Expression, regulation and function of AC133, a putative cell surface marker of primitive human haematopoietic cells

To explore the physiological significance of AC133 expression on human haematopoietic cells, we phenotyped normal and malignant human haematopoietic cells for AC133 expression, evaluated the utility of AC133 for isolating human stem/progenitor cells in comparison to other known early haematopoietic cell markers, investigated the role of AC133 in regulating hematopoiesis, and evaluated the possibility that MYB might regulate AC133. We found that while human CD34+ progenitor cells expressed AC133, expression was rapidly downregulated during differentiation. In apparent contrast, AC133 mRNA was detectable in cells isolated from CFU-Mix, BFU-E, CFU-GM and CFU-Meg colonies. Human cord blood CD34+ cells expressed AC133 at higher levels than their normal bone marrow counterparts. In apparent contrast to normal primitive haematopoietic cells, the AC133 protein was undetectable on cells from 24 different human haematopoietic cells lines, even though the majority of these cells expressed AC133 mRNA. Since CD34, AC133 and the c-kit (KIT) receptor are all co-expressed on human stem/progenitor cells, we compared the ability of monoclonal antibodies directed against each of these proteins to isolate early progenitor cells. Using these antibodies and magnetized particles in a standard immunoaffinity isolation protocol, we found that anti-CD34 and anti-KIT MoAbs could isolate > 80-90% of the clonogeneic cell population present in a given marrow sample. Anti-AC133 MoAbs recovered approximately 75-80% of CFU-GM and CFU-Meg, but only about 30% of CFU-Mix and BFU-E. Perturbation of AC133 expression with antisense oligodeoxynucleotides (AS ODN) resulted in transient downregulation of AC133 protein on human CD34+ cells but no apparent effect on cell survival or cloning efficiency ex vivo. Finally, downregulation of MYB expression with AS ODN had no effect on the AC133 expression at either the mRNA or protein level. Based on these results, we conclude that AC133 offers no distinct advantage over CD34 or c-kit as a target for immunoaffinity based isolation of primitive hematopoietic cells, that AC133 expression is not required for normal hematopoietic progenitor cell development in vitro, and finally that AC133 expression may not be MYB-dependent.

Evaluation of the red blood cell and plasma transfusion guidelines

OBJECTIVES

To determine physicians' preferred content and format for the Guidelines for Red Blood Cell and Plasma Transfusion for Adults and Children before development in order to guide the development process. To obtain physicians' recommendations about the Guidelines' content, format, dissemination and future directions after development to guide future work on the Guidelines.

DESIGN

Pre-post Guidelines qualitative design using 20 focus groups (nine pre and 11 post).

STUDY PARTICIPANTS

One hundred and seven physicians (5-11 per group) who used at least 1 unit of blood over the past 6 months; with a minimum of 1 year in practice and not retired. A total of 24 physicians attended both pre and post focus groups. In general, specialties of participants included: general practice, surgery pediatrics, obstetrics/gynecology and hematology/oncology. Years of practice ranged from 1 to 35 years (mean = 7 years).

MAIN OUTCOME MEASURES

Pre Guidelines focus groups made recommendations on the content and format of the Guidelines; post Guidelines focus groups made recommendations on the same areas along with dissemination and future directions.

RESULTS

Three main components of the Guidelines were evaluated: content, format and dissemination. The content, which followed as much as possible that recommended by pre Guidelines focus groups, was deemed appropriate by post Guidelines focus groups, with minor gaps noted (e.g. information on alternatives to blood products). The format addressed many of the concerns raised by pre Guidelines focus groups; however, the post Guidelines focus groups were concerned about the lack of visual aids and categorization of information. The dissemination strategy was successful at diffusing the Guidelines, with some concerns expressed about reaching specific physician target groups.

CONCLUSION

The pre-post focus group method was useful in conducting an evaluation of the Guidelines and this method which examined content, format and dissemination could contribute to evaluations of other guidelines.

Geochronological constraints on the evolution of the Nanga Parbat syntaxis, Pakistan Himalaya

New amphibole, muscovite and biotite Ar-Ar and K-Ar data and zircon and apatite fission track data are presented from the western margin of the Nanga Parbat syntaxis as well as from the Indus and Astor valley sections which cross the syntaxis. Amphibole data date a regional cooling through 500°C at 25±5 Ma and are inconsistent with earlier suggestions that the peak of regional metamorphism was Neogene in age, although there is no doubt that some rocks were still at upper amphibolite facies temperatures as recently as 5 Ma. The data can be used to constrain structural models for syntaxial uplift. After an initial phase of crustal-scale buckling, bodily uplift of the syntaxis was along subvertical shear zones developed along its margins, although with a significantly higher time-averaged strain rate for shears developed along the western margin than along the eastern margin. The latter may be antithetic to the former. These shears were operative from 10 to < 1 Ma. In the southwestern part of the syntaxis, this subvertical uplift was superseded, since 6 Ma, by uplift along moderately SE-dipping NW-vergent shears on the hanging wall of which are located Neogene-aged migmatites.

Utilization and outcome in an overnight psychiatric observation program at a Veterans Affairs Medical Center

OBJECTIVE

The effectiveness of an overnight psychiatric observation program was evaluated. The program was designed to avoid unnecessary hospitalization of patients experiencing acute psychiatric crises.

METHODS

Of 110 patients admitted to the observation unit at a Veterans Affairs medical center over a six-month period in 1996, the charts of 92 patients were retrospectively reviewed. Characteristics of patients referred to the program were documented, inpatient hospitalization rates and suicide rates in the six-month periods before and after admission to the observation unit were examined, and variables related to the need for hospitalization immediately after observation were explored.

RESULTS

Most of the 92 patients (98 percent) were referred from the medical center's emergency room. At the time of observation, 80 percent of the patients were unemployed, 55 percent expressed suicidal or homicidal ideation, 49 percent were intoxicated or at risk for alcohol withdrawal, and 41 percent were homeless. The most frequent psychiatric diagnosis was substance abuse or dependence (77 percent). The large majority of patients (88 percent) were referred the next day to other outpatient programs for follow-up and treatment, which avoided costly inpatient treatment. In the six months before admission to the observation program, the mean number of inpatient psychiatric bed days was 9.8, compared with 2.7 days in the six-month period after discharge from the observation program. No increase in suicide gestures or attempts was noted among the patients. No variables significantly predicted admission to inpatient care after the observation period.

CONCLUSIONS

Overnight observation programs may provide a cost-effective alternative to traditional inpatient treatment for some individuals with psychiatric disorders.

Use of the MMPI and MMPI-2 in patients being evaluated for cardiac transplant

The MMPI and MMPI-2 have been used extensively in the study of personality correlates in various coronary populations. It has been hypothesized that personality variables are associated with various clinical outcomes, such as quality of life, morbidity, and mortality; however, no data are available in a cardiac transplant sample. This study presents descriptive MMPI and MMPI-2 data for male and female patients awaiting cardiac transplant. Analyses of differences in MMPI-2 depression scales between cardiomyopathy groups for 366 men and 99 women were performed. Significant differences were found between ischemic and nonischemic male patients.

Quality of life changes following KTP/Nd:YAG laser treatment of the prostate and TURP

OBJECTIVE

To compare health-related quality of life (HRQL) changes in patients receiving hybrid KTP/Nd:YAG laser treatment of the prostate with TURP.

PATIENTS AND METHODS

Patients complaining of symptomatic benign prostatic enlargement were studied. Their symptoms (IPSS), disease-specific (BPH Impact Index (BPHII)) and generic HRQL (Short Form-36 (SF-36)) was evaluated before and at 6 weeks, 6 months and 1 year following treatment.

RESULTS

204 patients were randomized into the study. Patients in both groups reported an improvement in IPSS and BPHII at each postoperative assessment, but there were significant differences between the two groups at the 6-week stage in favor of the TURP group. At 6 weeks, patients in the laser group reported significantly worse scores in the SF-36 domains of bodily pain, social function and role emotional when compared to the TURP group. These differences disappeared at both the 6-month and 1-year follow-up assessments.

CONCLUSIONS

Although hybrid KTP/Nd:YAG laser treatment and TURP differed in the way they affected patients in the early postoperative period, at 1 year, patients reported similar improvements in symptoms and enjoyed a similar disease-specific and generic HRQL.

Physical mapping of the CC-chemokine gene cluster on the human 17q11. 2 region

Chemokines are a family of small secreted proteins that are involved in the trafficking of leukocytes by acting on G-protein-coupled receptors. Specific chemokines are also implicated in the regulation of angiogenesis and mobilization of hematopoietic cell precursors. Chemokines are subdivided into four groups on the basis of the relative positions of their conserved cysteines. For the CC-chemokine group, in which the first two (of four) conserved cysteines are adjacent, 22 members have been described so far. In this work, we have analyzed the genomic organization of these genes. We first assigned the genes encoding CC-chemokines to chromosomal regions and organized their relative positioning by using two radiation hybrid panels. Fifteen CC-chemokine genes were shown to be clustered within the 17q11.2 region of the human genome. These genes appeared to be segregated into two subclusters separated by about 2. 25 Mb (9 cR). Contigs of bacterial artificial chromosomes (BAC) covering these two subclusters were subsequently isolated and the localizations of the CC-chemokine genes within these contigs determined. The relative positioning of the BAC clones was determined with the help of fluorescence hybridization on combed genomic DNA. The cluster organization of the various CC-chemokine genes in the genome was found to be grossly consistent with their structural similarities. This map of the CC-chemokine gene cluster should facilitate the determination of the full sequence of the chromosomal region.

Development of a tetrazolium salt assay for rapid determination of viability of BCG vaccines

Standardisation and control of the live Mycobacterium bovis BCG (BCG) vaccine is performed as specified by the World Health Organisation (WHO) and the European Pharmacopoeia (EP). The conventional viable count for control of potency of BCG vaccine is performed by culturing on solid medium. This assay method is not only time consuming but may give variable results. A tetrazolium salt assay has been developed and evaluated as a potential additional, or replacement, test for determining number of viable organisms. The tetrazolium salts 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and 2,3-bis-(2-methoxy-4-nitro-5-sulphenyl)-(2H)-tetrazolium-5-carb oxanilide (XTT) used as alternative substrates in the assay both gave more rapid and reproducible results than the conventional viable count. XTT showed greater sensitivity than MTT with a lower detection limit of about 7x10(4) colony forming units (c.f.u.) ml(-1). The XTT assay has proven effective for determining viability of suspensions prepared from several BCG vaccine substrains, covering a range of viable units, without the need for modification. This assay is easily performed and takes just 48 h to produce an estimate of viable cell content compared with 3 weeks for the conventional method.

A prospective randomized controlled trial of hybrid laser treatment or transurethral resection of the prostate, with a 1-year follow-up

OBJECTIVE

To compare the clinical outcome after hybrid laser treatment of the prostate, combining potassium titanyl phosphate (KTP) and Nd:YAG lasers, with transurethral resection of the prostate (TURP).

PATIENTS AND METHODS

A prospective randomized trial was conducted to compare laser treatment and TURP. The hybrid laser treatment technique involved performing initial 30 W KTP vaporizing bladder neck incisions and prostatotomies followed by a 'free-paint' application of 60 W Nd:YAG coagulation energy. Patients were re-assessed after 6 weeks, 6 months and 1 year, using the International Prostate Symptom Score (IPSS) and uroflowmetry. TURP was conducted using conventional methods.

RESULTS

In all, 204 patients were randomized into the study; at 6 weeks there were significant differences between the groups for the IPSS (12.4 vs 9.1, P=0.001) and maximum urinary flow rates (16.1 vs 20.8 mL/S, P<0. 001) in favour of the TURP group. At 6 months and one year this difference had disappeared. Similar numbers of patients in each group complained of bothersome postoperative urinary symptoms (23% vs 19%). Blood transfusions (5% vs none) and urethral strictures (9% vs 2%) were more common after TURP, whereas more early infective complications occurred after hybrid laser treatment (24% vs 5%). Only one patient in each group required re-operation because of poor resolution of symptoms.

CONCLUSIONS

At one year, hybrid KTP/Nd:YAG laser treatment of the prostate was equivalent to TURP in the improvements in IPSS, maximum urinary flow rate and post-void residual urine.

An MRSA outbreak in a urology ward and its association with Nd:YAG coagulation laser treatment of the prostate

An outbreak of methicillin resistant Staphylococcus aureus (MRSA) involving 88 patients in a general urology ward is described. Symptomatic bacteraemia and epididymo-orchitis occurred in 10 and 8% of patients respectively. Patients had a particularly high risk of acquiring serious MRSA infection after endoscopic neodymium yttrium aluminium garnet (Nd:YAG) laser treatment of the prostate. Appreciation of the mode of transmission of MRSA, a programme of continuing education for all medical and nursing staff, simple changes in ward protocol and advances in surgical laser technique contributed to the control of the outbreak.

Strain as a moderator of the relationship between work characteristics and work attitudes

Research on the psychological effects of work characteristics has investigated their relationships with both work attitudes and psychological strain, with the latter 2 variables being treated as alternative or joint dependent variables. The focus of this article is to propose that strain moderates the relationship between perceptions of work characteristics and work attitudes. The proposition is tested on a maximum sample of 9,327 health care employees by using moderated multiple regression followed by subgroup comparisons. The results strongly support the moderating effect, showing that as strain increases, the strength of the relationship between perceptions of work characteristics and work attitudes decreases.

Role of vascular endothelial growth factor (VEGF) and placenta-derived growth factor (PlGF) in regulating human haemopoietic cell growth

Vascular endothelial growth factor (VEGF) and placental derived growth factor (PlGF) stimulate cell proliferation and differentiation by binding to their specific receptors, Flk-1/KDR and Flt-1 respectively. Flk-1/KDR-deficient murine embryos manifest failure of blood-island formation and vasculogenesis. The aim of this study was to directly evaluate the importance of VEGF, PlGF/Flt-1 and Flk-1/KDR receptor ligand interactions in regulating normal and malignant human haemopoiesis. Addition of VEGF and PlGF failed to enhance survival or cloning efficiency of human haemopoietic progenitors isolated from adult bone marrows, fetal livers or cord blood samples. This finding may be explained by the apparent absence of mRNA encoding Flt-1 and Flk-1/KDR receptors on stem cell rich CD34+ c-kit-R+ Rh123(low) cells. Further studies revealed that Fit-1 R mRNA, but not Flk-1/KDR mRNA was first detectable in the more mature cells isolated from haemopoietic colonies. Accordingly, VEGF receptors are either absent, or expressed at very low level, on human haemopoietic stem/progenitor cells. Of interest, normal and malignant human haemopoietic cells appeared to secrete VEGF protein. However, in contrast to normal haemopoietic progenitors, VEGF co-stimulated HEL cell proliferation as well as CFU-GM colony formation from approximately 15% of the chronic myeloid leukaemia (CML) and acute myeloid leukaemia (AML) patients studied. Therefore, although VEGF appeared to have minimal effects on normal haemopoietic cell growth it would appear to drive malignant haemopoietic cell proliferation to some degree. Of more importance, however, we speculate that VEGF may play an very important role in leukaemogenesis by stimulating growth of vascular endothelium, thereby providing a sufficient blood supply to feed the growing haematological tumour.

Methylene tetrahydrofolate reductase C677T genotype and stroke

High levels of homocysteine are associated with atherosclerosis. A thermolabile form of the enzyme methylene tetrahydrofolate reductase (MTHFR) has been proposed as a major cause of a genetic predisposition to hyperhomocysteinaemia and a point mutation at nucleotide 677 of the MTHFR gene causing a thermolabile MTHFR has been described. We looked for this mutation in 271 patients with CT proven cerebrovascular accidents and 173 control subjects. No significant difference in the frequency of the mutant genotype was found between patients with strokes and the control group. Separate analysis of those under 65 and subdividing stroke patients by anatomical location also revealed no significant difference. We conclude, therefore, that in this population the mutation evaluated is not a major contributor to the aetiology of cerebrovascular disease.

Sensitivity to grammatical morphemes in children with specific language impairment

Grammatical morphemes, such as articles and auxiliary verbs, provide potentially useful information to language learners. However, children with specific language impairment (SLI) frequently fail to produce grammatical morphemes, raising questions about their sensitivity to them. To address this issue, two experiments were conducted in which 3- to 5-year-old children with SLI and with normally developing language (NL) heard sentences asking them to identify a picture corresponding to a named target word. The target occurred in either a grammatical sentence or one with an incorrectly used grammatical morpheme. In Experiment 1, the picture representing the target occurred with three unrelated distractor pictures. In Experiment 2, distractor sets included pictures that were semantically related to the target. In both studies, the SLI group chose fewer correct pictures when the target followed an incorrectly used morpheme. In Experiment 2, the SLI group chose more semantically related than unrelated distractors. These results suggest that children with SLI are sensitive to grammatical morphemes and that their incorrect picture choices may reflect a failure to maintain the target in memory.

Factor XIII Val 34 Leu: a novel association with primary intracerebral hemorrhage

BACKGROUND AND PURPOSE

A common G-to-T point mutation (Val 34 Leu) in exon 2 of the alpha-subunit of the factor XIII is strongly negatively associated with the development of myocardial infarction. This result suggests that factor XIII Val 34 Leu is interfering with the formation of cross-linked fibrin. The role of factor XIII Val 34 Leu in the pathogenesis of cerebral infarction and primary intracerebral hemorrhage is unknown.

METHODS

Six hundred twelve patients with acute stroke, defined by World Health Organization criteria and cranial CT, and 436 age-matched control subjects free of cerebrovascular disease were genotyped for the factor XIII Val 34 Leu mutation. Venous blood was drawn for the determination of hemostatic variables and lipids. Factor XIII genotype was determined through a single-stranded conformational polymorphism technique and plasminogen activator inhibitor (PAI)-1 4G/5G promoter genotype by allele-specific polymerase chain reaction.

RESULTS

The mutation was more frequent in patients with primary intracerebral hemorrhage (n=62) (54.8%; P=.05) than in control subjects (41.7%) or in patients with cerebral infarction (n=529) (46.5%; P=.22). There was no relationship between PAI-1 levels and the PAI-1 4G/5G genotype.

CONCLUSIONS

There was a slightly higher incidence of factor XIII Val 34 Leu in patients with PICH. This may be related to impaired cross-linking of fibrin and/or coagulation proteins.

Estradiol and progesterone alter ethanol-induced effects on mu-opioid receptors in specific brain regions of ovariectomized rats

This study was conducted to evaluate the effects of estradiol and progesterone on ethanol-induced alterations of mu-opioid receptor binding kinetics in specific brain regions. Female ovariectomized rats were injected with ethanol (3 g/kg, i.p.), estradiol (50 microg/kg, s.c.) and/or progesterone (5 mg/kg, s.c.), or ethanol plus estradiol and/or progesterone daily for 7 days. Control animals received saline and olive oil. Brains were immediately removed and the cortex, hippocampus, hypothalamus, and midbrain were dissected and assayed for mu-opioid receptor binding kinetics. In the hypothalamus, ethanol alone and in combination with estradiol and/or progesterone significantly decreased Bmax. Ethanol alone also decreased Bmax in the midbrain and cortex. When administered with estradiol only, ethanol increased Bmax and Kd in the hippocampus. The administration of estradiol alone and progesterone alone decreased Bmax in the hypothalamus, while not affecting Bmax in any of the other brain regions. However, when estradiol and progesterone were combined, Bmax, as well as Kd, increased in the cortex. Progesterone alone and in combination with estradiol also increased Kd in the midbrain. In addition, Kd significantly increased following administration of ethanol in combination with either of the hormones, or both, in the midbrain and cortex. These results clearly indicate that the female hormones modulate the effects of ethanol on binding kinetics of mu-opioid receptors in specific brain regions. The present findings may in part explain sex differences in alcohol effects.

Clinical features in affected individuals from 21 pedigrees with dominant optic atrophy

OBJECTIVE

To assess phenotypic variation of affected individuals from British families with autosomal dominant optic atrophy.

DESIGN

Eighty-seven patients from 21 families showing evidence of linkage to chromosome 3q were identified via the Genetic Clinic of Moorfields Eye Hospital, London, England. Genetic linkage analysis was carried out with markers from chromosome 3q28-qter. Patients underwent clinical examination and psychophysical and electrophysiological testing.

RESULTS

Best-corrected visual acuity ranged from 20/20 (6/6 m) to light perception. Although visual acuity was not significantly worse in older patients in the group (chi2=3.20, df=4, P>.50), it did deteriorate with age in one third of the families. Subtle or temporal pallor of the optic disc occurred in 96 (55%) of 174 eyes and total atrophy in 76 (44%). Tritanopia was found in 6 (7.5%) of 80 patients; 65 (81.2%) had a mixed color deficit. A cecocentral scotoma was found in the vast majority. Peripheral motion detection threshold was elevated in areas of visual field with raised mean surround sensitivity but not elsewhere. Pattern visual evoked potentials were of reduced amplitude and delayed. Pattern electroretinograms showed a reduced N95 component in keeping with primary ganglion cell dysfunction.

CONCLUSIONS

There is wide intrafamilial and interfamilial phenotypic variation in autosomal dominant optic atrophy, with visual function in some, but not all, families deteriorating with age. There is evidence of degeneration of the ganglion cell layer predominantly from central retina, but this is not the exclusive result of either parvocellular or magnocellular cell loss.

Association of a common polymorphism in the factor XIII gene with myocardial infarction

Factor XIII when activated by thrombin, crosslinks fibrin, however its role in thrombotic disorders is unknown. A common point mutation (G-->T) in exon 2 of the A-subunit gene which codes for an amino acid change three amino acids from the thrombin activation site (Factor XIIIVal34Leu) is a candidate for a role in the pathogenesis of acute myocardial infarction. Factor XIII genotype frequencies were determined in a case-control study of 398 caucasian patients and 196 healthy controls. Patients had undergone angiography for investigation of coronary artery disease and were evaluated for a history of myocardial infarction. The prevalence of the mutation was lower in patients with myocardial infarction than without (32% vs. 50%), p = 0.0009 and than in controls (32% vs. 48%), p = 0.005. Patients possessing the mutation with a history of myocardial infarction had higher PAI-1 concentrations (mean, 27.9 vs. 16.7 ng/ml, p = 0.004) and the PAI-1 4G/4G genotype was commoner (43% vs. 26%, p = 0.03). There was no difference in PAI-1 4G/4G genotype (33% vs. 32%) and PAI-1 levels (mean, 21.0 vs. 20.9 ng/ml) in patients possessing wild type with MI compared to those without MI. These results indicate that the G-->T mutation coding for factor XIIIVal34Leu is protective against myocardial infarction and suggest a mechanism whereby elevated levels of PAI-1 may contribute to vascular risk.

Effect of hepatocyte growth factor on early human haemopoietic cell development

Hepatocyte growth factor (HGF) stimulates cell proliferation, differentiation and migration by binding to its receptor, MET R. Whether the HGF/MET R axis plays an important regulatory role in human haemopoietic cell growth is an unresolved issue. To investigate this situation, we employed several complementary strategies including RT-PCR, FACS analysis, and mRNA perturbation with oligodeoxynucleotides (ODN). We found that very primitive, FACS sorted, CD34+ Kit+ marrow mononuclear cells (MNC) failed to express RT-PCR detectable MET R mRNA. In contrast, MET R expression was easily detectable by RT-PCR in marrow stroma fibroblasts, in cells isolated from BFU-E and CFU-GM colonies, and in unselected normal MNC. Subsequent FACS analysis revealed that MET R protein was detectable on approximately 5% of the latter cells. HGF, at concentrations of 1-50 ng/ml, had no demonstrable effect on survival or cloning efficiency of normal CD34+ MNC in serum-free cultures. Antisense ODN mediated perturbation of MET R mRNA expression in normal CD34+ MNC, with FACS documented decline in protein expression, had no effect on the ability of these cells to give rise to haemopoietic colonies of any lineage. We also examined the biology of HGF/MET R expression in malignant haemopoietic cells. Using the strategies described above, we found that MET R mRNA was expressed in many human haemopoietic cell lines, and that the protein was expressed at high levels on HTLV transformed T lymphocytes. Wild-type CML and AML blast cells also expressed MET mRNA, and HGF was able to co-stimulate CFU-GM colony formation in approximately 20% of cases studied. Therefore, although the HGF/MET R axis appears to be dispensable for normal haemopoietic cell growth, it may play a role in the growth of malignant haemopoietic progenitor cells.

Caspase-1 processes IFN-gamma-inducing factor and regulates LPS-induced IFN-gamma production

Interferon-gamma-inducing factor (IGIF, interleukin-18) is a recently described cytokine that shares structural features with the interleukin-1 (IL-1) family of proteins and functional properties with IL-12. Like IL-12, IGIF is a potent inducer of interferon (IFN)-gamma from T cells and natural killer cells. IGIF is synthesized as a biologically inactive precursor molecule (proIGIF). The cellular production of IL-1beta, a cytokine implicated in a variety of inflammatory diseases, requires cleavage of its precursor (proIL-1beta) at an Asp-X site by interleukin-1beta-converting enzyme (ICE, recently termed caspase-1). The Asp-X sequence at the putative processing site in proIGIF suggests that a protease such as caspase-1 might be involved in the maturation of IGIF. Here we demonstrate that caspase-1 processes proIGIF and proIL-1beta with equivalent efficiencies in vitro. A selective caspase-1 inhibitor blocks both lipopolysaccharide-induced IL-1beta and IFN-gamma production from human mononuclear cells. Furthermore, caspase-1-deficient mice are defective in lipopolysaccharide-induced IFN-gamma production. Our results thus implicate caspase-1 in the physiological production of IGIF and demonstrate that it plays a critical role in the regulation of multiple proinflammatory cytokines. Specific caspase-1 inhibitors would provide a new class of anti-inflammatory drugs with multipotent action.

Ritual, habit, and perfectionism: the prevalence and development of compulsive-like behavior in normal young children

Young children engage in a significant amount of ritualistic, repetitive, and compulsive-like activity that appears to be part of their normal behavioral repertoire. Empirically, little is known about the onset, prevalence, and developmental trajectory of these phenomena. A parent-report questionnaire, the Childhood Routines Inventory (CRI), was developed to assess compulsive-like behavior in young children, and was administered to 1,492 parents with children between the ages of 8 and 72 months. The CRI has strong overall internal consistency and a distinct two-factor structure. The frequency of compulsive-like behaviors changes with age: Two-, 3-, and 4-year-olds engaged in more compulsive behavior than children younger than 1 year of age and older than 4 years of age. Results are discussed from a developmental psychopathology framework and for their implications for future research in this area.