Intermittent cyclical etidronate treatment of postmenopausal osteoporosis

BACKGROUND

To determine the effects of etidronate (a bisphosphonate that inhibits osteoclast-mediated bone resorption) in the treatment of postmenopausal osteoporosis, we conducted a prospective, two-year, double-blind, placebo-controlled, multicenter study in 429 women who had one to four vertebral compression fractures plus radiographic evidence of osteopenia.

METHODS

The patients were randomly assigned to treatment with phosphate (1.0 g) or placebo twice daily on days 1 through 3, etidronate (400 mg) or placebo daily on days 4 through 17, and supplemental calcium (500 mg) daily on days 18 through 91 (group 1, placebo and placebo; group 2, phosphate and placebo; group 3, placebo and etidronate; and group 4, phosphate and etidronate). The treatment cycles were repeated eight times. The bone density of the spine was measured by dual-photon absorptiometry, and the rates of new vertebral fractures were determined from sequential radiographs.

RESULTS

After two years, the patients receiving etidronate (groups 3 and 4) had significant increases in their mean (+/- SE) spinal bone density (4.2 +/- 0.8 percent and 5.2 +/- 0.7 percent, respectively; P less than 0.017). The rate of new vertebral fractures was reduced by half in the etidronate-treated patients (groups 3 and 4 combined) as compared with the patients who did not receive etidronate (groups 1 and 2 combined) (29.5 vs. 62.9 fractures per 1000 patient-years; P = 0.043); the effect of treatment was most striking in the subgroup of patients with the lowest spinal bone mineral density at base line, in whom fracture rates were reduced by two thirds (42.3 vs. 132.7 fractures per 1000 patient-years; P = 0.004). The addition of phosphate provided no apparent benefit. There were no significant adverse effects of treatment.

CONCLUSIONS

Intermittent cyclical therapy with etidronate for two years significantly increases spinal bone mass and reduces the incidence of new vertebral fractures in women with postmenopausal osteoporosis.

Cellulose biosynthesis and function in bacteria

The current model of cellulose biogenesis in plants, as well as bacteria, holds that the membranous cellulose synthase complex polymerizes glucose moieties from UDP-Glc into beta-1,4-glucan chains which give rise to rigid crystalline fibrils upon extrusion at the outer surface of the cell. The distinct arrangement and degree of association of the polymerizing enzyme units presumably govern extracellular chain assembly in addition to the pattern and width of cellulose fibril deposition. Most evident for Acetobacter xylinum, polymerization and assembly appear to be tightly coupled. To date, only bacteria have been effectively studied at the biochemical and genetic levels. In A. xylinum, the cellulose synthase, composed of at least two structurally similar but functionally distinct subunits, is subject to a multicomponent regulatory system. Regulation is based on the novel nucleotide cyclic diguanylic acid, a positive allosteric effector, and the regulatory enzymes maintaining its intracellular turnover: diguanylate cyclase and Ca2(+)-sensitive bis-(3',5')-cyclic diguanylic acid (c-di-GMP) phosphodiesterase. Four genes have been isolated from A. xylinum which constitute the operon for cellulose synthesis. The second gene encodes the catalytic subunit of cellulose synthase; the functions of the other three gene products are still unknown. Exclusively an extracellular product, bacterial cellulose appears to fulfill diverse biological roles within the natural habitat, conferring mechanical, chemical, and physiological protection in A. xylinum and Sarcina ventriculi or facilitating cell adhesion during symbiotic or infectious interactions in Rhizobium and Agrobacterium species. A. xylinum is proving to be most amenable for industrial purposes, allowing the unique features of bacterial cellulose to be exploited for novel product applications.

BCL-2 antisense therapy in patients with non-Hodgkin lymphoma

BACKGROUND

Overexpression of BCL-2 is common in non-Hodgkin lymphoma and leads to resistance to programmed cell death (apoptosis) and promotes tumorigenesis. Antisense oligonucleotides targeted at the open reading frame of the BCL-2 mRNA cause a specific down-regulation of BCL-2 expression which leads to increased apoptosis. Lymphoma grown in laboratory animals responds to BCL-2 antisense oligonucleotides with few toxic effects. We report the first study of BCL-2 antisense therapy in human beings.

METHODS

A daily subcutaneous infusion of 18-base, fully phosporothioated antisense oligonucleotide was administered for 2 weeks to nine patients who had BCL-2-positive relapsed non-Hodgkin lymphoma. Toxicity was scored by the common toxicity criteria, and tumour response was assessed by computed tomography scan. Efficacy was also assessed by quantification of BCL-2 expression; BCL-2 protein levels were measured by flow cytometry in samples from patients.

FINDINGS

During the course of the study, the daily dose of BCL-2 antisense was increased incrementally from 4.6 mg/m2 to 73.6 mg/m2. No treatment-related toxic effects occurred, apart from local inflammation at the infusion site. In two patients, computed tomography scans showed a reduction in tumour size (one minor, one complete response). In two patients, the number of circulating lymphoma cells decreased during treatment. In four patients, serum concentrations of lactate dehydrogenase fell, and in two of these patients symptoms improved. We were able to measure BCL-2 levels by flow cytometry in the samples of five patients, two of whom had reduced levels of BCL-2 protein.

INTERPRETATION

In patients with relapsing non-Hodgkin lymphoma, BCL-2 antisense therapy led to an improvement in symptoms, objective biochemical and radiological evidence of tumour response, and down-regulation of the BCL-2 protein in some patients. Our findings are encouraging and warrant further investigations of BCL-2 antisense therapy in cancer treatment.

Prospective randomized trial comparing mitomycin, cisplatin, and protracted venous-infusion fluorouracil (PVI 5-FU) With epirubicin, cisplatin, and PVI 5-FU in advanced esophagogastric cancer

PURPOSE

We report the results of a prospectively randomized study that compared the combination of epirubicin, cisplatin, and protracted venous-infusion fluorouracil (PVI 5-FU) (ECF) with the combination of mitomycin, cisplatin, and PVI 5-FU (MCF) in previously untreated patients with advanced esophagogastric cancer.

PATIENTS AND METHODS

Five hundred eighty patients with adenocarcinoma, squamous carcinoma, or undifferentiated carcinoma were randomized to receive either ECF (epirubicin 50 mg/m(2) every 3 weeks, cisplatin 60 mg/m(2) every 3 weeks and PVI 5-FU 200 mg/m(2)/d) or MCF (mitomycin 7 mg/m(2) every 6 weeks, cisplatin 60 mg/m(2) every 3 weeks, and PVI 5-FU 300 mg/m(2)/d) and analyzed for survival, response, toxicity, and quality of life (QOL).

RESULTS

The overall response rate was 42.4% (95% confidence interval [CI], 37% to 48%) with ECF and 44.1% (95% CI, 38% to 50%) with MCF (P =.692). Toxicity was tolerable, and there were only two toxic deaths. ECF resulted in more grade 3/4 neutropenia and grade 2 alopecia, but MCF caused more thrombocytopenia and plantar-palmar erythema. Median survival was 9.4 months with ECF and 8.7 months with MCF (P =.315); at 1 year, 40.2% (95% CI, 34% to 46%) of ECF and 32.7% (95% CI, 27% to 38%) of MCF patients were alive. Median failure-free survival was 7 months with both regimens. Global QOL scores were better with ECF at 3 and 6 months.

CONCLUSION

This study confirms response, survival, and QOL benefits of ECF observed in a previous randomized study. The equivalent efficacy of MCF was demonstrated, but QOL was superior with ECF. ECF remains one of the reference treatments for advanced esophagogastric cancer.

Prevention of bone loss with alendronate in postmenopausal women under 60 years of age. Early Postmenopausal Intervention Cohort Study Group

BACKGROUND

Estrogen-replacement therapy prevents osteoporosis in postmenopausal women by inhibiting bone resorption, but the balance between its long-term risks and benefits remains unclear. Whether other antiresorptive therapies can prevent osteoporosis in these women is also not clear.

METHODS

We studied the effect of 2.5 mg or 5 mg of alendronate per day or placebo on bone mineral density in 1174 postmenopausal women under 60 years of age. An additional 435 women who were prepared to receive a combination of estrogen and progestin were randomly assigned to one of the above treatments or open-label estrogen-progestin. The main outcome measure was the change in bone mineral density of the lumbar spine, hip, distal forearm, and total body measured annually for two years by dual-energy x-ray absorptiometry.

RESULTS

The women who received placebo lost bone mineral density at all measured sites, whereas the women treated with 5 mg of alendronate daily had a mean (+/-SE) increase in bone mineral density of 3.5+/-0.2 percent at the lumbar spine, 1.9+/-0.1 percent at the hip, and 0.7+/-0.1 percent for the total body (all P<0.001). Women treated with 2.5 mg of alendronate daily had smaller increases in bone mineral density. Alendronate did not increase bone mineral density of the forearm, but it slowed the loss. The responses to estrogen-progestin were 1 to 2 percentage points greater than those to the 5-mg dose of alendronate. Alendronate was well tolerated, with a safety profile similar to that of placebo or estrogen-progestin.

CONCLUSIONS

Alendronate prevents bone loss in postmenopausal women under 60 years of age to nearly the same extent as estrogen-progestin.

High level multiplex genotyping by MALDI-TOF mass spectrometry

A primer extension assay is used to perform highly multiplexed genotyping of single nucleotide polymorphisms (SNPs) present in genomic DNA amplified by a multiplex PCR. The assay uses matrix-assisted laser desorption ionization time-of-flight mass spectrometry to accurately measure the masses of short oligonucleotide primers extended by a single dideoxynucleotide. The multiplexed genotyping assays rely on the natural molecular weight differences of DNA bases. By careful analysis of primer composition complementary to the target, or by judicious addition of one or more noncomplementary 5' bases to the genotyping primers, mass spectra of interleaved genotyping products can be generated with no ambiguity in allele assignment. Using a model multiplex PCR system, we demonstrate the ability to perform 12-fold multiplex SNP analysis.

Three cdg operons control cellular turnover of cyclic di-GMP in Acetobacter xylinum: genetic organization and occurrence of conserved domains in isoenzymes

Cyclic di-GMP (c-di-GMP) is the specific nucleotide regulator of beta-1,4-glucan (cellulose) synthase in Acetobacter xylinum. The enzymes controlling turnover of c-di-GMP are diguanylate cyclase (DGC), which catalyzes its formation, and phosphodiesterase A (PDEA), which catalyzes its degradation. Following biochemical purification of DGC and PDEA, genes encoding isoforms of these enzymes have been isolated and found to be located on three distinct yet highly homologous operons for cyclic diguanylate, cdg1, cdg2, and cdg3. Within each cdg operon, a pdeA gene lies upstream of a dgc gene. cdg1 contains two additional flanking genes, cdg1a and cdg1d. cdg1a encodes a putative transcriptional activator, similar to AadR of Rhodopseudomonas palustris and FixK proteins of rhizobia. The deduced DGC and PDEA proteins have an identical motif structure of two lengthy domains in their C-terminal regions. These domains are also present in numerous bacterial proteins of undefined function. The N termini of the DGC and PDEA deduced proteins contain putative oxygen-sensing domains, based on similarity to domains on bacterial NifL and FixL proteins, respectively. Genetic disruption analyses demonstrated a physiological hierarchy among the cdg operons, such that cdg1 contributes 80% of cellular DGC and PDEA activities and cdg2 and cdg3 contribute 15 and 5%, respectively. Disruption of dgc genes markedly reduced in vivo cellulose production, demonstrating that c-di-GMP controls this process.

Four-year study of intermittent cyclic etidronate treatment of postmenopausal osteoporosis: three years of blinded therapy followed by one year of open therapy

PURPOSE

To determine the effect of long-term intermittent cyclic etidronate treatment on spinal bone density and vertebral fracture rates.

PATIENTS AND METHODS

Postmenopausal osteoporotic women (n = 423) were randomized initially into a 2-year, double-blind, multicenter study; it was extended to a third year of blinded treatment followed by open-label treatment: 357 patients continued treatment in Year 3 (305 receiving blinded therapy and 52 receiving calcium supplementation) and 277 in Year 4. During Years 1 through 3, patients received double-blind treatment with phosphate (1.0 g) or placebo twice daily for 3 days, etidronate (400 mg) or placebo daily for 14 days, and calcium (500 mg) daily for the remainder of each 91-day treatment cycle. During Year 4, open-label intermittent cyclic etidronate therapy (without preceding phosphate) was administered to all patients. Spinal bone density and vertebral fracture rates were the main outcome measures.

RESULTS

During Year 3, etidronate therapy maintained the significant increases in spinal bone mineral density of the first 2 years. Over the 3-year period, proximal femur bone density increased in etidronate-treated patients. Etidronate therapy for 3 years significantly decreased the vertebral fracture rate in patients at higher risk for fracture (low spinal bone density and three or more vertebral fractures at study entry), as compared with nonetidronate treatment (228 versus 412 fractures per 1,000 patient-years, respectively; p < 0.05). After 1 year of open-label treatment, patients previously treated with etidronate maintained bone mass, and vertebral fracture rates in all groups were lower than in any other study period. There were no apparent serious adverse effects.

CONCLUSIONS

Three years of intermittent cyclic etidronate therapy produced significant increases in spinal and hip bone density, with a significant reduction in vertebral fracture rates in patients at higher fracture risk. Maintenance of bone mass and low fracture rate were observed when etidronate was continued for an additional year.

The role of helper lipids in cationic liposome-mediated gene transfer

In the procedure for cationic liposome-mediated transfection, the cationic lipid is usually mixed with a "helper lipid" to increase its transfection potency. The importance of helper lipids, including dioleoylphosphatidylcholine (DOPC) and phosphatidylethanolamine (dioleoyl PE), DO was examined. Freeze-fracture electron microscopy of DNA:cationic complexes containing the pSV-beta-GAL plasmid DNA, the cationic lipid dioleoyl trimethylammonium propane, and these helper lipids showed that the most efficient mixtures were aggregates of ensheathed DNA and fused liposomes. PE-containing complexes aggregated rapidly when added to culture media containing polyanions, whereas PC-containing complexes did not. However, more granules of PC-containing complexes were formed on cell surfaces after the complexes were added to Chinese hamster ovary (CHO) cells in transfection media. Pronase treatment inhibited transfection, whereas dilute poly-L-lysine enhanced transfection, indicating that the attachment of DNA:liposome complexes to cell surfaces was mediated by electrostatic interaction. Fluorescence spectroscopy studies confirmed that more PC-containing complexes than PE-containing complexes were associated with CHO cells, and that more PC-containing complexes were located in a low pH environment (likely to be within endosomes) with time. Cytochalasin-B had a stronger inhibitory effect on PC-containing liposome-mediated than on PE-containing liposome-mediated transfection. Confocal microscopic recording of the fluorescently label lipid and DNA uptake process indicated that many granules of DNA:cationic liposome complexes were internalized as a whole, whereas some DNA aggregates were left out on the cell surfaces after liposomes of the complexes fused with the plasma membranes. For CHO cells, endocytosis seems to be the main uptake pathway of DNA:cationic liposome complexes. More PC-containing granules than PE-containing granules were formed on cell surfaces by cytoskeleton-directed membrane motion, after their respective DNA:liposome complexes attached to cell surfaces by electrostatic means. Formation of granules on the cell surface facilitated and/or triggered endocytosis. Fusion between cationic liposomes and the cell membrane played a secondary role in determining transfection efficiency.

Efficacy of 5-fluorouracil-based chemotherapy in elderly patients with metastatic colorectal cancer: a pooled analysis of clinical trials

BACKGROUND

Recently published population-based investigations showed elderly patients to be underrepresented in clinical trials and less often treated according to the standard therapy. Although there is evidence that elderly patients benefit from adjuvant (radio-) chemotherapy to the same extent as younger patients, no large series describes the influence of age on efficacy of chemotherapy in metastatic colorectal cancer.

PATIENTS AND METHODS

We carried out a retrospective analysis using source data of 3825 patients who received 5-fluorouracil (5-FU)-containing treatment in 22 European trials and identified 629 patients with an age of > or = 70 years.

RESULTS

We found an equal overall survival in elderly patients [10.8 months, 95% confidence interval (CI) 9.7-11.8] and in younger patients (11.3 months, 95% CI 10.9-11.7; P = 0.31). Response rate did not differ between age groups > or = 70 and <70 years (23.9% and 21.1%; respectively; P = 0.14). Progression-free survival was marginally prolonged in elderly patients (5.5 months, 95% CI 5.2-5.8; compared with 5.3 months, 95% CI 5.1-5.5; P = 0.01). In both age groups, infusional 5-FU resulted in significantly increased response rates, overall survival and progression-free survival compared with bolus 5-FU.

CONCLUSIONS

'Fit' elderly patients benefit at least to the same extent from palliative chemotherapy with 5-FU as younger patients. Infusional 5-FU was shown to be more effective than bolus 5-FU in both age groups. Therefore, standardized palliative chemotherapy should generally be offered to elderly patients and they should not be excluded from clinical trials.

Contaminant-induced immunotoxicity in harbour seals: wildlife at risk?

Persistent, lipophilic polyhalogenated aromatic hydrocarbons (PHAHs) accumulate readily in the aquatic food chain and are found in high concentrations in seals and other marine mammals. Recent mass mortalities among several marine mammal populations have been attributed to infection by morbilliviruses, but a contributing role for immunotoxic PHAHs, including the polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) was not ruled out. We addressed this issue by carrying out a semi-field study in which captive harbour seals were fed herring from either the relatively uncontaminated Atlantic Ocean or the contaminated Baltic Sea for 2 years. We present here an overview of results obtained during this study. An impairment of natural killer (NK) cell activity, in vitro T-lymphocyte function, antigen-specific in vitro lymphocyte proliferative responses, and in vivo delayed-type hypersensitivity and antibody responses to ovalbumin was observed in the seals fed the contaminated Baltic herring. Additional feeding studies in PVG rats using the same herring batches suggested that an effect at the level of the thymus may be responsible for changes in cellular immunity, that virus-specific immune responses may be impaired, and that perinatal exposure to environmental contaminants represents a greater immunotoxic threat than exposure as a juvenile or adult. Together with the pattern of TCDD toxic equivalents of different PHAHs in the herring, these data indicate that present levels of PCBs in the aquatic food chain are immunotoxic to mammals. A review of contaminant levels in free-ranging harbour seals inhabiting polluted areas of Europe and North America suggests that many populations may be at risk to immunotoxicity. This could result in diminished host resistance and an increased incidence and severity of infectious disease.

Relationship of menopause to skeletal and muscle mass

Cross-sectional and longitudinal changes in body composition with age were examined in white women to determine the relationship of body cell mass to menopause and of body fat to bone mass. There was statistical evidence for a curvilinear component to loss of total body potassium with negligible rates of loss before menopause. Longitudinal measurements also indicated a relationship between the proximity to menopause and the rate of loss of potassium. Total body potassium was significantly related to total body calcium and bone density of the spine, radius, and femoral neck. Total body fat was not related to any of these measurements. We found no evidence that adiposity plays a major role in protecting against bone loss.

Suppression of α-Cyano-4-hydroxycinnamic Acid Matrix Clusters and Reduction of Chemical Noise in MALDI-TOF Mass Spectrometry

Progress in high-throughput MALDI-TOFMS analysis, especially in proteome applications, requires development of practical and efficient procedures for the preparation of proteins and peptides in a form suitable for high acquisition rates. These methods should improve successful identification of peptides, which depends on the signal intensity and the absence of interfering signals. Contamination of MALDI samples with alkali salts results in reduced MALDI peptide sensitivity and causes matrix cluster formation (widely reported for CHCA matrix) observed as signals dominating in the range below m/z 1200 in MALDI spectra. One way to remove these background signals, especially for concentrations of peptides lower than 10 fmol/microL, is to wash matrix/sample spots after peptide cocrystallization on the MALDI plate with deionized water prior to analysis. This method takes advantage of the low water solubility of the CHCA compared to its alkali salts. We report here that the application of some ammonium salt solutions, such as citrates and phosphates, instead of deionized water greatly improves the efficiency of this washing approach. Another way to reduce matrix cluster formation is to add ammonium salts as a part of the MALDI matrix. The best results were obtained with monoammonium phosphate, which successfully suppressed matrix clusters and improved sensitivity. Combining both of these approaches-the addition of ammonium salts in the CHCA matrix followed by one postcrystallization washing step with ammonium buffer-provided a substantial ( approximately 3-5-fold) improvement in the sensitivity of MALDI-MS detection compared to unwashed sample spots. This sample preparation method resulted in improved spectral quality and was essential for successful database searching for subnanomolar concentrations of protein digests.

Predicting vertebral deformity using bone densitometry at various skeletal sites and calcaneus ultrasound

We investigated the usefulness of bone density measurements from multiple skeletal sites and calcaneus ultrasound for evaluating the probability of vertebral deformation. Bone mineral density (BMD) was measured at the second metacarpal and middle phalanges using radiographic absorptiometry of hand radiographs, and at the lumbar spine using dual-energy x-ray absorptiometry. Distal radius and proximal radius were measured using single-energy x-ray absorptiometry (SXA), expressed as bone mineral content (BMC, grams per centimeter), and as BMD (grams per square centimeter). The calcaneus was measured using both SXA (BMD) and broadband ultrasound attenuation (BUA). Among the women in this study (mean age 74, SD = 5), 84 women developed new vertebral deformations (57 cases with one and 27 cases with two or more deformations), which were identified on serial radiographs during an average of 9 years prior to the measurements of bone density. Logistic regression analysis was used to calculate odds ratios for risk of deformation corresponding to a 1-SD difference in density or ultrasound, adjusted for age. All bone measurements were significantly associated with vertebral deformation, with odds ratios (95% confidence intervals) ranging from 1.40 (1.10, 1.78) for proximal radius BMD to 1.88 (1.45, 2.44) for calcaneus BMD measurements. Measurements of calcaneal BUA, calcaneal BMD, and hand BMD generally remained significant when included simultaneously with another measurement in the same model, suggesting that spine or radius BMD may not provide much additional information about risk of deformation. It appears that all of the measurements of bone density and ultrasound provide useful information regarding the probability of deformation. These findings await confirmation in a prospective study.

Rickets in children of rural origin in South Africa: is low dietary calcium a factor?

Studies of nine children 4 7/12 to 13 years of age who had rickets are presented. No evidence of renal abnormalities, vitamin D deficiency, or of the inherited varieties of rickets was found. The salient features were their rural origins, mild hypocalcemia with evidence of secondary hyperparathyroidism, and improvement with a normal diet that contained an average of 944 mg calcium/24 hours. It is proposed that the etiology of the rickets is related to low calcium intake with or without a high oxalate concentration in the diet.

Cell proliferation in normal epidermis

A detailed examination of cell proliferation kinetics in normal human epidermis is presented. Using tritiated thymidine with autoradiographic techniques, proliferative and differentiated cell kinetics are defined and interrelated. The proliferative compartment of normal epidermis has a cell cycle duration (Tc) of 311 h derived from 3 components: the germinative labeling index (LI), the duration of DNA synthesis (ts), and the growth fraction (GF). The germinative LI is 2.7% +/- 1.2 and ts is 14 h, the latter obtained from a composite fraction of labeled mitoses curve obtained from 11 normal subjects. The GF obtained from the literature and from human skin xenografts to nude mice is estimated to be 60%. Normal-appearing epidermis from patients with psoriasis appears to have a higher proliferation rate. The mean LI is 4.2% +/- 0.9, approximately 50% greater than in normal epidermis. Absolute cell kinetic values for this tissue, however, cannot yet be calculated for lack of other information on ts and GF. A kinetic model for epidermal cell renewal in normal epidermis is described that interrelates the rate of birth/entry, transit, and/or loss of keratinocytes in the 3 epidermal compartments: proliferative, viable differentiated (stratum malpighii ), and stratum corneum. Expected kinetic homeostasis in the epidermis is confirmed by the very similar "turnover" rates in each of the compartments that are, respectively, 1246, 1417, and 1490 cells/day/mm2 surface area. The mean epidermal turnover time of the entire tissue is 39 days. The Tc of 311 h in normal cells in 8-fold longer than the psoriatic Tc of 36 h and is necessary for understanding the hyperproliferative pathophysiologic process in psoriasis.

A prospective randomised trial of protracted venous infusion 5-fluorouracil with or without mitomycin C in advanced colorectal cancer

BACKGROUND

To compare protracted venous infusion (PVI) 5-fluorouracil (5-FU) with and without mitomycin C (MMC) in a prospectively randomised study and analyse for tumour response, survival, toxicity and quality of life (QL).

PATIENTS AND METHODS

Two hundred patients with advanced colorectal cancer received PVI 5-FU 300 mg/m2/day for a maximum of 24 weeks and were randomised to PVI 5-FU alone or PVI 5-FU + MMC 10 mg/m2 (7 mg/m2 from June 1995) 6 weekly for 4 courses.

RESULTS

Overall response was 54% (95% confidence interval [CI] 44.1%-63.9%) with PVI 5-FU + MMC compared to 38% (95% CI: 28.3%-47.7%) for PVI 5-FU alone (P = 0.024). The median failure free survival was 7.9 months in PVI 5-FU plus MMC and 5.4 months with PVI 5-FU alone (P = 0.033) and at one year 31.9% for the combination compared to 17.7% for PVI 5-FU alone. Median survival was 14 months with MMC and 15 months in 5-FU alone; one-year survival 51.7% vs. 57.2%. PVI 5-FU + MMC caused more overall haematological toxicity but CTC grades 3/4 was increased only for thrombocytopaenia. Two patients treated with a cumulative dose of MMC of 40 mg/m2 developed haemolytic uraemic syndrome warranting the reduction in cumulative MMC dose to 28 mg/m2. The global QL scores were better for PVI 5-FU + MMC arm at 24 weeks, but the remaining QL data showed no differences.

CONCLUSIONS

PVI 5-FU + MMC results in failure-free survival and response advantage, tolerable toxicity and better QL when compared to PVI 5-FU alone but no overall survival advantage. There is no irreversible toxicity with MMC at a cumulative dose of 28 mg/m2.

Effect of thiazide on rates of bone mineral loss: a longitudinal study

OBJECTIVE

To determine the effect of thiazide diuretic drugs on rates of bone mineral loss.

DESIGN

Longitudinal, observational study with a mean follow up of five years.

SETTING

Hawaii Osteoporosis Center, Honolulu.

SUBJECTS

1017 Japanese-American men born between 1900 and 1920, of whom 378 were treated for hypertension (study group) and 639 did not have hypertension (control group).

INTERVENTION

Thiazide diuretics were taken by 325 men for a mean of 11.9 years; 53 men took antihypertensive drugs other than thiazides.

MAIN OUTCOME MEASURE

Rate of bone loss estimated from serial photon absorptiometric scanning at three skeletal sites (calcaneus, distal radius, and proximal radius).

RESULTS

Rates of bone loss at all three sites were significantly reduced among thiazide users when compared with controls. The reductions in loss rate ranged from 28.8% (p = 0.02) (distal radius) to 49.2% (p = 0.0005) (calcaneus) relative to the controls. At all three sites the men taking other antihypertensive drugs had faster loss rates (22.6-43.1%) than those of the controls but the difference was significant only for the distal radius.

CONCLUSION

Thiazide diuretics slow the rate of bone loss in elderly men.

Quantitative approach to single-nucleotide polymorphism analysis using MALDI-TOF mass spectrometry

Pooling of DNA samples before genotyping is a valuable means of streamlining large-scale genotyping efforts in disease association studies, single-nucleotide polymorphism (SNP) validation or mutant allele screening programs. In this report, we explore the application of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) to quantitative analysis of SNPs. The measurements are based on MALDI-TOF MS analysis of primer extension assays performed on standard mixtures of pooled PCR products at several test loci. The inherent high molecular weight resolution of MALDI-TOF MS conveys high specificity and good signal-to-noise ratio for performing accurate quantitation. The methods described maximize the sensitivity and quantitative capacity of MALDI-TOF MS while preserving the throughput and economic advantages of the MALDI-TOF platform. Using the format described, we demonstrate that allele frequencies as low as 5% can be detected quantitatively and unambiguously.

Respiratory health in a total very low birthweight cohort and their classroom controls

AIMS

To compare the respiratory health and function at 8 to 9 years of age of a total population based cohort of 300 very low birthweight (VLBW) children with that of two classroom controls (n = 590) matched for age and sex.

STUDY DESIGN

Cohort study with controls.

SETTING

Schools throughout Scotland.

RESULTS

The VLBW children were more likely than their peers to use an inhaler, to be absent from school, and to be admitted to hospital because of respiratory illness. They were significantly shorter than their classroom controls, but even after adjusting for differences in height, the VLBW children had reduced forced vital capacity (FVC); this was associated with a history of prolonged ventilation (> 28 days) and pneumothorax in the neonatal period. There were no significant differences between the groups in forced expiratory volume in one second (FEV1)/FVC but twice as many (7.9% v 3.7%) of the VLBW children had ratios < 70%, denoting obstructive airways disease. Poor expiratory function was associated with neonatal respiratory distress syndrome, prolonged ventilation, and the need for > 40% oxygen. Exercise induced airway narrowing was increased in VLBW children (odds ratio = 2.0; 95% confidence interval 1.2 to 3.4) and was very little changed by adjustment for inhaler use and exposure to cigarette smoke.

CONCLUSIONS

As in other low birthweight cohorts, respiratory morbidity was increased. Unlike previous studies, FVC was more affected than expiratory function in this VLBW population. Our findings support the hypothesis that poorer lung function is associated with very low birth weight, but not with intrauterine growth retardation.

Development and validation of a discriminative quality of life questionnaire for osteoporosis (the OPTQoL)

We report the development and validation of an osteoporosis-targeted quality of life questionnaire to measure the impact of the disease in the general population. From multiple focus groups with women with osteoporosis, healthy women at risk for osteoporosis, spouses and relatives of women with osteoporosis, and health care providers, we identified over 300 potential items related to the disease. A lengthy questionnaire incorporated these items and was administered to a second large study cohort of 222 women with clinical osteoporosis (history of fracture, significant height loss, and/or kyphosis); 101 women with known low bone mineral density levels that would categorize them as osteoporotic but who had not yet shown obvious physical manifestations of the disease; and 142 women with other conditions (such as arthritis, cancer, depression) expected to also have an impact on quality of life. Final items from among the original 300 were chosen for their demonstrated relationship with osteoporosis as measured by clinical manifestations and low bone density and with quality of life measured by a standard generic questionnaire, the SF-36. The final questionnaire contains 26 scored items in three domains-physical activity, adaptations, and fears- and six nonscored questions relating to osteoporotic changes and diagnosis. This instrument is unique among osteoporosis-targeted questionnaires in that it attempts to measure the total impact of the disease on quality of life within a population at a single point in time.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

Assessment of changes in tumor heterogeneity following neoadjuvant chemotherapy in primary esophageal cancer

To assess the changes in computed tomography (CT) tumor heterogeneity following neoadjuvant chemotherapy in esophageal cancer. Thirty-one consecutive patients who received neoadjuvant chemotherapy for esophageal cancer were identified. Analysis of primary tumor heterogeneity (texture) was performed on staging and post-chemotherapy CT scans. Image texture parameters (mean grey-level intensity, entropy, uniformity, kurtosis, skewness, standard deviation of histogram) were derived for different levels of image filtration (0-2.5). Proportional changes in each parameter following treatment were obtained. Comparison between pathological tumor response and texture parameters was analyzed using Mann-Whitney U-test. The relationship between CT texture and overall survival) was estimated using the Kaplan-Meier method. Tumor texture became more homogeneous after treatment with a significant decrease in entropy and increase in uniformity (filter 1.0 and 2.5). Pretreatment (filter 1.5, P = 0.006) and posttreatment standard deviation of histogram (filter 1.0, P = 0.009) showed a borderline association with pathological tumor response. A proportional change in skewness <0.39 (filter 1.0) was associated with improved survival (median overall survival 36.1 vs. 11.1 months; P < 0.001). CT tumor heterogeneity decreased following neoadjuvant chemotherapy and has the potential to provide additional information in primary esophageal cancer.