Light and transmission electron microscopic study of spinal cord in embalmed and fresh cadavers.

Objective : To observe and differentiate histological structures and ultrastructures by light microscope and transmission electron microscope between embalmed cadaveric spinal cord and fresh cadaveric spinal cord. Methods : The spinal cords were dissected from seven embalmed cadavers of the Department of Anatomy, Faculty of Medicine Siriraj Hospital, Mahidol University. The specimens were prepared for routine hematoxylin and eosin (H&E) staining for light microscope (LM)study. Some of the specimens were prepared to study by transmission electron microscope (TEM). Finally we observe and compare between spinal cord from embalmed cadaver and fresh cadaver. Results : By viewing with light microscope, the quality of spinal cords from embalmed cadavers are better and clearer than from fresh cadavers. Viewed by transmission electron microscope, the lipid part in the spinal cord from cadaveric embalmed tissues is degenerated but the protein part is not deformed. Conclusion : The spinal cords from cadavers which were fixed by excess formalin injection and embalmed in formalin for 1-2 years , are well-preserved for hematoxylin and eosin (H&E) staining techniques for light microscope (LM) study in Histology. However in the EM of spinal cord sections from embalmed cadavers, the protein component was more likely withstand to formalin and embalmment procedures compared to the lipid componennt (e.g.myelin sheath, cell membrane).

Light microscopy and transmission electron microscopy of cerebellum in embalmed and fresh cadavers.

Objective : The study is to examine the quality of the histological slide of cerebellum in embalmed cadaver when compares with fresh specimen or the standard textbook by using light and transmission electron microscopic studies. Method : The cerebellums were chosen from the embalmed cadavers who donated their bodies to the Department of Anatomy, Faculty of Medicine, Siriraj Hospital, Mahidol University. These cerebellums were prepared by two techniques for light and electron microscopic studies. The visualization of the cerebellar microscopic slides were compared with the fresh specimens or standard textbooks. Results : The cerebellar sections which were obtained from the cadaveric cerebellar embalmed were suitable for making the microscopic slides that can be used for studying histology of the medical students. From light microscopic study, the microscopic structures are as good appearances as in the standard textbooks. Some specimens have better microscopic structural appearances. The fixative formula is suitable for light microscopic study but not suitable for transmissiom electron microscopic study. Conclusion : The microscopic slides from sections of the cerebellums which were obtained from the embalmed cadavers which have been fixed by Siriraj fixative formula and kept in soaking preservative formula for 1 year and have been dissected for studying gross anatomy and neuroanatomy by the medical student under room temperature can be used for microscopic slides that suitable for further teaching or stydying histology.

The histology of the pineal gland in cadaveric embalmed specimens.

Objective: This study is to observe ultrastructurally of the pineal gland from cadaveric embalmed specimens by light microscopy (LM) and transmission electron microscopy (TEM) Methods: Ten pineal glands were removed from cadaveric embalmed specimens. Each pineal gland was disected into two groups, one was put into 10% formaldehyde and the other was put into 2.5% glutaraldehyde. The first group was processed for light microscopy. First of all, fixed the tissues in formalin and then embedded in paraffin. Next, serially sectioned at eight micron and finally stained. Staining methods were (i) haematoxylin and eosin, (ii) Masson-Fontana method for melanin. The second group well preserved in 2.5% glutaraldehyde was chosen to prepare for the TEM. Results: Only five out of ten cadaveric pineal glands viewed by light microscopy were well preserved. In LM, we saw clearly that all ultrastructures or morphology of the cadaveric embalmed pineal gland cells were the same as the standard textbook. Melanin pigments were accumulated in both of the cytoplasm of pinealocytes and the stroma of pineal gland proved by Masson-Fontana staining. Mast cells were found throughout the gland but preferably found in the connective tissue trabeculae. A neuronal-like cell was found in the parenchyma of pineal gland. Extrapineal and intrapineal calcified concretion called corpora arenacea or brain sand were presented. Intrapineal concretions in the parenchyma were globular and concentric lamellar patterns while extrapineal concretions which were adjacent to the capsule were concentric lamellar only. TEM of pineal gland showed that it was moderately preserved in the chemical fixative of this formula. Cadaveric pinealocyte showed some organelles and chromatin extraction while the environmental fibrillar structures were well preserved. Conclusion: The histological findings in the pineal glands from cadaveric embalmed specimens are similar to fresh cadavers. Moreover, they can be used to prepare the normal slides for Histology Lab of the second year medical students. The presences of the melanin pigments in the cytoplasm of pinealocytes and stroma, mast cells, corpora arenacea, and neuronal-like cells confirm the previous studies.

Histological and ultrastructure of the peripheral nerve in cadaveric embalmed specimens and in fresh cadavers: the efficacy of several fixatives.

Objective: The study is to observe the histological structure and the ultrastructure of the peripheral nerve from cadaveric embalmed specimens and from fresh specimens by light microscope and by transmission electron microscope. Also to study the efficacy of the embalmed fixative to the tissue. Methods: The peripheral nerves were dissected from the arms of five cadavers of the Department of Anatomy, Faculty of Medicine Siriraj Hospital, Mahidol University, and from fresh cadavers. Each specimen was bissected, one put into 10% formaldehyde which was prepared for routine H&E staining and study by light microscope. The other was put into 2.5% glutaraldehyde, the best preserved specimen was then chosen to prepare for the TEM study. Results: There is no significant difference between the peripheral nerves of the cadaveric embalmed and the fresh specimens when viewed with the light microscope. On the otherhand when viewed by transmission electron microscope, the lipid part of the myelin sheath of the peripheral nerves from the cadaveric embalmed specimens are totally degenerated while the protein part is still intact. While in the fresh specimens which are fixed by 2.5% glutaraldyhyde, there is a complete preservation of the lipid and protein part of the myelin sheath. Conclusion: The cadavers were fixed by excess formalin injection into the femoral artery and embalmed in formalin for at least 1 year, this could not preserve the lipid part of the myelin sheath. However, in the fresh peripheral nerves fixed in 2.5% glutaraldehyde it could preserve the lipid and proetin parts of the myelin sheath perfectly.

A histopathological study of hearts and spleens of hamsters (Mesocricetus auratus) infected with Leptospira interrogans, serovar pyrogenes.

The effects of Leptospira interrogans on the heart and spleen of hamsters were studied histopathologically. Infected hamsters were sacrificed at 1 hour, 6 hours and on days 1, 2, 3, 4, 5 and 6 after inoculation with Leptospira interrogans serovar pyrogenes. The heart and spleen of each of the sacrificed animals were removed and processed for routine conventional light microscopy. Infected hearts showed degenerative change of the cardiac muscle cells composed of cellular swelling, condensation of chromatin granules, pyknotic nuclei and acidophilic cytoplasm. Congestion of the cardiac blood vessels and hemorrhagic areas were found. Necrosis of the cardiac muscle cells was surrounded by numerous inflammatory cells. In the spleen, cellular necrosis was found scattered throughout the splenic cord. The splenic sinusoids were dilated and congested with many hemorrhagic areas. Inflammatory cell infiltration was also noted in the splenic parenchyma and the splenic sinusoids.

A Microanatomical study of the organs of hamsters (Mesocricetus auratus) infected with Leptospira interrogans, serovar pyrogenes which caused an outbreak in Thailand 1999.

The effects of Leptospira interrogans on various organs of hamsters were studied microanatomically. Three infected hamsters were sacrificed at 1 hour, 6 hours and on days 1, 2, 3, 4, 5 and 6 after infection with Leptospira interrogans serovar pyrogenes. The kidneys, lungs, liver, gastrocnemius and hamstring muscles of all the sacrificed animals were removed and processed for routine conventional light microscopy. The microscopic change of the infected kidney showed degenerative changes of the renal tubular cells, including vacuolar degeneration, cellular swelling of proximal tubules, dilatation of the distal tubular lumen and necrosis. The glomeruli had many pathological appearances including congestion and swelling of the glomerular tuft, imflammatory cell infiltration, hemorrhage in the glomerular tuft and the urinary space. This phenomenon may have been related to glomerular damage. Congestion of the renal blood vessels was demonstrated in both the cortex and the medulla. There were many other hemorrhagic areas including the interstitium and the renal tubule. Interstitial nephritis and pyelonepritis were also found. In the lung, the alveolar and interalveolar capillaries were distended and engorged with red blood cells. A small number of alveoli were filled with inflammatory cells which represented bronchopneumonitis. Most areas of the lungs showed intersitital and intra-alveolar hemorrhage as well as thickening of the alveolar septum. The interalveolar septum was also thickened by accumulation of inflammatory cells which is a sign of interstitial pneumonitis. The infected liver showed enlarged and vacuolated hepatocytes being related to cloudy swelling the hepatocytes. Vascular and sinusoidal congestion, prominent Kupffer cells, and inflammatory cell infiltration in the hepatic parenchyma and hepatic sinusoids were also demonstrated. The portal area showed a number of inflammatory cells. Hepatocellular necrosis was found scattered throughout the hepatic lobules which is a sign of hepatocellular damage and disorganization of the liver structure and function. In the gastrocnemius and hamstring muscles, dilation and congestion of blood vessels was shown in some hamsters in the infected groups. The congestion of blood vessels is a sign of hyperemia. One hamster of the infected group showed inflammatory cell infiltration in the perimysium of the gastrocnemius muscle. Another one showed necrosis of some muscle fibers together with inflammatory cell infiltration which are signs of muscular inflammation. The results of this research correspond with previous similar studies, however, the pathogenesis of this study was quicker and the infection was more severe than in other studies. This may be due to the difference in serovar studied.

The persistence of the median aretery in Thais.

The median artery is a main artery that supplies hand in embryonic period. When the radial and ulnar arteries are well developed, the median artery becomes smaller and soon disappeared. In order to find the incidence of persistant median artery in Thais, we study 266 upper extremities in our Department, 133 of right sides and 133 of left sides. The persistant median artery is found in 22 extremities, or 8%. Further studies reveal that, 77% of median artery are the branch of ulnar artery, 9% of common interosseous artery and 14% of brachial artery. 91% of median artery accompany the median nerve throughout forearm, while 9% traveling superficially in the same plane as supper veins. All of median artery end by joining superficial palmar arch. 95% pass deep to flexor retinaculum, only 5% pass superficial to this retinaculum before joining superficial palmar arch.

Anomalies of the popliteal artery and Its main branches in Thais.

The pattern of origin, course, branching and termination of the popliteal artery of 440 lower extremities of Thai cadavers was recorded with right-side supply being 224 and left-side 216. Various types of anomaly were found. In one lower extremity, the popliteal artery arose as a direct continuation of the sciatic artery instead of the femoral artery as normal. The femoral artery in this was very small. In the popliteal fossa, 2lower extremities showed the popliteal artery passing anterior to the popliteus muscle and 6 lower extremities showed the anterior tibial artery passing anterior to the popliteus muscle. In 33 lower extremities (7.5%), the popliteal arteries did not terminate at the lower border of the popliteus muscle. We found 3 levels of termination: on the posterior surface of the popliteus muscle (10 lower extremities), proximal to the upper border of the popliteus muscle (10 lower extremities) and distal to the lower border of the popliteus muscle (13 lower extremities). Abnormal patterns of branching of the main branches of the popliteal artery were found in 67 of the 440 lower extremities i.e., 15% and they were divided into 11 types. Each type of variation can be described by its development.