DNA synthesis and related enzymes altered in compensatory lung growth in rats.

Left pneumonectomy was performed on 4 week-old male Fischer-344 rats. Changes in DNA biosynthesis and the activities of related enzymes were studied in the contralateral lungs of the pneumonectomized animals (n = 55) and compared with sham-operated (n = 55) and untreated control animals (n = 40) The wet weight of the contralateral lung of the pneumonectomized rats reached that of both lungs of the untreated and sham-operated rats 14 days after the operation. The activities of thymidine kinase and DNA polymerase from the regenerating lungs were elevated on Days 1 and 7. To determine the molecular forms of DNA polymerase in the crude extract, phosphocellulose column chromatography was performed. The type of DNA polymerase with the highest activity was alpha in regenerating lung on Days 1, 3, and 7. These results suggest that DNA replication for cellular proliferation was elevated in the remaining lung after pneumonectomy. In addition, an interlobar difference in DNA biosynthesis was observed in the remaining lung. The increase was especially marked in the cardiac lobe, followed by increases in the DNA content of the remaining lobes on Day 7. From these observations we conclude (1) that increased activity of DNA polymerase alpha is likely to be an initial change in compensatory lung growth, and may be caused by some unknown stimulator in lung tissue, and (2) that DNA biosynthesis may differ among the lobes of the lung, at least until 3 days post-pneumonectomy.     

ENDOSCOPIC SUBMUCOSAL DISSECTION FOR RECURRENT GASTRIC TUMORS

Endoscopic resection has been accepted as the standard treatment for intramucosal gastric tumors of differentiated type. However, the indication was limited to small tumors to achieve en bloc resection and prevent local recurrence in cases of conventional endoscopic mucosal resection (EMR) such as the strip biopsy and the cap technique. To avoid multi‐fragmental resection, we have developed endoscopic submucosal dissection (ESD) as a new endoscopic resection technique. ESD is a remarkable technique, because we make it possible to remove the lesions en bloc regardless of size, shape, coexisting ulcer, and location. However, it is difficult or impossible to resect recurrent tumors en bloc in conventional EMR owing to hard fibrosis, and some patients need laparotomy. Using ESD, we can dissect the submucosal layer as we directly look at the submucosa, and remove the lesion safely and reliably even in cases of hard fibrosis. The key to treatment of recurrent tumors in ESD are as follows: (i) using enough submucosal injection solution (we use a mixture of Glyceol and 1% 1900 kDa hyaluronic acid preparation); (ii) incising the mucosa without fibrosis; (iii) understanding characteristics of various cutting devices, and changing other devices in difficult situations. In these ways we can remove the majority of the recurrent tumors en bloc. Hence, we consider that ESD is a very effective treatment which achieves excellent en bloc and complete resection rates and enables patients with intramucosal gastric tumors to a recurrent‐free survival even in recurrent tumors.     

Serial diffusion-weighted MRI (DWI) in a patient with sporadic Creuztfeldt-Jakob disease]

Serial DWIs were performed in a patient with CJD who developed symptoms acutely and progressed rapidly. DWI discloed an increased signal in the frontal and parietal inner cortical areas, and in the caudate nuclei and putamina 20 days after the onset of symptoms. T2-weighted images showed only signal abnormality in the caudate nuclei and putamina, but not in the cerebral cortex. In the CSF obtained 15 days after the onset of symptoms, total tau protein was markedly elevated and 14-3-3 protein was positive. Measurement of these proteins are highly specific and sensitive for the diagnosis of CJD, but not available as a rapid routine examination at present. DWI is not specific, but useful for making the diagnosis of CJD in the early stage of the disease.     

Case of Heerfordt's syndrome with prolonged peripheral nerve involvement]

A 28-year-old man complaining of myiodesopsia was given a diagnosis of uveitis. Subsequently he complained facial nerve palsy and enlargement of parotid gland. Heerfordt's syndrome was diagnosed based on the results of several examinations. Facial nerve palsy, enlargement of the parotid gland and uveitis were improved by systemic corticosteroid therapy. At present he is receiving systemic corticosteroid therapy, but numbness in the mouth, thought to be the involvement of the trigeminal nerve, remains. Systemic corticosteroid therapy is usually effective for most cases with Heerford's syndrome. On the other hand, there are some cases with the prolonged peripheral nerve involvement despite systemic corticosteroid therapy, as seen in this case. If peripheral nerve involvement is prolonged, it is necessary to consider small-fibre neuropathy as one possible cause.     

MULTICENTER STUDY DESIGN OF THE EX VIVO EVALUATION OF ENDOCYTOSCOPY IN ESOPHAGEAL SQUAMOUS CELL CARCINOMA

Optical technological innovations enable us to visualize cellular nuclei endoscopically. Herein is described a protocol design for a multicenter study for the ex vivo evaluation of endocytoscopy. The present study was performed by the Endoscopy Forum Japan study group.     

Dynamics of changes in blood flow, volume, and oxygenation: implications for dynamic functional magnetic resonance imaging calibration.

Changes in cerebral blood flow (CBF), volume (CBV), and oxygenation (blood-oxygenation level dependent (BOLD)) during functional activation are important for calculating changes in cerebral metabolic rate of oxygen consumption (CMRo2) from calibrated functional MRI (fMRI). An important part of this process is the CBF/CBV relationship, which is signified by a power-law parameter: gamma=ln (1+DeltaCBV/CBV)/ln (1+DeltaCBF/CBF). Because of difficulty in measuring CBF and CBV with MRI, the value of gamma is therefore assumed to be approximately 0.4 from a prior primate study under hypercapnia. For dynamic fMRI calibration, it is important to know if the value of gamma varies after stimulation onset. We measured transient relationships between DeltaCBF, DeltaCBV, and DeltaBOLD by multimodal MRI with temporal resolution of 500 ms (at 7.0 T) from the rat somatosensory cortex during forepaw stimulation, where the stimulus duration ranged from 4 to 32 secs. Changes in CBF and BOLD were measured before the administration of the contrast agent for CBV measurements in the same subjects. We observed that the relationship between DeltaCBF and DeltaCBV varied dynamically from stimulation onset for all stimulus durations. Typically after stimulation onset and at the peak or plateau of the DeltaCBF, the value of gamma ranged between 0.1 and 0.2. However, after stimulation offset, the value of gamma increased to 0.4 primarily because of rapid and slow decays in DeltaCBF and DeltaCBV, respectively. These results suggest caution in using dynamic measurements of DeltaCBF and DeltaBOLD required for calculating DeltaCMRo2 for functional stimulation, when either DeltaCBV has not been accurately measured or a fixed value of gamma during hypercapnia perturbation is used.     

STANDARD IMAGING TECHNIQUES OF ENDOSCOPIC ULTRASOUND‐GUIDED FINE‐NEEDLE ASPIRATION USING A CURVED LINEAR ARRAY ECHOENDOSCOPE

Standard imaging techniques using a curved linear array echoendocope are summarized to facilitate the attainment of expertise in endoscopic ultrasonography and endoscopic ultrasound‐guided fine needle aspiration, and to promote the widespread use of this diagnostic and therapeutic tool. Typical images of the mediastinal organs, the bilio‐pancreatic systems and neighboring organs by scanning from the esophagus, stomach, duodenal bulb, and descending portion of the duodenum, are shown in a sequential manner. The basic techniques of endoscopic ultrasound‐guided fine needle aspiration are also presented.     

Chromosomal Mapping of Genetic Locus Associated with Thymus-size Enlargement in BUF/Mna Rats

The thymoma-prone rat of the BUF/Mna strain is a useful model for human thymoma. In this strain thymoma development is regulated by a single autosomal susceptible gene, Tsr-1. At pre-thymoma age, BUF/Mna rats have extremely large thyrauses, when compared to those of other strains of rats. Genetic studies in crosses between BUF/Mna rats with large thymuses and WKY/NCrj rats with small thymuses suggested the presence of a major autosomal gene, Ten-1 , which contributes to thymus enlargement in a backcross population. Linkage studies between Ten-1 and microsatellite markers in backcross rats of (WKY/NCrj×BUF/Mna)Fl×BUF/Mna have led to the localization of Ten-1 in chromosome 1. This result may provide an approach to clone Tsr-1 , which could be allelic to Ten-1.     

Epidermal injury stimulates prenylation in the epidermis of hairless mice

Isoprenylation is the covalent attachment of isoprenyl groups, intermediates of the cholesterol biosynthesis pathway, to carboxy terminal cysteine residues of proteins. Numerous proteins are isoprenylated including small GTP binding proteins, trimeric G proteins, and nuclear lamins, and these prenylated proteins regulate a variety of cell functions, including cell growth, cytokinesis, and differentiation. Here, we quantitated protein prenylation and determined which proteins are prenylated in the epidermis of hairless mice by radiolabeling with ³ H-mevalonolactone following acute or chronic epidermal injury. In normal epidermis, four major radiolabeled bands, with molecular weights of 17–26, 48, 54, and 68 kDa, were observed. The levels of each of these bands increased by 24–63% 16 h following acute epidermal injury induced by topical acetone treatment or tape stripping, returning to normal by 24 h. On 2D gel electrophoresis, there were no major differences between the patterns of labeling following barrier disruption. Subacute epidermal injury induced by either acetone or tape stripping twice a day for 7 days and chronic injury induced by feeding an essential fatty acid-deficient (EFAD) diet, also resulted in a significant increase in protein prenylation. As with acute injury, SDS-PAGE and 2D gel electrophoresis did not reveal marked differences in the pattern of protein prenylation. These results demonstrate that the prenylation of proteins in the epidermis is stimulated by injury, suggesting that one or more of these prenylated species may be important in epidermal proliferation or differentiation. Received: 29 May 1996     

Evaluation of the measurement of plasma fructosamine concentration in aged subjects

Recently, plasma fructosamine concentration has been used as an indication of mean plasma glucose level preceding at last 1 to 2 weeks. In the present study, to characterize the clinical significance and problems of plasma fructosamine concentration in aged subjects (greater than or equal to 65 yrs), we determined plasma fructosamine concentration as well as serum albumin, total protein, HbA1, AbA1c and fasting plasma glucose concentrations in 81 (less than 65 yrs) non-diabetic subjects (group A), 161 aged (greater than or equal to 65 yrs) non-diabetic subjects and 26 aged diabetics (group D). Aged non-diabetic subjects were further classified into 75 subjects with good ADL (group B) and 86 with poor ADL (group C). The normal limit of plasma fructosamine concentration (mean +/- 2SD) in group A was 24% higher (3.1 mmol/l) than that in group B (2.5 mmol/l) but the plasma fructosamine/serum albumin ratio (F/ALB) was similar in these two groups. Plasma fructosamine correlated negatively (p less than 0.01) with age. This aging effect was explained by the reduced serum albumin in aged subjects. However, in group C, reduced plasma albumin was not associated with reduced plasma fructosamine. Plasma fructosamine corrected by albumin (F/ALB) is a useful parameter of blood glucose control in aged subjects. In aged subjects with poor ADL, HbA1, HbA1c and plasma glucose should be determined with fructosamine.