Decreasing podocyte number during human kidney intrauterine development.

Nephron number at birth has relevant clinical importance with implications for long-term renal health. In recent years, the podocyte depletion hypothesis has emerged as an important concept in kidney pathology. This study was aimed at verifying whether human podocyte number changes significantly during intrauterine life. To this end, 62 subjects with gestational ages ranging from 20 to 41 wk were examined. Kidney sections were stained with hematoxylin and eosin and digitally scanned at ×400 magnification. Subjects were subdivided into fetuses (gestational age≤24 wk, n=5), preterms (gestational age≥25 and ≤36 wk, n=39), and full-term newborns (gestational age≥37 wk, n=18). The average podocyte number of 1,908±645, 1,394±498, and 1,126±256 was, respectively, observed in fetuses, preterms, and full-term newborns. A significant main effect (P=0.0051) of gestational age on podocyte number was observed with a significantly lower number in full-term newborns than in fetuses (P<0.01). Intragroup variability was also observed. We speculate that variations in podocyte number could be correlated with factors such as drugs and maternal diet occurring during intrauterine life. In conclusion, this study shows, for the first time, a decreasing trend in podocyte number during gestation.

Reoxygenation of asphyxiated newborn piglets: administration of 100% oxygen causes significantly higher apoptosis in cortical neurons, as compared to 21%.

OBJECTIVE: Evaluation of neuronal changes in an animal experimental model of normocapnic hypoxia- reoxygenation. MATERIALS AND METHODS: Fifty male piglets were the study subjects; normocapnic hypoxia was induced in 40 piglets and ten were sham-operated (controls). When bradycardia and/or severe hypotension occurred, reoxygenation was initiated. Animals were allocated in 4 groups according to the oxygen concentration, they were resuscitated with 18%, 21%, 40%, and 100% O2. Persisting asystole despite 10 minutes of cardiopulmonary resuscitation and return of spontaneous circulation were the endpoints of the experiment. Surviving animals were euthanized and brain cortex samples were collected, hematoxylin and eosin-stained, and examined for apoptotic bodies observing 10 consecutive high power fields. RESULTS: Histological examination of the control group did not show any pathological change. On the contrary, apoptosis of neurons was found in 87.5% of treated animals. When specimens were examined according to the oxygen concentration used for resuscitation, we found marked intergroup variability; a higher percentage of apoptotic neurons was observed in piglets of group 4 (100% oxygen) compared to the others (P=0.001). CONCLUSIONS: This preliminary data shows that normocapnic hypoxia and reoxygenation in Landrace/Large White piglets resulted in significant histological changes in the brain cortex. The degree of pathological changes in cortical neurons was significantly associated with the oxygen concentration used for reoxygenation, with a higher percentage of apoptotic neurons being observed in piglets reoxygenated with 100% compared to 18% O2 and to 21% O2.

Thymosin beta 4 expression in normal skin, colon mucosa and in tumor infiltrating mast cells.

Mast cells (MCs) are metachromatic cells that originate from multipotential hemopoietic stem cells in the bone marrow. Two distinct populations of MCs have been characterized: mucosal MCs are tryptase-positive while mast cells in skin contain tryptase and chymase. We now show that a sub-population of MCs is highly immunoreactive for thymosin beta4, as revealed by immunohistochemical analyses of normal skin, normal colon mucosa and salivary gland tumors. Four consecutive serial sections from each case were immunostained for thymosin beta4 (Tbeta4), chymase, tryptase and stained for toluidine blue. In skin biopsies, MCs showed a comparable immunoreactivity for Tbeta4, chymase and tryptase. In normal colon mucosa the vast majority of mucosal MCs expressed a strong cytoplasmic immunoreactivity for tryptase and for Tbeta4, in the absence of chymase reactivity. A robust expression of Tbeta4 was detected in tumor-infiltrating and peritumoral mast cells in salivary gland tumors and breast ductal infiltrating carcinomas. Tumor-infiltrating MCs also showed a strong immunoreactivity for chymase and tryptase. In this paper, we first demonstrate that normal dermal and mucosal mast cells exhibit strong expression of thymosin beta4, which could be considered a new marker for the identification of mast cells in skin biopsies as well as in human tumors. The possible relationship between the degree of Tbeta4 expression in tumor-infiltrating mast cells and tumor behaviour warrants further consideration in future investigations.

Vasopressin excitatory action on smooth muscle from human renal calyx and pelvis.

The motor response to vasopressin, a neuropeptide promoting the reabsorption of water, was isometrically investigated in vitro in human renal calyces and pelvis in relation to possible modulation of urinary flow by these tubular structures. Kidneys were obtained from nine male patients who underwent nephrectomy for either renal or ureteral cancer. Minor calyces and pelvis were carefully removed. Strips (10 mm x 3 mm) were cut from infundibular region of minor calyces and from renal pelvis and placed in 10 ml organ bath for isometric tension recordings. Calyceal and pelvic smooth muscle strips exhibited spontaneous phasic contractions which occurred with regular frequency and amplitude. Vasopressin induced a dose-dependent [10(-10) to 10(-6) M] enhancement of basal tone (P <0.01) and a decrease of spontaneous contractions on isolated strips from minor calyces and pelvis. The effect of vasopressin was inhibited by prior administration of D(CH2)5Tyr(Me)2-Arg8-Vasopressin antagonist [10(-7) M]. The excitatory response to vasopressin was Tetrodotoxin [TTX]-resistant and was not affected by pre-treatment with phentolamine [10(-5) M], atropine [10(-5) M], and hexamethonium [10(-5) M]. After incubation of the specimens in Ca2+-free medium containing EGTA [0.5 mM] or after treatment with nifedipine [10(-5) M], both spontaneous and vasopressin-induced contractions [10(-10) to 10(-6) M] were completely inhibited in all specimens. Our results can be interpreted to imply that the tonic contractions induced by vasopressin facilitate the reabsorption of water by increasing the hydraulic resistance of the tubular structures below collecting ducts.

[ELISA analysis of salivary cotinine in smokers]. / Determinazioni ELISA della cotinina salivare in pazienti fumatori.

BACKGROUND: The presence in saliva of cotinine, the main and inactive metabolite of nicotine, reflects the extent of systemic distribution of nicotine and explains the increased susceptibility to periodontal disease in smokers. The aim of this study was to investigate the comparative amount of cotinine in the saliva of habitual cigarette smokers, non-smokers and passive smokers. METHODS: Saliva sample were obtained from 14 cigarette smokers and 13 non-smokers (8 passive-smokers), all without periodontal disease, and analyzed by Microplate EIA (a variation of ELISA based on cross-reactivity of cotinine with anti-cotinine antibody revealed by absorbance in spectrophotometry) to determine the presence and the amount of cotinine. RESULTS: Cotinine was detected in the saliva of smokers with a mean of 92.3 +/- 4.15 ng/ml and, unexpectedly, there was evidence of cotinine also in the saliva of non-smokers (mean 5.4 +/- 1.22 ng/ml), particularly, in passive-smokers (mean 12.9 +/- 6.67 ng/ml). CONCLUSIONS: The salivary concentration of cotinine can be used to estimate nicotine intake and its possible role in the pathogenesis of periodontal disease also in passive-smokers.

[Tests on ionic release from glass-ionomer cements]. / Prove sperimentali sul rilascio ionico da parte di sistemi ionomerovetrosi.

BACKGROUND: Dissolution process in oral liquids by the presence of glass-ionomer systems (due to surface corrosion, to diffusion through solutions and through mass) make an ionic release (particularly F, Al, Pb, As) which is a non secondary problem, due to the usual utilization of these materials in pedodontic and restorative dentistry. METHODS: In this work, considering the high toxicity of low quantity of Arsenic ion, a comparative research has been made in order to determine, by using high level liquid Cromatography (HPCL), the quantity in ppm of As hydro- and acid soluble given by five ionomeric products, in water and in nitric acid concentrated solution. RESULTS AND CONCLUSIONS: The results show that in some products arsenical concentrations are higher then the quantity accepted by ISO-FDI; therefore, a better control in the production of these products is needed as well as a limited use in dentistry. It is suggested to use glass-ionomer systems in patients with dental dike and varnish on the surfaces that are in contact with oral liquids action.

[Microanalytical determinations of gold alloys for fixed dentures]. / Determinazioni microanalitiche di leghe auree per protesi fisse.

In this work the authors analyse gold alloys for fixed prosthesis by X-ray spectrometry in energy dispersion (EDS). The results of this analysis, given in graphic and table form, show remarkable differences in alloy composition. For this reason recommended dentists are to be attentive and severe in the control of gold alloys for fixed prosthesis.