Lack of effects of atrazine on estrogen-responsive organs and circulating hormone concentrations in sexually immature female Japanese quail (Coturnix coturnix japonica).

The widely used herbicide, atrazine, has been reported to exhibit reproductive toxicity in rats and amphibians. The present studies investigate toxicity of atrazine in Japanese quail and its ability to influence reproduction in sexually immature females. Atrazine was administered in the diet at concentrations from 0.001 to 1000 ppm (approximately 109 mg kg-1 per day) or systemically via daily subcutaneous injections (1 and 10 mg kg-1) or Silastic implants. Atrazine did not cause overt toxicity in sexually immature female quail (no effects on change in body weight, feed intake, mortality or on circulating concentrations of the stress hormone, corticosterone). It was hypothesized that if atrazine were to have estrogenic activity or to enhance endogenous estrogen production, there would be marked increases in the weights of estrogen sensitive tissues including the oviduct, the liver and the ovary together with changes in gonadotropin secretion. However, atrazine had no effect on either liver or ovary weights. Atrazine in the diet increased oviduct weights at 0.1 and 1 ppm in some studies. These effects were not consistently observed and were not significant when data from studies were combined. Systemic administration of atrazine had no effect on oviduct weights. Dietary (concentrations from 0.001 to 1000 ppm) and systemically administered atrazine had no effect on circulating concentrations of luteinizing hormone (LH). The present studies provide evidence for a lack of general or reproductive toxicity of atrazine in birds.

Changes in tissue nitrite concentration in the crop of the turkey poult in response to Salmonella typhimurium challenge.

The present study examines whether Salmonella typhimurium colonization of the crop of young turkeys influences nitrite concentration in the component tissues of the crop. Nitric oxide (NO) is the principal compound in biological samples that is converted into nitrites and NO is known to be a component of the early host response to infection. Challenge with S. typhimurium increased the concentration of nitrite in the crop wall of 3-wk-old turkey poults. The magnitude of the response was reduced at 8 h and absent at 48 h after challenge. As would be expected, S. typhimurium concentrations in the crop were markedly increased following challenge, and were nondetectable in control poults.

Evaluation of corn furan fatty acid putative endocrine disruptors on reproductive performance in adult female chickens.

Based on evidence from rodent models, it was hypothesized that furan fatty acids found in corn would inhibit reproduction in the laying hen. An isomeric mixture of furan fatty acids [9, (12)-oxy-10,13-dihydroxystearic acid and 10, (13)-oxy-9,12-dihydroxystearic acid] was administered for a period of 3 wk via the diet (1 and 3 ppm) at levels greater than those in corn to 20-wk-old pullets. There were no overt indications of acute or chronic toxicity (no effects on mortality, feed intake, or average daily gain). Similarly, there was no dose-dependent effect on reproductive parameters [egg production, egg weight, shell thickness, ovarian weight, number or weight of large yolky preovulatory follicles, and number of small yellow follicles (4-8 mm in diameter)]. The present data do not suggest that furan fatty acids are a cause of concern to the poultry industry.

A multicenter comparison of isradipine and felodipine in the treatment of mild-to-moderate hypertension. The Physician's Study Group.

The objective of this study was to compare the tolerability of isradipine and felodipine in patients with mild-to-moderate hypertension. Following a 4-week placebo run-in, 143 patients entered a 12-week double-blind multicenter study. Patients were randomized to receive either isradipine (n = 72) or felodipine (n = 71) at a dose of 2.5 mg twice daily. Dose-doubling and the addition of enalapril (2.5 mg once daily) was permitted if diastolic blood pressure (DBP) was > 90 mm Hg at weeks 4 and 8, respectively. Isradipine reduced blood pressure from 165/104 +/- 13/6 mm Hg at baseline to 144/88 +/- 13/8 mm Hg at week 12 (P < .001) whereas felodipine reduced blood pressure from 171/104 +/- 17/6 mm Hg at baseline to 150/92 +/- 19/9 mm Hg at week 12 (P < .001). Similar incidences of headache, flushing, dizziness and tachycardia were reported in both groups. However, the incidence of ankle edema was significantly lower in the isradipine group (14% v 30%) (P = .028). It is concluded that isradipine represents a practical improvement over felodipine in the treatment of hypertension.

Direct replacement of failed CP titanium implants with larger-diameter, HA-coated Ti-6Al-4V implants: report of five cases.

Failure to osseointegrate traditionally mandates immediate implant removal, followed by a 1-year healing period before placing a second implant into the same area. This report presents five cases in which failed screw-type, commercially pure titanium implants were immediately replaced by ledge-type, hydroxyapatite-coated, Ti-6Al-4V implants in the same sockets. These cases suggest that the 1-year healing period may not be necessary, provided that (1) the socket can be reprepared to eliminate thread grooves and invasive soft tissue, (2) the replacement implant is larger in diameter than the original implant, and (3) sufficient available bone remains for the procedures.

Altered passive eruption: the undiagnosed entity.

Excessive gingiva can result from delayed or altered tooth eruption. This condition should be considered in restorative dentistry, orthodontic and esthetic treatment.

Routine anaerobic bacterial culture and systemic antibiotic usage in the treatment of adult periodontitis: a 6-year longitudinal study.

This investigation evaluated the efficacy of obtaining baseline culture and sensitivity data on a routine basis from the patient with adult periodontitis. Patients diagnosed with chronic adult periodontitis, rapidly progressive periodontitis, or refractory periodontitis were followed for up to 6 years. More than 95% of patients with chronic adult periodontitis were successfully treated with mechanical therapy alone. Approximately one half of the patients with rapidly progressive periodontitis were treated successfully without antibiotics. All of the patients with refractory periodontitis required systemic antibiotics as part of treatment. Most patients with chronic adult periodontitis exhibited one or two species of organisms at baseline, and these organisms were eliminated or reduced to low levels by mechanical therapy. In contrast, patients with rapidly progressive or refractory periodontitis consistently demonstrated multiple species and required systemic antibiotics in conjunction with mechanical therapy to alter the subgingival microbial milieu. Routine culturing and antibiotic therapy is contraindicated in patients with chronic adult periodontitis, but may be beneficial for successful treatment of patients with rapidly progressive or refractory periodontitis.

Guided tissue regeneration and GTAM for periodontal regenerative therapy, ridge augmentation and dental implantology.

In dentistry, the goals of regenerative therapy are to gain new attachment around natural teeth, improve the aesthetics and ridge form in cases of collapsed or deformed ridges and increase the amount of available bone for osseointegrated implants. The purpose of this paper is to describe the dental and periodontal applications of the principles of guided tissue regeneration (GTR) and guided tissue augmentation material (GTAM) therapy. Successful results can be achieved around periodontally diseased natural teeth, however, the procedures are not fully predictable at this time. Correct membrane placement and proper choice of defect configuration in the use of GTR can enhance clinical attempts to gain new attachment. Regenerative therapy can be utilized to augment edentulous ridges and improve ridge-pontic relationships as well as improve aesthetics in ridge abnormalities. Edentulous ridges augmented by GTR can have increased amount of bone height and width for endosseous implant placement. In areas where non-mobile implant fixtures have lost some osseous support, GTR has demonstrated successful gain of new bone support.

A calcitonin receptor (CALCR) single nucleotide polymorphism is associated with growth performance and bone integrity in response to dietary phosphorus deficiency.

Although concerns over the environmental impact of excess P in the excreta from pig production and governmental regulations have driven research toward reducing dietary supplementation of P to swine diets for over a decade, recent dramatic increases in feed costs have further motivated researchers to identify means to further reduce dietary P supplementation. We have demonstrated that genetic background impacts P utilization in young pigs and have identified genetic polymorphisms in several target genes related to mineral utilization. In this study, we examined the impact of a SNP in the calcitonin receptor gene (CALCR) on P utilization in growing pigs. In Exp. 1, 36 gilts representing the 3 genotypes identified by this CALCR SNP (11, 12, and 22) were fed a P-adequate (PA) or a marginally P-deficient (approximately 20% less available P; PD) diet for 14 wk. As expected, P deficiency reduced plasma P concentration, bone strength, and mineral content (P < 0.05). However, the dietary P deficiency was mild enough to not affect the growth performance of these pigs. A genotype x dietary P interaction (P < 0.05) was observed in measures of bone integrity and mineral content, with the greatest reduction in bone strength and mineral content due to dietary P deficiency being associated with the allele 1. In Exp. 2, 168 pigs from a control line and low residual feed intake (RFI) line were genotyped for the CALCR SNP and fed a PA diet. As expected, pigs from the low RFI line consumed less feed but also gained less BW when compared with the control line (P < 0.05). Although ADFI did not differ between genotypes, pigs having the 11 genotype gained less BW (P < 0.05) than pigs having the 12 or 22 genotypes. Pigs of the 11 and 12 genotypes had bones that tolerated greater load when compared with animals having the 22 genotype (P < 0.05). A similar trend was observed in bone modulus and ash % (P < 0.10). These data are supportive of the association of this CALCR SNP with bone integrity and its response to dietary P restriction. Although the allele 1 is associated with greater bone integrity and mineral content during adequate P nutrition, it is also associated with the greatest loss in bone integrity and mineral content in response to dietary P restriction. Understanding the underlying genetic mechanisms that regulate P utilization may lead to novel strategies to produce more environmentally friendly pigs.

Response to dietary phosphorus deficiency is affected by genetic background in growing pigs.

Concern over the environmental effect of P excretion from pig production has led to reduced dietary P supplementation. To examine how genetics influence P utilization, 94 gilts sired by 2 genetic lines (PIC337 and PIC280) were housed individually and fed either a P-adequate diet (PA) or a 20% P-deficient diet (PD) for 14 wk. Initially and monthly, blood samples were collected and BW recorded after an overnight fast. Growth performance and plasma indicators of P status were determined monthly. At the end of the trial, carcass traits, meat quality, bone strength, and ash percentage were determined. Pigs fed the PD diet had decreased (P < 0.05) plasma P concentrations and poorer G:F (P < 0.05) over the length of the trial. After 4 wk on trial, pigs fed the PD diet had increased (P < 0.05) plasma 1,25(OH)(2)D(3) and decreased (P < 0.05) plasma parathyroid hormone compared with those fed the PA diet. At the end of the trial, pigs fed the PD diet had decreased (P < 0.05) BW, HCW, and percentage fat-free lean and tended to have decreased LM area (P = 0.06) and marbling (P = 0.09) and greater (P = 0.12) 10th-rib backfat than pigs fed the PA diet. Additionally, animals fed the PD diet had weaker bones and also decreased (P < 0.05) ash percentage and increased (P < 0.05) concentrations of 1alpha-hydroxylase and parathyroid hormone receptor mRNA in kidney tissue. Regardless of dietary treatment, PIC337-sired pigs consumed more feed and gained more BW than their PIC280-sired counterparts (P < 0.05) during the study. The PIC337-sired pigs also had greater (P < 0.05) HCW, larger (P < 0.01) LM area, and tended to have (P = 0.07) greater dressing percentage. Meat from the PIC337-sired pigs also tended to have greater (P = 0.12) concentrations of lactate but decreased (P = 0.07) concentrations of total glucose units 24 h postslaughter. Although plasma 1,25(OH)(2)D(3) concentrations were elevated (P < 0.05) in all the animals fed the PD diet, this elevation due to P deficiency tended (P = 0.09) to be greater in the PIC337-sired pigs after 12 wk on the treatment. The PIC337-sired pigs had stronger (P < 0.01) bones with greater ash percentage than the PIC280-sired pigs. The difference in the strength of the radii between the PIC337-sired pigs fed the PA and PD diets was greater than their PIC280-sired counterparts, which resulted in sire line x treatment interactions (P < 0.05). These data indicate differing mechanisms of P utilization between these genetic lines. Elucidating these mechanisms may lead to strategies to increase efficiency of growth in a more environmentally friendly manner.

Dietary inclusion of colicin e1 is effective in preventing postweaning diarrhea caused by F18-positive Escherichia coli in pigs.

With worldwide concern over the use of antibiotics in animal agriculture and their contribution to the spread of antibiotic resistance, alternatives to conventional antibiotics are needed. Previous research in our laboratories has shown that colicin E1 is effective against some Escherichia coli strains responsible for postweaning diarrhea (PWD) in vitro. In this study we examined the efficacy of the dietary inclusion of colicin E1 in preventing experimentally induced PWD caused by F18-positive enterotoxigenic E. coli in young pigs. Twenty-four weaned pigs (23 days of age), identified by genotyping to be susceptible to F18-positive E. coli infections, were individually housed and fed diets containing 0, 11, or 16.5 mg colicin E1/kg diet. Two days after the start of the trial, all animals were orally inoculated with 1 x 10(9) CFU of each of two F18-positive E. coli strains isolated from pigs with PWD. The dietary inclusion of colicin E1 decreased the incidence and severity of PWD caused by F18-positive enterotoxigenic E. coli and improved the growth performance of the piglets. Additionally, the reduced incidence of PWD due to dietary colicin E1, lowered the levels of expression of the genes for interleukin 1beta and tumor necrosis factor beta in ileal tissues from these animals. The dietary inclusion of colicin E1 may be an effective alternative to conventional antibiotics in the diets of weaning pigs for the prevention of PWD caused by F18-positive enterotoxigenic E. coli.

Effects of Lactobacilli and lactose on Salmonella typhimurium colonisation and microbial fermentation in the crop of the young turkey.

1. Three experiments were performed to examine the effects of Lactobacilli and lactose on microbial fermentation and Salmonella enterica serovar Typhimurium colonisation in the crop of the young turkey. 2. The following carboxylic acids were detected in the crop ingesta: formic, acetic, butyric, lactic, valeric, caproic, oxalic, phenyl acetic, succinic and fumaric; propionic, isobutyric and isovaleric acids were not detectable. 3. At the beginning of the night, there were considerable quantities of ingesta in the crop of young turkeys. During the scotophase, there were progressive reductions in the contents and pH. Moreover, there were linear increases in the concentration of lactic, valeric and caproic acids (by approximately 7-fold over 8 h). Much smaller changes in crop pH were observed in the study where dietary treatments of Lactobacilli were not included. 4. Chronic addition of lactose or Lactobacilli to the diet exerted modest effects on the carboxylic acid concentration in the crop contents but did not consistently influence colonisation of the crop by Salmonella enterica serovar Typhimurium. 5. Young turkeys confine eating to the hours of illumination (photophase) with a peak in consumption prior to the subjective dusk.

The effect of cigarette smoking on the long-term success of guided tissue regeneration: a preliminary study.

Regenerative therapy has provided the clinician with an alternative to traditional procedures such as osseous surgery. However, there is a deficiency of data and research on long-term success of guided tissue regeneration (GTR). The purpose of this paper is to report the findings of a preliminary long-term clinical study of GTR in Class II furcation defects. In a private practice setting, 38 e-PTFE barrier membranes were placed in 38 periodontal Class II furcation lesions in patients diagnosed with chronic adult periodontitis (1 defect per patient). These patients were followed from 4 to 7 years. There were 21 maxillary Class II furcation defects and 17 mandibular Class II furcation defects. All patients had a non-contributory medical history; however, in retrospective examination, many of these patients smoked at least 10 cigarettes per day for at least 5 years. In this study, results after 4 to 7 years revealed a 58 per cent success rate and a 42 per cent failure rate: 80 per cent of the failures were in smokers. In this study, GTR in furcation defects was not as successful as previously reported in the literature from a clinical point of view and the success rate was significantly lower when a patient was a smoker.

A comparison of isradipine and felodipine in Australian patients with hypertension: focus on ankle oedema. The Physician's Study Group.

The aim of this study was to compare the tolerability and efficacy of isradipine and felodipine in the treatment of mild-moderate hypertension. After a 4 week placebo period, 143 patients entered a randomized, double-blind, multicentre study of 12 weeks duration. Patients received either isradipine (n = 72) or felodipine (n = 71) 2.5 mg twice daily. Doubling of this dose and the addition of enalapril (2.5 mg once daily) was permitted if DBP was > 90 mmHg at weeks 4 and 8, respectively. Isradipine monotherapy reduced BP from 165/104 +/- 13/6 mmHg at baseline to 149/91 +/- 14/10 mmHg at week 8 (p < 0.001), while felodipine alone reduced BP from 171/104 +/- 17/6 at baseline to 151/92 +/- 19/9 (p < 0.001). Following the addition of enalapril to 35% of patients in the isradipine group BP was further reduced to 144/88 +/- 13/8 mmHg at week 12 (p < 0.001). The addition of enalapril to 24% of the felodipine group further reduced BP to 150/92 +/- 19/9 mmHg at week 12 (p < 0.001). No differences in BP were found between the 2 groups while on monotherapy. However, the isradipine group had a significantly lower DBP than the felodipine group at the conclusion of the study (p = 0.008; 95% CI 0.7 to 6.9 mmHg). Similar incidences of headache, flushing, dizziness and tachycardia were reported in both groups. However, the incidence of ankle oedema was significantly lower in the isradipine group (p = 0.028). Overall, ankle oedema was reported more often by female patients and was not associated with an increase in weight.(ABSTRACT TRUNCATED AT 250 WORDS)

Periodontal considerations for esthetics: edentulous ridge augmentation.

Edentulous ridge augmentation is a plastic surgical technique that is performed to improve patient esthetics when unsightly, deformed ridges exist. This article describes the etiology of ridge deformities and the many procedures that can be executed to achieve an esthetic, functional result. Historically, soft-tissue mucogingival techniques were described to augment collapsed ridges. Pedicle grafts, free soft-tissue grafts, and subepithelial connective tissue grafts are predictable forms of therapy. More recently, ridge augmentation techniques were developed that regenerate the lost periodontium. These include allografts, bioglasses, guided tissue regenerative procedures, and tissue expansion.