for malignant dysphagia: assessment of a simple endoscopic method.

AIM: To assess the efficacy, safety and long-term results of self-expanding metallic prostheses, placed using an entirely endoscopic method, for the relief of dysphagia in oesophageal carcinoma. PATIENTS AND METHODS: A consecutive series of 50 patients (30 men, 20 women), aged 43-91 years (median, 75 years) underwent stent placement (Ultraflex Stent, Boston Scientific, Watertown, MA, USA) under general anaesthesia without fluoroscopic control. RESULTS: Stent placement was successful in all patients. Swallowing improved from dysphagia score 4, 3 or 2 to score 1 (or 0) in all patients available for long-term follow-up (excluding two patients who died, and two who had resection, in the immediate post-stenting period). There were two early deaths that were, or could have been, procedure-related and one early complication, in addition to technical problems in 6 cases, all early in the series. Seven patients required endoscopic laser treatment, on 13 occasions, subsequently for tumour in-growth or over-growth. Of the 46 patients with long-term stents in situ, 36 patients died with a median survival time of 4 months (range 10 days to 24 months). At the time of writing, 10 patients are still alive with a median survival of 4 months (range 1-11 months). CONCLUSIONS: Self-expanding metallic stents provide rapid, safe and effective relief of dysphagia. They can provide long-term palliation (> 1 year) with endoscopic laser treatment for recurrent in-growing/over-growing tumour. Fluoroscopic control is not necessary for the safe and accurate placement of such stents.

Adult↗
PubMed2000

Endoscopic ultrasound in the staging of tumours of the oesophagus and gastro-oesophageal junction.

BACKGROUND: Modern management of upper gastro-intestinal cancer demands accurate pre-operative staging. In continental Europe and Japan, endoscopic ultrasound (EUS) is established as the investigation of choice for local staging of these cancers, but British experience with this technique is limited. METHODS: A retrospective review of the medical records of patients with oesophageal or gastro-oesophageal junction tumours during our first 3.5 years' experience with EUS was undertaken and the findings at EUS correlated with the pathology of the resected specimen. RESULTS: A total of 124 patients (86 males), with a mean age of 64.5 years, underwent EUS: 84 had adenocarcinoma and 26 squamous cell carcinoma. There were 3 failed EUS examinations, 42 patients did not have surgery for a variety of reasons, and 10 patients had pre-operative chemoradiotherapy. In the remaining 69 patients, correlation for T stage showed an accuracy of EUS of 80% and for N staging of 54% overall. Comparison of the initial 2 years with the final 18 months showed no change in the T staging accuracy but an improvement in the N staging accuracy from 50% to 60%. CONCLUSION: Once initial experience has been gained, EUS is an accurate procedure for T and N staging of tumours of the oesophagus and gastro-oesophageal junction. It should be included with other imaging modalities, such as CT scanning, in the pre-operative assessment of these tumours.

Adenocarcinoma↗
PubMed1995

A preliminary re-assessment of the requirements for major minerals by growing pigs.

Forty-two mineral balances were measured in 50 kg pigs fed various diets, including barley, maize or potato, and used to examine the presumption that the current recommended dietary requirements for the major minerals, especially phosphorus, are essential to the well-being of the pig. All the diets contained similar levels of all the mineral elements, except potassium which was higher in the diets containing potato. The concentrations/kg dry matter were 11.0 g calcium, 6.9 g phosphorus, 0.96 g sodium, 1.5 g magnesium and 5.4 g potassium or 14.0 g potassium in the diets containing potato. The apparent digestibility coefficients were calcium 0.39, phosphorus 0.46, sodium 0.72, magnesium 0.26 and potassium 0.70 or 0.80 and the gross efficiencies with which the ingested elements were retained were calcium 0.36, phosphorus 0.25, sodium 0.32, magnesium 0.07 and potassium 0.22 or 0.16. The low efficiencies of utilisation of the digested minerals, especially phosphorus (0.53), suggested that a reduction in dietary phosphorus levels may be justified in terms of reducing the pollution of the environment with phosphorus caused by the application of pig slurry.

Animal Nutritional Physiological Phenomena↗
PubMed1995

Defining the susceptible period of developmental toxicity for the AT1-selective angiotensin II receptor antagonist losartan in rats.

Previous developmental and reproductive toxicity studies conducted in rats with Losartan, a potent AT1 subtype selective angiotensin II receptor antagonist, noted treatment-related effects on the pups of dams treated beyond the second trimester through lactation, as demonstrated by increases in pre- and postweaning pup deaths and decreased pup body weights [Spence et al. (1995) Teratology 51:000-000]. The studies presented here were designed to define the critical period for the induction of neonatal toxicity and to examine the effects of Losartan on kidney development when the drug is administered to the dam beyond the second trimester through lactation. In a developmental toxicity study with postweaning evaluation, pregnant rats were administered 5, 20, and 100 mg Losartan/kg/day on gestation days 6 through 15 (GD 6-15). There were no adverse effects on the F1 generation as assessed by mortality, clinical signs, weight gain, external examinations, developmental signs, behavioral tests, and gross or microscopic examination of the kidney. In a fostering/cross-fostering study, pregnant rats were administered 100 mg Losartan/kg/day on GD 15 through lactation day 20 (LD 20). Following delivery, pups from dams treated with Losartan were fostered to control dams, pups from control dams were fostered to Losartan-treated dams, and pups were also fostered to dams within the same group. Maternal exposure to Losartan during lactation increased the incidence of pup deaths on postnatal days 1-3 (PND 1-3), caused decreased pup weights on PND 7, and decreased performance in the auditory startle test in females and increased performance on the second swim maze test in males, relative to controls. Maternal exposure to Losartan during gestation was associated with decreased pup weight on PND 21 and effects observed on male performance in the swim maze test. Treatment during gestation was also associated with decreased pup cardiac weight as well as drug-induced histopathological changes of the kidneys from F1 pups, including medial hypertrophy of intracortical arterioles and dilatation of the renal pelvis. While the cardiac and renal vascular effects disappeared with time, significant renal lesions were still evident by PND 90. In a late-gestation/lactation study with renal evaluation, pregnant rats were administered 0.5, 1.0, 5.0, 20, and 100 mg Losartan/kg/day on GD 15-LD 20. Maternal toxicity was evident as decreased body weight gain in the 100 mg Losartan/kg/day group.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin Receptor Antagonists↗
PubMed1995

Evaluation of the reproductive and developmental toxicity of the AT1-selective angiotensin II receptor antagonist losartan in rats.

Losartan, an AT1-selective angiotensin II receptor antagonist, was evaluated in female rats for effects on fertility, reproduction, and perinatal and postnatal development. In a range-finding study, pregnant rats were treated orally from gestation days 6-17 (GD 6-17) with doses of 25, 75, 150, 225, and 300 mg Losartan/kg/day. There were treatment-related decreases in maternal body weight gain, slight treatment-related decreases in hemoglobin concentration, and slight treatment-related increases in serum urea nitrogen in the 225 and 300 mg/kg/day groups. In a fertility study, female rats were treated for 15 days prior to mating, during mating, and GD 0-19 with doses of 25, 100, and 300 mg Losartan/kg/day. The initial dose of 300 mg/kg/day was lowered to 200 mg/kg/day at the start of mating due to excessive body weight loss during the premating treatment interval. There were no treatment-related effects on reproductive performance, mating, or fertility indices in the F0 generation. There was no evidence of treatment-related or dose-related fetal malformations. However, decreased F1 pup body weights were observed in all drug-treated groups. In the 100 and 300/200 mg/kg/day groups there were treatment-related increases in F1 pup mortality and alterations in the pattern of postweaning body weight gains. There was also a delay in developmental signs in the 100 and 300/200 mg/kg/day groups, which were likely secondary to the decreased weight of the pups in these groups. In a developmental toxicity study, pregnant rats were administered 50, 100, and 200 mg Losartan/kg/day on GD 6-17. There was no evidence of developmental toxicity in any dose group. Maternal toxicity was evident in the 200 mg/kg/day group as a treatment-related decrease in body weight gain during gestation. In a late-gestation/lactation study, pregnant rats were administered 10, 25, and 100 mg Losartan/kg/day on GD 15 through lactation day 20 (LD 20). There were treatment-related decreases in maternal body weight gain during gestation and lactation in the 100 mg/kg/day group. Decreased pup weights were noted in all dose groups, and pre- and postweaning pup deaths were observed in the high dose group which were comparable to those observed in the female fertility study. The lack of fetal body weight effects at 100 mg Losartan/kg/day in the developmental toxicity study, with treatment ending on GD 17, indicates that adverse effects observed in the F1 generation in the fertility and late-gestation/lactation studies were due to exposure during late gestation and/or lactation.(ABSTRACT TRUNCATED AT 400 WORDS)

Angiotensin Receptor Antagonists↗
PubMed1995

Separation of epidermis from dermis in the rhesus monkey.

Effective methods exist for separating epidermis from dermis for many species; however, a simple and effective skin separation method for non-human primates is not available. This investigation describes an easy and reliable method for separating epidermis from dermis in Rhesus monkeys. Skin was shaved and washed prior to necropsy. Skin samples were placed on cardboard and then in Whirl-Pak bags, frozen on dry ice and stored at -70 degrees C. Just prior to the separation procedure, Whirl-Pak bags were returned to dry ice storage. Immediately after removal from dry ice, each closed Whirl-Pak bag was placed into a waterbath maintained between 60 and 67 degrees C. After 2 minutes, the Whirl-Pak bag was removed from the waterbath, opened and the skin surface of the application site was gently scraped with a scalpel blade to remove the epidermis. Effectiveness of removal was verified by histologic examination of the remaining dermal samples.

Administration, Cutaneous↗