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Biomedical subjects

L Mancini

Publications and source records attributed to L Mancini.

At least 73 records · Page 4Linked to original sources
PubMed1986

[A longitudinal entomologic survey on the transmission of malaria in Ouagadougou (Burkina Faso)].

A longitudinal entomological malaria survey was carried out in five zones of the town of Ouagadougou, Burkina Faso, and in three neighbouring villages. The main vector is Anopheles gambiae s.l. with An. funestus having a role in some localities during the dry season. Pyrethrum spray catches were carried out once or twice per month to determine variations in vector density. Inoculation rates were estimated from the number of blood-fed vectors per man and from the sporozoite rates. Larval sampling was routinely carried out all over the urban area in order to map the larval breeding sites. Widely different degrees of malaria transmission were documented in the urban area mainly related to the spatial and temporal distribution of An. gambiae larval breeding sites. Higher inoculation rates, depending both on higher vector densities and sporozoite rates, were documented in the villages.

Animals↗
PubMed1985

[Structure of alveolar bone during tooth eruption in the dog: preliminary findings].

The structure of the alveolar bone during the tooth eruption in the young dog mandibles was investigated by microradiographic and polarized light techniques. Around the first erupting molar root a trabecular network of primary alveolar bone, less mineralized than the surrounding cortical one, was found. Numerous calcified spicules parallel one to others radiate out the spongiosa near the periodontal ligament. The collagen fiber bundles of the alveolar, woven, bone are continuous with the periodontal ligament ones. This finding indicates that the alveolar bone increases by ossification of the periodontal ligament. Therefore the latter is the forming alveolar bone substratum. The trabeculae of the occlused premolar alveolar bone are ticker and more mineralized. This modification of the occlused tooth alveolar bone could be related to the occlusal stresses.

Alveolar Process↗
PubMed1985

[Structure of the periodontal ligament during tooth eruption in the dog: descriptive aspects].

Serially stained uncalcified sections of young dog mandibles were examined to study the structure of the periodontal ligament of the erupting first right molar. The periodontal ligament around tooth crown presents three zones. The first, near the dental follicle, is a tick layer of parallel collagen bundles with numerous flattened fibroblasts. The second, intermediate, contains a blood vessels network, particularly veins and capillaries. The third, outer, is occupied by a continuous layer of osteoclasts and osteoblasts. Also the periodontal ligament around the tooth presents three layers, the outer and the intermediate rich of cells more than the inner. Particularly, the outer layer shows numerous osteoblasts surrounding the developing trabeculae of the alveolar bone and the collagen fiber bundles of the periodontal ligament. These penetrate into the trabeculae and appear similar to the osteoid layer. These results indicate that the alveolar bone increases by ossification of the connective tissue of the periodontal ligament.

Alveolar Process↗
PubMed1985

[Differentiation of cerebellar Purkinje neurons of the normal and chronically hypoxic chick embryo].

A microscopical and ultrastructural study on the cerebellum development, with peculiar attention to the Purkinje cell differentiation, has been undertaken in chick embryos from the 8th incubation day (i.d.) until hatching, both in normal and hypoxic conditions; the development under hypoxia was obtained by covering, at the 2nd i.d., a half of fertilized egg shells with melted wax (Menkes et al., 1975). The observations, carried out on paraffin, semithin, and ultrathin sections of cerebellum anlagen, indicate that, under normal conditions, the cerebellar "folia" begin to appear on the 9th-10th i.d., and the secondary and tertiary ones are completely formed at the 14th i.d., when also the cortex layers begin to be recognizable owing to the successive migration processes of cells from two germinal layers and the mitotic proliferation of neuroblasts. The Purkinje cells are identifiable only at the 10th i.d. as large neuroblasts, irregularly stratified beneath the external granular layer, and characterized by a scanty amount of basophilic cytoplasm; they progressively acquire features of neurocytes, with abundant basophilic cytoplasm and numerous ramifications of their dendritic tree. The differentiation of Purkinje neurocytes, complete at the 17th i.d., is accompanied by degeneration events affecting some of them, which appear modified in shape, size and both structural and ultrastructural features (e.g. nuclear pycnosis, condensation and/or vacuolization of the cytoplasm). In the hypoxic embryos the main morphogenetic and histogenetic processes normally unfold during the embryonic life and the Purkinje cell differentiation occur like in the normal embryos until the 15th i.d.; afterwards a progressively greater number of them undergoes severe morphological modifications, comparable to those affecting only few neurons in the cerebellum of normally developed embryos.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

[Effects of chronic hypoxia on microcirculation of the central nervous system during embryonic development].

In the attempt to know the factors influencing the vasculogenesis and to verify whether the vessel formation and growth are influenced, during different ontogenetic periods, by oxygen deficiency, the intraneural vascular network has been morphometrically analyzed in chicken embryo optic tectum under conditions of aerogenic hypoxia. Chicken eggs, incubated under routine conditions, have been half-painted with melted wax at the 2nd incubation day (i.d.). Fragments of optic tectum, isolated from living embryos at the 8th, 14th and 17th i.d., have been fixed and embedded according to the usual E/M procedures. A parallel series of normally developed embryos of 8, 14 and 17 incubation days has been likewise prepared. On semithin sections from the hypoxic specimens and normal control embryos the area occupied by vessels (Av), the number of vessels (Nv) and the diameter of the radially directed ones (Dv) have been evaluated. The preliminary results indicate that hypoxia evokes, from the 8th to the 17th i.d., an increment of the Av parameter, due first to microvessel neoformation and enlargement from the 8th to the 14th i.d., then from the 14th to the 17th i.d. only to a growth of new capillary branches. The response of the vascular network to the hypoxic condition is more marked from the 8th to the 14th i.d., t.i. when, in relation to the differentiation and the stratification of the neurons, the metabolic requirements of the developing tectum are presumably increased. O2 deficiency causes severe developmental disorders of the cyto- and mieloarchitecture of the tectum: the vascular response can apparently prevent actual damages only when the hypoxic condition lasts for a relatively short time.

Animals↗
PubMed1983

[Organogenesis of cranial ganglia in the chick embryo: a comparison of the development of blood vessels and neurocytodifferentiation].

Neurohistogenetic and vasculogenetic processes have been analytically compared in several cranial ganglia, ciliary (III nerve), semilunar (V nerve), vestibulocochlear (VIII nerve), petrosal (IX nerve) and nodose (X nerve), of chicken embryos from the 3rd to the 12th incubation day. The results indicate that during the organogenesis of these ganglia the formation of the first intrinsic vessels and the successive development of vascular networks follow the beginning and, respectively, the main steps of the neuroblast morphological maturation. The differences noticed by the Authors as concerns the chronological sequence showed by the vasculogenetic events in the various ganglia have been ascribed to the different proceeding of the neurohistogenesis since blood vessels first appear and build networks where the ganglionic development and differentiation are more precocious.

Animals↗
PubMed1978

[Epidermoid cyst of the spleen with a picture of acute abdomen].

A case of epidermoid cyst of the spleen in an 8-yr-old boy presented as acute abdomen secondary to rupture of the cyst. The lesion is classified and the relevant literature surveyed. Particular reference is made to the pathogenetic mechanism responsible for the picture of acute abdomen.

Abdomen, Acute↗
PubMed1976

[IgA-IgG-IgM serum levels in blood donors. Examination of some variables].

IgA, IgG and IgM serum levels in 603 normal blood donors (510 males and 93 females) have been calculated by the method of single radial immunodiffusion. In every immunoglobulin class the normal values and other important statistical parameters have been determined. Several statistical examinations have been executed to test the influence of some factors as sex, weight, age and number of blood donations on IgA, IgG and IgM serum levels.

Adult↗
PubMedDate not supplied

Phagocytosis and intracellular killing of rokitamycin-exposed staphylococci by human polymorphonuclear leukocytes.

The exposure of bacteria to antibiotics at even sub-minimum inhibitory concentrations (sub-MICs) induces physicochemical and biochemical modifications that facilitate phagocytosis and intracellular killing by polymorphonuclear leukocytes (PMNs). These PMN functions were investigated by exposing Staphylococcus aureus strains to different sub-MICs (1/2 to 1/32 MIC) of rokitamycin (RKM). Although phagocytosis and the index of phagocytosis of the antibiotic-exposed staphylococci were not significantly modified with respect to controls, the percentage of killing significantly increased after exposure to 1/2 and 1/4 MIC by 31 and 22%, respectively. Taking into consideration the other aspect of a possible direct interaction between RKM and PMNs, it was observed that up to 10 micrograms/ml of RKM did not interfere with phagocytosis but significantly enhanced killing activity by up to 33%. This effect can be correlated with the high uptake of RKM by PMNs (cellular/extracellular ratio congruent to 30.5). The relevance of these in vitro observations to clinical situations remains to be further investigated.

Adult↗
PubMedDate not supplied

Influence of sub-minimum inhibitory concentrations of cefodizime on the phagocytosis, intracellular killing and oxidative bursts of human polymorphonuclear leukocytes.

It is generally recognized that sub-minimum inhibitory concentrations (sub-MICs) of antibiotics are still capable of interfering with some bacterial virulence parameters, thus facilitating host neutrophilic defenses such as phagocytosis, killing and oxidative bursts. This study investigated the interaction of Escherichia coli with these neutrophilic functions after pretreatment with various sub-MICs of cefodizime. E. coli exposed to 1/2 to 1/8 MICs of cefodizime showed the extensive production of long and very long filaments that interfere with the precise measurement of phagocytic and killing parameters. Our analysis was consequently extended to the activity of 1/16 to 1/64 MICs. The interesting finding was that, although phagocytosis was unaffected, killing was significantly increased in one strain at 1/16 MIC and in another at 1/32 MIC while in the last strain it was unaffected. Oxidative bursts were not modified by any of the sub-MICs. The knowledge that these sub-MICs are still effective in increasing bacteria killing, correlated with the pharmacokinetic curve of a common single dose of cefodizime 1 g i.m., showed that the killing effects of sub-MICs may last for as long as 12 h after the activity of the MIC value. This integrated information extends our knowledge of the ultimate efficacy of an antibiotic and provides further information for optimizing scheduling.

Adult↗