Increased platelet sensitivity to ADP in mice lacking platelet-type 12-lipoxygenase

Arachidonic acid metabolism is one of several mechanisms culminating in the production of an agonist for platelet activation and recruitment. Although the proaggregatory role of thromboxane A2, a product of the aspirin-inhibitable cyclooxygenase, is well established, relatively little is known regarding the biological importance of arachidonic acid metabolism via the 12-lipoxygenase (P-12LO) pathway to 12-hydro(pero)xyeicosatetraenoic acid. We observed that platelets obtained from mice in which the P-12LO gene has been disrupted by gene targeting (P-12LO-/-) exhibit a selective hypersensitivity to ADP, manifested as a marked increase in slope and percent aggregation in ex vivo assays and increased mortality in an ADP-induced mouse model of thromboembolism. The hyperresponsiveness to ADP is independent of dense granule release, cyclooxygenase-derived eicosanoid synthesis, and protein kinase C activity. The addition of 12-hydroxyeicosatetraenoic acid to P-12LO-/- platelet-rich plasma rescues the hyperresponsive phenotype resulting in a diminished ADP-induced aggregation profile. The enhanced ADP sensitivity of P-12LO-/- mice appears to reveal a mechanism by which a product of the P-12LO pathway suppresses platelet activation by ADP.     

High incidence of relapse after autologous stem-cell transplantation for B-cell chronic lymphocytic leukemia or small lymphocytic lymphoma

BACKGROUND: High-dose therapy followed by autologous stem-cell transplantation (autoSCT) induces complete remissions in the majority of patients with advanced B-cell chronic lymphocytic leukemia or small lymphocytic lymphoma (B-CLL). However, the long-term utility of this therapy for B-CLL is unknown. PATIENTS AND METHODS: Sixteen previously treated patients with B-CLL were transplanted using autologous blood (n = 13) or bone marrow (n = 3). The median age of the patients was 49 f1p4s (range 44-60 years), and the median number of prior chemotherapy regimens was two. Patients were eligible for transplantation if they had chemosensitive disease and no morphologic evidence of malignant cells in the graft. Preparative regimens included cyclophosphamide and total-body-irradiation, with or without cytarabine, or BEAC. RESULTS: All patients engrafted and achieved a complete remission posttransplant. Ten patients were alive at a median of 41 months (range 22-125 months), and five were disease-free. Eight patients have relapsed and six have died (three from progressive malignancy). The projected three-year overall survival, failure-free survival and relapse rates were 68%, 37%, and 56%, respectively. CONCLUSIONS: AutoSCT for advanced B-CLL is associated with a high relapse rate. Whether this therapy can prolong life or produce cures is uncertain.     

Gastric extramedullary plasmacytoma in a cat

A 5-year-old boy developed hemorrhagic mucocutaneous blisters on various parts of the body leading to fetor, dysphagia, dysuria, anal pruritus, pain on defecation, and weight loss. The histopathology showed the classic features of pemphigus vulgaris, and direct immunofluorescence showed intercellular deposition of IgG and C3 in the epidermis. Circulating pemphigus antibodies were also detected. He was treated with a combination of systemic prednisone and dapsone which induced a rapid remission and controlled the disease well. He has been in remission for 1 year and 7 months with no immunosuppressive therapy except for the use of topical agents for the oral lesions. An adjuvant to corticosteroids has been used only once before in children with pemphigus vulgaris under the age of 12 years. This is the third and the youngest child in the literature treated in this fashion.     

Sunlight exposure, hat use, and squamous cell skin cancer on the head and neck

TF (tissue factor) is a physiological inhibitor of blood coagulation in normal hemostasis and is a major initiator of clotting in thrombotic disease. TF functions as a protein cofactor for FVIIa. Coagulation at a site of injury is initiated by exposure of blood to cell-surface formation of TF/VIIa complex. The TF/VIIa complex then activates both factors IX and X leading to thrombin generation and fibrin formation. TFPI (tissue factor pathway inhibitor) appears to play a primary role in regulating TF-induced coagulation. Abnormal coagulation may contribute to the pathogenesis of many serious illnesses. In particular, induced expression of TF and TF-mediated coagulation occurs in atherosclerotic plaques, sepsis, malignancy, ARDS and glomerulonephritis. Several observations support the need for exogenous TFPI administration to effectively turn off the TF/VIIa complex in several clinical conditions with TF-induced coagulopathy. There are some reports about successful administration of rTFPI for antithrombotic therapy in humans.     

Evaluation of intracranial cysts by intraoperative MR

Eleven patients with intracranial cystic collections were evaluated in the open-bore intraoperative MR system. In each case, the cystic collection or the surrounding cerebrospinal fluid (CSF) space was injected with .02 to .5 cc of .5 mol/l gadopentetate dimeglumine. Serial imaging was performed using T1-weighted imaging. In seven patients, free communication was demonstrated between the cystic collection and the surrounding CSF spaces. In four cases, the cyst did not communicate with the CSF; two of these were drained in the intraoperative MR system with reduction in symptoms. One patient developed an aseptic meningitis 10 days after the study, which was successfully treated with steroids; no other complications were noted. We conclude that the communication of intracranial cystic collections with the cisterns and ventricles can be safely and effectively elucidated with gadolinium injection in the intraoperative MR system.     

Patients with isolated trisomy 8 in acute myeloid leukemia are not cured with cytarabine-based chemotherapy: results from Cancer and Leukemia Group B 8461

To date, neither the clinical significance of isolated trisomy 8, the most frequent trisomy in acute myeloid leukemia (AML), nor the effect of age within a single cytogenetic group has been examined. We report a large cohort of adult trisomy 8 patients and examine whether increasing age within a homogeneous cytogenetic group alters clinical outcome. Characteristics and outcome of patients with isolated trisomy 8 enrolled in the prospective Cancer and Leukemia Group B (CALGB) cytogenetic study CALGB 8461 are described. Isolated trisomy 8 was identified in 42 (3.03%) of 1387 patients enrolled in five CALGB treatment protocols. These patients had a median age of 64 (range, 16-79) years, 50% female proportion, and a low frequency of hepatomegaly (10%) or splenomegaly (10%). Laboratory features included a median white blood count of 7.3 x 10(9)/L, nonspecific French-American-British distribution, with 36% of patients having Auer rods. Treatment outcome was unsatisfactory with a complete remission (CR) rate of 59%, median CR duration of 13.6 months, and median survival of 13.1 months. Older age adversely affected outcome; trisomy 8 patients > or =60 years had both an inferior CR rate (40% versus 88%; P = 0.004) and overall survival (median, 4.8 versus 17.5 months; P = 0.01), as compared with those <60 years of age. Of the patients <60 years of age, only four remain alive, and all received noncytarabine-based intensive chemotherapy, followed in three cases by autologous (n = 2) or allogeneic (n = 1) stem cell transplant in CR1. Adults with AML and isolated trisomy 8 have a poor outcome that is accentuated by increasing age and is rarely cured with cytarabine-based therapy. Alternative investigational treatments should be considered for individuals with this AML subset.     

DNA fragmentation in human substantia nigra: apoptosis or perimortem effect?

DNA fragmentation was examined in situ in flash-frozen human postmortem midbrain as a marker for programmed cell death. A large series of cases comprising 16 pathologically confirmed idiopathic Parkinson's disease (IPD) cases, 14 control cases without brain pathology, and a group of 6 patients with other parkinsonian movement disorders were examined using TdT-mediated dUTP-biotin 3' end-labeling histology. Labeling of neurons and glia was seen in the substantia nigra of control and IPD cases and in other movement disorder cases. Labeled nuclei were seen in melanized nigral neurons; apoptotic bodies were also found but were more commonly associated with nigral glia. In the control group, labeling of neurons and glia was strongly associated with poor agonal status, assessed by tissue pH, a marker for antemortem hypoxia. The mean tissue pH of the control group with neuronal labeling was 6.28 (SEM .057), which was significantly different from that of the unlabeled group 6.55 (SEM .055). Mean tissue pH for all cases was 6.38. There was no association of nigral neuronal labeling with poor agonal status in the IPD cases, which showed labeling throughout the range of pH values. However, extranigral labeling, seen in the mesencephalon, red nucleus, superior colliculus, rostral pons, and periaqueductal gray matter, in all three subject groups was associated with tissue pH values of less than 6.3. These findings suggest that DNA fragmentation is influenced by antemortem hypoxia and that apoptosis-like changes seen in the postmortem nigra may parallel those seen in experimental ischemia in the animal brain. The likely influence of perimortem factors on these changes indicates that results from postmortem studies of apoptotic cell death in neurodegenerative disease should be treated with caution and underlines the importance of determining postmortem markers for agonal status in human brain.     

20q gain associates with immortalization: 20q13.2 amplification correlates with genome instability in human papillomavirus 16 E7 transformed human uroepithelial cells

Pisatin is the major phytoalexin produced by pea upon microbial infection. The enzyme that catalyzes the terminal step in the pisatin biosynthetic pathway is (+)6a-hydroxymaackiain 3-O-methyltransferase (HMM). We report here the isolation and characterization of two HMM cDNA clones (pHMM1 and pHMM2) made from RNA obtained from Nectria haematococca-infected pea tissue. The two clones were confirmed to encode HMM activity by heterologous expression in Escherichia coli. The substrate specificity of the methyltransferases in E. coli was similar to the activity detected in CuCl2-treated pea tissue. Nucleotide sequence analysis of Hmm1 and Hmm2 revealed an open reading frame of 1080 bp and 360 amino acid residues which would encode 40.36 kda and 40.41 kDa polypeptides, respectively. The deduced amino acid sequence of HMM1 has 95.8% identity to HMM2, 40.6% identity to Zrp4, a putative O-methyltransferase (OMT) in maize root, and 39.1% to pBH72-F1, a putative OMT induced in barley by fungal pathogens or UV light. Comparison of the deduced amino acid sequences of the cDNA clones to OMTs from other higher plants identified the binding sites of S-adenosylmethionine (AdoMet). Southern blot analysis showed two closely linked genes with strong homology to Hmm in the pea genome.     

Family support services for stroke patients

Provision of long-term support and rehabilitation after stroke varies in the UK. Patients and their carers are not always aware of services available. Family support service organisers can help increase awareness of risk factors and minimise recurrence of stroke.