Pylephlebitis: a Review of 95 Cases

Journal of Gastrointestinal Surgery - Pylephlebitis, or suppurative thrombophlebitis of the portal mesenteric venous system occurring in the setting of abdominal inflammatory processes, is a rare...     

Antitumor activity of rituximab plus thalidomide in patients with relapsed/refractory mantle cell lymphoma

We evaluated a treatment strategy targeting both lymphoma cells (by rituximab) and the microenvironment (by thalidomide) in 16 patients with relapsed/refractory mantle cell lymphoma (MCL). Rituximab was administered at 375 mg/m(2) for 4 weekly doses concomitantly with thalidomide (200 mg daily, with a dose increment to 400 mg on day 15), which was continued as maintenance therapy until progression/relapse. Thirteen patients (81%) experienced an objective response, with 5 complete responders (31%). Median progression-free survival (PFS) was 20.4 months (95% confidence interval [CI], 17.3-23.6 months), and estimated 3-year survival was 75%. In patients achieving a complete response, PFS after rituximab plus thalidomide was longer than PFS after the preceding chemotherapy. Severe adverse events included 2 thromboembolic events and 1 grade IV neutropenia associated with thalidomide. Our results suggest that rituximab plus thalidomide has marked antitumor activity in relapsed/refractory MCL and a low toxicity profile, which warrants further evaluation in MCL.     

Structure and expression of spinach leaf cDNA encoding ribulosebisphosphate carboxylase/oxygenase activase.

Ribulosebisphosphate carboxylase/oxygenase activase is a recently discovered enzyme that catalyzes the activation of ribulose-1,5-bisphosphate carboxylase/oxygenase ["rubisco"; ribulose-bisphosphate carboxylase; 3-phospho-D-glycerate carboxy-lyase (dimerizing), EC 4.1.1.39] in vivo. Clones of rubisco activase cDNA were isolated immunologically from spinach (Spinacea oleracea L.) and Arabidopsis thaliana libraries. Sequence analysis of the spinach and Arabidopsis cDNAs identified consensus nucleotide binding sites, consistent with an ATP requirement for rubisco activase activity. A derived amino acid sequence common to chloroplast transit peptides was also identified. After synthesis of rubisco activase in vitro, the transit peptide was cleaved and the protein was transported into isolated chloroplasts. Analysis of spinach and Arabidopsis nuclear DNA by hybridization indicated a single rubisco activase gene in each species. Leaves of spinach and Arabidopsis wild type contained a single 1.9-kilobase rubisco activase mRNA. In an Arabidopsis mutant lacking rubisco activase protein, mRNA species of 1.7 and 2.1 kilobases were observed under conditions of high-stringency hybridization with a wild-type cDNA probe. This observation indicates that the lesion in the mutant arises from an error in mRNA processing.     

The role of replay and theta sequences in mediating hippocampal‐prefrontal interactions for memory and cognition

Sequential activity is seen in the hippocampus during multiple network patterns, prominently as replay activity during both awake and sleep sharp‐wave ripples (SWRs), and as theta sequences during active exploration. Although various mnemonic and cognitive functions have been ascribed to these hippocampal sequences, evidence for these proposed functions remains primarily phenomenological. Here, we briefly review current knowledge about replay events and theta sequences in spatial memory tasks. We reason that in order to gain a mechanistic and causal understanding of how these patterns influence memory and cognitive processing, it is important to consider how these sequences influence activity in other regions, and in particular, the prefrontal cortex, which is crucial for memory‐guided behavior. For spatial memory tasks, we posit that hippocampal‐prefrontal interactions mediated by replay and theta sequences play complementary and overlapping roles at different stages in learning, supporting memory encoding and retrieval, deliberative decision making, planning, and guiding future actions. This framework offers testable predictions for future physiology and closed‐loop feedback inactivation experiments for specifically targeting hippocampal sequences as well as coordinated prefrontal activity in different network states, with the potential to reveal their causal roles in memory‐guided behavior.     

Studies of adsorption of α,β-unsaturated carbonyl compounds on heterogeneous Au/CeO2, Au/TiO2 and Au/SiO2 catalysts during reduction by hydrogen

Our research focuses on phenomena accompanying adsorption of mesityl oxide (4-methylpent-3-en-2-one) on the surface of heterogeneous supported gold catalysts: Au/CeO₂, Au/TiO₂ and Au/SiO₂. We have studied reduction in the gas phase of (volatile) α,β-unsaturated carbonyl compounds (R-(V)ABUCC) which mesityl oxide is a basic model of. In situ infrared (IR) spectroscopy was employed to establish that the most active catalysts allow adsorption of conjugated ketones or aldehydes in the enolate (i.e. bridge-like adsorption through the oxygen from the carbonyl group and the β-carbon) and carboxylic form or with the ^αC ^βC double bond on a Lewis acidic site. Reductive properties of the catalysts and pure supports were studied by temperature-programmed reduction (TPR). We show that cerium(iv) oxide (CeO₂, ceria) and titanium(iv) oxide (TiO₂, titania) when decorated with gold nanoparticles (AuNP) can interact with hydrogen at temperatures approx. 150 °C lower than typical for pure oxides what includes even cyclic adsorption and instant release of H₂ below 100 °C in the case of gold–ceria system. Morphology and structure characterisation by transmission electron microscopy (TEM) and powder X-ray diffraction (PXRD) confirms that, with the obtained Au loadings, we achieved excellent dispersion of AuNPs while maintaining their small size, preferably below 5 nm, even though the Au/CeO₂ catalyst contained broad distribution of AuNPs sizes.

We deliver spectroscopic IR data describing the adsorption phenomena accompanying reduction of conjugated carbonyl compounds aided by heterogeneous catalysts.     

Lytic effector cell function in schizophrenia and depression

Natural killer (NK) cell activity and antibody-dependent cellular cytotoxicity (ADCC) were tested in patients with schizophrenia or depression. It was found that NK activity as well as ADCC were significantly lower in both groups, as compared to healthy control individuals (P less than 0.001). Psychopharmacologic treatment with neuroleptics and antidepressives resulted in a significant increase in NK activity and ADCC (P less than 0.005) in patients with schizophrenia but not in treated patients with depression. In patients with schizophrenia, no correlation could be established between the dose of neuroleptic given and the increase in NK activity. Lithium also did not produce an increase in NK activity and ADCC. The addition of serum, derived from untreated patients with schizophrenia, to cell cultures in concentrations of 10 and 20% had an inhibitory effect upon the ADCC and, to a lesser degree, upon NK activity (20% serum concentration only); sera from treatment schizophrenics produced no inhibition of NK activity, but did affect ADCC. No serum-derived inhibitory effect upon either NK activity or ADCC was found to be present in sera from patients with depression. We conclude that lytic effector mechanisms are impaired in patients with schizophrenia or depression and that this defect is reversed in schizophrenic patients on treatment, but not in depressives on therapy. Patients with schizophrenia also tend to have a reversible serum-mediated inhibition of NK activity which is absent in patients with depression.     

Cognitive-behavioral prevention of postconcussion syndrome.

The symptoms of postconcussion syndrome (PCS) are persistent, and no empirically tested treatment is available. The treatment group (n = 29) in this study received a printed manual and met with a therapist prior to hospital discharge to review the nature and incidence of expected symptoms, the cognitive-behavioral model of symptom maintenance and treatment, techniques for reducing symptoms, and instructions for gradual resumption of premorbid activities. The control group (n = 29) received routine hospital treatment and discharge instructions. Both groups had sustained mild head injuries characterized by Glascow Coma Scale scores of 13-15 on admission without any measurable period of posttraumatic amnesia. Group assignment was random. Groups did not differ significantly on age, Glascow scores, litigation status, gender, or initial number of PCS symptoms. Patients were contacted 6 months following injury by an interviewer who was unaware of group assignment to obtain outcome data. Treated patients reported significantly shorter average symptom duration (33 vs. 51 days) and significantly fewer of the 12 symptoms at followup (1.6 vs. 3.1). Subjects were also asked how often each symptom had occurred in the previous week, and how severe the symptom typically was. The treatment group experienced significantly fewer symptomatic days (.5 vs. 1.3) and lower mean severity levels. Results suggest that brief, early psychological intervention can reduce the incidence of PCS.     

Intraosseus transplantation of donor-derived hematopoietic stem and progenitor cells induces donor-specific chimerism and extends composite tissue allograft survival

We investigated the effect of the intraosseous allotransplantation of the donor-derived hematopoietic stem cells (HSC) CD90+ on chimerism induction and survival of rat hind limb transplants. Eighteen rat hind limb transplantations were performed between Lewis-Brown-Norway and Lewis rats in three groups. Isograft and allograft rejection controls received no treatment. In the experimental group, 0.8 to 1.2 x 10(6) of separated and purified CD90+ HSC cells were transplanted intramedullary into the bone marrow cavity of the recipient's tibia during opposite hind limb transplantation, without immunosuppressive therapy. Transplants from isograft group survived indefinitely. Allograft controls rejected transplants on day 7 posttransplant. The injection of separated and purified CD90+ cells of the donor origin extended survival of the transplanted limbs up to 15 days in group III. We introduced a novel method of transplantation of the CD90+ cells of the donor origin into the recipient's bone marrow cavity. This technique resulted in extended allograft survival, without immunosuppressive therapy.     

Quantification of islet size and architecture

Human islets exhibit distinct islet architecture particularly in large islets that comprise of a relatively abundant fraction of α-cells intermingled with β-cells, whereas mouse islets show largely similar architecture of a β-cell core with α-cells in the periphery. In humans, islet architecture is islet-size dependent. Changes in endocrine cell mass preferentially occurred in large islets as demonstrated in our recent study on pathological changes of the pancreas in patients with type 2 diabetes. ( 1) The size dependency of human islets in morphological changes prompted us to develop a method to capture the representative islet distribution in the whole pancreas section combined with a semi-automated analysis to quantify changes in islet architecture. The computer-assisted quantification allows detailed examination of endocrine cell composition in individual islets and minimizes sampling bias. The standard immunohistochemistry based method is widely applicable to various specimens, which is particularly useful for large animal studies but is also applied to a large-scale analysis of the whole organ section from mice. In this article, we describe the method of image capture, parameters measured, data analysis and interpretation of the data.