Fetal tissue repair and wound healing

The fibrosis and scar formation that characterize adult wound healing are also the cause of clinical problems; scar contracture, hypertrophic scar, and pulmonary and hepatic fibrosis are only a few examples. Studies of fetal wound healing can provide an insight into the initiation and regulation of a scarless repair process akin to regeneration. Studies of fetal repair have already suggested mechanisms that might favorably alter adult healing. Topical application of hyaluronic acid to wounds in adult diabetic rats leads to enhanced epithelial migration. It has been recognized that the addition of TGF-beta to fetal wounds causes an adultlike healing response with fibrosis and inflammation. A subsequent study using neutralizing antibody to TGF-beta in adult wounds showed enhanced healing with a more normal dermal architecture with fewer macrophages, fewer blood vessels, and less collagen. As our understanding of regenerative tissue repair increases, the opportunities to modulate adult fibrotic conditions should expand.     

Hematological and blood chemical values of mallard, Anas p. platyrhynchos, drakes before, during and after remige moult

Hematological and blood chemical values were determined for wild and captive mallards, Anas p. platyrhynchos, for the late spring period prior to remige moult through early fall migration. Hemoglobin, packed cell volume, erythrocyte and total leukocyte counts, as well as the number of heterophils and lymphocytes, declined significantly during and after remige moult compared to values recorded prior to remige moult. During fall migration mallard drakes had elevated levels of glucose and uric acid. No significant changes were observed in total protein, alkaline phosphatase, glutamic oxaloacetic transaminase or creatine phosphokinase in pre- or post-moult periods. The hematological and biochemical values should prove useful in providing background information on mallard drakes, and documenting baseline data for intra and interspecies comparisons with diseased birds.     

Preparation and characterization of freeze-dried chitosan-poly(ethylene oxide) hydrogels for site-specific antibiotic delivery in the stomach

Sotos syndrome is included among the overgrowth disorders, most of which have an increased risk of neoplasms. Sotos syndrome does not appear to be related to a specific tumor type, but rather to the development of solid tumors of ectodermal or mesodermal origin in general. We report on two Sotos syndrome patients who developed a non-Hodgkin lymphoma and an acute lymphoblastic leukaemia, respectively. Our experience suggests that there may exist a high frequency of lymphoproliferative disorders in Sotos syndrome, and points out the importance of a long-term follow-up of Sotos syndrome patients, to detect a possible neoplastic evolution.     

Adverse drug reactions in pediatrics with a study of in-hospital intensive surveillance

A two-part prospective study of adverse drug reactions (ADRs) in Indian children was carried out at a teaching general hospital. Using an in-hospital intensive surveillance scheme (IISS) for the detection of ADRs, indoor patients of one of the two units in the pediatric ward were monitored daily for 6 months, with the other unit serving as a control group. A total of 347 patients were monitored, 2781 daily orders written and 24,474 doses of 96 different drugs given. Six patients suffered from ADRs (1.73%), and 1 reaction proved fatal (0.29%), while the control group reported only 1 ADR in the same time period. The frequency of ADRs (p < 0.001) and their resultant mortality in Indian children was less than that in a western prototype study. Though IISS showed a marked increase in ADR reporting, it was too cumbersome for routine use in our country. In the second part of the study, 40 cases of ADRs seen over 2 years were analyzed. Antimicrobials, especially sulphonamides, accounted for a high percentage of cases mostly as skin rashes and fairly severe reactions were common. Patients on anti-tuberculous and anti-convulsant drugs required prolonged supervision for late onset reactions.     

Effect of induced subclinical hypocalcemia on physiological responses and neutrophil function in dairy cows

The objectives were to study the effects of induced subclinical hypocalcemia [SCH, blood ionized Ca (iCa²⁺) <1.0 mM, without recumbency] on physiological responses and function of immune cells in dairy cows. Ten nonpregnant, nonlactating Holstein cows were blocked by lactation and assigned randomly to a normocalcemic (NC; intravenous infusion of 0.9% NaCl i.v. plus 43 g of oral Ca, as Ca sulfate and Ca chloride, at −1 and 11 h) or an induced SCH [SCHI, 5% ethylene glycol tetraacetic acid (EGTA), a selective iCa²⁺ chelator, intravenous infusion] treatment for 24 h, using a crossover design. The sequence of treatments was either NC–SCHI or SCHI–NC, with a 6-d washout period. Ionized Ca was evaluated before, hourly during the infusion period, and at 48 and 72 h, to monitor concentrations and adjust the rate of infusion, maintaining blood iCa²⁺ <1.0 mM in SCHI throughout the 24-h infusion period. Additional measurements included heart and respiratory rates, rectal temperature, dry matter intake, rumen contractions, whole-blood pH, concentrations of glucose and K in whole blood, concentrations of total Ca, Mg, nonesterified fatty acids, β-hydroxybutyrate, and insulin in plasma, and urinary excretion of Ca. Total and differential leukocyte count in blood was also performed. The concentration of cytosolic iCa²⁺ in neutrophils and lymphocytes was quantified and neutrophil function was assayed in vitro. Infusion of a 5% EGTA solution successfully induced SCH in all SCHI cows, resulting in decreased blood iCa²⁺ concentrations throughout the 24-h treatment period (0.77 ± 0.01 vs. 1.26 ± 0.01 mM iCa²⁺). Induction of SCH reduced dry matter intake on the day of infusion (5.3 ± 0.8 vs. 9.1 ± 0.8 kg/d) and rumen contractions (1.9 ± 0.2 vs. 2.7 ± 0.2 contractions/2 min) for the last 12 h of infusion. Cows in SCHI had decreased plasma insulin concentration (1.44 ± 0.23 vs. 2.32 ± 0.23 ng/mL) evident between 6 and 18 h after the beginning of the infusion, accompanied by increased concentrations of glucose (4.40 ± 0.04 vs. 4.17 ± 0.04 mM). Plasma nonesterified fatty acids concentration was greater for SCHI than NC cows (0.110 ± 0.019 vs. 0.061 ± 0.014 mM). Neutrophils of cows in SCHI had a faster decrease in cytosolic iCa²⁺ after stimulation with ionomycin (9.9 ± 1.0 vs. 13.6 ± 1.4 Fluo-4:Fura Red post-end ratio) in vitro. Furthermore, induction of SCH reduced the percentage of neutrophils undergoing phagocytosis (22.1 ± 2.1 vs. 29.3 ± 2.1%) and reduced the oxidative burst response after incubation of pathogenic bacteria (16.1 ± 1.7 vs. 24.2 ± 1.7%). Subclinical hypocalcemia compromised appetite, altered metabolism, and impaired function of immune cells in dairy cows.     

Effects of supplementation with ruminally protected choline on performance of multiparous Holstein cows did not depend upon prepartum caloric intake

Objectives were to evaluate the effect of prepartum energy intake on performance of dairy cows supplemented with or without ruminally protected choline (RPC; 0 or 17.3 g/d of choline chloride; 0 or 60 g/d of ReaShure, Balchem Corp., New Hampton, NY). At 47 ± 6 d before the expected calving date, 93 multiparous Holstein cows were assigned randomly to 1 of 4 dietary treatments in a 2 × 2 factorial arrangement. Cows were fed energy to excess [EXE; 1.63 Mcal of net energy for lactation/kg of dry matter (DM)] or to maintenance (MNE; 1.40 Mcal of net energy for lactation/kg of DM) in ad libitum amounts throughout the nonlactating period. The RPC was top-dressed for 17 ± 4.6 d prepartum through 21 d postpartum (PP). After calving, cows were fed the same methionine-balanced diet, apart from RPC supplementation, through 15 wk PP. Liver was biopsied at ?14, 7, 14, and 21 d relative to parturition. Cows fed EXE or MNE diets, respectively, consumed 40 or 10% more Mcal/d than required at 15 d before parturition. Cows fed the MNE compared with the EXE diet prepartum consumed 1.2 kg/d more DM postpartum but did not produce more milk (41.6 vs. 43.1 kg/d). Thus, PP cows fed the EXE diet prepartum were in greater mean negative energy balance, tended to have greater mean concentrations of circulating insulin, fatty acids, and β-hydroxybutyrate, and had greater triacylglycerol in liver tissue (8.3 vs. 10.7% of DM) compared with cows fed the MNE diet prepartum. Cows fed RPC in transition tended to produce more milk (43.5 vs. 41.3 kg/d) and energy-corrected milk (44.2 vs. 42.0 kg/d) without increasing DM intake (23.8 vs. 23.2 kg/d) during the first 15 wk PP, and tended to produce more milk over the first 40 wk PP (37.1 vs. 35.0 kg/d). Energy balance of cows fed RPC was more negative at wk 2, 3, and 6 PP, but mean circulating concentrations of fatty acids and β-hydroxybutyrate did not differ from those of cows not fed RPC. Despite differences in energy balance at 2 and 3 wk PP, mean concentration of hepatic triacylglycerol did not differ between RPC treatments. Feeding RPC reduced the daily prevalence of subclinical hypocalcemia from 25.5 to 10.5%, as defined by concentrations of total Ca of <8.0 mg/dL in serum in the first 7 d PP. Pregnancy at first artificial insemination tended to be greater for cows fed RPC (41.3 vs. 23.6%), but the proportion of pregnant cows did not differ by 40 wk PP. Heifers born from singleton calvings from cows fed RPC tended to experience greater daily gain between birth and 50 wk of age than heifers from cows not supplemented with RPC. Feeding RPC for approximately 38 d during the transition period tended to increase yield of milk for 40 wk regardless of amount of energy consumed during the pregnant, nonlactating period.     

Short communication: Effects of the progesterone receptor variants on fertility traits in cattle

The progesterone receptor (PGR) gene is a key factor in the initiation and maintenance of pregnancy and in embryo development. Currently, it is unknown what variants of the PGR gene are related to fertility traits in cattle. Identification of such variants would allow the implementation of marker-assisted selection in breeding schemes. The objective of this study was to investigate the association of single nucleotide polymorphisms (SNP) of PGR with fertility traits in Holstein dairy cattle. An in vitro fertilization system was used to maximize the efficiency of the identification of genetic factors affecting fertility. This in vitro fertilization system would allow the assessment of fertilization and embryonic survival rates independently of influences from the uterine environment. A total of 5,566 fertilization attempts were performed, and a total of 3,679 embryos were produced using oocytes from 324 Holstein cows and semen from 10 Holstein bulls. Sequencing of pooled DNA samples from ovaries revealed an SNP (G/C) in intron 3 of PGR. A generalized linear model was used to analyze the association of this SNP with fertilization and embryonic survival rates for each ovary. Oocytes obtained from CC ovaries showed a 61% fertilization rate, compared with 68 and 69% for GC and GG ovaries, respectively. The survival rate of embryos produced from GG ovaries was 5 and 6% higher than that of GC and CC ovaries. These results indicate that the PGR SNP could be used in marker-assisted selection breeding programs in Holstein dairy cattle.     

Localisation of insulin-like growth factor-I (IGF-I) immunoreactivity in the olivocerebellar system of developing and adult rats

The molecular mechanisms which underlie the development of the olivocerebellar topography are not fully understood. Insulin-like growth factor-I (IGF-I) is a growth factor known to play important roles in neural development and it has been identified within the cerebellum and the inferior olive. To assess the contribution of IGF-I to the development of climbing fibre topography, the distribution of IGF-I-like immunoreactivity (IGF-I IR) was identified in the cerebellar cortex and inferior olive of rats, 0, 3, 5, 7, 10, 15, 21, 28 and 90 days old. In the cerebellar cortex, IGF-I IR was localised solely to Purkinje cells and its distribution was spatially and temporally regulated in a manner which coincides with climbing fibre development. At birth, weak IGF-I IR was detected in a few Purkinje cells in the ventral vermis. More Purkinje cells became positive until at postnatal day 7(P7) all Purkinje cells displayed IGF-I IR. Subsequently, a subpopulation of Purkinje cells lost their reactivity for IGF-I to leave IGF-I-positive cells organised into sagittal bands by P15. IGF-I IR was also seen in all subdivisions of the inferior olive between birth and P10 in a distribution which paralleled the maturation of the inferior olive. The Purkinje cell and inferior olivary IGF-I IR parallels climbing fibre development and thus the results of this study support the hypothesis that IGF-I is involved in the development of climbing fibre topography.