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Biomedical subjects

H M Pucciarelli

Publications and source records attributed to H M Pucciarelli.

34 records · Page 2Linked to original sources
PubMed1987

Influence of food restriction during gestation on craniofacial growth of the weanling rat.

Holtzman rats were subjected to food restriction during gestation or lactation, or both periods (overall stress). At weaning, male pup skulls were measured and female brains and cranial masticatory muscles were weighed and a neuromuscular index was calculated. It was found that gestational protein-calorie malnutrition (PCM) without suckling restoration accounted for about 30% of the growth delay observed under overall stress. That effect disappeared after a normal suckling restoration. Under the same conditions of maternal food restriction in both periods, growth delay in the offspring was greater during lactation than gestation. As in lactation, craniofacial changes during gestational restriction were due to an adjustive response of bone growth to PCM. This response seemed to accrue from an altered relationship between the growth of the brain-less sensitive and highly restorable-and the growth of the masticatory muscles-more sensitive and less restorable. Some degree of delay in orthocephalization would be the skeletal outcome of such adjustive neuromuscular response.

Animals↗
PubMed1987

Quantitative ultrastructural study of somatotropic cells in malnourished weanling rats.

A quantitative ultrastructural study of somatotropic cells was carried out in 21-day-old malnourished rats after maternal food restriction during the nursing period. Changes represented mainly by a reduced cytoplasmic mass and diminished secretory material were found. A decrease in growth hormone secretion of malnourished weanling rats is suggested.

Animals↗
PubMed1987

Effects of pre-weaning undernutrition on 21 day-old male rat skull form as described by the finite element method.

Conventional Roentgenographic Cephalometric Methods (RCM) have certain conceptual and geometric constraints that ensure that their descriptions of cephalic growth and comparisons of cephalic form are reference-frame-dependent; and it is impossible to determine which, if any, RCM reference frame provides a biologically more correct description or comparison. The use of the concepts of continuum mechanics and of the numerical techniques of the Finite Element Method (FEM) overcomes these constraints and provides reference-frame-independent (invariant) growth descriptions and form comparisons. In the FEM, the structure of the head is subdivided (discretized) into a number of smaller, finite, elements. The FEM then describes the growth behavior, or compares the form, of the entire continuum of points enclosed with each element independently; in RCM only the behaviors, or comparisons, of the landmark points are described. The FEM is described and its use illustrated by a comparison of the cephalic forms of 4 groups of weanling (21 d old) rats. The 1st (control) group is derived from normally nourished dams, while the other 3 groups are derived from dams who were malnourished throughout the weaning period in 3 group specific manners. The FEM permitted reference-frame-independent comparisons of the 4 different, and group specific, head forms. These differences were reflected in the forms of each of the finite elements. The differences in element forms between the 4 groups were shown to be related primarily to nutritionally produced alterations of either neurocranial or splanchocranial viscera. These differences were expressed in the alterations of the forms of the continua enclosed within the boundaries of the several finite elements, and secondarily in the form of the cranial skeleton.

Animals↗
PubMed1986

Variations in sexual dimorphism in the skulls of rats subjected to malnutrition, castration, and treatment with gonadal hormones.

Two groups of weanling rats were subjected to malnutrition, one with periodic injections of testosterone (males) and the other with estradiol (females). Two other groups (castrated males or castrated females) received normal feedings. In control animals, the relative weights (mg/gm body weight) of testes, seminal vesicles, and ovaries were greater than in malnourished rats. However, relative weights of those organs in hormone-treated, malnourished animals were greater than in those subjected to malnutrition alone and still greater than in controls. Normal sexual cranial dimorphism (SCD) was decreased 16% by male castration, 23% by malnutrition, and 83% by estradiol treatment in malnourished females. On the other hand, normal SCD was increased 20% by female castration and more than 200% by testosterone treatment in malnourished males. All monosexual comparisons corroborated the bisexual range of distances found. Testicular but not ovarian secretions seemed to influence sexual cranial dimorphism. Malnutrition delayed SCD because of a deficiency of testosterone level in stressed males. It is suggested that estradiol in females may counteract sexual cranial development and that its inhibitory effect may be additive to the testosterone deficit evoked by malnutrition.

Animals↗
PubMed1984

Variations of rat skull bone robusticity evoked by malnutrition.

Weanling Holtzman rats of both sexes were fed a control (25% protein), a 10% protein, and a 2% protein semisynthetic diet. Protein deficit (PD) and protein calorie malnutrition (PCM) were estimated from comparisons between control and 10% protein, and control and 2% protein-fed animals, respectively. Animals were killed when they were 56 days old and their skulls cleaned and disarticulated. Individual bones and incisors were ovendried to constant weight. Total weight (TW), maximal projected length (MPL), and robusticity index (RI) were determined on each bone and incisor. It was found that all the bones and incisors did not behave uniformly. They followed two main patterns: (1) Proportional variation. RI values were not affected by nutritional deficiencies. All basicranial bones and 4 of 10 facial bones followed this pattern. (2) Non-proportional variation. RI values were affected by nutritional deficiencies. This pattern was subdivided into two trends: (2a) PD-diminished RI values. Both upper and lower incisors and 1 of 10 facial bones followed this trend. (2b) PCM, but not PD, decreased RI values. All vault bones and the remaining five facial bones followed this trend. It was concluded that there was a differential robusticity response among cranial base, calvaria, and incisors. This response may be connected with the differences in both histogenetic characteristics of those components and the functional roles they have to perform. The nonvault intramembranous bones showed a nonspecific behavior. This fact precluded the classification of the facial region in some of the previously defined patterns.

Analysis of Variance↗
PubMed1983

Effects of protein-calorie malnutrition during suckling and post-weaning periods on discontinuous cranial traits in rats.

The influences of protein-calorie malnutrition (PCM), and sex during lactation and post-lactation on the frequencies of 25 discontinuous cranial traits (DCT), were investigated in Holtzman rats. Significant differences were observed in about 20% of the traits. Those traits were: the interfrontal fusion, the posterior incurvation of the palatine border, the double maxillary foramen, the double posterior palatine foramen, and the double frontal foramen. Total PCM was the nutritional factor which showed the greatest influence on the variability of the DCTs. It was followed, in decreasing order, by the PCM imposed during post-lactation and lactation. Sex had more influence than early PCM but less than late PCM. It is concluded that despite their apparent stability, a substantial number of DCTs were altered by both biological (like sex) and environmental factors (like nutritional deficiencies) imposed at different stages of postnatal development.

Aging↗
PubMed1983

Effects of post-weaning malnutrition on the weight of the head components in rats.

Female Holtzman rats, weighing about 40 g, were given one of each of the following treatments: (a) 6% protein diet ad libitum throughout; (b) 6% protein diet for 2 weeks followed by 25% protein diet ad libitum for 2 weeks; (c) 25% protein diet fed in amounts isocaloric with treatment (a) and (d) 25% protein diet ad libitum throughout. These treatments were applied from weaning (21 days) to 49 days of age. Selected pairs of treatments were compared in order to elicit the influences of protein-calorie malnutrition, malnutrition recuperation, and protein deficit on both the absolute and relative weights of the following head components: skin (plus subcutaneous adipose tissue), muscular mass, eyeballs, skull, and encephalon. DNA and total protein concentrations in encephalon and muscle were also measured. The head components were classified into stables, for which growth decreased less than that of the head as a whole, and variables, for which growth decreased more than that of the head as a whole. The eyeballs, encephalon, and skull behaved as stable components, whereas the muscular mass and skin did so as variable components. The well-known modifications in the craniofacial growth pattern evoked by nutritional deficiencies were explained by the different reactions shown by the encephalon, functionally associated with the neurocranium, and the skeletal muscles, functionally associated with the masticatory apparatus. The changes observed in DNA concentration suggest that protein deficit delayed muscle growth through a decrease in cell size rather than a decrease in cell number in the muscular fibre.

Animals↗
PubMed1983

Alterations in protein and mineral contents of rat skull bones, evoked by different protein levels of the diet.

Holtzman rats of both sexes were fed one of the following semisynthetic diets; 25% protein (control), 10% protein (slight malnutrition), 5% protein (medium malnutrition), and 2% protein (severe malnutrition). The skulls were cleaned and disarticulated with papain; they were defatted, dried, and the total weight (Tw) of each bone was determined. A gravimetric method of estimating bone protein-mineral ratio was performed. Following a decalcification with EDTA, the protein matrix was weighed (PMw). A protein-mineral index (PMI) was defined as: PMI = 100 (Tw-PMw)/Tw. The nutritional deficiencies imposed affected the protein and/or mineral contents of the bones according to three different patterns. The first pattern was followed by the bones of the vault and the facial region. The second one included the basicranial bones. The third one comprised the incisors. These patterns were associated with the histogenetic characteristics of the bones and teeth. A relationship between these findings and previously ascertained functional craniofacial variations in malnourished rats was found. From the differential behavior of the base, the vault, the masticatory apparatus and the incisors, it was inferred that each of these functional cranial components reacted to the experimentally unbalanced nutrition, according to a specific kind of adaptive mechanism.

Animals↗
PubMed1981

Growth of the functional components of the rat skull and its alteration by nutritional effects. A multivariate analysis.

Weanling male Holtzman rats were subjected to each of the following nutritional treatments: malnutrition-recuperation; undernutrition; and undernutrition-recuperation. The rats were sacrificed when they were 49 days old, and dimensions of each one of the neurocranial, respiratory, and masticatory components were measured. Each component was compared with its counterpart in control rats (21, 28, 35, 42, and 49 day-old) by means of Mahalanobis D2 distances. The same functional components of 49 day-old control skulls were compared with their counterparts in younger control skulls. The means of the chosen cranial dimensions were compared by Tukey tests. Two periods of craniofacial development were identified. In the first, both facial components showed a similar growth that was greater than the neurocranial growth. In the second period, the growth of the masticatory component was greater than that of the respiratory component, which in turn, was greater than that of the neurocranial component. Nutritional deficiencies delayed the growth of the masticatory component more than that of the neurocranial component, which, in turn, was delayed more than that of the respiratory one. About 7% of the dimensions measured were insensitive to both growth and nutrition; 31% were insensitive to nutrition; and 62% were modified by nutrition. Craniofacial development in the rat seems to be a process more complex than what has been generally accepted. A nutritional stress may alter the relative growth between the facial functional components to a greater extent than that between the major functional components; viz. the neurocranium and the splanchnocranium. The cranial dimensions studied were classified according to their sensitivity to growth and/or nutrition into invariable, nutritionally stable, and nutritionally unstable traits.

Age Factors↗
PubMed1981

Effect of age, sex and nutrition on discontinuous traits of rat skull.

The effect of biological (age and sex) and environmental factors (protein-calorie malnutrition and protein deficit) on 24 discontinuous cranial traits was investigated in Holtzman rats. The traits affected were (a) the interfrontal fusion, by age and nutrition; (b) the double posterior palatine foramen, by sex and nutrition, and (c) the double maxillary foramen, by nutrition. It is concluded that most of the traits studied were fairly stable. Nevertheless, it must be pointed out that taxonomic studies based on discontinuous cranial traits should be interpreted with care due to the influence of environmental and biological factors on the phenotypic expression of some of them.

Age Factors↗
PubMed1980

The effects of race, sex, and nutrition on craniofacial differeniation in rats. A multivariate analysis.

Wistar and Holtzman rats were fed (a) control diet ad libitum (controls); (b) restricted control diet (undernourished); and (c) low-protein diet ad libitum (malnourished), from weaning to 70 days of age. Mahalanobis D2 distances between cranial groups were assessed. Besides, differences among traits were assessed by the analysis of variance and Tukey test. The relative influence of each factory yielded a decreasing sequence: protein-calorie malnutrition (PCM)-Protein deficit (PD)-race-sex. However, this sequence differed between races. The significant sexual dimorphism in Wistar controls disappeared because of PCM and PD. Race and sex, race and nutrition, and race, sex, and nutrition interacted. Traits were classified into: (a) specific, (b) nonspecific, and (c) invariable. The specific race traits were alveolar length and foraminal width. The specific nutritional traits were neurocranial and splanchnocranial length and heights, alveolar and neurocranial widths, and the neuro-splanchnocranial index (NSI) and the neurocranial vertico-transversal index (NVTI). There were no specific sexual traits. It was concluded that nutritional factors can modify a taxonomic distance in three different ways: (a) evoking morphological differences among populations of the same racial group, (b) altering differences among racial groups, and (c) modifying the pattern of sexual dimorphism of a population. It is suggested that craniological studies should take into account only the set of specific traits, disregarding both specific traits due to other factors and nonspecific ones.

Animals↗
PubMed1978

The influence of experimental deformation on craniofacial development in rats.

Cranial deformation was produced experimentally in rats 8 to 40 days old for the purpose of studying the rotation of the craniofacial bones and the modification of the growth rates of the functional cranial components. One hundred and twenty four skulls (65 males and 59 females) were employed, classified as: deformed , deformed-hydrocephalic, sham-operated and controls. A midsagittal diagram was drawn for each skull and the angle subtended by each bone with respect to the vestibular plane was measured. Growth indices were worked out for both the neural skull and the facial skull. Deformation altered the rotation of the parietal, interparietal and basisphenoidal bones and restricted the rotation of the fronto-ethmo-facial complex. Alteration of the longitudinal growth rates of the dorsal and basilar components of the neurocranium and the splanchnocranium produced the persistence of the klinorynchal state.

Animals↗
PubMed1978

Craniofacial development of the rat with respect to vestibular orientation.

The vestibular orientation was applied in the present work. Its purpose was to contribute to the knowledge of the craniofacial development of the growing rat. Sagittal cuts were made in 91 crania from Wistar rats (44 males and 47 females) at 8, 15, 30 and 60 days of age. The x and y coordinates of the sagittal points were determined. The sagittal intersection of the vestibular plane was employed as the abscissa and its perpendicular at the mid point of the external semicircular canal (mesovestibion) as the ordinate. Cranial diagrams were constructed in which the length of the sagittal projection of each bone and its angulation with respect to the abscissa were measured. It was confirmed a progressive evolution towards orthocrania due to the bone rotation complexes, which characterized three cranial regions: the anterior region (frontal-ethmiodal-facial complex) with trigonometric rotation; the mid region (parietal-sphenoidal complex) remained stable, and the posterior region (interparietal-occipital complex) with clockwise rotation. Each complex had its own pattern of rotation. The causal factors reside in the differential increment between the functional components: (a) neurocranium-splanchnocranium, (b) neurocranium-cervical column, (c) dorsal neurocranium-basilar neurocranium and (d) dorsal splanchnocranium-basilar splanchnocranium. Its etiology obeys to the functional requirements induced by the adaptation of the modern rodents.

Animals↗