INT Groups Research Articles

Does Targeted Education of Emergency Physicians Improve Their Comfort Level in Treating Psychiatric Patients?

Introduction:We determined if targeted education of emergency physicians (EPs) regarding the treatment of mental illness will improve their comfort level in treating psychiatric patients boarding in the emergency department (ED) awaiting admission.Methods:We performed a pilot study examining whether an educational intervention would change an EP’s comfort level in treating psychiatric boarder patients (PBPs). We identified a set of psychiatric emergencies that typically require admission or treatment beyond the scope of practice of emergency medicine. Diagnoses included major depression, schizophrenia, schizoaffective disorder, bipolar affective disorder, general anxiety disorder, suicidal ideation, and criminal behavior. We designed equivalent surveys to be used before and after an educational intervention. Each survey consisted of 10 scenarios of typical psychiatric patients. EPs were asked to rate their comfort levels in treating the described patients on a visual analogue scale. We calculated summary scores for the non intervention survey group (NINT) and intervention survey group (INT) and compared them using Student’s t-test.Results:Seventy-nine percent (33/42) of eligible participants completed the pre-intervention survey (21 attendings, 12 residents) and comprised the NINT group. Fifty-five percent (23/42) completed the post-intervention survey (16 attendings, 7 residents) comprising the INT group. A comparison of summary scores between ‘NINT’ and ‘INT’ groups showed a highly significant improvement in comfort levels with treating the patients described in the scenarios (P = 0.003). Improvements were noted on separate analysis for faculty (P = 0.039) and for residents (P = 0.012). Results of a sensitivity analysis excluding one highly significant scenario showed decreased, but still important differences between the NINT and INT groups for all participants and for residents, but not for faculty (all: P = 0.05; faculty: P = 0.25; residents: P = 0.03).Conclusion:This pilot study suggests that the comfort level of EPs, when asked to treat PBPs, may be improved with education. We believe our data support further study of this idea and of whether an improved comfort level will translate to a willingness to treat.

Effects of high intensity Intermittent and Continuous Endurance Training On Aerobic Power And 60s Performance

PURPOSE: To contrast the effects of a continuous (CONT) and a novel interval (INT: 10s heavy exercise intensity/5s light intensity) training regimes on aerobic and anaerobic adaptations. It was hypothesized that the specific physiological and performance adaptations elicited from both aerobic and anaerobic training adaptations may be realized from this INT regime. METHODS: 14 male subjects, (83.1 kg SD 6.1, 24 yrs SD 2), volunteered for this study. INT and CONT groups performed 12 heavy intensity cycle ergometer exercise sessions on alternate days. The first INT session work period was 10s (at heavy intensity 257W) and the recovery period was 5s (at light intensity 89W). The CONT utilized initial work rates of heavy-intensity set at 120% of VET. Work rates were increased 3 watts per training session (only the 10swork period of INT) until the end of the training period in both groups. Performance measures pre-post-training included VO2max, and 60s Wingate (WG) tests. VO2 was collected during the WG. RESULTS: Power output during the 12 training sessions increased in both groups, while average power output was lower in INT than CONT (208 W vs 218 W, p<0.05). Both groups significantly increased VO2max and peak power (CONT: pre 3.73 L/min; 341 W; post 4.06 L/min; 369 W; INT: pre 3.75 L/min; 332 W;: post 4.09 L/min; 352 W). PO during WG was increased post-training in the INT from 41-60s (p<0.05), with no changes observed for CONT. VO2 for INT during the WG increased between 15-30 s and from 50-60 s post compared to pre-training. (p<0.05). The percent aerobic contribution of INT was elevated post-training from 21-40 s (p<0.05). Total VCO2 on the test was higher in CONT, whereas VCO2 from 20s-60s was increased only for INT. This suggests increased ATP-PCr contribution with reduced metabolic and/or CO2 from buffering from 0-20s of INT, likely due to the increased ATP-PCr system adaptation post INT training. CONCLUSION: The specific physiological and performance adaptations elicited from both aerobic and anaerobic training may be realized from this single INT training regime. These data also suggest that INT training elicits similar changes in peak aerobic power output as well as greater aerobic contribution during a 60 s performance test that improves this predominantly anaerobic performance.

Screening and Brief Intervention to Reduce Marijuana Use Among Youth and Young Adults in a Pediatric Emergency Department

Marijuana was involved in 209,563 emergency department (ED) visits in 2006, according to the Drug Abuse Warning Network. Although screening and brief intervention (SBI) has been effective in changing drinking among ED patients in a number of studies, tests of marijuana SBI in a pediatric emergency department (PED) have not yet been reported. The aim of this pilot study was to test whether SBI is effective in reducing marijuana consumption among youth and young adults presenting to a PED with a diverse range of clinical entities. A three-group randomized controlled preliminary trial was structured to test 1) differences between Intervention (Int) and standard Assessed Control (AC) groups in marijuana consumption, from baseline to 12 months, and 2) the feasibility of adding a Nonassessed Control (NAC) group to evaluate regression to the mean and assessment reactivity. Patients aged 14-21 years in an urban, academic PED were screened during 2006-2007, using standardized risk factor questions. Subjects were eligible if they used marijuana three or more times in the past 30 days, but were excluded for co-occurring high-risk alcohol use. Consented enrollees were randomized to NAC, AC, and Int groups in a two-stage process that permitted blinding to status during assessment and follow-up. NACs received a resource handout, written advice about marijuana use risks, and a 12-month follow-up appointment. ACs were assessed using standardized instruments and received resources, written advice, and 3- and 12-month follow-up appointments. The Int group received assessment, resources, written advice, 3- and 12-month appointments, a 20-minute structured conversation conducted by older peers, and a 10-day booster telephone call. A peer educator utilized a motivational style interview protocol adapted for adolescents to elicit daily life context and future goals, provide feedback, review pros and cons of marijuana use, assess readiness to change, evaluate strengths and assets, negotiate a contract for change, and make referrals to treatment and/or other resources. Measurements included demographic information; 30-day self-report of marijuana use; attempts to quit, cut back, or change conditions of use; and risk factor questions repeated at follow-up. Among 7,804 PED patients screened, 325 were eligible; 210 consented and enrolled (Int, n = 68; AC, n = 71; NAC, n = 71), with a 12-month follow-up rate of 71%. For the primary objective, we compared Int to AC. At 12 months, Int participants were more likely to be abstinent for the past 30 days than ACs (odds ratio [OR] for reported abstinence = 2.89, 95% confidence interval [CI] = 1.22 to 6.84, p < 0.014). The Int group had greater reduction in days used, baseline to 12 months, controlling for baseline (Int = -7.1 vs. AC = -1.8), were less likely to have been high among those who smoked (OR = 0.39, 95% CI = 0.17 to 0.89, p < 0.05), and were more likely to receive referrals. In a linear regression model controlling for baseline use, NACs smoked 4 fewer days per month than ACs, but consumption was not significantly different, suggesting no assessment reactivity effect. A preliminary trial of SBI promoted marijuana abstinence and reduced consumption among PED patients aged 14-21 years. A no-contact condition for the NAC group over the year after enrollment was insufficient to capture enrollees for follow-up across a range of baseline acuity.

The Effects of Two Modes of Exercise on Aerobic Fitness and Fat Mass in an Overweight Population

We examined the effects of an 8-week exercise intervention on aerobic fitness, android and gynoid fat mass, and blood lipids in overweight and obese participants. Twenty-four sedentary participants (average BMI = 30 ± 2 kg/m2; 18 females, 6 males) were randomized into either interval training and diet education (INT group), continuous aerobic exercise and diet education (CON group), or diet education only (DIET group). Durations of exercise sessions were similar (∼30 minutes), with both exercise groups completing the same amount of work. The INT and CON groups demonstrated significant improvements over time for (p < 0.01 and p < 0.05, ES = 1.1 and 1.2, respectively) and time to exhaustion on a graded exercise test (p < 0.01 and ES = 0.8 for both groups). Further, a large effect size (0.7) was recorded for the loss in android fat mass over time in the INT group only.

Inflammatory Cells in Lung Disease Associated with Rheumatoid Arthritis

Rheumatoid arthritis (RA) is associated with numerous pulmonary manifestations. However, the inflammatory mechanism remains undetermined. We studied the features of inflammatory cells in bronchoalveolar lavage (BAL) fluid and biopsy lung tissue from patients with RA-associated lung disease. BAL findings were statistically compared between diseases. We divided RA patients into two groups, airway lesion group (AW) and interstitial lesion group (INT) according to predominant HRCT findings and compared the BAL findings. We immunohistochemically stained lung tissue for CD4, CD8, CD20, and CD163 and counted the immunopositive cells in five different regions. Twenty patients fulfilling the Japanese criteria for RA, 13 patients with systemic sclerosis (SSc), and 21 patients with polymyositis and dermatomyositis (PM-DM) with pulmonary disease detected by high-resolution CT (HRCT) were enrolled in this study. As for BAL in RA, we found a lower lymphocyte frequency with higher CD4/8 ratio compared with PM-DM and a higher neutrophil percentage than both PM-DM and SSc. Nine and eleven patients with RA were classified into AW and INT groups, respectively. BAL findings did not differ between the two groups. Immunohistochemically, most CD4(+) and CD20(+) lymphocytes were accumulated in lymphoid follicles and in the alveolar wall and T-lymphocytes; in particular CD8(+) lymphocytes were predominant in lung interstitium. These results suggest that 1) neutrophils may play an important role, 2) the inflammatory mechanism may be similar between airway lesion and interstitial pneumonia, and 3) CD8(+) lymphocytes may be major inflammatory cells in lung interstitium in RA-associated interstitial lung disease.

Nurse-coordinated multidisciplinary, family-based cardiovascular disease prevention programme (EUROACTION) for patients with coronary heart disease and asymptomatic individuals at high risk of cardiovascular disease: a paired, cluster-randomised controlled trial

Our aim was to investigate whether a nurse-coordinated multidisciplinary, family-based preventive cardiology programme could improve standards of preventive care in routine clinical practice. In a matched, cluster-randomised, controlled trial in eight European countries, six pairs of hospitals and six pairs of general practices were assigned to an intervention programme (INT) or usual care (UC) for patients with coronary heart disease or those at high risk of developing cardiovascular disease. The primary endpoints-measured at 1 year-were family-based lifestyle change; management of blood pressure, lipids, and blood glucose to target concentrations; and prescription of cardioprotective drugs. Analysis was by intention to treat. The trial is registered as ISRCTN 71715857. 1589 and 1499 patients with coronary heart disease in hospitals and 1189 and 1128 at high risk were assigned to INT and UC, respectively. In patients with coronary heart disease who smoked in the month before the event, 136 (58%) in the INT and 154 (47%) in the UC groups did not smoke 1 year afterwards (difference in change 10.4%, 95% CI -0.3 to 21.2, p=0.06). Reduced consumption of saturated fat (196 [55%] vs 168 [40%]; 17.3%, 6.4 to 28.2, p=0.009), and increased consumption of fruit and vegetables (680 [72%] vs 349 [35%]; 37.3%, 18.1 to 56.5, p=0.004), and oily fish (156 [17%] vs 81 [8%]; 8.9%, 0.3 to 17.5, p=0.04) at 1 year were greatest in the INT group. High-risk individuals and partners showed changes only for fruit and vegetables (p=0.005). Blood-pressure target of less than 140/90 mm Hg was attained by both coronary (615 [65%] vs 547 [55%]; 10.4%, 0.6 to 20.2, p=0.04) and high-risk (586 [58%] vs 407 [41%]; 16.9%, 2.0 to 31.8, p=0.03) patients in the INT groups. Achievement of total cholesterol of less than 5 mmol/L did not differ between groups, but in high-risk patients the difference in change from baseline to 1 year was 12.7% (2.4 to 23.0, p=0.02) in favour of INT. In the hospital group, prescriptions for statins were higher in the INT group (810 [86%] vs 794 [80%]; 6.0%, -0.5 to 11.5, p=0.04). In general practices in the intervention groups, angiotensin-converting enzyme inhibitors (297 [29%] INT vs 196 [20%] UC; 8.5%, 1.8 to 15.2, p=0.02) and statins (381 [37%] INT vs 232 [22%] UC; 14.6%, 2.5 to 26.7, p=0.03) were more frequently prescribed. To achieve the potential for cardiovascular prevention, we need local preventive cardiology programmes adapted to individual countries, which are accessible by all hospitals and general practices caring for coronary and high-risk patients.

Intermittent Ischemia but Not Ischemic Preconditioning Is Effective in Restoring Bile Flow After Ischemia Reperfusion Injury in the Livers of Aged Rats

Ischemic preconditioning (IPC) and intermittent ischemia (INT) reduce liver injury following ischemia reperfusion in liver resections. Aged livers are at higher risk for ischemia reperfusion injury, but little is known of the effectiveness of IPC and INT in aged livers. The aim of this study was to investigate the effects of IPC and INT on ischemia reperfusion injury in aged livers. A rat model of segmental hepatic ischemia (45 min) and reperfusion (60 min) was used. Bile flow, as an indicator of early hepatocyte damage and dynamic liver function, plasma concentrations of bilirubin, liver marker enzymes, and liver histology were assessed. In young rats (8-13 weeks), IPC regimes of 10 min clamping and 10 min reperfusion, and 5 min clamping and 30 min reperfusion, restored bile flow to 23 and 42%, respectively, of the initial value, compared to 14 and 88% for continuous clamping and controls, respectively. An INT regime of three cycles of alternating 15 min perfusion and 15 min clamping gave a substantially greater (70%) restoration of bile flow. In aged rats (20-24 months), the IPC regimes did not give any restoration of bile flow. By contrast, the INT regime restored bile flow to 68%. Plasma bilirubin concentrations were lowest in the INT groups, whereas alanine transaminase concentrations for the IPC and INT groups compared with the continuous clamping groups showed no significant differences. In young rats, INT is more effective than IPC in restoring the immediate consequences of IP-induced damage to hepatocytes and liver function after ischemia-reperfusion. In aged rats INT, but not IPC, reverses hepatocyte damage and restores liver function. INT may promote better hepatocyte and liver function than IPC following the surgical resection of aged livers.

Ischemic Preconditioning and Intermittent Ischemia Preserve Bile Flow in a Rat Model of Ischemia/Reperfusion Injury

Ischemia and reperfusion (IR) injury of the liver is associated with impaired bile secretion, but the effects of ischemic preconditioning (IPC) and intermittent ischemia (INT) on bile flow are unknown. A rat model of segmental (60%-70%) hepatic ischemia and reperfusion was employed to test the effects of IPC and INT on bile flow. Continuous clamping for 45 min (CC) substantially reduced bile flow, and this did not recover after 60 min of reperfusion. IPC and INT caused a significant recovery of bile flow. The elevation in plasma liver marker enzymes induced by CC was not reduced by IPC and INT. Light microscopy showed mild hepatocyte damage in all groups. In the CC group, the amount of F-actin localized around the bile canaliculi in the ischemic lobes was less than that in the nonischemic lobes, but this difference was not observed in the IPC and INT groups. It is concluded that IPC and INT substantially alleviate the decrease in bile flow induced by ischemia. Bile flow may be useful in the assessment of IR injury.

Ischemic Preconditioning and Intermittent Ischemia Preserve Bile Flow in a Rat Model of Ischemia Reperfusion Injury

Ischemia and reperfusion (IR) injury of the liver is associated with impaired bile secretion, but the effects of ischemic preconditioning (IPC) and intermittent ischemia (INT) on bile flow are unknown. A rat model of segmental (60%-70%) hepatic ischemia and reperfusion was employed to test the effects of IPC and INT on bile flow. Continuous clamping for 45 min (CC) substantially reduced bile flow, and this did not recover after 60 min of reperfusion. IPC and INT caused a significant recovery of bile flow. The elevation in plasma liver marker enzymes induced by CC was not reduced by IPC and INT. Light microscopy showed mild hepatocyte damage in all groups. In the CC group, the amount of F-actin localized around the bile canaliculi in the ischemic lobes was less than that in the nonischemic lobes, but this difference was not observed in the IPC and INT groups. It is concluded that IPC and INT substantially alleviate the decrease in bile flow induced by ischemia. Bile flow may be useful in the assessment of IR injury.

Early Intervention in Low Birth Weight Premature Infants: Results at 18 Years of Age for the Infant Health and Development Program

To assess whether improvements in cognitive and behavioral development seen in preschool educational programs persist, we compared those in a multisite randomized trial of such a program over the first 3 years of life (INT) to those with follow-up only (FUO) at 18 months of age. This was a prospective follow-up of the Infant Health and Development Program at 8 sites heterogeneous for sociodemographic characteristics. Originally 985 children were randomized to the INT (n = 377) or FUO (n = 608) groups within 2 birth weight strata: heavier low birth weight (HLBW; 2001-2499 g) and lighter low birth weight (LLBW; < or = 2000 g). Primary outcome measures were the Peabody Picture Vocabulary Test (PPVT-III), reading and mathematics subscales of the Woodcock-Johnson Tests of Achievement, youth self-report on the Total Behavior Problem Index, and high-risk behaviors on the Youth Risk Behavior Surveillance System (YRBSS). Secondary outcomes included Weschler full-scale IQ, caregiver report on the Total Behavior Problem Index, and caregiver and youth self-reported physical health using the Medical Outcome Study measure. Assessors were masked as to study status. We assessed 636 youths at 18 years (64.6% of the 985, 72% of whom had not died or refused at prior assessments). After adjusting for cohort attrition, differences favoring the INT group were seen on the Woodcock-Johnson Tests of Achievement in math (5.1 points), YRBSS (-0.7 points), and the PPVT-III (3.8 points) in the HLBW youth. In the LLBW youth, the Woodcock-Johnson Tests of Achievement in reading was higher in the FUO than INT group (4.2). The findings in the HLBW INT group provide support for preschool education to make long-term changes in a diverse group of children who are at developmental risk. The lack of observable benefit in the LLBW group raises questions about the biological and educational factors that foster or inhibit sustained effects of early educational intervention.

Maximal Accumulated Oxygen Deficit and Blood Responses of Ammonia, Lactate and pH after Anaerobic Test: a Comparison between International and National Elite Karate Athletes

The purpose of this study was to compare maximal accumulated oxygen deficit (MAOD) and the time course of blood markers of the anaerobic metabolism in response to exhaustive supramaximal test in two elite (international vs. national) class karate athletes. Ten male international competitors from the French national team (Int, age 21.2 +/- 3.1 years, 71.9 +/- 11.4 kg) and eight national class (Nat, 23.7 +/- 2.4 years, 70.7 +/- 12.2 kg) athletes with a similar maximal oxygen uptake of 57.6 and 59.4 ml . kg (-1) . min (-1), respectively, were involved in this study. The MAOD was determined after an exhaustive supramaximal exercise (2 - 3 min at 140 % of their VO2max velocity) on a treadmill ergometer. Blood lactate, pH and plasma ammonia were determined at rest, immediately at the end of exercise and during the recovery period at 2, 4, 6, 8, 10 and 15 min. After the supramaximal exercise, a dramatic higher increase in the blood concentration of ammonia until its peak was observed in the Nat compared with the Int. Time course of [NH4+] and [La] reveals significant (p < 0.01) differences between the two groups. Peak values for [H+] (89.2 +/- 6.7 vs. 75.9 +/- 8.8 nmol . l (-1); p < 0.01), [NH4+] (180 +/- 67.9 vs. 118.7 +/- 22.7 micromol . l (-1); p < 0.05) and [La] (20.7 +/- 2.7 vs. 17.9 +/- 1.1 mmol.l (-1); p < 0.05) were higher in Nat compared with Int group, respectively. However, the MAOD was similar in both groups (67.8 +/- 8 ml . kg (-1) and 64.5 +/- 6.4 for Int and Nat groups, respectively). These data suggest that ammonia and lactate accumulation are sensitive to the level of performance in karate. Higher concentrations of these metabolites in blood after supramaximal exhaustive exercise may be related to either higher anaerobic contribution to energy supply in Nat or higher removal ability in the Int group.

ARE GAINS IN BONE MINERAL ACCURAL OBSERVED FOLLOWING 20- MONTH INTERVENTION MAINTAINED AFTER ONE YEAR

BACKGROUND Our laboratory reported a greater increase in bone mineral at the femoral neck (4.6%) and at the lumbar spine (3.7%) following a 20 month intervention (10 min, 3x/week) in intervention girls compared with controls. Whether this increase is maintained following withdrawal of the targeted exercise stimulus is uncertain. PURPOSE To determine whether the bone mineral accrual advantage is maintained one year after cessation of the program. METHODS A subset of girls (11.8 ± 0.49yrs, n = 23 intervention (Int), 30 control (Con)) from the original Healthy Bones II Study (n = 191), were re-assessed one year after withdrawal of the high impact, circuit intervention. All children performed regular activities and PE following withdrawal of the program. We evaluated bone mineral content (g) at the femoral neck (FN) and lumbar spine (LS) with DXA (Hologic QDR 4500). We assessed height (cm), weight (kg) and Tanner staging with standard techniques. Physical activity and calcium intake were assessed by questionnaire. The primary outcome measures were 12 month adjusted change in BMC (g) and percent change. Data were analysed using ANCOVA, adjusting for ‘20 month’ (end of intervention) bone mineral and height, height change, final Tanner stage and physical activity. RESULTS Girls previously in Int and Con groups were similar for height (152.9 ± 7.9 cm), weight (46.7 ± 10.4kg) and maturity (81% in Tanner stage 2/3) and were performing similar amounts of physical activity at 20 months. Change in these variables over the follow-up period were similar between groups. Results of ANCOVA showed no difference between groups for adjusted change in BMC (g) during the follow up year at either the LS (Int = 6.7, Con = 6.1 NS) or the FN (Int = 19.1 Con = 17.7 NS). There was also no difference between groups in percent change BMC at the LS (Int = 0.21 Con = 0.14 NS) or FN (Int = 6.1 Con = 4.5 NS). CONCLUSION The benefits of a 20 month intervention are not maintained one year after removal of the stimulus in this cohort. Exercise must be maintained if bone mineral accural benefits are to remain.

Effectiveness of a community leaders' programme to promote healthy lifestyles in Tokyo, Japan.

The aim of this study was to evaluate a community-based health promotion programme in terms of changing: (i) attitudes with respect to a healthy lifestyle; (ii) behaviour with respect to access to health-related information; and (iii) attitudes and health literacy regardless of socio-economic status. In this programme, 20 people are selected every 2 years in each municipality from the lay people of the community, and they are designated as members of a 'community leaders' committee' by the Mayor. They, as a group, have opportunities to gain knowledge about and skills in healthy lifestyles, and undertake voluntary activities to serve the community. A programme intervention sample (INT group) was selected from programme participants from 13 municipalities in the greater Tokyo area. A questionnaire survey was carried out with the INT group and a general population group (REF group). The data obtained for female respondents, aged 30-59 years, in the two sample populations (n = 662 and 1361, respectively) were analysed using the chi(2) test, the Kruskal-Wallis test and multivariate log-linear methods. Another questionnaire was given to female programme participants (n = 200) to identify any changes since the start of their participation. The results showed that the people in the INT group were pursuing healthier lifestyles than those in the REF group; current non-smokers who performed physical exercise and who ate meals regularly paid more attention to a healthy lifestyle and were more interested in the relationship between food and health. From the INT and REF groups, 22 and 4% of people, respectively, frequently obtained information from health professionals, and 29.8 and 10.8%, respectively, were satisfied with their access to health-related information. Results of multivariate log-linear analysis showed that significantly more people in the INT group were doing exercise, eating meals regularly, paying attention to nutritional balance and to food additives, were interested in health, and were satisfied with access to health information, after excluding the effects of age and socio-economic factors (p < 0.05). The results also showed positive changes after the implementation of the programme. These findings indicated that the people in the INT group were significantly more likely to pursue a healthier lifestyle and to have greater health literacy than those in the REF group, regardless of socio-economic status. In conclusion, this community participation approach, employing a committee style, was effective in improving health-related behaviour and in promoting health literacy while overcoming socio-economic variation.

Estradiol exerts neuroprotective effects when administered after ischemic insult.

17beta-Estradiol (E2) has been reported to exert neuroprotective effects when administered before an ischemic insult. This study was designed to determine whether E2 treatment after ischemia exerts the same effects and, if so, how long this therapeutic window remains open, and whether the effects are related to changes in cerebral blood flow (CBF). Female Sprague-Dawley rats were subjected to permanent middle cerebral artery occlusion (MCAO). In protocol 1, E2 was administered (100 microg/kg IV followed immediately by subcutaneous implantation of crystalline E2 in a silicone elastomer tube) to ovariectomized females (OVX+E2) at 0.5 (n=8), 1 (n=6), 2 (n=7), 3 (n=6), or 4 (n=9) hours after MCAO. Intact (INT; n=6) and ovariectomized females (OVX; n=12) were subjected to MCAO and received vehicle instead of E2. Two days after MCAO the animals were killed, and ischemic lesion volume was determined by 2,3,5-triphenyltetrazolium chloride staining. In protocol 2, CBF was monitored before and at 1, 24, and 48 hours in a group of animals receiving E2 or vehicle 0.5 hour after ischemia induction (INT, n=6; OVX, n=8; OVX+E2, n=6). Lesion volume was 20.9+/-2.2% and 21.8+/-1.2% in the INT and OVX groups, respectively. E2 was found to decrease lesion volume significantly when administered within 3 hours after MCAO. The lesion volumes were 6.3+/-0.5%, 10.3+/-2.1%, 11.8+/-1.8%, 13.5+/-1.6%, and 17.9+/-2.8% when E2 was administered at 0.5, 1, 2, 3, or 4 hours after MCAO, respectively. CBF decreased to 43.1+/-2.2% and 25.4+/-1.0% in the INT and OVX animals, respectively, at 5 minutes after MCAO. In comparison to OVX rats, CBF was not different at 1 hour after E2 administration but was increased significantly in the OVX+E2 group 1 and 2 days after E2 administration. E2 exerts neuroprotective effects when administered after ischemia, with a therapeutic window in a permanent focal cerebral ischemia model of approximately 3 hours. This effect of estradiol was associated with no immediate change in blood flow but with a delayed increase in CBF.

Oscillatory Coupling of Hippocampal Pyramidal Cells and Interneurons in the Behaving Rat

We examined whether excitation and inhibition are balanced in hippocampal cortical networks. Extracellular field and single-unit activity were recorded by multiple tetrodes and multisite silicon probes to reveal the timing of the activity of hippocampal CA1 pyramidal cells and classes of interneurons during theta waves and sharp wave burst (SPW)-associated field ripples. The somatic and dendritic inhibition of pyramidal cells was deduced from the activity of interneurons in the pyramidal layer [int(p)] and in the alveus and st. oriens [int(a/o)], respectively. Int(p) and int(a/o) discharged an average of 60 and 20 degrees before the population discharge of pyramidal cells during the theta cycle, respectively. SPW ripples were associated with a 2.5-fold net increase of excitation. The discharge frequency of int(a/o) increased, decreased ("anti-SPW" cells), or did not change ("SPW-independent" cells) during SPW, suggesting that not all interneurons are innervated by pyramidal cells. Int(p) either fired together with (unimodal cells) or both before and after (bimodal cells) the pyramidal cell burst. During fast-ripple oscillation, the activity of interneurons in both the int(p) and int(a/o) groups lagged the maximum discharge probability of pyramidal neurons by 1-2 msec. Network state changes, as reflected by field activity, covaried with changes in the spike train dynamics of single cells and their interactions. Summed activity of parallel-recorded interneurons, but not of pyramidal cells, reliably predicted theta cycles, whereas the reverse was true for the ripple cycles of SPWs. We suggest that network-driven excitability changes provide temporal windows of opportunity for single pyramidal cells to suppress, enable, or facilitate selective synaptic inputs.

The Effect of Food Intake from 2 to 24 Weeks of Age on LHRH-I Content in the Median Eminence and Gonadotrophin Levels in Pituitary and Plasma in Female Broiler Breeder Chickens

The present study describes the effect of long-term food restriction on hypothalamopituitary function in the broiler breeder hen during the period prior to sexual maturity. From 1 week of age onward, chickens were divided into 3 groups: one group received foodad libitum(Ad lib); a second group was fed a restricted quantity of food (Res); and a third group was restricted to obtain an intermediate body weight (Int) in between groups one and two. The effects of these feeding regimes on hypothalamopituitary function were assessed by measuring the amounts of cLHRH-I stored in the median eminence (ME) and the pituitary content and plasma levels of gonadotrophins. The Res group had significantly lower levels of cLHRH-I in the ME compared to the Ad lib animals. In all groups, there was a major increase in cLHRH-I in the median eminence about 3 weeks before onset of lay. The age of first oviposition was delayed by 2 and 6 weeks in the Int and Res groups, respectively, compared to the Ad lib animals, indicating that body weight gain patterns are not directly related to the appearance of the first egg. The attainment of sexual maturity may be associated with a threshold value of cLHRH-I stored in the ME in the Ad lib and Int birds. The pituitary LH and FSH contents (after week 16) were positively related to the amount of cLHRH-I in the ME. Plasma FSH concentrations in Ad lib and Int chickens peaked about 3 weeks before the first oviposition and this prepubertal peak was associated with increased pituitary FSH and ME cLHRH-I. There were however no relationships between plasma LH concentrations and pituitary LH content and between plasma LH and cLHRH-I amounts in the ME. The present study demonstrates that the delayed sexual maturation, caused by a chronic food restriction, may be associated with (1) delayed ovarian and oviductal growth, (2) decreased cLHRH-I storage in the ME, and (3) lower levels of LH and FSH in the pituitary. These hormones were however not directly related to levels of food restriction.

Myocardial metabolism in chronic reperfusion after nontransmural infarction in pig hearts

The purpose of these studies was to evaluate metabolic behavior in a 4-day reperfusion model in pigs after induction of subendocardial infarction. Two groups of swine [sham and intervention (Int) groups, n = 7) and 10 hearts per group, respectively] were prepared comparably with two surgical procedures separated over 4 days. In the Int group at the time of the first surgery, coronary flow in the left anterior descending (LAD) circulation was partially restricted (by 60%) for 60 min and was then reperfused. LAD myocardium at the time of the second surgery in both groups was extracorporeally perfused aerobically (5.9 +/- 0.2 ml.min-1.g dry wt-1) for 60 min and infused by equilibrium labeling with [U-14C]-palmitate and [5-3H]glucose to estimate fatty acid oxidation and exogenous glucose utilization. During extracorporeal perfusion, regional myocardial shortening and oxygen consumption were comparable between groups despite a marginal impairment in ATP resynthesis by mitochondria (26% decrease, P < 0.071) in Int hearts and a significant decline in mitochondrial respiration (45% decrease in respiratory control rate, P < 0.008; and 41% decrease in state 3 respiration, P < 0.032) as compared with sham hearts. Fatty acid oxidation described by 14CO2 production was 34.00 +/- 4.72 mumol.h-1.g dry wt-1 (averaged from 30-60 min of perfusion) in sham hearts but was decreased (by 48%, P < 0.004) in Int hearts. This reduction in fatty acid utilization may in part be explained by declines in the observed activity of the mitochondrial membrane transporter enzyme, carnitine palmitoyltransferase.(ABSTRACT TRUNCATED AT 250 WORDS)

Orthostatic intolerance during a 13-day bed rest does not result from increased leg compliance

Increased leg compliance (LC) has been proposed as a mechanism for orthostatic intolerance after spaceflight or bed rest. Using venous occlusion plethysmography with mercury-in-Silastic strain gauge, we evaluated LC before, during, and after a 13-day head-down (-6 degrees) bed rest in 10 men. LC was measured by the relationship between the increased calf areas (in cm2) at thigh cuff occlusions of 20, 30, 50, 70, and 80 mmHg. Orthostatic tolerance was evaluated by a presyncopal-limited lower body negative pressure test (PSL-LBNP) before and after bed rest. The 10 subjects were divided into TOL (n = 5) and INT (n = 5) groups for which the orthostatic tolerance was similar and lower after bed rest, respectively. For TOL (INT) before bed rest, calf area increases were 2.2 +/- 0.5 (SE) (1.3 +/- 0.4), 3.5 +/- 0.7 (2.3 +/- 0.5), 5.0 +/- 0.9 (3.5 +/- 0.6), 5.6 +/- 0.9 (4.4 +/- 0.6), and 6.4 +/- 1.1 (4.7 +/- 0.6) cm2 for thigh occlusion pressures of 20, 30, 50, 70, and 80 mmHg, respectively. Neither for INT nor for TOL were these results significantly changed by bed rest. These results suggest that other mechanisms than increased LC have to be taken into account to explain the decreased orthostatic tolerance induced by this 13-day bed rest.

Effects of growth hormone on the tempo of sexual maturation in female rhesus monkeys.

The signal that initiates and maintains the developmental change in LHRH and, consequently, LH secretion in primates, thus regulating the tempo of puberty, is not known. Given the close association between reproductive development and bone maturation, we examined the hypothesis that GH was involved in developmental increases in LH release, specifically by augmenting the decrease in estradiol (E2) negative feedback inhibition of LH that characterizes late puberty in primates. Recombinant human GH (rhGH; 250 micrograms/kg) was given (sc) three times weekly to immature female rhesus monkeys to determine if developmental increases in basal serum LH would occur at an earlier age, and if menarche and first ovulation also would be advanced. The study groups included intact females receiving rhGH (INT + GH; n = 5), intact control animals (INT; n = 6), ovariectomized females receiving E2 plus rhGH (E2OVX + GH; n = 5), and E2-treated ovariectomized control monkeys (E2OVX; n = 4). The females were studied from 20 months of age until their serum LH levels increased (E2OVX groups) or until the occurrence of first ovulation (intact groups). After 12 months of rhGH treatment, the crown-rump lengths were significantly increased, regardless of ovarian status, an effect maintained in the intact females through 21 months of treatment. The mean age at the time of the initial rise in serum LH was advanced by rhGH treatment in intact females (29.6 +/- 0.4 vs. 31.3 +/- 0.3 months), but not E2OVX females. Subsequent maturational elevations in LH secretion were similar in the E2OVS + GH and E2OVX animals even after an incremental increase in E2. Ages at menarche were similar in the INT + GH and INT groups, whereas first ovulation was significantly advanced in three of five INT + GH females (31.5 +/- 0.7 months) compared to that in INT females (43.5 +/- 0.3 months). The remaining INT + GH females ovulated at an age (42.4 +/- 0.4 months) similar to that of INT females. Those females that ovulated by 32 months had higher skeletal maturity scores than the later ovulating INT females, with the other INT + GH females being intermediate. Furthermore, rhGH resulted in a significant increase in serum E2 levels within 12 h of injection, which remained elevated through 24 h. This effect of rhGH on ovarian E2 secretion did not occur until females had shown elevations in basal serum LH.(ABSTRACT TRUNCATED AT 400 WORDS)