Calcaneal quantitative ultrasound measurements in young male and female professional dancers

The aim of this study was to assess the bone status of dancers using calcaneal quantitative ultrasound (QUS). Twenty-four male and 26 female dancers (aged 19-36 years) and 100 age- and sex-matched nonathletic controls were included in this study. QUS parameters (broadband ultrasound attenuation [BUA], speed of sound [SOS], quantitative ultrasound index [QUI], and estimated heel bone mineral density [eBMD]) were obtained for both heels in all subjects using a gel-coupled QUS device. Two-way analysis of variance, including the factors of dancing status and gender, revealed significant differences in all QUS parameters between the dancers and the controls (p < 0.001 for all), without a significant interaction with gender status. For each heel (right versus left), the mean QUI, BUA, SOS, and eBMD values of the male and female dancers were 22.0% vs. 20.9% and 16.6% vs. 16.0%; 21.6% vs. 24.1% and 13.2% vs. 14.3%; 2.3% vs. 2.0% and 1.7% vs. 1.7%; and 25.0% vs. 23.9% and 19.0% vs. 18.6% higher than those of the male and female controls, respectively. Analysis of covariance still revealed significant differences between the dancers and the controls after controlling for the influence of body mass index (p < 0.001). Furthermore, the finding that significant bilateral differences in BUA did exist in the controls but not in the dancers demonstrated site-specific effects of exercise on bone, indicating that it is the dance that improved bone properties. Calcaneal QUS, with a strong discriminative ability between those involved in professional dance and normally active individuals, emerges as an attractive technology for exploring the benefits of exercise on bone, which might be a challenge for those in the conditioning field, who need to identify those who need intervention in terms of bone status and promote participation in high-impact physical activity, such as dance, to enhance bone quality.     

Anthropometric indices and physical fitness in university undergraduates with different physical activity.

Physical activity and fitness have important health promoting effects with respect to arterosclerosis and coronary heart disease in particular. An intervention study of physical status and physical activity in university undergraduates (University of Tartu) has been carried out. The physically inactive (Group I) consisted of 310 undergraduates (235 females and 75 males) of the Faculty of Medicine. The physically active (Group II) was recruited from among undergraduates (22 females and 23 males) of the Faculty of Exercise and Sport Sciences, who participated in training sessions regularly, 3 to 5 times per week. Anthropometric body measurements, arm force, vital capacity and exercise test on the bicycle ergometer (PWC170) were performed. There were no statistically significant differences between the mean values of anthropometric indices in case of physically inactive and physically active female subjects. In the group of physically active male undergraduates, weight and shoulder width were larger than in students with physically sedentary life style (p < 0.05). Most of the female and male students had normal BMI. There were statistically significant differences in the mean values of vital capacity, arm force and aerobic working capacity between the study groups, while physically active students had higher physical capacity (p < 0.001). Mean anthropometric indices demonstrated a statistically significant increase in both female and male university undergraduates after the interval of 30 years. Normal BMI and anthropometric indices do not serve a as guarantee of physical fitness for university undergraduates who are involved in sedentary life style. Regular physical activity has a strong positive impact on physical fitness, particularly on aerobic capacity which is the most important health promoting component of physical fitness with respect to coronary heart disease.     

Relationships between physical activity and musculoskeletal disorders in former athletes

The purpose of the study was to determine the prevalence and risks for musculoskeletal disorders (MSD) in relation to previous athletic status and current physical activity level in former athletes. Main anthropometric data, sports history, current physical activity and MSD were estimated using a questionnaire in 219 (148 males, 71 females) former athletes (35-75 years old) and 79 controls (33 males, 46 females). According to the previous participation in top-level sports, former athletes were divided into three groups: (a) endurance, n=120 (76 males, 44 females); (b) speed-power, n=57 (43 males, 14 females); (c) team sports, n=42 (29 males, 13 females). The most prevalent MSD among the male and female ex-athletes were back and knee pain. The endurance ex-athletes group (both males and females) had significantly higher risk for the knee problems than the control group (Odds ratio--OR 5.9, 95% CI 1.7-20.00, p < 0.05). Team sports athletes (males and females) showed significantly higher risk for Achilles' tendon injuries (OR 3.19 95% CI 1.19-8.5, p < 0.05) as compared to controls. Back pain did not show any significant associations with previous physical activity and current physical activity level. Current physical activity was significantly associated with a lower risk for the knee and hip pain. Body mass index was positively associated with knee problems. In conclusion, our study results revealed that previous participation in enduranve sports events is associated with a significantly higher risk for knee problems. At the same time current regular physical exercise 6-11 times per month is associated with a lower prevalence of knee and hip problems as compared to those who exercised less than 6 times per month.     

Iron deficiency caused by 7 weeks of intensive physical exercise

The present study was designed to evaluate the effect of an intensive physical training program involving both isometric and isotonic activities on the body iron status of 8 females and 11 males (age 20 +/- 1 year). The training was carried out over a 7 week period and included 8 h of varying physical activities each day. Venous blood samples were obtained from the subjects prior to the beginning of the training, on day 2 and in weeks 2, 4, 6 and 7 of the program. Blood samples were analyzed for iron, ferritin and hemoglobin (Hb) concentrations, total iron binding capacity (TIBC) and red blood cell count (RBC). Iron levels of males and females decreased 65% after 2 weeks of training (p less than 0.001). At the end of the training program 5 males and 6 females had lower than normal iron values (less than 13.4 mumol.l-1). TIBC increased 25% in women and 18% in men following 2 and 4 weeks of training (p less than 0.001) and remained at this elevated level throughout the training period. Ferritin levels decreased 50% in both sexes after 4 weeks of exercise (p less than 0.05) and remained at this level until the end of the training. Hb and RBC decreased 8-10% in both sexes during the training period. In two of the women anemia occurred after 4 weeks of training. The development of latent iron deficiency in a substantial number of participants after a relatively short period of training is uncommon and may reflect the high intensity of exercise required in this program.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of a 5-month endurance-training programme on physical activity: evidence for a sex-difference in the metabolic response to exercise

The effect of a 5-month endurance training programme on physical activity and average daily metabolic rate (ADMR) was studied. Subjects were 16 males and 16 females preparing for a half marathon. Total physical activity, measured using an accelerometer, had increased by 62% and 63% after 20 weeks in males and females, respectively. Physical activity during the non-exercise part of the day did not change although in males it tended to increase (15%, NS). The ADMR had increased significantly in males after 8 and 20 weeks (+2.3 and +3.3 MJ.day-1, respectively, P less than 0.05) and exceeded the net energy expenditure for endurance-training three to four times. In females no significant increase in ADMR was found (+1.5 and +1.3 MJ.day-1, after 8 and 20 weeks, respectively). In females the change in ADMR could be largely attributed to the net cost of running itself and a small increase (10%) in resting metabolic rate during the time of day they were awake. In males a discrepancy was observed between the increase of ADMR and the expenditure due to exercise and non-exercise activities. We suggest exercise stimulates habitual physical activity and diet-induced thermogenesis in males but not in females.     

Focal palatine erosion in captive and free-living cheetahs (Acinonyx jubatus) and other felid species

We examined 1,092 skulls of captive and free-living individuals, representing 33 felid species, to determine the prevalence of focal palatine erosion (FPE). FPE was detected in 3.2% of cats evaluated, including cheetah (Acinonyx jubatus) and 14 other felid species. The prevalence of FPE between cheetah (9.4%; n = 64) and non-cheetah species (2.8%; n = 1,028) (χ(2) test; P = 0.004) and between captive (5.7%; n = 246) and free-living (2.4%; n = 824) individuals (χ(2) test; P = 0.010) were significantly different, with prevalence between captive (19%; n = 21) and free-living (2.9%; n = 34) cheetahs approaching significance (Fisher's exact test; P = 0.064). FPE was diagnosed with equal prevalence in skulls from individuals in which the lower molars did not meet the palatine bone (60.6%) and individuals in which it did (39.4%; n = 33) (χ(2) test; P = 0.139). In cheetahs with FPE, one was a captive animal in Germany, one a free-living cheetah from Mali, one captive cheetah from Kenya, and three captive cheetahs of unknown origin. Additionally, we evaluated the medical records of 49 captive cheetahs in Namibia. Of these cheetahs, 48 (98.0%) had clinical signs consistent with FPE, although only 16 of these 48 (39.6%) had perforation of the palatine bone. Based on physical examinations, FPE was diagnosed in two caracals (Caracal caracal) and one fishing cat (Prionailurus viverrinus) from a North American Zoo. Results from this study confirm FPE in cheetahs outside of Namibia, in a minimum of 15 felid species, and a higher FPE prevalence in captive individuals than free-living ones. Clinical implications of these findings and recommendations for future studies are provided.     

Somatotype and physical performance in a sample of university students from Madrid

A sample of 303 Madrid Complutense University students (100 males and 203 females), aged 21–29 years has been studied in order to establish the relationship between somatotype components and physical work performance. Since particular interest is focused on a possible sexual difference in that relationship, males and females were analyzed separately. Results prove the high correlation of test scores implying muscularity (hand grips, pulling strength) with the mesomorphic component of the somatotype, mainly in males. Variability in tests relative to physical totype, mainly in males. Variability in tests relative to physical fitness is mainly explained by differences in endomorphy, although regarding the step test, ectomorphy is also a factor to be taken into account in females, as well as the pulling strength in males.     

Myocellular triacylglycerol breakdown in females but not in males during exercise

The resting content and use of myocellular triacylglycerol (MCTG) during 90 min of submaximal exercise [60% of peak oxygen uptake (VO(2 peak))] were studied in 21 eumenorrheic female and 21 male subjects at different training levels [untrained (UT), moderately trained (MT), and endurance trained (END)]. Males and females were matched according to their VO(2 peak) expressed relative to lean body mass, physical activity level, and training history. All subjects ingested the same controlled diet for 8 days, and all females were tested in the midfollicular phase of the menstrual cycle. Resting MCTG, measured with the muscle biopsy technique, averaged 48.4 +/- 4.2, 48.5 +/- 8.4, and 52.2 +/- 5.8 mmol/kg dry wt in UT, MT, and END females, respectively, and 34.1 +/- 4.9, 31.6 +/- 3.3, and 38.4 +/- 3.0 mmol/kg dry wt in UT, MT, and END males, respectively (P < 0.001, females vs. males in all groups). Exercise decreased MCTG content in the female subjects by an average of 25%, regardless of training status, whereas in the male groups MCTG content was unaffected by exercise. The arterial plasma insulin concentration was higher (P < 0.05) and the arterial plasma epinephrine concentration was lower (P < 0.05) in the females than in the males at rest and during exercise. MCTG use was correlated to the resting concentration of MCTG (P < 0.001). We conclude that resting content and use of MCTG during exercise are related to gender and furthermore are independent of training status.     

Diet and exercise reduce low-grade inflammation and macrophage infiltration in adipose tissue but not in skeletal muscle in severely obese subjects

Obesity is associated with low-grade inflammation, insulin resistance, type 2 diabetes, and cardiovascular disease. This study investigated the effect of a 15-wk lifestyle intervention (hypocaloric diet and daily exercise) on inflammatory markers in plasma, adipose tissue (AT), and skeletal muscle (SM) in 27 severely obese subjects (mean body mass index: 45.8 kg/m2). Plasma samples, subcutaneous abdominal AT biopsies, and vastus lateralis SM biopsies were obtained before and after the intervention and analyzed by ELISA and RT-PCR. The intervention reduced body weight (P < 0.001) and increased insulin sensitivity (homeostasis model assessment; P < 0.05). Plasma adiponectin (P < 0.001) increased, and C-reactive protein (P < 0.05), IL-6 (P < 0.01), IL-8 (P < 0.05), and monocyte chemoattractant protein-1 (P < 0.01) decreased. AT inflammation was reduced, determined from an increased mRNA expression of adiponectin (P < 0.001) and a decreased expression of macrophage-specific markers (CD14, CD68), IL-6, IL-8, and tumor necrosis factor-alpha (P < 0.01). After adjusting for macrophage infiltration in AT, only IL-6 mRNA was decreased (P < 0.05). Only very low levels of inflammatory markers were found in SM. The intervention had no effect on adiponectin receptor 1 and 2 mRNA in AT or SM. Thus hypocaloric diet and increased physical activity improved insulin sensitivity and reduced low-grade inflammation. Markers of inflammation were particularly reduced in AT, whereas SM does not contribute to this attenuation of whole body inflammation.     

Effects of sex differences on constitutive nitric oxide synthase expression and activity in response to pressure overload in rats

Clinical studies have documented sex differences in left ventricular (LV) hypertrophy patterns, but the mechanisms are so far poorly defined. This study aimed to determine whether 1) severe pressure overload altered expression and/or activity of cardiac constitutive nitric oxide synthase (NOS1 and NOS3) and 2) these changes were modulated according to sex. Analyses were performed 0.4-20 wk after thoracic aortic constriction (TAC) in male and female Wistar rats. Male rats with TAC exhibited early signs of cardiac dysfunction, as shown by echocardiographic and LV end-diastolic pressure measurements, whereas females with TAC exhibited higher LV hypertrophy (+96% vs. males at 20 wk; P < 0.05). After TAC, cardiac NOS1 expression was rapidly induced (0.4 wk) and stable afterward in males (P < 0.05 vs. sham groups), whereas it was delayed in females. Accordingly, specific NOS1 activity was increased by 2 wk in male rats with TAC (+122%; P < 0.001 vs. sham groups) and only by 20 wk in females (+220%; P < 0.001 vs. sham groups). NOS1 activity was correlated with NOS1 level. Regarding cardiac NOS3, expression was unaffected by TAC, and the decrease in activity observed at early and late times in male and female rats with TAC, respectively, is shown to be related to NOS3 allosteric regulator caveolin-1 level. The data demonstrated a unique sex-dependent regulation of the constitutive NOSs in response to TAC in rats; such a difference might play a role in the sex-dependent adaptability of the heart in response to pressure overload.     

Skeletal and functional status in patients with long-standing stroke

Introduction: Skeletal and functional status can be affected after stroke, mainly due to subjects' immobilisation. The aim of our study was to assess the functional and bone status in post-stroke patients with hemiplegia. Quantitative ultrasound at hand phalanges and bone mineral density (BMD) in the wrist and the calcaneal bone were compared between the paralysed and the non-paralysed side. The study was performed at the Department of Rehabilitation in Nowa Sol. Material and methods: The study included a group of 71 subjects (29 females and 42 males) who had suffered a stroke. Skeletal status was assessed by densitometry (Pixi, Lunar Corp., USA, forearm, calcaneus) and ultrasound (DBM Sonic 1200, IGEA, Italy, hand phalanges). Functional status was evaluated by the Barthel index. Results: The mean values of forearm BMD and ultrasound measurements were significantly lower in the affected limbs versus the opposite site. The mean Barthel index value was 73 ± 21.5. Reduction of the time interval between stroke and standing up positively influenced the difference between wrist BMD in the affected versus the opposite limb, both in the whole group of patients (r = 0.3, p 〈 0.05) and females (r = 0.41, p 〈 0.05). Forearm BMD in males in the affected limb correlated with the Barthel index (r = 0.35, p 〈 0.05). Conclusion: Fracture risk in post-stroke subjects may be increased due to disturbed skeletal and functional status. Reduction of the time interval between stroke and standing up improved wrist densitometric results. (Pol J Endocrinol 2011; 62 (1): 2-7).     

The influence of female presence and seasonality on the home range size and activity patterns of male domestic cats in Brazil’s Atlantic Forest

The factors that affect the home range size of domestic cats (Felis silvestris catus) in a semi-domesticated condition (i.e., cats that receive shelter and food from humans but are free to move in the wider natural environment) is not completely understood. Here, using radio telemetry, we present the first assessment of the home range size and activity patterns of male domestic cats living in the insular environment of Brazil’s Atlantic Forest, and examine the extent to which these were influenced by the presence (‘resident males with females’: RMF group) or absence (‘single males’: SM group) of females in the residences of their owners. Daily and seasonal activity patterns have also been characterized. Home ranges of the RMF were markedly smaller than that of the SM and exhibited less overlap with the home ranges of other males than did those of the SM. Male cats were most active at twilight and evening (44.68 ± 1.07) and least active in the afternoon (28.76 ± 2.79). RMF presented nocturnal activity greater than SM, especially in the dry season. Our data indicate that presence of females is an important factor in shaping these parameters of domestic male cats.     

Is lower limb muscle synchrony during landing affected by gender? Implications for variations in ACL injury rates.

This study examined whether lower limb muscle synchrony during abrupt landings was affected by gender, thereby predisposing females to a higher incidence of non-contact anterior cruciate ligament (ACL) injuries than males. Seven males and 11 females landed in single-limb stance on a force platform after receiving a chest-height netball pass and decelerating abruptly. Ground reaction force and electromyographic data for rectus femoris, vastus lateralis, vastus medialis, semimembranosus (SM), biceps femoris, and gastrocnemius were sampled (1000 Hz) during landing. Subjects' sagittal plane motion was also filmed (200 Hz). Knee joint reaction forces and sagittal planar net moments of force were estimated using Newtonian equations of motion and inverse dynamics. Tibiofemoral shear forces (F(s)) were obtained and muscle bursts temporally analysed with respect to initial foot-ground contact (IC) and peak F(s) times. Males displayed significantly delayed SM onset relative to IC (113+/-46 ms) compared to females (173+/-54 ms; p=0.03), and significantly delayed SM peak activity relative to peak F(s) (54+/-27 ms) compared to females (77+/-15 ms; p=0.03). Delayed SM activity during landing was suggested to allow peak muscle activity to better coincide with high anterior F(s), thereby acting as an ACL synergist via increased joint compression and posterior tibial drawer. It was concluded that females displayed muscle synchrony less protective of the ACL than males, possibly increasing their susceptibility to non-contact ACL injuries.     

Relationships between elevation, reproduction and the hematocrit level of brown-headed cowbirds

Hematocrit, furcular fat level and oviducal egg presence were determined for 267 brown-headed cowbirds (Molothrus ater) at eight sites ranging from 15 to 2390 m above sea level in California. Near the end of the breeding season males at a mid-elevation site (1250 m) possessed higher hematocrits than females, but there was no difference between yearling and adult males. Birds were bled during three 11-day periods beginning 1 May 1984 at one montane site (2075 m). The percentage of females with oviducal eggs increased significantly from 0 to 10 to 67% and the mean female hematocrit increased from 0.54 to 0.56 and then decreased significantly to 0.52. The hematocrit of males increased significantly from 0.54 to 0.57 and then remained level during the final period. Correlations were calculated between mean hematocrit and elevation for males (r = 0.94, N = 8 sites, P less than 0.001), females (r = 0.96, N = 7 sites, P less than 0.001) and juveniles (r = 0.99, N = 4 sites, P less than 0.01).     

Body shape in relation to socio-economic status in young adults from the basque Country

Body shape has a great variability determined, partly, by energy intake and physical activity, as well as by gender and age. The aim of this research was to analyse the relation between socio-economic status (SES) and body shape estimated through the somatotype, in a sample of university students. The sample included 316 males and 635 females aged 18-33. Somatotype was estimated by the Heath-Carter anthropometric technique. The information included data of SES. A MANOVA test was used to test differences among groups. The mean somatotypes were 4.0-4.4-2.3 in males and 5.4 -3.4-2.2 in females. Sexual dimorphism for the whole somatotype was found (p < 0.001). There is a greater stability of the body shape in females regarding SES and more variability in males. Males' somatotype was significantly related to SES, low socioeconomic levels were associated with high values of endomorphy and mesomorphy.     

Influence of age and sex in serum osteocalcin levels in thoroughbred horses.

In this study, we assessed the potential value of free serum osteocalcin or bone gla protein (BGP), the most abundant non collagenous matrix protein found in bone and dentin, to reflect changes of bone turnover in thoroughbred horses. Levels of osteocalcin were analyzed in serum samples of 54 clinically normal animals divided into three groups (A, B, C) according to age: 8, 16-18 and 24-36 months, in order to determine the standard for young horses of different age and sex. Serum BGP was measured by an in-house developed double antibody radioimmunoassay using bovine antigen. The mean BGP levels (ng/ml) were 45.65 +/- 11.69; 33.65 +/- 16.65; 15.08 +/- 6.70 respectively for groups A, B and C; statistically significant differences were found between groups (A vs B and C; Bvs C). Difference between males and females was found significant in group C with higher values in the females: 18.75 +/- 5.00 against 14.43 +/- 10.47 i n the males. This can be considered a sex related effect on BGP serum levels after the onset of puberty. Correlation coefficient between age and serum BGP for females and males were r 5 20.598 ( P < 0.001) and r 5 200.807 (P < 0.001) respectively. A significant negative linear relationship could be established between these two parameters in males during the growth period. The regression equation between serum BGP and age for males was (month of age = 65.14-1.68. BGP). In the female group the gestation and lactation are variables that lower the correlation coefficient between age and serum BGP levels. These results suggest that serum BGP decreases in thoroughbred horses during the growth period, and significant differences between sexes were found only after the onset of puberty.     

The differential prevalence of obesity and related behaviors in two- vs. four-year colleges

The objective of this study was to determine whether obesity prevalence and weight-related behaviors (e.g., diet, physical activity) differ among students enrolled in 2-year community/technical colleges and those attending 4-year colleges/universities. This information could inform the development of intervention strategies. Through an existing surveillance system of Minnesota postsecondary education institutions, survey data were collected from 16,539 students from 27 campuses (14 two-year college campuses, 13 four-year college/university campuses; 2007-2008), including self-reported physical activity, media use, dietary patterns, weight control behaviors, height, and weight. Unadjusted analyses indicated that students enrolled in 2-year colleges, particularly females, had a higher prevalence of overweight/obesity, lower levels of physical activity, more television viewing, higher intakes of soda, fast food, and diet pills compared to students attending 4-year colleges (P < 0.05). Females attending 4-year colleges were more likely to engage in certain unhealthy weight control behaviors (taking diet pills, binge eating, self-induced vomiting) compared to females attending 2-year institutions. Among male students there were fewer differences between 2-year and 4-year colleges. Controlling for sociodemographic factors (e.g., race/ethnicity, age), most disparities in prevalence estimates remained, though many were attenuated. Overall, few young adults engage in weight-related behaviors consistent with national recommendations. Two-year college students may represent a particularly at-risk group. Disparities between 2- and 4-year college students exist beyond the sociodemographic differences in these populations. Effective weight-related interventions are needed for young adults, particularly females attending 2-year colleges and all males attending postsecondary institutions.     

Effects of chronic physical activity and of ultrasound treatment on bone consolidation

The objective of this study was to investigate the effects of ultrasound treatment and physical exercise on the velocity of bone consolidation and resistance to deformation. We performed osteotomy in the upper third of the right tibia of rats. Physical training consisted of swimming 1 h per day with a load of 5% b.w. for 30 days. Therapy with medium-intensity ultrasound was applied daily on the damaged area. Wistar rats were divided into the following groups: osteotomized sedentary animals with no ultrasound treatment (1.OSnUS), osteotomized trained animals with no ultrasound treatment (2.OTnUS), osteotomized sedentary animals with ultrasound treatment (3.OSwUS), and osteotomized trained animals with ultrasound treatment (4.OTwUS). The animals were sacrificed for the following analyses: muscle glycogen, serum alkaline phosphatase at the 5th, 10th, 20th, and 30th days, test of maximum resistance to flexion, rupture flexion and mean tibial rigidity at the 30th day. Muscle glycogen was increased at the 20th day; alkaline phosphatase was elevated at the 5th and 20th days in groups 3.OSwUS and 4.OTwUS, and decreased at the 10th day. Groups 1.OSnUS and 2.OTnUS did not show significant variations. In the mechanical resistance tests, we noted that ultrasound therapy and the association of physical activity used in the present study showed significant differences in bone resistance and bone rigidity after 30 days of treatment. These facts suggest that ultrasound or physical activity, or their combination may accelerate the process of bone tissue repair.     

In vivo cytogenetic effects of a commercially formulated mixture of cypermethrin and quinalphos in mice

In vivo cytogenetic effects of commercially formulated cypermethrin (CYP, synthetic pyrethroid insecticide) and/or quinalphos (QUI, organophosphate insecticide), generally used in combination, were examined through chromosomal aberrations (CA) and micronucleus test (MT) in mice. Male mice were orally gavaged to a single dose of CYP/QUI commercial mixture (22, 44 or 67 mg/kg b.wt.) for 24h (CA) or 48 h (MT). Based on the concentrations of active ingredients of CYP and QUI present in the test doses of CYP/QUI mixture, mice were orally exposed to 0.66, 1.32 and 2 mg/kg of CYP or 4.4, 8.8 and 13.4 mg/kg of QUI. For reference, a group of five mice was intraperitoneally administered to cyclophosphamide (20 or 50 mg/kg) or orally gavaged to peanut oil for vehicle control. Exposure of CYP/QUI mixture inhibited the mitotic index (MI) and induced CA in a dose-dependent manner at 24 h; however, significant (p<0.01 or 0.001) frequencies of CA were observed at 44 mg/kg onwards, whereas inhibition of MI at 67 mg/kg. Independent exposure of QUI at 8.8 mg/kg onwards also significantly (p<0.01 or 0.001) inhibited MI and induced CA, whereas CYP at 2 mg/kg (highest concentration in CYP/QUI mixture) inhibited MI significantly but failed to induce CA. Chromatid breaks and fragments found to be frequent aberrations in all the test groups. Treatment of CYP/QUI mixture also induced micronucleus formation dose-dependently at 48 h, yet statistically significant (p<0.001) frequencies of micronucleated polychromatic erythrocytes (MNPCE) were observed at 44 mg/kg onwards. QUI (8.8 and 13.4 mg/kg) alone also induced significant frequencies of MNPCE, whereas frequencies of MNPCE observed with the CYP even at 2 mg/kg were comparable to that of vehicle control. Present findings indicate the genotoxicity potential of CYP/QUI mixture and suggest that the simultaneous presence of the toxic doses of CYP and QUI can lead to synergistic genotoxicity in mice and may pose mutagenic risk in human beings.     

Male reproductive condition is the limiting factor of efficiency in the male effect during seasonal anestrus in female goats

Two experiments were conducted to determine whether the failure of males to induce sexual activity in goats during seasonal anestrus is due to unresponsiveness of females to male stimulus or insufficient stimulation from males. In the first study, one group of males (sexually inactive, SI; n = 4) was kept under natural photoperiod while the other (sexually active, SA; n = 4) was subjected to 2.5 mo of long days (16L:8D) and received 2 s.c. implants of melatonin. Two mo later, 2 different flocks of anovulatory goats previously separated from bucks were exposed to either SI (n = 34) or SA (n = 40) bucks. Progesterone assays and estrous behavior were used to determine ovarian and behavioral responses of the females to teasing. Of the goats exposed to SI males, only 2 ovulated, and none showed estrous behavior during the 35 days of the study. In contrast, all females (40 of 40) in contact with SA males ovulated and showed at least one estrous behavior during the first 11 days following male introduction (P < 0.001). Overall, 38 of 40 females stimulated with SA bucks were diagnosed pregnant at Day 35, according to progesterone assay (versus 0 in SI-treated group: P < 0.001). To control for a possible difference of responsiveness between flocks, the experiment was repeated 1 yr later using a single flock of goats divided into 2 groups. Again, over the first 14 days, 1 of 33 goats showed estrous behavior in the SI-treated group versus 27 of 33 in the SA-treated group (P < 0.001). Therefore, treating bucks with long days and melatonin increased their teasing capacity to induce sexual activity in females during anestrus. These results indicate that the absence of response to teasing at this time of the year is not due to female unresponsiveness, but to insufficient stimulation from the male.