Endogenous synthesis of arginine plays an important role in maintaining arginine homeostasis in postweaning growing pigs

This study was conducted to determine whether endogenous synthesis of arginine plays a role in regulating arginine homeostasis in postweaning pigs. Pigs were fed a sorghum-based diet containing 0. 98% arginine and were used for studies at 75 d of age (28.4 kg body weight). Mitochondria were prepared from the jejunum and other major tissues for measuring the activities of Delta1-pyrroline-5-carboxylate (P5C) synthase and proline oxidase (enzymes catalyzing P5C synthesis from glutamate and proline, respectively) and of ornithine aminotransferase (OAT) (the enzyme catalyzing the interconversion of P5C into ornithine). For metabolic studies, jejunal enterocytes were incubated at 37 degrees C for 30 min in Krebs-Henseleit bicarbonate buffer containing 2 mmol/L L-glutamine, 2 mmol/L L-[U-14C]proline, and 0-200 micromol/L gabaculine (an inhibitor of OAT). The activities of P5C synthase, proline oxidase and OAT were greatest in enterocytes among all of the tissues studied. Incubation of enterocytes with gabaculine resulted in decreases (P < 0.05) in the synthesis of ornithine and citrulline from glutamine and proline. When gabaculine was orally administered to pigs (0.83 mg/kg body weight) to inhibit intestinal synthesis of citrulline from glutamine and proline, plasma concentrations of citrulline (-26%) and arginine (-22%) decreased (P < 0.05), whereas those of alanine (+21%), ornithine (+17%), proline (+107%), taurine (+56%) and branched-chain amino acids (+21-40%) increased (P < 0.05). On the basis of dietary arginine intake and estimated arginine utilization, the endogenous synthesis of arginine in the 28-kg pig provided >/=50.2% of total daily arginine requirement. Taken together, our results suggest an important role for endogenous synthesis of arginine in regulating arginine homeostasis in postweaning growing pigs, as previously shown in neonatal pigs.     

The coming of age of agroforestry

The success of modern agricultural and forestry production can be largely attributed to monoculture systems using a few select species. In the drive for maximizing yield and profit, the age‐old tradition of using combined farming systems was essentially avoided and in some cases this has resulted in environmental problems such as land and water degradation and increased land clearing. During the last 30 years, however, the positive benefits of agroforestry to the producer and the environment have been increasingly recognized. Combining trees and crops in spatial or temporal arrangements has been shown to improve food and nutritional security and mitigate environmental degradation, offering a sustainable alternative to monoculture production. By providing supportive and complimentary roles with a flexible approach, agroforestry can offer specific social and environmental benefits across a range of landscapes and economies. More research and effort is needed to explore the full potential of agroforestry applications and to fuel awareness. As the plethora of benefits of agroforestry are realized, modern land‐use systems are evolving towards a more sustainable and holistic approach to land management. Copyright © 2007 Society of Chemical Industry     

Cortical and hippocampal volume deficits in temporal lobe epilepsy

PURPOSE: To use quantitative magnetic resonance imaging (MRI) methods to examine the extent of volume abnormalities in the hippocampus and in extrahippocampal brain regions in localization-related epilepsy of temporal lobe origin (TLE). METHODS: Hippocampal, temporal lobe, and extratemporal lobe volumes were examined with 3-mm spin-echo coronal MRI scans in patients with unilateral TLE who were candidates for temporal lobe resection. Measures were adjusted for normal variation due to intracranial volume and age based on 72 healthy male controls. Group differences between 14 male TLE [7 left TLE (LTLE), 7 right TLE (RTLE)] patients and a subset of 49 age range-matched controls were examined with analysis of variance (ANOVA). RESULTS: As compared with controls, patients with TLE had smaller temporal lobe and frontoparietal region gray matter volumes, bilaterally, smaller temporal lobe white matter volumes bilaterally, and larger ventricular volumes. In contrast to these bilateral tissue volume deficits, hippocampal volume deficits in TLE were ipsilateral to the epileptogenic temporal lobe. CONCLUSIONS: Extrahippocampal volume abnormalities were bilateral and occurred in both temporal and extra-temporal cortical regions in TLE, whereas hippocampal deficits were related to the side of the epileptogenic focus. These data suggest that brain abnormalities in TLE are not limited to the epileptogenic region.     

Lichtenstein herniotomy

All standard methods of hernia repair involve suturing together tissues which are not normally in apposition. This violates the basic surgical principle that tissue must never be approximated under tension and accounts for an unacceptable number of failures. Total reinforcement of the inguinal floor with a sheet of suitable biomaterial and employment of a "tension-free" technique is a more effective approach. Since June 1984, 3250 primary inguinal hernias have been repaired at the Lichtenstein Hernia Institute by the open tension-free technique using Marlex mesh. All operations were performed under local anesthesia. Patients were discharged from the hospital within two or four hours after the operation. The patients were followed from one to 8 years by physician examination. The follow-up rate was 87%. There were four recurrences. The causes of recurrence and how to avoid them are discussed.     

The limit of viability--neonatal outcome of infants born at 22 to 25 weeks' gestation

BACKGROUND: With improved survival of preterm infants, questions have been raised about the limit of viability. To provide better information and counseling for parents of infants about to be delivered after 22 to 25 weeks' gestation, we evaluated the mortality and neonatal morbidity of preterm infants born at these gestational ages. METHODS: We studied retrospectively all 142 infants born at 22 to 25 weeks' gestation (as judged by best obstetrical estimate) from May 1988 through September 1991 in a single hospital. Mortality in the first six months, including stillbirths, and neonatal morbidity (i.e., the presence of intracranial pathologic conditions, chronic lung disease, and retinopathy of prematurity) were analyzed. RESULTS: Fifty-six infants (39 percent) survived for six months. Survival improved with increasing gestational age; none of 29 infants born at 22 weeks' gestation survived, as compared with 6 of 40 (15 percent) born at 23 weeks, 19 of 34 (56 percent) born at 24 weeks, and 31 of 39 (79 percent) born at 25 weeks. There were seven stillbirths at 22 weeks' gestation and four stillbirths at 23 weeks. The more immature the infant, the higher the incidence of neonatal complications as determined by the number of days of mechanical ventilation, the length of the hospital stay, and the presence of retinopathy of prematurity, periventricular or intraventricular hemorrhage, or periventricular leukomalacia. Only 2 percent of infants born at 23 weeks' gestation survived without severe abnormalities on cranial ultrasonography, as compared with 21 percent of those born at 24 weeks and 69 percent of those born at 25 weeks. CONCLUSIONS: We believe that aggressive resuscitation of infants born at 25 weeks' gestation is indicated, but not of those born at 22 weeks. Whether the occasional child who is born at 23 or 24 weeks' gestation and does well justifies the considerable mortality and morbidity of the majority is a question that should be discussed by parents, health care providers, and society.