Effect of natural and synthetic androgen hormone on sex reversal of Nile Tilapia (Oreochromis niloticus)

The present study aimed to produce a monosex population of all male Nile tilapia (Oreochromis spp.) using 17α-methyl testosterone and common carp testes (as a source of natural androgen). Trial was conducted into two consecutive phases, the first was fry (4-5 days old)administration with negative control (without hormone) and positive control (with hormone) feed viz., MT1:60mg/kg, MT2:70mg/kg (17α-MT), carp testis CT1:70% and CT2:80% for 30 days to reverse the sex of male fish and the second phase was nursing the fingerlings for two months on control diet (32% Crude protein).Results revealed a significant growth rate (P<0.05) in the control group where final weight (4.8±0.34ab) and weight gained was recorded as 0.66±0.03ac. In proximate chemical composition of body meat, CT2 treatment showed maximum retention of crude protein, crude fat, and ash whereas dry matter showed maximum retention in MT2 and CT1 treatments. Morphological and histological examination revealed significant difference (p<0.05) in phenotypic males of Nile tilapia fed with the highest percent in MT-treated diet (MT2) of 95±0.58a while MT1, CT2 and CT1 had males of 85±6.0b, 70±5.0b and 65±6.5b, respectively. It was concluded that synthetic androgen (17αMT) was more effective for masculinization but natural androgen scan be an alternative method to produce male tilapia population in an environment-friendly manner as they are inexpensive, eco-friendly, and radially available. These results suggested that synthetic and natural androgen supplementation in the diet plays a significant role in improving growth performance and body composition.

Chromium supplemented carbohydrate diets for Cirrhinus mrigala: effects on body composition, gut enzyme activity and hematological parameters

A ninety days nutritional trial was directed to explore the effects of dietary chromium on body composition, gut enzyme activity and physiological status of Cirrhinus mrigala by using G & NG corn. Six experimental diets were prepared by using different levels of chromium chloride hexahydrate (0, 0.2, 0.4 mg/kg, each with G & NG corn). For this experimental trial, 480 fingerlings, irrespective of sex were distributed in six aquariums each with replicate. Results revealed that gelatinized corn along with increasing level of Cr2Cl3.6H2O have a positive impact upon body composition of fish. Hematology was positively correlated with chromium chloride hexahydrate supplementation in gelatinized corn. Amylase gut enzyme also showed significant (P<0.05) increase in group fed with chromium chloride hexahydrate supplemented diet (G corn). However, corn with chromium chloride hexahydrate supplementation did not revealed any significant impact on gut protease enzyme activity. From these results it can be concluded that both chromium chloride hexahydrate and gelatinized corn in fish feed are very beneficial to improve body composition, enzymes activity and physiological health status of fish.

Masculinization in common carp (Cyprinus carpio) by androgen immersion: The interaction effect of hormone concentration and immersion time

Synthetic androgens (male hormones) administered to fish nursery are being used in aquaculture to avoid sexual differentiation and unwanted spawning at the eggs or the first feeding fry stage of fish. Present trial was conducted with the aim to produce male common carp (Cyprinus carpio) by egg immersion technique. Through this little insight, the effect of different hormone concentrations (17α-methyltestosterone @ HC:150, 300, 450 and 600 µgl-1) with immersion times (IT: 24, 48 and 72 hrs) and their interaction effect (HC x IT) on the hatching percentage of Cyprinus carpio eggs, percent survival and percent of male's production was evaluated specifically. Results showed that egg hatching percentage decreased with increased IT likewise, survival of treated fry was affected by increasing the IT (P<0.001). The main interaction effect of HC x IT showed that the highest percent of male individuals (95%) was obtained at 450-600 µgl-1 HC for 72 hrs IT, followed by 88-92.50% at 150-300 µgl-1 HC for 72-hrsof IT, 87.50% at 48-hrs of IT for rest of the hormone treatments, and lowest 47.50% was recorded in control (P<0.05). Increased percent male of Cyprinus carpio was obtained with increasing HC across all ITs. It was observed that the immersion treatment at 600µgl-1 for 72 hours was more effective to change the sex ratio of pre hatch Cyprinus carpio. A comparative outlook made from this experimental trial that sex induction of Cyprinus carpio by eggs immersion using synthetic male steroid hormone is an alternative safe technique of fish sex reversal in contrast to oral administration of hormone in fish feed.

Pattern of first- and second-line drug resistance among pulmonary tuberculosis retreatment cases in Pakistan

BACKGROUND

Drug resistance in general, and multidrug-resistant tuberculosis (MDR-TB) in particular, threatens global tuberculosis (TB) control efforts. Population-based estimates of drug resistance are needed to develop strategies for controlling drug-resistant TB in Pakistan.

OBJECTIVE

To obtain population-based data on Mycobacterium tuberculosis drug resistance in Pakistan.

METHODS

To obtain drug resistance data, we conducted a population-based study of TB cases in all provinces of Pakistan. We performed culture and drug susceptibility testing on M. tuberculosis isolates from patients with a prior history of anti-tuberculosis treatment (retreatment cases) from all over the country.

RESULTS

Of 544 isolates from previously treated cases, 289 (53.1%) were susceptible to all first-line drugs, 255 (46.9%) were resistant to at least one anti-tuberculosis drug and 132 (24.3%) were MDR-TB. Among MDR-TB isolates, 47.0% were ofloxacin (OFX) resistant. Extensively drug-resistant TB was found in two (0.4%) isolates.

CONCLUSION

Prevalence of drug resistance in retreatment isolates was high. The alarmingly high prevalence of OFX resistance among MDR-TB isolates may threaten the success of efforts to control and treat MDR-TB.

Prevalence of primary multidrug resistance to anti-tuberculosis drugs in Pakistan

SETTING

Pakistan ranks sixth in the world in terms of tuberculosis (TB) burden, with a World Health Organization estimated incidence of 181 per 100000, or 286000 new cases annually. Hospital-based data indicate a significant problem of multidrug-resistant TB (MDR-TB) in the country and highlight the need to assess its extent at community level. In this cross-sectional study, sputum samples from 742 untreated newly diagnosed pulmonary TB patients from all over the country were used.

OBJECTIVE

To assess the prevalence of primary drug resistance in Pakistan.

RESULTS

Of 672 culture-positive patients, 76 (11.3%) showed resistance to one or more drugs. Resistance to streptomycin (10 microg/ml) was found in 36 (5.4%) patients, isoniazid (INH) (1 microg/ml) in 51 (7.6%), rifampicin (RMP) (5 microg/ml) in 15 (2.2%), ethambutol (10 microg/ml) in 12 (1.8%) and pyrazinamide in 22 (3.3%) samples. Forty-six (6.8%) of the isolates tested were resistant to a single drug, 10 (1.5%) to two drugs, 12 (1.8%) to three drugs, and 6 (0.9%) to four drugs, while 2 (0.3%) isolates were resistant to all five first-line agents. Primary MDR-TB was 1.8% (n=12) (INH 1 microg/ml, RMP 5 microg/ml).

CONCLUSION

The results of this study show a prevalence of primary MDR-TB in Pakistan of <2%, which needs to be addressed through an effective DOTS strategy.

Breath-holding time in normal subjects, snorers, and sleep apnea patients

BACKGROUND

The onset of irregular inspiratory muscle activity has been observed toward the breakpoint of the breath-holding maneuver. We wondered if this was similar to the increased respiratory effort with paradoxical breathing seen during the resolution of an apnea in obstructive sleep apnea syndrome (OSAS).

STUDY OBJECTIVE

To compare the breakpoint of breath holding in normal subjects, OSAS patients, and snorers.

METHODS

Thirty normal subjects, 30 patients with OSAS, and 16 snorers performed serial breath-holding maneuvers at functional residual capacity (FRC) under standardized pretest conditions using the rebreathing method of Read.

RESULTS

Intergroup comparisons were carried out by analysis of variance with post hoc Tukey's Highest Significant Difference tests. Basal end-tidal carbon dioxide (EtCO2) was significantly higher in OSAS than in normal subjects and snorers. Basal breath-holding time (BHT) was shorter in OSAS as compared with that in normal subjects and snorers (p < 0.05). The maximal EtCO2 level attained was higher in OSAS as compared with normal subjects (p < 0.05) and snorers (p = 0.052). The maximal BHT in OSAS was shorter than in normal subjects (p < 0.05) but not in snorers. The slope of BHT/EtCO2 differed significantly in OSAS compared with normal subjects and snorers (p < 0.05). No significant correlation was found between slope BHT/EtCO2 and age or body mass index using multiple regression analysis. The FRC of OSAS patients and snorers were similar (p = 0.792).

CONCLUSION

We conclude that BHT and slope of BHT/EtCO2 are different in OSAS subjects as opposed to those in normal subjects and snorers.