Hyperplastic epithelial foci in honeycomb lesions in idiopathic pulmonary fibrosis

Seventy-two cases of idiopathic pulmonary fibrosis (IPF) were examined from 2856 consecutive autopsy cases at the Japanese Red Cross Medical Center in Tokyo from 1973-1996. Primary lung cancer had arisen in 31 of 72 cases of IPF (43%), significantly higher than the incidence in cases without IPF (8.1%) and in the cases with non-IPF chronic lung diseases (11.9%). Hyperplastic epithelial foci in the honeycomb lesions of IPF cases were significantly more prominent in the lower than in the upper lobe, in cases with or without lung cancer, and they were more prominent in the lower lobe of IPF with than in those without cancer. The length of hyperplastic epithelial foci in the lower lobe of IPF cases was longer than that in interstitial pneumonia-associated with collagen vascular diseases. There was a higher PCNA labeling index of hyperplastic epithelial foci in IPF cases than in cases of interstitial pneumonia-associated with collagen vascular diseases. The PCNA labeling index was almost the same between smokers and nonsmokers with IPF. Overexpression of p53 was observed in hyperplastic epithelial foci in honeycomb lesion of IPF. DNA ploidy analysis of hyperplastic epithelial foci in the paraffin sections of 12 IPF cases revealed aneuploidy patterns in eight cases. These results strongly suggest that accelerated cell proliferation occurs in the honeycomb lesion of IPF, and that regenerative epithelia becomes susceptible to carcinogenic agents in addition to the smoking effect.     

The chitosan prepared from crab tendon I: the characterization and the mechanical properties

Crystalline chitosan was prepared from crab tendon consisting mainly of chitin, including various proteins and calcium phosphates. The crab tendon has high mechanical properties due to its aligned molecular structure. Crab tendon components, i.e. proteins and calcium phosphates, were removed by deacetyl treatment using 50wt% NaOH aqueous solution at 100 degrees C, and a subsequent ethanol treatment. As judged from microscopic observations using an optical polarizer, the treated chitosan remained intact regarding its aligned molecular structure, and had a high tensile strength of 67.9+/-11.4MPa. The tensile strength was further enhanced to 235+/-30MPa by a thermal treatment at 120 degrees C, corresponding to the formation of the intermolecular hydrogen bonds.     

Mevalonic acidemia: First case of Japan

Summary Mevalonic acidemia is a rare metabolic disorder due to mevalonate kinase deficiency which affects the biosynthesis of cholesterol and nonsterol isoprenes. We report the first case of Japan. The clinical course is characterized by intrauterine growth retardation, postnatal growth failure, intractable diarrhea, liver dysfunctions and death at three months of age. Dysmorphic features including triangular face, protrusion of forehead, hypertelorism, low set ears and micrognathism were noted. High mevalonic acid level was found by GC/MS.     

Kupffer cell-mediated cytotoxicity against hepatoma cells occurs through production of nitric oxide and adhesion via ICAM-1/CD18

Rat Kupffer cell (KC)-mediated cytotoxicity against both thesyngeneic hepatoma cell line AH70 and hepatocytes was evaluatedby changes in mitochondrial function, and the possible roleof ICAM-1/CD18 in the interaction between the cells was studied.Rhodamine 123 fluorescence, a marker of the mitochondrial membranepotential, decreased in AH70 cells after co-culture with KC,while that in hepatocytes was unchanged by co-culture. Thisdecrease was blocked by anti-ICAM-1, anti-CD18 and the Inhibitionof nitric oxide synthesis. Cytometric studies demonstrated thatICAM-1 expression on AH70 cells increased after addition ofIFN-, IL-1ß, tumor necrosis factor (TNF)- or KC, whilein hepatocytes ICAM-1 was not increased. Anti-ICAM-1 pretreatmentinhibited the increase in ICAM-1 expression and the decreasein rhodamine 123 fluorescence on AH70 cells after co-culturewith KC. CD18 on KC was increased only after co-culture withAH70. TNF- but not IFN- was detected in the supernatant of co-culturebetween KC and AH70 cells, and this production was partiallyinhibited by anti-ICAM-1 and anti-CD18. The activity of Induciblenitric oxide synthase in Kupffer cells and the levels of nitritesand nitrates in the co-culture supernatant increased over time,and this increase was attenuated either by addition of NO synthesisinhibitors, anti-ICAM-1 or anti-CD18. These results indicatethat the rat KC causes mitochondrial dysfunction in cancer cellsvia the production of NO and cell-to-cell adhesion via ICAM-1/CD18has an Important role in this cytotoxic process.     

Observation of cavitation in a mechanical heart valve in a total artificial heart

Recently, cavitation on the surface of mechanical heart valves has been studied as a cause of fractures occurring in implanted mechanical heart valves. The cause of cavitation in mechanical heart valves was investigated using the 25 mm Medtronic Hall valve and the 23 mm Omnicarbon valve. Closing of these valves in the mitral position was simulated in an electrohydraulic totally artificial heart. Tests were conducted under physiologic pressures at heart rates from 60 to 100 beats per minute with cardiac outputs from 4.8 to 7.7 L/min. The disk closing motion was measured by a laser displacement sensor. A high-speed video camera was used to observe the cavitation bubbles in the mechanical heart valves. The maximum closing velocity of the Omnicarbon valve was faster than that of the Medtronic Hall valve. In both valves, the closing velocity of the leaflet, used as the cavitation threshold, was approximately 1.3-1.5 m/s. In the case of the Medtronic Hall valve, cavitation bubbles were generated by the squeeze flow and by the effects of the venturi and the water hammer. With the Omnicarbon valve, the cavitation bubbles were generated by the squeeze flow and the water hammer. The mechanism leading to the development of cavitation bubbles depended on the valve closing velocity and the valve stop geometry. Most of the cavitation bubbles were observed around the valve stop and were generated by the squeeze flow.     

Implantation study of a novel hydroxyapatite/collagen (HAp/col) composite into weight-bearing sites of dogs

A hydroxyapatite/type I collagen (HAp/Col) composite, aligning hydroxyapatite nanocrystals along collagen molecules, has been prepared. The biocompatibility, osteoconductive activity, and efficacy as a carrier of rhBMP-2 of this novel biomaterial implanted in the weight-bearing site have been examined. The HAp/Col implants (15 mm in diameter and 20 mm in length) with a surface cross-linked layer containing rhBMP-2 (0 or 400 microg/ml) were implanted into bone defects of tibiae in three beagle dogs and fixed according to the Ilizarov method. As a control, bone defects of 20 mm in two beagle dogs did not receive implants, and the dogs were allowed to walk using an Ilizarov extraskeletal fixator. The specimens were removed from one dog in each group after 12 weeks. Also, the Ilizarov fixators in the rhBMP-treated dogs were removed after 12 weeks, after which full weight bearing started. The specimens were further taken out after 18 and 24 weeks in the rhBMP-treated and non-rhBMP-treated dogs, and after 24 weeks in the control group. The change of bone mineral density, as well as radiological and histological findings, suggest that the implants are able to induce bone remodeling units and are a superior carrier of rhBMP-2 due to the stimulation of early callus and new bone formation.     

Measurement and clinical significance of the posterior cranial fossa volume of patients with hemifacial spasm

The etiology of hemifacial spasm had long been obscure until 1962 when Gardner proved that this hyperdysfunction of the facial nerve was caused by mechanical compression of the facial nerve by vascular structures in the posterior cranial fossa. In 1977, Jannetta proposed a specific location at the root entry zone of the facial nerve; this area has consequently been considered to be especially vulnerable to minor trauma such as vascular compression. In patients with hemifacial spasm, the posterior cranial fossa cavity is commonly found to be small or shallow on plain craniogram; this anatomical change in the skull is regarded as pathognomonic for the facial nerve hyperdysfunction. To make a quantitative analysis of the posterior cranial fossa volume in these patients, the following method was used. In the preliminary study, a dry human skull with an artificial "tentorium" made of thick paper was prepared to decide the fundamental plane for volume measurement by CT scan. This plane included attachments of posterior clinoid ligaments, superior petrosal veins and lateral sinuses. When this fundamental plane was projected to the lateral view on CT scan, it appeared to be almost identical to the line connecting the tip of posterior clinoid process to the internal occipital protuberance (the fundamental line). A horizontal CT scan for an intracranial volume measurement was performed in a parallel fashion to this fundamental line, with a 5 mm slice for the infratentorial and a 10 mm slice for the supratentorial area. The intracranial area of each horizontal slice was calculated by computed planimeter.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effects of lifestyle and type a behavior on the life-stress process

To evaluate the effects of personal factors such as lifestyle and Thpe A behavior on the life-stress process, we analyzed data randomly collected from 428 metropolitan Tokyo residents. Path analysis techniques were implemented to examine the direct and indirect effects of lifestyle and the Type A behavior pattern between life events, subjective stress and depressive symptoms. The following results were obtained: 1. Persons with a healthy lifestyle perceived a lower subjective stress level. 2. Although females with a healthy lifestyle had fewer direct depressive symptoms, males with a healthy lifestyle had fewer indirect depressive symptoms due to alleviation of subjective stress. 3. Type A males perceived a lower subjective stress level and Type A females experienced more life events. It is suggested that mental health is modified not only by lifestyle but also by Type A behavior in the life-stress process. In particular, the preservation and promotion of a healthy lifestyle appear to reduce subjective stress and may be an important factor for the improvement of mental ill health.     

Flow cytometric analysis of the DNA content of thymomas

In this study, the prognostic value of determining the nuclear DNA content of thymomas by flow cytometry was evaluated. Of a total 31 resected thymomas, 10 (32%) showed DNA aneuploidy, the presence of which was significantly correlated with an advanced clinical stage of disease. The patients with an aneuploid tumor had a poorer prognosis than those with a diploid tumor, demonstrating a survival rate of 50% at 7 postoperative years, which was considerably less favorable than that of the patients with a diploid tumor, being 100% in the same period (p<0.05). Moreover, patients with a high DNA index (DI), i.e., a DI1.5, tended to have a poorer prognosis than those with a low DI. These findings indicated that the DNA content can be an important prognostic index in patients with thymomas.