c-Src tyrosine kinase co-associates with and phosphorylates signal transducer and activator of transcription 5b which mediates the proliferation of normal human B lymphocytes.

c-Src is the normal human cellular protein homologue of the viral oncogene v-src. c-Src activity was reported recently to increase in CD40-activated human B lymphocytes, suggesting its involvement in proliferation. To elucidate the exact role of c-Src in this process, we investigated the effects of c-Src over-expression on normal B lymphocyte growth. B lymphocytes purified from human peripheral blood were infected with Ad5/F35 vector encoding either a constitutively active c-Src (c-Src/dominant-positive) or a dominant-negative c-Src (c-Src/DN). Little variation of B lymphocytes expansion could be observed between control enhanced yellow fluorescent protein and c-Src/dominant-positive-infected cells. In contrast, over-expression of c-Src/DN results in a 40% inhibition of B lymphocyte expansion. These results suggest that DN c-Src may compete with endogenous c-Src, resulting in partial inhibition of a transcriptional pathway involved in B lymphocyte proliferation. We demonstrate further that c-Src can phosphorylate signal transducer and activator of transcription 5b (STAT5b) on tyrosine 699 and that c-Src and STAT5b co-associate during B lymphocyte proliferation. These results confirm an important role for c-Src in the expansion of normal human B lymphocytes in vitro, in which c-Src may regulate STAT5b in the intracellular signalling pathway important for the proliferation of normal human B lymphocytes.

Advanced bronchioloalveolar carcinoma: a phase II trial of paclitaxel by 96-hour infusion (SWOG 9714): a Southwest Oncology Group study.

BACKGROUND: There are no published prospective trials of chemotherapy for advanced bronchioloalveolar carcinoma (BAC), a subtype of non-small-cell lung cancer for which there is no current standard therapy. This phase II study assesses the efficacy and toxicity of 96-h paclitaxel in chemotherapy-naive patients with advanced BAC. PATIENTS AND METHODS: Patients with histologically confirmed stage IIIB (with pleural effusion) or stage IV BAC were eligible. Treatment consisted of paclitaxel 35 mg/m2/24 h continuously infused over 96 h (days 1-4) every 21 days for up to six courses. RESULTS: A total of 58 eligible patients were enrolled. The objective response rate was 14% (all partial responses, 9% confirmed); 40% of patients demonstrated stable disease. The median progression-free and overall survivals were 5 and 12 months, respectively. Grade 3 or greater toxicities included neutropenia/granulocytopenia (43%), febrile neutropenia (12%), infection (22%), and stomatitis/pharyngitis (10%); there were five treatment-related deaths. CONCLUSIONS: S9714 represents the first prospective multi-institutional cooperative group trial focusing on treatment outcomes in BAC. Studies targeting this population are feasible, and while first-line paclitaxel administered as a prolonged infusion is active in this setting, toxicities limits the utility of this regimen. S9714 serves as a historical control for BAC patients against which future therapeutic approaches can be compared.

Phase II trial of 5-fluorouracil plus eniluracil in patients with advanced pancreatic cancer: a Southwest Oncology Group study.

BACKGROUND: Eniluracil is a potent, irreversible inactivator of dihydropyrimidine dehydrogenase, the major catabolic enzyme for 5-fluorouracil (5-FU). Pretreatment with eniluracil significantly increases plasma half-life, plasma concentration and oral bioavailability of 5-FU. This multicenter phase II trial was designed to estimate the 6-month survival rate in patients with metastatic adenocarcinoma of the pancreas treated with 5-FU and eniluracil. PATIENTS AND METHODS: One hundred and sixteen patients (61 with no prior chemotherapy and 55 with prior chemotherapy) were registered for treatment with eniluracil 50 mg (total dose) p.o. on days 1-7 and 5-FU 20 mg/m(2)/day p.o. on days 2-6 of a 28-day treatment cycle. RESULTS: In 106 patients evaluable for survival, the 6-month survival rate was 34% [95% confidence interval (CI) 22% to 47%, median survival 3.6 months] for patients who had not been treated previously with chemotherapy and 29% (95% CI 16% to 42%, median survival 3.4 months) for those who had received prior chemotherapy. For those patients with measurable disease, the confirmed response rates were 8% and 2%, respectively. The most common grade 3-4 toxicities were neutropenia (29% of patients) and diarrhea (12% of patients). Overall, 69% of patients experienced a grade 3 or worse adverse event during treatment. CONCLUSIONS: These results suggest that the combination of a 7-day course of eniluracil and a 5-day course of oral 5-FU has limited activity in patients with advanced pancreatic cancer, and is associated with a high frequency of clinically significant adverse events.

When the auditory cortex turns visual.

We studied visually guided behavior and the visual response properties of single auditory cortex (A1) neurons in neonatally operated hamsters with surgically induced, permanent, ectopic retinal projections to auditory thalamic nuclei and to visual thalamic nuclei which normally receive little direct retinal input. The surgically induced retino-thalamo-cortical pathways can mediate visual guided behaviors whose normal substrate, the pathway from the retina to the primary visual cortex via the primary thalamic visual nucleus, is missing. The visually evoked response properties of A1 neurons resemble in many respects those of neurons in V1 of normal hamsters: many A1 neurons have well-defined visual receptive fields and preferences for orientation or direction of movement. In addition, some visually responsive cells in A1 are bimodal--they also respond to auditory stimuli. The visually responsive neurons in A1 probably account for the capacity of the auditory cortex to mediate visual behavior in 'rewired hamsters'.

Evaluation of gemcitabine in patients with recurrent or metastatic squamous cell carcinoma of the head and neck: a Southwest Oncology Group phase II study.

A phase II trial of gemcitabine (Gemzar), a nucleoside analogue with broad activity in solid tumors, was performed in patients with recurrent or metastatic squamous cell carcinoma of the head and neck. A total of 26 eligible patients were registered to receive a dose of 1250 mg/m2 weekly for 3 weeks, followed by a 1 week rest. Toxicity was evaluable in 26 patients. Nausea and vomiting occured in 11 and 6 patients, repectively. Grade 3 or 4 hematologic toxicities were infrequent. Two patients developed neutropenic infections. One patient developed fatal liver failure which was thought due to progressive liver metastases or infection 14 days after a single dose of gemcitabine. There were no objective treatment responses (95% CI 0-13%), with a median survival of 6 months in this highly resistant disease population. Gemcitabine is not considered active enough as monotherapy for further evaluation in this disease population.

Biological activities of glucagon-like peptide-1 analogues in vitro and in vivo.

Studies support a role for glucagon-like peptide 1 (GLP-1) as a potential treatment for diabetes. However, since GLP-1 is rapidly degraded in the circulation by cleavage at Ala(2), its clinical application is limited. Hence, understanding the structure-activity of GLP-1 may lead to the development of more stable and potent analogues. In this study, we investigated GLP-1 analogues including those with N-, C-, and midchain modifications and a series of secretin-class chimeric peptides. Peptides were analyzed in CHO cells expressing the hGLP-1 receptor (R7 cells), and in vivo oral glucose tolerance tests (OGTTs) were performed after injection of the peptides in normal and diabetic (db/db) mice. [D-Ala(2)]GLP-1 and [Gly(2)]GLP-1 showed normal or relatively lower receptor binding and cAMP activation but exerted markedly enhanced abilities to reduce the glycemic response to an OGTT in vivo. Improved biological effectiveness of [D-Ala(2)]GLP-1 was also observed in diabetic db/db mice. Similarly, improved biological activity of acetyl- and hexenoic-His(1)-GLP-1, glucagon((1-5)-, glucagon((1-10))-, PACAP(1-5)-, VIP(1-5)-, and secretin((1-10))-GLP-1 was observed, despite normal or lower receptor binding and activation in vitro. [Ala(8/11/12/16)] substitutions also increased biological activity in vivo over wtGLP-1, while C-terminal truncation of 4-12 amino acids abolished receptor binding and biological activity. All other modified peptides examined showed normal or decreased activity in vitro and in vivo. These results indicate that specific N- and midchain modifications to GLP-1 can increase its potency in vivo. Specifically, linkage of acyl-chains to the alpha-amino group of His(1) and replacement of Ala(2) result in significantly increased biological effects of GLP-1 in vivo, likely due to decreased degradation rather than enhanced receptor interactions. Replacement of certain residues in the midchain of GLP-1 also augment biological activity.

[Association between work exposure to neurotoxic substances with workers' relationships with their social network]. / Liens entre l'exposition des travailleurs à des substances neurotoxiques et leurs relations interpersonnelles.

BACKGROUND: This study explored the impact on family life and social relations that may result from symptoms associated with exposure to neurotoxic substances in the workplace. We assessed the associations between exposure to neurotoxic substances in the workplace, workers'mental health, and workers'relationships with their social network. METHODS: A sample of 53 workers and their spouse completed a series of questionnaires, an interview on work history, and a structured interview assessing their personal relationships. Exposure to neurotoxic substances in the workplace were assessed by an interview, using a semiquantitative classification system. Mental health was measured with the Profile of Mood States (POMS), and marital satisfaction with the Marital Adjustment Test (MAT). The social network's characteristics were assessed with the Northern California Community Study Interview Schedule (NCCS). The associations between exposure and social networks were assessed with regression analyses. RESULTS: There were no associations between exposure and marital satisfaction. However, we found a negative association between workers'exposure and degrees of overlap between husbands' and wives' social networks (Pearson's correlation r=-0.27; p<0.05) and a positive association between exposure and workers' dependency on their support network (r=0.46; p<0.01). CONCLUSION: The results are discussed in terms of variables potentially linking exposure to social relationships as well as in terms of couples' vulnerability to marital distress among exposed workers.

Airbags and children: a spectrum of C-spine injuries.

Over 30 children who were improperly restrained or in rear facing safety seats have been reported killed in motor vehicle accidents (MVA) involving airbags. The authors report one minor and two major injuries in properly restrained children in the front passenger seat. In case 1, A 10-year-old seat-belted boy was involved in an MVA (40 km/h) with deployment of both airbags. Physical examination findings showed right hyphema with corneal abrasion, right cheek abrasion and minimal cervical tenderness. C-spine x-ray was normal. He was treated for whiplash and facial burns resulting from contact with hot gas released by the airbags and discharged. In case 2, a 4-year-old boy wearing a lapbelt was in a MVA (20 km/h) with airbag deployment. On arrival, his Glasgow coma score was 3 and he was hemodynamically unstable. Secondary survey after stabilization showed left neck abrasions and ecchymoses, quadraplegia, priapism, and absent rectal tone. C-spine x-ray showed atlanto-occipital dislocation with possible complete spinal cord transection at C1. Aggressive maneuvers were withheld, and the patient was pronounced dead. Autopsy findings confirmed the clinical diagnosis. In case 3, a 3-year-old boy in a forward-facing safety seat was in a MVA (60 km/h) with air bag deployment. The patient was fully awake. C-spine x-rays were normal. Because of fluctuating level of consciousness, he underwent head computed tomography (CT) scan, which demonstrated a posterior fossa subarachnoid hemorrhage and a hematoma posterior to the odontoid, suggesting a ligamentous tear. He remained asymptomatic and was discharged on day 6. A head CT scan at 1 month showed a periosteal reaction in the area of the alar ligament suggestive of partial ligamentous avulsion; this injury was the forerunner of atlanto-occipital dislocation. Airbags deploy by releasing a hot effluent at 300 km/h. Mechanisms of injury include direct contact of hot gas with facial skin and energy transmitted directly from the airbag system to the child's head and neck. These cases illustrate a spectrum of C-spine injuries caused by airbag deployment and support the recommendation that children under 12 years of age travelling in a car equipped with dual airbags be seated in the back.

Advances in diagnosis and therapies for breast cancer.

Major achievements in the field of breast cancer research have occurred in the last year. Improved treatment options with reduced toxicities, better methods of diagnosing disease at a low stage and determining women who are at genetic risk, and the prospect of breast cancer prevention will hopefully translate into further reductions in breast cancer incidence and mortality.

Carmustine, Ara C, cyclophosphamide and etoposide with autologous bone marrow transplantation in relapsed or refractory lymphoma: a dose-finding study.

The purpose of this study was to define the dose-limiting non-hematologic toxicity of carmustine, Ara C, cyclophosphamide and etoposide (BACE). Between October 1986 and March 1990, 37 patients with relapsed or refractory lymphoma received escalating doses of combination chemotherapy followed by autologous bone marrow transplant (ABMT). Twenty patients with Hodgkin's disease (HD) and 17 patients with intermediate or high grade non-Hodgkin's lymphoma (NHL) initially received conventional-dose therapy with either a 7 week course of modified MACOP-B or a single dose of cyclophosphamide (CY) at 2 g/m2 depending on prior therapy and response. Regardless of response, patients then received escalating doses of BACE, toxicity permitting. Ten patients obtained complete responses (CR) and 12 patients were partial responders (PR), CR+PR (75%) with modified MACOP-B and 7 (64%) patients obtained PR with CY. The maximum-tolerated dose (MTD) for BACE was determined to be carmustine 700 mg/m2, Ara C 1500 mg/m2, CY 150 mg/kg and etoposide 1500 mg/m2. When Ara C was escalated from 1500 mg/m2 to 3000 mg/m2 holding the other drugs at the prior doses, the next two patients died secondary to diffuse alveolar damage. Overall and event-free survivals are identical with 14 of 37 patients (38%) alive with a median follow-up of 61 months (range 38-79 months). Ten patients were treated at the MTD, none of whom died a toxic death and 3 (30%) are alive with a median follow-up of 42 months (range 38-52 months). We defined the MTD and BACE showing pulmonary toxicity to be the dose-limiting non-hematologic toxicity.(ABSTRACT TRUNCATED AT 250 WORDS)

Flumazenil in cirrhotic patients in hepatic coma: a randomized double-blind placebo-controlled crossover trial.

Previous reports have suggested that "endogenous" benzodiazepines could contribute to neural inhibition in hepatic encephalopathy. RO 15-1788 (flumazenil), a specific antagonist of brain benzodiazepine receptors, could thus reverse the neurological symptoms of hepatic encephalopathy. To test this possibility, we conducted a double-blind, placebo-controlled crossover trial of the efficacy of flumazenil in cirrhotic patients in hepatic coma. Seventy-seven cirrhotic patients in hepatic coma were evaluated. Fifty-six were excluded from the trial because of multiorgan failure or because coma was precipitated by prior use of benzodiazepines, and 21 patients were randomly assigned to the flumazenil group (11 patients) or the placebo group (10 patients). Treatment was administered intravenously as a 20-ml solution (placebo or 2 mg flumazenil); seven patients were crossed over. Clinical status was assessed blindly by two observers, using a modified Glasgow scale, every 15 min for 6 hr. Electroencephalogram tracings obtained before and after drug administration were evaluated blindly by two independent observers. Serum concentrations of benzodiazepines before treatment were measured by means of a fluorescence polarization immunoassay. Improvement in neurological symptoms was observed in six patients treated with flumazenil, whereas none in the placebo group showed improvement (p < 0.05; Fisher's exact test). Improvements in electroencephalogram tracings were demonstrated in four patients treated with flumazenil, compared with two patients in the placebo group (p = NS). Benzodiazepines were found in the serum of four patients treated with flumazenil (two responders and two nonresponders); all of these patients had received pharmaceutical benzodiazepines 4 to 6 days before the trial.(ABSTRACT TRUNCATED AT 250 WORDS)

Region-selective reductions in activities of glutamine synthetase in rat brain following portacaval anastomosis.

Portacaval anastomosis in the rat results in liver atrophy, sustained hyperammonemia and mild encephalopathy. Previous studies have demonstrated region-selective alterations of glutamine and other ammonia-related amino acids in brain following portacaval anastomosis. Ammonia removal by brain relies on glutamine synthesis and the enzyme responsible, glutamine synthetase, has an almost exclusively astrocytic localization. Glutamine synthetase activities were measured using a radioenzymatic assay in homogenates of seven brain regions of rats four weeks after end-to-side portacaval anastomosis. Enzyme activities were significantly reduced in hippocampus (by 25%, p < 0.01), in cerebellum (by 29%, p < 0.01) and in cerebral cortex (by 14%, p < 0.05). Enzyme activities in other brain regions were within normal limits. Region-selective reductions of glutamine synthetase following portacaval anastomosis could result in disruption of neuron-glial metabolic interactions and in a deficit of glutamatergic synaptic regulation. Similar mechanisms could be implicated in the pathogenesis of hepatic encephalopathy accompanying chronic liver disease in humans.

Increased activities of MAOA and MAOB in autopsied brain tissue from cirrhotic patients with hepatic encephalopathy.

Using radioenzymatic assays, activities of MAOA and MAOB were measured in autopsied brain tissue from cirrhotic patients who died in hepatic coma and in material from an equal number of age-matched subjects who were free from hepatic, neurological or psychiatric disorders. Activities of both MAOA and MAOB were significantly increased in frontal cortex and caudate nucleus, two brain regions shown previously to be the site of functional and morphological alterations of astrocytes and increased concentrations of the acid metabolites of dopamine and serotonin. These findings suggest that increased monoamine metabolism and subsequent modifications of monoaminergic synaptic function could contribute to the pathogenesis of hepatic encephalopathy.

Cerebral amino acid changes in an animal model of intrauterine growth retardation.

As part of a series of experiments to ascertain the effects of prenatal malnutrition on brain development, we measured brain amino acids in an animal model of intrauterine growth retardation (IUGR) obtained by restriction of blood supply to the fetus in utero during the last 5 days of gestation. In the present study, amino acids were measured during development by HPLC as their O-phthaldialdehyde derivatives in cerebral cortex, cerebellum and hippocampus. In rats with IUGR, significant increase of alanine (by 20% to 50%) and taurine (by 20% to 80%) were observed prior to weaning in the cerebellum and the cerebral cortex respectively. Alanine levels were also increased in hippocampus. In control animals, at birth, activities of the GABA nerve terminal marker enzyme glutamic acid decarboxylase (GAD) were found to be 32%, 17%, and 11% of adult values in cerebellum, hippocampus and cerebral cortex respectively. Two-day-old rats with IUGR had significantly lower GAD activities in all brain regions. Thus, impairment of nutrient supply to fetal brain results in selective regional abnormalities of amino acids particularly in the cerebral cortex.

Increased densities of binding sites for the 'peripheral-type' benzodiazepine receptor ligand [3H]PK 11195 in rat brain following portacaval anastomosis.

Using quantitative receptor radioautography, binding sites for the 'peripheral-type' benzodiazepine receptor ligand [3H]PK 11195 were studied in rats 4 week after end-to-side portacaval anastomosis and in sham-operated controls. Portacaval anastomosis resulted in region-selective increases in density of [3H]PK 11195 binding sites in cerebellum, pons greater than thalamus, cerebral cortex greater than hippocampus greater than striatum. Possible mechanisms implicated in these changes include (i) the action of endogenous ligands for the mitochondrial benzodiazepine receptor such as octadecaneuropeptide and (ii) neurotoxic actions of ammonia. In view of the proposed role of these receptors as modulators of intermediary metabolism and neurosteroid biosynthesis, such changes could contribute to the neurochemical mechanisms responsible for portal-systemic encephalopathy.

Increased cerebrospinal fluid lactate reflects deterioration of neurological status in experimental portal-systemic encephalopathy.

Increased brain and CSF lactate have been described in human and experimental portal-systemic encephalopathy (PSE). Using a recently described cisterna magna catheter technique, CSF lactate was measured in relation to deterioration of neurological status in portacaval shunted rats administered ammonium acetate to precipitate severe PSE. Loss of righting reflex (precoma stage of PSE) was accompanied by 2-3 fold increased CSF lactate and onset of coma by 4-fold increases of lactate (p less than 0.001 compared to either sodium acetate treated portacaval shunted rats or sham-operated controls administered ammonium acetate). The most likely explanation for increased CSF lactate is ammonia-induced inhibition of malate-aspartate shuttle and/or inhibition of tricarboxylic acid cycle flux in brain. Similar mechanisms could be involved in the pathogenesis of PSE in patients with chronic liver disease.

The pattern of intrathoracic Hodgkin's disease assessed by computed tomography.

Computed tomography (CT) was used to define the sites of intrathoracic abnormality in Hodgkin's disease, determine a pattern of progression of disease in the thorax, and establish the place of this pattern of spread in the differential diagnosis of thoracic abnormalities. One hundred eight patients with newly diagnosed Hodgkin's disease were studied by chest CT. Seventy-seven patients had intrathoracic abnormalities. The pattern seen was one of contiguous spread from the anterior mediastinal/paratracheal area to the other mediastinal lymph node groups (aortopulmonary, subcarinal, posterior mediastinal, and internal mammary), to the hila, and then into the lung by extension or as discrete nodules. Involvement of the pleura, pericardium, or chest wall occurred only after the anterior mediastinal/paratracheal mass had enlarged to greater than 30% of the thoracic diameter. The probability that this pattern of contiguous lymph node spread occurred by chance alone was very small. Hodgkin's disease spreads from the anterior mediastinal/paratracheal area in a contiguous manner. Exceptions are unusual enough that when they occur, diagnoses other than Hodgkin's disease are more likely.

Increased brain content of the endogenous benzodiazepine receptor ligand, octadecaneuropeptide (ODN), following portacaval anastomosis in the rat.

Evidence suggests that endogenous benzodiazepine receptor ligands such as diazepam binding inhibitor (DBI) and its metabolite octadecaneuropeptide (ODN) may be implicated in the pathogenesis of hepatic encephalopathy. Using an immunocytochemical technique and an antibody of high specific activity to synthetic ODN, we studied the effects of portacaval anastomosis (PCA) on ODN distribution in rat brain. Four weeks after PCA, ODN immunolabeling was increased in several brain regions including cerebral cortex, hippocampus, hypothalamus and thalamus. Increased ODN immunolabeling was confined to nonneuronal elements such as astrocytes and ependymal cells. Neuropathological evaluation of brain following PCA reveals astrocytic rather than neuronal changes. These results are consistent with a role for endogenous neuropeptide ligands for astrocytic benzodiazepine receptors in the pathogenesis of hepatic encephalopathy.