Induction of HSP72 in Rat Liver by Chronic Ethanol Consumption Combined with Exercise: Association with the Prevention of Ethanol-Induced Fatty Liver by Exercise

Ethanol-induced fatty liver in rats was attenuated by repeated running exercise, and the protective effect of exercise was associated with the synergistic expression of heat shock proteins (HSP72). Rats were placed in four groups of six. The two ethanol-fed groups of rats received a liquid diet (Lieber-DeCarli formulation) in which 36% of the calories were derived from ethanol. One group remained sedentary (S/E), whereas the other was trained to run on a rodent treadmill at a speed of 27 m/min, 1 hr/day, 5 days/week, for 7 weeks (R/E). Two other groups–one exercised as previously mentioned (R/C) and one sedentary (S/C)–received control-liquid diets in which the ethanol was isocalorically substituted with a dextran/maltose mixture. The degree of fatty infiltration in liver sections stained with hematoxylin and eosin was graded on a 0–4 scale and the data analyzed by ANOVA on ranks. Ethanol significantly induced fatty infiltration in the S/E group, whereas fatty infiltration in the livers of the R/E group was not different from the S/C group. Electrophoresis and Western blotting of liver homogenates demonstrated that HSP72 was not expressed in either the S/C or S/E groups and was only slightly expressed in the R/C group. The combination of exercise and ethanol, however, resulted in an elevated expression of HSP72 in the R/E group. The content of HSP73 was unaffected by any treatment.     

Genes involved in the regulation of beta-lactamase production in enterococci and staphylococci.

In enterococci, the structural gene for beta-lactamase (blaZ) is identical to blaZ from Staphylococcus aureus. However, in the enterococci studied to date, beta-lactamase is produced constitutively, whereas in staphylococci it is often inducible. Recent reports have revealed the presence of two adjacent genes upstream of the staphylococcal blaZ thought to be the antirepressor (blaR1) and repressor (blaI) genes. In the present study, beta-lactamase expression mutants of the staphylococcal beta-lactamase plasmid pI524 were generated by transposon mutagenesis with the transposon Tn917. Tn917 insertions upstream of blaZ in either blaR1 or blaI resulted in constitutive beta-lactamase production, indicating that the repressor function is lost with insertion of Tn917 into either gene. This finding supports the concept that the staphylococcal beta-lactamase regulatory genes are encoded on a polycistronic mRNA. The corresponding region upstream of the enterococcal blaZ from Enterococcus faecalis HH22 was sequenced and compared with the staphylococcal blaR1 sequence. The two sequences were identical for 893 nucleotides, and then the sequences diverged completely. Therefore, in strain HH22, only 51% of the putative antirepressor gene is present and the repressor gene is also absent. In conclusion, constitutive beta-lactamase production in HH22 appears to be due to a lack of the regulatory genes blaR1 and blaI which regulate expression of blaZ in staphylococci.     

Health Behavior Correlates of Depression in a Sample of High School Students

Frequency of symptoms of depression and selected health-related practices and events were measured in a sample of 219 high school students. Students reported numerous symptoms of depression. Relative proportions of boys and girls reporting symptoms of depression were not significantly different. However, girls reported experiencing more severe depression than their male counterparts. Depression correlated significantly with several of the 22 health practices and states of affect examined. Both the determinants and manifestations of depression in adolescent cohorts require in-depth investigation. Possible implications for school health personnel are discussed.     

“Helper:” A critical events prompter for unexpected emergencies

Objective. The medical practitioner is faced with an increasing list of protocols and algorithms related to patient care. These recommendations are often difficult to recall, particularly in stressful emergency situations. Using advanced cardiac life support (ACLS) protocols, we built a computer-based system to exhibit precompiled response plans for medical emergencies. To validate the usefulness of this prompting device, we tested application of two of the nine ACLS algorithms, pulseless ventricular fibrillation/ventricular tachycardia (Vfib/Vtach) and bradycardia, in a simulated operating room (OR) environment.Methods. The system utilized the software authoring system IconAuthor (Aimtec Inc., Nashua, NH) and a touch-screen monitor (DiamondScan, Microtouch, Methuen, MA). Prior to testing our system, all 39 subjects were given time to familiarize themselves with its operation. Subsequently, all subjects were videotaped while managing a standard simulated anesthetic. During the anesthetic, the subjects were presented with two emergency scenarios, not viewed during the familiarization period. The electrocardiographic (EKG) signals for normal sinus rhythm, ventricular fibrillation, and second-degree heart block were presented. By random selection, the prompter was available to half of the subjects for help with arrhythmia management (experimental group), while to half it was not (control group).Results. A total of 39 subjects completed the exercise. Use of the prompter enabled significantly more subjects to administer correct drugs and dosages during ventricular fibrillation. The correct lidocaine dose was chosen more often by the experimental group than by the control (p=0.015); similarly MgSO₄ was appropriately ordered more often in the experimental group (p=0.003). During second-degree heart block, atropine was correctly followed with a dopamine infusion (p=0.004), and epinephrine infusion was ordered for refractory bradycardia (p=0.002) more often in the experimental than the control group.Conclusions. These data demonstrate the value of a prompting device at the anesthesia workstation. We foresee the use of such prompters in many areas of medicine.This study was made possible by a grant from the Anesthesia Patient Safety Foundation. Results were presented, in part, at the meeting of the STA/SEA Orlando, Florida, January 1994.     

Galanin gene expression declines with adulthood in the cholinergic fields of the horizontal diagonal band of male rats

The neuropeptide galanin (GAL) influences leaming and memory processes, perhaps by inhibiting cholinergic function. We recently reported that, in the rat, the nucleus of the horizontal limb of the diagonal band (HDB) exhibits the highest level of GAL mRNA coexpression by basal forebrain (BF) cholinergic neurons and, in the HDB, virtually all GAL mRNA-expressing neurons correspond to the cholinergic cell type. Since GAL gene expression is induced across puberty in many brain regions, we used in situ hybridization histochemistry and quantitative autoradiography to assess GAL gene expression across the rostro-caudal extent of the HDB in prepubertal and adult male rats and to determine whether GAL gene expression is also regulated during maturation in this BF region. Our results show that the number of GAL mRNA-expressing cells per section is significantly reduced in the HDB with adulthood. Post-hoc analysis indicated that these age-associated differences in the number of GAL mRNA-expressing cells per section could be ascribed to the rostral and central subregions of the HDB. Age-related differences in the labeling intensity of GAL mRNA-expressing neurons were also detected in the rostral and central subregions of the HDB. No age-associated differences in GAL gene expression were found in the caudal HDB subregion. These results suggest that: (1) in contrast to other brain regions, GAL gene expression in the cholinergic BF may be negatively regulated by factors concomitant with puberty; and (2) the inhibition of cholinergic function by cosecreted GAL may be enhanced prior to puberty within cholinergic neurons of the rostral and central aspects of the HDB.     

The AMPA receptor potentiator LY404187 increases cerebral glucose utilization and c-fos expression in the rat.

AMPA receptor potentiators enhance AMPA receptor-mediated glutamatergic neurotransmission and may have therapeutic potential as cognitive enhancers or antidepressants. The anatomical basis for the action of AMPA receptor potentiators is unknown. The aim of this study was to determine the effects of the biarylpropylsulfonamide AMPA receptor potentiator, LY404187 (0.05 to 5 mg/kg subcutaneously), upon cerebral glucose utilization and c-fos expression using 14C-2-deoxglucose autoradiography and c-fos immunocytochemistry. LY404187 (0.5 mg/kg) produced significant elevations in glucose utilization in 28 of the 52 anatomical regions analyzed, which included rostral neocortical areas and the hippocampus, as well the dorsal raphe nucleus, lateral habenula, and locus coeruleus. No significant decreases in glucose utilization were observed in any region after LY404187 administration. The increases in glucose utilization with LY404187 (0.5 mg/kg) were blocked by pretreatment with the AMPA receptor antagonist LY293558 (25 mg/kg), indicating that LY404187 acts through AMPA receptor-mediated mechanisms. LY404187 (0.5 mg/kg) also produced increases in c-fos immunoreactivity in the cortex, locus coeruleus, and the dorsal raphe nucleus. These studies demonstrate neuronal activation in key brain areas that are associated with memory processes and thus provide an anatomical basis for the cognitive enhancing effects of AMPA receptor potentiators.     

Neck pain: a long-term follow-up of 205 patients

Two hundred five patients with neck pain were evaluated clinically and roentgenographically for a minimum of 10 years after onset of symptoms. Seventy-nine percent had a decrease in pain, and 43% were free of pain; however, 32% had moderate or severe residual pain. Patients who had been injured and initially had severe pain were the most likely to have an unsatisfactory outcome; however, no other clinical features were of value in predicting the final result. The presence or severity of pain was not related to the presence of degenerative changes, the sagittal diameter of the spinal canal, the degree of cervical lordosis, or to any changes in these measurements over the evaluation period.