Mitochondrial tissue specificity of substrates utilization in rat cardiac and skeletal muscles.

As energetic metabolism is crucial for muscles, they develop different adaptations to respond to fluctuating demand among muscle types. Whereas quantitative characteristics are known, no study described simultaneously quantitative and qualitative differences among muscle types in terms of substrates utilization patterns. This study thus defined the pattern of substrates preferential utilization by mitochondria from glycolytic gastrocnemius (GAS) and oxidative soleus (SOL) skeletal muscles and from heart left ventrical (LV) in rats. We measured in situ, ADP (2 mM)-stimulated, mitochondrial respiration rates from skinned fibers in presence of increasing concentrations of pyruvate (Pyr) + malate (Mal), palmitoyl-carnitine (Palm-C) + Mal, glutamate (Glut) + Mal, glycerol-3-phosphate (G3-P), lactate (Lact) + Mal. Because the fibers oxygen uptake (Vs) followed Michaelis-Menten kinetics in function of substrates level we determined the Vs and Km, representing maximal oxidative capacity and the mitochondrial sensibility for each substrate, respectively. Vs were in the order GAS < SOL < LV for Pyr, Glu, and Palm-C substrates, whereas in the order SOL = LV < GAS with G3-P. Moreover, the relative capacity to oxidize Palm-C is extremely higher in LV than in SOL. Vs was not stimulated by the Lact substrate. The Km was equal for Pyr among muscles, but much lower for G3-P in GAS and lower for Palm-C in LV. These results demonstrate qualitative mitochondrial tissue specificity for metabolic pathways. Mitochondria of glycolytic muscle fibers are well adapted to play a central role for maintaining a satisfactory cytosolic redox state in these fibers, whereas mitochondria of LV developed important capacities to use fatty acids.

Phase I/II trial of irinotecan plus high-dose 5-fluorouracil (TTD regimen) as first-line chemotherapy in advanced colorectal cancer.

BACKGROUND: We conducted a phase I/II study of weekly irinotecan [30 min intravenous (i.v.) infusion] combined with 5-fluorouracil (5-FU 3 g/m(2) weekly 48 h i.v. infusion, TTD regimen) as first-line chemotherapy for patients with advanced colorectal cancer (CRC). PATIENTS AND METHODS: The maximum tolerated dose (MTD) and the dose-limiting toxicity (DLT) in the treatment of gastrointestinal solid tumors (in phase I), and the antitumor activity and toxicity of the recommended phase I dose (in phase II) were determined. RESULTS: Diarrhea was the DLT, and irinotecan 80 mg/m(2) plus 5-FU 3 g/m(2) was the recommended phase I dose. In phase II, the confirmed response rate was 44% [95% confidence interval (CI) 29% to 59%] and the median overall survival was 23.8 months. However, grade 3/4 diarrhea affected 59% of patients and led to withdrawal of three patients. A second cohort of patients studied using the same schedule but with a reduced 5-FU starting dose of 2.25 g/m(2) showed improved tolerance (the incidence of grade 4 diarrhea decreased from 28% to 11% and overall grade 3/4 diarrhea to 56%, with no patient withdrawals) but the confirmed response rate was 28% (95% CI 14% to 45%) and median overall survival was 17.2 months. CONCLUSIONS: We found weekly irinotecan 80 mg/m(2) plus TTD regimen (5-FU 2.25 g/m(2) given as 48-h i.v. infusion) to be a feasible and active combined chemotherapy for the first-line treatment of advanced colorectal cancer.

Physical activity changes the regulation of mitochondrial respiration in human skeletal muscle.

This study explores the importance of creatine kinase (CK) in the regulation of muscle mitochondrial respiration in human subjects depending on their level of physical activity. Volunteers were classified as sedentary, active or athletic according to the total activity index as determined by the Baecke questionnaire in combination with maximal oxygen uptake values (peak V(O2), expressed in ml min(-1) kg(-1)). All volunteers underwent a cyclo-ergometric incremental exercise test to estimate their peak V(O2) and V(O2) at the ventilatory threshold (VT). Muscle biopsy samples were taken from the vastus lateralis and mitochondrial respiration was evaluated in an oxygraph cell on saponin permeabilised muscle fibres in the absence (V(0)) or in the presence (V(max)) of saturating [ADP]. While V(0) was similar, V(max) differed among groups (sedentary, 3.7 +/- 0.3, active, 5.9 +/- 0.9 and athletic, 7.9 +/- 0.5 micromol O2 min(-1) (g dry weight)(-1)). V(max) was correlated with peak V(O2) (P < 0.01, r = 0.63) and with V(T) (P < 0.01, r = 0.57). There was a significantly greater degree of coupling between oxidation and phosphorylation (V(max)/V(0)) in the athletic individuals. The mitochondrial K(m) for ADP was significantly higher in athletic subjects (P < 0.01). Mitochondrial CK (mi-CK) activation by addition of creatine induced a marked decrease in K(m) in athletic individuals only, indicative of an efficient coupling of mi-CK to ADP rephosphorylation in the athletic subjects only. It is suggested that increasing aerobic performance requires an enhancement of both muscle oxidative capacity and mechanisms of respiratory control, attesting to the importance of temporal co-ordination of energy fluxes by CK for higher efficacy.

Oxidative capacity of skeletal muscle in heart failure patients versus sedentary or active control subjects.

OBJECTIVES: We investigated the in situ properties of muscle mitochondria using the skinned fiber technique in patients with chronic heart failure (CHF) and sedentary (SED) and more active (ACT) controls to determine: 1) whether respiration of muscle tissue in the SED and ACT groups correlates with peak oxygen consumption (pVO(2)), 2) whether it is altered in CHF, and 3) whether this results from deconditioning or CHF-specific myopathy. BACKGROUND: Skeletal muscle oxidative capacity is thought to partly determine the exercise capacity in humans and its decrease to participate in exercise limitation in CHF. METHODS: M. Vastus lateralis biopsies were obtained from 11 SED group members, 10 ACT group members and 15 patients with CHF at the time of transplantation, saponine-skinned and placed in an oxygraphic chamber to measure basal and maximal adenosine diphosphate (ADP)-stimulated (V(max)) respiration rates and to assess mitochondrial regulation by ADP. All patients received angiotensin-converting enzyme (ACE) inhibitors. RESULTS: The pVO(2) differed in the order CHF < SED < ACT. Compared with SED, muscle alterations in CHF appeared as decreased citrate synthase, creatine kinase and lactate dehydrogenase, whereas the myosin heavy chain profile remained unchanged. However, muscle oxidative capacity (V(max), CHF: 3.53 +/- 0.38; SED: 3.17 +/- 0.48; ACT: 7.47 +/- 0.73, micromol O(2).min(-1).g(-1)dw, p < 0.001 vs. CHF and SED) and regulation were identical in patients in the CHF and SED groups, differing in the ACT group only. In patients with CHF, the correlation between pVO(2) and muscle oxidative capacity observed in controls was displaced toward lower pVO(2) values. CONCLUSIONS: In these patients, the disease-specific muscle metabolic impairments derive mostly from extramitochondrial mechanisms that disrupt the normal symmorphosis relations. The possible roles of ACE inhibitors and level of activity are discussed.

Influence of overload on phenotypic remodeling in regenerated skeletal muscle.

We studied the effects of 10 wk of functional overload on the expression of myosin heavy chain (MHC), sarcoplasmic reticulum Ca(2+)-ATPase isoforms (SERCA), and the activity of several metabolic enzymes in sham and regenerated plantaris muscles. Overload was accomplished by bilateral surgical ablation of its synergists 4 wk after right plantaris muscles regenerated after myotoxic infiltration. The overload-induced muscle enlargement was slightly less in regenerated than in sham muscles [28% (P < 0.005) and 43% (P < 0.001), respectively]. Overload led to an increase in type I MHC expression (P < 0.01) to a similar extent in sham and regenerated plantaris, while the expected shift from type IIb to type IIa MHC was less marked in regenerated than in sham plantaris. The overload-induced decrease in the expression of the fast SERCA isoform and in the activity of the M subunit of lactate dehydrogenase occurred to a similar extent in sham and regenerated plantaris [66% (P < 0.01) and 27% (P < 0.005), respectively]. In conclusion, the lesser responses of muscle mass and fast MHC composition of regenerated plantaris to mechanical overload suggest an alteration of the transcriptional, translational, and/or posttranslational control of gene expression in regenerated muscle.

Selective changes in mitochondria respiratory properties in oxidative or glycolytic muscle fibers isolated from G93AhumanSOD1 transgenic mice.

Cases of familial amyotrophic lateral sclerosis (FALS) are associated with mutations in cytosolic copper, zinc superoxide dismutase (SOD1). Total SOD activity and functional mitochondrial properties were studied in muscles and nervous tissues of control and transgenic mice mimicking the disease. It was found that total SOD activity was lower in nervous tissues than in muscles in both transgenic and control mice. In addition SOD activity increased during progression of disease in muscle but not in nervous tissue of transgenic mice. Maximal oxygen consumption and apparent Km for ADP were decreased in mitochondria from transgenic soleus (an oxidative muscle). However there was no difference between control and transgenic mice in respiratory parameters of mitochondria in the EDL muscle (a glycolytic muscle). These findings indicate that oxidative stress due to SOD1 mutations could alter energy metabolism in FALS mice, thereby affecting primarily oxidative muscle of the limbs, independently of motoneuron loss.

Granulocyte colony-stimulating factor in the treatment of high-risk febrile neutropenia: a multicenter randomized trial.

BACKGROUND: Granulocyte colony-stimulating factors (G-CSFs) have been shown to help prevent febrile neutropenia in certain subgroups of cancer patients undergoing chemotherapy, but their role in treating febrile neutropenia is controversial. The purpose of our study was to evaluate-in a prospective multicenter randomized clinical trial-the efficacy of adding G-CSF to broad-spectrum antibiotic treatment of patients with solid tumors and high-risk febrile neutropenia. METHODS: A total of 210 patients with solid tumors treated with conventional-dose chemotherapy who presented with fever and grade IV neutropenia were considered to be eligible for the trial. They met at least one of the following high-risk criteria: profound neutropenia (absolute neutrophil count <100/mm(3)), short latency from previous chemotherapy cycle (<10 days), sepsis or clinically documented infection at presentation, severe comorbidity, performance status of 3-4 (Eastern Cooperative Oncology Group scale), or prior inpatient status. Eligible patients were randomly assigned to receive the antibiotics ceftazidime and amikacin, with or without G-CSF (5 microg/kg per day). The primary study end point was the duration of hospitalization. All P values were two-sided. RESULTS: Patients randomly assigned to receive G-CSF had a significantly shorter duration of grade IV neutropenia (median, 2 days versus 3 days; P = 0.0004), antibiotic therapy (median, 5 days versus 6 days; P = 0.013), and hospital stay (median, 5 days versus 7 days; P = 0.015) than patients in the control arm. The incidence of serious medical complications not present at the initial clinical evaluation was 10% in the G-CSF group and 17% in the control group (P = 0.12), including five deaths in each study arm. The median cost of hospital stay and the median overall cost per patient admission were reduced by 17% (P = 0.01) and by 11% (P = 0.07), respectively, in the G-CSF arm compared with the control arm. CONCLUSIONS: Adding G-CSF to antibiotic therapy shortens the duration of neutropenia, reduces the duration of antibiotic therapy and hospitalization, and decreases hospital costs in patients with high-risk febrile neutropenia.

[Hypovitaminosis D: its high prevalence in elderly outpatients in Barcelona. Associated factors]. / Hipovitaminosis D: alta prevalencia en ancianos de Barcelona atendidos ambulatoriamente. Factores asociados.

BACKGROUND: Hypovitaminosis D is a frequent finding in the elderly of northern countries. In Spain because of high sun irradiation it has been traditionally considered that hypovitaminosis D is not a frequent problem. In this study we have evaluated the prevalence of hypovitaminosis D in the elderly and the associated factors. SUBJECTS AND METHODS: All individuals older than 65 years attending a primary care unit (november 1995-march 1996) and without any disease modifying vitamin D status were included. The following data were recorded: age, gender, height, weight, white and red cell counts, glycaemia, serum ions, albuminemia, plasma creatinine, creatinine clearance, urinary creatinine and calcium, parathyroid hormone (PTHi), calcidiol and calcitriol. Sun exposure and fish ingestion was also determined by questionnaire. RESULTS: 127 individuals were evaluated (age: mean [SD] 74.8 [6.4] years; 47 men, 37.0%). Forty-four subjects (34.6%; CI 95%: 26.3-42.9%) had calcidiol levels < or = 10 ng/ml, 15 (11.8%; CI 95%: 6.2-17.4%) low values of calcidiol, and 13 (10.2%; CI 95%: 4.9-15.5%) high PTHi values. Subjects with hypovitaminosis D (calcidiol levels < or = 10 ng/ml) were mainly women, older, short stature, had a lower values of body surface, albuminemia, phosphatemia, creatinine clearance, sun exposure and fish intake and higher PTHi levels. In the logistic regression model, hypovitaminosis D was positively associated with age and negatively with sun exposure, albuminemia, height and phosphoremia. CONCLUSIONS: Hypovitaminosis D is a very frequent finding in Spanish elderly people. Its presence is independently associated with age (positively) and sun exposure, serum albumin, height and phosphoremia (negatively).

Mutation in the calcium-binding domain of the mitochondrial glycerophosphate dehydrogenase gene in a family of diabetic subjects.

The Ca(2+)-sensitive and mitochondrial enzyme FAD-linked glycerophosphate dehydrogenase (m-GDH) represents an essential component of the pancreatic B-cell glucose-sensing device. This report deals with the first identified case of mutation in the calcium-binding domain of the m-GDH gene in a patient with type-2 diabetes and his glucose-intolerant half sister. Single strand conformation polymorphism analysis indeed revealed an abnormal mobility of the 32P-labelled polymerase chain reaction product in these two subjects. The corresponding base pair mutations and amino acid changes were documented. In the diabetic proband, the relative extent of the Ca(2+)-induced activation of m-GDH in CD3+ T-lymphocytes was lower than in his brother with a normal m-GDH gene sequence.

Estradiol, progesterone and steroid receptors. Benign cycling versus malignant non cycling cells.

Levels of estradiol and progesterone from blood together with oestrogen (ER) and progesterone receptors (PgR) from breast tissue were studied from a total of 2500 data bank cases of breast neoplastic disease. We report here, 340 premenopausal women with recorded menstrual cycle data which enabled the study of the effect of peripheral hormone variation on ER and PgR with respect to cycle phase. The findings were also correlated with 30 immunohistochemical specimens. In the specimens with benign neoplasm (141 cases, age 28 +/- 18 years) the ER levels were low (9.2+/-9.4 fmol/mg protein) as in normal breast tissue, whereas PgR levels were high ( 76+/-102.4 fmol/mg protein). Both ER and PgR levels decreased in association with the peak of blood progesterone of the early secretory phase. In the 15 cases of benign neoplasm from the luteinic phase studied by immunohistochemistry there were few ER positive cells (29+/-15%) which were small (265+/-27 pixels) and faintly stained (MOD: 34+/-3UA), while the PgR positive cells were more numerous (79+/-15%), bigger (377+/-70 pixels), strongly stained (MOD: 48+/-5UA), and centrally located in the breast ducts. The differences in size and optical density were statistically significant indicating that both receptors are expressed by different cells. The cell cycle dependence of these differences is discussed. In the series of malignant neoplasms (199 cases, age 41+/-6 years), ER and PgR cytosol levels were both generally high (ER: 38+/-75.9, PgR: 86.6+/-137), and did not show variations due to the menstrual cycle, while blood progesterone, PgR, and the percentage of ER positive cases increased during the menstrual cycle. The 15 malignant cases in the luteinic phase showed, through immunohistochemistry, that size and staining intensities of receptor positive cells were similar to the other 199 cases and were not found to be directly influenced by hormonal activity related to the menstrual cycle. Comparisons between benign and malignant specimens showed significant biochemical and immunohistochemical differences in the degree of ER positivity while, on the contrary, PgR levels were similar.

Changes in left ventricular mass and filling after renal transplantation are related to changes in blood pressure: an echocardiographic and pulsed Doppler study.

To examine changes in left ventricular (LV) mass and function (diastolic and systolic) after successful renal allograft transplantation (RT), we prospectively studied 30 patients (19 men, 11 women, aged 37 +/- 13 years) by M-mode, two-dimensional and pulsed Doppler echocardiography at the time of surgery and 10 +/- 1.8 months later. At the time of transplantation all patients had been undergoing dialysis (4 peritoneal dialysis, 26 hemodialysis) for 2.5 +/- 3.2 years. A hematocrit of < or = 30% was present in 26 patients. After RT the mean hematocrit increased from 26 +/- 4 to 40 +/- 7 (p < 0.01), whereas systolic, diastolic and mean blood pressure (BP) remained unchanged. The LV mass index (LVMI) decreased from 201 +/- 56 to 171 +/- 41 g/m2, (p < 0.01); LV diastolic diameter corrected by body surface area (LVDDI) decreased from 298 +/- 38 to 279 +/- 35 (p < 0.01) and the LV end-diastolic volume index (LVEDVI) from 72 +/- 18 to 63 +/- 15 (p < 0.01). There were no changes in LV fractional shortening or LV end systolic wall stress. Peak late transmitral velocity (A wave) decreased from 77 +/- 16 to 68 +/- 12 cm/s (p < 0.01) with no changes in other Doppler-derived indexes of diastolic function. No fistula patency influence on changes in LV mass and function was found. After RT, BP decreased in 21 patients from 150 +/- 20 to 132 +/- 15 (p < 0.001; group I) and increased in 9 patients from 130 +/- 14 to 153 +/- 16 (p < 0.05, group II). Patients in group I suffered a reduction in LVMI (p < 0.001), LV end-diastolic diameter (p < 0.05), LVDDI (p < 0.001); LV end-diastolic volume (p < 0.05); LVEDVI (p < 0.01); cardiac index (p < 0.05), and peak late transmitral velocity (p < 0.01), but no changes in group-II patients were observed. We concluded that BP is a major determining factor with regard to changes in LV hypertrophy and function following RT. LV mass and volumes can be expected to decrease after RT in patients with BP reduction.

[Intervention to improve the quality of continuing drug prescription at a primary care center]. / Intervención de mejora de la calidad de la prescripción farmacológica continuada en un centro de atención primaria.

An evaluation study has been done on the quality of long-term drugs prescription. The aim was to check the effectiveness of certain corrective measures agreed by the professionals working in a primary care centre. Using the results of a first evaluation made in 1989, a series of recommendations were made to reduce the prescription of drugs with a low intrinsic value (LIV). A further evaluation took place 9 months later. A relative reduction of 20.2% in LIV drugs was obtained. This represented a reduction from 25% to 20.8% of the total number of prescriptions. In the relevant pharmacological subgroups a reduction of 77.9% in the prescription of nitrites linked to barbiturites was obtained; of 60% in LIV antacids; of 50.3% in antivaricose drugs; of 36.1% in LIV laxatives; and of 30.1% in Dipiridamol. There was no improvement in the prescription of external LIVs nor cerebral vasodilators. It is concluded that the intervention has proved its usefulness in the improvement of long-term drugs prescription.

Dexamethasone suppression test and primary obsessional compulsive disorder.

This report explores the role played by DSM-III Major Depression in the Nonsuppressor status of a sample of 29 subjects suffering from DSM-III Obsessive Compulsive Disorder (OCD). Five subjects were found to be Nonsuppressors. Further analysis showed that it is likely that Nonsuppressor status depended upon the concomitant presence of Major Depression rather than upon the OCD itself.

Effect of angiotensin-II blockade on systemic and hepatic haemodynamics and on the renin-angiotensin-aldosterone system in cirrhosis with ascites.

We have studied the effect of angiotensin-II blockade with saralasin on the cardiovascular and hepatic hemodynamics and on the renin-angiotensin-aldosterone system in fourteen patients with cirrhosis and ascites. Control measurements showed that most of the patients had a low mean arterial pressure, high plasma volume, normal or high cardiac index, low peripheral resistance and high plasma renin activity and aldosterone concentration. The wedged hepatic venous pressure was increased in each patient and the estimated hepatic blood flow was normal in most of them. Overall, saralasin induced a significant reduction of the mean arterial pressure, cardiac index and peripheral resistance. The decrease of the peripheral resistance was greater than that of the cardiac index. Six of the patients developed a marked reduction of the mean arterial pressure with low doses of saralasin (1--2.5 microgram/kg/min), and they had significantly higher plasma renin activity and lower mean arterial pressure than the remaining eight patients who showed a slight or no hypotensive response in spite of infusing saralasin up to a dose of 10 micrograms/kg/min. Overall, the decrease of the mean arterial pressure correlated directly with the baseline values of plasma renin activity. Angiotensin-II blockade induced a significant reduction of the wedged hepatic venous pressure. The hepatic blood flow did not show any significant change. The decrease of the wedged hepatic venous pressure was directly related to the reduction of the mean arterial pressure and also to the control plasma renin activity. Our study indicates that in most patients with cirrhosis, ascites and high plasma renin activity, arterial pressure is maintained by the effect of endogenous angiotensin II on the peripheral vasculature, and we suggest that a pre-existing arterial hypotension secondary to an arteriolar vasodilatation is the cause of renin release in these patients. Our results also show that angiotensin-II blockade is accompanied by a reduction of the post-sinusoidal hepatic vascular resistance.

[Anosmia and hypogonadism (Kallman's or Maestre de San Juan's syndrome (author's transl)]. / Hipogonadismo y anosmia (síndrome de Kallman o síndrome de Maestre de San Juan).

A patient, aged 15 years and three months, with hypogonadism and anosmia (Kallman's syndrome or Maestre de San Juan's syndrome) is presented. It is an sporadic case, with no associated abnormalities, who had been seen due to a lack of sexual development. Basal levels of plasmatic LH and FSH were lower than the sensitivity threshold of the method: 1.5 mlU/ml. Administration of 100 ng of GnRH alone in one dose did not evoke any change of these levels; when the same dosage was given during five consecutive days, plasmatic levels of both gonadotropins increased. Initial treatment with HCG (5,000 IU, biweekly) evoked very favourable changes in somatic and genital development.