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Biomedical subjects

G Lanza

Publications and source records attributed to G Lanza.

At least 19 recordsLinked to original sources
PubMed1992

A Doppler guided retrograde catheterization system.

A Doppler guided retrograde catheterization system was developed to accurately catheterize the aortic root and left ventricular chamber without X-ray. This system consists of a 20 MHz, 0.076 mm thick x 1.016 mm diameter pulsed Doppler crystal integrated into the tip of a 100 cm multipurpose triple lumen catheter. Two lumens (0.61 mm) are used for electrodes; a third lumen (1.245 mm) may be used for guidewire and pressure determination; and the system is attached to a flow velocimeter. In an aortic arch flow model, the principles of Doppler signal guidance were confirmed with flow toward the catheter tip demonstrating positive signals and flow away from the catheter tip demonstrating negative signals. The magnitude and polarity (direction) of the detected phasic and mean velocities were utilized to guide catheterization in six dogs. Using the reversal of Doppler signal polarity to indicate branch entry and manipulating the catheter so as to maintain maximal positive axial velocity, the Doppler catheter was successfully advanced from the femoral artery to the aortic valve. Branches detected by the Doppler system were confirmed by fluoroscopy. The aortic valve was audible when approached and the left ventricular chamber was recognized by its characteristic pressure waveform. The Doppler guided retrograde catheterization system offers new technology to perform left heart catheterization without X-ray and may prove useful in a variety of settings including the development of invasive ultrasonic diagnostic and therapeutic technology.

Animals↗
PubMed1992

[Arterial hypertension and macroangiopathic complications in a group of diabetic out-patients].

We have retrospectively studied 814 diabetic outpatients, 407 hypertensives and 407 normotensives. The aim of the study was to investigate on possible associations between macroangiopathic complications (coronary heart disease, peripheral and cerebral arteriopathy) and well recognized risk factors for atherosclerosis. Macroangiopathy was present in 27% of males and 24% of females (p = NS), and in 32% of hypertensives and 18% of normotensives (p < 0.0001). Macroangiopathy associated, in both sexes, with age and duration of diabetes, but did not correlate, instead, with metabolic control, obesity, serum cholesterol and triglycerides. High triglyceride levels were associated strictly with arterial hypertension, in both sexes, but are more elevated in men. Risk factors for atherosclerosis seem not to be simply considered in the same way in diabetic and non diabetic populations.

Aged↗
PubMed1991

Reliability of 3H-thymidine labeling index: cell proliferation of colorectal carcinoma in three different centers.

Although the 3H-thymidine labeling index (TLI) has been used extensively as a biologic marker of increased susceptibility to neoplasms or as a prognostic indicator of the clinical outcome in cancer patients, there is still some concern regarding its accuracy and reliability as a marker of cell replication. A study on the prognostic value of TLI in colorectal cancer gave us the ability to evaluate how such a measurement may vary in different laboratories. A total of 150 malignant tumors of the large bowel were studied in the period from 1988 to 1989. Microautoradiography was carried out in tumor fragments taken at surgery. There were only slight differences among the three centers involved in the investigation, mainly as regards the culture medium, exposure time, and the addition of O2 + CO2 during the incubation. No significant difference was observed among TLI values recorded in the three centers (18.3 +/- 0.9; 17.4 +/- 0.9; 15.7 +/- 1.0 mean +/- SE), and the ranges of values were almost identical. Similarly, the numbers of total and of labeled cells counted for each patient were comparable among the three centers. The frequency distribution of TLI showed a peak value between 10 and 19.9% in all three centers. Moreover, more than 80% of the observed values were within the range of 10 to 29.9%. In addition, the neoplastic areas with the highest proliferative activity ("high" TLI) showed a frequency distribution once again rather similar among the three centers.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Immunohistochemical assessment of growth fractions in colorectal adenocarcinomas with monoclonal antibody Ki-67. Relation to clinical and pathological variables.

Immunostaining with monoclonal antibody Ki-67 (MAb Ki-67) has been employed to determine the growth fractions in a series of 139 primary adenocarcinomas of the large bowel. A wide range (18.9-71.4%; mean 39.4%; median 37.2%) in the percentage of Ki-67 reacting cells (Ki-67 index) was observed. The Ki-67 index was found to be unrelated to tumour stage, lymph node involvement, and presence of synchronous distant metastases. Mucinous carcinomas showed higher levels of Ki-67 reactivity than non-mucinous adenocarcinomas (P = 0.0003). Among non-mucinous adenocarcinomas a significant inverse correlation was demonstrated between the percentage of Ki-67 stained cells and the degree of differentiation (P = 0.002), and preservation of nuclear polarity (P less than 0.001). Moreover, tumours of patients younger than 45 years were generally characterized by high numbers of proliferating cells. There was no correlation between Ki-67 index and the other clinical and pathological variables examined. In most cases small differences in Ki-67 reactivity were observed in different samples from the same tumour. These results demonstrate that immunohistochemical assay with MAb Ki-67 represents a simple and reliable method for the assessment of proliferative activity in colorectal adenocarcinomas and suggest that Ki-67 labeling may provide information of clinical relevance in the management of patients with large bowel cancer.

Adenocarcinoma↗
PubMed1990

Functional chiral asymmetry in descending thoracic aorta.

To determine whether rotational blood flow or chiral asymmetry exists in the human descending thoracic aorta, we established the ability of color Doppler ultrasound to detect rotational flow in a tornado tube model of a vortex descending fluid column. In a model of the human aortic arch with a pulse duplicator, color Doppler was then used to demonstrate that rotational flow occurs first in the transverse arch and then in the proximal descending thoracic aorta. With the use of color Doppler esophageal echocardiography, 53 patients (age range, 25-78 years; mean age, 56.4 years) were prospectively examined for rotational flow in the descending thoracic aorta. At 10 cm superior to retro-left ventricular position, 22 of 38 patients (58%) revealed rotational flow with obvious diastolic counterclockwise rotation but less obvious systolic clockwise rotation. At 5 cm superior to retro-left ventricular position, 29 of 46 patients (63%) revealed rotational flow with a tendency toward systolic clockwise and diastolic counterclockwise rotation. At the retro-left ventricular position, 47 of 53 patients (89%) revealed rotational flow, usually of a clockwise direction, occurring in systole. Our data suggest that aortic flow is not purely pulsatile and axial but has a rotational component. Rotational flow begins in the aortic arch and is carried through to the descending thoracic aorta, where flow is chirally asymmetric with systolic clockwise and diastolic counterclockwise components. These data demonstrate an aortic rotational flow component that may have physiological implications for organ perfusion.

Adult↗
PubMed1990

[The rhabdomyolytic syndrome: a not uncommon occurrence].

The paper examines one aspect of a medical pathology that is rather unusual and often wrongly diagnosed: rhabdomyolysis (RMC). The series examined suggests that the pathology is relatively common and arises in a wide variety of clinical conditions. In view of the fact that the consequences of rhabdomyolysis may be serious, emphasis is placed on the fact that correct diagnosis may be obtained by the careful consideration of simple clinical parameters such as subjective symptoms, urine colour, urine strip test and serum CPK assays.

Adult↗
PubMed1989

Monoclonal antibodies for specific immunoperoxidase detection of Campylobacter pylori.

Monoclonal antibodies were raised against Campylobacter pylori to detect the organism in clinical specimens by the immunoperoxidase technique. Twenty-one hybridoma cultures obtained were screened on tissue sections of gastric mucosa to identify antibodies that did not cross-react with host cells. To select antibodies with high grade of specificity to C. pylori, hybridomas were also screened by an enzyme-linked immunosorbent assay against a wide panel of gram-negative bacteria. Fifteen antibodies showed a variable grade of cross-reactivity with gastric mucosa, indicating the presence of at least three epitopes shared by C. pylori and epithelial cells. Three of the six antibodies non-reacting with gastric mucosa (CB-1, CB-26, and CB-31) also were found to be specific for C. pylori. Using CB-26 in an indirect immunoperoxidase test, gastric brushings from 60 patients consecutively undergoing endoscopic examination were examined. By light microscopy, we observed the presence of large amounts of C. pylori in smears from all the 32 patients with positive culture. A small number of bacterial cells were also seen in 8 of 28 patients whose cultures were negative. These findings suggest that the monoclonal antibody CB-26 might be of value for rapid and specific detection of C. pylori.

Animals↗
PubMed1988

ras p21 oncoprotein expression in human colonic neoplasia--an immunohistochemical study with monoclonal antibody RAP-5.

Expression of the ras oncogene product p21 (ras p21) in benign and malignant human colonic tissues was studied using the monoclonal antibody RAP-5 and the avidin-biotin-peroxidase technique. Histologically normal colonic mucosa and hyperplastic mucosa adjacent to carcinomas (transitional mucosa) were found, in most cases, to be negative for reactivity with the antibody or showed weak staining of a few epithelial cells. Similar findings were observed in hyperplastic and juvenile polyps. Of the 145 adenomas studied, 47 (32.4%) showed detectable levels of ras p21 expression. RAP-5 immunohistochemical staining was significantly associated with the degree of epithelial dysplasia (P less than 0.01) and the size of adenoma (P less than 0.05), but not with the histological type. Fifty-four of 70 primary adenocarcinomas (77.1%) were reactive with RAP-5 and usually demonstrated a higher percentage of stained cells and more intense cytoplasmic staining than that observed in adenomas. Although metastases often displayed a similar or even higher levels of ras p21 expression compared with the primary carcinomas, in 10 cases one or more metastatic lesions showed lower levels of ras p21. These results suggest that enhanced ras p21 expression may, at times, occur in the early stages of human colon carcinogenesis but are probably not associated with metastatic tumour progression.

Adenocarcinoma↗
PubMed1987

[Prolonged treatment of hypertension in diabetic patients with enalapril. 1-year follow-up].

In view of the pharmacological and chemical reasons for using ACE-inhibitors to treat diabetic hypertension, a group of 40 outpatients were treated with Enalapril. The sample consisted of 20 outpatients, 6 males, 14 females aged 48-76 (mean age 63.75), 18 of whom had type II and 2 type I diabetes and 11 under treatment by diet and hypoglycaemic drugs or insulin. All these patients presented slight or moderate essential arterial hypertension (diastolic pressure less than 115 mmHg). For about one year 17 of the patients were given 20 mg/die Enalapril and the remaining three 10 mg/die in a single morning dose. In 16 cases no other treatment was given. In 4 a non-potassium conserving diuretic was also given. Check-ups before six months into and at the end of treatment showed: a statistically significant reduction in systolic (p less than 0.05) and diastolic (p less than 0.01) pressure. In contrast no significant change was noted in heart beat, glycaemia before or after meals, body weight, glycosylated haemoglobin or any other blood chemical parameter considered. In one case only there was a slight increase in proteinuria that was however present at the start of treatment. As far as side effects are concerned there was one case of cardiac palmus during treatment and one case of coughing that regressed totally when treatment was suspended but nothing else of significance. It should be noted that the antidiabetic treatment remained unchanged throughout the period considered in most cases and at most was subjected to minimal qualitative and quantitative adjustments.

Aged↗
PubMed1986

[Comparison of 12-month treatment with porcine and human insulin (semisynthetic and biosynthetic)].

In recent years two forms of human insulin--semisynthetic and biosynthetic--have been perfected and several experiments have been conducted to assess their effective therapeutic advantages. The present study compares the activity of porcine and human insulin. On the basis of the parameters considered--fasting and post-prandial glycaemia, body weight, glycosilated Hb--it is concluded that are no substantial therapeutic advantages in either porcine or human insulin. For this reason the latter should be reserved for special cases like initial juvenile etc., but offers no advantage in patients already responding adequately to the old insulin preparations.

Adolescent↗
PubMed1985

[Treatment of hypertension in the diabetic with captopril].

The apparently excellent pharmacological properties of Captopril as treatment for insulin-dependent and other hypertensive diabetics of all ages were investigated at a Diabetes Centre. Fifteen out-patients receiving oral hypoglycaemic drugs or insulin and suffering from slight or moderate hypertension (diastolic AP: 95-115 mmHg) were selected for treatment. The Captopril was administered in daily doses of 50 or 100 mg for 60 days. Tests on the 30th and 60th days revealed a statistically significant reduction in max/min OAP values, but no statistically significant variations in either cardiac frequency or glycaemia before and after meals. Nor did the main haematochemical parameters show any significant alteration.

Aged↗
PubMed1985

Colonic mucosa adjacent to adenomas and hyperplastic polyps--a morphological and histochemical study.

The morphological and histochemical features of colonic mucosa adjacent to 142 adenomas and 31 hyperplastic polyps were studied. Three predominant patterns were identified: (1) normal mucosa, showing normal histological architecture and secretion of sulphomucins; (2) N+ type, histologically normal mucosa with predominance of sialomucins; (3) transitional mucosa; hyperplastic mucosa secreting sialomucins. Hyperplastic changes were observed in the immediate neighbourhood or at the base of adenomas and were more frequent and extensive near large adenomas than around smaller lesions. Sialomucins were often predominant in the mucosa adjacent to large adenomas, but N+ type mucosa was also seen near minute adenomas and hyperplastic polyps and remote from polypoid lesions. Moreover, both hyperplastic and secretory changes were more frequent in the left colon than in the right. These findings seem to suggest that mucosal hyperplasia more likely represents a local change, parallel with or secondary to tumour development rather than a pre-adenomatous lesion. Secretory modifications are widespread and may result from the action of various factors among which carcinogens cannot be excluded.

Adenoma↗
PubMed1978

Ependymomas, malignant tumors of pancreatic islets, and osteosarcomas induced in hamsters by BK virus, a human papovavirus.

BK virus (BKV), a human papovavirus, was inoculated iv into 3-week-old Syrian golden hamsters. Between 2 1/2 and 9 months after inoculation, 82% of the animals developed tumors. The induced neoplasms were ependymoma, carcinoma of the pancreatic islets, osteosarcoma, adenocarcinoma, angiosarcoma, angioma, lymphoma, and seminoma. Hypersecretion of insulin, glucagon, C-peptide, and calcitonin was detected in tumors of pancreatic islets. BKV etiology of tumors was supported by the following evidence: 1) No tumors with BKV-specific markers appeared in animals given injections of buffer, animals inoculated with BKV neutralized by anti-BKV-specific serum, or uninoculated controls; 2) BKV tumor (T) antigen was detected by immunofluorescence and complement fixation tests in tumors of animals inoculated with infectious BKV and in transplanted tumors; 3) antibodies to BKV T-antigen were detected in sera of animals bearing primary or transplanted tumors; 4) BKV could be activated by Sendai virus-mediated fusion of neoplastic cells with susceptible Vero cells; and 5) no endogenous hamster oncornaviruses were found in tumors.

Animals↗