Daily acute intermittent hypoxia improves breathing function with acute and chronic spinal injury via distinct mechanisms.

Daily acute intermittent hypoxia (dAIH) elicits respiratory plasticity, enhancing respiratory motor output and restoring breathing capacity after incomplete cervical spinal injuries (cSCI). We hypothesized that dAIH-induced functional recovery of breathing capacity would occur after both acute (2 weeks) and chronic (8 weeks) cSCI, but through distinct cellular mechanisms. Specifically, we hypothesized that dAIH-induced breathing recovery would occur through serotonin-independent mechanisms 2wks post C2 cervical hemisection (C2Hs), versus serotonin-dependent mechanisms 8wks post C2Hs. In two independent studies, dAIH or sham (normoxia) was initiated 1 week (Study 1) or 7 weeks (Study 2) post-C2Hs to test our hypothesis. Rats were pre-treated with intra-peritoneal vehicle or methysergide, a broad-spectrum serotonin receptor antagonist, to determine the role of serotonin signaling in dAIH-induced functional recovery. Our data support the hypothesis that dAIH-induced recovery of breathing capacity transitions from a serotonin-independent mechanism with acute C2Hs to a serotonin-dependent mechanism with chronic C2Hs. An understanding of shifting mechanisms giving rise to dAIH-induced respiratory motor plasticity is vital for clinical translation of dAIH as a therapeutic modality.

Diaphragm long-term facilitation following acute intermittent hypoxia during wakefulness and sleep.

Acute intermittent hypoxia (AIH) elicits a form of respiratory plasticity known as long-term facilitation (LTF). Here, we tested four hypotheses in unanesthetized, spontaneously breathing rats using radiotelemetry for EEG and diaphragm electromyography (Dia EMG) activity: 1) AIH induces LTF in Dia EMG activity; 2) diaphragm LTF (Dia LTF) is more robust during sleep vs. wakefulness; 3) AIH (or repetitive AIH) disrupts natural sleep-wake architecture; and 4) preconditioning with daily AIH (dAIH) for 7 days enhances Dia LTF. Sleep-wake states and Dia EMG were monitored before (60 min), during, and after (60 min) AIH (10, 5-min hypoxic episodes, 5-min normoxic intervals; n = 9), time control (continuous normoxia, n = 8), and AIH following dAIH preconditioning for 7 days (n = 7). Dia EMG activities during quiet wakefulness (QW), rapid eye movement (REM), and non-REM (NREM) sleep were analyzed and normalized to pre-AIH values in the same state. During NREM sleep, diaphragm amplitude (25.1 ± 4.6%), frequency (16.4 ± 4.7%), and minute diaphragm activity (amplitude × frequency; 45.2 ± 6.6%) increased above baseline 0-60 min post-AIH (all P < 0.05). This Dia LTF was less robust during QW and insignificant during REM sleep. dAIH preconditioning had no effect on LTF (P > 0.05). We conclude that 1) AIH induces Dia LTF during NREM sleep and wakefulness; 2) Dia LTF is greater in NREM sleep vs. QW and is abolished during REM sleep; 3) AIH and repetitive AIH disrupt natural sleep patterns; and 4) Dia LTF is unaffected by dAIH. The capacity for plasticity in spinal pump muscles during sleep and wakefulness suggests an important role in the neural control of breathing.

Sleep state dependence of ventilatory long-term facilitation following acute intermittent hypoxia in Lewis rats.

Ventilatory long-term facilitation (vLTF) is a form of respiratory plasticity induced by acute intermittent hypoxia (AIH). Although vLTF has been reported in unanesthetized animals, little is known concerning the effects of vigilance state on vLTF expression. We hypothesized that AIH-induced vLTF is preferentially expressed in sleeping vs. awake male Lewis rats. Vigilance state was assessed in unanesthetized rats with chronically implanted EEG and nuchal EMG electrodes, while tidal volume, frequency, minute ventilation (Ve), and CO(2) production were measured via plethysmography, before, during, and after AIH (five 5-min episodes of 10.5% O(2) separated by 5-min normoxic intervals), acute sustained hypoxia (25 min of 10.5% O(2)), or a sham protocol without hypoxia. Vigilance state was classified as quiet wakefulness (QW), light and deep non-rapid eye movement (NREM) sleep (l-NREM and d-NREM sleep, respectively), or rapid eye movement sleep. Ventilatory variables were normalized to pretreatment baseline values in the same vigilance state. During d-NREM sleep, vLTF was observed as a progressive increase in Ve post-AIH (27 + or - 5% average, 30-60 min post-AIH). In association, Ve/Vco(2) (36 + or - 2%), tidal volume (14 + or - 2%), and frequency (7 + or - 2%) were increased 30-60 min post-AIH during d-NREM sleep. vLTF was significant but less robust during l-NREM sleep, was minimal during QW, and was not observed following acute sustained hypoxia or sham protocols in any vigilance state. Thus, vLTF is state-dependent and pattern-sensitive in unanesthetized Lewis rats, with the greatest effects during d-NREM sleep. Although the physiological significance of vLTF is not clear, its greatest significance to ventilatory control is most likely during sleep.

Cerebral microembolisation during radiofrequency ablation of lung tumours: detection by carotid duplex ultrasound.

The aim of this study was to investigate the appearance of microbubbles during radiofrequency ablation (RFA) of lung tumours. Eight consecutive patients (mean age, 73.1 years; 3 men and 5 women; 10 malignant lesions; mean lesion size, 24.8 mm) who underwent RFA of lung tumours using internally cooled single electrodes were enrolled. During the RFA procedure, the right internal carotid artery was continuously monitored by duplex ultrasound. High-intensity transient signals (HITS) that occurred in the Doppler blood flow waveform were taken to indicate microbubbles. 21 RFA applications were performed for the 10 lesions. HITS were observed in 19 of 21 RFA applications; the mean frequency in a single application was 10+/-13.3. A statistical correlation was seen between the duration of energy deposition and the number of HITS, and between tumour size and the number of HITS. Microbubbles were detected in all patients in the late phase of the first session of RFA.

Improvement in respiratory function by percutaneous vertebroplasty.

BACKGROUND: Percutaneous vertebroplasty (PVP) improves back pain and corrects spinal misalignment to some extent, and thus may improve respiratory function. PURPOSE: To retrospectively investigate changes in respiratory function after PVP. MATERIAL AND METHODS: 41 patients (mean age 72.0 years, range 59-86 years; 39 women, two men) who had undergone PVP for vertebral compression fractures (37 thoracic vertebral bodies [Th6-Th12] and 50 lumbar vertebral bodies [L1-L5]) caused by osteoporosis visited our hospital for follow-up consultation between January and June 2005. At this follow-up consultation, respiratory function testing, including percent forced vital capacity (FVC%) and percent forced expiratory volume in 1 s (FEV(1)%), was performed. We retrospectively compared these values with those taken before PVP using a Wilcoxon signed-rank test. RESULTS: FVC% was 85.2+/-30.3% before PVP and 91.5+/-16.8% at follow-up (mean 10 months after PVP), which represented a significant difference (P<0.003). No significant difference in FEV(1)% was detected. Regarding the number of treatment levels, that is, single vertebroplasty versus multiple vertebroplasty, no significant difference in improvement of FVC% was confirmed (P=0.1). FVC% was abnormally low (

[Possibility of alpha-tricalcium phosphate (alpha-TCP) particles as a drug carrier for treatment of abdominal carcinomatosis].

It is reported that cancer foci are unevenly distributed in abdominal carcinomatosis after intraperitoneal inoculation of cancer cells in rats. The organs may be briefly classified into two groups in terms of the deposit of cancer cells: one that shows an affinity to the cells includes the greater omentum, mesenterium, and gonadal fat and etc., and the other having lesser affinity the stomach, intestine, and spleen and etc. Such uneven distributions are likely to occur in clinical cases of abdominal carcinomatosis resulting from progressive digestive cancers. We have explored the possibility of alpha-Tricalcium Phosphate (alpha-TCP) particles as a drug carrier in which carboplatin (CBDCA) was incorporated. alpha-TCP, which has chemically similar properties to hydroxyapatite, is known to have an excellent biocompatibility with human tissues and is biodegradable. The present study focused on the localization and the forms of alpha-TCP particles, and the morphological changes of the surrounding tissues after intraperitoneal administration using normal and cancer-bearing rats. The following results were obtained: (1) alpha-TCP particles were taken up to a large extent in the "milky spot" of the greater omentum, followed by the "stomata" of the mesenterium, gonadal fat, diaphragm, peritoneum, and liver in normal rats. No alpha-TCP particles were caught up in the tissues of the stomach, small intestine, colon, and spleen. The margination and emigration of lymphocytes were slightly observed around those organs. (2) alpha-TCP particles were predominantly detected on the cancer mass of the greater omentum in abdominal carcinomatosis-bearing rats. It should be noted that the particles collected in the same place where cancer cells were caught, suggesting that the localization of the drug-containing particles result in higher drug concentrations in the cells possibly for extended times. The alpha-TCP particles system is expected to be a good candidate for targeting chemotherapy and specially for abdominal carcinomatosis.

[Intraperitoneal administration of carboplatin loaded alpha-tricalcium phosphate (alpha-TCP) particles in rats bearing abdominal carcinomatosis].

It is difficult to treat abdominal carcinomatosis with conventional chemotherapy, and many kinds of localized chemotherapy have been attempted. We used alpha-tricalcium phosphate (alpha-TCP) particles as a drug carrier in this study. alpha-TCP, which has chemically similar properties to human bone, has an excellent biocompatibility with human tissues and is biodegradable. The particles measured 50 to 100 microns in diameter, were round in shape and very porous. These particles have many open micro-pores of about 1 to 3 microns, which are beneficial for containing drugs. The compatibility and biodegradation of alpha-TCP particles were studied following intraperitoneal (ip) administration in normal rats. The following results were obtained: (1) alpha-TCP particles were intaken in the great omentum, and dissolved gradually. (2) The efficacy of ip administration of carboplatin-loaded alpha-TCP (alpha-TCP-CBDCA) was examined using a Donryu rat model with AH130 abdominal carcinomatosis. The alpha-TCP-CBDCA contained 200 mg alpha-TCP and 4 mg CBDCA. The pharmacokinetics of CBDCA following ip administration of alpha-TCP-CBDCA were studied. Pt levels in ascites and great omentum were higher in the alpha-TCP-CBDCA ip from 0.5 to 168 hours than those in the free-CBDCA ip and iv groups. These results suggest that the efficacy of CBDCA may be enhanced by utilizing alpha-TCP particles as a drug delivery carrier.

[A case of advanced gastric cancer treated effectively with neo-adjuvant chemotherapy using l-leucovorin and 5-FU].

A 59-year old man was diagnosed as having advanced gastric cancer, liver metastasis and lymph node metastases after a closed medical examination. Because Schnitzler metastasis was also suspected, chemotherapy was started pre-operatively. The schedule of administration was as follows. One course was l-LV 250 mg/m2 and 5-FU 600 mg/m2 injected intravenously every week and continued for 6 weeks. The UGI examination showed partial response in stomach cancer, and liver metastasis disappeared on CT-scan after 2 courses. We performed total gastrectomy, lymphadenectomy, splenectomy and partial resection of liver. Histological effects showed Grade 1a on main tumor, Grade 2 on liver metastasis, and No. 3 lymphnode metastasis. The survival time was 476 days.

[Antitumor effects of liposome-entrapped carboplatin (Lipo-CBDCA) after intraperitoneal administration in rats bearing carcinomatous peritonitis].

We examined the distribution of Lipo-CBDCA after intraperitoneal administration and antitumor effects in rats. The serum levels of platinum in Lipo-CBDCA were lower than in free-CBDCA intraperitoneal or intravenous administration at 15 and 30 min. after administration. After 3 hours, Lipo-CBDCA showed higher levels of serum platinum than free-CBDCA. These data showed the slow release of Lipo-CBDCA. The antitumor effects of Lipo-CBDCA were studied in rats with peritoneal dissemination due to AH 130 tumors. Intraperitoneal treatment with Lipo-CBDCA prolonged the life span significantly compared with Lipo-CBDCA. No side effects of chemotherapy were found in the liver, kidney, spleen or small intestine. A gastric cancer patient suffering from carcinomatous peritonitis with remarkable ascites was treated with Lipo-CBDCA intraperitoneally. After several injections of Lipo-CBDCA, the ascites disappeared completely and the CEA level of ascites decreased dramatically. These results indicate that intraperitoneal chemotherapy with Lipo-CBDCA may be more effective than free-CBDCA to manage carcinomatous peritonitis, and may be therapeutically useful without toxic side effects.

[A case of graft-versus-host disease following irradiated fresh blood transfusion].

We reported a case of a fatal graft-versus-host disease (GVHD) which developed in a 65-year-old, male patient which was considered to have been induced by irradiated fresh blood donated by his son after a coronary bypass surgery. Fresh blood was obtained from his relatives, and a 15 Gy irradiation was performed before transfusion. The diagnosis of acute GVHD was made by clinical symptoms and histological examinations of the skin and the bone marrow. He died of sepsis on the 19th post-operative day. The HLA typing of the lymphocytes, revealed that the patient had A 2, A 24, Bw 52, Bw 62, Cw 4, DR 2, and his son had A 24, Bw 52, DR 2. A 24 and Bw 52 were homogeneous making his son histocompatible with one of the patient's haplotype. This might well be attributable to the occurrence of GVHD in this case, meaning that 15 Gy irradiation was not sufficient for the prevention of this disease.

Calvin-Benson Cycle Enzymes in Guard-Cell Protoplasts from Vicia faba L: Implications for the Greater Utilization of Phosphoglycerate/Dihydroxyacetone Phosphate Shuttle between Chloroplasts and the Cytosol.

Activities of Calvin-Benson cycle enzymes were found in protoplasts of guard cells from Vicia faba L. The activities of NADP-glyceraldehyde-3-phosphate dehydrogenase (NADP-GAPD) and ribulose-1,5-bisphosphate carboxylase (RuBPC) were 2670 and 52 micromoles per milligrams chlorophyll per hour, respectively. Activities of NADP-GAPD and RuBPC in guard cells were increased by red light illumination, and the light activations were inhibited completely by 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), an inhibitor of photosystem II. Enzymes related to the Calvin-Benson cycle such as 3-phosphoglycerate kinase (PGAK), triose phosphate (TP) isomerase, and fructose-1,6-bisphosphatase (FBPase) were shown to be present in guard-cell chloroplasts. From these results, we conclude that the photosynthetic carbon reduction pathway is present in guard-cell chloroplasts of Vicia faba. We compared these enzyme activities in guard cells with those in mesophyll cells. The activities of NADP-GAPD and PGAK were more than several-fold higher and that of TP isomerase was much higher in guard-cell chloroplasts than in mesophyll chloroplasts. In contrast, activities of RuBPC and FBPase were estimated to be roughly half of those in mesophyll chloroplasts. High activities of PGAK, NAD-GAPD, and TP isomerase were found in fractions enriched in cytosol of guard cells. Illumination of guard-cell protoplasts with red light increased the cellular ATP/ADP ratio from 5 to 14. These results support the interpretation that guard cells utilize a shuttle system (e.g. phosphoglycerate [PGA]/dihydroxyacetone phosphate [DHAP] shuttle) for an indirect transfer of ATP and reducing equivalents from chloroplasts to the cytosol.