P180 Pulmonary valve stenosis and pulmonary trunk aneurysm in old female with syncope

Discussion

According to the ESC guidelines for grown up congenital heart disease in 2010, this pulmonary valve should be intervened upon as it is severe symptomatic PS (1), but there are 2 problems with this case; the first is significant associated PR, so no place for balloon dilatation here, the second problem is the pulmonary artery aneurysm (PAA). The dilemma of management of pulmonary PAA is that all the available data are about aortic aneurysms. Indications for intervention for PAA include: Absolute PAA diameter ≥ 5.5 cm, Increase in the diameter of the aneurysm of ≥ 0.5 cm in 6 mo, Compression of adjacent structures, Thrombus formation in the aneurysm sack, Evidence of valvular pathologies or shunt flow Verification of PAH, Signs of rupture or dissection (2). Surgery could include: Aneurysmorrhaphy only decreases the diameter of the vessel (3). Aneurysmectomy and repair or replacement of the right ventricular outflow tract is commonly used technique recently and mostly suits connective tissue disorders (6). Also, Replacement of the PA and the pulmonary trunk with a conduit (Gore-Tex or Dacron tubes, homografts, or xenografts) starting in the right ventricular outflow tract with replacement of the pulmonary valve (4).

Conclusion

PAA management is currently challenging because there are no clear guidelines on its optimal treatment. The presence of significant pulmonary valve dysfunction could affect the decision making of the associated PAA management.

Abstract P180 Figure.

Choroidal Granuloma Caused by Atypical Mycobacterium in a Patient with AIDS: A Case report

The case presented is a chorioretinal granuloma in a patient with AIDS. The neoformation appeared to be caused by atypical mycobacterium, although it was not possible to isolate the germ. The chorioretinal infection caused by atypical mycobacterium in patients with AIDS occurs very rarely and has so far been described only as a post-mortem finding.

Abstract P2-04-03: Epigenomic analysis of cancer stem cell (CSC)-enriched triple-negative breast cancer (TNBC) populations reveals gene regulatory circuitry and novel tumor cell vulnerabilities

Tumor-initiating cells (TICs), also termed cancer stem cells (CSCs) are involved in breast cancer chemoresistance, metastasis and disease progression. To pinpoint tumor cell vulnerabilities and transcriptional drivers of therapeutic relevance, we have characterized the triple negative breast cancer (TNBC) CSC transcriptional landscape using epigenome mapping and nucleosome occupancy determination. We identify a set of transcriptional regulators and signaling mediators that enforce the cancer stem cell state and instruct potential therapeutic strategies.

The basal epithelial marker, integrin-β4 (ITGB4), can be used to stratify mesenchymal-like triple-negative breast cancer (TNBC) cells into populations of low and high tumor-initiating ability in vivo. We used ChIP-seq to measure H3K27ac occupancy and map the transcriptional enhancers in SUM159 cells segregated into ITGB4HI (High tumor initiating ability) and ITGB4LOW (Low tumor initiating ability) populations. Gene-enhancer linking and comparative analysis of enhancer usage revealed an epigenomically defined set of genes that are candidate drivers of the CSC cell state, including GSK3β, DNA-binding transcription factors and cellular adhesion proteins. To further define the chromatin architecture and transcriptional regulatory circuitry that underlies CSC state, we deployed ATAC-seq (Assay for Transposase-Accessible Chromatin with high throughput sequencing) within ITGB4HI and ITGB4LOW populations. By pairing nucleosome occupancy and transcription factor kinetics, we created enhancer-linked transcriptional regulatory circuitry of these tumor-initiating cells.

Together, the isolation of partially mesenchymal ITGB4HI CSCs, coupled with enhancer mapping and distillation of transcriptional regulatory circuitry from these cells enable the identification of cancer vulnerabilities and therapeutic opportunities for high-risk patients with TNBC.

Citation Format: Guenther MG, Lambert AW, Chen MW, Fiore C, Eaton M, Orlando D, Bierie B, Weinberg RA, Fritz CC, Olson ER. Epigenomic analysis of cancer stem cell (CSC)-enriched triple-negative breast cancer (TNBC) populations reveals gene regulatory circuitry and novel tumor cell vulnerabilities [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-04-03.

Abstract P6-11-18: A novel subgroup of estrogen receptor positive breast cancer may benefit from super-enhancer guided patient selection for retinoic acid receptor α agonist treatment

Endocrine-resistance remains a major challenge for treatment of breast cancer. Multiple mechanisms for endocrine resistance have been proposed, including altered expression of ER co-regulators such as Retinoic Acid Receptor Alpha (RARα). Furthermore, crosstalk between estradiol and RA signaling is known and upregulation of RARα has been observed in tamoxifen resistance. We propose a novel treatment paradigm for a newly-defined subset of HR+ patients based on our discovery of a super-enhancer (SE) associated with the RARA locus. SEs are large, highly active chromatin regions that pinpoint cancer vulnerabilities. The RARA SE-identified vulnerability can be targeted using the potent, selective, and metabolically stable RARα agonist SY-1425 (tamibarotene). SY-1425 is approved in Japan to treat Acute Promyelocytic Leukemia, has a well-established efficacy and safety profile, and may enhance response to hormonal therapy (HT) in this newly-defined subset of HR+ patients potentially delaying the need for alternate treatment.

Tumor samples from 42 breast cancer patients were analyzed across a range of molecular subtypes. We identified an SE linked to the RARA gene in 54.5% of the hormone positive patient samples. RARA SEs predicted sensitivity to SY-1425 in 12 breast cancer cell lines confirming their functional role, and showed a correlation with RARA gene expression. A panel of 37 breast cancer cell lines was tested for SY-1425 anti-proliferative activity and gene expression levels, and identified RARA as the single best predictor of response. Proliferation of RARA-high cells was inhibited by SY-1425 with low nanomolar EC50s. Transcriptional profiling was performed on 4 HR+ and 3 HER2+/HR- breast cancer cell lines and analyzed by GSEA to examine the molecular response to SY-1425. Signatures for growth including E2F, MYC, DNA replication, and cell cycle were significantly downregulated while retinol metabolism and luminal signaling were upregulated. Estrogen signaling was also significantly altered by SY-1425, supporting known crosstalk between RARα and ER. Consistent with differentiation, CYP26A1 and VE-Cadherin were induced and Actin and Ki67 were diminished at relevant concentrations of SY-1425 and could serve as pharmacodynamic markers of response.

To test responses to SY-1425 in vivo, two cell line-derived models and two patient-derived breast cancer models (one RARA-high, and one RARA-low each) were treated with SY-1425. SY-1425 inhibited tumor growth in the RARA-high models, but not the RARA-low models (43% versus 0% TGI). Consistent with the observed changes in transcription, SY-1425 in combination with tamoxifen synergistically inhibited proliferation of RARA-high breast cancer cell lines.

Although a few clinical studies have investigated the use of ATRA in HR+ breast cancer without success, our results suggest that patient selection based on the RARA SE may predict which HR+ breast cancer patients could derive benefit by adding an RARα agonist to HT. The potential to prolong or increase the clinical effect of anti-estrogen therapy with SY-1425, which has improved potency, selectivity, and PK stability versus ATRA, would be an attractive strategy to explore.

Side effects of cocaine abuse: multiorgan toxicity and pathological consequences

Cocaine is a powerful stimulant of the sympathetic nervous system by inhibiting catecholamine reuptake, stimulating central sympathetic outflow, and increasing the sensitivity of adrenergic nerve endings to norepinephrine (NE). It is known, from numerous studies, that cocaine causes irreversible structural changes on the brain, heart, lung and other organs such as liver and kidney and there are many mechanisms involved in the genesis of these damages. Some effects are determined by the overstimulation of the adrenergic system. Most of the direct toxic effects are mediated by oxidative stress and by mitochondrial dysfunction produced during the metabolism of noradrenaline or during the metabolism of norcocaina, as in cocaine-induced hepathotoxicity. Cocaine is responsible for the coronary arteries vasoconstriction, atherosclerotic phenomena and thrombus formation. In this way, cocaine favors the myocardial infarction. While the arrhythmogenic effect of cocaine is mediated by the action on potassium channel (blocking), calcium channels (enhances the function) and inhibiting the flow of sodium during depolarization. Moreover chronic cocaine use is associated with myocarditis, ventricular hypertrophy, dilated cardiomyopathy and heart failure. A variety of respiratory problems temporally associated with crack inhalation have been reported. Cocaine may cause changes in the respiratory tract as a result of its pharmacologic effects exerted either locally or systemically, its method of administration (smoking, sniffing, injecting), or its alteration of central nervous system neuroregulation of pulmonary function. Renal failure resulting from cocaine abuse has been also well documented. A lot of studies demonstrated a high incidence of congenital cardiovascular and brain malformations in offspring born to mothers with a history of cocaine abuse.

Energetic ion loss detector on the Alcator C-Mod tokamak

A scintillator-based energetic ion loss detector has been successfully commissioned on the Alcator C-Mod tokamak. This probe is located just below the outer midplane, where it captures ions of energies up to 2 MeV resulting from ion cyclotron resonance heating. After passing through a collimating aperture, ions impact different regions of the scintillator according to their gyroradius (energy) and pitch angle. The probe geometry and installation location are determined based on modeling of expected lost ions. The resulting probe is compact and resembles a standard plasma facing tile. Four separate fiber optic cables view different regions of the scintillator to provide phase space resolution. Evolving loss levels are measured during ion cyclotron resonance heating, including variation dependent upon individual antennae.

[Lung diffusion capacity and quality of life 6 months after discharge from the ICU among survivors of acute respiratory distress syndrome due to influenza A H1N1]

OBJECTIVE

An evaluation is made of lung function and quality of life 6 months after discharge from the Intensive Care Unit (ICU) among survivors of acute respiratory distress syndrome (ARDS) due to pandemic 2009 influenza A H1N1, based on studies of lung function and the EQ-5D health questionnaire.

DESIGN

Case series.

SETTING

The ICU of Dr. Leónidas Lucero Acute Cases Municipal Hospital, Bahía Blanca, Argentina.

PATIENTS

PATIENTS discharged from the ICU who had been admitted with ARDS in 2009 due to influenza A H1N1.

RESULTS

Eleven patients were studied. Seven were positive for influenza H1N1 and four were negative. The mean age was 37±9.5 years, and 73% were males. Quality of life, as measured by the EQ-5D, showed changes in the 5 components in all patients, particularly in the pain/discomfort dimension 1.55±0.52; health status (EQ%health) was 70%±24. The indices adjusted for Argentina were Time Trade Off (TTO) 0.903±0.085 and Visual Analog Scale (VAS) 0.827±0.153. In all patients, spirometry and the study of pulmonary diffusion (DLCO) showed values of >80%. There was no correlation between lung diffusion and quality of life (%DLCO and EQ%health). A correlation was observed between quality of life and TTO (EQ%health and TTO), and between quality of life and the VAS score (EQ%health and VAS).

CONCLUSION

Although the sample is small, our results suggest that patients with ARDS due to influenza A H1N1 evaluated 6 months after discharge from the ICU show no deterioration of lung function, and the impact on quality of life is moderate-in contrast to the situation found in patients with ARDS of other etiologies.

Analytical techniques in androgen anabolic steroids (AASs) analysis for antidoping and forensic purposes

A survey on the main analytical challenges related to the analysis of Androgen Anabolic Steroids (AASs) is reported. AASs analysis is an issue regarding antidoping analyses as well as forensic toxicology applications. This paper reports an overview of the more recent literature regarding various aspects of sample preparation, analytical techniques and interpretation of results for AASs identification in biological samples. New analytical approaches, mainly for their application to the antidoping field, are reported. The application of AASs analysis in forensic cases is also described, taking into consideration mainly the different biological samples that can be analysed for forensic purposes. Particular attention was played on the application of hair analysis as alternative biological specimen for the determination of AASs abuse.

Renal heat shock proteins over-expression due to anabolic androgenic steroids abuse

Chronic use of anabolic adrogenic steroids (AAS) has been known to cause serious adverse effects. While the effects of AASs on cardiovascular system are well known, toxicity on other organs has received less attention. A doserelated nephrotoxic effect has been proposed and a wide variety of morpho-functional damages have been observed, but the exact pathophysiological mechanism of action is still not well known. In the present minireview, we highlight the remaining issues through an analysis of the pertinent literature. As with HSPs toxic agents their overexpression could be considered a protective reaction against AAS abuse however, comprehensive studies concerning the whole range of Hsps/chaperones expressions in all organs after long term use of AAS are needed.

Endogenous reactive oxygen species content and modulation of tyrosine phosphorylation during sperm capacitation

Generation of controlled amounts of reactive oxygen species (ROS) and phosphorylation of protein tyrosine (Tyr) residues are two main cellular changes involved in sperm capacitation. This study examined the relationship between tyrosine-phosphorylation (Tyr-P) and endogenous ROS production during sperm capacitation, and correlated them with both sperm motility and functionality expressed as acrosome-reacted cells. Immediate ROS generation was observed to peak after a 45-min incubation, followed by a rapid decrease in ROS content and successive regeneration of the ROS peak in 3 h and later. These two peaks were directly correlated with both the Tyr-P process involving sperm heads and tails, and the acrosome reaction (69 ± 8% and 65 ± 4%, respectively). The period of low-ROS content resulted in low Tyr-P patterns, located exclusively in the cell midpiece, and drastic reduction in acrosome-reacted cells. Ascorbic acid addition inhibited both Tyr-P patterns and acrosome reactions, whereas NADPH induced high ROS generation, with Tyr-P patterns located only on sperm tails, and prevented the acrosome reaction. Sperm hyperactivation was insensitive to ROS content. This is an important parameter for evaluation of sperm capacitation, which is achieved only when both ROS generation reaches a peak and Tyr-P involves the sperm head.

Effect of canrenone and amiloride on the prooxidative effect induced by aldosterone in human mononuclear leukocytes in vitro

Clinical studies have demonstrated that aldosterone receptor antagonists do improve the survival of patients with chronic heart diseases and in vitro studies have shown that canrenone blocks the proinflammatory effect of aldosterone in mononucler leukocytes (MNL). The aim of the study was to compare, in the model of human MNL, the effect of potassium-sparing diuretics amiloride and canrenone, on the protein expression of p22phox, a NADPH-oxidase system subunit, that is a principal marker of production of superoxide anions. MNL were isolated from 10 informed healthy volunteers (5 males and 5 females, age range 24-36 yr) and the proteins extracted. p22phox protein expression was evaluated by Western blot and quantified using a densitometric semiquantitative analysis. The experiments showed that aldosterone (10(-8) M) enhances the protein expression of p22phox and that its effect is reversed by co-incubation with canrenone (10(-6) M), while incubation with amiloride (10(-6) M) reduced the prooxidative effect of aldosterone at a significantly lower extent than canrenone. Co-incubation with canrenone, amiloride, and aldosterone together produced the same effect as aldosterone plus canrenone. Incubation with cortisol (40(-8) M) was not effective. These data confirm the prooxidative effect of aldosterone in MNL. The addition of aldosterone-receptor antagonist canrenone produced a higher inhibition than sodium channel blocker amiloride on the effect of aldosterone on p22phox protein expression.

Some considerations about evolution of idiopathic primary aldosteronism

The prevalence of primary aldosteronism has increased since many patients who were previously considered as being affected by low renin essential hypertension are actually satisfying the new diagnostic criteria using plasma aldosterone/ plasma renin activity (PRA) ratio. Many of these cases could be classified as subclinical hyperaldosteronism, having normal aldosterone and low PRA, or in alternative the normal range of aldosterone should be revised. Idiopathic hyperaldosteronism can, in many cases, be considered as an evolutive disease: it can be hypothesized that the biochemical picture can be preceded by essential hypertension and that, after several years, primary aldosteronism can evolve back to essential hypertension due to age-related reduced vascular and adrenal sensitivity to angiotensin II. This effect is also evident after longterm treatment with aldosterone receptors blockers and therefore it possible that aldosterone-receptors blockers are able to normalize the sensitivity of glomerulosa to angiotensin II even after long-term withdrawal. The use of aldosterone receptors blockers prevents cardiovascular complications due to local aldosterone effect at the level of endothelium and mononuclear leukocytes; therefore, these drugs should be also considered for therapy of patients with hypertension. It is not excluded that aldosterone receptor blockers could prevent the onset of idiopathic hyperaldosteronism and its complications in patients with hypertension without primary hyperaldosteronism. From all these considerations it follows that the concept of normal range of aldosterone should be revised and the use of aldosterone receptor blockers should be revisited.

Identification of the 11 beta-hydroxysteroid dehydrogenase type 1 mRNA and protein in human mononuclear leukocytes

The enzyme 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) catalyzes the interconversion between inactive 11-ketoglucocorticoids and their active 11beta-hydroxy derivatives, such as cortisol and corticosterone. We have investigated the expression of 11beta-HSD1 in freshly isolated human peripheral mononuclear leukocytes (MNL). The presence of 11beta-HSD1 mRNA was demonstrated in total RNA by RT-PCR using specific primers designed on the 4th and 5th exons of the human 11beta-HSD1 gene. Fragments of the expected size were consistently detected on agarose gels, and sequencing showed complete identity with the corresponding sequence deposited in GenBank. The occurrence of 11beta-HSD1 protein was established by Western immunoblot analysis with a specific polyclonal antibody. Enzyme oxo-reductase activity was investigated by incubating 12 samples of MNL isolated from from 8 subjects with [3H]cortisone and formation of cortisol was established only in 4 subjects (yield range: 0.15-1.3%) after acetylation and TLC, blank subtraction and correction for losses. 18beta-Glycyrrhetinic acid, an inhibitor of 11 beta-HSD1, reduced cortisol production below detection limit. Dehydrogenase activity could not be demonstrated. It is suggested that, although enzyme activity of 11beta-HSD1 in circulating MNL is low, it is apparently ready for enhancement after MNL migration to sites of inflammation.

Observation of self-generated flows in tokamak plasmas with lower-hybrid-driven current

In Alcator C-Mod discharges lower hybrid waves have been shown to induce a countercurrent change in toroidal rotation of up to 60 km/s in the central region of the plasma (r/a approximately <0.4). This modification of the toroidal rotation profile develops on a time scale comparable to the current redistribution time (approximately 100 ms) but longer than the energy and momentum confinement times (approximately 20 ms). A comparison of the co- and countercurrent injected waves indicates that current drive (as opposed to heating) is responsible for the rotation profile modifications. Furthermore, the changes in central rotation velocity induced by lower hybrid current drive (LHCD) are well correlated with changes in normalized internal inductance. The application of LHCD has been shown to generate sheared rotation profiles and a negative increment in the radial electric field profile consistent with a fast electron pinch.

Suicide due to oral ingestion of lidocaine: a case report and review of the literature

The Authors describe a rare case of suicide in a 31-year-old woman, due to oral ingestion of lidocaine; the histological and toxicological findings are discussed to provide useful information to the present experience with this particular modality of death. Histological examination revealed generalized stasis. In the myocardium we observed segmentation of the myocardial cells and/or widening of intercalated discs and associated group of hypercontracted myocardial cells with "square" nuclei in line with hyperdistended ones. Non-eosinophilic bands of hypercontracted sarcomeres alternating with stretched, often apparently separated sarcomeres, small foci of paradiscal contraction band necrosis, and perivascular fibrosis were observed too. Lidocaine was detected in the subject's urine through immunoenzymatic screening. Toxicological analysis by solid-liquid extraction and gas chromatography-mass spectrometry (GC-MS) analysis, was carried out to identify and quantify the individual substances present in the biological fluids and organs. Lidocaine concentrations were as follows: blood 31 microg/mL, gastric content 2.5 g, liver 10 microg/g, kidney 12 microg/g, brain 9 microg/g, spleen 24 microg/g, lung 84 microg/g, heart 9 microg/g, urine 9 microg/mL, and bile 6 microg/mL. No other drugs or alcohol were detected. When blood lidocaine reaches toxic levels, serious toxic symptoms associated with the central nervous system and cardiac system are noted. The overdose of lidocaine produces death from ventricular fibrillation or cardiac arrest. In this case, according to macroscopic and microscopic findings, the cause of death was most likely cardiac and possibly related to ventricular fibrillation.

Tissue-specific transcriptional initiation and activity of steroid sulfatase complementing dehydroepiandrosterone sulfate uptake and intracrine steroid activations in human adipose tissue

Expression analysis by reverse transcriptase (RT)-PCR indicates that human adipose tissue is not likely to perform de novo synthesis of steroid hormones from cholesterol because the mRNAs of cytochromes P450scc and P450c17, and of the steroidogenic-related proteins, steroidogenic acute regulatory protein and steroidogenic factor 1, were not detected. Instead, our data support an intracrine role of adipose tissue, in which adrenal dehydroepiandrosterone sulfate (DHEA-S), the most abundant circulating androgen in man, is selectively uptaken, desulfated, and converted into bioactive androgens and estrogens. Three organic anion-transporting polypeptides-B, -D, and -E, presumably involved in DHEA-S transmembrane transport, were demonstrated at the mRNA level. While sulfotransferase expression was not found, the occurrence of steroid sulfatase (STS), converting DHEA-S to DHEA, was established at the mRNA, protein and catalytic activity levels. The 5'-rapid amplification of cDNA ends analysis showed that STS transcription in adipose tissue is regulated by the use of two promoters which differ from the prevalent placental one. The adipose transcripts contain a distinct untranslated first exon, 0a or 0b, followed by a common partially translated exon 1b, and nine other exons that are also shared by the main placental transcript. The presence of an upstream open reading frame in the new transcript variants could lead to an N-terminal divergence restricted to the cleavable signal peptide and thus not interfering with the catalytic activity of the mature STS protein. The adipose transcripts are also present in the placenta as minor isoforms. Western blotting revealed the characteristic approximately 64 kDa band of STS in both the placenta and adipose tissue. The specific enzymatic activity of STS in adipocytes was 118 pmol/10(6) cells per hour, about 50-100 times lower than in the placenta. A similar rate of [3H] DHEA-S uptake plus desulfation was measured in preadipocytes and adipocytes, equivalent to 40-45 pmol/10(6) cells per hour. Thus, an excessive accumulation of fat may out-compete other peripheral organs that are also dependent on intracrine DHEA-S utilization, especially when the adrenal production is low or declining with aging.

Aldosterone and the conquest of land

The sequence of the phylogenetic events that preceded the appearance of aldosterone in vertebrates is described, starting from the ancestral conversion of cytochrome P450s from oxygen detoxification to xenobiotic detoxification and synthesis of oxygenated endobiotics with useful functions in intercellular signalling, such as steroid hormones. At the end of the Silurian period [438-408 million yr ago, (Mya)], a complete set of cytochrome P450s for corticoid synthesis was presumably already available, except for mitochondrial cytochrome P450c18 or aldosterone synthase encoded by CYP11B2. This gene arose by duplication of the CYP11B gene in the sarcopterygian or lobe-finned fish/tetrapod line after its divergence from the actinopterygian or ray-finned fish line 420 Mya, but before the beginning of the colonization of land by tetrapods in the late Devonian period, around 370 Mya. The fact that aldosterone is already present in Dipnoi, which occupy an evolutionary transition between water- and air-breathing but are fully aquatic, suggests that the role of this steroid was to potentiate the corticoid response to hypoxia, rather than to prevent dehydration out of the water. In terrestrial amphibians, there is no differentiation between the secretion rates and gluco- and mineralocorticoid effects of aldosterone and corticosterone. In sauropsids, plasma aldosterone concentrations are much lower than in amphibians, but regulation of salt/water balance is dependent upon both aldosterone and corticosterone, though sometimes with opposed actions. In terrestrial mammals, aldosterone acquires a specific mineralocorticoid function, because its interaction with the mineralocorticoid receptor is protected by the coexpression of the enzyme 11beta-hydroxysteroid dehydrogenase type 2, which inactivates both cortisol and corticosterone. There is evidence that aldosterone can be also synthesized extra-adrenally in brain neurons and cardiac myocytes, which lack this protection and where the effects of aldosterone oppose those of glucocorticoids. In conclusion, the phylogenetic history of aldosterone documents the erratic progression of evolutionary changes in the course of the strenuous struggle for environmental resources and survival.

Superiority of alfacalcidol compared to vitamin D plus calcium in lumbar bone mineral density in postmenopausal osteoporosis

In a randomized multicenter, double-blind, double-dummy, parallel group study a comparison of the efficacy and safety of 1 microg alfacalcidol to 880 IU vitamin D plus calcium carbonate (1 g calcium) once daily per os was performed on 148 postmenopausal osteoporotic Caucasian patients with normal vitamin D serum levels for 18 months. Bone mineral density (BMD) was measured at baseline, 12 and 18 months. Safety parameters were followed during the entire study period. Sixty-nine (90.8%) in the alfacalcidol group and 67 (93.1%) in the vitamin D group were included in the ITT analysis. Lumbar BMD in the alfacalcidol group increased by 0.017 g/cm2 (2.33%) and 0.021 g/cm2 (2.87%) from baseline (P<0.001) at 12 and 18 months, respectively, whereas in the vitamin D plus calcium group the increase was 0.005 g/cm2 (0.70%) from baseline (N.S.) at both 12 and 18 months. The higher changes from baseline in the alfacalcidol group, as compared to the changes in the vitamin D plus calcium group at both 12 and 18 months, were found to be statistically significant (P=0.018, 0.005). A small increase of mean femoral BMD was achieved in both groups (N.S.). Adverse events were similar in both groups. No significant differences were noted between the groups in serum calcium. In conclusion, alfacalcidol was found to be superior in significantly increasing lumbar BMD as compared to vitamin D plus calcium while safety characteristics were found to be similar in both treatments.

Idiopathic primary hyperaldosteronism: normalization of plasma aldosterone after one month withdrawal of long-term therapy with aldosterone-receptor antagonist potassium canrenoate

We have re-evaluated 15 patients with idiopathic primary aldosteronism one month after withdrawal of therapy with aldosterone-receptor antagonist potassium canrenoate. Therapy had lasted for 3 to 24 yr. Median blood pressure (BP) in the sitting position at the time of diagnosis was 160/100 (ranges 150-200/95-110 mmHg); while 1 month after withdrawal of therapy median BP was 145/90 (ranges 125-160/80-100 mmHg). One month after withdrawal, the ratio aldosterone (ng/dl)/plasma renin activity (ng/ml/h) in the upright position was increased only in 3 cases (median 18, range 6.1-125). We found a significant inverse correlation between the upright aldosterone/plasma renin activity (aldo/PRA) ratio, 1 month after withdrawal, and the number of years of therapy with potassium canrenoate. We conclude that long-term therapy with the aldosterone-receptor blocker, potassium canrenoate, can normalize the aldo/PRA ratio in many cases of idiopathic primary hyperaldosteronism after one-month withdrawal of the drug. These data are consistent with possible regression of idiopathic primary hyperaldosteronism after long-term therapy with potassium canrenoate, or in alternative to a persistent effect of potassium canrenoate, on aldosterone synthesis.

Molecular and technological approaches to evaluate strain biodiversity in Hanseniaspora uvarum of wine origin

AIMS

The characterization by molecular and physiological methods of wild apiculate strains, isolated from 'Aglianico del Vulture' grape must.

METHODS AND RESULTS

The restriction analysis of 18S rDNA allowed the identification of strains at the species level, which were predominantly Hanseniaspora uvarum. The RAPD analysis and the evaluation of technological traits, such as the metabolic and enzymatic activities, were useful to evaluate the polymorphism of this species.

CONCLUSIONS

The RAPD analysis clustered the wild H. uvarum strains in four main genetic groups and a very high phenotypic variability confirmed this genetic polymorphism. The technological variables, which determined the strain biodiversity differed significantly, demonstrating that these technological traits are strain dependent. A certain correlation was found between the strain behaviour and its isolation zone, indicating the influence of the environment on the genetic patrimony of the population.

SIGNIFICANCE AND IMPACT OF THE STUDY

The genetic and technological biodiversity recorded among H. uvarum wild strains represents the basis for organizing a collection of apiculate strains exhibiting oenological characteristics at different levels, such as high/low production of secondary compounds, and, therefore, potentially useful for a selection programme.

Licorice consumption and serum testosterone in healthy man

We have previously found that licorice can reduce serum testosterone in healthy men. These results were not confirmed in another study, where the same amounts of licorice did not decrease salivary testosterone values. In the actual study we treated more cases with the same amount of licorice and reproduced our previous data. The mean testosterone values decreased by 26 % after one week of treatment (p < 0.01). There was also a significant increase in 17-OHP and LH concentrations and a slight, but not significant decrease in free testosterone. Licorice treatment, in addition, did not affect the response of testosterone and 17-OHP to stimulation with beta-HCG.

Function of yeast species and strains in wine flavour

The diversity and the composition of the yeast micropopulation significantly contribute to the sensory characteristics of wine. The growth of each wine yeast species is characterized by a specific metabolic activity, which determines concentrations of flavour compounds in the final wine. However, it must be underlined that, within each species, significant strain variability has been recorded. The wide use of starter cultures, mainly applied to reduce the risk of spoilage and unpredictable changes of wine flavour, can ensure a balanced wine flavour, but it may also cause a loss of characteristic aroma and flavour determinants. Thus, the beneficial contribution from the yeast increases when starter cultures for winemaking are selected on the basis of scientifically verified characteristics and are able to complement and optimise grape quality and individual characteristics. Here we report the characterization of a large number of strains of different wine yeast species, isolated from spontaneous wine fermentations and included in the culture collection of the Basilicata University.

Effect of licorice on the reduction of body fat mass in healthy subjects

The history of licorice, as a medicinal plant, is very old and has been used in many societies throughout the millennia. The active principle, glycyrrhetinic acid, is responsible for sodium retention and hypertension, which is the most common side-effect. We show an effect of licorice in reducing body fat mass. We studied 15 normal-weight subjects (7 males, age 22-26 yr, and 8 females, age 21-26 yr), who consumed for 2 months 3.5 g a day of a commercial preparation of licorice. Body fat mass (BFM, expressed as percentage of total body weight, by skinfold thickness and by bioelectrical impedance analysis, BIA) and extracellular water (ECW, percentage of total body water, by BIA) were measured. Body mass index (BMI) did not change. ECW increased (males: 41.8+/-2.0 before vs 47.0+/-2.3 after, p<0.001; females: 48.2+/-1.4 before vs 49.4+/-2.1 after, p<0.05). BFM was reduced by licorice: (male: before 12.0+/-2.1 vs after 10.8+/-2.9%, p<0.02; female: before 24.9+/-5.1 vs after 22.1+/-5.4, p<0.02); plasma renin activity (PRA) and aldosterone were suppressed. Licorice was able to reduce body fat mass and to suppress aldosterone, without any change in BMI. Since the subjects were consuming the same amount of calories during the study, we suggest that licorice can reduce fat by inhibiting 11beta-hydroxysteroid dehydrogenase Type 1 at the level of fat cells.

History of the endocrine effects of licorice

The history of licorice as an officinal plant dates back thousands of years, and licorice is still appreciated as a medicinal root. Many of its endocrine properties can be derived from observations of Authors of the ancient world, when hormones were not known. Inappropriate use of licorice can produce pseudoaldosteronism, by inactivating 11beta-hydroxysteroiod-dehydrogenase and by binding to mineralocorticoid receptors. Licorice possesses many other therapeutic properties as to potentiate the action of cortisol, to reduce testosterone synthesis, especially in women, to exert an estrogen-like activity and to reduce body fat mass. The chronological development of research on these effects is described.

Developmental gonadal expression of the transcription factor SET and its target gene, P450c17 (17alpha-hydroxylase/c17,20 lyase)

Cytochrome P450c17 catalyzes the 17alpha-hydroxylase/17,20 lyase activity needed for sex steroid synthesis. We recently characterized the nuclear phosphoprotein SET as a novel transcriptional regulator that binds to the -447/-399 region of the rat P450c17 gene, along with the transcription factors COUP-TF II, NGF-IB, and SF-1. Gel shift studies localized SET binding to nucleotides -410/-402. We have shown that SET activates transcription of the rat P450c17 gene in neuronal precursor cells and now show that it also activates transcription from the -418/-399 region of the rat P450c17 gene in mouse Leydig MA-10 cells. Studying the ontogenic expression of SET and P450c17 in the rodent gonad, we found that SET expression preceded P450c17 expression in the embryonic genital ridge, suggesting that SET may be important for initiating P450c17 expression in this region. Expression of SET also preceded P450c17 expression in the testis and ovary, and its expression was much greater during embryogenesis than in the adult gonad. In the adult rat testis, P450c17 was expressed only in Leydig cells, while SET was expressed in Leydig cells and in spermatocytes. In the adult rat ovary, P450c17 was expressed only in theca cells, while SET was expressed in theca cells and also in oocytes. Because SET is expressed early in development in the genital ridge and in the testis and ovary, and because SET has many functions in addition to its activity as a transcription factor, we determined whether SET acts a transcription factor in oocytes. The SET protein was detected by Western blots in Xenopus oocytes from stages II through VI and in mature oocytes. Using extracts of Xenopus oocytes in gel shift assays, we detected a protein that bound to the -418/-399 region of the rat P450c17 gene, to which SET binds. Nuclear injection of either a -418/-399TK32LUC wildtype reporter construct or a construct containing a mutant SET site into Xenopus oocytes from stages III through VI resulted in activation of luciferase activity with the wildtype but not the mutant construct in all stages. These data suggest that Xenopus SET is able to bind to specific DNA sequences to activate transcription at all stages of Xenopus oogenesis. These data indicate that SET is an evolutionarily conserved transcription factor that participates in the early ontogenesis of the gonadal system, regulates P450c17 gene transcription in Leydig cells, and may also activate other genes expressed in immature oocytes, thus playing a role in oocyte development.

Fluorometric detection of ADP/ATP carrier deficiency in human muscle

Defects in mitochondrial energy metabolism lead to severe disorders in humans referred to as mitochondriocytopathies. Most of them have been reported to result from deficiencies of one or more complexes of the respiratory chain and, more rarely, from mitochondrial transmembrane metabolite carrier defects. Dysfunctioning of the ADP/ATP carrier, which catalyses the export of matrix ATP in exchange for cytosolic ADP, has been demonstrated to induce myopathies in mouse and in humans. To screen for ADP/ATP carrier deficiency in patients suffering from mitochondriocytopathy with no defined etiology, we have set up a fluorometric assay to quantify the ADP/ATP carrier in small muscle homogenates, without preliminary isolation of mitochondria. The assay is based on the use of a fluorescent derivative of atractyloside, namely naphthoyl-atractyloside, a highly specific inhibitor of ADP/ATP transport. Here, we describe analysis of healthy and pathological muscle samples, and characterization of ADP/ATP carrier deficiencies in two patients, one displaying an absence of the carrier and the second one containing a limited amount of the carrier with altered binding properties.

Mitochondrial adaptation to in vivo polyunsaturated fatty acid deficiency: increase in phosphorylation efficiency

Polyunsaturated fatty acid (PUFA) deficiency affects respiratory rate both in isolated mitochondria and in hepatocytes, an effect that is normally ascribed to major changes in membrane composition causing, in turn, protonophoriclike effects. In this study, we have compared the properties of hepatocytes isolated from PUFA-deficient rats with those from control animals treated with concentrations of the protonophoric uncoupler 2,4-dinitrophenol (DNP). Despite identical respiratory rate and in situ mitochondrial membrane potential (delta psi), mitochondrial and cytosolic ATP/ADP-Pi ratios were significantly higher in PUFA-deficient cells than in control cells treated with DNP. We show that PUFA-deficient cells display an increase of phosphorylation efficiency, a higher mitochondrial ATP/ADP-Pi ratio being maintained despite the lower delta psi. This is achieved by (1) decreasing mitochondrial Pi accumulation, (2) increasing ATP synthase activity, and (3) by increasing the flux control coefficient of adenine nucleotide translocation. As a consequence, oxidative phosphorylation efficiency was only slightly affected in PUFA-deficient animals as compared to protonophoric uncoupling (DNP). Thus, the energy waste induced by PUFA deficiency on the processes that generate the proton motive force (pmf) is compensated in vivo by powerful adaptive mechanisms that act on the processes that use the pmf to synthesize ATP.

Purification and preliminary characterization of the zonula occludens toxin receptor from human (CaCo2) and murine (IEC6) intestinal cell lines

In the present study, we report the preliminary characterization of the epithelial cell receptor for Vibrio cholerae zonula occludens toxin (Zot). Zot receptor was purified by ligand-affinity chromatography. Analysis of affinity-purified preparations by polyacrylamide gel electrophoresis revealed a protein of ca. 66 kDa. Partial N-terminal sequence obtained from purified murine and human Zot receptor revealed homology between the two proteins and with human alpha-1-chimaerin. Zot protein domain(s) involved in receptor binding were also analyzed by constructing several in frame deletion derivatives of a recombinant fusion Zot protein tagged with maltose binding protein. Our results suggest that Zot binding to its cellular membrane receptor requires a sequence that spans between amino acids 118 and 299.

Two distinct regions of the yeast mitochondrial ADP/ATP carrier are photolabeled by a new ADP analogue: 2-azido-3'-O-naphthoyl-[beta-32P]ADP. Identification of the binding segments by mass spectrometry

A novel photoactivatable radioactive ADP derivative, namely, 2-azido-3'-O-naphthoyl-[beta-(32)P]ADP (2-azido-N-[(32)P]ADP), was synthesized with the aim at mapping the substrate binding site(s) of the yeast mitochondrial ADP/ATP carrier. It was used with mitochondria isolated from genetically modified strains of Saccharomyces cerevisiae, producing the native or the His-tagged Anc2p isoform of the carrier. In darkness, 2-azido-N-[(32)P]ADP was reversibly bound to the carrier in mitochondria, without being transported. Upon photoirradiation, only the ADP/ATP carrier was covalently radiolabeled among all mitochondrial proteins. Specificity of labeling was demonstrated since carboxyatractyloside (CATR), a potent inhibitor of ADP/ATP transport, totally prevented the incorporation of the photoprobe. To localize the radioactive region(s), the purified photolabeled carrier was submitted to CNBr or hydroxylamine cleavage. The resulting fragments were characterized and identified by SDS-PAGE, Western blotting, amino acid sequencing, and MALDI-MS and ESI-MS analyses. Two short photolabeled distinct segments, eight and nine residues long, were identified: S183-R191, located in the central part of the ADP/ATP carrier; and I311-K318, belonging to its C-terminal end. Plausible models of organization of the nucleotide binding site(s) of the carrier involving the two regions specifically labeled by 2-azido-N-[(32)P]ADP are proposed.

Purification of histidine-tagged mitochondrial ADP/ATP carrier: influence of the conformational states of the C-terminal region

A functional recombinant mitochondrial ADP/ATP carrier from the yeast Saccharomyces cerevisiae that bears a six-histidine tag at the C-terminus, Anc2(His(6))p, has been engineered to allow its purification by immobilized metal-ion affinity chromatography (IMAC). The tagged carrier was expressed at a level similar to that of unmodified Anc2p as determined by immunodetection and titration of the specific atractyloside binding sites. Anc2(His(6))p, enriched by chromatography on hydroxyapatite of detergent extracts of mitochondria, was still contaminated by mitochondrial proteins and a large amount of ergosterol. It was highly purified after adsorption on Ni-NTA resin and elution by imidazole buffer, with a 90-95% overall yield. Anc2(His(6))p interacted differently with immobilized ions depending on whether it was unliganded or bound to carboxyatractyloside (CATR) or bongkrekic acid (BA), two specific inhibitors of the ADP/ATP transport, thus indicating that accessibility of the C-terminus is markedly influenced by the conformational state of the carrier. Fluorometric assays demonstrated that purified unliganded Anc2(His(6))p was in a functional state since it underwent CATR- and BA-sensitive and ADP (or ATP)-induced conformational changes. Large-scale purification of Anc2(His(6))p-CATR and Anc2(His(6))p-BA complexes by IMAC will be of major interest for structural analysis of the ADP/ATP carrier.

A covalent tandem dimer of the mitochondrial ADP/ATP carrier is functional in vivo

The adenine nucleotide carrier, or Ancp, is an integral protein of the inner mitochondrial membrane. It is established that the inactive Ancp bound to one of its inhibitors (CATR or BA) is a dimer, but different contradictory models were proposed over the past years to describe the organization of the active Ancp. In order to decide in favor of a single model, it is necessary to establish the orientations of the N- and C-termini and thus the parity of the Ancp transmembrane segments (TMS). According to this, we have constructed a gene encoding a covalent tandem dimer of the Saccharomyces cerevisiae Anc2p and we demonstrate that it is stable and active in vivo as well as in vitro. The properties of the isolated dimer are strongly similar to those of the native Anc2p, as seen from nucleotide exchange and inhibitor binding experiments. We can therefore conclude that the native Anc2p has an even number of TMS and that the N- and C-terminal regions are exposed to the same cellular compartment. Furthermore, our results support the idea of a minimal dimeric functional organization of the Ancp in the mitochondrial membrane and we can suggest that TMS 1 of one monomer and TMS 6 of the other monomer in the native dimer are very close to each other.

Surface replacement hemiarthroplasty for the treatment of osteonecrosis of the femoral head

We reviewed the results of thirty-three femoral resurfacing procedures in twenty-five patients who had stage-III or early stage-IV osteonecrosis of the femoral head according to the classification system of Ficat and Arlet. There were no perioperative complications. Thirty hip prostheses (91 percent) survived for a minimum of five years. At a mean of 10.5 years (range, four to fourteen years) postoperatively, sixteen (62 percent) of the twenty-six hips with stage-III disease had a good or excellent Harris hip score. Four of the seven hips with stage-IV disease did not have or need a total hip arthroplasty. Overall, twenty hips (61 percent) had a good or excellent result according to the scoring system of Harris, and thirteen (39 percent) had a fair or poor result and subsequently had or needed a total hip arthroplasty. The mean interval between the hemiarthroplasty and the total hip arthroplasty was sixty months (range, thirty-six to 136 months). These thirteen hips all had a successful clinical result (a Harris hip score of at least 80 points) at a mean of thirty months (range, twenty-four to seventy-two months) after the total hip arthroplasty. The results of the present study suggest that resurfacing of the femoral head can be a successful interim procedure for the management of patients who have Ficat and Arlet stage-III or early stage-IV disease with a large lesion that is not amenable to other treatment options except total hip arthroplasty.

The mitochondrial ADP/ATP carrier: structural, physiological and pathological aspects

Under the conditions of oxidative phosphorylation, the mitochondrial ADP/ATP carrier catalyses the one to one exchange of cytosolic ADP against matrix ATP across the inner mitochondrial membrane. The ADP/ATP transport system can be blocked very specifically by two families of inhibitors: atractyloside (ATR) and carboxyatractyloside (CATR) on one hand, and bongkrekic acid (BA) and isobongkrekic acid (isoBA) on the other hand. It is well established that these inhibitors recognise two different conformations of the carrier protein, the CATR- and BA-conformations, which exhibit different chemical, immunochemical and enzymatic reactivities. The reversible transition of the ADP/ATP carrier between the two conformations was studied by fluorometric techniques. This transconversion, which is only triggered by transportable nucleotides, is probably the same as that which occurs during the functioning of ADP/ATP transport system. The fluorometric approach, using the tryptophanyl residues of the yeast carrier as intrinsic fluorescence probes, was combined to a mutagenesis approach to elucidate the ADP/ATP transport mechanism at the molecular level. Finally, recent reports that myopathies might result from defect in ADP/ATP transport led us to develop a method to quantify the carrier protein in muscular biopsies.

The enterotoxic effect of zonula occludens toxin on rabbit small intestine involves the paracellular pathway

BACKGROUND & AIMS

Zonula occludens toxin is a novel toxin elaborated by Vibrio cholerae that modulates intestinal tight junctions. The aim of this study was to establish whether the permeabilizing effect of the toxin leads to intestinal secretion.

METHODS

Rabbit intestine was mounted in Ussing chambers and exposed to increasing concentrations of purified toxin. The tissues were also fixed, exposed to zonula occludens toxin, and processed for fluorescence microscopy to determine the distribution of the toxin receptor within the intestine. Then purified toxin was simultaneously perfused in three distinct rabbit intestinal segments in vivo, and water and electrolyte absorption were measured.

RESULTS

Zonula occludens toxin induced a time- and dose-dependent decrease of tissue resistance starting at a toxin concentration of 1.1 x 10(-13) mol/L. When tested in vivo, the toxin induced a secretion of water and chloride and the passage of polyethylene glycol 4000 in the bloodstream. Both the in vitro and in vivo effects of the toxin were observed only in the small intestine but not in the colon and paralleled the distribution of the toxin receptor within the intestine.

CONCLUSIONS

The intestinal secretion induced by zonula occludens toxin follows the opening of tight junctions caused by the toxin, possibly representing a novel mechanism of intestinal secretion.

Conformational changes of the yeast mitochondrial adenosine diphosphate/adenosine triphosphate carrier studied through its intrinsic fluorescence. 2. Assignment of tryptophanyl residues of the carrier to the responses to specific ligands

Tryptophanyl substitution of the Saccharomyces cerevisiae adenine nucleotide carrier (Anc2p isoform) was not deleterious for the transport activity or the folding of the carrier [preceding paper by Le Saux et al. (1996) Biochemistry 35, 16116-16124]. Conformational changes of the isolated wild-type and Trp-substituted Anc2p variants, induced upon binding of specific substrates [adenosine triphosphate (ATP) or diphosphate (ADP)] or inhibitors [carboxyatractyloside (CATR) or bongkrekic acid (BA)], were studied by measurement of intrinsic fluorescence. Titration of CATR and BA binding sites ended in the same number of sites, namely, 6-7 nmol/mg of wild-type and variant Anc2p. Isolated Anc2p in detergent presented similar emission spectra, suggesting that all tryptophanyl residues were in environments of similar hydrophobicity. Trp87 and Trp126 contributed largely and to a similar extent to the fluorescence enhancement observed in response to ATP binding, while Trp235 contributed negatively and to a small extent to the fluorescence change. Both Trp126 and Trp235, and to a lower extent Trp87, participate in the CATR-induced fluorescence decrease of Anc2p. Responses to BA binding were observed only in the presence of ATP; they consisted of a further fluorescence increase of the Anc2p.ATP complex, which was mainly due to Trp87 and Trp126, Trp235 being much less responsive. The different fluorescence responses of the three Trp residues of Anc2 variants to ATP, CATR, and BA are in agreement with distinct binding sites for these ligands and distinct conformations of the carrier protein recognizing specifically CATR or BA. A mechanistic model is proposed to interpret the transitions between the different conformational states of Anc2p.

Conformational changes of the yeast mitochondrial adenosine diphosphate/adenosine triphosphate carrier studied through its intrinsic fluorescence. 1. Tryptophanyl residues of the carrier can be mutated without impairing protein activity

During the transport process the mitochondrial adenine nucleotide carrier (Ancp) undergoes conformational changes which result in modifications of the intrinsic fluorescence of the carrier. To further study these changes by a fluorometric approach, the three tryptophanyl residues (Trp87, Trp126, and Trp235) of the Saccharomyces cerevisiae Anc2p were individually mutated to their tyrosine counterparts. The resulting mutated genes (two-Trp, one-Trp or Trp-less variants) were integrated at the ANC2 locus. A prerequisite for such studies is that all the engineered carrier molecules are still able to catalyze ADP/ATP exchange. The cellular characteristics of the strains expressing the mutated Anc2p and the biochemical properties of the variant Anc2p in mitochondria were examined. Although Trp87 is absolutely conserved in all 30 available Ancp sequences, none of the tryptophanyl residues is essential to the carrier protein folding and the transport activity. The mutated and wild-type Anc2p were expressed to the same level, as evidenced by both ligand binding and immunochemical analyses. When isolated in the presence of detergent, all the variant Anc2p preparations contained ergosterol in similar amounts (9 mol/mol of 35 kDa Anc2p) but no specific interaction was revealed. Our results show that the tryptophanmutated Anc2p are suitable for fluorescence studies, which are reported in the accompanying paper by Roux et al. [(1996) Biochemistry 35, 16125-16131].

Fluorometric titration of the mitochondrial ADP/ATP carrier protein in muscle homogenate with atractyloside derivatives

We describe here the chemical synthesis of the novel methylanthraniloyl (Mant-) derivative of atractyloside (ATR), which is a specific inhibitor of the mitochondrial ADP/ATP carrier. The spectral properties of Mant-ATR and naphthoyl-ATR (N-ATR) are analyzed. Both derivatives bind to the membrane-bound ADP/ATP carrier at the same sites as ATR and carboxyatractyloside (CATR). When Mant-ATR and N-ATR are displaced by CATR, their fluorescence emissions are decreased and increased, respectively. These fluorescence changes allow the titration of the CATR binding sites and therefore the quantitation of the amount of ADP/ATP carrier protein in a biological preparation. The validity of the fluorometric titration was tested with beef heart mitochondria and confirmed by binding assays using radioactive ATR. The fluorometric method was applied to rabbit skeletal muscle homogenate and the results of titration were confirmed by binding assays of radioactive ATR. The reliability of the fluorometric method was assessed by comparing the amounts of CATR binding sites and the content of heme aa3 in muscle homogenates and in isolated mitochondria from the same homogenates. Because of its high sensitivity, the fluorometric titration of the ADP/ATP carrier requires small amounts of tissue. Mant-ATR and N-ATR can therefore be considered as convenient, reliable, and sensitive probes to quantify the amount of ADP/ATP carrier and detect a putative carrier protein deficiency in biopsy samples from human patients suffering from myopathies with no clear identified etiology.

Evaluation of functionality of cochlear outer hair cells in patients with retinitis pigmentosa and in their relatives

Hearing functionality was studied in 36 patients with retinitis pigmentosa (R P) and 29 of their relatives. These patients were defined as having bilateral normal hearing on the basis of tonal-threshold audiometric and acoustic-immittance tests. The transiently evoked otoacoustic emissions (T E O A Es) were studied in these normal hearing patients. T E O A Es represent an extremely sensitive method to study the functionality of the outer hair cells of the organ of Corti. When the values of T E O A E amplitude, intensity, and frequency in R P patients and in their relatives were compared with those in control subjects, they were found to be significantly reduced. The T E O A Es were clearly pathological in 52.8% of patients with R P and in 24.1% of their relatives. During embryologic development, there is one transitory axoneme in the outer hair cells of the organ of Corti; this transitory axoneme is important for the organization of the stereocilia. Axonemes are found in mature hair cells, including photoreceptors. The alteration of cochlear outer hair cells in a high percentage of patients with R P and in some of their relatives corroborates the hypothesis that, in some instances, retinitis pigmentosa may be due to a structural anomaly of the ciliated cells.

Stages of change and decisional balance for 12 problem behaviors

This integrative study investigated the generalization of the transtheoretical model across 12 problem behaviors. The cross-sectional comparisons involved relationships between two key constructs of the model, the stages of change and decisional balance. The behaviors studied were smoking cessation, quitting cocaine, weight control, high-fat diets, adolescent delinquent behaviors, safer sex, condom use, sunscreen use, radon gas exposure, exercise acquisition, mammography screening, and physicians' preventive practices with smokers. Clear commonalities were observed across the 12 areas, including both the internal structure of the measures and the pattern of changes in decisional balance across stages.

Evoked otoacoustic emissions behaviour in retinitis pigmentosa

The hearing function was studied in 26 patients affected by retinitis pigmentosa (RP) and in their relatives. Sixteen patients showed bilateral normal hearing when examined with traditional audiometric methods. In these normoacusic patients evoked otoacoustic emissions (EOE) have been studied. The EOE offer a unique opportunity to measure objectively the function of outer hair cells: they record the amplitude of the energy produced by the outer hair cells of the coclea following an acoustic stimulation. The data have been statistically compared, using the Student's t-test, with those obtained in a homogeneous control-group of normal subjects. In normoacusic subjects with RP the average values of EOE intensity are statistically lower than those of normal subjects in 64 of the 127 frequency bands examined. Moreover, the distribution of the EOE in patients with retinitis pigmentosa proved to be more discontinous than that observed in the normal subjects. The EOE recorded in 14 normoacusic relatives show in some cases small anomalies but the data, on account of the limited sample group, cannot be statistically evaluated. Therefore a subclinical alteration of the Organ of Corti is found in 100% of the patients affected by RP, although they appear to be normoacusic to usual audiometric tests.

Stages of change and decisional balance for 12 problem behaviors

This integrative study investigated the generalization of the transtheoretical model across 12 problem behaviors. The cross-sectional comparisons involved relationships between two key constructs of the model, the stages of change and decisional balance. The behaviors studied were smoking cessation, quitting cocaine, weight control, high-fat diets, adolescent delinquent behaviors, safer sex, condom use, sunscreen use, radon gas exposure, exercise acquisition, mammography screening, and physicians' preventive practices with smokers. Clear commonalities were observed across the 12 areas, including both the internal structure of the measures and the pattern of changes in decisional balance across stages.