Pretreatment with SR48692 has different effects on central neurotensin-induced gastric mucosal defense and inhibition of gastric acid secretion in rats.

Neurotensin is a tridecapeptide present in the brain and gastrointestinal tract. Administration of neurotensin into the brain results in responses in the gastrointestinal tract, suggesting a role for neurotensin in the interrelationships that comprise the brain-gut axis. Intracerebroventricular (i.c.v.) administration of neurotensin protects the gastric mucosa against injury caused by cold water restraint (CWR) and also inhibits gastrin-stimulated gastric acid secretion. The hypothesis tested was that these two actions of neurotensin are mediated via its high-affinity receptor. Rats were given neurotensin (60 microgram, i.c.v.) prior to CWR or pylorus ligation after pretreatment with SR48692, a nonpeptide antagonist of the high-affinity neurotensin receptor (0.25 or 2.5 microgram, i.c.v., or 10, 100, or 500 microgram kg-1, i.p.). Neurotensin reduced cold water restraint (CWR)-induced gastric mucosal injury and inhibited gastrin-stimulated acid secretion. Pretreatment with SR48692 (2.5 microgram, i.c.v., or 100 microgram kg-1, i.p.) prior to CWR blocked neurotensin's protection of the gastric mucosa against injury. In contrast, pretreatment with 2.5 microgram SR48692, i.c.v., did not block neurotensin-induced inhibition of acid secretion, whereas 500 microgram kg-1, i.p., partially blocked the inhibition. SR48692 (2.5 microgram, i.c.v.) inhibited acid secretion, suggesting that SR48692 has agonist activity in this system. These results suggest that central neurotensin protects the gastric mucosa against CWR-induced injury via its high-affinity receptor. The receptor that mediates central neurotensin-induced inhibition of gastric acid secretion does not appear to be the high-affinity receptor since the neurotensin receptor antagonist SR48692, when given i.c.v., had agonist activity, inhibiting stimulated acid secretion. High-affinity neurotensin receptors in the periphery appear to play a role in inhibition of stimulated gastric acid secretion.

Hereditary syndactyly in Angus cattle.

Twenty-five syndactylous Angus cattle, characterized pathologically, were reported from 16 herds in 10 states from 1979 to 1994. Twenty-one (84%) had all 4 legs syndactylous, 3 (12%) had 3 legs syndactylous, and 1 (4%) had 2 legs syndactylous. All syndactylous cattle walked with considerable difficulty. Hooves of aged animals became curled and bent laterally or medially. Affected hooves had the appearance of a truncated cone, the base of which was located at the coronary band. Most hooves were fused completely with no indication of dual anlage. An occasional hoof had a distal notch, and other hooves had a dorsally located groove indicating dual embryonic origin. Lateral dewclaws were enlarged in most cases. Radiographs and dissections of limbs of 19 animals revealed a consistent pattern of fusion in most affected calves. Lesions included 1 or more of the following: disappearance of the large metacarpal and metatarsal intertrochlear notches, horizontal fusion of 1 or more carpals and tarsals, fusion of proximal sesamoids, 1 distal sesamoid, and fusion of paired phalanges. Evidence of a genetic cause consisted of 11 syndactylous calves among 70 offspring of 4 3/4 sib families, 8 preterm syndactylous fetuses among 148 preterm fetuses and 13 calves in progenies of 19 animals tested for possible heterozygosity, and 5 syndactylous calves from matings of an Angus syndactylous bull with 1 Angus and 4 Holstein syndactylous cows. Data were consistent with recessive inheritance at a single locus. Angus cattle with sydactytly had a larger number of affected limbs than did syndactylous Holsteins and their Angus crosses, suggesting existence of 2 recessive alleles. The allele of Holsteins (syH) appeared to influence phenotypic expression in a dominant pattern over the Angus allele (syA). Both syA and syH alleles acted as recessives to the normal SY allele. Phenotypic effects on limb development were most dramatic in calves with the syA/syA genotype.

Family therapy education for psychiatry residents : a pilot study of efficacy.

Teaching and clinical supervision of family therapy can enhance a resident's clinical skills and also promote movement from a linear, reductionistic type of thinking to a dynamic understanding of complex systems. Second-year postgraduate residents who completed a 10-month family therapy program were tested for their ability to understand family systems dynamics with the Family Therapy Assessment Exercise. Comparison of their test results before and after the program indicated significant improvement, which was entirely accounted for by improvement in the area of therapeutic skills.

Practical aspects of teaching home parenteral nutrition therapy.

With the implementation of the prospective pricing system there has been a greater emphasis on discharging patients on home health care therapy. Home parenteral nutrition (HPN) has been a successful method of treating patients with compromised gastrointestinal tracts. The key to the success of these programs remains patient and family training. Adequate knowledge and skills must be demonstrated and documented in the areas of aseptic technique, procedures of catheter care, complications, and equipment, prior to discharge. This paper describes the various aspects of identifying and training patients for HPN, and some of the problems and complications that may occur.

Dosage form and formulation effects on the bioavailability of vitamin E, riboflavin, and vitamin B-6 from multivitamin preparations.

The effects of formulation factors and pharmaceutical dosage form on the bioavailability of RRR-alpha-tocopherol (d-alpha-tocopherol), riboflavin, and pyridoxine hydrochloride were studied after administration of two capsule formulations and a tablet to 12 normal humans. Absorption of RRR-alpha-tocopherol was increased from the Aquabiosorb soft elastic gelatin (SEG) capsule formulation compared with the modified standard-SEG capsule and the commercial tablet. There were no significant differences in bioavailability of riboflavin and pyridoxine hydrochloride between the SEG formulation and the tablet albeit a trend toward consistent absorption was seen from the SEG formulation. The modified-SEG formulation exhibited significantly lower bioavailability for these water-soluble vitamins. The enhanced bioavailability of vitamin E and the trend towards faster and more consistent absorption of riboflavin and vitamin B-6 from the SEG formulation may be related to the surfactant vehicle employed and the attendant wetting properties. The results also suggest ethnic differences in vitamin bioavailability.

Bacterial endotoxin retention by inline intravenous filters.

Filters used in i.v. administration sets were tested for their ability to retain bacterial endotoxins for up to 96 hours of continuous infusion. Inline filters composed of cellulose ester, polyacrylate, polypropylene, polyethylene, or Posidyne Nylon 66 were used during continuous infusion of 5% dextrose injection at 83 mL/hr. One milliliter of inoculum containing 10(8) Escherichia coli was injected through a port upstream from the filter. A bacterial filter was used to monitor the sterility of effluent from the inline filters. The effluent was tested with limulus amebocyte lysate (LAL) that could detect endotoxin concentrations greater than 50 pg/mL. A control solution was monitored for viability of the bacteria throughout the course of the study, and positive endotoxin controls were used to confirm the sensitivity of the LAL. Samples of effluent were tested at 0, 4, 19, 24, 48, 72, and 96 hours. Effluent from all filters was sterile throughout the study. LAL assay indicated that only the effluent from filters containing Posidyne Nylon 66 was free of endotoxins for 96 hours. Effluent from the other filters contained endotoxins immediately after injection of the E. coli. Of the inline filters tested, only the one composed of Posidyne Nylon 66 was able to retain E. coli endotoxin for 96 hours. Further study is needed with E. coli and other microorganisms that are likely contaminants of i.v. infusions.

Parenteral handling precaution: particulate introduction resulting from needle sheath contamination.

The purpose of this in vitro experiment was to determine if inadvertent needle cap nicking would introduce particulate contamination. After a preliminary observation (n = 21), a more thorough confirmatory experiment (n = 28) was performed. Twenty-four of 28 needles were contaminated before, and 18 of 28 needles after, entry into a Latex injection port; 5 of these 18 needles remained contaminated post sterile water injection and withdrawal from the port. Since 19 of 24 contaminated needles lost their contamination within the simulated injection system, it was proposed that inadvertent needle cap particulate contamination to needle shafts may be introduced into in vivo tissue or delivered intravascularly.

Cost containment using cysteine HCl acidification to increase calcium/phosphate solubility in hyperalimentation solutions.

The purpose of this study was to determine if (1) the calcium/phosphate insoluble product was inversely related to pH [when cysteine HC1 (CH) was added as neonatal supplementation at 0.5 mM/kg/day to hyperalimentation (HAL) solutions] and (2) the potential cost savings to the hospital. The pH of the HAL solutions was adjusted by adding various amounts of CH to the HAL solution. HAL solutions containing 27 mEq of calcium/liter and 30 mEq (15 mM) of phosphate/liter were compounded. Ten-milliliter aliquots were analyzed at 0, 12, 24, and 48 hr. All samples (n = 56) were filtered (0.22 mu), viewed with 7-10,000 X magnification scanning electron microscopy, and qualitatively analyzed with a Philips Energy Dispersive X-Ray Analysis System equipped with a SW9100 Microprocessor. Calcium/phosphate insoluble product was present in the 0-, 12-, 24-, and 48-hr samples from the CH-free solutions. The solutions containing 759 mg (4.17 mM)/liter of CH however, remained free of precipitant. This investigation demonstrated that addition of CH to HAL can foster significant cost containment (projected $82,000/yr tangible hospital savings) by the elimination of current calcium/phosphate separation procedures for neonates on parenteral nutrition.

Drug interactions in psychopharmacology.

The mechanisms underlying psychotropic drug interactions include alterations in gastrointestinal absorption, protein-binding, specific and nonspecific metabolic degradation, receptor interactions, and renal clearance. The risk of interactions can be minimized by detailed drug history-taking, use of rapid reference sources, patient education, and physician behaviors that include serious attention to somatic complaints, identification of "at risk" situations, and rational prescribing habits.

Structure of the Chromatium sulfur particle and its protein membrane.

Sulfur particles extracted from Chromatium vinosum strain D were found to be bounded by a unique proteinaceous membrane. Ultrastructural examination of the membrane in Epon sections and bovine serum albumin sections and examination of negatively stained, sulfur-free membrane ghosts revealed a monomolecular sheet composed of 2.5-nm globular components. The internal sulfur was found to bind large amounts of a variety of negative stains and to form myelin-like structures upon rupture of the surrounding membrane.