Biomedical subjects
Publications and source records attributed to L Rizzo.
The authors report a rare case of megacalycosis located on a duplex system upper moiety, and analyse the problems related to its pathology, etiopathogenesis, clinical manifestations and diagnosis.
BACKGROUND: The context memory deficit hypothesis of schizophrenia postulates that the long-term deficit associated with this disorder is related to a memory impairment for contextual information. METHOD: To test this hypothesis, memory for temporal context was assessed in 33 patients with schizophrenia and 33 normal subjects, using a recency discrimination task. RESULTS: Whereas patients were able to recall and recognise target items, they were unable to recognise from among the target items those which had been most recently learned. CONCLUSIONS: Schizophrenia is associated with a temporal context memory deficit.
Secondary aorto-enteric fistula is one of the most serious complications of abdominal aortic reconstruction. Conventional management includes removal of all infected prosthetic graft, oversewing of aortic stump and restoration of lower limbs blood flow by extraanatomic bypass grafting, reporting high rates of mortality, limb loss, and even infection of the extraanatomic grafts. Dissatisfied by these results, frequently, due to aortic stump blowout or extraanatomic by-pass reinfection, some authors attempted a more conservative approach with au in situ replacement by a new synthetic graft. The aim of this paper was to verify the role of in situ graft replacement. From December 1989, 8 patients with secondary aorto-enteric fistula underwent in situ PTFE graft replacement. One patient (12.5%) died perioperatively for acute myocardial infarction. No limb loss occurred. One patient died after 44 months from pulmonary neoplasia without signs of graft infection. The others are doing well at 34 months follow-up. The authors suggest that, in selected patients, in situ prosthetic graft replacement provides better early and late results than extranatomic bypass.
Thymectomy of 3-day-old mice results in the development of multi-organ-specific autoimmune diseases. The disease process is mediated by CD4+ T cells and is characterized by an inflammatory infiltrate in the affected organ(s) and the presence of autoantibodies. Our analysis of the phenotype of the CD4+ T cells that remain in the 3-day thymectomized animal revealed that the majority (approximately 80%) of the CD4+ lymph node cells express an activated (MEL-14low) phenotype and a smaller percentage expressed the T cell activation Ag CD69 and IL-2R alpha-chain. Thymectomized animals also had an increase in the frequency of mitogen-induced CD4+ IL-4 producers and significantly higher levels of total serum IgG. Functional studies demonstrated that lymph node T cells from 3-day thymectomized mice had an enhanced response in the syngeneic MLR and appeared to preferentially respond to syngeneic dendritic cells. To determine whether the syngeneic MLR-reactive T cells were involved in the pathogenesis of the organ-specific disease, we developed a model that mimicked the 3dTx model by grafting neonatal thymi to adult nu/nu recipients followed by removal of the thymus graft on day 3 or 4. When compared with mice transplanted with an untreated thymus, nu/nu mice transplanted with adult APC-containing thymi demonstrated a decrease in the incidence and severity of gastritis, a marked decrease in the titer of anti-parietal cell Ab, and a decrease in total serum IgG. Thus, intrathymic tolerization to complexes of self-peptides and MHC class II on adult APC prevents organ-specific autoimmune disease.
Eighteen patients (6 female, 12 male; average age 51 years, range 37-79) with clinical and radiological evidence (MRI) of cervical spondylotic myelopathy (CSM) were examined. The subjects were divided into two groups depending on whether radiology indicated single level (9 patients) or multilevel (9 patients) compression of the cervical cord. All of the patients underwent surgical decompression. Seriate exam with trans-cranial magnetic stimulation was performed in double session before surgery, and 3 and 12 months after surgery. The follow-up study of these patients revealed a statistically significant neurophysiological improvement only in those patients with single-level compression. In these cases, the cervical cord pathology revealed by MRI signal hyperintensity in T2 may at least partially consist of an edematous component and/or an initial demyelinization that has still a chance of recovery. In patients with multilevel damage, the compression may cause irreversible lesions.
OBJECTIVE: To test the hypothesis that there is a link between the memory deficit associated with schizophrenia and an impairment of consciousness, an experiential approach was used to assess recognition memory and awareness in schizophrenic patients and normal subjects. METHOD: On a recognition memory task with low- and high-frequency words, the schizophrenic (N = 30) and normal (N = 30) subjects gave "remember" responses to recognized items that were accompanied by conscious recollection and "know" responses to items that were recognized on the basis of familiarity without any recollective experience. RESULTS: Schizophrenia selectively impaired recognition based on recollective experience, as measured by "remember" responses, but had no effects on "know" responses. In the comparison group, low-frequency words, relative to high-frequency words, enhanced conscious recollection but not familiarity. The schizophrenic patients did not display the same word-frequency effect. CONCLUSIONS: These results indicate that schizophrenia affects differentially two means of access to the personal past: it impairs recognition memory with, but not without, conscious recollection. They suggest that the impairment of conscious recollection observed in schizophrenic patients could be due to a failure of elaborative processing of information.
OBJECTIVE: To evaluate microvascular permeability by the transcapillary escape rate of albumin (TERalb) in type II diabetic patients with normo- and microalbuminuria. RESEARCH DESIGN AND METHODS: The TERalb has been measured following intravenous injection of 125I-labeled human serum albumin in 32 normotensive type II diabetic patients and 9 healthy control subjects matched for sex and age. Type II diabetic subjects were grouped in normoalbuminuric, albumin excretion rate (AER) < 20 micrograms/min (n = 18), and microalbuminuric, AER 20-200 micrograms/min (n = 14) categories. RESULTS: In type II diabetic patients, no differences were noted between normo- and microalbuminuric groups for known diabetes duration (8.3 +/- 5.9 vs. 11.7 +/- 8.0 years), blood pressure (BP) (129/76 +/- 16/8 vs. 131/76 +/- 14/5 mmHg), current metabolic control (HbA1c: 8.0 +/- 1.4 vs. 8.5 +/- 1.6%), and serum lipids. However, previous 2-year mean HbA1c levels were significantly higher in microalbuminuric patients (8.7 +/- 1.45 vs. 7.6 +/- 1.29%; P < 0.05). The TERalb was similar in control subjects and normoalbuminuric patients (5.16 +/- 1.09 vs. 5.71 +/- 1.66 %/h) and significantly higher in the microalbuminuric group (8.98 +/- 1.35 %/h; P < 0.0001). The increased leak of albumin was not explained by differences in diabetes duration, BP, or metabolic control at the time of investigation and was independently related to the presence of microalbuminuria (r = 0.63, percent explained variance approximately 40) and mean "historical" HbA1c (multiple r = 0.705; total explained variance approximately 50%). CONCLUSIONS: Type II diabetic patients with microalbuminuria show an increased TERalb, i.e., a widespread microvascular damage that may be important in the pathogenesis of long-term complications. Our findings may contribute to the explanation of why albuminuria seems to be an independent cardiovascular risk factor in type II diabetes.
A case of pyeloureteral junction obstruction in the upper moiety of a duplex system is reported. Pathologic, clinical and diagnostic aspects of this rare condition are discussed.
The prevalence of hypertension in diabetes is significantly higher than in non-diabetics, perhaps twice as common. The excess is related to diabetic nephropathy, mainly in type 1 diabetes, to obesity, mainly in type 2 diabetes, but also to increased sympathetic activity. Furthermore, the increased prevalence of hypertension may relate to insulin resistance and its sequelae. Insulin resistance leads to hyperinsulinemia, relates to increased LDL and reduced HDL levels, causes the development of impaired glucose tolerance and type 2 diabetes and might also be causally related to the onset of hypertension. Syndrome X has relevant therapeutic implications in the management of hypertension. Hypertension is a major risk factor for large vessel disease in diabetics and also a risk factor for microangiopathy, particularly nephropathy. The incidence of atherosclerotic disease is dramatically increased in both type 1 and type 2 diabetics and is the major cause of morbidity and premature death mainly in patients with raised urinary albumin excretion. Thus, diabetics show a two-fold increased risk of coronary heart disease, 2-6 fold increased risk of stroke and a several-fold increased risk of peripheral vessel disease. Some evidence suggests that hypertension may be a risk factor for retinopathy, particularly its progression, but surely hypertension is a significant risk factor for nephropathy, accelerating its progression and perhaps even causing the onset of the glomerulopathy. The mechanisms by which hypertension might contribute to the evolution of both large vessel as well as small vessel disease is still unknown, although increased capillary leakage and vascular endothelium alterations might be important factors.(ABSTRACT TRUNCATED AT 250 WORDS)
BACKGROUND: Succinylcholine is contraindicated in "open eye" surgery because it raises intraocular pressure. High dose vecuronium reduces onset time for orothracheal intubation. The objective of the study was to evaluate clinical efficacy of high dose vecuronium (0.2 and 0.3 mg/kg) and its effects on intraocular pressure for its use in "open eye" emergency surgery. DESIGN: Randomized, prospective, clinical trial. SETTING: Eye clinic of University of Florence. PATIENTS: 40 patients scheduled for vitrectomy, excluding any drug action on IOP, subdivided into two groups: the first (20 patients) had 0.2 mg/kg vecuronium at the induction of anaesthesia, the second (20 patients) 0.3 mg/kg. ANAESTHESIA: Premedication: atropine 0.01 mg/kg. Preinduction: fentanyl 3 micrograms/kg. Induction: thiopentone 4 mg/kg+ after 1 minute) vecuronium. Orotracheal intubation after 90". MEASURES: IOP was obtained by applanation tonometry in three time: T0 = preinduction; T1 = 50" after thiopentone; T2 = 50" after vecuronium. Systodiatolic pressure was obtained at the same time. Neuromuscular function was evaluated by vocals cord relaxation and by clinical evaluation of response to ulnar nerve stimulation (by train of four). STATISTIC: "t"-Student. MAIN RESULTS AND CONCLUSIONS: No modification of IOP and systodiastolic pressure was caused by administration of vecuronium; no statistic differences are between T1 and T2 values. All patients were intubated after 90" vecuronium administration; the vocal cord relaxation was maxima in all the patients. High dose vecuronium seems to be useful in "open eye" emergency surgery when succinylcholine is contraindicated.
BACKGROUND: Anaesthesia drugs cause the cutaneous vasodilatation that produces core temperature lowering at the beginning of general anaesthesia; when the thermal threshold for vasoconstriction is reached the cutaneous heat losses are decreased. Furthermore, the soda lime begins to produce water and heat after 40 minutes of closed circuit ventilation. WORK HYPOTHESIS: The technique of inhalatory anaesthesia affects the thermal loss of patients after some hours of ventilation. DESIGN: Prospective randomized clinical trial. SETTING: Surgical Clinical operating theatre of the University of Florence. PATIENTS: 50 patients submited to abdominal non vascular surgery, for longer than 2 hours, with xifo-pubic cut, subdivided into two groups with the same anthropometric characters and age; the first ventilated with open system, the second with low flow circuit (fresh gas flow 700 ml/min). STATISTIC: "t" Student test; MEASURES: Lower one third oesophageal and inspiratory jaw of the circuit temperatures recorded for three hours. MAIN RESULTS: The savings of low flow anaesthesia begin to be significant in the third hour of anaesthesia. CONCLUSIONS: The thermal saving of closed circuit anaesthesia is, very probably, related to the humidifying and the warming of inspired air by soda lime reaction; the effect is more evident if cutaneous losses are reduced.
A 5-year experience of 19 aortic graft infections is reviewed. Of these, 13 (68%) had a late onset (more than 4 months after graft implantation) and usually presented with anastomotic pseudo-aneurysm or thrombosis. The remaining six infections (32%) had an early onset and presented more often with surgical wound infection. Aorto-enteric fistulae and inguinal sinus tracts were observed in both early and late onset infections. Coagulase-negative staphylococci (all slime negative, oxacillin susceptible strains) were the prevalent pathogens in both groups of infections and were isolated in six (32%) patients. Next most commonly seen were Pseudomonas aeruginosa in four (21%) patients, Enterococcus spp. in three (16%) patients, Staphylococcus aureus in three (16%) patients, other bacteria in six (32%) patients. No organisms were isolated in three (16%) patients. Mortality and major amputation rates were 47.3% and 31.6%, respectively. The therapeutic procedures included total graft removal (15 patients), partial graft excision (two patients), partial graft excision followed by total graft removal (one patient) and local treatment without graft removal (one patient). Six patients recovered, including two who underwent total graft removal associated with a non-conventional 'in situ' graft replacement and one patient treated conservatively with local treatment and antibiotics. The three patients undergoing partial graft excision showed signs of active infection of the residual graft.
Patients with severe bilateral carotid lesions (stenosis and contralateral internal carotid occlusion) are at high risk of having a stroke, and carotid endarterectomy has been proposed as the best treatment. In spite of improvements in surgical technique, this operation is still associated with significant perioperative complications (5-13%) which are frequently (up to 40%) correlated with intolerance to internal carotid artery clamping. For this reason, intraoperative cerebral monitoring able to accurately detect ischaemia during surgery would be useful. Reviewing our experience from the last 7 years in 74 patients operated on for stenosis and contralateral occlusion of the internal carotid artery, we found a 1.3% neurological morbidity and 1.3% mortality rate. Presenting symptoms included focal transient ischaemia attacks (TIAs) in 57 patients, stroke in 16 patients and two patients were asymptomatic. Half of these patients (37) were operated on under general anaesthesia with electroencephalogram (EEG) monitoring, stump pressure measurement and selective shunting. In this group, two patients (5.4%) sustained a postoperative stroke, one of which was fatal. The remaining 37 patients were operated on under local-regional anaesthesia with selective shunting on the basis of neurological deficit onset or loss of consciousness during the test clamp. There were no postoperative neurological complications in this group but one patient died of acute myocardial infarction on the 6th postoperative day. This experience suggests that it is possible to perform carotid endarterectomy in patients with severe bilateral lesions with a postoperative complication rate similar to that in patients with less complicated obstructive lesions if accurate intraoperative cerebral monitoring is used.
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PURPOSE: To reduce the rates of morbidity and mortality in aortic graft infection, a new diagnostic approach is needed to help identify low-grade stages, specifically when there are minimal or no clinical signs of overt infection. The aim of this study was to evaluate the role of technetium 99m--hexametazime white blood cell scanning (99mTc scanning) in detecting aortic graft infection, particularly in the low-grade stages. METHODS AND RESULTS: Thirty-seven patients with suspected aortic graft infection were categorized into three groups according to their signs and symptoms on readmission. Ten patients (group A) had advanced graft infections that were correctly diagnosed by use of computed tomography (CT) scanning and 99mTc scanning and confirmed by intraoperative findings and culture results. Eighteen patients (group B) had nonspecific signs and symptoms of graft infection. Patients only underwent CT and 99mTc scanning for graft infection after standard clinical work-ups failed to reveal disease processes that accounted for the clinical symptoms. In this group of patients 99mTc scanning identified four cases of low-grade graft infection, which was confirmed by intraoperative findings and graft cultures. None of these four cases was confirmed by results of CT scanning. On an average 18-month follow-up in patients who did not undergo surgery graft infections developed. Nine patients (group C) had anastomotic aneurysms; CT scanning and 99mTc scanning correctly diagnosed five patients as being infected. The result of 99mTc scanning was false-positive in one patient. CONCLUSIONS: The diagnostic accuracy of 99mTc scanning in patients who did not have specific signs of graft infection (groups B and C) was 100% for sensitivity, 94.4% for specificity, 90% for the positive predictive value, and 100% for the negative predictive value. 99mTc scanning seems to be a useful diagnostic technique for detecting aortic graft infection, particularly in low-grade stages.
We have compared the chemical and clinical characteristics of an immunonephelometric assay (INA), two immunoturbidimetric assays (ITA) and two semi-quantitative methods with those of a solid-phase radioimmunoassay (RIA) for measurement of urinary albumin (UA) concentration in 136 diabetic patients. INA and RIA had similar accuracy, and provided comparable results. However, RIA has slightly greater sensitivity than INA, which is easier and faster. Good agreement was also found between RIA and the two ITA methods, although one of these overestimated RIA values in the low-medium range (5-30 mg/l) of urinary albumin. ITA seems suitable for initial screening of albuminuria in diabetic patients but more sensitive procedures (such as RIA and INA) seem preferable for measurement of UA concentrations in the normal range. The two semi-quantitative methods showed high sensitivity but poor specificity, because of the large number of false positive results. About 50% of diabetic patients "positive" by these methods did not have microalbuminuria. The utility of these methods is questionable, because many samples from diabetic patients need to be reassayed by a more specific and sensitive assay such as the RIA, INA or ITA methods.
Cholinergic neurotransmission exerts a physiological control on GH secretion. Pirenzepine (Pz), an antagonist of muscarinic receptors, by enhancing hypothalamic somatostatin release, inhibits stimulated GH secretion in normal subjects but not in acromegalic patients. To address the hypothesis that a feedback effect of GH hypersecretion can be involved in this condition, GH responses to GHRH 1-29, 1 microgram/kg iv, with and without administration of Pz, 40 mg iv before tests, were investigated in eight acromegalic patients, before and 20-30 days after transsphenoidal adenomectomy. Pz diminished (p < 0.001) the incremental area under the curve (AUC) of GH responses to GHRH in seven normal controls. In contrast, GHRH responsiveness in untreated acromegalic patients was not affected by Pz. Postoperative basal GH levels decreased by 62.4 +/- 14.9% (p < 0.01). Pz inhibited GH responses to GHRH (p < 0.01). Furthermore, a direct relationship (r = 0.73, p < 0.01) between basal concentrations and the AUC of GH responses following Pz plus GHRH-test was found. The finding that muscarinic receptor activity recovered after the reduction of serum GH basal levels by pituitary surgery lends support to the proposed pathophysiological role of GH excess as a possible determinant factor in cholinergic-somatostatinergic dysfunction in acromegaly.
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