Somatic mutations in the thyrotropin receptor gene cause hyperfunctioning thyroid adenomas

The pituitary hormone thyrotropin stimulates the function, expression of differentiation and growth of thyrocytes by cyclic AMP-dependent mechanisms. Tissue hyperplasia and hyperthyroidism are therefore expected to result when activation of the adenylyl cyclase-cAMP cascade is unregulated. This is observed in several situations, including when somatic mutations impair the GTPase activity of the G protein Gsa (ref 6, 7). Such a mechanism is probably responsible for the development of a minority of monoclonal hyperfunctioning thyroid adenomas. Here we identify somatic mutations in the carboxy-terminal portion of the third cytoplasmic loop of the thyrotropin receptor in three out of eleven hyperfunctioning thyroid adenomas. These mutations are restricted to tumour tissue and involve two different residues (aspartic acid at position 619 to glycine in two cases, and alanine at position 623 to isoleucine in one case). The mutant receptors confer constitutive activation of adenylyl cyclase when tested by transfection in COS cells. This shows that G-protein-coupled receptors are susceptible to constitutive activation by spontaneous somatic mutations and may thus behave as proto-oncogenes.

Cold-adapted enzymes: from fundamentals to biotechnology

Psychrophilic enzymes produced by cold-adapted microorganisms display a high catalytic efficiency and are most often, if not always, associated with high thermosensitivity. Using X-ray crystallography, these properties are beginning to become understood, and the rules governing their adaptation to cold appear to be relatively diverse. The application of these enzymes offers considerable potential to the biotechnology industry, for example, in the detergent and food industries, for the production of fine chemicals and in bioremediation processes.

The YDp plasmids: a uniform set of vectors bearing versatile gene disruption cassettes for Saccharomyces cerevisiae

The YDp plasmids (Yeast Disruption plasmids) are pUC9 vectors bearing a set of yeast gene disruption cassettes, all uniform in structure and differing only in the selectable marker used (HIS3, LEU2, LYS2, TRP1 or URA3). The markers, surrounded by translational termination codons, are embedded in the slightly modified sequence of the pUC9 multiple cloning sites.

Germline mutations in the thyrotropin receptor gene cause non-autoimmune autosomal dominant hyperthyroidism

The thyrotropin receptor (TSHR), a member of the large family of G protein-coupled receptors, controls both the function and growth of thyroid cells via stimulation of adenylyl cyclase. We report two different mutations in the TSHR gene of affected members of two large pedigrees with non-autoimmune autosomal dominant hyperthyroidism (toxic thyroid hyperplasia), that involve residues in the third (Val509Ala) and seventh (Cys672Tyr) transmembrane segments. When expressed by transfection in COS-7 cells, the mutated receptors display a higher constitutive activation of adenylyl cyclase than wild type. This new disease entity is the germline counterpart of hyperfunctioning thyroid adenomas, in which different somatic mutations with similar functional characteristics have been demonstrated.

The proteasome inhibitor lactacystin induces apoptosis and sensitizes chemo- and radioresistant human chronic lymphocytic leukaemia lymphocytes to TNF-alpha-initiated apoptosis

Apoptosis can be triggered by cytotoxic agents and radiation currently used in cancer treatment. However, the apoptotic response appears to vary between cell types (normal or transformed) and between types of malignancy. Thus, irradiation induces apoptosis in normal human lymphocytes but not in lymphocytes derived from a subset of chronic lymphocytic leukaemia (CLL). Moreover, in this subset, spontaneous apoptosis is inhibited by irradiation. Why irradiation does not allow the initiation of the apoptotic death pathway could be explained, at least in part, and in agreement with recent findings on experimental models, by the activation of the transcriptional factor NF-kappaB, which is able to inhibit apoptotic cell response. Low doses (at which no effect is observed with normal human lymphocytes) of the highly specific proteasome inhibitor lactacystin are sufficient to trigger apoptosis in these malignant cells. Proteasome inhibition by lactacystin prevents the nuclear translocation of both p50 and p65 NF-kappaB subunits and sensitizes these cells to apoptosis by tumour necrosis factor (TNF)-alpha treatment. As this subset of CLL is totally resistant to any treatment, proteasome inhibition by lactacystin provides a new therapeutic approach to be explored, considering the sensitivity of malignant CLL-derived lymphocytes to be quite different from that of normal human lymphocytes.

Iodine and selenium deficiency associated with cretinism in northern Zaire

Selenium status was determined in an endemic-goiter area and in a control area of Zaire. Compared with the reference values of a noniodine-deficient area, serum selenium in subjects living in the core of the northern Zaire endemic-goiter belt (Karawa villages) was seven times lower in 52 school-children and similarly low in 23 cretins; erythrocyte glutathione peroxidase (RBC-GPX) was five times lower in schoolchildren and still two times lower in cretins (P = 0.004). In a less severely iodine-deficient city of the same endemia (Businga), selenium status was moderately altered. RBC-GPX activity was linearly associated with serum selenium concentration up to a value of 1140 nmol/L and leveled off at approximately 15 U/g Hb at greater selenium concentration. At Karawa villages, selenium supplementation normalized both the serum selenium and the RBC-GPX. This combined iodine and selenium deficiency could be associated with the elevated frequency of endemic myxedematous cretinism in Central Africa.

Increased sensitivity of CLL-derived lymphocytes to apoptotic death activation by the proteasome-specific inhibitor lactacystin

Ubiquitin-proteasome-dependent protein processing appears to be an essential component in the control of radiation-induced apoptosis in human lymphocytes. This control is altered in chronic lymphocytic leukaemia (CLL), compared to that of normal human lymphocytes which mainly showed high apoptotic values after irradiation, but in some cases no sensitivity was observed. Interestingly, lactacystin activated the apoptotic pathway in both radio-resistant and sensitive CLL cells, at doses which had no effect in normal cells where significantly higher concentrations were required. Therefore the resistance of some CLL cells to apoptosis initiation by radiation does not correlate to observed increased sensitivity to lactacystin. The nuclear level of the transcription factor NF-kappaB or the cytoplasmic level of IkappaBalpha remained unaltered upon irradiation or lactacystin CLL cells treatment, suggesting that the activity of the other factors involved in apoptotic death control were altered through proteasomal inhibition. These results strongly suggest an essential role of the ubiquitin system in apoptotic cell death control in CLL lymphocytes. The inhibition of proteasome-ubiquitin-dependent processing could be a discriminatory apoptotic stimulus between normal versus malignant lymphocytes and therefore might potentially be of use in this specific human pathology.

Thyrotropin controls transcription of the thyroglobulin gene

The availability of rat thyroglobulin cDNA clones was exploited to study the regulation of thyroglobulin gene transcription by thyrotropin (TSH). Groups of rats were subjected to treatments leading to reduction or increase in the rat serum TSH (rTSH) levels. Thyroid gland nuclei were isolated, incubated in vitro in the presence of 32P-labeled uridine triphosphate, and thyroglobulin transcripts were quantitated by hybridization to immobilized rat thyroglobulin cDNA clones. Transcription of the thyroglobulin gene was found to be very active in thyroid nuclei from control animals. It represented about 10% of total RNA polymerase II activity. Chronic hyperstimulation of the thyroid glands with endogenous rTSH was achieved in rats treated with the goitrogen propylthiouracil. No significant increase of thyroglobulin gene transcription could be measured in thyroid nuclei from these animals. On the contrary, a dramatic decrease in thyroglobulin gene transcription was observed in those animals in which endogenous rTSH levels had been suppressed by hypophysectomy or by the administration of triiodothyronine. Injection of exogenous bovine TSH in such animals readily restored transcriptional activity of the gene. Our results identify transcription as an important regulatory step involved in TSH action. They suggest that normal TSH levels induce close to maximal expression of the thyroglobulin gene but that continuous presence of TSH is required in order to maintain the gene in an activated state.

Hairy-cell leukaemia with polyarteritis nodosa

In four patients a systemic vasculitis similar to polyarteritis nodosa developed within 2 years of the onset of hairy-cell leukaemia. Arteriographic studies in two patients revealed microaneurysms, and biopsy specimens in three patients revealed a vasculitis affecting medium-sized vessels. Blood neutrophilia and neutrophilic vascular infiltrate were absent. One patient had circulating immune complexes. Two patients responded to corticosteroids alone, one required cyclophosphamide as well as steroids, and one improved without chemotherapy. The association of vasculitis with hairy-cell leukaemia may provide insight into the pathogenesis of arteritis.

Production of matrix metalloproteinase-9 in early stage B-CLL: suppression by interferons

Besides vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF), matrix metalloproteinases (MMPs) play critical roles in angiogenesis, tumor invasion and metastasis. Increased angiogenesis is observed in chronic B lymphocytic leukemia (B-CLL) and published data reported VEGF and bFGF production in this disease. The purpose of this study was to investigate MMP expression in early stage B-CLL. Elevated MMP-9 concentrations were detected by ELISA in the sera of B-CLL patients (median level 250 ng/ml) compared with healthy donors (67 ng/ml) (P < 0.0001), and immunostaining with antibodies against MMP-9 and B cell antigens (CD19, CD23) substantiated the presence of MMP-9 in tumoral B lymphocytes. By using RT-PCR, ELISA and zymography experiments, we confirmed that B-CLL cells expressed and released the pro-form of MMP-9 with Mr 92 kDa (158-1300 pg/ml/10(6) cells/48 h), p-aminophenylmercuric acetate generating a 82 kDa active form. In contrast, the production of MMP-9 by normal counterpart B cells was significantly low (28-169 pg/ml/10(6)cells/48 h). Moreover, B-CLL culture supernatants contained bFGF (median levels 17 pg/ml/10(6) cells/48 h), VEGF (1.4 pg/ml/10(6) cells/48 h) and TNF-alpha (0.2 pg/ml/10(6) cells/48 h). TNF-alpha and VEGF antibodies blocked MMP-9 at the mRNA and protein levels. Interferons (IFNs) type I or type II repressed MMP-9 gelatinolytic activity in a dose and time dependency, and this was reflected by a parallel inhibition of MMP-9 mRNA and protein. IFNs however did not affect the production of bFGF, VEGF and TNF-alpha. Together, our data show that B-CLL lymphocytes synthesize MMP-9 and emphasize the specific inhibitory actions of IFNs on its expression.

Regulation of CD26/DPPIV gene expression by interferons and retinoic acid in tumor B cells

Interferons (IFNs alpha, beta and gamma) and all trans retinoic acid (RA) have the ability to activate genes with GAS sites. We have found that the promoter of CD26/dipeptidylpeptidase IV (DPPIV) contains a consensus GAS site TTCnnnGAA located at bp-35 to -27, and computer analysis confirmed this sequence to be a putative Stat binding site. Consistent with this finding, we show that IFNs and RA rapidly enhanced CD26 gene and protein expression in chronic B lymphocytic leukemia (B-CLL) cells. Immunoblot analyses revealed that unstimulated B-CLL cells expressed detectable levels of serine/tyrosine-phosphorylated Stat1alpha, and RA and IFN-gamma treatment led to increased levels of tyrosine phosphorylation of Stat1alpha and its nuclear accumulation. As shown by electrophoretic mobility shift assay, RA and IFN-gamma increased the binding of a nuclear protein to the GAS-CD26 element. Shift-Western blotting identified Stat1alpha as the GAS-CD26 binding factor. Augmented levels of CD26 protein in malignant B cells cultured with IFNs or RA coincided with the enhancement of DPPIV activity. Taken together, our results are in favor of the IFN-/RA-mediated upregulation of CD26/DPPIV in B-CLL through the signaling pathway involving Stat1alpha and the GAS response element of CD26 promoter.

Non-Hodgkin's lymphoma of the testis: a retrospective study of 84 patients treated in the French anticancer centres

Primary non-Hodgkin's lymphoma of the testicle is rare. We analysed cases treated in French anticancer centres from 1969 to 1995. All cases were reviewed and classified according to the R.E.A.L. Classification. Eighty-four cases were included in this study. The median age was 67 years (17-85). Disease was classified as stages I in 42 cases, stages II in 19 and stages III-IV in 23. Diffuse large B-cell lymphoma was diagnosed in 75% of cases. Treatment included orchidectomy and radiotherapy and/or chemotherapy. A complete response was obtained in 72.6% of the patient population and in 100%, 68% and 33% of stage I, II and III-IV disease respectively. Recurrence occurred in 32 cases and the most frequent site was the central nervous system: six of these patients presented stage I disease. Median overall survival was 32 months for the entire population, 52 months for stage I, 32 months for stage II, and 12 months for stage III-IV cases (P < 0.0001). Among patients presenting stage I disease, no difference was found between those treated with combined surgery and chemotherapy or surgery followed or not followed by radiotherapy. This study confirms that non-Hodgkin's lymphoma of the testicle carries a poor prognosis. Systemic adjuvant chemotherapy should be discussed because of the high recurrence rate. Inclusion of these cases in large co-operative prospective studies is recommended.

In vitro radiation-induced apoptosis and early response to low-dose radiotherapy in non-Hodgkin's lymphomas

PURPOSE

Prospective investigation of spontaneous and in vitro radiation-induced apoptosis to predict early response to palliative radiotherapy in patients with non-Hodgkin's lymphomas.

PATIENTS AND METHODS

Fine-needle sampling was performed in 28 tumor sites (26 patients) and yielded adequate cell numbers in 27 cases. Apoptotic cells were counted by fluorescence microscopy immediately after sampling and after 24-h culture (spontaneous apoptosis) and 24 h after 2- and 10-Gy in vitro irradiation (radiation-induced apoptosis). Early response to low-dose in vivo radiotherapy (mostly 4 Gy in two fractions over 3 days) was evaluated 15 days after treatment.

RESULTS

The tumor response rates at 15 days were 11 (39%) complete responses, nine (32%) responses of greater than 50% reduction in volume, six (21%) responses of less than 50% reduction in volume and two (7%) cases of no response. Tumors achieving complete or major response after in vivo irradiation had higher percentages of apoptotic cells after in vitro irradiation, while no significant differences in terms of spontaneous apoptosis were observed between responders and non-responders.

CONCLUSION

Spontaneous and in vitro radiation-induced apoptosis can be easily and quickly assessed on cells obtained by fine-needle sampling of non-Hodgkin's lymphoma lesions. The present results suggest that in vitro radiation-induced apoptosis could be used as a predictive assay of early response to low-dose in vivo irradiation in patients with non-Hodgkin's lymphomas.

Mature full-thickness articular cartilage explants attached to bone are physiologically stable over long-term culture in serum-free media

Mature tissue explants containing the entire depth of articular cartilage, calcified and uncalcified, attached to a thin layer of subchondral bone were isolated from bovine humeral heads of 1-2-year-old steers. These explants were placed in defined serum-free culture medium for a period of 3 weeks to investigate their biological and mechanical stability and thus to determine their potential utility in studies of cartilage physiology. Tissue mass remained constant over the culture period and no evident tissue swelling or distortion was observed. Chondrocytes were viable in all zones at the time of tissue isolation and throughout the culture period, with the exception of a thin layer of cells at the articular surface and the cut radial edge of the disks. Proteoglycan metabolism attained a steady state after 5 days of culture when the rate of loss of proteoglycan to culture media was compensated by new synthesis to maintain a stable proteoglycan content. Collagen metabolism was also stable with a constant content of type II collagen and a constant content of denatured collagen II throughout culture; the content of the C-propeptide of type II procollagen as a measure of procollagen synthesis, dropped slightly during the first week to attain a steady state after that time. Dynamic and equilibrium mechanical properties of these explant disks were also stable confirming maintenance of these tissue properties during long-term culture. In addition, the disk geometry of the system, with the cut surface in the bone parallel to the intact articular surface, is well-suited to study tissue regulation by mechanical load. Taken together, the stability of these indicators of tissue physiology indicates the maintenance in serum-free conditions of normal metabolism for organ cultures containing full-depth mature articular cartilage attached to bone.

Cognitive-behavioral treatment for adolescent pathological gamblers

This study evaluated the effectiveness of a cognitive-behavioral treatment for adolescent pathological gamblers. Perception of control and severity of the problem served as dependent variables. Four adolescent pathological gamblers meeting DSM-III-R criteria were treated in a multiple baseline design across individuals. Results showed clinically significant changes for all subjects; they remained abstinent at 1-, 4-, and 6-month follow-ups. The clinical implications of these results are discussed.

High dose chemotherapy and autologous bone marrow transplantation in refractory Hodgkin's disease

Seventeen patients with Hodgkin's disease (HD) were treated with high-dose chemotherapy followed by autologous bone marrow transplantation (ABMT). Eleven patients were resistant to initial therapy. Three patients had relapsed and were still responders to second or third line therapy. Three patients had relapsed but were progressing under second or third line therapy. Pre-ABMT chemotherapy included high dose cyclophosphamide in all patients (50 mg Kg-1 day-1 bolus for 4 days), most often associated with BCNU or CCNU, aracytine and 6 thioguanine. Four patients received additional TBI (10 Gy). In 9 patients complete remission (CR) was achieved, 4 failed to respond and 4 cases were not evaluable due to early death. Among CR patients, 2 died from late toxicity, 4 relapsed between the 2nd and 5th months, but 3 patients remain in CR, off therapy at 25+, 43+, and 66+ months, including 1/11 initially resistant and 2/6 who had relapsed. There were 9 treatment related deaths: 6 due to infection, 1 cardiac failure and 2 multiorgan failure. The high complete response rate in these heavily pretreated patients suggests that there may be an indication for high dose therapy earlier in resistant HD. Moreover under such conditions, treatment related morbidity would be expected to be lower.

Thyroid adenocarcinomas secondary to tissue-specific expression of simian virus-40 large T-antigen in transgenic mice

A hybrid gene comprising the bovine thyroglobulin gene promoter and the coding region for the simian virus-40 large T- and small t-antigens was used to generate 30 transgenic mice by microinjection into the pronuclei of single cell embryos. All animals except three developed, as single primitive pathology, a dramatic enlargement of the thyroid gland. Compression of trachea and esophagus, accompanied by dyspnea, inspiratory stridor, and dysphagia, led to a progressive cachexia and premature death attributed to respiratory failure. Despite the large thyroid volume, T4 levels were abnormally low, and the progression of the syndrome could be delayed by a substitutive treatment with thyroid hormones. The rapid evolution of the disease, leading to the death of most founder transgenic animals before the breeding age, prevented transmission of the transgene to their offspring. Only two transgenic lines are presently surviving. Immunohistochemical analysis of the tissues revealed a specific expression of the simian virus-40 antigens in the thyroid cells. Hyperplasia was already obvious at birth. Older animals displayed moderately to poorly differentiated thyroid adenocarcinomas. Electron microscopy revealed, however, the persistence of cell polarity and the presence of microfollicles between the densely packed cells. Cell lines derived from these large T-expressing thyroids were shown to have lost expression of both thyroglobulin and thyroperoxidase, while expressing low levels of TSH receptors. These transgenic mice could constitute an interesting model of aggressive adenocarcinoma, sharing phenotypical similarities with the anaplastic type of human thyroid tumors.

Evidence for induction of the ornithine transcarbamylase expression in Alzheimer's disease

To more rapidly identify candidate genes located within chromosomal regions of interest defined by genome scan studies in Alzheimer's disease (AD), we have developed a customized microarray containing all the ORFs (n=2741) located within nine of these regions. Levels of gene expression were assessed in total RNA from brain tissue of 12 controls and 12 AD patients. Of all genes showing differential expression, we focused on the ornithine transcarbamylase (OTC) gene on Xp21.1., a key enzyme of the urea cycle which we found to be expressed in AD brains but not in controls, as confirmed by RT-PCR. We also detected mRNA expression of all the other urea cycle enzymes in AD brains. Immunochemistry experiments revealed that the OTC expression was strictly restricted to vascular endothelial cells in brain. Furthermore, OTC activity was 880% increased in the CSF of probable AD cases compared with controls. We analysed the association of the OTC -389 G/A and -241 A/G promoter polymorphisms with the risk of developing AD. We observed that rare haplotypes may be associated with the risk of AD through a possible modulation of the methylation of the OTC promoter. In conclusion, our results suggest the involvement of a new pathway in AD brains involving the urea cycle.

Improved joint health in subjects with severe haemophilia A treated prophylactically with recombinant factor VIII Fc fusion protein

INTRODUCTION

Joint arthropathy is the long-term consequence of joint bleeding in people with severe haemophilia.

AIM

This study assessed change in joint health over time in subjects receiving recombinant factor VIII Fc fusion protein (rFVIIIFc) prophylaxis.

METHODS

ALONG is the phase 3 pivotal study in which the benefit of rFVIIIFc as a prophylactic treatment for bleeding control was shown in previously treated severe haemophilia patients ≥12 years of age (arm 1: 25-65 IU/kg every 3-5 days, arm 2: 65 IU/kg weekly and arm 3: episodic). After completing ALONG, subjects had the option to enrol into the extension study (ASPIRE). This interim, post hoc analysis assessed changes in joint health over ~2.8 years in these patients.

RESULTS

Forty-seven subjects had modified Haemophilia Joint Health Score (mHJHS) data at A-LONG baseline, ASPIRE baseline and ASPIRE Year 1 and Year 2. Compared with A-LONG baseline (23.4), mean improvement at ASPIRE Year 2 was -4.1 (95% confidence interval [CI], -6.5, -1.8; P = .001). Regardless of prestudy treatment regimen, subjects showed continuous improvement in mHJHS from A-LONG baseline through ASPIRE Year 2 (prestudy prophylaxis: -2.4, P = .09; prestudy episodic treatment: -7.2, P = .003). Benefits were seen in subjects with target joints (-5.6, P = .005) as well as those with severe arthropathy (-8.8, P = .02). The mHJHS components with the greatest improvement at ASPIRE Year 2 were swelling (-1.4, P = .008), range of motion (-1.1, P = .03) and strength (-0.8, P = .04).

CONCLUSIONS

Prophylaxis with rFVIIIFc may improve joint health over time regardless of prestudy prophylaxis or episodic treatment regimens.

Impact of REV-ERB alpha gene polymorphisms on obesity phenotypes in adult and adolescent samples

BACKGROUND

REV-ERBα has been shown to regulate adipogenesis and lipid metabolism as well as to link the circadian timing system to whole body metabolic homeostasis. We thus tested whether polymorphisms in REV-ERBα could be associated with metabolic phenotypes in human population samples.

METHODS

We analyzed the associations between 5 REV-ERBα polymorphisms and anthropometric (body weight, body mass index (BMI), waist and hip circumferences), biochemical (plasma lipid, glucose and insulin levels) and clinical (systolic and diastolic blood pressure) variables in three population-based studies (MONICA Lille n=1155 adults, MONA LISA Lille n=1170 adults and HELENA n=1155 adolescents). We assessed in vitro, the potential influence of one REV-ERBα polymorphism in transient transfection assays using two different cell lines.

RESULTS

We observed significant and consistent associations between the T minor allele of the REV-ERBα rs2071427 polymorphism (located in intron 1) and higher BMI (mean allele effect=+0.33 kg m(-2)) in the MONICA Lille (P=0.02), MONA LISA (P=0.02) and HELENA (P=0.03) studies. The odds ratios for obesity associated with this allele were 1.67 (1.00-2.79) (P=0.05) in MONICA Lille, 1.29 (1.01-1.65) (P=0.04) in MONA LISA Lille and the odds ratio for overweight was 1.48 (1.08-2.03) (P=0.01) in HELENA. In transfection experiments in human hepatocyte-derived cell lines, the REV-ERBα intron 1 directed the transcription of a luciferase reporter gene independently of the rs2071427 polymorphism.

CONCLUSION

Our results suggest that the REV-ERBα rs2071427 polymorphism modulates body fat mass in both adult and young people.

Constitutive expression of CD26/dipeptidylpeptidase IV on peripheral blood B lymphocytes of patients with B chronic lymphocytic leukaemia

We have investigated the expression of the ectoenzyme dipeptidylpeptidase IV (DPP IV)/CD26 on lymphocytes obtained from patients with B chronic lymphocytic leukaemia (B-CLL) and compared it with healthy subjects. Using two-colour immunofluorescence analysis with CD26 and CD20 or CD23 monoclonal antibodies, CD26 was found undetectable on peripheral resting B-cells (CD20+ CD23-) from normal donors whereas it was expressed on B-cells activated in vitro with interleukin (IL)-4 and Staphylococcus aureus strain cowan I (CD20+ CD23+). The expression of CD26 on leukaemic B-cells (CD20+ CD23+) was clearly induced in 22 out of 25 patients examined. Consequently, induced levels of CD26 cell surface expression on either normal activated and malignant B-cells coincided with the enhancement of DPP IV activity detected on the surface of these cells. Reverse transcription polymerase chain reaction analyses showed that the transcript levels of the CD26 gene was higher in normal activated B-cells and B-CLL cells than in resting B-cells, suggesting that CD26 was expressed at the level of transcriptional activation. These observations provide evidence of the abnormal expression of DPPIV/CD26 in B-CLL which, therefore, may be considered as a novel marker for B-CLL. Further investigation in relation to CD26 expression and other B malignancies needs to be defined.

Selenium status in pregnant women of a rural population (Zaire) in relationship to iodine deficiency

Endemic myxoedematous cretinism has been associated with combined selenium and iodine deficiency in several areas of Zaire. To determine selenium and iodine status across the country, serum selenium and thyroid function parameters including urinary iodide were determined at prenatal clinics in 30 health centres of rural villages distributed over the whole country. Only in Bas-Zaire was the mean serum selenium level similar to that in non-deficient areas (80-120 ng/ml); in the regions of Bandunda and Kasai levels were marginally decreased (55-80 ng/ml), and in Kivu, Haut-Zaire, Equateur and Shaba they were marginally or moderately decreased (< 55 ng/ml). The frequency of abnormally low urinary iodide (< 5 micrograms/dl) varied from 20% in the region of Bas-Zaire to 50% in Kasai (P < 0.001), and to still higher percentages in the 5 other regions of Zaire (Bandundu, 57%; Kivu, 63%; Equateur, 72%; Shaba, 76%; Haut-Zaire, 84%). With the exception of Bas-Zaire, biochemical maternal hypothyroidism (serum TSH > 5mU/l) was present in every region, with a frequency ranging from 3% in Kivu to 12% in Equateur. Iodine deficiency affects most of the Zairean population and requires public health measures on a larger scale than previously estimated. Combined iodine and selenium deficiency affects Equateur, Haut-Zaire and Kivu, where endemic myxoedematous cretinism occurs, but also Shaba, where it was not previously described. Besides combined iodine and selenium deficiency which is permissive, another factor (thiocyanate?) must be taken into account to explain the peculiarly elevated prevalence of endemic myxoedematous cretinism in Central Africa.