G. Chandi

Prediction of the femoral neck‐shaft angle from the length of the femoral neck

A total of 171 adult South Indian femora, devoid of gross pathology, are used to measure the neck‐shaft angle, length of the neck, intertrochanteric apical axis length, maximum vertical diameter of the head, kinematic radius, and maximum femoral length. The neck‐shaft angle ranges from 120° to 136° with a mean of 126.7° and no significant side difference. The angle significantly and positively correlates with neck length, intertrochanteric apical axis length, kinematic radius, and minimum femoral length (P < 0.001) but not with the vertical diameter of the head. Regression equations for the neck‐shaft angle against the correlated parameters are derived but only that against the length of the neck is strongly significant. From those correlations, 1) the neck‐shaft angle can be estimated from a proximal femoral fragment, and 2) the required size of the length of the neck can be determined to design prostheses for the restoration of normal neck‐shaft angle. Further, any estimated defective angle can be of help for forensic identification of an individual with pathological changes leading to an abnormal gait. Clin. Anat. 10:318–323, 1997.

Angle of torsion of the femur and its correlates

Unpaired femora (171), devoid of gross pathology and grouped by gender (94 male and 77 female) and side (88 left and 83 right), were used to measure the angle of femoral torsion and the maximum femur length and to score the degree of prominency of the superior cervical tubercle, intertrochanteric line, quadrate tubercle, linea aspera, and adductor tubercle. The angle of torsion ranged from −9 to +35° with a mean of +12.3°. The means were not significantly different either by gender or side. The angle correlated negatively with superior cervical tubercle, intertrochanteric line, and adductor tubercle (P < 0.001), positively with quadrate tubercle (P < 0.001) but not with linea aspera, neck‐shaft angle, or length of femur. Bony prominences were significantly more apparent in males. There was no significant association between prominency and side. The torsion seems to be brought about by muscular activity and capsular and ligamentous strain at the hip. This study suggests to clinicians the possibility of correction of torsion defects in certain hip diseases of growing children by suitable alteration in posture of the lower extremity.

Quantitative analysis of CD1a (T6) positive Langerhans cells in human tonsil epithelium

Fifty-one human palatine tonsils of both sexes and 4-54 years of age were studied for quantitative analysis of Langerhans cells in the epithelium using CD1a (T6), which is a specific immunological marker for Langerhans cells and indeterminate cells. Cryo-sections were stained using the avidin biotin peroxidase method. Using light microscopy, CD1a-positive dark brown cells with dendritic processes were identified as Langerhans cells, which were located in the epithelium, subepithelial tissue, follicles and interfollicular areas. The Langerhans cells were counted only in the tonsil epithelium per zone of 1.1 mm length of basement membrane. For each biopsy, 25 such zones were studied. The mean number (SEM) of Langerhans cells per zone of tonsil epithelium was found to be 37 (+/- 0.5). In the male, it was 36 (+/- 0.7) but in the female, it was 38 (+/- 0.2). In different age subgroups, the mean number (SEM) varied between 40 (+/- 1.7) and 14 (+/- 1.1). In the age subgroups of 11-15, 16-20, and 21-25 years, the mean number showed significant sex differences. Since the 11-15, 16-20, and 21-25 age subgroups in the female showed an increased number of Langerhans cells, it is concluded that the immunological role of the palatine tonsils is increased during puberty and adolescence. In the female, there was a negative correlation (r = -0.196, p < 0.01) between age subgroups and mean numbers, but in the male there was no correlation (r = 0.008). Overall, in all the 51 biopsies together, there was a negative correlation (r = -0.017, p < 0.01) and significant (p < 0.001) sex and age differences.

Route of lymphocyte migration through the high endothelial venule (HEV) in human palatine tonsil

Eleven palatine tonsils were collected from subjects who underwent tonsillectomy in Christian Medical College Hospital and the route of migration of lymphocytes through the high endothelial vessel was studied under EM. In the interendothelial route, migration of a lymphocyte through HEV wall began with the adhesion of a lymphocyte to the surface of endothelial cells by means of a short cytoplasmic projection in the vicinity of intercellular space. The projection extended into the cleft between adjacent endothelial cells. The lymphocyte migrated through HEV by diapedesis. After the lymphocyte had traversed the interendothelial space, it occupied the subendothelial space. In the transendothelial route, migration of a lymphocyte through HEV was initiated by adherence of the lymphocyte to the endothelial cell. The adherent lymphocyte compressed or invaginated into the cytoplasm of the endothelial cell, entered the endothelial cell, was completely enclosed within the endothelial cell cytoplasm, and emerged from the endothelial cell to occupy the subendothelial space. Evidence is presented from static transmission electron microscopic pictures for the migration of lymphocytes by both interendothelial and transendothelial routes through the high endothelial venule.

Gross morphology and ultrastructure of dendritic cells in the normal human decidua.

Five normal placentae of normal pregnancy and delivery were used to study the gross morphology and ultrastructure of the dendritic cells in the normal human decidua. Zinc iodide osmium (ZIO) mixture was prepared. Small pieces of the placenta were processed for light microscopy and electron microscopy. For light microscopy, the small pieces of placenta were incubated in 20 mM PBS‐EDTA solution, ph 7.4 at 37°C to detach the basal plate. The basal plate pieces were incubated in ZIO. A wholemount preparation of the basal plate demonstrated the whole profile and gross morphology of the dendritic cell. For electron microscopy, the placenta pieces were fixed in 3% glutaraldehyde in 0.1 M phosphate buffer, ph 7.4, washed with phosphate buffer, put in ZIO mixture, washed in distilled water, dehydrated in graded ethanol, cleared in propylene oxide, and embedded in resin. Ultra thin sections of the ZIO blocks were cut using a diamond knife and stained with lead citrate. Ultrastructure of the dendritic cell presented multiple cytoplasmic processes, lobulated or round or oval, heterochromatic or euchromatic nucleus, mitochondria, free ribosomes, and pieces of rough endoplasmic reticulum, but no Birbeck granules. Clin. Anat. 13:177–180, 2000.

Reconstruction of femur length from markers of its proximal end.

Length of femur and stature are of forensic and anthropological significance. Bony markers such as the head and neck of the femur can be of use in determining the femoral length when only a fragment of the proximal femur is available. A total of 171 South Indian unpaired femora, devoid of gross pathology and grouped by genders and sides, were used to measure the neck‐shaft angle, neck length, intertrochanteric apical axis length, maximum vertical diameter of the femur head, and maximum femur length. The data were statistically analyzed for regression. Length of femur significantly correlated with the other dimensions. Simple (linear) regression equations of the length of femur against the neck‐shaft angle, neck length, intertrochanteric apical axis length, and maximum vertical diameter of the head have been derived. The equations seem to be robust and can be used for different populations.

Bony markers at the distal end of the radius for estimating handedness and radial length

Measurements of the size of the bony markers at the distal end of the radius as well as the length of the radius in 61 left and 64 right dry radii were statistically analyzed. Since 90-95% of the general population is right-handed, as based on differences in the size of the right sided markers relative to the left, it is proposed that the greater distance between the dorsal tubercle and styloid process and the greater dorso-palmar diameter of the carpal articular surface opposite the dorsal tubercle are indicative of right-handedness. The length of the radius correlated with: the radio-ulnar transverse diameter at the distal end; the distance between the dorsal tubercle and the styloid process; the dorso-palmar diameter of the distal end opposite the dorsal tubercle; the dorso-palmar diameter of the carpal articular surface opposite to the dorsal tubercle; the dorso-palmar diameter of the distal end opposite the medial margin of the groove for the extensor pollicis longus; the dorso-palmar diameter of the distal end opposite the floor of the groove for the extensor pollicis longus and, finally, the height of the dorsal tubercle in relation to the posterior margin of the carpal articular surface (P < 0.001). Regression equations of the length of the radius for these markers have been derived.

Introduction to histology through the use of familiar objects: Innovative teaching module

To introduce first‐year medical students to fundamental concepts in histology and facilitate interpretation of two‐dimensional images in the context of the three‐dimensional nature of the object, a simple teaching module consisting of active exercises plus group discussions, using familiar objects from everyday use, was planned. In the process of mentally reconstructing sections through familiar objects, and representing in diagrams the appearance of these sections, students learned the use of common histology terms; the value of studying sections in series and at different planes; and spatial relationships of a) a nucleus within a cell, and b) tissue components within solid and hollow organs. Their understanding of these concepts was found to be good when evaluated by a multiple‐choice‐questions test, suggesting that this is an effective method for introducing beginners to fundamentals of histology. Clin. Anat. 10:333–336, 1997.