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Biomedical subjects

R Fraser

Publications and source records attributed to R Fraser.

At least 37 records · Page 2Linked to original sources

Dose-escalating conformal thoracic radiation therapy with induction and concurrent carboplatin/paclitaxel in unresectable stage IIIA/B nonsmall cell lung carcinoma: a modified phase I/II trial.

BACKGROUND: A modified Phase I/II trial was conducted evaluating the incorporation of three-dimensional conformal radiation therapy into a strategy of sequential and concurrent carboplatin/paclitaxel in Stage III unresectable nonsmall cell lung carcinoma (NSCLC). The dose of thoracic conformal radiation therapy (TCRT) from 60 to 74 gray (Gy) was increased. Endpoints included response rate, toxicity, and survival. METHODS: Sixty-two patients with unresectable Stage III NSCLC were included. Patients received 2 cycles of induction carboplatin (area under the concentration curve [AUC], 6) and paclitaxel (225 mg/m(2) over 3 hours) every 21 days. On Day 43, concurrent TCRT and weekly (x 6) carboplatin (AUC, 2) and paclitaxel (45 mg/m(2)/3 hours) were initiated. The TCRT dose was escalated from 60 to 74 Gy in 4 cohorts (60, 66, 70, and 74 Gy). RESULTS: The response rate to induction carboplatin/paclitaxel was 40%. Eight patients (13%) progressed on the induction phase. No dose-limiting toxicity was observed during the escalation of the TCRT dose from 60 to 74 Gy. The major toxicity was esophagitis, however, only 8% developed Grade 3/4 esophagitis using Radiation Therapy Oncology Group criteria. The overall response rate was 52%. Survival rates at 1, 2, 3, and 4 years were 71%, 52%, 40%, and 36%, respectively, with a median survival of 26 months. The 1-, 2-, and 3-year progression free survival probabilities were 47%, 35%, and 29%, respectively. CONCLUSIONS: Incorporation of TCRT with sequential and concurrent carboplatin/paclitaxel is feasible, and dose escalation of TCRT to 74 Gy is possible with acceptable toxicity. Overall response and survival rates are encouraging. Both locoregional and distant failure remain problematic in this population of patients.

Adult↗

Increased membrane sphingomyelin and arachidonic acid in stroke-prone spontaneously hypertensive rats.

BACKGROUND: Cell membrane composition and fluidity are altered in hypertension. Previous reports suggest arachidonic acid, a metabolically active fatty acid, is increased in the membranes of hypertensive animals compared to control. This increase in unsaturated fatty acids does not explain the observed reduction in fluidity in hypertensive rats, suggesting some other factors affecting fluidity may be present. It has been suggested that the metabolism of sphingomyelin is altered in genetic hypertension. We hypothesized that membrane sphingomyelin content is increased in hypertensive animals. PROCEDURES: Stroke-prone spontaneously hypertensive rats (n = 8) were compared with Wistar-Kyoto rats (n = 8). Erythrocyte membranes were prepared and the lipids extracted and separated. Fatty acid methyl esters were produced, identified, and quantified by gas chromatography-mass spectrometry; membrane lipid content was also assessed. RESULTS: The concentration of sphingomyelin was higher in the membrane of the hypertensive rats (45.7+/-6 v 22.4+/-2 microg/mg of protein) compared to control. The previously observed increase in membrane arachidonic acid content was observed in hypertensive animals when compared to control (130+/-32 v 40+/-3 microg/mg of protein). However, this difference was confined to the phosphatidylinositol (18+/-4 v 6.5+/-1.5 microg/mg of protein) and free fatty acid (2.1+/-0.4 v 0.6+/-0.1 microg/mg of protein) fractions. CONCLUSION: We hypothesize that reports of reduced membrane fluidity observed in hypertension may be due to an increase in the proportion of sphingomyelin in the cell membrane.

Animals↗

An influence of variation in the aldosterone synthase gene (CYP11B2) on corticosteroid responses to ACTH in normal human subjects.

OBJECTIVE: Previous evidence suggests that the efficiency of 11beta-hydroxylase is at least partly heritable and also that it may be mildly impaired in essential hypertension. In both cases, assessment of activity was based on the response of 11-deoxycorticosterone (DOC) and 11-deoxycortisol to ACTH. The gene (CYP11B1) coding for this enzyme is highly homologous with and lies a relatively short distance downstream from the gene coding for aldosterone synthase (CYP11B2) on chromosome 8. Two polymorphisms of CYP11B2 have been described. The first involves a change of -344C to T in a putative steroidogenic factor-1 (SF-1) binding site and the other, the intron conversion, an exchange of intron 2 for that of CYP11B1. These polymorphisms are in linkage dysequilibrium. Their effects on 11beta-hydroxylation were studied. METHODS AND RESULTS: Normal subjects (n = 135) were genotyped and those homozygous for either or both the polymorphisms were given ACTH (250 microg, i.v.). Plasma was sampled before and 30 minutes after administration. Basal concentrations of DOC, corticosterone, 11-deoxycortisol and cortisol and responses of corticosterone and cortisol to ACTH were not affected by genotype. However, the responses of DOC (P = 0.002 and P = 0.001, respectively) and 11-deoxycortisol (P = 0.025 and P = 0.002, respectively) were significantly greater in subjects homozygous for SF-1 T and/or intron conversion than in those homozygous for SF-1 C and/or normal intron. CONCLUSIONS: These results indicate different 11beta-hydroxylase efficiencies. Thus, variation in CYP11B2 appears to affect the product of CYP11B1. The mechanism is unclear. The close proximity of the two genes may lead to competition for transcription factors or specific differences in intron 2 may affect transcription. Alternatively, the polymorphisms may be acting as markers for adjacent functional genetic variations.

Adrenocorticotropic Hormone↗

Polymorphic differences from normal in the aldosterone synthase gene (CYP11B2) in patients with primary hyperaldosteronism and adrenal tumour (Conn's syndrome).

OBJECTIVE: The hypertension of Conn's syndrome is due to autonomous aldosterone production by a unilateral adrenocortical adenoma. The source of tumour initiation and the reasons for excess aldosterone production as opposed to cortisol are not known, although variations in the promoter region of the gene coding for aldosterone synthase (CYP11B2) might account for the altered rate of aldosterone secretion. DESIGN: In a series (n = 27) of well-characterized Conn's syndrome cases, the aldosterone synthase gene (CYP11B2) was screened by single-strand conformational polymorphism (SSCP) for differences from the consensus sequence. RESULTS: No new mutations were found. The frequencies of two previously described linked polymorphisms, one a change of -344C to T in a putative steroidogenic factor-1 (SF-1) binding site and the other an exchange of intron 2 for that of CYP11B1 (conversion) were measured in tumour and genomic DNA. The frequency of the SF-1 T allele (P < 0.0001) and the conversion allele (P < 0.001) were markedly different between the Conn's syndrome group and the normal controls. However, the frequency did not differ between tumour and genomic DNA in the patient group. CONCLUSION: While it is unlikely that this difference from normal is related to tumour growth, these genotypes may predispose the tumour to aldosterone production.

Adenoma↗

Seasonal variation in glucocorticoid receptor binding characteristics in human mononuclear leucocytes.

OBJECTIVE: Glucocorticoid sensitivity varies between individuals and between tissues in the same individual. Although some of this variation is explained by the activity of the 11 beta-hydroxysteroid dehydrogenase enzymes, the possibility that glucocorticoid receptor sensitivity is modulated remains unexplored. This study examined glucocorticoid receptor binding in leucocytes and assessed the effects of seasonal hormonal variation on receptor binding. PATIENTS AND MEASUREMENTS: Two populations were studied. In the first, 318 healthy subjects were studied over 2 years with a single measurement of receptor binding made on each. In the second study nine healthy male subjects each had receptor binding measurements made at 3-week intervals over 1 year. RESULTS: In both populations there was significant seasonal variation in receptor binding. In the first population Kd for dexamethasone was highest in November and lowest in July (8.37 +/- 0.5 nmol/l vs. 1.58 +/- 0.7, mean +/- SEM P < 0.00001) and the number of receptor sites per leucocyte was highest in January and lowest in June (10 440 +/- 580 vs. 4969 +/- 302, P < 0.00001). In multivariate analysis, climate was the main determinant for both Kd and the number of receptor sites per cell: increases in day length and environmental temperature reduced Kd and the number of receptor sites per cell. Co-incubation with physiological concentrations of melatonin raised Kd without affecting receptor number. Co-incubation with forskolin lowered Kd suggesting that melatonin might act through the ML1 receptor class by inhibiting adenylyl cyclase. No correlations were found with 0900 h plasma cortisol. CONCLUSIONS: The results suggest that the glucocorticoid receptor might be modulated by season. Melatonin might mediate part of these effects. The lack of correlation with cortisol suggests that it is not an important determinant of receptor binding and that leucocyte receptors are regulated differently from central receptors.

Adenylyl Cyclase Inhibitors↗

The effect of acute hyperglycaemia on appetite and food intake in Type 1 diabetes mellitus.

AIMS: To determine the effects of acute hyperglycaemia on appetite and food intake in Type 1 diabetes mellitus. METHODS: Two separate studies, each involving eight adults with uncomplicated Type 1 diabetes, were performed: one in the fasted state (A) and the other after a nutrient preload (B). In both studies, perceptions of appetite (hunger and fullness) and food intake at a buffet meal were evaluated during euglycaemia (blood glucose, approximately 6 mmol/l) and hyperglycaemia (blood glucose, approximately 14 mmol/l). Both experiments were randomized and single-blind. In study A, appetite was assessed in the fasted state for 90 min before the buffet meal. In study B, a nutrient 'preload' of Ensure and milk containing 13C-octanoic acid was consumed 90 min before the meal. Gastric emptying of the preload was quantified with a radioisotopic breath test technique. RESULTS: There was no significant difference in plasma insulin concentrations between euglycaemia and hyperglycaemia in either study. In study A, there were no differences in hunger, fullness or energy intake between the two treatment days. In study B, subjects were slightly less hungry between the preload and buffet meal during hyperglycaemia than euglycaemia (P = 0.04), and tended to have slower gastric emptying during hyperglycaemia (emptying coefficient, 3.89 +/- 0.16 vs. 3.57 +/- 0.21; P = 0.052), but there was no difference in food intake between hyperglycaemia and euglycaemia. CONCLUSIONS: Acute hyperglycaemia suppresses hunger after a nutrient preload, but not in the fasted state, in patients with uncomplicated Type 1 diabetes. This effect is small and not associated with changes in food intake.

Adolescent↗

Disorders of mineralocorticoid synthesis.

Abnormalities of mineralocorticoid synthesis and/or metabolism profoundly affect the regulation of electrolyte and water balance and of blood pressure. Characteristic changes in extracellular potassium, sodium and hydrogen ion concentrations are usually diagnostic. Serious deficiency may be acquired, for example in Addison's disease, or inherited. In most of the inherited syndromes, the precise molecular changes in specific steroidogenic enzymes have been identified. Mineralocorticoid excess may be caused by aldosterone or 11-deoxycorticosterone by inadequate conversion of cortisol to cortisone by 11beta-hydroxysteroid dehydrogenase type 2 in target tissues (see Chapter 4), by glucocorticoid receptor deficiency or by constitutive activation of renal sodium channels. Changes in electrolyte balance and renin as well as the abnormal pattern of corticosteroid metabolism are usually diagnostic. Where these abnormalities are inherited (e.g. 11beta- or l7alpha-hydroxylase deficiencies, glucocorticoid remediable hyperaldosteronism (GRA), receptor defects, Liddle's syndrome), the molecular basis is again usually known and, in some cases, may provide the simplest diagnostic tests. Primary aldosteronism, although readily identifiable, presents problems of differential diagnosis, important because optimal treatment is different for each variant. Moreover, the mechanisms by which the variants develop are poorly understood. Finally, a significant proportion of patients with essential hypertension show characteristics of mild mineralocorticoid excess, for example low renin levels. Is this relevant to pathophysiology and, if so, is the effect induced via classic mechanisms of action or through newly discovered direct actions on the brain, heart and blood vessels? These questions are the subject of current research.

Adrenal Cortex Hormones↗

Determination of in vivo absorption, metabolism, and transport of drugs by the human intestinal wall and liver with a novel perfusion technique.

BACKGROUND AND AIMS: The contribution of the gastrointestinal tract in comparison with the liver for the low and variable bioavailability of orally administered drugs is still poorly understood. Here we report on a new intestinal perfusion technique for the direct assessment of absorption, metabolism, and transport of drugs by the intestinal wall. METHODS: In 6 healthy volunteers a multilumen perfusion catheter was used to generate a 20-cm isolated jejunal segment that was perfused with 80 mg verapamil. Simultaneously, 5 mg [(2)H(7)]verapamil was given intravenously. Blood, perfusate, and bile samples were analyzed for parent verapamil and its major metabolites. RESULTS: The mean fraction of the verapamil dose absorbed from the 20-cm segment was 0.76 but substantial interindividual variability (0.51-0.96) was shown. Bioavailability was low (19.3%). The intestinal wall contributed to the same extent as the liver to extensive first-pass metabolism (mean extraction ratio, 0.49 versus 0.48). Substantial transport of verapamil metabolites from the systemic circulation via the enterocytes into the intestinal lumen was observed. Compared with biliary excretion, intestinal secretion into a 20-cm jejunal segment contributed to drug elimination to a similar extent. CONCLUSION: First-pass metabolism by the intestinal wall is extensive and contributes to the same extent as the liver to low bioavailability of some drugs such as verapamil. Moreover, intestinal secretion is as important as biliary excretion for the elimination of metabolites.

Adult↗

Delayed gastric emptying in ventilated critically ill patients: measurement by 13 C-octanoic acid breath test.

OBJECTIVE: To measure gastric emptying in ventilated critically ill patients with a new noninvasive breath test. DESIGN: Single-center, open study. SETTING: Combined medical and surgical intensive care unit of a university hospital. SUBJECTS: Thirty unselected mechanically ventilated critically ill patients receiving gastric feeding and 22 healthy volunteers. INTERVENTIONS: None. PATIENTS: After 4 hrs without feeding, intragastric infusion of 100 mL of a liquid meal (Ensure) labeled with 100 microL 13C-octanoic acid. End-expiratory breath samples were collected into evacuated tubes from the respirator circuit every 5 mins for the first hour, then every 15 mins for 3 hrs. End-expiratory breath samples were also collected from volunteers studied supine after an overnight fast following an identical infusion via a nasogastric tube. Breath 13CO2 was measured with an isotope ratio mass spectrometer. MEASUREMENTS AND MAIN RESULTS: Performance of the breath test posed no difficulty or interference with patient care. The CO2 level was >1% in 1297/1300 breath samples, indicating satisfactory end-expiratory timing. Data are median and interquartile range. Gastric emptying was slower in patients compared with volunteers: gastric emptying coefficient 2.93 (2.17-3.39) vs. 3.58 (3.18-3.79), p <.001 and gastric half emptying time, derived from the area under the 13CO2 curve, 155 min (130-220) vs. 133 min (120-145), p <.008. Fourteen of the 30 patients had a gastric emptying coefficient <95% of all volunteers and 11 had a gastric half emptying time longer than 95% of all volunteers. The Acute Physiology and Chronic Health Evaluation (APACHE II) score (median 22, range 13-43) either at admission or on the day of the study did not correlate with gastric emptying coefficient. CONCLUSION: Gastric emptying of a calorie-dense liquid meal is slow in 40% to 45% of unselected mechanically ventilated patients in a combined medical and surgical intensive care unit. The 13C-octanoic acid breath test is a novel and useful bedside technique to measure gastric emptying in these patients.

APACHE↗

Small intestinal motor patterns in critically ill patients after major abdominal surgery.

OBJECTIVES: In patients who have had major surgery or trauma, early enteral feeding is safer and more effective than parenteral or nasogastric feeding but is frequently associated with diarrhea. Limited recordings have shown that the patterning of duodenal interdigestive motor activity is frequently abnormal after surgery or in patients who are critically ill. The aims of this study were to evaluate the effects of major abdominal surgery on small intestinal motility, and to elucidate the motor patterns that occur postoperatively in critically ill patients in response to enteral feeding. METHODS: The effects of elective aortic aneurysm repair on small intestinal motility were studied in 11 patients aged 63-77 yr. A 3.5-mm diameter multilumen extrusion was used to monitor pressures at 12 points, distributed between the antrum and 100 cm distal to the pylorus. An additional lumen allowed enteral feeding into the duodenum. Recordings commenced immediately postoperatively and continued for up to 4 days. Data are given as means and SEMs. RESULTS: Bursts (frequency > 10/min) of small intestinal pressure waves that resembled phase III interdigestive motor activity occurred in all patients immediately after surgery. During mechanical ventilation, the timing of bursts along the segment evaluated was frequently abnormal for true interdigestive phase III activity, with simultaneous onset in multiple channels (46%), multiple or distal origins (8%), or retrograde migration (20%). When patients were not being ventilated, the migration pattern of the bursts was more typical of interdigestive phase III activity. The interval between bursts was unusually short for interdigestive motor activity, although it increased from 30+/-12 min on day 1 to 41+/-18 min on day 3 (p < 0.05). A phase II pattern of pressure waves was virtually absent in all patients on all study days. In six patients who received postoperative enteral nutrition, the bursts of pressure waves were not abolished by feeding, contrary to normal phase III activity. CONCLUSIONS: Small intestinal pressure wave bursts are seen immediately after elective aortic aneurysm repair, but the migration of these bursts is frequently abnormal for phase III interdigestive activity. Duodenal nutrient delivery did not interrupt the occurrence of these bursts. Persistence of pressure wave bursts in this setting may be important in the delivery of enteral nutrition.

Aged↗

Enteral nutrition in the critically ill: a prospective survey in an Australian intensive care unit.

Nutritional support is routine practice in critically ill patients and enteral feeding is preferred to the parenteral route. However this direct delivery of nutrients to the gut is potentially ineffective for a variety of reasons. We performed a prospective audit of 40 consecutive intensive care patients to determine whether enteral feeding met the nutritional requirements of our patients. The ideal requirements for each patient were calculated using the Harris-Benedict equation with an adjustment determined by the patient's diagnosis. We compared the amount of feed delivered with the daily requirements over a seven-day period Successful feeding was defined as the achievement of 90% of the ideal calorie requirement for two consecutive days. The mean calculated (+/- SD) energy requirement was 9,566 kJ (+/- 2,586). Patients received only 51% (SD 38) of their energy requirements throughout the study period. Only 10 patients (25%) were successfully fed for at least any two-day period in the seven days. Feeding was limited mainly by gastrointestinal dysfunction or by the need to fast the patient for medical, surgical and airway procedures. Success of feeding was not related to the use of sedative orparalysing agents and had no correlation with plasma albumin concentration. There was no difference in the volume of feed delivered to patients who survived or died. Prokinetic agents were used in 25 patients and in these patients there was a trend towards improved delivery of feed.

Adolescent↗

Effects of 18-hydroxylated steroids on corticosteroid production by human aldosterone synthase and 11beta-hydroxylase.

In glucocorticoid-suppressible hyperaldosteronism, 11beta- hydroxylase activity is impaired. A chimeric enzyme formed from the control elements of 11beta-hydroxylase and the structural elements of aldosterone synthase is expressed ectopically in the zona fasciculata, thus exposing cortisol to aldosterone synthase. Increased quantities of 18-hydroxycortisol and 18-oxocortisol are synthesized, which, it has been suggested, might have a local inhibitory effect on the normal 11beta-hydroxylase. The effects of these compounds and also of 18-hydroxydeoxycorticosterone were tested in cells stably transfected with CYP11B1 and CYP11B2, the genes encoding 11beta-hydroxylase and aldosterone synthase, respectively. Neither 18-hydroxycortisol nor 18-oxocortisol affected the efficiency of use of 11-deoxycorticosterone or 11-deoxycortisol as substrates by the enzymes. 18-Hydroxydeoxycorticosterone significantly reduced the conversion rate of 11-deoxycorticosterone to corticosterone and that of 11-deoxycortisol to cortisol by both enzymes, but the production rate of 18- hydroxycorticosterone and aldosterone by aldosterone synthase increased. Aldosterone synthase was able to convert 18-hydroxydeoxycorticosterone to 18-hydroxycorticosterone and aldosterone, although its affinity for this substrate was lower (4.76 micromol/liter) than that for 11-deoxycorticosterone (0.11 micromol/liter). 11beta-Hydroxylase was unable to convert 18- hydroxydeoxycorticosterone to 18-hydroxycorticosterone. 18-Hydroxycortisol and 18-oxocortisol are not, therefore, the cause of lower 11beta-hydroxylase activity in glucocorticoid- suppressible hyperaldosteronism. 18-Hydroxydeoxycorticosterone can be converted to aldosterone, but its local concentration in man and its K(m) suggest that it is unlikely to be important.

Adrenal Cortex Hormones↗

Induction carboplatin/paclitaxel followed by concurrent carboplatin/paclitaxel and dose-escalating conformal thoracic radiation therapy in unresectable stage IIIA/B nonsmall cell lung carcinoma: a modified Phase I trial.

BACKGROUND: A modified Phase I trial was conducted evaluating the incorporation of 3-dimensional conformal radiation therapy (3DCRT) into a strategy of sequential and concurrent carboplatin/paclitaxel in Stage III, unresectable nonsmall cell lung carcinoma (NSCLC). In addition, dose escalation of thoracic conformal radiation therapy (TCRT) from 60 to 74 gray (Gy) was performed. Endpoints included response rate, toxicity, and survival. METHODS: Twenty-nine patients with unresectable Stage III NSCLC were included. Patients received 2 cycles of induction carboplatin (AUC 6) and paclitaxel (225 mg/m(2)/3 hours) every 21 days. On Day 43, concurrent TCRT and weekly (x6) carboplatin (AUC 2) and paclitaxel (45 mg/m(2)/3 hours) was initiated. The TCRT dose was escalated from 60 to 74 Gy in 4 cohorts. RESULTS: The response rate to induction carboplatin/paclitaxel was 52%. Three patients (10%) experienced disease progression during the induction phase. No dose-limiting toxicity was seen during the escalation of the TCRT dose from 60 to 74 Gy. The major toxicity was esophagitis, with 18% of patients developing Radiation Therapy Oncology Group Grade 3 esophagitis. The overall response rate was 70% (1 complete response and 18 partial responses). Survival rates at 1 and 2 years were 69% and 45%, with a median survival of 21 months. The 1-year progression free survival probability was 41% (95% confidence interval, 23-59%). CONCLUSIONS: Incorporation of 3DCRT with sequential and concurrent carboplatin/paclitaxel is feasible, and dose escalation of TCRT to 74 Gy is possible with acceptable toxicity. Overall response and survival rates are encouraging. Accrual is continuing in a Phase II fashion at 74 Gy with sequential and concurrent carboplatin/paclitaxel.

Adult↗

Chronic effects of therapeutic irradiation for localized prostatic carcinoma on anorectal function.

PURPOSE: To evaluate prospectively the prevalence and pathophysiology of anorectal dysfunction following radiation therapy (RTH) for localized carcinoma of the prostate. METHODS AND MATERIALS: The following parameters of anorectal function were evaluated in each of 35 patients (aged 55-82 years) with localized prostatic carcinoma treated with RTH either to a dose of 55 Gy/20 fractions/4 weeks (18 patients) or 64 Gy/32 fractions/6.5 weeks (17 patients), before RTH and 4-6 weeks and at a mean (+/- SD) of 1.4 (+/- 0.2) years after its completion: (1) anorectal symptoms (questionnaire), (2) anorectal pressures at rest and in response to voluntary squeeze and increases in intra-abdominal pressure (multiport anorectal manometry), (3) rectal sensation (balloon distension) and (4) anal sphincteric morphology (endoanal ultrasound). RESULTS: All but 1 patient completed three series of measurements. RTH had no effect on anal sphincteric morphology. The increase in frequency of defecation and fecal urgency and incontinence scores previously reported in the patients 4-6 weeks after RTH were sustained 1 year later (p < 0.001, p < 0.001, and p < 0.05, cf. baseline, respectively). At this time, 56% (19 of 34), 50% (17 of 34) and 26% (9 of 34) of the patients had increased frequency of defecation, fecal urgency, and incontinence, respectively. Decreases in anal sphincteric pressures at rest and in response to voluntary squeeze recorded in the patients 4-6 weeks after RTH were not sustained 1 year later but the volumes of rectal distension associated with perception of the stimulus and desire to defecate were lower compared with baseline volumes (p < 0.01 and p < 0.05, respectively), reflecting heightened rectal sensitivity in the patients. There was no difference in measurements between the two radiation dose regimens. Univariate logistical regression analysis was performed on patients who had experienced increased symptom scores or decreases in recorded motor and sensory manometric parameters at 1 year, cf. baseline. The predictor variables used included individual patient tumor and treatment characteristics as well as individual patient symptom scores and parameters of anorectal motor and sensory function at baseline and 4-6 weeks after RTH. The results of the univariate logistical regression analysis showed that (1) frequency of defecation at 4-6 weeks and (2) rectal volumes at baseline both for (a) perception (p < 0.001) and (b) desire to defecate (p < 0.001), predicted significantly for the patients who had symptoms and signs of anorectal dysfunction at 1 year. Individual patient tumor and treatment-related variables tested, in contrast, had no predictive significance. CONCLUSIONS: Anorectal symptoms following RTH for prostatic carcinoma are common and persist at least until 1 year after its completion and are associated with objective evidence of heightened rectal sensitivity.

Aged↗

Liposome encapsulation of a soluble recombinant fragment of the respiratory syncytial virus (RSV) G protein enhances immune protection and reduces lung eosinophilia associated with virus challenge.

Respiratory syncytial virus (RSV) is a leading cause of bronchiolitis and pneumonia in young children and infants. Previous animal studies have shown that immunizing intramuscularly or intraperitoneally with the RSV G protein has elicited protective as well as harmful immune responses upon RSV challenge. In an RSV immunization strategy designed to target the respiratory tract directly (the site of RSV replication), we immunized BALB/c mice intranasally with a liposome-encapsulated, prokaryotically expressed thioredoxin fusion protein consisting of amino acids 128-229 of the RSV G protein (Trx-G(128-229)). Upon intranasal challenge with RSV, a 100 to 500-fold reduction in lung RSV replication was observed in mice immunized with liposome-encapsulated Trx-G(128-229) compared to a sham-immunized control group. Analysis of bronchoalveolar lavage fluids revealed an influx of eosinophils (18% of total cells) in mice immunized with Trx-G(128-229) alone. Such eosinophilic infiltration was diminished (to 4.5% of total cells), however, in mice immunized with liposome-encapsulated Trx-G(128-229). Histological analysis of lung tissue revealed an accumulation of cells around the bronchioles and vessels in mice immunized with Trx-G(128-229) alone followed by RSV challenge which was not increased further in mice immunized with liposome-encapsulated Trx-G(128-229). These results show that intranasal immunization of BALB/c mice with Trx-G(128-229), when encapsulated in liposomes, can reduce the level of RSV replication in the lung as well as specifically reduce the degree of eosinophilic infiltration compared to mice immunized with Trx-G(128-229) alone. This demonstrates the potential of liposomes and particular recombinant fragments of the RSV G protein as an effective combination in RSV vaccine studies.

Animals↗