Canine reproductive ultrasound examination for predicting future sperm quality.

The reproductive potential of male animals is commonly evaluated using a breeding soundness examination incorporating B-mode ultrasound examination of the testes and recently Doppler ultrasound examination of the testicular arteries. These techniques may detect testicular normality or pathology, and while some measured parameters are associated with semen quality at the time of ultrasound examination, few studies have investigated the relationship with future semen quality. We hypothesized that B-mode and Doppler ultrasound measurements would correlate with future semen quality. Within two studies, we investigated the relationship between ultrasound measured testicular volume, testicular echogenicity, testicular homogeneity, subjective assessment of the testicular parenchyma, testicular artery resistance index, and pulsatility index with subsequent semen quality. Fifty-five normal fertile dogs of which 29 had stable semen quality and 26 had a subsequent decline in semen quality were examined during a 6-month period commencing 62 days after the ultrasound examination. Statistical analysis showed that no ultrasound parameters were predictive of future total sperm output or percentage live normal sperm. However, mean testicular echogenicity was positively related to future sperm motility (t = 2.202, p = .039). We conclude that quantitative ultrasound assessment of the appearance of the testicular parenchyma has potential for the evaluation of future semen quality in dogs.

Stimulation of mating-induced uterine contractions in the bitch and their modification and enhancement of fertility by prostatic fluid.

Little is known about the response of the bitch's reproductive tract to mating or of the role of male accessory gland secretions in the female. In this clinical study, the component stimuli causing mating-induced uterine contractions were investigated in 64 bitches. Basal uterine contractions were present during oestrus and a significant increase in the frequency of contractions was observed during natural mating. Neither teasing with a male nor stimulation of the vagina or cervix by vaginal or transcervical insemination (TCI) caused an increase in the frequency of uterine contractions. Increased contractions were however present after both vaginal and transcervical insemination when the vestibule was distended, and dorsal wall of the vaginal was manually stimulated. Interestingly, this increase in uterine contractions was partially ameliorated when prostatic fluid was used as a flushing component following transcervical insemination. Two further studies performed with 72 bitches of which 18 were each inseminated transcervically with fresh or frozen semen flushed into the uterus with either saline or prostatic fluid demonstrated that prostatic fluid significantly increased the pregnancy rate and litter size of both groups. There are important mechanisms regulating the transport and elimination of sperm from the bitch's reproductive tract. Whilst physical aspects of coitus are undoubtedly involved in initiating uterine contractions, prostatic fluid appears to have an important role in modulating uterine contractions and fertility.

Normal and abnormal response to sperm deposition in female dogs: A review and new hypotheses for endometritis.

In mammalian species there are significant physiological responses of the female reproductive tract to the deposition of sperm. These are particularly notable in species where sperm are deposited directly into the uterus, and function both to facilitate sperm transport to the sperm reservoir, and to eliminate introduced contaminants. In the bitch, sperm are deposited into the vagina and are rapidly transported through the open cervix. Sperm are then distributed around the uterus by uterine contractions such that transportation to the tip of the uterine horns occurs within 1 min of the start of mating. The main sperm reservoir appears to be the distal part of the utero-tubal junction which forms a pre-uterine tube reservoir. Sperm remain attached here by their heads to uterine epithelium and remain viable. In non-capacitating conditions sperm slowly detach from this site and this seems important to replenish the uterine tube reservoir, where sperm may re-attach to the epithelium. Post-ovulatory signals trigger capacitation changes and subsequent hyperactivated motility that is associated with detachment of sperm from both reservoirs; thus facilitating fertilization. After mating, a physiological post-mating uterine inflammatory response occurs, evidenced by an influx of polymorphonuclear neutrophils, increased uterine contractions, an increased uterine artery blood flow and a decrease of the resistance index indicating a short-duration vasodilation. Disturbance of this tightly regulated system has the potential to impact fertility by a failure of elimination of the introduced contaminants (such that a clinically-significant post-breeding endometritis ensues) but also by impairing sperm transport.

Contribution of genomics to bacterial pathogenesis.

Genomics is changing the landscape of modern biology. The impact is far-reaching because it provides both the most economical means of acquiring large amounts of information and because it has forced the creation of new technologies to exploit this information. Five of the six genomes published in the year from August 1998 to August 1999 were human pathogens, all of which are highly host-adapted. Four of these are obligate intracellular pathogens and the study of these genomes is providing novel insights into the intricacies of pathogen-host interactions and co-evolution. These genomes are also significant because they mark the beginning of an important trend in the sequencing of closely related genomes, including the sequencing of more than one strain from a single pathogenic species. As comparative genomics truly comes of age, the ability to compare the genomes of pathogenic and non-pathogenic organisms will hopefully provide insight into what makes certain bacterial strains and species pathogens.

Incidence and impact of dog attacks on guide dogs in the UK: an update.

Data on dog attacks on Guide Dogs' stock were reviewed to investigate the characteristics of the attacks. An average of 11.2 attacks occurred each month. Nearly all of the attacks occurred in public areas, 68.4 per cent of victim dogs were qualified guide dogs and 55.5 per cent of victim dogs were working in harness when they were attacked. Guide Dogs' stock were injured in 43.2 per cent of attacks and veterinary costs for attacks were estimated at £34,514.30. Over 40 per cent of qualified guide dogs' working ability was affected and >20 per cent of qualified guide dogs required some time off from working after a dog attack. Twenty dogs were permanently withdrawn from the Guide Dogs' programme as a result of dog attacks, 13 of which were qualified and working with guide dog owners at the time of the withdrawal; this resulted in a financial cost of >£600,000 to the charity. More importantly perhaps, temporary and permanent withdrawals have a significant impact upon the mobility and independence of guide dog owners and in many cases significantly impacted their emotional well-being.

Thoracoscopic debridement of empyema thoracis.

BACKGROUND: The primary treatment of empyema thoracis remains intercostal tube drainage together with antibiotics. Failure of primary treatment has until recently been an indication for thoracotomy and decortication. Video-assisted thoracoscopic debridement (VATD) has increased the available treatment options but requires validation. METHODS: A retrospective analysis was undertaken of 44 consecutive patients who presented for surgical treatment of empyema thoracis over a 3-year period. RESULTS: Two patients were unsuitable for VATD and were treated with open decortication (OD). Thirty patients were successfully treated by VATD. Two patients were converted to OD at the first operation, and 10 patients required OD as a second procedure. The mean duration of preoperative symptoms before referral was 37.6 +/- 11.8 days (VATD) and 40.1 +/- 11.6 days (OD) (p = not significant). The mean duration of hospitalization before transfer was 13.7 +/- 2.4 days (VATD) and 11.5 +/- 3.4 days (OD) (p = not significant). Intercostal drainage was required for 4.0 +/- 0.3 days (VATD) and 8.5 +/- 2.0 days (OD) (p = 0.004). The postoperative hospital stay was 5.3 +/- 0.4 days (VATD) and 10.3 +/- 2.1 days (OD) (p = 0.001). CONCLUSIONS: Primary surgical therapy with VATD should be considered for all patients with pleural empyema, irrespective of the duration of symptoms. This approach does not preclude OD as a secondary procedure or conversion to OD after initial thoracoscopic assessment. The major advantages of VATD over OD are a shorter duration of postoperative intercostal drainage and reduced postoperative hospitalization.

Primary esophageal repair for Boerhaave's syndrome.

BACKGROUND: Boerhaave's syndrome is the most sinister cause of esophageal perforation. The mediastinal contamination with microorganisms, gastric acid, and digestive enzymes results in a mediastinitis that is often fatal if untreated. METHODS: We present a series of 21 patients seen in our unit in the 10 years 1987 to 1996. Esophageal repair was performed in 17 (81%) of them. After the resuscitation of the patient in the intensive care unit, our strategy is primary esophageal repair with a single layer of interrupted absorbable sutures combined with mediastinal toilet, mediastinal drainage, and drainage gastrostomy. The majority of patients (12/21) were referred more than 24 hours after perforation. RESULTS: The mean age of the patients was 60+/-17 years. The mean stay in the intensive care unit was 1.6+/-1.8 days and the median hospital stay, 14 days. There were three deaths, an overall mortality rate of 14.3%. CONCLUSIONS: When combined with mediastinal toilet, mediastinal drainage, and drainage gastrostomy, primary esophageal repair for Boerhaave's syndrome gives an acceptable mortality and should not be reserved for patients seen within 24 hours after spontaneous rupture.

Iatrogenic oesophageal perforations: a clinical review.

Thirty patients with iatrogenically induced perforation of the oesophagus were managed in our unit between January 1986 and December 1996. Thirteen (43%) of these injuries were referred after upper gastrointestinal endoscopy performed by physicians. Ten (33%) cases were referred by ENT surgeons and general surgeons referred 7 (23%) cases. Of these patients, 15 (50%) had no abnormality of the oesophagus found before perforation. Only 18 (60%) of patients were referred within 24 h of injury. The mean duration of care required in the intensive care unit was 1.5 days +/- 2.5 days and the mean inpatient hospital stay 26.5 days +/- 22.1 days. The mortality was 10% (three cases). Oesophageal perforation remains a serious life-threatening injury. The early diagnosis of this uncommon condition requires a high index of suspicion as the symptoms are often non-specific. Identification of the site of perforation is necessary as the management of cervical and thoracic perforations differs considerably. Early referral combined with appropriate therapy would appear to result in a better outcome than previously published data. It is therefore suggested that patients with this relatively rare condition should be referred as soon as possible to a centre with expertise in its management.

Double-ended pigtail polyethylene stents in management of benign and malignant ureteric obstruction.

Surgical urinary diversion for incurable pelvic malignancy has a high morbidity and mortality, and external drainage provides less than ideal palliation. Six patients with ureteric obstruction caused by cancer have been managed by operative or endoscopic insertion of self-retaining polyethylene tubes. These techniques also have applications in non-malignant disease, and the treatment of two patients with benign ureteric stricture is described.

A joint health and social services initiative for children with disabilities.

The children's disability team in Cambridge provides an integrated health and social care service for children with complex learning and physical disabilities and their families. The team uses a multidisciplinary and multi-agency teamwork approach to care provision. The effectiveness of the team was evaluated using a cooperative review of its functions, in which all the 'subjects' were active participants in defining and delivering the evaluation. This was combined with individual questionnaires regarding the team's perceived strengths and weaknesses. Particular implications for training and supervision emerged from the findings. This article discusses the ways in which the team has successfully refined its practice of collaborative working in a developmental way between 1992-1998.

Periovulatory changes in the endoscopic appearance of the reproductive tract and teasing behavior in the bitch.

A variety of diagnostic techniques have been applied to address the problem of determining optimal mating time in the bitch, although some have not been objectively investigated. Nine healthy bitches were examined daily using routine clinical methods as part of their normal breeding management with the aim of establishing which method was most useful. Accordingly, measurement of the degree of vulval swelling, endoscopic measurement of the vaginal mucosal color and appearance, and objective evaluation of behavior of the bitch were related to the time of ovulation (calculated when progesterone reached 5 ng/mL; Day 0) and the duration of the fertilization period (Day 2 to Day 5) determined by measurement of plasma progesterone concentration and assessment of vaginal cytology. There was a surprisingly large individual variation in measurements of vulval swelling, such that although trends were apparent this technique was not precise enough to establish the optimal mating time. However, measuring color saturation and vaginal mucosal fold width was successful. A consistent change in the mucosal color saturation was observed that related to the beginning (Day -5) and duration of the fertile period although there was no difference in measurement of color saturation between Day -5 and Day 2 (P = 0.31), and Day 2 and Day 5 (P = 0.43). The vaginal mucosal folds were smaller in width at the beginning of the fertilization period (Day 2) than at the beginning of the fertile period (Day -5) (P = 0.008), and all bitches had a consistent appearance of mucosal contours on Day 3. Assessment of sexual behavior was not considered precise enough to enable determination of the optimal time for mating because of the large amount of individual variation in behavioral scores. There was no difference in female behavior scores between Day -5 and Day 2 (P = 0.29), or between Day 2 and Day 5 (P = 0.06). Using objective techniques this study has quantified changes in the color and fold width of the vaginal mucosa that have previously only been subjectively reported. These changes can be used to identify the fertilization period and it is possible, with future refining of the technique, that endoscopic examination could replace vaginal cytology to be used in conjunction with plasma progesterone concentration when examining bitches to determine the optimal time to breed.

Delayed uterine fluid clearance and reduced uterine perfusion in bitches with endometrial hyperplasia and clinical management with postmating antibiotic.

In many species a transient uterine inflammatory response follows mating and is proposed to remove excess spermatozoa, bacteria, and other contaminants from the uterus. Similar events have been documented in the bitch involving increased uterine contractions, polymorphonuclear neutrophil influx and uterine artery vasodilation. Some healthy bitches with endometrial hyperplasia have increased numbers of uterine luminal polymorphonuclear neutrophils after mating and reduced fertility; it is purported that this represents a presumed postmating endometritis. This study used B-mode and Doppler ultrasonography at the time of mating to measure uterine contractions, clearance of ejaculated fluid, and uterine artery velocity in normal bitches and those with endometrial hyperplasia. Mating resulted in an increase in the number of uterine contractions, although fewer mating-induced contractions were noted in bitches with endometrial hyperplasia. Interestingly, uterine fluid cleared significantly more slowly after mating from the bitches with endometrial hyperplasia than the normal bitches (P = 0.01). In a further study, Doppler ultrasonography showed that in normal bitches there was a significant increase in uterine artery blood velocity (P = 0.04) and a decrease in the resistance index after mating (P = 0.04), indicating vasodilation. In bitches with endometrial hyperplasia the baseline resistance index was significantly higher than normal bitches (P = 0.05), and furthermore, although there was a significant decrease in resistance index after mating, in the bitches with endometrial hyperplasia this was of a smaller magnitude that in normal bitches. These findings indicate lower baseline uterine perfusion, and a blunted vasodilation response to mating in bitches with endometrial hyperplasia. Short-duration postmating administration of systemic antibiotic increased pregnancy rates in bitches with endometrial hyperplasia (P < 0.01). Litter sizes in bitches with endometrial hyperplasia were lower than those of normal bitches both before and after treatment with postmating antibiotic (P = 0.04 and < 0.01, respectively). Mating-induced endometritis in bitches with endometrial hyperplasia appears to affect fertility by reducing the uterine vasodilatory response to mating and delaying clearance of uterine fluid as a result of decreased uterine contractions but the effect can be ameliorated in part by the postmating administration of antibiotic.

Fertility and whelping complications in bitches following correction of vaginal abnormalities.

The fertility and whelping complications of normal bitches and of bitches that had had surgery to correct a vaginal abnormality of varying severities were compared retrospectively. Reproductive performance and whelping statistics were compared between 37 bitches that had been diagnosed with a vaginal abnormality and 37 age- and breed-matched bitches with no history of vaginal abnormalities. There were no significant differences in reproductive performance between the affected and control bitches. When analysed by the severity of the abnormality, pregnancy rates were significantly lower for the group of bitches with the most severe abnormalities compared with the group of bitches that had mild vaginal abnormalities. Furthermore, the bitches that had severe abnormalities were significantly more likely to require a caesarean section than those with mild abnormalities.

Technical and financial evaluation of assays for progesterone in canine practice in the UK.

The concentration of progesterone was measured in 60 plasma samples from bitches at various stages of the oestrous cycle, using commercially available quantitative and semi-quantitative ELISA test kits, as well as by two commercial laboratories undertaking radioimmunoassay (RIA). The RIA, which was assumed to be the 'gold standard' in terms of reliability and accuracy, was the most expensive method when analysing more than one sample per week, and had the longest delay in obtaining results, but had minimal requirements for practice staff time. When compared with the RIA, the quantitative ELISA had a strong positive correlation (r=0.97, P<0.05) and a sensitivity and specificity of 70.6 per cent and 100.0 per cent, respectively, and positive and negative predictive values of 100.0 per cent and 71.0 per cent, respectively, with an overall accuracy of 90.0 per cent. This method was the least expensive when analysing five or more samples per week, but had longer turnaround times than that of the semi-quantitative ELISA and required more staff time. When compared with the RIA, the semi-quantitative ELISA had a sensitivity and specificity of 100.0 per cent and 95.5 per cent, respectively, and positive and negative predictive values of 73.9 per cent and 77.8 per cent, respectively, with an overall accuracy of 89.2 per cent. This method was more expensive than the quantitative ELISA when analysing five or more samples per week, but had the shortest turnaround time and low requirements in terms of staff time.

Quality assurance of canine vaginal cytology: a preliminary study.

Regulatory controls of quality assurance in veterinary laboratories are less common than in human reproduction laboratories and the intra- and inter-technician variation in the assessment of canine vaginal cytology has not been reported. This study was designed to determine whether variation in classification of vaginal epithelial cells and interpretation of vaginal cytology smears existed within and between technicians in a canine reproductive laboratory. Sixteen vaginal cytology smears representing different known stages of the oestrous cycle were examined twice by one experienced technician and three inexperienced technicians in a blinded random order study design. Seven assessments were made; counting and classifying one hundred vaginal epithelial cells into four morphological classifications and assessment of three cellular categories. Technicians also interpreted their results and reported the stage of the cycle they thought each slide represented. In addition, selected samples were sent to four external commercial laboratories for interpretation. For the experienced technician, intra-technician variation was low for the morphological classifications and cellular assessments (r = 0.69-0.95). There was more intra-technician variation between results from Examination One and Examination Two for the inexperienced technicians (r = 0.53-0.92 where correlations were found). When inexperienced technicians' results were compared to results from the experienced technician, the inter-technician variation was low; results were correlated for 17 of the 21 observations (four morphological classifications and three cellular assessments across the three technicians) (r = 0.38-0.87). When technician interpretations of stage of the oestrous cycle were compared to the known stage of the cycle for each smear, the experienced technician correctly interpreted 19 of the 32 smears, whilst the three inexperienced technicians correctly interpreted 14, 16, and 18 of the 32 smears. The interpretation of vaginal smears by external laboratories was varied and sometimes inconclusive; 50% of laboratories incorrectly identified metoestrus smears as proestrus and 25% of the laboratories incorrectly identified an oestrus smear as proestrus. The results of this study are highly important for clinicians undertaking canine reproductive assessments since they demonstrate the potential for variability of results. While the greatest precision was found when vaginal smears were examined by an experienced technician (who, on a daily basis, examines many smears), more variability in both the reporting of different cell types and interpretation of the smears was observed by inexperienced technicians and when samples were sent to external commercial laboratories. These findings suggest that suitable quality control programmes should be implemented for laboratories that are undertaking routine assessments of canine reproductive function.

Incidence and impact of dog attacks on guide dogs in the UK.

In a retrospective survey, researchers identified 100 incidents of attacks on guide dogs by other dogs. These were reviewed in order to determine the number, severity and impact on the handler and dog, and the characteristics of the aggressors and victims. During the study period there were more than three attacks reported each month, with 61 per cent of the attacks being upon dogs that were in harness and working with an owner or trainer. The majority of the dogs that were attacked were male (62 per cent), and the breeds that were over-represented (relative to their prevalence in the general guide dog population) were the labrador and the golden retriever x flat-coated retriever crossbreed. Most of the attacks occurred in public places between 09.00 and 15.00 and the majority (61 per cent) of the attacking dogs were off the lead at the time of the attack. Thirty-eight per cent of the attacking dogs were of bull breeds, which were over-represented among attackers compared with the proportion of this breed type in the general dog population. Veterinary attention was sought after 41 per cent of the attacks, and in 19 per cent of instances there was injury to the handler or to a member of the public. The attacks were reported to have affected the working performance and behaviour of the victim dog in 45 per cent of the instances, and two dogs had to be subsequently withdrawn from working as guide dogs.

Host and environmental factors associated with Hib in England, 1998-2002.

BACKGROUND: Declining effectiveness of the UK's Hib vaccine programme was observed between 1998 and 2002. OBJECTIVE: To provide insight into non-vaccine factors contributing to ongoing Hib disease in England after immunisation. DESIGN: Postal questionnaire study, matched case-control design. SETTING: Health Protection Agency Centre for Infections, England. PATIENTS: Cases were children born after 1 January 1993 presenting with confirmed Hib infection in England between the start of 1998 and end of 2002, regardless of vaccination status. Controls were matched by date of birth and region. MAIN OUTCOME MEASURES: Odds ratios were calculated to assess the impact of host and environmental variables on disease risk. RESULTS: Increased disease risk was noted among children with frequent antibiotic use (adjusted OR (AOR) (trend) 1.51 (95% CI 1.06 to 2.13); p = 0.02) and from sole-parent households (AOR 2.56 (95% CI 1.24 to 5.29); p = 0.01). These two risk factors were further related to each other, consistent with previously reported associations between infection and social deprivation. In fully immunised children, receipt of all three doses of the primary course as an acellular pertussis-containing combination vaccine (DTaP-Hib) increased the risk of vaccine failure (OR 2.88 (95% CI 0.99 to 8.37), p = 0.01). Day care attendance between 2 and 5 years of age was linked with a dose-dependent reduction in risk (AOR (trend) 0.79 (95% CI 0.66 to 0.93); p = 0.01), possibly because of natural boosting of immunity. CONCLUSIONS: The association noted between invasive infection and social deprivation in this and other studies is concerning and merits further investigation. The importance of ongoing surveillance of vaccine-preventable diseases to allow nested studies of this kind was reinforced.

Challenge of investigating biologically relevant functions of virulence factors in bacterial pathogens.

Recent innovations have increased enormously the opportunities for investigating the molecular basis of bacterial pathogenicity, including the availability of whole-genome sequences, techniques for identifying key virulence genes, and the use of microarrays and proteomics. These methods should provide powerful tools for analysing the patterns of gene expression and function required for investigating host-microbe interactions in vivo. But, the challenge is exacting. Pathogenicity is a complex phenotype and the reductionist approach does not adequately address the eclectic and variable outcomes of host-microbe interactions, including evolutionary dynamics and ecological factors. There are difficulties in distinguishing bacterial 'virulence' factors from the many determinants that are permissive for pathogenicity, for example those promoting general fitness. A further practical problem for some of the major bacterial pathogens is that there are no satisfactory animal models or experimental assays that adequately reflect the infection under investigation. In this review, we give a personal perspective on the challenge of characterizing how bacterial pathogens behave in vivo and discuss some of the methods that might be most relevant for understanding the molecular basis of the diseases for which they are responsible. Despite the powerful genomic, molecular, cellular and structural technologies available to us, we are still struggling to come to grips with the question of 'What is a pathogen?'