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Biomedical subjects

M L Cristina

Publications and source records attributed to M L Cristina.

At least 19 recordsLinked to original sources
PubMed2006

Fungal contamination in hospital environments.

OBJECTIVES: To assess the degree of fungal contamination in hospital environments and to evaluate the ability of air conditioning systems to reduce such contamination. METHODS: We monitored airborne microbial concentrations in various environments in 10 hospitals equipped with air conditioning. Sampling was performed with a portable Surface Air System impactor with replicate organism detection and counting plates containing a fungus-selective medium. The total fungal concentration was determined 72-120 hours after sampling. The genera most involved in infection were identified by macroscopic and microscopic observation. RESULTS: The mean concentration of airborne fungi in the set of environments examined was 19 +/- 19 colony-forming units (cfu) per cubic meter. Analysis of the fungal concentration in the different types of environments revealed different levels of contamination: the lowest mean values (12 +/- 14 cfu/m(3)) were recorded in operating theaters, and the highest (45 +/- 37 cfu/m(3)) were recorded in kitchens. Analyses revealed statistically significant differences between median values for the various environments. The fungal genus most commonly encountered was Penicillium, which, in kitchens, displayed the highest mean airborne concentration (8 +/- 2.4 cfu/m(3)). The percentage (35%) of Aspergillus documented in the wards was higher than that in any of the other environments monitored. CONCLUSIONS: The fungal concentrations recorded in the present study are comparable to those recorded in other studies conducted in hospital environments and are considerably lower than those seen in other indoor environments that are not air conditioned. These findings demonstrate the effectiveness of air-handling systems in reducing fungal contamination.

Air Conditioning↗
PubMed1994

Environmental and personal monitoring of exposure to urban noise and community response.

Noise exposure of a population sample living in a city in northern Italy (Genoa) was assessed by measuring the noise in the area as well as with personal sound detectors. Sampling was conducted during a standard day and covered a period of time spent out-of-doors, at work (service sector) and at home. Ambient noise at home and at work was assessed with sound-level meters, personal exposure levels were assessed with personal sound-level/dosimeters. Information regarding each environment was obtained with an interview including also a subjective judgement on traffic intensity and noise levels. The mean individual equivalent continuous sound level (Leq) of recorded noise was 74.5 dB(A) for 24 h and 63.9 dB(A) at night. A further distinction was made between noise exposure at home (Leq 74.4), work (Leq 74.0) and during city transfers (Leq 79.3). Leq values for individual hours, Leq daytime (Leq, d), Leq nighttime (Leq,n) and Leq day-night (Ldn) indices calculated in the different environments, i.e. at work, home and out-of-doors, are reported here. Individual noise levels have then been compared with environmental data and with subjective noise exposure judgement.

Environmental Monitoring↗
PubMed1994

Blood lead levels in shopkeepers and car traffic pollution in Liguria, Italy.

A study was conducted into the exposure to atmospheric pollution caused by car traffic by measuring blood lead (PbB) levels in a sample of 657 adult individuals (shopkeepers) all living in Liguria. The mean level of blood lead in all examined individuals was 9.39 micrograms dl-1 (0.45 mumol per liter; C.I. 95%: 9.06-9.75 micrograms dl-1; 0.44-0.47 mumol per liter) with a range between 2.0 and 46.03 micrograms dl-1 (0.10-2.22 mumol per liter). The average Pb values in individuals working in streets with high and very high traffic was 8.30 micrograms dl-1 (0.40 mumol per liter; C.I. 95%: 7.41-9.31 micrograms dl-1; 0.36-0.45 mumol per liter) and 9.98 micrograms dl-1 (0.48 mumol per liter; C.I. 95%: 9.62-10.37 micrograms dl-1; 0.46-0.50 mumol per liter), respectively. These average blood lead levels were statistically greater than the average PbB values of those working in low traffic streets (7.06 micrograms dl-1; 0.34 mumol per liter; C.I. 95%: 6.22-7.94 micrograms dl-1; 0.30-0.38 mumol per liter). The percentile distribution (50th, 90th and 98th P) for all subgroups surveyed has always proved to be below the maximum limits specified by EC Directive No. 77/312.

Adolescent↗
PubMed1990

[Determination of cesium in human placenta 3 years after Chernobyl].

Three years after the nuclear reactor accident in Chernobyl, 80 human placentae were tested to determine concentrations of cesium 134 and cesium 137 radionuclides. The activities of radionuclides were measured using a low-back ground gamma-ray spectrometry system. Human placentae were obtained from normal and at term pregnancies in women who lived in rural areas of northern-Italy and north-west of Yugoslavia and who in particular used locally grown vegetables and meats. According to the data of other Authors, the low cesium isotopes 134 and 137 levels detected (inferior to 2 Bq/kg) in human placentae suggest that, in the observed geographic areas, the fetal risk following the reactor accident in Chernobyl was negligible.

Accidents↗
PubMed1989

[Possible correlations between urinary cadmium and fetal growth retardation in pregnant women who smoke].

The results of a study on Ligurian women at the third day of puerperium are presented. The data obtained from the analysis of urinary cadmium levels in puerperae are related to their smoking habits and to the newborn weight. We found that women who smoked during pregnancy run the risk of giving birth to small-weight children one-and-a-half times higher than women who didn't smoke; moreover, cadmium levels in the urine of the women who smoked are higher too. The cadmium levels in urine on average are higher in women who gave birth to small-weight children, independently of smoke habits. We didn't find a significant relationship between cadmium levels in urine and newborn weight.

Adult↗
PubMed1988

Intraventricular schwannoma.

A case of schwannoma occurring in the right lateral ventricle of an 8-year-old boy is described. The child made an excellent recovery. Three years later there is no evidence of recurrence. The precise origin of such an unusual tumor is uncertain, but it probably arises from the sympathetic nerve supply to the choroid plexus.

Cerebral Ventricle Neoplasms↗
PubMed1981

Correlative immunocytochemical and electron microscopic studies: identification of (entero)glucagon- somatostatin- and pancreatic polypeptide-like-containing cells in the human colon.

Correlative immunocytochemical and electron microscopic studies, using the semi thin-thin technic, were performed to identify the (entero) glucagon, somatostatin and pancreatic polypeptide-like immunoreactive cells of the human colonic mucosa. Mean granule diameter for each cell type was estimated according to two methods and histograms showing the granule size distribution were constructed. A total of 139 immunostained cells identified at the ultrastructural level were analyzed. Mean granule diameter for (entero)glucagon-containing cells was 318 +/- 11 nm but a reduction of granule size with age was noteworthy: granules were larger in the fetus (mean diameter 350 +/- 15) than in adults (mean diameter 310 +/- 10 nm). Somatostatin-containing cells, very rare in adults, were present in the fetal distal colon. Their general mean granule diameter was 354 +/- 18 nm but many cells had a mean granule diameter of more than 400 nm. A pancreatic polypeptide-like immunoreactivity was found only in (entero)glucagon-containing cells, pointing out the possible occurrence of both peptides (or of similar sequences) in the same cells. Previous ultrastructural studies dealing with a tentative classification of the human colonic endocrine cells were compared with the present data.

Adult↗
PubMed1979

Emiocytotic granule release without intraluminal stimulus in human colonic endocrine cells of fetuses, children and adults.

In endocrine cells of the colon of adults, children and fetuses, exocytotic granule release without any specific stimulation is reported. Omega-invaginations are observed on both the lateral and basal surfaces of all types of colonic endocrine cells. Several explanations for the phenomenon are suggested: 1) emiocytosis is probably more frequent in the colon than in the proximal gut, this allows its observation without requiring an exogenous stimulus, 2) since most of the exocytotic figures are from anaesthetized subjects it is also assumed that contraction of the muscular layer induced by anaesthetics and the resulting increase in intraluminal pressure were the possible causes of granule release, 3) in non-anaesthetized subjects release may have taken place in response to a normal endogenous physiological stimulus, or to the dilation of colon during colonoscopy. Certain figures on lateral surfaces between endocrine and adjacent cells i.e., bulges of parallel plasma membranes surrounding a secretory granule, were observed. Their significance is unknown.

Adult↗
PubMed1979

Ontogeny and distribution of certain oendocrine cells in the human fetal large intestine. Histochemical and immunocytochemical studies.

In 9 fetuses, 9 to 24 weeks-old, the occurrence and relative distribution of argentaffin cells, as well as of cells immunoreactive to somatostatin (SRIF), glucagon-like polypeptide (GLI), pancreatic polypeptide (PP) and substance P (SP) were studied in five segments of the colon (appendix, cecum, ascending colon, descending colon, and rectosigmoid). For each colonic segment, data concerned with the occurrence of endocrine cells were expressed either as mean absolute numbers of specific cells per entire mucosal section, or as cell densities per mm3 of mucosa after calculation of the mucosal volume of the sections. Argentaffin, GLI, SRIF and PP immunoreactive cells are all present in relatively large numbers, scattered along the entire length of the colonic mucosa as early as the 9th-10th week of gestation, whereas substance P-containing cells occur sporadically and first appear during the 4th-17th week. Until the 20th week, with progressing embryonic development, an increase was determined in absolute numbers per section of all types of endocrine cells in all segments of the colon. This observation is clearly related to the general growth of the colonic mucosa, since cell densities per mm3 of mucosa do not greatly change or even decrease during gestation. However, it is possible that densities of argentaffin, GLI and BPP cells increase in the appendix around the 14th-17th week of gestation. Between 20th and 24th weeks, absolute numbers of cells per section remain stable or slightly increase, while cell densities tend rather to decrease in all segments. These data demonstrate that some endocrine cells are present very early in the human fetal colon, but their functional significance remains to be elucidated.

Colon↗
PubMed1978

Endocrine cells of the colon in Hirschsprung's and control children.

The large intestine resected from 6 Hirschsprung's patients and surgical colonic biopsies from 6 control children were examined with light and electron microscopy. The presence and the relative distribution of various endocrine cell types in both groups of mucosa were determined. In light microscope studies endocrine cell data were expressed as number of cells per unit area of mucosa using a quantitative method after argentaffin and Grimelius's argyrophilic techniques and an immunoperoxidase reaction with glucagon and somatostatin (SRIF) antisera. The results indicate that endocrine cells are apparently not involved in Hirschsprung's disease, since their number and frequency did not differ significantly between the ganglionic and aganglionic segments of Hirschsprung's patients nor between the latter and control children. Glucagon immunoreactive cells were, on the average, 5-6 times and 7-9 times more numerous that SRIF cells in the rectum and the sigmoid, respectively. Ultrastructurally, five endocrine cell types could be distinguished. The fifth type, probably a transition type, apparently disappears in adults.

Child, Preschool↗
PubMed1978

Fine structural classification and comparative distribution of endocrine cells in normal human large intestine.

Rectosigmoid- or colonoscopy biopsies were performed at different levels of the large intestine of 16 adult subjects free from major intestinal disease. Tissue specimens were subsequently examined by electron microscopy. Four different endocrine cell types could be distinguished on the basis of the shape and ultrastructural appearance of secretory granules, of their silver affinity, and of their morphometry. Type I cells (enterochromaffin cells, 60.5%) were argentaffin and presented granules with widely different morphologies, which could correspond to several subtypes. The three other cell types were nonargentaffin. Type II (21.3%) contained granules with a diameter distribution peak of 200 to 300 nm. Type III cells, rare (3.2%), were characterized by small and infrequent granules with a diameter distribution peak of 150 to 200 nm. Type IV cells (7.4%) were characterized by large and round granules with a diameter distribution peak of 300 to 400 nm and resembled the "L cell" of the small intestine. The most endocrine cell-rich portion of the colon was the rectum (179 of 618 cells examined). Type I cells represented approximately 73% of the endocrine cell population from the cecum to the descending colon and decreased to 42% in the rectum. Both the absolute number and the percentage of type II cells increased from the cecum (8%) to the rectum (31%). Type IV cells also increased in the rectum both in absolute number and percentage (14%). The absolute number of type III cells was too small to enable significant differences to be observed.

APUD Cells↗
PubMedDate not supplied

Increased urinary excretion of hydroxyproline in runners training in urban areas.

In this study, the authors investigated urinary excretion of hydroxyproline in 120 subjects to test the hypothesis that physical activity is associated with increased exposure to pollution derived from traffic exhaust. The study population comprised active noncompetitive runners (i.e., 21.1% trained < 2.5 hr/wk, 20% trained for 2.5-5.0 hr/wk, and 54.4% trained > 5 hr/wk) who lived in Genoa, an urban area of Northern Italy. The mean hydroxyproline value (24.39 +/- 8.38 standard deviation] mg/24 hr x m2) in a group of 69 runners who trained in tracks and streets located in downtown Genoa was higher (p < .05) than the mean value recorded in a group of 21 runners (13.33 +/- 2.51 mg/24 hr x m2) who trained mainly in a rural environment of Genoa. The difference was even greater (p < .01) when a third comparable group of 30 nonrunners was considered (mean = 12.54 +/- 3.41 [standard deviation] mg/24 hr x m2). In the urban environment, urinary levels of hydroxyproline were correlated significantly with intensity and frequency of running, but they were unrelated to smoking status.

Adult↗
PubMedDate not supplied

Increased blood lead levels in runners training in urban areas.

In an attempt to examine the hypothesis of whether physical activity causes increased uptake of lead in humans, blood lead levels were measured in 231 individuals. Included in the study were subjects who lived in Northern Italy and who practiced noncompetitive running in urban areas or along the countryside. The mean values (1.25 +/- 0.27 mumol/l) measured in a group of 28 runners who trained at tracks and on roads of a large town, characterized by heavy traffic and high atmospheric lead levels, were slightly higher than those recorded in a group of 10 runners of the same town who trained mostly in a rural environment (0.99 +/- 0.29 mumol/l) and, with a striking and significant difference, in a comparable group of 182 nonrunners (0.46 +/- 0.22 mumol/l). These background figures were similar to those found in 11 runners who lived in a smaller, less polluted urban area who trained in country roads (0.40 +/- 0.11 mumol/l). Blood lead levels were correlated significantly with the intensity and frequency of the running practice and were unrelated to smoking habits.

Adult↗