Reversal of startle gating deficits in transgenic mice overexpressing corticotropin-releasing factor by antipsychotic drugs.

Chronically elevated levels of corticotropin-releasing factor (CRF) in transgenic mice overexpressing CRF in the brain (CRF-OE) appear to be associated with alterations commonly associated with major depressive disorder, as well as with sensorimotor gating deficits commonly associated with schizophrenia. In the present study, we tested the hypothesis that antipsychotics may be effective in normalizing prepulse inhibition (PPI) of acoustic startle in CRF-OE mice, which display impaired sensorimotor gating compared to wild-type (WT) mice. The typical antipsychotic haloperidol and atypical antipsychotic risperidone improved PPI in the CRF-OE mice, but were ineffective in WT mice. The atypical antipsychotic clozapine did not influence PPI in CRF-OE mice, but reduced gating in WT mice. This effect of clozapine in the CRF-OE mice may thus be regarded as a relative improvement, consistent with the observed effect of haloperidol and risperidone. As expected, the anxiolytic, nonantipsychotic chlordiazepoxide was devoid of any effect. All four compounds dose-dependently reduced the acoustic startle response irrespective of genotype. These results indicate that antipsychotic drugs are effective in improving startle gating deficits in the CRF-OE mice. Hence, the CRF-OE mouse model may represent an animal model for certain aspects of psychotic depression, and could be a valuable tool for research addressing the impact of chronically elevated levels of CRF on information processing.     

Use of the deoxyuridine suppression test to evaluate localized folate deficiency in rat colonic epithelium

In this study the deoxyuridine suppression test (dUST) was performed on isolated rat colonocytes to establish its value as an indicator of folate status in the colonic epithelium. [3H]thymidine incorporation into DNA was suppressed greater than 90% by deoxyuridine (dU) concentrations greater than 2.5 mumol/L. Preincubation of cells with 5-fluorouracil (1-100 mumol/L) but not methotrexate (10-100 mumol/L) resulted in a significant decrease in the degree of suppression. The dUST performed on colonocytes from folate-deficient animals displayed less suppression than on colonocytes from folate-replete animals (P less than 0.05). The abnormal degree of suppression was corrected by adding 100 mumol folinic acid/L. There was a negative correlation between the degree of suppression and the folate concentration of the colonic epithelium (P less than 0.001). These data indicate that the dUST is useful for detecting folate deficiency in the colonic epithelium and may therefore be valuable in assessing a deficiency state localized to that epithelium.     

Mesenteric vein thrombosis associated with primary cytomegalovirus infection: a case report.

In the past few years several studies have supported an interplay between cytomegalovirus infections and a prothrombotic state. We describe a case of primary cytomegalovirus infection in an immunocompetent adult that was complicated with mesenteric vein thrombosis. Transient protein C deficiency, lupus anticoagulant and activated protein C resistance were found, in combination with a heterozygous prothrombin G20210A mutation. We discuss the possible mechanisms of cytomegalovirus-related venous thrombosis.     

Development of three parallel cytochrome P450 enzyme affinity detection systems coupled on-line to gradient high-performance liquid chromatography.

A high resolution screening (HRS) technology is described, in which gradient high-performance liquid chromatography (HPLC) is connected on-line to three parallel placed bioaffinity detection systems containing mammalian cytochromes P450 (P450s). The three so-called enzyme affinity detection (EAD) systems contained, respectively, liver microsomes from rats induced by beta-naphthoflavone (CYP1A activity), phenobarbital (CYP2B activity), and dexamethasone (CYP3A activity). Each P450-EAD system was optimized for enzyme, substrate, and organic modifier (isopropyl alcohol, methanol, and acetonitrile) in flow injection analysis mode. Characteristic P450 ligands were used to validate the P450-EAD systems. IC(50) values of the ligands were measured and found to be similar to those obtained with conventional microtiter plate reader assays. Detection limits (n = 3; signal-to-noise ratio = 3) of potent inhibitors ranged from 1 to 3 pmol for CYP1A activity, 4 to 17 pmol for CYP2B activity, and 4 to 15 pmol for CYP3A activity. The three optimized P450-EAD systems were subsequently coupled to gradient HPLC and used to screen compound mixtures for individual ligands. Finally, to increase analysis efficiency, a HRS system was constructed in which all three P450-EAD systems were coupled on-line and in parallel to gradient HPLC. The triple parallelized P450-EAD system was shown to enable rapid profiling of individual components in complex mixtures for inhibitory activity to three different P450s.     

The use of recombinant-activated factor VII in von Willebrand disease: a case series.

Spontaneous and surgery-associated bleeding in patients with von Willebrand disease (vWD) cannot always be controlled with desmopressin or replacement therapy. This paper presents results on the use of recombinant-activated factor VII (rFVIIa) in patients with vWD included in the internet registry Haemostasis.com. Twenty-eight reports on the use of rFVIIa in vWD were identified from the database and included in this analysis. The bleeding episodes were classified as mild (n = 7), moderate (n = 16), or severe (n = 2), and were unspecified in three cases. The median dose of rFVIIa administered was 94 microg/kg body weight (40-127.3 microg/kg). Bleeding stopped in 23 of 27 evaluable patients (85%) and markedly decreased in three patients; the total response rate was 96% (26/27 patients). Response did not correlate with the type of vWD, the site or severity of the initial bleed, or the rFVIIa dose. Other replacement therapies were infrequently used, and their use was similar in the 24 h before and after rFVIIa administration. Eighteen patients also received antifibrinolytic treatment, but its impact on response was not recorded. Only one adverse event (mild fever) was observed. These cases suggest a role for rFVIIa as a safe and effective therapy for vWD.     

Standardized quick en bloc technique for procurement of cadaveric liver grafts for pediatric liver transplantation

This paper describes a quick procedure for cadaveric liver graft retrieval during multiple organ harvesting. The technique is based on minimal preliminary dissection, absence of in situ direct portal perfusion, and en bloc removal of the liver and pancreas, with an aortic patch encompassing the coeliac trunk and superior mesenteric artery. The results of 110 pediatric liver transplantations with 109 organs harvested using this technique are reported. There were no graft harvesting injuries. The liver graft primary nonfunction rate was 4.5% (5/110). The 3-month retransplantation rate was 10%. The actual patient survival rates were 93% at 3 months and 90% at 1 year; actual graft survival rates were 85.5% and 78%, respectively. The technique described was at least as safe as conventional procedures. A major advantage of the procedure is its flexibility, which allows for the easily combined procurement of other organs (whole pancreas and intestine).     

Localizing and photosensitizing mechanism by tetra(3-hydroxyphenyl)porphin in vivo on human malignant melanoma xenografts in athymic nude mice

Observations on time-dependent localization of tetra(3-hydroxyphenyl)porphin (3-THPP) in human malignant melanoma transplanted to athymic nude mice from 1 to 120 h after intraperitoneal (i.p.) 10 mg kg^–1 b.w. administration were made by means of fluorescence microscopy. Fluorescence was found on the membrane of the melanoma cells and in the cytoplasm with a peak fluorescence intensity at 24 h post-injection of 3-THPP. The growth of the tumour cells was obviously inhibited at an early stage after PCT. Morphological changes of the tumour at various intervals after treatment by PCT with 3-THPP were also observed. Diffuse degeneration of the tumour cells with swelling of mitochondria and endoplasmic reticulum, heterochromatin aggregation and margination, etc., and subsequently diffuse necrosis with little or no the background of tumorous vascular response were found at an early stage after PCT. On the other hand, it was also observed that the necrosis of the melanoma areas was caused as a consequence of tumorous vascular injury at a later stage after PCT. Thus, two tumoricidal processes caused by PCT with 3-THPP were seen: a direct phototoxic action on tumour cells at an early stage after PCT and an indirect effect secondary to tumorous vascular injury at a later period after PCT.