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Safety, tolerability, and pharmacokinetics of sumatriptan suppositories following single and multiple doses in healthy volunteers.

A suppository formulation of the 5HT1 agonist sumatriptan could prove an important therapeutic option in migraine patients who dislike or poorly tolerate injectable therapy and where oral tablet administration is unsuitable because of severe migraine-related vomiting. Two independent double-blind, randomized clinical studies were conducted to evaluate the safety, tolerability and pharmacokinetics of sumatriptan suppositories following ascending single doses (four different dose levels) and multiple doses. In the four-period, crossover, single-dose study, 24 healthy male subjects were randomized to receive a suppository containing 12.5, 25, 50, or 100 mg on separate occasions 3-14 days apart. The suppositories were generally well tolerated; transient asthenia, drowsiness, and headache were the most frequently reported adverse events, and these were not dose-related. Peak plasma concentrations (Cmax) of sumatriptan were proportional to dose from 25 to 100 mg; area under the plasma concentration-time curve (AUC infinity) values were proportional to dose except at the highest doses, when they were greater than those predicted from lower doses. For all doses, the tmax of sumatriptan occurred within 2.5 h, and the t1/2 was approximately 2 h. In the two-period, placebo-controlled, crossover, repeat-dose study, 12 healthy adult male subjects were randomized to receive either a 50-mg sumatriptan suppository or placebo suppository, administered rectally twice a day, for 11 doses (5 1/2 days). Adverse events were no more frequent with sumatriptan than with placebo, and stool guaiac, rectal examinations, and physical examinations remained normal. No significant differences were noted between Day 1 and Day 6 values in the AUC, Cmax, time of peak serum concentration (tmax), elimination half-life (t 1/2), fraction of the dose excreted in the urine (fe), or renal clearance (Clr) of sumatriptan or its pharmacologically inactive indole acetic acid metabolite. Serum metabolite concentrations were two to three-fold higher than corresponding sumatriptan concentrations. No clinically significant accumulation of sumatriptan or its metabolite occurred. Overall, these studies show that sumatriptan administration via a suppository formulation is well tolerated, allows rapid absorption of sumatriptan, results in sumatriptan Cmax values that are proportional to dose from 25 to 100 mg, and is not associated with accumulation of sumatriptan or its metabolite.

Adolescent↗

Review article: problematic proctitis and distal colitis.

About two-thirds of patients with ulcerative colitis have an inflammatory involvement distal to the splenic flexure, and therefore may be effectively treated with topical treatment, allowing the delivery of the active drug directly to the site of inflammation and limiting systemic absorption and potential side-effects. Topical aminosalicylate therapy is the most effective approach, and most patients will benefit hugely, provided that the formulation reaches the upper extent of the disease. Therefore, the choice of topical preparation should be based on the proximal extent of the disease and on patient preference. Oral aminosalicylates are less effective than topical therapies; however, a combination of oral and topical aminosalicylates can be successful in refractory patients. Alternatives to aminosalicylates are the new glucocorticoids, budesonide and beclometasone dipropionate, either as enemas or oral formulations (only beclometasone dipropionate). A combination of oral or rectal new glucocorticoids with rectal aminosalicylates should be considered in patients refractory to either approach. When these measures fail, treatment with oral glucocorticoids is necessary. An intensive intravenous steroid regimen is also helpful for patients refractory to oral steroids. Alternative treatments include short-chain fatty acid enemas, nicotine enemas and patches, acetarsol suppositories, ciclosporin enemas and epidermal growth factor enemas. Several factors potentially having a negative impact on therapeutic response include concurrent enteric pathogens, coexistent irritable bowel syndrome, patient nonadherence to therapy, inadequate dosing and duration of therapy, and proximal progression of the disease. Surgical colectomy may be required in those rare patients refractory or intolerant to pharmacotherapy.

Aminosalicylic Acids↗

Postoperative pain management using fentanyl patches in dogs.

To the ability of the fentanyl patch to control pain in a postoperative canine model, we provided two male beagles with 25-mg/h patches and two with 50-mg/h patches 24 h prior to surgery. Each animal underwent a major abdominal surgical procedure to place three separate catheters with associated vascular access ports. Serum plasma levels of fentanyl were analyzed at multiple time points throughout the study period. Animals were subjectively assessed for postoperative pain by using a Simple Descriptive Scale at regular intervals postoperatively. Other parameters observed and recorded included heart and respiration rates, rectal temperature, appetite, and activity. The fentanyl patch appeared to adequately control postoperative pain in our canine abdominal surgical model. Three animals demonstrated mild pain 1 to 2 h postoperatively. Two animals, one from each dose group, showed mild pain 8 h postoperatively. Mild pain is commensurate with USDA category C, which encompasses procedures that do not result in more than momentary or slight pain or distress and do not require intervention. At no other time points were any of the animals considered to be in pain. Our study also suggested that increased subcutaneous fat delayed the rate of absorption of fentanyl. The lower body-weight beagles, which had the 25-mg/h patches, reached reported human serum analgesic levels within 8 h after placement, whereas the heavier beagles with the 50-mg/h patches reached human serum analgesic levels 12 h after placement. Fentanyl concentrations remained at the reported human analgesic levels in all animals between 2 to 4 h after the patches were removed. Regardless of the dose, decreases in heart rate, respiration rate, and temperature were observed in all four animals 12 h after placing the patches. Issues regarding the regulatory requirements to prevent drug abuse, the side effects and potency of fentanyl, and the prolonged duration of action as a transdermal system should be addressed by the veterinarian when considering usage of this analgesic method.

Administration, Cutaneous↗

Drug delivery systems.

New and emerging drug delivery systems for traditional drugs and the products of biotechnology are discussed, and the role of the pharmacist in ensuring the appropriate use of these systems is outlined. Advantages of advanced drug delivery systems over traditional systems are the ability to deliver a drug more selectively to a specific site; easier, more accurate, less frequent dosing; decreased variability in systemic drug concentrations; absorption that is more consistent with the site and mechanism of action; and reductions in toxic metabolites. Four basic strategies govern the mechanisms of advanced drug delivery: physical, chemical, biological, and mechanical. Oral drug delivery systems use natural and synthetic polymers to deliver the product to a specific region in the gastrointestinal tract in a timely manner that minimizes adverse effects and increases drug efficacy. Innovations in injectable and implantable delivery systems include emulsions, particulate delivery systems, micromolecular products and macromolecular drug adducts, and enzymatic-controlled delivery. Options for noninvasive drug delivery include the transdermal, respiratory, intranasal, ophthalmic, lymphatic, rectal, intravaginal, and intrauterine routes as well as topical application. Rapid growth is projected in the drug delivery systems market worldwide in the next five years. Genetic engineering has mandated the development of new strategies to deliver biotechnologically derived protein and peptide drugs and chemoimmunoconjugates. The role of the pharmacist in the era of advanced drug delivery systems will be broad based, including administering drugs, compounding, calculating dosages based on pharmacokinetic and pharmacodynamic monitoring, counseling, and research. The advent of advanced drug delivery systems offers pharmacists a new opportunity to assume an active role in patient care.

Administration, Oral↗

[Demonstration of antibodies against tumor-associated antigens in the serum patients with bronchogenic carcinoma using anticomplement immunofluorescence on xenotransplants of human tumors].

209 sera of tumor-bearing patients and 133 control sera were tested by anti-complement immunofluorescence (ACIF) on 2 xenotransplants of human bronchogenic cancer and on 2 xenotransplants of rectum carcinoma passaged in nu/nu mice. Testing of sera from patients with bronchogenic carcinoma resulted in a positive reaction with the xenotransplants of bronchogenic cancer in 48.5 to 58.5%, and sera of patients with digestive tract cancer in 6.6 to 16.1%. On xenotransplants of rectum carcinoma 73.2 to 78.1% of the sera from patients with bronchogenic carcinomas and 22.6 to 29.1% of the sera of patients with digestive tract cancer reacted positively. Control sera were positive dependent on the xenotransplants in 2.0 to 12.5%. These results indicate that there are antibodies in the sera of tumor-bearing patients against one or more non organ specific tumor-associated antigen(s) occurring in an elevated concentration in carcinomas of the digestive tract than in bronchogenic carcinomas. After absorption of the sera with homogenates of bronchogenic carcinoma and liver metastases of colon carcinoma the reaction was inhibited in the ACIF, reaching control values.

Adenocarcinoma↗

Patterns of gastrointestinal neoplasms in Israel.

Review of the incidence of gastrointestinal neoplasms in Israel reveals that gastric and colorectal cancers present a major problem in the country. Diet has been postulated as a possible etiologic factor on the basis of a) an indirect correlation between disease incidence and the consumption of various food constituents, b) animal experimentation, and c) case-control dietary studies. Studies conducted in Israel point to high starch consumption as a risk factor in gastric cancer and low fiber intake as a risk factor in colon cancer. Mechanisms by which fiber may exert its protective effect include shortening of intestinal transit time, bulkier stool, lowered absorption of potential carcinogens, reduction of the conversion of bile salts to potentially carcinogenic sterols, interference with the cholesterol pool and a lower ratio of anaerobic:aerobic bacteria in the intestinal flora. The potential effect of excessive starch consumption is unclear, although it may facilitate the formation of nitrosamines.

Africa↗

Uninhibited sigmoid colon syndrome (sigmoid hyperreflexia): description of a new clinicopathological entity.

PURPOSE: To present 10 patients who complained of passage of frequent loose stools which was found to be due to sigmoid colon hyperreflexia, a condition that, to our knowledge, has not been described before. PATIENTS AND METHODS: Ten patients (6 women, 4 men, mean age 46.6 years) complaining of frequent loose stools of 5-8 years' duration and 10 healthy volunteers (controls) matching the patients in age and gender, were included in the study. Colonoscopy, barium enema and intestinal transit studies were normal in all. The anorectal physiological studies comprised: recording of rectal, anal and intra-abdominal pressures, EMG of the external and internal anal sphincters and levator ani muscles, sigmoidometry and determination of the sigmoido-rectal junction reflex. RESULTS: Apart from sigmoidometry, all the aforementioned anorectal physiological studies were in accordance with those of the controls. Sigmoidometry showed that balloon expulsion occurred at a distending volume of 32.4 ml and a sigmoid colon pressure of 86.4 cmH2O in the patients, and of 86.2 ml and 98.6 cmH2O, respectively, in the controls. The tone limb exhibited major fluctuations (mean pressure rise 43.8 cmH2O) in the patients, while it was smooth or showed minor fluctuations (insignificant pressure changes) in the controls. CONCLUSIONS: The sigmoid colon contractions produced by small volumes of stools and the lack of proper storage necessary for water absorption from the stools, are suggested to explain the frequent loose stools in the studied patients and to be the result of sigmoid colon hyperreflexia.

Adult↗

Efficacy and specificity of vindesine monoclonal anti-carcinoembryonic antigen conjugate with nine human cancer cell lines.

To establish a model for evaluation of the efficacy and specificity of monoclonal anti-CEA-vindesine (VDS) conjugates, we have characterized 10 human tumor cell lines (7 colorectal cancer and 3 lung cancer) with 3 monoclonal antibodies that recognize different epitopes of the CEA molecule. Immunocytochemistry indicated high, medium, low, or no capacity of the cell lines to bind antibody and express CEA. We used 125I-labeled antibodies to quantitate the number of antibody molecules binding per cell. The most thoroughly evaluated monoclonal antibody, 11-285-14, which is nonreactive with nonspecific cross-reacting antigen and is known to localize in xenografts and in cancer patients, was selected for assessment of VDS-conjugate efficacy. This was evaluated by 24- and 72-hour exposure in tritiated uridine microcytostasis assays with nine of the cell lines. Conjugates were shown to retain anti-CEA activity after conjugation, and the efficacy of VDS-11-285-14 in vitro was found to be correlated with target antigen expression, except with two lines that were resistant to free drug. Absorption of VDS-11-285-14 with purified CEA resulted in loss of efficacy in positive cell lines, thereby giving a further indication of the selectivity of conjugate efficacy.

Antibodies, Monoclonal↗

[Intestinal lavage solution for orthograde intestinal irrigation].

Gut lavage by ingestion of large volumes of electrolyte solutions has been shown to be an effective method of cleansing the colon before colonoscopy, barium enema or surgery. Absorption of water and electrolytes, which might be hazardous to patients who are unable to readily excrete an additional sodium and/or water load, is prevented by addition of non-absorbable substances to the solutions, but systematic studies are lacking. We have evaluated the influence of three solutions for gut lavage with different electrolyte composition (sodium concentration 67 mmol/l and 125 mmol/l) and addition of different non-absorbable substances (mannitol and polyethylene glycol [PEG]) on water and electrolyte homeostasis and subjective tolerance, both in healthy volunteers and in patients before endoscopy of the colon. In a randomized, blind study 6 liters of the three solutions were administered via a nasogastric tube to 6 healthy volunteers during 4 hours (i.e. 1.5 l/h). Body weight, serum concentrations of sodium, potassium and of phosphate were measured before infusion of the solution and after the last rhythmic rectal effluent. No significant changes were observed in any of the studied parameters and the incidence of side effects (nausea, abdominal cramps) was comparable. In an additional clinical double blind study, 26 patients before diagnostic colonoscopy were asked to drink 4 liters of the gut lavage solutions as quickly as possible in order to clean out the colon. The time for drinking was significantly shorter in patients using the mannitol and low sodium solution (204 +/- 70 minutes) than in patients drinking the solution with polyethylene glycol and a high sodium concentration (387 +/- 137 minutes). There was a tendency to a longer drinking period in patients ingesting the solution with polyethylene glycol and low sodium (306 +/- 106 minutes). Thus, the acceptance for solutions containing polyethylenglycol and high sodium concentration is reduced because of low palatibility. Again no influence on serum electrolyte concentrations or body weight could be observed in any patient, the spectrum of side effects was similar and the cleansing effect of all three solutions was adequate. In conclusion solutions for gut lavage containing a balanced electrolyte concentration and nonresorbable substances such as mannitol or polythylenglycol are equivalent. However, solutions containing mannitol and a low sodium concentration are better tolerated by the patients but the use of mannitol is limited because of the risk of releasing explosive gases during interventional endoscopy. To enhance the acceptance and palatibility of solutions for gut lavage containing polethylenglycol the addition of flavoured substances is recommended.

Adult↗

Iron bezoar retained in colon despite 3 days of whole bowel irrigation.

Concretion formation is a documented complication of large iron ingestions. The generally accepted treatment is supportive care, whole bowel irrigation, and intravenous deferoxamine for systemic toxicity. Laparotomy and gastrotomy have also been used in patients with a high iron burden and bezoar formation. Though experiments suggest that iron is poorly absorbed in the colon, there are no case reports of iron overdose without systemic toxicity, despite a retained colonic bezoar. We report the case of a 16-month-old who presented to an Emergency Department 19 h after an iron ingestion. Initial laboratory studies revealed an anion gap of 14 mEq/L, and a 20 h serum iron concentration of 429 mcg/dL. An abdominal radiograph revealed multiple pills throughout the stomach and small bowel; whole bowel irrigation was initiated. Deferoxamine was administered at 10 mg/kg/h and then stopped when the serum iron level reached 27 mcg/dL, 36 h later. At this time, the abdominal radiograph showed an iron bezoar remaining in the ascending colon despite a clear rectal effluent from whole bowel irrigation. Despite whole bowel irrigation over the next 36 h, the iron bezoar was not removed and actually migrated proximally in the colon. Treatment was stopped on the third day and a normal diet was instituted with prompt passage of the bezoar.

Antidotes↗

A dissolution test for a pressure-controlled colon delivery capsule: rotating beads method.

The rotating beads method is a new in-vitro dissolution test proposed for drugs formulated as pressure-controlled colon delivery capsules (PCDCs). The apparatus consisted of a glass vessel (500 mL) containing 4-mm (i.d.) glass beads (5000, 10000 or 15000) and dissolution medium (0-067 M phosphate buffer, pH 7; 25, 50 or 100 mL) containing polyvinyl alcohol (PVA; 5, 10 or 20 w/v%) to simulate the viscosity of the colon. The vessel was rotated at 5, 10 or 25 rev min(-1) and the temperature was maintained at 37 degrees C. Fluorescein was used as a model drug to explore the optimized conditions under which differences in the drug dissolution rate are detected between colon delivery systems. Fluorescein was formulated in four types of colon delivery systems. One was a tablet coated with an enteric polymer, Eudragit S-100, and the other three were PCDCs prepared with different thicknesses of ethylcellulose coating membrane (type I, II, III). The dissolution behaviour of fluorescein from the PCDC formulation was significantly different from that of the Eudragit S-100-coated tablets, when the dissolution conditions were as follows: rotation speed, 10 rev min(-1); bead number, 10000; dissolution medium, 50mL with 10% PVA. This dissolution method was applied to acetaminophen sustained-release tablets and two other drugs having low solubility in the colon, tegafur and 5-aminosalicylic acid. Similarly, significant differences in the dissolution rates of drugs from the PCDC formulation and the enteric tablet were detected. There was good correlation between the in-vitro dissolution rates and in-vivo absorption rates using T50 (the time for half of the amount of drug to be released from the preparation) and Cmax/Tmax (enteric tablet) or Cmax/(Tmax-Ti) (PCDC), where Ti is the first appearance time in the systemic circulation. The rotating beads method is a valuable technique for evaluating the dissolution rate of drugs formulated in PCDC.

Administration, Rectal↗

Segmental heterogeneity of epithelial transport in rat large intestine.

Functionally isolated segments of rat colon and rectum were perfused in situ in a closed loop system. Rectum was defined as the lower 25--35% of the length of large intestine (cecum excluded). Perfusion conditions were optimized at 0.5 ml.min-1 and 3 cm H2O luminal pressure. Variation of perfusion rate between 0.2 and 2 ml.min-1 did not influence net volume transport (JNV). Luminal distension following elevation of hydrostatic pressure to 18 cm H2O reversibly increased Jnv. Under control conditions Jnv and Na+-transport rates (JnNa) of colon were 2--3 times higher than those of rectum. In colon transepithelial electrical potential difference (psims) was time independent --12 mV (lumen negative) whereas rectal psims increased with time from --6 mV, reaching a plateau of --67 mV within 6 h. Amiloride 10(-4) mol.l-1 had no effect on psims, Jnv, and JnNa in colon but did slightly depress K+-secretion in colon descendens. In contrast, psims in rectum was dose-dependently depressed, being reversed to +7 mV at 10(-4) mol.l-1. Jnv and JnNa were decreased by half. Acetazolamide in addition to amiloride lowered the positive post-amiloride rectal psims by half. Adrenalectomy had no effect on colonic psims, but abolished psims of the rectum. A single dose of 40 microgram.kg-1 b.w. aldosterone during the experiment restored the typical time course of rectal psims, but did not affect psims in colon. It is concluded that aldosterone induces an amiloride-sensitive Na+-pathway only in rectum, but not in colon, and that colon and rectum differ basically in their transport properties, quantitatively as well as qualitatively, as do the kidney distal convoluted tubule and the cortical collecting duct.

Acetazolamide↗

Investigation of seemingly pathogen-negative diarrhoea in patients infected with HIV1.

Thirty three consecutive patients infected by human immunodeficiency virus type 1 (HIV1) with persistent diarrhoea which remained undiagnosed after microbiological examination of six stool samples and rectal histology were investigated for malabsorption. All had xylose and Schilling tests, distal duodenal biopsy, comprehensive barium studies, microbiological examination of six further stool samples, and repeat rectal histology. A microbiological or histological diagnosis of infection was made in 12 patients (multiple organisms in three). Cryptosporidia were identified on five occasions, cytomegalovirus on four, Giardia lamblia on two, and herpes simplex, Campylobacter jejuni, Salmonella enteritidis, and Entamoeba histolytica once each. No organism was found when weight loss was less than 5 kg or stool volume less than 400 ml/day (n = 9). Pathogens were identified in nine of 13 patients (69%) with weight loss greater than 10 kg and stool volume more than 800 ml/day. Barium studies were normal except for ileal flocculation in two patients with cryptosporidiosis. Evidence for malabsorption existed in 24 patients--impaired xylose absorption (n = 19) and abnormal Schilling test (n = 21). Of the patients with a severely abnormal Schilling test, a pathogen was identified in 11 (79%) (including all five with cryptosporidia, and two of the patients with only moderate diarrhoea and weight loss). A simple scoring system based on degree of weight loss and Schilling test result may help to identify the HIV positive patient with seemingly pathogen-negative diarrhoea in whom further investigations are likely to show a specific cause.

Acquired Immunodeficiency Syndrome↗

Indomethacin sustained-release suppositories containing sugar ester.

We prepared indomethacin (IM) sustained-release suppositories using sugar ester (SE) as an additive. The suppositories were prepared by the fusion method with IM, SE, and Witepsol H-15 (H-15) and their availabilities in vitro and in vivo were evaluated mainly by the drug release test and the absorption test in rabbits, respectively. The softening point of the suppositories increased with increasing SE content. In the release test with the Muranishi method, slow-release profiles were obtained when the SE content was more than 52.5%. The absorption of IM from these suppositories, however, was very little. In the other release test, e.g. immersion method with gauze, all of the suppositories with SE showed slow-release profiles, and the drug release rates clearly depended on the SE content. The drug was released from the suppositories by the following leaching-type mechanism proposed by Higuchi. The suppository with a 30% SE content showed a sustained-plasma level of IM, but the other suppositories did not. It was concluded that an appropriate content of SE (i.e. 30%) in the suppository base was required to obtain sustained-release because it reasonably regulated the infiltration of rectal fluid into the suppository and the mechanical strength of the suppository against disintegration.

Animals↗

IP6-induced growth inhibition and differentiation of HT-29 human colon cancer cells: involvement of intracellular inositol phosphates.

Inositol hexaphosphate (InsP6 or IP6) ubiquitous in plants and animals is not only a natural antioxidant, but may also be the precursor/storage of intracellular inositol phosphates, important for various cellular functions. A novel anti-tumor action of InsP6 was demonstrated in models of experimental colon and mammary carcinogenesis in vivo. We now show its effects on growth and differentiation of HT-29 human colon carcinoma cells in vitro. A dose- and time-dependent (0.33-20 mM InsP6 and 1-6 days treatment) growth inhibition was observed as tested by MTT- incorporation assay. The inhibition was statistically significant (p < 0.05) at 1 mM concentration as early as first day after treatment and continued up to 6 days. DNA-synthesis was also suppressed by InsP6 and significantly inhibited as early as 6 h after treatment at 1 mM concentration (p < 0.05) and continued to 48 h (p < 0.01). The expression of proliferation marker PCNA was down-regulated (p < 0.05) by InsP6 (1 and 5 mM) after 48 h of treatment. To investigate the mechanism of action of InsP6 the intracellular phosphatases (including phytase) were inhibited by F to slow down the dephosphorylation of InsP6. Ion-exchange chromatographic separation of intracellular inositol phosphates demonstrated a 84-98% decrease of Ins, InsP1 and InsP2 InsP3 was reduced by 39% and InsP4 and InsP5 by 21% and 13% respectively, whereas intracellular InsP6 was increased by 24.6% at 5 min following 3H-InsP6. Since neither the rate of uptake of 3H-InsP6 was unaffected, nor was the efficacy of growth inhibition altered by F inhibition of phytase, data suggest that contrary to the popular misconception, phytase plays no role in influencing the anti-neoplastic action of InsP6. Alkaline phosphatase activity (brush border enzyme, associated with absorptive cell differentiation), increased following 1 and 5 mM InsP6 treatment for 1-6 days. The expression of a mucin antigen associated with goblet cell differentiation and defined by the monoclonal antibody CMU10 was augmented (p < 0.0001) by InsP6. The tumor mucin marker Gal-GalNAc, expressed by precancer and cancer of colon, but not by the normal cells showed a time-dependent biphasic change by InsP6; an increased expression after 1 day of treatment followed by suppression after 2 days suggest progression of mucin synthesis and differentiation of cancer cells with reversion to normal phenotype. Because the tumor marker Gal-GalNAc is a) easily detected in rectal mucin of patients with colonic cancer and precancer with high sensitivity and specificity, and b) suppressed by InsP6 treatment, it can be used to monitor the efficacy of chemoprevention by InsP6 or other such agents. Since InsP6 a natúral dietary ingredient of cereals and legumes, inhibits growth and induces terminal differentiation of HT-29 cancer cells, it is an excellent candidate for adjuvant chemotherapy and prevention of cancer.

6-Phytase↗

Colonic delivery of sodium butyrate via oral route: acrylic coating design of pellets and in vivo evaluation in rats.

Few pharmaceutical studies, with the exception of those on rectal solutions, are described on short chain fatty acid (SCFA) formulations-especially for sodium butyrate, which is a colonocyte preferential substrate. Highly dosed butyrate pellets (90%) were prepared and their coating was designed for colonic delivery. In vivo determination (pH and transit time of pellets in rats) allowed to respectively choose the grade and thickness (resistance of 6 h) of the pH-dependent coating (Eudragi L+S, 1:1). The coated pellets were administered to naturally butyrate-deprived rats. The rats' colonic mucosa had the particularity to weakly express mitochondrial HMG-CoA synthase, an enzyme that responds to luminal butyrate. The results did not show early absorption of butyrate, but a probable cecal loss in the rat cecum as cecal residence time of the pellets was important and as pH was propitious for the coating hydrolysis. It seemed that butyrate, given daily for 7 days without the other main SCFA. was unable to induce the enzyme and/or that the dose (0.32 mmol/day) was insufficient.

Administration, Oral↗

Microwaves modify thermoregulatory behavior in squirrel monkey.

Squirrel monkeys (Saimiri sciureus) trained to regulate environmental temperature (Ta) behaviorally were exposed in the far field of a horn antenna to ten-minute periods of 2,450 MHz CW microwaves. Incident power density ranged from 1 to 22 mW/cm2. The corresponding specific absorption rate (SAR), derived from temperature increments in saline-filled styrofoam models, ranged from 0.15 to 3.25 W/kg. Controls included exposure to infrared radiation equivalent incident energy and no radiation exposure. Normal thermo-regulatory behavior produces tight control over environmental and body temperatures; most monkeys select a Ta of 34-36 degrees C. Ten-minute exposures to 2,450 MHz CW microwaves at an incident power density of 6-8 mW/cm2 stimulated all animals to select a lower Ta. This threshold energy represents a whole-body SAR of 1.1 W/kg, about 20% of the resting metabolic rate of the monkey. Thermoregulatory behavior was highly efficient, and skin and rectal temperatures remained stable, even at 22 mW/cm2 where the preferred Ta was lowered by as much as 4 degrees C. No comparable reduction in selected Ta below control levels occurred during exposure to infrared radiation of equal incident power density.

Animals↗

Use of clonidine to decrease intestinal fluid losses in patients with high-output short-bowel syndrome.

BACKGROUND: Some patients who have short bowel syndrome (SBS) have high intestinal outputs, which increases the risk of dehydration and fluid-electrolyte abnormalities and impairs quality of life. METHODS: We evaluated the use of clonidine, an alpha2-adrenergic receptor agonist, in 2 patients with SBS and high intestinal outputs, who were refractory to conventional therapy with antidiarrheal and antisecretory agents (loperamide, belladonna, opiates, somatostatin, histamine2 receptor antagonists and proton pump inhibitors). The first patient (case 1) was a 29-year-old woman who had 175 cm of small bowel anastamosed to 8 cm of descending colon, ending in a colostomy. The second patient (case 2) was a 22-year-old man who had 30 cm of jejunum anastomosed to 30 cm of sigmoid colon and rectum. RESULTS: The addition of clonidine, 0.1 mg per os (PO) 2 times per day, to the treatment regimen of case 1 decreased her ostomy output from approximately 4 L/day to approximately 1 L/day, eliminating the need for parenteral nutrition and fluids and decreasing the need for opiate therapy. The addition of clonidine, 0.2 mg PO 2 times per day in case 2 resulted in decreased rectal outputs from approximately 4 L/day to approximately 1.5 L/day. CONCLUSIONS: These results demonstrate that clonidine can effectively reduce intestinal fluid and electrolyte losses and should be considered as an additional treatment option in patients with SBS and high intestinal outputs.

Adrenergic alpha-Agonists↗