Presumed primary cardiac mast cell tumor, pericardial effusion, and arrhythmia in a dog.

A 13-year-old female spayed border collie cross presented for pericardial effusion, arrhythmia, and a suspected cardiac mass. Echocardiogram revealed severe thickening and hypokinesis of the interventricular septum with a heterogenous, cavitated myocardium, concerning for neoplasia. Electrocardiogram revealed predominantly accelerated idioventricular rhythm with frequent periods of nonsustained ventricular tachycardia. Occasional prolonged PR intervals terminating in an aberrantly conducted QRS complex were present. These beats were postulated to represent either first-degree atrioventricular block with aberrant QRS conduction or atrioventricular dissociation. Cytology of the pericardial effusion revealed atypical, suspected neoplastic, mast cells. The patient was euthanized, and postmortem examination confirmed full-thickness infiltration of the interventricular septum by a mast cell tumor, with metastasis to the tracheobronchial lymph node and spleen. Given the anatomic location of the mass, the observed atrioventricular nodal conduction delay may represent neoplastic infiltration of the atrioventricular node. Neoplastic infiltration of the ventricle was suspected to cause the accelerated idioventricular rhythm and ventricular tachycardia. To the authors' knowledge, this is the first reported case of a primary cardiac mast cell tumor causing arrhythmia and pericardial effusion in a dog.

Systems Pharmacology Approach for Prediction of Pulmonary and Systemic Pharmacokinetics and Receptor Occupancy of Inhaled Drugs.

Pulmonary drug disposition after inhalation is complex involving mechanisms, such as regional drug deposition, dissolution, and mucociliary clearance. This study aimed to develop a systems pharmacology approach to mechanistically describe lung disposition in rats and thereby provide an integrated understanding of the system. When drug- and formulation-specific properties for the poorly soluble drug fluticasone propionate were fed into the model, it proved predictive of the pharmacokinetics and receptor occupancy after intravenous administration and nose-only inhalation. As the model clearly distinguishes among drug-specific, formulation-specific, and system-specific properties, it was possible to identify key determinants of pulmonary selectivity of receptor occupancy of inhaled drugs: slow particle dissolution and slow drug-receptor dissociation. Hence, it enables assessment of factors for lung targeting, including molecular properties, formulation, as well as the physiology of the animal species, thereby providing a general framework for rational drug design and facilitated translation of lung targeting from animal to man.

Polyethylene glycol-drug ester conjugates for prolonged retention of small inhaled drugs in the lung.

Typically, inhaled drugs are rapidly absorbed into the bloodstream, which results in systemic side effects and a brief residence time in the lungs. PEGylation was evaluated as a novel strategy for prolonging the retention of small inhaled molecules in the pulmonary tissue. Hydrolysable ester conjugates of PEG1000, PEG2000, 2000, PEG3400 and prednisolone, a model drug cleared from the lungs within a few minutes, were synthesised and thoroughly characterised. The conjugates were stable in buffers with hydrolysis half-lives ranging from 1h to 70 h, depending on the pH and level of substitution. With the exception of PEG3400-prednisolone, conjugates did not induce a significant lactate dehydrogenase (LDH) release from Calu-3 cells after a 20 h exposure. Following nebulisation to isolated perfused rat lungs (IPRL), the PEG2000 and mPEG2000 conjugates reduced the maximum prednisolone concentration in the perfusate (Cmax) by 3.0 and 2.2 fold, respectively. Moreover, while prednisolone was undetectable in the perfusion solution beyond 20 min when the free drug was administered, prednisolone concentrations were still quantifiable after 40 min following delivery of the conjugates. This study is the first to demonstrate hydrolysable PEG drug ester conjugates are a promising approach for optimising the pharmacokinetic profile of small drugs delivered by inhalation.

Local gene delivery of heme oxygenase-1 by adeno-associated virus into osteoarthritic mouse joints exhibiting synovial oxidative stress.

OBJECTIVE: To evaluate the role of synovial oxidative stress on joint pathology in a spontaneous mouse model of osteoarthritis (OA) by intra-articular (IA) delivery of recombinant adeno-associated virus (rAAV) expressing anti-oxidant protein heme oxygenase-1 (HO-1). METHODS: Joint transduction by rAAV vectors was evaluated with serotype 1, 2, 5 and 8 capsids carrying LacZ gene administered by IA injections into STR/ort mice. Transduced cell types were identified by ß-galactosidase staining in sectioned joints. Effect of oxidative stress on AAV transduction of primary synoviocytes in vitro was quantitated by fluorescence-activated cell sorting (FACS) analysis. In vivo, the efficacy of rAAV1/HO-1 was tested by IA administration into STR/ort mice followed by histopathological scoring of cartilage. Levels of 3-nitrotyrosine (3-NT) and HO-1 were assessed by immunohistochemistry (IHC) of joint sections. RESULTS: Administration of a rAAV1 based vector into OA mouse joints resulted in transduction of the synovium, joint capsule, adipocytes and skeletal muscle while none of the serotypes showed significant cartilage transduction. All OA joints exhibited significantly elevated levels of oxidative stress marker, 3-NT, in the synovium compared to OA-resistant CBA-strain of mice. In vitro studies demonstrated that AAV transgene expression in primary synoviocytes was augmented by oxidative stress induced by H(2)O(2) and that a rAAV expressing HO-1 reduced the levels of oxidative stress. In vivo, HO-1 was increased in the synovium of STR/ort mice. However, delivery of rAAV1/HO-1 into OA joints did not reduce cartilage degradation. CONCLUSIONS: AAV-mediated HO-1 delivery into OA joints during active disease was not sufficient to improve cartilage pathology in this model.

Sentinel node procedure in vulvar squamous cell carcinoma: a histomorphologic review of 32 cases. The significance of anucleate structures on immunohistochemistry.

The sentinel lymph node (SLN) procedure is used in our institute in the setting of an observational multicenter study investigating the reliability of the sentinel node procedure in vulvar carcinoma (GROINSS-V: The Groningen International Study on Sentinel Nodes in Vulvar Cancer). One of our patients had a groin recurrence where the SLN had been reported as negative. After reviewing this SLN, it contained several anucleate, keratin-positive structures on immunohistochemistry, and in the same area on hematoxylin and eosin coloring, one single cell with a nucleus interpreted as a tumor cell. Our objective was to assess how frequently these anucleate structures occur and whether such nodes should be regarded as positive. The sentinel nodes from 32 patients with early-stage vulvar squamous cell carcinoma were reviewed. Seventy-seven SLN's were identified. In ten patients, the SLN was positive and a bilateral inguinofemoral lymph node dissection was subsequently performed. In two of these ten patients, both with a macrometastasis on SLN, further metastatic disease was present in the dissection specimen. Anucleate keratin-positive structures were seen on immunohistochemistry in 14 SLN's (18%), usually along with metastasis or single tumor cells, but in five nodes this was the only abnormality (mean follow-up period of 26.28 months). Anucleate keratin-positive structures are a common finding in immunohistochemical examination of SLN's. Our findings suggest that they are of no clinical significance and the SLN should be regarded as negative. When an atypical cell with a nucleus is present, the SLN should be classified as positive and further management should be accordingly.

Recurrent endometrial cancer: a retrospective study.

OBJECTIVE: The value of follow-up after treatment for endometrial cancer will be discussed. STUDY DESIGN: We evaluated our clinical experience, including mode of detection, of patients with recurrent endometrial cancer treated in the Erasmus Medical Centre in Rotterdam over a 20-year period. Clinical data and histopathological features from 64 patients were analyzed. Survival was analyzed with a Kaplan-Meier curve. RESULTS: Twenty-two patients had a local recurrence, 30 had a distant recurrence and 12 had simultaneous local and distant recurrent disease. Ninety-five percent of the local recurrences and 67% of the distant recurrences were detected within three years. Twenty-seven patients had a screen-detected recurrence, 34 had an interval screening recurrence and two had a chance finding recurrence. The overall survival rate at two years was 70% and at five years 53%. Patients with a screen-detected recurrence had a 5-year survival rate of 62%, while patients with interval screening and chance finding recurrences had a 5-year survival rate of 47%. CONCLUSION: A follow-up program in the first three years after primary treatment of endometrial cancer is useful in detecting recurrent disease. We have no reason to use a different program of follow-up in patients with low risk primary disease.

Epithelioid trophoblastic tumour: a case report and review of the literature.

Epithelioid trophoblastic tumour (ETT) is an unusual type of trophoblastic tumour, which can cause difficulties in diagnosis and (as a consequence) in treatment. The literature suggests that surgery should be the treatment of choice for ETT as it is not responsive to chemotherapeutic agents, used in the treatment of other types of gestational trophoblastic diseases. This case report describes an ETT, which was initially diagnosed as a carcinoma of the cervix. Surgical management was chosen based on the literature. 6 months later the patient also developed a plasmacytoma and was treated with radiotherapy. The occurrence of ETT and plasmacytoma in combination has never been described before. This case report describes a rare case of an atypical trophoblastic tumour, with problematic differential diagnosis. Treatment of carcinoma of the cervix would have necessitated postoperative radiotherapy, but on diagnosis of ETT, surgical management was considered sufficient. Hence, it is important to consider the occurrence of ETTs, although rare, in patients with atypical cervical or endometrial cancer, and in patients diagnosed with a gestational trophoblastic tumour, who do not respond to appropriate chemotherapy.

Alterations in the p53 pathway and prognosis in advanced ovarian cancer: a multi-factorial analysis of the EORTC Gynaecological Cancer group (study 55865).

PURPOSE: The study was designed to determine independent prognostic variables in suboptimally debulked advanced ovarian cancer patients entered in the randomised phase III study EORTC 55865. EXPERIMENTAL DESIGN: Retrospectively collected paraffin blocks from 169 patients with stages IIb-IV epithelial ovarian cancer, taken at primary debulking surgery, were analysed. All patients were treated with cyclophosphamide and cisplatin (CP), and followed up for a median of 10 years. Expression of p53, bcl-2, P21, Ki-67 and HER-2 status was assessed by immunohistochemistry (IHC). RESULTS: Expression of p21, a downstream effector of the p53 gene, was found to be a favourable prognostic factor for survival (HR 0.58, CI 0.36-0.94, p=0.025) in addition to FIGO stage (HR 1.54, CI 1.08-2.21, p=or<0.02). For progression free survival (PFS), both p21 (HR 0.52) and Ki-67 (HR 0.6) were significant factors. CONCLUSION: P21 overexpression is a positive prognostic factor for survival and PFS in advanced ovarian carcinoma with residual lesions of more than 1 cm.

Stage III and IV endometrial cancer: a 20-year review of patients.

In advanced endometrial cancer, the importance of peritoneal cytology and optimal surgical cytoreduction remain subjects of discussion. We evaluated our clinical experience of 67 patients with FIGO stage III and IV endometrial cancer treated in the Erasmus Medical Centre in Rotterdam over a 20-year period with an emphasis on stage IIIA disease based on positive cytology only and optimal cytoreduction. Lymphadenectomy was not routinely performed and peritoneal cytology was examined in 74% of the patients. Stage IIIA disease was found in 33 patients, 10 of whom had positive cytology only. Analysis showed that incidence of recurrence and survival rates of patients with stage IIIA disease based on positive cytology only were comparable with stage IIIA disease based on other factors. In 50 patients, it was possible to remove all macroscopic tumor, whereas in 17 patients, an optimal cytoreduction was not achievable. The 2- and 5-year survival rates after optimal cytoreduction were 82.2% and 65.6%; where this could not be achieved, these figures were 50.8% and 40.6%. In advanced endometrial cancer patients, positive peritoneal cytology seems an important prognostic factor in stage IIIA disease if lymph node status is unknown. Survival is improved if optimal surgical cytoreduction is achievable.

Tamoxifen treatment for breast cancer enforces a distinct gene-expression profile on the human endometrium: an exploratory study.

Tamoxifen treatment for breast cancer increases proliferation of the endometrium, resulting in an enhanced prevalence of endometrial pathologies, including endometrial cancer. An exploratory study was performed to begin to understand the molecular mechanism of tamoxifen action in the endometrium. Gene-expression profiles were generated of endometrial samples of tamoxifen users and compared with matched controls. The pathological classification of samples from both groups included atrophic/inactive endometrium and endometrial polyps. Unsupervised clustering revealed that samples of tamoxifen users were, irrespective of pathological classification, fairly similar and consequently form a subgroup distinct from the matched controls. Using SAM analysis (a statistical method to select genes differentially expressed between groups), 256 differentially expressed genes were selected between the tamoxifen and control groups. Upon comparing these genes with oestrogen-regulated genes, identified under similar circumstances, 95% of the differentially expressed genes turned out to be tamoxifen-specific. Finally, construction of a gene-expression network of the differentially expressed genes revealed that 69 genes centred around five well-known genes: TP53, RELA, MYC, epidermal growth factor receptor and beta-catenin. This could indicate that these well-known genes, and the pathways in which they function, are important for tamoxifen-controlled proliferation of the endometrium.

Expression of heme oxygenase-1 protects endothelial cells from irradiation-induced apoptosis.

A common side effect of therapeutic use of ionizing irradiation is endothelial cell damage resulting in a variety of clinical complications. Thus, preservation of endothelial function after irradiation could potentially limit toxicity. Using the murine endothelioma cell line bEnd2 we show here that induction of heme oxygenase-1 (HO-1) by cobalt protoporphyrine IX (CoPP) inhibits irradiation-induced apoptosis. In contrast, HO-1 induction by tin protoporphyrine IX (SnPP), a HO-1 inhibitor, does not affect survival after irradiation. The protective effects of CoPP could be partially reversed by blockade of HO-1 function with SnPP after induction by CoPP. Vice versa, blockade of HO-1 function by SnPP was reversible using CoPP. Treatment with CoPP inhibited cytochrome c release induced by irradiation. These results demonstrate that HO-1 induction and activation prior to irradiation inhibits endothelial apoptosis and might be used for possible cell protection in vivo.

A shift to a peripheral Th2-type cytokine pattern during the carcinogenesis of cervical cancer becomes manifest in CIN III lesions.

BACKGROUND: A shifted balance between T helper 1 (Th1)-type and Th2-type cytokines has been hypothesised in cervical dysplasia. AIMS: To evaluate possible deregulation of the cytokine network by estimating the expression of peripheral cytokines in different stages of cervical disease and in relation to the presence or absence of high risk human papillomavirus (HR-HPV). METHODS: Twenty one HR-HPV positive women with high grade cervical intraepithelial neoplasia (CIN II-III) and 12 patients with invasive cervical carcinoma formed the study groups. Two control groups consisted of 10 HR-HPV positive and 11 HR-HPV negative women without CIN. Differences in leucocyte subgroups were evaluated by a differential leucocyte count. Plasma concentrations of tumour necrosis factor alpha (TNFalpha), TNFalpha receptors TNFRI and TNFRII, interferon gamma (IFNgamma), interleukin 2 (IL-2), IL-12, IL-4, and IL-10 were determined by enzyme linked immunosorbent assays. RESULTS: Leucocyte counts in patients with CIN III and carcinoma were significantly higher than in controls. Plasma IFNgamma concentrations were significantly lower in patients with CIN III and carcinoma than in women with CIN II or controls. Plasma concentrations of IL-12, IL-2, IL-4, and TNFalpha did not differ significantly between groups, but significantly lower plasma concentrations of TNFRII were found in CIN III and carcinoma compared with CIN II. IL-10 was detected with increased frequency in the plasma of patients with CIN III and carcinoma. CONCLUSIONS: These results indicate that a shift to a Th2-type cytokine pattern during the carcinogenesis of cervical cancer occurs in women with CIN III lesions.

Primitive neuroectodermal tumor of the cervix uteri: a case report -- changing concepts in therapy.

BACKGROUND: Peripheral primitive neuroectodermal tumor (PNET) of the cervix uteri is extremely rare. Between 1987 and 2002, there have been eight cases described in the English literature. The treatment policies in these eight cases differed considerably, partly due to the rarity of the disease and to differing time periods of diagnosis and treatment. CASE: At the end of 2002, a 21-year-old woman presented with a PNET of the cervix uteri at our institute, the Erasmus Medical Center. For the appropriate treatment in this case, we reviewed the literature and decided that the treatment should be different from the local surgical treatment followed by additional treatments as most of the earlier reports describe. CONCLUSION: In view of the current knowledge of PNET belonging to the family of Ewing's sarcoma, and the improvement of treatment outcome in these tumors due to dose-intensive neo-adjuvant chemotherapy, patients with PNET of the cervix should be treated in accordance to the protocol for bony Ewing's sarcoma with multimodality therapy by means of induction chemotherapy, surgery, and consolidation chemotherapy.

Novel erythromycin derivatives with aryl groups tethered to the C-6 position are potent protein synthesis inhibitors and active against multidrug-resistant respiratory pathogens.

A novel series of erythromycin derivatives has been discovered with potent activity against key respiratory pathogens, including those resistant to erythromycin. These compounds are characterized by having an aryl group tethered to the C-6 position of the erythronolide skeleton. Extensive structural modification of the C-6 moiety led to the discovery of several promising compounds with potent activity against both mef- and erm-mediated resistant Streptoccoccus pneumoniae. Preliminary mechanistic studies indicated that the new macrolides are potent protein synthesis inhibitors, which interact with methylated ribosomes isolated from resistant organisms. In experimental animal models, these compounds exhibited excellent in vivo efficacy and balanced pharmacokinetic profiles.

Efficacies of ABT-773, a new ketolide, against experimental bacterial infections.

ABT-773 is a novel ketolide effective against antibacterial-resistant respiratory tract pathogens. The pharmacokinetic profile of ABT-773 was studied in rats and consisted of a mean peak concentration in plasma of 1.07 microg/ml and an area under the concentration-time curve (AUC) of 12.03 microg. h/ml when the compound was delivered at a dose of 25 mg/kg of body weight. It concentrated in rat lung tissue, with a lung tissue-to-plasma ratio of 29 based on the AUC. In acute systemic infections in mice, ABT-773 showed efficacy against macrolide-susceptible strains of Staphylococcus aureus, Streptococcus pneumoniae, S. pyogenes, and Listeria monocytogenes. Additionally, ABT-773 improved the survival of mice infected with resistant S. pneumoniae containing either the ermB gene, the mefE gene, or altered penicillin binding protein genes. In a rat lung model of infection, ABT-773 demonstrated 50% effective doses lower than those of comparator macrolides when evaluated against the following strains of S. pneumoniae: a macrolide-lincosamide-streptogramin B-susceptible strain, an ermB strain, and an mefE strain. ABT-773 was also effective against Haemophilus influenzae lung infections in rats. Thus, ABT-773 may prove to be a useful new antibacterial agent for the treatment of respiratory tract infections.

Identification and characterization of A-105972, an antineoplastic agent.

A high-throughput screening assay was designed to select compounds that inhibit the growth of cultured mammalian cells. After screening more than 60,000 compounds, A-105972 was identified and selected for further testing. A-105972 is a small molecule that inhibits the growth of breast, central nervous system, colon, liver, lung, and prostate cancer cell lines, including multidrug-resistant cells. The cytotoxic IC50 values of A-105972 were between 20 and 200 nM, depending on the specific cell type. The potency of A-105972 is similar in cells expressing wild-type or mutant p53. A majority of cells treated with A-105972 were trapped in the G2-M phases, suggesting that A-105972 inhibits the progression of the cell cycle. Using [3H]A-105972, we found that A-105972 bound to purified tubulin. Unlabeled A-105972 competed with [3H]A-105972 binding with an IC50 value of 3.6 microL. Colchicine partially inhibited [3H]A-105972 binding with an IC50 value of approximately 90 microM, whereas paclitaxel and vinblastine had no significant effect. Tumor cells treated with A-105972 were observed to contain abnormal microtubule arrangement and apoptotic bodies. DNA ladder studies also indicated that A-105972 induced apoptosis. A-105972 caused a mobility shift of bcl-2 on SDS-PAGE, suggesting that A-105972 induced bcl-2 phosphorylation. A-105972 treatment increased the life span of mice inoculated with B16 melanoma, P388 leukemia, and Adriamycin-resistant P388. These results suggest that A-105972 is a small molecule that interacts with microtubules, arrests cells in G2-M phases, and induces apoptosis in both multidrug resistance-negative and multidrug resistance-positive cancer cells. A-105972 and its analogues may be useful for treating cell proliferative disorders such as cancer.

Discovery of a series of cyclohexylethylamine-containing protein farnesyltransferase inhibitors exhibiting potent cellular activity.

Synthesis of a library of secondary benzylic amines based on the Sebti-Hamilton type peptidomimetic farnesyltransferase (FTase) inhibitor FTI-276 (1) led to the identification of 6 as a potent enzyme inhibitor (IC(50) of 8 nM) which lacked the problematic thiol residue which had been a common theme in many of the more important FTase inhibitors reported to date. It has previously been disclosed that addition of o-tolyl substitution to FTase inhibitors of the general description 2 had a salutary effect on both FTase inhibition and inhibition of Ras prenylation in whole cells. Combination of these two observations led us to synthesize 7, a potent FTase inhibitor which displayed an IC(50) of 0.16 nM for in vitro inhibition of FTase and an EC(50) of 190 nM for inhibition of whole cell Ras prenylation. Modification of 7 by classical medicinal chemistry led to the discovery of a series of potent FTase inhibitors, culminating in the identification of 25 which exhibited an IC(50) of 0.20 nM and an EC(50) of 4.4 nM. In vivo tests in a nude mouse xenograft model of human pancreatic cancer (MiaPaCa cells) showed that oral dosing of 25 gave rise to impressive attenuation of the growth of this aggressive tumor cell line.