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Biomedical subjects

K R Kimes

Publications and source records attributed to K R Kimes.

15 recordsLinked to original sources

Anterior paraseptal cartilage development in normal and cleft lip and palate human fetal specimens.

As part of an ongoing study of age-related variation in fetal cleft lip and palate nasal capsule morphology, anterior paraseptal cartilage development was examined histologically in a sample of nine complete cleft lip and palate human fetuses, and 20 without clefts ranging in age from 8 to 21 weeks. A computer reconstruction technique was used to quantify lengths, volumes, and generate growth curves from various regression equations. Anterior paraseptal cartilage length was seen to change in a sigmoidal fashion while volume changes were best described by a logarithmic curve for both groups, with the steepest increases from 15 to 21 weeks. Cleft specimens exhibited significantly different growth rates (line slopes) for both length and volume dimensions compared with the normal specimens. The larger, for age, cartilages were associated with an enlarged, inferior border of the nasal septal cartilage and vomer in the cleft sample. These results are consonant with previous findings in this cleft fetal sample of other enlarged midline structures (i.e., nasal septal cartilage and vomer). Results suggest that growth abnormalities in one or all of these structures may be yet another mechanism for early nasal airway impingement and reduction in cleft lip and palate neonates.

Case-Control Studies↗

Multivariate analysis of second trimester midfacial morphology in normal and cleft lip and palate human fetal specimens.

To better understand the contribution of congenital dysmorphogenesis to postnatal midfacial dysplasia in individuals with complete cleft lip and palate (CLP), a series of studies were undertaken to investigate age related changes in a number of midfacial components for a sample of 20 normal and 9 complete CLP second trimester fetal specimens. Using data from this sample, the present study assessed the complex multivariate relationships among these variables which represent the fetal normal and CLP midface. Ten variables were standardized relative to crown-rump length and used in Canonical Discriminant Function Analysis (CDFA). CDF analysis revealed that five variables best described the midface and accounted for 72% of the overall variance. These included nasal capsule length, nasal airway volume, premaxillary length, premaxillary volume, and tongue volume. Classification using the CDFA coefficients resulted in correct group membership assignment for 26 of 29 total specimens (89.66%), 8 of 9 cleft (88.9%), and 18 of 20 normal specimens (90.0%). These results suggest that by as early as the second trimester CLP fetuses have a significantly distinct set of midfacial morphological relationships. Some or all of these factors may be responsible for postnatal growth dysplasias noted in CLP individuals.

Cleft Lip↗

Growth rate of the vomer in normal and cleft lip and palate human fetal specimens.

The present study, part of an ongoing investigation of normal and dysmorphic development of the human fetal oronasal capsule, examined the rate of growth of the vomer. For comparative purposes, 29 human fetal specimens (20 "normal" and 9 cleft lip and palate [CLP]) were celloidin embedded, sectioned, stained with hematoxylin and eosin, and serially digitized. The specimens ranged from 8 to 21 weeks in postmenstrual age. The application of a well-documented three-dimensional reconstruction technique provided quantification of several aspects of the vomer. CLP vomer length and volume were growing at a faster rate in the 8 to 21 week age range. Growth curves were produced by plotting length and volume against postmenstrual age and a significant difference was noted between the slopes (growth rate) of the linear component of the normal and CLP growth curves for vomer length (p less than .001) and volume (p less than .001). This study tested the hypothesis of a more rapidly growing 8 to 21 week CLP vomer and observed that the growth trends of the CLP vomer are similar to those of the CLP nasal septum, which also was found to possess a significantly larger (p less than .001) volumetric growth rate throughout the course of the vomer. Comparative findings suggest that a pathogenetic correlate of CLP is the rapid enlargement of the midline structures of the oral and nasal capsules.

Cephalometry↗

Premaxillary development in normal and cleft lip and palate human fetuses using three-dimensional computer reconstruction.

As part of an ongoing study of cleft lip and palate fetal morphology, premaxillary development was examined cross-sectionally in a sample of 20 "normal" fetuses and 9 fetuses with complete clefts of the lip and palate ranging in age from 8 to 21 weeks. The specimens were stained with H and E and sectioned at 20 microns in the coronal plane. A computer reconstruction technique was used to produce three-dimensional images of the premaxilla. Premaxillary length and volume were quantified and used to produce fetal growth curves. Qualitatively, normal fetal specimens exhibited symmetrical premaxillary ontogenesis with development of the distinctive perinatal midfacial morphology noted by 14 weeks. In contrast, complete unilateral cleft specimens exhibited severe asymmetry and dysmorphogenesis through 20.5 weeks. Quantitatively, premaxillary length and volume values for the two samples were similar from 8 to 14 weeks and changed in a curvilinear fashion with the steepest increases seen in normal specimens from 14 to 21 weeks. Cleft specimens exhibited significantly (p less than 0.001) reduced premaxillary length and volume rate changes (i.e., slopes of regression lines generated from polynomial and logarithmic regression models) for this time period. Results suggest that premaxillary deficiencies noted clinically in cleft perinates may be related more to early prenatal midfacial growth deficits than initial mesenchymal tissue deficiencies or abnormal growth patterns.

Cephalometry↗

Size and growth rate of the tongue in normal and cleft lip and palate human fetal specimens.

In the present study, the size and rate of growth of the tongue was assessed in human fetuses. For comparative purposes, 29 human fetal specimens (20 "normal" and 9 with cleft lip and palate were celloidin embedded, sectioned, stained with hematoxylin and eosin, and serially photomicrographed. The specimens ranged from 8 to 21 weeks postmenstrual age. The application of a well documented three-dimensional reconstruction technique provided quantification of several aspects of the tongue. Tongue length and volume were larger in the cleft specimens than for the normal specimens, while both length and volume were growing at a faster rate. Growth curves were produced by plotting length and volume against postmenstrual age and a significant difference was noted between the slopes (growth rate) of the growth curves for tongue length and volume for the two groups. Tongue length increase was approximately 2.27 times greater and tongue volume increase was approximately 1.64 times more for the cleft specimens than for the normal specimens from 8 to 21 weeks. In support of these findings, tongue volume was relatively larger expressed as a contribution of total oronasal capsule volume in the cleft specimens. For an initial age category (8 to 12 weeks), tongue volume in the cleft specimens was larger, growing at a faster rate than normal tongue volume and a significant difference was noted between the slopes of the growth curves. No significant difference was observed between the tongue length indices in the initial or the 8 to 21 week age category.(ABSTRACT TRUNCATED AT 250 WORDS)

Cephalometry↗

Developmental correlates of midfacial components in a normal and cleft lip and palate human fetal sample.

Midfacial hypoplasia in patients with complete clefts of the lip and palate is considered to be the result of congenital dysmorphogenesis combined with surgical effects. The present study describes congenital correlates of midfacial hypoplasia by examining the relationships between premaxillary size and a number of adjacent oronasal capsular components in a sample of second trimester normal and complete cleft fetal specimens. Midfacial relationships from previously published data from 3-D computer reconstructions of histologic material were assessed by multiple regression and path analyses. Stepwise multiple regression analysis revealed that the combination of age (body size) and nasal septal length were the best predictor variables of premaxillary length and accounted for 90 percent and 93 percent (p less than .01) of the variance in normal and cleft fetal specimens, respectively. Tongue length was seen to slightly increase the R2 values in the cleft, but not the normal sample. Path analysis results revealed that with body size held constant, nasal capsule volume explained only 3 percent of premaxillary variance, while septal length accounted for approximately 45 percent of the variance (p less than .05). Results show that the relationships of the midfacial components in the cleft fetal sample closely followed normal second-trimester midfacial growth patterns and suggest that the septal-traction model may be a more parsimonious and primary explanatory mechanism of early midfacial growth than the functional matrix model in both normal and complete cleft fetal specimens.

Body Constitution↗

A test of two midfacial growth models using path analysis of normal human fetal material.

Predictions about the temporal sequencing (i.e., primacy) and causal relationships between various midfacial growth components, as suggested by two midfacial growth models (functional matrix and septal traction), were examined in the present study. The relationships between quantitative changes in the nasal septum, nasal airway, nasolabial musculature, and premaxilla of 15 normal human fetal specimens, ranging in age from 12 to 20 weeks postmenstrual age, were assessed using the multivariate technique of path analysis. Path analysis results revealed that the causal sequence of variables proposed by the septal-traction model explained more of the variance in premaxillary size (87 percent goodness-of-fit) than did the sequence of variables proposed by the functional matrix model (65 percent goodness-of-fit). These results suggest that the septal-traction model may be a more parsimonious and primary explanation of early human fetal midfacial growth than the functional matrix model. Path analysis results also reiterate the observed complex developmental relationships within the fetal labioseptopremaxillary region, knowledge of which may be important in the surgical management of infants with complete cleft.

Cross-Sectional Studies↗

Development of the orbicularis oris muscle in normal and cleft lip and palate human fetuses using three-dimensional computer reconstruction.

As part of an ongoing study of cleft lip and palate fetal morphology, normal and dysmorphic development of the human fetal orbicularis oris muscle was studied in a cross-sectional sample of 29 human fetuses (20 "normal" and 9 cleft lip and palate) ranging in age from 8 to 21 postmenstrual weeks. The specimens were embedded in celloidin and sectioned at 20 microns, and every tenth section was stained with hematoxylin and eosin. A computer reconstruction technique was applied to produce three-dimensional representations of the orbicularis oris muscle. The orbicularis oris muscle in the normal fetal sample with discernible lip fibers (N = 15) increased symmetrically in both fiber density and complexity from 12 to 21 weeks. Metrically, muscle volume and thickness growth curves were consistent with qualitative observations. In contrast, the unilateral cleft lip and palate fetal specimens with discernible lip fibers (N = 3) exhibited a 3.5-week delay in overall muscle development, asymmetrical fiber distribution, and abnormal fiber insertions. However, quantitatively, no significant (p greater than 0.05) differences were noted in orbicularis oris muscle thickness or volume between the normal and cleft lip and palate fetal specimens through 21 weeks. Findings suggest that orbicularis muscle deficiency, noted clinically in cleft lip and palate neonates, may be a result of perinatal functional dysmorphogenesis rather than congenital mesenchymal reduction or deficiency.

Cleft Lip↗

Relative contributions of the nasal septum and airways to total nasal capsule volume in normal and cleft lip and palate fetal specimens.

The present study examines the relative contributions of the nasal septum and airway volumes to the total volume of the fetal nasal capsule. For comparative purposes, 29 human fetal specimens (20 "normal" and 9 with cleft lip and palate (CLP] were celloidin embedded, sectioned, and stained with hemotoxylin and eosin. The specimens ranged from 8 to 21 weeks in postmenstrual age. Photomicrographs of the serial sections allowed selected anatomic structures to be computer digitized, reconstructed as three-dimensional computer representations, and quantified. Various nasal capsule component measurements were compared with overall nasal capsule size values, producing relative size indices. Significant differences (p less than 0.05) were noted between the "normal" and CLP fetal samples in the relative sizes of the nasal capsule, airways, and septum. Relative mean CLP nasal capsule volume was 14% smaller than normal, relative mean CLP airway volume was approximately 43% smaller than that of the normal specimens, whereas relative mean CLP septum volume was approximately 45% larger. Aspect ratios (i.e., height:width ratios) were utilized for shape analysis of the nasal septal cartilage and indicated that the CLP septal shape was one of increased width relative to height compared with normal specimens. Results were consonant with clinical impressions of nasal capsule deficiency in the CLP nasal capsule and revealed some new structural associations in the fetal nasal capsule.

Airway Obstruction↗

Analysis of the size variability of the human normal and cleft palate fetal nasal capsule by means of three-dimensional computer reconstruction of histologic preparations.

As part of an ongoing study of cleft palate fetal morphology, normal and dysmorphic development of the human fetal nasal capsule was studied in a cross-sectional sample of 29 human fetuses (20 "normal" and 9 cleft), ranging in age from 8 to 21 postmenstrual weeks. The specimens were celloidin embedded, sectioned at 20 microns, and every tenth section stained with hematoxylin and eosin. A computer reconstruction technique was applied to produce three-dimensional representations of the nasal capsule, nasal septal cartilage, and nasal airway. Qualitatively, the cleft palate nasal capsule exhibited gross abnormalities including cartilaginous nasal septum deformities, abnormal septal volume and hypertrophy, reduced nasal airway and capsule volumes, and abnormal spatial relationships between the nasal capsule components. These results suggest that the reduced nasal airways, noted clinically in cleft perinates, may be a function of an interaction of nasal capsule deficiency and nasal septum hypertrophy. However, when lengths and volumes were plotted against fetal postmenstrual age, producing fetal "growth" curves, no significant differences (p greater than 0.05) were noted for growth rates (slopes) or nasal capsule size between the normal and cleft palate fetal samples. Curvilinear regression analysis revealed that both normal and cleft palate nasal capsule and septum lengths changed in a sigmoidal fashion, with the steepest increases from 13 to 17 weeks. In contrast, nasal capsule, airway, and septum volumes changed curvilinearly, showing slow relative growth rates from 8 to 17 weeks, which increased sharply from 18 to 21 weeks. Results suggest that from 8 to 21 weeks prenatally, normal and cleft palate specimens exhibited a similar pattern of fetal nasal capsule development that was characterized by an initial anteroposterior elongation followed by circumferential (i.e., volumetric) growth.

Cleft Palate↗

Traction, prenatal development, and the labioseptopremaxillary region.

Twenty-nine human fetuses ranging in age from 8 to 22 weeks were coronally sectioned for gross light microscope analysis of the labioseptopremaxillary region. In "normal" fetuses from 8 to 15 weeks, the septopremaxillary ligament was present. The horizontal and oblique fibers of the orbicularis oris muscle were poorly developed initially and increased in density with age. The anterior nasal spine and the alveolar process of the maxillae were present and in the same coronal plane. From 15 to 22 weeks, the horizontal and oblique fibers were well developed and inserted into the perichondrium of both alar and nasal cartilages. The septopremaxillary ligament was thus obliterated or more difficult to define, and the anterior nasal spine was located anterior to the alveolar process. In the cleft fetuses from 8 to 15 weeks, the nasal septum was absent or horizontally rotated. No septopremaxillary ligament or orbicularis oris fibers were noted, and the anterior nasal spine was not distinguishable. From weeks 15 to 20, the fibers of the orbicularis oris muscle were poorly differentiated, inserting asymmetrically into the perichondrium of the lateral alar cartilage on the noncleft side, the septopremaxillary ligament was absent, and the anterior nasal spine and the premaxillae were in the same coronal plane. These results suggest that the midfacial deficiencies seen in some cleft patients might have an origin in prenatal dysmorphology.

Cleft Palate↗

Alteration of Scapular morphology through experimental behavioral modification in the laboratory mouse (Mus musculus).

It is demonstrated that the behavior/morphology interface can be studied in controlled experiments. The normal locomotor behavior of the laboratory mouse (Mus musculus) was modified so that animals were restricted to either a plantigrade, 'non-climbing', control environment or an experimental, suspensory, 'climbing' environment. Distinct scapular correlates of the modified behavior were observed. Climbing experimental animals exhibited narrower scapulae with angular measurements consistent with reduced scapular breadth. Plantigrade control animals exhibited broader more squared scapulae. It is suggested that the methodology used here can be extended to natural populations with analogous locomotor behaviors.

Animals↗

Scapular correlates of muscle morphology in Papio cynocephalus.

The scapula responds to the compressive states of its surrounding matrix produced by muscle functioning and weight bearing in the upper extremity with discernible structural correlates. These structural correlates can be utilized to infer locomotor behavior. After dissection and drying, the weights of several muscles of the shoulder region of 11 adult female baboons (Papio cynocephalus) were statistically compared to various dimensions of the bony scapula. A significant correlation was obtained between the weights of the individual compressive muscles, the combined weights of the compressive muscles and a scapular dimension of width. A nonsignificant correlation between these muscles and a sscapular dimension of length was also found. The results of this study were compared to those of a previous study of the scapular musculature in Macaca and opposing conclusions were obtained. The advisability of lumping macaques and baboons into a single gross locomotor category is rejected.

Animals↗