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Biomedical subjects

A McIntyre

Publications and source records attributed to A McIntyre.

At least 19 recordsLinked to original sources
PubMed2006

Acute supraclavicular skin toxicity in patients undergoing radiotherapy for breast cancer: an evaluation of the 'T'-grip method of patient positioning.

AIMS: Supraclavicular fossa (SCF) radiotherapy plays an important part in the adjuvant management of breast cancer but data on acute radiotherapy toxicity are lacking, particularly when differing patient treatment positions are used to allow computed tomography planning or to reduce cardiac doses. MATERIALS AND METHODS: We evaluated SCF and breast/chest wall acute skin toxicity in a cohort of 92 women with breast cancer, who were planned in a 'T'-grip (n = 72) or 90 degrees-grip (n = 20) position, while 'on treatment' and at 6 weeks. The modified Radiation Therapy Oncology Group (RTOG) criteria were used to score toxicity. Data on age, body mass index, smoking history, type of breast operation, prior chemotherapy, radiation dose, number of fields and field size were recorded and correlated with outcome. RESULTS: Maximum SCF reaction score was RTOG 2a, with no moist desquamation observed. SCF reactions were less severe compared with chest wall reactions and no worse than breast reactions. There was significant resolution of toxicity at 6 weeks. SCF radiotherapy in 'T'-grip patients was well tolerated and no worse than the 90 degees-grip group. Pain scores and sore throat occurrences were minimal. Univariate and multivariate analyses showed that smoking was associated with worsening SCF toxicity (odds ratio [OR] 2.92; P = 0.045) and delayed healing. Incremental SCF dose worsened toxicity (OR 3.65; P = 0.023). Smoking worsened breast but not chest wall toxicity. CONCLUSIONS: SCF radiotherapy was at least as well tolerated as breast radiotherapy and better tolerated than chest wall radiotherapy. The 'T'-grip position did not affect toxicity negatively. Smoking and radiation dose affected SCF toxicity.

Adult↗
PubMed2004

Prevalence of Streptococcus pneumoniae and Staphylococcus aureus nasopharyngeal colonization in healthy children in the United States.

This study documents the colonization of Staphylococcus aureus (SA), Streptococcus pneumoniae (SP) and specific resistant forms of these organisms among healthy children and identifies risk factors associated with these pathogens. Prospective point prevalence survey of nasopharyngeal specimens were obtained from 291 healthy children seeking routine well-child care at a university-based ambulatory paediatric clinic in a large urban city in the United States. A total of 291 children less than 5 years were enrolled during a 1-year period. Fifty-four (18.6%) were colonized with SA and 47 (16.2%) were colonized with SP. Among the 54 SA isolates, five (9.2%) were methicillin resistant (MRSA) and among the SP isolates, three (6.4%) were intermediate to penicillin (DRSP). Eighty per cent of all children enrolled reported no underlying medical condition. Care outside their home was more common among colonized (40.8%, 40/98) than non-colonized children (25.4%, 49/193), P=0.007. Healthy children from households of four or more people were also more likely to be colonized. The colonization rate of SA and SP among healthy children is consistent with what has been reported in the literature. The prevalence of MRSA and DRSP among healthy children colonized with SA or SP is low in this population of children attending a university-based ambulatory care centre in the United States.

Age Factors↗
PubMed2001

Waveform optimization for internal atrial defibrillation: effects of waveform rounding, phase duration, and voltage swing.

The aim of this study was to compare the efficacy of internal atrial defibrillation by conventional truncated exponential biphasic waveforms with and without waveform rounding (1-2 phases) and to determine optimal duration for this novel double rounded waveform. Atrial fibrillation, induced by rapid electrical stimulation, was converted by internal shocks through defibrillation catheters (lateral right atrium and coronary sinus) in anesthetised sheep. Rounding the leading edges of the conventional biphasic waveform (Ventritex HVS-02; settings 100/-50 V, 150/-70 V, and 200/-100 V; n = 8) reduced delivered peak and trough voltages, currents, and energy (by > or = 21 %, P < 0.001; for double (both phases) rounded) without decreasing cardioversion success. At 100/-50 V the efficacy of single (first phase) rounded (53 +/- 13%; mean +/- SEM) and double rounded (59 +/- 11%) shocks was similar to the conventional waveform (56 +/- 14%). Double rounded waveform (phase durations 1-20 ms) efficacy was optimum at 6-10 ms phase duration (100% success at 10-ms phase duration; 1.52 +/- 0.04 J delivered energy; n = 6). Successful cardioversion by conventional, single rounded, and double rounded biphasic waveforms (duration 6 ms each phase), conventional monophasic, rounded monophasic (duration 12 ms), and a damped sine waveform correlated strongly with peak-to-trough voltage swing within the waveform (r = 0.882; P < 0.01; n = 8). For internal atrial defibrillation, rounding both phases of the conventional biphasic waveforms, the double rounded waveform, permits similar efficacy to the conventional truncated exponential biphasic waveform at reduced peak voltage, current, and delivered energy. Optimum phase duration is 6-10 ms (tested range 1-20 ms).

Animals↗
PubMed2000

Does intrathecal morphine alter the stress response following coronary artery bypass grafting surgery?

PURPOSE: Intrathecal morphine administered prior to coronary artery revascularization (CABG) surgery was studied to determine its effects on the stress response. METHODS: In a single centre, open, randomized clinical trial, first time elective CABG surgery patients, < 75 yr, were studied. Control subjects (n=12) received a standardized anesthetic consisting of fentanyl (maximum cumulative dose of 35 microg x kg(-1)), propofol, and pancuronium. In addition, spinal subjects (n=13) received 1.0 mg (age > 60 yr) or 1.5 mg (age < or = 59 yr) intrathecal morphine prior to induction of anesthesia. Control subjects received continuous i.v. morphine at 2 mg x hr(-1) on arrival in the ICU with i.v. bolus morphine supplementation as required while spinal subjects received bolus i.v. morphine as required. Changes in plasma cortisol and catecholamine concentrations were measured preoperatively, poststernotomy, on admission to ICU, following tracheal extubation, at 0800 hr on the first postoperative day, and 24 and 48 hr after ICU admission. RESULTS: No differences between groups were detected for demographic variables. The percent change in cortisol concentration relative to preoperative values (control vs spinal; (38 (87) vs -41 (46)%: P < 0.05)) was lower in the spinal group on admission to ICU. The percent change in plasma epinephrine levels (control vs spinal) on admission to ICU (285 (337) vs -10 (37)%) and 0800 hr after surgery (314 (341) vs -4 (37)%) was also significantly different. CONCLUSION: Intrathecal morphine only partially attenuated the postsurgical stress response in CABG surgical patients.

Adult↗
PubMed1999

Relationship of hydrolase activities to epithelial cell turnover in distal colonic mucosa of normal rats.

BACKGROUND: The relationships between changes induced by diet in colonic epithelial kinetics and in the activities of brush border hydrolases are poorly defined. The aims of this study are to define these relationships, as changes in kinetics would be expected to influence differentiation, and to determine whether the type of ingested dietary indigestible carbohydrates influences hydrolase activities. METHODS: Groups of eight rats were fed a low fibre diet +/- supplements of different types of indigestible carbohydrates for 4 weeks. Alkaline phosphatase (ALP) and dipeptidyl peptidase IV (DPPIV) activities and epithelial kinetics were measured in distal colonic mucosa. RESULTS: Median ALP activities correlated positively and DPPIV activity negatively with the median proportion of cells entering metaphase (r = 0.58 and -0.58, respectively; P < 0.05) and number of metaphase arrests per crypt column across the diets (r = 0.59 and 0.58, respectively; P < 0.05). Stepwise regression analysis showed that both hydrolases independently predicted these kinetic indices (R2 > 63% for each). Mucosal ALP activities were markedly elevated during consumption of raw potato starch, guar gum and methylcellulose, while only potato starch caused a significant elevation of DPPIV activities. CONCLUSIONS: The type of indigestible carbohydrate in the diet influences colonic mucosal hydrolase activities. The opposite relationship between kinetics and each of the two hydrolases indicates that these hydrolases do not reflect the same event; dipeptidyl peptidase IV might relate to differentiation status while ALP could also be influenced by epithelial irritation due to changes in luminal conditions.

Alkaline Phosphatase↗
PubMed1997

Effect of bran, ispaghula, and inert plastic particles on gastric emptying and small bowel transit in humans: the role of physical factors.

BACKGROUND: Coarse bran is known to accelerate transit through the whole gut and to increase stool weight. This effect is much reduced by grinding the bran, suggesting that particle size influences gut motor patterns. AIMS: To compare the effect of 15 g coarse bran with 15 g inert plastic particles and 7 g of ispaghula on the gastric emptying and small bowel transit of a rice pudding test meal. SUBJECTS: 13 healthy volunteers. METHODS: Transit of 99mTc labelled rice studied by gamma-scintigraphy measuring gastric emptying and colonic arrival over 10 hours. Small bowel transit was estimated from the difference between time to 50% gastric emptying and 50% colonic arrival. RESULTS: Bran delayed gastric emptying by 22 (SEM 8) minutes compared with control values of 88 (SEM 6) minutes p < 0.05. Ispaghula and plastic particles had no significant effect. Small bowel transit was accelerated compared with control values of 322 (SEM 29) minutes, decreasing by 95 (29) minutes and 62 (22) minutes after bran and plastic particles respectively. Ispaghula again showed no significant effect. CONCLUSION: Coarse bran delays gastric emptying and accelerates small bowel transit. The marked acceleration of small bowel transit also seen with inert plastic particles may be due to increased upper gut secretions after stimulation of enteric nerves.

Aged↗
PubMed1996

Forcing of Atlantic Equatorial and Subpolar Millennial Cycles by Precession

Abundance cycles of the marine alga Florisphaera profunda centered on a period of 7600 carbon-14 years (8400 calendar years) are present in high-resolution records from the equatorial Atlantic spanning 0 to 45,000 years ago. These cycles correlate with Heinrich events 1 through 5, which document rapid changes in continental ice melting around the subpolar North Atlantic. These variations in F. profunda are a direct response to modulation in zonal wind-driven divergence produced by a precessional component of orbital variation during a time of reduced eccentricity modulation.

Journal Article↗
PubMed1996

Wheat bran suppresses potato starch--potentiated colorectal tumorigenesis at the aberrant crypt stage in a rat model.

BACKGROUND & AIMS: Starch that escapes digestion in the small intestine (resistant starch [RS]) may act similarly to nonstarch polysaccharides in the colon. The aim of this study was to examine the effect of raw potato starch alone and in combination with wheat bran on tumor development and precancer events in a rat model of colorectal cancer. METHODS: Three groups of rats received either a low-RS/low-fiber ("basic") diet, the basic diet containing raw potato starch as 20% of carbohydrate content, or the potato starch diet plus 10% of "wheat bran" fiber. Epithelial proliferation, aberrant crypt foci (ACF), and tumors were measured 6 and 20 weeks after a 10-week course of dimethylhydrazine. RESULTS: Rats on the potato starch diet had tumors more frequently and had larger tumors than rats consuming the wheat bran or basic diets. Parallel effects on the density of ACF were found 6 weeks after the carcinogen. Although epithelial proliferation was significantly enhanced by potato starch compared with the basic diet, the addition of wheat bran did not suppress this enhancement. CONCLUSIONS: This type-2 RS enhances epithelial proliferation, ACF density, and tumor formation. The addition of wheat bran to an RS-containing diet suppresses tumorigenesis, acting on events responsible for the formation of ACF but not the events controlling the hyperproliferative phase.

Analysis of Variance↗
PubMed1995

Dietary fibers differ in their effects on large bowel epithelial proliferation and fecal fermentation-dependent events in rats.

The effects of different fiber types and processing on putative protective mechanisms for colorectal cancer were evaluated. Rats were fed diets of similar nutrient balance containing either no added fiber or 10% fiber from various sources. The rate of distal colonic epithelial proliferation, measured by the metaphase arrest method, was dependent on fiber type; ranking of fibers from highest to lowest yielded the following order: methylcellulose > coarse wheat bran > fine wheat bran approximately parboiled and extruded rice brans > no fiber (P = 0.012). Effect on stool output ranked identically. Ranking of effect on fecal pH, from most to least acidic was as follows: coarse wheat bran approximately the rice brans > fine wheat bran > no fiber approximately methylcellulose (P = 0.00001). Coarse wheat bran gave significantly higher fecal butyrate concentrations than did the rice brans, which in turn gave higher levels than fine wheat bran, methylcellulose and the no-fiber diet. Proximal colon epithelial proliferation was unaffected by diet although cecal short-chain fatty acid concentrations and pH were affected. Different fibers have different effects on events in the fecal environment and distal colonic epithelium. Putative protective events (increased output, low fecal pH, high butyrate, low proliferation) are not equally affected and are unlikely in themselves to allow prediction of the protective effect of a fiber.

Animals↗
PubMed1993

A double-blind, placebo-controlled study of fluoxetine in patients with DSM-III-R obsessive-compulsive disorder. The Lilly European OCD Study Group.

We have studied the effect of three fixed daily doses of fluoxetine in patients with obsessive-compulsive disorder (OCD) diagnosed according to DSM-III-R. Two hundred and fourteen patients were evaluated in an 8-week double blind, placebo-controlled study. A statistically significantly greater number of fluoxetine-treated patients achieved the prospectively defined criteria for clinical response when compared to placebo treatment. There was a statistically significant overall difference in the PGI rating of symptom change (P = 0.045) and a marginally significant difference (P = 0.089) in the CGI severity rating between groups. Pairwise comparison against placebo showed a marginally statistically significantly greater improvement (P = 0.059) in Y-BOCS-Total score for patients receiving fluoxetine 60 mg daily, and a significantly higher response rate in patients receiving fluoxetine 40 mg or 60 mg daily (P < 0.05). One hundred and sixty one patients continued to a 16-week extension evaluation. There was no significant difference in the rate of reporting of any individual adverse event between placebo and fluoxetine, and the rate of discontinuation due to adverse events was low (< 6% in each study phase). This study supports the growing evidence for the safety and efficacy of fluoxetine in the treatment of OCD.

Adolescent↗
PubMed1993

Butyrate production from dietary fibre and protection against large bowel cancer in a rat model.

Butyrate slows the growth of cancer cells cultured in vitro. To determine the relevance of the fermentative production of butyrate in vivo, colonic butyrate concentrations were manipulated by feeding different dietary fibres and were related to tumour development in the rat dimethylhydrazine model of large bowel cancer. It has previously been shown that guar gum and oat bran, while highly fermentable, are associated with low butyrate levels in the distal colon, while wheat bran causes significantly higher concentrations. Diets containing these fibres (nominally 10% w:w) were administered for 3 weeks before, for 10 weeks during, and for 20 weeks after dimethylhydrazine administration, after which animals were killed and examined for tumours. Significantly fewer tumours were seen in the rats fed wheat bran compared with those fed guar or oat bran, and the total tumour mass was lowest in rats fed wheat bran. Rats on a 'no added fibre diet' had an intermediate tumour mass. Regression analysis, performed regardless of dietary group, showed that the concentration in stools of butyrate but not of acetate or stool volume, correlated significantly (and negatively) with tumour mass. These findings indicate that fibre which is associated with high butyrate concentrations in the distal large bowel is protective against large bowel cancer, while soluble fibres that do not raise distal butyrate concentrations, are not protective. Thus, butyrate production in vivo does bear a significant relationship to suppression of tumour formation.

Animals↗
PubMed1993

A consultative study as a catalyst for improving mental health services for rural children and adolescents.

The consultative study is one model of academic involvement in public mental health services. However, the effects of consultation and how it acts as a catalyst for change have been poorly documented. The authors describe a consultative study in which a team from a academic training center examined the system of mental health and related human services for children and adolescents in a semirural county in western Pennsylvania. They also present results of a six-year follow-up survey assessing the study's effects. Improvement in the system of care during the follow-up period included creation and maintenance of a children's unit and a partial hospital program for adolescents at the country's community mental health center. The consultative study and the follow-up survey were instrumental in establishing a comprehensive range of services, including intensive case management for severely disturbed youngsters and a home-based mental health services program.

Adolescent↗