Severe Homozygous Protein C Deficiency: Identification of a Splice Site Missense Mutation (184, Q → H) in Exon 7 of the Protein C Gene

Single strand conformation polymorphism (SSCP) analysis of exon 7 of the protein C gene has identified a novel splice site missense mutation (184, Q → H), in a newborn child with purpura fulminans and undetectable protein C levels. The mutation, seen in the homozygous state in the child and in the heterozygous state in her mother, was characterized and found to be a G to C nucleotide substitution at the -1 position of the donor splice site of intron 7 of the protein C gene, which changes histidine 184 for glutamine (184, Q → H). According to analysis of the normal and mutated sequences, this mutation should also abolish the function of the donor splice site of intron 7 of the protein C gene. Since such a mutation is compatible with the absence of gene product in plasma and since DNA sequencing of all protein C gene exons in this patient did not reveal any other mutation, we postulate that mutation 184, Q → H results in the absence of protein C gene product in plasma, which could be the cause of the severe phenotype observed in this patient.

Role of FK778 Alone or in Combination with Tacrolimus or mTOR Inhibitors as an Immunomodulator of Immunofunctions: In Vitro Evaluation of T Cell Proliferation and the Expression of Lymphocyte Surface Antigens

We evaluated the in vitro capacity of FK778, alone or in combination with other immunosuppressive drugs: Tacrolimus (TRL); Sirolimus (SRL), Everolimus (EVL), to inhibit clonal expansion of T-lymphocytes and expression of lymphocyte-activation surface antigens; secondly, we compared the immunosuppressive potential of FK778 combined with TRL, SRL and EVL with the same combinations using Mycophenolic acid (MPA) as antimetabolite. Lymphocyte proliferation was assessed by 3H-Thymidine incorporation, in whole blood cultures stimulated with ConA. The effect of FK778 on alloresponse was evaluated by MLC and the expression of lymphocyte surface antigens by cytometry. FK778, TRL, SRL and EVL showed a high in vitro capacity to inhibit lymphocyte proliferation in a concentration-dependent way. Combinations of FK778 with TRL, SRL, or EVL presented an additive effect, especially FK778+TRL. Similar inhibition capacity of the clonal expansion was observed, when FK778 was combined with TRL, SRL or EVL, respecting the same combinations but using MPA instead of FK778. In addition, FK778 inhibited the expression of lymphocyte surface antigens involved in activation, co-stimulatory and apoptosis signals. In conclusion, FK778 inhibits the proliferative response induced by mitogeneic and allogeneic stimuli and the expression of surface antigens. Combinations of FK778 with TRL or mTOR inhibitors presented an additive effect and their action on T cell proliferation was similar to that of combinations with MPA. Since FK778, TRL and mTOR inhibitors present different action mechanisms and involve different cellular targets, these combinations may help prevent episodes of allorejection in organ transplants. FK778 and mTOR inhibitors may represent an alternative treatment for patients with renal failure.

Endogenous jasmonic and salicylic acids levels in the Cd-hyperaccumulator Noccaea (Thlaspi) praecox exposed to fungal infection and/or mechanical stress

Sensitivity to Erysiphe in Noccaea praecox with low metal supply is related to the failure in enhancing SA. Cadmium protects against fungal-infection by direct toxicity and/or enhanced fungal-induced JA signaling. Metal-based defense against biotic stress is an attractive hypothesis on evolutionary advantages of plant metal hyperaccumulation. Metals may compensate for a defect in biotic stress signaling in hyperaccumulators (metal-therapy) by either or both direct toxicity to pathogens and by metal-induced alternative signaling pathways. Jasmonic acid (JA) and salicylic acid (SA) are well-established components of stress signaling pathways. However, few studies evaluate the influence of metals on endogenous concentrations of these defense-related hormones. Even less data are available for metal hyperaccumulators. To further test the metal-therapy hypothesis we analyzed endogenous SA and JA concentrations in Noccaea praecox, a cadmium (Cd) hyperaccumulator. Plants treated or not with Cd, were exposed to mechanical wounding, expected to enhance JA signaling, and/or to infection by biotrophic fungus Erysiphe cruciferarum for triggering SA. JA and SA were analyzed in leaf extracts using LC-ESI(-)-MS/MS. Plants without Cd were more susceptible to fungal attack than plants receiving Cd. Cadmium alone tended to increase leaf SA but not JA. Either or both fungal attack and mechanical wounding decreased SA levels and enhanced JA in the Cd-rich leaves of plants exposed to Cd. High leaf Cd in N. praecox seems to hamper biotic-stress-induced SA, while triggering JA signaling in response to fungal attack and wounding. To the best of our knowledge, this is the first report on the endogenous JA and SA levels in a Cd-hyperaccumulator exposed to different biotic and abiotic stresses. Our results support the view of a defect in SA stress signaling in Cd hyperaccumulating N. praecox.

[Breast MRI: the usefulness of diffusion-weighted sequences for differentiating between benign and malignant lesions]

OBJECTIVE

To evaluate the usefulness of diffusion-weighted MRI sequences and of the apparent diffusion coefficient (ADC) to differentiate between benign and malignant breast lesions.

MATERIAL AND METHODS

We prospectively studied 88 patients (aged 31 to 79 years) with 94 lesions (80 malignant and 14 benign) who were referred for preoperative local staging. All patients underwent dynamic MRI examination after intravenous contrast administration and a diffusion-weighted sequence with ADC calculation. The results obtained at diffusion-weighted imaging were correlated with those obtained at histological examination.

RESULTS

The mean value of the ADC for malignant lesions (1.12+/-0.25x10(-3)mm(2)/s) was significantly lower (p<0.001) than for benign lesions (1.61+/-0.52x10(-3)mm(2)/s). No significant differences in ADC values were found between the different subtypes of invasive carcinomas or between intraductal carcinoma and invasive carcinoma (p>0.05). Using an ADC lower than 0.95x10(-3)mm(2)/s as a threshold for malignancy, the sensitivity is 52% and the specificity is 100%.

CONCLUSION

Diffusion-weighted sequences provide additional information in breast MRI that is useful for differentiating between benign and malignant lesions, thus improving the specificity of the technique.

Transfer of selected mineral nutrients and trace elements in the host-hemiparasite association, Cistus-Odontites lutea, growing on and off metal-polluted sites

The role of a hemiparasitic life-style in plant resistance to toxic trace elements in polluted soils is unclear. Restriction of metal uptake by the host, restriction of metal transfer from host to parasite, or transformation of metals into a less toxic form may play a role. This study analysed the transfer of selected mineral elements from soil to host (Cistus spp.) and from host to hemiparasite (Odontites lutea) at locations with different metal burdens: a Cu-rich serpentine site, Pb-Ba mine spoil and an unpolluted soil. Highest soil-to-host transfer factors for K, Mg, Ca, Zn, Cu and Pb were observed on the unpolluted soil. Statistically significant differences among locations of host-to-parasite transfer factors were only found for Ca and Pb. Restriction of transfer of unfavourable Ca/Mg ratios, characteristic at the serpentine site, and of high Pb and Zn concentrations at the Pb-Ba mine occurred mainly at the soil-host, and not at the host-parasite, level. Odontites lutea was able to withstand enhanced Zn and Pb concentrations and low Fe/Cu ratios in shoot tissue without developing toxicity symptoms. This could be caused by specific metal resistance mechanisms in this hemiparasite and/or the transformation and transfer of these metals into a less toxic form by the metal-tolerant host.

Effect of single-nucleotide polymorphisms of the 5' untranslated region of the human α-galactosidase gene on enzyme activity, and their frequencies in Portuguese caucasians

BACKGROUND

The α-galactosidase gene (GLA) has three single-nucleotide polymorphisms in the 5' untranslated region of exon 1, respectively g.1150G>A, g.1168G>A, g.1170C>T. The g.1150A allele is associated with increased plasma α-galactosidase (α-Gal) activity in hemizygotes, while the others are regarded as biologically neutral. The primary goal of this investigation was to test the hypothesis, raised by a clinical observation and results of a family study, that the g.1170T allele polymorphism is associated with lower α-Gal expression.

SUBJECTS AND METHODS

Plasma and leukocyte α-Gal activities were assayed in unrelated healthy young adults of both sexes, who had been genotyped for GLA exon 1, and enzyme activity values in carriers of any of the polymorphisms were compared to those of individuals with the standard genotype; GLA exon 1 was genotyped in males who had α-Gal activity in dried blood spots lower than 2 SD below the cohort average.

RESULTS AND CONCLUSIONS

Mean α-Gal leukocyte activity was ∼ 25% higher in subjects with the g.1170C or CC genotype than in those with the alternative genotypes (p < 0.05). The frequency of the g.1170T allele in subjects with low α-Gal activity in dried blood spots was 4-fold higher (p < 0.05) than in the general population. As in hemizygotes, the g.1150A heterozygote identified in this study had plasma α-Gal activity more than 2-fold above the normal mean. The g.1168A allele did not affect enzyme activity. Surprisingly, females with the standard GLA exon 1 genotype had significantly higher plasma α-Gal activity than genetically comparable males.

Optimally discriminant moments for speckle detection in real B-scan images

The paper presents and evaluates a speckle detection method for B-scan images. This is a fully automatic method and does not require information about the sensor parameters, which is often missing in retrospective studies. The characterization and posterior detection of speckle noise in ultrasound (US) has been regarded as an important research topic in US imaging, for improving signal-to-noise ratio by removing speckle noise and for exploiting speckle correlation information. Most of the existing methods require either manual intervention, the need to know sensor parameters or are based on statistical models which often do not generalize well to B-scans of different imaging areas. The proposed method aims to overcome those limitations. The main novelty of this work is to show that speckle detection can be improved based on finding optimally discriminant low order speckle statistics. In addition, and in contrast with other approaches the presented method is fully automatic and can be efficiently implemented to B-scan images. The method detects speckle patches using an ellipsoid discriminant function which classifies patches based on features extracted from optimally discriminant low order moments of the uncompressed intensity B-scan information. In addition, if the uncompressed signal is not available, we propose and evaluate a method for the estimation of this factor. The computation of low order moments using an optimality criteria, the decompression factor estimation and other key aspects of the method are quantitatively evaluated using both simulated and real (phantom and in vivo) data. Speckle detection results are obtained using again phantom and in vivo studies which show the validity of our approach. In addition, speckle probability images (SPI) are presented which provide valuable information about the distribution of speckle and non-speckle areas in an image. The presented evaluation and results show the effectiveness of our approach. In particular, the need for using discriminant analysis to determine the optimal discriminant power of the statistical moments and that this optimal value strongly depends on the characteristics and imaged tissues in the B-scan data.

Palatability of Thlaspi caerulescens for snails: influence of zinc and glucosinolates

* The hypothesis that zinc (Zn) hyperaccumulation defends Thlaspi caerulescens against herbivores is tested with the snail Helix aspersa. We investigated the effects of leaf zinc, cadmium, glucosinolate, nitrogen and dry matter concentrations on the feeding preferences of snails. * Four T. caerulescens populations from southern France (two from metalliferous and two from normal soils) were grown on low- and high-Zn soils to obtain contrasting leaf Zn concentrations. Plants were also collected in the field, and binary feeding choices involving low- and high-Zn leaves were conducted. * Foliar Zn, Cd, N and dry matter concentrations did not affect the feeding choices of snails, whereas glucosinolate had a significant negative effect on herbivore preferences. Compared with metallicolous plants, nonmetallicolous ones appeared to be better protected against snails, whatever their Zn concentration. * These results do not support the defence hypothesis, as glucosinolates appear to decrease the degree of herbivory when Zn does not.

The role of root exudates in aluminium resistance and silicon-induced amelioration of aluminium toxicity in three varieties of maize (Zea mays L.)

Aluminium (Al) toxicity is widely considered to be the most important growth-limiting factor for plants in strongly acid soils (pH<5.0). The inhibition of root elongation in three varieties of maize (Zea mays L. vars Clavito, HS701b and Sikuani) was followed over the first 48 h of Al treatment, and during the initial 10 h elongation was determined on an hourly basis. The silicon (Si)-induced amelioration of Al toxicity was investigated by pre-treating seedlings for 72 h in nutrient solutions with 1000 microM Si before transfer into solutions with 0, 20 or 50 microM Al (without Si). Plants were either grown in complete low ionic strength nutrient solutions (CNS) or in low salt solutions of 0.4 mM CaCl2 (LSS). In addition, the role of root exudation of organic compounds as a mechanism of Si-induced alleviation of Al toxicity was investigated. Aluminium-induced inhibition of root elongation in the maize var. HS701b was observed within 1 h of Al exposure. After a lag time of at least 8 h, Si-induced alleviation of Al toxicity was observed in this variety when grown in LSS. In the Al-resistant var. Sikuani, Al-resistance was only observed after exposure to 50 microM Al, and not after exposure to 20 microM Al, suggesting that there exists a threshold Al concentration before the mechanisms of Al resistance are activated. Aluminium stimulated root exudation of oxalic acid in all three varieties, but exudate concentrations did not increase with either Al resistance or with Si pretreatment. Aluminium and Si triggered release of catechol and of the flavonoid-type phenolics: catechin, and quercetin. In the Al-resistant variety, Sikuani, Al-exposed plants pretreated with Si exuded up to 15 times more phenolics than those plants not pretreated with Si. The flavonoid-type phenolics, to date unconsidered, appear to play a role in the mechanism(s) of Si-induced amelioration of Al toxicity.

The value of endorectal MR imaging to predict positive biopsies in clinically intermediate-risk prostate cancer patients

The aim of this study was to assess the effectiveness of endorectal MR imaging in predicting the positive biopsy results in patients with clinically intermediate risk for prostate cancer. We performed a prospective endorectal MR imaging study with 81 patients at intermediate risk to detect prostate cancer between January 1997 and December 1998. Intermediate risk was defined as: prostatic specific antigen (PSA) levels between 4 and 10 ng/ml or PSA levels in the range of 10-20 ng/ml but negative digital rectal examination (DRE) or PSA levels progressively higher (0.75 ng/ml year(-1)). A transrectal sextant biopsy was performed after the endorectal MR exam, and also of the area of suspicion detected by MR imaging. The accuracies were measured, both singly for MR imaging and combined for PSA level and DRE, by calculating the area index of the receiver operating characteristics (ROC) curve. Cancer was detected in 23 patients (28%). Overall sensitivity and specificity of endorectal MRI was 70 and 76%, respectively. Accuracy was 71% estimated from the area under the ROC curve for the total patient group and 84% for the group of patients with PSA level between 10-20 ng/ml. Positive biopsy rate (PBR) was 63% for the group with PSA 10-20 ng/ml and a positive MR imaging, and 15% with a negative MR exam. The PBR was 43% for the group with PSA 4-10 ng/ml and a positive MR study, and 13% with a negative MR imaging examination. We would have avoided 63% of negative biopsies, while missing 30% of cancers for the total group of patients. Endorectal MR imaging was not a sufficient predictor of positive biopsies for patients clinically at intermediate risk for prostate cancer. Although we should not avoid performing systematic biopsies in patients with endorectal MR imaging negative results, as it will miss a significant number of cancers, selected patients with a PSA levels between 10-20 ng/ml or clinical-biopsy disagreement might benefit from endorectal MR imaging.

Assessment of barium toxicity in bush beans

External and internal lowest observed effect concentrations (LOECs) for Ba in bean plants (Phaseolus vulgaris) were established using a nutrient solution culture system where BaSO(4) precipitation in the growth medium was avoided. This was achieved by alternating every 24 h with a nutrient solution containing Ba (0, 50, 500, or 5000 microM) and all essential elements except S, with another containing S and all other nutrients but no Ba. The external LOEC for acute toxicity symptoms in the form of leaf withering and leaf growth inhibition was 481 microM of free Ba(2+). This was also the LOEC for the complete inhibition of elongation of secondary roots, while for the elongation of the primary root the external LOEC was 4,821 microM. Barium interfered with both the sulfate transport from roots to shoots and the import of Ca into leaves. However, K was the most Ba-sensitive nutrient. External LOEC for reduced leaf K concentrations was 48 microM free Ba(2+); the corresponding internal LOECs for primary and trifoliolate leaves were 700 and 460 mg kg(-1) DW, respectively.

Determination of glucosinolates in rapeseed and Thlaspi caerulescens plants by liquid chromatography-atmospheric pressure chemical ionization mass spectrometry

Liquid chromatography-atmospheric pressure chemical ionization mass spectrometry was used to identify glucosinolates in plant extracts. Optimization of the analytical conditions and the determination of the method detection limit was performed using commercial 2-propenylglucosinolate (sinigrin). Optimal values for the following parameters were determined: nebulization pressure, gas temperature, flux of drying gas, capillar voltage, corona current and fragmentor conditions. The method detection limit for sinigrin was 2.85 ng. For validation of the method the glucosinolates in reference material (rapeseed) from the Community Bureau of Reference Materials (BCR) were analyzed. The method was applied for the determination of glucosinolates in Thlaspi caerulescens plants.

Surgical treatment of aortic dissections: initial experience with the adventitial inversion technique

BACKGROUND

The adventitial inversion technique obliterates the false lumen and converts a dissected aorta into a conduit with tough adventitia on the inside and outside. Dacron grafts can be anastomosed to the aorta with fine sutures, which hold without tears.

METHODS

From August 1995 to March 1997, we treated 6 patients with acute dissecting aneurysms. Three aneurysms were type I (A) involving the entire aorta, two type II (A) involving the ascending aorta, and one type III (B) involving the thoracoabdominal aorta. Circulatory arrest was used in 3 patients, 1 with type I aneurysm (A), 1 type II (A), and 1 type III (B).

RESULTS

All Dacron-aorta anastomoses held sutures well and did not bleed intraoperatively or postoperatively. One patient (type II [A]) died of intraoperative low cardiac output. In patients with type I (A) aneurysms, the false lumen was obliterated, but 1 patient required resection of a 6-cm abdominal aortic aneurysm.

CONCLUSIONS

The adventitial inversion technique is a safe technique for the treatment of acute dissecting aneurysms, which facilitates operation and solves the problem of intraoperative or postoperative bleeding due to tissue friability.

Respiratory chain activity and mitochondrial DNA content of nonpurified and purified pancreatic islet cells

Considerable interest has recently focused on the possible role of alterations in mitochondrial activity and mutations in the mitochondrial genome for the development of non-insulin-dependent diabetes. Our study aimed at investigating the normal mitochondrial respiratory chain activity of nonpurified and purified islet cells to further explore whether some diabetic states are associated with alterations of mitochondrial oxidative processes. For this purpose, pancreatic islets were isolated from Wistar rats. Unpurified islet cells were obtained in the presence of trypsin and DNAse, and purified beta and non-beta cells were prepared by autofluorescence-activated sorting using a flowcytometer. Intact cell respiration and substrate oxidation in digitonin-permeabilized cells were measured polarographically with a Clark oxygen electrode in a micro-water-jacketed cell. Specific activity of the individual complexes of the respiratory chain was determined spectrophotometrically in unpurified islet cells. The relative amount of mitochondrial (mtDNA) and nuclear (nDNA) DNA in all three cell populations and in rat brain and skeletal muscle was estimated by dot blotting. The intact cell respiration of unpurified islet cells corresponds to the mean of values obtained for beta and non-beta islet cells. Oxidation rates of different substrates by permeabilized beta cells were lower than those for unpurified and non-beta cells. The amount of mtDNA relative to nDNA was similar in all three groups of cells, and was also similar to that obtained from brain and skeletal muscle. In summary, we have described mitochondrial respiratory chain activity in unpurified, beta, and non-beta islet cells. Our results represent an initial step in investigating the potential pathogenic role that alterations in oxidative phosphorylation could play in some diabetic states.

Anti-Sia-lb (anti-Gd) cold agglutinins bind the domain NeuNAc alpha2-3Gal in sialyl Lewis(x), sialyl Lewis(a), and related carbohydrates on nucleated cells and in soluble cancer-associated mucins

Anti-Sia-lb (formerly anti-Gd) cold agglutinins (CAs) recognize sialylated carbohydrates on both adult and neonate red blood cells (RBCs). RBC CA activity inhibition experiments reported here indicate that the domain NeuNAc alpha2-3Gal, as found in sialyllactose, synthetic sialyl(s) Lewis(Le)(x) and sLe(a), sialyllactosamine, sialyl-fucosyllactose, and nonfucosylated sLe(a), constitutes the minimal epitope for these CAs, implicating that these autoantibodies could be able to bind this domain in sLe(x) and sLe(a) and related carbohydrates expressed on nucleated cells and in soluble cancer-related mucins. The following data obtained with the previously characterized monoclonal IgMk anti-Sia-lb CA, GAS, show that this is the case. GAS epitope expression among leukocytes that lack sLe(a) parallels that of sLe(x) determinant as detected by mouse monoclonal antibodies (MoAbs), especially MoAb KM-93. It is also found on epithelial malignant cells bearing both sLe(x) and sLe(a). GAS epitope on these nucleated cells, (1) like that present on RBC, is abolished by sialidase, unaffected by proteases, and inhibited by sialyllactose; and (2) is overlapping and/or proximal to that recognized by anti-sLe(x) MoAb, CSLEX-1, and KM-93. Moreover, CAGAS binds soluble cancer-associated mucins bearing sLe(x) and sLe(a) determinants. This binding is inhibited by sialyllactose and these mucins inhibit the RBC CA activity of CAGAS. The possible significance of anti-Sia-lb (anti-Gd) CAs as autoantibodies directed to carbohydrate ligands of host adhesion molecules that might be receptors of microbial adhesins of some CA-inducing pathogens is discussed.

Stimulation through CD50 (ICAM-3) induces both activation and programmed cell death of human thymocytes

CD50 (ICAM-3) has been identified as the third CD11a/CD18 (LFA-1) counter receptor. We investigated the expression and possible role of this molecule in the induction of early and late activation events in human thymocytes. We observed that CD50 expression is acquired by early T cell progenitors (CD34+) and maintained during thymic development, reaching the highest levels in the most mature population of thymocytes (CD3high). Neither basal nor cytokine-induced expression of CD50 was observed on untransformed human thymic epithelial cell lines. Cross-linking of CD50 expressed on the surface of human thymocytes, by using mAbs recognizing epitopes not related to the CD11a binding site, transduced transmembrane signals leading to an increase of intracellular calcium concentration. This calcium mobilization was inhibited when CD50 was co-cross-linked with CD45, suggesting that tyrosine phosphorylation is also involved in CD50 signaling. The same anti-CD50 mAbs that were able to affect intracellular calcium levels were shown to induce CD69 but not CD25 expression on human thymocytes. This effect was preferentially observed on CD3low/CD3high thymocyte subpopulations. Cross-linking of CD50 also significantly increased activation-induced cell death of human thymocytes. These results support the idea that CD50 molecule can play a role in developing functionally mature T lymphocytes.

Anti-islet cell and anti-insulin antibody production by CD5+ and CD5- B lymphocytes in IDDM

Although CD5 + B lymphocytes are mostly committed to the production of polyreactive natural autoantibodies, CD5 + B lymphocytes committed to the production of somatically mutated and monoreactive high-affinity IgM autoantibodies have been also shown. Increased proportions of CD5 + B lymphocytes in some autoimmune diseases, including insulin-dependent diabetes mellitus (IDDM), have been noticed. The present study was undertaken to analyse the differences between CD5 + and CD5- B lymphocyte subsets for production of IDDM-related autoantibodies, i.e. anti-human insulin antibodies (IA) and anti-human islet cell antibodies (ICA). For this purpose, Epstein-Barr Virus (EBV)-transformation of FACS cell-sorted CD5 + and CD5- B lymphocytes and unfractionated enriched B lymphocytes from nine IDDM patients treated exclusively with recombinant human insulin, and from four healthy control subjects was performed; a mean of 102-216 microcultures with a mean of 1,000-2,333 cells/microculture for each B-lymphocyte fraction and individual was established. Data show that both CD5 + and CD5- B-lymphocyte subsets from either normal subjects or from IDDM patients receiving recombinant human insulin, contain B lymphocytes committed to the production of IA-IgM as a common element of their repertoire. In contrast, cells committed to the production of IA-IgG were only detected among the CD5- B lymphocyte subset from some IDDM patients. Only one microculture, out of a total of 6,211 screened (from control subjects and patients), in the CD5- B-cell subset from a recently-diagnosed IDDM patient, was found to produce ICA-IgM lambda. This might suggest that the frequency of circulating B lymphocytes committed to the production of ICA is very low even in IDDM patients bearing serum ICA. EBV-transformed B cells producing the ICA-IgM lambda were stabilized and cloned by somatic hybridization technique. This ICA-IgM lambda human monoclonal antibody, designated HY1-MB91, is not polyreactive, but shows a restricted reactivity with human pancreatic islets, failing to react with other human tissues including cerebellar cortex, and lacking rheumatoid factor and anti-DNA antibody activities. It also lacks reactivity with pancreatic islets from other mammalian species (rat, mouse and monkey) as well as with other rat tissues, including cerebellar cortex. The antigen recognized by HY1-MB91 antibody in human islet cells is a cytoplasmic component mostly found in beta cells.

Severe homozygous protein C deficiency: identification of a splice site missense mutation (184, Q-->H) in exon 7 of the protein C gene

Single strand conformation polymorphism (SSCP) analysis of exon 7 of the protein C gene has identified a novel splice site missense mutation (184, Q-->H), in a newborn child with purpura fulminans and undetectable protein C levels. The mutations, seen in the homozygous state in the child and in the heterozygous state in her mother, was characterized and found to be a G to C nucleotide substitution at the -1 position of the donor splice site of intron 7 of the protein C gene, which changes histidine 184 for glutamine (184, Q-->H). According to analysis of the normal and mutated sequences, this mutation should also abolish the function of the donor splice site of intron 7 of the protein C gene. Since such a mutation is compatible with the absence of gene product in plasma and since DNA sequencing of all protein C gene exons in this patient did not reveal any other mutation, we postulate that mutation 184, Q-->H results in the absence of protein C gene product in plasma, which could be the cause of the severe phenotype observed in this patient.

Reduction in size of the myotonic dystrophy trinucleotide repeat mutation during transmission

Myotonic dystrophy (DM) is an autosomal-dominant disorder that affects 1 in 8000 individuals. Amplification of an unstable trinucleotide CTG repeat, located within the 3' untranslated region of a gene, correlates with a more severe DM phenotype. In three cases, the number of CTG repeats was reduced during the transmission of the DM allele; in one of these cases, the number was reduced to within the normal range and correlated at least with a delay in the onset of clinical signs of DM. Haplotype data of six polymorphic markers in the DM gene region indicate that, in this latter case, two stretches of the affected chromosome had been exchanged with that region of the wild-type chromosome.

Isolation and characterisation of a CDw50 negative Jurkat T-cell line variant (PPL.1)

PPL.1, a Jurkat cell line variant deficient in CDw50 surface expression, has been selected by fluorescence-activated cell sorting and expanded in cell culture. We have studied the expression of several leukocyte surface markers (CD2, CD3, CD4, CD8, CD7, CD26, CD25, CD14, CD18, kCD20, CD43, CD45, CD45R, CD71 and HLA class I and II) and we find no differences in their expression between PPL.1 and its parental Jurkat cell line. Immunoprecipitation analysis of metabolically labelled PPL.1 cells ([35S]-cysteine plus [35S]-methionine) fails to detect the presence of a preformed cytoplasmic pool of CDw50 molecules. The deficient CDw50 expression on PPL.1 cells is stable after several weeks of continuous culture and even after exposure of cells to several lymphocyte activating agents (PGE2, PHA, Con A, calcium ionophore A23187 and human recombinant IFN-gamma). No karyotype changes responsible for such phenotype deficiency are found. PPL.1 cells are as efficient as wild-type Jurkat or K562 cells, when used as targets in cytotoxicity assays with fresh or PHA-stimulated peripheral blood lymphocytes. No blocking effects of CDw50-specific mAb are observed in such assay. These results are consistent with the fact that CDw50 is not involved in alloreactive T-cell-specific cytotoxicity. They also suggest that this antigen is implicated only on a very specialized type of cell-cell interactions.

Correlation between CTG trinucleotide repeat length and frequency of severe congenital myotonic dystrophy

The myotonic dystrophy (DM) mutation has recently been identified as an unstable trinucleotide CTG repeat which is present 5-30 times in the normal population but which is amplified up to 2,000 times in DM. We have determined the status of the CTG repeat in 272 DM individuals. Infants with severe congenital DM, as well as their mothers, are shown to have on average a greater amplification of the CTG repeat than is seen in the noncongenital DM population. This fact, when viewed in conjunction with the tendency to increased CTG repeat length in our DM kindreds, provides evidence for the existence of genetic anticipation in the transmission of DM.

Myotonic dystrophy mutation: an unstable CTG repeat in the 3' untranslated region of the gene

Myotonic dystrophy (DM) is the most common inherited neuromuscular disease in adults, with a global incidence of 1 in 8000 individuals. DM is an autosomal dominant, multisystemic disorder characterized primarily by myotonia and progressive muscle weakness. Genomic and complementary DNA probes that map to a 10-kilobase Eco RI genomic fragment from human chromosome 19q13.3 have been used to detect a variable length polymorphism in individuals with DM. Increases in the size of the allele in patients with DM are now shown to be due to an increased number of trinucleotide CTG repeats in the 3' untranslated region of a DM candidate gene. An increase in the severity of the disease in successive generations (genetic anticipation) is accompanied by an increase in the number of trinucleotide repeats. Nearly all cases of DM (98 percent or 253 of 258 individuals) displayed expansion of the CTG repeat region. These results suggest that DM is primarily caused by mutations that generate an amplification of a specific CTG repeat.

Cardiac surgery on Jehova's Witnesses at Instituto Cardiovascular-Hospital Pavia

Jehovah's Witnesses (J.W.) can undergo successful cardiac operations. We have operated five J.W. patients. Of these patients, two had coronary artery bypass surgery and three had correction of congenital anomalies. These included an atrial septal defect with infundibular pulmonic stenosis, a tetralogy of Fallot and a patient with a ventricular septal defect. Our treatment protocol includes a meticulous surgery, the use of early heparinization to collect all shed blood into the pump oxygenator, observation in the operating room for early exploration if the patient bleeds and administration of iron preparations. Recombinant human erythropoietin, although available and in our treatment protocol, has not been used yet. All patients survived the operation and left the hospital with an excellent hemoglobin and hematocrit. The length of stay varied from 7 to 15 days.

Myotonic dystrophy mutation: an unstable CTG repeat in the 3' untranslated region of the gene

Myotonic dystrophy (DM) is the most common inherited neuromuscular disease in adults, with a global incidence of 1 in 8000 individuals. DM is an autosomal dominant, multisystemic disorder characterized primarily by myotonia and progressive muscle weakness. Genomic and complementary DNA probes that map to a 10-kilobase Eco RI genomic fragment from human chromosome 19q13.3 have been used to detect a variable length polymorphism in individuals with DM. Increases in the size of the allele in patients with DM are now shown to be due to an increased number of trinucleotide CTG repeats in the 3' untranslated region of a DM candidate gene. An increase in the severity of the disease in successive generations (genetic anticipation) is accompanied by an increase in the number of trinucleotide repeats. Nearly all cases of DM (98 percent or 253 of 258 individuals) displayed expansion of the CTG repeat region. These results suggest that DM is primarily caused by mutations that generate an amplification of a specific CTG repeat.

[Hemoptysis: a prospective study of 108 cases in an emergency service]

A prospective study is performed in 108 patients presenting hemoptysis who were attended in the emergency department. Final diagnosis was achieved in 89 cases (82.4%), being lung infections of tuberculous origin or not, neoplasias, and chronic obstructive lung emphysema the main observed etiologies. A low percentage of severe hemoptysis is found (5.6%). Diagnosis was obtained in 79.6% of patients by clinical history, physical exam, chest x-ray and ORL exam. Only 13.6% of patients who were not diagnosed in the Emergency department were later diagnosed by follow up and performance of complementary tests. Similarly, the lack of an initial etiological diagnosis had no repercussion, by itself, in a worse prognosis. Therefore, it is recommended to perform a single strict evolution control in patients with hemoptysis of unknown origin who present risk factors of lung neoplasia (male sex, age greater than 40 years, smoking greater than 45 packs/year).

Pulvinus structure and leaf abscission in cadmium-treated bean plants (Phaseolus vulgaris)

The effects of a phytotoxic cadmium concentration (4.45 × 10−5 M) on the structure of primary and secondary pulvini of bean (Phaseolus vulgaris L.) leaves were studied by light and scanning electron microscopy. Pulvini were also analysed for dry weight, water content, and cadmium, calcium and potassium concentrations. Relatively high amounts of Cd accumulated in the pulvini. The Cd treatment affected Ca more intensively than K concentrations, resulting in increased K/Ca molar ratios. Increase in the density of covering, glandular, and hydathode trichomes on the pulvini and internodes was observed in Cd-treated plants. Cadmium caused premature leaf abscission. Within both primary and secondary pulvini of unifoliolate and first trifoliolate leaves, Cd induced formation of a secondary abscission zone, which involved cortical cells parallel to the vascular cylinder. Cytological alterations associated with this zone were similar to those of normal plants in which the abscission zone lies at the pulvinus–petiole junction. Results suggest that Cd probably indirectly induces the conversion to cells with the competence of abscission zone cells in the cortex of pulvini.

Influence of cadmium on water relations, stomatal resistance, and abscisic Acid content in expanding bean leaves

Ten day old bush bean plants (Phaseolus vulgaris L. cv Contender) were used to analyze the effects of 3 micromolar Cd on the time courses of expansion growth, dry weight, leaf water relations, stomatal resistance, and abscisic acid (ABA) levels in roots and leaves. Control and Cd-treated plants were grown for 144 hours in nutrient solution. Samples were taken at 24 hour intervals. At the 96 and 144 hour harvests, additional measurements were made on excised leaves which were allowed to dry for 2 hours. From the 48 hour harvest, Cd-treated plants showed lower leaf relative water contents and higher stomatal resistances than controls. At the same time, root and leaf expansion growth, but not dry weight, was significantly reduced. The turgor potentials of leaves from Cd-treated plants were nonsignificantly higher than those of control leaves. A significant increase (almost 400%) of the leaf ABA concentration was detected after 120 hours exposure to Cd. But Cd was found to inhibit ABA accumulation during drying of excised leaves. It is concluded that Cd-induced decrease of expansion growth is not due to turgor decrease. The possible mechanisms of Cd-induced stomatal closure are discussed.

Structural and ultrastructural disorders in cadmium-treated bush bean plants (Phaseolus vulgaris L.)

The effect of a growth reducing cadmium concentration (5 μg ml^-1 ) on the structure and ultrastructure of leaves, stomata and plastids of bush bean plants (Phaseolus vulgaris L. cv. Contender) grown on perlite was studied using light, transmission electron and scanning electron microscopy. The structural and ultrastructural alterations observed were not directly related to the average Cd content of the whole organs. In roots, where the highest Cd concentration was found, plastid ultrastructure was hardly affected, while in the upper parts of the plant the chloroplasts showed severe alterations. Disruption of chlorophyll synthesis and plastid ultrastructure was greater in young trifoliate leaves than in primary leaves. The effects of Cd toxicity on the structure and ultrastructure and their physiological implications are discussed in relation to Cd uptake.

Structural and ultrastructural disorders in cadmium-treated bush bean plants (Phaseolus vulgaris L.)

The effect of a growth reducing cadmium concentration (5 μg ml^-1 ) on the structure and ultrastructure of leaves, stomata and plastids of bush bean plants (Phaseolus vulgaris L. cv. Contender) grown on perlite was studied using light, transmission electron and scanning electron microscopy. The structural and ultrastructural alterations observed were not directly related to the average Cd content of the whole organs. In roots, where the highest Cd concentration was found, plastid ultrastructure was hardly affected, while in the upper parts of the plant the chloroplasts showed severe alterations. Disruption of chlorophyll synthesis and plastid ultrastructure was greater in young trifoliate leaves than in primary leaves. The effects of Cd toxicity on the structure and ultrastructure and their physiological implications are discussed in relation to Cd uptake.