Comparison of effects of suture and cyanoacrylate tissue adhesive on bacterial counts in contaminated lacerations.

We studied the effects of closing lacerations with suture or cyanoacrylate tissue adhesive on staphylococcal counts in inoculated guinea pig lacerations. Wounds closed with adhesive alone had lower counts than wounds containing suture material (P < 0.05). The results of a time-kill study were consistent with a bacteriostatic adhesive effect of the adhesive against Staphylococcus aureus.

Opioid antagonism alters blood glucose homeostasis during exercise in humans.

In an attempt to clarify the role of endogenous opioid peptides in substrate mobilization and hormonal responses to dynamic exercise, eight trained cyclists completed exercise trials at 90% of maximal O2 consumption (VO2max) until exhaustion and at 70% VO2max for 90 min. Trials were conducted after intravenous administration of the opiate antagonist naloxone (NAL, 0.1 mg/kg bolus + 0.1 mg.kg-1.h-1) or volume-matched saline (SAL) at each intensity. Serum glucose was maintained at significantly higher levels at 60 and 90 min of exercise in the 70%-NAL than in the 70%-SAL trial and at all points during exercise and at 30 and 60 min of recovery in the 90%-NAL than in the 90%-SAL trial. The serum insulin response to exercise was not altered by NAL administration at either intensity. Serum C-peptide was approximately 50% higher at 60 and 90 min of exercise in the 70%-NAL than in the 70%-SAL trial but was significantly lower during exercise in the 90%-NAL than in the 90%-SAL trial. The plasma glucagon response to exercise at 70% VO2max was not altered by NAL administration but was significantly elevated in the 90%-NAL vs. the 90%-SAL trial. Plasma epinephrine was 50-150% (approximately 2-3 nM) higher during exercise from 30 to 90 min of exercise in the 70%-NAL than in the 70%-SAL trial and was higher at termination (4.9 +/- 2.1 vs. 2.7 +/- 1.7 nM) in the 90%-NAL than in the 90%-SAL trial, although the difference in the 90% trial was not statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of scrubbing and irrigation on staphylococcal and streptococcal counts in contaminated lacerations.

We studied the effects of scrubbing with poloxamer 188 (SCR), irrigating with povidone iodine (PI), and scrubbing followed by irrigation (SCR-PI) on staphylococcal and streptococcal counts in inoculated guinea pig lacerations. PI irrigation and SCR-PI significantly lowered streptococcal counts (P < 0.05). Staphylococcal counts were not different from those in controls.

The distribution of water in the intracellular and extracellular compartments and the lipid and protein composition of the Mongolian gerbil (Meriones unguiculatus) during water deprivation.

1. The plasma, interstitial, extracellular and intracellular volumes fell to similar extents after 5 days of water deprivation in male and female gerbils. There was no selective plasma volume conservation. 2. The female gerbils lost more weight on water deprivation yet the total body water loss was very similar to that in the male animals. While there was a small fall in the protein content of the male animals the extra loss of weight in the females appeared to be due to the considerable catabolism of lipid stores.

Variations in velar position over time: a nasal videoendoscopic study.

Changes in velar position during production of nonnasal speech in two adults were measured using field-by-field videoendoscopic tracking procedures. The data suggested that the changes in velar position were coordinated with syllable production. Peak velar displacement occurred during maximum oral closure for oral consonant production and was followed by lowering of velar position during vowel production. This pattern of velar movement was not altered by changes in speaking rate or by jaw fixation. The timing of peak velar elevation relative to peak intraoral air pressure and peak jaw elevation was also examined. Timing of peak velar displacement was statistically associated with timing of peak intraoral air pressure in one subject. The data are discussed with regard to the potential value of studying variations in velar position during nonnasal speech in patients with marginal velopharyngeal incompetence.

Water balance during saline imbibition in the Mongolian gerbil (Meriones unguiculatus).

1. There were few changes in the water balance of gerbils drinking 0.25 and 0.50 M NaCl solutions for 5 days. 2. Imbibition of 0.75 and 1.0 M saline resulted in some dehydration of the body fluids and considerable depletion of the neural lobe vasopressin store. 3. Although large amounts of NaCl were excreted, the maximum urine osmolality was considerably less than that found following water deprivation. 4. The imbibition of 1.0 M saline caused similar changes in water balance to water deprivation showing that little, if any, water was gained from this solution.

A clinical pharmacy-oriented drug surveillance network: II. Results of a pilot project.

A nationwide network of clinical pharmacists has been organized for the purpose of collecting drug experience data generated during the routine clinical care of patients. In order to assess the utility of this network a pilot project was performed to obtain a cross-sectional view of antibiotic utilization in the U.S. and to identify potential problems with a more widespread implementation of this program. One hundred eleven pharmacists enrolled in the drug surveillance network participated in this survey and collected information on more than 2000 patients treated with antimicrobial agents over approximately a three-month period (February-April 1987). The most common sites of infection were the lung, genitourinary tract, skin and soft tissue, and the abdomen, and accounted for approximately 75 percent of infections. Overall, the aminoglycosides, the first-generation cephalosporins, and the aminopenicillins remain the most commonly used antibiotics and represent approximately 50 percent of antimicrobials used in the surveyed population. The results of this pilot project suggest that the use of a nationwide network of clinical pharmacists is a promising source of clinically relevant drug experience data. The ability to concurrently evaluate patients and link information regarding patient demographics, drug therapy regimens, diagnosis, and clinical outcomes fills an important gap in our knowledge of clinical drug utilization.

The activity of the hypothalamo-neurohypophysis during rehydration following water deprivation in the gerbil (Meriones unguiculatus) and the laboratory rat (Rattus norvegicus).

Water deprivation in gerbils and rats for 5 and 3 days respectively resulted in the same degree of dehydration of the animals and similar depletion of the neurohypophyseal vasopressin stores. Following access to drinking water, the vasopressin stores were replenished in the gerbil and rat in 2 and 6 days respectively. It was suggested that the quicker restoration of the store in the gerbil was due to the greater ability to synthesize vasopressin and to continuing high activity of the neurosecretory cells until the stores were replete.

Water balance and protein intake in the Mongolian gerbil (Meriones unguiculatus).

During water deprivation the gerbil increasingly reduced its intake of protein as the protein content of the diet increased thus minimising water stress. When given a choice of diet, increased preference was shown for that with the lower protein content. Despite the reduction in intake, the gerbils became dehydrated, the extent being least on the low protein diet. Gerbils remained in water balance on a high protein diet with 2% saline to drink. The predicted maximum urine osmolality, from renal structural indices, was less than the actual measured value, possibly reflecting the well-developed pelvic anatomy.

Abnormal electric membrane properties of Down's syndrome DRG neurons in cell culture.

Cell cultures were prepared from normal and Down's syndrome dorsal root ganglia (DRG). Both pre- and postnatal specimens were utilized; 8 normal and 4 Down's. Cultures were maintained in medium with normal (4 mM) and elevated (20 mM) potassium (K) since the latter was found to enhance neuron survival. After various period of incubation, cultures were transferred to normal K medium and their electrical membrane properties (EMP) determined using intracellular recording techniques. An analysis of variance was performed with 5 covariates: developmental stage, culture duration, K concentration, type of action potential, and neuronal surface area. This analysis indicated that the Down's neurons had abnormal EMP, the most affected being the after hyperpolarization (-41%), membrane time constant (+30%), threshold rheobasic depolarization (-22%), rate of falling phase of action potential (-20%), specific membrane resistance (+18%) and absolute refractory period (+12%). All differences were also observed when samples of normal and Down's neurons were matched for the 5 covariates mentioned above, take separately. If the abnormal EMP observed in the present study for Down's DRG neurons in culture occurred for CNS neurons in situ they would disrupt the normal function of the nervous system and could therefore constitute the neurobiological basis of the mental retardation observed in Down's syndrome.

Effect of chronic ethanol exposure on the electric membrane properties of DRG neurons in cell culture.

Neural cell cultures of adult mouse dorsal root ganglia were utilized to investigate the effects of chronic ethanol exposure on neuronal electric membrane properties (EMP). After 12 days of exposure to various ethanol concentrations, the EMP of the neurons were determined in ethanol-free medium. Significant changes in a number of EMP were observed. Of particular physiological significance were decreased specific membrane resistance, increased specific membrane capacitance, relatively little change in membrane time constant, and increased electrical excitability. Various features of the action potential were also affected, e.g., reduced overshoot, afterhyperpolarization, and rate of rise. In preliminary experiments, EMP were determined at varying periods after the cultures had been withdrawn from ethanol medium and maintained in ethanol-free medium. These results indicated that the altered EMP persisted as long as one (Cm) to two (Rm) weeks after ethanol withdrawal. A possible mechanism for these ethanol-induced changes in EMP was suggested, utilizing the membrane expansion theory of anesthesia. Because of few previous reports demonstrating significant electrophysiological effects of ethanol at pharmacological concentrations, the neural cell culture system provides a useful new experimental model for studying the action of chronic ethanol exposure on neuronal EMP and the physical basis of the tolerance and withdrawal phenomena found in alcoholism and addiction in general. After being maintained for 12 days in culture media containing various concentrations of ethanol, non-neuronal cell survival was observed to have decreased in an approximately linear manner with increasing ethanol levels. By contrast, neuron survival was not affected until ethanol concentrations greater than 0.34 g % were used. This decreased cell survival due to chronic exposure to physiological levels of ethanol has not been reported previously. Neural cell cultures may therefore be useful for investigating the cellular pathology of chronic alcoholism and fetal alcohol syndrome.

Electric membrane properties of adult mouse DRG neurons and the effect of culture duration.

The electrical membrane properties (EMP) of adult mouse dorsal root ganglion (DRG) neurons were characterized by an extensive electrophysiological investigation of 450 cells. The neurons were divided into two types: an M-type having an action potential with monophasic falling phase and a B-type with a more complex biphasic or triphasic falling phase. Compared to M-type, B-type were "slow" neurons with a higher specific membrane resistance (Rm), and a longer time constant (tau), duration of action potential (delta t), and absolute refractory period (ARP). B-type also had a larger amplitude action potential, afterhyperpolarization and positive overshoot. The action potential of the M-type neuron had only a Na+ component while that of the B-type had both a Na+ and a Ca2+ component. After two days in culture, M-type neurons exhibited phase bright cytoplasmic granules, which were seldom observed for B-type neurons. Although neuron survival remained constant during the first six days in culture (DIV), the relative frequency of occurrence of the M-type decreased from 82 to 50%. Thereafter, it decreased more gradually to a final value of approximately 20% after 40 DIV. It was concluded that at least during the first 6 DIV and possibly through to 40 DIV, M-type neurons transformed into B-type. Both M- and B-type neurons showed significant and similar changes in their EMP with increasing DIV (up to 40 DIV). For M- and B-types combined, Rm increased approximately 142%, tau by 204%, and no significant change in specific membrane capacitance was observed. Rheobasic threshold depolarization decreased 58%, while the resting membrane potential decreased by only 19%. These changes in the EMP of adult neurons are strikingly similar to changes in EMP observed in adult denervated muscle and in cultures of either embryonic nerve or muscle. This similarity suggested that the adult DRG neurons in cell culture undergo progressive dedifferentiation because of isolation from their usual trophic interactions. Determination of neuronal membrane electrical characteristics provides a new method for evaluating the effects of various possible trophic agents, e.g., hormones and tissue extracts, on the state of differentiation of neurons in cell culture.

Variability in neurosecretory material and responses to reserpine of the pituitary neural lobe in five strains of rat.

The levels of vasopressin and neurophysin in the neural lobe of the pituitary were measured in five strains of rat: Wistar, Sprague-Dawley, PVG, Chester Beatty and DA strains. The effect of reserpine administration (5 mg/kg body weight) was determined. There were significant differences in the weight of the neural lobe and the vasopressin and neurophysin contents of this tissue in the various strains. It was possible to show that weight of the neural lobe was not necessarily related to hormone content. The effects of reserpine also varied within the species for, while there was a fall in the vasopressin content in the Wistar and Chester Beatty strains, no change was observed in the Sprague-Dawley, PVG and DA strains. The fall in the vasopressin level in the Wistar animals was not accompanied by a simultaneous fall in the vasopressin-neurophysin content.

Electric membrane properties of human DRG neurons in cell culture and the effect of high K medium.

Cell cultures were prepared from human fetal and newborn dorsal root ganglia (DRG) and maintained in culture medium with normal (4 mM) and elevated (20 mM) potassium (K). Both types of cultures were transferred to 4 mM K, and the electrical membrane properties of the DRG neurons characterized by an extensive investigation of resting membrane potential, specific membrane resistance (Rm) and capacitance, time constant (tau), rheobasic current, and various aspects of the action potential, including overshoot, duration (DT), afterhyperpolarization and absolute refractory period (ARP). No previous quantitative determinations of these membrane properties for human neurons could be found. However, our values were in good agreement with those reported for the DRG neurons of other mammalian species both in vitro and in situ. Significant correlations occurred between membrane properties and the developmental age of each specimen used for culturing. However, the data must be interpreted cautiously due to the limited number of specimens used (4) and the possibility of differential responses of the specimens to the experimental situation. Precultivation in high K medium had profound effects on both passive and active membrane properties: the primary effect being to reduce Rm, and as a result tau, DT, and ARP were also reduced. These observations add further support to the hypothesis that high K in vitro can substitute to some extent for trophic factors normally present in situ.

Neurophysin(s) of the golden hamster (Mesocricetus auratus) and the effects of saline imbibition.

The neural lobe of the golden hamster contains one major and two minor proteins. The major protein was identified as a neurophysin in view of its electrophoretic properties, its high cysteine content and its depletion from the neural lobe upon saline imbibition. The depletion of neurophysin and vasopressin from the neural lobe and the alterations of several indices of dehydration in the blood of the hamster were less than those found in the rat upon saline imbibition, suggesting that the hamster has a greater ability to adapt to conditions in which water is scarce.