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Biomedical subjects

M Marchini

Publications and source records attributed to M Marchini.

At least 73 records · Page 4Linked to original sources
PubMed1988

Prediction and self-prediction of ovulation in clomiphene citrate-treated patients.

We studied 15 infertile patients for a total of 25 cycles in order to compare the predictive value of the following parameters in timing ovulation: basal body temperature (BBT), cervical mucus, serum E2 and LH, follicular growth as shown by ultrasonography, and urinary LH. The patients themselves tested urinary LH at home using Clearplan kits. BBT had low value as a predictive test for the time of ovulation, whereas ultrasonography had a predictive value of 9%, serum E2 50%, cervical mucus 59%, serum LH 63.6% and Clearplan kits 63.6%. The best predictive reliability in timing ovulation was obtained by considering both serum LH and E2 measurements. The Clearplan kits were as reliable as serum LH measurements and have greater practical advantages.

Adult↗
PubMed1988

Protection by opioids against gastric lesions caused by necrotizing agents.

The synthetic opioid met-enkephalin analog [D-Ala2, MePhe4, Met(0)5ol] enkephalin (DAMME) and the opiate morphine injected intraperitoneally to rats at doses of 0.5-2 and 5-20 mg/kg, respectively, showed a protective effect on gastric damage induced by oral administration of necrotizing agents (0.6 N HCl or 0.2 N NaOH solutions, 1 ml/rat). The protection was prevented by naltrexone (10 mg/kg s.c.), an opioid antagonist with long-lasting activity. Histological sections of mucosal samples from animals pretreated with morphine (10 mg/kg i.p.) and DAMME (1 mg/kg i.p.) showed less alteration of the columnar epithelium, with a normal glandular structure, than untreated rats. A mediation of prostaglandins is suggested, since indomethacin (10 mg/kg s.c.) significantly reduced the protective effects of opioids.

Animals↗
PubMed1988

Structural and ultrastructural patterns of the human preovulatory endometrium following clomiphene citrate treatment.

To investigate ultrastructural modifications in the endometrium of women receiving clomiphene citrate (CC) treatment, we performed endometrial biopsies in the preovulatory phase in 17 patients with anovulatory infertility and 16 normo-ovulating women with tubal or male sterility. Histology, scanning and transmission electron microscopy (SEM and TEM) revealed midproliferative phase aspects in 11.7% of the treated group and 6% of the controls, late proliferative aspects in 76.4% and 82%, and postovulation days 1-3 characteristics in 11.7% and 12% respectively. No significant differences were observed between the patients and controls; our data indicate that CC taken in a dose not exceeding 100 mg/day from day 3 of the cycle can induce endometrial maturation that is almost identical with that of a spontaneous preovulatory phase. This type of endometrium should therefore allow implantation of a fertilized egg and maintain unmodified the complex biohumoral relations with the embryo.

Clomiphene↗
PubMed1988

Localization of different alcian blue-proteoglycan particles in the intervertebral disc.

A histochemical investigation was carried out on proteoglycans of bovine intervertebral disc. Samples obtained from the "annulus fibrosus" (A.F.) and "nucleus pulposus" (N.P.) were treated with Alcian blue (AB) diluted in solutions of MgCl2 at critical electrolyte concentrations (CEC); some samples were incubated in testicular hyaluronidase before AB treatment. At least four types of elongated AB-proteoglycan particles were recognized: a) in A.F. lamellae and N.P., 1 nm rod-like particles were arranged orthogonally to the collagen fibrils and spaced at a distance equivalent to the fibril D-period (Figs. 1-5); b) within the A.F. lamellae, other 16-20 nm particles formed a close network among the collagen fibrils (Figs. 1,2,3,5); c) in the A.F. interlamellar crevices, 30-50 nm leaf-like particles were present (Fig. 6); d) in the N.P.Z., 20-30 nm leaf-like particles formed a wide-mesh (Fig. 4). The alcianophylic particle sizes suggest they may correspond to proteoglycan monomers in the A.F. lamellae and mostly proteoglycan aggregates in A.F. interlamellar crevices and N.P.. Both alcianophylia degrees at MgCl2 CEC solutions and enzymatic susceptibility indicate the presence of chondroitin sulphate and keratan sulphate and that the large particles in the A.F. interlamellar crevices are the keratan sulphate richest proteoglycans. The features of the observed AB-proteoglycan particles are consistent with previous morphological data reported for other tissues as well as some biochemical data for the intervertebral disc and may be correlated to the composite mechanical properties of this tissue.

Alcian Blue↗
PubMed1987

Marked deciliation and insufficient secretory modification of endometrial surface during treatment with a new progestogen-estrogen combination.

Endometrial modifications induced by SHB 209 AE, a new progestogen-estrogen combination, was investigated using scanning and transmission electron microscopy, in order to demonstrate specific variations of the endometrial surface and if these contribute to the contraceptive effects of the preparation. Endometrial biopsies were performed in 27 volunteers who had taken SHB 209 AE during the preceding 3 months. Endometrial biopsies of 15 normomenstruating volunteers were used as controls. Each fragment was subdivided for scanning and transmission electron microscopy examination. The ciliated cells were always significantly fewer in the various phases of the treatment cycle than in the control endometria although, as in the controls, their number and ratio with nonciliated cells was greater mid-way through the cycle. Ciliogenesis was always notably delayed compared to the normal endometria during the different treatment cycle phases. Secretory modifications appeared prematurely but remained incomplete through the treatment cycle. These modifications caused total and characteristic alterations of the mucosal architecture and cellular maturation that comprised the implantation phase.

Adolescent↗
PubMed1987

Cytochemical study on human spermatozoa metabolism during in vitro capacitation.

In eutherian mammalian spermatozoa the capacitation is coupled to a specific type of metabolism, that is glycolysis or oxidative respiration. A cytochemical study was carried out on cytochrome oxidase and lactate dehydrogenase in human spermatozoa collected at different times during in vitro capacitation. Human spermatozoa were incubated in Biggers, Whitten and Wittingham's medium supplemented with 15% heat-inactivated human serum. Both histoenzymological reactions based on oxidative polymerization of diaminobenzidine (cytochrome oxidase) or on tetrazolium salts reduction (lactate dehydrogenase) can be quantitated and have been evaluated by microdensitometric method (Vickers M85). The results suggest that human spermatozoa depend almost quite on the anaerobic glycolysis during in vitro capacitation.

Electron Transport Complex IV↗
PubMed1987

Pirprofen, naproxen and placebo in the treatment of primary dysmenorrhoea.

In a double-blind between-patient clinical trial, 82 patients were admitted to the study and after a preliminary period with placebo administered in single-blindness, they were divided into two groups: "placebo-responders" and "placebo non-responders". Responders were treated with pirprofen capsules (400 mg, b.i.d.) or placebo capsules b.i.d.; non-responders were treated with pirprofen capsules (400 mg, b.i.d.) or naproxen capsules (250 mg, b.i.d.) according to two different randomisation lists, for four menstrual cycles. A complete medical examination, including evaluation of associated symptomatology, menstrual flow entity and global efficacy, was performed after each cycle. In the responders group results were significantly better with pirprofen than with placebo after only the second cycle of treatment (p less than 0.01). In the non-responders group both treatments showed "good" or "excellent" results in more than 80% of patients in all cycles. In all patients there were no significant differences in the evaluation of the menstrual flow entity, of the associated symptomatology and of the number of side-effects.

Adult↗
PubMed1986

Differences in the fibril structure of corneal and tendon collagen. An electron microscopy and X-ray diffraction investigation.

A detailed analysis of the D-period and axial electron density distribution of cornea and tendon collagen was carried out by means of X-ray diffraction and electron microscopy. Ultrastructural observations were made on replicas of freeze fractured and deep-etched specimens. Synchrotron radiation was used to obtain high resolution small angle X-ray diffraction patterns. The data provide evidence that D-period and intraperiod distances in cornea are shorter than in tendon collagen fibrils. The observed different banding observed is interpreted on the basis of the different morphological arrangement of the microfibrils in the two tissues: "helicoidal" in cornea and "straight" in tendon microfibrils.

Animals↗
PubMed1985

Ultrastructural aspects of rat tail tendon sheaths.

An investigation was carried out on the sheaths which envelop rat tail tendons. The samples were processed for observation by light and electron microscopy. In the case of electron microscopy, thin sections of specimens embedded in epoxy resin and replicas of freeze etched samples were used. On the basis of histological and ultrastructural observations, four distinct connective tissue sheaths have been detected. The paratendineum is a thick fibrous sheath that covers externally the four groups of tendons arranged around the vertebrae of the tail; the epitendineum is a distinct fibrous sheath surrounding each tendon group; the peritendineum is composed of concentric cellular laminae enveloping each tendon; lastly, the endotendineum is made up of one cellular lamella which adheres to the fibres of the tendon, projecting trabeculae between the individual tendon fascicles. In the para- and epitendineum, thick bundles of collagen fibrils, running parallel to the fibres of the tendon, were visible. The collagen fibrils had a wide variability of diameters (from 35 to 220 nm) and, when examined in replica, their microfibrillar arrangement appeared to be straight. In the peri- and endotendineum, thin bundles of collagen fibrils were visible between the cellular laminae, parallel to the main axis of the tendon. Among these collagen bundles, elastic fibres and numerous glycoproteins containing microfibril-like filaments were visible. The collagen fibrils were small and of uniform diameter (50 nm) and, when observed on replica, showed a helicoidal microfibrillar arrangement. The cell layers of the peri- and endotendineum were made up of flattened fibroblasts which were connected by specialised junctions and which contained numerous micropinocytotic vesicles. A thin layer of granular electron-dense material, with ultrastructural characteristics similar to those of a basement membrane, was visible on the surface of the most external cellular layer of the peritendineum and on the outer surface of the cellular lamella of the endotendineum. Due to their morphological characteristics it is supposed that the four tendon sheaths are involved in different and special functions. Moreover, collagen Type I and collagen Type III, demonstrated by means of immunofluorescence techniques in previous investigations, show respectively a close similarity in distribution to the thick collagen fibrils, with a straight microfibrillar arrangement, of the two external sheaths, and to the thin collagen fibrils, with a helicoidal microfibrillar arrangement, of the two internal sheaths.

Animals↗
PubMed1984

Heterogeneity of proteoglycan particles in thin sections and replicas of human articular cartilage.

Proteoglycans were studied in articular cartilage of human femoral condyles. On the basis of the histochemical data obtained by means of light microscopy (AB + CEC MgCl2; pre-incubation with hyaluronidase or with chondroitinase ABC), the proteoglycan concentration as well as the keratan sulfate-chondroitin sulfate ratio seemed to increase proportionally to the articular cartilage depth. AB-proteoglycan particles of various shapes (filament-like or leaf-like) and sizes (10 nm or 16-18 nm), depending on the articular cartilage depth and on the histochemical conditions (as above), were visualized in thin sections. Similar heterogeneity of elongated non-collagen particles was shown in replicas of fresh freeze-fractured and deep-etched specimens. An interpretation of the distribution and nature of articular cartilage proteoglycans was made by comparing the obtained morphological findings.

Adolescent↗
PubMed1984

Recent and long-established lesions of the capsular ligaments of the knee.

Twenty-two cases of capsulo-ligamentous lesions of the knee are presented. These cover a period of 2 years. They are subdivided into two groups - recent lesions and late lesions. Emphasis is given to the predominance of the medial compartment in recent lesions and of the posterior cruciate ligament in the late lesions.

Adolescent↗
PubMed1983

The banding pattern of rat tail tendon freeze-etched collagen fibrils.

Banding patterns of freeze-etched and replicated rat tail tendon collagen fibrils were studied. Better banding definition was obtained by freezing the samples without using a cryoprotectant and by prolonging etching. Under these conditions, the banding pattern was characterized by a sequence of elevated and depressed segments with a D-period of 65 nm, by two ridges at the margins of the elevations and by a third ridge at an intermediate point in the depressions. A comparison between replicas and isolated negatively stained collagen fibril micrographs as well as densitometric determinations have allowed interpretation of the elevations and depressions as overlap and gap zones and of the three ridges as the main bands with higher molecular density. Estimates, carried out on densitometric diagrams obtained from replicas, gave values which may represent a new parameter in the study of collagen banding and led to the calculation of a 0.55 D long gap zone and of a 0.45 D long overlap zone.

Animals↗
PubMed1982

Why inclusion bodies do assume different locations in thalassaemic erythrocytes.

The reported scanning (SEM), transmission (TS), and freeze-etching (FE) electron microscopic studies have agreed in confirming that in thalassaemic erythrocytes, previously incubated with brilliant cresyl blue (BCB), the unpaired alpha chains precipitate in the central portions of the cell whereas excess beta chains locate in the submembranous regions. This is due to the fact that beta chains, possessing two thiols instead of only one (as in alpha chains), are more liable to bind to similar groups contained in the inner red cell leaflet. Less soluble alpha chains tend to form inter-chain bridges and thus precipitate centrally. SEM observations have given evidence that on the surface of the affected red cells denaturated alpha chains give rise to large and shallow invaginations whereas denatured beta chains lead to diffuse wrinkled appearance. The causes of the different SEM aspects have been suggested.

Adolescent↗
PubMed1982

Pseudo-elastica in alcoholic hepatic fibrosis: histochemical and ultrastructural aspects.

During the early phases of alcoholic hepatic fibrosis, histochemical studies show positivity to both specific elastin and the specific collagen stains at the level of the centrolobular vein, the portal triad and portacaval anastomosis. Ultrastructural investigation in the portacaval anastomosis demonstrates the presence of collagen fibrils and afibrillar material. Treatment with tannic acid increases the contrast of these structures. The possible correlations between histochemical and ultrastructural findings are discussed.

Collagen↗