Clinic blood pressure, ambulatory blood pressure and cardiac structural alterations in nonagenarians and in centenarians.

scant information is available on the alterations in cardiac structure and function characterizing very elderly people as well as on their relationships to clinic and ambulatory blood pressure (BP) values. In 106 subjects aged 95.3 ± 3.7 years (mean ± standard deviation, 89 nonagenarians and 17 centenarians) in good clinical conditions and living in the municipal house in Milan, we measured, along with standard clinical and laboratory variables, clinic BP, 24-h ambulatory BP and echocardiographic parameters. Forty-five of the recruited subjects were normotensive individuals, whereas 61 were treated hypertensive patients. Subjects with an age greater than 90 years showed clinic systolic (SBP) and diastolic BP (DBP) both within the normal range, with values that for clinic SBP were slightly lower than the corresponding 24-h SBP (120.8 ± 15.9 vs 128.0 ± 16.3 mmHg) and for DBP slightly higher (69.7 ± 8.8 vs 64.9 ± 8.0 mmHg). Daytime average mean BP was slightly lower than night-time average mean BP, indicating the attenuation of the BP reduction during night-time. Left ventricular mass index (LVMI) was increased and significantly related to both 24-h and clinic BP values (r = 0.24, p < 0.04 and r = 0.20, p < 0.05). Thus in nonagenarians and centenarians, abnormalities in left ventricular pattern are of frequent detection and may be related both to the ageing process and to BP load.

The Adipose Organ Is a Unitary Structure in Mice and Humans.

Obesity is the fifth leading cause of death worldwide. In mice and humans with obesity, the adipose organ undergoes remarkable morpho-functional alterations. The comprehension of the adipose organ function and organization is of paramount importance to understand its pathology and formulate future therapeutic strategies. In the present study, we performed anatomical dissections, magnetic resonance imaging, computed axial tomography and histological and immunohistochemical assessments of humans and mouse adipose tissues. We demonstrate that most of the two types of adipose tissues (white, WAT and brown, BAT) form a large unitary structure fulfilling all the requirements necessary to be considered as a true organ in both species. A detailed analysis of the gross anatomy of mouse adipose organs in different pathophysiological conditions (normal, cold, pregnancy, obesity) shows that the organ consists of a unitary structure composed of different tissues: WAT, BAT, and glands (pregnancy). Data from autoptic dissection of 8 cadavers, 2 females and 6 males (Age: 37.5 ± 9.7, BMI: 23 ± 2.7 kg/m2) and from detailed digital dissection of 4 digitalized cadavers, 2 females and 2 males (Age: 39 ± 14.2 years, BMI: 22.8 ± 4.3 kg/m2) confirmed the mixed (WAT and BAT) composition and the unitary structure of the adipose organ also in humans. Considering the remarkable endocrine roles of WAT and BAT, the definition of the endocrine adipose organ would be even more appropriate in mice and humans.

Synthesis and biological activity of Akt/PI3K inhibitors.

Phosphatidylinositol 3-kinase (PI3K) and serine/threonine protein kinase B (PKB or Akt) pathways regulate important cellular processes and are related to a number of human pathologies, such as cancer. The development of kinase inhibitors, with particular attention to small molecule analogues of natural phosphoinositides for pathway interruption and therapeutic applications will be reviewed.

Enzymatic properties of human hemalbumin.

The binding of hemin to the primary site of human serum albumin (HSA) has been reinvestigated using UV-Vis, CD and NMR techniques. The major fraction of bound hemin contains a five-coordinated high-spin iron(III) center, but a minor fraction of the metal appears to be in a six-coordinated, low-spin state, where a 'distal' residue, possibly a second histidine residue, completes the coordination sphere. The reduced, iron(II) form of the adduct contains six-coordinated low-spin heme. The distal residue hinders the access to the iron(III) center of hemin-HSA to small anionic ligands like azide and cyanide and destabilizes the binding of neutral diatomics like dioxygen and carbon monoxide to the iron(II) form. In spite of these limitations, the hemin-HSA complex promotes hydrogen peroxide activation processes that bear the characteristics of enzymatic reactions and may have biological relevance. The complex is in fact capable of catalyzing peroxidative reactions on phenolic compounds related to tyrosine and hydrogen peroxide dismutation. Kinetic and mechanistic studies confirm that the low efficiency with which peroxidative processes occur depends on the limited rate of the reaction between hydrogen peroxide and the iron(III) center, to form the active species, and by the competitive peroxide degradation reaction.

Prolongation of allograft survival by 1,25-dihydroxyvitamin D3.

BACKGROUND: 1,25-Dihydroxyvitamin D3, the hormonal form of vitamin D, is now believed to play a significant role in the immune responses, both in vitro and in vivo, preventing the development of several autoimmune diseases. These studies suggest that 1,25-dihydroxyvitamin D3 may be effective in prolonging allograph survival. METHODS: To test the hypothesis that 1,25-dihydroxyvitamin D3 would prolong allograft survival, neonatal heart grafts were transplanted to allogeneic recipients receiving either 19-nor-1,25-dihydroxyvitamin D2 (200 ng/day) or 1,25-dihydroxyvitamin D3 (50 ng/mouse/day) orally through the diet. The efficacy of 1,25-dihydroxyvitamin D3 in prolonging graft survival in a vascularized model was determined by heterotopic ACI to Lewis heart transplants. RESULTS: The provision of exogenous 1,25-dihydroxyvitamin D3 or an analog, 19-nor-1,25-dihydroxyvitamin D2, to mice markedly prolonged the survival of neonatal mouse heart allografts. Similar results were obtained with a vascularized heterotopic heart transplant model in rats. Cyclosporine at a maximum 25 mg/kg dose for mice proved less effective than 1,25-dihydroxyvitamin D3. Graft survival in mice differing at class I and class II loci (B10.A(4R) --> C57BL/10) increased from 13.0+/-1.1 days to 51.0+/-5.6 days and was significantly better than cyclosporine monotherapy (33.2+/-3.6). Rat heart survival in a high responder strain combination (ACI --> Lewis) increased from 6.2+/-0.3 to 25.2+/-2.8 days. The increased survival of the transplants brought about with 1,25-dihydroxyvitamin D3 was not accompanied by hypercalcemia in rats. CONCLUSION: These results suggest that 1,25-dihydroxyvitamin D3 can be used as an effective agent in preventing graft rejection.

1,25-Dihydroxyvitamin D3 prolongs graft survival without compromising host resistance to infection or bone mineral density.

BACKGROUND: Recently, we have shown that 1,25-dihydroxyvitamin D3 prolongs graft survival in mice and rats when the donor and recipient differ at two or more major histocompatability loci. Among the most serious side effects encountered with the currently available transplantation antirejection drugs are an increased susceptibility to infection and decreased bone mineralization. Our results suggest that 1,25-dihydroxyvitamin D3 prolongs graft survival without these side effects of bone loss and susceptibility to infection. METHODS: We compared the ability of 1,25-dihydroxyvitamin D3-treated, nontreated, or cyclosporine (CsA)-treated mice to resist infection with Candida albicans and herpes simplex virus-1. To determine bone density, femurs were collected from nontreated, 1,25-dihydroxyvitamin D3-treated (50 ng/mouse/day), or CsA-treated (25 mg/kg/day) mice, and bone ash was determined. RESULTS: Here we show that 1,25-dihydroxyvitamin D3 treatment does not increase the susceptibility of the host to fungal or viral infection. Furthermore, CsA causes bone loss, whereas 1,25-dihydroxyvitamin D3 actually increases bone mass. CONCLUSIONS: The use of 1,25-dihydroxyvitamin D3 and its analogs to increase transplant survival will avoid bone loss and opportunistic infection, two important disadvantages of the most widely used transplant antirejection drugs--CsA and the glucocorticoids.

Genetic heterogeneity in uveitis.

Eighty-nine unrelated patients with ocular inflammation (uveitis) were investigated for the HLA class I and class II genetic markers, We subdivided our patients according to: 1. the anatomical location of the lesion; 2. the temporal course of the disease; 3. the aetiology. We eliminated from our sample of patients the individuals with other systemic diseases. We could not find an association with B27, as previously described, but we did note statistically significant differences between the class II antigen distribution in the different anatomical subgroups. HLA-DR3 seems a marker of the intermediate form of uveitis (p, uncorrected 0.03); the absence of DR1 in the patient group with posterior uveitis may be a protecting factor (p. uncorrected less than 0.01); the presence of DR4 in all cases of panuveitis is statistically significant (p, uncorrected = 0.0006).

Intrathecal levels of complement-derived soluble membrane attack complex (sC5b-9) correlate with blood-brain barrier dysfunction in patients with traumatic brain injury.

It has become evident in recent years that intracranial inflammation after traumatic brain injury (TBI) is, at least in part, mediated by activation of the complement system. However, most conclusions have been drawn from experimental studies, and the intrathecal activation of the complement cascade after TBI has not yet been demonstrated in humans. In the present study, we analyzed the levels of the soluble terminal complement complex sC5b-9 by ELISA in ventricular cerebrospinal fluid (CSF) of patients with severe TBI (n = 11) for up to 10 days after trauma. The mean sC5b-9 levels in CSF were significantly elevated in 10 of 11 TBI patients compared to control CSF from subjects without trauma or inflammatory neurological disease (n = 12; p < 0.001). In some patients, the maximal sC5b-9 concentrations were up to 1,800-fold higher than in control CSF. The analysis of the extent of posttraumatic blood-brain barrier (BBB) dysfunction, as determined by CSF/serum albumin quotient (Q(A)), revealed that patients with a moderate to severe BBB impairment (mean Q(A) > 0.01) had significantly higher intrathecal sC5b-9 levels as compared to patients with normal BBB function (mean Q(A) < 0.007; p < 0.0001). In addition, a significant correlation between the individual daily Q(A) values and the corresponding sC5b-9 CSF levels was detected in 8 of 11 patients (r = 0.72-0.998; p < 0.05). These data demonstrate for the first time that terminal pathway complement activation occurs after head injury and suggest a possible pathophysiological role of complement with regard to posttraumatic BBB dysfunction.

Ruptured abdominal aortic aneurysms: predictors for early complications and death.

BACKGROUND: Urgent operation for ruptured aneurysm is still associated with a high operative mortality rate. The purpose of the study was to determine the risk factors that truly influence early complications and death. METHODS: Between 1979 and 1991, 314 consecutive patients with a mean age of 69 years were treated surgically for a ruptured infrarenal abdominal aortic aneurysm. Twenty-two preoperative, perioperative, and intraoperative variables were subjected to a multivariate analysis to identify the independent predictors. RESULTS: Early death occurred in 92 (29%) of 340 patients. Significant primary predictors for early death were duration of cross-clamp (p < 0.0001), preoperative shock (p = 0.0005), suprarenal cross clamp (p = 0.002), and a history of coronary artery disease (CAD) (p = 0.004). The following postoperative complications were risk factors for death: myocardial failure (p < 0.0001), renal failure (p < 0.0001), sepsis (p = 0.01), and colon ischemia (p = 0.03). Predictors for postoperative myocardial insufficiency were a history of CAD (p < 0.0001), amount of intraoperative volume substitution (p < 0.0001), suprarenal cross clamp (p = 0.0007), and preoperative shock (p = 0.05). CONCLUSIONS: Preoperative and perioperative risk factors that result in fatal postoperative complications can be partially influenced by the surgeon. Short clamping time and infrarenal position of aortic clamp may lower overall early mortality rates. A history of CAD is a highly significant predictor for postoperative complications and early death.

High coincidence of Mirizzi syndrome and gallbladder carcinoma.

BACKGROUND: Mirizzi syndrome is a rare complication of long-standing cholelithiasis. It is defined as obstructive jaundice caused by external compression of the common hepatic duct by an impacted stone in the gallbladder neck. Gallstone disease and cholelithiasis-associated chronic biliary inflammation may play a causative role in the pathogenesis of gallbladder carcinoma. The purpose of this study was to investigate the coincidence of gallbladder carcinoma associated with Mirizzi syndrome. Furthermore, the diagnostic value of elevated CA 19-9 levels as indicator for a coincidental gallbladder carcinoma in this syndrome was studied. METHODS: Patient demographics, clinical findings, laboratory data, results of diagnostic studies, pathologic reports, and intraoperative findings of 1579 patients undergoing cholecystectomy were obtained from patient records and were retrospectively studied. Only patients with proven Mirizzi syndrome (i.e., extrinsic mechanical compression of the common hepatic duct by impacted gallstones, associated chronic cholecystitis, and a history of jaundice) were included in this study. RESULTS: Eighteen cases of Mirizzi syndrome (1.0%) out of 1759 cholecystectomies performed between January 1986 and March 1995 were identified. The seven male patients and 11 female patients had an average age of 74.8 years (range, 32 to 87 years). In five of these patients (27.8%) coincidental cases of gallbladder carcinoma were detected. The incidence of unsuspected malignancies in long-standing gallstone disease was 36 (2%) of 1759 and was statistically significantly different (p < 0.001) from the incidence in patients with Mirizzi syndrome (27.8%, 5 of 18). No significant difference was noted in age, gender, duration of jaundice, and type of lesions between these two groups. Tumor-associated antigen CA 19-9 level was elevated in 12 patients with Mirizzi syndrome, but it was significantly higher (p < 0.0001) in all five patients with coincidental gallbladder neoplasm and peaked at 1000 units/ml. All patients diagnosed with gallbladder carcinoma died within 18 months after operation. CONCLUSIONS: There is high association of gallbladder cancer in Mirizzi syndrome. Elevated CA 19-9 levels in this syndrome are indicative of a coincidental gallbladder malignancy. Because of this high coincidence of Mirizzi syndrome and gallbladder cancer we recommend an intraoperative frozen section of the gallbladder in all patients presenting with Mirizzi syndrome.

Pancreatic infection in severe pancreatitis: the role of fungus and multiresistant organisms.

HYPOTHESIS: Recent controlled clinical studies suggest a positive effect of early antibiotic treatment on late morbidity and mortality in severe acute pancreatitis. However, widespread use of antibiotics may lead to an increased number of fungal infections and multiresistant bacteria, thereby worsening the outcome of the disease. DESIGN: Single-center prospective study. SETTING: University hospital, gastrointestinal surgical service. PATIENTS: One hundred three patients with necrotizing pancreatitis seen consecutively in our service. INTERVENTIONS: In addition to standard treatment, patients with proven necrotizing pancreatitis received a prophylactic intravenous antibiotic treatment. Pancreatic infection was regarded as an indication for surgery. MAIN OUTCOME MEASURES: Pancreatic infection, microbiological findings, drug resistance, fungal infections. RESULTS: Thirty-three patients (32%) had infected necrosis. Gram-negative organisms were isolated from 19 patients (58%), Gram-positive organisms were isolated from 18 patients (55%), fungal organisms were isolated from 8 patients (24%), and multiresistant organisms were isolated from 3 patients (9%). In 7 patients (21%), the organisms cultured from the pancreatic tissue were resistant to the antibiotics given in for prophylaxis. Infection with multiresistant organisms or organisms resistant to the antibiotic used for prophylaxis, but not with fungal infection or Gram-positive or Gram-negative infection, was correlated with a negative outcome. CONCLUSIONS: Fungal infection under adequate treatment is not associated with a negative outcome. The occurrence of multiresistant organisms seems to be a rare finding (3 of 103 patients). Antibiotic prophylaxis is effective in preventing infection in necrotizing pancreatitis, but optimal choice and duration of administration of the antibiotic agent(s) need to be carefully determined to avoid the sequelae of multiresistant organisms.

Microcirculation in chronic alcoholic pancreatitis: a laser Doppler flow study.

Experimental chronic pancreatitis is associated with microcirculatory disturbances but can also be induced or aggravated by perfusion changes. Microcirculatory alterations in human chronic pancreatitis are poorly defined. In this clinical study we investigated pancreatic microcirculation in the normal human pancreas and in chronic pancreatitis by laser Doppler flowmetry. Laparotomy was performed on 13 patients with nonpancreatic disease and on nine patients with chronic alcoholic pancreatitis for pancreatic head resection. Blood flow was measured over the pancreatic head, the uncinate process, over the mesenteric vein, the pancreatic corpus, and over the pancreatic tail by laser Doppler flowmetry. Blood flow was highest in the head of a normal pancreas with a mean of 436 +/- 34 perfusion units (PU), 399 +/- 43 PU in the uncinate process, 286 +/- 30 PU in the pancreatic corpus, and 351 +/- 46 PU in the tail of the pancreas. In the normal pancreas, lowest blood flow was measured over the mesenteric vein (228 +/- 23 PU). In chronic pancreatitis, blood flow in the pancreas was significantly decreased across the whole pancreas (p < 0.01). Furthermore flow-wave pattern was altered in chronic pancreatitis as compared with the normal pancreas. The normal human pancreas has a spatial variation in blood flow, correlating with the pancreatic arterial blood supply. In the chronically inflamed human pancreas, blood flow is significantly diminished, with a lower flow toward the pancreatic head.

Splanchnic microcirculatory changes during CO2 laparoscopy.

BACKGROUND: Splanchnic macrocirculatory changes during high-pressure CO2 pneumoperitoneum include a decrease in mesenteric arterial blood flow, and decreased gastric perfusion with a drop in gastric pH in experimental studies. Microcirculatory changes in abdominal organs under clinical conditions with a low pressure CO2 pneumoperitoneum are unknown. STUDY DESIGN: In 18 patients undergoing routine laparoscopy with a CO2 pneumoperitoneum (7 symptomatic cholecystolithiasis, 3 acute cholecystitis, and 8 acute appendicitis) gastric, duodenal, jejunal, colonic, hepatic, and peritoneal blood flow was measured with a custom-made laser Doppler flow probe at an intra-abdominal pressure of 0, 10, and 15 mm Hg. RESULTS: Intra-abdominal pressure elevation from 10 mm Hg to 15 mm Hg significantly decreased the blood flow in the stomach by 40 percent to 54 percent, the jejunum by 32 percent, the colon by 44 percent, the liver by 39 percent, the parietal peritoneum by 60 percent, and the duodenum by 11 percent. Splanchnic blood flow decreased with operative time at a constant intra-arterial pressure (r = 0.88, p < 0.0001). CONCLUSIONS: From our study, we concluded that laparoscopic procedures with a CO2 pneumoperitoneum should be performed at a pressure of 10 mm Hg or lower to avoid splanchnic microcirculatory disturbances.

Effect of preoperative biliary drainage on surgical outcome after pancreatoduodenectomy.

BACKGROUND: The role of preoperative biliary drainage in patients with biliary obstruction undergoing pancreatoduodenectomy remains controversial. Several authors failed to show any effect of preoperative biliary drainage, whereas others even reported an increased morbidity following pancreatoduodenectomy. METHODS: Retrospective analysis was performed in a consecutive series of 257 patients undergoing pancreatoduodenectomy between November 1993 and November 1999. RESULTS: Ninety-nine patients (38%) underwent preoperative biliary drainage for a median time period of 10 days (range 1 to 41) prior to resection. Cumulative postoperative morbidity was 47% (120 patients), the reoperation rate was 4.3% (11 patients), and mortality was 2.3% (6 patients). There was no difference in total morbidity, infectious complications, reoperation rate, mortality, or long-term survival between patients with or without preoperative biliary drainage. CONCLUSIONS: Preoperative biliary instrumentation and biliary drainage do not affect early or late outcome in patients undergoing pancreatoduodenectomy.

Covalently modified microperoxidases as heme-peptide models for peroxidases.

Microperoxidase-8 (MP8) and microperoxidase-9 (MP9) have been covalently modified by attachment of proline-containing residues to the amino terminal peptide chain in order to obtain new peroxidase model systems. The catalytic activities of these derivatives in the oxidation of p-cresol by hydrogen peroxide have been compared to that of MP8. The presence of steric hindrance above the heme reduces the formation rate of the catalytically active species, while the reactivity is increased when the amino group of a proline residue is close to the iron. The modification of the catalyst affects the rate of degradation processes undergone by the heme group during catalysis. A bulky aromatic group on the distal side decreases the stability of the complex because it reduces the mobility of a phenoxy radical species formed during catalysis, while the presence of proline residues increases the number of turnovers of the heme catalysts before degradation. The complex Pro2-MP8 obtained by addition of two proline residues to MP8 exhibits the best catalytic performance in terms of activity and chemical stability.

A novel class of cholinergic agents structurally related to 2-morpholinol.

A series of esters and ethers of N-alkylmorpholin-2-ols, and their methiodides, which can be considered cyclic analogues of acetylcholine, were synthesized. The amines were obtained by acylation or etherification of morpholinols with the appropriate acyl chlorides and alcohols. All compounds were tested for their ability to interact with the muscarinic receptor M2 (guinea-pig atria) or M3 (rat ileum and urinary bladder) subtype. Some compounds, although endowed with relatively low potency, proved interesting for their organ selectivity. Some considerations on the structure-activity relationship are made and the results obtained with reference agonists and antagonists are also shown.

[Surgery of extracranial aneurysms of the carotid artery. Analysis of 8 cases]. / Die Chirurgie der extrakraniellen Aneurysmen der Arteria carotis. Analyse von 8 Fällen.

This article reviews the clinical manifestations, operative techniques, results and complications associated with the treatment of 8 aneurysms of the extracranial carotid artery encountered over a 13-year period. The etiology was atherosclerosis in 4 cases, congenital in two, posttraumatic in one and mycotic in another case. All patients were operated on because of symptomatic disease. Six patients had resection and reconstruction with end-to-end anastomosis, one with a patch of the saphenous vein. One patient had aneurysmorrhaphy and the last one had reconstruction with Gore Tex graft interposition. Two patients had a hemiparesis prior to the operation; this manifestation disappeared slowly in both patients but residual neurological deficit is still present in one of them 9 months postoperatively. One patient developed transient neurological symptomatology after the operation. We conclude that accessible aneurysms of the extracranial carotid artery can be operated with acceptable morbidity and mortality. Operative management is the treatment of choice because these lesions are attended by a high incidence of neurological complications if left untreated.

[Rupture of the Achilles tendon--fibrin gluing or suture?]. / Achillessehnenruptur--Fibrinklebung oder Naht?

The rise of recreational sports activities and the incidence of ruptures of the Achilles tendons has increased simultaneously. Recently the use of fibrin sealing for surgical therapy of ruptured Achilles tendons has emerged as an alternative technique. Between 1982 and 1989 62 consecutive patients were operated for unilateral Achilles tendon rupture. Following causes for ruptures are known: 36 indirect traumas in sport (74%), 9 direct blunt injuries at occupational work (18%), 3 traffic-accidents (11%) and 1 rupture after operation of a Haglund exostosis. 25 patients (56%) were treated by suture technique and 20 patients (44%) with fibrin sealant. The mean long term follow-up of 49 months is known of 49 patients. There were 3 (12%) postoperative infections in the suture group and none in the fibrin group. After suturing the Achilles tendon 3 (12%) reruptures occurred 8-10 weeks after tendon repair and 1 (5%) rerupture after fibrin sealing. All reruptures are caused by a new adequate trauma. The time of return to social and recreational activities was 9 months in the suture group and 7 months in the fibrin group. The functional and cosmetic results after use of fibrin was significant better, and the long-term results were very satisfactory. We prefer fibrin sealing for the treatment of acute ruptures of Achilles tendons.

[Compared progression of visual-evoked potentials in preterm and term newborns]. / Evolution comparée des potentiels évoqués visuels chez des enfants nés à terme et prématurément.

PURPOSE: To compare the development of the visual pathway in healthy preterm and full-term newborns using flash and patterned (both transient and steady-state) visual-evoked potentials (fVEP, pVEP-t, pVEP-ss). PATIENTS AND METHODS: Twenty-nine preterm newborns (28-35 weeks gestational age) were evaluated at four different times: at 3 months postnatal and corrected age, at 8 months postnatal and corrected age. They were matched with 92 term newborns tested at 3 and 8 months of life. RESULTS: The maximal perceived spatial frequencies in the groups were: 2 C/d at 3 months postnatal age, >2 C/d at 3 months corrected age and at 3 months at term, between 3 and 5C/d, >=5C/d at 8 months corrected age and at 8 months of life, respectively. The latencies of the P1 and P100 waves for the flash and the transient stimulation were, respectively, 192 ms and 207.9 ms at 3 months postnatal age, 144 ms and 137.7 ms at 3 months corrected age, 126.3 ms and 124.1 ms at 8 months postnatal age, 112.7 ms and 112.5 ms at 8 months corrected age, 137.3 and 110.1 ms at 3 months of life; and 122.3 and 100.5 ms at 8 months of life. DISCUSSION: In the preterm infants of 3 gestational months, the latencies of the fVEP are comparable to those of the 3-month-old full-term infants, although the pVEP-t latencies are still delayed at 8 months. In the fVEP; however, we noted a shorter latency in the preterm infants at 8 months corrected age compared to those of the full-term infants. This tendency inversion was also evidenced at the steady-state stimulation. CONCLUSIONS: As evidenced by our results, at 8 months of corrected age the preterm infants recovered the fVEP and pVEP-ss, but not the pVEP-t. Different results obtained with different visual-evoked stimulations suggest that similar neural pools are developed in not completely equal amounts of time.