Dirlotapide: a review of its properties and role in the management of obesity in dogs.

Dirlotapide is a microsomal triglyceride transfer protein (MTP) inhibitor developed specifically for canine weight reduction. MTP catalyzes the assembly of triglyceride-rich apolipoprotein-B containing lipoproteins to form chylomicrons in the intestinal mucosa and very low-density lipoproteins in the liver. Following oral administration, dirlotapide has in vivo selectivity for intestinal MTP compared with hepatic MTP. In addition to reducing intestinal fat absorption, dirlotapide also reduces food intake in a dose-dependent manner, probably via increased release of peptide YY into the circulation. The decrease in food intake is responsible for the majority of the weight reduction effect. In clinical use, it is recommended to adjust the dose according to the observed weight loss of each individual. The initial dose of 0.05 mg/kg is doubled after 14 days and then adjusted monthly, the maximum permitted daily dose is 1.0 mg/kg, although doses as high as 10 mg/kg have been administered to dogs without severe adverse experience in safety studies. Dirlotapide can be used without necessitating changes to the current feeding or exercise regimens, but it is desirable to monitor the food intake during weight-stabilization to establish revised feeding and exercise routines that will minimize the risk of weight regain post-treatment. The drug offers a novel approach that is applicable in cases where dietary management alone has proved to be unsuccessful.

Canine obesity: an overview.

Canine patients are generally regarded as being clinically obese when their body weight is at least 15% above ideal. The incidence of obesity in dogs is thought to be in the range of 20-40% of the general population and, since obesity is known to predispose or exacerbate a range of serious medical conditions, its importance cannot be overstated. Management of obesity through dietary restriction and increased exercise is often difficult to achieve and dependent upon owner compliance. Until recently there has been no authorized therapeutic medication available for weight reduction in dogs, and drugs used in people have proved unsuitable. However, with the development of microsomal triglyceride transfer protein inhibitors for canine use, such as dirlotapide, the veterinarian has a novel method with which to augment traditional weight control programmes. This approach has the additional advantage that weight loss is achieved without dietary restriction or change in exercise regimen, providing encouragement for the owner to comply with subsequent dietary and exercise recommendations, thereby increasing the likelihood for long-term success.

Evaluation of dirlotapide for sustained weight loss in overweight Labrador retrievers.

The effects of dirlotapide on body weight (BW) reduction were investigated in overweight Labradors in two parallel-design studies. Study A involved 42 dogs randomized to 0.0, 0.025, 0.05, 0.1, 0.2 or 0.4 mg dirlotapide/kg/day orally for 4 weeks. Study B involved 72 dogs randomized to nine treatments: placebo (24 weeks); dirlotapide (24 weeks) followed by placebo (28 weeks); or dirlotapide (52 weeks); on diets containing 5%, 10% or 15% fat. Dirlotapide dose (initially 0.1 mg/kg) was adjusted monthly during 24-week weight-loss and subsequent 28-week weight-stabilization phases. Food was offered above maintenance energy requirements (MERx 1.1-1.2) based on initial BW. Body composition (body fat, lean tissue and bone mineral content) was monitored using dual-energy X-ray absorptiometry. After treatment, dogs that had received dirlotapide for 52 weeks were fed 90% of quantity consumed at week 52. In study A, BW and food intake decreased asymptotically with dose: mean weekly weight loss exceeded 1% at 0.1-0.4 mg/kg. In study B, dirlotapide resulted in significant mean weekly weight loss (>0.8%) and decreased food intake over 24 weeks compared with placebo (P = 0.0001) for all diets. Food restriction minimized post-treatment weight rebound. Dirlotapide administered daily to dogs for up to 52 weeks was clinically safe and resulted in sustained weight reduction.

An evaluation of dirlotapide to reduce body weight of client-owned dogs in two placebo-controlled clinical studies in Europe.

The clinical efficacy for weight loss and safety of dirlotapide in dogs were evaluated in two multi-centre studies with parallel designs. Overweight, adult dogs (n = 245) of various breeds were randomized to treatment with dirlotapide or placebo in a 2:1 ratio. Dirlotapide was administered orally once daily to dogs at an initial dose of 0.05 mg/kg/day commencing on day 0 and doubled after 14 days. Every 28 days, dogs were examined, weighed, body condition scores (BCS) were recorded, and dose was adjusted to meet weight loss targets. Each study comprised three consecutive phases: weight-loss (up to day 196); weight-stabilization (84 days); and post-treatment (28 days). pre-treatment feeding and exercise regimens were continued during treatment. Dirlotapide-treated dogs showed mean weight loss of 15.9% (study A) and 14.0% (study B) by the end of weight loss phase (up to day 196). Percentage weekly weight losses for dirlotapide were significantly greater than for placebo (P < or = 0.0002). Emesis and diarrhoea were experienced in both treatments but were more frequent with dirlotapide; resolution was spontaneous. BCS improved for 75.7-82.5% of dogs on dirlotapide treatment compared with 15.4-41.4% for placebo. Mean dirlotapide dosage at end of weight-loss phase was 0.38 (study A) and 0.29 (study B) mg/kg initial body weight/day. Dirlotapide was found to be clinically safe and effective in the reduction of body weight in overweight dogs.

Influence of dirlotapide, a microsomal triglyceride transfer protein inhibitor, on the digestibility of a dry expanded diet in adult dogs.

The objectives of this study were to evaluate the effects of dirlotapide, a microsomal triglyceride transfer protein inhibitor, on apparent nutrient digestibility of an expanded dry dog food, on defecation frequency and fecal consistency. Eighteen beagles were randomized to either placebo (n = 6) or dirlotapide (n = 12). Testing was divided into a 21-day adaptation phase (days -21 to -1) and a 35-day treatment (digestibility testing) phase (days 0-35). During the treatment phase, dogs were administered oral dirlotapide (0.3 mg/kg) or placebo (0.06 mL/kg) once daily. For digestibility testing, feces were collected over two periods for 7 days each starting on days -9 and 28. All dogs were fed a commercial adult dog food throughout the study. Food intake was adjusted to maintain body weight during adaptation, followed by pair-feeding placebo dogs the amount of food ingested by the dirlotapide dogs during the treatment period. Dogs in both groups had reduced food intake and lost similar amounts of body weight during treatment. Dogs receiving 0.3 mg dirlotapide/kg once daily had a small but significant (P = 0.018) decrease (6.16 +/- 2.22%, mean +/- SD) in crude fat digestibility compared with the placebo-treated food-restricted dogs, but no difference in crude protein, dry matter, or energy digestibility was observed. Fecal consistency and volume and defecation frequency were similar between groups. Dirlotapide effectively reduced appetite and energy intake without affecting nutrient digestibility, except for a minimal decrease in fat digestibility.

Efficacy and safety of dirlotapide in the management of obese dogs evaluated in two placebo-controlled, masked clinical studies in North America.

Dirlotapide was evaluated in the management of obesity in dogs in two multicenter, clinical studies in North America. A total of 335 obese dogs of various breeds were randomized to dirlotapide or placebo in a 2:1 ratio. Dirlotapide was administered orally once daily to dogs at an initial dose of 0.05 mg/kg, increased after 14 days to 0.1 (study B, label dose) or 0.2 mg/kg (study A) and then adjusted according to individual weight loss at 28-day intervals. Dogs were examined and weighed, and body condition scores (BCSs) were recorded every 28 days. Study A had three consecutive phases: weight loss (16 weeks, day 0-112); weight management (12 weeks); and post-treatment (8 weeks). Study B had a weight loss phase only. For dirlotapide-treated dogs, mean weight loss by day 112 was 11.8-14.0% compared with 3.0-3.9% for placebo (P = 0.0001). In study A, weight losses for dirlotapide were 19.3% after 12 weeks of weight management and 16.7% (regain of 3.4%) by 8 weeks after dirlotapide was discontinued. In both studies, dogs in both treatments had emesis, lethargy, anorexia, diarrhea, and mildly elevated hepatic transaminase activity, that resolved spontaneously with time. These were experienced more frequently with dirlotapide. Improved activity levels and BCS for >50% dogs were reported with dirlotapide. Dirlotapide was safe and effective in the reduction and management of body weight in obese dogs.

Efficacy of tulathromycin in the treatment of respiratory disease in pigs caused by Actinobacillus pleuropneumoniae.

The efficacy of a single dose of tulathromycin, a novel triamilide antimicrobial of the macrolide class, given at 2.5 mg/kg or 5 mg/kg bodyweight, or three daily doses of ceftiofur, given at 3 mg/kg bodyweight, was evaluated in pigs with respiratory disease induced experimentally with Actinobacillus pleuropneumoniae. On day 0, 100 pigs with clinical signs of respiratory disease were randomly assigned to groups of 25 pigs, which were treated with either saline, one of the doses of tulathromycin, or ceftiofur. The pigs' rectal temperatures and clinical scores for respiratory signs and general attitude were recorded daily until day 10. Animals withdrawn from the study for welfare reasons were recorded. On day 10, the animals remaining in the study were weighed, euthanased and examined postmortem. Three of the animals treated with saline and one of those treated with 2.5 mg/kg tulathromycin were withdrawn from the study, but none of those treated with 5 mg/kg tulathromycin or ceftiofur were withdrawn. The least squares mean bodyweight gains of the pigs treated with the antimicrobial agents were significantly (P<0.05) higher than that of the saline-treated group, and the least squares mean percentages of the total lung involvement and incidence of respiratory disease associated with A. pleuropneumoniae were significantly (P<0.05) lower, but there were no significant differences between the three groups of pigs treated with the antimicrobial agents.

Pharmacokinetics and lung tissue concentrations of tulathromycin in swine.

The absolute bioavailability and lung tissue distribution of the triamilide antimicrobial, tulathromycin, were investigated in swine. Fifty-six pigs received 2.5 mg/kg of tulathromycin 10% formulation by either intramuscular (i.m.) or intravenous (i.v.) route in two studies: study A (10 pigs, i.m. and 10 pigs, i.v.) and study B (36 pigs, i.m.). After i.m. administration the mean maximum plasma concentration (C(max)) was 616 ng/mL, which was reached by 0.25 h postinjection (t(max)). The mean apparent elimination half-life (t(1/2)) in plasma was 75.6 h. After i.v. injection plasma clearance (Cl) was 181 mL/kg.h, the volume of distribution at steady-state (V(ss)) was 13.2 L/kg and the elimination t(1/2) was 67.5 h. The systemic bioavailability following i.m. administration was >87% and the ratio of lung drug concentration for i.m. vs. i.v. injection was > or =0.96. Following i.m. administration, a mean tulathromycin concentration of 2840 ng/g was detected in lung tissue at 12 h postdosing. The mean lung C(max) of 3470 ng/g was reached by 24 h postdose (t(max)). Mean lung drug concentrations after 6 and 10 days were 1700 and 1240 ng/g, respectively. The AUC(inf) was 61.4 times greater for the lung than for plasma. The apparent elimination t(1/2) for tulathromycin in the lung was 142 h (6 days). Following i.m. administration to pigs at 2.5 mg/kg body weight, tulathromycin was rapidly absorbed and highly bioavailable. The high distribution to lung and slow elimination following a single dose of tulathromycin, are desirable pharmacokinetic attributes for an antimicrobial drug indicated for the treatment of respiratory disease in swine.

Efficacy of danofloxacin in the treatment of respiratory disease in European cattle.

The efficacy of an injectable formulation of danofloxacin (180 mg/ml) in the treatment of naturally occurring bovine respiratory disease was evaluated in field studies on farms in France, Ireland and the United Kingdom. Cattle aged one week to 15 months with clinical respiratory disease were randomly allocated to treatment with 6 mg/kg danofloxacin or 10 mg/kg tilmicosin, administered by a single subcutaneous injection on day 0. A second injection of danofloxacin was administered on day 2, only if predefined clinical criteria were met. Mannheimia haemolytica, Pasteurella multocida and Haemophilus somnus were isolated from pretreatment nasopharyngeal swabs taken on all the farms. After the treatment, there was a more rapid improvement in the clinical response of the 178 animals treated with danofloxacin by day 2 (P < 0.01) than in the 90 treated with tilmicosin. For both treatments, there were similar significant (P < 0.001) reductions in the mean rectal temperature and severity of clinical signs of abnormal respiration and depression, on days 4 and 10 compared with day 0; 78.1 per cent of the animals treated with danofloxacin and 78.5 per cent of those treated with tilmicosin completed the studies. Danofloxacin 18 per cent was clinically safe and as effective as tilmicosin in the treatment of bovine respiratory disease.

Efficacy of a pour-on formulation of doramectin against lice, mites, and grubs of cattle.

OBJECTIVE: To determine effectiveness of a pour-on formulation of doramectin against Damalinia bovis, Haematopinus eurysternus, Linognathus vituli, Solenopotes capillatus, Chorioptes bovis, Sarcoptes scabiei, Hypoderma bovis, and Hypoderma lineatum. ANIMALS: Cattle of various ages with naturally acquired or artificial infestations with 1 or more species of lice, mites, or grubs. PROCEDURE: In 10 louse and 6 mite studies, cattle were treated with doramectin (500 microg/kg, topically) on day 0, and parasite counts were performed approximately weekly from days 0 to 35. In 6 grub studies, cattle expected to harbor Hypoderma spp were treated before emergence of warbles. After warbles began to emerge, they were counted every 2 weeks, and grubs were collected and identified by species. RESULTS: Burdens of D bovis, H eurystemus, L vituli, and S capillatus on doramectin-treated cattle were 0 by 28 days after treatment. Burdens of C bovis and S scabiei decreased to 0 in naturally infested cattle and approximately 0 in artificially infested cattle by day 14 to 15. In grub studies, 107 of 136 control cattle had warbles, whereas 2 of 136 doramectin-treated cattle had 1 warble each, which represented a cure rate of 98.5%. CONCLUSION AND CLINICAL RELEVANCE: One topical application of doramectin was highly efficacious against common species of lice, mites, and grubs known to affect performance, health, and appearance of cattle.

Validation of a sensitive radioimmunoassay to measure serum follicle-stimulating hormone in cattle: correlation with biological activity.

Meaningful biological interpretation of the role of follicle-stimulating hormone (FSH) requires use of a validated radioimmunoassay (RIA) that closely estimates biologically active FSH, which was the objective of this work. Three FSH antibodies [NIDDK anti ovine FSH (oFSH); JAD anti oFSH; USDA anti bFSH] were screened against three tracer preparations [USDA oFSH-19-SIAFP-I2(USDA oFSH I2); LER1976a oFSH; USDA bFSH I2] in a RIA using USDA bFSH B1 or I2 as the assay standard. Sera obtained from three heifers at 4- to 8-h intervals for 5 days after injection of PGF2 alpha during the luteal phase were assayed for both FSH immunoactivity using each of the three optimized assay formats (NIDDK anti oFSH and JAD anti oFSH with USDA oFSH I2 as tracer; USDA anti bFSH with USDA bFSH I2 as tracer), and FSH bioactivity, using a rat Sertoli cell bioassay. Cross reactivity of bLH (NIH bLH B9) in all three assay formats was minimal (0.7, 0.9 and < 0.4% at 50% binding for the NIDDK, JAD and USDA antibodies, respectively). There was parallel displacement of tracer between bovine serum dilutions of 10 to 500 microliters and the two FSH standards. Correlations between JAD and USDA RIA data and bioassay results were not significant (P > or = 0.10), but were significant (r = 0.78; P = 0.0001) for the NIDDK RIA FSH and the bioactive FSH measurements. The assay sensitivity of the NIDDK RIA was 0.55 ng USDA bFSH B1 (0.013 ng USDA bFSH I2)/ml. The inter- and intra-assay CV were between 5.8 and 7.9 %. This RIA detected a pre-ovulatory FSH surge coincident with the LH surge, in all heifers studied. Furthermore, the emergence of each wave of follicle growth (up to day 12 of the cycle), was preceded by a transient increase (P < 0.02; days 0.5 to 1.5 and 8 to 10.5 of the cycle) in serum FSH, while LH concentrations remained unchanged. In conclusion, the RIA utilising NIDDK anti oFSH and USDA oFSH I2 as tracer provides a good estimate of bioactive FSH in cattle, and detects physiologically relevant increases in serum FSH related to emergency of each new wave of follicle growth.

A clinical study of the hydroxyapatite orbital implant.

The hydroxyapatite orbital implant has been used in the anophthalmic patient to give good motility of the artificial eye and a cosmetic result which matches that of the natural eye. It is thought to reduce the unacceptable complication rate that has been associated with other implants, as its buried, vascularized state deters extrusion and migration of the implant. Eighty consecutive patients were followed, 33 of whom had been referred for primary enucleation or evisceration, and 47 for secondary implant surgery. Thirteen of the secondary patients already had implants in situ. There were 44 males and 36 females in the study. The age range was 2.5 to 72 years with a mean of 36 years. The follow-up time was 2 to 30 months with a mean of 15 months. Twenty patients had been pegged at the time of review. A standardised operative and post-operative protocol was followed. The patients were assessed for the results of the motility of the artificial eye for both smooth pursuit and saccades, and for the cosmetic result. The amount of upper lid sulcus deformity was assessed to give an indication of volume replacement by the implant. The nature of any complications was noted as well as any further surgical procedures undertaken. The results show the hydroxyapatite orbital implant to give good cosmetic results with good motility of the artificial eye and to be associated with a low rate of complications. Drilling of the implant is simple to perform and also not associated with any significant complications. The hydroxyapatite orbital implant can be used successfully not only as a primary but also as a secondary or exchange implant with very few contraindications.

Alterations in intrafollicular levels of different molecular mass forms of inhibin during development of follicular- and luteal-phase dominant follicles in heifers.

The experiment reported here characterized changes in serum concentrations of FSH, follicular fluid (FF) concentrations of immunoreactive alpha inhibins and dimeric inhibins, and different molecular forms of inhibin during development of dominant follicles in both luteal and follicular phases of the estrous cycle in heifers. Follicular status was determined daily by ultrasound examination of ovaries, and blood samples were taken at 4-6-h intervals. Heifers (5-6 per treatment) were ovariectomized on Days 0 (follicular phase, pre-LH surge), 1-Ov (post-LH surge, preovulation), 1 + Ov (postovulation), 3 (selection phase), 6 (dominance phase), and 12 (atretic phase) of the estrous cycle. Follicles were classified on the basis of FF estradiol (E) to progesterone (P) ratio and by ultrasound morphology. Concentrations of E, P, immunoreactive alpha inhibin, LH, and FSH were determined by RIA, and concentrations of dimeric inhibins were determined by a two-site dimeric-specific immunoradiometric assay (IRMA); the different molecular mass forms of inhibin were determined by immunoblot analysis. Serum FSH was transiently elevated during Days 0.5-1.5 and 8-10.5, in association with emergence of each new wave of follicular growth. The follicular-phase dominant follicle of heifers before the preovulatory LH/FSH surge had less immunoreactive alpha inhibin and 29-kDa inhibin but more 110-kDa inhibin compared with concentrations after the surge (p < 0.05). During growth of the dominant follicle between Days 3 and 6, there were no changes in either proportions or amounts of any inhibin forms (p > 0.05). However, while concentrations of dimeric inhibins decreased between Days 1 and 6, the concentration of immunoreactive alpha inhibin increased (p < 0.05). Atresia of the luteal-phase dominant follicle during Days 6-12 was associated with a decrease in amounts and proportions of the 110- and > 160-kDa forms, an increase in amounts and proportions of the 34-kDa form, and an increase in dimeric inhibin concentration (p < 0.05). Alterations in FF E concentrations were positively correlated with changes in amounts of the 77- and 110-kDa precursor forms of inhibin, but negatively correlated with 34-kDa inhibin. The results of this experiment demonstrate that 1) seven different molecular mass forms of inhibin were present in bovine FF during all stages of development of follicular- and luteal-phase dominant follicles examined, 2) amounts and proportions of most inhibin forms are altered differently in follicular- and luteal-phase dominant follicles, 3) FF inhibins and E are regulated by different factors, and 4) RIA, IRMA, and immunoblot measurements of inhibin in bovine FF produced divergent results.

The hydroxyapatite orbital implant: a prospective study.

The hydroxyapatite orbital implant was first released for use as an orbital implant in humans in August 1989. It has been shown to be well tolerated, providing good motility of the artificial eye with a low complication rate when used as a primary implant. This prospective study evaluated the hydroxyapatite orbital implant used as both a primary and a secondary implant. Sixty patients were implanted between October 1992 and November 1994, 28 being implanted as a primary procedure at the time of enucleation or evisceration, and 32 as a secondary procedure. Seven patients underwent second-stage drilling and pegging of the implant. The mean follow-up time was 13 months (range 2-26 months). A standardised operative and post-operative protocol was followed. The patients were evaluated post-operatively for the amount of enophthalmos, degree of upper lid sulcus deformity, motility of the prosthesis, location of the implant in the socket, socket status and the presence or absence of discharge, position of the drill hole and coverage of the implant. Complications and their management were documented. Both patient and surgeon made a subjective assessment of cosmesis and the patient's satisfaction with the overall result was noted. The results of this study show the hydroxyapatite orbital implant to provide excellent motility of the artificial eye and good cosmesis with a low rate of complications when used both as a primary and as a secondary implant.

Effect of photoperiod before and after birth on puberty in ewe lambs.

Previous studies have shown that exposure to long days followed by short days after 12 wk of age advances the onset of puberty in ewe lambs. The aim of this experiment was to determine whether or not puberty would be advanced by exposure of lambs to such a photoperiodic regime when the long days were given before birth and the short days immediately after birth. Ewes kept in natural photoperiod (NP) were housed on January 15 and allocated at random to one of four treatments: 1) NP/NP, natural photoperiod before and after parturition (n = 26); 2) SD/SD, short days (SD; 9L:15D) before and after parturition (n = 27); 3) LD/NP, long days (LD; 18L:6D) before parturition and NP after parturition (n = 27); and 4) LD/SD, LD before parturition and SD after parturition (n = 26). Mean (+/- SEM) birth date for all lambs was March 20 +/- 1 day, and the number of days of exposure to long and short days prior to parturition was 64 +/- 2 and 67 +/- 2 days, respectively. From ewes on the four treatments, 24, 20, 14, and 16 female lambs, respectively, were reared. Lambs were weighed at birth and at weekly intervals after weaning. Reproductive activity in ewe lambs was assessed from serum progesterone concentrations in blood samples collected twice weekly from August 1 until puberty was reached or the experiment terminated on November 17 (34 wk after birth).(ABSTRACT TRUNCATED AT 250 WORDS)

Use of Proplast II as a subperiosteal implant for the correction of anophthalmic enophthalmos.

BACKGROUND: A variety of autogenous and alloplastic materials have been used as subperiosteal implants to correct anophthalmic enophthalmos. Proplast II is a synthetic porous composite of Teflon polymer and alumina. Proplast II offers a number of advantages over other commonly used alloplastic materials such as silicone and polymethyl methacrylate. It is light, porous, resilient, malleable, and easy to shape. It can be readily sterilised after shaping. It has been found to integrate with the surrounding tissues, thereby minimising the risk of subsequent implant migration and extrusion. METHODS: Proplast II was used as a subperiosteal implant in a total of 15 anophthalmic patients during the period June 1990 to March 1994. The indication for this procedure in all patients was poor orbital volume replacement despite the prior insertion of an adequately sized spherical socket implant. RESULTS: The results were excellent with a good correction of preoperative upper eyelid sulcus deformity. There were no operative complications nor any serious postoperative complications. The implants were well tolerated. CONCLUSION: Proplast II can be highly recommended for use as a subperiosteal implant.

Selection, dominance and atresia of follicles during the oestrous cycle of heifers.

This study examined the correlation between measurement of follicle growth by ultrasound, and measurement of intrafollicular ratios of oestradiol and progesterone concentrations and the serum concentrations of FSH during selection, dominance and atresia or ovulation of dominant follicles in heifers. Heifers were ovariectomized on days 0 (before LH surge), 1 (after LH surge, preovulation), 1 (postovulation), 3, 6 and 12 of the oestrous cycle. Blood samples were collected at 4-6 h intervals. After ovariectomy all follicles > or = 5 mm were measured and follicular fluid was aspirated. Follicles were classified by size according to ultrasound (F1, largest; F2, second largest; F3, all remaining follicles > or = 5 mm) and by the ratio of oestradiol:progesterone concentrations. During the follicular phase, a single dominant oestrogen-active follicle increased in diameter while serum concentrations of LH increased and FSH decreased (P < 0.05). On day 1 (after LH surge, preovulation), serum LH and FSH decreased to pre-surge concentrations (P < 0.0001), while follicle size and intrafollicular progesterone concentration increased and oestradiol concentration decreased (P < 0.05). A dominant nonovulatory follicle, classified as oestrogen-active on days 1, 3 and 6 and oestrogen-inactive on day 12, increased in size from day 1 to day 7 and lost dominance during days 10-12, coincident with the growth of multiple oestrogen-active follicles. The serum FSH concentration increased transiently (P < 0.05) before each new wave of dominant follicular growth. The overall correlation of ultrasound measurements of follicle diameter with measures of follicle size after ovariectomy was high.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of the presence of male and female flockmates on reproductive activity in ewes.

Four experiments were carried out to determine the effect of the presence of ewes and rams on the reproductive state of ewes. In Expt 1, the breeding season of ewes kept with a vasectomized ram ended later (April 18 +/- 8 days; mean +/- SEM) than that of ewes isolated from rams (6 March +/- 7 days; P < 0.01). In Expt 2, the end of the breeding season was later (5 May +/- 6 days; P < 0.05) and the onset of the next breeding season earlier (29 September +/- 2 days; P < 0.001) in ewes maintained with rams, compared with ewes isolated from rams (14 April +/- 7 days and 1 November +/- 2 days, respectively). There was no difference in the timing of, or variation in, reproductive transitions between ewes maintained either as individuals or in groups. In Expt 3, all ewes exposed to artificial short days from the date of the winter solstice and interrupted with 35 long days in spring resumed cyclicity (median date, 7 September; range, 59 days). Most ewes (seven of nine) exposed to short days from the date of the winter solstice and isolated from other ewes did not resume cyclicity in the following 11 months. In contrast, all ewes resumed cyclicity (median date, 19 October; range, 144 days) when exposed to short days but housed in social contact with other ewes that became reproductively active in early September; however, the onset of cyclicity was later than in ewes exposed to long days (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

The 'baseball' orbital implant: a prospective study.

The 'baseball' orbital implant was described by Frueh and Felker in 1976. Although this implant was originally described for use as a secondary implant, it has also been widely used as a primary implant at the time of enucleation. This prospective study evaluated the effectiveness of this implant used both primarily and secondarily. Forty-four patients were implanted between April 1990 and May 1991, 19 of the implants being primary and 25 secondary. A standardised operative and post-operative protocol was followed. The mean follow-up time was 31 months (range 24-36 months). The patients were evaluated for the degree of volume replacement, implant and associated prosthesis motility, secondary eyelid and socket problems, patient satisfaction, the need for further surgery and post-operative complications. The overall results achieved by primary implantation were superior to those of secondary implantation. Our results suggest that this implant provides a satisfactory functional and cosmetic rehabilitation of the anophthalmic patient with few complications.