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Biomedical subjects

L Bosco

Publications and source records attributed to L Bosco.

At least 55 records · Page 3Linked to original sources
PubMed1986

Eye factors and lens-forming transformations of outer cornea in Xenopus laevis larvae.

Outer cornea of lensectomized Xenopus laevis tadpoles at state 50 (according to Nieuwkoop, P.D. and Faber, J., ('56) Normal Table of Xenopus laevis, Daudin, North-Holland, Amsterdam, pp. 1-243) was removed 3, 7 and 10 days after lensectomy and implanted between the outer and the inner cornea of larvae of the same species at stage 51-52. In these conditions, the implanted outer cornea remained isolated from the retinal factor of the vitreous chamber, although it received the nutritional factors normally reaching the outer cornea. Results show that lens-forming transformation process of the outer cornea is arrested, and lens-forming structures undergo regression at speed which increases with increasing precocity of the stage of lens-forming transformation undergone by the implanted cornea. These data suggest that the process of lens-forming transformation is not a single-step process, but a sequence of interactions extending over a long period of time requiring the continuous presence of the retinal factor in the vitreous chamber until complete differentiation of the lens is achieved.

Age Factors↗
PubMed1985

[Intraserosal proximal hemideferentectomy versus classical proximal hemivasectomy in the rat. Anatomo-functional aspects and proposal for a new terminology].

According to new trends and terms in microsurgery, the intra-serous proximal hemideferentectomy is compared to the classical vasectomy in rat. The effects of these surgical models are evaluated on morphological and functional bases. The anatomo-pathological parameters considered (stenosis and leakage of the anastomosis of the epididymal tubule conseguent on local ischemia) have been correlated with functional parameters "in vitro" (spontaneous motility and field stimulation) in order to plan the best microsurgical procedure in the experimental tubulo-vasostomy.

Animals↗
PubMed1985

[Effects of tubulo-deferens stenosis secondary to intraserosal proximal hemideferentectomy and end-to-end tubulo-vasostomy on the testicle of the rat. Histopathological aspects].

The histopathological aspects of the testis in rat after intra-serous proximal hemideferentectomy and end-to-end tubulo-vasostomy are evaluated. The histomorphometric variations of the convoluted seminiferous tubules and the quantitative modifications of the stages of spermatogenesis are correlated with the obstruction's degree of the tubulo-deferential anastomosis.

Animals↗
PubMed1984

[Morphometric observations on the number of neurons in spinal ganglia].

Nerve cell number has been determined in the thoracic spinal ganglia XVII to XXII of chick embryos of 14-18 days of incubation. It is shown that these ganglia constitute a statistically homogeneous population in respect of the number of their constituent nerve cells. The statistical frequency distribution of the thoracic spinal ganglia according to the number of their neurons is unimodal, but markedly asymmetrical with a distinct positive skewness; the distribution differs significantly (P less than 0.05) from a normal (Gaussian) distribution.

Animals↗
PubMed1984

[Effects of radiation emission of the CO2-laser on embryonal ocular bulb tissues (Gallus gallus)].

The wall of the eye bulbs of 15 chick embryos, immediately after their transfer to Hanks fluid, was irradiated with a CO2 laser, focused on the 12th conjunctival papilla or on its prospective area. This 'in vitro' irradiation was performed under the following main parameters: (a) beam power congruent to 4W; (b) exposure time = 1/30 sec; (c) thickness of the fluid (Hanks solution) on the target surfaces = 0, 3 divided by 0, 7 mm. The same area of the eye bulb surface of other 15 chick embryos was irradiated 'in ovo' under the following conditions: (a) congruent to 4W; (b) = 1/10 sec; (c) (amniotic fluid + albumen) = 1 divided by 1, 5 mm. In the L/M analysis so far carried out, the lesions produced 'in vitro' and 'in ovo' showed a number of qualitative resemblances: i.e., disappearance of epithelial cells and numerous pyknoses in the cells left 'in situ'; decrease in thickness of the outer layer of the scleral mesenchyme, whose cells appeared closer to each other-owing to reduction of the intercellular spaces-, and often pyknotic. It is possible that the same mechanisms underlie such morphological aspects, observed in both groups of irradiated eyes. On the other hand, some quantitative differences were observed between the 'in vitro' and 'in ovo' lesions, the extent in surface and depth of the latter being appreciably lesser. Presumably the genesis of such differences could have been influenced by the physico-chemical differences between the fluids covering the target surfaces: Hanks fluid and, respectively, amniotic fluid + albumen.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

[Histomorphogenesis of spinal ganglia developing on the chorioallantoic membrane].

The aim of the present research is to study the development of spinal ganglia implanted onto chorio-allantoic membrane (CAM), where they are supplied by 'foreign', extraembryonic vessels. Small blocks including a segment of the neural tube and 4 pairs of somites were isolated from the brachial or thoracic or lumbar region (neuromeres C13 - T1 or T3 - T6 or L1 - L4) of thirty 3-day donor chick embryos and grafted on the CAM of as many 10-day host chick embryos. At regular time intervals after grafting, the implants were fixed, embedded in paraffin, serially cross-sectioned and stained. The preliminary results are similar for the ganglia from the 3 regions: they seem to indicate that in the spinal ganglia grafted on the CAM the developing blood vessels do not exert any morphogenetic influence on the substratum; this corroborates results from previous researches (2) on the normally 'in situ' developing ganglia. It is now the author purpose to submit to a careful analysis a datum from the present research: namely, the earlier appearance of the endoganglionic vessels in the brachial and lumbar grafted ganglia than in the thoracic ones.

Allantois↗
PubMed1983

[Cystic dilatation of the choledochus].

The authors show a case of cystic dilatation of choledochus in a woman patient aged 10. After reporting its nosologic classification, drawn from the world literature, they dissert about the treatment, which should be essentially surgical. The Authors performed a new surgical technique, as an alternative to the suggestion of other Authors. The method adopted consists of the partial resection of the cyst and subsequent reconstruction of choledochus on Kohr's tube.

Child↗
PubMed1983

[Treatment of acute cholecystitis: our experience].

The authors consider the questions involved in the treatment of acute cholecystitis. They show their casuistry and experiences. As to the therapeutical behaviour to be followed, they are inclined to an eclectic attitude adopted about acute cholecystitis, preferring an early or postposed operation, and never resorting to tardy operations.

Acute Disease↗
PubMed1982

Relationships between nervous component histomorphogenesis of chick embryo spinal ganglia and development of their vascular supply in chorioallantoic grafts.

The blood vessel formation as well as the neuroblast differentiation were studied in chick embryo spinal ganglia grafted onto chorioallantoic membrane, and comparatively in those developing in situ under normal conditions. The preliminary results seem to indicate that also in the grafted spinal ganglia, as already suggested, in previous researches, for the orthotopically developing ganglia, the vascular networks apparently do not exert influences on the nervous substratum morphohistogenesis.

Allantois↗
PubMed1982

Inhibition of lens regeneration in larval Xenopus laevis.

The present research aims at showing the role played by the lens in inhibiting lens-forming transformations of the outer cornea of Xenopus laevis tadpoles. Two types of experiment were carried out: 1) lentectomy and insertion of a Millipore filter disk at the side of the lens, and 2) lentectomy and insertion of a Millipore disk with a central hole. Results indicate that when the lens is replaced by a mechanical obstacle capable of preventing direct communication between vitreous and anterior chambers, definite inhibition of the lens-forming transformations of the outer cornea occurs. These data strongly suggest that the inhibition exerted by the lens on lens-forming transformations of the outer cornea in Xenopus laevis eyes is mechanical rather than chemical in nature.

Animals↗
PubMed1981

[Effects of monolateral ablations of the presumptive limb buds on the early developmental phases of the central and peripheral nervous system].

The size of the spinal ganglia, as well as of the posterior and lateral funiculi of the spinal cord, at the cervical, thoracic, lumbar and sacral levels, was carefully evaluated, on both sides, by measuring their surfaces on each transverse histological section from chick embryos submitted, at the second-second and a half day, to ablations of the right presumptive limb buds, and fixed at the 9th - 13th day. On the extirpation side, the ganglion and posterior funiculus size always resulted significantly smaller, the average degree of reduction being nearly the same at the levels of the brachial and the lumbo-sacral plexuses (-50-60% for the ganglia, -25-30% for the posterior funiculus). However, within the same group of metameres (e.g., the corresponding to the brachial plexus), the analysis carried out metamere by metamere showed that the reduction degree was not homogeneous, owing probably to a) the extent of the different peripheral fields supplied by the various metameres, b) the degree of the regulative processes occurred after the ablations, and/or c) the extent of the extirpated regions. The size reduction of the posterior funiculus, observed also in the neuromeres immediately cranial to those related to the plexuses, could depend upon its peculiar composition, relatively short intersegmental tracts representing the majority of its fibers. No significant reduction was remarked for the lateral funiculus size.

Animals↗
PubMed1981

Experimental analysis of the lens-forming competence of the cornea, iris, and retina in Xenopus laevis tadpoles.

The present research was carried out using Xenopus laevis tadpoles at stage 50-51 to ascertain whether eye territories other than the outer cornea and the pericorneal epidermis have lens-forming competence, particularly the iris and/or retina. Five experiments were performed: simple lentectomy; removal of lens, outer cornea, and pericorneal integument; removal of lens, outer cornea, and pericorneal integument, and simultaneous incision of retina; removal of lens, outer cornea and pericorneal integument, and simultaneous incision of dorsal iris; removal of lens and simultaneous lesion of iris and retina. Results show that when lentectomy is performed without damaging any territories other than the outer and inner cornea, lens regeneration is always from the outer cornea, and the iris and retina do not exhibit any lens-forming competence. The iris and retina show no clear-cut lens-forming competence even after they have been stimulated by comparatively extensive lesions.

Animals↗
PubMed1981

[A case of carcinoma of the gallbladder with unusual clinical course].

A case of carcinoma of the gallbladder with particular clinic course is described, stressing the problem of the precocious diagnosis of this kind of tumor. The insufficient knowledge about this argument, confirmed by conflicts of the studies about this, is denounced. Considering the far better prognosis when the diagnosis of cancer of the gallbladder is done in the stage "in situ", the AA. confirmed the importance of a careful anamnesis and, above all, of the histological examination on all the gallbladders removed for every cause.

Female↗