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Nimesulide: some pharmaceutical and pharmacological aspects--an update.

Nimesulide, a non-steroidal anti-inflammatory drug (NSAID), is administered orally or rectally twice daily for a variety of inflammation and pain states. This is a unique NSAID, not only because of its chemical structure but also because of its specific affinity to inhibit cyclooxygenase-2 (COX-2), thus exerting milder effects on the gastrointestinal mucosa. Current data on selective COX-2 inhibitors suggest that they may have an efficacy similar to that of standard NSAIDs. Initial general clinical experience with selective COX-2 inhibitors appears to show that they are particularly promising in individuals at risk because of renal diseases, hypertension or congestive heart failure. Various experimental models and clinical studies have demonstrated the anti-inflammatory efficacy of nimesulide. Nimesulide is superior, or at least comparable in efficacy, to other NSAIDs, but is better tolerated and has less potential for adverse reactions. Thus, selective COX-2 inhibitors should have anti-inflammatory effects devoid of side effects on the kidney and stomach. They may also demonstrate new important therapeutic benefits as anticancer agents as well as help prevention of premature labour and even retard the progression of Alzheimer's disease. No clinically significant drug interactions have been reported for nimesulide. Not much has been reported about the pharmaceutical aspects of nimesulide. Its poor aqueous solubility poses bioavailability problems in-vivo. This could be overcome by the formation of inclusion complexes with beta-cyclodextrin, as has been reported by various researchers. However, absence of any in-vivo data regarding the relative absorption of nimesulide from beta-cyclodextrin complex compared with that from conventional formulations of the drug makes the use of such fast-releasing complexes rather questionable. Only a limited number of assay procedures (HPLC, spectrophotometric, spectrofluorimetric) for the determination of nimesulide and its metabolite in plasma/urine samples or in dosage forms have been reported in the literature. The purpose of this review is to provide a concise overview of the pharmacological and pharmaceutical profile of nimesulide. Various investigations carried out recently are reported, although older references to research performed on nimesulide have also been included, where appropriate.

Animals↗

Action of linoleic acid on phospholipase C activity at the rectal level of the African locust under the control of protein kinase C.

Linoleic acid (18:2n-6), linolenic acid and eicosatrienoic acid stimulated fluid reabsorption in locust rectum. Only 18:2n-6 was able to enhance phospholipase C activity, inositol(1,4,5) trisphosphate production and to increase cytosolic free Ca2+ concentrations in epithelial cells via the opening of L-type Ca2+ channels. These effects resemble those exerted by neuroparsin, an antidiuretic neuronal hormone extracted from the storage lobes of the locust corpora cardiaca. As for neuroparsin, the effects of 18:2n-6 were abolished after pre-treatment with the protein kinase C inhibitor, polymyxin B. The results were consistent with a regulation of neuroparsin-sensitive phospholipase C activity by 18:2n-6 under control of protein kinase C, possibly by increasing membrane fluidity. Cyclooxygenase inhibitors attenuated the effects of 18:2n-6. This demonstrated that the results should be produced via the metabolites of 18:2n-6 HODEs rather than the PUFA itself.

8,11,14-Eicosatrienoic Acid↗

Starchy foods and colon proliferation in mice.

The effect of starch contained in different foods on colonic proliferation was studied in C57BL/6N mice after four weeks of feeding with 20% fat diets containing cornstarch, white bread, pasta, and rice; an equicaloric amount of sucrose was used in a control diet. Cell proliferation was evaluated in different subsites of the colon (rectal end, mid colon and cecal end) by colchicine arrest and [3H]thymidine incorporation. The following parameters were analyzed: mitotic index (MI), labeling index (LI), and the distribution of labeled cells along the crypt. Different results were obtained in the different subsites. At the rectal end of the colon, all diets containing starch lowered cell proliferation compared with the sucrose diet. The values for MI in the different diets were 2.56 +/- 0.22, 1.73 +/- 0.30, 1.37 +/- 0.19, 1.61 +/- 0.29, and 1.29 +/- 0.31 for control, cornstarch, white bread, pasta, and rice, respectively. Values are means +/- SE (n = 10). The values for LI showed a similar pattern. In the mid colon, the MI was significantly lowered only by the diet containing rice, whereas the DNA synthetic activity (LI) was lowered by cornstarch, pasta, and rice. Toward the cecal end, we observed a significant reduction in MI with diets containing pasta and rice and in the LI with diets containing pasta. The distribution of the LI along the crypt in the different subsites was not significantly affected by experimental dietary variations. The results suggest that starch from different dietary sources might reduce colon proliferation in the mouse.

Analysis of Variance↗

Levamisole in the adjuvant treatment of colon cancer.

The chemistry, pharmacology, pharmacokinetics, assay methodologies, adverse effects, and dosage of levamisole are described, and the clinical studies of levamisole therapy in patients with colorectal carcinoma are reviewed. Levamisole is a synthetic, orally active agent that has antihelmintic and immunomodulatory properties. It is capable of inducing T-cell differentiation and restoring depressed effector functions of peripheral lymphocytes and phagocytes to normal. The drug is well absorbed from the gastrointestinal tract after oral administration and is extensively metabolized by the liver. Gas chromatography and high-performance liquid chromatography are the most common methods used to measure concentrations of levamisole in biologic fluids. Levamisole combined with fluorouracil has been associated with a one-third reduction in recurrence and risk of death in patients with surgically resected Dukes stage C colon cancer; this combination is now recommended as standard therapy in these patients. Uses in patients with rectal carcinoma, Dukes stage B colon cancer, metastatic colon cancer, other malignancies, or nonmalignant disorders remain investigational. Common adverse effects include nausea, abdominal pain, vomiting, diarrhea, metallic or altered taste, flulike symptoms, mood elevation, insomnia, hyperalertness, dizziness, and headache. The most serious adverse effect associated with levamisole is granulocytopenia. The FDA-approved dosage of levamisole is 50 mg orally every eight hours for three days every two weeks. Levamisole therapy is to be initiated no earlier than 7 and no later than 30 days after surgery and is to be continued for one year. Levamisole combined with fluorouracil has been associated with a one-third reduction in recurrence and risk of death in patients with resected stage C colon cancer. Further research is needed to more clearly define the mechanism of action, optimum dose and scheduling, and clinical efficacy of levamisole in treating other malignancies.

Adenocarcinoma↗

Effect of partial dehulling of two- and six-row barley varieties on precaecal digestibility of amino acids in pigs.

Five barrows (German Landrace; initial BW 58 kg, final BW 80 kg) fitted with an ileo-rectal anastomosis were used to determine the effect of partial dehulling and addition of barley hulls of two- and six-row barley varieties on the precaecal digestibility (pD) of CP and amino acids. The following diets were provided according to a standardized diet formulation and tested in seven consecutive periods (repeated group-period design): two-row barley (TRB) + casein (C), dehulled TRB + C, TRB + C + 10% hulls, six-row barley (SRB) + C, dehulled SRB + C, SRB + C + 1% hulls, and wheat starch + C. The diets were supplied at daily rates of 79-86 g DMI x kg BW(-0.75) in barley containing diets and at 49 g DMI x kg BW(-0.75) in the casein diet. The digestibility of amino acids in barley varieties was determined by the difference method (casein as basal diet) using quantitative digesta collection. In both varieties of barley the pD of CP and amino acids did not differ. The pD of CP was unchanged in regard to the treatments in both barley varieties. Due to dehulling in TRB the pD was improved significantly for most indispensable amino acids and in SRB for Met and Cys. Addition of 10% hulls to TRB led to equivalent pD of Arg, His, Leu, Tyr, and Trp compared to TRB, but the pD of Lys, Phe, Thr and Val was significantly decreased below the levels of TRB. Addition of even 1% hulls to SRB impaired the pD of Lys below the level in SRB. In conclusion, addition of barley hulls to pig diets impairs amino acids absorption in the small intestine. The pD values, measured under standardized experimental conditions (without a correction using basal endogenous amino acids), are similar to the values of true digestibility published by NRC (1998).

Amino Acids↗

A comparative study of the localization of CEA and NCA2 in cancerous and normal gastrointestinal tissues.

The histological localization of CEA in gastrointestinal tissues was re-evaluated after absorption of anti-CEA antiserum with NCA2, another normal antigen cross-reacting with CEA. This absorbed antiserum showed clearly the presence of CEA in colonic tumors and some non-cancerous colonic mucosae, obtained even from non-cancerous patients. In contrast, some of the gastric adenocarcinomas we studied were strained very weakly by absorbed anti-CEA antiserum, although non-absorbed antiserum (or serum absorbed with NCA alone) labelled them strongly. The same difference in reactivity between both antisera was observed in intestinal metaplasia. The localization of NCA2 was studied with a specific antiserum, previously absorbed with CEA and NCA. NCA2 was found to be a noromal cytoplasmic and mucus-associated antigen of gastrointestinal tissues. It was present also in fetal stomach and colon. Sections of gastric and colonic tumors as well as intestinal metaplasia of gastric mucosae always reacted brilliantly with absorbed anti-NCA2 antiserum.

Antigens↗

Clinical pharmacokinetics of drugs for Alzheimer's disease.

Pharmacological treatment of patients with Alzheimer's disease is becoming more important, as evidenced by the number of drugs being developed in different countries. It has been shown in the majority of clinical trials that cholinesterase inhibitors, such as tacrine (tetrahydroaminoacridine), are able to induce beneficial effects in cognition and memory. Tacrine, like most of the other oral antidementia agents, is rapidly absorbed from the gastrointestinal tract. It is excreted mainly through the kidney, with a terminal elimination half-life of about 3 hours. Tacrine has nonlinear pharmacokinetics and there are large interindividual differences in pharmacokinetic parameters after oral, intravenous and rectal administration. A positive relationship between cognitive changes and plasma tacrine concentrations has been recently described. Similarly, velnacrine exhibits evidence of nonlinearity in some pharmacokinetic parameters, but renal excretion is a minor route of elimination for this drug. Pharmacokinetic data pertaining to eptastigmine, a third cholinesterase inhibitor, is more limited. However, the drug is rapidly distributed to the tissues after oral administration and readily enters the central nervous system, where it can be expected to effectively inhibit acetylcholinesterase in the brain for a prolonged period. Pharmacokinetic data for the nootropic agents are more limited. However, of the 3 agents reviewed only pramiracetam penetrates the central nervous system (CNS) poorly. Indeed, oxiracetam crosses the blood-brain barrier and persists for longer in the CNS than in the serum. Selegiline (deprenyl), a neuroprotective agent, is readily absorbed from gastrointestinal tract. It is metabolised mainly in the liver, and to a minimal extent in the lung or kidneys. The steady-state concentrations of metabolites in the cerebrospinal fluid (CSF) and serum are very similar, reflecting their easy penetration into the CNS. Idebenone, another neuroprotective agent, likewise is rapidly absorbed and achieves peak concentrations in the brain comparable to those in plasma. Similarly, CSF concentrations of metabolites of ST 200 (acetyl-L-carnitine) parallel those in plasma, suggesting that they easily cross the blood-brain-barrier. Gangliosides (GM1) can be given intramuscularly or subcutaneously, but the latter route of administration provides a concentration 50% higher both in the serum and the ganglioside fraction. However, because of its longer elimination, the intramuscular route is the best form of administration when the brain is the target organ for the treatment. Absorption of nimodipine is quite rapid. The pharmacokinetics of nimodipine during multiple-dose treatment have not been studied extensively; however, the drug does not appear to accumulate during repeated administration of standard doses.(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗

In vivo butyrate metabolism and colonic permeability in extensive ulcerative colitis.

BACKGROUND & AIMS: Impaired short-chain fatty acid metabolism by the colonocyte has been suggested as a pathogenic factor in ulcerative colitis (UC). The aim of this study was to measure in vivo butyrate metabolism in UC and to correlate butyrate oxidation with colonic permeability. METHODS: Butyrate oxidation was measured by means of a 14CO2-breath test after rectal instillation of 14C-butyrate. 51Cr-ethylenediaminetetraacetic acid (EDTA) was added to the enema, and the urinary % dose excretion of 51Cr-EDTA after 6 hours was a measure for permeability. RESULTS: Patients with active extensive UC showed a significantly lower butyrate oxidation and increased colonic permeability in comparison to healthy controls. Butyrate oxidation correlated significantly negative with clinical activity. Oxidation of butyrate was not decreased in most patients with inactive extensive UC. In 3 patients with inactive disease and decreased oxidation, a relapse occurred within a few weeks after the test, whereas all patients with normal oxidation maintained their remission for at least 3 months. A significantly negative correlation existed between butyrate oxidation and colonic permeability. CONCLUSIONS: Patients with active extensive UC have a decreased colonic butyrate oxidation. However, the fact that remission is associated with normal oxidation suggests that UC mucosa is not intrinsically altered in butyrate oxidation, making this unlikely to be a primary defect in UC.

Breath Tests↗

Bioavailability and preliminary clinical efficacy of intrarectal artesunate in Ghanaian children with moderate malaria.

We report the first detailed pharmacokinetic assessment of intrarectal (i.r.) artesunate (ARS) in African children. Artesunate was given intravenously (i.v.; 2.4 mg/kg of body weight) and i.r. (10 or 20 mg/kg formulated as 50- or 200-mg suppositories [Rectocaps]) in a crossover study design to 34 Ghanaian children with moderate falciparum malaria. The median relative bioavailability of dihydroartemisinin (DHA), the active antimalarial metabolite of ARS, was higher in the low-dose i.r. group (10 mg/kg) than in the high-dose i.r. group (20 mg/kg) (58 versus 23%; P = 0.018). There was wide interpatient variation in the area under the concentration-time curve after i.r. ARS administration (up to 9-fold in the high-dose group and 20-fold in the low-dose group). i.r. administered ARS was more rapidly absorbed in the low-dose group than the high-dose group (median [range] absorption half-lives, 0.7 h [0.3 to 1.24 h] versus 1.1 h [0.6 to 2.7 h] [P = 0.023]. i.r. administered ARS was eliminated with a median (range) half-life of 0.8 h (0.4 to 2.7 h) (low-dose group and 0.9 h (0.1 to 2.5 h) (high-dose group) (P = 1). The fractional clearances of DHA were 3.9, 2.6, and 1.5 liters/kg/h for the 20-mg/kg, 10-mg/kg and i.v. groups, respectively (P = 0.001 and P = 0.06 for the high-and low-dose i.r. groups compared with the i.v. groups, respectively). The median volumes of distribution for DHA were 1.5 liters kg (20 mg/kg, i.r. group), 1.8 liters/kg (10 mg/kg, i.r. group), and 0.6 liters/kg (i.v. group) (P < 0.05 for both i.r. groups compared with the i.v. group). Parasite clearance kinetics were comparable in all treatment groups. i.r. administered ARS may be a useful alternative to parenterally administered ARS in the management of moderate childhood malaria and should be studied further.

Administration, Rectal↗

Isodon japonicus decreases immediate-type allergic reaction and tumor necrosis factor-alpha production.

BACKGROUND: The immediate-type allergic reaction is involved in many allergic diseases such as asthma, allergic rhinitis and sinusitis. The discovery of drugs for the treatment of immediate-type allergic disease is a very important subject in human health. Isodon japonicus Hara (Labiatae) (IJAE) has been used for centuries as a traditional medicine in Korea and is known to have an anti-inflammatory effect. However, its specific mechanism of action is still unknown. In this report, we investigated the effect of IJAE on the immediate-type allergic reaction and studied its possible mechanisms of action, focusing on the mast cell-mediated allergic reaction. METHODS: IJAE extracts were anally administered to mice for high and fast absorption. Compound 48/80-induced mortality and compound 48/80- or immunoglobulin E (IgE)-induced histamine release were measured to evaluate the antiallergic effects of IJAE. The effect of IJAE on the model of local allergic reaction in vivo, passive cutaneous anaphylaxis (PCA), was investigated. The production of tumor necrosis factor-alpha (TNF-alpha) was measured by Western blotting. RESULTS: IJAE inhibited compound 48/80-induced systemic reactions and plasma histamine release in mice. IJAE decreased the PCA reaction activated by anti-dinitrophenyl (DNP) IgE antibody. IJAE dose-dependently reduced histamine release from rat peritoneal mast cells activated by compound 48/80 or anti-DNP IgE. Furthermore, IJAE decreased the production of TNF-alpha in phorbol 12-myristate 13-acetate plus calcium ionophore A23187-stimulated human mast cells. CONCLUSION: Our findings provide evidence that IJAE inhibits mast cell-derived immediate-type allergic reactions, and also demonstrate the involvement of TNF-alpha in these effects. We propose the clinical use of IJAE in mast cell-mediated immediate-type allergic diseases.

Administration, Rectal↗

The effect of exercise on the gastrointestinal tract.

Surveys of athletes, primarily runners, have shown that digestive disorders are common, associated both with training and racing. Women, in particular, seem to suffer most commonly. Nearly half have loose stools and nausea and vomiting occur frequently after hard runs. Diarrhoea, incontinence and rectal bleeding occur with surprising frequency. Runners may use medications prophylactically to minimise some of these symptoms. Upper digestive symptoms seem to occur more commonly in multisport events such as triathlons or enduro. The published literature is difficult to analyse and the basic intestinal physiology not well studied. Most gastroenterologists are accustomed to evaluating the fasting patient at rest and exercise physiologists are seldom experienced with digestive techniques. Digestive symptoms occurring with exercise referable to the oesophagus include chest pain, gastro-oesophageal reflux symptoms, or symptoms related to alterations in motility. While little is known of the oesophageal physiology during exercise, it is believed that only minimal changes occur in most subjects. Gastro-oesophageal reflux occurs more frequently with exercise than at rest and may produce symptoms of chest pain suggestive of ischaemic disease. Acid exposure may be reduced by pretreatment with histamine H2-receptor antagonists. Oesophageal symptoms, though common, are rarely disabling to the athlete, and the clinical importance lies in confusion with ischaemic disease. Cases of acute gastric stasis following running have been reported and gastric physiology during exercise, particularly bicycling, has been more actively investigated. Gastric emptying during exercise is subject to a number of factors including calorie count, meal osmolality, meal temperature and exercise conditions. However, it is generally accepted that light exercise accelerates liquid emptying, vigorous exercise delays solid emptying and has little effect upon liquid emptying until near exhaustion. Gastric acid secretion probably changes little with exercise although some have postulated that ulcer patients may increase secretion with exercise. Some exercise-associated digestive symptoms, such as diarrhoea and abdominal pain, have been attributed to changes in intestine function. Small bowel transit is delayed by exercise when measured by breath hydrogen oral caecal transit times and motility may be reduced as well. Intestinal absorption during exercise has not been well evaluated but probably changes little in ordinary circumstances. Passive absorption of water, electrolytes and xylose are not affected by submaximal effort. Colonic transit and function is even more difficult to evaluate and published results have been conflicting. However, it is likely that many of the lower digestive complaints of runners such as diarrhoea and lower abdominal cramps are due to direct effects of exercise upon the colon.(ABSTRACT TRUNCATED AT 250 WORDS)

Digestive System↗

A dynamic study of rectally absorbed ammonia in liver cirrhosis using [13N]ammonia and a positron camera.

[13N]Ammonia produced by the cyclotron was instilled intrarectally in patients with cirrhosis and other liver diseases to study the turnover of rectally absorbed [13N]ammonia. A positron camera connected to an on-line computer system was used for the measurement of sequential changes of 13N activity in blood and for coincidence positron imaging of the liver and heart. 13N activity over the head was also recorded. Chromatographic analysis of 13N-labeled substances in blood was carried out using a Dowex 50Wx8 column at varying times after the administration. In the control, [13N]ammonia was absorbed quickly and visualized the liver, whereas in patients with cirrhosis, the lungs and heart were first visualized, and 13N activity over the head was also higher. It was suggested that a large proportion of absorbed [13N]ammonia bypassed hepatocytes and reached peripheral tissues in cirrhosis. The heart/liver ratio of 13N and 13N over the head were correlated with various indices of portal hypertension. The relative proportion of nonammonia 13N metabolites in blood was lower at 5 and 15 min after administration in cirrhosis, suggesting a reduced capacity of the liver to remove and metabolize ammonia.

Acute Disease↗

Effects of thermal stress during rest and exercise in the paediatric population.

Thermoregulation during exposure to hot or cold environments differs between children and adults. Many physical and physiological changes occur during growth and maturation that can affect thermoregulation during rest as well as during exercise. Thus, physical as well as physiological differences between children and adults may explain the different response to thermal stress. The main physical difference between children and adults affecting thermoregulation is the much higher surface-area-to-mass ratio of children. In a warm environment this allows them to rely more on dry heat loss and less on evaporative cooling. However, in extreme conditions, hot or cold, the greater surface-area-to-mass ratio results in a higher rate of heat absorption or heat loss, respectively. The lower body fat in girls compared with women provides lower insulation and presents a disadvantage in a cold environment. The smaller blood volume in children compared with adults, even relative to body size, may limit the potential for heat transfer during heat exposure and may compromise exercise performance in the heat. The main physiological difference between children and adults is in the sweating mechanism, affecting their thermoregulation in the heat, but not in the cold. The lower sweating rate characteristic of children is due to a lower sweating rate per gland and not to a lower number of sweat glands. In fact, children are characterised by a higher density of heat-activated sweat glands. The lower sweating rate per gland may be explained by the smaller sweat gland size, a lower sensitivity of the sweating mechanism to thermal stimuli and, possibly, a lower sweat gland metabolic capacity. Other physiological differences between children and adults that may affect thermoregulation include metabolic, circulatory and hormonal disparities. The higher metabolic cost of locomotion in children provides an added strain on the thermoregulatory system during exercise in the heat. On the other hand, during acute exposure to cold it may prove advantageous by increasing heat production. Circulatory differences, such as a lower cardiac output at any given exercise intensity and the lower haemoglobin concentration in boys compared with men, are likely to increase the cardiovascular strain during exercise in the heat, although their effects in a cold environment are unknown. Finally, testosterone and prolactin are 2 hormones that differ in baseline levels between children and adults and may affect sweat gland function and sweat composition. These possible effects need to be further investigated. The effectiveness of thermoregulation is reflected by the stability of core temperature. In a thermoneutral environment, children are characterised by a similar rectal temperature and a higher skin temperature when compared with adults. The latter may reflect the higher reliance on dry heat loss compared with evaporative cooling in children. In a hot environment, children's body temperatures are higher compared with adults while walking and running but not necessarily while cycling. This may be related to the higher metabolic cost, and therefore higher heat production, in children while walking or running but not while cycling. In a cold environment, children are characterised by lower skin temperatures, reflecting greater vasoconstriction. Their metabolic heat is increased in the cold to a greater extent than that of adults, although this appears to be sufficient to maintain their body temperature during exercise but not during prolonged rest. Neither children nor adults sufficiently replace fluid loss during exercise in the heat. Nevertheless, recent studies suggest that in children, when the available beverage is flavoured and enriched with NaCl and carbohydrates, dehydration can be prevented. (ABSTRACT TRUNCATED)

Adolescent↗

Aldosterone mediates the changes in hexose transport induced by low sodium intake in chicken distal intestine.

1. In chickens, low Na+ diets markedly decrease the hexose transport in the rectal segment of the large intestine; transport in the ileum shows a lower, but significant reduction and transport in the jejunum is unaffected. These effects involve both apical (SGLT1) and basolateral (GLUT2) hexose transporters. 2. The role of the renin-angiotensin-aldosterone axis (RAAS) in the epithelial response to Na+ intake was studied in chickens fed high-NaCl (HS) and low-NaCl (LS) diets. The V(max) of alpha-methyl-D-glucoside and D-glucose were determined in vesicles from the brush-border (BBMVs) and basolateral (BLMVs) membranes, respectively. The binding of phlorizin to BBMV and cytochalasin B to BLMV were used as indicators of the abundance of SGLT1 and GLUT2, respectively. 3. In HS-adapted chickens, the serum concentration of aldosterone (means +/- S.E.M.) was 35 +/- 5 pg ml(-1) (n = 6) and that of renin was 20 +/- 2 ng ml(-1) (n = 3). In LS-fed birds, these values were 166 +/- 12 pg ml(-1) (n = 6) and 122 +/- 5 ng ml(-1) (n = 3), respectively. Administration of captopril, the inhibitor of the angiotensin-converting enzyme (ACE), to LS-chickens lowered the aldosterone serum concentration without affecting the renin concentration. Captopril also prevented the reduction of apical and basolateral hexose transport in ileum and rectum characteristic of the intestinal response to LS adaptation. 4. Administration of the aldosterone antagonist spironolactone to LS-adapted chickens did not affect the serum concentrations of aldosterone, but prevented the effects of LS intake on hexose transport in both apical and basolateral membranes. This suggests that the effects of aldosterone are mediated by cytosolic mineralcorticoid receptors. 5. Administration of exogenous aldosterone to HS-fed birds induced hexose transport and binding properties typical of the LS-adapted animals. These findings support the view that aldosterone, besides its primary role in controlling intestinal Na+ absorption, can also modulate the expression of apical and basolateral glucose transporters in the chicken distal intestine.

Aldosterone↗

Acute hemorrhagic hypotension and its effect on the pulmonary clearance of helium instilled into the rabbit colon.

The study investigates the effect of acute and incremental posthemorrhagic hypotension on pulmonary clearance of helium (CHe) introduced into the colon. Eighteen New Zealand White rabbits were cannulated and connected to a respirator at constant minute ventilation. A helium mass spectrometer was used to monitor airway gas. After 30 min stabilization, 10 ml/kg of helium were injected rectally while CHe and mean aortic blood pressure (BPm) were continuously monitored. Control animals (group 1, n = 5) achieved constant CHe (0.8-3.0 microliter/kg/min) by 20 min, with CHe and BPm continuing unchanged over a 90-min period. Group 2 animals (n = 5) underwent acute blood loss of 12 ml/kg with reinfusion after 30 min. Group 3 animals (n = 8) underwent incremental blood loss of 4 ml/kg up to a maximum of 28 ml/kg without reinfusion. Two animals in group 3 had electromagnetic flow probes placed around their distal abdominal aortae. At 12 ml/kg blood loss, group 2 and 3 animals experienced falls in BPm of 46 and 58% along with simultaneous falls in CHe of 33 and 53%, respectively. These changes were statistically significant (p less than 0.05). Reinfusion (group 2) caused initial parallel increases in CHe and BPm. However, CHe remained elevated as BPm returned to baseline, a finding consistent with colonic reperfusion hyperemia. At blood loss of more then 12 ml/kg (group 3), BPm and electromagnetic flow stabilized while CHe continued to decrease. Under these conditions CHe appeared to reflect shunting of intestinal blood flow away from the mesenteric bed.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Temperature and SAR measurements in deep-body hyperthermia with thermocouple thermometry.

Multisensor (7-14) thermocouple thermometry is used at our department for temperature measurement with our 'Coaxial TEM' regional hyperthermia system. A special design of the thermometry system with high resolution (0.005 degrees C) and fast data-acquisition (all channels within 320 ms) together with a pulsed power technique allows assessment of specific absorption rate (SAR) information in patients along catheter tracks. A disadvantage of thermocouple thermometry, EM interference, is almost entirely eliminated by application of absorbing ferrite beads around the probe leads. We investigated the effect of remaining disturbance on the temperature decay after power-off, both experimentally in phantoms and in the clinic, and with numerical simulations. Probe and tissue characteristics influence the response time tau dist of the decay of the disturbance. In our clinical practice a normal pulse sequence is 50 s power-on, 10 s power-off: a response time longer than the power-off time results in a deflection of the temperature course at the start. Based on analysis of temperature decays correction of temperature is possible. A double-pulse technique is introduced to provide an initial correction of temperature, and fast information about accuracy. Sometimes disturbance with a relatively long response time occurs, probably due to a bad contact between probe, catheter and/or tissue. Thermocouple thermometry proved to be suitable to measure the SAR along a catheter track. This is used to optimize the SAR distribution by patient positioning before treatment. A clinical example illustrates this.

Body Temperature↗

Anti-allergic effects of Lycopus lucidus on mast cell-mediated allergy model.

The current study characterizes the mechanism by which the aqueous extract of Lycopus lucidus Turcz. (Labiatae) (LAE) decreases mast cell-mediated immediate-type allergic reaction. The immediate-type allergic reaction is involved in many allergic diseases such as asthma and allergic rhinitis. LAE has been used as a traditional medicine in Korea and is known to have an anti-inflammatory effect. However, its specific mechanism of action is still unknown. LAE was anally administered to mice for high and fast absorption. LAE inhibited compound 48/80-induced systemic reactions in mice. LAE decreased the local allergic reaction, passive cutaneous anaphylaxis, activated by anti-dinitrophenyl (DNP) IgE antibody. LAE dose-dependently reduced histamine release from rat peritoneal mast cells activated by compound 48/80 or anti-DNP IgE. Furthermore, LAE decreased the secretion of TNF-alpha and IL-6 in phorbol 12-myristate 13-acetate (PMA) plus calcium ionophore A23187-stimulated human mast cells. The inhibitory effect of LAE on the pro-inflammatory cytokine was p38 mitogen-activated protein kinase (MAPK) and nuclear factor-kappaB (NF-kappaB) dependent. LAE attenuated PMA plus A23187-induced degradation of IkappaBalpha and nuclear translocation of NF-kappaB, and specifically blocked activation of p38 MAPK, but not that of c-jun N-terminal kinase and extracellular signal-regulated kinase. Our findings provide evidence that LAE inhibits mast cell-derived immediate-type allergic reactions and involvement of pro-inflammatory cytokines, p38 MAPK, and NF-kappaB in these effects.

Administration, Rectal↗

Microvillus inclusion disease. In vitro jejunal electrolyte transport.

Microvillus inclusion disease is an inherited intestinal brush border membrane defect that causes severe fluid and electrolyte malabsorption. In an infant with microvillus inclusion disease (confirmed by electron microscopic evaluation of rectal, jejunal, and gallbladder mucosae), basal stool output was massive (greater than 125 mL . kg-1 . day-1) and was not altered by treatment with clonidine or octreotide. A proximal jejunostomy with mucous fistula was placed, allowing separation of proximal from distal tract outputs (60 mL . kg-1 . day-1 and 100 mL . kg-1 . day-1, respectively). A 10-cm jejunal segment was excised during surgery and mounted in Ussing chambers for determination of transepithelial Na+ and Cl fluxes. Compared with intestine of normal infants, this infant's epithelium showed transmural conductance and unidirectional ion fluxes that were only 30% of normal. With respect to both Na+ and Cl, the excised jejunum was in a net secretory state. Theophylline (5 mmol/L) increased net Cl secretion slightly. In response to mucosal D-glucose (30 mmol/L), jejunal mucosal-to-serosal Na+ flux doubled. In the infant, glucose-electrolyte solution administered intrajejunally did not significantly change stool output, suggesting that all of the solution (40 mL/kg) was absorbed. Subtotal enterocolectomy, in theory, could have decreased purging by 66% in this infant with microvillus inclusion disease, but diarrhea would still have been significant.

Biological Transport, Active↗