Characterization of the metabolic shift of Saccharomyces bayanus var. uvarum by continuous aerobic culture

Saccharomyces bayanus, being of interest for wine-making, is not as well known as S. cerevisiae and, due to many changes in the yeast classification, accurate data concerning its metabolic activity are difficult to find. In order to produce this yeast as an active dry yeast to be used as a starter in wine-making, its sensitivity to glucose was determined as the objective of our work. Using the pulse technique in continuous culture, it was found that growth in a synthetic medium was not limited by vitamins or mineral salts. We determined the critical dilution rate of a continuous culture and performed an aerobic continuous culture, measuring the respiratory quotient on-line in order to observe the metabolic shift from respiratory to fermentative metabolism. The S. bayanus var. uvarum strain studied was Crabtree-positive (glucose-sensitive) but had a weaker respiratory capacity than S. cerevisiae since the dilution rate of the metabolic shift was only 0.15 h(-1). These new data provide essential information for the biomass production of this yeast strain for wine-making.

Vasculitides with predominantly renal involvement: influence of age on the mode of presentation

Vasculitis with predominant renal involvement are increasingly observed in elderly patients. It predominantly involves patients with microscopic polyangiitis, Wegener's granulomatosis, renal limited vasculitis and, in a smaller proportion, Churg Strauss syndrome. The elderly patients present very few obvious symptoms or signs of vasculitis such as hemoptysis and pulmonary infiltrates, and they are often submitted to: 1/renal biopsy when renal failure is already advanced; 2/ have more severe renal disease than do young and middle-aged patients (81% of acute and/or rapidly progressive renal failure versus 62%, and 30% of oliguria versus 6%); and 3/ a worse prognosis compared with younger individuals (probability of survival at 3 months, 1 year and 5 years of 93%, 93% and 92% in patients under 65, versus 67%, 62% and 46% in the elderly). Management of all patients with vasculitis and predominant renal involvement requires a quick diagnosis and immunosuppressive treatment aimed at controlling the disease. Treatment is mantained for 18 to 24 months. Nevertheless, relapses do occur (between 20% to 52%) of all patients with microscopic polyangiitis and Wegener's granulomatosis.

Audiological range in Turner's syndrome

Turner's syndrome is generally characterised by bilateral gonadal disgenesis, short stature and inadequate sexual development secondary to anomalous karyotype. The purely otorhinolaryngoiatric pathology considerably influences the symptomatological features in Turner's subject and this is based on possible morphologically structured anomalies in the external, middle and inner ear, but also on the oral cavity and pharynx. From this there is evidence of otological emergence on a phlogistic infectious basis with remarkable long-term repercussion on the hearing process. Otofunctional evaluation in 21 Turner's syndrome patients shows predominance of conductive hearing loss (42.8%), proven through evidence of otitis media (33.3%) and chronic otitis media (9.5%). This, therefore, demands an attentive audiologic monitoring related to the possible development of chronic forms or cholesteatoma and the possible rehabilitative-prothesis procedure.

Internalization-associated proteins among Streptococcus pyogenes isolated from asymptomatic carriers and children with pharyngitis

Sixty-two strains of Streptococcus pyogenes isolated from 30 asymptomatic school children and 32 children with pharyngitis were characterized to analyze the involvement of 2 fibronectin-binding proteins (F/SfbI and PrtF2/PfbpI) in S. pyogenes colonizing asymptomatic carriers and to determine the possible association between these proteins and the genes associated with macrolide resistance. In this study, we demonstrated that the proportion of S. pyogenes strains carrying the pfbpI gene was significantly higher among asymptomatic carriers (80%) than among children with pharyngitis (53%; P<.05). With regard to the proportion of prtF1-positive strains, no significant differences were found between the 2 groups (70% vs. 69%, for asymptomatic carriers and children with pharyngitis, respectively). Another important finding is the significant association between macrolide resistance and protein F/SfbI (P<.001) in both groups. These results suggest that the presence of the pfbpI gene can be linked to the ability of S. pyogenes to persist in the throat of asymptomatic carriers.

Within-gene interaction between c.135 G/A genotypes and RET proto-oncogene germline mutations in HSCR families

Hirschsprung disease (HSCR) is considered a model for a complex inheritance disorder. Several genes, including the major HSCR-susceptibility RET proto-oncogene, play an aetiological role in the development of HSCR. Genetic linkage analysis in familial HSCR with both long- and short-segment phenotypes has demonstrated a tight linkage to the RET locus, while the phenotype within a HSCR family is characterised by an incomplete penetrance or a variable extension of the aganglionosis. Therefore, additional genetic alterations of RET are postulated in the aetiology or modification of the HSCR phenotype. In this study, the coding region of all 21 exons of the RET proto-oncogene, including the flanking intronic sequences, were investigated by direct DNA sequencing in a HSCR population. We genotyped the c.135 G/A polymorphism and resolved haplotypes comprising the mutation locus and the c.135 G/A polymorphism. Twenty different mutations were detected in 18 of 76 HSCR patients. In ten families the mutations were inherited from the parents, while only four patients had a positive family history for the disease. Moreover, in all ten families an incomplete penetrance of the HSCR phenotype was observed. We have investigated the effect of the non-mutated wild-type allele as well as the c.135 G/A polymorphism on the phenotype within the HSCR families. Our findings support the notion that both RET alleles are involved in the pathogenesis of a subgroup of HSCR patients in a dose-dependent fashion. Additionally, we have shown a modifying effect of the c.135 G/A polymorphism on the HSCR phenotype within HSCR families.

Role of eye movement examination and subjective visual vertical in clinical evaluation of multiple sclerosis

BACKGROUND AND PURPOSE

Modern neuroimaging has demonstrated progression of disease in multiple sclerosis (MS) that may not be detected by standard clinical protocols, prompting a search for new, sensitive tests.

METHODS

In fifty patients with MS, we examined eye movements, with particular attention to the speed and accuracy of saccades, and the vestibulo-ocular reflex during small, high-speed head rotations. We also measured the subjective visual vertical (SVV), using a modified laser-pointer. Visual function was measured, and patients were graded using the Kurtzke Functional Neurological Status (FSS), and Expanded Disability Status Scale (EDSS).

RESULTS

Our main finding was that patients showing abnormalities of eye movements (20/50) were more disabled than those with a normal examination (EDSS scores significantly different, p < 0.01), although the ages and duration of disease were similar in both groups. Saccadic dysmetria and internuclear ophthalmoparesis were common. SVV was abnormally large in 36 % of patients; these showed abnormal eye movements and poorer visual acuity more commonly than those with normal SVV. In patients with the largest deviations of SVV, Kurtzke FSS cerebellar functions were significantly worse (p = 0.021).

CONCLUSIONS

Clinical examination of eye movements, with attention to dynamic properties of saccades and the vestibulo-ocular reflex, takes only a few minutes to perform, but may provide better information concerning the presence of brainstem and cerebellar involvement than Kurtzke protocols. Measurement of SVV is possible in the clinic and is a sensitive sign of brainstem dysfunction; our present study suggests that SVV is also affected when cerebellar circuits are involved in MS. Prospective studies are required to determine whether the development of abnormalities with ocular motor and SVV testing are predictive of disease activity and progressive disability in MS.

Diagnostic value of nystagmus: spontaneous and induced ocular oscillations

Research over the past 20 years has provided a clearer understanding of the pathogenesis of most forms of nystagmus and other ocular oscillations. To the clinician, these advances translate into greater accuracy of nystagmus as a diagnostic sign. However, to capitalise on these advances, it is important to systematically examine eye movements and interpret the findings with reference to pathophysiology. In this review we describe a scheme for examining the patient with nystagmus and interpreting common ocular oscillations; some examples are provided as video clips.

Quantitative assessment of WT1 expression by real time quantitative PCR may be a useful tool for monitoring minimal residual disease in acute leukemia patients

In order to verify if quantitative assessment of the WT1 transcript amount by the real time quantitative PCR (RQ-PCR) can be used as a marker for minimal residual disease detection, the WT1 transcript amount was determined in BM and PB samples of patients with myeloid and lymphoid acute leukemia, in normal controls, in regenerating bone marrow samples and in purified CD34-positive cells from normal subjects. In 10 patients bearing a fusion gene transcript suitable for minimal residual disease quantitative assessment, we performed a simultaneous analysis of the WT1 and of the fusion-gene transcript at sequential time intervals during follow-up. Sequential WT1 analysis was also performed in five AML patients lacking additional molecular markers. The data obtained show that normal and regenerating BM samples and purified CD34-positive cells consistently express minimal amounts of WT1 transcript and that this is extremely low and frequently undetectable in normal PB. By contrast, high levels of WT1 expression are present in the BM and PB samples of all acute leukemia (AL) cases at diagnosis. The WT1 levels during follow-up were found to follow the pattern of the other molecular markers (fusion gene transcripts) used for MRD monitoring and increased WT1expression in the BM and/or PB during follow-up of AL patients was always found to be predictive of an impending hematological relapse.

Serotonin and serotonin receptor expression in the aorta of carotid intact and denervated newborns

Pharmacological blocking of serotonin (5-HT) 5A receptors abolishes aortic ventilatory chemosensitivity of carotid body denervated (CBD) piglets [J. Appl. Physiol. 92 (2002) 893]. Accordingly, the purpose of the present study was to determine whether 5-HT and 5-HT receptors exist at aortic sites that are chemosensitive after CBD. Aortas from CBD and sham CBD rats and piglets and from aortic denervated (AOD) and combined AOD+CBD piglets were harvested, sectioned and then studied using immunohistochemistry and western blot techniques. 5-HT immunoreactivity in piglets and rats was concentrated in the endothelium and sub-endothelial areas in several aortic regions studied, and in some areas also in the adventitia. At the aortic chemosensitive site (descending aorta in CBD piglets and the ascending aorta in CBD rats), the immunoreactivity was greater (P < 0.05) than in other aortic regions and greater than in other groups studied. The 5-HT(5a) receptor was expressed only at the chemosensitive sites and only in aortic innervated piglets. We conclude that the data from this and a previous study [J. Appl. Physiol. 92 (2002) 893] suggest that a serotonergic mechanism contributes to the aortic ventilatory chemoreflex after CBD.

MyD-1 (SIRPalpha) regulates T cell function in the absence of exogenous danger signals, via a TNFalpha-dependent pathway

Signal inhibitory regulatory proteins are a family of transmembrane glycoproteins involved in the negative regulation of receptor tyrosine kinase signaling pathways. MyD-1 is a recently described member of this family. In this report we have assessed the function of MyD-1 in regulating T cell function utilizing an anti-MyD-1-specific monoclonal antibody (mAb). We show that ligating MyD-1 on antigen-presenting cells (APC) inhibits subsequent T cell activation induced by either anti-CD3 mAb or by allogeneic APC but has no effect on responses to either tuberculin purified protein derivative or tetanus toxoid antigens. Moreover, we show that the inhibition of T cell responses is not due to any change of costimulatory molecule expression on APC. We observed that the production of TNFalpha, a cytokine that we have earlier identified as important in the mechanism of MyD-1 immune regulation, is inhibited by cross-linking of MyD-1. We further show that TNFalpha is critically important in the regulation of T cell responses in the absence of danger signals, and indeed addition of TNFalpha can overcome the inhibitory effects of anti-MyD-1 antibody. This information may lead to a better understanding of the regulation of T cell responses in the absence of danger and therefore offer a possible therapeutic target to modulate aberrant immune responses.

Assessment of minimal residual disease (MRD) in CBFbeta/MYH11-positive acute myeloid leukemias by qualitative and quantitative RT-PCR amplification of fusion transcripts

The inv(16)(p13q22) chromosomal rearrangement associated with FAB M4Eo acute myeloid leukemia (AML) subtype is characterized by the presence of the CBFbeta/MYH11 fusion transcript that can be used to detect minimal residual disease (MRD). However, qualitative RT-PCR studies of MRD have so far produced conflicting results and seem of limited prognostic value. We have evaluated retrospectively MRD in a large series of CBFbeta/MYH11-positive patients employing both qualitative and quantitative (real-time PCR) approaches. 186 bone marrow samples from 36 patients were examined with a median follow-up of 27.5 months; 15 patients relapsed during follow-up. In qualitative studies, carried out by 'nested' RT-PCR assay, all patients in complete remission (CR) immediately after induction/consolidation therapy were found to be PCR positive. However, follow-up samples at later time points were persistently negative (except one case) in patients remaining in continuous CR (CCR) for more than 12 months. 16 patients were evaluated by quantitative real-time PCR assay: CBFbeta/MYH11 transcript copy number was normalized for expression of the housekeeping gene ABL, expressed as fusion gene copy number per 10(4) copies of ABL. A 2-3 log decline in leukemic transcript copy number was observed after induction/consolidation therapy. After achieving CR, the mean copy number was significantly higher in patients destined to relapse compared to patients remaining in CCR (151 vs 9, P < 0.0001 by Mann-Whitney test). Moreover, in CCR patients, the copy number dropped below the detection threshold after the treatment protocol was completed and remained undetectable in subsequent MRD analysis in accordance with results obtained by qualitative RT-PCR. On the contrary, in the seven patients who relapsed, the copy number in CR never declined below the detection threshold; thus a cut-off value discriminating these two groups of patients could be established. The findings of our study, if confirmed, might confer an important predictive value to quantitative real-time PCR determinations of MRD in patients with inv(16) leukemia.

[Neonatal vocal cord palsy. Clinical and therapeutical approaches]

Between 1998 and 2000, four newborns have been observed for laryngeal stridor occurred some hours after birth. Otorhinolaryngologic examinations, as well as cardiac, neuroradiologic and serologic investigations have been performed to formulate the diagnosis and verify the etiology. The fiberoptic laryngoscopy showed a bilateral paralysis of the vocal cord in two newborns, a monolateral paralysis of the left vocal cord in another and in the last one, instead, a bilateral cordal hypomobility. The follow-up performed till the age of one year showed a complete remission of the symptomatology in two newborns, respectively in the one with monolateral paralysis and in the other affected by hypomobility of the vocal cords; of the two newborns with bilateral paralysis, instead, one is dead because of Haemophilus Influenzae epiglottitis, three weeks after discharge without physicians' consensus, while in the other patient, affected by lobar holoprosencephaly, it was necessary to perform a tracheotomy because of a severe obstructive apnea. The lobar holoprosencephaly, is a cerebral malformation characterized by the partial separation of the cerebral hemispheres, and it is described for the first time associated with bilateral vocal cords paralysis.

Effects of carotid and aortic chemoreceptor denervation in newborn piglets

The objective of the present study was to test the hypothesis that in neonatal piglets there would be no hypoventilation after sham denervation or aortic denervation (AOD) alone, but there would be transient hypoventilation after carotid body denervation (CBD) and the hypoventilation would be greatest after combined carotid and aortic denervation (CBD+AOD). There was a significant (P < 0.05) hypoventilation in CBD and CBD+AOD piglets denervated at 5, 15, and 25 days of age. The hypoventilation in CBD+AOD piglets denervated at 5 days of age was greater (P < 0.05) than that of all other groups. Conversely, sham-denervated and AOD piglets did not hypoventilate after denervation. Injections of sodium cyanide showed that aortic chemoreceptors were a site of recovery of peripheral chemosensitivity after CBD. This aortic sodium cyanide response was abolished by prior injection of a serotonin 5a receptor blocker. Residual peripheral chemosensitivity after CBD+AOD was localized to the left ventricle. We conclude that 1) aortic chemoreceptors contribute to eupneic breathing in piglets that were carotid denervated at 5 days of age and 2) there are multiple sites of residual peripheral chemosensitivity after CBD.

Non-invasive proportional assist and pressure support ventilation in patients with cystic fibrosis and chronic respiratory failure

BACKGROUND

Patients with advanced cystic fibrosis can benefit from non-invasive positive pressure ventilation (NPPV) for the treatment of acute decompensation as well as for the management of chronic respiratory failure. This study was undertaken to compare the physiological effects of non-invasive proportional assist ventilation (PAV) and pressure support ventilation (PSV) on ventilatory pattern, transcutaneous blood gas tensions, and diaphragmatic effort in stable patients with cystic fibrosis and chronic CO2 retention.

METHODS

In 12 patients two periods of spontaneous breathing were followed randomly by PSV (12 (3) cm H2O) and PAV (flow assist 4.9 (1.3) cm H2O/l.s, volume assist 18.9 (5.1) cm H2O/l) set for the patient's comfort and administered for 40 minutes with 2 cm H2O continuous positive airway pressure. Ventilatory pattern, transcutaneous blood gas tensions, and surface diaphragmatic electromyography were measured in the last 10 minutes of each application.

RESULTS

On average, both PSV and PAV improved ventilation (+30%), tidal volume (+30%), and transcutaneous CO2 (-7%) while reducing diaphragmatic activity (-30% with PSV, -20% with PAV). Mean inspiratory airway pressure was lower during PAV than during PSV (9.7 (1.9) and 12.9 (2.7) cm H2O, respectively; p<0.05). The mean coefficient of variation of tidal volume was about 20% (range 11-39%) during spontaneous breathing and did not change with either PAV or PSV.

CONCLUSIONS

These results show that short term administration of nasal PAV and PSV to patients with stable cystic fibrosis with chronic respiratory insufficiency is well tolerated, improves ventilation and blood gas tensions, and unloads the diaphragm.

Prophylactic hemodialysis after radiocontrast media in patients with renal insufficiency is potentially harmful

PURPOSE

Acute renal failure induced by contrast media is an important cause of hospital-acquired renal insufficiency. Preexisting renal failure and the dose of contrast media are known risk factors for the development of radiocontrast nephropathy. We performed a randomized trial to test whether radiocontrast nephropathy can be avoided by prophylactic hemodialysis immediately after the administration of contrast media in patients with impaired renal function.

SUBJECTS AND METHODS

Renal function and other parameters, hemodialysis requirement, and relevant clinical events were recorded before and during the 6 days after administration of contrast media in 113 patients with a baseline serum creatinine level >200 microm/L (>2.3 mg/dL). Patients were randomly assigned to either hemodialysis (n = 55) or nonhemodialysis (n = 58) treatment after parenteral low-osmolality contrast media.

RESULTS

The characteristics of the patients in the two groups were similar. Compared with baseline levels, the mean [+/- SD] serum creatinine level decreased at day 1 (277 +/- 95 microm/L), peaked at day 4 (353 +/- 126 microm/L), and returned to baseline at day 6 (327 +/- 119 microm/L, P <0.05 by analysis of variance) after administration of contrast media in the hemodialysis group, whereas in the nonhemodialysis group, no significant changes in mean serum creatinine level were observed. Eleven patients required 1 or more hemodialyses (8 in the hemodialysis group and 3 in the nonhemodialysis group, P = 0.12), 6 of whom (4 vs. 2, P = 0.44) required 3 or more hemodialyses. Clinically relevant events included pulmonary edema (1 vs. 4 patients, P = 0.36), myocardial infarction (2 vs. 2), stroke (2 vs. 0, P = 0.24), and death (1 vs. 1).

CONCLUSIONS

The strategy of performing hemodialysis immediately after the administration of low-osmolality contrast media in all patients with a reduced renal function did not diminish the rate of complications, including radiocontrast nephropathy.