First symmetry tests in polarized Z0 decays to bbg

We have made the first direct symmetry tests in the decays of polarized Z0 bosons into fully identified bbg states, collected in the SLD experiment at SLAC. We searched for evidence of parity violation at the bbg vertex by studying the asymmetries in the b-quark polar- and azimuthal-angle distributions, and for evidence of T-odd, CP-even or CP-odd, final-state interactions by measuring angular correlations between the three-jet plane and the Z0 polarization. We found results consistent with standard model expectations and set 95% C. limits on anomalous contributions.

Linguistic analysis to assess medically related posttraumatic stress symptoms

The authors examined the presence of posttraumatic stress symptoms (PTSS) in 20 patients requiring ventilation after acute respiratory distress. The subjects completed a semistructured interview about their ventilation experience that was subject to content and linguistic analysis. Subjects also completed two self-report measures to assess PTSS and socioemotional adjustment. Subjects who endorsed PTSS were more likely to use a narrative style suggesting emotional involvement in their recall of the stressful event. The authors indicate that the presence of PTSS is a common consequence of traumatic medical experiences and that denial of distress may be an adaptive short-term coping strategy.

A loss of function mutant of the presenilin homologue SEL-12 undergoes aberrant endoproteolysis in Caenorhabditis elegans and increases abeta 42 generation in human cells

The familial Alzheimer's disease-associated presenilins (PSs) occur as a dimeric complex of proteolytically generated fragments, which functionally supports endoproteolysis of Notch and the beta-amyloid precursor protein (betaAPP). A homologous gene, sel-12, has been identified in Caenorhabditis elegans. We now demonstrate that wild-type (wt) SEL-12 undergoes endoproteolytic cleavage in C. elegans similar to the PSs in human tissue. In contrast, SEL-12 C60S protein expressed from the sel-12(ar131) allele is miscleaved in C. elegans, resulting in a larger mutant N-terminal fragment. Neither SEL-12 wt nor C60S undergo endoproteolytic processing upon expression in human cells, suggesting that SEL-12 is cleaved by a C. elegans-specific endoproteolytic activity. The loss of function of sel-12 in C. elegans is not associated with a dominant negative activity in human cells, because SEL-12 C60S and the corresponding PS1 C92S mutation do not interfere with Notch1 cleavage. Moreover, both mutant variants increase the aberrant production of the highly amyloidogenic 42-amino acid version of amyloid beta-peptide similar to familial Alzheimer's disease-associated human PS mutants. Our data therefore demonstrate that the C60S mutation in SEL-12 is associated with aberrant endoproteolysis and a loss of function in C. elegans, whereas a gain of misfunction is observed upon expression in human cells.

First direct measurement of the parity-violating coupling of the Z0 to the s quark

We present the first direct measurement of A(s), the parity-violating coupling of the Z0 boson to the strange quark, using approximately 550 000 e(+)e(-)-->Z0-->hadrons events recorded by the SLC Large Detector with a polarized e(-) beam. We tagged Z0-->s&smacr; events by the absence of B or D hadrons and the presence in each hemisphere of a high momentum K+/- or K(0)(s). Fitting the polar angle distributions of the strangeness-signed thrust axis gave A(s) = 0.895+/-0.066(stat)+/-0.062(syst). The analyzing power and uu+d&dmacr; background were constrained using the data, greatly reducing any model dependence.

A family of peptidoglycan recognition proteins in the fruit fly Drosophila melanogaster

Peptidoglycans from bacterial cell walls trigger immune responses in insects and mammals. A peptidoglycan recognition protein, PGRP, has been cloned from moths as well as vertebrates and has been shown to participate in peptidoglycan-mediated activation of prophenoloxidase in the silk moth. Here we report that Drosophila expresses 12 PGRP genes, distributed in 8 chromosomal loci on the 3 major chromosomes. By analyzing cDNA clones and genomic databases, we grouped them into two classes: PGRP-SA, SB1, SB2, SC1A, SC1B, SC2, and SD, with short transcripts and short 5'-untranslated regions; and PGRP-LA, LB, LC, LD, and LE, with long transcripts and long 5'-untranslated regions. The predicted structures indicate that the first group encodes extracellular proteins and the second group, intracellular and membrane-spanning proteins. Most PGRP genes are expressed in all postembryonic stages. Peptidoglycan injections strongly induce five of the genes. Transcripts from the different PGRP genes were found in immune competent organs such as fat body, gut, and hemocytes. We demonstrate that at least PGRP-SA and SC1B can bind peptidoglycan, and a function in immunity is likely for this family.

Intramembrane proteolysis by presenilins

Many neurodegenerative diseases involve the deposition of insoluble amyloid molecules. In Alzheimer's disease, for example, the amyloid beta-peptide (A beta) is the main component of the characteristic senile plaques. Proteolytic enzymes called secretases are involved in generating A beta, and one of these may have been identified as presenilin--a discovery that paves the way for a more complete understanding of presenilin structure and function.

Glycine 384 is required for presenilin-1 function and is conserved in bacterial polytopic aspartyl proteases

Endoproteolysis of beta-amyloid precursor protein (betaAPP) and Notch requires conserved aspartate residues in presenilins 1 and 2 (PS1 and PS2). Although PS1 and PS2 have therefore been proposed to be aspartyl proteases, no homology to other aspartyl proteases has been found. Here we identify homology between the presenilin active site and polytopic aspartyl proteases of bacterial origin, thus supporting the hypothesis that presenilins are novel aspartyl proteases.

Maturation and pro-peptide cleavage of beta-secretase

Amyloid beta-peptide is generated by two sequential proteolytic cleavages mediated by beta-secretase (BACE) and gamma-secretase. BACE was recently identified as a membrane-associated aspartyl protease. We have now analyzed the maturation and pro-peptide cleavage of BACE. Pulse-chase experiments revealed that BACE is post-translationally modified during transport to the cell surface, which can be monitored by a significant increase in the molecular mass. The increase in molecular mass is caused by complex N-glycosylation. Treatment with tunicamycin and N-glycosidase F led to a BACE derivative with a molecular weight corresponding to an unmodified version. In contrast, the mature form of BACE was resistant to endoglycosidase H treatment. The cytoplasmic tail of BACE was required for efficient maturation and trafficking through the Golgi; a BACE variant lacking the cytoplasmic tail undergoes inefficient maturation. In contrast a soluble BACE variant that does not contain a membrane anchor matured more rapidly than full-length BACE. Pro-BACE was predominantly located within the endoplasmic reticulum. Pro-peptide cleavage occurred immediately before full maturation and trafficking through the Golgi.

Mutation of conserved aspartates affects maturation of both aspartate mutant and endogenous presenilin 1 and presenilin 2 complexes

Presenilin (PS1 and PS2) holoproteins are transiently incorporated into low molecular weight (MW) complexes. During subsequent incorporation into a higher MW complex, they undergo endoproteolysis to generate stable N- and C-terminal fragments. Mutation of either of two conserved aspartate residues in transmembrane domains inhibits both presenilin-endoproteolysis and the proteolytic processing of beta-amyloid precursor protein and Notch. We show that although PS1/PS2 endoproteolysis is not required for inclusion into the higher MW N- and C-terminal fragment-containing complex, aspartate mutant holoprotein presenilins are not incorporated into the high MW complexes. Aspartate mutant presenilin holoproteins also preclude entry of endogenous wild type PS1/PS2 into the high MW complexes but do not affect the incorporation of wild type holoproteins into lower MW holoprotein complexes. These data suggest that the loss of function effects of the aspartate mutants result in altered PS complex maturation and argue that the functional presenilin moieties are contained in the high molecular weight complexes.

Mammalian peptidoglycan recognition protein binds peptidoglycan with high affinity, is expressed in neutrophils, and inhibits bacterial growth

Peptidoglycan recognition protein (PGRP) is conserved from insects to mammals. In insects, PGRP recognizes bacterial cell wall peptidoglycan (PGN) and activates prophenoloxidase cascade, a part of the insect antimicrobial defense system. Because mammals do not have the prophenoloxidase cascade, its function in mammals is unknown. However, it was suggested that an identical protein (Tag7) was a tumor necrosis factor-like cytokine. Therefore, the aim of this study was to identify the function of PGRP in mammals. Mouse PGRP bound to PGN with fast kinetics and nanomolar affinity (K(d) = 13 nm). The binding was specific for polymeric PGN or Gram-positive bacteria with unmodified PGN, and PGRP did not bind to other cell wall components or Gram-negative bacteria. PGRP mRNA and protein were expressed in neutrophils and bone marrow cells, but not in spleen cells, mononuclear cells, T or B lymphocytes, NK cells, thymocytes, monocytes, and macrophages. PGRP was not a PGN-lytic or a bacteriolytic enzyme, but it inhibited the growth of Gram-positive but not Gram-negative bacteria. PGRP inhibited phagocytosis of Gram-positive bacteria by macrophages, induction of oxidative burst by Gram-positive bacteria in neutrophils, and induction of cytokine production by PGN in macrophages. PGRP had no tumor necrosis factor-like cytotoxicity for mammalian cells, and it was not chemotactic on its own or in combination with PGN. Therefore, mammalian PGRP binds to PGN and Gram-positive bacteria with nanomolar affinity, is expressed in neutrophils, and inhibits growth of bacteria.

Cocaine effects on gene regulation in the striatum and behavior: increased sensitivity in D3 dopamine receptor-deficient mice

Central effects of psychostimulants such as cocaine are predominantly mediated by dopamine receptors. We have used mice with a targeted deletion of the D3 dopamine receptor subtype to investigate the role of this receptor in the regulation of gene expression in striatal neurons and behavior by acute and repeated treatment with cocaine (25 mg/kg). In mice lacking D3 receptors, acute administration of cocaine has more pronounced stimulatory effects on c-fos and dynorphin expression in the dorsal and ventral striatum. The behavioral response to cocaine is also increased in these mice. These findings indicate that the D3 receptor plays an inhibitory role in the action of cocaine on behavior and gene regulation in the striatum.

Regulation of rat cortex function by D1 dopamine receptors in the striatum

Interactions between the basal ganglia and the cerebral cortex are critical for normal goal-directed behavior. In the present study, we used immediate-early genes (c-fos, zif 268) as functional markers to investigated how basal ganglia output altered by stimulation/blockade of D1 dopamine receptors in the striatum affects cortical function. Systemic administration of the mixed D1/D2 receptor agonist apomorphine (3 mg/kg) increased immediate-early gene expression in the striatum and throughout most of the cortex. Unilateral intrastriatal infusion of the selective D1 receptor antagonist SCH-23390 (0.5-10 microg) blocked this response bilaterally in striatum and cortex in a dose-dependent manner. Even apparently regionally restricted blockade of striatal D1 receptors attenuated gene expression throughout striatum and cortex in both hemispheres. Intrastriatal administration of the D1 antagonist inhibited apomorphine-induced sniffing/whisking, whereas other motor behaviors were unaffected. To determine whether such changes in cortical gene expression could reflect altered cortical function, we examined the effects of blocking striatal D1 receptors on whisker stimulation-evoked immediate-early gene expression in the sensorimotor cortex. Apomorphine increased sensory stimulation-evoked gene expression in the barrel cortex, and intrastriatal infusion of SCH-23390 attenuated this effect. These results suggest that stimulation of D1 dopamine receptors in the striatum exerts a widespread facilitatory effect on cortical function.

Trauma spectrum adaptation: somatic symptoms in long-term pediatric cancer survivors

The authors assessed somatic symptoms and the degree of association among somatic symptoms, global adjustment, trauma symptoms, and personality characteristics in long-term pediatric cancer survivors. Forty cancer survivors completed self-report questionnaires and clinical interviews. Participants' level of somatic symptoms fell between nonclinic and psychiatric populations. Somatic symptom scores correlated with general adjustment in the negative direction and with posttraumatic stress disorder (PTSD) scores in the positive direction. The majority of participants met at least partial current PTSD criteria. Because these survivors demonstrate a repressive adaptive style but endorse somatic symptoms, the latter may represent a method for detecting trauma-related distress in this population.

Perinatal complications and child abuse in a poverty sample

OBJECTIVE

Perinatal medical illness has been associated with child maltreatment. Using a Child Protective Service (CPS) report as the defining event, this study explores to what extent perinatal morbidity is a risk factor for maltreatment.

METHOD

Medical charts of 206 children ages 0-3 years were reviewed. Data regarding birth history were collected and analyzed in three groups of children: children whose medical record indicated a report to CPS based on prenatal findings (Early Maternal Inadequacy group [EMI]), children whose medical record indicated a report to CPS based only on postnatal findings (Child Maltreatment group [CM]), and a control group without CPS report (NM).

RESULTS

Compared to the CM and the NM groups, children in the EMI group showed significantly lower birth weight and higher neonatal morbidity as measured by Apgar scores, frequency of oxygen requirement and intubation at birth, frequency of admission to Neonatal Intensive Care unit, and frequency of neonatal medical problems. There was no significant difference between the CM and the NM groups in birth weight, gestational age, and other measures of morbidity.

CONCLUSION

The results of the study suggest that perinatal complications are associated with prenatal maltreatment. Previously reported strong associations between neonatal morbidity and child abuse are more likely a result of antecedent prenatal maternal behaviors (early maternal inadequacy). Early maternal inadequacy, a clinically and demographically distinct phenomenon, is important due to serious health, development and financial implications and deserves further exploration.

Separation of presenilin function in amyloid beta-peptide generation and endoproteolysis of Notch

Most of the genetically inherited Alzheimer's disease cases are caused by mutations in the presenilin genes, PS1 and PS2. PS mutations result in the enhanced production of the highly amyloidogenic 42/43 amino acid variant of amyloid beta-peptide (Abeta). We have introduced arbitrary mutations at position 286 of PS1, where a naturally occurring PS1 mutation has been described (L286V). Introduction of charged amino acids (L286E or L286R) resulted in an increase of Abeta42/43 production, which reached almost twice the level of the naturally occurring PS1 mutation. Although pathological Abeta production was increased, endoproteolysis of Notch and nuclear transport of its cytoplasmic domain was significantly inhibited. These results demonstrate that the biological function of PS proteins in the endoproteolysis of beta-amyloid precursor protein and Notch can be separated.

Precise measurement of the b-quark fragmentation function in Z0 boson decays

We have developed a new technique for inclusive reconstruction of the energy of B hadrons. The excellent efficiency and resolution of this technique allow us to make the most precise determination of the b-quark fragmentation function, using e(+)e(-)-->Z0 decays recorded in the SLAC Large Detector experiment. We compared our measurement with the predictions of a number of fragmentation models. We excluded several of these models and measured the average scaled energy of weakly decaying B hadrons to be <x(B)> = 0.714+/-0. 005(stat)+/-0.007(syst)+/-0.002 (model dependence).

Prenatal diagnosis of partial trisomy 4q26-qter and monosomy for the Wolf-Hirschhorn critical region in a fetus with split hand malformation

We describe the results of prenatal analyses and postnatal findings in a male fetus with a partial trisomy for the long arm and a small terminal monosomy for the short arm of chromosome 4 with the following karyotype: 46,XY,add(4)(p16.3).ish dup(4)(q26qter)(wcp4+, D4S2336x3,AFMb280xa5x2,4ptel-,WHCR-). G-banding did not identify the origin of the additional chromosomal segment, but this was achieved prenatally by application of RxFISH and whole chromosome painting probes. Subsequent FISH analysis with region-specific YAC clones was used to relate the phenotypic findings such as bilateral split hand formation, specific cardiac and kidney anomalies, microtia, and hypoplastic thorax more exactly to the partial trisomy of the segment 4q26-qter.

Psychiatric phenomenology of child and adolescent bipolar offspring

OBJECTIVE

To establish prodromal signs of and risk factors for childhood bipolar disorder (BD) by characterizing youths at high risk for BD.

METHOD

Structured diagnostic interviews were performed on 60 biological offspring of at least one parent with BD. Demographics, family histories, and parental history of childhood disruptive behavioral disorders were also assessed.

RESULTS

Fifty-one percent of bipolar offspring had a psychiatric disorder, most commonly attention-deficit/hyperactivity disorder (ADHD), major depression or dysthymia, and BD. BD in offspring tended to be associated with earlier parental symptom onset when compared with offspring without a psychiatric diagnosis. Bipolar parents with a history of childhood ADHD were more likely to have children with BD, but not ADHD. Offspring with bilineal risk had increased severity of depressed and irritable mood, lack of mood reactivity, and rejection sensitivity, while severity of grandiosity, euphoric mood, and decreased need for sleep were not preferentially associated with such offspring.

CONCLUSIONS

Bipolar offspring have high levels of psychopathology. Parental history of early-onset BD and/or childhood ADHD may increase the risk that their offspring will develop BD. Prodromal symptoms of childhood BD may include more subtle presentations of mood regulation difficulties and less presence of classic manic symptoms.

Presenilin-1 differentially facilitates endoproteolysis of the beta-amyloid precursor protein and Notch

Mutations in the presenilin-1 (PS1) gene are associated with Alzheimer's disease and cause increased secretion of the neurotoxic amyloid-beta peptide (Abeta). Critical intramembraneous aspartates at residues 257 and 385 are required for the function of PS1 protein. Here we investigate the biological function of a naturally occurring PS1 splice variant (PS1 Deltaexon 8), which lacks the critical aspartate 257. Cell lines that stably express PS1 Deltaexon 8 or a PS1 protein in which aspartate residue 257 is mutated secrete significant levels of Abeta, whereas Abeta generation is severely reduced in cells transfected with PS1 containing a mutation of aspartate 385. In contrast, endoproteolytic processing of Notch is almost completely inhibited in cell lines expressing any of the PS1 variants that lack one of the critical aspartates. These data indicate that PS1 may differentially facilitate gamma-secretase-mediated generation of Abeta and endoproteolysis of Notch.

Trichoplusia ni lebocin, an inducible immune gene with a downstream insertion element

A cDNA clone encoding a lebocin-like protein was obtained from the cabbage looper Trichoplusia ni by using differential display PCR. Northern blot analysis showed that lebocin gene expression was inducible upon bacterial challenge. Transcripts were mainly found in fat body but were also observed in hemocytes. Expression reached its highest level at 20 h and continued at least until 60 h after bacterial injection. The deduced protein is proline-rich and contains 143 amino acid residues. At position 128, a possible O-glycosylation site is observed. The whole protein shows 35% identity to Bombyx mori lebocin. The mature peptide displays an N-terminus similar to that of lebocin and a C-terminus to that of Drosophila metchnikowin. A 39-bp repetitive element is located downstream of the coding region.

Genes and mechanisms involved in beta-amyloid generation and Alzheimer's disease

Alzheimer's disease is characterized by the invariable accumulation of senile plaques that are predominantly composed of amyloid beta-peptide (Abeta). Abeta is generated by proteolytic processing of the beta-amyloid precursor protein (betaAPP) involving the combined action of beta- and gamma-secretase. Cleavage within the Abeta domain by alpha-secretase prevents Abeta generation. In some very rare cases of familial AD (FAD), mutations have been identified within the betaAPP gene. These mutations are located close to or at the cleavage sites of the secretases and pathologically effect betaAPP processing by increasing Abeta production, specifically its highly amyloidogenic 42 amino acid variant (Abeta42). Most of the mutations associated with FAD have been identified in the two presenilin (PS) genes, particularly the PS1 gene. Like the mutations identified within the betaAPP gene, mutations in PS1 and PS2 cause the increased generation of Abeta42. PS1 has been shown to be functionally involved in Notch signaling, a key process in cellular differentation, and in betaAPP processing. A gene knock out of PS1 in mice leads to an embryonic lethal phenotype similar to that of mice lacking Notch. In addition, absence of PS1 results in reduced gamma-secretase cleavage and leads to an accumulation of betaAPP C-terminal fragments and decreased amounts of Abeta. Recent work may suggest that PS1 could be the gamma-secretase itself, exhibiting the properties of a novel aspartyl protease. Mutagenesis of either of two highly conserved intramembraneous aspartate residues of PS1 leads to reduced Abeta production as observed in the PS1 knockout. A corresponding mutation in PS2 interfered with betaAPP processing and Notch signaling suggesting a functional redundancy of both presenilins. In this issue, some of the recent work on the molecular mechanisms involved in Alzheimer's disease (AD) as well as novel diagnostic approaches and risk factors for AD will be discussed. In the first article, we like to give an overview on mechanisms involved in the proteolytic generation of Amyloid beta-peptide (Abeta), the major pathological player of this devastating disease. In the second part of this article recent results will be described, which demonstrate an unexpected biological and pathological function of an AD associated gene.

Trauma and dissociation in delinquent adolescents

OBJECTIVES

To assess history of trauma and dissociation in a group of juvenile delinquents and to assess how adolescents would respond to a structured interview for dissociative symptoms.

METHOD

Sixty-four adolescents in juvenile probation hall participated in 2 investigational sessions in 1996-1997. For session 1 they answered the Childhood Trauma Questionnaire (CTQ), the Response Evaluation Measure for Youth-71 (REMY-71), and the Weinberger Adjustment Inventory. For session 2 they were given the Childhood Trauma Interview (CTI) and the Structured Clinical Interview for DSM-IV Dissociative Disorders (SCID-D).

RESULTS

In this sample 28.3% met criteria for a dissociative disorder and 96.8% endorsed a history of traumatic events. There were significant positive correlations between CTI and CTQ trauma scores and SCID-D and REMY-71 dissociative symptoms. All dissociative symptoms were endorsed, but depersonalization was the most common experience. There was a lack of congruence between the different methods of assessing dissociation.

CONCLUSIONS

This study provides support for an early link between history of trauma and dissociation. Adolescents were able to answer questions from a structured interview assessing dissociation.

Laparoscopic cholecystectomy and interventional endoscopy for gallstone complications during pregnancy

BACKGROUND

Symptomatic or complicated gallstone disease is the most common reason for nongynecological operations during pregnancy. Gallstones are present in 12% of all pregnancies, and more than one-third of patients fail medical treatment and therefore require surgical endoscopy or laparoscopy. Gallstone pancreatitis and jaundice during pregnancy is associated with a high recurrence rate, exposing both fetus and mother to an increased risk of morbidity and mortality.

METHODS

During a 4-year period, all pregnant patients (n = 37) with symptomatic or complicated gallstone disease were studied prospectively at the Landeskrankenhaus in Salzburg, Austria. Five patients had an endoscopic retrograde cholangiopancreatogram (ERCP) for biliary pancreatitis or jaundice; two of these underwent subsequent laparoscopic cholecystectomy. Another seven patients required laparoscopic cholecystectomy for severe pain or cholecystitis; all were in their 13th-32nd gestational week. Access was established by Veress needle in all cases. Insufflation pressure was 8-10 mm Hg, and mean operative time was 62 min.

RESULTS

All patients delivered full-term, healthy babies. There were no postendoscopic or postoperative complications. All patients enjoyed full relief from their symptoms; there were no recurrences of pancreatitis or jaundice.

CONCLUSIONS

The combination of ERCP and laparoscopic cholecystectomy offers a safe and effective option for the definitive treatment of complicated gallstone disease and intractable pain during pregnancy, and there is sufficient access for the combined treatment to be employed.

Adolescents and sports: risk or benefit?

In order to begin to compensate for a lack of data on the effects of athletic participation in the development of adolescent mental health patterns, as well as to assess general health of the adolescent population, the Juvenile Wellness and Health Inventory (JWHS-76) was administered to 1,769 high school students. Our results indicate that sports participation is associated with self-reported lower total risk scores, mental and physical health benefits, and an increased risk of injury. This suggests a positive role for organized sports participation in youth populations. Prospective studies are needed to assess the impact of different sports, mounting performance pressure, and transition into collegiate levels of participation.