Effect of carbon disulphide intoxication on fecal excretion of end products of cholesterol metabolism

Summary The aim of this study was to compare the time course of ¹⁴C-steroid excretion following administration of ¹⁴C-cholesterol in normal and CS₂intoxicated rats. The excretion of steroid with the feces was evaluated in the normal and CS₂ intoxicated rats at the end of 7 month exposure to CS₂. The results of the experiment indicated that in rats exposed to CS₂ excretion of ¹⁴C-steroid is lower. It was due to a reduced excretion of ¹⁴C-bile acid fraction while at the same time the share of sterol + rose. On the basis of our former results which excluded the influence of CS₂ on absorption of cholesterol and indicated its effect on cholesterol synthesis it was revealed in this experiment that intoxication with CS₂ also inhibits cholesterol degradation. Disturbances of both processes can be essential for accumulation of cholesterol in blood of animals intoxicated with CS₂.This investigation has been carried out under the Polish-American agreement No. 05-008-2 with the Occupational Health Program, U.S. Public Health Service     

Specific language impairment in families: evidence for co-occurrence with reading impairments.

Two family aggregation studies report the occurrence and co-occurrence of oral language impairments (LIs) and reading impairments (RIs). Study 1 examined the occurrence (rate) of LI and RI in children with specific language impairment (SLI probands), a matched control group, and all nuclear family members. Study 2 included a larger sample of SLI probands, as well as their nuclear and extended family members. Probands and their family members who met specific criteria were classified as language and/or reading impaired based on current testing. In Study 1, the rates of LI and RI for nuclear family members (excluding probands) were significantly higher than those for control family members. In the SLI families, affected family members were more likely to have both LI and RI than either impairment alone. In Study 2, 68% of the SLI probands also met the diagnostic classification for RI. The language and RI rates for the other family members, excluding probands, were 25% and 23% respectively, with a high degree of co-occurrence of LI and RI (46%) in affected individuals. Significant sex ratio differences were found across generations in the families of SLI probands. There were more male than female offspring in these families, and more males than females were found to have both LIs and RIs. Results demonstrate that when LIs occur within families of SLI probands, these impairments generally co-occur with RIs. Our data are also consistent with prior findings that males show impairments more often than females.     

Nuclear Pedigree Criteria for the Identification of Individuals Suspected to Be at Risk of an Inherited Predisposition to Gastric Cancer

Gastric cancer is the second most frequently diagnosed malignancy worldwide and therefore represents a significant healthcare burden. Environmental and genetic factors are involved in the development of gastric cancer. To date only one clear genetic predisposition has been identified involving mutations in the E-cadherin gene. The disease phenotype in patients harbouring E-cadherin mutations appears to be specifically related to diffuse gastric cancer. Little is known genetically about the other forms of gastric cancer. Since there is a growing awareness about the necessity of early intervention criteria have been developed that aid the identification of hereditary forms of gastric cancer. The aim of the current study was to identify minimal inclusion criteria so that nuclear pedigree families can be provided with risk assessment and/or genetic testing.The results reveal that inclusion features described herein such as (a) gastric cancer diagnosed before 46 years of age; (b) two gastric cancers among first degree relatives diagnosed over the age of 50 are useful in identifying suspected hereditary gastric cancer patients.     

Use of the humanized anti-epidermal growth factor receptor monoclonal antibody h-R3 in combination with radiotherapy in the treatment of locally advanced head and neck cancer patients.

PURPOSE: To evaluate safety and preliminary efficacy of the humanized anti-epidermal growth factor receptor monoclonal antibody h-R3 in combination with radiotherapy (RT) in unresectable head and neck cancer patients. Secondary end points were the measurement of h-R3 serum levels and the assessment of the potential mechanisms of antitumor effect on patient biopsies. Anti-idiotypic response to h-R3 was assessed. To predict pharmacologic effect, a mathematical model for antibodies recognizing antigens expressed in tumors and normal tissues was built. PATIENTS AND METHODS: Twenty-four patients with advanced carcinomas of the head and neck received six once-weekly infusions of h-R3 at four dose levels in combination with RT. Pretreatment tumor biopsies were obtained to evaluate epidermal growth factor receptor expression as an enrollment criterion. Second biopsies were taken to evaluate the proliferative activity and angiogenesis in comparison with the pretreatment samples. Patient serum samples were collected to measure h-R3 levels and anti-idiotypic response. RESULTS: The combination of h-R3 and RT was well tolerated. Antibody-related adverse events consisted in infusion reactions. No skin or allergic toxicity appeared. Overall survival significantly increased after the use of the higher antibody doses. Immunohistochemistry studies of tumor specimens before and after treatment revealed that antitumor response correlated with antiproliferative and antiangiogenic effect. One patient developed antibodies to h-R3. The mathematical model predicted that the maximum difference between the area under the curve in tumors and normal tissues is reached when the antibody has intermediate affinity. CONCLUSION: h-R3 is a well-tolerated drug that may enhance radiocurability of unresectable head and neck neoplasms.     

Advanced colorectal cancer in the elderly: results of consecutive trials with 5-fluorouracil-based chemotherapy

To evaluate toxicity and efficacy of chemotherapy in elderly patients (≥65 years of age) with advanced colorectal cancer, data from two consecutive trials conducted between 1984 and 1995 at the National Institute for Cancer Research were analysed comparing the results of treatment in those 65 years of age or older and in those younger than 65 years. Of 215 patients recruited, 82 elderly patients (median age 70 years, median performance status 1) received one of the following regimens based on 5-fluorouracil (5-FU): (1) weekly 5-FU 600 mg/m² i.v. bolus (30 patients); (2) weekly 5-FU 600 mg/m² bolus plus leucovorin (LV) 500 mg/m² 2-h i.v. infusion (28 patients); (3) Weekly 5-FU 2600 mg/m² 24-h continuous i.v. infusion plus LV 100 mg 4-h i.v. infusion and 50 mg orally every 4 h for five doses (24 patients). Overall, 1071 chemotherapy cycles were administered with a median number of 12 courses per patient. The main side effects were diarrhoea, observed in 38% of patients, stomatitis in 24% of patients and hand-foot syndrome in 13% of patients, and haematological toxicity affected only 15% of patients. No patient suffered grade IV toxicity. In three patients chemotherapy was discontinued because of toxicity (two patients suffered grade III diarrhoea, one patient grade III hand-foot syndrome). No significant difference in toxicity was evident between patients older than or younger than 65 years. Analysis of median dose intensity demonstrated no difference between the two groups. Overall objective response was observed in 18% (95% confidence limits 11–29) of elderly patients (15/82) in comparison with 23% (95% CL 17–32) of patients <65 years of age (31/133 pts). In conclusion, chemotherapy in elderly patients with advanced colorectal cancer is a safe and effective treatment with acceptable toxicity and comparable objective response rates. Received: 6 January 1998 / Accepted: 27 February 1998     

Inhibition of bone repair in a rat model for chronic and excessive alcohol consumption.

Alcohol abuse is associated with increases in both the incidence of fractures and complications in fracture healing. The purpose of this study was to determine the dose-dependent effects of ethanol on bone repair in a rat model. Three-month-old male Wistar rats were continuously fed liquid diets containing ethanol as either 36% or 26% of total calories or control diets for 6 weeks. Then, a bone repair model was created in all rats. Bone healing and liver metabolism were evaluated 7 weeks after bone injury. For each dose, there were three ethanol-feeding groups receiving (1) ethanol for 13 weeks, (2) control diet for 13 weeks (pair-fed), and (3) ethanol before bone injury and control diet (pair-fed) after injury. Another group was fed ethanol (36%) before injury and given control diet ad libitum after injury. There were also two nutritional controls consuming control diet and standard rat chow ad libitum for 13 weeks. Abnormal liver metabolism was evident at the higher ethanol dose - increases in cytochrome P4502E1 specific activity (5-fold; P < .01), triglyceride content (4-fold; P < .02), and liver weight (25%; P = .05) - compared with pair-fed controls. The higher dose of ethanol resulted in deficient bone repair when compared with rats receiving ethanol-free control diet by pair-feeding: 26% less (P = .02) rigidity of the repaired bone, 41% less (P = .02) intrinsic stiffness, 24% less intrinsic strength (P = .05), and 14% less (P = .001) ash density of the repair tissue. The reduced food consumption of ethanol-fed rats compared with that in the nutritional controls did not contribute to this deficiency. Furthermore, removal of ethanol (as 36% of calories) from the diet after bone injury completely restored normal bone healing and nearly normalized the liver metabolism. The lower ethanol dose (26% of calories) had a minimal effect on liver metabolism and bone repair. We conclude that ethanol (as 36% of calories) in the rat diet, especially during the postinjury period, was solely responsible for the observed inhibition of bone repair.     

Human metabolism of the proteasome inhibitor bortezomib: identification of circulating metabolites.

Bortezomib [N-(2,3-pyrazine)carbonyl-L-phenylalanine-L-leucine boronic acid] is a potent first-in-class dipeptidyl boronic acid proteasome inhibitor that was approved in May 2003 in the United States for the treatment of patients with relapsed multiple myeloma where the disease is refractory to conventional lines of therapy. Bortezomib binds the proteasome via the boronic acid moiety, and therefore, the presence of this moiety is necessary to achieve proteasome inhibition. Metabolites in plasma obtained from patients receiving a single intravenous dose of bortezomib were identified and characterized by liquid chromatography/mass spectrometry (LC/MS) and liquid chromatography/tandem mass spectrometry (LC/MS/MS). Metabolite standards that were synthesized and characterized by LC/MS/MS and high field nuclear magnetic resonance spectroscopy (NMR) were used to confirm metabolite structures. The principal biotransformation pathway observed was oxidative deboronation, most notably to a pair of diastereomeric carbinolamide metabolites. Further metabolism of the leucine and phenylalanine moieties produced tertiary hydroxylated metabolites and a metabolite hydroxylated at the benzylic position, respectively. Conversion of the carbinolamides to the corresponding amide and carboxylic acid was also observed. Human liver microsomes adequately modeled the in vivo metabolism of bortezomib, as the principal circulating metabolites were observed in vitro. Using cDNA-expressed cytochrome P450 isoenzymes, it was determined that several isoforms contributed to the metabolism of bortezomib, including CYP3A4, CYP2C19, CYP1A2, CYP2D6, and CYP2C9. The development of bortezomib has provided an opportunity to describe the metabolism of a novel boronic acid pharmacophore.     

Induction of apoptosis/necrosis in various human cell lineages by Haemophilus ducreyi cytolethal distending toxin.

We investigated the impact of highly purified Haemophilus ducreyi cytolethal distending toxin (HdCDT) on the apoptosis and necrosis of various human cells; including myeloid cells, epithelial cells, keratinocytes, and primary fibroblasts. The levels of apoptosis and necrosis induced in these cells were compared to those induced by HdCDT in human T cells and in the Jurkat T cell line. Levels of caspase-3 activity were measured, and membrane changes like phosphatidylserine (PS) translocation was evaluated after double-staining with the fluorescein isothiocyanate (FITC)-labeled annexin V and propidium iodide (PI) using flow cytometry. HdCDT induced various degrees of apoptosis and necrosis in dose- and time-dependent manners in cells of various lineages. Early and late apoptosis (annexin V-stained cells) were induced in more than 90% of T cells and monocytes after treatment with 100 ng/ml HdCDT for 24 and 48 h, respectively. The corresponding numbers for epithelial cells, keratinocytes, and fibroblasts were 26-32% after treatment with 100 ng/ml HdCDT for 48 h. HdCDT appears to eliminate effectively by inducing apoptosis those cells that are involved in immune responses. Epithelial cells, keratinocytes and fibroblasts, which are important for the healing of chancroid ulcers, are eliminated by apoptosis or necrosis after contact with HdCDT, albeit slower and to a lesser extent than T cells.     

Breast-feeding in a woman with cystic fibrosis undergoing antibiotic intravenous treatment.

We report the case of a 30-year-old woman with cystic fibrosis (CF) chronically infected with Pseudomonas aeruginosa who delivered and breast-fed a healthy boy. While breast-feeding the woman had to undergo an i.v. antibiotic course with tobramycin, due to pulmonary exacerbation. Tobramycin was not detected in her milk and lactation could be continued. This is the first time that the presence of tobramycin in the milk of a CF woman during i.v. administration has been investigated.