A rescue factor abolishing neuronal cell death by a wide spectrum of familial Alzheimer's disease genes and Abeta

Through functional expression screening, we identified a gene, designated Humanin (HN) cDNA, which encodes a short polypeptide and abolishes death of neuronal cells caused by multiple different types of familial Alzheimer's disease genes and by Abeta amyloid, without effect on death by Q79 or superoxide dismutase-1 mutants. Transfected HN cDNA was transcribed to the corresponding polypeptide and then was secreted into the cultured medium. The rescue action clearly depended on the primary structure of HN. This polypeptide would serve as a molecular clue for the development of new therapeutics for Alzheimer's disease targeting neuroprotection.

Separation and characterization of the aldehydic products of lipid peroxidation stimulated by carbon tetrachloride or ADP-iron in isolated rat hepatocytes and rat liver microsomal suspensions

Carbonyl products were separated and identified in suspensions of rat liver microsomal fractions and in isolated hepatocytes, after stimulation of lipid peroxidation by incubation with the pro-oxidants CCl4 and ADP-iron. The carbonyl products were allowed to react with 2,4-dinitrophenylhydrazine, and the derivatives were extracted and separated by t.l.c. into three zones of non-polar materials, and one fraction of polar derivatives that remained at the origin. Separation of the individual non-polar hydrazones in each zone by h.p.l.c. demonstrated that zone I prepared from microsomal fraction or hepatocytes incubated with CCl4 or ADP-iron contained mainly 4-hydroxyhex-2-enal, 4-hydroxynon-2-enal and 4-hydroxynona-2,5-dienal. Zone III consisted mainly of the alkanals propanal, pentanal and hexanal, the 2-alkenals propenal, pent-2-enal, hex-2-enal, hept-2-enal, oct-2-enal and non-2-enal, the ketones butanone, pentan-2-one and pentan-3-one, and deca-2,4-dienal. Incubation of a microsomal fraction with ADP-iron was much more effective in producing malonaldehyde and other carbonyl products than an incubation with CCl4. Despite such quantitative differences, there were no obvious qualitative differences in the h.p.l.c. spectra obtained from zones I and III. However, the stoichiometric evaluation of fatty acid loss and the production of malonaldehyde and other carbonyls suggests that the pathways of lipid peroxidation triggered by CCl4 and ADP-iron are different. The accumulation of carbonyl products of lipid peroxidation in isolated hepatocytes is strongly affected by their metabolism; in particular, 4-hydroxyalkenals were found to be metabolized very rapidly. Nonetheless, both CCl4 and ADP-iron produced stimulation in the production of malonaldehyde and non-polar carbonyl production. After incubation of rat hepatocytes with CCl4 or ADP-iron it was found that approx. 50% of the total amount of non-polar carbonyls produced during incubation escaped into the external medium. This was not leakage from dead cells, as 90-95% of the hepatocytes had retained their integrity at the end of the incubation. Release of carbonyl products from cells stimulated to undergo lipid peroxidation may be a mechanism for spreading an initial intracellular disturbance to affect critical targets outside the parent cell.

What is the optimal goal of primary cytoreductive surgery for bulky stage IIIC epithelial ovarian carcinoma (EOC)?

OBJECTIVE

Recent studies have suggested that the definition of optimal cytoreduction for advanced EOC should be changed from the current Gynecologic Oncology Group threshold of < or =1 cm residual disease to no gross residual disease owing to improved survival of patients (pts) rendered macroscopically disease-free. The objective of this study was to analyze survival rates at very specific residual disease diameters to determine the optimal goal of primary cytoreduction for bulky stage IIIC EOC.

METHODS

A prospectively kept database was used to identify and review the records of all pts with Stage IIIC EOC who underwent primary cytoreductive surgery at our institution between January 1989 and December 2003. To analyze a homogeneous cohort of cases, we excluded pts with stage IIIC disease based on nodal metastasis alone (without bulky abdominal tumor), fallopian tube or primary peritoneal carcinomas, and borderline tumors. Standard statistical analyses were utilized.

RESULTS

The study cohort included 465 pts. The median age was 60 years (range, 25-87), and the median follow-up was 38 months (range, 1-199). Univariate and multivariate analyses, which included various prognostic factors, identified amount of residual disease as a significant prognostic factor (P < 0.001). Median overall survival in relation to the 5 residual disease categories was: no gross residual, 106 months; gross < or =0.5 cm, 66 months; 0.6-1.0 cm, 48 months; 1-2 cm, 33 months; >2 cm, 34 months. Statistical comparison between the 5 residual disease categories revealed 3 distinct groups with significantly different survival rates (P < 0.01). These 3 groups were: (1) no gross residual; (2) gross < or =1 cm residual; and (3) >1 cm residual. Although the difference in survival did not reach statistical significance, within the gross < or =1 cm residual group, there was a trend toward improved survival in pts left with smaller volume, < or =0.5 cm residual compared with those with 0.6-1.0 cm residual (P = 0.06).

CONCLUSION

Our data suggest that removal of all evidence of macroscopic disease is associated with prolonged survival and should be the goal of primary cytoreductive surgery. If complete gross resection is not feasible, however, cytoreduction to as minimal residual tumor as possible should be the focus of cytoreductive efforts, as each incremental decrease in residual disease below 1 cm may be associated with an incremental improvement in overall survival.

Encapsulation of Inorganic Particles by Dispersion Polymerization in Polar Media

Polymer encapsulation of small silica particles, using dispersion polymerization of styrene in aqueous ethanol medium with poly(N-vinyl pyrrolidone) (PVP) as stabilizer, is described. Silica particles, directly synthesized by the Stober process in an aqueous ethanol medium, are either unreacted (hydrophilic character) or coated with 3-(trimethoxysilyl)propyl methacrylate (MPS) (hydrophobic character), which is grafted at the silica particle surface. When the bare silica particles are used as the seed, there is a strong tendency of the silica beads to cover the surface of the polystyrene particles and obviously encapsulation does not occur. On the contrary, when the silica surface is made hydrophobic by coating, the inorganic particles are entirely contained in the polystyrene particles as evidenced by microscopy techniques (TEM, SEM, AFM). It is shown that some polystyrene chains are then chemically bonded to the silica particles, through the coupling agent MPS, and that only a small amount of bonded polystyrene, compared to the total polystyrene synthesized, is sufficient to obtain encapsulation of the silica particles with the entire amount of polystyrene synthesized during the polymerization. Under our experimental conditions, each polystyrene latex particle contains, on average, 4 to 23 silica beads depending, in particular, on the size of the silica. We believe that it is possible to control the composite particle size and morphology by a convenient choice of the composition of the system. Moreover, this new polymer-encapsulation process could be used to synthesize other organic-inorganic composite particles, using, for example, other monomers or minerals. Copyright 1998 Academic Press. Copyright 1998Academic Press

Studies on the mechanism of formation of 4-hydroxynonenal during microsomal lipid peroxidation

The mechanism of the formation of 4-hydroxynonenal through the NADPH-linked microsomal lipid peroxidation was investigated. The results were as follows: 4-hydroxynonenal arises exclusively from arachidonic acid contained in the polar phospholipids, neither arachidonic acid of the neutral lipids nor linoleic acid of the polar or neutral lipids are substrates for 4-hydroxynonenal generation. This finding results from the estimation of the specific radioactivity of 4-hydroxynonenal produced by microsomes prelabelled in vivo with [U-14C]arachidonic acid. Phospholipid-bound 15-hydroperoxyarachidonic acid would have the structural requirements needed for 4-hydroxynonenal (CH3-(CH2)4-CH(OH)-CH=CH-CHO). Microsomes supplemented with 15-hydroperoxyarachidonic acid and NADPH, ADP/iron converted only minimal amounts (0.6 mol%) of 15-hydroperoxyarachidonic acid into 4-hydroxynonenal; similarly, 15-hydroperoxyarachidonic acid incubated at pH 7.4 in the presence of ascorbate/iron yielded only small amounts of 4-hydroxynonenal with a rate orders of magnitude below that observed with microsomes. Phospholipid-bound 15-hydroperoxyarachidonic acid is therefore not a likely intermediate in the reaction pathway leading to 4-hydroxynonenal. The rate of 4-hydroxynonenal formation is highest during the very initial phase of its formation and the onset does not show a lag phase, suggesting a transient intermediate predominantly formed during the early phase of microsomal lipid peroxidation. After 60 min of incubation, 204 nmol polyunsaturated fatty acids (20 nmol 18:2, 143 nmol 20:4, 41 nmol 22:6) were lost per mg microsomal protein and the incubation mixture contained 206 nmol lipid peroxides, 71.6 nmol malonic dialdehyde and 4.6 nmol 4-hydroxynonenal per mg protein. Under artificial conditions (pH 1.0, ascorbate/iron, 20 h of incubation) not comparable to the microsomal peroxidation system, 15-hydroperoxyarachidonic acid can be decomposed in good yields (15 mol%) into 4-hydroxynonenal. Autoxidation of arachidonic acid in the presence of ascorbate/iron gave after 25 h of incubation 2.8 mol% (pH 7.4) and 1.5 mol% (pH 1.0) 4-hydroxynonenal. The most remarkable difference between the non-enzymic system and the enzymic microsomal system is that the latter forms 4-hydroxynonenal at a much higher rate.

Randomised comparison of percutaneous endoscopic gastrostomy and nasogastric tube feeding in patients with persisting neurological dysphagia

OBJECTIVE

To compare percutaneous endoscopic gastrostomy and nasogastric tube feeding in patients with persisting neurological dysphagia.

DESIGN

Randomised 28 day study of inpatients requiring long term enteral nutrition.

SETTING

Three Glasgow teaching hospitals.

SUBJECTS

40 patients with dysphagia for at least four weeks secondary to neurological disorders: 20 patients (10 women) were randomised to nasogastric feeding and 20 (eight women) to endoscopic gastrostomy.

MAIN OUTCOME MEASURES

Treatment failure (blocked or displaced tubes on three or more occasions or refusal to continue treatment); duration of feeding; intake of liquid diets; complications; nutritional status at end of trial.

RESULTS

One patient in each group died before starting feeding. Treatment failure occurred in 18 of the 19 nasogastric patients and in none of the gastrostomy group. The mean (SE) duration of feeding for the nasogastric group was 5.2 (1.5) days. No complications occurred in the nasogastric group but three (16%) of the gastrostomy group developed minor problems (aspiration pneumonia (two patients) wound infection (one)). Gastrostomy patients received a significantly greater proportion of their prescribed feed (93% (2%)) compared with the nasogastric group, (55% (4%); p less than 0.001) and also gained significantly more weight after seven days of feeding (1.4 (0.5) kg v 0.6 (0.1) kg; p less than 0.05). Analyses at days 14, 21, and 28 were not possible due to the small numbers remaining in the nasogastric group.

CONCLUSION

Percutaneous endoscopic gastrostomy tube feeding is a safe and effective method of providing long term enteral nutrition to patients with neurological dysphagia and offers important advantages over nasogastric tube feeding.

Molecular mechanisms and regulation of insulin exocytosis as a paradigm of endocrine secretion

Secretion of the peptide hormone insulin from pancreatic beta cells constitutes an important step in the regulation of body homeostasis. Insulin is stored in large dense core vesicles and released by exocytosis, a multistage process involving transport of vesicles to the plasma membrane, their docking, priming and finally their fusion with the plasma membrane. Some of the protein components necessary for this process have been identified in beta cells. The export of potent and potentially harmful substances has to be tightly controlled. The secretory response in pancreatic beta cells requires the concerted action of nutrients together with enteric hormones and neurotransmitters acting on G-protein coupled receptors. It is well established that glucose and other metabolizable nutrients depolarize the beta-cell membrane and the ensuing Ca2+ influx through voltage-dependent channels constitutes a main stimulus for insulin exocytosis. Theoretical considerations and recent observations suggest in addition an organizing role for the Ca2+ channel similar to neurotransmission. A second regulatory control on exocytosis is exerted by monomeric and heterotrimeric G-proteins. The monomeric GTPase Rab3A controls insulin secretion through cycling between a guanosine triphosphate liganded vesicle-bound form and a guanosine diphosphate liganded, cytosolic form. The effect of neurohormones is transduced by the heterotrimeric GTPases. Whereas pertussis-toxin sensitive alpha-subunits exert direct inhibition at the level of exocytosis, the Gbeta gamma-subunits are required for stimulation. It is possible that these GTPases exert immediate regulation, while protein kinases and phosphatases may modulate long-term adaptation at the exocytotic machinery itself. The molecular nature of their activators and effectors still await identification. Insights into the progression of the exocytotic vesicle from docking to fusion and how these processes are precisely regulated by proteins and second messengers may provide the basis for new therapeutic principles.

Smoking and mortality among older men and women in three communities

BACKGROUND

Although cigarette smoking is the leading avoidable cause of premature death in middle age, some have claimed that no association is present among older persons.

METHODS

We prospectively examined the relation of cigarette-smoking habits with mortality from all causes, cardiovascular causes, and cancer among 7178 persons 65 years of age or older without a history of myocardial infarction, stroke, or cancer who lived in one of three communities: East Boston, Massachusetts; Iowa and Washington counties, Iowa; and New Haven, Connecticut. At the time of the initial interview, prevalence rates of smoking in the three communities ranged from 5.2 to 17.8 percent among women and from 14.2 to 25.8 percent among men. During five years of follow-up there were 1442 deaths, 729 due to cardiovascular disease and 316 due to cancer.

RESULTS

In both sexes, rates of total mortality among current smokers were twice what they were among participants who had never smoked. Relative risks, as adjusted for age and community, were 2.1 among the men (95 percent confidence interval, 1.7 to 2.7) and 1.8 among the women (95 percent confidence interval, 1.4 to 2.4). Current smokers had higher rates of cardiovascular mortality than those who had never smoked (as adjusted for age and community, the relative risk was 2.0 [95 percent confidence interval, 1.4 to 2.9] among the men and 1.6 [95 percent confidence interval, 1.1 to 2.3] among the women), as well as increased rates of cancer mortality (relative risk, 2.4 [95 percent confidence interval, 1.4 to 4.1] among the men and 2.4 [95 percent confidence interval, 1.4 to 3.9] among the women). In both sexes, former smokers had rates of cardiovascular mortality similar to those of the participants who had never smoked, regardless of age at cessation, whereas the rates for all cancers, as well as smoking-related cancers, remained elevated among men who had once smoked.

CONCLUSIONS

Our prospective findings indicate that the mortality hazards of smoking extend well into later life, and suggest that cessation will continue to improve life expectancy in older people.

Diaphragm disease: pathology of disease of the small intestine induced by non-steroidal anti-inflammatory drugs

Operative small bowel resection specimens received over a period of 16 years were reviewed to assess whether any intestinal disease could be directly attributed to the use of non-steroidal anti-inflammatory drugs (NSAID). Seven cases of intestinal disease associated with the use of NSAID were identified, all of which occurred in the final six years of the survey, which may reflect the increasing use of these compounds. A spectrum of patterns was found from multiple pathognomonic ileal mucosal diaphragms to broad strictures similar to those seen as a complication of enteric potassium. It seems likely that the formation of diaphragm lesions requires an additional factor, but what is not known as yet is whether the effects of NSAID are local or systemic.

Effects of the lipid peroxidation product 4-hydroxynonenal on the aggregation of human platelets

The stimulation by ADP or arachidonic acid of the aggregation of human platelets in plasma was inhibited by 4-hydroxynonenal (HNE). This reduction of aggregation was time related, and was increased by prolonged preincubation of the platelets with the aldehyde. HNE was more potent than its homologue 4-hydroxypentenal (HPE). HNE was less active in decreasing the aggregation induced by calcium ionophore A23187 or collagen in comparison with ADP. HNE was inactive against aggregation of platelet-rich plasma (PRP) stimulated by thrombin whereas it potently inhibited the aggregation of washed platelets in response to both thrombin and collagen. Platelets were found to degrade HNE, and mechanisms additional to covalent binding to glutathione are indicated by the results obtained. The aldehydes, including HNE, generated by platelets originated principally from arachidonic acid metabolism.

SNAP-25 is expressed in islets of Langerhans and is involved in insulin release

SNAP-25 is known as a neuron specific molecule involved in the fusion of small synaptic vesicles with the presynaptic plasma membrane. By immunolocalization and Western blot analysis, it is now shown that SNAP-25 is also expressed in pancreatic endocrine cells. Botulinum neurotoxins (BoNT) A and E were used to study the role of SNAP-25 in insulin secretion. These neurotoxins inhibit transmitter release by cleaving SNAP-25 in neurons. Cells from a pancreatic B cell line (HIT) and primary rat islet cells were permeabilized with streptolysin-O to allow toxin entry. SNAP-25 was cleaved by BoNT/A and BoNT/E, resulting in a molecular mass shift of approximately 1 and 3 kD, respectively. Cleavage was accompanied by an inhibition of Ca(++)-stimulated insulin release in both cell types. In HIT cells, a concentration of 30-40 nM BoNT/E gave maximal inhibition of stimulated insulin secretion of approximately 60%, coinciding with essentially complete cleavage of SNAP-25. Half maximal effects in terms of cleavage and inhibition of insulin release were obtained at a concentration of 5-10 nM. The A type toxin showed maximal and half-maximal effects at concentrations of 4 and 2 nM, respectively. In conclusion, the results suggest a role for SNAP-25 in fusion of dense core secretory granules with the plasma membrane in an endocrine cell type- the pancreatic B cell.

Metabolism of the lipid peroxidation product 4-hydroxynonenal by isolated hepatocytes and by liver cytosolic fractions

The metabolism of the lipid peroxidation product 4-hydroxynonenal and of several other related aldehydes by isolated hepatocytes and rat liver subcellular fractions has been investigated. Hepatocytes rapidly metabolize 4-hydroxynonenal in an oxygen-independent process with a maximum rate (depending on cell preparation) ranging from 130 to 230 nmol/min per 10(6) cells (average 193 +/- 50). The aldehyde is also rapidly utilized by whole rat liver homogenate and the cytosolic fraction (140 000 g supernatant) supplemented with NADH, whereas purified nuclei, mitochondria and microsomes supplemented with NADH show no noteworthy consumption of the aldehyde. In cytosol, the NADH-mediated metabolism of the aldehyde exhibits a 1:1 stoichiometry, i.e. 1 mol of NADH oxidized/mol of hydroxynonenal consumed, and the apparent Km value for the aldehyde is 0.1 mM. Addition of pyrazole (10 mM) or heat inactivation of the cytosol completely abolishes aldehyde metabolism. The various findings strongly suggest that hepatocytes and rat liver cytosol respectively convert 4-hydroxynonenal enzymically is the corresponding alcohol, non-2-ene-1,4-diol, according to the equation: CH3-[CH2]4-CH(OH)-CH = CH-CHO + NADH + H+----CH3-[CH2]4-CH(OH)-CH = CH-CH2OH + NAD+. The alcohol non-2-ene-1,4-diol has not yet been isolated from incubations with hepatocytes and liver cytosolic fractions, but was isolated in pure form from an incubation mixture containing 4-hydroxynonenal, isolated liver alcohol dehydrogenase and NADH and its chemical structure was confirmed by mass spectroscopy. Compared with liver, all other tissues possess only little ability to metabolize 4-hydroxynonenal, ranging from 0% (fat pads) to a maximal 10% (kidney) of the activity present in liver. The structure of the aldehyde has a strong influence on the rate and extent of its enzymic NADH-dependent reduction to the alcohol. The saturated analogue nonanal is a poor substrate and only a small proportion of it is converted to the alcohol. Similarly, nonenal is much less readily utilized as compared with 4-hydroxynonenal. The effective conversion of the cytotoxic 4-hydroxynonenal and other reactive aldehydes to alcohols, which are probably less toxic, could play a role in the general defence system of the liver against toxic products arising from radical-induced lipid peroxidation.

Safety and efficacy of chimeric yellow Fever-dengue virus tetravalent vaccine formulations in nonhuman primates

To construct chimeric YF/DEN viruses (ChimeriVax-DEN), the premembrane (prM) and envelope (E) genes of yellow fever (YF) 17D virus were replaced with those of each wild-type (WT) dengue (DEN) virus representing serotypes 1 to 4. ChimeriVax-DEN1-4 vaccine viruses were prepared by electroporation of Vero cells with RNA transcripts prepared from viral cDNA (F. Guirakhoo, J. Arroyo, K. V. Pugachev, C. Miller, Z.-X. Zhang, R. Weltzin, K. Georgakopoulos, J. Catalan, S. Ocran, K. Soike, M. Ratteree, and T. P. Monath, J. Virol. 75:7290-7304, 2001; F. Guirakhoo, K. Pugachev, J. Arroyo, C. Miller, Z.-X. Zhang, R. Weltzin, K. Georgakopoulos, J. Catalan, S. Ocran, K. Draper, and T. P. Monath, Virology 298:146-159, 2002). Progeny viruses were subjected to three rounds of plaque purifications to produce the Pre-Master Seed viruses at passage 7 (P7). Three further passages were carried out using U.S. current Good Manufacturing Practices (cGMP) to produce the Vaccine Lot (P10) viruses. Preclinical studies demonstrated that the vaccine candidates are replication competent and genetically stable and do not become more neurovirulent upon 20 passages in Vero cells. The safety of a tetravalent vaccine was determined and compared to that of YF-VAX in a formal monkey neurovirulence test. Brain lesions produced by the tetravalent ChimeriVax-DEN vaccine were significantly less severe than those observed with YF-VAX. The immunogenicity and protective efficacy of four different tetravalent formulations were evaluated in cynomolgus monkeys following a single-dose subcutaneous vaccination followed by a virulent virus challenge 6 months later. All monkeys developed low levels of viremia postimmunization, and all the monkeys that had received equal concentrations of either a high-dose (5,5,5,5) or a low-dose (3,3,3,3) formulation seroconverted against all four DEN virus serotypes. Twenty-two (92%) of 24 monkeys were protected as determined by lack of viremia post-challenge. This report is the first to demonstrate the safety of a recombinant DEN virus tetravalent vaccine in a formal neurovirulence test, as well as its protective efficacy in a monkey challenge model.

Modification of human low-density lipoprotein by the lipid peroxidation product 4-hydroxynonenal

The effects of the lipid peroxidation product 4-hydroxynonenal on freshly prepared human low-density lipoprotein (LDL) were studied. At a fixed LDL concentration (5.7 mg/ml) the amount of 4-hydroxynonenal incorporated into the LDL increased with increasing aldehyde concentration from 28-30 (0.2 mM) to 140 (1 mM) mol per mol LDL, whereas at a fixed aldehyde concentration (0.2 mM) its incorporation into LDL decreased with increasing LDL concentration from 48 (1 mg LDL/ml) to 26 (12 mg LDL/ml) mol 4-hydroxynonenal bound per mol LDL. Of the total hydroxynonenal taken up 78% was bound to the protein and 21% to the lipid moiety; the remaining 1% was dissolved as free aldehyde in the lipid fraction. Amino acid analysis of the apolipoprotein B revealed that 4-hydroxynonenal attacks mainly the lysine and tyrosine residues and to a lesser extent also serine, histidine and cysteine. Treatment of LDL with 4-hydroxynonenal results in a concentration-dependent increase of the negative charge of the LDL particle as evidenced by its increased electrophoretic mobility. Moreover, 4-hydroxynonenal treatment leads to a partial conversion of the apolipoprotein B-100 into higher molecular weight forms most probably apolipoproteins B-126 and B-151. Compared to malonaldehyde, 4-hydroxynonenal exhibits a much higher capacity to modify LDL and it is therefore believed that this aldehyde is a more likely candidate for being responsible for LDL modification under in vivo lipid peroxidation conditions.

Encapsulation of Inorganic Particles by Dispersion Polymerization in Polar Media

Following a previous work (Bourgeat-Lami, E., and Lang, J., J. Colloid Interface Sci. 197, 293 (1998)), encapsulation of silica beads has been achieved by dispersion polymerization of styrene in an aqueous ethanol medium using poly(N-vinyl pyrrolidone) as stabilizer. Silica beads, prepared according to the Stöber method, were coated prior to polymerization by grafting 3-(trimethoxysilyl)propyl methacrylate onto the surface. A great number of silica beads per composite particle were previously found using beads that had diameters between 49 and 120 nm. In the present work, larger silica beads with diameters between 191 and 629 nm are investigated. We demonstrate by transmission electron microscopy that, consequently, only a small number of silica beads are contained in the composite particles. By counting the composite particles containing precisely zero, one, two, three, four, and more than four silica beads, it clearly appears that the encapsulation of only one silica bead can be obtained simply by increasing the size of the beads. Under our experimental conditions, the optimal bead diameter for achieving composite particles containing only one silica bead turns out to be around 450 nm. We show that increasing the silica bead size above this value results in an increased number of composite particles without silica beads. In contrast, the number of composite particles with two, three, four, or more than four silica beads increases with decreasing silica bead size. In addition to the above variations in composition of the composite particles, changes in particle shapes were also observed as a function of the size of the silica beads and the styrene concentration in the polymerization medium. Hypotheses concerning these variations are presented. Copyright 1999 Academic Press.

Intrapartum maternal fever and neonatal outcome

OBJECTIVE

Much of fever during term labor may not be infectious but rather a consequence of the use of epidural analgesia. Therefore, we investigated the association of elevated maternal intrapartum temperature with neonatal outcome when the infant does not develop an infection.

METHODS

We studied 1218 nulliparous women with singleton, term pregnancies in a vertex presentation and spontaneous labor. Women were excluded if their temperature was >99.5 degrees F at admission for delivery, if they were diabetic or had an active genital herpes infection or if their infant developed a neonatal infection, had a congenital infection, or had a major malformation. Maximum intrapartum temperature was categorized as: </=100.4 degrees F (afebrile), 100.5 degrees F to 101 degrees F, and >101 degrees F.

RESULTS

During labor, 123 women (10.1%) developed a fever >100.4 degrees F; 62 (5.1%) women had a maximum temperature of 100.5 degrees F to 101 degrees F and 61 (5.0%) women had a maximum temperature >101 degrees F. Of febrile women, 97.6% had received epidural analgesia for pain relief. Infants of women developing a fever >100.4 degrees F were more likely to have a 1-minute Apgar score <7 (22.8% for >100.4 degrees F vs 8.0% for afebrile) and to be hypotonic after delivery (4.8% for >100.4 degrees F vs.5% for afebrile). Compared with infants of afebrile women, infants whose mothers' maximum temperature was >101 degrees F were more likely to require bag and mask resuscitation (11.5% vs 3.0%) and to be given oxygen therapy in the nursery (8.2% vs 1.3%). We also found a higher rate of neonatal seizure with fever (3.3% vs.2%), but the number of infants with seizure was small (n = 4). All associations remained essentially the same after controlling for confounding in logistic regression analyses.

CONCLUSIONS

Intrapartum maternal fever, particularly if >101 degrees F, was associated with a number of apparently transient adverse effects in the newborn. Larger studies are needed to investigate the association of intrapartum fever with neonatal seizures and to determine whether any lasting injury to the fetus may occur.

VAMP-2 and cellubrevin are expressed in pancreatic beta-cells and are essential for Ca(2+)-but not for GTP gamma S-induced insulin secretion

VAMP proteins are important components of the machinery controlling docking and/or fusion of secretory vesicles with their target membrane. We investigated the expression of VAMP proteins in pancreatic beta-cells and their implication in the exocytosis of insulin. cDNA cloning revealed that VAMP-2 and cellubrevin, but not VAMP-1, are expressed in rat pancreatic islets and that their sequence is identical to that isolated from rat brain. Pancreatic beta-cells contain secretory granules that store and secrete insulin as well as synaptic-like microvesicles carrying gamma-aminobutyric acid. After subcellular fractionation on continuous sucrose gradients, VAMP-2 and cellubrevin were found to be associated with both types of secretory vesicle. The association of VAMP-2 with insulin-containing granules was confirmed by confocal microscopy of primary cultures of rat pancreatic beta-cells. Pretreatment of streptolysin-O permeabilized insulin-secreting cells with tetanus and botulinum B neurotoxins selectively cleaved VAMP-2 and cellubrevin and abolished Ca(2+)-induced insulin release (IC50 approximately 15 nM). By contrast, the pretreatment with tetanus and botulinum B neurotoxins did not prevent GTP gamma S-stimulated insulin secretion. Taken together, our results show that pancreatic beta-cells express VAMP-2 and cellubrevin and that one or both of these proteins selectively control Ca(2+)-mediated insulin secretion.

Heat shock protein Hsp60-reactive gamma delta cells: a large, diversified T-lymphocyte subset with highly focused specificity

Previously, we detected a subset of gamma delta T cells in the newborn mouse thymus that responded to the mycobacterial heat shock protein Hsp60, as well as with what seemed to be a self-antigen. All of these cells expressed V gamma 1, most often in association with V delta 6+. It was not clear, however, whether similar, mature gamma delta cells with Hsp60 reactivity are common outside of the thymus, or rather, whether they are largely eliminated during development. From the data presented here, we estimate that gamma delta cells responding to Hsp60 comprise 10-20% of normal splenic and lymph node gamma delta T cells. Such cells, derived from adult spleen, always express a V gamma 1-J gamma 4-C gamma 4 gamma chain, although not all cells with this gamma chain show Hsp60 reactivity. Many of these V gamma 1+ cells also express V delta 6-J delta 1-C delta, though fewer than in V gamma 1+ cells from the newborn thymus. Extensive diversity is evident in both the gamma and delta chain junctional amino acids of the receptors of these cells, indicating that they may largely develop in the thymus of older animals or undergo peripheral expansion. Finally, we found that all such cells responding to both a putative self-antigen and to mycobacterial Hsp60 respond to a 17-amino acid synthetic peptide representing amino acids 180-196 of the Mycobacterium leprae Hsp60 sequence. This report demonstrates that a large subset of Hsp60-reactive peripheral lymphoid gamma delta T cells preexists in normal adult mice, all members of which respond to a single segment of this common heat shock protein.