Is there a genetic relationship between alcoholism and depression?

The Collaborative Study on the Genetics of Alcoholism (COGA) seeks to identify genes contributing to alcoholism and related traits (i.e., phenotypes), including depression. Among alcoholic subjects the COGA study found an increased prevalence of depressive syndrome (i.e., depression that may or may not occur in conjunction with increased drinking). This combination of alcoholism and depression tends to run in families. Comorbid alcoholism and depression occurred substantially more often in first-degree relatives of COGA participants with alcoholism than in relatives of control participants. Based on these data, COGA investigators defined three phenotypes--"alcoholism," "alcoholism and depression," and "alcoholism or depression"--and analyzed whether these phenotypes were linked to specific chromosomal regions. These analyses found that the "alcoholism or depression" phenotype showed significant evidence for genetic linkage to an area on chromosome 1. This suggests that a gene or genes on chromosome 1 may predispose some people to alcoholism and others to depression (which may be alcohol induced).

Phenotypic characteristics of colo-rectal cancer in I1307K APC germline mutation carriers compared with sporadic cases

The I1307K APC germline mutation is associated with an increased risk to colo-rectal cancer (CRC). Whether and to what extent the phenotype of CRC in mutation carriers differs from sporadic cases, remains unknown. To gain insight into this issue, we analysed 307 unselected Israeli patients with CRC, who were treated in a single medical centre, for harbouring the I1307K mutation. Twenty-eight mutation carriers (9.1%) were detected. Two of 28 mutation carriers (7.1%) and 93/277 (33.6%) of non-carriers, were of non-Ashkenazi origin (P < 0.01). In 74/278 (26.6%) of the sporadic cases, and only 1/28 (3.6%) of mutation carriers (3.6%) the tumour was located in the right colon (P < 0.01). Mutation carriers had a more advanced disease stage (14/28 - 50% Dukes C), as compared with 60 (19.5%) of non-carriers (P = 0.02). The mean age at diagnosis was similar: 65 (+/- 9.7) years and 66.3 (+/- 11.6) years, for mutation carriers and non-carriers, respectively. No statistical differences were noted between the two groups in sex distribution, tumour grade, and family history of cancer. We conclude that early age at diagnosis and family history of cancer cannot be used to predict who is likely to harbour the I1307K APC germline mutation carriers. However, the tumours in patients with this mutation appear different than those without, are less likely to be proximal and more likely to be advanced than tumours in non-carriers.

Influence of gender and oral contraceptives on CYP2D6 and CYP2C19 activity in healthy volunteers

AIMS

The study was carried out in order to assess the effects of gender and the use of oral contraceptives (OCs) on CYP2D6 and CYP2C19 activities in healthy volunteers.

METHODS

Six hundred and eleven Caucasian volunteers (330 males and 281 females; age range 18-49 years) were phenotyped with respect to CYP2D6 and CYP2C19 by means of the probe drugs dextromethorphan and mephenytoin, respectively. Extensive metabolisers were selected for this study.

RESULTS

The median dextromethorphan/dextrorphan metabolic ratio in non-OC using females was significantly lower than in males (0.067 vs 0.080; P = 0.033) (mean difference in ln dextromethorphan/dextrorphan metabolic ratio 0.023, 95% CI 0.03-0.43). For the mephenytoin S/R ratio, no such difference was observed. However, OC using females had a significantly higher median mephenytoin S/R ratio than non-OC using females (0.230 vs 0.090; P < 0.001) (mean difference in ln mephenytoin S/R ratio 0.082, 95% CI 0.60-1.04). Moreover, females using combined OCs had a significantly higher median ratio than females using OCs with progestins only (median 0.258 vs 0.135; P = 0.008) (mean difference in ln mephenytoin S/R ratio 0.82, 95% CI 0.21-1.34).

CONCLUSIONS

Given certain assumptions, the study indicates that females in the fertile age have a slightly higher CYP2D6 activity compared with males. There was no evidence of a gender difference in CYP2C19 activity. The use of combined OCs reduces the activity of CYP2C19, an effect that seems to be related to the ethinyloestradiol component.

'CFTR-opathies': disease phenotypes associated with cystic fibrosis transmembrane regulator gene mutations

Cystic fibrosis is a genetic disease that is associated with abnormal sweat electrolytes, sino-pulmonary disease, exocrine pancreatic insufficiency, and male infertility. Insights into genotype/phenotype relations have recently been gained in this disorder. The strongest relationship exists between 'severe' mutations in the gene that encodes the cystic fibrosis transmembrane regulator (CFTR) and pancreatic insufficiency. The relationship between 'mild' mutations, associated with residual CFTR function, and expression of disease is less precise. Atypical 'mild' mutations in the CFTR gene have been linked to late-onset pulmonary disease, congenital bilateral absence of the vas deferens, and idiopathic pancreatitis. Less commonly, sinusitis, allergic bronchopulmonary aspergillosis, and possibly even asthma may also be associated with mutations in the CFTR gene, but those syndromes predominantly reflect non-CFTR gene modifiers and environmental influences.

Effects of peroxisome proliferators on the thymus and spleen of mice

The effects of peroxisome proliferators on the immune system of male C57B1/6 mice have been investigated. Significant atrophy of the thymus and spleen was observed in animals treated with potent peroxisome proliferators (e.g. perfluorooctanoic acid (PFOA), di(2-ethylhexyl)phthalate (DEHP), Wy-14643 and nafenopin), whereas the effects of a moderate peroxisome proliferator (i.e. acetylsalicylic acid (ASA)) were relatively weak. The time course of thymic and splenic atrophy caused by PFOA was found to resemble the time course of the increase in liver weight and of peroxisome proliferation. Analysis of the numbers and phenotypes of thymocytes and splenocytes from PFOA-treated mice revealed the following: (i) the numbers of thymocytes and splenocytes were decreased > 90% and about 50%, respectively, by PFOA treatment; (ii) although all populations of thymocytes were decreased, the immature CD4+CD8+ population was decreased most dramatically; (iii) the numbers of both T and B cells in the spleen were decreased by PFOA treatment. Analysis of the cell cycle of thymocytes indicated that the thymic atrophy caused by PFOA in mice results, at least in part, from inhibition of thymocyte proliferation. Interestingly, in vitro exposure to PFOA for up to 24 h did not produce analogous effects in either thymocytes or splenocytes. Thus, the thymic and splenic atrophy caused by PFOA appears to involve an indirect pathway.

Characterization of the diffuse mucosal associated lymphoid tissue of feline small intestine

Characterization of the feline intestinal mucosal associated lymphoid tissue (MALT) will facilitate investigation of intestinal disease in the cat and promote the cat as an animal model for a range of human diseases which involve the intestinal lymphoid tissue. This includes inflammatory bowel disease, viral and non-viral associated intestinal lymphomas and immunodeficiency associated syndromes. Morphologic and phenotypic characterization of the normal small intestinal diffuse MALT in 22 SPF cats was performed using flow cytometry and cytology on isolated intestinal leukocytes from the intra-epithelial and lamina proprial compartments, as well as immunohistology on tissues from the feline duodenum, jejunum and ileum. The intra-epithelial compartment (IEC) was dominated by lymphocytes (>85%) which frequently contained intracytoplasmic granules. The most striking findings in the IEC were the elevated percentages of CD8 alpha+ lymphocytes (40%), presumed to express CD8 alpha alpha chains, and CD4-/CD8- (double negative) lymphocytes (44%), and the consistent presence of a minor subpopulation of CD3+/CD11d+ IELs (6%). Small percentages of CD4+ lymphocytes (10%) were observed such that the IEL CD4:CD8 ratio (0.25) was low. The LPC also contained a majority of T cells and few plasma cells. However, this compartment had reduced percentages of CD8 alpha+ lymphocytes (28%) and increased percentages of CD4+ lymphocytes (27%) relative to the IEC. However, the LPL CD4:CD8 ratio (1.0) remained low compared with the ratio in peripheral blood. In feline MALT, MHC class II expression was lower than in other peripheral lymphoid compartments. The results of this study provide important reference values for future investigations involving feline intestinal lymphocytes and demonstrates that the leukocyte distribution and phenotypic characteristics of the feline diffuse MALT appear largely similar to the murine, rat and human counterparts.

A discordance of the cytochrome P450 2C19 genotype and phenotype in patients with advanced cancer

AIMS

To examine the relationship between cytochrome P450 2C19 (CYP2C19) genotype and expressed metabolic activity in 16 patients with advanced metastatic cancer.

METHODS

Individual CYP2C19 genotypes were determined by PCR-based amplification, followed by restriction fragment length analysis, and compared with observed CYP2C19 metabolic activity, as determined using the log hydroxylation index of omeprazole.

RESULTS

All 16 patients had an extensive metabolizer genotype. However, based on the antimode in a distribution of log omeprazole hydroxylation indices from healthy volunteers, four of the patients had a poor metabolizer phenotype and there was a general shift of the remaining 12 patients towards a slower metabolic phenotype. This suggests a reduction in metabolic activity for all patients relative to healthy volunteers. A careful analysis of patient medical records failed to reveal any drug interactions or other source for the observed discordance between genotype and phenotype.

CONCLUSIONS

There are no previous reports of a 'discordance' between genotype and expressed enzyme activity in cancer patients. Such a decrease in enzyme activity could have an impact on the efficacy and toxicity of chemotherapeutic agents and other drugs, used in standard oncology practice.

Inhibition of debrisoquine hydroxylation with quinidine in subjects with three or more functional CYP2D6 genes

AIMS

To study whether the CYP2D6 capacity in ultrarapid metabolizers of debrisoquine due to duplication/multiduplication of a functional CYP2D6 gene, can be 'normalised' by low doses of the CYP2D6 inhibitor quinidine and whether this is dose-dependent.

METHODS

Five ultrarapid metabolizers of debrisoquine with 3, 4 or 13 functional CYP2D6 genes were given single oral doses of 5, 10, 20, 40, 80 and 160 mg quinidine. Four hours after quinidine intake, 10 mg debrisoquine was given. Urine was collected for 6 h after debrisoquine administration. Debrisoquine and its 4-hydroxymetabolite were analysed by h.p.l.c. and the debrisoquine metabolic ratio (MR) was calculated.

RESULTS

Without quinidine the MR in the ultrarapid metabolizers ranged between 0.01 and 0.07. A dose-effect relationship could be established for quinidine with regard to the inhibitory effect on CYP2D6 activity. To reach an MR of 1-2, subjects with 3 or 4 functional genes required a quinidine dose of about 40 mg, while the sister and brother with 13 functional genes required about 80 mg quinidine. After 160 mg quinidine, the MRs, in the subjects with 3, 3, 4, 13 and 13 functional genes, were 12.6, 10.1, 9.2, 2.4 and 2.2, respectively.

CONCLUSIONS

A dose-effect relationship could be established for quinidine inhibition of CYP2D6 in ultrarapid metabolizers. The clinical use of low doses of quinidine as an inhibitor of CYP2D6 might be considered in ultrarapid metabolizers taking CYP2D6 metabolized drugs rather than giving increased doses of the drug. Normalizing the metabolic capacity of CYP2D6, by giving a low dose of quinidine, may solve the problem of 'treatment resistance' caused by ultrarapid metabolism.

IL-6 production in ovarian carcinoma is associated with histiotype and biological characteristics of the tumour and influences local immunity

The presence of interleukin (IL)-6 in peritoneal carcinomatous fluid (PCF) and its effect on immune cells composition in PCF in patients with advanced ovarian carcinoma was studied. In 21 out of 30 ovarian carcinoma patients, PCF IL-6 levels were found to exceed those seen in PCFs of patients with gastrointestinal cancer. IL-6 activity was higher in serous/mucinous than in endometrioid and undifferentiated ovarian carcinoma PCF (P = 0.05). Ovarian carcinoma PCF IL-6 activities were correlated with serum C-reactive protein levels (r = 0.65, P = 0.0000, n = 25). Ovarian carcinoma PCF leucocyte profile differed from that in blood with respect to: (i) lower percentage of NK and CD8+ and (ii) higher percentage of B and CD45RO+, CD14+ and HLA-DR+ cells. The proportions of CD45RO+ in blood were correlated with IL-6 levels in PCF. Corresponding to PCF ovarian carcinoma tumours were stained for the presence of Ki-67 antigen and p53. The highest proportions of Ki-67+ cells and cells showing accumulation of p53 were seen in undifferentiated tumours. A low grade of p53 staining was seen in tumours associated with high IL-6 levels in PCF. It was evident that IL-6 production (i) depended on the histiotype of the tumour, (ii) influenced the local immune system in favour of accumulation of B, and T memory cells, and (iii) was higher in patients lacking p53 accumulation.

Association of specific chromosome alterations with tumour phenotype in posterior uveal melanoma

Posterior uveal melanomas have recurrent alterations of chromosomes 1, 3, 6 and 8. In particular, changes of chromosomes 3 and 8 occur in association, appear to characterize those tumours with a ciliary body component, and have been shown to be of prognostic significance. The relevance of other chromosome alterations is less certain. We have performed cytogenetic analysis on 42 previously untreated primary posterior uveal melanomas. Of interest was the observation that as tumour size increased the involvement of specific chromosome changes, and the amount of chromosome abnormalities likewise increased. Loss, or partial deletions, of the short arm of chromosome 1 were found to associate with larger ciliary body melanomas; typically, loss of the short arm resulted from unbalanced translocations, the partners of which varied. Trisomy of chromosome 21 occurred more often in ciliary body melanomas, whilst rearrangements of chromosomes 6 and 11 were primarily related to choroidal melanomas. Our results imply that alterations of chromosome 1 are important in the progression of some uveal melanomas, and that other chromosome abnormalities, besides those of chromosomes 3 and 8, are associated with ocular tumours of particular locations.

Selected lines and inbred strains. Tools in the hunt for the genes involved in alcoholism

In their quest to elucidate the genetic influences contributing to alcoholism, researchers have long used selected lines and inbred strains of rodents. Selected lines are obtained by repeatedly mating those animals within a population that show extremely high or low values of the desired trait. Inbred strains are generated by mating male and female siblings, irrespective of any particular trait, over several generations. Both of these approaches have provided researchers with extensive knowledge about the genetic and neurobiological mechanisms contributing to alcohol-related traits. However, the use of these models is associated with some limitations, mostly resulting from the inbreeding involved in generating such lines and strains. Nevertheless, these models can offer some advantages over other genetic approaches, such as the analysis of quantitative trait loci or the generation of transgenic and knockout mice.

Quantitative trait locus analysis

Alcoholism is a quantitative disorder that is caused by the combined influences of numerous genes (i.e., quantitative trait loci [QTLs]) and environmental factors. To identify QTLs for alcoholism, researchers compare subject groups (e.g., inbred mouse strains) that differ in both their genetic makeup (i.e., genotype) and alcohol-related trait (e.g., sensitivity to certain alcohol effects). Using statistical tests one can then determine whether a specific gene or DNA region contributes to the trait of interest. This strategy requires that the relevant gene exists in several variants (i.e., is polymorphic). To conduct such QTL analyses, researchers study either a large population of mice that all differ in their genotypes or compare several strains, each of which has a fixed genotype. However, QTL analyses still have several limitations. Nevertheless, such studies already have identified several DNA regions and genes that may affect the response to alcohol and thus may contribute to the risk for alcoholism.

Extensive characterization of the immunophenotype and pattern of cytokine production by distinct subpopulations of normal human peripheral blood MHC II+/lineage- cells

Dendritic cells (DC) represent the most powerful professional antigen-presenting cells (APC) in the immune system. The aim of the present study was to analyse, on a single-cell basis by multiparametric flow cytometry with simultaneous four-colour staining and a two-step acquisition procedure, the immunophenotypic profile and cytokine production of DC from 67 normal whole peripheral blood (PB) samples. Two clearly different subsets of HLA-II+/lineage- were identified on the basis of their distinct phenotypic characteristics: one DC subset was CD33strong+ and CD123dim+ (0.16 +/- 0.06% of the PB nucleated cells and 55.9 +/- 11. 9% of all PB DC) and the other, CD33dim+ and CD123strong+ (0.12 +/- 0.04% of PB nucleated cells and 44.53 +/- 11.5% of all PB DC). Moreover, the former DC subpopulation clearly showed higher expression of the CD13 myeloid-associated antigen, the CD29 and CD58 adhesion molecules, the CD2, CD5 and CD86 costimulatory molecules, the CD32 IgG receptor and the CD11c complement receptor. In addition, these cells showed stronger HLA-DR and HLA-DQ expression and a higher reactivity for the IL-6 receptor alpha-chain (CD126) and for CD38. In contrast, the CD123strong+/CD33dim+ DC showed a stronger reactivity for the CD4 and CD45RA molecules, whereas they did not express the CD58, CD5, CD11c and CD13 antigens. Regarding cytokine production, our results show that while the CD33strong+/CD123dim+ DC are able to produce significant amounts of inflammatory cytokines, such as IL-1beta (97 +/- 5% of positive cells), IL-6 (96 +/- 1.1% of positive cells), IL-12 (81.5 +/- 15.5% of positive cells) and tumour necrosis factor-alpha (TNF-alpha) (84 +/- 22.1% of positive cells) as well as chemokines such as IL-8 (99 +/- 1% of positive cells), the functional ability of the CD123strong+/CD33dim+ DC subset to produce cytokines under the same conditions was almost null. Our results therefore clearly show the presence of two distinct subsets of DC in normal human PB, which differ not only in their immunophenotype but also in their functionality, as regards cytokine production.

Phenotype of adults with the 22q11 deletion syndrome: A review

22q11 deletion syndrome (22qDS) is due to microdeletions of chromosome region 22q11.2. Little is known about the phenotype of adults. We reviewed available case reports of adults (age >/=18 years) with 22qDS and compared the prevalence of key findings to those reported in a large European survey of 22qDS (497 children and 61 adults) [Ryan et al., 1997: J. Med. Genet. 34:798-804]. Fifty-five studies reported on 126 adults (83 women, 40 men, 3 unknown sex), mean age 29.6 years (SD = 8.7 years). Compared with the European survey, adults with 22qDS reviewed had a lower rate of CHD, 30% versus 75%; chi(2) = 88.65, df = 1, P < 0.0001, but higher rates of identified palate anomalies, 88% versus 15%; chi(2) = 37.45, df = 1, P < 0.0001, and learning difficulties, 94% versus 79%; chi(2) = 12.13, df = 1, P = < 0.0008. The most common finding reported was minor facial anomalies. Few reports provided details of minor physical anomalies. Psychiatric conditions were more prevalent, 36% versus 18%; chi(2)= 5.71, df = 1, P < 0.02, than in the survey: 60% of reviewed adults were transmitting parents (72% mothers) ascertained following diagnosis of affected offspring. They had lower rates of CHD, cleft palate, and psychiatric disorders but similar rates of learning disabilities, and other palate and facial anomalies compared with adults ascertained by other methods. The results suggest that learning disabilities and facial and palate anomalies may be key findings in 22qDS adults, but that ascertainment is a key factor in the observed phenotype. Comprehensive studies of adults with 22qDS identified independently of familial transmission are necessary to further delineate the phenotype of adults and to determine the natural history of the syndrome.

Op18/stathmin mediates multiple region-specific tubulin and microtubule-regulating activities

Oncoprotein18/stathmin (Op18) is a regulator of microtubule (MT) dynamics that binds tubulin heterodimers and destabilizes MTs by promoting catastrophes (i.e., transitions from growing to shrinking MTs). Here, we have performed a deletion analysis to mechanistically dissect Op18 with respect to (a) modulation of tubulin GTP hydrolysis and exchange, (b) tubulin binding in vitro, and (c) tubulin association and MT-regulating activities in intact cells. The data reveal distinct types of region-specific Op18 modulation of tubulin GTP metabolism, namely inhibition of nucleotide exchange and stimulation or inhibition of GTP hydrolysis. These regulatory activities are mediated via two-site cooperative binding to tubulin by multiple nonessential physically separated regions of Op18. In vitro analysis revealed that NH(2)- and COOH-terminal truncations of Op18 have opposite effects on the rates of tubulin GTP hydrolysis. Transfection of human leukemia cells with these two types of mutants result in similar decrease of MT content, which in both cases appeared independent of a simple tubulin sequestering mechanism. However, the NH(2)- and COOH-terminal-truncated Op18 mutants regulate MTs by distinct mechanisms as evidenced by morphological analysis of microinjected newt lung cells. Hence, mutant analysis shows that Op18 has the potential to regulate tubulin/MTs by more than one specific mechanism.

The influence of CYP2D6 activity on the kinetics of propafenone enantiomers in Chinese subjects

AIMS

To determine role of CYP2D6 activity in the pharmacokinetics of propafenone (PPF) enantiomers in native Chinese subjects.

METHODS

Sixteen extensive metabolizers (EMs) and one poor metabolizer (PM), whose phenotype had been previously assessed with dextromethorphan metabolic phenotyping, were enrolled. Blood samples (0 approximately 15 h) were taken after oral administration of a single dose (400 mg) of racemic-propafenone hydrochloride. A reverse-phase h.p.l.c. method with pre-column derivatization was employed to quantitate enantiomeric concentrations of propafenone in plasma.

RESULTS

For the EM subjects, S-PPF was less rapidly metabolized and had higher peak plasma concentrations than R-PPF (413+/-143 vs 291+/-109 ng ml-1, P<0.001). The AUC was markedly higher for S-PPF than for R-PPF (2214+/-776 vs 1639+/-630 microg h l-1, P<0.001), whereas the clearance of S-PPF was significantly lower than that of R-PPF (96.0+/-39.0 vs 138+/-78 l h-1, P<0.01). There were no differences in t1/2, and Cmax between the two isomers (P >0.05). In the one PM subject, not only did S-PPF appear to undergo less rapid metabolism than R-PPF, but the subject also showed 2 approximately 3 fold differences in Cmax, CL and AUC compared with EMs. The correlation coefficients (rs ) between dextromethorphan metabolic ratio (lg MR) and pharmacokinetic parameters (Cmax, CL and AUC) were 0.63, -0.87, 0.87 for S-PPF and 0. 57, -0.73, 0.86 for R-PPF, respectively.

CONCLUSIONS

Our results suggest that CYP2D6 activity contributes to the pharmacokinetic variability of propafenone enantiomers in Chinese subjects.

atSRp30, one of two SF2/ASF-like proteins from Arabidopsis thaliana, regulates splicing of specific plant genes

SR proteins are nuclear phosphoproteins with a characteristic Ser/Arg-rich domain and one or two RNA recognition motifs. They are highly conserved in animals and plants and play important roles in spliceosome assembly and alternative splicing regulation. We have now isolated and partially sequenced a plant protein, which crossreacts with antibodies to human SR proteins. The sequence of the corresponding cDNA and genomic clones from Arabidopsis revealed a protein, atSRp30, with strong similarity to the human SR protein SF2/ASF and to atSRp34/SR1, a previously identified SR protein, indicating that plants possess two SF2/ASF-like proteins. atSRp30 expresses alternatively spliced mRNA isoforms that are expressed differentially in various organs and during development. Overexpression of atSRp30 via a strong constitutive promoter resulted in changes in alternative splicing of several endogenous plant genes, including atSRp30 itself. Interestingly, atSRp30 overexpression resulted in a pronounced down-regulation of endogenous mRNA encoding full-length atSRp34/SR1 protein. Transgenic plants overexpressing atSRp30 showed morphological and developmental changes affecting mostly developmental phase transitions. atSRp30- and atSRp34/SR1-promoter-GUS constructs exhibited complementary expression patterns during early seedling development and root formation, with overlapping expression in floral tissues. The results of the structural and expression analyses of both genes suggest that atSRp34/SR1 acts as a general splicing factor, whereas atSRp30 functions as a specific splicing modulator.

Surface phenotype analysis of CD16+ monocytes from leukapheresis collections for peripheral blood progenitors

In peripheral blood progenitor cell (PBPC) collections from patients with solid tumour or haematological malignancy, monocytes were separated into two subpopulations. The majority of monocytes expressed CD14 at a high density without CD16 antigen (the CD14+CD16- monocytes). The remaining monocytes co-expressed CD14 and CD16 (the CD14+CD16+ monocytes). These CD14+CD16+ monocytes amounted to 20.6 +/- 15.8%, while those in peripheral blood (PB) obtained from healthy volunteers were 7.3 +/- 3.1% (P < 0.05). When subdividing the CD14+CD16+ monocytes into CD14brightCD16dim and CD14dimCD16bright cells, both populations were found to be increased in PBPC collections. Since typical CD14+CD16+ monocytes are the CD14dimCD16bright population, we compared the additional surface antigens on CD14dimCD16bright monocytes with those of CD14+CD16- monocytes. In PBPC collections, the CD14dimCD16bright monocytes exhibited lower levels of CD11b, CD15, CD33 and CD38 expression and higher levels of CD4, CD11a, CD11c and MHC class II, and also revealed a higher percentage of CD4+ cells and a lower percentage of CD15+ cells and CD38+ cells, compared with the CD14+CD16- monocytes. When compared with the CD14dimCD16bright monocytes in PB, those in PBPC collections exhibited higher expression of CD4 and lower expression of CD11b, and also showed higher percentages of CD4+ cells and CD38+ cells and a lower percentage of CD11b+ cells. These results suggest that PBPC collections may be rich in the CD14+CD16+ monocytes in which the proportion of the immature population is increased. It is likely that these monocytes participate in the haematological and immune recovery after PBPC transplantation.

A novel mutant gammac chain from a patient with typical phenotype of X-linked severe combined immunodeficiency (SCID) has partial signalling function for mediating IL-2 and IL-4 receptor action

Mutations of the common gamma (gammac) chain result in X-linked SCID (X-SCID), which is characterized by the reduction in number or absence of peripheral blood T cells and natural killer (NK) cells, with retention of normal numbers of B cells. In the present study we describe a novel mutant gammac chain of an X-SCID patient with a typical X-SCID phenotype. This mutant receptor subunit is able to associate with Jak3 to transduce a weak signal. The Jak3-specific action is demonstrated by the induction of gene expression through the haematopoietin receptor response element (HRRE) by IL-2 and IL-4 in the experimental model of transiently transfected hepatoma cells over-expressing Jak3. This result suggests that a threshold in the gammac-Jak3 interaction determines the X-SCID phenotype.

Reliability of the omeprazole hydroxylation index for CYP2C19 phenotyping: possible effect of age, liver disease and length of therapy

AIMS

To evaluate the reliability of the omeprazole hydroxylation index as a marker for polymorphic CYP2C19 activity in a Japanese population of healthy young subjects (n = 78) and patients with peptic ulcer (n = 72).

METHODS

Healthy subjects were administered a single dose of omeprazole (20 mg), whereas patients received 20 mg daily for at least 1 week. The ratio of the serum concentration of omeprazole to hydroxyomeprazole at 3 h postdose was determined and used as a measure of CYP2C19 activity. The CYP2C19 wild type (wt) gene and four mutant alleles associated with the poor metaboliser phenotype of (S)-mephenytoin, CYP2C19*2 in exon 5, CYP2C19*3 in exon 4, CYP2C19m4 in exon 9, and CYP2C19m3 in the initial codon were analysed.

RESULTS

In the healthy volunteer study there was complete concordance between genotype and phenotype. However, eight of the patients who had the EM genotype had a high value for their hydroxylation index, and were classified as phenotypic PMs. No CYP2C19m4 and CYP2C19m3 mutations were detected in the eight mismatched patients. They were all genotypic heterozygous EMs, elderly (> or = 65 years) and/or had hepatic disease. Therefore, impaired CYP2C19 activity combined with partial saturation of omeprazole metabolism during multiple dosing may have contributed to the discrepancy between CYP2C19 genotyping and phenotyping.

CONCLUSION

Although omeprazole has been used instead of mephenytoin as a probe for polymorphic CYP2C19, it does not appear to be reliable enough for clinical application in Japanese patients.

CYP2D6 polymorphism in a Gabonese population: contribution of the CYP2D6*2 and CYP2D6*17 alleles to the high prevalence of the intermediate metabolic phenotype

AIMS

To determine the molecular basis of the intermediate extensive metaboliser (EM) CYP2D6 phenotype in healthy Gabonese subjects.

METHODS

The CYP2D6 phenotype of 154 healthy Gabonese subjects was assessed by giving the subject a single dose of 30 mg dextromethorphan, and collecting their urine for the next 8 h. The CYP2D6 genotype was determined for 50 individuals of the EM phenotypic group by Southern blotting and various PCR-based procedures aimed at identifying different CYP2D6 alleles.

RESULTS

We found that in the studied Gabonese population, as compared with a French population, there is significantly higher frequency of intermediate EM phenotype having lower frequency of CYP2D6 PM alleles. To clarify this discrepancy phenotype-genotype relationship was studied. We found that the CYP2D6*17 and CYP2D6*2 alleles, prevalent in this black population, are characterised by their low capacity for dextromethorphan demethylation. Our data also show that the CYP2D6*1 allele is associated with the highest in vivo activity followed by the CYP2D6*2 allele and then the CYP2D6*17 allele.

CONCLUSIONS

The higher frequencies of the CYP2D6*2 and CYP2D6*17 alleles than the CYP2D6*1 allele account for the high frequency of the intermediate EM phenotype in this black population. The polymorphism of the CYP2D6 enzyme activity in African populations could have important implications for use of drugs that are substrates for CYP2D6 and have a narrow therapeutic window.

Normal and clonal B lineage cells can be distinguished by their differential expression of B cell antigens and adhesion molecules in peripheral blood from multiple myeloma (MM) patients--diagnostic and clinical implications

Human MM is a haematologic disorder characterized by the accumulation of malignant plasma cells (PC), primarily in the bone marrow (BM). Although these cells characteristically home to the BM, in recent years several groups have detected the presence of related malignant B cells in the peripheral blood (PB) which could be implicated in the progression and spread of the disease. However, the proportion and origin of these clonotypic circulating B cells is still controversial. In this study, using a triple-staining flow cytometric procedure and a whole blood lysis method, PB B lineage cells could be divided into two populations according to their distinct repertoires of cell adhesion molecules and B cell antigens in untreated MM patients. The results show that: (i) the percentage and the absolute number of PB CD19+ B cells were decreased in MM patients compared with controls; (ii) the quantity and percentage of B cell antigens (CD20, CD22, CD24, DR, CD138) and adhesion molecules (beta1- and beta2-integrins, CD44, CD54, CD56, CD61 and CD62L) expressed by these PB CD19+ cells of MM patients and healthy subjects were similar and all of them were virtually polyclonal cells; (iii) a very minor circulating CD19-CD38++CD45-/dim subset was also detected which expressed CD138 (B-B4) (high intensity), monoclonal cytoplasmic immunoglobulin (cIg), and was negative for pan-B antigens (CD19, CD20, CD24, DR), surface immunoglobulin (sIg) and several adhesion molecules such as CD62L, CD18 and CD11a; this CD19-CD38++CD45-/dim CD138++ subset was not found in normal blood and exhibited a phenotypic profile which was closely related to that of malignant BM plasma cells, with the exception of the CD56 antigen. Polymerase chain reaction (PCR) analysis of IgH clonotypic rearrangements confirmed these results. We postulate that, in MM patients, circulating B lineage cells may be divided into two different categories: polyclonal CD19+ B cells and a very minor proportion of clonal CD138++ PC that escape from the BM.

Contrasting phenotypes of liver-infiltrating leucocytes isolated from MCMV-infected BALB/c and C57BL/6 mice

We characterized liver-infiltrating leucocytes (LIL) from BALB/c and C57BL/6 mice 0-56 days after murine cytomegalovirus (MCMV) infection. Inflammation clears from C57BL/6 mice 4-5 weeks post infection (pi), but persists for several months in BALB/c mice. The LIL obtained were 60-80% Thy 1.2+ by flow cytometry. The percentage of CD8+ cells rose sharply in all mice 7 days pi, with little decrease in BALB/c mice by day 56. CD4-CD8-Thy 1.2+/TCR alpha beta + cells were more prevalent in LIL than lymph node cells (LNC) irrespective of MCMV infection, whilst infection increased the proportion of CD8+ L-selectin- LIL (but not LNC). LIL from both mouse strains demonstrated cytotoxic activity against YAC-1 cells, but only LIL from BALB/c mice proliferated spontaneously ex vivo 21 days pi, as measured by tritiated thymidine incorporation. BALB/c LIL produced IFN gamma and IgG2a 7-21 days pi, whilst IL-10 secretion was similar in both strains. Thus, persistent hepatitis in BALB/c mice is associated with activation and proliferation of intrahepatic leucocytes with some bias towards a Th1 response.

Activation antigen expression on human T cells. I. Analysis by two-colour flow cytometry of umbilical cord blood, adult blood and lymphoid tissue

Activation antigens (actags) were detected on T cells at low levels of intensity by carefully defining negative cells with a panel of control antibodies. The mean percentage of blood T cells from healthy volunteers that expressed actags were 22% (CD25), 54% (CD26), 38% (CD38), 12% (CD54), 6% (CD69) and 21% (HLA-DR). The variability of actag expression detected by this sensitive method was determined on healthy volunteers by repeated estimation over a year. The percentage of T cells expressing CD25 and CD26 varied no more than repeated estimation of the CD4 T cell subset, whereas other actags showed greater variability. The antigen density of these actags on T cells was determined in relation to CD4 antigen density, and for most actags ranged from 10% to 75% of the level of CD4 antigen density except for CD7 and HLA-DR, which could exceed that of CD4. Different degrees of actag expression characterized T cells from different blood and lymphoid tissues. CD26, CD38 and CD45RA were universally expressed in cord blood at higher antigen density than adult blood. This immature pattern was consistent with recent thymic emigration. CD25, CD45RO, CD54 and HLA-DR progressively increased from cord blood through adult blood to lymphoid tissues, consistent with antigen-driven activation, whereas CD26 and CD45RA decreased. CD69, a very early activation antigen, abruptly increased in lymphoid tissue, exceeding CD25 by two-to-three-fold and suggesting a pre-activation state that may not involve commitment to antigen-driven proliferation. CD7 and CD38 expression was higher in cord blood and lymphoid tissue than in adult blood, indicating both an antigen-independent and -dependent up-regulation.

In vitro characterization of rat bone marrow-derived dendritic cells and their precursors

Although the rat is commonly used for basic immunology and transplantation research, phenotypic and functional characterization of rat dendritic cells (DCs) lags behind similar studies in the human and mouse. Therefore, these features were examined using DCs propagated from cultures of rat bone marrow maintained in a medium supplemented with granulocyte-monocyte colony-stimulating factor. Analysis of cytospin preparations of cultured cells showd that DCs arise from OX7+ myelomonocytic precursors. Typical mature rat DCs were morphologically similar to their mouse and human counterparts and expressed major histocompatibility complex (MHC) class II (common part determinant of Ia), OX62 (integrin molecule), OX7 (CD90), ICAM-1 (CD54), and CTLA4 counterreceptor, but were negative for OX8 (CD8), OX19 (CD5), W3/25 (CD4), and ED2, a rat macrophage marker. Functional analysis of OX62+ sorted DCs showed that they could effectively present the soluble antigen ovalbumin to naive T cells in vitro. A combination of anti-MHC class II monoclonal antibody and CTLA4-immunoglobulin inhibited allostimulatory ability more effectively than either reagent alone. Implications for studying the role of DCs in immune responses in the rat are discussed.

Culture of tumour-infiltrating lymphocytes from melanoma and colon carcinoma: removal of tumour cells does not affect tumour-specificity

The therapeutic potential of adoptive therapy using tumour-infiltrating lymphocytes (TIL) has been demonstrated in a number of clinical trials. However, freshly isolated tumour-infiltrating lymphocytes (TIL) are often impaired in their proliferative and cytotoxic responses, which limits their use in immunotherapy. Several hypotheses with regard to the poor effector function of TIL have been postulated, including the production of immunosuppressive factors by tumour cells. In a previous paper we reported the efficient expansion of immunoreactive TIL from a variety of solid tumours by stimulation with a combination of monoclonal antibodies (mAbs) against CD3 and CD28. In the present study we analysed whether this protocol would be improved by the removal of tumour cells at the start of the culture. We tested a highly immunogenic tumour, melanoma, and a poorly immunogenic tumour, colon carcinoma. Removal of tumour cells highly improved anti-CD3/CD28 stimulated expansion of TIL from colon carcinoma, resulting in a significantly higher percentage of potentially tumour-specific CD8-positive T-cells and a reduced CD4/CD8 ratio compared to expansion in the presence of tumour cells. In contrast, expansion and CD4/CD8 ratio of melanoma-derived TIL was not significantly influenced by the removal of autologous tumour cells. CD3/CD28-stimulated melanoma TIL cultured in the absence of tumour cells showed specific lysis of autologous tumour cells comparable to melanoma TIL cultured in high-dose IL2. However, no cytotoxicity could be detected in colon TIL irrespective of the culture conditions used. On the other hand, 3/8 colon carcinoma TIL cultures and 9/12 melanoma-derived TIL cultures showed IFN gamma secretion upon stimulation with autologous tumour cells. We conclude that stimulation of TIL with a combination of mAbs to CD3 and CD28 in the absence of tumour cells induces efficient expansion of potentially tumour-specific cells from a highly and a poorly immunogenic tumour. Removal of tumour cells does not have a negative influence on the generation of tumour-specific T cells, while cell yield improves. Therefore, for large-scale cultures this protocol can efficiently induce the outgrowth of tumour-specific TIL, at the same time providing a useful source of autologous tumour cells that can be stored and used to direct or test antitumour specificity.

The Collaborative Study on the Genetics of Alcoholism

In 1989 the National Institute on Alcohol Abuse and Alcoholism initiated the Collaborative Study on the Genetics of Alcoholism (COGA), a large-scale, multidisciplinary research program to investigate the genetic components of the susceptibility to alcohol abuse and dependence. COGA involves six research centers located across the United States. The following articles by leading COGA investigators provide an overview of the design of this study and its components and of the challenges inherent to an endeavor of this scope. The authors also present some of the results obtained through COGA to date. Although sometimes still preliminary in nature, these findings reflect COGA's potential for greatly improving our knowledge of the complex disorder of alcoholism.

Inter- and Intraspecific Variation in Wild-type and Single Female-derived Populations of Xiphinema americanum-group Nematodes

Ten populations of Xiphinema americanum-group nematodes were reared from individual females to evaluate inter- and intraspecific variation under identical host and environmental conditions. Data indicated that morphometric variability of X. americanum was the result of genetic variation rather than phenotypic plasticity and that genetic heterogeneity was greater than previously thought. Morphometrics of single female derived (SFD) populations identified different genotypes present in the field populations. Stylet length was the least variable morphometric character of SFD populations, but collectively stylet measurements of all individuals formed an uninterrupted continuum ranging from 107-148 mum. Range and frequency of stylet measurements of field populations could be accounted for by the relative proportion of different genotypes in the population. Nine SFD populations were identified as X. americanum sensu stricto, and one SFD population was similar to X. californicum.

Monovalent antibodies directed to transformation-sensitive membrane components inhibit the process of viral transformation

Monovalent antibodies (Fab) directed to two classes of transformation-sensitive cell surface components, ganglioside and galactoprotein a (Gap a), inhibit the process of oncogenic viral transformation of cells. Mouse 3T3 cells infected with murine sarcoma virus were not transformed in terms of morphology change and enhancement of sugar uptake when the infected cells were cultured in the presence of monovalent antibodies directed to GM(1) ganglioside or to Gap a. Transformation inhibitory activity of these cell surface ligands was not related to cell growth inhibition because the monovalent antibodies to globoside and divalent Con A were growth inhibitory but did not inhibit oncogenic transformation. Neither anti-GM(1) Fab nor anti-Gap a Fab inhibited virus production. The transformation inhibitory activity of antiganglioside and anti-Gap a Fab was additionally assessed by inhibiting the transformed phenotype in NRK cell lines with mutants of avian sarcoma virus that are temperature sensitive for expression of the transformation phenotype (NRK/LA25). In this cell line, the GM(3) ganglioside (not GM(1)) and Gap a were transformation-sensitive cell surface components. The expression at permissive temperature of transformed phenotypes, such as morphology change and capability of growth in 0.3% agar, was inhibited by preincubation of the cells with anti-GM(3) Fab or anti-Gap a Fab.GM(3) labeling of NRK/LA25 cells decreased at permissive temperature, whereas preincubation of cells with anti-Gap a, which induces the inhibition of transformation after a temperature shift, prevented the decline of GM(3) label on the cell surface. The data suggest a possible correlation between GM(3) and Gap a expression. Application of monovalent antibodies to these transformation-sensitive components may prevent changes of these components on cell surfaces, and thus may result in abortion of phenotypic expression of transformation, although the transforming gene (src) has been set active. These results indicate that pericellular structures influence gene expression.