[Morbidity and mortality in patients undergoing dialysis. Comparison of hemodialysis and peritoneal dialysis. Our experience]. / Morbilità e mortalità in pazienti in dialisi. Confronto fra emodialisi e dialisi peritoneale. Nostra esperienza.

BACKGROUND: We have compared the hemodialysis and peritoneal dialysis populations of our Center for morbidity and mortality, in a retrospective study of six years of activity. METHODS: We enrolled 125 patients (104 patients/year/million inhabitants), who had been in chronic dialysis from 1992 to 1997: 90 (22-90 years old) initiated in hemodialysis and 35 (27-82 years old) in peritoneal dialysis. RESULTS: We have evaluated survival and morbility, as hospitalization/patient/year in both groups. Mortality did not prove significantly different in the two groups. The global average of hospitalization was 8 days/patient/year for hemodialysis and 6 for peritoneal dialysis. CONCLUSIONS: In spite of the short time of observation and the exiguity of numbers, our experience shows that the two methods are equivalent.

[Prevalence of anti-HCV antibody positivity and seroconversion incidence in hemodialysis patients]. / Prevalenza di positività per anticorpi antiHCV e incidenza di sieroconversione in pazienti in emodialisi.

BACKGROUND AND AIMS: The prevalence of positivity to anti-HCV antibodies and the incidence of seroconversion in a group of patients undergoing replacement hemodialytic treatment was evaluated using a retrospective analysis. The study was carried out in a hemodialysis centre with no areas and/or equipment dedicated to patients positive to anti-HCV antibodies. The aim was to check whether the rigid application of universal aseptic precautions, which are always adopted by the centre, are sufficient to prevent contagion by hepatitis C virus in patients undergoing dialysis. METHODS: The study was carried out in patients receiving dialysis in the Centre (74 patients at the start of the observation period) for two years (7/95-7/97). Anti-HCV antibodies were assayed every two months using a third generation ELISA tests and positive results were confirmed by RIBA III test. At the start of the observation period, 10/74 patients showed positive levels of anti-HCV antibodies (13.5%). RESULTS: During the period in question none of the patients with negative levels of anti-HCV antibodies at the start of the study became positive. Of the patients undergoing dialysis after 1/7/95, four were already positive for anti-HCV antibodies and none of the others became positive. CONCLUSIONS: The experience confirms that the application of universal aspeptic precautions may be sufficient to prevent the spread of hepatitis C virus in dialysis centres.

Blunt cardiac rupture: the utility of emergency department ultrasound.

BACKGROUND: Rupture of the heart is usually a fatal injury in patients sustaining blunt trauma. Those arriving in the emergency department alive can be saved with prompt diagnosis and treatment. METHODS: We describe the cases of 4 consecutive patients with rupture of the free cardiac wall whom we treated at Grady Hospital. Two had a tear of the right ventricle, 1 had a tear of the right atrium, and 1 had two tears of the left atrium. All patients were involved in motor vehicle accidents. The diagnosis was made by ultrasound in 3 patients and during exploratory surgical intervention in the other. All tears were repaired primarily without the aid of cardiopulmonary bypass. RESULTS: Three of the patients survived, and 1 died. CONCLUSIONS: Rarely are patients with rupture of the free cardiac wall seen in an emergency department. The improvements in the prehospital care and the transportation may result in an increase in the numbers of such patients. Physicians treating patients with blunt trauma must suspect the presence of cardiac rupture. Immediate use of ultrasonography will establish the diagnosis and prompt repair of the injury may improve overall survival.

Sex differences in circulating human leptin pulse amplitude: clinical implications.

Leptin, a product of fat cells, provides a signal of nutritional status to the central nervous system. Leptin concentrations have ultradian and diurnal fluctuations. We conducted this study to assess sex differences in the levels of organization of frequently sampled leptin concentrations in healthy, normal weight women and men. Leptin levels were sampled every 7 min for 24 h in 14 healthy, normal weight individuals (6 women and 8 men). The 14 leptin time series containing a total of 2898 leptin measurements were assessed by 1) algorithms that characterize statistically significant pulsatility, 2) Spectral (Fourier) analysis, 3) analysis of time intervals and variability, and 4) approximate entropy. We found that frequently sampled plasma leptin concentrations have a 24-h profile that is numerically more than twice as high in women as in men, and leptin pulse amplitude is likewise more than twice as high in women. However, healthy men and women have nearly identical concentration-independent and frequency-related 24-h and ultradian patterns. Leptin concentrations have nonrandom fluctuations over 24 h, independent of their absolute value and underlying 24-h periodicity, that are similar in men and women. Ultradian periodicities detected by Fourier time series have similar values in men and women. The strongest distinction between the sexes in the level of organization of leptin concentration is not at the level of pulse organization or oscillation frequency, but, rather, in the mass or amount of leptin released (or removed) per unit time, indicating that women might be more resistant to the effects of leptin than men. Because leptin is clinically relevant to the regulation of body weight, future studies should examine whether the relative leptin resistance exhibited by women might contribute to their increased susceptibility to disorders whose pathophysiology involves dysregulation of food intake and body weight.

Correlations between bone histopathology and serum biochemistry in uremic patients on chronic hemodialysis.

To define which noninvasive investigations are of value in predicting bone histology, we analyzed transiliac bone specimens (66 biopsies, 14 autopsies) from 80 uremic patients on chronic dialysis. Results were compared with values of different measurements of parathyroid hormone (PTH), alkaline phosphatase (APH), osteocalcin, calcitonin, baseline and post-deferroxamine (DFO) aluminium (Al),--beta 2 microglobulin, ferritin and bone mineral density. Among histomorphometric parameters, woven osteoid, active osteoblastic surface and resorption surface showed the best correlations with dynamic and biochemical marks of active bone metabolism. Among biochemical parameters, intact PTH and APH were better related to histomorphometric and dynamic bone parameters than other PTH measurements as well as osteocalcin, while calcitonin was related to no parameters. Stainable Al alone, and not total bone Al content was related to bone histology. Baseline Al was related to lamellar osteoid, while post-DFO Al was related to stainable Al. beta 2 microglobulin was positively related to active osteoid surface and ferritin was inversely related to the mineral apposition rate, while bone mineral density was related only to total bone volume. We conclude that, though definite diagnosis requires the use of histological methods, few simple biochemical parameters may offer insight to the bone metabolic status, useful to the physician in day to day clinical practice.

[Vascular access for hemodialysis under difficult conditions. Our experience]. / Accessi vascolari per emodialisi in condizioni difficili. Nostra esperienza.

Having examined the causes that lead, on the one hand, to an increased number of vascular accesses in difficult conditions and, on the other, to their reduction and having examined their personal series of vascular accesses for hemodialysis studied between 4 December 1974 to 30 September 1996, and lastly having outlined the correct protocol for the preparation of these accesses, the authors focus on vascular accesses created in difficult conditions, namely the exhaustion of the natural venous and/or arterial bed below the proximal third of the upper limb. In particular, they examine the use of definitive jugular catheters, a more recent and therefore non-standardised method, and conclude that, although not regarded as vascular accesses of first choice, they should no longer be regarded as heroic but, after a short period of learning, they are easy to position and maintain.

Synchronicity of frequently sampled, 24-h concentrations of circulating leptin, luteinizing hormone, and estradiol in healthy women.

Leptin, an adipocyte hormone, is a trophic factor for the reproductive system; however, it is still unknown whether there is a dynamic relation between fluctuations in circulating leptin and hypothalamic-pituitary-ovarian (HPO) axis hormones. To test the hypothesis that fluctuations in plasma leptin concentrations are related to the levels of luteinizing hormone (LH) and estradiol, we sampled plasma from six healthy women every 7 min for 24 h during days 8-11 of the menstrual cycle. Cross-correlation analysis throughout the 24-h cycle revealed a relation between release patterns of leptin and LH, with a lag of 42-84 min but no significant cross-correlation between LH and estradiol. The ultradian fluctuations in leptin levels showed pattern synchrony with those of both LH and estradiol as determined by cross-approximate entropy (cross-ApEn). At night, as leptin levels rose to their peak, the pulsatility profiles of LH changed significantly and became synchronous with those of leptin. LH pulses were fewer, of longer duration, higher amplitude, and larger area than during the day. Moreover, the synchronicity of LH and leptin occurred late at night, at which time estradiol and leptin also exhibited significantly stronger pattern coupling than during the day. We propose that leptin may regulate the minute-to-minute oscillations in the levels of LH and estradiol, and that the nocturnal rise in leptin may determine the change in nocturnal LH profile in the mid-to-late follicular phase that precedes ovulation. This may explain the disruption of hypothalamic-pituitary-ovarian function that is characteristic of states of low leptin release, such as anorexia nervosa and cachexia.

Endogenous interleukin-1 receptor antagonist is neuroprotective.

Interleukin-1 (IL-1) has been implicated in chronic and acute cerebral neuropathologies. IL-1 receptor antagonist (IL-1ra), a naturally occurring protein that binds to IL-1 receptors without inducing signal transduction, blocks several actions of IL-1. IL-1ra acts at the local level and it also circulates in the bloodstream. We now report evidence for a biological function of IL-1ra in the brain as an endogenous neuroprotective molecule. Cerebral expression of IL-1ra mRNA is induced rapidly by focal cerebral ischemia in rats, and inhibition of the action of IL-1ra, by passive immuno-neutralization, markedly enhances ischemic damage. To our knowledge this is the first report of an action of endogenous IL-1ra in the brain. Control of IL-1ra expression or action may therefore provide a useful therapeutic strategy to limit acute neurodegeneration.

Human leptin levels are pulsatile and inversely related to pituitary-adrenal function.

Leptin communicates nutritional status to regulatory centers in the brain. Because peripheral leptin influences the activity of the highly pulsatile adrenal and gonadal axes, we sought to determine whether leptin levels in the blood are pulsatile. We measured circulating leptin levels every 7 minutes for 24 hours, in six healthy men, and found that total circulating leptin levels exhibited a pattern indicative of pulsatile release, with 32.0 +/- 1.5 pulses every 24 hours and a pulse duration of 32.8 +/- 1.6 minutes. We also show an inverse relation between rapid fluctuations in plasma levels of leptin and those of adrenocorticotropic hormone (ACTH) and cortisol that could not be accounted for on the basis of glucocorticoid suppression of leptin. As leptin levels are pulsatile, we propose that a key function of the CNS is regulated by a peripheral pulsatile signal. In a separate pilot study we compared leptin pulsatility in 414 plasma samples collected every 7 minutes for 24 hours from one obese woman and one normal-weight woman. We found that high leptin levels in the obese subject were due solely to increased leptin pulse height; all concentration-independent pulsatility parameters were almost identical in the two women. Leptin pulsatility therefore can be preserved in the obese.

Detection of p53 nuclear protein accumulation in brushings and biopsies of Barrett's esophagus.

Alterations in the tumor suppressor gene p53 may represent a useful prognostic marker of premalignant or malignant disease in Barrett's dysplasia or esophageal adenocarcinoma. Immunohistochemistry was used to establish the ability to detect nuclear accumulation of altered p53 protein in esophageal brushings as well as biopsies, and to examine for p53 alterations in a group of 18 patients with Barrett's esophagus enrolled in a surveillance and endoscopy program, p53 protein accumulation was easily detected in esophageal brushings, and the results correlated well with matched biopsies (9/11). In patients enrolled in surveillance endoscopy, 1 brushing of 22 was positive for p53 protein accumulation. In this patient, who received preoperative radiation and chemotherapy, the positive p53 result correlated with positive cytology for residual adenocarcinoma. All Barrett's esophagus brushings negative for p53 protein were benign by cytologic, morphologic criteria. The immunohistochemical detection of p53 alterations in esophageal brushing and biopsy specimens may provide useful information in patients undergoing surveillance for esophageal dysplasia and adenocarcinoma.

Interleukin (IL) 1beta, IL-1 receptor antagonist, IL-10, and IL-13 gene expression in the central nervous system and anterior pituitary during systemic inflammation: pathophysiological implications.

The pathophysiology of systemic inflammation and sepsis involves peripheral organs, causing gastrointestinal, renal, and cardiovascular alterations, as well as the central nervous system (CNS), affecting sleep, temperature regulation, behavior, and neuroendocrine function. The molecular basis of the CNS effects of systemic inflammation are not fully elucidated. Here we show that the CNS responds to systemic inflammation with pronounced IL-1beta gene expression and limited IL-1 receptor antagonist (IL-1ra), IL-10, and IL-13 gene expression. This pattern occurs throughout the CNS, including areas such as the subfornical organ, pineal gland, neurohypophysis, and hypothalamus. In contrast, in the anterior pituitary, we found limited IL-1beta gene expression but marked induction of the mRNA encoding for the secreted isoform of IL-1ra, secreted IL-1ra. We conclude that the central manifestations of peripheral inflammation are mediated by endogenous brain IL-1beta synthesized during systemic inflammation in the context of limited central cytokine counter regulation of IL-1. As IL-1beta is a potent stimulus for inducible nitric oxide synthase expression and activity, these findings explain our previous observation that systemic inflammation promotes inducible nitric oxide synthase gene expression in the brain and the spillover of NO metabolites into cerebrospinal fluid. The CNS transcription of the HIV-1 replication factor IL-1beta in the context of limited transcription of the IL-1 replication inhibitors IL-1ra, IL-10, and IL-13 might help explain the negative impact of systemic inflammation on the clinical course of AIDS. In addition, we propose that IL-1ra may be secreted by the anterior pituitary as a systemic anti-inflammatory hormone that is released in response to IL-1beta originated from multiple sources.

IL-1 beta, IL-1 receptor type I and iNOS gene expression in rat brain vasculature and perivascular areas.

The mechanism by which IL-1 beta exerts its actions in the brain during systemic inflammation is not fully understood, as neither IL-1 receptor gene expression nor IL-1 binding have been identified in significant levels in key areas that respond to IL-1 beta. Having hypothesized that perivascular nitric oxide (NO) might modulate the effects of systemic IL-1 beta in the brain, we studied the expression of the genes encoding for IL-1 beta, the signal-transducing IL-1 receptor type I (IL-1RI) and inducible NO synthase (iNOS) constitutively and during systemic inflammation in vascular and perivascular regions of the rat brain. Our results show that IL-1RI is constitutively expressed at the interface of the vascular wall and perivascular glia. During systemic inflammation there is induction of IL-1 beta gene expression in the vascular wall, accompanied by perivascular induction of iNOS mRNA. We conclude that during systemic inflammation vascular IL-1 beta, binding to vascular and perivascular IL-1RI receptors, may induce perivascular iNOS gene expression, leading to the production of NO and modulation of the effects of IL-1 beta in the brain. We propose that the vascular and peri-vascular induction of iNOS mRNA by IL-1 beta might represent a mechanism for the modulation of the central nervous system effects of peripheral inflammatory mediators.

Localization of urocortin messenger RNA in rat brain and pituitary.

Pituitary function is regulated by hypothalamic releasing hormones secreted into hypophyseal-portal blood. A new hypothesis is that pituitary function might also be regulated at the local level by releasing hormones synthesized within the pituitary. Here we show that the pituitary expresses high levels of the gene encoding for urocortin. We suggest that urocortin synthesized by the pituitary may modulate pituitary function, and that adrenocorticotropic hormone (ACTH) secretion is dependent on input not only from the hypothalamus as previously described, but it may also be regulated by urocortin synthesized locally. Urocortin binds to the corticotropin-releasing hormone (CRH) receptor type 1 (CRH-R1) with high affinity and potently stimulates pituitary-adrenal function. Our group and others have previously localized high levels of CRH-R1 mRNA in the pituitary. Using a 35S-labeled rat urocortin riboprobe we have now localized urocortin mRNA in rat brain and pituitary. The finding of urocortin gene expression in the pituitary may help explain why proopiomelanocortin (POMC) mRNA levels are not decreased during hypothalamo-pituitary disconnection, and also describes a new level of complexity in the regulation of hypothalamo-pituitary function. Future studies should consider the possibility that pituitary function might be regulated at the local level by urocortin.

Inducible nitric oxide synthase gene expression in the brain during systemic inflammation.

Inducible nitric oxide synthase (iNOS) is a transcriptionally regulated enzyme that synthesizes nitric oxide from L-arginine that has a key role in the pathophysiology of systemic inflammation and sepsis. Transgenic animals with a null mutation for the iNOS gene are resistant to hypotension and death caused by Escherichia coli lipopolysaccharide (LPS). The regulation of peripheral iNOS has been well studied in sepsis, but little is known about iNOS regulation in the brain during systemic inflammation or sepsis. We know that at baseline there is no detectable iNOS gene expression in the brain, but a detailed neuroanatomical study reveals that early in the course of systemic inflammation there is a profound induction of iNOS messenger RNA in vascular, glial and neuronal structures of the rat brain, accompanied by the production of nitric oxide (NO) metabolites in brain parenchyma and cerebrospinal fluid (CSF). We propose that the spillover of nitrite into the CSF has the potential to be a diagnostic marker for systemic inflammation and sepsis. Pharmacological interventions aimed at regulating iNOS function in the brain might represent a new treatment strategy in sepsis. Brain iNOS may be relevant to the pathophysiology, diagnosis and treatment of systemic inflammation and sepsis.

[Treatment with erythropoietin and iron requirements in dialyzed patients]. / Trattamento con eritropoietina (Epo) e fabbisogno di ferro nel paziente dializzato.

The use of erythropoietin in dialysed patients leads to the gradual depletion of the body's iron reserves. It is important to assay iron blood levels in both patients receiving Epo therapy and those undergoing dialysis without this treatment. The most common method used is to assay ferritinemia, transferrinemia and the transferrin saturation levels. Using a retrospective study it was found that there is no significant difference in the request for iron supplementation in patients receiving Epo treatment compared to a control group not treated with Epo.

The gene encoding for the novel transacting factor proopiomelanocortin corticotropin-releasing hormone responsive element binding protein 1 (PCRH-REB-1) is constitutively expressed in rat pituitary and in discrete brain regions containing CRH or CRH receptors: pathophysiological implications.

The nucleotide sequence CTGTGCGCGCAG is a core corticotropin-releasing hormone (CRH) responsive element in the proopiomelanocortin (POMC) promoter that gives 5-7 fold stimulation of POMC transcription by CRH. This region binds a novel transacting factor, proopiomelanocortin corticotropin-releasing hormone responsive element binding protein 1 (PCRH-REB-1), recently cloned from CRH-stimulated pituitary cells. We conducted in situ hybridization histochemistry experiments, using a species-specific, antisense, 35S-labeled PCRH-REB-1 riboprobe, to determine the pattern of PCRH-REB-1 gene expression in the brain, and showed that PCRH-REB-1 mRNA is localized not only in pituitary, but it is also found in discrete brain regions such as septal nuclei, hypothalamus, cortex, hippocampus, amygdala, and cerebellum. Those regions contain CRH or CRH receptors, and respond to CRH. We hypothesize that PCRH-REB-1 may be a marker of cellular responsiveness to CRH in the brain and pituitary, and might therefore be useful in the evaluation of CRH function and in the identification of clinically effective CRH agonists and antagonists.

Focal cerebral ischemia induces CRH mRNA in rat cerebral cortex and amygdala.

Corticotropin-releasing hormone (CRH) antagonism has neuroprotective effects in models of ischemia. We examined CRH mRNA by in situ hybridization in a well-established rat model of focal cerebral ischemia caused by permanent middle cerebral artery occlusion (MCAo). In ischemic cortex CRH mRNA levels were elevated 2.6-fold 60 min after MCAo, compared with sham operated animals. CRH mRNA was also induced in the amygdala, 60 min following ischemia, in a pattern which was qualitatively different from that of sham operated animals. This rapid and profound increase in CRH mRNA levels during focal cerebral ischemia is likely to be associated with neurotoxicity, as CRH antagonism has been reported to cause a significant reduction in neuronal loss during ischemia.

Expression and activation of erbB-2 and epidermal growth factor receptor in lung adenocarcinomas.

ErbB-2 and EGFR (epidermal growth factor receptor) are expressed in lung adenocarcinomas and associated with a poor prognosis. Immunocytochemical analysis revealed erbB-2 and EGFR coexperession as a characteristic feature of most lung adenocarcinomas, and at levels of receptor expression present in bronchial epithelial cells. In primary lung tumours and cell lines, erbB-2 detected using Western blot analysis demonstrated low-level phosphotyrosine staining of the 185 kDa band, as compared with breast cancer cell lines. A549 and A427 lung adenocarcinoma cells treated with neu differentiation factor (NDF) showed increased erbB-2 phosphotyrosine staining, but to a much lesser extent than breast cancer cells. The lung cells were examined for expression of the potential autocrine growth factors NDF and transforming growth factor alpha (TGF-alpha) by Northern blot analysis. Both NDF and TFG-alpha mRNA were abundantly expressed in the A549 cells. NDF mRNA was highest during active cell proliferation and decreased in confluent cells or after treatment with the growth-inhibitory steroid dexamethasone. Primary tumours and cell lines expressed EGFR, showing higher basal level phosphotyrosine staining than erbB-2. Treatment with NDF and EGF (epidermal growth factor) stimulated cell growth, and in A549 cells the presence of both factors provided an additive increase in cell growth. The growth stimulus that ligand-activated erbB-2 and EGFR provides to lung adenocarcinoma cells may establish a background of continued cell proliferation over which other critical transforming events may occur.

Localization of interleukin-1 beta converting enzyme mRNA in rat brain vasculature: evidence that the genes encoding the interleukin-1 system are constitutively expressed in brain blood vessels. Pathophysiological implications.

Interleukin (IL)-1 beta-converting enzyme (ICE) cleaves the biologically inactive precursor form of IL-1 beta into mature, bioactive IL-1 beta. Because of the potent effects of IL-1 in blood vessels, we conducted an in situ hybridization study to determine whether ICE mRNA is constitutively expressed in adult rat brain vasculature. Using in situ hybridization histochemistry, we were able to demonstrate that mRNA in blood vessels scattered throughout the brain. In a second set experiments, we found that the genes encoding not only ICE, but also IL-1 alpha, IL-1 beta, IL-1 receptor antagonist (IL-1ra), and the IL-1 type I receptor are expressed in brain vasculature. To our knowledge this is the first report documenting the expression of the genes encoding all of the functional elements of the IL-1 system in the same tissue. Our findings have three pathophysiological implications. First, they indicate a possible site where peripheral IL-1 may act in the brain. The vascular IL-1 system stimulates the production of nitric oxide and prostanoids, which could act as mediators of the effects of peripheral IL-1 in the central nervous system. Additionally, vascular IL-1 is known to activate adhesion molecules; our data that the genes encoding the IL-1 system are expressed in brain vasculature further support the concept that IL-1 is implicated in the pathophysiology of atherosclerosis and stroke. Finally, in the context of previous studies documenting that IL-1ra inhibits the effects of IL-1 on endothelial cells, our findings of endogenous IL-1ra mRNA in brain vasculature indicate that IL-1ra might be an endogenous vascular protective agent.

E-cadherin expression in primary and metastatic thoracic neoplasms and in Barrett's oesophagus.

Reduced expression of E-cadherin, a Ca(2+)-dependent cell adhesion molecule present in normal epithelium, has been associated with invasive and metastatic cancer. Immunohistochemistry was used in examining the relationship between E-cadherin expression and stage in 59 oesophageal and 52 lung cancers. Advanced-stage oesophageal cancers were associated with both reduced and disorganised E-cadherin expression (P < 0.01). Advanced-stage lung adenocarcinomas generally exhibited disorganised or reduced E-cadherin expression, but no statistical association between expression pattern and stage was found (P > 0.05). No differences in stage were seen between tumours with reduced or disorganised E-cadherin expression. Altered E-cadherin expression was detected in dysplastic, non-invasive Barrett's oesophagus. Importantly, high-level E-cadherin expression was detected in 17 of 17 lymph nodes containing metastatic cancer. E-cadherin mRNA expression was decreased in tumours with reduced protein expression, but not in tumours with disorganised expression. Expression of alpha-catenin mRNA, an E-cadherin-associated protein, was detected in tissues with altered E-cadherin protein expression. Reduced and disorganised expression of E-cadherin appear to be related to transcriptional and post-translational events respectively, and both appear to represent altered cell adhesion associated with invasion and metastasis in thoracic neoplasms.