1,721,020 research outputs found
Human visceral fat in different anthropometric patterns and in diabetes : a morphometric study
No full textObjective: To evaluate the cellularity of the adipose tissue and the size of adipocytes in unrelated adults and investigate any correlation between morphometric and anthropometric or clinical variables.
Study Design: Surgical biopsies of visceral fat (epiploic appendixes) were obtained from the large intestines of 56 patients. A morphometric model was applied to obtain the volume fraction occupied by adipocytes and the size distribution and number in unit volume of the adipocytes. Body mass index (BMI), lifestyle factors, significant body weight variations and clinical disorders (diabetes) were evaluated.
Results: Volume fraction occupied by adipocytes and size distribution and number in unit volume of the adipocytes have an opposite trend in underweight, normal and overweight subjects and subjects with referred gain, normal, or loss weight. Regression analysis reveals a significant negative linear relationship between number in unit volume of the adipocytes and BMI and body weight variations. The group of normal patients is characterized by a unimodal size distribution of adipocytes when compared with the group affected by diabetes, who show a likely plurimodal pattern.
Conclusion: Our observations seem to confirm the hypothesis that hypertrophy, rather than adipose tissue hyperplasia, plays a fundamental role when significant ponderal variations occur in adult life
Position of follicles in normal human ovary during definitive histogenesis
No full textBackground: Follicular growth in the mammalian ovary follows a geographically determined pattern, but no exhaustive data about their spatial localization in the cortex of human ovary exists. Aim: The aim of this study is to assess the spatial position of the follicles during human ovarian definitive histogenesis using morphometric methods. Subjects: Ovaries removed from four fetuses, five newborns and one 8-month-old child with 46,XX karyotype was used. Outcome measures: The position of the different follicle categories (primordial, primary, secondary and antral) was estimated as percentage distance of the centroid of the follicle from the cortico-medullary boundary. Results: In normal ovaries, during definitive histogenesis, the primordial follicles progressively occupy more peripheral parts of the cortex (on average, 41% of cortical length at 20 weeks of fetal development, 53% at birth, 68% at 8 postnatal months). Primary follicles were crowded in the inner part of the cortex (newborn: 30-40% of cortical length; 8 months: 52% of cortical length). Secondary and antral follicles were sampled in all neonatal specimens and in the 8-month old specimen; they were grouped next to the cortico-medullary boundary. Conclusions: Ovarian development corresponded to a migration of the maximum crowding of follicles from a position next to the medulla towards a more peripheral location. The control of the primordial follicle assembly, recruitment and development are coordinated by locally produced paracrine factors. The action of these factors seems to follow a negative gradient from the cortex toward the medulla
Liver transplantation in man : morphometric analysis of the parenchymal alterations following cold ischaemia and warm ischaemia/reperfusion
Full text linkIschaemia and reperfusion phases represent critical events during liver transplantation. The purpose of this study was to describe morphological alterations of both vascular and parenchymal compartments after ischaemia and reperfusion and to evaluate the possible relationship between morphometric parameters and biochemical/clinical data. Three needle biopsies were drawn from 20 patients who underwent orthotopic liver transplantation. The first biopsy was taken before flushing with preservation solution, and the second and the third to evaluate respectively the effects of cold ischaemia and of warm ischaemia/reperfusion. Biopsies were examined by an image analyser and morphometric parameters related to the liver parenchyma were evaluated. At the second biopsy we observed a decrease of the endothelium volume fraction while the same parameter referred to the sinusoidal lumen achieved a peak value. The hepatocytes showed a lower surface parenchymal/vascular sides ratio. This parameter was reversed at the end of the reperfusion phase; furthermore the third biopsy revealed endothelial swelling and a decreased volume fraction of the sinusoidal lumen. The results quantify the damage to the sinusoidal bed which, as already known, is one of the main targets of cold ischaemia; warm ischaemia and reperfusion accentuate endothelial damage. The end of transplantation is characterised by damage chiefly to parenchymal cells. Hepatocytes show a rearrangement of their surface sides, probably related to the alterations of the sinusoidal bed. In addition, the fluctuations of morphometric parameters during ischaemia/reperfusion correlate positively with biochemical data and clinical course of the patients
Variations in facial soft tissues of Italian individuals with ectodermal dysplasia
No full textOBJECTIVE: To supply quantitative information about the facial soft tissues of patients with ectodermal dysplasia (ED). DESIGN, SETTING, AND PATIENTS: The three-dimensional coordinates of soft tissue facial landmarks were obtained using an electromagnetic digitizer in 20 Caucasian patients with ED (11 male and 9 female patients aged 7 to 41 years) and 391 healthy controls (163 female and 228 male subjects of comparable ages). From the landmarks, 15 facial dimensions and two angles were calculated. Data were compared with those collected in healthy individuals by computing z-scores. Two summary anthropometric measurements for quantifying craniofacial variations were assessed in both the patients and reference subjects: the mean z-score (an index of overall facial size) and its standard deviation, called the craniofacial variability index (an index of facial harmony). RESULTS: In patients with ED, a large variability was found for both the mean z-score and the craniofacial variability index. On average, the patients had a somewhat smaller facial size than the normal individuals, with a global disharmonious appearance. Overall, 70% of patients fell outside the quantitative definitions for normal facial size, harmony or both. When examining the distribution of the single z-scores of the 17 selected measurements, variable patterns were found, without consistent effects of age or sex. CONCLUSIONS: The facial soft tissue structures of patients with ED differed both in size and shape from those of normal controls of the same age, sex, and ethnic group
An expert system aimed to automatic diagnosis in normal microanatomy. 1, The flow chart of a decision tree
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Morphometric evaluation of rat liver after castration: effects of testosterone
No full textIn men and animals subject to orchiectomy, varying degrees of hypotrophy have often been observed, even involving non-reproductive organs. Liver hypotrophy appears particularly interesting in view of the metabolic alterations that could possibly ensue. We have applied the morphometric approach to the study of this kind of hypotrophy in castrated rats and in animals receiving a substitutive, testosterone-based treatment after castration. The morphometric model adopted was built on the basis of an interactive approach, using an image analyser (IBAS) with specially-designed software, and consists of number and size, as well as surface and volume fractions, of hepatocytes, their nuclei, cytoplasm, and the relevant relation to the sinusoidal bed. The effects of castration were revealed by a reduction of the mean volume of hepatocytes, associated with a reduction of the sinusoidal bed. Such reduction is correspondingly associated with an increase of the extraparenchymal components (endothelia, Glisson capsule). In the testosterone-treated group, while no appreciable symptoms of retrieval were yet observable in the volume of hepatocytes, the sinusoidal bed was instead superimposable onto the control group data as far as both volume and blood/hepatocyte interface were concerned. In the castrated animals the number of hepatocytes per mm3 was found to be increased. The group of testosterone administered rats also showed a high level for this parameter which, associated with the spread of the capillary bed, could be compatible with a picture of precocious hyperplastic response to the therapy. The correlation between the available morphometric data and the biochemical results which are being currently sought will further clarify the meaning of this phenomenon
Circadian Rhythmicity in the Rat Exocrine Pancreas : Chronomorphological Patterns
No full textOrcadian rhythmicity of the structural morphometric model of rat endocrine pancreas has been studied in 24 Wistar female rats, four months old, kept in LD 12:12. The following parameters were evaluated: the volume fractions of nucleus and cytoplasm of exocrine cells, the size distribution and number in unit tissue volume of acinar cell nuclei, the mean nuclear diameter, the shape coefficient of glandular acini (that is the ratio acinar area/perimeter2 which indicates the shifting of structures from circularity). A statistically significant circadian rhythm was demonstrated for the shape coefficient of glandular acini. Results obtained in the present experiment are compared with data recorded in a previous study
Three-dimensional nasal morphology in cleft lip and palate operated adult patients
No full textNasal morphology was assessed three-dimensionally in 18 cleft lip and palate operated patients aged 19 to 27 years, and in 161 sex- and age-matched control subjects. Comparisons were performed by Student t and Watson-Williams' tests. No differences were found in nasal volume or surface. Nasal width, alar base width, and inferior width of the nostrils were significantly larger in male patients than in the reference men. The nasal bridge was shorter. Similar differences were found in the female patients. In addition, the right nostril was larger and the nasal height shorter. In men, the nasolabial and the nasal tip angles were smaller in the patients than in the reference subjects, whereas the facial convexity angle was larger in the patients. In conclusion, the nose of adult operated cleft lip and palate patients differed from that of normal control subjects. Surgical corrections of the cleft lip and palate failed to provide a completely normal appearance. The methods might be used to indicate where additional procedures might be performed to approximate a reference population
An expert system aimed to automatic diagnosis in normal microanatomy. 2, An interactive, web available model for guided description and diagnosis
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