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At least 811 records · Page 45Linked to original sources
PubMed1987

Physiologic assessment of the four commonly performed endorectal pullthroughs.

The popularity of the endorectal pullthrough for the treatment of benign mucosal diseases of the rectum has created a controversy regarding the need for a reservoir. The four currently advocated procedures, the straight endorectal anastomosis, the J pouch, the S pouch, and the lateral isoperistaltic ileal reservoir were evaluated in a puppy model with four animals in each experimental group. Measurement of rectal capacitance showed that all groups achieved 80-85% of control values at 6 months after surgery. Intestinal transit time decreased by one-half in all groups. Stool consistency, stool culture, water, and electrolyte absorption did not show any statistical superiority of one group over another. Stool frequency varied widely at 6 months; 10 stools per 8-hour period were counted in the lateral reservoir group versus 25 with the J pouches, and 16 with the straight and S groups. Stool frequency did not correlate with transit time, stool consistency, or rectal capacitance. Barium enemas showed that straight pullthroughs more closely resembled the measurements of the normal animal's endorectal canal. Based on these studies, there appears to be no advantage to adding a reservoir to the endorectal pullthrough.

Anal Canal↗
PubMed2004

[Intestinal complications after the radiation treatment of the rectum cancer--retrospective review of 70 patients].

The radiation of small pelvis is a component of the complex therapy of tumors located in the rectum. Frequently exceeding of the tolerant dose of 45 Gy for the most sensitive organ in the pelvis--the small bowel--is required. The goal of the present research is to analyse the frequency and the gravity of chronic enteritis and what caused it. The analysis is on 70 rectal patients radiated in the time period 1986-1996 with doses 50-60 Gy for the small pelvis by different programs. Well expressed chronic enteritis with"mal absorption syndrom" is found in 5.2% of all the group. In 3.9% of all patients urgent surgical intervention has been required because of adhesive ileus or intestine necrosis. A few conclusions are drawn, the basic one being that the grave chronic radiation enteritis occurs mostly in patients after postoperative radiation with doses above 56-60 Gy.

Acute Disease↗
PubMedDate not supplied

Pharmacokinetics of heptacaine, a novel potent local anaesthetic agent, after rectal administration to rats.

The pharmacokinetics of heptacaine, N-(2-(2-heptyloxyphenylcarbamoyloxy)ethyl)-piperidinium chloride, a new long-acting potent carbanilate type local anaesthetic, proposed for local anaesthesia in complex treatment of hemorrhoids, was studied following its rectal administration to rats in the form of cocoa butter suppositories. The heptacaine plasma concentration, 0.0083% of dose/ml, peaked at 90 min post administration and the maximum rate of its bioavailability, 0.19% of dose/min, assessed by deconvolution, occurred 38 min post administration. The plasma elimination half-life of heptacaine was 133 min and its biological availability of 52% was comparable to other agents of the class.

Administration, Rectal↗
PubMed1999

Whole-body microwave exposure emitted by cellular phones and testicular function of rats.

This study investigated whether there are adverse effects due to microwave exposure emitted by cellular phones in male rats. Eighteen Wistar Albino rats were separated into three groups, a sham group and two experimental groups. The rats were confined in Plexiglas cages and cellular phones were placed 0.5 cm under the cages. In the first experimental group, cellular phones were in standby position for 2 h. In the second experimental group, phones were turned to the speech position three times each for 1 min duration over 2 h. Rats in the first and second experimental groups were exposed to microwaves emitted by phones for 2 h/day for a duration of 1 month. After the last exposure the rats were killed. Brain, eyes, ears, liver, heart, lungs, stomach, kidneys, testes, small and large intestines and skin of the rats were observed histologically. The decrease of epididymal sperm counts in the speech groups were not found to be significant (P > 0.05). Differences in terms of normal and abnormal sperm forms were not observed (P > 0.05). Histological changes were especially observed in the testes of rats of the speech groups. Seminiferous tubular diameter of rat testes in the standby and speech groups was found to be lower than the sham group (P < 0.05). Rectal temperatures of rats in the speech group were found to be higher than the sham and standby groups (P < 0.05). The rectal temperatures of rats before and after exposure were also found to be significantly higher in the speech group (P < 0.05). Specific absorption rate (SAR) was determined as 0.141 W/kg.

Animals↗
PubMed1981

The effect of sulphasalazine withdrawal on rectal mucosal function and prostaglandin E2 release in inactive ulcerative colitis.

We have used in vivo rectal dialysis to assess mucosal prostaglandin E2 (PGE2) release and water and electrolyte transport before and 2 weeks after withdrawal of oral sulphasalazine in eight patients with inactive ulcerative colitis. Although rectal mucosal PGE2 release was unaffected by withdrawal of sulphasalazine, significant reductions in mucosal potential difference (P less than 0.01) and net absorption of water (P less than 0.05), sodium (P less than 0.05), and chloride occurred (P less than 0.05). Clinical assessment showed no change in disease activity. Sulphasalazine withdrawal thus has a detrimental effect on large-intestinal salt and water transport, which does not appear to be mediated through changes in net mucosal prostaglandin production.

Body Water↗
PubMed1979

Pharmacokinetics of theophylline in young children with asthma: comparison of rectal enema and suppositories.

Six children, aged 2 months - 4 years, received theophylline 5-6 mg/kg intravenously. Its disposition could be described by a two-compartment open model, the mean serum half life (t 1/2 beta) was 3.75 h, i.e., shorter than in adults, but there was a considerable interindividual variation (1.8-7.0 h, in one patient 13.3 h). Thirteen children (2 months - 4 years) received theophylline suppositories in a dose of 3.8-5.0 mg/kg, and ten (6 months - 4 years) in a dose of 8.4-14.5 mg/kg. Absorption was slow (mean half-time 43 min), incomplete and variable (biological availability 8-100%, mean 80%). Only four of the patients given the higher dose and none given the lower dose reached a therapeutic serum concentration (10-20 microgram/ml). Nine children (6 months - 4 years) received rectal enemas of theophylline 4.1-9.2 mg/kg. Absorbtion was rapid (mean half-time 5.5 min) and biological availability averaged 100%. Six patients reached a serum concentration within the therapeutic range. Using the mean values of the calculated pharmacokinetic parameters, rectal enemas providing a dose of theophylline of 6-8 mg/kg t.i.d. were computed to give serum concentrations between 8-20 microgram/ml, without producing too high a level during the absorption phase.

Age Factors↗
PubMed1983

Mechanism and control of salt absorption in locust rectum.

The rectum is the main reabsorptive site in the excretory system of locusts. The primary urine entering this organ from the Malpighian tubules is rich in K+ (140 mM) and Cl- (90 mM), and most of this fluid is normally reabsorbed. Fluid and active Cl- reabsorption in the rectum are regulated by neuropeptide hormones from the corpus cardiacum. We have studied the mechanism of KCl reabsorption using voltage clamp, tracers, double-barreled ion-sensitive microelectrodes, and ion substitutions. Locust Cl- absorption differs from vertebrate systems in that it is not dependent on Na+ or HCO-3/CO2, and it is insensitive to normal inhibitors of Cl- transport. Entry of Cl- into rectal cells is active, electrogenic, and stimulated by luminal K+. This cation substantially increases the electrochemical gradient across the apical membrane against which Cl- is pumped; therefore K+ does not act solely and indirectly by electrical coupling. Kinetic studies also suggest that K+ activates the Cl- pump. Consequently at least two levels of control are exerted during cAMP stimulation; K+ permeability of the epithelium and the transepithelial potential generated by active Cl- transport both increase. The enhanced net K+ absorption from the lumen side after stimulation is largely passive, being electrically coupled to Cl- transport. However, this general increase in KCl absorption is "fine tuned" by K+ itself, through its direct effect on the Cl- pump.

Animals↗
PubMedDate not supplied

Intestinal mucosa in nephropathic cystinosis.

The major manifestations of nephropathic cystinosis are renal tubular acidosis, vitamin D-resistant rickets, and dwarfism. Cystine crystals are deposited in a variety of cells, mainly phagocytic, including macrophages of the intestinal lamina propria. Previously, ultrastructural changes were suggested to occur in the absorptive epithelium as well, possibly as a result of local cystine toxicity. We report here on the light- and electron-microscopic findings in the jejunal mucosa of two patients, aged 4 and 9 years with nephropathic cystinosis. Cystine crystals were easily identified in semithin sections of plastic-embedded specimens as brick- and hexagon-shaped spaces in macrophages. Electron microscopy showed that all crystals were in single-membrane-limited bodies (lysosomes), within phagocytic cells, and exclusively located in the lamina propria. In contrast to previous findings, the absorptive epithelium showed no abnormalities. We conclude that the growth failure in cystinosis is not a consequence of morphological toxic alterations in the intestinal epithelium, but is related to the known metabolic abnormalities of this condition. The use of rectal suction biopsy as a means of diagnosing cystinosis is also suggested as an alternative to other diagnostic methods.

Biopsy↗
PubMed1991

Population pharmacokinetics of rectal theophylline in neonates.

The population pharmacokinetics of theophylline were studied in 35 neonates receiving aminophylline suppositories for the treatment of apnoea of prematurity. Routinely measured theophylline serum concentrations (n = 138, range 3-20 mg/L) were modelled in NONMEM according to a one-compartment model. The influence of a number of clinical and demographic factors, e.g., weight (range 0.8-2.5 kg) and postnatal age (2-80 days), on clearance/bioavailability (CL/F) and volume/bioavailability (V/F) was investigated. Both these parameters were found to significantly correlate to weight alone in a directly proportional manner: CL/F = 40 +/- 2 ml/h/kg and V/F = 1.3 +/- 0.2 L/kg. The absorption was best described by a first-order process, having a half-life of 1.6 +/- 0.7 h. The interindividual variability in CL/F was 25%, whereas the same estimates in V/F and in the first-order absorption rate constant could not be obtained. The residual variability in theophylline concentrations was modelled with additive error with an estimated standard deviation of 1.78 mg/L. From these results, it was concluded that rectal administration of aminophylline in neonates is a therapeutically acceptable alternative to oral administration. The convenience gained by rectal, compared to oral, administrations may compensate, in many instances, for the possibly slightly higher variability in CL/F of the former.

Administration, Rectal↗
PubMed1980

Dosimetry for a study of effects of 2.45-GHz microwaves on mouse testis.

In order to determine the effects of microwave radiation on the testis, it is necessary to express the physical insult in animal studies in a way that can be replicated elsewhere and ultimately used as a basis for extrapolation to man. However, there is conflict--especially in chronic experiments--between the desire for precise dosimetry and the need to minimise alteration of the normal physiological functions of the animals. The compromise arrangement used in this study was to house the mice singly, in cages with limited food and water, and to irradiate them for up to 30 days (16 h/day) in an anechoic chamber. The only measurements taken routinely were of power density in the positions normally occupied by the cages. In addition, a series of absorption measurements was made in mouse carcasses: Whole-body specific absorption rate (SAR); energy-deposition patterns (determined thermographically); and local SAR in testis (using a miniature electric (E)-field probe). It was concluded that the SAR in testis was considerably less than the whole-body SAR. Exposure for 16 h at 50 mW/cm2 elevated rectal but not testis temperature, thus demonstrating the ability of the conscious mouse to regulate the temperature of its testis.

Abdomen↗