Risk factors for candidaemia in hospitalized patients with liver cirrhosis: a multicentre case-control-control study

OBJECTIVES

The aim of this study was to evaluate the risk factors for candidaemia in patients with liver cirrhosis.

METHODS

This was a case-control-control (1:2:2) study performed in four Italian tertiary centres from 2006 to 2015. Cases were patients with liver cirrhosis developing candidaemia. For every case of candidaemia we enrolled two additional patients undergoing blood cultures for suspected infection yielding isolation of a bacterial pathogen (control A) and two additional patients undergoing blood cultures for suspected infection yielding negative results (control B). Patients were matched according to age, sex and model for end stage liver disease at hospital admission.

RESULTS

During the study period 90 cases, 180 controls A and 180 controls B were included. At multivariate analysis assessed by means of multinomial conditional regression models, factors independently associated with candidaemia were previous (<30 days) acute-on-chronic liver failure (relative risk ratio (RRR) 2.22 (95% confidence interval (CI) 1.09-4.54), p = 0.046), previous(<30 days) gastrointestinal endoscopy (RRR 2.38 (95% CI 1.19-4.78) p = 0.014), previous(<30 days) antibiotic treatment for at least 7 days (RRR 2.74 (95% CI 1.00-7.48), p = 0.049), presence of central venous catheter (RRR 2.77 (95% CI 1.26-6.09, p = 0.011), total parenteral nutrition (RRR 3.90 (95% CI 1.62-9.40), p = 0.002) at infection onset and length of in-hospital stay >15 days (RRR 4.63 (95% CI 2.11-10.18), p <0.001] Conversely, rifaximin treatment was associated with lower rate of candidaemia (RRR 0.38 (95% CI 0.19-0.77), p = 0.007). Multivariable analysis for 30-day mortality showed that patients with isolation of Candida spp. from blood cultures had worse outcome when compared with controls even though the difference did not reach a statistical significance (hazard ratio 1.64 (95% 0.97-2.75) p = 0.06).

CONCLUSIONS

We identified previous antibiotic use, gastrointestinal endoscopy or acute-on-chronic liver failure and presence of central venous catheter especially for parenteral nutrition as independent factors associated with candidaemia. Surprisingly, chronic rifaximin use was a protective factor.

A fast and validated mass spectrometry method for the evaluation of human serum albumin structural modifications in the clinical field

A relatively fast analytical method for the identification and quantification of the post-transcriptional changes (PTCs) occurring in circulating human serum albumin (HSA) was developed. HSA is the most abundant protein in plasma and it represents the main determinant of plasma oncotic pressure, thus being the main modulator of fluid distribution between body compartments. Cirrhotic patients have low levels of HSA. Moreover, recent studies have demonstrated that during liver cirrhosis HSA presents PTCs affecting its properties. The HSA isoforms derived from these modifications could represent promising biomarkers for liver disease. Human plasma samples were collected from a cirrhotic patient (CH) and from an aged-matched non- cirrhotic subject (CT), purified by reverse-phase chromatography and analysed by an electrospray ionization quadrupole time-of-flight (ESI-Q-ToF) spectrometer. The deconvoluted ESI mass spectra from healthy subjects were all characterized by peaks attributed to mercaptoalbumin, nitrosylated, cysteinylated, glycated and N- terminal truncated HSA isoforms. The relative abundance of each isoform was derived and transformed into a relative per cent amount and the results were compared to those obtained analysing HSA from a CH plasma. The method was validated in terms of intra-day and inter-day reproducibility, both for quantitative results and PTCs molecular weight determination. The optimized method resulted in being effective in disclosing changes in HSA isoforms relative abundance and then it could be used for the systematic screening of cirrhotic patients to identify promising new biomarkers for liver diseases.

New trends in bio/nanotechnology: stable proteins as advanced molecular tools for health and environment

In this work the thermophilic trehalose/maltose-binding protein from Thermococcus litoralis is presented as a probe for the design of a high stable fluorescence biosensor for glucose. In particular, we show the possibility of modulating the protein specificity by changing temperature. In addition to glucose sensing, we also report on the possibility of utilizing odorant-binding proteins as a probe for the development of optical sensors for analytes of environmental interests.

Fecal expression of human β-defensin-2 following birth

BACKGROUND

Newborns display high intestinal permeability and a naive adaptive immune system, but infections are rare, indicating strong innate defense mechanisms.

OBJECTIVE

To measure the kinetics of fecal β-defensin-2 (HBD2), an inducible endogenous antimicrobial peptide produced by intestinal epithelial cells, in full-term and preterm infants.

METHODS

As a first step of this bicentric study, we enrolled 30 healthy full-term infants and 20 healthy preterm infants, with fecal samples collected at days 3, 7, 12 and 30 in full-term infants and at days 15, 30 and 60 in preterm infants. As a second step, we enrolled 10 preterm infants with intestinal distress, either necrotizing enterocolitis (NEC) Bell's stage III (n = 3) or isolated rectal bleeding (n = 7) and 20 controls, cross-matched for gestational age and age at sampling.

RESULTS

HBD2 decreased significantly from day 3 to day 7 (227 ng/g; 14-440 vs. 117 ng/g; 30-470, p = 0.01) then moderately until day 30 (84 ng/g; 10-500) in healthy full-term infants. Healthy preterm infants showed similar high levels between days 15 and 60 (82 ng/g; 30-154 and 85 ng/g; 26-390, respectively). No significant variation of fecal HBD2 levels was observed between infants with clinical features of intestinal distress (77 ng/g, 2-1,271) and cross-matched controls (56 ng/g, 31-164). However, 2/3 infants with NEC and 1/7 infants with isolated rectal bleeding had HBD2 levels above the maximal level observed in controls.

CONCLUSIONS

The kinetics of fecal HBD2 in the neonatal period indicate that this inducible defensin can be detected at high level in the feces of full-term and preterm infants, independently of gestational age or mode of feeding. The potential role of fecal HBD2 in detecting NEC is suggested.

Multichannel intraluminal impedance to detect relationship between gastroesophageal reflux and apnoea of prematurity

BACKGROUND

The association between gastroesophageal reflux and apnoea of prematurity is still controversial. Available data are biased by the heterogeneity of the infants enrolled as regard to some confounding factors and by the use of the traditional pH monitoring that is unable to detect non acid reflux events which might be prevalent in infants receiving frequent milk feeding. Multichannel intraluminal impedance has been recently introduced as a pH-independent method to investigate the bolus transport in hollow organs.

OBJECTIVE

To assess if combined multichannel intraluminal impedance-pH study could be useful to detect an association between gastroesophageal reflux and apnoea of prematurity.

METHODS

We prospectively evaluated a group of premature infants with apnoea of prematurity in absence of any confounding factors (ventilatory support, treatment with caffeine, permanent nasogastric tube, post-natal age older than 30 days) by simultaneous recording of 24-h multichannel intraluminal impedance-pH and cardiorespiratory monitoring. A temporal relationship between an apnoea and a reflux event was considered if both commenced within 20s of each other.

RESULTS

Six premature infants [three male; median gestational age 31 weeks (range 27-36); birth weight 1335g (range 1200-2350); age at study 17 days (range 7-28)] were studied. A total of 405 reflux events [306 (76%) weakly acid and 99 acid reflux] and 142 apnoeas were detected. The frequency of apnoeas occurring during the reflux events period was significantly greater than the one calculated for reflux-free period [0.42/min (0.00-1.28) versus 0.016/min (0.003-0.028); p<0.05]. The sub-analysis based on chemical composition and duration of refluxate showed that the frequency of apnoeas associated with weakly acid reflux events was significantly greater than the one calculated for reflux-free period [0.416/min (0.00-1.30) versus 0.016/min (0.003-0.028), respectively; p<0.05] and that the frequency of apnoeas occurring during reflux events longer than 30s was significantly higher than those occurring during shorter reflux events (22% versus 11%; p<0.004).

CONCLUSION

Our data show that weakly acidic reflux events are more prevalent than acid reflux events in premature infants, confirming the need for the use of multichannel intraluminal impedance-pH monitoring for diagnosis of gastroesophageal reflux in those patients. Gastroesophageal reflux and apnoea of prematurity are both common occurrences and, in our experience, may be temporally related especially as regard to weakly acid refluxate and reflux events longer than 30s.

Composition and seasonal variation of soluble cuticular waxes inActinidia deliciosaleaves

This research examines the annual evolution and composition of soluble cuticular waxes of Actinidia deliciosa Chev. cv Hayward leaves. Soluble cuticular waxes of foliar blade were extracted in chloroform and analysed by GC-MS. The seasonal weighted mean of the wax coverage was about 24 microg cm(-2). The alkyl alkanoates were the main class of components (10 microg cm(-2)) followed by hydrocarbons (6 microg cm(-2)), terpenes (3 microg cm(-2)), alkanols (1 microg cm(-2)), ketones (1 microg cm(-2)), alkanoic acids (1 microg cm(-2)), alkanals (0.7 microg cm(-2)), and sterols (0.6 microg cm(-2)). The concentration of the soluble cuticular components reached a peak (43 microg cm(-2)) on the 83rd day after bud break. Different causes were proposed to explicate the seasonal evolution of the leaf waxes: biosynthesis of the waxes prevalently during rapid leaf growth; natural wax erosion and evaporation; progressive reduction in the extractability of the intracuticular free compounds due to the slow polymerization of the cutin matrix.

Urinary pharmacokinetics and theoretical pharmacodynamics of intravenous levofloxacin in intensive care unit patients treated with 500 mg b.i.d. for ventilator-associated pneumonia

This study assessed the urinary pharmacokinetics and theoretical pharmacodynamics of levofloxacin in ICU patients treated with 500 mg b.i.d. i.v. for ventilator associated pneumonia to evaluate if this high dosage regimen might ensure appropriate exposure in the treatment of severe UTIs in ICU patients. Nineteen patients (11M, 8F; age, 52 +/- 21 years; weight, 75 +/- 16 kg) presenting with normal renal function (estimated creatinine clearance, 1.83 +/- 0.61 ml/min/kg; diuresis, 1709 +/- 643ml / 24h) were assessed. In steady-state conditions, urine samples were collected at 0-2h, 2-4h, 4-8h and 8-12h during a dosing interval, and urinary concentrations of levofloxacin were assayed by HPLC. Mean (+/- SD) levofloxacin urinary concentrations were 329.1 +/- 159.9, 388.6 +/- 143.5, 266.0 +/- 102.8 and 168.1 +/- 93.3mg/L at 0-2h, 2-4h, 4-8h and 8-12h, respectively, with urinary AUC0-tau of 3171.4 +/- 1192.1mg/L x h. Mean (+/- SD) levofloxacin excretion rates were 44.1 +/- 20.7, 42.8 +/- 8.2, 31.7 +/- 5.8 and 19.8 +/- 4.2 mg/h during the 0-2h, 2-4, 4-8h and 8-12h interval, respectively. Our findings suggest that, consistently with levofloxacin showing high renal excretion as unmodified drug, 500mg b.i.d. i.v. of levofloxacin ensure and maintain urinary concentrations at least 50-fold higher than the MIC90 of most sensitive uropathogens during the overall dosing interval in ICU patients with normal renal function. Considering the major pharmacodynamic determinants for the concentration-dependent bactericidal activity of levofloxacin as applicable at the urinary level (CU/MIC of >12.2 and/or AUC24h U /MIC of >125h), this high dosage regimen may ensure optimal exposure for the treatment of catheter-related and severe lower UTIs not only against sensitive microorganisms, but probably also whenever microorganisms usually considered as intermediate susceptible or resistant to levofloxacin may be involved.

Burden of first-ever ischemic stroke in the oldest old: Evidence from a population-based study

OBJECTIVE

To evaluate the contribution of subjects 80 years old or older to the burden of ischemic stroke as compared with subjects younger than 80 years.

METHODS

All first-ever ischemic strokes occurring in a 5-year period (1994 to 1998) in the population-based L'Aquila registry were traced. Incidence, total health care utilization, disability, and mortality were assessed in patients 80 years old or older, and differences with those younger than 80 years were assessed by univariate and survival analyses.

RESULTS

One thousand three hundred sixteen of 3,594 first-ever ischemic strokes (36.6%) occurred in patients 80 years old or older, accounting on average for one-third of health care utilization. The crude annual incidence rate was 21.54 per 1,000 (95% CI 20.42 to 22.72). At the 1-year follow-up, 27.7% of patients had mild or no disability, 20.7% had severe disability, and 51.6% had died. With respect to patients under 80 years of age, older patients showed a higher proportion of women (61.3 vs 47.7%), atrial fibrillation (30.2 vs 20.7%), coronary heart disease (31.0 vs 23.4%), and peripheral arterial disease (14.6 vs 10.8%) and a lower proportion of cigarette smoking (15.3 vs 29.2%) and hypercholesterolemia (20.4 vs 29.4%). Thirty-day (34.6 vs 13.4%) and 1-year (51.6 vs 22.3%) mortality were higher in patients 80 years old or older than in those younger than 80, mostly in the presence of atrial fibrillation (hazard ratio [HR] was 1.39 for 30-day mortality and 1.37 for 1-year mortality) and diabetes mellitus (HR was 1.39 for 30-day mortality and 1.31 for 1-year mortality).

CONCLUSION

The burden of ischemic stroke is high in subjects 80 years old or older, contributing about one-third of health care utilization and 59.8% of deaths within 30 days.

Determination of cerebral water content by magnetic resonance imaging after small volume infusion of 18% hypertonic saline solution in a patient with refractory intracranial hypertension

Hypertonic saline solution (HSS) has been investigated in the treatment of intracranial hypertension (ICH) in a limited number of studies, usually after failure of conventional treatment. HSS, used in concentrations that vary from 3% to 23.4%, seems to be effective in reducing refractory ICH and to be devoid of adverse effects. We treated a patient with refractory ICH with a small-volume infusion of 18% HSS, and performed magnetic resonance imaging (MRI) before and after HSS infusion. MRI showed a marked reduction in cerebral water content 1 h after the infusion. To our knowledge, this is the first MRI study in a patient with brain injury to evaluate the effect of HSS on brain water content. Further studies are necessary to test HSS efficacy and to identify, through MRI or computed tomography (CT) scan imaging, a subgroup of patients with brain injury who would be best treated with HSS.

Proportion of older people in the community as a predictor of increasing stroke incidence

OBJECTIVES

To compare stroke incidence rates among comparable registries and to make correlations with aging of the resident populations.

METHODS

This correlation study included all comparable stroke registries maintained in industrialized countries (Italy, France, United Kingdom, Denmark, Norway, United States, and Australia). Eleven community-based stroke registries with similar high proportions of radiologically confirmed diagnoses based on standard definitions were identified. Incidence rates of first-ever stroke from the prospective L'Aquila registry and from the other registries were compared after age and sex standardization to the 1996 European population. The rates were then correlated with the proportion of individuals aged 65 and over in the corresponding resident populations by means of the Poisson regression analysis.

RESULTS

In the L'Aquila registry, the crude annual incidence of first-ever stroke was 281/100,000 (95% confidence interval 271-293) based on 2,515 patients included during a 3-year period. The rate standardized to the European population was 249/100,000. Standardized incidence ratios indicated a significant excess of first-ever strokes in the L'Aquila registry up to 51% with respect to most of the compared studies. A significant correlation was also found between crude (p < 0.0001) and standardized (p = 0.0012) stroke incidence rates and proportions of individuals aged 65 and over in the different populations.

CONCLUSIONS

The L'Aquila experience suggests that any further aging of a population will increase the stroke occurrence for both the reasons of a direct and predictable effect of the growing proportion of elderly individuals within that population and a disproportionately increased stroke risk in the older age groups.

Contrast-enhanced transcranial Doppler sonography in patients with acute cerebrovascular diseases

The aim of the study was to evaluate the diagnostic potential of galactose-based microbubble suspension (Levovist) in patients with acute cerebrovascular disease and inadequate transtemporal acoustic window, when examined by transcranial Doppler (TCD). We studied 10 patients with either transient ischemic attack (no. = 3) or stroke (no. = 7). Inadequate transtemporal acoustic window was unilateral in 3 patients and bilateral in the remaining 7 patients. Signals from middle, anterior, and posterior cerebral arteries (MCA, ACA, PCA) were recorded after injecting Levovist 300 mg/ml. Six patients needed 3 injections of Levovist, 1 patient two, and 3 patients one. Mean +/- SD duration of optimal signal enhancement was 175.2 +/- 53.2 s, range 70-290 s. Doppler waveform analysis was possible in 14 (82.3%) MCA, 11 (65%) ACA, and 9 (53%) PCA. Levovist improved the reliability of TCD in patients with acute cerebrovascular disease and insufficient transtemporal insonation.

Stroke in young adults in the community-based L'Aquila registry: incidence and prognosis

BACKGROUND AND PURPOSE

Stroke type in the young may influence the outcome and may have a dramatic impact on the quality of life in survivors. This study aimed to evaluate the incidence and prognosis of first-ever stroke in the young and to make comparisons with older patients within a well-defined population.

METHODS

All first-ever strokes occurring in the L'Aquila district, central Italy, were traced by active monitoring of inpatient and outpatient health services. Incidence rates were standardized to the 1996 European population according to the direct method. Long-term survival was estimated by the Kaplan-Meier method; outcome in survivors was evaluated by the modified Rankin scale.

RESULTS

Of 4353 patients who had a first-ever stroke, 89 patients <45 years of age (55 men and 34 women) (2%) were identified in a 5-year period. Mean age+/-SD was 36.1+/-8.1 years. Twenty patients (22.5%) had a subarachnoid hemorrhage, 18 (20.2%) an intracerebral hemorrhage, and 51 (57.3%) a cerebral infarction. The corresponding proportions in patients >45 years of age were 2.4%, 13.3%, and 83.1%. Neuroimaging studies of the brain detected 14 intracranial aneurysms and 6 arteriovenous malformations in 20 of 38 patients (52.6%) with either subarachnoid (n=17) or intracerebral (n=3) hemorrhage. The crude annual incidence rate was 10.18/100,000 (95% CI, 8.14 to 12.57) and 10.23/100,000 when standardized to the 1996 European population. The 30-day case-fatality rate was 11.2% (95% CI, 6.2 to 19.4). Patients with subarachnoid hemorrhage had the highest proportion of good recovery (60%), patients with intracerebral hemorrhage had the highest mortality (44%), and patients with cerebral infarction had the highest proportion of severe disability (47%).

CONCLUSIONS

Stroke patients <45 years of age showed a disproportionate cumulative high prevalence (42.7%) of subarachnoid and intracerebral hemorrhage with respect to older patients (15.7%), mainly (52.6%) due to aneurysms and arteriovenous malformations. Therefore, screening procedures and preventive strategies in the young should also be addressed to subjects at risk of subarachnoid and intracerebral hemorrhage.

The lysosomal protease cathepsin D is efficiently sorted to and secreted from regulated secretory compartments in the rat basophilic/mast cell line RBL

Basophils and mast cells contain a peculiar class of inflammatory granules that discharge their content upon antigen-mediated crosslinking of IgE-membrane receptors. The pathways for granule biogenesis and exocytosis in these cells are still largely obscure. In this study we employed the rat basophilic leukemia (RBL)/mast cell line to verify the hypothesis that inflammatory granules share common bioactive molecules and functional properties with lysosomes. We demonstrate that inflammatory granules, as identified by the monoclonal 5G10 antibody (which recognises an integral membrane protein) or by Toluidine Blue staining, have an intralumenal acidic pH, possess lysosomal enzymes and are accessible by fluid-phase and membrane endocytosis markers. In addition, we studied the targeting, subcellular localisation and regulated secretion of the lysosomal aspartic protease cathepsin D (CD) as affected by IgE receptor stimulation in order to obtain information on the pathways for granule biogenesis and exocytosis. Stimulation with DNP-BSA of specific IgE-primed RBL cells led to a prompt release of processed forms of CD, along with other mature lysosomal hydrolases. This release could be prevented by addition of EGTA, indicating that it was dependent on extracellular calcium influx. Antigen stimulation also induced exocytosis of immature CD forms accumulated by ammonium chloride, suggesting the existence of an intermediate station in the pathway for granule biogenesis still sensitive to regulated exocytosis. The targeting of molecules to secretory granules may occur via either a mannose-6-phosphate-dependent or mannose-6-phosphate-independent pathway. We conclude that endosomes and lysosomes in basophils/mast cells can act as regulated secretory granules or actually identify with them.

Regulation of protein sorting at the TGN by plasma membrane receptor activation

We show that in the rat basophilic leukemia cell line RBL, the physiological stimulation of the IgE receptor or direct activation of PKC leads to the missorting of proteins to the plasma membrane, diverting them from their normal intracellular destination. This is demonstrated for two classes of proteins that are normally targeted to the secretory lysosomes via completely different mechanisms, i.e. proteoglycans and the aspartic protease cathepsin D. In the latter case, normal processing of the enzyme is also affected, leading to secretion of the immature form of cathepsin. The present study shows how completely different sorting mechanisms, such as those for delivering proteoglycans and cathepsin D to secretory lysosomes, might share common regulatory signals and are similarly affected when the levels of these signals are perturbed. Finally, protein kinase C appears to be a major player in the signal transduction pathways, leading to proteoglycan and cathepsin D missorting.

Spontaneous rupture of the iliac vein

Two unusual cases of iliac vein spontaneous rupture into the retroperitoneum are presented together with 18 cases reported by the literature. In one patient of ours, entrapment of clots in an IVC filter and proximal iliac vein involvement into the scar tissue surrounding the left limb of an aortoiliac bifurcation graft might have caused flow disturbances and subsequent predisposition to rupture of the thrombosed external iliac vein. Inflammatory parietal changes, including infiltration of macrophages, T and B lymphocytes producing elastin degradation by means of cytokines, may have led ultimately to vein disruption. Despite clinical features and CT scan findings, the physician's awareness of this disease remains the most important factor for the early treatment.

Morphological and biochemical analysis of the secretory pathway in melanoma cells with distinct metastatic potential

In this report, we have investigated whether alterations of the morphological and functional aspects of the biosecretory membrane system are associated with the metastatic potential of tumor cells. To this end, we have analyzed the morphology of the Golgi complex, the cytoskeleton organization and membrane trafficking steps of the secretory pathway in two human melanoma A375 cell line variants with low (A375-P) and high metastatic (A375-MM) potential. Immunofluorescence analysis showed that in A375-P cells, the Golgi complex showed a collapsed morphology. Conversely, in A375-MM cells, the Golgi complex presented a reticular and extended morphology. At the ultrastructural level, the Golgi complex of A375-P cells was fragmented and cisternae were swollen. When the cytoskeleton was analyzed, the microtubular network appeared normal in both cell variants, whereas actin stress fibers were largely absent in A375-P, but not in A375-MM cells. In addition, the F-actin content in A375-P cells was significantly lower than in A375-MM cells. These morphological differences in A375-P cells were accompanied by acceleration and an increase in the endoplasmic reticulum to Golgi and the trans-Golgi network to cell surface membrane transport, respectively. Our results indicate that in human A375 melanoma cells, metastatic potential correlates with a well-structured morphofunctional organization of the Golgi complex and actin cytoskeleton.

Cerebrovascular reactivity evaluated by transcranial Doppler: reproducibility of different methods

Transcranial Doppler is routinely used to assess the cerebrovascular reactivity, despite scarce information on its reproducibility. We evaluated the reproducibility of cerebrovascular reactivity measurements by this method utilizing different vasodilatory and vasoconstrictor stimuli. The cerebrovascular reactivity was measured in 45 healthy volunteers during hypercapnia induced by inhalation of a mixture of 5% CO2 and 95% O2, breath holding and rebreathing, and during hypocapnia induced by voluntary hyperventilation. Three sets of measurements were performed at times 0, 1, and 24 h to assess the within-observer short- and long-term reproducibility. The reproducibility was analyzed using the intraclass correlation coefficient. For the CO2 inhalation method, a good short-term (rI = 0.55; 95% CI = 0.39-0.68) and a good long-term (rI = 0.43; 95% CI = 0.25-0.59) reproducibility was found. For the breath-holding method a good short-term agreement was found (rI = 0.41; 95% CI = 0.22-0. 57), while the long-term reproducibility was poor (rI = 0.17; 95% CI = -0.03-0.36). Rebreathing showed a fair (rI = 0.31; 95% CI = 0.11-0. 48) short-term and a poor (rI = 0.17; 95% CI = -0.03-0.36) long-term reproducibility. For voluntary hyperventilation, the short-term reproducibility was good (rI = 0.53; 95% CI = 0.36-0.66), and the long- term reproducibility was fair (rI = 0.31; 95% CI = 0.11-0.48). In our study, CO2 inhalation and voluntary hyperventilation had the highest reproducibility and should be preferred when assessing cerebral vasoreactivity, especially in follow-up studies.

Procollagen traverses the Golgi stack without leaving the lumen of cisternae: evidence for cisternal maturation

Newly synthesized procollagen type I (PC) assembles into 300 nm rigid, rod-like triple helices in the lumen of the endoplasmic reticulum. This oligomeric complex moves to the Golgi and forms large electron-dense aggregates. We have monitored the transport of PC along the secretory pathway. We show that PC moves across the Golgi stacks without ever leaving the lumen of the Golgi cisternae. During transport from the endoplasmic reticulum to the Golgi, PC is found within tubular-saccular structures greater than 300 nm in length. Thus, supermolecular cargoes such as PC do not utilize the conventional vesicle-mediated transport to traverse the Golgi stacks. Our results imply that PC moves in the anterograde direction across the Golgi complex by a process involving progressive maturation of Golgi cisternae.

[High prevalence of hepatitis C virus infection in patients with non-Hodgkin's lymphoma at the onset. Preliminary results of an Italian multicenter study]

143 patients with non-Hodgkin lymphoma (NHL) at the onset entered this perspective study on NHL-associated risk factors. They were 87 males and 56 females with a mean age of 52.3 years (range 14.6-82.3). An associated hepatitis C virus (HCV) infection was found in 16 of the 143 NHL cases (11.2%; 95% CI 6.5-17.5). They were 11 males and 5 females [mean age 59.9] year with disseminated (13/16) or localized NHL disease (3/16)]. The NHL histological subgroup was low grade (6/16), intermediate grade (2/16) or high grade (8/16). The cell origin was B in 15/16 cases and B cell-T cell rich in 1/16. The discovery of HCV infection was contemporary to lymphoma diagnosis in 6/16 cases but preceded the NHL onset in the other 10 patients. In these 10 patients the median time between HCV infection diagnosis and NHL onset was 3.6 years (range 1-14.5). These data confirm that in Italy the prevalence of HCV infection in patients with NHL (11.2%) is significantly higher than expected in the general population (1.3-3.2%). The finding that, in most cases, HCV infection was definitely antecedent to NHL onset, usually by years, adds evidence to the possible causative role of the HCV in lymphomagenesis.

High stroke incidence in the prospective community-based L'Aquila registry (1994-1998). First year's results

BACKGROUND AND PURPOSE

Changes in stroke incidence are likely to occur as a consequence of aging of the population, but evidence for this hypothesis is lacking.

METHODS

A prospective community-based registry of first-ever strokes (1994 to 1998) classified according to the International Classification of Diseases, 9th Revision (ICD-9) was established in the L'Aquila district, central Italy, with a total population of 297,838 (1991 census). Patients were identified by active monitoring of multiple sources, including general practitioners.

RESULTS

In 1994, 819 patients (398 men and 421 women; mean +/- SD age, 74.8 +/- 11.3 years) suffered from a first-ever stroke. Eighty-nine percent of the patients had neuroimaging studies of the brain and were reclassified with the recent Application of the International Classification of Diseases to Neurology (ICD-10 NA). The occurrence of subarachnoid hemorrhage, intracerebral hemorrhage, cerebral infarction, and ill-defined events was 2.9%, 14.9%, 80.2%, and 2.0%, respectively. Crude annual incidence of first-ever stroke was 2.75/1000 (95% confidence interval [CI], 2.57 to 2.94) and 24.23/1000 (95% CI, 21.65 to 27.10) in patients older than 80 years. Incidence rates were higher in men and steeply increased with age. The standardized rate was 2.37/1000 for the Italian and 2.28/1000 for the European population. The 30-day case-fatality rate was 25.6% (95% CI, 22.8% to 28.7%). The occurrence of death, disability, and full recovery at 1 year was 36.9%, 38.9%, and 24.2%, respectively. No differences were found in stroke incidence and case-fatality according to income and urban or rural residences.

CONCLUSIONS

In our population-based study, we found a high stroke incidence notably in the older age subgroups, suggesting that rather than declining, stroke is only being postponed until later in life.

Sumatriptan and cerebral blood flow velocity changes during migraine attacks

Transcranial Doppler studies on the effects of sumatriptan on cerebral hemodynamics have shown conflicting results. We evaluated blood flow velocity changes in 21 patients suffering from migraine with (n = 4) or without aura (n = 17) during a spontaneous attack, before and after treatment with sumatriptan. Flow velocity in the internal and external carotid, middle cerebral, and basilar arteries was measured by means of transcranial Doppler. During the attack, measurements were taken before subcutaneous sumatriptan injection, then after 30 minutes, 2 hours, and 24 hours. An additional measurement was taken 1 week later, in a headache-free state. We found a significant reduction of flow velocity during the attack in the middle cerebral artery on both sides (P < 0.05). After sumatriptan administration, flow velocity increased in the internal carotid artery on both sides (P < 0.05) and in the middle cerebral artery on the headache side (P = 0.0001), but not in the external carotid and basilar arteries (P > 0.05). Flow velocity changes may reflect the vasodilation present at the onset of the migraine attack followed by vasoconstriction in the internal carotid and middle cerebral arteries after sumatriptan treatment. Since vasoconstriction occurs in responders and nonresponders to treatment, it is unlikely to be the primary mechanism by which sumatriptan relieves headache.

Neutrophil extracted lipocortin inhibits corticotropin secretion in the AtT-20 D16:16 clonal mouse pituitary cell line. Lipocortin inhibition of ACTH release in vitro

The mechanism of short-term glucocorticoid (GC) inhibition of the hypothalamic-pituitary-adrenal axis is not well understood. The direct anti-inflammatory activities of lipocortins (LCs) have suggested a role for them as extra- and intracellular mediators of the biological effects of GCs. It has been reported that recombinant human (rh) LC1 inhibits corticotropin (ACTH) release from pituitary tissue in vitro but not from AtT-20 D16:16 corticotrophs. Using the same cell line we have tested whether other exogenous rhLCs or native LC extracted from polymorphonucleate neutrophils (neLC), likely LC1, have an effect on ACTH secretion. It is shown that: (1) basal release was not affected by a short-term incubation with neLC; (2) secretion induced by corticotropin-releasing factor (CRF) and other secretagogues (phorbol ester, potassium ion or calcium ionophore) was inhibited by neLC; (3) GC inhibition of CRF-stimulated release was reverted by a monoclonal anti-neLC antibody; (4) rhLC2, rhLC5 and the fragment 212-234 of rhLC5 were without effect. Thus, only neLC is effective on AtT-20 D16:16 cells, suggesting for this annexin a role in the early phase GC inhibition of ACTH secretion.

Role of pancreatic impairment in growth recovery during gluten-free diet in childhood celiac disease

BACKGROUND & AIMS

Clinical significance and duration of insufficient release of pancreatic enzymes in childhood celiac disease have not been clarified. The aim of this study was to evaluate the role that pancreatic impairment plays in growth recovery and the duration of this impairment.

METHODS

Forty-six patients with celiac disease who had a median age of 2.5 years were enrolled. Fecal chymotrypsin level was determined at diagnosis and then every 15 days after the beginning of a gluten-free diet in all patients.

RESULTS

At diagnosis, 17 of 46 patients with celiac disease had subnormal fecal chymotrypsin values. During the gluten-free diet, a progressive reduction in the percentage of patients with subnormal fecal chymotrypsin values was observed: 12 of 46 patients after 30 days and 2 of 46 patients after 60 days. Weight increase after 2 months of gluten-free diet was significantly greater in patients with normal fecal chymotrypsin values at diagnosis than in patients with subnormal values, and a positive correlation was found between fecal chymotrypsin at diagnosis and weight increase (r = 0.56).

CONCLUSIONS

A small percentage of patients with celiac disease still had subnormal chymotrypsin concentrations after 60 days of gluten-free diet. Fecal chymotrypsin is a predictive index of weight recovery in the first months after diagnosis of celiac disease; it could be used to select patients for enzyme supplementation therapy.

Popliteal artery entrapment syndrome: diagnosis and management

A variety of anatomical abnormalities may product an external compression of the popliteal artery, resulting in a thrombotic occlusion. Between 1983 and 1995, 9 patients presented a popliteal artery entrapment syndrome, bilateral in two cases. Ultrasonography, Angio-CT scan and MRI showed the abnormal structures and position of the popliteal artery on popliteal fossa. Arteriography detected an arterial compression in 6 limbs and occlusion in 4 limbs as well as an associated popliteal aneurysm in one patient and distal embolism in four. The abnormal medial head of the gastrocnemius muscle was resected in 8 limbs, while fibrous membranes were resected in 3 limbs. Autogenous vein replacement was performed in 4 cases of popliteal artery occlusion and following resection of a popliteal artery aneurysm in one case. All patients recovered. In the followup period, the occlusion of the arterial reconstruction occurred after 28 months in one patient, with a mild claudication. Noninvasive vascular imaging techniques may allow early diagnosis and management of PAES, avoiding popliteal arterial wall lesions and its occlusion, with a better outcome.

Aortic blisters: diagnosis and evolution

In order to evaluate the incidence, the diagnostic modalities and significance of blisters of the abdominal aortic aneurysm wall, in a retrospective review, 14 patients (2.6%) having these lesions were identified between 1983 and 1995. At preoperative examination, aortography had less accuracy (1 case = 20%) than CT scan (3 cases = 27.2%) or MRI angiography (6 cases = 85.7%) to detect blisters; others were discovered intraoperatively in the remaining four patients. Most blisters were located on the anterior or antero-lateral wall of aneurysms; its area ranged from 0.8 to 2.6 cm2. One patient with a suspected blister diagnosed at aortography, during chest physiotherapy for his COPD, presented sudden abdominal pain: at urgent laparotomy, an acute contained rupture of a large blister, without extraluminal blood loss, was found. All patients underwent aneurysm repair, with no postoperative deaths. Occurrence of rupture in one patient clearly indicates the natural course of aortic blisters. MRI angiography may accurately detect these lesions; surgical treatment is necessary for preventing imminent rupture.

Combined vascular injuries and limb fractures

Blunt arterial injuries secondary to bone fractures are frequently associated with nerve, vein and soft tissue lesions. A delayed diagnosis or treatment is the main cause of high amputation rate. Thirty-four patients presenting acute arterial occlusion (15 cases), false aneurysms (13 cases) or AVFs (6 cases) of the extremity were identified between 1983 and 1995. To repair injured arteries, ligation (3 cases), patch angioplasty (6 cases), autogenous vein (15 patients) or PTFE (4 cases) interposition or bypass grafting were made. Percutaneous embolization by coils was performed in 3 AVFs of small limb arteries. Associated venous lesions were treated in 9 patients. External fixation of long bone fractures was made in 29 patients, before vascular reconstruction, to prevent further injury during orthopedic stabilization. Fasciotomies were made in 6 patients to treat compartmental hypertension. Early reexplorations were necessary to correct technical defects in 4 patients. Hyperbaric oxygen therapy was applied in 7 patients to control bacterial contamination and improve wound healing. Primary (2 cases) or secondary (3 cases) amputations were carried out in unsalvageable limbs. Nerve or extensive muscle damage caused poor functional outcome in 4 patients. A multidisciplinary diagnostic and management strategy is required to improve limb and patient survival.

Late arteriovenous fistulas and pseudoaneurysms of the extremity secondary to civilian firearms

To evaluate the treatment of late sequelae of penetrating arterial injuries associated with civilian firearms, such as false aneurysms and arteriovenous fistulas (AV-Fs) of the extremities, a retrospective clinical study was carried out. Whenever diagnosis or operative management is delayed because of local fibrosis or morphological and structural vessel changes, primary repair is not feasible and segmental resection is required. Twenty-four patients presenting late false aneurysms (14) and AV-Fs (11) of the extremities, caused by firearms (6 rifle wounds, and 18 pistol wounds), were identified between 1983 and 1995. Twenty-three patients were submitted to resection of pseudoaneurysms (13) or AV-Fs (8), while arterial patch angioplasty was applied in two patients. The venous lesions were repaired by an interposition graft (7) or lateral venorraphy (3). Saphenous vein (15) or PTFE (6) grafts were placed in injured arteries. Percutaneous embolization by coils was performed in two patients. Twenty-three out of 24 patients (95.8%) recovered; one patient (4.1%), affected by aneurysmal AV-Fs of a lower limb dating from 12 years, with enlarged and weakened artery, bled to death. No limb loss occurred. A better evaluation of minimal vascular injuries is required to avoid late sequelae of civilian firearms lesions, with significant blood loss, which need segmental excision of the injured vessels.

[Hand ischemia due to "steal syndrome" in vascular access for hemodialysis]

Among complications of vascular access operations, symptomatic steal syndrome is uncommon, but may lead to ischemia of the hand. Between 1983 and 1995, 5 patients with hemodialysis fistulas presented rest pain of finger necrosis with a wrist-brachial index of 0.56 (range 0.35 to 0.63) improving to 0.96 (range 0.72 to 1.05) after digital pressure of the fistula. Ligation of distal radial artery was performed in 3 patients with side-to-end radiocephalic fistula, while basilic vein was distally ligated in a case of side-to-side brachiobasilic fistula. A vein "banding" procedure reduce fistula flow and improved distal perfusion in one patient, while a true venous aneurysm of the cephalic vein was treated by excision and replacement with a tapered PTFE graft. Hemodynamic assessment is required during surgical correction, but it may also be useful in pre- and intra-operative evaluation of patients undergoing therapeutical AVFs to prevent arterial insufficiency of the hand.

[Arteriosclerotic aneurysms of the subclavian artery]

OBJECTIVE

To evaluate diagnostic investigations, operative management and long-term outcome of atherosclerotic aneurysms of the subclavian artery.

DESIGN

A retrospective clinical study through a follow-up period of 68 months (8 months to 11 years).

SETTING

Department of Vascular Surgery, University Hospital.

PATIENTS

Between 1983 and 1995, 5 patients with atherosclerotic aneurysms of the extrathoracic subclavian artery were reviewed. All patients presented a pulsatile supraclavicular mass. Ultrasonography and angiography confirmed the diagnosis and were useful in planning the operation.

INTERVENTIONS

Four patients were submitted, through a supraclavicular incision, to resection of the aneurysm and replacement of a prosthetic graft (dacron in 2 cases, PTFE in the remaining 2 cases). In one patient, with a small saccular aneurysm, a tangential aneurysmectomy with a patch angioplasty (PTFE) was performed.

RESULTS

All patients recovered after a mean hospital-stay of 9 days and had a valid radial pulsation. During the follow-up period, a dacron graft failure occurred 38 months later in one patient: she remains today asymptomatic.

CONCLUSIONS

Resection is today recommended for all patients with diagnosed subclavian artery aneurysms. Because of unknown natural history of asymptomatic aneurysms, with an unpredictable risk of complications, more accurate evaluations are required for optimal clinical decision making (early surgery vs watchful waiting?).

[Physiopathology of cerebral circulation]

Autoregulation of the cerebral circulation is the key mechanism that keeps CBF constant within wide limits of arterial pressure. The mechanism for autoregulation and the influence of arterial hypertension and extracranial carotid stenosis are discussed. Brain function and metabolism are critically dependent on sufficient CBF and oxygen supply. Cerebral ischemia occurs when flow drops below about 10-15 ml/100 g/min. Metabolic and therapeutic aspects of acute cerebral ischemia are discussed.

[Aneurysms of the external jugular vein]

External jugular vein aneurysms are rare and appear as a soft, compressible mass in the neck. Three cases are herein reported. Ultrasonography is the investigation of choice. Surgical excision is indicated, specially in case of giant and thrombosed venous aneurysm.

Popliteal-to-tibial bypass for acute leg ischemia complicating aortic reconstruction

Between 1983 and 1995, elective aortic surgery was performed on 1018 patients for aneurysmal (417 cases) or occlusive disease (489 cases), or both (112 cases). Intraoperative acute popliteal occlusion, despite of aortic graft patency, developed in 2 patients due to distal embolization (0.19%) and in 5 patients secondary to acute popliteal trifurcation thrombosis (0.49%). Preoperative ankle index was 0.46 +/- 0.12, but intraoperatively it went down to zero; distal popliteal occlusion was confirmed by intraoperative arteriography. A balloon catheter embolectomy was performed in two patients. Distal bypass from popliteal artery above knee (1) and below knee (3) to the posterior tibial artery was implanted in four patients using reversed autogenous saphenous vein. In one patient, revascularization was not feasible because of diffuse calcified obstructive disease of leg arteries. Reoperations resulted in a satisfactory outcome in 6 out of 7 patients (85.7%). The patient, in which revascularization was not possible, was submitted to major amputation. In the four popliteal-to-tibial bypasses evaluated through a follow up period of 43 months, graft patency was 75% and limb salvage rate was 100%. Instead of amputation, popliteal-to-tibial bypass is a useful treatment for acute in situ thrombosis of popliteal trifurcation following aorto-iliac reconstruction.

Intestinal ischemia after aortic surgery

Intestinal ischemia after abdominal aortic surgery is a highly lethal complication. In order to evaluate the pathogenesis, the diagnostic modalities and the best management, in a retrospective review, 12 patients undergoing postoperative small bowel or colonic ischemic lesions were identified between 1983 and 1995. Preoperative occlusion of IMA was present in nine patients, while a selective angiography of SMA demonstrated occlusive disease of peripheral branches in two asymptomatic diabetic patients. No patent IMA was ligated. When possible, hypogastric circulation was preserved by distal anastomosis into iliac bifurcation (4 cases). Postoperative leukocytosis or elevated LDH values were present. Colonscopy showed a suspected ischemic colitis in two patients and necrotic lesions in three cases. One patient died and diagnosis was made at autopsy. Nine patients were submitted to reoperation and a bowel resection with a proximal stoma was performed in seven of them. In two patients, the aorta or iliac artery below the proximal anastomosis and hypogastric artery suffered acute thrombosis, while prosthetic grafts were patent. A coagulation disorder caused thrombosis of intramural arterioles of the small bowel while peripheral branches of SMA were pulsatile. Eight of the patients submitted to relaparotomy died; non-operative management resulted in a left colon late stricture, while the remaining patient survived without sequelae. Overall mortality rate was 66.6%. Symptoms of this complication are not specific and diagnosis is delayed; consequently surgical repair is often unsuccessful. One patient with small bowel necrosis after elective AAA resection survived, which is extremely rare.

Regulation of constitutive exocytic transport by membrane receptors. A biochemical and morphometric study

Biochemical and morphometric approaches were combined to examine whether constitutive secretory transport might be controlled by plasma membrane receptors, as this possibility would have significant physiological implications. Indeed, IgE receptor stimulation in rat basophilic leukemia cells potently increased the rate of transport of soluble pulse-labeled 35S-sulfated glycosaminoglycans from distal Golgi compartments to the cell surface. This effect was largely protein kinase C (PKC)-dependent. Direct activation of PKC also stimulated constitutive transport of glycosaminoglycans, as indicated by the use of agonistic and antagonistic PKC ligands. PKC ligands also had potent, but different, effects on the exocytic transport from distal Golgi compartments to the plasma membrane of a membrane-bound protein (vesicular stomatitis virus glycoprotein), which was slightly stimulated by activators and profoundly suppressed by inhibitors of PKC. Morphological analysis showed impressive changes of the organelles of the secretory pathway in response to IgE receptor stimulation and to direct PKC activation (enhanced number of buds and vesicles originating from the endoplasmic reticulum and Golgi and increase in surface and volume of Golgi compartments), suggestive of an overall activation of exocytic movements. These results show that rapid and large changes in constitutive transport fluxes and in the morphology of the exocytic apparatus can be induced by membrane receptors (as well as by direct PKC stimulation).

Congenital generalized lipodystrophy associated with multiple sclerosis

We report the case of a 22 year old woman with congenital generalized lipodystrophy who presented a left brachiocrural pyramidal hemisyndrome, bilateral cerebellar signs and a left cranial nerve VI deficit. The clinical pattern had a tendency to regress. MRI brainscan, CSF examination and clinical features led to the diagnosis of "probable demyelinating syndrome". Published data on CNS involvement in patients with congenital generalized lipodystrophy are few and we have found no cases in which a demyelinating syndrome is associated. In the case we report it is tempting to see the disorder of the lipid metabolism underlying the congenital generalized lipodystrophy as underlying the myelin disorder as well.

MR imaging of degenerative disorders of brainstem and cerebellum

In pathologies such as progressive ataxias, clinical criteria are often not enough to provide the correct diagnosis. Therefore, we studied by means of MRI 30 normal volunteers and 19 patients affected by different progressive ataxias, diagnosed by typical standards. On all the subjects measurements were performed in order to identify normal and pathological ranges. Our experience confirms that typical involvement can be detected in the different kinds of progressive ataxias. Peculiar compromissions were found in spinocerebellar diseases, able to differentiate them from the forms mostly involving the cerebellum and brainstem. The differentiation between typical Friedreich and non-Friedreich diseases can also be suggested in most cases.

Iopamidol 300-induced epilepsy: intensive treatment and pathogenic hypothesis

A case of adverse event induced by Iopamidol 300 is reported. Its clinical course and the intensive treatment performed are described.

Multiple pilomatrixomas and myotonic dystrophy: a case report

Clinical and histopathological data of a patient affected by myotonic dystrophy (Steinert Disease) and multiple pilomatrixomas (calcifying epithelioma of Malherbe) are reported. This association has been previously reported in other 16 cases. The prevalence of pilomatricoma in myotonic dystrophy results much greater than in general population. This association affects females as well as males. This tumour, when associated with myotonic dystrophy, is more frequently multiple than single.

Prolactin response to acute administration of different L-dopa plus decarboxylase inhibitors in Parkinson's disease

Plasma prolactin (PRL) levels modifications after acute administration of L-dopa, L-dopa plus carbidopa and L-dopa plus benserazide were studied in parkinsonian patients. PRL increase after benserazide was compared with PRL response after carbidopa at the same dosage in untreated parkinsonian patients. A further study of the hyperprolactinemic effect of benserazide was performed in vitro on isolated and dispersed rat pituitary cells. The data gathered indicate that benserazide-induced hyperprolactinemia in parkinsonian patients could be due to a direct effect of the drug at the hypothalamic level and consequently to an inhibition of dopamine decarboxylation in the tuberoinfundibular dopaminergic system. It is not possible to exclude, however, that benserazide could exert its biological activity through the production of active metabolites in vivo.