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 degrees 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.

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.

Significance of the role of self-study and group discussion.

The study of anatomy is experiencing a reduction in course duration and content, lecture and dissection hours, and number of lectures and examinations. This necessitates that medical students develop skills for self-study. Toward that end, a self-study module in basic anatomy was tested. Fifty-seven new entrants were given a pretest (Pretest A) containing a questionnaire on basic anatomy. Then, in three groups each of 11 and two groups each of 12, they learned basic anatomy from recommended books in the library by self-study for 2 hours. They discussed what they had learned among their group members during a practical exercise, followed by a posttest (Posttest A). A control group of 57 new entrants during another year was given the same pretest (Pretest B) and a lecture on basic anatomy. Then, without opportunity for self-study, they were given a posttest (Posttest B). The answers were scored out of 40. The students' mean mark in Pretest A was poor. All the groups performed well in the practical exercise. In Posttest A, the mean mark increased significantly (P < 0.001), by 9.4. It shows that self-study and group discussions significantly helped the students in construction of core anatomical knowledge as well as the acquisition, assimilation, and application of anatomical concepts and content. The mean mark in Pretest B was also poor. In Posttest B, the mean mark increased significantly (P < 0.001), by 14.2. This indicates that the traditional teaching session is also useful and serves to advance student knowledge. Thus our innovative study module can create a positive learning environment and can become an alternative to traditional instruction in teaching anatomical terminology and basic anatomy.

Handedness identification from intertubercular sulcus of the humerus by discriminant function analysis.

The accurate determination of skeletal handedness is a critical requirement in physical anthropology and forensic science. To differentiate handedness, discriminant function analysis is applied using the parameters of right and left intertubercular sulci. A total of 200 matched unpaired adult humeri (100 right and 100 left), collected from the Department of Anatomy, were used to measure four parameters of the intertubercular sulcus namely, width (X1), depth (X2), angle of medial wall (X3) and angle of lateral wall (X4) and to note the presence of supratubercular ridge of Meyer (X5). The discriminant function obtained with the significant variables, angle of medial wall (X3), angle of lateral wall (X4) and presence of the supratubercular Meyer (X5) is: Y = 0.093X3 + 0.056X4 + 0.775X5 - 13.46. The accuracy of correct classification using the discriminant function is 89% which is the best starting point for handedness determination approach. The methodology of using discriminant function can be crucial for medicolegal jurisprudence.

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 degrees to 136 degrees with a mean of 126.7 degrees 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.

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.

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.

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.

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 degrees with a mean of +12.3 degrees. 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.

Intertubercular sulcus of the humerus as an indicator of handedness and humeral length.

Measurements of the maximum width and depth of the intertubercular sulcus (ITS), angles of the medial and lateral walls with the floor of the ITS, as well as the length of the humerus in 100 right and 100 left matched, unpaired dry humeri of 100 adults were statistically analyzed. Since 90-95% of the general population is right handed, on the basis of altered size of the dimensions of the right ITS relative to the left, it is proposed that greater width and smaller angles of the medial and lateral walls of the ITS of one side are indicative of handedness on that side. Handedness can further be deduced by the presence of a < 50 degrees angle of the medial wall and of a supratubercular ridge of Meyer on that side. The length of the humerus correlated with the width and depth of the ITS (P < 0.001). Regression equations of the length of the humerus on width, depth, as well as width and depth of the ITS have been derived.

Ultrastructural specialization of intestinal epithelium over Peyer's patches in the bonnet monkey, Macaca radiata.

The follicle associated epithelium (FAE) which separates the lymphoid follicle of Peyer's patch from the gut lumen is known to have specialized cells called M cells or "microfold" cells in man and certain animals. These cells are considered to be involved in antigen uptake and transport. Our light microscopic study of the small intestine of bonnet monkeys suggested the presence of such specialised cells in FAE. We have confirmed the presence of M cells in bonnet monkey FAE having ultrastructural features very similar to those of human M cells.

Microscopic anatomy of small intestine of Macaca radiata with special reference to gut associated lymphoid tissue.

The hitherto unreported microscopic anatomy of the small intestine of the bonnet monkey (M. radiata) was studied. There was a striking similarity in the general structure and cellular composition of the small intestine of the animal and that of humans. Of special interest was our observation of the occurrence of cells interspersed in the follicle associated epithelium which were morphologically similar to human M cells. These cells were pale, devoid of a brush border and frequently had lymphocytes apparently enclosed within them.

Variations in the intertubercular sulcus of the humerus related to handedness.

Measurements of the maximum width and depth of the intertubercular sulcus (ITS) and the angles formed by the medial and lateral walls of the ITS with the plane of its floor were recorded in 200 adult human humeri, 100 each from the right and left sides. The ITS was more often wider and its medial wall formed a more acute angle with the plane of its floor in right-sided humeri. A supratubercular ridge on the humerus was present more frequently on the right than on the left. The presence of this ridge is probably more necessary on the right to prevent medial displacement of the long head of the biceps tendon from the ITS. The greater thrust exerted by the taut tendon of the long head of the biceps in the upper limb that is used preferentially probably induces structural differences in the ITS.