Possible role of HMG-CoA reductase inhibitors for the treatment of sudden sensorineural hearing loss (SSHL)

The term 'idiopathic' is used to design sudden sensorineural hearing loss when causative factors cannot be identified. In most cases a viral infection or a circulatory defect are considered to play a significant role when an alternative satisfactory explanation cannot be found. However some significant points remain unclear, since the great variability in age and general conditions of the affected people makes it difficult to find a reliable interpretation of the exact nature of this phenomenon which is reasonably considered to have a multifactorial origin. Under these conditions many different therapeutic strategies have been put forward, thus suggesting some degree of uncertainty not only about the pathogenetic mechanisms of the disease but also on the actual effectiveness of the disparate treatment approaches. In this paper the use of statins in sudden sensorineural hearing loss is firstly proposed on the basis of their metabolic and hemodynamic effects, and the possible clinical implications are outlined.     

Systemic hypotension and the development of acute sensorineural hearing loss in young healthy subjects

BACKGROUND: Sudden sensorineural hearing loss (SSHL) is an acute disorder whose origin is often unclear. A vascular disorder may be a causative factor. OBJECTIVE: To determine whether hypotension influences the genesis of SSHL in healthy subjects. DESIGN: To investigate the role of a 24-hour blood pressure (BP) profile in a population of young subjects with SSHL from January 1, 1996, to December 31, 1999, by a nonrandomized controlled trial. SETTING: The Ear, Nose and Throat Section of the Department of Surgical and Anaesthesiological Sciences and the Department of Internal Medicine, S. Orsola Hospital, University of Bologna, Bologna, Italy. PATIENTS: The study population consisted of 23 untreated healthy patients diagnosed as having SSHL compared with 20 age- and sex-matched normotensive control subjects. Both groups underwent 24-hour BP monitoring, and their BP profiles were analyzed and compared with routine BP values. The data were analyzed with the Statistical Package for the Social Sciences, version 7.1, and the results are expressed as mean +/- SD. MAIN OUTCOME MEASURES: The mean BP values were expected to be lower in the study population. RESULTS: The average clinic and ambulatory BP values were significantly lower in patients with SSHL, for systolic (clinic, P =.004; ambulatory BP, P =.02) and diastolic (clinic, P =.03; ambulatory BP, P =.03) values. The occurrence of persistent hypotension (the presence of >2 consecutive recordings of systolic BP of < or =105 mm Hg and/or diastolic BP of < or =60 mm Hg) was increased in the population with SSHL. CONCLUSION: Systemic hypotension must be considered as the possible cause responsible for the development of SSHL in young healthy subjects.     

The development of the suprarenal gland: surgical and anatomical considerations

BACKGROUND: Aim of this research is to study the situation and relationships of the adrenal gland in the first stage of development in order to give some contributes for the application of laparoscopic adrenalectomy; in the meantime we describe the series of the debate changes occurring in the constitution of the cortex and medulla. METHODS: Analysis of histologic slices of thoraco-abdominal and abdominal regions of human embryos and fetuses ranging from the fifth (12 mm CR) to the twentieth week (170 mm CR). RESULTS: At 12 mm CR an unique type of cells is present in the cortex; at 16 mm CR there are two different groups of cells. Sympathogonia enter into the cortex at 16 mm CR. The right adrenal gland seems enclosed into the liver and a ligament containing the middle adrenal vein reaches the vena cava inferior sulcus. The left adrenal gland, through the coelomic cavity, is in relationship with the stomach, the medial border of the spleen and the pancreatic body contained in the primitive dorsal mesogastrium. CONCLUSIONS: The timing of penetration of the ganglion cells into the cortex is defined as well as the hypothesis that the matrix of the fetal and definitive cortex is the same: moreover the study of the early development allows to understand the main characteristics of both the adrenal glands which are significant for a rational and differential laparoscopic approach.     

Microsatellite instability and mismatch-repair protein expression in hereditary and sporadic colorectal carcinogenesis

Aberrant crypt foci (ACF) are microscopic clusters of altered colonic crypts considered premalignant lesions in the large bowel. Genomic instability at short tandem repeats in the DNA, referred to as microsatellite instability (MSI) is the hallmark of hereditary nonpolyposis colorectal carcinoma (HNPCC) caused by mutations in DNA mismatch-repair genes, mostly hMLH1 and hMSH2. In this study, we evaluated for MSI ACF (n = 16), adenomas (n = 18), carcinomas (n =22), and lymph node metastases (n = 3) from 17 patients with colorectal cancer positive for MSI. Ten patients were members of HNPCC families; 7 patients had no family history of cancer. MSI was found in 7 of 7 (100%) ACF and 11 of 12 (91%) adenomas from patients with HNPCC. MSI was not related to histology and size of ACF. A progressive increase in instability as estimated by the number of shifted bands was observed along the ACF-adenoma-carcinoma sequence. In contrast, two of nine (22%) ACF and none of six adenomas from patients with MSI sporadic carcinoma were unstable at microsatellite loci. hMLH1 or hMSH2 protein expression was altered only in MSI-positive premalignant lesions (ACF and/or adenomas), but not in all MSI-positive lesions in patients with HNPCC. These observations provide evidence of the premalignant nature of ACF in HNPCC and suggest that MSI is a very early event both in HNPCC and in sporadic colorectal carcinogenesis, although in the latter it seems infrequent.     

Relationship of systemic hemodynamics, left ventricular structure and function, and plasma natriuretic peptide concentrations during pregnancy complicated by preeclampsia

OBJECTIVE: This study was done to evaluate left ventricular structure and function among pregnant patients with preeclampsia and compare them with those of normotensive pregnant and nonpregnant subjects. It also tested the hypothesis that abnormalities in left ventricular structure and function are associated with elevated plasma levels of natriuretic peptides. STUDY DESIGN: The study compared 75 pregnant women (n = 40 with preeclampsia; n = 35 normotensive pregnant women) and 10 nonpregnant normotensive control subjects undergoing an echocardiographic and biohumoral (renin activity and aldosterone, atrial natriuretic peptide, and brain natriuretic peptide concentrations) evaluation. The statistical analysis was carried out by analysis of variance, and significance was set at P <.05. RESULTS: Comparison of pregnant patients with preeclampsia versus both normotensive pregnant women and nonpregnant women showed significant increases in left ventricular mass and left ventricular endsystolic and end-diastolic volumes and significant reductions in left ventricular ejection fraction and percentage of fractional shortening. These changes coincided with increases in plasma levels of atrial natriuretic peptide and brain natriuretic peptide that were linearly related to the left ventricular structural and functional changes observed in patients with preeclampsia. CONCLUSION: Pregnant patients with preeclampsia showed adaptation to the increase in systemic blood pressure, with significant modification of left ventricular structure and function related to the plasma levels of both atrial natriuretic peptide and brain natriuretic peptide. A simple evaluation of plasma natriuretic peptide concentrations could help to discriminate patients with preeclampsia who have a condition of mild left ventricular overload.     

Comparison of Costs of Home and Facility-based Basic Obstetric Care in Rural Bangladesh

This study compared the costs of providing antenatal, delivery and postnatal care in the home and in a basic obstetric facility in rural Bangladesh. The average costs were estimated by interviewing midwives and from institutional records. The main determinants of cost in each setting were also assessed. The cost of basic obstetric care in the home and in a facility was very similar, although care in the home was cheaper. Deliveries in the home took more time but this was offset by the capital costs associated with facility-based care. As use-rates increase, deliveries in a facility will become cheaper. Antenatal and postnatal care was much cheaper to provide in the facility than in the home. Facility-based delivery care is likely to be a cheaper and more feasible method for the care provider as demand rises. In settings where skilled attendance rates are very low, home-based care will be cheaper.Key words: Comparative studies, Cost-benefit analysis, Healthcare costs, Maternal health, Obstetric care, Bangladesh     

Probabilistic approach for the risk assessment of nanomaterials: A case study for graphene nanoplatelets

An experimental probabilistic approach for health risk assessment was applied for graphene nanoplatelets (GNPs). The hazard assessment indicated a low level of toxicity for the GNPs. The benchmark dose method, based on sub-chronic and chronic inhalation exposure studies, was used to quantify a guidance value (BMC_h) for occupational inhalation exposure to GNPs, expressed as a lognormal distribution with a geometric mean?±?geometric standard deviation of 0.212?±?7.79?mg/m³ and 9.37?×?10⁴?±?7.6 particle/cm³. Exposure scenarios (ES) were defined based on the scientific literature for large-scale production (ES1) and manufacturing (ES2) of GNPs; a third ES, concerning in-lab handling of GNPs (ES3) was based on results of experiments performed for this study. A probability distribution function was then assumed for each ES. The risk magnitude was calculated using a risk characterization ratio (RCR), defined as the ratio of the exposure distributions and the BMC_h distribution. All three ES resulted in RCR distributions ≥1 (i.e. risk present); however, none of the ES had a statistically significant level of risk at a 95% confidence interval. A sensitivity analysis indicated that ～75% of the variation in the RCR distributions was due to uncertainties in the BMC_h calculation.     

Effect of ascorbic acid-rich diet on in vivo-induced oxidative stress

Using hyperbaric oxygen (HBO) therapy as an in vivo oxidation model, we investigated the effect of a diet enriched in ascorbic acid (AA) on HBO-induced oxidative stress. Volunteers (n 46) were allocated to the AA-rich diet group or the control group. Blood samples were collected at the basal time, after the 1-week diet before and immediately after the HBO treatment, and 1 week after the HBO treatment. AA level, total antioxidant status (TAS), hydroperoxides (HP), lymphocyte DNA oxidation and DNA repair capacity were assessed. The expression of genes involved in oxidative stress was evaluated in lymphocytes and the protein activity of the modulated genes was determined in the plasma. The AA level and the antioxidant status of plasma were increased by AA-rich food consumption. HBO exposure did not affect the AA levels or TAS, but induced HP formation in the control group. The lymphocytes isolated from dietary-supplemented subjects were resistant to ex vivo DNA oxidation, showing an increased DNA repair capacity compared with controls. A difference in gene expression pattern was observed between the groups. AA-rich foods provide dual protection against oxidative stress, enhancing plasma antioxidant levels and stimulating genes involved in cell detoxification.