Intrathymic lymph nodes in humans.

An unusual lymph node exists in the centre of the human thymus. This lymph node, which we call an intrathymic lymph node (ITLN), possesses some interesting morphological characteristics. In ontogeny, this node seems to appear at the latter half of fetal period. The function of the ITLN is still unknown, but it is assumed that it may play a different role in the immune system than other peripheral lymph nodes by its characteristics.

Lectin-histochemical detection of degenerative glycoconjugate deposits in human brain.

Several lectins were used to study the localization of glycoconjugates in brain of elderly people and patients with Alzheimer type dementia (ATD) and Down's syndrome (DS). Five kinds of degenerated or deposited materials stained clearly by lectins specific to GalNAC, Gal, Fuc, and/or Man were recognized much in ATD and DS, less in elderly peoples, in addition to the binding of the lectins to neurons. (i) Round shape deposits called corpora amylacea (CA) which consisted of various sizes of round material, existed mainly on the surface of cerebral cortex and some in white matter of the brain. They were colored by Alcian blue (AB), Aldehyde fucsin (AF) and periodic acid shiff (PAS) and weakly by Hematoxylin (H), but not by Eosin (B). They showed clear reactivity with lectins specific to GalNAC, Gal, Fuc and Gal-GalNAC. (ii) Amorphous and variform amyloid deposits existed around blood vessels in the white matter were stained by thioflavin and lectins specific to GalNAC, Gal and Fuc, but not with Man specific lectins and PAS, AB, AF and HE. (iii) Another kind of amyloid deposits which showed a similar characteristic to the previous one and were recognized mainly in white matter and independent blood vessels. These deposits were stained by thioflavin but not by PAS, AB, AF and HE and showed good reactivity with lectins specific to GalNAC, Gal, Fuc, Gal-GalNAC, Gal-GIcNAc and Man. The reactivity with lectins specific to Gal, Fuc, and Man was seen in senile plaques (iv) and neurofibrillary tangles (v). Although at present we are unable to explain the origin of these deposits, it is clear from this study that the glycoconjugates form an integral part of the degeneration in the brain. The lectin staining with GS-I is useful in the forensic pathology to diagnose brain disorders at postmortem examination, since these lectin were able to detect five types of degeneration changes and/or deposits.

Fatal acute alcohol intoxication in an ALDH2 heterozygote: a case report.

On an evening in November, a 25-year-old man was found dead in his bedroom. There were many empty snap-out sheets for flunitrazepam tablets in the trash at his bedside. He had been beaten by a gang of young people earlier in the morning of the same day. At the medico-legal autopsy, although there were many bruises and/or abrasions on the whole body, only slight subdural hemorrhage was observed, and none of them was thought to be the cause of death. Flunitrazepam and its metabolites were not detected in his body fluid by gas chromatography-mass spectrometry (GC-MS). Marked lung edema and a severe congestion of organs were observed. His blood alcohol concentration from the femoral vein was 2.00 mg/ml. Fatal cases of acute alcohol intoxication usually have shown higher alcohol concentration (2.25-6.23 mg/ml). Although the genotype of aldehyde dehydrogenase 2 (ALDH2) has not previously been mentioned as a contributing factor in determining the cause of death, in this case the genotype of ALDH2 was ALDH2*1/2 and thus is important. Those who possess the ALDH2*2 gene show high concentrations of acetaldehyde (AcH) at even comparatively lower alcohol levels. Consequently, the cause of death was considered to be acute alcohol intoxication including AcH poisoning.

[A sudden death case in the bath with peculiar scald].

A 60-year-old man was found dead in the bathtub of his house on the 2nd of February. Erythema with a clear border was observed on the right side of the face, trunk and around the knees, though the left side of the face, the hips and the feet were normal. The water heater was set outside of the bath, and the heated water flowed from the heater to the bath through the upper pipe. In order to determine the mechanism of the peculiar scalding, changes in the water temperature in the bathtub were measured under the same conditions. An hour after turning on the water heater, the surface water temperature of the bath was 73 degrees C. Zonal gradation of the temperature was observed. At the level of the opening for the lower intake pipe, it was 50 degrees C. The border of the scalding was consistent with the water layer above 50 degrees C.

Human parathymic lymph node: morphological and functional significance.

Parathymic lymph nodes (PTLNs) have been identified in several species, but in humans they have been noted only once before in a study 90 years ago using fetal material. We now report their occurrence in children. Human PTLNs are small but distinctive lymphatic organs located on the surface of the thymus (or sometimes between the upper and lower lobes of the thymus) and covered with the thymic capsule. Histologically, the medullary cords of these lymph nodes were found to be thin, with only small numbers of plasma cells. In addition, they had a well-developed paracortical area rich with high endothelial venules (HEV), but a thin cortex, including only a few undeveloped follicles. Flow cytometric analysis of PTLNs revealed that the ratios of T:B cells (14.6+/-9.3) and of CD4+:CD8+ T cells (4.9+/-1.4) in PTLNs were much higher than in other peripheral lymphoid tissues and in peripheral blood. Because of these characteristics of the human PTLNs, we propose that the human PTLNs might influence the functional differentiation of T cells.

Estimation of stress in child neglect from thymic involution.

It is difficult to evaluate the extent of stress in cases of suspected child abuse/neglect in a medico-legal autopsy. We have previously reported that stress due to abuse/neglect was found to have led to thymic involution. To elucidate the influence upon thymocytes differentiation, we compared the proportion of the thymocyte subpopulation in the thymus of a neglected child with one in an age-matched control obtained from cardiac surgery. We found that the relative number of CD4+ CD8+ double positive (DP) thymocytes decreased in the neglected child. It was presumed that the selective decrease in the number of the immature DP thymocytes with CD3- to low bcl-2low caused the thymic involution in the neglected child. It was suggested that an alteration in the proportion of thymocytes subpopulation might be used as an index of stress in cases of child abuse/neglect.

Changes in choice of method and lethality between last attempted and completed suicides: how did suicide attempters carry out their desire?

Some researchers have emphasized that, from the perspective of suicide prevention, research into the methods of suicide seemed to be particularly promising, as it has been shown repeatedly that restricting access to the prevailing method of suicide in a country will decrease suicide rates and that the lethality of the method used significantly correlated with the degree of intention to die. In this study, we examined changes in choice of method and the lethality score between the last attempted suicide (LAS) and completed suicide (CS) in 416 victims (male: 197, female: 219) to point out the tendency on their choice of method in LAS and CS. There was a significant difference in choice of suicide method between LAS and CS, and injury to themselves (33.7%) was the most common method of LAS, while hanging (37.5%) was the most common method of CS. The mean lethality score of CS method was significantly higher than that of LAS method in both sex groups, suggesting that at least one of the causes that drives suicide attempters to commit suicide finally may be the difference in the lethalities of LAS and CS. At the time of CS, suicidal victims tend to choose the same method as that of LAS again. These findings suggest that although suicide attempters tend to choose the same method, they will use a more lethal method if they change the suicide method. Interestingly, moreover, there was no sex difference in the percentage of the mean lethality score at CS.

Tissue-specific expression of Le(Y) antigen in high endothelial venules of human lymphoid tissues.

In this study, we demonstrated that the anti-Le(Y) antibody (BM-1) especially reacted with high endothelial venules (HEVs) in peripheral lymph nodes of blood group O individuals. The Le(Y) expression on HEVs showed a unique tissue-specific pattern, i.e., a large amount of the Le(Y) expression in peripheral lymph nodes and no or small amounts in mesenteric lymph node. Statistical analysis showed that there was the significant difference between the percentage of Le(Y)-positive HEVs in peripheral lymph nodes and mesenteric lymph nodes. No expression of Le(Y) was observed in vessels of Payer's patch, thymus, spleen and other non-lymphoid organs. In blood group A or B individuals, the reactivity between HEVs and anti-Le(Y) antibody increased after enzyme digestion with alpha-N-acetylgalactosaminidase or alpha-galactosidase. These findings show that the expression of difucosylated blood group ABH antigens are especially expressed on HEVs in peripheral lymph nodes. Furthermore, the tissue-specific pattern suggests that these antigens may be related to intercellular adhesion between lymphocytes and HEVs.

[Determination methods for human blood acetaldehyde].

Although a number of reports on human blood acetaldehyde have been published, most of them during alcohol intoxication are still various in each researcher. The difficult problems are summarized as follows; 1) low boiling point of acetaldehyde, 2) low level in blood, 3) rapid disappearance in blood, and 4) artefactual formation during the procedures. The most crucial problem is the artefactual formation from ethanol or other sources during the procedures. Hemolysation, heating and/or other analytical procedures cause the artefacts. In this report, several methods for the determination and the evaluation of the acetaldehyde levels are reviewed.

Immunodeficiency induced by child abuse.

We report the case of a 9-year-old girl who died from sepsis from cellulitis of the neck caused by a right ear injury. The autopsy findings showed severe involution of the thymus and atrophy of lymphoid tissues. The impairment of T- and B-cell functions was demonstrated both histologically and immunohistologically. Thymic involution caused by child abuse might lead to secondary immunodeficiency.

Liquefied petroleum gas (LPG) poisoning: report of two cases and review of the literature.

Two autopsy cases of men who died while connecting a liquefied petroleum gas (LPG) pipe are reported. Their blood concentrations of propane (the main content of LPG) were 0.12 and 3.40 mg/100 g, respectively. The cause of death after exposure of LPG has generally been considered to be asphyxia from hypoxia. The large differences in the blood propane levels found here and reported in the literature, however, suggest that direct toxic effects of propane poisoning may be the cause of death in some cases. Propane concentrations and the cause of death are reviewed and discussed.

Ethnic differences in the expression of blood group antigens in the salivary gland secretory cells from German and Japanese non-secretor individuals.

Type 1 ABO blood group antigens (peripheral core structure: Gal beta 1-3GlcNAc beta 1-R) are expressed mainly in endodermally-derived tissues, but are not synthesized in mesodermally-derived tissues. In the former tissues, H type 1 antigen is generated largely by alpha-2-L-fucosyltransferase encoded by secretor (Se) gene and acting on the terminal galactose of the type 1 precursor chain. This theory has been generally accepted, and it seems that the expression of ABO blood group antigens is absent, or expressed at a low level, in these tissues from non-secretor individuals. In this immunohistochemical study on the secretory cells of salivary glands, we found ethnic difference between German and Japanese non-secretor individuals in the expression of blood group antigens: i.e. the expression of the type 1 blood group antigens is present in these cells from Japanese non-secretor individuals but absent from German. A possible explanation is that another alpha-2-L-fucosyltransferase, independent of the secretor gene, is present in Japanese non-secretor individuals.

[Shotshell injuries--single or multiple shots?--a case report].

The case of a 64-year-old hunter who was accidentally shot at a distance of 40 meters with a shotgun by a member of hunting group was reported. At the scene, the victim was found dead and showed two bullet wounds in the left lateral chest and thigh, and a penetrated wound in the left knee. Autopsy findings revealed that the former two wounds were discharged from the left side of the body, and the last one in the knee from the right. The assailant and comrades who happened to be on the scene of the accident deposed that the only one shot sound was heard at that time. Whether quite different directions of these three wound tracks could be explained with single shot or multiple ones, we discussed the locus of the bullets in consideration of the posture of the victim.

Determination of ABO genotypes with DNA extracted from formalin-fixed, paraffin-embedded tissues.

The gene encoding the specific glycosyltransferases which catalyze the conversion of the H antigen to A or B antigens shows a slight but distinct variation in its allelic nucleotide sequence and can be divided into 6 genotypes when digested with specific restriction enzymes. We extracted DNA from formalin-fixed, paraffin-embedded tissues using SDS/proteinase K treatment followed by phenol/chloroform extraction. The sequence of nucleotides for the A, B and O genes was amplified by the polymerase chain reaction (PCR). DNA fragments of 128 bp and 200 bp could be amplified in the second round of PCR, using an aliquot of the first round PCR product as template. Degraded DNA from paraffin blocks stored for up to 10.7 years could be successfully typed. The ABO genotype was deduced from the digestion patterns with an appropriate combination of restriction enzymes and was compatible with the phenotype obtained from the blood sample.

Necrotizing arteritis causing fatal massive intraperitoneal hemorrhage from a pancreatic pseudocyst.

We report the histopathological findings from a medicolegal autopsy case caused by sudden massive hemorrhage from a necrotic pancreatic cyst into the abdominal cavity. The histological examination revealed that the wall of the cyst was filled with hematoma and consisted of granuloma at a relative early stage, involving marginating lymphocytes, foamy lipophages, cholesterin crystals, foreign body giant cells with neutrophiles, mast cells and fibrous tissues. Since there was no epithelial lining, the lesion was diagnosed as a pseudocyst. In the wall of this pseudocyst, small arteries showed acute intense necrotizing inflammatory reactions in association with fresh thrombi. Trace of elastic fibers remained in the wall of the arteries. Since the small veins in the wall showed varix-like changes without necrosis or inflammation, it is proposed that the lethal bleeding was caused by rupture of the small arteries that exhibited severe arteritis.

ABH-related antigens in human male genital tract. A histochemical examination.

The localization of ABH related antigens in human male reproductive tract was examined using monoclonal antibodies and an avidin biotin complex method. No positive reaction with blood group antibodies on spermatozoa was observed in testis and ductus epididymidis apart from erythrocytes and endothelial cells. The expression of ABH and ABH related antigens in ductuli efferents testis, ductus epididymidis, seminal vesicle and prostate was complexly coded by a combination of H, Se, Le and X genes. The results obtained in this study indicate that the ABH antigens detected on spermatozoa of seminal stains are coating antigens and not inherent to the cell membrane, and the ABO, H, Se, Le and X genes are subjected to a tissue-dependent differential expression.