Effect of age on cardiac index,stroke index and left ventricular ejection fraction at rest and during exercise as studied by radiocardiography

Radiocardiography was used to measure cardiac output, stroke volume and left ventricular ejection fraction at rest and during muscular exercise in relation with age in 148 healthy subjects (age range: 6–78 years). A clear dependence of these parameters on age was found. The mean annual decrease at rest was 22±9 ml/min/m² for cardiac index, 0.22±0.04 ml/m² for stroke index and 0.0017±0.0003 for left ventricular ejection fraction. Male subjects had significantly (p < 0.001) greater cardiac (9±4%) and stroke indices (11±23%) than females. During submaximal exercise cardiac index increased from 3.5±0.7 l/min/m' to 8.1±1.6 l/min/m² in male subjects (mean age: 32 years) and from 3.1±0.4 l/min/m² to 7.2±1.2 l/min/ m² in female subjects (mean age: 29 years). The corresponding increases in stroke index and left ventricular ejection fraction were: from 52±7 ml/m² to 62±9 ml/m². from 46±7 ml/m² to 51±9 ml/m² and from 0.66±0.08 to 0.79±0.05 and from 0.64±0.10 to 0.72±0.10. In subjects who were 60 years and older the increases of these parameters during exercise were considerably smaller.     

Cell shrinkage stimulates bradykinin-induced cell membrane potential oscillations in NIH 3T3 fibroblasts expressing the ras-oncogene

In NIH 3T3 fibroblasts expressing the Ha-ras oncogene (+ras) bradykinin leads to sustained oscillations of cell membrane potential due to oscillations of intracellular Ca²⁺ with subsequent activation of Ca²⁺-sensitive K⁺ channels. In cells not expressing the oncogene (-ras), bradykinin leads only to a single transient hyperpolarization of the cell membrane. The present study has been performed to elucidate the possible interaction of cell volume, intracellular pH and bradykinin-induced oscillations of the cell membrane potential. Bradykinin leads to cell shrinkage and intracellular alkalinization of both +ras cells and –ras cells. Inhibition of Na⁺/H⁺ exchanger by HOE 694 abolishes the bradykinin-induced alkalinization but does not significantly interfere with the bradykinin-induced oscillations of cell membrane potential. In contrast, prevention of bradykinin-induced cell shrinkage by simultaneous reduction of extracellular osmolarity blunts the oscillations. Thus, cell shrinkage stimulates bradykinin-induced oscillations of cell membrane potential. On the other hand, cell shrinkage alone does not elicit oscillations unless, in addition, Ca²⁺ entry is stimulated by ionomycin.     

Multiple endocrine cell types in thyroid medullary carcinoma

Summary 10 cases of thyroid medullary carcinoma (TMC) have been studied ultrastructurally and histochemically. Well differentiated calcitonin-producing C cells were present in all tumours, being prevalent in 9 cases. 5-Hydroxytryptamine (5HT) storing cells were found in two cases, somatostatin immunoreactive cells in at least 5 cases and ACTH-immunoreactive cells in 4 cases. Ultrastructurally, at least 3 types of apparently non-C cells were observed. Type 1 cells with large, poorly osmiophilic granules resembling those of gastroenteropancreatic D cells, were present in 6 cases; they appeared to correlate well with somatostatin immunoreactive cells. Type 2 cells with large osmiophilic granules were found in 5 cases; they resembled ACTH-MSH cells of the human pituitary and may correspond to the ACTH-immunoreactive cells of light microscopy. Type 3 cells with small granules and an unknown function were found in 6 cases, always in scarce number. It is concluded that TMC, although mainly made up of C cells, usually contains large proportions of other endocrine cell types.Supported in part by grant N. 75.00630.04 from the Italian National Research Council (C.N.R.). P.F. is a fellow of the Fondazione Anna Villa Rusconi, Varese     

ACE Genotype May Have an Effect on Single versus Multiple Set Preferences in Strength Training

A polymorphic variant of the human angiotensin converting enzyme (ACE) gene was identified. The 'D' (rather than 'I') variant was associated with improvements in strength related to physical training. We set out to determine whether the response to different patterns of strength training might also differ. Ninty-nine Caucasian male non-elite athletes were randomly allocated into one of three groups: 31 non-training/control (CG: 31), single-set (SSG: 35) and multiple-set (MSG: 33). SSG and MSG trained three times a week for 6 weeks. Both training groups were underwent a strength-training program with two mesocycles (12-15 repetition maximum (RM) and 8-12 RM mesocycles). One RM loads in half squat and bench press were assessed before training and after the first and second mesocycles. ACE polymorphisms analysed by polymerase chain reaction (PCR) methods. Subjects with ACE II genotype in the MST group had improved strength development in 12-15 RM, while SST and MST groups had similar gains in 8-12 RM. Subjects with ACE DD genotype in both the SSG and the MSG had similar benefits from both 12-15 RM and 8-12 RM. Strength gains for subjects with ACE ID genotype in the SSG were similar to MSG gains in response to 8-12 RM loads but not with 12-15 RM loads. Additionally, subjects with DD genotype had superior strength gains in both strength training groups. Tailoring strength training programmes (single-set vs. multiple set) according to the athlete's ACE genotype may be advantageous.     

Glucose-6-phosphate dehydrogenase activity in monolayer cultures of thyroid epithelial cells: TSH and inhibition of nitrogen oxide synthase affect the enzyme activity and the oxygen sensitivity of the histochemical assay

The objective was to investigate glucose-6-phosphate dehydrogenase (G6PD) activity in monolayer cultures of thyroid epithelial cells and to examine whether inhibition of nitric oxide synthase affects activity of G6PD or oxygen sensitivity of the assay. Primary cultures without TSH addition prior to experiments demonstrated a TSH-dependent increase in G6PD activity. G6PD activity was higher in F12 medium than in a serum-free physiological medium. Secondary cultures grown in F12 medium demonstrated a diminished activity of G6PD and a lack of response to TSH. In the serum-free physiological medium, G6PD activity was comparable to that found in primary cultures and a response to high concentrations of TSH was maintained. In primary cultures grown in F12 medium devoid of TSH, G6PD activity decreased dose-dependently when nitric oxide synthase activity was inhibited. The oxygen sensitivity of the assay was comparable to that reported previously in malignant cells and correlated with the activity of G6PD in primary cultures. We suggest that thyroid epithelial cells may be an appropriate system to investigate oxygen sensitivity of the G6PD assay as the cells demonstrate a reduced oxygen sensitivity which can be influenced by culture conditions.     

Kinetics of cardiorespiratory response to dynamic and rhythmic — static exercise in men

Summary Kinetics of cardiorespiratory response to dynamic (DE) and then to rhythmic-static exercise (RSE) was compared in nine male subjects exercising in an upright position on a cycle ergometer at an intensity of about 50 % O_2max and a mean pedalling frequency of 60 rpm over 5 min. Respiratory frequency (f _R), tidal volume (V _T), minute ventilation ( _E), heart rate (f _c), stroke volume (SV), and cardiac output (Q _t) were measured continuously. The RSE caused a greater increase in f _R than DE, whereas V _T increased more during DE. The effect of reciprocal changes in f _R and V _T was that _E and its kinetics, expressed as a time constant (), did not differ between experimental situations. The ventilatory equivalent for O₂ ( _E: O₂) was greater for RSE (31.3) than for DE (23.0, P<0.01). Elevation of f _c was similar for both types of exercise. The SV increased suddenly at the beginning of DE from 54 ml to 74 ml and then decreased to the end of exercise. At the onset of RSE only a moderate increase in SV was observed, from 56 ml to 62 ml, and then SV remained stable. The DE caused a greater and faster increase in Q _t (4.20 l · min^–1, for equal to 16.1s) than RSE (3.25 l · min^–1, for equal to 57.0s, P<0.05 and P<0.002, respectively). Total peripheral resistance was almost 40% greater for RSE than for DE. No relationship was found between Q _t and V_E at the first 15 s of both types of exercise. It is concluded that the kinetics of _E did not depend on to kinetics of Q _t in the exercising subjects. This finding contradicts the hypothesis of cardiodynamic hyperpnoea indicating an importance of neurogenic factors, mediated either centrally or peripherally, in fast cardiorespiratory responses to exercise.     

血清抗甲状腺球蛋白抗体和抗甲状腺过氧化物酶抗体检测在甲状腺疾病诊断及甲亢预后判断中的价值

采用放免法检测甲状豚疾病患者抗甲状腺球蛋白抗体（ＴＧＡｂ）和抗甲状腺过氧化物酶抗体（ＴＰＯＡｂ）、并对部分Ｇｒａｖｅｓ病患者停药后随诊一年的结果进行分析。结果显示：（１）自身免疫性甲状腺疾病患者ＴＧＡｂ和ＴＰＯＡｂ活性及阳性率明显高于非ＡＩＴＤ，尤以桥本甲状腺炎为然。（２）ＧＤ治疗前及停药时ＴＧＡｂ和ＴＰＯＡｂ均阴性者与均阳性者停药一年内的复发率分别为０．５８３和０．２３１。（３）ＴＧＡｂ和ＴＰＯＡｂ均阴性，而停药时甲状腺刺激抗体（ＴＳＡｂ）阳性者，停药时ＧＤ复发的机率最大（０．９０９），提示ＴＧＡｂ和ＴＰＯＡｂ检测在ＡＩＴＤ诊断，鉴别诊断以及ＧＤ预后判断中具有重要的临床意义。     

Evaluation of encephalic ventricular volume from the magnetic resonance imaging scans of thirty-eight human subjects

Summary Accurate volume determination of the encephalic ventricles is of importance in several clinical conditions, including Alzheimer's presenile dementia, schizophrenia, and benign intracranial hypertension. Previous studies have investigated the accuracy with which magnetic resonance imaging (MRI) can be used in clinical practice to evaluate the encephalic ventricles. However, adequate evaluation of pathological conditions depends on a sufficient amount of morphometric data from normal subjects. To begin establishing this data base for normal subjects, we evaluated the MRI scans of 38 subjects found to have no apparent pathology and calculated the ventricular volume in each case by using methods previously developed in our laboratory. The results were then compared with published volumes determined from studies that used either ventricular casts or computerized tomographic scans. The average total ventricular volume for all 38 subjects was 17.4 cm³, while that for males was 16.3 cm³ and that for females was 18.0 cm³. A small but significant correlation was found between age of subject and ventricular volume, with ventricular size increasing with age.

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Evaluation du volume des ventricules cérébraux à partir des images obtenues en résonance magnétique nucléaire chez 38 sujets humains

Résumé La détermination exacte du volume des ventricules cérébraux est importante en clinique comme par exemple dans la démence présénile d'Alzheimer, la schizophrénie et l'hypertension intracrânienne bénigne. Des études antérieures ont étudié la fiabilité de la résonance magnétique nucléaire en pratique clinique pour évaluer le volume des ventricules cérébraux. Toutefois une évaluation correcte dans les conditions pathologiques implique une bonne connaissance des données morphométriques du sujet normal. Pour établir ces données sur « le sujet normal », nous avons étudié les coupes obtenues en IRM chez 38 sujets apparemment indemnes de toute pathologie; nous avons calculé le volume ventriculaire dans chaque cas en utilisant des méthodes mises au point auparavant dans notre laboratoire. Les résultats ont été ensuite comparés avec ceux obtenus par d'autres études utilisant soit des moules ventriculaires, soit des coupes tomographiques computérisées. Le volume ventriculaire total moyen chez 38 sujets est de 17,4 cm³, mais il est chez les sujets masculins de 16,3 cm³ et chez les sujets de sexe féminin de 18 cm³. Une corrélation faible mais significative a été trouvée entre l'âge du sujet et le volume ventriculaire, étant entendu que la taille du ventricule augmente avec l'âge.

     

IgG-KAPPA-PRODUCING PRIMARY PLASMACYTOMA OF THE THYROID GLAND WITH PREOPERATIVE SERUM M PROTEIN

A case of primary plasmacytoma of the thyroid gland which occurred in a 63-year-old woman is reported. Histologic and ultramicroscopic examination revealed that the excised thyroid tumor was plasmacytoma superimposed on lymphocytic thyroiditis. Immunohistological study showed that the tumor cells produced intracytoplasmic immunoglobulin (IgG-kappa). Electropho-retic and immunoelectrophoretic studies disclosed the presence of monoclonal immunoglobulin (IgG-kappa) in samples of the patient's serum which had been obtained preoperatively. After completion of irradiation therapy to the neck following tumor removal, the serum monoclonal immunoglobulin disappeared. The patient is currently alive and well without any evidence of the tumor three years after surgery.