Depth resolution and recoil cross section for analyzing hydrogen in solids using elastic recoil detection with 4He beam

Two aspects of the elastic recoil detection technique for analyzing H and D are described; i) experimental factors which effectively limit the depth resolution in Al film, and ii) determination of the recoil cross section for H(⁴He, ⁴He)H and D(⁴He, ⁴He)D reactions in the range of 1.5–3.0 MeV energy of ⁴He. Both experimental and theoretical estimates of the depth resolution are presented and are in good agreement each other. The theoretical estimate therefore provides a reliable guide to find optimum resolution conditions. The recoil cross section for H is more than double the theoretical Rutherford scattering value and that for D becomes greater than 30 times Rutherford near the resonance energy of 2.1 MeV ⁴He.     

Interleukin-6 and development of vasospasm after subarachnoid haemorrhage

The authors characterized the role of interleukins in the cerebrospinal fluid (CSF) in the development of vasospasm after subarachnoid haemorrhage (SAH), particularly interleukin-6 (IL-6). Concentrations of interleukin-1 beta (IL-1 beta), IL-6, and interleukin-8 (IL-8) were measured serially in CSF of 24 patients and in serum of 9 patients with SAH and correlated clinically. Additionally, the effects of the same cytokines on the cerebral arteries of dogs were analyzed on angiograms after intracisternal injection. Changes in levels of eicosanoids, angiogenic factors, and soluble cell adhesion molecules were investigated in the CSF of injected dogs. CSF concentrations of IL-6 and IL-8 were elevated significantly above control levels from the acute stage of SAH until the chronic stage. Patients with symptomatic vasospasm had significantly higher levels of IL-6 as well as IL-8 in CSF on days 5 and 7. Intracisternal injection of IL-6 induced long-lasting vasoconstriction in five out of eight dogs, while IL-8 did not. The diameter of canine basilar artery after IL-6 was reduced 29 +/- 5% from pretreatment diameter at 8 hours. Prostaglandins E2 and I2 were elevated in CSF for the first 4.5 hour of this IL-6-induced vasospasm. Neither angiogenic factors such as platelet-derived growth factor-AB and vascular endothelial growth factor nor soluble cell adhesion molecules were significantly elevated in CSF. IL-6, which increases to very high concentrations in CSF after SAH, may be important in inducing vasospasm, as IL-6 produced long-lasting vasoconstriction in the canine cerebral artery, which may be partly related to activation of the prostaglandin cascade.     

A case of subacute necrotizing fasciitis

We report a 48-year-old woman who developed necrotizing groin fasciitis with insidious onset. Before she visited us, she had been unsuccessfully treated with several kinds of antibiotics by other doctors for one month, because of a small ulcer covered by blackish necrotic tissue. She was referred to us because of high fever, an ulcer on the left labium majus, and a cellulitis-like lesion with severe pain on the lower abdomen. Methicillin-resistant Staphylococcus aureus (MRSA), Streptococcus intermedius, and Bacteroides uniformis were isolated from the wound. After aggressive debridement on the eighth day after admission of the whole indurated area and the fascia of the underlying muscle, healthy granulation tissue covered the defect, and the wound was finally closed with a skin graft Long-term administration of antibiotics along with insufficient and delayed surgical treatment were considered to have caused the full development of this disease.     

Lack of the response to nicotine in 21-day-old rat adrenal chromaffin cells in vivo

Response to nicotine of adrenal chromaffin cells was studied in suckling and young adult male rats in vivo. When 5 mg/kg of nicotine was injected subcutaneously to 8-week-old rats, the content of adrenaline and noradrenaline in the chromaffin granule fraction decreased about by 36 and 45%, respectively, 2 min after the administration. In electron microscopy, the number of chromaffin granules in the perinuclear region of adrenaline-storing cells decreased markedly. The number of vacuoles, probably produced by membrane recycling resulting from exocytosis, increased significantly in adrenaline- and noradrenaline-storing cells. Omega-shaped profiles (exocytosis) were frequently observed both in adrenaline- and noradrenaline-storing cells. On the other hand, nicotine injection did not significantly alter the catecholamine content in the 21-day-old rat chromaffin granule fraction, although severe convulsion was evoked. In electron microscopy, the changes indicative of exocytosis mentioned above were scarcely observed. Cholinergic nerve fibers of mature appearance were observed in the adrenal medulla of 21-day-old rats. These results indicate that the responsiveness of the chromaffin cells to nicotine in 21-day-old rats differs from that in 8-week-old rats.     

Vitamin E prevents apoptosis in cortical neurons during hypoxia and oxygen reperfusion

Cerebral ischemia followed by oxygen reperfusion induces apoptosis in hippocampal neurons in stroke-prone spontaneously hypertensive rats (SHRSP) but not in Wistar Kyoto rats (WKY). The overproduction of oxygen-free radicals that occurs in the tissues of SHRSP is implicated in reoxygenation injury after hypoxia. Antioxidants inhibit reoxygenation injury in hippocampal slices, and temporal cortices in Alzheimer's disease increase sensitivity to oxygen-free radicals. Because this sensitivity may contribute to the development of the disease, we have studied hypoxia and oxygen reperfusion using cortical neurons isolated from WKY and SHRSP (at 15 days of gestation). We have tried to determine whether cortical neurons are damaged under these conditions, and whether neurons from SHRSP are more vulnerable than those from WKY. We have tried also to verify whether neuronal damage is minimized by vitamin E using the following techniques: (a) Trypan blue staining, (b) in situ staining of apoptosis, (c) ultrastructural examination, and (d) measurement of lactic dehydrogenase (LDH) activity in the bathing medium. Furthermore, we have examined the mechanisms involved in the development of neuronal damage and have studied ways of minimizing it. We demonstrated that 36 hours of hypoxia significantly increased the rate of cell death in SHRSP (p < 0.01), although 12 to 24 hours of hypoxia did not increase cell death in either WKY or SHRSP. In addition, 6 to 36 hours of hypoxia and 1.5 to 5 hours of oxygen reperfusion heavily damaged cells of both WKY and SHRSP, and most became apoptotic or necrotic. In contrast, cells incubated with 50 to 300 microg/ml of vitamin E remained intact, although 10 to 20 microg/ml of vitamin E did not totally preserve the cells. Moreover, vitamin E protected the neurons from high concentrations of sodium nitroprusside (nitric oxide donor) in a dose-dependent manner. Vitamin E, when added to the cells, increased in concentration in a time-dependent manner over a 24-hour period and in a dose-dependent manner below 200 microg/ml, and it was detected mostly in the mitochondria. We also demonstrated that serial treatments with allopurinol (a xanthine oxidase inhibitor) or superoxide dismutase preserved neurons during hypoxia and oxygen reperfusion. These data indicate that SHRSP neurons are weaker than WKY neurons in long-term hypoxia; oxygen radical generation occurs in the early minutes after reperfusion, and then the oxygen-free radicals cause heavy damage to the cells; and antioxidants including vitamin E react with the radicals, thereby preventing apoptosis and necrosis. Therefore, antioxidants appear to be the most important agents in lowering oxygen-free radical damage in cortical neurons.     

Free skin flap from the retroauricular region to the nose

We present two new, one-stage methods for resurfacing a part of the face-- (1) the microvascular transfer of a free retroauricular flap, and (2) an island flap from the galea covered by a full-thickness skin graft from the retroauricular region. Both procedures provided the same good color match, without leaving a readily visible donor scar.     

Immunogenetics of episcleritis in leprosy

BACKGROUND: Neurenteric cysts are rare endothelium-lined structures. Two patients with symptomatic neurenteric cysts at the craniovertebral junction are presented. CASE PRESENTATION: Intermittent progression of neurologic symptoms delayed diagnosis for both patients. In one case, marked enlargement of the cyst was detected on serial imaging studies, and pathological examination of the excised lesion indicated rupture of the cyst. These cysts were totally resected by transoral or suboccipital approaches, as they were not firmly adherent to surrounding neural structures. The diagnosis of neurenteric cyst was confirmed by immunohistochemical analysis of the cyst wall. CONCLUSION: In view of the clinical course of these patients, we recommend early surgical resection of neurenteric cysts located at the craniovertebral junction.     

Lymphoepithelioma-like carcinoma of the skin

Lymphoepithelioma-like carcinoma of the skin is a rare tumor with a microscopic resemblance to lymphoepitheliomatous tumors of the nasopharynx. A 62-year-old woman exhibited such a tumor on the nose together with regional lymph node metastases. Histologically, irregular islands of atypical epithelial cells unconnected to the overlying epidermis were surrounded by or mixed with numerous lymphocytes in the primary tumor. No squamous or glandular differentiation was present. Metastases to the submandibular lymph nodes appeared as glassy squamous cells that resembled trichilemmal keratinization. Staining of the tumor tissues with S-100 protein antibody revealed the presence of numerous short dendritic cells in clusters of epithelial cells. Total resection and adjunctive radiotherapy have led to a 6-year period free of recurrence. This is the second case report of this condition in Japan.     

Particle flow and collection process in single wire HGMS studies

A television system for the observation of HGMS particle flow and buildup on a ferromagnetic wire or small array of wires is described for three geometries. Data for the collection process and a sequence of pictures of buildup are presented for Mn2P2O7, Mn2O3, and Cr2O3particles collected on 125 μm nickel wires. The wake, formed in some cases downstream from the particle collection, has been studied. Data on the wake is given and compared with published data on wake formation. New results on downstream and upstream collection on a wire as a function of slurry velocity is presented.