Genetic diversity in mesoamerican populations of mahogany (Swietenia macrophylla), assessed using RAPDs

Swietenia macrophylla King, a timber species native to tropical America, is threatened by selective logging and deforestation. To quantify genetic diversity within the species and monitor the impact of selective logging, populations were sampled across Mesoamerica, from Mexico to Panama, and analysed for RAPD DNA variation. Ten decamer primers generated 102 polymorphic RAPD bands and pairwise distances were calculated between populations according to Nei, then used to construct a radial neighbour-joining dendrogram and examine intra- and interpopulation variance coefficients, by analysis of molecular variation (AMOVA). Populations from Mexico clustered closely together in the dendrogram and were distinct from the rest of the populations. Those from Belize also clustered closely together. Populations from Panama, Guatemala, Costa Rica, Nicaragua and Honduras, however, did not cluster closely by country but were more widely scattered throughout the dendrogram. This result was also reflected by an autocorrelation analysis of genetic and geographical distance. Genetic diversity estimates indicated that 80% of detected variation was maintained within populations and regression analysis demonstrated that logging significantly decreased population diversity (P = 0.034). This study represents one of the most wide-ranging surveys of molecular variation within a tropical tree species to date. It offers practical information for the future conservation of mahogany and highlights some factors that may have influenced the partitioning of genetic diversity in this species across Mesoamerica.

Intrapartum fetal invasive procedures and perinatal transmission of HIV

OBJECTIVE

To study the effect of intrapartum use of fetal invasive procedures (scalp electrodes or scalp pH sampling) on perinatal transmission rate of HIV.

STUDY DESIGN

We compared the perinatal transmission of 57 HIV pregnancies in which invasive procedures (IP) were performed with a control group of 214 pregnancies without IP. We controlled for potentially risk factors (maternal CD4 level, gestational age, antiretroviral therapy use, duration of rupture of membranes (ROM), length of labor and mode of delivery) by stratification and logistic regression.

RESULTS

Transmission rate in the group with IP was 26.3% (15/57) versus 13.6% (29/214) in the control group, relative risk (RR) 1.9, 95% CI (1.1-3.4). By logistic regression we observed three significant factors involved in transmission of HIV: low maternal CD4 level (odds ratio (OR)=3.3, 95% CI=1.2-9.4), duration of ROM (OR=2.9, 95% CI=1.1-7.9) and IP use (OR=3.5, CI 95%=1.2-9.6). Interaction between duration of ROM and IP are also significant (OR=5.1, CI 95%=1.5-17.5).

CONCLUSIONS

Intrapartum use of fetal scalp electrodes or fetal scalp pH sampling increases the perinatal transmission of HIV and should therefore be avoided in HIV patients.

Flower development in pisum sativum: from the war of the whorls to the battle of the common primordia

The ontogeny of pea (Pisum sativum L.) flowers, as in many legume and nonlegume plant species, proceeds through a very different sequence of events from the same process in Antirrhinum majus and Arabidopsis thaliana. Using scanning electron microscopic analysis, we have characterized the early development of wild-type pea flowers and selected morphological characters or markers to break it down into different developmental stages. We used these markers as tools to characterize early alterations in flower development of several pea floral homeotic mutants. These mutants display phenotypes resembling those of: (1) floral meristem identity mutations, frondosus (brac); (2) class A mutations, calix carpellaris (cc); (3) class B mutations, stamina pistilloida (stp-1 and stp-2); and (4) class C mutations, petalosus (pe). According to the homeotic transformations observed in the pea floral mutants, it would appear feasible that the identity and developmental pattern of the four organ types in pea flowers are governed by at least the same three developmental functions, A, B, and C, proposed for the two model systems. However, our results suggest that, in pea, although these functions do have a similar role in the specification of organ identity shown by their counterparts in Arabidopsis or Antirrhinum, they may differ in the control of other processes, such as floral determinacy, organ number, or leaf development. The more remarkable features of pea flower ontogeny were the existence of four common primordia to petals and stamens, the early carpel primordium initiation, and the abaxial-adaxial unidirectional initiation of organ primordia within each different floral whorl, in contrast to the centripetal and sequential floral ontogeny in other plants. Organ differentiation within each of these common primordia appears to be a complex process that plays a central role in the ontogeny of pea flowers. Analysis of flower developmental pea homeotic mutants suggests that A, B, and C functions are necessary for the correct differentiation of organs from common primordia and that, in addition to its role in the specification of petals and stamens, B function, would be involved in conferring common primordia identity. Copyright 1999 Wiley-Liss, Inc.

A new mutation in the regulatory domain of the myophosphorylase gene affecting protein dimer contact

We have identified a novel missense mutation in the myophosphorylase gene in a Spanish patient with McArdle's disease. The patient was homozygous for a T-to-C transition at codon 115 (L115P) in exon 3, which changed an encoded leucine (CUG) to a proline (CCG). This is the first mutation to be described in exon 3 and in a protein domain related to dimer contact. These data further emphasize the importance of private mutations in McArdle's disease, some of which are associated with specific ethnic groups.

Lipoid proteinosis. A biochemical and ultrastructural investigation of two new cases

Lipoid proteinosis is a rare autosomal recessive disease characterized by cutaneous and visceral lesions, in which large amounts of amorphous material are constantly found in stroma. Morphological and biochemical studies indicate abnormal collagen production, but little attention has been paid to the lipid component of lesions. Microscopic and ultrastructural studies of skin, with special emphasis on fibroblasts, vessels, nerve endings and eccrine sweat glands, were conducted in two patients with lipoid proteinosis. Biochemical studies were undertaken in cultured fibroblasts. Evidence of lysosomal storage in epithelial cells of eccrine sweat glands and in dermal histiocytes, very similar to that found in some metabolic disorders, particularly Farber disease, was found in both cases. Our findings suggest that two alterations might coexist in lipoid proteinosis, one characterized by impaired normal collagen production and the other related to a metabolic defect which may lead to accumulation of ceramide or more complex lipids.

Prevalence of germline mutations of hMLH1, hMSH2, hPMS1, hPMS2, and hMSH6 genes in 75 French kindreds with nonpolyposis colorectal cancer

Hereditary nonpolyposis colorectal cancer (HNPCC) is a syndrome characterized by familial predisposition to colorectal carcinoma and extracolonic cancers of the gastrointestinal, urological, and female reproductive tracts. This dominant disorder is caused by germline defects in one of at least five DNA mismatch repair (MMR) genes: hMLH1, hMSH2, hPMS1, hPMS2, and hMSH6 (GTBP). Germline mutations of hMSH2 and hMLH1 are also frequently identified in families not fulfilling all the Amsterdam criteria, thereby demonstrating that the involvement of these genes is not confined to typical HNPCC. To evaluate the respective involvement of the various MMR genes in typical and incomplete HNPCC syndromes, we have performed an analysis of the hMLH1, hMSH2, hPMS1, hPMS2, and hMSH6 genes in a large series of French kindreds (n=75) with colorectal tumors and/or aggregation of extracolonic cancers belonging to the HNPCC spectrum. Mutational analysis has been performed in all families, without preselection for the tumor phenotype. We have detected 26 pathogenic germline mutations of the hMLH1 and hMSH2 genes and several novel variants of the hPMS1, hPMS2, and hMSH6 genes. Our data confirm that, regardless of the type of families and the tumor phenotype, hPMS1, hPMS2, and hMSH6 germline mutations are rare in familial aggregation of colorectal cancers. Furthermore, they suggest that the presence of multiple primary malignancies in a single individual and the observation of extracolonic tumors in relatives of a colorectal cancer patient should be included among the guidelines for referring patients for genetic testing.

Sonographic presentation of uterine sex cord-stromal tumor

A 24-year-old woman presented with continuous vaginal bleeding and anemia. Pelvic sonography demonstrated an enlarged uterus measuring 8.9 x 4.9 x 4.7 cm and a mass within the endometrial cavity measuring 3.0 x 1.8 cm. The mass appeared to be polypoid and echogenic, contained a small cyst, and was suggestive of a polyp. The patient underwent total vaginal hysterectomy. Pathologic examination revealed a uterine sex cord-stromal tumor. To our knowledge, the sonographic features of uterine sex cord-stromal tumor have not been previously reported. The sonographic appearance mimicked that of a polyp.

A new mutation in the myophosphorylase gene (Asn684Tyr) in a Spanish patient with McArdle's disease

We have identified a novel missense mutation, an A-T transition at codon 684 in exon 17, changing an encoded asparagine to a tyrosine (Asn684Tyr) in a Spanish patient with typical McArdle's disease. The patient was a compound heterozygote, with a previously-described mutation (Gly204Ser) on the other allele. This report expands the molecular genetic heterogeneity in McArdle's disease, emphasizes the presence of private mutations in specific ethnic groups, and indicates that geographic origin must be considered before undertaking DNA analysis for diagnosis.

Adult glycogenosis II with paracrystalline mitochondrial inclusions and Hirano bodies in skeletal muscle

Hirano bodies constitute eosinophilic intracytoplasmic inclusions, typically seen in the central nervous system, where they are related to senility and certain dementias such as Alzheimer's disease or the Parkinson-dementia complex. They have been found in different tissues of experimental animals and, on rare occasions, in extraocular muscles of elderly individuals. However, to our knowledge they have not been described in skeletal muscle in locations other than extraocular muscles or associated with muscle pathology. Glycogenosis II or Pompe's disease, is a metabolic disorder caused by acid maltase deficiency and is characterized by glycogen accumulation in lysosomes in various tissues, including skeletal muscle. There are three clinical forms depending on age at onset, the most frequent being the childhood form. We present the histopathological and ultrastructural findings of a muscle biopsy performed in a case of the adult form of glycogenosis II which showed, in addition to characteristic lysosomal glycogen storage, paracrystalline mitochondrial inclusions and, as an exceptional finding, intracytoplasmic Hirano bodies in some muscle fibres.

Dietary intake of vegetables and fruits among adults in five regions of Spain. EPIC Group of Spain. European Prospective Investigation into Cancer and Nutrition

OBJECTIVE

To assess the consumption of vegetables and fruits (V&F) in adults from five regions in Spain according to sex, age and educational level.

DESIGN

Cross-sectional study within the members of the EPIC cohort in Spain.

SETTING

Three regions of the north of Spain (Asturias, Guipúzcoa and Navarra) and two regions of the south of Spain (Granada and Murcia).

SUBJECTS

41448 healthy volunteers (15365 men, 25813 women), aged 29-69 y.

INTERVENTIONS

Information on habitual diet during the previous year was collected by means of a computerised version of a diet history questionnaire.

RESULTS

Among men, the mean daily consumption of vegetables and of fruits was 273.7 g (3.4 servings) and 348.3 g (4.4 servings) respectively. Among women, the corresponding vegetables and fruit intakes per day were 244.4g (3.1 servings) and 349.4g (4.4 servings). The total V&F intake tended to increase with age and educational level. Overall, 74% of subjects consumed 400 g/d (5 servings) of vegetables and fruit.

CONCLUSIONS

Consumption of vegetables and fruits in healthy adults in Spain is considerably higher than in most European countries and the United States; this complies with what is considered to be the Mediterranean diet. Despite some regional differences, there were no clearly differentiated patterns of V&F intake between southern and northern regions within Spain.

[Dystrophin and dystrophin-associated proteins. Their evaluation at the neuromuscular pathology laboratory]

OBJECTIVE

To describe the main techniques used to detect skeletal muscle proteins and to discuss the results regarding the new classification of limb-girdle muscular dystrophies.

MATERIAL AND METHODS

Over three hundred muscle biopsies with a suspected diagnosis of muscular dystrophy were immunostained for dystrophin, dystrophin-associated proteins, spectrin and utrophin. In one hundred and twenty of them, Western blot for different proteins was performed.

RESULTS

Duchenne muscular dystrophy showed negative immunostaining and Western blot for dystrophin and dystrophin-associated proteins, and overexpression of utrophin. In Becker muscular dystrophy there is an abnormal dystrophin immunolabelling and molecular weight. Sarcoglycanopathies present decreased sarcoglycans and normal dystrophin. In some forms of congenital muscular dystrophy there is absence of merosin and alpha 2-laminin, with variable results on Western blot analysis.

CONCLUSION

The immunohistochemical analysis of several cytoskeletal and transmembrane proteins as well as Western blot analysis, are necessary to elaborate a correct diagnosis of dystrophinopathies, sarcoglycanopathies and the different forms of congenital muscular dystrophy [REV NEUROL 1999; 28: 154-8].

Neurofibromatosis and early onset of cancers in hMLH1-deficient children

Hereditary nonpolyposis colon cancer is a common hereditary disorder caused by the germ-line mutations of DNA mismatch repair (MMR) genes, especially hMLH1 and hMSH2. We report here the first identification of human compounds with a homozygous inactivation of a MMR gene. In a typical hereditary nonpolyposis colon cancer family, MMR-deficient children conceived from matings between heterozygotes for a hMLH1 deleterious mutation exhibited clinical features of de novo neurofibromatosis type I and early onset of extracolonic cancers. This observation demonstrates that MMR deficiency is compatible with human development but may lead to mutations during embryogenesis. On the basis of clinical symptoms observed in MMR-deficient children, we speculate that the neurofibromatosis type 1 gene is a preferential target for such alterations.

Cardiovascular risk factors and educational attainment in Southern Spain: a study of a random sample of 3091 adults

STUDY OBJECTIVE

To analyze the associations between educational attainment and major cardiovascular disease risk factors in the Murcia Region (Southern Spain).

DESIGN

During 1992 we conducted a survey by interview, with multi-stage random sampling, representative of the general adult population. We calculated odds ratios (OR) and trends by logistic regression as a measure of the association between educational levels and cardiovascular risk factors, taking the university level as the reference category.

PARTICIPANTS

A total of 1514 men and 1577 women aged between 18 and 65 years was included in the study. Rate of response to the questionnaire was 61%. Seventy-eight percent of the respondents provided a blood sample. A telephone survey on a representative sample of non-respondents (n = 347), showed no statistical differences in the level of studies.

MEASUREMENTS

We asked for educational level (highest schooling qualification completed), and according to the WHO MONICA protocol we measured: blood pressure, cigarette smoking, height, weight and total cholesterol, triglycerides and HDL-cholesterol. We also obtained the leisure-time physical activity by a validated questionnaire.

MAIN RESULTS

In a context of a low level of schooling, mainly among the older age groups, the prevalence of risk factors except smoking in women is higher in the lower educational levels. Systolic blood pressure tends slightly to increase as schooling level decreases (both genders, p<0.02). Conversely, serum total cholesterol and triglycerides decrease with higher level of schooling in men. The high levels of HDL-cholesterol observed in all educational groups show no trend in both genders. Arterial hypertension in men and women and overweight in women tend to decrease with higher educational attainment. Moreover, higher level of education is associated with vigorous physical exercise in both genders and cigarette smoking in women. We observed the strongest significant magnitude association in nonschooling with hypertension in men (OR: 1.82; 95% CI: 1.15, 2.89), in women (OR: 2.39; 95% CI: 1.05, 5.44), and with overweight in women (OR: 3.22; 95% CI: 1.97, 5.27), meaning that compared to people at the university level, people without schooling showed two to three times higher prevalence of hypertension and overweight (only women). Also non-schooling obtained the lowest significant association with protective physical exercise for coronary heart disease in men (OR: 0.32; 95% CI: 0.18, 0.56) and in women (OR: 0.31; 95% CI: 0.15, 0.62) pointing out that people at the university level of education had three times the prevalence of vigorous physical activity than their non schoolarized counterparts.

CONCLUSIONS

After adjusting for environmental factors, in our adult general population, educational attainment is inversely associated with arterial hypertension in both genders and with overweight in women, and directly associated with cigarette smoking in women and with leisure-time physical activity in both genders.

Subsarcolemmal expression of utrophin in neuromuscular disorders: an immunohistochemical study of 80 cases

The immunohistochemical expression of utrophin in 80 muscle biopsies from patients with dystrophinopathies and other neuromuscular disorders is reported. All biopsy specimens were routinely studied by a battery of 12 histoenzymatic techniques, and immunohistochemistry was performed for spectrin, three domains of dystrophin and two domains of utrophin. Abnormal utrophin expression was observed in all dystrophinopathic muscles compared with normal controls or biopsy samples from several other muscular diseases. Inflammatory myopathies presented abnormal overexpression of utrophin and an abnormal dystrophin immunolabeling pattern. This overexpression of utrophin appears to be directly related to the decrease in dystrophin. We conclude that the study of utrophin is important for the histological interpretation and differential diagnosis of dystrophin-related muscular disorders.

Molecular genetic analysis of McArdle's disease in Spanish patients

We analyzed leukocyte DNA of 19 patients from 12 Spanish families with McArdle's disease (myophosphorylase deficiency). In 15 patients, the enzyme defect was documented histochemically in muscle, and in four the diagnosis was based on clinical and laboratory data. Three patients were homozygous and six were heterozygous for the nonsense mutation at codon 49 (R49X). Our findings indicate that the R49X mutation, which is common in English and American patients, is also present in Spanish patients with McArdle's disease, but at a lower frequency.

Familial multiple symmetric lipomatosis associated with the A8344G mutation of mitochondrial DNA

We describe familial multiple symmetric lipomatosis in a pedigree harboring the 8344 mutation in the tRNA(Lys) gene of mitochondrial DNA (mtDNA). The proband showed neuromuscular involvement but lacked the typical manifestations of myoclonic epilepsy and ragged-red fibers disease. The distribution of the mutation was unusual because the proportion of mutated genomes was higher in blood and lipomas than in muscle tissue.

Aging and venous thromboembolism influence the pharmacodynamics of the anti-factor Xa and anti-thrombin activities of a low molecular weight heparin (nadroparin)

Venous thromboembolism may be efficiently treated by one single daily administration of a high dose of low molecular weight heparin (LMWH). The present study investigates if the physiological deterioration of renal function associated with normal aging or the presence of an acute venous thromboembolism influences the pharmacodynamic pattern of the anti-factor Xa and anti-thrombin activities. Three groups of 12 subjects were investigated. The first 2 groups were composed of healthy volunteers differing by age (25 +/- 4 and 65 +/- 3 yrs) and creatinine clearance (114 +/- 15 and 62 +/- 6 ml x min(-1)). The third group was composed of patients hospitalized for deep vein thrombosis, having a mean age of 65 +/- 11 yrs and creatinine clearance of 76 +/- 8 ml x min(-1). Nadroparin was administered subcutaneously once daily at the dose of 180 anti-factor Xa IU.kg(-1) for 6 to 10 days. Serial sampling on day 1 and on the last day of administration (day n) allowed the pharmacodynamic parameters of the anti-factor Xa and anti-thrombin activities to be compared at the beginning and at the end of the treatment. The main findings were the following: (1) After repeated administration, a significant accumulation of the anti-factor Xa activity was observed in the healthy elderly and in the patients but not in the healthy young subjects (accumulation factor: 1.3). There was no evidence of accumulation of anti-thrombin activity; (2) There were significant correlations between the clearance of creatinine and the clearance of the anti-factor Xa activity but not with that of the anti-thrombin activity; (3) In the patients, the clearance of the anti-factor Xa and of the anti-thrombin activities were 1.4 and 2 times higher respectively than those calculated in the healthy elderly; (4) The mean ratio of the of anti-factor Xa and anti-thrombin clearances was close to 2 in the healthy subjects but equal to 5.4 in the patients. These results suggest that the mechanisms involved in the clearance of polysaccharide chains which support the anti-thrombin activity are different from those of the anti-factor Xa activity and that the enhanced binding properties of plasma proteins to unfractionated heparin reported in patients presenting an acute venous thromboembolism also exists for LMWH, predominantly for the anti-thrombin activity.

Embryology of esophageal atresia in the adriamycin rat model

PURPOSE

The aim of this study was to describe the dysmorphogenetic process leading to esophageal atresia and tracheoesophageal fistula (EA + TEF) in the recently developed Adriamycin model of the malformation.

METHODS

Time-mated pregnant rats were given either Adriamycin (1.75 mg/kg intraperitoneally) or saline on days 6 to 9 of gestation, and their embryos recovered on days 12, 12.5, and 13 were serially sectioned in the transversal plane and studied microscopically after H&E and PAS staining. The findings were compared with those of age-matched untreated embryos.

RESULTS

All untreated and saline embryos were normal, whereas 49% of Adriamycin embryos had foregut malformations. Tracheoesophageal separation was complete on day 12 in control embryos, whereas 9 of 10 Adriamycin-exposed embryos had a common esophagotrachea with low emergence of the bronchi at that stage. This pattern had evolved into that of a regular EA + TEF in all nine malformed embryos by day 13. On day 12.5, esophagotrachea was found in 6 of 13 and EA + TEF in 5 of 13 embryos. Two had less well-defined malformations.

CONCLUSIONS

Esophagotrachea equivalent to complete tracheoesophageal cleft is the first step leading to EA + TEF in this model. The full-blown malformation is finally acquired by partial loss of the posterior wall of the foregut, which tapers-off in the mediastinal mesenchyme and respiratory differentiation of the anterior wall down to the level of bronchial bifurcation, where it constitutes the fistula and the distal esophagus.