Canine subcutaneous mast cell tumors: cellular proliferation and KIT expression as prognostic indices.

Molecular assays are widely used to prognosticate canine cutaneous mast cell tumors (MCT). There is limited information about these prognostic assays used on MCT that arise in the subcutis. The aims of this study were to evaluate the utility of KIT immunohistochemical labeling pattern, c-KIT mutational status (presence of internal tandem duplications in exon 11), and proliferation markers--including mitotic index, Ki67, and argyrophilic nucleolar organizing regions (AgNOR)--as independent prognostic markers for local recurrence and/or metastasis in canine subcutaneous MCT. A case-control design was used to analyze 60 subcutaneous MCT from 60 dogs, consisting of 24 dogs with subsequent local recurrence and 12 dogs with metastasis, as compared to dogs matched by breed, age, and sex with subcutaneous MCT that did not experience these events. Mitotic index, Ki67, the combination of Ki67 and AgNOR, and KIT cellular localization pattern were significantly associated with local recurrence and metastasis, thereby demonstrating their prognostic value for subcutaneous MCT. No internal tandem duplication mutations were detected in exon 11 of c-KIT in any tumors. Because c-KIT mutations have been demonstrated in only 20 to 30% of cutaneous MCT and primarily in tumors of higher grade, the number of subcutaneous MCT analyzed in this study may be insufficient to draw conclusions on the role c-KIT mutations in these tumors.

Canine subcutaneous mast cell tumor: characterization and prognostic indices.

Histologic grading schemes for canine cutaneous mast cell tumors (MCTs) were not developed for subcutaneous MCTs. Despite this, subcutaneous MCTs are currently categorized by many as grade II or higher. The aim of this investigation was to assess the pathology and clinical outcome for subcutaneous MCTs to provide a more accurate prognosis. Information on clinical outcome for 306 dogs was obtained from veterinarians and correlated with histologic features. Mean and median follow-up was 842 and 891 days, respectively (range, 3-2,305 days). Only 27 (9%) were confirmed as mast cell-related deaths. Metastasis occurred in 13 (4%), and 24 (8%) had local reoccurrence, even though 171 (56%) cases had incomplete surgical margins. Median survival time was not reached, and the estimated 6-month, 1-, 2-, and 5-year survival probabilities were 95%, 93%, 92%, and 86%, respectively. Dogs were euthanized or died as a result of local tumor reoccurrence, additional MCT development distant to the surgical site, or metastasis. Decreased survival time was linked to mitotic index (number of mitotic figures per 10 high-power fields), infiltrative growth pattern, and presence of multinucleation. Both univariable and multivariable analysis showed mitotic index to be strongly predictive of survival, local reoccurrence, and metastasis. The results of the study indicate that the majority of subcutaneous MCTs have a favorable prognosis, with extended survival times and low rates of reoccurrence and metastasis.

Quality of human immunodeficiency virus viral load testing in Australia.

This study determined the proficiencies of laboratories measuring human immunodeficiency virus type 1 (HIV-1) viral loads and the accuracies of two assays used for HIV-1 viral load measurement in Australia and investigated the variability of the new versions of these assays. Quality assessment program panels containing (i) dilutions of HIV-1 subtype B, (ii) replicates of identical samples of HIV-1 subtype B, and (iii) samples of subtype E and B were tested by laboratories. Total variability (within and between laboratories) was tested with quality control samples. The coefficients of variation (CVs) for the Roche AMPLICOR HIV-1 MONITOR version (v) 1.0 and Chiron Quantiplex bDNA 2.0 assays ranged from 53 to 87% and 22 to 31%, respectively. The widespread occurrence of invalid runs with the AMPLICOR HIV-1 MONITOR 1.0 assay was identified. The CVs of the new versions of the assays were 82 to 86% for the AMPLICOR HIV-1 MONITOR v 1.5 assay and 16 to 23% for the Quantiplex bDNA 3.0 assay. For virus dilution samples, all but 5 of 19 laboratories obtained results within 2 standard deviations of the mean. The Quantiplex bDNA 2.0 assay reported values lower than those reported by the AMPLICOR HIV-1 MONITOR version 1.0 assay for samples containing HIV-1 subtype B, whereas the reverse was true for subtype E. Identification and resolution of the problem of invalid runs markedly improved the quality of HIV-1 viral load testing. The variability observed between laboratories and between assays, even the most recent versions, dictates that monitoring of viral load in an individual should always be by the same laboratory and by the same assay. Results for an individual which differ by less than 0.5 log(10) HIV-1 RNA copy number/ml should not be considered clinically significant.

Beta radiation as an adjunct to low-risk trabeculectomy.

PURPOSE: To assess a single dose of intraoperative beta radiation used to enhance the success rate of trabeculectomy in a population of low-risk glaucoma patients in whom antimetabolites might not be indicated. METHODS: A prospective randomized trial of 65 eyes was designed, with 31 eyes receiving 750 rads of intraoperative beta radiation (group 1), and 34 eyes receiving no supplementation (group 2). RESULTS: Mean follow-up time was 24 months. Mean postoperative intraocular pressure was 12.2 mmHg in group 1, and 13.7 mmHg in group 2 (P = 0.16). Mean decrease in intraocular pressure was 10.3 mmHg in group 1, and 9.3 mmHg in group 2 (P = 0.49). The two groups were not significantly different in terms of surgical complications. CONCLUSION: For this population of low-risk patients, there was no significant difference in outcome after applications of a single intraoperative dose of beta radiation.

Influences on parent perceptions of inclusive practices for their children with mental retardation.

Influences on parent perceptions regarding the practice of integrating students with significant cognitive disabilities into general education classrooms were examined. Findings confirmed that perceptions were significantly influenced by characteristics of the parent and the child as well as by factors associated with the child's placement history. Further, factors influencing these perceptions differed according to varying dimensions of inclusion being considered. We argue that the efficacy of any specific type of educational model cannot be determined without a consideration of the complex dynamics involved in the interplay between individual child characteristics, parent and family values, and the perceived role of the school.

The prevalence of hepatitis C in patients admitted with acute hepatitis to Fairfield Infectious Diseases Hospital, 1971-1975.

OBJECTIVE: To identify and determine trends in the prevalence of hepatitis C virus (HCV) antibody in stored sera from 1971 to 1975 and to determine associations with HCV seropositivity, including markers for other hepatitis infections and possible routes of transmission. DESIGN: A retrospective cross-sectional study. PATIENTS AND SETTING: 1511 adults admitted to Fairfield Infectious Diseases Hospital, Victoria, with a clinical and biochemical diagnosis of hepatitis between 1 January 1971 and 31 December 1975. MAIN OUTCOME MEASURES: Prevalence over study period of hepatitis A virus antibody (anti-HAV) IgM, hepatitis B core antibody (anti-HBc), hepatitis B surface antigen (HBsAg) and hepatitis C virus antibody (anti-HCV) in stored sera; sociodemographic data and risk factors for blood-borne viruses documented in original medical records. RESULTS: Anti-HCV was detected in 17% of adults admitted with hepatitis from 1971 through 1975. Prevalence increased significantly over this period. Most cases were in young men who had a history of injecting drug use. HCV seropositivity was also significantly associated with markers for hepatitis B infection. CONCLUSIONS: Given the 20-30-year period between infection with hepatitis and the development of liver disease, our findings predict significant liver-related morbidity in Australia in the next decade. The increase in prevalence over the five years studied suggests rapid spread of HCV through susceptible populations, principally injecting drug users.

Enhanced T-cell immunogenicity and protective efficacy of a human immunodeficiency virus type 1 vaccine regimen consisting of consecutive priming with DNA and boosting with recombinant fowlpox virus.

The induction of human immunodeficiency virus (HIV)-specific T-cell responses is widely seen as critical to the development of effective immunity to HIV type 1 (HIV-1). Plasmid DNA and recombinant fowlpox virus (rFPV) vaccines are among the most promising safe HIV-1 vaccine candidates. However, the immunity induced by either vaccine alone may be insufficient to provide durable protection against HIV-1 infection. We evaluated a consecutive immunization strategy involving priming with DNA and boosting with rFPV vaccines encoding common HIV-1 antigens. In mice, this approach induced greater HIV-1-specific immunity than either vector alone and protected mice from challenge with a recombinant vaccinia virus expressing HIV-1 antigens. In macaques, a dramatic boosting effect on DNA vaccine-primed HIV-1-specific helper and cytotoxic T-lymphocyte responses, but a decline in HIV-1 antibody titers, was observed following rFPV immunization. The vaccine regimen protected macaques from an intravenous HIV-1 challenge, with the resistance most likely mediated by T-cell responses. These studies suggest a safe strategy for the enhanced generation of T-cell-mediated protective immunity to HIV-1.

Assays for HIV with improved sensitivity and specificity.

Increased knowledge of the human immunodeficiency virus (HIV) and the infection it causes in humans has resulted in an enormous expansion in the understanding of viral parameters and host changes. HIV is a virus which mutates readily and rapidly, presenting many challenges to assay developers, and monitors of therapy and drug-resistance. Prolific viral replication at all the stages of the disease means that an accurate assessment of viral burden, viral load and changes to immune system markers is essential for effective clinical management and treatment. In the present review we have summarised current opinion on the kinetics of HIV infection and the pathogenesis of the disease it causes, and have provided a background to the evolution of HIV assays. Sensitivities and specificities of assays used for anti-HIV and HIV detection have improved, and new assays have been developed employing novel molecular techniques, which are being applied to meet continually evolving demands for more sensitive measurement of an increasing number of parameters. The future of HIV testing is also considered in the light of new knowledge concerning virus dynamics in vivo, the likelihood of the emergence of new subtypes and the changing approach to therapy. Assays will be, on the whole, used to quantify virus and to measure the host reactions to infection, often in the presence of antivirals. Thus, extreme sensitivity and specificity will be required.

Early successful treatment of postoperative necrotizing pseudomonas scleritis after trabeculectomy.

PURPOSE: The authors describe a patient who developed pseudomonas scleritis after a routine trabeculectomy. METHOD: The patient underwent trabeculectomy for poorly controlled intraocular pressure and progressive visual field loss. On the second postoperative date he developed severe pain, significant anterior chamber reaction, and hypotony. Scleral cultures taken at the time of surgical choroidal drainage grew pseudomonas aeruginosa. RESULT: Surgical reconstruction of the necrotic scleral area and intensive antibiotic treatment lead to a successful outcome. CONCLUSION: Early recognition and aggressive treatment with antibiotics initially, followed by surgical debridement of necrotic tissue, resulted in an unexpected successful outcome in a patient with pseudomonas scleritis.

Spontaneous adult-onset hypothyroidism in a cat.

Spontaneous adult-onset hypothyroidism, confirmed by a thyroid-stimulating hormone stimulation test, thyroid biopsy, and response to replacement therapy, is described in a female cat. Clinical signs consisted of profound apathy, hypothermia, poor hair growth, severe seborrhea sicca, and a puffy face. Cutaneous histological changes consisted of epidermal and follicular hyperkeratosis, teloginization of hairs, and dermal mucin deposition. There was no adnexal atrophy. Lymphocytic thyroiditis, equivalent to Hashimoto's thyroiditis, was shown by thyroid biopsy. Clinical signs rapidly responded to thyroxine replacement therapy. Glucose intolerance was coexistent with the hypothyroidism, but was not dramatically influenced by thyroxine therapy and probably was an independently occurring endocrinopathy.

Visual fields in glaucoma and neuro-ophthalmology.

1. Automated visual fields are psychophysiologic tests that require attention to details for accuracy. 2. Glaucoma visual field defects reflect the local anatomy of the optic disc. 3. Visual fields in neuro-ophthalmology reflect pathology of the visual pathways and are important in diagnosis.

The McCollough effect as a measure of central cholinergic activity in man.

The McCollough Effect (ME) is an orientation contingent colour after-effect which has been proposed as an indicator of central neurotransmitter activity. Shute (1979) suggested that the ME could reflect a hippocampal "forgetting" mechanism which should be inhibited by GABAergic neurones and stimulated by cholinergic neurones. The purpose of the present study was to demonstrate that the ME is in fact sensitive to cholinergic and anticholinergic drugs and to compare its sensitivity to more conventional tests of psychomotor and cognitive function. Ten healthy subjects received single doses of physostigmine (0.75 mg SC), hyoscine (1.2 mg), temazepam (20 mg), flecainide (200 mg) or placebo in a double-blind double-dummy presentation. Subjects were tested on a battery of psychomotor and cognitive function tests at baseline and 1 h, and adapted to the ME at 1.5 h. Visual analogue rating scales and conventional tests of psychomotor function and saccadic eye movements indicated that both subjective and objective measures of arousal were impaired by temazepam. The subjective, but not the objective, measures of arousal were also impaired by both hyoscine and physostigmine, but not by flecainide. Initial strength and duration of the ME were decreased by physostigmine and increased by hyoscine and temazepam, relative to placebo (P less than 0.01). Thus, the ME is capable of detecting cholinergic, anticholinergic and GABA mimetic drug effects in man, in therapeutic doses.

Metastatic cutaneous malignant melanoma of the vitreous and retina.

A case of cutaneous malignant melanoma metastasising to the retina in a 71-year-old patient who presented with vitreous opacities is discussed. In view of the increasing incidence of cutaneous malignant melanoma in our community the possibility of ocular metastases merits consideration.

Protective activity of different hepatic cytosolic glutathione S-transferases against DNA-binding metabolites of aflatoxin B1.

To evaluate the role of glutathione S-transferase (GST) isoenzymes in induced resistance of hepatocytes to aflatoxin B1 (AFB1), we compared DNA protective activities of different hepatic cytosol preparations and purified GSTs from normal rats, rats exposed to different polychlorinated biphenyls (PCBs), and rats with carcinogen-induced hepatocellular neoplasms, with cytosols or purified GSTs from mouse, rainbow trout, and human livers. These comparisons were performed in an in vitro assay for [3H]AFB1-DNA binding after activation by rat liver microsomes. Cytosol and S-hexylglutathione-affinity-purified GST preparations from livers of mice consistently had strong protective activity against AFB1-DNA binding. The majority of this activity was dependent on the presence of reduced glutathione (GSH) but some GSH-independent protection was observed in mouse hepatic cytosol, but not in purified GST preparations. We found that all of the GSH-dependent DNA-protective activity in mouse liver eluted as a single GST isoenzyme by hydroxyapatite chromatography. Preparations of cytosol and purified GSTs from normal rat liver, rainbow trout liver, and human liver had much less AFB1-specific DNA protective activity than GSTs found in mouse liver preparations. Cytosol from rats with carcinogen-generated liver neoplasms and livers induced with 3,3',4,4'-tetrachlorobiphenyl and 2,2',4,4',5,5'-hexachlorobiphenyl had more GST activity toward CDNB than cytosol from normal rat liver. When equivalent units of GST activity (CDNB) were compared, there was little difference observed between the DNA-protective activities of PCB-induced and normal rat liver cytosols, yet cytosol from rat liver neoplasms was more protective. Purified GST-P (7-7), the GST isoenzyme most induced in carcinogen-generated rat liver neoplasms, was not protective when added at protein concentrations found to be protective for total GSTs isolated from these neoplasms. These studies demonstrate that the resistance of mouse liver to AFB1 can be explained primarily by a single constitutive GST isoenzyme (YaYa or 4-4) with a relatively high activity toward DNA-binding metabolites of AFB1. GST isoenzymes with such high specific DNA protective activity against AFB1 metabolites were not evident in human, rat, or rainbow trout liver or in PCB-induced or neoplastic rat liver preparations.

Human papillomavirus types in anogenital warts of children.

Tissue from anogenital warts of 25 children, 10 of whom were suspected of being victims of sexual abuse, was investigated by dot blot and Southern blot techniques for human papillomavirus (HPV) types. HPV DNA was detected in 22 children, two of whom had double infections. The genital HPV types 6 and/or 11 were detected in 20 children, and in three children other HPV types were found. One had HPV 18 (as well as 11); in a second child a possible skin type, HPV 2, was detected; and the third child was infected with an unidentified type. In three cases genital wart material was available from one of the parents, and in all three the HPV type was the same as that of the child. For nine other children one or both parents were reported to have genital warts. The source of infection appeared to be the adult genital tract, but sexual contact might not be the only means of transmission.

HIV surveillance by testing saliva.

Saliva specimens were tested for HIV antibody (anti-HIV) by an immunoglobulin G (IgG) antibody capture radioimmunoassay (GACRIA) and three sensitive commercial assays. In tests on 460 seronegative subjects and 196 seropositive subjects GACRIA was 99.8% specific and 100% sensitive. The Wellcome HIV monoclonal and Abbott recombinant DNA enzyme-linked immunosorbent assays (ELISAs) were also highly specific (99.8%, 100%) but they were less sensitive (90.9%, 82.0%). The Fujirebio particle agglutination assay was sensitive (97.8%) but its specificity was poor (84.1%). In testing saliva specimens from populations with an anti-HIV prevalence greater than 0.5%, sampling by GACRIA alone could provide a good estimate of the true prevalence. For true prevalences less than 0.5% good estimates could only be obtained if positive GACRIA reactions were confirmed by another independent salivary assay. Salivary testing for anti HIV is a convenient and potentially an accurate epidemiological tool.

Population dynamics in echinococcosis and cysticercosis: economic assessment of control strategies for Echinococcus granulosus, Taenia ovis and T. hydatigena.

An official control programme against Echinococcus granulosus and Taenia hydatigena has been in operation in New Zealand for more than 28 years and against Taenia ovis for more than 18 years. This unique effort to control three metazoan parasites at the same time has led to a change from endemic to extinction status for E. granulosus but only a change from hyperendemic to endemic status for T. hydatigena and T. ovis. This has presented problems in determining the most cost-effective future control strategies. To facilitate this, a benefit/cost analysis of 20 options for the combined control of E. granulosus, T. hydatigena and T. ovis in New Zealand was undertaken. This showed that for E. granulosus a future change from the current non-targeted to a targeted approach is strongly indicated. For T. ovis 6 options were cost-effective using a discount rate of 10%. These were (1) a targeted control package using a vaccine in the non-targeted attack phase; (2) a targeted control package using a larvicide in the attack phase; (3) the transfer of all losses due to and responsibility for the control of T. ovis to the producer who administers a larvicide to sheep to be killed for dog food; (4) the transfer of all losses due to and responsibility for the control of T. ovis to the producer who administers praziquantel every 6 weeks to dogs; (5) and (6) two options involving the discontinuation of control. Control of T. hydatigena was assumed to be an incidental outcome of the policies for the other two parasites.

An indirect haemolysis test (IHLT) for bovine brucellosis.

A simple indirect haemolysis test (IHLT) was developed to avoid the problem of prozones in the complement fixation test (CFT) for bovine brucellosis. It makes use of a sheep or bovine erythrocytes, treated with a crude lipopolysaccharide fraction of Br. abortus, which are lysed by specific antibody in the presence of excess complement (C'). A number of bovine serum which gave large prozones in the warm CFT, and some in which C'-fixation was completely blocked, were found to react to high titre, without prozones, in the IHLT. Following primary vaccination with Br. abortus strain 19, fewer animals gave positive reactions in the IHLT than in the CFT. Following two doses of 45/20 vaccine, however, positive reactions were more frequent in the IHLT than in the CFT. Preliminary studies of serums from animals known to be infected indicate that the IHLT may be of diagnostic value. The test is easy to carry out, especially when bovine erythrocytes are used, since very few bovine serums require preliminary absorption.