Effects of genetic selection for fast growth on the development of wooden breast myopathy in broilers

1. This study investigated the physiological and molecular mechanisms leading to wooden breast (WB) by comparing growth parameters, oxygen consumption rate, thyroid hormone and gene expression patterns in fast- versus slow-growing broiler lines (Cobb500 and L1986, respectively).2. WB was observed in Cobb500 broilers only and was first diagnosed on d 21 post-hatch. Compared to the slow-growing L1986, Cobb500 showed a significantly higher growth rate, relative breast weight, breast thickness, meat pH and water-retention capacity (drip loss). Correspondingly, there was significantly lower relative heart weight, relative right ventricular weight, triiodothyronine and thyroxine concentrations and oxygen consumption rate.3. Compared to No-WB Cobb500, the WB-affected samples exhibited higher relative breast weight, breast thickness and drip loss and lower plasma total thyroxine (T4) concentrations.4. Selection for fast growth was associated with differential expression of genes involved in hypoxia (PLOD2), energy metabolism (FABP3, FABP4, CD36, and LPL), endoplasmic reticulum stress, muscle regeneration (CSRP3) and fibre-type switching (ANKRD1). WB-affected samples exhibited an upregulation of CSRP3, PLOD2 and ANKRD1, while CD36 was downregulated. Taken together, selection for fast growth and muscle gain is not matched by adequate cardiac and metabolic support systems.

Post-Hatch Performance of Broilers Following Hypoxic Exposure During Incubation Under Suboptimal Environmental Temperature

The modern broiler is selected to exploit its full genetic potential, to sustain a rapid growth rate, and to lower the feed conversion rate (FCR). Recently reported reductions in FCR have been associated with augmented tissue formation at the expense of physiological functions such as thermoregulation. In turn, modern broilers exhibit a relatively low capability to balance energy expenditure under suboptimal ambient temperature. Hypoxic conditions at late incubation stages play a role in reforming metabolic plasticity. This work examined the effect of exposure to 12-h hypoxia (12H; 17% O2) for three consecutive days (from E16 through E18), or continuous hypoxia exposure for 48 h (48H), from E16 through E17, as compared to standard incubation (21% O2) on post-hatch performance of broilers maintained under suboptimal ambient temperatures (cold, hot, and diurnal cyclic ambient temperature). 12H chicks kept under hot ambient temperature had significantly lower body temperature (Tb) as compared to the control chicks. On day 42, both 12H and 48H chicks grown in the cyclic temperature room had significantly lower Tbs than controls. In parallel, from week 4, onward, 12H chicks had a significantly lower FCR than controls, and the 48H chicks demonstrated a lower FCR from week 5 and on. 12H and 48H broilers maintained under diurnal cyclic ambient temperature, exhibited significantly greater relative breast muscle weight, and a similar pattern was found in hypoxic broilers raised under standard and hot ambient temperatures. Hypoxic manipulation affects and create an adaptive bias in allocating metabolic energy between maintenance and growth, thus resulting in improved broiler performance, thermoregulation, and rearing under suboptimal environmental temperature.

Effects of hypoxic conditions during the plateau period on pre- and posthatch broiler performance

Adequate ambient temperature and oxygenation are necessary to maintain normal embryonic development of broilers; however, hypoxia challenge during incubation can aid in improving regulatory plasticity and lead to different phenotypes later in life. This study aimed to examine the effects of moderate hypoxia (O₂ 17%) during the plateau phase on the embryonic physiological parameters and on posthatch performance (growth rate, feed consumption and feed conversion) up to the age of poultry marketing. The study included examined embryos exposed to O₂ 17% for 12 h per day (h/d) from E16 through E18 (designated as 12H), or O₂ 17% continuously, from E16 through E17 (designated as 48H) and a standard incubation control group (21% O₂). Physiological and morphological parameters of embryos and hatched chicks were measured. Male Chicks from all 3 treatment groups were raised under recommended temperature regime, and body weight, feed intake and FCR were recorded on a weekly basis. The intermittent hypoxia protocol (12H), allowed embryos to properly adapt to the shortage of oxygen, compensate for the gap in body mass that developed following the first exposure window, and hatch with characteristics similar to those of the control embryos. In contrast, while the 48H embryos were able to adapt to the hypoxic stress, the prolonged exposure prevented them from catching up with both control and 12H embryos. Broilers that were subjected to hypoxia showed hatchling body weights and growth rates similar to those of controls, throughout the entire growth phase. During the fifth wk, lower feed consumption was observed in the 12H and 48H groups and became significantly lower than the control chicks in the sixth wk of growth. Following hypoxia exposure, chicks managed to reach normal body weight with less feed, with the 12H group demonstrating lower and more efficient FCR during the last 2 wk of growth. Broiler embryos reacted to plateau-phase hypoxia challenge with numerous physiological and metabolic modifications. The prudent alterations in metabolism and cardiovascular system during exposure to hypoxia and posthatch, resulted in more efficient energy utilization in broilers, which may have a long-lasting enhancing effect on posthatching thermotolerance and sustainability in chicks reared under sub-optimal environmental conditions.

Patient and procedure selection for bariatric and metabolic surgery in Malaysia- The Malaysian Consensus

The rise in obesity has fuelled the current debate of its classification as a disease. Contrary to just being a medical condition or a risk factor for other diseases, obesity is a complex disease with multifaceted aetiology as well as its own disabling capacities, pathophysiology, and comorbidities. The problem of obesity in Malaysia is serious and calls for active intervention by all stakeholders ranging from government agencies to insurers and healthcare providers. To aid efforts to curb obesity, this consensus statement for bariatric surgery provides a basis for inclusion and exclusion criteria as well as the types of procedures accepted as the norm in Malaysia. This consensus statement was initiated by the Society of Endoscopic and Laparoscopic Surgeons of Malaysia and was collaborated with representatives from the Ministry of Health Malaysia.

Differential physiological response of slow- and fast-growing broiler lines to hypoxic conditions during chorioallantoic membrane development

Ambient conditions during chicken embryogenesis, such as insufficient oxygen or changes in temperature, are expected to cause permanent phenotypic changes and affect their posthatch performance. Decades of genetic selection for high growth rate resulted with various physiological and morphological changes that can affect the broiler fitness under environmental stress. To evaluate the selection effect on responses to environmental challenge during embryonic development, and the long-term implications, we have used a unique genetic line, that was not selected for over 30 yr (since 1986), as control for the modern commercial genetic line. At embryonic day 5 (E5), broiler embryos from these 2 genetic lines were divided into 2 treatments: 1) control; 2) 15% O2 concentration for 12 h/day from E5 through E12 the embryonic period of chorioallantoic membrane formation. Embryos and hatched chicks were characterized for physiological and morphological parameters. Significant differences in relative embryo weight and yolk consumption were found between the 2 lines. The modern line was characterized by a higher metabolic rate and rapid growth, supported by higher hemoglobin levels and hematocrit concentrations, whereas the 1986 line had slower metabolism, lower levels of hematocrit and hemoglobin, higher oxygen volume per 1 g of embryonic tissue indicating higher oxygen availability. Both lines exhibited changes in heart rate, and blood parameters corresponding to cardiovascular system adaptation after hypoxic exposure, seemingly implemented to increase oxygen-carrying capacity to the embryo tissues. Our finding stand in agreement that the genetic selection for high growth rate that led to higher metabolism without a fit of the cardiovascular system, increased the imbalance between oxygen supply and demand.

Effects of low oxygen during chorioallantoic membrane development on post-hatch growing performance of broiler chickens

The prenatal circulatory system is adaptive and capable of plasticity designed for the needs of the growing tissue. When a broiler embryo is faced with hypoxic stress, the process of angiogenesis in tissues begins. Exposure to hypoxic conditions of 17% oxygen during the chorioallantoic membrane (CAM) development (E5 to E12) affected the circulatory system and contributed to an increase in the blood oxygen carrying capacity. The present study aimed to evaluate the effects of hypoxic exposure during CAM development on post-hatch performance of broilers and to examine whether hypoxic exposure improved sustainability of birds exposed to acute heat stress.Two consecutive trials, with male broilers from each of the incubation treatments-optimal conditions and exposure to hypoxia of 15 or 17% oxygen, for 12 h/day, during CAM development-were conducted. In experiment 1, 60 male chicks from each group were raised in individual cages. In experiment 2, 160 male chicks from each group were raised in 40-chick pens until marketing. On d 35, 20 birds from each group were transferred to individual cages kept at a temperature of 23°C for 72 h, and then birds were exposed to 35°C for 5 hours. Body temperatures were measured at 0, 2, and 5 h of the heat exposure. In both experiments BW, feed intake, and FCR were recorded. At marketing, chicks were slaughtered, and relative weights of breast muscle, abdominal fat pad, heart, and liver were calculated.Hypoxia treatment resulted in a FCR advantage. Food intake was similar in all treatments, but groups exposed to hypoxia grew better than controls until the age of 35 days. Hypoxia-treated groups had higher relative breast, heart, and liver weights than controls. Body temperatures of hypoxia-treated chickens remained lower during heat stress exposure, and their mortality rate was lower as well. Intermittent exposure to moderate hypoxia during CAM development confers advantages to broilers in feed utilization efficiency and in coping with heat stress. It may be considered as a mitigating step in incubation to facilitate broilers in achieving their full growth potential.

Physiological effects of hypoxic conditions during the plateau period on the chicken embryo

The chick embryo employs several adaptive responses to hypoxic challenges, affecting both metabolism and oxygen (O₂) transport. The present study assessed the effects of hypoxic conditions (17% O₂) during the plateau phase on embryonic metabolic rate, cardiovascular parameters, and development up to hatching. The study was divided into 2 experiments: (1) Control; 17% O₂ for 6h/d on E16-E18 (6H), and 17% O₂ for 12h/d on E16-E18 (12H), and (2) Control; 12H, and 17% O₂ continuously for 72h on E16-E18, (72H). Hypoxic embryos exhibited a significant increase in heart rate and an upward trend starting on E17 in hematocrit and hemoglobin levels. We observed a decrease in metabolism in 12H and 72H embryos during the plateau period; their oxygen consumption as well as yolk consumption were lower compared to Control and they hatched with a significantly lower body temperature, indicating lower heat production. There was no evidence of adaptation or long-term effects of exposure to 17% O₂ for 6h/d. Exposure to 72h of hypoxic conditions led to significant physiological changes and had a detrimental influence on embryonic development and growth. In contrast, exposure to 12h/d produced moderate hypoxic changes, which helped the embryo to cope with the stress without significant influences on its growth and development. The decrease in metabolism may represent a metabolic adaptation through a decrease in resting metabolic rate and lower heat production. Such alterations may affect post-hatch performance and energy allocation between maintenance and growth, especially under stress when there is increased oxygen demand.

Ototoxicity screening of patients treated with streptomycin using distortion product otoacoustic emissions

OBJECTIVE

Pure tone audiometry (PTA) is currently widely used to monitor ototoxicity, but this method is time-consuming. Here we validate distortion product otoacoustic emission (DPOAE) as an instrument for early detection of ototoxicity.

METHODS

A cohort study was performed on newly diagnosed tuberculosis patients who were treated with streptomycin. The patients underwent hearing assessment using conventional PTA and high-frequency DPOAE (8, 9 and 10 kHz) on days 0, 7, 14, 28 and 56 of streptomycin treatment. Detection of ototoxicity according to the duration of streptomycin treatment was compared between DPOAE and PTA.

RESULTS

Of 96 newly diagnosed patients treated with streptomycin, 50 completed the study. During the treatment period, 62.5% of the patients had vertigo, while 37.5% complained of tinnitus. DPOAE detected ototoxicity in 47.7% of the cases at day 7, 66.0% at day 14, 70.0% at day 28 and 77.1% at day 56 of streptomycin treatment. The higher frequencies were affected more by ototoxicity, with significant differences at 8 vs. 9 kHz on all testing days and at 9 vs. 10 kHz except on days 7 and 56 (p < 0.001). Hearing loss was detected by PTA in 2.3% of patients on day 7, in 10.6% on day 14, in 22.0% on day 48 and in 29.2% on day 56.

CONCLUSION

DPOAE is a sensitive tool that can detect early changes in the cochlea due to ototoxicity. Use of DPOAE rather than PTA to screen for ototoxicity could reduce screening time and would allow clinical monitoring of more patients.

Spontaneous closure of a persistent post-traumatic pancreatic fistula in a child: incidental therapeutic effect of ERCP

A child with a post-tramatic pancreatic pseuodocyst developed pancreatic fistula, following percutaneous drainage of the cyst. The fistula output was about 120ml/day and lasted for a month. A diagnostic ERCP revealed main pancreatic duct disruption. The fistula output ceased over the next two days following the ERCP. The patient has been well for the past four years. This patient's immediate recovery after ERCP could possibly be due to dislodgement of a mucus plug by the contrast injected during ERCP. Such a mechanism can explain the previous sporadic reports of spontaneous cure of persistent pancreatic fistulae in children.

Helicobacter pylori related functional dyspepsia in a defined malaysian population

The objective of the study was to determine the prevalence of H. pylori in functional dyspepsia among the three main races in Malaysia. Gastric antral biopsies from 233 (98 males, 135 females; age range: 17-75 years, mean age 39.5 years) patients attending the Universiti Kebangsaan Malaysia (UKM) gastroenterology clinic were assessed for the presence of H. pylori by culture and histology. About a third of the cases (79 of 233 (34%); 34 males, 45 females; mean age 42.6 yrs) were positive for H. pylori. The presence of H. pylori was always associated with antral gastritis. Malay patients were least likely to be positive for H. pylori (10 of 88 (11.4%); 5 males, 5 females; mean age 35.7 yrs) compared to the Chinese (43 of 95 (45%); 19 males; 24 females; mean age 40.2 yrs) and Indian patients (23 of 41 (56%); 10 males, 13 females; mean age 48.1 yrs). We found that H. pylori were most common among Chinese followed by Indians. However, the relative risk for the Indians was 8.58 and 6.29 for the Chinese compared to Malays. We conclude that the prevalence of H. pylori in patients with functional dyspepsia differs considerably with respect to ethnic groups.

Polycystic liver disease treated by fenestration and segmental liver resection

A case of symptomatic polycystic liver disease treated by fenestration and segmental liver resection is reported. The intraoperative use of ultrasound to define the plane of liver resection is emphasised. No significant post-operative complication was encountered. The clinical presentation, management and treatment are discussed.

Antibiotics and immunity: effects of antibiotics on mitogen responsiveness of lymphocytes and interleukin-2 production

The immunomodulating properties of antimicrobial drugs may have important implications in prescriptive practice. This is particularly so for patients whose immune system has been compromised. In this study, tetracycline, cephalothin, rifampicin, polymyxin B and nitrofurantoin reduced mitogen responsiveness of both B and T lymphocytes of mouse spleen cells and human peripheral blood lymphocytes in vitro in a dose-dependent fashion. Ampicillin, chloramphenicol, gentamicin, streptomycin and erythromycin had no effect. In the in vivo study none of the antibiotics affected mouse spleen cell transformation in response to mitogen. The addition of interleukin-2 (IL-2) did not prevent the effect of the antibiotics tested on human lymphocytes in vitro. Cephalothin, chloramphenicol and gentamicin decreased IL-2 production by mouse spleen cells in vitro.

Antibiotics and immunity: effects of antibiotics on natural killer, antibody dependent cell-mediated cytotoxicity and antibody production

We studied the effects of antibiotics on natural killer (NK), antibody dependent cell-mediated cytotoxicity (ADCC) and immunoglobulin production. When human peripheral blood lymphocytes were incubated overnight with the antibiotic before the assay, nitrofurantoin significantly reduced NK but not ADCC activity. Nitrofurantoin also suppressed both spontaneous and interferon-enhanced NK activities in a dose-dependent fashion. Though it did not affect spontaneous ADCC activity, nitrofurantoin suppressed interferon enhancement of ADCC. Chloramphenicol significantly decreased the number of plaque forming cells in mice. In addition to chloramphenicol, tetracycline, rifampicin, cephalothin, polymyxin B and nitrofurantoin reduced mitogen-induced polycloned immunoglobulin synthesis. Results of this study may have clinical relevance, especially in treating immunocompromised patients.