Efficacy of intravenous continuous infusion of fluorouracil compared with bolus administration in advanced colorectal cancer

PURPOSE

The administration of fluorouracil (5-FU) by continuous intravenous infusion (CI) is an alternative to the bolus administration of 5-FU in patients with advanced colorectal cancer. Although more than 1,200 patients have been enrolled onto randomized trials that compared these two treatment modalities, there is still no definitive evidence of an advantage of 5-FU CI, and the magnitude of this advantage, if any, is also controversial. A meta-analysis was performed to assess this benefit in terms of tumor response and survival, and to compare the toxicity profiles of these two modalities of administration of 5-FU.

DESIGN

Individual data of 1,219 patients included in six randomized trials served as the basis for this meta-analysis, which was conducted by an independent secretariat in close collaboration with the investigators.

RESULTS

Tumor response rate was significantly higher in patients assigned to 5-FU CI than in patients assigned to 5-FU bolus (22% v 14%; overall response odds ratio, 0.55; 95% confidence interval [95% CI], 0.41 to 0.75; P = .0002). Overall survival was also significantly higher in patients assigned to 5-FU CI (overall hazards ratio [HR], 0.88; 95% CI, 0.78 to 0.99; P = .04), although the median survival times were close. Multivariate analyses showed that randomized treatment and performance status were the only two significant predictors of tumor response, whereas the same plus primary tumor site were independent significant predictors of survival (patients with rectal cancer did somewhat better). Grade 3 or 4 hematologic toxicity was more frequent in patients assigned to 5-FU bolus (31% v 4%; P < 10(-16)), whereas hand-foot syndrome was more frequent in the 5-FU CI group (34% v 13%; P < 10(-7)).

CONCLUSION

5-FU CI is superior to 5-FU bolus in terms of tumor response and achieves a slight increase of overall survival. The hematologic toxicity is much less important in patients who receive 5-FU CI, but hand-foot syndrome is frequent in this group of patients.

Effect of recombinant human granulocyte-macrophage colony-stimulating factor on chemotherapy-induced myelosuppression

An increase in the dose of chemotherapy enhances the response of many experimental and clinical cancers, but the extent of dose escalation is often limited by myelosuppression. In preliminary trials, recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) has augmented leukocyte numbers and function, but the optimal dose is not established. We treated 16 adults who had inoperable or metastatic sarcomas with escalating doses of rhGM-CSF before and immediately after a first cycle of chemotherapy (cycle 1) to assess hematologic response and toxicity. A second cycle of chemotherapy (cycle 2) was given without rhGM-CSF. RhGM-CSF was tolerated well at doses of 4 to 32 micrograms per kilogram of body weight per day. At 64 micrograms per kilogram per day, edema and thrombi around a central venous catheter developed in two of four patients. Leukocyte and granulocyte counts increased significantly during the rhGM-CSF infusion. Neutropenia after cycle 1 was significantly less severe and shorter in duration than after cycle 2 (P less than 0.01). Mean total leukocyte and platelet nadirs were 1.0 and 101 x 10(9) per liter for cycle 1 and 0.45 and 44 x 10(9) per liter for cycle 2 (P less than 0.01), and the median intervals from day 1 of chemotherapy to neutrophil recovery (greater than 0.500 x 10(9) per liter) were 15 and 19 days, respectively (P less than 0.01). The duration of neutropenia was 3.5 days with cycle 1 and 7.4 days with cycle 2 (P less than 0.01). We conclude that rhGM-CSF is tolerated well at doses up to 32 micrograms per kilogram per day and is biologically active in leukopenic patients. It merits further evaluation for the prevention of morbidity from chemotherapy.

A functional imaging study of cooperation in two-person reciprocal exchange

Cooperation between individuals requires the ability to infer each other's mental states to form shared expectations over mutual gains and make cooperative choices that realize these gains. From evidence that the ability for mental state attribution involves the use of prefrontal cortex, we hypothesize that this area is involved in integrating theory-of-mind processing with cooperative actions. We report data from a functional MRI experiment designed to test this hypothesis. Subjects in a scanner played standard two-person "trust and reciprocity" games with both human and computer counterparts for cash rewards. Behavioral data shows that seven subjects consistently attempted cooperation with their human counterpart. Within this group prefrontal regions are more active when subjects are playing a human than when they are playing a computer following a fixed (and known) probabilistic strategy. Within the group of five noncooperators, there are no significant differences in prefrontal activation between computer and human conditions.

Toxicity of fluorouracil in patients with advanced colorectal cancer: effect of administration schedule and prognostic factors

PURPOSE

Fluorouracil (5-FU) continuous infusion is superior to 5-FU bolus in patients with advanced colorectal cancer, but the survival difference between the two treatments is small and, therefore, the difference in toxicity profile is crucial in choosing a treatment for individual patients.

MATERIALS AND METHODS

We conducted a meta-analysis of all randomized trials that compared 5-FU bolus with 5-FU CI, based on individual data from 1,219 patients, to compare the toxicity of the two schedules of 5-FU administration and to identify predictive factors for toxicity. The toxicities considered were World Health Organization (WHO) grade 3 to 4 anemia, thrombopenia, leukopenia, neutropenia, nausea/vomiting, diarrhea, mucositis, and hand-foot syndrome.

RESULTS

Hematologic toxicity, mainly neutropenia, was more frequent with 5-FU bolus than with 5-FU CI (31% and 4%, respectively; P < .0001). Hand-foot syndrome was less frequent with 5-FU bolus than with 5-FU CI (13% and 34%, respectively; P < .0001). There was no difference between the two treatment groups in terms of other nonhematologic toxicities. Independent prognostic factors were age, sex, and performance status for nonhematologic toxicities, performance status, and treatment for hematologic toxicities, and age, sex, and treatment for hand-foot syndrome.

CONCLUSION

Based on a large data set, this study confirmed and quantified the toxicity profile of the two schedules of administration of 5-FU and allowed the identification of clinical predictors of toxicity.

Multiple trace theory of human memory: computational, neuroimaging, and neuropsychological results

Hippocampal-neocortical interactions in memory have typically been characterized within the "standard model" of memory consolidation. In this view, memory storage initially requires hippocampal linking of dispersed neocortical storage sites, but over time this need dissipates, and the hippocampal component is rendered unnecessary. This change in function over time is held to account for the retrograde amnesia (RA) gradients often seen in patients with hippocampal damage. Recent evidence, however, calls this standard model into question, and we have recently proposed a new approach, the "multiple memory trace" (MMT) theory. In this view, hippocampal ensembles are always involved in storage and retrieval of episodic information, but semantic (gist) information can be established in neocortex, and will survive damage to the hippocampal system if enough time has elapsed. This approach accounts more readily for the very long RA gradients often observed in amnesia. We report the results of analytic and connectionist simulations that demonstrate the feasibility of MMT. We also report a neuroimaging study showing that retrieval of very remote (25-year-old) memories elicits as much activation in hippocampus as retrieval of quite recent memories. Finally, we report new data from the study of patients with temporal lobe damage, using more sensitive measures than previously the case, showing that deficits in both episodic and spatial detail can be observed even for very remote memories. Overall, these findings indicate that the standard model of memory consolidation, which views the hippocampus as having only a temporary role in memory, is wrong. Instead, the data support the view that for episodic and spatial detail the hippocampal system is always necessary.

DNA damage in human sperm is related to urinary levels of phthalate monoester and oxidative metabolites

BACKGROUND

The ubiquitous use of phthalate esters in plastics, personal care products and food packaging materials results in widespread general population exposure. In this report, we extend our preliminary study on the relationship between urinary concentrations of phthalate metabolites and sperm DNA damage among a larger sample of men and include measurements of mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP), two oxidative metabolites of di-(2-ethylhexyl) phthalate (DEHP).

METHODS

Among 379 men from an infertility clinic, urinary concentrations of phthalate metabolites were measured using isotope-dilution high-performance liquid chromatography-tandem mass spectrometry. Sperm DNA damage measurements, assessed with the neutral comet assay, included comet extent (CE), percentage of DNA in tail (Tail%) and tail distributed moment (TDM).

RESULTS

Monoethyl phthalate (MEP), a metabolite of diethyl phthalate, was associated with increased DNA damage, confirming our previous findings. Mono-(2-ethylhexyl) phthalate (MEHP), a metabolite of DEHP, was associated with DNA damage after adjustment for the oxidative DEHP metabolites. After adjustment for MEHHP, for an interquartile range increase in urinary MEHP, CE increased 17.3% [95% confidence interval (CI) = 8.7-25.7%], TDM increased 14.3% (95% CI = 6.8-21.7%) and Tail% increased 17.5% (95% CI = 3.5-31.5%).

CONCLUSIONS

Sperm DNA damage was associated with MEP and with MEHP after adjusting for DEHP oxidative metabolites, which may serve as phenotypic markers of DEHP metabolism to 'less toxic' metabolites. The urinary levels of phthalate metabolites among these men were similar to those reported for the US general population, suggesting that exposure to some phthalates may affect the population distribution of sperm DNA damage.

Risk of internal cancers from arsenic in drinking water

The U.S. Environmental Protection Agency is under a congressional mandate to revise its current standard for arsenic in drinking water. We present a risk assessment for cancers of the bladder, liver, and lung from exposure to arsenic in water, based on data from 42 villages in an arseniasis-endemic region of Taiwan. We calculate excess lifetime risk estimates for several variations of the generalized linear model and for the multistage-Weibull model. Risk estimates are sensitive to the model choice, to whether or not a comparison population is used to define the unexposed disease mortality rates, and to whether the comparison population is all of Taiwan or just the southwestern region. Some factors that may affect risk could not be evaluated quantitatively: the ecologic nature of the data, the nutritional status of the study population, and the dietary intake of arsenic. Despite all of these sources of uncertainty, however, our analysis suggests that the current standard of 50 microg/L is associated with a substantial increased risk of cancer and is not sufficiently protective of public health.

Human toll-like receptor 2 mediates monocyte activation by Listeria monocytogenes, but not by group B streptococci or lipopolysaccharide

Human Toll like receptor (TLR) 2 has been implicated as a signaling receptor for LPS from Gram-negative bacteria and cell wall components from Gram-positive organisms. In this study, we investigated whether TLR2 can signal cell activation by the heat-killed group B streptococci type III (GBS) and Listeria monocytogenes (HKLM). HKLM, but not GBS, showed a time- and dose-dependent activation of Chinese hamster ovary cells transfected with human TLR2, as measured by translocation of NF-kappaB and induction of IL-6 production. A mAb recognizing a TLR2-associated epitope (TL2.1) was generated that inhibited IL-6 production from Chinese hamster ovary-TLR2 cells stimulated with HKLM or LPS. The TL2.1 mAb reduced HKLM-induced TNF production from human monocytes by 60%, whereas a CD14 mAb (3C10) reduced the TNF production by 30%. However, coadministrating TL2.1 and 3C10 inhibited the TNF response by 80%. In contrast to this, anti-CD14 blocked LPS-induced TNF production from monocytes, whereas anti-TLR2 showed no inhibition. Neither TL2.1 nor 3C10 affected GBS-induced TNF production. These results show that TLR2 can function as a signaling receptor for HKLM, possibly together with CD14, but that TLR2 is unlikely to be involved in cell activation by GBS. Furthermore, although LPS can activate transfected cell lines through TLR2, this receptor does not seem to be the main transducer of LPS activation of human monocytes. Thus, our data demonstrate the ability of TLR2 to distinguish between different pathogens.

Malignant mesothelioma: prognostic variables in a registry of 180 patients, the Dana-Farber Cancer Institute and Brigham and Women's Hospital experience over two decades, 1965-1985

All mesothelioma patients identified by a computer search of pathologic diagnoses at the Dana-Farber Cancer Institute (DFCI) between 1965 and 1985 were the subjects of this analysis. A total of 180 patients were identified, 136 with pleural and 37 with peritoneal mesothelioma. There were five pericardial and two testicular primaries. Of the two decades included in the study, later patients were significantly older, with a more advanced disease stage, and a lower performance status than those accrued early in the study. Factors at diagnosis associated with a significantly prolonged survival for all patients with mesothelioma included a 0 to 1 performance status, absence of chest pain, age less than 50 years, and epithelial histology. Factors at diagnosis associated with prolonged survival for the subset of patients with pleural mesothelioma included epithelial histology, 0 to 1 performance status, the absence of chest pain, an interval of greater than 6 months from onset of symptoms, and treatment with chemotherapy and pleuropneumonectomy. This last result must be interpreted with caution, since this was not a randomized study.

Association between air pollution and low birth weight: a community-based study

The relationship between maternal exposure to air pollution during periods of pregnancy (entire and specific periods) and birth weight was investigated in a well-defined cohort. Between 1988 and 1991, all pregnant women living in four residential areas of Beijing were registered and followed from early pregnancy until delivery. Information on individual mothers and infants was collected. Daily air pollution data were obtained independently. The sample for analysis included 74,671 first-parity live births were gestational age 37-44 weeks. Multiple linear regression and logistic regression were used to estimate the effects of air pollution on birth weight and low birth weight (< 2,500 g), adjusting for gestational age, residence, year of birth, maternal age, and infant gender. There was a significant exposure-response relationship between maternal exposures to sulfur dioxide (SO2) and total suspended particles (TSP) during the third trimester of pregnancy and infant birth weight. The adjusted odds ratio for low birth weight was 1.11 (95% CI, 1.06-1.16) for each 100 micrograms/m3 increase in SO2 and 1.10 (95% CI, 1.05-1.14) for each 100 micrograms/m3 increase in TSP. The estimated reduction in birth weight was 7.3 g and 6.9 g for each 100 micrograms/m3 increase in SO2 and in TSP, respectively. The birth weight distribution of the high-exposure group was more skewed toward the left tail (i.e., with higher proportion of births < 2,500 g) than that of the low-exposure group. Although the effects of other unmeasured risk factors cannot be excluded with certainty, our data suggests that TSP and SO2, or a more complex pollution mixture associated with these pollutants, contribute to an excess risk of low birth weight in the Beijing population.

The role of dietary fat in body fatness: evidence from a preliminary meta-analysis of ad libitum low-fat dietary intervention studies

The role of high-fat diets in weight gain and obesity has been questioned because of inconsistent reports in the literature concerning the efficacy of ad libitum low-fat diets to reduce body weight. We conducted a meta-analysis of weight loss occurring on ad libitum low-fat diets in intervention trials, and analysed the relationship between initial body weight and weight loss. We selected controlled trials lasting more than 2 months comparing ad libitum low-fat diets with a control group consuming their habitual diet or a medium-fat diet ad libitum published from 1966 to 1998. Data were included from 16 trials with a duration of 2-12 months, involving 1728 individuals. No trials on obese subjects fulfilled the inclusion criteria. The weighted difference in weight loss between intervention and control groups was 2.55 kg (95% CI, 1.5-3.5; P < 0.0001). Weight loss was positively and independently related to pre-treatment body weight (r = 0.52, P < 0.05) and to reduction in the percentage of energy as fat (0.37 kg/%, P < 0.005) in unweighted analysis. Extrapolated to a BMI of about 30 kg/m2 and assuming a 10% reduction in dietary fat, the predicted weight loss would be 4.4 kg (95% CI, 2.0 to -6.8 kg). Because weight loss was not the primary aim in 12 of the 16 studies, it is unlikely that voluntary energy restriction contributed to the weight loss. Although there is no evidence that a high intake of simple sugars contributes to passive overconsumption, carbohydrate foods with a low glycaemic index may be more satiating and exert more beneficial effects on insulin resistance and cardiovascular risk factors. Moreover, an increase in protein content up to 25% of total energy may also contribute to reducing total energy intake. In conclusion, a low-fat diet, high in protein and fibre-rich carbohydrates, mainly from different vegetables, fruits and whole grains, is highly satiating for fewer calories than fatty foods. This diet composition provides good sources of vitamins, minerals, trace elements and fibre, and may have the most beneficial effect on blood lipids and blood-pressure levels. A reduction in dietary fat without restriction of total energy intake prevents weight gain in subjects of normal weight and produces a weight loss in overweight subjects, which is highly relevant for public health.

Response to ifosfamide and mesna: 124 previously treated patients with metastatic or unresectable sarcoma

European and American investigators have reported response rates of 38% to 83% for ifosfamide alone in pretreated sarcomas. In a phase II trial of ifosfamide 2.0g/m2 days 1 to 4 with mesna uroprotection in 124 patients with previously failed sarcomas, four (3%) responded completely (95% exact confidence interval, 1% to 8%) and 26 (21%) had a complete or partial response (95% exact confidence interval, 14% to 29%). The median time to progression was 5 and 9 months for partial and complete responders, respectively. In the subset of soft tissue sarcomas, the response rate for the patients receiving bolus administration was 26%, compared with 9% for the patients receiving a continuous infusion schedule (P = .03). The response rates among patients with soft tissue and bony sarcomas with a performance score of 0-2 and 0-1 prior to chemotherapy administration were 20% and 40%, respectively. Somnolence or confusion developed in 19%. Neurotoxicity was significantly associated with poor performance status (P less than .01), elevated creatinine (P less than .01), and low bicarbonate levels (P = .05). A serum bicarbonate less than 20 developed in 31% of the patients and was significantly associated with older age (P = .01), elevated creatinine (P = .02), and female sex (P = .06). Hematuria was significantly associated with no uroprotection (the first four patients did not receive mesna because it was unavailable), but was not associated with prior cyclophosphamide, pelvic radiotherapy, age, or bolus v continuation infusion schedule. Thus, ifosfamide is active in failed sarcomas and warrants further study in previously untreated patients with sarcoma.

Hippocampal complex and retrieval of recent and very remote autobiographical memories: evidence from functional magnetic resonance imaging in neurologically intact people

It has been argued that the role of the hippocampus in memory is time-limited: during a period of memory consolidation, other brain regions such as the neocortex are said to acquire the ability to support memory retention and retrieval on their own. An alternative view is that retention and retrieval of memory for autobiographical episodes depend on the hippocampal complex, regardless of the age of the memory. We examined the participation of the hippocampal complex in a functional magnetic resonance imaging (fMRI) study in which participants were asked to recollect autobiographical events that occurred either within the last 4 years or more than 20 years ago. We found equivalent levels of hippocampal activation in both conditions in all participants (N = 10). In addition, activation in neocortical regions did not differ as a function of the age of the memory, even though most of the recent memories recalled were less than 2 years old and the remote memories more than 35 years old. The results support the notion that the hippocampal complex participates in retention and recovery of even very old autobiographical memories, and place boundary conditions on theories of memory consolidation.

Response to mesna, doxorubicin, ifosfamide, and dacarbazine in 108 patients with metastatic or unresectable sarcoma and no prior chemotherapy

In this phase II trial, 105 eligible patients with no prior chemotherapy and advanced sarcoma received doxorubicin, ifosfamide, and dacarbazine (DTIC) with mesna uroprotection (MAID). Starting doses of these drugs were 60, 7,500, and 900 mg/m2 divided over 72 hours by continuous infusion, respectively. Mesna was given for 84 to 96 hours at 2,500 mg/m2/d. Myelosuppression was dose limiting, causing the only toxic death (sepsis). Nonhematologic toxicity consisted predominantly of anorexia and vomiting. Severe mucositis, macroscopic hematuria, renal tubular acidosis, renal failure, and CNS toxicity occurred in less than 5% of cycles. No cardiotoxicity was detected. The overall response rate (10% complete response [CR]) was 47% (95% confidence intervals, 5% to 18% and 37% to 57%, respectively). Most responses (approximately 70%) were observed within two cycles. Median times to progression were 10 and 9 months, respectively. Histologic high tumor grade, lesions less than 5 cm, and less than 1 year from diagnosis to study entry correlated with the probability of response. The median survival was 16 months. Time from diagnosis to study entry, performance status, and extent of disease, but not histologic grade, correlated with survival. Following CR, two patients remain disease-free at 32 and 16 months. Of the 15 additional patients rendered disease-free with surgery, two remain disease-free at 30 and 18 months with no further therapy. While most relapses occurred in sites of prior involvement, death from CNS metastases occurred in 11 of the 80 patients with high-grade sarcomas, of whom seven were still responding systematically (three complete responders). Because of its substantial response in this phase II trial, the MAID regimen is being compared with doxorubicin and DTIC alone in advanced sarcomas and to observation in the adjuvant treatment of high-grade sarcomas in randomized trials.

Adjuvant active specific immunotherapy for stage II and III colon cancer with an autologous tumor cell vaccine: Eastern Cooperative Oncology Group Study E5283

PURPOSE

A randomized phase III clinical trial of adjuvant active specific immunotherapy (ASI) with an autologous tumor cell-bacillus Calmette-Guérin (BCG) vaccine was conducted to determine whether surgical resection plus ASI was more beneficial than resection alone in stage II and III colon cancer patients.

PATIENTS AND METHODS

Patients (n = 412) with colon cancer (297 with stage II disease, 115 with stage III disease) were randomly allocated to an observation arm or to a treatment arm in which they received three weekly intradermal vaccine injections of 10(7) irradiated autologous tumor cells beginning approximately 4 weeks after surgery. The first two weekly injections also contained 10(7) BCG organisms. Patients were observed for determination of time to recurrence and disease-free and overall survival.

RESULTS

This was a negative study in that after a 7.6-year median follow-up period, there were no statistically significant differences in clinical outcomes between the treatment arms. However, there were disease-free survival (P =.078) and overall survival (P =.12) trends in favor of ASI when treatment compliance was evaluated, ie, patients who received the intended treatment had a delayed cutaneous hypersensitivity (DCH) response to the third vaccination (induration >/=5 mm). Also, the magnitude of the DCH response correlated with improved prognosis. The 5-year survival proportion was 84.6% for those with indurations greater than 10 mm, compared with 45.0% for those with indurations less than 5 mm.

CONCLUSIONS

When all randomized patients were evaluated, no significant clinical benefit was seen with ASI in surgically resected colon cancer patients with stage II or III colon cancer. However, there was an indication that treatment compliance with effective immunization results in disease-free and overall survival benefits.

The cytokine stimulating activity of (1-->3)-beta-D-glucans is dependent on the triple helix conformation

The immunomodulating properties of comb-like branched (1-->3)-beta-D-glucans scleroglucan, schizophyllan and lentinan depend on branching pattern, molecular weight and higher-order structure. The effect of weight average molecular weight Mw and higher order structure of scleroglucan, on stimulation of human monocytes cultured in vitro to secrete tumor necrosis factor-alpha (TNF-alpha) was investigated. The higher order structures of the scleroglucan samples were determined by electron microscopy. The data showed that the samples with a linear wormlike, triple helical structure with Mw less than 50 x 10(4) g/mol or larger than 110 x 10(4) g/mol stimulated the monocytes more efficiently than samples with Mw in the range (67-110) x 10(4) g/mol. The denaturation of the linear triple helices by NaOH (> 0.25 M), followed by neutralization yielded blends of linear and macrocyclic topologies with concomitant irreversible reduction of the cytokine inducing activity compared with the untreated scleroglucans. The dose-dependent ability to activate monocytes to cytokine production was not restored following annealing of the denatured-renatured samples, despite the fact that electron micrographs revealed similar structures of these annealed samples to the starting material. Pre-incubation of monocytes with antibodies against cluster of differentiation antigens CD14 or CD11b reduced the scleroglucan potency to stimulate TNF-alpha secretion mainly for mAb against CD14 in the presence of serum.

Understanding triclabendazole resistance

Triclabendazole (TCBZ) has been the drug of choice to treat liver fluke infections in livestock for >20 years, due to its high activity against both adult and juvenile flukes. More recently, it has been used successfully to treat human cases of fascioliasis. Resistance to TCBZ first appeared in the field in Australia in the mid-1990s. Since then, resistance has been reported from a number of countries throughout Europe: Ireland, Scotland, Wales, Spain and The Netherlands. The heavy reliance on a single drug puts treatment strategies for fascioliasis at risk. Should resistance develop further, the prospect is an alarming one. This review will present an overview of progress in understanding the mechanism of resistance to TCBZ, examining possible changes in the target molecule, in drug influx/efflux mechanisms and in the metabolism of TCBZ by the fluke. The review will also consider ways to deal with resistance, covering drug-oriented options such as: the use of alternative drugs, drug combinations and the search for new compounds.

The involvement of CD14 in stimulation of cytokine production by uronic acid polymers

In this study the molecular mechanisms behind the stimulatory activities of the uronic acid polymers poly mannuronic acid (poly M), high M alginate and oxidized cellulose (C60XY) were investigated and compared with lipopolysaccharide (LPS). The cytokine-inducing abilities of the uronic acid polymers and LPS were examined on CD14-positive human monocytes and CD14-negative U373 astrocytoma cells. It was found that LPS induced monocytes and U373 cells to produce tumor necrosis factor (TNF) and interleukin(IL)-6, respectively, by different mechanisms. The poly uronic acids induced monocytes to produce TNF, but with 100-1000 times less potency compared to LPS. On U373 cells, LPS at concentrations > or = 32 ng/ml resulted in a dose-related IL-6 production, whereas the poly uronic acids had negligible effects even at 1 mg/ml. The binding data demonstrate that only the CD14-positive monocytes in the peripheral blood mononuclear cells population bound poly M. Furthermore, poly M was found to bind to CD14 in the presence of serum. Antibodies against CD14 also inhibited the TNF-inducing activity of the three uronic acid polymers tested. In conclusion, these results demonstrate that uronic acid polymers induce TNF production through mechanisms which involve CD14.

Cocaine abuse in pregnancy: effects on the fetus and newborn

The outcome of infants born to cocaine-using drug dependent women was compared to that of infants of non-cocaine using drug dependent and non-drug dependent women. The study population included 150 pregnant women: 50 women used heroin and methadone plus cocaine, 50 used heroin and methadone minus cocaine, and 50 were non-drug dependent women. Significant differences were found between the cocaine and drug-free groups in infant birth weight, length, head circumference and Apgar scores, with the cocaine group having lower values for each variable. Average gestational age did not vary between the 3 groups. The cocaine group included 1 spontaneous abortion and 4 fetal deaths; non-cocaine drug dependent women had 2 fetal deaths, with none in the control group. Mean abstinence scores for 19 of the physiological and behavioral parameters were lower in the cocaine group than in the non-cocaine drug dependent women with the exception of vomiting and convulsions. These data suggest that: (1) infants born to drug dependent women have a poorer general outcome than those born to non-drug dependent women; (2) maternal cocaine use does not appear to increase the incidence of severe neonatal abstinence symptomatology; (3) pregnancies complicated by cocaine abuse have a greater chance for fetal loss resulting from both spontaneous abortions and fetal death; (4) infants born to cocaine abusing women had infants with decreased birth weight, head circumference, length and Apgar scores.

Micellarisation of carotenoids from raw and cooked vegetables

The efficiency of carotenoid micellarisation from plant foods can be used as an effective tool for the initial screening of carotenoid bioavailability. Therefore, the objectives of the present study were to assess the effects of cooking on the micellarisation of beta-carotene, lycopene, beta-cryptoxanthin and lutein from courgette (zucchini), red pepper and tomato; and, to a minor extent, investigate uptake of lutein by Caco-2 cells from micellar fractions obtained from raw and cooked courgettes. Both raw and cooked vegetables were subjected to an in vitro digestion procedure. beta-Carotene levels were significantly decreased in the digesta from each vegetable after boiling, grilling, microwave-cooking, or steaming, however all of the cooking methods enhanced beta-carotene transfer to micelles. Carotenoid micellarisation ranged from 1.7% to 100% depending on the food, carotenoid, and the cooking method tested. Grilling and microwave-cooking were generally the most detrimental on the transfer of xanthophyll carotenoids, namely beta-cryptoxanthin, to the micelles. Caco-2 cells absorbed greater amounts of lutein from the micelles of microwave-cooked courgettes than those that were raw, boiled, grilled, or steamed. Depending on the cooking methods used, carotenoid retention as well as micellarisation varied for each carotenoid among the different vegetables and different carotenoids present in each particular food.

Similar mechanisms of action of defined polysaccharides and lipopolysaccharides: characterization of binding and tumor necrosis factor alpha induction

Little has been reported about the effects of different polysaccharides on cytokine production from human monocytes. In this study, we show that several well-defined polysaccharides, including polymers with different sizes of beta 1-4-linked D-mannuronic acid (poly-M, high-M alginate, and M-blocks) and cellulose oxidized in the C-6 position, induced human monocytes to produce tumor necrosis factor alpha (TNF-alpha). Poly-M was the most efficient polysaccharide tested and, on a weight basis, was approximately as efficient as lipopolysaccharide (LPS) from Escherichia coli. TNF-alpha production was shown to depend strongly on the molecular weights of poly-M and high-M alginate, with maximal TNF-alpha production occurring at molecular weights above 50,000 and 200,000, respectively. G-blocks, alpha 1-4-linked L-guluronic acid polymers that did not induce cytokine production from monocytes, reduced the cytokine production induced by the beta 1-4-linked polyuronic acids and LPS. Furthermore, both G-blocks and LPS were found to inhibit the binding of poly-M to monocytes, as measured by flow cytometry. In addition, we found that the binding of LPS to monocytes was inhibited by G-blocks, M-blocks, and poly-M. Our results indicate that beta 1-4-linked polyuronic acids and LPS may stimulate monocytes to produce TNF-alpha by similar mechanisms and may bind to a common receptor.

Transplantation of alginate microcapsules: generation of antibodies against alginates and encapsulated porcine islet-like cell clusters

BACKGROUND

Microencapsulation of islets of Langherhans in alginate poly-L-lysine capsules provides an effective protection against cell-mediated immune destruction, and ideally should allow the transplantation of islets in the absence of immunosuppression. It has previously been suggested that alginate rich in mannuronic acid (high M) is more immunogenic than alginate rich in guluronic acid (high G). The ability of these alginates to induce an antibody response in the recipient or act as an adjuvant to antibody responses against antigens leaked from the capsule was investigated in the present study.

METHODS

Empty capsules made from these different types of alginate were transplanted intraperitoneally to Wistar rats or Balb/c mice. In addition, some animals were also injected with bovine serum albumin to assess the ability of the alginates to act as an adjuvant to this antigen. Antibody responses to intraperitoneally transplanted free and microencapsulated fetal porcine islet like cell clusters (ICC) were also evaluated, in animals treated with or without cyclosporine.

RESULTS

Antibodies against high M-alginate capsules were detected in the sera of mice transplanted with this capsule type. However, this response was not seen after the transplantation of high G capsules. When Wistar rats were used as recipients, no antibody responses were detected against any type of alginate capsules. Neither type of capsule acted as an adjuvant. Antibodies against ICC were present, in rats transplanted with both nonencapsulated and encapsulated ICCs. Administration of cyclosporine could abolish this production of antibodies against ICC.

CONCLUSIONS

High G-alginate capsules are less immunogenic than high M capsules. Because encapsulation did not protect against the generation of antibodies against ICC, it can be assumed that antigen leakage from the capsules occurs, as no evidence was found for capsules breaking in vivo.

Mechanical stability, muscle strength and proprioception in the functionally unstable ankle

Functional instability of the ankle is common following inversion sprain. Factors suggested as causes of this disability include mechanical instability of the talocrural joint, peroneal muscle weakness and motor incoordination due to impaired proprioception. This study documented physical examination characteristics of functionally unstable ankles relevant to these theories. Each ankle of 45 subjects with unilateral functional instability was examined. Mechanical stability was assessed by standard clinical instability tests. Evertor and inventor muscle strength was measured using the Cybex II dynamometer. The Uni-axial Balance Evaluator (UBE) was used to assess dynamic control of the ankle and was considered capable of detecting unilaterally impaired proprioception. Mechanical instability was frequently absent in the functionally unstable ankles tested. Evertor muscle strength was similar in the normal and functionally unstable ankles. UBE results were consistent with the theory of impaired proprioception contributing to functional instability, but the need for further research is emphasised.

A nonlinear effect of hyperglycemia and current cigarette smoking are major determinants of the onset of microalbuminuria in type 1 diabetes

Cigarette smoking and poor glycemic control are risk factors for diabetic nephropathy in type 1 diabetes. However, the specifics of the relation of these risk factors to the onset of this complication have not been elucidated. To investigate these issues, we followed for 4 years 943 Joslin Clinic patients aged 15-44 years with type 1 diabetes who had normoalbuminuria during the 2-year baseline period. Microalbuminuria developed in 109 of the 943 individuals, giving an incidence rate of 3.3/100 person-years. The risk of onset of microalbuminuria was predicted somewhat more precisely by the measurements during the 1st and 2nd years preceding onset than by all the measurements during the longer (4-year) interval, suggesting attenuation of the impact of past hyperglycemia over time. Point estimates of the incidence rate (per 100 person-years) according to quartiles of HbA(1c) during the 1st and 2nd years preceding the outcome were 1.3 in the 1st, 1.5 in the 2nd, 3.1 in the 3rd, and 6.9 in the 4th (P = 1.3 x 10(-9)). Point estimates of the incidence rate (per 100 person-years) according to smoking status were 7.9 for current smokers, 1.8 for past smokers, and 2.2 for those who had never smoked (P = 2.0 x 10(-7)). In a multiple logistic model, the independent effects of HbA(1c) level and cigarette smoking remained highly significant, but their magnitudes were reduced. Using the same covariates in a generalized additive model, we examined the shape of the relationship between HbA(1c) and onset of microalbuminuria and found significant nonlinearity in the logarithm of odds scale (P = 0.04). The slope was steeper with HbA(1c) >8% than <8%. Furthermore, the change in the slope was magnified among current smokers. In conclusion, patients with type 1 diabetes who smoke and have an HbA(1c) >8% have the highest risk of onset of microalbuminuria.