Three-dimensional helical coiling structures and band patterns of hydrous metaphase chromosomes observed by low vacuum scanning electron microscopy

Helical coiling structures and band patterns of hydrous metaphase chromosomes were documented three-dimensionally by low vacuum scanning electron microscopy (SEM). Fixed or unfixed isolated Chinese hamster metaphase chromosomes were stained with platinum blue (Pt blue) and observed in the backscattered electron mode for low vacuum SEM without any hypotonic treatment or drying processes. Fibrous structures were shown both in the fixed and unfixed hydrous chromosomes; helical chromatid coils and their subcoils were clarified especially in the fixed chromosomes having contrasting alternative bands of light and darkness, while the translucent perichromosomal matrix and compact fibrous structures were recognized in the unfixed chromosomes. The helical coils were more clearly represented in a loosened chromatid of metaphase chromosomes. Treatment with a tris-HCl buffer solution and Pt blue staining in a hydrous condition successfully produced banding patterns similar to G-bands on metaphase chromosomes. These banded chromosomes observed by low vacuum SEM were also analyzed stereoscopically by field emission SEM after critical point drying. These findings indicate that: 1) native or unfixed chromosomes maintain the compact arrangement of high-order helical structures covered with the peri-chromosomal matrix; 2) helical coiling appearances of chromatids frequently observed in previous papers might be caused by loosening of the final level of the high-order structure of the metaphase chromosome; and 3) banding patterns might be produced by the rearrangement or reorganization of chromatin fibers at the 30 nm fiber level after the extraction of some chromosomal components including the peri- or intra-chromosomal materials during the banding procedure.     

Immune aspects of intestinal metaplasia of the stomach: An immunohistochemical study

Summary Immune characteristics of intestinal metaplasia of the stomach were analyzed by the immunoperoxidase technique in frozen and paraffin-embedded specimens. In fetal and minimally inflamed adult gastric mucosa, secretory component (SC) was absent from epithelial cells. Non-intestinalized gastric mucosa with evident inflammatory changes showed weak SC immunoreactivity at the generative cell zone. Enhanced immunoreactivity of SC with evidence of transepithelial transport of IgA and IgM, but not of IgG, was demonstrated in intestinalized glands of either the complete or incomplete type. The number of inflammatory cells and lymphoid follicles was decreased in intestinalized mucosa when compared with that in non-intestinalized gastritic mucosa; J chain-negative IgG plasma cells and T cells, both of which were fairly abundant in the latter mucosa, were remarkably decreased in the former mucosa, whereas the decrease of J chain-positive IgA or IgM plasma cells was slight or equivocal. In either mucosa, IgA was the most popular immunoglobulin class in plasma cells. IgD plasma cells were very rare. In the germinal centers of lymphoid follicles which were preferentially distributed in non-intestinalized gastritic mucosa, IgM or IgG germinocytes predominated over IgA germinocytes, and a few T cells and NK cells also were present. Intraepithelial lymphoid cells with a T-suppressor phenotype were detected in intestinalized glands. The possibility that intestinal metaplasia is an adaptation to long-standing chronic gastritis is discussed.     

Light and electron microscopic localization of the N-terminal fragment of human pro-opiomelanocortin in the human pituitary gland and in neoplasms

Summary Immunohistochemical localization of theN-terminal fragment (1–76) (NTF) of human pro-opiomelanocortin (POMC) was studied in human adult and fetal pituitary glands, as well as in pituitary adenomas associated with Cushing's syndrome and in ectopic ACTH-producing tumors. Comparison of localization between NTF and ACTH was performed using mirror sections. Our results indicated concomitant localization of NTF and ACTH in the same cells, not only in normal adult and fetal pituitaries but also in pituitary adenomas and ectopic ACTH producing tumours. Specificity of the NTF staining was confirmed by immunoabsorption. Negative staining of the bovine pituitary gland indicated the immunohistochemical localization ofN-terminal (1–45) of human POMC as there is a known species difference in the sequence 1–45 between human and the bovineN-terminal fragment. Presence of NTF in cisterna of rough endoplasmic reticulum indicates its production by small cell carcinoma. These findings, together with the previous studies, suggest that the complete form of POMC is produced in the tumours as well as in normal pituitaries.This work was supported in part by the Grant-in-Aid for Cancer Research (58-Z) from the Ministry of Health and Welfare.Supported by NIH # 16315-04 and by a program grant from the Medical Research Center of Canada     

Personal exposure to nitrogen dioxide from indoor heaters and cooking stoves

The personal exposure to NO₂ generated from various heaters and cooking stoves were studied, using 85 university students. The students attached NO₂ filter badges to their chests or collars and wrote down the period of time for heating and cooking for 1 week. Types of heaters and smoking habits were described through a questionnaire. The urinary hydroxyproline/creatinine ratio (HOP/C) was examined as a biomarker for health effects. The outdoor NO₂ concentration during the study period was 13.5–13.7 g/m³. Smoking and the usage of electric heaters did not affect the exposure to NO₂. Exposure increased according to the length of time kerosene heaters or oil fan heaters were used. The NO₂ concentration during the heating by a kerosene heater and an oil fan heater was calculated to be 219 and 474 g/m³, respectively. The correlation between the period of cooking and personal exposure was also observed. The NO₂ levels during cooking were calculated to be 290 g/m³. Using these calculated values of NO₂ concentration, it is possible to presume the personal exposure levels from the length of time heaters and cooking stoves are used even if the subjects do not attach the filter badges. Neither smoking nor exposure to NO₂ were associated with the increase of urinary HOP/C.     

Epidural administration and analgesic spread: Comparison of injection with catheters and needles

This study was designed to investigate differences in epidural analgesic spread between catheter and needle injections in 48 patients with comparable physical characteristics. The spread of analgesia in the catheter injection group with a 0.24ml·sec^–1 injection rate (n = 16) was 16.8 ± 1.5 spinal segments and that in the needle injection group at the same injection rate (n = 16) was 12.5 ± 1.8 spinal segments (P 0.01). Needle injection at the faster rate of 1.2ml*237sec^–1 (n = 16) produced a significantly greater spread of analgesia than with the 0.24ml·sec^–1 rate through the needle (16.2 ± 1.6 vs 12.5 ± 1.8 spinal segments, P 0.01). Thirteen of 16 patients receiving the fast needle injection complained of back compression or discomfort during the injection.The injection through an epidural catheter and the fast (1.2ml·sec^–1) injection through a needle produced extensive and equivalent epidural analgesic spread. However, because of patients discomfort with fast injection through the needle, the authors conclude that when using continuous epidural anesthesia, the initial injection of local anesthetic should be administered through the epidural catheter not the needle.(Omote K, Namiki A, Iwasaki H: Epidural administration and analgesic spread: comparison of injection with catheters and needles. J Anesth 6: 289–293, 1992)     

A blood cyanide distribution study in the rabbits intoxicated by oral route and by inhalation

Summary Blood cyanide concentration was determined in rabbits intoxicated orally or by inhalation. Experiments were carried out under urethane anaesthesia. In the inhalation experiments, rabbits inhaled a combustion product containing HCN via the tracheal cannula and in the oral studies animals were administered NaCN solution into the stomach. In addition to the carotid artery and jugular vein blood samples, postmortem samples were obtained from both sides of the heart and the descending vena cava.The arterial cyanide concentration in the inhalation group showed a close relationship with ventilation. After an initial rise, blood levels decreased a little, in some cases with transient apnea. At the last stage it again increased with gasping, reaching its maximal value. After ultimate apnea, the blood cyanide concentration declined. The blood cyanide values were higher in the oral group than in the inhalation group. The difference between the two groups became larger in the inferior order, the left heart blood-the right heart blood-blood in the descending vena cava. The left heart/right heart ratio of the inhalation group was significantly higher than that of the oral group (1.28 ±0.28 vs. 0.95 ±0.09). The coefficient of variation (c.v.) of the inhalation group was larger than that of the other group. Within the inhalation group, the left heart blood showed the largest c.v. values and this was probably due to redistribution of the cyanide by bloodstream after attainment of the maximal concentration.

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Bestimmung der Blutzyanidkonzentration in oral oder inhalatorisch vergifteten Kaninchen

Zusammenfassung Die Blutzyanidkonzentrationen wurden an Zyanid-vergifteten Kaninchen in Urethannarkose bestimmt. Die Kaninchen inhalierten HCN-haltige Verbrennungsgase durch die Trachealkanüle. Eine andere Gruppe von Tieren erhielt NaCN-Lösung per os. Während der Versuche wurden Blutproben aus einer katheterisierten Halsarterie gewonnen. Postmortale Blutproben wurden aus beiden Ventrikeln des Herzens und der kaudalen Hohlvene entnommen.Der arterielle Blutzyanidspiegel der ersten Gruppe zeigte eine enge Beziehung mit der Ventilation auf. Nach einer Konzentrationszunahme im Anfangsstadium nahm der Blutspiegel mit einer vorübergehenden Apnoe ab. Mit der terminalen Atembewegung stiegen die Blutspiegel und erreichten ihre maximalen Werte. Die Blutzyanidwerte verminderten sich nach endgültiger Apnoe. Der Blutspiegel der per-os-Gruppe nahm stetig unabhängig von der Ventilationsgröße zu. Die inhalatorische Gruppe hatte niedrigere Zyanidwerte als die orale Gruppe.

     

Evaluation of the Maruyama Computer Program Accuracy for Preoperative Estimation of Lymph Node Metastases from Gastric Cancer

Controversy still exists about the optimal lymph node (LN) dissection for potentially curable gastric cancer. For rational LN dissection it is important to know the incidence of metastasis at each LN station. For this purpose a computer program was developed using data from 4302 primary gastric cancers treated at the National Cancer Center Hospital in Tokyo between 1969 and 1989. To evaluate the accuracy of the computer program, the differences between the individual reports generated by the computer and the stored data were investigated in 282 Italian patients submitted to curative gastrectomy and D₂ or more extended LN dissections for gastric cancer. Receiver operating characteristic (ROC) analysis was used to assess the sensitivity and specificity of the program for predicting LN metastases in each of the 16 regional LN stations. The computer program showed good predictive ability for LN metastases in most of the 16 LN stations, as the areas under the curve ranged from 0.741 (station 15) to 0.944 (station 8), with a mean of 0.856. A critical cutoff point of 18% of the program's expected percentage was the value maximizing the validity of the prediction. Using an “absolute” cutoff point of 0%, the overall rate of false-negative (FN) predictions in 176 N+ patients was 11.9%; of these, 11 (6.2%) were absolute FNs, in which the program totally failed to estimate LN metastases; the remaining 10 cases (5.7%) were relative FNs because the specific prediction was positive for a different depth of stomach invasion. The low number of D₃/D₄ lymphadenectomies in the historical database may affect the low estimate of metastases to N₃/N₄ nodes generated by the program. Based on these data, the program predicts with good accuracy the extent of LN metastases from gastric cancer, but it is not recommended for directing the surgeon to perform more extensive lymphadenectomy.     

Evaluation of cell proliferation and apoptosis in Helicobacter pylori gastritis using an image analysis processor.

BACKGROUND: Infection of the gastric mucosa by helicobacter pylori is primarily responsible for gastritis, gastric ulcer, adenocarcinoma, and lymphoproliferative disorders. H. pylori appears to accelerate apoptosis and the proliferation of the gastric epithelium directly or indirectly. To precisely assess the proliferative and apoptotic profile of .H pylori-infected gastric mucosa, a quantitative imaging system is now required. METHODS: Fifty-two patients with H. pylori gastritis were the subjects of the study. Biopsy materials were taken from at least two sites (usually three to five sites) including the antrum and corpus. The grade of gastritis was evaluated by the updated Sydney System. The proliferative and apoptotic profile was examined by Ki-67 immunohistochemistry and by a terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end-labeling method. In addition, Ki-67-positive cells were quantitated by an image processor for analytical pathology (IPAP) system. RESULTS: H. pylori density and polymorphonuclear neutrophil activity were significantly decreased after H. pylori eradication ( P< 0.0001). Chronic inflammation (P< 0.0001) and lymphoid follicle numbers ( P < 0.0005) were also significantly decreased after the eradication. Glandular atrophy and intestinal metaplasia were slightly decreased after eradication, but the decrease did not reach the significant level. the Ki-67 labeling index was significantly decreased after the eradication P< 0.0001). The apoptosis index was also decreased after the eradication, but this decrease did not reach the significant level ( P = 0.06). CONCLUSION: our data suggest that the activation of proliferative cells and induction of apoptosis in the gastric mucosa is a response to H. pylori-induced mucosal damage. Moreover, IPAP may be a useful technology for evaluating the results of immunohistochemistry, and it could provide quantitative and reliable data for studying H. pylori gastritis.     

DIAGNOSIS OF CONGENITAL CYTOMEGALOVIRUS INFECTION BY EXAMINATION OF PLACENTA: Application of Polymerase Chain Reaction and in Situ Hybridization

We examined the placentas of 12 patients in whom congenital cytomegalovirus CMV infection was suspected from serological and or pathological evaluation. Seven patients died including four intrauterine deaths and five survived. On histological examination, the characteristic inclusion bodies were detected in only three placentas, and villitis with plasma cell infiltration was seen in eight placentas. Immunohistochemistry using a specific antibody against CMV improved the sensitivity of CMV detection 10 cases were positive . With the polymerase chain reaction PCR following the extraction of DNA from formaldehyde-fixed placenta samples, CMV DNA was detected in seven cases. All 12 subjects were diagnosed with CMV infection by additional Southern blot analysis after the PCR. CMV DNA was also detected by an in situ hybridization method in all cases. With current molecular biological techniques the placenta can be reliably used for the diagnosis of congenital CMV infection.