Transfer of IP3 through gap junctions is critical, but not sufficient, for the spread of apoptosis.

Decades of research have indicated that gap junction channels contribute to the propagation of apoptosis between neighboring cells. Inositol 1,4,5-trisphosphate (IP3) has been proposed as the responsible molecule conveying the apoptotic message, although conclusive results are still missing. We investigated the role of IP3 in a model of gap junction-mediated spreading of cytochrome C-induced apoptosis. We used targeted loading of high-molecular-weight agents interfering with the IP3 signaling cascade in the apoptosis trigger zone and cell death communication zone of C6-glioma cells heterologously expressing connexin (Cx)43 or Cx26. Blocking IP3 receptors or stimulating IP3 degradation both diminished the propagation of apoptosis. Apoptosis spread was also reduced in cells expressing mutant Cx26, which forms gap junctions with an impaired IP3 permeability. However, IP3 by itself was not able to induce cell death, but only potentiated cell death propagation when the apoptosis trigger was applied. We conclude that IP3 is a key necessary messenger for communicating apoptotic cell death via gap junctions, but needs to team up with other factors to become a fully pro-apoptotic messenger.

Serum lactate dehydrogenase activity in canine malignancies.

Lactate dehydrogenase (LDH) is commonly used in human cancer patients for prognostic purposes. Aim of this study was to determine the magnitude of serum LDH elevation in dogs with cancer compared with healthy dogs and dogs with non-neoplastic disease, and to verify whether it may support the diagnosis of specific malignancies. About 128 healthy dogs, 211 diseased dogs and 188 cancer dogs were enrolled. Dogs with cancer had significantly higher LDH than diseased (P < 0.001) and healthy dogs (P < 0.001), but large overlap was found. Dogs with lymphoma showed significantly higher LDH compared with dogs with carcinoma (P < 0.001) or mast cell tumour (MCT; P < 0.05) but not compared with other malignancies. When considering lymphoma and MCT, LDH levels were not different between early and advanced clinical stages. Measuring LDH levels may not be useful as a screening tool for cancer detection. More studies are needed to define its role in specific tumours.

Clinical utility of electrophysiological evaluation in Crigler-Najjar syndrome.

We evaluated the neurological and neurophysiological features in ten patients with genetically characterized Crigler-Najjar (CN) syndrome: four with typical type I CN had undergone orthotopic liver transplantation (OLT); six had type II CN, and three of them developed severe hyperbilirubinemia with a limited response to phenobarbital leading to an intermediate phenotype I/II. Clinical neurological and multimodal electrophysiological evaluations [electroencephalogram (EEG), visual (VEPs), motor (MEPs) and brainstem auditory (BAEPs) evoked potentials] were performed. Neurological examinations showed mild hand tremor in four patients (one pre-OLT and one post-OLT type I, two type I/II). EEG revealed high voltage paroxysmal discharges in four patients (three type I/II, and one type I with a marked improvement after OLT). VEPs showed P100 wave increased latency in five patients (three type I, and two type I/II considered for OLT evaluation). MEPs showed prolonged central motor conduction time in five patients (two type I; one type I/II; two type II). Only EEG and VEPs findings showed a correlation with high bilirubin levels. BAEPs were normal. In conclusion, VEPs and EEG contribute to identify and monitor bilirubin neurotoxic effects, and may play a decisional role in some cases of severe hyperbilirubinemia without overt neurologic damage.

Life saving cyclophosphamide treatment in a girl with giant cell hepatitis and autoimmune haemolytic anaemia: case report and up-to-date on therapeutical options.

We report the case of a girl affected by giant cell hepatitis associated with autoimmune haemolytic anaemia. Both conditions were severe with a number of life-threatening episodes of liver failure and anaemia unresponsive to several immunosuppressant drugs but cyclophosphamide. After a low-dose long-term treatment with this drug the patient is stably well without any therapy. A review of therapeutical options in this condition is also presented.

CD27 in B-cell chronic lymphocytic leukemia. Cellular expression, serum release and correlation with other soluble molecules belonging to nerve growth factor receptors (NGFr) superfamily.

BACKGROUND AND OBJECTIVE: CD27, a transmembrane homodimer belonging to the nerve growth factor (NGF) receptor superfamily, is typically expressed on leukemic CD5+ cells in B-cell chronic lymphocytic leukemia (CLL) and found in soluble form in the serum of CLL patients. Therefore, we investigated clinico-biological implications of increased serum levels of sCD27 in an unselected series of B-CLL patients. DESIGN AND METHODS: Serum CD27 (sCD27) levels were determined at the time of diagnosis in 82 previously untreated B-CLL patients using a sandwich enzyme-linked immunoassay (ELISA). Results were correlated with either clinico-hematological or biological features. Finally, quantitative flow cytometric analyses of membrane CD27 (mCD27) expression were carried out on peripheral blood (PB) cells of 22 B-CLL patients and 5 healthy controls, respectively. RESULTS: CD27 was found to be expressed on the surface of both resting normal and leukemic B cells. sCD27 levels were significantly higher in B-CLL patients (median value 2150 U/mL) than in healthy controls (median value 220 U/mL) (p < 0.0001). There was a close relationship between sCD27 and soluble TNF-alpha, another molecule belonging to the NGF receptor superfamily. Changes in sCD27 level correlated with clinical stage, beta 2 microglobulin and LDH. INTERPRETATION AND CONCLUSIONS: These findings indicate that sCD27 is a reliable marker of tumor mass in B-CLL. Its potential prognostic value should be tested in prospective studies.

Comparative flow cytometric evaluation of bcl-2 oncoprotein in CD5+ and CD5- B-cell lymphoid chronic leukemias.

BACKGROUND AND OBJECTIVES: Levels of intracellular bcl-2 oncoprotein have been found to be increased in leukemic cells of CD5+ B-chronic lymphocytic leukemia (CLL) patients. However, it is not clear whether bcl-2 overexpression is a peculiar feature of CD5+ B-CLL. Based on this background we carried out a quantitative flow cytometric evaluation of intracellular bcl-2 levels on leukemic cells of CD5+ and CD5- B-CLL. METHODS: We assessed in flow cytometry levels of bcl-2 protein using a quantitative indirect immunofluorescence assay (QIFI kit) on samples from 46 previously untreated CD5+ B-CLL patients. Results were compared with those obtained on either normal peripheral blood B-lymphocytes or leukemic cells from 7 CD5- B-CLL patients intentionally selected for statistical comparison. RESULTS: A relatively homogeneous amount of bcl-2 protein which did not reflect either clinical-biological features at the time of diagnosis nor in vivo response to therapy was found. Results expressed as antibody binding capacity (ABC) accounted for a mean value of 12.2 +/- 1.5 x 10(3) molecules/cell (range, 6.4-13 x 10(3) molecules/cell). Levels of bcl-2 detected on CD5+ B-CLL leukemic cells were significantly lower than those of B peripheral blood lymphocytes from healthy donors (p = 0.0001). The same applied when comparing CD5+ and CD5- B-CLL patients (bcl-2 ABC, 8.07 +/- 0.26 x 10(3) molecules/cell vs. 12.2 +/- 1.5 x 10(9) molecules/cell; p = 0.0001). INTERPRETATION AND CONCLUSIONS: According to the role of bcl-2 in preventing apoptosis, our results indicate that differences in the pattern of expression of such an oncoprotein, might, at least in part, explain the more aggressive clinical course of CD5- B-CLL forms.

Selective perhydroxylation of squalene: taming the arithmetic demon.

Osmium-catalyzed asymmetric dihydroxylation, which produces 1,2-diols of high enantiopurity from prochiral olefins, is an example of the synthetic catalysts that have been developed that rival enzymes in their efficiency and high enantioselectivity. Although the asymmetric dihydroxylation catalyst lacks an enzyme's ability to effectively distinguish among the subtly different olefinic sites in a polyolefin such as squalene, this very inability permits it to bring about the "exhaustive" polyhydroxylation of squalene to give a dodecahydroxy derivative. Twelve chemical and stereochemical events proceed in tandem with a remarkable average yield of 98 percent per step, giving 1 out of the 36 possible stereoisomers in (0.98)12 = 78.9 percent overall yield.

Precocious puberty and neurofibromatosis of von Recklinghausen. A clinical report.

A case of a 9-year-old boy with neurofibromatosis of von Recklinghausen and precocious puberty is reported. The patient was referred to us because of an unexplained onset of precocious puberty. Clinical manifestations of neurofibromatosis included multiple café-au-lait spots, skeletal anomalies, progressive impairment of vision and precocious sexual development. CT scan and NMR demonstrated the presence of optic gliomas. The correlation between the lesions of retino-hypothalamic projection and production of the neuroendocrinology mechanism of sexual changes is discussed.

Modest decrements in plasma glucose concentration cause early impairment in cognitive function and later activation of glucose counterregulation in the absence of hypoglycemic symptoms in normal man.

To establish the glycemic threshold for onset of neuroglycopenia (impaired cognitive function, measured by the latency of the P300 wave), activation of hormonal counterregulation and hypoglycemic symptoms, 12 normal subjects were studied either under conditions of insulin-induced, glucose-controlled plasma glucose decrements, or during maintenance of euglycemia. A decrement in plasma glucose concentration from 88 +/- 3 to 80 +/- 1 mg/dl for 150 min did not result in changes in the latency of the P300 wave nor in an activation of counterregulatory hormonal response. In contrast, a greater decrement in plasma glucose concentration from 87 +/- 3 to 72 +/- 1 mg/dl for 120 min caused an increase in the latency of the P300 wave (from 301 +/- 12 to 348 +/- 20 ms, P less than 0.01), a subsequent increase in all counterregulatory hormones but no hypoglycemic symptoms. Finally, when plasma glucose concentration was decreased in a stepwise manner from 88 +/- 2 to 50 +/- 1 mg/dl within 75 min, the increase in the latency of the P300 wave was correlated with the corresponding plasma glucose concentration (r = -0.76, P less than 0.001). The glycemic threshold for hypoglycemic symptoms was 49 +/- 2 mg/dl. Thus, in normal man the glycemic threshold for neuroglycopenia (72 +/- 1 mg/dl) is greater than currently thought; the hormonal counterregulation follows the onset of neuroglycopenia; the hypoglycemic symptoms are a late indicator of advanced neuroglycopenia.