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PubMed2001

Helical antenna arrays for interstitial microwave thermal therapy for prostate cancer: tissue phantom testing and simulations for treatment.

Interstitial microwave therapy is an experimental treatment for prostate cancer. The objective of this work was to measure the power deposition (specific absorption rate, SAR) patterns of helical microwave antennae both individually and in array patterns that would be useful for clinical treatment protocols. Commercial helical antenna 3D SAR patterns were measured in muscle equivalent phantoms using a thermographic technique. Two array patterns were tested: a 'square' and a 'crescent' array, both surrounding the urethra. To assess the feasibility of pre-treatment planning, the measured SAR patterns were input to a treatment planning computer simulation program based on a series of trans-rectal ultrasound images from a prostate cancer patient. The simulation solved the Pennes linear bioheat heat transfer equation in prostate tissue, with the aim of achieving a target of 55 degrees C at the prostate periphery while not allowing normal surrounding tissues (bladder, urethra, rectum) to rise above 42 C. These criteria could not be met with the square array but they could be met with the crescent array, provided that the prostate was first dissected away from the rectum. This can be done with a procedure such as 'hydrodissection', where sterile saline is injected to separate the prostate and rectum. The results of these SAR measurements and heat transfer simulations indicate that arrays of helical antennae could be used for safe and effective thermal therapy for prostate cancer.

Acrylic Resins↗

PubMed1978

Observations on the osmotic pressure measurement in cryptonephric insects.

Osmotic pressure of the haemolymph, perirectal fluid and of the rectal fluid of four "Species of cryptonephric insects (Tenebrio, Dermestes, Galleria and Pieris) has been measured. In all cases the osmotic pressure of the rectal fluid is much higher than that of the haemolymph and the osmotic pressure of the perirectal fluid is intermediate between these two. The cryptonephric Malpighian tubules increase the osmotic pressure in the perirectal fluid. Consequently between the blood and the rectum there is a chamber which has an osmotic pressure higher than that of the blood but lower than that of the rectum. This higher osmotic pressure in the perinephric chamber enables the modified epithelium to do less work in the absorption of water and nutrient salts from the faecal waste.

Animals↗

PubMed1993

Fluid replacement during exercise.

Current evidence indicates that adequate fluid ingestion during exercise enhances athletic performance, prevents a fall in plasma volume, stroke volume, cardiac output and skin blood flow, maintains serum sodium concentrations and serum osmolality, lowers rectal temperature and the perception of effort, and prevents a progressive rise in heart rate. Rates of sweating and urine flow are not influenced by fluid ingestion. The evidence suggests that the maintenance of serum osmolality and serum sodium concentrations at pre-exercise levels is the important determinant of these beneficial effects of fluid ingestion on cardiovascular function and thermoregulation. The provision of glucose in the ingested solution may be necessary to optimize performance; glucose ingestion that enhances fluid and sodium absorption in the small bowel may also present a progressive rise in oxygen consumption during exercise. Sweetened carbohydrate-containing drinks may also increase fluid intake during exercise, thereby minimizing voluntary dehydration. Hence, the optimum solution for ingestion during exercise should provide carbohydrate, probably at rates of about 1 g/min and electrolytes in concentrations that, when drunk at the optimum rate, maintain serum osmolality and plasma volume at pre-exercise levels by replacing exactly that water and electrolyte losses from the extracellular space. At present, the composition of the fluid that will optimize electrolyte and fluid replacement of the extracellular space is not established. Neither are the optimum rates of fluid ingestion during exercise known. At low sweat rates (< 1 liter/hr), it is probable that all of the lost fluid can and should be replaced; rates of fluid ingestion needed to offset higher sweat rates may exceed the maximum intestinal absorptive capacity for water. Furthermore, high rates of fluid intake (> 1 liter/hr) are achieved with difficulty during exercise, especially when running, and are likely to lead to feelings of abdominal discomfort, possibly due to the accumulation of unabsorbed fluid in the small bowel or colon. Practicing to drink regularly during training might reduce the severity and frequency of these symptoms, possibly by increasing intestinal absorptive capacity. Most athletes are "reluctant" drinkers during exercise and do not ingest fluid at rates equal to their rates of fluid loss; hence, they develop progressive (voluntary) dehydration during prolonged exercise. Surprisingly, the level of voluntary dehydration that develops during exercise is relatively independent of the duration or intensity of the activity. The factors that explain these phenomena remain elusive. Fluid consumption during exercise is enhanced by the ingestion of cold, sweet fluids. Simultaneous food consumption also stimulates fluid ingestion.(ABSTRACT TRUNCATED AT 250 WORDS)

Dehydration↗

PubMed1985

Aldosterone metabolism and transepithelial potential difference in normal and cystic fibrosis subjects.

The transepithelial potential difference (PD) is raised across cystic fibrosis (CF) respiratory epithelia. This raised voltage reflects active sodium absorption across a relatively chloride impermeable membrane. Because relatively little is known about the regulation of the rate of sodium absorption across mammalian airways, we assessed the possible contribution of aldosterone to the PD in normal and CF respiratory epithelia. Aldosterone excretion in five CF patients was 12.2 +/- 0.9 micrograms/24 h, a mean value not different from normal control subjects (13.6 +/- 1.5 micrograms/24 h, n = 5). Despite similar aldosterone excretion rates, nasal PD was more than 2-fold greater in the CF patients (-53.6 +/- 6.4 mV) than normal subjects (-21.3 +/- 1.4 mV). The effect of an aldosterone antagonist, spironolactone, on aldosterone excretion and nasal and rectal PD was evaluated in four CF patients and five normal subjects. During spironolactone administration, aldosterone excretion increased (2- to 4-fold) and rectal PD decreased in both groups. However, nasal PD was unchanged in each group (CF = -52.1 +/- 4.3 mV pre, -53.6 +/- 1.4 mV during; normal = -21.2 +/- 3.1 mV pre, -21.6 +/- 3.2 mV during). We conclude that neither increased aldosterone secretion rates nor organ sensitivity to aldosterone can account for the abnormally raised PD that characterizes the respiratory epithelium of subjects with CF.

Adult↗

PubMed1975

Bile acid metabolism in cirrhosis. IV. Characterization of the abnormality in deoxycholic acid metabolism.

Several recent studies have demonstrated that patients with cirrhosis frequently lack deoxycholic acid in bile and plasma. In order to explain this observation, comparative experiments on the colonic absorption of deoxycholic acid and on the colonic conversion of cholic to deoxycholic acid were carried out in the cirrhotic patients with normal and very low percentages of deoxycholic acid. Deoxycholic or cholic acid (100 mg) plus 5 muc of each [14C] bile acid were administered by enema to 8 patients with and 5 without liver disease. Deoxycholic acid produced a significant increase in the percentage of biliary deoxycholic acid in patients with cirrhosis. However, the rate of appearance of 14C-deoxycholic acid in patients with cirrhosis was slower than in normal control subjects. Distribution of the 14C activity among the bile acids indicated that rehydroxylation of deoxycholic to cholic acid did not occur. The distribution of 14C activity in biliary bile acids after the rectal administration of [14C]cholic acid showed that patients with severe cirrhosis converted [14C]cholic to [14C]deoxycholic acid at a much slower rate than did cirrhotic patients with normal percentages of biliary deoxycholic acid. Feeding of cholic acid (450 mg per day) for 3 days to 4 cirrhotic patients resulted in a 2-fold increase in the percentage of biliary cholic acid, but only a small increase in the percentage of deoxycholic acid. In a separate group of 9 cirrhotic patients, fecal bile acid analysis indicated that cirrhotic patients had a significantly lower percentage of deoxycholic acid than 12 patients without liver disease; there was no significant difference in fecal lithocholic acid. The data suggest that alteration of bacterial flora and/or altered conditions for bacterial 7alpha-dehydroxylase enzyme activity in the colon could account for the virtual absence of biliary deoxycholic acid in severely cirrhotic patients.

Adult↗

PubMed2004

Butyrate as an effective treatment of congenital chloride diarrhea.

BACKGROUND & AIMS: Many therapeutic attempts have demonstrated to be ineffective in reducing the severity of congenital chloride diarrhea and its long-term complications. The short-chain fatty acid butyrate stimulates intestinal water and ion absorption through a variety of mechanisms, including the activation of a parallel Cl-/butyrate and Na+/H+ exchanger. In this case report, we report the therapeutic efficacy of butyrate on an 11-year-old patient affected by congenital chloride diarrhea. METHODS: The efficacy of increasing doses of oral butyrate (from 50 to 100 mg/kg/day) was investigated through the daily evaluation of stool volume, bowel movements, fecal incontinence, serum, and stool electrolytes concentrations. The modifications in transepithelial intestinal ion transport elicited by butyrate were examined by rectal dialysis study. RESULTS: A butyrate dose of 100 mg/kg/day induced a normalization of stool pattern and of serum and fecal electrolytes concentration. The rectal dialysis study demonstrated a proabsorptive effect induced by butyrate on Na+, Cl-, and K+ intestinal transport. Butyrate therapy was well tolerated during the entire 12-month observation period, and the stool pattern and fecal and serum ion concentrations remained stable within the normal ranges. No clinical adverse events or episodes of dehydration requiring hospital care were observed. CONCLUSIONS: Butyrate could be effective in treating congenital chloride diarrhea. It is easily administered, useful in preventing severe dehydration episodes, and may be a promising therapeutic approach for a long-term treatment in this rare and severe condition.

Butyrates↗

PubMed1994

Fibre utilization by Kalahari dwelling subterranean Damara mole-rats (Cryptomys damarensis) when fed their natural diet of gemsbok cucumber tubers (Acanthosicyos naudinianus).

Kalahari dwelling Damara mole-rats (Cryptomys damarensis) naturally feed on a high fibre diet of underground gemsbok cucumber tubers, Acanthosicyos naudinianus. We investigated the degree of fibre utilization and fermentation on this diet by measuring caecal characteristics (namely temperature, pH and weight) and in vitro rates of gas and short chain fatty acid (SCFA) production in these underground dwelling hind-gut fermentors. Rectal temperatures (33.8 +/- 0.6 degrees C) were consistently higher than caecal temperatures (33.3 +/- 0.6 degrees C). Furthermore, a 0.8 degrees C gradient of temperatures existed within the caecum, with the lowest temperature occurring in the corpus caeci. Both rates of gas production (4.74 +/- 0.6 ml/g dry matter/hr) and SCFA production (266.80 +/- 9.251 mumol/caecum per hr) were high, with proportionately more acetic acid produced than any other SCFA. Nevertheless, the initial concentrations of SCFAs present in the caecum were low (52 +/- 17 mM) implying a rapid rate of absorption of these SCFAs. The high rates of fermentation provide a considerable amount of energy that would otherwise be trapped in fibre and thus unavailable to the animal. This highly efficient caecal fermentation enables the Damara mole-rat to maximally exploit the underground food resources in the arid-zone ecotope.

Animals↗

PubMed2002

Proteinases and proteinase-activated receptor 2: a possible role to promote visceral hyperalgesia in rats.

BACKGROUND & AIMS: PAR-2s are highly expressed throughout the gastrointestinal tract. These receptors are cleaved by trypsin and mast cell tryptase and can be activated by peptides corresponding to the tethered ligand of the receptor (SLIGRL-NH2 for rat). The aim of this study was to determine whether colonic administration of PAR-2 agonists affects visceral sensitivity to rectal distention in conscious rats. METHODS: Abdominal contractions (a criteria of visceral pain) were recorded in rats equipped with intramuscular electrodes. Rectal distention was performed at various times after intracolonic infusion of SLIGRL-NH2 and trypsin. Inflammation parameters and permeability were followed in the colon after the intracolonic injections. Fos expression at a spinal level (L4-L6) was also studied 2 hours after intracolonic injection of SLIGRL-NH2. RESULTS: Rectal distention significantly increased abdominal contractions starting at the RD volume of 0.8 mL. Intracolonic injection of SLIGRL-NH2 (200 microg/rat) and trypsin (200 U/rat), but not vehicle, LRGILS-NH2 (control peptide), boiled trypsin, or SLIGRL-NH2 injected IP, significantly increased (P < 0.05) abdominal contractions for high volumes of distention, 10- and 24-hour postinfusion. SLIGRL-NH2-induced hyperalgesia was inhibited by a NK1 receptor antagonist (SR 140333) but not by indomethacin. Intracolonic injection of SLIGRL-NH2 elevated spinal Fos expression and caused increased intestinal permeability but did not cause detectable inflammation. CONCLUSIONS: Intracolonic infusion of subinflammatory doses of PAR-2 agonists activated spinal afferent neurons and produced a delayed rectal hyperalgesia that involves changes in intestinal permeability and the activation of NK1 receptors. These results identify a possible role for proteinases and PAR-2 in the genesis of visceral hyperalgesia.

Animals↗

PubMed2000

Ultrastructure of the midgut and hindgut of Derocheilocaris remanei (Crustacea, Mystacocarida).

Ultrastructural features and structure of the midgut and hindgut of Derocheilocaris remanei were studied. The large endodermal midgut is differentiated into an anterior midgut and a posterior midgut separated by a conspicuous constriction. Both circular and longitudinal striated muscle bands surround the midgut, while the hindgut only presents longitudinal muscles. The limit between the midgut and the cuticle-lined hindgut is marked by a rectal valve. In cross-section, the short hindgut is triradiate and has a distinct Y-shaped lumen. The hindgut cuticular lining appears interrupted at the tip of every branch of the Y. Three different cell types are found in the midgut epithelium: basally located undifferentiated cells that give rise to the other two specialized cell types; secretory zymogen-like cells responsible for extracellular digestion and located mainly in the anterior midgut; and vacuolated cells, distributed all along the midgut and appearing to have several functions, including absorption, intracellular digestion, and nutrient transport. A single basic cell type forms the hindgut epithelium. The suggested function for the hindgut is the transport and ejection of waste products.

Animals↗

PubMed1993

[How to improve physiological disorders?].

Physiological disturbances can be caused by loss of large intestine, ileocecal valve and half of anal canal mucosa. Pouch can not compensate the whole colonic absorptive function and patients have to live with some of functional abnormality. Pouch should be made as large as possible with good compliance to maintain reservoir function. Post-operative anal complications also should be minimized to prevent anal dysfunction caused by late fistula or stricture.

Adrenal Cortex Hormones↗

PubMed2000

Is bisacodyl absorbed at all from suppositories in man?

A HPLC procedure was developed to determine free BHPM in human plasma and urine after prior deconjugation of its glucuronides with glucuronidase. A single dose administration of a 10 mg bisacodyl suppository from Glaxo Wellcome, Poznań (Poland) to 16 volunteers each resulted in its low active metabolite (BHPM) plasma levels (10-55 microgram l(-1)) according to general assumptions. Its prompt laxative effect appeared within 56.6+/-10.8 min. The calculated serum half-life time of BHPM glucuronide excretion in urine was approximately 7.32+/-0.99 h. BHPM was excreted in urine in only 3. 36+/-0.52% if compared with the above bisacodyl rectal dose administered. Any relationship between BHPM plasma and/or urine levels and its laxative action does not occur. These results confirm the thesis that the laxative action of bisacodyl suppositories is initiated through a direct interaction of the drug in the rectum.

Adolescent↗

PubMed1998

[Phase I study of orally administered UFT plus l-leucovorin].

A Phase I study of UFT plus l-LV was conducted in 29 patients (pts) with G.I. cancer on a multicenter cooperative study. UFT and l-LV were given orally in two divided doses for 28 consecutive days, followed by a 14 day-rest period. UFT was fixed in three doses, 250, 313 and 375 mg/m2/day, and l-LV was increased in dose from 25 to 50 and to 100 mg/body/days. Dose-limiting toxicities were anorexia, diarrhea, and nausea/vomiting. The maximum tolerated dose of UFT was 375 mg/m2/day, and l-LV 25 mg/body/day. Severe myelotoxicity was not observed. There were three responders (PR) out of 21 pts with measurable disease at UFT doses of 313 mg/m2/day and l-LV 50 and 100 mg/body/day. Responses observed were abdominal mass (rectal ca), liver metastasis (pancreas ca) and metastasis of liver and lymph-node (gastric ca). As a result of pharmacokinetics, plasma concentrations of 5-methyl-THF were maintained > 1.0 microM for over 5 hours that was considered to have a modulating effect on the plasma concentration. In doses of 50 mg and 100 mg/body/day of l-LV. No accumulations in plasma were observed in patient treated in 28 days by l-LV/UFT therapy. It was suggested UFT and l-LV did not interfere with each other's absorption. A Phase II study is recommended, with doses of 313 mg/m2/day of UFT and 50 or 100 mg/body/day of l-LV.

Administration, Oral↗

PubMed1991

The clinical pharmacokinetics of two different preparations of intrarectal ketoprofen following spinal or local anesthesia for anal surgery.

Two different preparations of commercially available suppositories containing Ketoprofen (KP) were administered to 49 patients immediately following anal surgery. The KP was prepared as either fatty suppositories (FS) or gelatin capsulated suppositories (GCS) and surgery was performed under either spinal (n = 37) or local anesthesia (n = 12). Similar results were observed in the kinetics of KP after both FS and GCS administration. The extent of bioavailability of the two dosage forms in the patient groups and control subjects (n = 10) were essentially equal. When the pharmacokinetic parameters of KP were compared between patient groups under spinal and local anesthesia, significant differences were found in the values of the peak level (C max), peak time (T max), and terminal phase half-life (t 1/2). The C max decreased by one-half, while the T max and t 1/2 increased twice and four times, respectively, in patient operated on under spinal anesthesia compared to those operated on under local anesthesia. The absorption rate constant (Ka) following spinal anesthesia was significantly less than that following local anesthesia or that of the healthy subjects (p less than 0.01). A "flip-flop" phenomena could be seen in the time profiles of plasma KP concentration following spinal anesthesia.

Administration, Rectal↗

PubMedDate not supplied

Pharmacokinetics and bioavailability of theophylline following enema and suppository administration in man.

The pharmacokinetics and bioavailability of theophylline from a commercial oral elixir of theophylline, a rectal suppository of aminophylline, and a rectal enema of theophylline monoethanolamine was compared in six normal subjects. Using a complete crossover design, the fasted subjects received a single dose of each dosage form. Blood and saliva samples were collected at frequent time intervals for 24 h, and the plasma assayed for theophylline by a specific thin-layer chromatography densitometric method. No statistically significant differences existed among the three dosage forms with respect to Cmax and AUC corrected for the elimination rate constant and the dose (mg kg-1). However, tmax was significantly larger for the suppository. While the rate of absorption was significantly slower for the suppository, no differences in the extent of absorption existed among the three dosage forms. A one-compartment open model with apparent first-order absorption adequately described the plasma concentration-time data for the elixir and enema, whereas the suppository data were best fitted by a one-compartment open model with apparent zero-order absorption and a lag time. A rate-limiting, concentration-independent release of drug from the base most likely accounts for the slow absorption of theophylline from the suppository. While the saliva:plasma ratio remained fairly constant for most of the study period, the large variability found during the absorption phase following drug administration limits the usefulness of this parameter as a monitor of theophylline plasma concentrations.

Adult↗

PubMed1985

The relative bioavailability of paracetamol after rectal administration of suppositories containing a mixture of paracetamol, codeine phosphate and buclizine hydrochloride in healthy volunteers.

'New' and 'old' suppositories (6 months and 30 months since manufacture) containing 800 mg paracetamol, 16 mg codeine phosphate and 12.5 mg buclizine hydrochloride in an identical base were administered to 10 normal volunteers at an interval of 2 weeks. Blood samples were taken at intervals up to 300 minutes after administration for estimation of paracetamol plasma concentrations using high pressure liquid chromatography. Mean peak concentrations were obtained of 4.75 +/- 0.74 mg/ml at 1.75 hours with the new suppositories and of 4.6 +/- 0.67 mg/ml at 2.0 hours with the old suppositories. The difference was not significant. Mean elimination half-life was 4.4 +/- 0.42 hours and 3.73 +/- 0.28 hours, respectively. Again, the difference was not significant, indicating that the absorption characteristics for the suppositories did not appear to deteriorate with ageing for 24 months. Bioavailability data for paracetamol derived from the results were similar to those reported by other workers who studied suppositories containing paracetamol as the only active ingredient. This indicates that the inclusion of codeine phosphate and buclizine hydrochloride in the suppository formulation investigated in the present study did not affect adversely the absorption of paracetamol.

Acetaminophen↗

PubMed1996

Effect of boar seminal immunosuppressive fraction on B lymphocytes and on primary antibody response.

Repeated i.p. or rectal treatment of male and female mice with an immunosuppressive component isolated from boar seminal vesicle secretion reduced responses of B lymphocytes to mitogen as evaluated by [3H]thymidine or bromo-deoxyuridine incorporation. The proliferative activity of T lymphocytes was not affected. By means of the immunofluorescence method, the seminal immunosuppressive component was detected on the membranes of B lymphocytes separated from the spleens of mice treated in vivo with immunosuppressor. An i.p. injection or rectal infusion of the immunosuppressive component also led to a suppression of primary antibody response to soluble and particulate antigens. These findings indicate that in vivo deposition of semen may compromise some aspects of the immune system and may be an important cofactor in the development of viral and bacterial infections in homosexual men.

Absorption↗

PubMed2005

Establishment and characterization of a human colonic mucinous carcinoma cell line with predominant goblet-cell differentiation from liver metastasis.

Many human colorectal adenocarcinoma cell lines have been developed. However, differentiated type colorectal cancer cell lines, particularly, the goblet-cell differentiated type, are scarce. In the present study a novel colorectal adenocarcinoma cell line (designated as COLM-6) with predominant goblet-cell differentiation was established from the rectal mucinous adenocarcinoma of a Japanese woman. COLM-6 cells grow in a typical epithelial monolayer in culture. They expressed epidermal growth factor (EGF) receptor and HER2 on their surface and accordingly, their growth was significantly stimulated by EGF, transforming growth factor (TGF)-alpha and heregulin. COLM-6 cells form tumor with typical mucinous adenocarcinomatous appearance in nude mice. Immunohistochemical analysis of these subcutaneous tumors demonstrated that COLM-6 cells strongly express MUC2 as a goblet-cell marker and Cdx2 in the nucleus. Some weakly express villin and carbonic anhydrase 1 as a columnar absorptive-cell marker as well. They were also positive for adenomatous polyposis coli (APC) cytoplasmically and expressed beta-catenin in their cytoplasm and cell membrane without nuclear accumulation. These results indicate that COLM-6 cell line has unique characteristics and may provide a useful tool to study the mechanism of growth and differentiation of colonic epithelium as well as the biological behavior of colorectal mucinous adenocarcinoma.

Adenocarcinoma, Mucinous↗

PubMed1995

[Surgical treatment of vaginal prolapse after hysterectomy].

Forty-five women were treated with a sacrospinous ligament fixation of the vaginal apex between 1979 and 1993. The patients had a complete vaginal prolapse following abdominal or vaginal hysterectomy or in three cases a combined uterine and vaginal prolapse. The sacrospinous ligament fixation was carried out as described by Amreich, Sederl and Richter. The fixation of the vagina was successful performed in 43 women. These results were obtained using absorbable suture material. A sciatic nerve damage was observed in two patients for a short time with spontaneous recovery, coincident with suture absorption and nerve regeneration. We consider and recommend fixation of the vaginal apex to the sacrospinous ligament as the technique preferred for the operative treatment of a vaginal prolapse and for the rare cases of uterine prolapse, which cannot be corrected otherwise.

Adult↗