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Biomedical subjects

M Negri

Publications and source records attributed to M Negri.

At least 19 recordsLinked to original sources
PubMed1999

Diverticulitis: the effect of age and location on the course of disease.

To examine the effect of patient's age and the location of diverticular disease on the course of the acute disease we retrospectively collected demographic data, symptoms, laboratory findings, imaging techniques, type of treatment (conservative vs. surgical), early and late complications, and follow-up data on 119 patients with acute diverticulitis (74 women, 45 men; mean age 64+/-14 years; follow-up 7-102 months, median 40). Patients were divided by their age into two groups (42 aged 60 years or younger, 77 aged over 60) and on the location of their disease (108 to the left of the middle transverse, 11 to the right). Lower abdominal pain, abdominal tenderness, and fever were the most common complaints (70-97%). In the younger patients we found a significantly greater preponderance in the right colon (P = 0.02) than in older patients. Abdominal abscesses and fistulas were more common in right-sided diverticulitis (P = 0.01). Patients with right-sided colon diverticulitis were treated surgically (82%) and on an emergency basis more often than patients with left-side colon diverticulitis (25%; P = 0.001). Older patients treated conservatively suffered more than younger patients (61% and 33% respectively; P = 0.04) from recurrent abdominal pain but not from recurrent, confirmed diverticulitis. Patients with right-sided diverticulitis treated conservatively suffered more from recurrent diverticulitis episodes than patients with left-sided diverticulitis (P = 0.05). Younger patients thus do not have a more aggressive form of diverticulitis than older patients. Patients with acute diverticulitis in the right colon are likely to be operated earlier and for mistaken diagnoses than patients with left-sided diverticulitis.

Adult↗
PubMed1999

Fatal cardiac tamponade as a late complication of central venous catheterization: a case report.

Central venous catheterization is a reliable technique in neonatal surgery. Nevertheless, the rate of mechanical catheter-related complications remains high. We report a neonate with gastroschisis in which the successful placement of a central venous catheter was followed later by a cardiac tamponade with a fatal outcome. This complication occurred without perforation of the cardiac wall. A similar finding has been reported in only one other pediatric patient. Vigilant observation is required in any neonate with a central venous line in place to prevent the occurrence of this life-threatening event.

Cardiac Tamponade↗
PubMed1998

Increased plasma concentration of atrial natriuretic hormone in myotonic dystrophy.

Atrial natriuretic hormone (ANH) concentrations were measured in 16 patients affected with myotonic dystrophy (MyD) undergoing 24-hour Holter ECG and in 15 age-matched normal subjects. Although the MyD patients did not show overt left ventricular function impairment, their plasma ANH levels were found to be higher (183.76 +/- 113.25 pg/ml) compared to those of the control subjects (39.73 +/- 9.95 pg/ml, p < 0.001). Nine patients with arrhythmias and some echocardiographic alterations formed subgroup A. Seven patients without cardiac alterations formed subgroup B. No significant difference in ANH emerged between the two subgroups. This evidence suggests that high plasma ANH levels in MyD cannot always be related to overt or latent heart failure and to arrhythmias.

Adult↗
PubMed1998

External Quality Assessment of stat test intralaboratory turnaround times. Pilot study from the Members of the Working Group for the Standardization and Promotion of Turnaround Time Control under the Auspices of the Comitato Italiano per la Standardizzazione dei Metodi Ematologici e di Laboratorio.

We describe procedures, results and prospects of a pilot program in External Quality Assessment (EQA) of the stat test intralaboratory turnaround times. Our goals are to promote quality by systematic monitoring and comparison of performances by laboratories, continuous investigation into the state of the art of the processes from receipt of sample to transmission of results and creation of a data base for standardization of measures and definition of consensus values for turnaround time. Of 30 laboratories invited to participate, 25 took part, agreeing to record times of arrival and transmission for all determinations of three analytes (blood hemoglobin, serum/plasma potassium and plasma prothrombin time) for seven consecutive days and to continue for one or more further periods of seven days as necessary if there were less than 300 determinations for each analyte. Within a preset time limit, data were sent by e-mail on an Excel file and we sent back two reports per analyte, showing: i) the graph for time vs. percentage of tests completed and several measures of turnaround time; ii) results of all laboratories in graph form, allowing each laboratory to identify only its own data. The high proportion of participating laboratories among those invited (83%) encourages us to implement the EQA program systematically, on a half-yearly basis, extending it to all laboratories wishing to participate in Italy or elsewhere in Europe.

Italy↗
PubMed1998

Plasma atrial natriuretic hormone in hyperthyroidism.

In 22 hyperthyroid patients, atrial natriuretic hormone (ANH) levels (71.91 +/- 21.03 pg/ml), measured during a 3-h-Holter, were found to be significantly higher (p < 0.001) than those in 20 age-matched normal subjects (37.22 +/- 8.73 pg/ml). We have demonstrated that the presence of tachiarrhythmias does not influence ANH release. The positive and significant correlation of FT3 with both ANH and heart rate confirms the hypothesis of a direct action of thyroid hormones on ANH release.

Adult↗
PubMed1998

[Progressive sensorineural hearing loss: neoplastic causes].

Acoustic neuromas represent about 90% of all space-occupying lesions of the cerebellopontine angle and account for approximately 6% of all intracranial tumors. Progressive unilateral sensorineural hearing loss is the most frequent initial symptom occurring in over 90% of patients. A sudden onset of hearing loss occurs in 5%, while 5% of cases present with normal hearing. The incidence of hearing loss does not seem to be related to tumor size. Accuracy of the tumor detection by gadolinium-enhanced magnetic resonance imaging has been reported as 99-100% even for intracanalicular tumors. The ABR false negative rate for intracanalicular tumors has been reported to be as high as 9-11%. Rare lesions of the cerebellopontine angle include: meningiomas, epidermoids, arachnoid cysts, trigeminal nerve neuromas, facial nerve neuromas, neurinomas of lower cranial nerves, glomus tumors and metastases. Therefore, a high suspicion index and awareness of symptoms and an adequate audiologic and neuroradiologic work-up are the clues to early diagnosis and appropriate surgical treatment.

Cerebellar Neoplasms↗
PubMed1998

Coronary sinus plasma beta endorphin levels in cardioischemic patients undergoing PTCA.

Plasma beta-endorphin levels were studied in the coronary sinus of 8 patients undergoing percutaneous transluminal coronary angioplasty (PTCA). All the patients had ECG ischemic signs and pain during the inflation of the balloon. No significant changes in plasma beta-endorphin levels were observed during PTCA-induced ischemia. Baseline coronary sinus plasma beta-endorphin levels were found to be elevated when compared with peripheral ones which would suggest an accumulation of beta-endorphin in the ischemic heart.

Aged↗
PubMed1997

Pulse oxymetry evaluation of oxygen saturation in the upper extremity with an arteriovenous fistula before and during hemodialysis.

We noticed that some patients with arteriovenous (AV) fistula on chronic hemodialysis experience pain in the limb with the fistula a short time after being connected to the dialysis machine. We postulated that the pain is caused by relative ischemia and therefore performed this study to determine whether oxygen saturation (SaO2) of the extremities with AV fistula decreases during hemodialysis. Seventy-two patients with a side-to-side primary AV fistula were evaluated by pulse oxymetry. SaO2 was measured before hemodialysis and 20 minutes after initiation of dialysis. The contralateral arm served as a control. In 48 patients, SaO2 difference between the arms of each patient before hemodialysis was less than 4%. SaO2 values of this group of patients did not change significantly 20 minutes after initiation of dialysis. In 24 patients, SaO2 differences between the hands of each patient before hemodialysis were 4% or more. In this group of patients, SaO2 values of the hands with the AV fistula decreased significantly 20 minutes after hemodialysis from a mean of 90.85 +/- 2.84% to 81.60 +/- 3.94 (P < 0.001). SaO2 remained unchanged in the contralateral arm. Nine patients in this group complained of pain and change in sensation in the arm with the fistula during hemodialysis. One patient complained of severe pain in the arm with the fistula before hemodialysis, and SaO2 was unmeasurable. We conclude that, in some patients, SaO2 of the arm with the AV fistula decreases only during hemodialysis. This phenomenon may be symptomatic. A predialysis SaO2 difference of 4% or more between the arms predicts decreased SaO2 of the arm with the AV fistula during hemodialysis.

Arm↗
PubMed1997

[Intraoperative tonal-threshold audiometry in the surgery of otosclerosis].

At the end of stapedioplasty, performed under local anesthesia, the surgeon usually tests the hearing function making questions to the patient turning his voice from a soft whisper to a loud tone. At the ENT Department, University of Parma Italy, a more precise method is employed in order to measure the air conduction threshold of the patient at the beginning and at the end of surgery. From April 1996 to October 1996, intraoperative pure-tone audiometry was performed in 36 patients who underwent stapedioplasty. A portable audiometer "Amplaid 161/C Amplifon" was used in the operating room. Air conduction thresholds were measured at 125-8000 Hz. Intraoperative pure-tone audiometry allows an instantaneous and a more accurate evaluation of the surgical functional results.

Adult↗
PubMed1996

Retinoic acid-induced growth arrest and differentiation of neuroblastoma cells are counteracted by N-myc and enhanced by max overexpressions.

N-myc expression is negatively regulated by retinoic acid (RA) which induces the growth arrest and differentiation of neuroblastoma (NB) cells. However, it has not been completely defined whether N-Myc promotes growth and/or antagonises neuronal differentiation of NB cells or whether the down regulation of N-myc occurs as a consequence of the onset of differentiation. By transfecting an N-myc gene construct into these cells, we found that the constitutive overexpression of N-myc stimulated proliferation in RA containing medium and, although these cells were still responsive to RA, they were no longer able to differentiate. Since N-Myc functions appear to be mediated by heterodimerization with Max, the ectopic overexpression of max in NB cells was also investigated. In contrast to N-Myc, Max strongly induced the differentiation by enhancing the effects of RA. Max-transfected cells rapidly arrested growth and differentiated fully within a few days of RA treatment. These findings suggest that the relative levels of N-Myc compared to Max appears to be crucial in stimulating neuroblastoma growth or differentiation, and may contribute to explain the remarkable clinical behaviour of neuroblastomas.

Base Sequence↗
PubMed1996

Is male gender a risk factor for conversion of laparoscopic into open cholecystectomy?

BACKGROUND: Based on a clinical observation that the conversion rate of laparoscopic cholecystectomy (LC) to open cholecystectomy (OC) is higher in males, we decided to review our records and to verify whether a significant difference in conversion rates exists between sexes. METHODS: A retrospective study on conversion rates of elective laparoscopic cholecystectomy (LC) into open cholecystectomy (LC) in relation to gender was carried out in 329 patients: 267 females and 62 males. RESULTS: Our data revealed that the probability of conversion is fivefold greater in males than females, 21% vs 4.5%, respectively (p = 0.0001). We attribute this striking difference to significantly more adhesions p = 0.0002) and anatomical difficulties (p = 0.003) in males during LC, leading to conversion. CONCLUSIONS: We conclude that conversion of LC to OC is more prevalent among males and is probably attributable to a greater incidence of anatomical difficulties.

Cholecystectomy↗
PubMed1996

The laparoscopic second look for ischemic bowel disease.

BACKGROUND: Survival after acute vascular ischemia depends on a second look laparotomy to detect extending bowel compromise and to verify the integrity of the anastomosis. In a series of five consecutive patients with acute ischemic bowel disease, we used laparoscopic technique to determine if a formal laparotomy could be avoided. METHODS: following the resection of ischemic bowel in five consecutive patients, two laparoscopic trocars were inserted in the lower abdominal quadrants and covered by sterile gloves. Forty-eight to 72 h following the primary operation, the abdomen was inflated via a trocar and secondary assessment done by laparoscopy. RESULTS: In all patients, the integrity of the anastomosis and viability of the remaining bowel was accurately assessed by laparoscopy. CONCLUSIONS: Using minimally invasive techniques, a second look laparotomy was avoided in 5 patients with ischemic bowel disease.

Aged↗
PubMed1996

The effect of metformin on liver blood flow in vivo in normal subjects and patients with non insulin dependent diabetes.

We previously reported that metformin improves insulin-mediated glucose liver metabolism in patients with non insulin dependent diabetes (NIDDM). It is not clear whether this is a direct effect of metformin on liver metabolism or mediated by other mechanisms such as increased liver blood flow. In this respect it has recently been reported that metformin increases hepatic blood flow (HBF) in diabetic rats. The aim of this study was to evaluate whether the administration of metformin is associated with modifications in HBF in humans. Patients affected by NIDDM (n = 11) and normal subjects (n = 6) were studied. In the first protocol HBF was investigated in six overweight (BMI 27 +/- 2 Kg/m2) NIDDM patients and six normal subjects (age and BMI matched) already on metformin treatment before and 2 h after the administration of 500 mg metformin. In the second protocol HBF was investigated in obese (BMI 32 +/- 1 Kg/m2) NIDDM patients (n = 5) in good metabolic control before and after 15 days of metformin at the dose of 1 g daily. HBF was measured by intravenous injection of 3 mCi 99mTc-phytate. In both protocols no significant changes in HBF were observed following metformin administration either in NIDDM patients or normal subjects. No significant differences were observed in HBF between diabetic patients and normal subjects. These data indicate that metformin has no effect on HBF in man. The previously reported improvement of insulin mediated liver metabolism induced by metformin is likely to be a consequence of the direct effect of the drug at hepatocyte level which is independent of HBF modifications.

Adult↗
PubMed1996

How does infected bile affect the postoperative course of patients undergoing laparoscopic cholecystectomy?

OBJECTIVES: To assess the rate of infected bile in patients undergoing laparoscopic cholecystectomy (LC) and to study the influence on the postoperative infective complications in this group of patients. METHODS: Bile samples of 247 patients undergoing LC were collected and cultured for aerobic and anaerobic bacteria. All patients were given prophylactic antibiotics. RESULTS: The overall rate of infected bile was 12.8% (56 positive cultures); of these, 54 were aerobic and 2 anaerobic bacteria. Only 2 patients developed infection at the umbilical site, and in both, the bile was sterile. None of the patients with positive bile cultures developed any signs of infection during a mean follow-up period of 26 months. CONCLUSION: The overall rate of septic complications following LC is extremely low, and at least in our study no correlation was found between infected bile and septic complications.

Adolescent↗
PubMed1996

Plasma met-enkephalin levels in diabetic patients: influence of autonomic neuropathy.

The presence of opioid peptides within pancreatic islets in several animal species and in humans suggests that these peptides could play a role in pancreatic endocrine secretion, influencing glucose metabolism. We measured plasma met-enkephalin (met-Enk) levels in eight neuropathic (four with insulin-dependent diabetes mellitus [IDDM] and four with non-insulin-dependent diabetes mellitus [NIDDM]) and eight nonneuropathic (four IDDM and four NIDDM) diabetic patients to study met-Enk secretion in diabetic patients with asymptomatic autonomic neuropathy. Plasma met-Enk levels were significantly lower in neuropathic compared with nonneuropathic patients both in the IDDM group (28.7 +/- 4.8 v 61.6 +/- 4.1 pg/mL, P < .0025) and in the NIDDM group (26.5 +/- 3.6 v 44.3 +/- 4.6 pg/mL, P < .0125). This study suggests that the presence of neuropathy in diabetic patients, even if asymptomatic, is associated with a significant decrease of plasma met-Enk levels, thus contributing to a worsening of metabolic control under stress conditions.

Adult↗
PubMed1996

Gastric Emptying Half-time Following Silastic Ring Vertical Gastroplasty: A Scintigraphic Study (Preliminary Results).

BACKGROUND: The mechanism for weight loss following gastroplasty surgery is unknown. A few studies have checked gastric emptying patterns following gastroplasty, but none have analyzed their pattern over time. METHODS: Gastric emptying half-time of Tc-99 phytate-labeled semi-solid meal was studied in 23 obese non-diabetic and one diabetic patient (BMI 34.6-55.7). Gastric emptying was measured by gamma scintigraphy before Silastic Ring Vertical Gastroplasty (SRVG) and 1, 3 and 6 months following surgery. RESULTS: Gastric emptying half-times were maximal in all areas of the stomach 1 month after operation, declined to base-line 3 months following the procedure, and showed statistically significant delay in the upper area of the stomach 6 months after the operation. No correlation was found between the delay in food passage following surgery and loss of weight. CONCLUSIONS: Prolongation of gastric emptying half-time following surgery may be a result of two separate mechanisms: asymptomatic or early inflammatory processes in the ring area and pouch distention as a result of partial denervation.

Journal Article↗