1. Regarding the prevalence of epiretinal membrane (ERM), ... a. the peak prevalence for patients with epiretinal membrane is in the 5th decade. b. epiretinal membrane is more common in males. c. there is large variability in the overall prevalence of ERMs due to differences in classifications, imaging modalities, reading methodologies and retinal appearances across ethnic groups. d. the prevalence of ERM does not appear to vary with ethnicity. e. the reported prevalence of ERM in Australia is under 5%.
The current standard of care for women diagnosed with early stage breast cancer is breast-conserving surgery (BCS) followed by external beam radiation therapy, commonly delivered over 3–6 weeks. As an alternative, select patients can undergo intra-operative radiation therapy (IORT) at the time of BCT. This technique delivers a single fraction of radiation at the time of surgery, enabling patients to undergo both surgery and radiation in a single session. Our current study analyzed the value of incorporating breast MRI into the routine work-up of patients deemed eligible for IORT, to quantify the impact on patient eligibility and requirement for additional work-up.We retrospectively identified patients treated by a single surgeon who were eligible for IORT based on institutional eligibility criteria which included: women age ≥55, grades 1–2, size <3 cm, estrogen receptor (ER) positive, Her-2 neu non-amplified and low/intermediate Ki-67, unifocal invasive ductal/mixed histology carcinomas. All patients must have undergone a physical exam and bilateral diagnostic mammography with ultrasound. From this population, we identified all patients who had undergone bilateral breast MRI as part of pre-operative evaluation.A total of 215 women were identified who met all eligibility criteria. MRI detected additional abnormalities in the breast in 89 patients (41%). Sixty-eight women underwent additional biopsies, with a total of 117 separate lesions biopsied. Of these, pathology was benign in 61 (52.1%), atypical ductal hyperplasia (ADH) in 21 (18%), ductal carcinoma in-situ (DCIS) in 17 (14.5%) and invasive disease in 18 (15.4%). Six patients had MRI-detected abnormalities in the contralateral breast only, with biopsies identifying invasive disease (3), DCIS (1) and benign (2) findings. MRI showed abnormalities in both breasts in 6 patients and 18 additional lesions were biopsied which reveled invasive carcinoma (6), DCIS (7), ADH (3) and benign findings (2). Fifteen patients had either multifocal/multicentric disease or index lesion >3 cm on MRI and were deemed ineligible for IORT. Based on either MRI size or biopsy results, management was ultimately changed for 27 patients (12.5%). Extramammary findings were observed in 17 patients and 11 of these patients underwent further imaging studies all of which returned negative results.Preoperative bilateral breast MRI is a valuable tool in the proper selection of patients best suited for IORT. Even in highly selected, favorable risk patients, MRI detected additional lesions that changed surgical and radiation therapy recommendations in 12.5% of patients. However, the cost/benefit ratio needs to be taken into consideration given the high frequency of benign biopsies and additional radiological work-up.
This review considers progress toward immune control of nematode parasites that feed on mammalian host blood. Approaches to identify relevant parasite antigens include use of irradiated larvae, somatic antigens, metabolites, enzymes and gut antigens. Because significant immune protection has more recently been achieved using gut antigens of the blood-feeding parasite Haemonchus contortus, these antigens are considered in greater detail. Issues discussed are implications of gut antigens in immune control, potential mechanisms involved in this immunity, biochemical characteristics of gut antigens and potential application of gut antigens to immune control of other blood-feeding nematodes.
Peripheral deafness may be inherited or acquired, congenital or later-onset, and sensorineural or conductive. The most commonly observed forms are inherited congenital sensorineural, acquired later-onset sensorineural (ototoxicity, presbycusis) and acquired later-onset conductive (chronic otitis externa/media). In most dog and cat breeds inherited congenital sensorineural deafness results from perinatal degeneration of the stria vascularis, the vascular bed of the outer wall of the cochlear duct, which leads to hair cell degeneration. The strial degeneration appears to result from the absence of melanocytes, but their function in this structure is unknown. Ototoxicity may result from any of a large number of drugs and chemicals that directly or indirectly destroy cochlear hair cells. The effects are dose-dependent and in rare cases reversible. The most commonly recognized ototoxic drugs are the aminoglycoside antibiotics. Presbycusis, the ageing-related progressive hearing loss unattributable to other causes, is sensorineural but may also include mechanical changes in the tympanum and ossicles. Hearing aids may be accepted by some dogs as long as some residual function remains. Breeds reported to have been affected by congenital sensorineural deafness are listed and those with the highest prevalence are noted. Methods for diagnosis of deafness are described.
Despite early attempts to control the spread of the disease, porcine reproductive and respiratory syndrome (PRRS) has now become endemic in many countries including Britain. The occurrence of subclinical herd infections, the prolonged circulation of virus within herds and probable aerogenic virus spread all mitigated against the success of control measures. The origin of the disease is unknown but the causative agent has been shown to be an arterivirus with shared features to lactate dehydrogenase virus of mice. There is evidence of extreme genetic and antigenic variability between American and European isolates. PRRS virus has a predilection for alveolar macrophages and does not grow in most cell lines. In infected pigs, viraemia can persist for many weeks in the face of circulating antibodies and little is known about the mechanisms by which immunity to infection develops. A wide spectrum of disease has been reported from the field, accompanied in some cases by heavy economic losses. Reproductive and perinatal losses were most prominent when the disease first appeared. In the endemic phase, PRRS may be more significant as a contributory factor to a post-weaning respiratory syndrome of young pigs of 3-8 weeks. On-farm techniques have been developed to reduce the recycling of PRRS virus fi om older infected nursery pigs to the younger newly weaned pig. Vaccines are now marketed for the control of PRRS, but are not licensed for use in Britain. Improvements in knowledge of virion composition and antigenic stability and in the nature of the immune response of the pig should result in genetically engineered subunit vaccines becoming available. Diagnosis of PRRS is still difficult as many animals do not show clinical signs and may only be detected by serology and often only when other respiratory diseases are being investigated, Now that the infection is widespread, serological testing must be properly targeted and interpreted to give meaningful results about virus circulation. An increasing arsenal of diagnostic methods are becoming available to detect virus in both fresh and fixed specimens. The pathogenic mechanisms of PRRS remain poorly defined and more work is needed to reveal the nature of the interaction between PRRS virus and other factor's in disease.
Although it has long been thought that a retrovirus is the responsible agent for ovine pulmonary carcinoma (OPC), identification of a replicative viral agent has proven difficult. Recently, the genome of a new retrovirus, jaagsiekte sheep retrovirus (JSRV), found in the lung-was of affected sheep lung, has bee cloned and sequenced; characterization of this virus and its consistent presence in tumor cells argue for its role as the aetiologic agent of OPC. Analysis of the nucleic acid sequence of the JRSV genome, suggests a new class of retrovirus, one that is chimeric according to the morphological classification scheme used for retroviruses. The genome of this virus does not appear to contain an oncogene, and the mechanism by which it causes disease is still unknown. The presence of multiple copies of endogenous retroviruses related to JSRV in DNA of OPC-affected and unaffected sheep further complicates investigation of oncogenesis in OPC. This review examines the evidence for a retrovirus as the causative agent for OPC, with particular emphasis on the viruses studied to date. The significance of endogenous, JSRV-related sequences is considered. The mechanisms by which a retrovirus such as JSRV might induce lung tumours in sheep, and which of these are most likely, are discussed in light of these developments, as are the prospects for new means of diagnosis and treatment of this disease.
Medetomidine is a relatively new sedative analgesic in dogs and cats but some precautions are required when using it. It is a potent α2-adrenoceptor agonist and stimulates receptors centrally to produce dose-dependent sedation and analgesia and receptors centrally and peripherally to cause marked bradycardia and decrease the cardiac output. While hypotension occurs frequently, higher doses of the sedative can raise the blood pressure due to an affect on peripheral receptors. Slowing of the respiratory rate is a frequent effect of medetomidine with some dogs showing signs of cyanosis. Other actions that follow medetomidine use are slowing of gastrointestinal motility, hypothermia, changes to endocrine function and, occasionally, vomiting and muscle twitching. The clinical use of medetomidine in dogs and cats is discussed. Recommended dose rates are presented along with precautions that should be taken when it is used alone for sedation, as an anaesthetic premedicant or in combination with ketamine, propofol or opioids. Hypoxaemia occurs frequently in dogs given medetomidine and propofol. The actions of medetomidine can be rapidly reversed with the specific α2-adrenoceptor antagonist, atipamezole, which is an advantage because undesirable and sedative actions of medetomidine can be terminated.
