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Biomedical subjects

M Franchini

Publications and source records attributed to M Franchini.

At least 19 recordsLinked to original sources

Statistical approaches to stability protocol design.

In stability protocols, data are usually visualized as being generated, and stability evaluation is accomplished at a point in time when sufficient data have been accumulated. Often, data are simply treated by the "statistically best fit" and, as a consequence, statements describing some batches as being first order and some being zero order are frequently used. From a scientific point of view, it is more advantageous at the preformulation stage to ascertain what the stability profile should be (i.e., what the mechanism is) and then apply the statistics to this format. Examples are given of pH profiles, Arrhenius plotting, and dissolution data. In the first case, the use of fractional factorials (a matrix approach) is suggested.

Chemical Phenomena

Vaccination of cats experimentally infected with feline immunodeficiency virus, using a recombinant feline leukemia virus vaccine.

A group of 15 cats experimentally infected with a Swiss isolate of feline immunodeficiency virus (FIV) and a group of 15 FIV-negative control cats were inoculated with an FeLV vaccine containing recombinant FeLV-envelope. High ELISA antibody titer developed after vaccination in FIV-positive and FIV-negative cats. Vaccinated and nonvaccinated controls were later challenge exposed by intraperitoneal administration of virulent FeLV subtype A (Glasgow). Although 12 of 12 nonvaccinated controls became infected with FeLV (10 persistently, 2 transiently), only 1 of 18 vaccinated (9 FIV positive, 9 FIV negative) cats had persistent and 2 of 18 had transient viremia. From these data and other observations, 2 conclusions were drawn: In the early phase of FIV infection, the immune system is not depressed appreciably, and therefore, cats may be successfully immunized; a recombinant FeLV vaccine was efficacious in protecting cats against intraperitoneal challenge exposure with FeLV.

Animals

Progressive immune dysfunction in cats experimentally infected with feline immunodeficiency virus.

Within 6 months of infection with the Petaluma isolate of feline immunodeficiency virus, specific-pathogen-free domestic cats exhibited a decrease in the percentage and number of circulating CD4+ lymphocytes and in the CD4+/CD8+ T-cell ratio, along with a marginally significant depression of pokeweed mitogen-induced lymphocyte proliferation in vitro. There was no loss of responsiveness to concanavalin A during this stage, and the cats were capable of mounting a satisfactory antibody response to a T-dependent, synthetic polypeptide immunogen. The pokeweed mitogen response deficit became clearly demonstrable by 11 to 12 months postinfection. A decline in the lymphocyte proliferative response to concanavalin A and a diminished ability to mount an in vivo antibody response to the T-dependent immunogen evolved by 25 to 44 months postinfection. Virus infection did not affect the ability of cats to mount an antibody response to a T-independent synthetic polypeptide immunogen. These data indicate that feline immunodeficiency virus produces a slowly progressive deterioration of T-cell function but does not affect the ability of B cells to recognize and respond to a T-independent antigenic stimulus.

Amino Acid Sequence

Transesophageal echocardiography in the definition of intracardiac sources of emboli in patients with recent ischemic stroke.

Using both transthoracic and transesophageal echocardiography we studied 13 consecutive patients with recent CT-proven ischemic stroke in which a carotid arteries high-resolution ultrasound study failed to detect thrombosis or other relevant atherosclerotic lesions in the pertinent arteries. The mean age was 53 years (range: 36-65). Two patients exhibited clinical signs of cardiac disease at physical examination i.e. absolute arrhythmia, mitral stenosis. Conventional transthoracic echocardiography allowed the detection of potential cardiac sources of emboli in 2/13 patients (15.4%): mitral stenosis in one patient and dilated cardiomyopathy in another. Transesophageal echocardiography was successfully performed without general sedation in all patients. Potential cardiac sources of emboli could be identified in 12/13 patients (92%). Left atrial thrombi were found in 3 patients: in two of them they were associated with rheumatic alterations of mitral valve leaflets; in the third patient a small thrombus was located inside a normal-sized, poorly contracting left atrial appendage. Left atrial appendage could be clearly visualized in all patients. A myxoid degeneration of a prolapsing mitral leaflet was found in 3 patients and an interatrial septum aneurysm in 2. Furthermore, at color-flow Doppler and contrast transesophageal echocardiography, 7 patients (54%) showed patency of the foramen ovale. In 5 of these patients paradoxical right to left shunting after cough or Valsalva manoeuvre could be evidenced. With reference to 11/13 patients with no clinical signs of cardiac disease at physical examination, subclinical potential cardiac sources of emboli could be detected at conventional transthoracic echocardiography in 1 and at transesophageal echocardiography in 10 patients (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

[Functional anatomy of the left ventricle in hypertensive subjects. Correlations with the clinical severity of hypertension].

Using computerized M-mode echocardiography we have investigated 58 hypertensive subjects in order to assess whether a correlation could be demonstrated between left ventricular changes induced by hypertension and age of the patients, the duration and severity of hypertension, and damage to other target organs. Various morphological changes of the left ventricle were detected: 14 patients (24%) had concentric hypertrophy of the left ventricle, 12 (20%) had asymmetric septal hypertrophy, 5 (8%) had dilated left ventricle without hypertrophy. Left ventricular mass was increased, when compared to normal controls in 24 patients (41%). With respect to functional abnormalities, the peak lengthening rate of left ventricular dimension in diastole was decreased (+dD/dt less than s-1) in 25 patients (43%). Eight of these patients (14%) also had depressed peak shortening rate of left ventricular diameter in systole (-dD/dt less than 1.9 s-1). Hypertensive retinopathy was present in 23 patients (39%) and impairment of renal function in 8 (14%). Left ventricular mass and systolic and diastolic parameters of left ventricular function did not correlate significantly either with the age of the patients, or with the duration and severity of hypertension, or with the damage present in target organs other than the heart. Left ventricular mass was inversely correlated with the index of left ventricular relaxation (r = -0.53; P less than 0.001), whereas neither the latter nor left ventricular mass were correlated with peak systolic stress. Instead, peak systolic stress was inversely correlated with peak shortening rate of left ventricular diameter, an index of systolic function (r = -0.50; P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Fibronectin distribution during lymph node development in guinea pig: an immunohistochemical study.

We carried out an immunohistochemical study on mesenteric guinea pig lymph nodes, from the 10th day prepartum till the 26th day postpartum, to assess the role of fibronectin in their organization during development. This glycoprotein is diffusely distributed in embryonic lymph nodes, suggesting a primer function during organogenesis. After birth, in fact, it is less widespread and is mainly localized around sinuses and vessels. Our data, supporting the important role of this glycoprotein during lymph node organization, are in agreement with the results obtained in other tissues and organs.

Animals

Urinary hydroxylysine and hydroxylysyl glycosides excretion in patients with Turner's syndrome.

Urinary excretion of 5-hydroxylysine (Hyl) and its two glycosides, a monoglycoside (Gal-Hyl) and a diglycoside (Glc-Gal-Hyl), and the ratio of the diglycoside to monoglycoside have been studied in 30 patients with Turner's syndrome and in 38 healthy controls. In patients, the urinary excretion of Hyl and its diglycoside was similar to that obtained in the controls, while the excretion of the monoglycoside was significantly lower before the age of 17 years. As a consequence, between 6 and 17 years of age the Glc-Gal-Hyl/Gal-Hyl ratio is significantly higher in patients with Turner's syndrome than in normal subjects. The results of our study seem to indicate a disturbance in the turnover of collagen in Turner's syndrome.

Adolescent

Morphological characterization of stationary reticulum cells of the stromal in the mesenteric lymph node of the guinea pig.

The large mesenteric lymph node taken from guinea pigs in a period of time ranging from the 10th day prepartum till the 26th day postpartum has been examined in order to study: the morphological features of the stromal stationary reticulum cells with particular regard to recognize their stages of development; the possible ontogenetic relationship between these cells during the maturation of the lymphoid tissue. Our data support the hypothesis that from local mesenchymal cells originates a pool of poorly differentiated reticulum cells that can give rise to stromal stationary reticulum cells (myofibroblast-like cells, fibroblast-like cells, pericyte-like cells and dendritic cells). These elements have a characteristic distribution pattern likely related to different local functional requirements.

Aging

[Computerized tomography: analysis of the characteristics of various pieces of equipment].

Spatial resolution, statistical noise and patient dose are important parameters for the evaluation of the performances of CT-scanners. These parameters may be combined to develope some "synthetic indices", able to describe intrinsic properties of a CT-scanner (the maximum obtainable spatial resolution and dose efficiency). This type of analysis has been applied to the evaluation of four CT-scanners, three of 3rd and one of 4th generation.

Image Enhancement

Spermatic and peripheral oestradiol levels in patients affected by azoospermia due to seminiferous tubular damage.

Plasma levels of testosterone, androstenedione and oestradiol were determined in the spermatic venous blood of both testes of 17 patient affected by azoospermia due to tubular damage (Group I). The results were compared with those found in 5 patients affected by azoospermia of obstructive origin and 5 patients with an inguinal hernia (Group II). Mean spermatic levels of testosterone and androstenedione were not significantly different in the two groups, while the mean (+/- SE) oestradiol spermatic level was significantly higher in patients of Group I (5.02 +/- 0.75 nM/l vs. 2.20 +/- 0.365 nM/l; P less than 0.05). Moreover, while the testosterone/androstenedione and the androstenedione/oestradiol ratios were not significantly different in the two groups, the mean (+/- SE) testosterone/oestradiol ratio was significantly lower in patients of Group I (552.71 +/- 80.94 vs. 939.86 +/- 129.45; P less than 0.025). Peripheral testosterone and androstenedione mean levels were not significantly different between the two groups while the mean peripheral oestradiol level (+/- SE) was significantly higher in Group I (0.107 +/- 0.021 nM/l vs. 0.038 +/- 0.05 nM/l; P less than 0.025). Peripheral oestradiol was not significantly related to peripheral FSH, nor to spermatic oestradiol in both groups. These results suggest the possibility that oestradiol may be involved in the pathogenesis of some cases of male infertility.

Adult

Chronic prostato-vesiculitis and sperm-cell mobility in male infertility.

The purpose of this research has been to value the importance of chronic inflammation of the prostatovesicular apparatus in sterile patients. The authors wish to underline the high incidence of chronic inflammation if this apparatus in such patients, the low incidence of bacterial forms and the high frequence of association with bradycinesia. The therapy of such forms gives excellent results.

Adult