LE Groups Research Articles

Anti-Cancer Immune Reaction Induced by Cryo-Ablation Therapy for Unresectable Advanced Liver Tumor

Background: Cryogenic treatment sometimes stimulates the immune system by releasing intracellular antigens. We evaluated anti-tumor immune response after cryotherapy by analyzing alterations in serum cytokine levels. Methods: Percutaneous cryosurgery was performed in 13 patients with unresectable advanced tumors. The size of the ice ball was confirmed by intraoperative ultrasound 15 minutes freezing to make a 3-cm ice ball. The therapy was performed for three freeze/thaw cycles per a tumor per a treatment and was continued eight times for once a week. Evaluation of serum factors was done before and after ablation therapy, and serum tumor markers were measured after every four treatments. Tumors were evaluated by abdominal computed tomography after eight treatments. Serum levels of interleukin (IL) -4, -6, and -10, tumor necrosis factor (TNF)-alpha, and interferon (IFN)-gamma were measured by ELISA. The Th1/Th2 ratio was estimated from the IFN-gamma/IL-4 ratio. Results: In five cases, tumor necrosis was identified not only in the treated area but also away from the treated area, and then these cases belonged to immune reaction (IR) group. In other cases, just local effect was noted (LE), and then levels of serum factors were compared with those in IR. Serum levels of AA and CRP were increased in both the IR and LE groups after the third treatment, and that of IL-6 paralleled CRP increases. No differences in the level of serum IL-2 was observed after treatment in any of the patients. The serum level of IL-10 was low in three patients in the IR group and in one patient in the LE, but it group tended to increase with the number of treatments. In contrast, the level of TNF-alpha was increased in the IR group but showed no remarkable changes in the LE group. The Th1/Th2 ratio was increased in the IR group, compared to that in the LE group. To evaluate the clinical significance of these alterations in serum cytokines, pretreatment levels, maximum levels in response to therapy, and the number of treatments necessary to induce maximum levels were compared between the two groups. Pretreatment levels of IL-10 in the LE group were significantly greater than those in the IR group (p=0.0071), and the maximum value (67.9±6.3 pg/mL) was greater than that for the IR group (58.4±8.1 pg/mL), but no significant difference was found between the two groups. In contrast, both pretreatment levels and maximum levels in response to treatment of TNF-alpha were significantly greater in the IR group than in the LE group. The maximum Th1/Th2 ratio was significantly greater in the IR group than in the LE group, despite the factor that pretreatment levels and treatment times to induce maximum levels were similar between the two groups. Conclusion: It might be possible to evaluate the appearance of immune responses to cryosurgery by monitoring serum cytokine levels.

Influence of lung oxidant and antioxidant status on alveolarization: Role of light-exposed total parenteral nutrition

Parenteral multivitamins (MVP) are linked to the generation of peroxides, which cause oxidant injury in lungs associated with alveolar remodelling linked to lung disease of prematurity. This study was to investigate the relationship between alveolar development and lung oxidant-antioxidant status as modulated by the mode of administration of multivitamins with total parenteral nutrition (TPN). Four groups of guinea pig pups received parenteral nutrition differing by 1) mode of MVP admixture: with amino acid solution (AA-MVP) or lipid emulsion (LIP-MVP); 2) light exposure: TPN exposed (LE) or shielded from light (LP). After 2 or 4 days of TPN, vitamins C and E, 8-isoprostaneF 2α and alveolarization index were determined in lungs and GSSG/GSH in lungs and blood. Exposure to light and the mode of MVP admixture did not influence vitamin E and isoprostane levels. Blood glutathione redox potential was more oxidized in LE and LIP-MVP groups after 4-day infusions, whereas lung redox potential was more reduced in LE groups. LP and LIP-MVP had a beneficial effect, with higher number of alveoli. Globally, results indicate that in this model, alveolarization and modifications in lung redox potential are two independent events induced by light exposed TPN.

The influence of eye dominance on saccade characteristics and slow presaccadic potentials

Characteristics of saccades and presaccadic slow potentials were studied in 36 right-handed men with right (the RE group) and left (the LE group) eye dominance. Three light-emitting diodes located in the center of the visual field (the central fixation stimulus, CFS) and 10 deg to the left and to the right of the center (peripheral stimuli, PSs) were used for stimulation. The subjects performed a task with simple saccades to a PS and a task with antisaccades to the horizontal mirror position of the PS. Monopolar EEGs at 19 derivations and electrooculograms (EOGs) were recorded. Back averaging of the EEG time-locked to the PS onset or the saccade onset was used to obtain slow presaccadic potentials. The saccade characteristics in the RE and LE groups were similar. Differences between them were found only in the antisaccade task. The amplitude of negative presaccadic potentials (NPPs) time-locked to the PS in the frontal cortex was lower in the LE group compared to the RE group. Analysis of potentials time-locked to the saccade onset showed that changes in the slow potentials during the last 50 s before the saccade depended on the saccade direction and reflected the activation of the hemisphere opposite to the saccade direction. The activation of the right hemisphere before left-side saccades was higher in the LE than the RE group. In addition, the amplitude of NPPs was decreased in the frontal area and increased in the left posterior temporal area in the LE group compared to the RE group. The obtained results indicate that the involvement of the frontal cortex in cognitive and motor processes is decreased in subjects with the left eye dominance.

Land versus water exercise in patients with coronary artery disease: effects on body composition, blood lipids, and physical fitness

We examined the effects of combined resistance and aerobic training on land versus combined resistance and aerobic training in water in patients with coronary artery disease. Thirty-four patients were randomly assigned to land exercise (LE, n = 12), water exercise (WE, n = 12), and control (n = 10) groups. The LE group trained 4 times per week, twice with aerobic exercise and twice with resistance training. The WE program included aquatic aerobic activities 2 times per week and resistance exercise at the same frequency carried out in water. The duration of the training programs was 4 months. Body composition measurements, blood lipids, exercise stress testing, and muscular strength were obtained at the beginning and at the end of the training period. After 4 months of training, analysis of covariance revealed that body weight and sum of skinfolds were lower for WE and LE groups than for the control group. Patients who trained in water improved exercise time (+11.7% vs +8.1%) and maximum strength (+12.8% vs +12.9%) in a similar manner compared to the patients who trained on land. Total cholesterol (WE -4.4%, LE -3.3%) and triglycerides (WE -10.2%, LE -11.8%) decreased significantly for both exercise groups but not for the control group. Exercise programs that combine resistance and aerobic exercise performed either on land or in water can both improve exercise tolerance and muscular strength in patients with coronary artery disease. Furthermore, both programs induce similar favorable adaptations on total cholesterol, triglycerides, and body composition.

Soybean Phosphatidylcholine-Induced Enhancement of Lymphatic Absorption of Triglyceride Depends on Chylomicron Formation in Rats

We investigated whether chylomicron formation is involved in the dietary phosphatidylcholine (PC)-induced increase in triglyceride (TG) absorption using an inhibitor of chylomicron formation, pluronic L-81 (L-81). In rats, cannulas were implanted into the duodenum (exps. 1 and 2) and the mesenteric lymph duct (exp. 1), and an emulsified lipid solution containing the test lipids (soybean oil, SO or soybean oil plus phosphatidylcholine, LE) with or without L-81 was infused through a duodenal cannula at a rate 3 ml/h for 2 h, and followed by infusion of a glucose-NaCl solution for 2 h. Mesenteric lymph was collected for 4 h (exp. 1). In exp. 2, the mucosa and contents of the small intestine were collected at 20, 40, or 90 min after the start of duodenal infusion of the test lipid to evaluate accumulation of lipids incorporated into the mucosa in the rats without a lymph cannula. In exp. 1, lymphatic TG outputs rapidly increased with infusion of both test lipids without L-81, but L-81 abolished these increases. TG accumulated in the small intestinal mucosa with L-81 treatment in a time-dependent manner, but the levels of accumulation were similar between the SO and LE groups (exp. 2). There were no differences in the amounts of lipid remaining in the small intestinal lumen between the L-81-treated SO and LE groups. These results indicate that uptake of lipid into the mucosal cells was not increased by LE. We conclude that the formation of chylomicron is responsible for increases in the promotive effect of a high level of dietary PC on the lymphatic absorption of TG.

The Effect of Combined Ephedrine and Lidocaine Pretreatment on Tracheal Intubation Condition and Maximum Neuromuscular Block after Rocuronium Administration

Background: Rocuronium is a nondepolarizing muscle relaxants used for trying rapid-sequence intubation due to its relatively rapid onset of action and low side effects. Methods to further reduce the onset time of a muscle relaxant include increasing the dose of muscle relaxant, pretreatment for potentiating neuromuscular block of the muscle relaxants or increasing the cardiac output and muscle blood flow. The purpose of this study was to examine the pretreatment effect of combined lidocaine and ephedrine, as a pretreatment, on the onset time and intubation conditions of rocuronium-induced neuromuscular block in adults. Methods: Sixty ASA physical stati 1 and 2 patients were randomly allocated to four groups. Normal saline 10 ml was administered to Group NS prior to induction, lidocaine (1.5 mg/kg) to Group L, ephedrine (70μg/kg) to Group E, and combined lidocaine (1.5 mg/kg) and ephedrine (70μg/kg) to Group LE. Anesthesia was induced with propofol (2.0 mg/kg) and rocuronium (0.6 mg/kg). Intubation was performed 45 seconds after the administration of rocuronium and the intubation conditions then evaluated. The change in the mean arterial pressure and heart rate were checked and compared during the peri-induction periods. Results: There were no differences in the hemodynamics between the four groups. The intubation conditions were graded as good to excellent in 33.3, 53.3, 66.7 and 93.3% of patients in NS, L, E and LE groups, respectively. The intubation conditions in group LE were significantly better than those in group NS (P ＜ 0.05). Conclusions: The above results demonstrated that pretreatment with a combination of ephedrine and lidocaine, following rocuronium, improves the tracheal intubation conditions. (Korean J Anesthesiol 2007; 53: 325～31)

Adaptation of mechanical, morphological, and biochemical properties of the rat growth plate to dose-dependent voluntary exercise

Mechanical loading has been shown to modulate longitudinal bone growth and cellular activity of the growth plate. Nevertheless, limited and controversial results exist regarding the effect of exercise on a physiological level on the growth plate. The present study investigated whether dose-dependent voluntary exercise has an influence on morphological, biochemical, and mechanical factors of the distal femoral growth plate of immature rats. Female growing Sprague–Dawley rats were randomly assigned to a unlimited exercise group (UE, n = 10), a limited exercise group (LE, n = 10), and a sedentary control group (CON, n = 10). The exercise groups were trained voluntarily in a running wheel for 8 weeks. The UE group could use the running wheel everytime, whereas the LE group had timely restricted (50%) access. After sacrifice, the right femur was prepared for histomorphometric analysis and immunohistochemical staining of the distal growth plate. Mechanical testing was carried out on the distal growth plate of the left femur in shear direction. At the end of the study, the UE group had a significantly lower body mass than the CON group. There was no significant difference in overall femoral length between the groups. The height of the growth plate and the proliferation zone was significantly greater in the CON group than in both exercise groups. Only the LE group had a significantly lower hypertrophic zone and matrilin-3 staining pattern than the CON group. Osteonectin was located in the matrix of the upper hypertrophic zone in the UE group, whereas the LE and CON group showed more chondrocytes in the hypertrophic and lower proliferation zones stained for osteonectin, suggesting a higher level of mineralization in the growth plate of the UE group. No variations of mechanical properties of the distal femoral growth plate were detected. These results clearly demonstrate adaptations of morphology and biochemical parameters to the dose of running exercise, which do not result in significant differences in mechanical properties or bone length between the UE, LE, and CON groups.

Association between level of education and oral health status in 35-, 50-, 65- and 75-year-olds.

The aim of the present study was to evaluate the association between educational level and dental disease, treatment needs and oral hygiene habits. Randomized samples of 35-, 50-, 65- and 75-year-olds, classified according to the educational level: [low (LE): elementary school or higher (HE)], were identified. In 1091 subjects, a number of characteristics such as (i) number of teeth, (ii) periodontal attachment levels (PAL), (iii) caries and (iv) occlusal function were recorded. Educational level, oral hygiene and dietary habits were self-reported. Non-parametric variables were analyzed by chi2, Mann-Whitney U-Wilcoxon's rank sum tests, and parametric variables by Student's t-test (level of significance 95%). A two-way anova was performed on decayed, missing and filled surfaces to investigate the interaction between age and educational level. All statistical procedures were performed in the SPSS statistical package. The number of remaining teeth was similar for LE and HE in the 35-year olds (25.8 versus 26.6), but in the older age groups LE had significantly a larger number of missing teeth. The LE groups (except in 65-year olds) exhibited significantly more PAL loss. LE had significantly fewer healthy gingival units in all but the 75-year age group. In all age groups, LE had fewer intact tooth surfaces and a significantly poorer occlusal function. The frequency of tooth cleaning measures and dietary habits did not differ between LE and HE. Educational level was shown to influence the oral conditions and should be considered in assessing risk, and in planning appropriate preventive measures.

PHYSICAL EXERCISE INCREASES EXPRESSION OF TNF A AND GLUT 1 IN MUSCLE TISSUE OF DIABETES PRONE PSAMMOMYS OBESUS

Tumor necrosis factor-α is a major mediator of insulin resistance. On the other hand, according to previous studies, TNFα facilitates glucose uptake through GLUT 1 expression. PURPOSE The aim of the present study was to characterize the influence of physical exercise on the expression of TNFα and GLUT 1 in muscle tissue of diabetes prone Psammomys obesus. METHODS Animals were assigned for four weeks to four groups: high-energy diet (HC), high-energy diet and exercise (HE), low-energy diet (LC), low-energy diet and exercise (LE). TNFα and GLUT 1 expression were analyzed using Western Blot technique. RESULTS 80% of the animals in the HC group became diabetic, whereas only 7% of the animals in the HE group became diabetic. None of the animals in the LE and LC groups became diabetic. TNFα expression was higher in the HE and LE groups (by 220% and 90%, respectively) compared to the HC and LC groups (p < 0.01). No significant differences were found between the two latter groups. Muscle GLUT 1 expression was higher in the LE and HE groups (by 35% and 25%, respectively) (p < 0.05) and lower by 25% in the HC group compared to the control LC group (p < 0.05). CONCLUSIONS Physical exercise, regardless of diet, augments the expression of TNFα in muscle tissue. This, in turn, facilitates the expression of GLUT 1, a secondary mechanism that may increase glucose uptake and prevent the diabetic state.

Heart and blood pressure adaptations in Wistar rats fed with different high-fat diets for 18 months

Objective We investigated the effect of long-term administration of four different high-fat diets on systolic blood pressure (SBP), body and heart biometry, and left ventricular myocyte nuclei number (N[lvm]). Methods Twenty-four Wistar rats were assigned to one of four groups from weaning to age 18 mo. The rats were fed experimental diets containing soybean oil (S group), canola oil (CA group), lard and egg yolk (LE group), and canola oil plus lard and egg yolk (CA + LE group). N(lvm) was measured with the disector method in isotropic uniform random sections of the left ventricular myocardium. Results There were no significant differences across experimental groups in morphometric indices. SBP was higher in the LE group at all ages and lower in the 18-mo CA group. The myocardium structure analysis separated the animals in three major categories: the CA and LE groups as the extreme and the S and CA + LE groups as the intermediary. In the LE group the myocardium presented more important structural changes: cardiac myocytes were enlarged and surrounded with thick collagen bundles, and some regions exhibited myocardial necrosis. Conclusion Long-term intake of the CA diet was more efficient in maintaining normal N(lvm) and SBP than the S and LE diets. The CA + LE diet resulted in balanced levels of SBP and N(lvm) in rats, suggesting that canola oil reduces cardiovascular injury caused by intake of lard and egg yolk.

The role of alcohol abuse in the etiology of heroin-related deaths. Evidence for pharmacokinetic interactions between heroin and alcohol.

In order to evaluate pharmacokinetic interactions between heroin and alcohol and their role in the etiology of heroin-related deaths (HRD), the alcohol concentration in blood (BAC), the free (FM) and total morphine (TM) concentrations in blood (determined by DPC Coat-A-Count radioimmunoassay before and after enzymatic hydrolysis), and the TM concentration in urine and bile (DPC Coat-A-Count after enzymatic hydrolysis) in a population of 39 lethal cases included in the records of the Department of Legal Medicine and Public Health at the University of Pavia from the period January 1997-April 1998 were examined. The cause of death in each case was attributed to either heroin or associated heroin-ethanol intoxication. Cases were arbitrarily divided into two groups according to BAC (low-ethanol group, LE, BAC < or = 1000 mg/L and high-ethanol group, HE, BAC > 1000 mg/L). The differences in the FM and TM concentrations in blood, bile, and urine and in the FM/TM ratios between the two . groups were statistically evaluated (Mann-Whitney U test). A similar statistical evaluation was carried out on data from a previously published study concerning the disposition of heroin and its metabolites (6-acetylmorphine and morphine) in blood and urine in 23 lethal cases attributed to either heroin or heroin and alcohol intoxication. The values of the following variables in the LE and HE groups were compared: FM, TM, and 6-acetylmorphine concentrations in blood (6-AM); the FM/ (FM + 6-AM) ratio; the FM/TM ratio; and the urinary concentrations of heroin, 6-acetylmorphine, and free morphine. Statistical analyses of data indicated that high BACs are associated with reduced hydrolysis of 6-AM to morphine (FM/[FM + 6-AM], p = 0.0022) and that a good inverse correlation exists between BAC and hydrolysis of 6-AM to morphine (r2 = 0.67). High BACs were also found to be associated with an increased FM/TM ratio and with reduced excretion of free and total morphine. These results suggest the hypothesis that pharmacokinetic interactions between heroin and alcohol do occur in individuals exposed to high doses of these substances.

Expression of the H Type 1 Blood Group Antigen during Enterocytic Differentiation of Caco-2 Cells

We made a comparative study of the structures of the oligosaccharides on the glycoproteins from Caco-2 human colonic adenocarcinoma cells, before and after differentiation. Enterocytic differentiated Caco-2 cells highly express H type 1 blood group antigen on the cell surface as well as activities of brush border membrane hydrolases, such as dipeptidyl peptidase IV and alkaline phosphatase. A strong correlation was observed between the amounts of H type 1 blood group antigen and the degrees of differentiation. Structural analysis with use of lectin affinity high performance liquid chromatography revealed that typical mucin-type sugar chains of the glycoproteins from undifferentiated cells have H type 2 group, linear polylactosamines, and core 1 structure. On the other hand, differentiated cells newly contain H type 1 and Le(b) groups and core 2 structure. Mucins with H type 1 group make contact with brush border membrane enzymes on differentiated cells. Furthermore benzyl 2-acetamide-2-deoxy-alpha-D-galactopyranoside inhibited both expression of H type 1 group on the cell surface and enhancement of brush border membrane enzyme activities even in the presence of a differentiating inducer. These results suggest that the mucin-type sugar chains with H type 1 group have important functions regarding differentiation of Caco-2 cells.

Quality of life of breast cancer patients with lymphedema

Background: Quality of life has increasingly become an important issue in breast cancer treatment. One of the impetuses for sentinel lymph node biopsy or selective axillary lymph node dissection (ALND) is the assumed decreased incidence of lymphedema compared with standard ALND. This is based on the assumption that ALND is associated with a clinically significant incidence of lymphedema and that this lymphedema decreases the quality of life of these patients. However, few data exist on this issue. This study attempts to define the incidence and effect on quality of life of postoperative lymphedema in breast cancer patients. Methods: To determine the incidence of postoperative lymphedema, the Breast Cancer Registry at Henry Ford Hospital was accessed to obtain information on all patients who underwent ALND in the management of breast cancer over a 7-year period. The registry is a prospectively gathered data base to include the development of various complications, such as lymphedema. To determine the effects of lymphedema on quality of life , 101 consecutive, unselected patients who underwent breast surgery were asked to complete the SF-36, a generic quality of life instrument. The SF-36 measures eight domains of quality of life. Patients were then divided into three groups: (1) breast surgery without ALND (-ALND), (2) breast surgery with ALND but no lymphedema (-LE), and (3) breast surgery with ALND and lymphedema (+LE). Results: In all, 827 patients with ALND were identified in the registry. Of these, 8.3% developed clinically apparent lymphedema. Patients in -ALND and -LE groups had similar scores in all domains of the SF-36. However, patients in the +LE group had significantly lower scores in the domains of role-emotional and bodily pain. A significantly higher percentage of patients in the +LE group had scores below one standard deviation compared with national norms in the domains of bodily pain ( P = 0.005), mental health ( P = 0.01), and general health ( P = 0.04). Conclusions: Although postoperative lymphedema occurs in a minority of patients, when it does occur it can produce demonstrable diminutions in quality of life. Therefore, efforts to reduce the incidence of lymphedema, such as sentinel lymph node biopsy or selective ALND, would benefit breast cancer patients.

Lewis blood group phenotype as an independent risk factor for coronary heart disease (the NHLBI Family Heart Study)

In the Copenhagen Male Study, men with Lewis blood group phenotype Le(a−b−) were found to have increased risk for coronary heart disease (CHD); such a relation has not been confirmed in men, and has not been evaluated in women. In the NHLBI Family Heart Study, we determined the Lewis blood type of 1,620 white subjects (790 male and 830 female subjects). The Lewis(a−b−) phenotype was found in 142 subjects (8.8%), 6.3% of subjects from randomly chosen families and 9.7% of subjects from families found to be at high risk for CHD. A history of CHD was present in 39.1% of men with Le(a−b−) versus 27.2% of men with other Lewis types; for women, the corresponding numbers were 12.3% versus 9.4%, respectively. In multivariate analysis, adjusting for age, sex, and risk group, the odds ratio for CHD was 2.0 (95% confidecne interval = 1.2 to 3.1) for Le(a−b−) versus other Lewis groups. Mean values for body mass index, blood pressure, total cholesterol, low-density lipoprotein and high-density lipoprotein cholesterol, glucose, insulin, homocysteine, and fibrinogen were not significantly different between Le(a−b−) subjects and others, but triglycerides (p = 0.002) were higher in the Le(a−b−) subjects. However, inclusion of all risk factors in multivariate analysis did not diminish the increased risk for CHD associated with the Le(a−b−) phenotype. We conclude that the Le(a−b−) phenotype is associated with an increased risk for CHD; its effect does not appear to act predominantly through conventional cardiovascular risk factors. At present, mechanisms of effect are unknown.

An experimental study on effects of occlusion of the cystic duct in mice with or without emptying of the gallbladder.

To study consequences of cystic duct occlusion, 121 NMRI mice were operated: 40 had cystic duct ligature (L group), 41 had cystic duct ligature and evacuation of bile from the gallbladder (LE group), and 40 were sham-operated (S group). Ten mice from each group were sacrificed at 1 week, 1, 3 and 6 months, respectively. All but 2 mice showed signs of wellbeing during the observation time, and weight gain was the same in the three groups. Distended gallbladder occurred in 14 animals, 7 each in the L and the LE group, more frequent after 3 and 6 months. In the remainder mice the gallbladders were smaller than at the time of operation (p < 0.0001). Fibrosis and adhesions around the gallbladder were frequent in the L and the LE groups, and more pronounced in the latter (p = 0.0001). At microscopy there were signs of inflammation in the gallbladder wall in 16 cases in the L group, 28 in the LE group and 2 in the S group, and the degree of inflammation was more pronounced in the LE group than in the L group (p = 0.002). Eleven mice in the LE group had empyema, and slight intralumininal inflammation was more frequent in the LE group than in the L group (p < 0.0001). In conclusion, despite a high incidence of microscopic inflammation the study gave no indication that occlusion of the cystic duct did serious harm to the mice in this series.

Effects of Niacin and Aspirin on Performance Parameters in Heifers Fed Endophyte-Infected Tall Fescue

Cattle grazing endophyte-(Acremonium coenophialum) infected tall fescue perform poorly because of the adverse effects of endophyte toxicosis. One of the manifestations of this toxicosis is elevated body temperature caused by an inability to dissipate body heat Niacin has vasodilatory activity and has shown a beneficial heat dissipation effect in some animal species. Aspirin affects body temperature via prostaglandin synthesis and may be beneficial in alleviating high body temperature induced by consumption of endophyte-infected fescue. To evaluate these two compounds, 20 beef heifers, stratified by weight, were allotted to one of four treatments: LE: low-endophyte fescue hay HEC: endophyte-infected hay (70% infestation rate), HEN: endophyte-infected hay plus 2g niacin/d, and HEA: endophyte-infected hay plus 200mg aspirin/kg BW per d. Neither aspirin nor niacin was effective in lowering body temperatures vs HEC. Heifers fed HEA had maximum body temperatures that were higher (P<0.01) than both the HEC and LE groups. Heifers fed HEN had body temperatures that were higher (P<0.01) than those of LE-treated heifers but not different (P>0.10) than HEC heifers. Heifers fed LE had higher (P<0.01) serum prolactin concentrations than HEA and HEC heifers, but not HEN heifers (P>0.10). Dietary inclusion of aspirin had no beneficial effect on body temperature and prolactin levels in heifers fed high-endophyte fescue forage, whereas inclusion of niacin tended to increase serum prolactin levels.

The influence of exercise on energy balance changes induced by ventromedial hypothalamic lesion in the rat

The effects of a hypothalamic ventromidial area lesion on energy balance were tested in exercising rats and in sedentary rats to add further information about the type of obesity developed after ventromedial lesion. Four groups of six male Sprague-Dawley rats were used. Group 1: sham-lesioned and sedentary rats, which were utilized as control rats (C); group 2: sham-lesioned and exercising rats (E); group 3: lesioned and sedentary rats (L); group 4: lesioned and exercising rats (LE). The exercise consisted of daily swimming for 30 min. Resting oxygen consumption, food intake, and body weight were measured before any treatment and 3 weeks after the lesion or/and the exercise period. The results showed that the oxygen consumption increased in the E and LE groups but not in the C and L groups. Food intake increased more in E and LE groups than in L group. The increases in body weight were higher in L and LE than in the E and C groups. These findings suggest that exercise modifies resting oxygen consumption and food intake in lesioned rats, but does not influence the degree of obesity. Thus, the ventromedial syndrome can be considered a type of obesity not completely unregulated.

Effect of 17β-estradiol on the preovulatory surge of LH in the bovine female

The hypothesis tested was that increasing concentration of 17β-estradiol (E 2) subsequent to luteolysis stimulates the preovulatory surge of LH and that a decline in E 2 after the initial rise is not necessary to trigger the preovulatory surge of LH in the bovine female. Beef cows were synchronized to Day 16 of the estrous cycle. At Hour 0, all cows were ovariectomized and received one of four E 2 treatments: 1) luteal phase E 2 (LE; n=5), 2) increasing then decreasing E 2 (DE; n=5), 3) increasing and subsequent maintenance of high E 2 (IE; n=4), and 4) no E 2 (NE; n=3). Cows in the LE group received one E 2 implant at Hour 0 which provided low concentrations of E 2. Cows in the DE group received one E 2 implant at 0, 8, 16, 24, 32 and 40 hours; implants were subsequently removed at 8-hour intervals, thus mimicking the preovulatory rise and fall of E 2. Cows in the IE group were treated with the same regimen of E 2 implants as cows of the DE group, except that no E 2 implants were removed. Blood samples were collected at Hour 0 and at hourly intervals from Hour 2 through 80, for serum LH and E 2 quantification. The number of cows responding with a surge of LH was 0/3, 0/5, 4/5 and 3/4 for the NE, LE, DE and IE treatments, respectively. The proportion of cows responding with an LH surge was different (P<0.01) when data for cows in the NE and LE groups were pooled and compared with the pooled data of cows in the DE and IE groups. The mean time of the LH surge was not different (P>0.80) for cows responding with an LH surge (DE and IE treatments). Thus, increased levels of E 2 greater than luteal phase concentrations are needed to initiate preovulatory surges of LH, and it appears that concentrations of E 2 need to reach a certain level but do not need to decrease after this initial rise to stimulate a surge release of LH.

Life cycle patterns and their genetic control: an attempt to reconcile evolutionary and mechanistic speculation.

A model is proposed which implicates molecular recognition systems as the major controlling factors in life cycle expression. It is envisaged that such systems are important in immune functioning and catabolic, metabolic molecule recognition at both inter- and intra-cellular level. These recognition systems have the following characteristics: 1) Specific recognition molecules (recognisers), e.g. vertebrate antibodies, invertebrate agglutinins and plant agglutinins may recognise specific substances, e.g. antigens, catabolic and metabolic molecules. 2) The range of possible recognisable substances is very wide and variable. 3) The recognisers may themselves be recognised by other recognisers. 4) Recognisers are usually produced in large amounts only on presentation of the appropriate recognisable molecule. 5) The progressive introduction of new recognisable molecules increases the recogniser interaction, this interaction causing depression of some recogniser types (immune depression) and facilitation of other types among which may be recognisers specific for self components (e.g. auto-immunity). 6) Low juvenile viability is associated with a restricted range of available recognisers, high adult viability with increasing recogniser range and some auto-immunity/immune depression, senescence with a wide range of available recognisers and extensive auto-immunity/immune depression. Life cycle patterns and their control are discussed. It is suggested control mechanisms may include: 1) Dietary restriction and in some periods complete nutritional abstinence. 2) Specific recogniser depression, genes implicated here are the various antigens (species and polymorphic) found on cell surfaces, in the serum and in various body fluids of vertebrates, e.g. ABO, MNSs, P, Rh, Le and other blood groups, the ABO and Le secretor antigens and the HL-A antigens. In addition the immune response and mixed lymphocyte culture loci are implicated. Finally life cycle control is discussed with relation to sexual selection.