Differential response of antioxidative enzymes of chloroplasts and mitochondria to long-term NaCl stress of pea plants

In this work the activity of superoxide dismutase (SOD) and the enzymes of the ascorbate-glutathione (ASC-GSH) cycle were investigated in chloroplasts and mitochondria from leaves of Pisum sativum L. cv. Puget after 15 days treatment with 0-130 mM NaCl. The main chloroplastic SOD activity was due to CuZn-SOD II, which was increased significantly (about 1.7-fold) by NaCl, although during severe NaCl stress (110-130 mM) chloroplastic Fe-SOD exhibited a stronger enhancement in its activity (about 3.5-fold). A sudden induction in chloroplastic APX, DHAR and GR was also caused by NaCl (70-110 mM), but not by the highest salt concentration (130 mM), at which GR and DHAR activities were similar to the control values and APX decreased. In addition, the H2O2 concentration and lipid peroxidation of membranes increased significantly, 3.5- and 7-fold, respectively, in chloroplasts under severe NaCl stress. In purified mitochondria DHAR and GR were significantly induced only at 90 and 130 mM NaCl, respectively, although DHAR activity was below control values in the highest NaCl concentrations. APX and MDHAR activities started their response to salt in mild NaCl conditions (70 mM) and increased significantly with the severity of the stress. Mn-SOD was induced only under severe NaCl concentrations. The mitochondrial H2O2 and lipid peroxidation were increased at the highest NaCl concentration although to a lesser extent (about 2-2.5-fold) than in chloroplasts, whereas the increase in carbonyl protein contents was higher in mitochondria. The results suggest that the degree of enhanced tolerance to NaCl seems to require the induction of specific isoforms, depending on the different organelles.

[The efficacy of the radioiodine treatment of toxic thyroid adenoma and multinodular goiter]

OBJECTIVE

To investigate the effect of radioiodine therapy of thyroid adenoma (TA) and toxic multinodular goitre (TMG) on function and thyroid volume.

MATERIALS AND METHODS

Prospective study which includes 14 consecutive patients with TA and 15 with TMG treated with radioiodine and followed for two years. The therapeutic dose was fixed at 15 mCi for TA and 150 microCi x g of thyroid tissue/uptakes at 6 h (mean dose: 14.4 +/- 4.1 mCi) for TMG. Thyroid function and echographic thyroid volume were determined before and at 1, 3, 6, 12 and 24 months.

RESULTS

90% of patients with TA and 80% with TMG recovered euthyroidism at the third month. One patient with TA and three with TMG required two doses. The latter patients were the only ones with hypothyroidism at two years. The TA volume decreased from 20 +/- 8.5 ml to 10.4 +/- 8.1 ml at two years (p = 0.004). The extranodular thyroid volume did not change (initial: 16.4 +/- 10.4 ml versus 15.6 +/- 3.8 ml at the second year). The thyroid volume in TMG decreased from 66.5 +/- 28 ml to 39.8 +/- 13.5 ml at two years (p = 0.006). The largest reductions for TA and TMG were 54% and 38%, respectively, within the first six months. Only one patient with TA and another patient with TMG had their volumes transiently increased, lower than 10%.

CONCLUSIONS

Therapy with radioiodine of TA and TMG achieves a rapid recovery of euthyroidism and a gradual decrease in thyroid volume with a low incidence of hypothyroidism, with no additional secondary effects. It has proved to be a valid alternative to surgical therapy.

Blood volumes and renal function in overt and subclinical primary hypothyroidism

INTRODUCTION

Thyroid dysfunction is associated with marked alterations in cardiovascular and renal functions. In hypothyroidism, myocardial contractility, cardiac output, and oxygen consumption are decreased, whereas peripheral resistance is increased.

METHODS

We assessed blood volumes and effective renal plasma blood flow (ERPF) and glomerular filtration rate (GFR) in 17 patients with overt primary hypothyroidism and in 15 of these patients when in euthyroid state after substitutive therapy. We performed the same measurements in eight patients with subclinical hypothyroidism.

RESULTS

In the hypothyroid state, the plasma volume measured by dilution of 125I-albumin (APV) was higher than the calculated plasma volume (CPV) from packed red cell mass, suggesting an extravascular escape of albumin. After substitutive therapy, the CPV showed a statistical increase (P < 0.05), whereas APV remained unchanged. Both ERPF and GFR increased after thyroxine therapy (p < 0.05). In the subclinical group, blood volumes and renal function were similar to those found in the other group of patients when in the euthyroid state.

CONCLUSIONS

We conclude that in primary hypothyroidism, ERPF and GFR are low, but that these values improve with substitutive therapy. CPV is a better index of the current plasma volume than APV. The difference between these two parameters suggests that the escape of albumin into the extravascular space in primary hypothyroidism is terminated by treatment. There are no clear abnormalities either in blood volumes or in renal function in subclinical hypothyroidism.

Insulin regulation of leptin synthesis and secretion in humans: the model of myotonic dystrophy

OBJECTIVE

Myotonic dystrophy (MyD) is a systemic disorder in which insulin resistance is well recognized. In the present study we have characterized plasma leptin levels in patients with MyD and in age, sex and body mass index (BMI) matched controls and assessed the influence of leptin on the clinical manifestations of MyD.

DESIGN AND PATIENTS

Body composition, plasma leptin, fasting and post-oral glucose tolerance test insulin, IGF-I and IGFBP3 were studied in 34 MyD patients and 33 controls.

MEASUREMENTS

Body composition was measured using a bioelectrical impedance analyzer, and circulating levels of insulin, leptin, IGF-I, IGFBP3 were measured by IRMA or RIA. Insulin sensitivity was modelled according to a homeostasis model assessment (HOMA) computer-solved model.

RESULTS

Percentage body fat was higher in patients than in controls (25.6 +/- 2.28% vs 18.8 +/- 1.53%, P = 0.013). Insulin levels, both fasting and after oral glucose were higher in patients than in controls, and insulin sensitivity was lower in patients than in controls. Serum leptin was higher in patients than in controls (20.98 +/- 3.11 micrograms/l vs 10.4 +/- 1.31 micrograms/l, P = 0.004), and higher in women than in men, both in patients and in controls. In patients, leptin levels were correlated with age, BMI, fasting insulin, insulin area under curve and lower insulin sensitivity, whereas leptin levels were not correlated with body fat or other parameters of body composition. In controls, leptin levels were correlated with BMI and body fat. The results were evaluated using logistic regression models for each of the 2 populations. In the model of MyD, insulin resistance and age correctly identified higher leptin levels in relation to controls out of 87.88% of patients, and in the model of controls male sex with a negative correlation and BMI correctly identified their leptin levels out of 84.33% cases.

CONCLUSIONS

These findings show that MyD provides a different model of leptin regulation in humans, and suggest that in MyD patients there are correlations between leptin and insulin resistance and age, irrespective of body fat. In contrast, leptin levels in controls, correlate with sex and BMI. The data on leptin in this population of patients can not be related aetiologically to the muscle disease itself.

Neuromas and prominent corneal nerves without MEN 2B

PURPOSE

We studied a family composed of 2 members with the characteristic phenotype of the MEN 2B and without RET protooncogene mutations in order to determine whether they had multiple endocrine neoplasia associated with MEN 2B in the 5-year follow-up.

SUBJECTS AND METHODS

The family consisted of a 15 year old female complaining of burning eyes, examined ophthalmologically in 1992 and her mother and sister, who were examined later on in 1992. The proband and the mother were affected with multiple mucosal neuromas and visible corneal nerves. Pentagastrin-stimulated serum calcitonin levels, catecholamines, serum calcium and phosphate levels were measured. Molecular genetic studies were performed on the 2 affected members to look for the specific RET mutation seen in MEN 2B.

RESULTS

Endocrine neoplasia of the syndrome MEN 2B, medullary thyroid carcinoma, pheochromocytoma and hyperparathyroidism, were ruled out in the first examination and after 5-year follow-up. In the 2 cases no mutation at codon 918 for the RET proto-oncogene was found.

CONCLUSIONS

We consider that familial multiple mucosal neuromas are a highly distinctive entity of MEN 2B.

Clinical presentation and early course of type 1 diabetes in patients with and without thyroid autoimmunity

OBJECTIVE

To evaluate the prevalence of thyroid autoimmunity (TAI) in patients with recent-onset type 1 diabetes and to determine the influence of TAI on the clinical presentation and evolution of type 1 diabetes.

RESEARCH DESIGN AND METHODS

We studied 111 newly diagnosed type 1 diabetes patients > 13 years old. The diagnosis of TAI was based on medical history and measurement of thyroid peroxidase (microsomal) antibodies (TPOAs). Clinical presentation of diabetes, beta-cell autoimmune markers (GADAs and 1A2As), and evolution of insulin-secretory reserves and metabolic control during the first 2 years of follow-up were analyzed. Differences between groups were evaluated by Student's t test or the chi 2 test. The influence of TAI on follow-up data was evaluated by multiple logistic regression analysis.

RESULTS

TAI was present in 31 patients (14 TPOA+ patients with normal thyroid function, 12 TPOA+ patients with thyroid dysfunction, and 5 patients with previously diagnosed TAI). TAI was more prevalent in women than in men (43.7 vs. 15.9%, P = 0.001). beta-Cell autoimmunity was more prevalent in patients with TAI than in those without TAI (93.5 vs. 76.3%, P = 0.03). The evolution of insulin requirements, metabolic control, and insulin-secretory reserves was comparable in the two groups.

CONCLUSIONS

TAI is present in many type 1 diabetes patients at the time of diagnosis and is associated with a high prevalence of thyroid dysfunction. The clinical presentation of diabetes and the evolution of metabolic control and insulin-secretory reserves are not influenced by the presence of TAI. Patients with type 1 diabetes should be screened for TAI at diagnosis.

Leptin after IGF-I generation test in a patient with hypopituitarism and myotonic dystrophy disease

A 54-years-old woman diagnosed of myotonic dystrophy (MyD) with past medical history of massive postpartum haemorrhage at age 28 and panhypopituitarism was studied. BMI and body composition were determined and we determined baseline serum IGF-I, IGFBP3, insulin and leptin levels and after the IGF-I generation test performed after the GH administration of 0.1 U/kg/day s.c each evening for 4 days. As expected the patient had lower baseline IGF-I and IGFBP3 with high insulin and leptin levels. After IGF-I generation test, IGF-I, IGFBP3 and insulin levels increases without changes in body composition and leptin levels. In the current study, high leptin baseline levels may reflect the hyperinsulinism action over the adipose tissue in MyD and the effect of hypopituitarism over leptin regulation. After 4 days of GH administration, we demonstrated the lack of a modulatory role on leptin levels of GH and acute insulin increase, and a direct effect of GH on leptin can be excluded.

[Usefulness of the genetic study in the diagnosis of medullary carcinoma of the thyroid]

Germ-line mutations in the RET proto-oncogene are associated with multiple endocrine neoplasia type 2A (MEN 2A) and with familial medullary thyroid carcinoma (FMTC). Detection of these mutations allows the identification of the affected kindred members, who will develop medullary thyroid carcinoma (MTC) in 100% of cases. We studied 24 patients of two kindreds (MEN 2A and FMTC). Basal calcitonin levels and pentagastrin-stimulated calcitonin were measured in all patients. The RET mutations were detected by DNA analysis. The RET mutations were identified in 14 patients. Two of them had been operated in the past, 2 refused operation and 4 were living abroad. In the 6 remaining, only one showed a thyroid mass, basal calcitonin was normal in all patients except one, and pentagastrin-stimulated calcitonin was negative in 2 patients. Total thyroidectomy was performed in all cases. Histology showed C-cell hyperplasia in all patients and MTC in 5 of them. In MEN 2A and FMTC DNA analysis allows the identification of RET mutation carriers, in which presymptomatic thyroidectomy allows and improvement in survival.

Changes in medical education in Spain

In Spain, the lack of homogeneous criteria among medical institutions has led to gaps between medical school, residency, and continuing medical education. The authors describe the background and early history of the Spanish medical education system, early reforms, and the start of modern postgraduate medical education. They discuss the current system, highlighting ongoing concerns about how physicians are trained, including the emphasis on lectures and traditional assessment methods; the focus of faculty on research activities rather than teaching; inadequate assessment of residents; and the lack of coordination among providers of continuing medical education. However, they also highlight ongoing reform efforts, most notably the development of a new medical curriculum that has just begun to be implemented. They conclude with a discussion of the future direction of medical education in Spain, in which the growing movement toward greater unity among European nations is likely to play a large role.

[An analysis of the impact of the COMBELL project on clinical medical competence. Competencia clínica Bellvitge]

OBJECTIVE

The most frequent tests for evaluate medical education in our country, do not analyze clinical competence. The aims of this project was to introduce a method for the assessment of clinical skills in two different groups of students using the simulation methodology with standardized patients and to compare with classical methods of assessment.

METHODS

Seventy three last year medical students were evaluated using 10 standardized patients encounters in April 1995 (COMBELL III project) and the other group of last year medical students was assessed in March 1996 using the same group of standardized patients (COMBELL IV project).

RESULTS

The global score for the COMBELL III, was 50.6% +/- 4.8 lower to COMBELL IV, 55.6% +/- 6 (p = 0.0001), remarking the improving of the item of physical examination (39.6% +/- 7.7 versus 48.1 +/- 9.6 p < 0.0001). Personal intercommunication also improved, 63.1% +/- 11.4 versus 70.4% +/- 12.2 (p = 0.0008). We did not find differences between academic grades and did not find correlations between clinical competence assessment and academic grades in COMBELL III but we found correlations in COMBELL IV.

CONCLUSIONS

Our results show that when this new assessment method was introduces in our medical school the clinical competence levels improved.

[Assessment of prognosis factors in the cure of Cushing's disease surgically treated via a +septotransphenoidal approach]

INTRODUCTION

In Cushing's disease (CD) pituitary surgery or radiotherapy has been proposed by some authors, when plasmatic cortisol after surgery is not clearly low.

AIM

To assess if the different prognostic factors, specially plasmatic cortisol seven days after surgery and/or hypocortisolism phase are predictive of the CD outcome.

METHODS

From 1988, 11 women with CD underwent 13 transsphenoidal microsurgery, because two patients relapsed. The mean age of patients was 27 years (11-52). Plasmatic cortisol was measured seven days after pituitary surgery, and since 45 days, every three-six months, basal plasmatic cortisol and after ACTH and urinary free cortisol were determined.

RESULTS

Follow-up evaluations ranged from 18-84 months (median, 38 months). After pituitary surgery in 13 cases the cumulative remission was 100%, two cases relapsed. In 10 cases plasmatic cortisol seven days after surgery was less than 137 nmol/l and in three cases higher than 137 nmol/l. Three cases did not presented hypocortisolism phase. The two patients who relapsed, one was after eight months of pituitary surgery an previously showed low plasmatic cortisol and the other relapse 25 months after pituitary surgery without low cortisol plasmatic levels.

CONCLUSION

Remission in CD can happen either low or normal plasmatic cortisol levels seven days posttreatment or without hypocortisolism phase. Ours findings ascribe new importance to the different presentations after treatment of CD, and patients with these findings are not a risk for relapse and pituitary surgery or irradiation would not be early indicated.

[Bronchial atresia and bronchogenic cyst in an adult]

We present the case of an asymptomatic patient, with a right paracardiac mass discovered in a preoperative radiologic study. The bronchoscopy showed the intermedius bronchus atresia, finished in bottom of sack, with absence of middle and lower right lobes. With the chest computed tomographic scan, two lobulated contour mediastinal masses were seen. The patient was submitted to surgery, being the pathological findings consistent with bronchogenic cysts with atresia of the intermediarius bronchus. The patient evolved favourably after surgery.

Clinical skills assessment with standardized patients

Previous projects (Combell I & II) to assess clinical skills were conducted in medical schools in Catalonia, in order to introduce a model of such an assessment using standardized patients (SP). The aim of this study (Combell III) was to measure selected characteristics of our model. Seventy-three medical students in the final year at the Bellvitge teaching unit of the University of Barcelona participated in a clinical skills assessment (CSA) project that used 10 SP cases. The mean group scores for the four components of clinical skills for each day of testing were studied, and ratings for each student in the 10 sequential encounters were checked. The study also compared the clinical skills scores with their academic grades. The total case mean score (mean score of history-taking, physical examination and patient notes scores) was 51.9%, and the mean score for communication skills was 63.6%. The clinical skills scores over the 8 testing days showed no day-to-day differences. The study did not find differences among the sequential encounters for each student (training effect). There was a lack of correlation between clinical skills scores and academic grades. The project demonstrated the feasibility of the method for assessing clinical skills, confirmed its reliability, and showed that there is no correlation between scores with this method and academic examinations that mainly reflect knowledge.

[Vasculitis caused by Pseudomonas: a case report]

Pseudomona vasculitis is an exceptional disease. Only a few cases have been reported, non with oropharyngeal involvement. The case of a 30-year-old, HIV-positive man who suddenly developed septicemia and necrotizing lesions with tissue destruction of the oropharynx is reported. Histological study confirmed vasculitis. Pseudomona aeruginosa was isolated in peripheral blood and in the biopsy of the palatal lesion. Antibiotic treatment produced satisfactory results.

Transient hypothyroidism after iodine-131 therapy for Grave's disease

We studied 355 patients with Grave's disease to characterize transient hypothyroidism and its prognostic value following 131I therapy.

METHODS

The patients received therapeutic 131I treatment as follows: 333 received a dose < 10 mCi (6.6 +/- 1.9 mCi) and 22 received a dose > 10 mCi (12.8 +/- 2.9 mCi). Diagnosis of transient hypothyroidism was based on low T4, regardless of TSH within the first year after 131I followed by recovery of T4 and normal TSH.

RESULTS

After administration of < 10 mCi 131I, 40 patients developed transient hypothyroidism during the first year; transient hypothyroidism was symptomatic in 15. There was no transient hypothyroidism after high doses (> 10 mCi) of 131I. Iodine-131 uptake > 70% at 2 hr before treatment was a risk factor for developing transient hypothyroidism (Odds ratio 2.8, 95% confidence interval 0.9-9.4). At diagnosis of transient hypothyroidism, basal TSH levels were high (51%), normal (35%) or low (14%); therefore, the transient hypothyroidism was not centralized. If hypothyroidism developed during the first 6 mo after basal TSH > 45 mU/liter ruled out transient hypothyroidism.

CONCLUSION

The development of transient hypothyroidism and its hormonal pattern did not influence long-term thyroid function. Since no prognostic factors reliably predicted transient hypothyroidism before 131I or at the time of diagnosis, if hypothyroidism appears within the first months after 131I, the reevaluation of thyroid function later is warranted to avoid unnecessary chronic replacement therapy.

Secretion of growth hormone and thyroid-stimulating hormone in patients with dementia

We studied the growth hormone (GH) response to GH-releasing hormone (GHRH) and the thyroid-stimulating hormone (TSH) response to thyrotropin-releasing hormone (TRH) in four groups of patients with dementia and examined whether GH and TSH secretion is altered in patients with Alzheimer's disease. The four groups included those with Alzheimer's disease (n = 28), parkinsonism with dementia (n = 10), progressive supranuclear palsy with dementia (n = 10), and dementia of vascular origin (n = 28). The results showed no differences among the four groups in GH response to GHRH (12.2 +/- 2, 10.7 +/- 2, 8.9 +/- 1.1, and 9.9 +/- 1.9 micrograms/ml, respectively); there was no correlation between GH response to GHRH and sex, stage of the disease, or cerebral atrophy. The proportion of patients with exaggerated, normal, or lower GH response was similar in the four groups in terms of TSH response to TRH (9.2 +/- 0.9, 11.1 +/- 1, 11.1 +/- 1, and 10.3 +/- 1 mU/ml, respectively), nor was there a correlation between TSH response to TRH and sex, stage of the disease, cerebral atrophy, or GH response to GHRH. The proportion of those with exaggerated, normal, or lower TSH response was similar in the four groups. Cerebrospinal somatostatin levels were similar in Alzheimer's disease and vascular dementia patients. These findings indicate that neither GH response to GHRH nor TSH response to TRH provides a useful diagnostic adjunct in Alzheimer's disease patients.

[Basal cortisol and ACTH in the immediate postoperative period in ACTH-producing hypophyseal adenomas]

BACKGROUND

Evaluate the usefulness of basal cortisol and ACTH during the immediate postoperative period following hypophyseal surgery, as early indicators of remission in patients with Cushing's disease.

METHODS

Nine patients with Cushing's disease and on whom selective transphenoidal adenomectomy was performed were included in the study. Basal cortisol and ACTH levels were compared the first week after surgery, with definitive results being obtained after a month's time during which basal cortisol levels below 165 nmol/l indicated patients cured of Cushing's disease.

RESULTS

Cortisol levels determined post-op, in five patients in remission, were found to be lower than those in patients who were not cured (63 +/- 55.8 versus 606 +/- 267 nmol/l, p < 0.01). However, ACTH levels were not lower. All the patients in remission had initial cortisol levels lower than 182 nmol/l, whereas the uncured patients had levels higher than 404 nmol/l. There was a correlation between cortisol measured in the first week and the definitive value (r = 0.81, p < 0.01).

CONCLUSION

Cortisol in the immediate postoperative period following hypophyseal surgery is a good indicator of definitive adrenocorticotropic function and permits the identification of those patients in remission.

Tuberculous Addison's disease. Utility of CT in diagnosis and follow-up

The computed tomographic (CT) findings in five patients with tuberculous Addison's disease were evaluated. All patients had extra-adrenal tuberculosis. Two patients had enlarged adrenal glands with calcifications at the times of diagnosis. Follow-up CT from 4 to 30 months showed a progressive decrease in the size of adrenal glands from bilateral enlargement to small calcified glands and provides a clue to the etiology of Addison's disease and proper therapy.

[Value of basal cortisol and ACTH in the immediate postoperative period of hypophyseal surgery in non-ACTH secretory adenomas]

BACKGROUND

The aim of this study was to evaluate the usefulness of basal cortisol and ACTH in the immediate postoperative period of pituitary surgery as indicators of definitive adrenocorticotropin function.

METHODS

Twenty-one patients with pituitary, non producers of ACTH, adenomas, three microadenomas and 18 macroadenomas treated by adenomectomy by a trans-sphenoidal route were respectively studied. The basal cortisol and ACTH were compared in the first week following surgery with the definitive results obtained after one month by dynamic tests (stimulation with ACTH or insulin hypoglycemia).

RESULTS

The six patients with secondary adrenal failure (AF) in the definitive evaluation had lower basal cortisol in the immediate postoperative period than the patients with AF (135.3 +/- 225.3 nmol/l versus 473.6 +/- 147.2 nmol/l; p < 0.05). The values of ACTH were also lower (2.3 +/- 1.6 nmol/l versus 4.8 +/- 3.4; p < 0.05). In all the patients with definitive AF except one, the basal cortisol in the first week was lower than 130 nmol/l and in those who did not present AF it was greater than 220 nmol/l.

CONCLUSIONS

In the immediate postoperative period after pituitary surgery cortisol is a good indicator of definitive adrenocorticotropin function. This parameter may identify the patients requiring posterior substitutive treatment.