Endocardial Endothelial Dysfunction Progressively Disrupts Initially Anti then Pro-Thrombotic Pathways in Heart Failure Mice

Objective

An experimental model of endocardial thrombosis has not been developed and endocardial endothelial dysfunction in heart failure (HF) is understudied. We sought to determine whether disruption of the endothelial anti-coagulant activated protein C (APC) pathway in CREB_A133 HF mice promotes endocardial thrombosis in the acute decompensated phase of the disease, and whether alterations in von Willebrand factor (vWF) secretion from HF endocardium reduces thrombus formation as HF stabilizes.

Approach and results

Echocardiography was used to follow HF development and to detect endocardial thrombi in CREB_A133 mice. Endocardial thrombi incidence was confirmed with immunohistochemistry and histology. In early and acute decompensated phases of HF, CREB_A133 mice had the highest incidence of endocardial thrombi and these mice also had a shorter tail-bleeding index consistent with a pro-thrombotic milieu. Both APC generation, and expression of receptors that promote APC function (thrombomodulin, endothelial protein C receptor, protein S), were suppressed in the endocardium of acute decompensated HF mice. However, in stable compensated HF mice, an attenuation occurred for vWF protein content and secretion from endocardial endothelial cells, vWF-dependent platelet agglutination (by ristocetin), and thrombin generation on the endocardial surface.

Conclusions

CREB_A133 mice develop HF and endocardial endothelial dysfunction. Attenuation of the anti-coagulant APC pathway promotes endocardial thrombosis in early and acute decompensated phases of HF. However, in stable compensated HF mice, disruptions in endothelial vWF expression and extrusion may actually reduce the incidence of endocardial thrombosis.

Supported housing for people with severe mental disorders

BACKGROUND

There has been a significant reduction in the number of people with severe mental illness who spend extended periods in long-stay hospitals. District health authorities, local authorities, housing associations and voluntary organisations are jointly expected to provide support for people with severe mental disorder/s. This 'support' may well involve some kind of special housing.

OBJECTIVES

To determine the effects of supported housing schemes compared with outreach support schemes or 'standard care' for people with severe mental disorder/s living in the community.

SEARCH STRATEGY

For the 2006 update we searched the Cochrane Schizophrenia Group Trials Register (April 2006) and the Cochrane Central Register of Controlled Trials (CENTRAL, 2006 Issue 2).

SELECTION CRITERIA

We included all relevant randomised, or quasi-randomised, trials dealing with people with 'severe mental disorder/s' allocated to supported housing, compared with outreach support schemes or standard care. We focused on outcomes of service utilisation, mental state, satisfaction with care, social functioning, quality of life and economic data.

DATA COLLECTION AND ANALYSIS

We reliably selected studies, quality rated them and undertook data extraction. For dichotomous data, we would have estimated relative risks (RR), with the 95% confidence intervals (CI). Where possible, we would have calculated the number needed to treat statistic (NNT). We would have carried out analysis by intention-to-treat and would have summated normal continuous data using the weighted mean difference (WMD). We would have presented scale data for only those tools that had attained pre-specified levels of quality and undertaken tests for heterogeneity and publication bias.

MAIN RESULTS

Although 139 citations were acquired from the searches, no study met the inclusion criteria.

AUTHORS' CONCLUSIONS

Dedicated schemes whereby people with severe mental illness are located within one site or building with assistance from professional workers have potential for great benefit as they provide a 'safe haven' for people in need of stability and support. This, however, may be at the risk of increasing dependence on professionals and prolonging exclusion from the community. Whether or not the benefits outweigh the risks can only be a matter of opinion in the absence of reliable evidence. There is an urgent need to investigate the effects of supported housing on people with severe mental illness within a randomised trial.

Supported housing for people with severe mental disorders

BACKGROUND

There has been a significant reduction in the number of people with severe mental illness who spend extended periods in long-stay hospitals. Psychiatric and social services, both statutory and voluntary, aim to assist these people to stay in their local community. District health authorities, local authorities, housing associations and voluntary organisations are jointly expected to provide support for people with severe mental disorder/s. This 'support' may well involve some sort of special housing.

OBJECTIVES

To determine the effects of supported housing schemes compared with outreach support schemes or 'standard care' for people with severe mental disorder/s living in the community.

SEARCH STRATEGY

Cochrane Schizophrenia Group's Register of trials (February 2001) and the Cochrane Library (Issue 1, 2001) were searched using relevant phrases. These databases are compiled by methodical searches of BIOSIS, CINAHL, Dissertation abstracts, EMBASE, LILACS, MEDLINE, PSYNDEX, PsycINFO, RUSSMED, Sociofile, supplemented with hand searching of relevant journals and numerous conference proceedings. Reference list screening of relevant papers was performed.

SELECTION CRITERIA

Relevant randomised, or quasi-randomised, trials dealing with people with 'severe mental disorder/s' allocated to supported housing, outreach support schemes or standard care focusing on outcomes of service utilisation, mental state, satisfaction with care, social functioning, quality of life, and economic data, were sought.

DATA COLLECTION AND ANALYSIS

Studies were reliably selected, quality rated and data extracted. For dichotomous data, relative risks (RR) would have been estimated, with the 95% confidence intervals (CI). Where possible, the number needed to treat statistic (NNT) was to have been calculated. Analysis would have been by intention-to-treat. Normal continuous data were to have been summated using the weighted mean difference (WMD). Scale data were to have been presented for only those tools that had attained pre-specified levels of quality. Tests of heterogeneity and for publication bias were to have been undertaken.

MAIN RESULTS

No studies met the inclusion criteria although 139 citations were acquired from the searches.

REVIEWER'S CONCLUSIONS

Dedicated schemes whereby people with severe mental illness are located within one site or building with assistance from professional workers have potential for great benefit as they provide a 'safe haven' for people in need of stability and support. This, however, may be at the risk of increasing dependence on professionals and prolonging exclusion from the community. Whether or not the benefits outweigh the risks can only be a matter of opinion in the absence of reliable evidence. There is an urgent need to investigate the effects of supported housing on people with severe mental illness within a randomised trial.

Painful knee joint prostheses: evaluation for loosening by combined radionuclide arthrography and transmission imaging

Interpretation of radionuclide arthrograms (RNA) of the knee after total knee joint replacement (TKR) may be difficult because of the lack of sufficient anatomic reference information. Additional transmission images may provide the necessary reference information required for correct interpretation of RNA of the knee.

METHODS

Tc-99m tin colloid (20 MBq) RNA was combined with cobalt-57 transmission imaging in six patients with painful TKRs in whom loosening of the TKR was suspected. Knee surgery was then performed on these six cases.

RESULTS

RNA correctly detected loosening of the tibial component in five of six cases, but did not detect loosening of the femoral component in any of three cases.

CONCLUSION

RNA combined with transmission imaging is recommended for detection of loosening of the tibial component of a TKR. RNA may not be of value for detecting loosening of the femoral component.

Chronic (exertional) compartment syndrome of the legs diagnosed with thallous chloride scintigraphy

Over the past 4 yr, we obtained 201Tl lower leg scans on 14 patients with suspected chronic exertional compartment syndrome. Qualitative assessment of the images revealed that 12 scans showed reversible compartment ischemia. Retrospective quantitation confirmed redistribution in seven of nine patients. Seven patients had surgery with partial or complete resolution of their symptoms.

Radionuclide arthrography and transmission imaging for assessment of painful hip prostheses

Interpretation of the radionuclide hip arthrogram may present difficulty because of a lack of anatomical reference information. Additional transmission images to determine tracer localization may facilitate scan interpretation.

METHODS

Isotope arthrography (20 MBq 99mTc-tin colloid and 57Co transmission imaging) was prospectively performed on 21 patients with painful hip prostheses and suspected stem loosening.

RESULTS

The radionuclide arthrogram was positive in 10 patients and negative in 9 patients. Extravasation of tracer, confirmed by transmission images, resulted in two nondiagnostic studies. Surgery was undertaken in 10 patients and loosening was confirmed in 6 patients. In this surgical subgroup, the scan was true-positive in six patients, true-negative in two patients, false-positive in one patient and nondiagnostic in one patient.

CONCLUSIONS

The combination of radionuclide arthrography and transmission imaging facilitates scan interpretation and is a recommended method for investigating suspected loosening of the femoral stem.

Computer quantitation of gallium 67 lung uptake in crocidolite (blue asbestos) workers of Western Australia

Pulmonary inflammation has been evaluated in 43 crocidolite-exposed asbestos (ASB) workers and 12 control subjects, using a quantitative index of gallium uptake (GI). The GI was compared with chest roentgenographs (CXRs) graded by the ILO classification. The ASB workers included 15 with asbestosis (CXR greater than or equal to 1/0), 19 with a normal CXR (CXR 0/0), and 9 with equivocal CXR changes (CXR 0/1). In individuals with asbestosis the GI was 3.6 +/- 0.3 (mean +/- SEM), P less than 0.01 compared with exposed patients without asbestosis. In exposed patients with equivocal CXR changes (0/1) the GI was 3.1 +/- 0.3, and in exposed patients with a normal CXR (0/0) the GI was 2.4 +/- 0.2. The GI for subjects without lung disease was 1.2 +/- 0.2, P less than 0.01 compared with exposed patients without asbestosis. The scans were scored independently by two observers, and the correlation coefficient of the two sets of GI was 0.95. These data demonstrate that subjects with crocidolite-induced asbestosis and exposed patients with equivocal CXR changes or a normal CXR have significantly increased GI.

Iodine-131 treatment of Graves' disease using modified early iodine-131 uptake measurements in therapy dose calculations

We hypothesized that early uptake of iodine-131 (131I) at 3-6 hr (EU) by the thyroid could be used to calculate 131I therapy with results comparable to those obtained using late uptake of 131I at 20-28 hr (LU) results. A retrospective study was undertaken. Twenty-seven patients with untreated thyrotoxic Graves' disease were given 3-5 microCi of 131I and EU and LU were determined with an uptake probe. We derived a "best fit" curve on plots of EU (X-axis) and LU (Y-axis). The equation for the curve (LU = -55.7 + 73.2 log EU) was used to predict late uptake (PU) from EU results on a second group of 24 similarly defined Graves' patients. PU and measured LU were then applied to 131I treatment calculations in these 24 patients. PU correlated closely with LU (r = 0.94). Dose calculations based on PU and LU gave very similar results (r = 0.97). Using this method, same day diagnosis and treatment of Graves' is achievable.

Asbestos-induced release of a human alveolar macrophage-derived neutrophil chemotactic factor

Neutrophils accumulate in the alveoli of asbestos-exposed individuals. In determining whether asbestos fibers induce the release of neutrophil chemotactic factor (NCF) from human alveolar macrophages, alveolar macrophages (10(6) cell/mL) obtained by bronchoalveolar lavage from six non-asbestos-exposed control subjects were exposed to crocidolite (0.1 and 1 mg/mL), chrysotile (1 mg/mL), or medium alone for 4 h, and NCF activity was measured in the supernatants in a 48-well microchemotaxis chamber with polycarbonate membrane filters (pore size, 3 microns) and purified human neutrophils. Alveolar macrophages in medium alone released negligible amounts of NCF (4 +/- 1 neutrophils per high-power field [N/HPF]). When macrophages were exposed to crocidolite (0.1 and 1 mg/mL), significant NCF release occurred (43 +/- 9 and 105 +/- 32 N/HPF, respectively; p less than 0.01 for each amount compare to alveolar macrophages cultured in medium alone). Chrysotile (1 mg/mL) induced similar NCF release (96 +/- 14 N/HPF; p less than 0.01 compared to unstimulated alveolar macrophages). Partial characterization of the NCF by Sephadex G-25 fine gel filtration demonstrated a molecular size of less than 1,000 daltons. These results show that human alveolar macrophages release NCF after exposure to asbestos. Release of NCF by alveolar macrophages in asbestos-exposed individuals may play a central role in the pathogenesis of asbestosis.

Deoxyuridylate effects on thymidylate synthase-5-fluorodeoxyuridylate-folate ternary complex formation

The competitive basis and specificity of deoxyuridylate (dUMP)-mediated decreases in thymidylate synthase-5'-fluorodeoxyuridylate-folate (TS-FdUMP-folate) ternary complex formation at low concentrations of folates were investigated using charcoal isolation of protein-bound [3H]FuUMP ligand. Reaction conditions used 0.02 microM TS (Lactobacillus casei) and 0.10 microM [3H]FdUMP incubated for 10 min at 37 degrees and pH 7.4. Decreases in counts below control (C) values in dUMP-added samples (S) were expressed as C/S ratios. At CH2--H4PteGlu1 or H4PteGlu1 concentrations below 10 microM, highly linear relationships were found to exist between C/S value and dUMP concentrations, expressed as dUMP/FdUMP ratios. For H4PteGlu1, maximal C/S values for dUMP interference occurred at the lowest H4PteGlu1 concentrations, approaching the value of the TS-FdUMP binary complex. The efficiency of ternary complex formation by H4PteGlu1 was 28 +/- 5% of CH2--H4PteGlu1 values at concentrations below 1.0 microM. The protective effect of increasing H4PteGlu1 against dUMP interference resulted in a linear relationship between the logarithm of H4PteGlu1 concentration and the slope of dUMP interference (C/S vs dUMP/FdUMP). In contrast, the results with CH2--H4PteGlu1 were biphasic. At concentrations of CH2--H4PteGlu1 lower than 0.5 microM, C/S values were greater than those for binary complex alone, a result related to CH2--H4PteGlu1 consumption based on [5-3H]dUMP tritium-release studies. At concentrations of CH2--H4PteGlu1 above 1.0 microM, however, dUMP interference was nearly abolished. Kinetic analysis of the data suggests that this effect of the 5,10-methylene moiety may result in part from positive allosteric effects of first site TS-FdUMP-CH2--H4PteGlu1 ternary complex binding on acceleration of second site binding, in addition to slowed rates of dissociation. Other folylmonoglutamates showed relatively poor TS-[3H]FdUMP-folate complex formation: at 500 microM folate, as a percentage of CH2--H4PteGlu1 values, these were 29.6% for dihydrofolate, 7.5% for 5-CH3--H4PteGlu1, 3.0% for CH = H4PteGlu1, 1.6% for folic acid, 1.1% for 5-CHO--H4PteGlu1 (leucovorin) and 0.9% for 10-CHO--H4PteGlu1. Inhibitory effects by dUMP were consistent with binary complex effects alone for these folates. Study of methotrexate, as the monoglutamate and the hexaglutamate, suggested that ternary complexes with dUMP are favored over those with FdUMP at high concentrations of the antifolate. Our results indicate that activation of leucovorin to over 0.5 microM in intracellular CH2--H4PteGlu1 equivalents may be a requirement for achieving complete TS inhibition by FdUMP in the presence of excess conce

Gallium lung scanning and bronchoalveolar lavage in crocidolite-exposed workers

Gallium lung scanning is widely used to evaluate pulmonary inflammation in patients with interstitial lung disease but has not previously been reported in crocidolite-exposed workers. In order to characterize the pulmonary inflammation caused by crocidolite inhalation, GLS and BAL findings were related to chest x-ray film changes graded according to the ILO classification of roentgenograms of pneumoconioses. In individuals with roentgenographic evidence of asbestosis (CXR greater than or equal to 1/0, n = 15), 13 had a positive GLS and 13 had an abnormal BAL. In asbestos-exposed individuals with equivocal chest x-ray film changes (CXR 0/1, n = 12), six had a positive GLS and six had BAL changes (both GLS and BAL abnormal in three). In individuals with a normal chest x-ray film (CXR 0/0 n = 8), two had a positive GLS and two BAL changes (both abnormal in 1). These data demonstrate that most subjects with crocidolite-induced asbestosis have an abnormal GLS and BAL. In addition, many individuals with asbestos exposure and equivocal or no chest x-ray film changes have an abnormal GLS and/or BAL, suggesting the presence of active subclinical pulmonary inflammation in these individuals.

Treatment and prognostic factors in lymphoma in cats: 103 cases (1977-1981)

The records of 103 cats with lymphoma that underwent chemotherapy were reviewed. Diagnosis was confirmed by cytologic or histopathologic examination of appropriate tissue specimens. Sixty-four cats (62%) had a complete response to chemotherapy (median survival time, 7 months); 21 cats (20%) had a partial response (median survival time, 2.5 months); and 18 cats had a minimal response (median survival time, 1.5 months). Seventy-seven cats (75%) died of recurrent or progressive lymphoma, 9 cats died of feline leukemia-related anemia, 13 cats died of unrelated causes, and 4 cats were alive. Stage of disease was significantly (P = 0.009) related to response to treatment, and stage of disease and FeLV status were both significantly (P = 0.002 and P less than 0.001, respectively) related to survival.

Mechanisms of innate resistance to thymidylate synthase inhibition after 5-fluorouracil

Fifty-four patients with metastatic adenocarcinoma received i.v. bolus 5-fluorouracil, 500 mg/m2, prior to surgical biopsy of tumor at 20-400 min, for analysis of biochemical parameters of resistance to thymidylate synthase (TS) inhibition. The majority of patients, 37, had colon or rectal adenocarcinoma, five had breast cancer, five had gastric primary disease, four had pancreatic adenocarcinoma, and three had hepatocellular adenocarcinoma. Fluorodeoxyuridylate (FdUMP) was assayed by isotope dilution of [3H]FdUMP binding to bacterial TS; free and total TS was determined by [3H]FdUMP binding; and deoxyuridylate (dUMP) was assayed by conversion to [14C]thymidylate. Free levels of TS were lower in breast cancers, 0.08 +/- 0.06 pmol/g, than in other histologies (overall average, 1.41 +/- 2.25), associated with significantly greater percentages of TS inhibition (88.6% versus 62.0% overall). Colorectal tumors showed significantly greater FdUMP levels than other gastrointestinal malignancies, associated with somewhat lower free TS values. Plots of FdUMP levels, or (FdUMP/dUMP) x 100 values versus percentages of TS inhibition suggested minima of 75 pmol/g and 0.10, respectively, for achieving maximal enzyme inhibition. Analyses of normal tissues showed: poor TS inhibition in liver and normal colonic mucosa, related to low FdUMP levels; and very high dUMP levels in bone marrow leukocytes suggestive of reactive increases in dUMP as an important mechanism of recovery in this tissue. Among the 30 of the 37 colorectal tumors that showed suboptimal (less than 85%) inhibition of TS, 16 (53%) showed FdUMP levels less than 75 pmol/g, 8 (27%) showed relatively high dUMP levels (over 35 nmol/g), and 16 (53%) showed poor efficiency of inhibition of TS, with the major overlap between these mechanisms of resistance being high dUMP and poor binding in 6 (20%). These data provide a strong rationale for administration of leucovorin to the majority of patients receiving 5-fluorouracil, since increased intratumoral reduced folates potentially can overcome multiple mechanisms of resistance including low FdUMP, high dUMP, and high total TS levels, in addition to that caused by isolated folate deficiency.

Neutrophil chemotactic factor release and neutrophil alveolitis in asbestos-exposed individuals

Alveolar neutrophil accumulation occurs in asbestosis. To evaluate a possible role for release of neutrophil chemotactic factor (NCF) in the pathogenesis of asbestosis, spontaneous NCF release from alveolar macrophages obtained by bronchoalveolar lavage (BAL) in eight individuals with asbestosis, 13 asbestos-exposed individuals without asbestosis, and five control subjects has been studied. Alveolar macrophages were incubated in medium (four hours; 37 degrees C), and neutrophil responses to the supernatants were assayed in a microchemotaxis chamber. Alveolar macrophages from subjects with asbestosis released more NCF (97 +/- 19 neutrophils per high-power field [N/HPF]) than controls (3 +/- 1 N/HPF; p less than 0.01). Alveolar macrophages from individuals with asbestos exposure and increased BAL neutrophil proportions (n = 7) released more NCF (93 +/- 24 N/HPF) than individuals with asbestos exposure and normal BAL neutrophil proportions (n = 6; 11 +/- 6 N/HPF; p less than 0.02). The results show that spontaneous NCF release occurs in asbestosis and that NCF release is associated with neutrophil alveolitis in asbestos-exposed individuals without asbestosis, suggesting a pathogenic role for NCF in mediating this neutrophil alveolitis. The results of the study also suggest that the presence of crackles is a better predictor of the presence of neutrophil alveolitis than is an abnormal chest x-ray film.

Renal lymphoma in cats: 28 cases (1977-1984)

Renal lymphoma was diagnosed, staged, and treated in 28 cats. Renal lymphoma staging was done according to clinical findings: 11 cats had stage-2 lymphomas, 5 had stage-3 lymphomas, 6 had stage-4 lymphomas, and 6 had stage-5 lymphomas. All cats were treated with chemotherapy: 17 cats had a complete response, 9 cats had a partial response, and 2 cats had no response. The cats with stage-2 lymphomas that were FeLV-test negative had the best response to treatment.

Generalized lymphadenopathy resembling lymphoma in cats: six cases (1972-1976)

Six cases of prominent generalized peripheral lymphadenopathy in the cat were reviewed. The lymph node biopsy specimens of these cats had many histologic features of lymphoma. One cat was euthanatized after the initial diagnosis of lymphoma. In the other 5 cats, the lymphadenopathy regressed without therapy within 1 to 17 weeks.

Evaluation of some prognostic factors for advanced multicentric lymphosarcoma in the dog: 147 cases (1978-1981)

A total of 147 dogs treated with a combination of chemotherapy procedure (vincristine, L-asparaginase, cyclophosphamide, and methotrexate) were evaluated for response to therapy and the influence of age, sex, clinical stage, and body weight to duration of response. Complete response was achieved in 113 dogs (77%), partial response in 26 dogs (17.7%), and no response in 8 dogs (5.4%). The median survival time for the dogs with complete and partial responses was 265 days. An analysis of factors associated with prognosis revealed that age, clinical stage, and body weight were not associated with response to therapy, whereas sex was. Females had a significantly prolonged remission and survival time (P = 0.0001).

Canine oral melanoma: comparison of surgery versus surgery plus Corynebacterium parvum

Eighty-nine dogs with malignant oral melanoma were selected for study. All dogs were clinically staged and treated with either surgical excision alone or surgery plus C. parvum immunotherapy. There was no difference in survival time between the two treatment groups. However, in dogs with advanced disease (Stages II, III) there was a statistical difference between surgery alone versus surgery plus C. parvum (p = 0.01). Dogs with Stage I disease (tumor less than 2 cm diameter) had a statistically improved survival (p = 0.02) regardless of the therapy given. These results suggest that C. parvum, when combined with surgery, may have antitumor activity in the canine melanoma model.

Hemangiosarcoma in the cat: retrospective evaluation of 31 surgical cases

Hemangiosarcoma was diagnosed in 31 cats. Diagnosis was confirmed by surgical biopsy. Locations of the primary tumors were the abdominal cavity (15 cats), sc tissue (13 cats), thoracic cavity (2 cats), and nasal cavity (1 cat). Nine (60%) of the 15 cats with abdominal hemangiosarcoma had extrathoracic evidence of metastasis: this was not found in the other cats. Of the cats with tumors located in the sc tissue, 6 of 10 (60%) evaluated on a long-term basis had local recurrence of the tumor. Eleven cats were not available for follow-up evaluation, 3 cats were euthanatized at the time of surgery, and 2 others were euthanatized within the first postoperative week subsequent to histologic diagnosis of hemangiosarcoma. Of the remaining 15 cats, 4 with abdominal hemangiosarcoma and 5 with hemangiosarcoma of the sc tissue died at means of 22 and 44 weeks, respectively.

Levamisole as adjuvant to chemotherapy for canine lymphosarcoma

Ninety-eight dogs with previously untreated lymphosarcoma were selected for study. All dogs were clinically staged and stratified on the basis of stage. All dogs were treated with combination chemotherapy (vincristine, L-asparaginase, cyclophosphamide, and methotrexate) and randomized to either a levamisole or placebo group. There was no significant difference in either remission time or survival time between the levamisole and placebo groups. Clinical stage, age, and body weight had no influence on remission or survival time. The most significant prognostic factor was sex: Female dogs had significantly enhanced remission time (p = 0.004) and survival time (p = less than 0.001).

Feline mammary tumors

The characteristics of feline mammary cancer--that is, the rapid growth of primary mammary tumors, the high rate of tumor recurrence, and the poor survival statistics--demonstrate the need for (1) early diagnosis of the primary tumor; (2) immediate, aggressive surgical therapy; and (3) frequent follow-up examinations to detect early clinical signs of recurrent disease. A number of factors that influence prognosis have been described. As more information becomes available concerning the behavior of feline mammary tumors and the results of various forms of treatment, more effective protocols can be developed. Continued etiologic research may play a vital role in determining the direction of therapy.

Evaluation of effect of levamisole on feline mammary cancer

Seventy-three cats with untreated malignant mammary tumors (64 with adenocarcinoma, 9 with carcinoma in situ) were selected for study. All cats were clinically staged and stratified on the basis of tumor volume. Following radical mastectomy, the cats were randomized for treatment with either levamisole or placebo. There was no significant difference in either survival time or recurrence rate between the levamisole and placebo groups. The most significant prognostic factor was tumor volume: Cats with small tumors had a significantly enhanced survival time (p = 0.00006) and lower recurrence rate (p = 0.00004). Breed of cat was also an important prognostic factor; the domestic short-haired cats had a significantly (p = 0.038) longer survival time than the cats of other breeds.

Prognostic factors for feline mammary tumors

The case records of 100 cats with malignant mammary tumors were reviewed. All cats were staged clinically according to the staging system of the World Health Organization. The following information was obtained from the medical records: age at time of diagnosis, breed, tumor size, date of surgery, type of surgical procedure performed, histologic type of tumor, disease-free interval, survival time, and cause of death. Factors of no prognostic value were age (less than or equal to 10 years vs greater than 10 years) and breed. Tumor size was the most significant prognostic factor (P less than 0.0001). Cats with small tumors (1 cm3 to 8 cm3) had the best prognosis. The type of surgery, conservative vs radical, was significantly (P less than 0.01) related to disease-free interval, but was of no significance in prolonging survival time.

The epidemiology of the feline leukemia virus (FeLV)

Clustering of cases of feline lymphosarcoma (LSA) has been observed by veterinarians for many years. In 1964 it was discovered that feline LSA was caused by an oncornavirus, the feline leukemia virus (FeLV). In 1970, a simple, indirect immunoflourescent antibody (IFA) test for FeLV was developed which enabled large numbers of cats, living in their natural (household) environments, to be tested for the virus. In one study, over 2,000 cats were tested and the results showed conclusively that FeLV is a contagious agent for cats. This finding was independently confirmed by several other investigators using different testing procedures. After discovering the contagious nature of FeLV a test and removal program was devised which successfully prevents the spread of FeLV and the development of FeLV diseases in the pet cat population. There is, at present, no evidence that FeLV infects humans living with FeLV infected cats.