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Biomedical subjects

A Antonello

Publications and source records attributed to A Antonello.

At least 19 recordsLinked to original sources
PubMed1999

Water and its effects when drunk cold. The Physician's view (1576-1751).

Starting with Baldassare Pisanelli's book Trattato della natura de' cibi et del bere, published in Venice in 1586, the controversies that have kept physicians busy over the centuries regarding the relative importance of water in human health are traced. These controversies were of considerable importance as the Latin word for water 'aqua' is derived from the phrase 'a qua vinimus' (from whence we come). However, until the studies of Nicolas Lemery, one of the most important pharmacologists of the 18th century, the controversies were debated using more theoretical, philosophical arguments. Lemery's studies shifted the debates from those based on philosophical arguments to more physiologically and scientifically based arguments.

Attitude of Health Personnel↗
PubMed1999

Giovan Battista Morgagni, a pioneer of clinical nephrology.

In the 18th century, Giovanni Battista Morgagni was the first to propose that specific signs and symptoms are linked to particular anatomical changes at autopsy and that these changes were the cause of the disease. This paper describes the report by Morgagni wherein he linked the anatomic findings at autopsy, specifically atrophied kidneys, with the signs and symptoms of a disease now known as uremia. From these findings, Morgagni felt that he had identified the factors responsible for the disease as well as its clinical course.

History, 18th Century↗
PubMed1999

Increased endothelial nitric oxide synthase mRNA level in Bartter's and Gitelman's syndrome. Relationship to vascular reactivity.

AIM: Patients with Bartter's syndrome and Gitelman's syndrome have reduced vascular reactivity, normo-hypotension and decreased peripheral resistances in spite of biochemical and hormonal abnormalities typical of hypertension. Since we found that both types of patients have increased urinary NO2-/NO3-, metabolites of NO, that correlated with their increased urinary cGMP, second messenger of NO, we examined the possible role of NO system in the pathophysiology of these syndromes. PATIENTS AND METHODS: We used a molecular biologic approach and studied ecNOS gene expression by PCR-amplification of cDNA obtained by RT-PCR of RNA extracted by patients and healthy controls monocytes. RESULTS: ecNOS is overexpressed in monocytes from patients with Bartter's and Gitelman's syndrome relative to controls: - 0.306 +/- 0.012 Densitometric Units (0.313 +/- 0.006, N = 3 for Bartter's patients; 0.302 +/- 0.009, N = 5 for Gitelman's patients) vs. 0.192 +/- 0.018, p < 0.0001. CONCLUSION: This overexperession presumably accounts for their increased NO production; thus it could be likely that elevated ecNOS and NO levels are a part of pathophysiological process(es) that leads to their characteristic reduced vascular responses. However, the relationship between the alterations in the NO signalling system observed in this study and the mutations in either Na+-K+-2Cl cotransporter or in a K+ channel ROMK or in Cl- channel ClCNKB in Bartter's syndrome and in Na+-Cl- cotranstransporter in Gitelman's syndrome, recently reported as their primary defects remains to be defined.

Adult↗
PubMed1998

Constitutive endothelial nitric oxide synthase (ecNOS) gene expression in human monocytes.

This study evaluates using a polymerase chain reaction (PCR)-based molecular biological approach to study the gene expression of the constitutive endothelial isoform of nitric oxide synthase (ecNOS) in human monocytes. When PCR was carried out with specific primers for ecNOS, 302 bp product was amplified, which sequence analysis determined as having 100% identity to the reported human ecNOS isoform gene sequence. The data presented here demonstrate a reliable technique for assessing ecNOS mRNA levels in circulating human monocytes. This then permits use of this easily available cell to monitor ecNOS levels and provides a means to investigate mechanisms involved in controlling NO synthase levels as well as NO synthesis.

Gene Expression↗
PubMed1997

Inhibition of furosemide-sensitive cation transport and activation of sodium-lithium exchange by endogenous circulating factor(s) in Bartter's and Gitelman's syndromes.

BACKGROUND: The nature of the cellular abnormality causing hypokalemia, hypotension, and hypovolemia in Bartter's and Gitelman's syndromes is still being debated. In fact, despite the recent descriptions of an array of nonconservative missense or point mutations in some ion transporters and in K+ channel, the lack of detectable defects in some patients suggests that other abnormalities of cell ion homeostasis may be involved in the pathophysiology of these syndromes. The study of the activity of cell ion transporters in patients with these syndromes using red blood cells (RBC) as a cellular model never investigated the role of plasma factor(s) affecting ion transport. OBJECTIVE: To evaluate the effect of plasma from patients with these syndromes on furosemide-sensitive lithium efflux (FSLE) from lithium (Li+)-loaded RBC of healthy subjects in vitro. METHODS: RBC of healthy controls were loaded with Li+ in the presence of nystatin and FSLE was evaluated in the presence of various concentrations of plasma from controls and patients with the two syndromes. RESULTS: Plasma from controls did not affect FSLE (0.08 +/- 0.02 mmol/l cells per h with 1:4 vol:vol and 0.07 +/- 0.02 mmol/l cells per h with 1:2 vol:vol plasma dilution). In contrast, doubling concentrations of plasma from patients with either syndrome in the efflux solution halved FSLE (from 0.10 +/- 0.0 mmol/l cells per h with 1:4 vol:vol to 0.05 +/- 0.01 mmol/l cells per h with 1:2 vol:vol plasma dilution, P < 0.05). Na+/Li+ exchange was significantly greater for RBC from patients with either syndrome than it was for RBC from controls (0.373 +/- 0.06 versus 0.257 +/- 0.01 mmol/l cells per h, P < 0.01), but the kinetic properties of furosemide-sensitive Na+-K+-2Cl- cotransport were similar. CONCLUSION: These data provide evidence for the hypothesis that plasma factor(s) affect ion transport in patients with these two syndromes. Since FSLE estimates Na+-K+-2Cl- cotransport the data suggest that plasma factor(s) contribute(s) to K+ wasting, hypokalemia, and hypotension by inhibiting cotransport in patients with these syndromes. The increase of Na+/Li+ exchange is most likely a secondary phenomenon associated with the hypermineralocorticoid state.

Adult↗
PubMed1997

Evidence of myocardial dysfunction in Bartter's syndrome.

Bartter's syndrome (BS) is characterized by arterial normohypotension despite biochemical and hormonal abnormalities generally associated with hypertension. An abnormal intracellular calcium homeostasis due to a reduced capacity to increase intracellular calcium has been demonstrated by us in BS and proposed as the main pathophysiological factor of the vascular hyporeactivity in BS. The present study was designed to assess whether this altered intracellular calcium homeostasis could also impair contractile recruitment at the myocyte level. Left-ventricular function of patients with BS and normal subjects (C) were studied by quantitative 2-D echocardiography at rest and by postextrasystolic potentiation (PESP), an inotropic stimulus able to recruit the maximal contractile reserve. A group of patients with hypokalemia other than BS (PB) was also included in the study to evaluate the effect of hypokalemia on myocardial contractile recruitment. Baseline left-ventricular end-diastolic volume (EDV) and ejection fraction (EF) did not differ in the 3 groups: EDV: 62 +/- 6 vs. 64 +/- 9 and 60 +/- 12 ml/m2; EF: 64 +/- 9 vs. 67 +/- 8 and 64 +/- 8%. PESP determines an increase of EF in C and PB: 82 +/- 5%, p < 0.01 and 76 +/- 6%, p < 0.01, while in BS it is unchanged: 69 +/- 9% and is reduced in comparison with the increment of myocardial function shown by C and PB (p < 0.01). This study is the first demonstration in BS of a depressed inotropic recruitment causing an exercise-induced left-ventricular dysfunction likely due to an abnormal intracellular calcium homeostasis in the myocytes.

Adult↗
PubMed1997

Is the red cell morphology really useful to detect the source of hematuria?

Morphological analysis of urinary red blood cells by phase-contrast microscopy to identify the source of bleeding was, and still is, widely used also as a starting point for workup. To evaluate the reliability of this approach, we studied 129 outpatients presenting with persistent isolated microhematuria; 31 subjects also had mild proteinuria (1 g/day), while 21 had pathological albumin levels. All patients were followed for a period of 6 years. During this time, 6 patients underwent renal biopsy for the onset of macrohematuria episodes and proteinuria of 2-3 g/day. Glomerular bleeding was identified in only 14.7% of the patients, despite the persistent microhematuria and the presence of proteinuria or microalbuminuria. The renal origin of the urinary erythrocytes correlated with histological findings in only 2 of 6 patients with dysmorphic erythrocytes who developed proteinuria (exceeding 1 g/day), and none with isomorphic erythrocytes showed urological abnormalities. These results challenge the validity and reliability of morphological analysis to identify the source of bleeding along the urinary tract.

Adult↗
PubMed1996

Carotid artery lesions in patients with nondiabetic chronic renal failure.

Atherosclerotic complications are the leading cause of death in chronic renal failure (CRF) patients. Therefore, we wished to investigate the prevalence of carotid artery lesions (CALs) in these subjects. Two groups were evaluated by high-resolution echo Doppler: group 1 included 103 patients (68 males and 35 females) affected by nonnephrotic CRF and group 2 included 100 control subjects (60 males and 40 females). The prevalence of hypertension was 84% in both groups. The exclusion criteria included diabetes mellitus and symptoms of cerebrovascular disease. In the two groups we evaluated clinical history, physical examination, total cholesterol, triglycerides, fibrinogen, blood cell counts, blood urea nitrogen, creatinine, 24-hour proteinuria, and urine analysis. In group 1 patients the following lipid profile parameters were also evaluated: low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, lipoprotein(a), ApoAI, ApoAII, and ApoB. Group 1 had higher triglycerides and fibrinogen than group 2. A lower body mass index was found in group 1 than in group 2. The prevalence of CALs was significantly higher in the CRF patients than in the control subjects (62% v 47%; P = 0.04). The difference between the two groups was more striking among normotensive patients (62% v 19%; P = 0.03). All CRF patients affected by peripheral arterial disease and 86% of those having coronary artery disease had associated CALs. In CRF patients the severity of CALs was positively correlated to age, white blood cell count, triglycerides, and fibrinogen. Nondiabetic CRF patients have a higher prevalence of carotid artery lesions than control subjects. Several factors besides hypertension, including lipids, blood coagulation, and leukocytes, could contribute to the accelerated atherosclerosis of CRF patients.

Adult↗
PubMed1996

Increased urinary NO2-/NO3- and cyclic guanosine monophosphate levels in patients with Bartter's syndrome: relationship to vascular reactivity.

Nitric oxide (NO) is a potent endogenous vasodilator and plays a pivotal role in the control of vascular tone by the formation of cyclic guanosine monophosphate (GMP). Patients affected by Bartter's syndrome have lower than normal vascular reactivity with normohypotension and decreased peripheral resistances in spite of biochemical and hormonal abnormalities typical of hypertension, and it is possible that increased production of NO may be involved in maintaining this reduced vascular response and vasodilatation. We have examined this possibility by studying NO2-/NO3- and cyclic GMP urinary excretions to assess NO production in vivo in seven patients affected by Bartter's syndrome compared with seven healthy controls. A group of five patients with hypokalemia other than Bartter syndrome (pseudo-Bartters) was also included in the study to evaluate the effect of hypokalemia on NO production. NO2-/NO3- urinary excretion (0.45 +/- 0.14 v 0.25 +/- 0.04 micromol/micromol urinary creatinine [controls], P < 0.005, v 0.28 +/- 0.05 [pseudo-Bartters], P < 0.01) and cyclic GMP urinary excretion (0.057 +/- 0.028 v 0.022 +/- 0.01 micromol/micromol of urinary creatinine [controls], P < 0.009, v 0.024 +/- 0.004 [pseudo-Bartters], P < 0.02) were increased in patients with Bartter's syndrome in comparison with controls and pseudo-Bartters, and a linear correlation between these two parameters was also present (P < 0.001). We conclude that in Bartter's syndrome the increased NO2-/NO3- and cyclic GMP urinary excretions point to an increased NO synthesis, which could account for the reduced vascular response of the disease, therefore adding its role in determining the vascular hyporeactivity of Bartter's syndrome.

Adolescent↗
PubMed1996

Intracellular calcium signalling and vascular reactivity in Bartter's syndrome.

We investigated patients affected by Bartter's syndrome in the attempt to localize the intracellular defect mediating the reduced intracellular Ca2+ mobilization that may be responsible for the decreased vascular reactivity characteristic of Bartter's syndrome. Using the formylmethionyl-leucyl-phenylalanine (fMLP) receptor system, which causes, intracellular calcium release, we investigated fMLP-stimulated intracellular inositol 1,4,5-trisphosphate (IP3) production as well as the number and affinity of fMLP receptors in neutrophils from Bartter's syndrome patients and healthy controls. Scatchard plot analysis of radioactive fMLP binding to neutrophils indicated that there were no differences in either cell receptor number and affinity for ligand between healthy controls (n = 5) and patients with Bartter's syndrome (n = 5): 6,151 +/- 1,431 vs. 7,112 +/- 2,566 receptors/cell; K(D): 0.446 +/- 0.14 vs. 0.454 +/- 0.09 pM of fMLP. 5- and 10-second fMLP-stimulated intracellular IP3 production was instead reduced in patients affected by Bartter's syndrome: 2.479 +/- 1.07 vs. 4.073 +/- 1.04 nmol/10(7) cells at 5 s (n = 8; p < 0.01); 1.673 +/- 0.741 vs. 3.766 +/- 1.348 nmol/10(7) cells at 10 s (n = 8; p < 0.005). The results of this study indicate that the anomaly of intracellular calcium mobilization in patients with Bartter's syndrome arises from a defect at the postreceptor level. The anomalous calcium signalling that takes place in Bartter's syndrome may provide a mechanism for the hyporesponsiveness to pressor stimuli characteristic of these patients.

Adult↗
PubMed1996

[7-year-follow up (1987-1994) of a population with asymptomatic persistent microhematuria and normal renal function].

A group od 129 patients with persistent asymptomatic microhematuria was studied for 7 years (1987-1994). At the beginning of the study, 31 patients showed mild proteinuria (less than 1 g/day) and in the rest of 98 patients, 21 showed microalbuminuria. At the end of the study none of the patients developed renal failure, urological disease, hypertension. Six patients out of 31 with mild proteinuria (less than 1 g/day), developed an increase of proteinuria over 2 and 3/day and underwent a renal biopsy while 2 out of 21 patients with altered microalbuminuria completely recovered after the follow-up period. The rest of 77 patients at the end of the study still showed isolated microhematuria. The results of this study support the hypothesis that in a population with age range between 16 and 28 years, the presence of persistent microhematuria, also associated with mild proteinuria, even for a long time, does not seem to lead to changes of renal function or to urological diseases.

Adolescent↗
PubMed1995

Endothelium-derived vasoactive substances in Bartter's syndrome.

An imbalance between endothelium-derived vasoactive substances such as endothelin and endothelium-derived nitric oxide (NO) might be viewed as a possible determinant of vascular hyporeactivity. To check this possibility the authors evaluated the role of endothelin and NO in the reduced vascular reactivity of Bartter's syndrome. Plasma immunoreactive endothelin (22.07 +/- 7.06 vs 13.80 +/- 1.43 pmol/L, P < 0.011), urinary excretion of NO2- (0.28 +/- 0.10 vs 0.15 +/- 0.02, mumol/mumol of urinary creatinine, P < 0.01) and NO3- (0.17 +/- 0.07 vs 0.09 +/- 0.02 mumol/mumol of urinary creatinine, P < 0.011), and forearm resting blood flow (FRBF) (6.67 +/- 1.69 vs 4.30 +/- 0.38 mL/m'/100 mL, P < 0.005) were increased in patients with Bartter's syndrome in comparison with normal controls (C). No difference in postischemic maximal FBF was found (34.14 +/- 4.67 vs 31.35 +/- 2.86 mL/minute/100 mL), while patients showed a slower recovery after peak flow (PF) (77.57 +/- 61.35 vs 9.42 +/- 3.69 seconds, P < 0.013). Higher plasma endothelin supports the defect in vascular reactivity of Bartter's syndrome already shown for angiotensin II and norepinephrine and is in keeping with the altered intracellular calcium signaling previously demonstrated by the authors in this syndrome. The increased excretion of NO2- and NO3- in this syndrome, together with the higher FRBF and the slower recovery of the FBF and PF, argues in favor of an increased NO synthesis in Bartter's syndrome and of assigning it a role in the vascular hyporeactivity of Bartter's syndrome.

Adolescent↗
PubMed1994

Familial hypertension in Morgagni's De Sedibus et Causis Morborum per Anatomen Indagatis.

Morgagni was a contemporary of Malpighi, but unlike the latter he concentrated on macroscopic clinical and anatomic observations. His De Sedibus et Causis Morborum per Anatomen Indagatis consists of 5 books, written as letters to other scientists and members of foreign academies. He dealt with diseases of the head, the chest and the abdomen and with surgically treatable diseases. The final book contains corrections to the previous 4 in the light of new studies and extended clinical experience. One case history presented, of a patient of Valsalva's who died with edema and a bladder stone, can probably be considered as the first description of familial hypertension. From his clinical and autopsy investigations, Morgagni concluded that the patient died of hereditary bladder stone disease and apoplexy.

Anatomy↗