A randomized dose-response and pharmacokinetic study of methotrexate for refractory inflammatory Crohn's disease and ulcerative colitis

BACKGROUND AND AIMS: The optimum initial dose of methotrexate for steroid-requiring inflammatory bowel disease is not known. AIM: To compare directly the efficacy and toxicity of methotrexate 15 and 25 mg/week, and to explore the value of methotrexate blood levels as predictors of outcome. METHODS: A 16-week randomized single-blind comparison of subcutaneous methotrexate 15 or 25 mg/week was performed in 32 patients with steroid-requiring Crohn's disease or ulcerative colitis. Patients who did not respond to methotrexate 15 mg/week were further studied for an additional 16 weeks on methotrexate 25 mg/week. Blood was drawn every 2 weeks for methotrexate levels. RESULTS: After 16 weeks, 17% of patients in each group achieved remission; 39% of patients randomized to 15 mg/week and 33% of patients randomized to 25 mg/week improved (P=N.S. ). Clinical status improved in four out of 11 patients after methotrexate dose escalation from 15 to 25 mg/week. Toxicity was not different between the treatment groups. Methotrexate blood levels did not predict efficacy or toxicity. CONCLUSIONS: For induction of remission in steroid-requiring inflammatory bowel disease, subcutaneous methotrexate at initial doses of 15 and 25 mg/week are equally efficacious. At these doses, response is not associated with blood methotrexate concentrations.     

FIELD TRIAL OF Bacillus thuringiensis var israelensis PELLET FORMULATION IN THE CONTROL OF MOSQUITOES

In a simulated field trial Bacillus thuringiensis var israelensis (BTI) pellet formulation exhibited an enhanced efficacy with increasing dose. A dosage of 1.0 and 1.5 ppm was most effective under simulated field conditions. In field trials persistence of BTI pellet (1.0 ppm) was observed for 35 days in moderately polluted water collection as compared to 21 days in highly polluted water bodies.KEY WORDS: Bacillus thuringiensis, Malaria, Mosquito control     

Single-cell studies on hapten-specific B cells: response to T-cell-dependent antigens.

The effectiveness of the hapten-gelatin antigen-affinity fractionation technique for selection of hapten-specific B cells activatable by "T-cell-dependent" (TD) stimuli was assessed. Normal adult murine spleen cells were fractionated on fluorescein (Flu)-gelatin layers and the adherent cells were cultured singly or in small numbers with various sources of syngeneic keyhole limpet hemocyanin (KLH)-primed T lymphocytes. Conditions were defined under which the addition of Flu-KLH caused optimal clonal proliferation and differentiation of B cells into anti-Flu directly hemolytic plaque-forming cells (pfc). It was found that 3-5% of the Flu-specific B cells could be activated, versus 1 in 5000 unfractionated spleen cells. The mean enrichment factor for fractionation was 179, almost identical to that seen when the stimulus is "T-cell-independent" (TI), showing that the method is capable of isolating B cells responsive to antigenic stimuli requiring specific T-cell help. Efforts were made to determine whether TD B cells constituted a separate population from TI B cells by determining clone frequencies using Flu-KLH, the TI antigen Flu-polymerized flagellin (Flu-POL), or a mixture of both for stimulation. With Flu-POL alone and with the mixed stimulus 2-3 times more pfc clones were produced than with Flu-KLH, yet evidence for separate B-cell subsets was not obtained because of strong "bystander" stimulation due to the presence of the carrier-primed T cells in a confined volume of 10 microliters.     

The epidemiology of endometrial cancer in young women

A case-control study was conducted in Los Angeles County, California, of 127 endometrial cancer cases aged 45 years or less at diagnosis, to investigate the role of fertility, obesity and exogenous oestrogens in the development of the disease in young women. Use of sequential oral contraceptive (SOCs) or oestrogen replacement therapy (ERT) for greater than or equal to 2 years was strongly associated with increased risk of endometrial cancer. After excluding these cases, since the SOC or ERT use was probably the cause of their disease, we were left with 110 case-control pairs for further study. Among these remaining case-control pairs increasing parity was strongly associated with decreased risk (relative risk of 0.12 for women of parity 3 compared to nulliparous women, P less than 0.001). Current weight was associated with increased risk (relative risk of 17.7 for women weighing greater than or equal to 190 lbs compared to women weighing less than 130 lbs, P less than 0.001). Combination oral contraceptive (COC) use was associated with a decreased risk, which decreased with duration of COC use (relative risk of approximately 0.28 at 5 years of use, P less than 0.001), but the estimate of the protective effect was reduced and became statistically non-significant when allowance was made for weight and parity. The protective effect of COC use was only clearly evident in women who had less than 3 live-births and weighed less than 170 lbs. These results provide further support for the "unopposed" oestrogen hypothesis of the aetiology of endometrial cancer.     

Unusual tumours of the lung

Unusual lung tumors are not simply pathological curiosities. They demonstrate features of major significance in diagnosis, treatment, and prognosis. Six of these tumours are discussed: (1) Carcinosarcoma is rarely found in the lung. The histogenis of the lesion is unclear and the prognosis is poor. (2) Only three cases of pleomorphic adenoma have previously been described. Differentiation from other "mixed tumours" of the lung is essential. (3) A rare case of bronchial adenoma producing ectopic ACTH is described. Early recognition of these polypeptide hormone-secreting tumours is stressed. (4) Oat cell carcinoma with the myasthenic (Eaton-Lambert) syndrome shows the clinical features which should permit early tumour diagnosis. The hazards of muscle relaxants must be recognized. (5) Prostatic carcinoma with endobronchial metastases is is discussed. The importance of localization of the primary tumour is emphasized. (6) An example of double primary carcinoma is presented. The rarity of this finding may be related to the poor prognosis of patients with bronchogenesis carcinoma.     

Effects of P-Aminophenyl Dichloroarsine on Reduced High-affinity [3H]Nicotine Binding Sites from Chick Brain: A Covalent,Yet Reversible,Agent for Neuronal Nicotinic Receptors

Neuronal nicotinic acetylcholine receptor (nAChR) α-subunits contain a conserved disulphide that is essential for function. Here, we have examined the effects of sulphydryl redox reagents on [³H]nicotine binding to chick brain nAChR immunoisolated with the monoclonal antibody mAb35. The disulphide reducing agent, dithiothreitol (DTT), inhibited [³H]nicotine binding [50% inhibitory concentration (IC₅₀) = 146 μM] but this effect was reversed (93±1.5%) by subsequent reoxidation with 1 mM dithio-bis(nitrobenzoic acid) (DTNB). The trivalent arsenical, p -aminophenyl dichloroarsine (APA), which reacts with pairs of spatially close sulphydryls, was a potent inhibitor of reoxidation by DTNB (IC₅₀= 35 nM). However, application of the 'anti-arsenical', 2,3-dimercaptopropane sulphonic acid (DMPS), restored agonist binding after APA treatment (50% effective concentration = 120 μM). Paradoxically, DMPS was also found to be a potent oxidizing agent of these receptors. Affinity alkylation of reduced nAChRs with bromoacetylcholine (BAC; 100 μM) irreversibly blocked nicotine binding (>90%). We propose (but have not proven) that APA interacts with the cysteines homologous to Cys192–193 in Torpedo AChRs, since APA pretreatment of reduced neuronal receptors protected against irreversible BAC alkylation, as shown by subsequent reversal of DMPS (2 mM; 20 min). This study illustrates the potent and reversible nature of the arsenical's covalent interaction with an isolated nAChR and suggests that modified arsenicals could be useful nAChR probes.     

Distribution of 5-HT4 receptors in the postmortem human brain--an autoradiographic study using [125I]SB 207710.

The autoradiographic distribution of the 5-HT4 receptor was described using human postmortem brain sections and the selective radioligand [125I]SB 207710 [(1-n-butyl-4-piperidinyl)methyl-8-amino-7-[125I]iodo-1,4-benzodioxane-5-carboxylate]. The specific binding was highest in regions of the basal ganglia (caudate nucleus, putamen, nucleus accumbens, globus pallidus and substantia nigra) and the hippocampal formation (CA1 and subiculum). In the neocortex, the binding showed a distinct lamination pattern with high levels in superficial layers and a band displaying lower levels in deep cortical layers. The results confirm previous studies on the distribution of 5-HT4 receptors in the human brain in vitro and provide high-resolution correlates for in vivo imaging studies using the radioligand recently developed for single photon emission tomography (SPET), [123I]SB 207710.     

Small-cell carcinoma of the cervix: fourteen years of experience at a single institution using a combined-modality regimen of involved-field irradiation and platinum-based combination chemotherapy.

PURPOSE: To determine the efficacy and toxicity of a combined-modality regimen of irradiation with platinum-based combination chemotherapy in small-cell carcinoma of the cervix (SCCC). PATIENTS AND METHODS: Thirty-four patients with SCCC were seen and treated at the British Columbia Cancer Agency between May 1988 and November 2002. Two protocols were used, SMCC (May 1988 to December 1995) and SMCC2 (January 1996 to November 2002). Both protocols used cisplatin, etoposide, and involved-field irradiation (essentially pelvis plus or minus para-aortics) with concurrent chemotherapy. In addition, SMCC2 included carboplatin and paclitaxel, and the para-aortics were irradiated routinely. RESULTS: Thirty-one patients received either SMCC (n = 17) or SMCC2 (n = 14), and three patients did not (disease too extensive, n = 1; patient refusal, n = 1; and alternative regimen, n = 1). For the 31 patients treated on one of the protocols, the 3-year overall and failure-free survival (FFS) rates were 60% and 57%, respectively. The results were equivalent for SMCC and SMCC2. Radiologic stage was the only independent predictor for FFS (80% at 3 years for stage I and II patients v 38% at 3 years for stage III and IV patients). Distant failure (28%) was the most common cause of failure, with local failure occurring in 13% of patients. The switch to SMCC2 did not improve efficacy but did lessen the toxicity. CONCLUSION: SCCC can be successfully treated in approximately 55% of patients with a combination of irradiation and platinum-based chemotherapy. Disease extent predicts for chance of curability.     

Stretch injury causes calpain and caspase-3 activation and necrotic and apoptotic cell death in septo-hippocampal cell cultures

Traumatic brain injury (TBI) results in numerous central and systemic responses that complicate interpretation of the effects of the primary mechanical trauma. For this reason, several in vitro models of mechanical cell injury have recently been developed that allow more precise control over intra- and extracellular environments than is possible in vivo. Although we recently reported that calpain and caspase-3 proteases are activated after TBI in rats, the role of calpain and/or caspase-3 has not been examined in any in vitro model of mechanical cell injury. In this investigation, varying magnitudes of rapid mechanical cell stretch were used to examine processing of the cytoskeletal protein alpha-spectrin (280 kDa) to a signature 145-kDa fragment by calpain and to the apoptotic-linked 120-kDa fragment by caspase-3 in septo-hippocampal cell cultures. Additionally, effects of stretch injury on cell viability and morphology were assayed. One hour after injury, maximal release of cytosolic lactate dehydrogenase and nuclear propidium iodide uptake were associated with peak accumulations of the calpain-specific 145-kDa fragment to alpha-spectrin at each injury level. The acute period of calpain activation (1-6 h) was associated with subpopulations of nuclear morphological alterations that appeared necrotic (hyperchromatism) or apoptotic (condensed, shrunken nuclei). In contrast, caspase-3 processing of alpha-spectrin to the apoptotic-linked 120-kDa fragment was only detected 24 h after moderate, but not mild or severe injury. The period of caspase-3 activation was predominantly associated with nuclear shrinkage, fragmentation, and apoptotic body formation characteristic of apoptosis. Results of this study indicate that rapid mechanical stretch injury to septo-hippocampal cell cultures replicates several important biochemical and morphological alterations commonly observed in vivo brain injury, although important differences were also noted.     

A multiethnic cohort in Hawaii and Los Angeles: baseline characteristics

The authors describe the design and implementation of a large multiethnic cohort established to study diet and cancer in the United States. They detail the source of the subjects, sample size, questionnaire development, pilot work, and approaches to future analyses. The cohort consists of 215,251 adult men and women (age 45-75 years at baseline) living in Hawaii and in California (primarily Los Angeles County) with the following ethnic distribution: African-American (16.3%), Latino (22.0%), Japanese-American (26.4%), Native Hawaiian (6.5%), White (22.9%), and other ancestry (5.8%). From 1993 to 1996, participants entered the cohort by completing a 26-page, self-administered mail questionnaire that elicited a quantitative food frequency history, along with demographic and other information. Response rates ranged from 20% in Latinos to 49% in Japanese-Americans. As expected, both within and among ethnic groups, the questionnaire data show substantial variations in dietary intakes (nutrients as well as foods) and in the distributions of non-dietary risk factors (including smoking, alcohol consumption, obesity, and physical activity). When compared with corresponding ethnic-specific cancer incidence rates, the findings provide tentative support for several current dietary hypotheses. As sufficient numbers of cancer cases are identified through surveillance of the cohort, dietary and other hypotheses will be tested in prospective analyses.