Human epithelial cells induce human melanocyte growth in vitro but only skin keratinocytes regulate its proper differentiation in the absence of dermis.

Human keratinocytes isolated from a skin biopsy and cultured in vitro reconstitute a stratified squamous epithelium suitable for grafting on burned patients. Melanocytes coisolated from the same skin biopsy also proliferate under these culture conditions and maintain differentiated functions (i.e., synthesize melanin granules, regularly intersperse in the basal layer of the cultured epidermis, and transfer melanosomes in the cytoplasm of contiguous keratinocytes) (De Luca, M., A. T. Franzi, F. D'Anna, A. Zicca, E. Albanese, S. Bondanza, and R. Cancedda. 1988. Eur. J. Cell Biol. 46:176-180). Isolated melanocytes in culture grow in the presence of specific growth factors with a mean population doubling time of 4-10 d. In this paper we show that (a) human keratinocytes and oral epithelial cells possess strong and specific melanocyte growth stimulating activity (doubling time, 24 h); (b) melanocyte growth is not autonomous but requires close keratinocyte contact and is regulated to maintain a physiological melanocytes/keratinocytes ratiol and (c) pure skin keratinocytes, but not oral epithelial cells, have all the information required for the proper physiological location and differentiation of melanocytes in the epidermis.

Antiviral activity of tiazofurin and mycophenolic acid against Grapevine leafroll-associated virus 3 in Vitis vinifera explants.

The ability to control plant viral diseases with chemicals has great potential value for agriculture, but few chemicals are available to date due to the difficulty in obtaining effective drugs. IMP dehydrogenase is an enzyme which catalyzes the conversion of inosine 5'-monophosphate to xanthosine 5'-monophosphate in the de novo purine nucleotide synthetic pathway, and is considered a sensitive target for antiviral drugs. Two IMPDH inhibitors, tiazofurin (TR) and mycophenolic acid (MPA), were tested for their inhibitory effect on Grapevine leafroll-associated virus 3 (GLRaV-3) in in vitro grapevine explants. TR administration produced plantlets characterized by negative ELISA readings. No PCR products were obtained from these samples. This was confirmed by the absence of viral particles. MPA was essentially ineffective against GLRaV-3 replication in Sangiovese explants. This is the first report of GLRaV-3 eradication in grapevine explants following TR administration.

A case of clear renal cell cancer associated to meningioma and verrucous carcinoma of frontal region in an old patient.

Here we report the concomitant development in an 82 year-old patient of three different neoplasms with different histology, degree of differentiation and clinical aggressiveness. In fact, the patient presented a verrucous carcinoma with unusual location at her head frontal region and a concomitant calcified meningioma of the frontal region of the brain. At the moment of the examination also a clear renal cell carcinoma, that was the cause of patient decease, was discovered. At our knowledge, this is the first case of concomitant presentation of these three tumours. Even if the present case was not correlated with any hereditary feature the presence of a genetic predisposition common to all the three tumours can not be excluded, but the casual co-existence of different both genetic and environmental factors can be also suggested.

Hybrid supramolecular gels of Fmoc-F/halloysite nanotubes: systems for sustained release of camptothecin.

Supramolecular gel hybrids obtained by self-assembly of Fmoc-l-phenylalanine (Fmoc-F) in the presence of functionalized halloysite nanotubes (f-HNT) were obtained in biocompatible solvents and employed as carriers for the delivery of camptothecin (CPT) molecules. The synthesis of the new f-HNT material as well as its characterization are described. The properties of the hybrid hydrogels and organogels were analyzed by several techniques. The presence of small amounts of f-HNT allows good dispersion of the tubes and the subsequent formation of homogeneous gels. The experimental results show that f-HNT functions only as an additive in the hybrid gels and does not demonstrate gelator behavior. The in vitro kinetic release from both f-HNT/CPT and Fmoc-F/f-HNT/CPT was studied in media that imitates physiological conditions, and the factors controlling the release process were determined and discussed. Furthermore, the antiproliferative in vitro activities of the gels were evaluated towards human cervical cancer HeLa cells. A comparison of data collected in both systems shows the synergistic action of f-HNT and the gel matrix in controlling the release of CPT in the media and maintaining the drug in its active form. Finally, a comparison with pristine HNT is also reported. This study suggests a suitable strategy to obtain two-component gel hybrids based on nanocarriers with controlled drug carrier capacity for biomedical applications.

Coculture of human keratinocytes and melanocytes: differentiated melanocytes are physiologically organized in the basal layer of the cultured epithelium.

Human epidermal keratinocytes differentiate in vitro into a stratified epithelium suitable for grafting on burned patients. In this paper, we show that differentiated melanocytes are present in the cultured epithelium. In particular, we have found that i) melanocytes proliferate in the same culture conditions that allow keratinocyte growth, ii) during the culture the ratio between keratinocytes and melanocytes tends to remain constant, iii) melanocytes organize into the basal layer of the cultured epithelium independently of the presence of dermis, develop dendritic arborizations with melanosome-containing processes and transfer melanosomes into keratinocyte cytoplasm.

Analysis of human peripheral blood lymphocytes isolated by counterflow centrifugation-elutriation.

Human peripheral blood mononuclear cells isolated by Ficoll-Hypaque density gradient centrifugation have been fractionated by counterflow centrifugal elutriation (CCE). Six CCE fractions were obtained and subsequently analyzed as for their content of monocytes, T cells, NK cells and B cells. The various cell types were identified through the expression of specific surface membrane determinants or by cytochemical staining for alpha-naphthyl acid esterase (ANAE). Monocytes were elutriated at the highest counterflow rates whereas the majority of B cells were collected at the lowest counterflow rates. T cells as well as NK cells were mostly concentrated in the intermediate fractions. No differences in the elutriation profile of T cells with the helper-inducer or with the cytotoxic-suppressor surface phenotype were observed. However, the percentages of T cells as determined by surface marker expression decreased with increasing counterflow rates, whereas the percentage of ANAE-positive T cells increased. Yet, T cells recovered at the high counterflow rates had ANAE-reactive organelles larger than those of T cells collected at low counterflow rates. These findings suggest that T cells at different maturational stages could be separated by CCE.

Scleroembolization for treatment of hypertension caused by intrarenal arterial fibrodysplasia.

This paper reports a 13-year-old girl with severe hypertension due to fibrodysplasia of intrarenal arterial branches in the upper pole of the left kidney. Scleroembolization of the abnormal vascular region was carried out by injecting, via a transcutaneous catheter, an 80% solution of sodium iothalamate in ethanol, followed by a suspension of Gore-Tex particles in the same solution, which resulted in complete and persistent normalization of blood pressure.

[Enzymatic reaction of the follicular cell population in the human appendix]. / Reazioni enzimatiche della popolazione follicolare in appendici umane.

Histochemical techniques were employed to determine acid phosphatase and alpha-naphthylesterase activities in follicular cells from the mucosa of surgically removed human appendixes. These very reactive cells are found in two areas: in the middle of the light centre and in the surroundings of this centre. The former are globose, arranged with a certain degree of order, and have a reticular anchorage that does not appear to be particularly affected by the physiological and pathological events that occur in the appendix, whereas those of the border vary in number or may even be absent. They have an elongated shape and are also anchored in a reticulum that in this case is more consistent. The result is that in certain forms of appendiceal disease the pale centre of the follicle is closed in a kind of shell formed of very reactive cells. The identification and significance of these two groups of cells of the light centre are discussed.

[The usefulness of cytodiagnosis in nonpalpable breast lesions]. / Utilità della citodiagnostica nelle lesioni non palpabili della mammella.

The paper underlines the importance of early diagnosis in the treatment of breast tumours and emphasises the value of cytodiagnosis as a very sensitive and specific predictive method for detecting impalpable lesions. In conclusion, the Authors affirm that cytodiagnosis, together with the introduction of new diagnostic instruments such as the TRC Mammotest, allows the diagnostic and therapeutical approach to impalpable breast tumours to be improved. It adds to the already high sensitivity of mammography and to the high predictive specificity of cytology, thus contributing to the reduction of the so-called "bioptic cost".

[Minimal breast carcinoma (the authors' experience)]. / Il carcinoma minimo della mammella (nostra esperienza).

The authors relate their experience about twenty-one cases of impalpable lesions of the breast come to their observation during the years 84-88. After expanding therapeutical tactics carried out by them, the promoters infer asserting that a wide diffusion of screening programmes allowed a more verifications of the minute lesions of the breast, addressing the surgeon towards operations more and more conservatives.

[Histochemical studies of the peroxidase activity of the bursa of Fabricius of Gallus dom.; study of the enzymatic metabolism of that immunocompetent organ during its development]. / Ricerche istochimiche sulle attivita' perossidasiche nella borsa di Fabrizio del Gallus dom.; contributi alla conoscenza del metabolismo enzimatico di quest'organo immunocompetente durante la sua evoluzione

By means of the technique proposed by De Robertis and Grasso (1946) for the histochemical localization of peroxidase activity, we have shown in the developing chicken Bursa of Fabricius positive cells from the 12th day onwards. They are localized in the mesenchymal network and increase during the development, reaching their top level in a period between the 18th-20th day before hatching and the 3rd day after hatching. After the first week these cells decrease and disappear during the second month. Peroxidase positive cells are tentatively identified as eosinophilic granulocytes (pseudoeosinophilic according to Romanoff); their variations should express fluctuations in the pattern of bursal granulocytopoiesis.

Multiple hereditary trichoepithelioma and cylindroma (Brooke-Spiegler syndrome).

Three cases of trichoepithelioma associated with cylindroma (Brooke-Spiegler syndrome) in the same family are reported. Three generations were affected. The syndrome usually beginning at puberty is inherited as an irregular autosomal dominant trait.

Hassall's corpuscle: a regressive formation.

Alpha naphthylesterase and leucineaminopeptidase activities in Hassall's corpuscles in the Gallus dom, and Cavia cobaya were found to be similar to those in man and in other animals. Histochemical findings of the thymus during the course of the growing phase have shown that these two enzymes are closely connected with the initial formation of a Hassall's corpuscle. Some medullary parenchymal epitheliocytes react strongly at this time. At first present in small clusters, they gradually become more numerous and finally escape from the network. Next they tend to cluster together, enclosing other cells with them. This change is connected with a new structure acquired by the cells. Enzymatic activity, antigenic properties and immunological reactions are only present in the early growth stages of a Hassall's corpuscle, when the cells are often hypertrophic. The component parts of the lamellated corpuscle are subject to involutive phenomena; they cease to function and to supply structural material until they finally disappear. The thymus is able to provide formative material without having recourse to Hassall's corpuscle. However, we are inclined to consider the progressive phase of Hassall's corpuscle to be important, as then elements in growth are clearly differentiated.

Histochemical enzymatic assessment of the human appendix at different ages.

The appendectomy specimens submitted to surgical pathology exhibit a wide variety of morphological appearances. We have evaluated the activities of acid phosphatase, alpha-naphthyl esterase, and leucineaminopeptidase in 100 human appendixes divided into six age groups in order to ascertain whether any histochemical pattern was related to the age group rather than to pathological condition. Our findings support that the submucosal fibrosis is unrelated to the patient's age, as well as appendiceal obliteration. It is noteworthy that the mucosa of the appendix may retain its lymphoid constituents at any age and that young subjects may already show appearances of involution up to lumen obliteration.