Rapid irreversible G protein alpha subunit misfolding due to intramolecular kinetic bottleneck that precedes Mg2+ "lock" after GTP/GDP exchange

Stoichiometric exchange of GTP for GDP on heterotrimeric G protein alpha (Galpha) subunits is essential to most hormone and neurotransmitter initiated signal transduction. Galphas are stably activated in a Mg2+ complex with GTPgammaS, a nonhydrolyzable GTP analogue that is reported to bind Galpha, with very high affinity. Yet, it is common to find that substantial amounts (30-90%) of purified G proteins cannot be activated. Inactivatable G protein has heretofore been thought to have become "denatured" during formation of the obligatory nucleotide-free or empty (MT) Galpha-state that is intermediary to GDP/GTP exchange at a single binding site. We find Galpha native secondary and tertiary structure to persist during formation of the irreversibly inactivatable state of transducin. MT Galpha is therefore irreversibly misfolded rather than denatured. Inactivation by misfolding is found to compete kinetically with protective but weak preequilibrium nucleotide binding at micromolar ambient GTPgammaS concentrations. Because of the weak preequilibrium, quantitative protection against Galpha aggregation is only achieved at free nucleotide concentrations 10-100 times higher than those commonly employed in G protein radio-nucleotide binding studies. Initial GTP protection is also poor because of the extreme slowness of an intramolecular Galpha refolding step (isomerization) necessary for GTP sequestration after its weak preequilibrium binding. Of the two slowly interconverting Galpha x GTP isomers described here, only the second can bind Mg2+, "locking" GTP in place with a large net rise in GTP binding affinity. A companion Galpha x GDP isomerization reaction is identified as the cause of the very slow spontaneous GDP dissociation that characterizes G protein nucleotide exchange and low spontaneous background activity in the absence of GPCR activation. Galpha x GDP and Galpha x GTP isomerization reactions are proposed as the dual target for GPCR catalysis of nucleotide exchange.

Discovery and SAR of org 24598-a selective glycine uptake inhibitor

The discovery of Org 24598, one of the first potent and selective inhibitors of the glycine transporter is discussed. In vitro structure-activity relationships (SARs) data for interaction of a ligand with this system is discussed.

No association of an interleukin 4 gene promoter polymorphism with Graves' disease in the United Kingdom

Graves' disease (GD) is an autoimmune thyroid disease of unknown etiology, although predisposition to the development of this disease is thought to be caused by both genetic and environmental factors. Recently, an association between a promoter polymorphism of the interleukin 4 gene and GD has been reported. A C-T base change at position -590 showed modest protection against the development of GD in a United Kingdom data set of 135 patients with GD and 101 controls. This polymorphism was, therefore, investigated in a much larger case-control cohort of 384 patients with GD and 288 control subjects using PCR, followed by restriction fragment length polymorphism analysis. No protective effect of the T allele of this polymorphism was observed in our data set, and indeed no significant difference in either allelic or genotypic distribution was seen between the patient and control groups. Moreover, calculation of probabilities indicate that the original study lacked sufficient power to support the conclusions drawn. Our data support the hypothesis that the C-T promoter polymorphism of the interleukin 4 gene does not confer protection against the development of GD in Caucasians in the United Kingdom.

Episodic Evolution of Growth Hormone in Primates and Emergence of the Species Specificity of Human Growth Hormone Receptor

Growth hormone (GH) evolution is very conservative among mammals, except for primates and ruminant artiodactyls. In fact, most known mammalian GH sequences differ from the inferred ancestral mammalian sequence by only a few amino acids. In contrast, the human GH sequence differs from the inferred ancestral sequence by 59 amino acids. However, it is not known when this rapid evolution of GH occurred during primate evolution or whether it was due to positive selection. Also, human growth hormone receptor (GHR) displays species specificity; i.e., it can interact only with human (or rhesus monkey) GH, not with nonprimate GHS: The species specificity of human GHR is largely due to the Leu-->Arg change at position 43, and it has been hypothesized that this change must have been preceded by the His-->Asp change at position 171 of GH. Is this hypothesis true? And when did these changes occur? To address the above issues, we sequenced GH and GHR genes in prosimians and simians. Our data supported the above hypothesis and revealed that the species specificity of human GHR actually emerged in the common ancestor of Old World primates, but the transitional phase still persists in New World monkeys. Our data showed that the rapid evolution of primate GH occurred during a relatively short period (in the common ancestor of higher primates) and that the rate of change was especially high at functionally important sites, suggesting positive selection. However, the nonsynonymous rate/synonymous rate ratio at these sites was <1, so relaxation of purifying selection might have played a role in the rapid evolution of the GH gene in simians, possibly as a result of multiple gene duplications. Similar to GH, GHR displayed an accelerated rate of evolution in primates. Our data revealed proportionally more amino acid replacements at the functionally important sites in both GH and GHR in simians but, surprisingly, showed few coincidental replacements of amino acids forming the same intermolecular contacts between the two proteins.

Nutritional status in elderly female hip fracture patients: comparison with an age-matched home living group attending day centres

Fractured neck of femur occurs mostly in the older female population and is generally caused by falls. Malnutrition has been postulated as a factor that increases the tendency to suffer falls. Nutritional status of older female hospital patients admitted for emergency surgery for fractured neck of femur recruited (n 75), was compared with an age-matched independent-living group of females attending one of three local day centres (n 50). Dietary assessment was undertaken using three consecutive 24 h dietary recalls and, in the hip fracture group, completed menu cards were used as memory prompts. Data concerning key lifestyle characteristics were obtained using a face-to-face administered questionnaire. Blood samples were taken to determine levels of plasma albumin, transferrin, C-reactive protein (CRP), cholesterol, vitamin C, Se, Zn and total antioxidant status. Haemolysate samples were analysed for Se-dependent glutathione peroxidase activity. There were no significant differences in age between the two groups, but the hip fracture patients had lower mean values for body weight (59.6 v. 67.5 kg; mindex (weight/demispan) (83.1 v. 94.4 kg/m; calculated BMI (24.1 v. 27.5 kg/m2 mid-upper arm circumference; 27.1 v. 31.3 cm, and triceps skinfold thickness; 17.0 v. 18.9 mm, than the home-living group. The hip fracture patients had lower intakes of energy (4.3 v. 5.4 MJ, fat carbohydrate protein thiamine vitamin B6 calcium K Mg P Fe Se and NSP Mean intakes of both groups were below the estimated average requirement for energy and below the reference nutrient intakes for folate, Ca, vitamin D, Mg, K, Se and Zn. In a high percentage of the hip fracture group the dietary intake of particular nutrients fell below the lower reference nutrient intake for Se (73 %), Mg (54 %) and Fe (19 %). As expected, the fracture patients had reduced plasma albumin and increased CRP values. They had higher plasma vitamin C levels and lower cholesterol levels than the day centre attendees. There were no significant differences in plasma levels of Se, Zn, transferrin or haemolysate glutathione peroxidase activity between the two groups. However, there was evidence of under-nutrition in both groups as key anthropometric values were low, plasma nutrient and metabolite levels were below the standard reference ranges and many individuals had low dietary intakes for specified nutrients.

A randomized controlled trial of the effects of multi-sensory stimulation (MSS) for people with dementia

OBJECTIVES

To investigate short-term effects of Multi-Sensory Stimulation (MSS) on behaviour, mood and cognition of older adults with dementia, the generalization of effects to day hospital and home environments and the endurance of any effects over time.

DESIGN

A randomized controlled trial comparing MSS with a credible control of one-to-one activities.

METHODS

Fifty patients with diagnoses of moderate to severe dementia were randomized to either MSS or Activity groups. Patients participated in eight 30-minute sessions over a 4-week period. Ratings of behaviour and mood were taken before, during and after sessions to investigate immediate effects. Pre, mid, post-trial, and follow-up assessments were taken to investigate any generalization of effects on cognition, behaviour at the day hospital and behaviour and mood at home and endurance of effects once sessions had ceased.

RESULTS

Immediately after MSS and Activity sessions patients talked more spontaneously, related better to others, did more from their own initiative, were less bored/inactive, and were more happy, active or alert. Both groups were more attentive to their environment than before, with a significantly greater improvement from the MSS group. At the day hospital, patients in the Activity group improved on their 'speech skills' (amount of speech; initiation of speech), whereas the MSS group remained unchanged during the trial. The MSS group showed a significant improvement in mood and behaviour at home compared to the Activity group whose behaviour deteriorated. No longer-term benefits were shown; indeed, behaviour declined sharply during the month follow-up period.

CONCLUSIONS

Both MSS and Activity sessions appear to be effective and appropriate therapies for people with dementia.

Reovirus-induced apoptosis is mediated by TRAIL

Members of the tumor necrosis factor (TNF) receptor superfamily and their activating ligands transmit apoptotic signals in a variety of systems. We now show that the binding of TNF-related, apoptosis-inducing ligand (TRAIL) to its cellular receptors DR5 (TRAILR2) and DR4 (TRAILR1) mediates reovirus-induced apoptosis. Anti-TRAIL antibody and soluble TRAIL receptors block reovirus-induced apoptosis by preventing TRAIL-receptor binding. In addition, reovirus induces both TRAIL release and an increase in the expression of DR5 and DR4 in infected cells. Reovirus-induced apoptosis is also blocked following inhibition of the death receptor-associated, apoptosis-inducing molecules FADD (for FAS-associated death domain) and caspase 8. We propose that reovirus infection promotes apoptosis via the expression of DR5 and the release of TRAIL from infected cells. Virus-induced regulation of the TRAIL apoptotic pathway defines a novel mechanism for virus-induced apoptosis.

Dental caries in pre-school children: associations with social class, toothbrushing habit and consumption of sugars and sugar-containing foods. Further analysis of data from the National Diet and Nutrition Survey of children aged 1.5-4.5 years

This project examined the relative significance of dietary sugars, toothbrushing frequency and social class as predictors of caries experience (caries vs. no caries) among 1,450 British pre-school children who took part in the National Diet and Nutrition Survey. This cross-sectional survey was based on a representative sample of children aged 1.5-4.5 years studied in 1992/3. Children were classified into four groups according to social class and toothbrushing habit. Diet/caries associations were examined for biscuits and cakes, sugar confectionery, chocolate confectionery and soft drinks, and the percentage of energy from non-milk extrinsic sugars, using data on amount and frequency of consumption from 4-day weighed dietary records. In stepwise logistic regressions, the strength of the association between social class and caries experience was twice that between toothbrushing and caries, and nearly three times that between sugar confectionery and caries (other dietary variables were not significant). The association of caries with sugar confectionery (both in amount and frequency) was only present among children whose teeth were brushed less than twice a day. Toothbrushing frequency appeared to have a stronger impact on caries prevention in non-manual compared with manual children. Household expenditure on confectionery was associated with caries only among children from the manual group. The findings suggest the hypothesis that regular brushing (twice a day) with a fluoride toothpaste may have greater impact on caries in young children than restricting sugary foods.

Delayed recurrence of hepatocellular carcinoma after liver transplantation: detection of origin by chromosomal analysis

We report on a 41-year-old man undergoing liver transplantation for chronic hepatitis C who presented 26 months later with hepatocellular carcinoma. No evidence of hepatocellular carcinoma could be found in the native liver, although features of small cell dysplasia were prominent. Although he had recurrent hepatitis C, the transplanted liver was not cirrhotic. Chromosomal analysis was used to resolve whether this was a de novo tumor or a recurrence of an unsuspected tumor present at the time of transplantation. This male patient had received a liver from a female donor, and in situ hybridization for the Y chromosome showed reactivity in the tumor but not in surrounding nontumorous liver. Thus, this is an example of the use of chromosomal analysis to resolve the origin of a tumor occurring in the transplant setting.

Antisense-mediated inhibition of the bcl-2 gene induces apoptosis in human malignant glioma

BACKGROUND

The bcl-2 protooncogene represses a number of cellular apoptotic pathways and is known to be expressed in increasing amounts in glial tumors of higher malignancy. We tested whether antisense oligonucleotides to the bcl-2 gene would affect glioma cell viability.

METHODS

Antisense oligonucleotides directed to the first six codons of the human bcl-2 gene, and nonsense oligonucleotides as a control, were transfected into malignant glioma cells. Two human Bcl-2 positive glioblastoma cell lines from our tumor bank (Jon52 and Roc) were both transfected in vitro with bcl-2 antisense (AS) and nonsense (NS) oligonucleotides at 1 microm and 5 microm concentrations for 5 and 24 hr. Cell viability was assessed at 2, 4, 5, and 7 days by using an MTT mitogenic assay and by cell counting via direct visualization using a hemocytometer.

RESULTS

There was up to a log-fold decrease in cell growth of the bcl-2 AS treated cells compared to the NS transfected cells for both Roc (p = 0.007 and p = 0.004) and Jon52 (p = 0.02 and p = 0.004) at 5 and 24 hr of transfection. There was as much as 50% cytotoxicity in both glioblastoma cell lines at 1 microm and 5 microm concentrations after 24 hr transfection with AS bcl-2 oligonucleotides (all p < 0.01). Western blot analysis demonstrated a decrease in the expression of the Bcl-2 protein in one cell line, whereas there was a statistically significant increase in the apoptotic index of both cell lines (p < 0.05 by chi square analysis).

CONCLUSIONS

Our results suggest that transfection of human glioma cells with antisense bcl-2 results in an increase in apoptotic death. This provides evidence that Bcl-2 plays a role in tumor progression of glioma by acting as an oncogene, and suggests that inhibition of the bcl-2 gene could have a therapeutic effect.

Pain and hyperalgesia in osteoarthritis of the hands

OBJECTIVE

Tissue damage and pain can lead to a change in the stimulus/response characteristics of the nociceptive system. Hyperalgesia has been described in experimental pain states and some clinical conditions, but has not been investigated in osteoarthritis (OA). We sought to establish the presence of hyperalgesia at the thumb in subjects with OA of the hand and to explore any relationship between sensitivity to extrinsic stimuli and the experience of clinical pain.

METHODS

Subjects with OA of the hand were divided into groups according to their pain profile. The sample also included pain-free OA cases and pain-free controls. Intensity ratings were obtained for each of 3 types of pain: continuous pain, incident pain, and movement pain. Thermal and mechanical detection and pain thresholds were measured over the forearm and the carpometacarpal joint of the thumb.

RESULTS

Lower thermal and mechanical pain thresholds were evident over the thumb relative to forearm in the groups with persistent pain. Subjects complaining only of incident pain, pain-free OA cases, and pain-free controls did not exhibit regional differences in sensitivity to thermal and mechanical stimuli. Increased ratings of continuous pain were associated with lower thermal and mechanical pain thresholds. Variance in movement pain ratings was predicted by mechanical forearm pain thresholds.

CONCLUSION

OA in the hands is associated with cutaneous and deep hyperalgesia to thermal and mechanical stimuli. Increased levels of continuous pain are associated with more pronounced hyperalgesia. The associations of movement pain suggest the contribution of central mechanisms in the stimulus/response changes accompanying movement pain.

Species-specific, postentry barriers to primate immunodeficiency virus infection

By using replication-defective vectors derived from human immunodeficiency virus type 1 (HIV-1), simian immunodeficiency virus (SIV(mac)), and murine leukemia virus (MuLV), all of which were pseudotyped with the vesicular stomatitis virus (VSV) G glycoprotein, the efficiency of postentry, early infection events was examined in target cells of several mammalian species. Titers of HIV-1 vectors were significantly lower than those of SIV(mac) and MuLV vectors in most cell lines and primary cells from Old World monkeys. By contrast, most New World monkey cells exhibited much lower titers for the SIV(mac) vector compared with those of the HIV-1 vector. Prosimian cells were resistant to both HIV-1 and SIV(mac) vectors, although the MuLV vector was able to infect these cells. Cells from other mammalian species were roughly equivalent in susceptibility to the three vectors, with the exception of rabbit cells, which were specifically resistant to the HIV-1 vector. The level of HIV-1 vector expression was very low in transduced cells of rodent, rabbit, cow, and pig origin. Early postentry restriction of primate immunodeficiency virus infection exhibits patterns largely coincident with species borders and applies to diverse cell types within an individual host, suggesting the involvement of species-specific, widely expressed cellular factors.

Schizophrenia and HLA: No association with PCR-SSOP typed classical loci in a large Irish familial sample

Susceptibility to autoimmunity is strongly influence by genes clustered in the MHC region, particularly class I and class II antigens. It has been proposed that there is an immune component in the aetiology of schizophrenia, and the distribution of human leukocyte antigens (HLA) in schizophrenic patients and controls has been investigated in numerous studies. Positive associations have been reported between schizophrenia and the HLA-A1, A2, A9, B5, Cw4, and DR8 and negative associations with HLA-DR4 and HLA-DQbeta*0602. Small sample size, variable diagnostic methodology, unreliable laboratory and statistical procedures, and possible mismatching of cases and controls may have contributed to a lack of consistency of results to date. Therefore, in this investigation we used a large and carefully diagnosed homogeneous Irish familial schizophrenic sample compared with ethnically matched controls. All alleles were determined using polymerase chain reaction amplification followed by short specific oligoprobes. We found no evidence of association with 80 HLA alleles (some previously not examined) from 4 genes. Our data therefore do not support the involvement of these classical HLA loci in the aetiology of schizophrenia at least in these Irish families. The remaining classical HLA loci (HLA-B and HLA-C) should be typed when reliable DNA-based methods become available.

HLA and schizophrenia: refutation of reported associations with A9 (A23/A24), DR4, and DQbeta1*0602

The aim of this study was to test previous hypotheses of association between schizophrenia and human leukocyte antigen (HLA) specificities A9 (A23/24), DR4, and allele DQbeta1*0602. Using sequence-specific oligonucleotide probes, 256 familial schizophrenic patients and 261 unrelated controls were genotyped at polymorphisms for HLA-A, DRbeta1, and DQbeta1 loci. No significant (p < 0.05) differences in the allele frequencies between schizophrenics and controls were found, either when examining the sample as a whole or when subdivided by clinical subtype or gender. The present data do not support association between these HLA specificities and schizophrenia, and our review of previous studies suggests that reported associations may well be false positive results.

Experience journals: using computers to share personal stories about illness and medical intervention

Medical advances make it increasingly possible for children with previously fatal illness to live and thrive. However, a significant number still experience repeated operations, hospitalization, and invasive procedures, or need special care at home. Many do so with little or no intervention to help them and their families cope with the emotional stresses involved. One significant source of emotional and cognitive support is the community of patients and families who have experienced similar medical procedures. However, in spite of a general willingness to share experiences, communication among patients and families is usually limited. To facilitate this process, we are investigating the use of computer technology to record, organize, and display stories about the experiences of families with children who have been treated for cardiac and neurological illness at Children's Hospital, Boston. We are asking children and their families to record text and multimedia vignettes describing some aspect of their illness, coping strategies, or care that might be useful to others. These contributions will be available for browsing at a secure World-Wide-Web site. However, economic realities preclude reliance on a professional site administrator to organize and monitor what we hope to be a rapidly growing Web site with a large, distributed authorship. The need to make the Web site fully accessible to users who have varying familiarity with computers and Web browsing imposes further constraints. We are therefore developing software to automate the process of managing and organizing an easily accessed Web site that contains an "Experience Journal." We describe this software, the rationale for its development, and our plans for its use in the coming year.

Epidermal growth factor protects epithelial cells against Fas-induced apoptosis. Requirement for Akt activation

Chemotherapeutic drugs that damage DNA kill tumor cells, in part, by inducing the expression of a death receptor such as Fas or its ligand, FasL. Here, we demonstrate that epidermal growth factor (EGF) stimulation of T47D breast adenocarcinoma and embryonic kidney epithelial (HEK293) cells protects these cells from Fas-induced apoptosis. EGF stimulation of epithelial cells also inhibited Fas-induced caspase activation and the proteolysis of signaling proteins downstream of the EGF receptor, Cbl and Akt/protein kinase B (Akt). EGF stimulation of Akt kinase activity blocked Fas-induced apoptosis. Expression of activated Akt in MCF-7 breast adenocarcinoma cells was sufficient to block Fas-mediated apoptosis. Inhibition of EGF-stimulated extracellular signal-regulated kinase (ERK) activity did not affect EGF protection from Fas-mediated apoptosis. The findings indicate that EGF receptor stimulation of epithelial cells has a significant survival function against death receptor-induced apoptosis mediated by Akt.

MEK kinase 1 (MEKK1) transduces c-Jun NH2-terminal kinase activation in response to changes in the microtubule cytoskeleton

Cell shape change and the restructuring of the cytoskeleton are important regulatory responses that influence the growth, differentiation, and commitment to apoptosis of different cell types. MEK kinase 1 (MEKK1) activates the c-Jun NH2-terminal kinase (JNK) pathway in response to exposure of cells to microtubule toxins, including taxol. MEKK1 expression is elevated 3-fold in mitosis and microtubule toxin-treated cells accumulated at G2/M of the cell cycle. Targeted disruption of MEKK1 expression in embryonic stem cells resulted in the loss of JNK activation and increased apoptosis in response to taxol. Targeted disruption of the MEK kinase 2 gene had no effect on activation of the JNK pathway in response to microtubule toxins demonstrating a specific role of MEKK1 in this response. Cytochalasin D-mediated disruption of actin fibers activates JNK and stimulates apoptosis similarly in MEKK1(-/-) and wild type cells. The results show that MEKK1 is required for JNK activation in response to microtubule but not actin fiber toxins in embryonic stem cells. MEKK1 activation can protect cells from apoptosis in response to change in the integrity of the microtubule cytoskeleton.

Differential involvement of MEK kinase 1 (MEKK1) in the induction of apoptosis in response to microtubule-targeted drugs versus DNA damaging agents

MEK kinase 1 (MEKK1) is a 196-kDa enzyme that is involved in the regulation of the c-Jun N-terminal kinase (JNK) pathway and apoptosis. In cells exposed to genotoxic agents including etoposide and cytosine arabinoside, MEKK1 is cleaved at Asp874 by caspases. The cleaved kinase domain of MEKK1, itself, stimulates caspase activity leading to apoptosis. Kinase-inactive MEKK1 expressed in HEK293 cells effectively blocks genotoxin-induced apoptosis. Treatment of cells with taxol, a microtubule stabilizing agent, did not induce MEKK1 cleavage in cells, and kinase-inactive MEKK1 expression failed to block taxol-induced apoptosis. MEKK1 became activated in HEK293 cells exposed to taxol, but in contrast to etoposide-treatment, taxol failed to increase JNK activity. Taxol treatment of cells, therefore, dissociates MEKK1 activation from the regulation of the JNK pathway. Overexpression of anti-apoptotic Bcl2 blocked MEKK1 and taxol-induced apoptosis but did not block the caspase-dependent cleavage of MEKK1 in response to etoposide. This indicates Bcl2 inhibition of apoptosis is, therefore, downstream of caspase-dependent MEKK1 cleavage. The results define the involvement of MEKK1 in the induction of apoptosis by genotoxins but not microtubule altering drugs.

Religious support from parish clergy for hospitalized parishioners: availability, evaluation, implications

Reports the results of interviews with a random sample (N = 500) of hospital patients responding to the following questions: What percentage of hospital patients consider themselves part of a church or synagogue? How many patients identify a specific parish clergy or some other source who could provide them pastoral support? How many patients received pastoral support during hospitalization from clergy or some other person, and by visit or phone call (excluding hospital chaplains)? How do hospital patients evaluate the helpfulness of these pastoral visits? Discusses the results of the survey, implications for pastoral caregivers, and suggests future research possibilities.

Experiences of 100 men who have sex with men using the Reality condom for anal sex

A self-administered, anonymous questionnaire examining opinions and experiences of using Reality, the "female" condom, for anal sex was completed by a convenience sample of 100 men who have sex with men (MSM). Eighty-six percent of respondents said they would use Reality again; 54% would rather use Reality than penile condoms. Acceptability was higher among MSM who were HIV positive, in nonmonogamous relationships, or who had serodiscordant partners. Negative experiences included: difficulty inserting (33%), irritation (17%), bunching up (12%), unpleasant texture (10%), and noise (9%). Breakage was reported three times in 334 episodes of use. Although no available data compare preferences and efficacy of Reality to penile condoms, Reality is a welcome alternative for some MSM who have difficulty consistently using penile condoms and probably reduces HIV transmission compared with unprotected anal sex. Research to more definitively assess Reality as a risk reduction method for MSM is greatly needed.

Dietary amino acids as new and novel agents to enhance allograft survival

Dietary supplementation with arginine was previously found to enhance cardiac allograft survival in rats when given with a donor-specific transfusion and a short low-dose course of cyclosporine. This study was performed to determine further the role of amino acid supplementation in prolonging allograft survival. Standard isocaloric, isonitrogenous diets were modified to contain 2 or 4% of energy from arginine, 2 or 4% from glutamine, 4% from glycine or the following combinations: 2% arginine with 2% glutamine, 2% arginine with 4% glutamine, or 1% arginine with 2% glutamine. These diets were started along with a donor-specific transfusion and a 7-d course of cyclosporine the day before cardiac transplantation from an ACI to Lewis strain rat. Median survival times in days for the groups were as follows: control without amino acids, 19.0; 2% arginine, 68.0; 4% arginine, 35.5; 2% glutamine, 28.5; 4% glutamine, 53.5; 4% glycine, 31.5; 2% arginine with 2% glutamine, 39.5; 2% arginine with 4% glutamine, 42.5 and 1% arginine with 2% glutamine, 35.5. Each experimental diet except 2% glutamine and 4% glycine significantly enhanced allograft survival (P < 0.05) with the 2% arginine diet being the best (91.6 +/- 32.3 d [mean +/- SEM] versus 20.1 +/- 3.2 d for control). It is concluded that both arginine and glutamine enhance the immunosuppressive effects of donor-specific transfusion and cyclosporine.

Mitogen-activated protein kinase: conservation of a three-kinase module from yeast to human

Mitogen-activated protein kinases (MAPK) are serine-threonine protein kinases that are activated by diverse stimuli ranging from cytokines, growth factors, neurotransmitters, hormones, cellular stress, and cell adherence. Mitogen-activated protein kinases are expressed in all eukaryotic cells. The basic assembly of MAPK pathways is a three-component module conserved from yeast to humans. The MAPK module includes three kinases that establish a sequential activation pathway comprising a MAPK kinase kinase (MKKK), MAPK kinase (MKK), and MAPK. Currently, there have been 14 MKKK, 7 MKK, and 12 MAPK identified in mammalian cells. The mammalian MAPK can be subdivided into five families: MAPKerk1/2, MAPKp38, MAPKjnk, MAPKerk3/4, and MAPKerk5. Each MAPK family has distinct biological functions. In Saccharomyces cerevisiae, there are five MAPK pathways involved in mating, cell wall remodelling, nutrient deprivation, and responses to stress stimuli such as osmolarity changes. Component members of the yeast pathways have conserved counterparts in mammalian cells. The number of different MKKK in MAPK modules allows for the diversity of inputs capable of activating MAPK pathways. In this review, we define all known MAPK module kinases from yeast to humans, what is known about their regulation, defined MAPK substrates, and the function of MAPK in cell physiology.

Analysis and interpretation of short tandem repeat microvariants and three-banded allele patterns using multiple allele detection systems

The Palm Beach County Sheriffs Office (PBSO) Crime Laboratory and the Alabama Department of Forensic Sciences (ADFS) have validated and implemented analysis of short tandem repeat (STR) sequences on casework using silver staining kit and SYBR Green I detection systems and are presently validating fluorescently tagged STR alleles using the Hitachi FMBIO 100 instrument. Concurrently, the Broward County Sheriff's Office (BSO) Crime Laboratory is validating the ABI Prism310 Genetic Analyzer capillary electrophoresis STR detection system (ABI CE310) from Perkin Elmer Applied BioSystems. During the course of analyzing over 10,000 individuals for the STR loci CSF1PO, TPOX and THO1 (CTT) using silver staining for allele detection, 42 samples demonstrated alleles that were "off ladder," contained three-banded patterns at a single locus, or exhibited an apparent THO1 "9.3,10" allele pattern. PBSO, ADFS and BSO Crime Laboratories have collaborated on the verification of the allele patterns observed in these 42 samples using the following allele detection systems: (1) manual silver staining, (2) SYBR Green I staining, and/or (3) fluorescently tagged amplified products separated by polyacrylamide gel electrophoresis or capillary electrophoresis followed by laser detection. Regardless of the CTT allele detection system utilized, concordant results were obtained for 41 of the 42 samples. The only exception was a sample in which a wide band within the THO1 locus was identified as a THO1 "9.3, 10" genotype by silver staining kit and SYBR Green I staining but was verified to be a THO1 "9.3" homozygote by all other allele detection systems. Manual allele detection could readily identify microvariants, as a visual assessment of stained gels clearly shows that alleles do not migrate coincident with well-characterized allele size standards. As would be predicted, however, the manual detection systems did not provide adequate resolution to approximate the basepair size for off-ladder variants. All fluorescent software program systems were consistent in designating alleles "not in range" or "off ladder," thereby indicating true microvariants. All single-locus three-banded patterns were detected using all of the STR multiplex systems. In addition, individual locus-specific primers verified multiplexed amplified products were specific for the locus in question.