Different strategies of Lotus japonicus, L. corniculatus and L. tenuis to deal with complete submergence at seedling stage.

Two main strategies allow plants to deal with submergence: (i) escape from below water by means of shoot elongation, or (ii) remaining quiescent under the water until water subsides and then resume growth. We investigated these strategies in seedlings of Lotus japonicus, L. corniculatus and L. tenuis subjected to control and submergence for 12 days, with a subsequent 30-day recovery period. All three species survived submergence but used different strategies. Submerged seedlings of L. japonicus exhibited an escape strategy (emerging from water) as a result of preferential carbon allocation towards shoot mass and lengthening, in detriment to root growth. In contrast, seedlings of L. corniculatus and L. tenuis became quiescent, with no biomass accumulation, no new unfolding of leaves and no shoot elongation. Upon de-submergence, seedlings of L. japonicus had the lowest recovery growth (a biomass and shoot height 58% and 40% less than controls, respectively), L. corniculatus was intermediate and L. tenuis showed the greatest recovery growth. Previously submerged seedlings of L. tenuis did not differ from their controls, either in final shoot biomass or shoot height. Thus, for the studied species, quiescence appears to be an adequate strategy for tolerance of short-term (i.e., 12 days) complete submergence, being consistent with field observations of L. tenuis colonisation of flood-prone environments.

HLA Genes in Mayos Population from Northeast Mexico.

HLA class I and class II alleles have been studied in 60 unrelated people belonging to Mayos ethnic group, which lives in the Mexican Pacific Sinaloa State. Mayos HLA profile was compared to other Amerindians and worldwide populations' profile. A total of 14,896 chromosomes were used for comparisons. Genetic distances between populations, Neigbour-Joining dendrograms and correspondence analyses were performed to determine the genetic relationship among population. The new specific Mayo HLA haplotypes found are: HLA-A*02-B*35-DRB1*1406-DQB1*0301; HLA-A*02-B*48-DRB1*0404-DQB1*0302; HLA-A*24-B*51-DRB1*0407-DQB1*0302 and HLA-A*02-B*08-DRB1*0407-DQB1*0302. However, the typical Meso American HLADRB1*0407 represents a 40% of all DRB1 alleles. While common HLA characteristics are found in Amerindian distant ethnic groups, still new group specific HLA haplotypes are being found, suggesting that a common founder effect (i.e. high DRB1*0407) is noticed. Moreover, new HLA haplotypes are almost certainly appearing along time probably due to specific pathogen (?) selection for diversity. Mayo language is close to the Tarahumara one (another geographically close group); notwithstanding both groups are not genetically close according to our results, showing again the different evolution of genes and languages, which do not correlate. Finally, Sinaloa is one of the Mexican States in which more European genes are found. However, the results presented in this paper, where no European HLA genes are seen in Mayos, should have a bearing in establishing transplant programs and in HLA and disease studies.

Functional approach to investigate Lp(a) in ischaemic heart and cerebral diseases.

BACKGROUND: Lp(a), a major cardiovascular risk factor, contains a specific apolipoprotein, apo(a), which by virtue of structural homology with plasminogen inhibits the formation of plasmin, the fibrinolytic enzyme. A number of clinical reports support the role of Lp(a) as a cardiovascular or cerebral risk factor, and experimental data suggest that it may contribute to atherothrombosis by inhibiting fibrinolysis. DESIGN: A well-characterized model of a fibrin surface and an apo(a)-specific monoclonal antibody were used to develop a functional approach to detect pathogenic Lp(a). The assay is based on the competitive binding of Lp(a) and plasminogen for fibrin, and quantifies fibrin-bound Lp(a). High Lp(a) binding to fibrin is correlated with decreased plasmin formation. In a transversal case-control study we studied 248 individuals: 105 had a history of ischaemic cardiopathy (IC), 52 had cerebro-vascular disease (CVD) of thrombotic origin, and 91 were controls. RESULTS: The remarkably high apo(a) fibrin-binding in CVD (0.268 +/- 0.15 nmol L-1) compared with IC (0.155 +/- 0.12 nmol L-1) suggests the existence of peculiar and poorly understood differences in pro- or anti-thrombotic mechanisms in either cerebral and/or coronary arteries. CONCLUSIONS: Our results demonstrated that Lp(a) fibrin-binding and small Apo(a) isoforms are associated with athero-thrombotic disease.

LMP2 and LMP7 gene polymorphism in Mexican populations: Mestizos and Amerindians.

Low molecular weight polypeptide (LMP) genes are located within the major histocompatibility complex and have been associated with autoimmune diseases such as ankylosing spondylitis. In order to define the distribution of LMP genes in Mexican populations, the LMP2 and LMP7 polymorphism was analyzed in 312 Mexican individuals (95 Mexican Mestizos, 48 Nahuas, 56 Mazatecans, 50 Teenek, and 63 Mayos) belonging to different ethnic groups. In Mexican populations both Mestizos and Amerindians presented similar distribution of LMP2 and LMP7 polymorphisms, except Nahuas and Mayos who presented the higher frequencies of LMP2-H/H and the lowest frequencies of LMP2-H/R genotypes (P < 0.05 when compared with Mexican Mestizos). The LMP7-K/K genotype was absent in Nahuas, Teenek and Mayos and only one Mazatecan individual presented this genotype. Differences with other populations were found in Mexicans. An increased frequency of LMP2-H and a decreased frequency of LMP2-R alleles were observed in Mexican Amerindians (Nahuas and Mayos) when compared with Brazilian Amerindians (Kaingang and Guarani) and Caucasians (Spaniards) (P < 0.05). All Mexican populations (Mestizos and Amerindians) presented an increased frequency of LMP7-Q allele and a decreased frequency of LMP7-K allele when compared to Brazilian Amerindians (Kaingang), Caucasians (United States) and Asian (Japan) populations (P < 0.05). Genetic distances showed that Mexican Mestizos have an important relation with Spaniards and with all Mexican Amerindians. The present data corroborate the influence of Spaniard and Amerindian genes in the Mexican Mestizo population and could help to define the true significance of LMP polymorphism as genetic and evolutive marker in the Amerindian populations.

[Heart disease, anticoagulants and pregnancy]. / Cardiopatía, anticoagulantes y embarazo.

In patients with mechanical prosthetic heart valves, long-term anticoagulant therapy is mandatory to prevent thromboembolic phenomena. Anticoagulation is also necessary in patients with mitral valvular disease and atrial fibrillation. The risk of maternal thromboembolic events is heightened during pregnancy because of the patient's hypercoagulable state. Controversy exists concerning the appropriate treatment of these patients. No method of anticoagulation is risk free. Coumarin derivatives provide adequate protection against thromboembolism and should be used during pregnancy in patients with mechanical prostheses. The administration of coumarin derivatives in the first trimester is associated with an incidence of 26.7% of spontaneous abortion and a risk of 4.1% of coumarin embryopathy. Heparin does not cross the placental barrier and it is the obvious therapeutic alternative. The teratogenic effects of the coumarinics are prevented if these agents are discontinued and replaced by heparin from before the 6th until the end of the 12th week of gestation. However, subcutaneous unfractionated heparin, in the doses that have been employed, does not provide adequate prophylaxis against thromboembolism in these women. In patients treated with heparin, the incidence of spontaneous abortion is similar to that observed when the mothers are treated with coumarin agents. In order to avoid the delivery of an anticoagulated infant, intravenous heparin in full doses, should be substituted for the coumarin agent in the last two weeks of gestation.When anticoagulant therapy is not necessary, the course of pregnancy in women with bioprostheses is similar to that of the general population. However, the short duration of tissue valves is a clear disadvantage for these women

Effect of perezone, aminoperezone and their corresponding isomers isoperezone and isoaminoperezone upon in vitro platelet aggregation.

The effect on platelet aggregation of perezone, isoperezone, aminoperezone and isoaminoperezone has been determined in human platelets, using adenosinediphosphate (ADP), epinephrine and collagen as inducers. Perezone inhibited ADP- epinephrine- and collagen-induced platelet aggregation; isoperezone, aminoperezone and isoaminoperezone did not. The difference in biological responses could be the result of their structures. While isoperezone, aminoperezone and isoaminoperezone have carbonyl groups in the vicinity of other functional groups, this is not the case for perezone, in which one of the carbonyl groups has an adjacent free position.

Failure of adjusted doses of subcutaneous heparin to prevent thromboembolic phenomena in pregnant patients with mechanical cardiac valve prostheses.

OBJECTIVES: This report describes our experience with the use of an anticoagulant regimen of adjusted doses of subcutaneous heparin during pregnancy in women with cardiac valve prostheses. BACKGROUND: Gravid patients with prosthetic heart valves require long-term anticoagulant therapy. To avoid the increased incidence of fetal morbidity and mortality associated with the use of coumarin agents in such patients during pregnancy, anticoagulation with subcutaneous heparin has been suggested. Controversy exists concerning the appropriate treatment of these patients. METHODS: Forty pregnancies in 37 women with prosthetic heart valves were prospectively followed up. Subcutaneous heparin was administered from the 6th until the end of the 12th week and in the last 2 weeks of gestation. Heparin was given every 8 h in the first 36 cases and every 6 h in the last 4 cases, and the dose adjusted to maintain the activated partial thromboplastin time at 1.5 to 2.5 times the control level. Acenocoumarol was used at other times. RESULTS: The incidence rate of spontaneous abortions was 37.5%; there was one neonatal death (2.5%) due to cerebral hemorrhage. No signs of coumarin-induced embryopathy were found in any of the 16 live-born infants studied by the geneticist. One mother died of gastrointestinal bleeding while receiving oral anticoagulant agents. There were two cases of fatal massive thrombosis of a mitral tilting-disk prosthesis during heparin therapy. The study was interrupted after the last of these two cases. CONCLUSIONS: The regimen of adjusted doses of subcutaneous heparin used in this study is not effective to prevent thrombosis of mechanical valve prostheses during pregnancy. The use of heparin from the 6th to the 12th week of gestation does not decrease the high incidence of fetal wastage associated with anticoagulant therapy. Coumarin agents provide adequate protection against thromboembolism during pregnancy in patients with mechanical valve prostheses.

Primary antiphospholipid syndrome presenting as chronic thromboembolic pulmonary hypertension. Treatment with thromboendarterectomy.

Pulmonary hypertension may occur in the antiphospholipid syndrome as a result of recurrent pulmonary embolism or microthrombosis of pulmonary vessels. We describe 3 cases of primary antiphospholipid syndrome (APS) and cor pulmonale that fulfilled the criteria for chronic major vessel thromboembolic pulmonary hypertension. Pulmonary thromboendarterectomy was performed in all 3 patients and it was successful in 2. One patient died in the immediate postoperative period from hemorrhagic pulmonary edema. Chronic thromboembolic pulmonary hypertension should be added to the list of pulmonary vascular complications of primary APS. Despite its risk, pulmonary thromboendarterectomy represents a treatment option for this otherwise lethal condition.

[Hematological differences between the effects of roller vs, centrifugal pump]. / Diferencias hematológicas entre los effectos de las bombas de rodillo y centrífuga.

A secondary complication in the utilization of the CPB (cardiopulmonary bypass) is post-op bleeding due to alterations in the red blood cells and the activation sequences between coagulation, fibrinolysis and complement. We did this study with the objective to evaluate the behavior of the blood cells and coagulation factors using centrifugal pump (n = 12) roller pump (n = 12); we evaluated the consumption of blood products as well as measuring the amount of blood products used. There were no demographic differences between the two groups, the time on CPB was less than 85 minutes, blood flow in the centrifugal pump was maintained at an average of 3.6 l Vs 3.37 l in the roller pump, this being statistically significant. The blood values were compared in each group there were no statistically significant differences, however factor VIII, fibrinogen and platelets presented a tendency (p < 0.05) to be higher in the centrifugal pump group than in the control group (roller pump). Thus 1. In patients in whom we used centrifugal pump there was a tendency for preservation of factor VIII, platelets and fibrinogen. 2. There was no significant difference in the number of blood units transfused between the centrifugal vs roller pump. 3. patients in the centrifugal group were better perfused during CPB.4. 24 hrs. post-op, both groups showed no difference in post-op bleeding.

Gestational diabetes in a Mexican-U.S. border population: prevalence and epidemiology.

OBJECTIVE: To determine the prevalence of gestational diabetes (GD) in a Mexican-U.S. border population and to observe the response of such a population to a 100 gram challenge of glucose. RESEARCH DESIGN AND METHODS: The sample was a cross section of 519 pregnant women accesing different health institutions in Juarez, Mexico, with 24-36 weeks of gestation. An oral glucose tolerance test (OGTT) with a 100 gram challenge of glucose was done on all. Results were interpreted according to the diagnostic criteria of O'Sullivan and Mahan. Information on family history of diabetes, obstetric history, height and weight was obtained. RESULTS: A total of 20.4% of the patients examined had some kind of glucose intolerance 11% with GD and 9.4% with one abnormal value during the glucose tolerance test. The patients with GD tended to be older, had higher gravidity, lower height, higher weight and reported frequently a family history of diabetes. The patients with one abnormal value were similar to those with GD in weight and number of pregnancies, and were comparable to the group with normal glucose tolerance test in height and family history of diabetes. CONCLUSIONS: We found a high prevalence of GD and of one abnormal value during the OGTT in a Mexican population. The recommendations for screening for GD must be consistently implemented in pregnant women of Mexican ancestry.

Prothrombotic states in young people with idiopathic stroke. A prospective study.

BACKGROUND AND PURPOSE: Although 4% of cerebral infarcts in the young can be attributed to hematologic disturbances that predispose to thrombosis, the frequency of cerebral infarcts caused by prothrombotic states is not known. Recently, the association between cerebral infarction and deficiencies of elements of the natural anticoagulant system has been recognized. METHODS: Thirty-six consecutive patients under 40 years of age with cerebral infarction of undetermined cause were prospectively studied. Quantitation of natural anticoagulants was done at least 3 months after the cerebral infarction. The following activity tests were performed, all by the chromogenic method: antithrombin III, protein C, plasminogen, tissue plasminogen activator, and inhibitor of tissue plasminogen activator. Protein S was quantified by the Laurell rocket method. All patients underwent a complete cardiological examination, including two-dimensional echocardiography, as well as four-vessel cerebral angiography. Some patients were also studied by transesophageal echocardiography. RESULTS: Of 36 patients, 17 were male, with a mean age of 28 years. Mean age for women was 25 years. Nine patients (25%; 5 women, 4 men) had a deficiency of one natural anticoagulant and constituted group I. In these patients, isolated protein S deficiency was detected in five cases (13.8%); in one case, we observed the association between protein S deficiency and antiphospholipid antibodies; and deficiency of protein C was seen in one case (2.7%), of antithrombin III in one case (2.7%), and of plasminogen in one case (2.7%). Instances of cerebral infarction without natural anticoagulant deficiency (group II) included 12 women and 15 men. There were no differences in clinical and radiological findings between the two groups. CONCLUSIONS: Considering the importance of prothrombotic state, especially caused by deficiency of protein S, in the development of cerebral infarcts, we suggest that it should be looked for in every young patient affected by this pathological entity and in whom no etiologic factors can be determined.

Progressive intracranial occlusive disease associated with deficiency of protein S. Report of two cases.

BACKGROUND AND PURPOSE: Deficiency of the free fraction of protein S has been associated with arterial or venous stroke. The pathogenesis of vascular occlusion in patients with protein S deficiency is not known. We present two cases of cerebral infarction and deficiency of protein S in which the subjects had progressive intracranial occlusions. CASE DESCRIPTION: A 16-year-old girl was admitted because of left brain stem infarction and protein S deficiency. Cerebral angiography disclosed stenosis of the right intracranial vertebral artery and occlusion of the left posterior cerebral artery. A second angiogram performed 18 months later disclosed occlusion of the right vertebral intracranial artery. In the second case, a 17-year-old girl was admitted because of left hemispheric cerebral infarction and protein S deficiency. Cerebral angiography showed stenosis of the left anterior cerebral artery, left supraclinoid internal artery, and left middle cerebral artery. A second cerebral angiogram performed 5 months later disclosed occlusion of the left anterior cerebral artery and poor hemispheric perfusion through the left middle cerebral artery. CONCLUSIONS: Based on our cases, we postulate that some patients with prothrombotic states may develop progressive intracranial arterial occlusions, possibly secondary to a permanent thrombogenic stimulus. We suggest routinely searching for prothrombotic states in young patients with intracranial occlusion, especially if the occlusion is progressive and other causes are not obvious.

Comparative effect of synthetic aminoestrogens with estradiol on platelet aggregation.

The in vitro effect upon platelet aggregation of estradiol and synthetic estrogens (prolame, buame, and proacame) is described. Prolame and buame produced a dose-dependent inhibition on platelet aggregation. Estradiol and proacame did not show anti-aggregating effects. The results suggest that the use of prolame and buame in estrogen therapy could reduce the risk of thrombo-embolic accidents.

[Takayasu arteritis; IV. Absence of autoantibodies and coagulation/fibrinolysis abnormalities]. / Arteritis de Takayasu; IV. Ausencia de autoanticuerpos y anomalías de la coagulación/fibrinolisis.

The etiopathogenesis of the non-specific arteritis known as Takayasu's arteritis, an inflammatory occlusive disease of the aorta and its main branches, is unknown. We searched for abnormalities in clotting and fibrinolytic systems, as well as the presence of non-organ specific autoantibodies, including those potentially reactive with vascular endothelium, in 21 untreated patients. There were only minor abnormalities in coagulation and fibrinolysis in a few patients, and the occasional presence of non-organ specific antibodies, including antiphospholipid antibodies. The findings had no clinical relevance. This study suggests that there is no support for a significative role of humoral immunity, coagulation and fibrinolysis in the pathogenesis of Takayasu's arteritis.

The vascular plasminogen activator as source of the fibrinolytic potential observed during cardiopulmonary bypass.

Increased fibrinolytic activity is a well recognized constant finding observed during cardiopulmonary bypass (CPB). The purpose of the present work was to study and estimate the factors involved in the plasminogen activation and prekallikrein-kallikrein systems in a population of adult patients undergoing open heart surgery with CPB. Plasminogen activator activity determinations with a fibrinolytic method as well as plasminogen activation and prekallikrein-kallikrein determinations with synthetic substrates were carried out. Our results indicate that no active fibrinolysis but a fibrinolytic potential, similar to that observed in blood obtained after venous occlusion, can be demonstrated in circulating plasma during CPB. This fibrinolytic potential is related to the presence of vascular plasminogen activator released from endothelial cells by the CPB stimulus.

El habito de fumar y el alcoholismo como factores de riesgo en el cáncer de labio

Se estudian 32 pacientes con cáncer de labios, en el trienio 1984-1986. El tabaquismo se asoció en el 87,5 porciento de los casos y el alcoholismo en el 21,8 porciento coincidiendo ambos hábitos en el 25 porciento de los pacientes. La diferencia con respecto al grupo control según el hábito de fumar fue significativa (t>1,96) y fumaron más hombres que las mujeres. La localización superior o inferior del tumor no se relacionó con el alcoholismo y sí con el hábito de fumar. No hubo influencia en la diferenciación celular del tumor con relación a ambos métodos. (AU)