Is centralization in emergency rural medicine always right? Lessons learned from two cases of decompression sickness.

The cases of two patients with decompression sickness (DS) are described to add to the discussion about whether centralization, especially when accompanied by air-medical transport, is always justifiable in island emergency medicine. One patient received hyperbaric oxygen (HBO) treatment on another island after island-to-island transfer by boat; the other received HBO treatment on a ship that was anchored, by chance, close to the island where he became ill. Both cases had a good outcome. Island-to-island transport and within-island treatment, rather than island-to-urban-center transport, was effective, indicating that treatment centralization may not be the most effective protocol all cases. A DS treatment strategy is proposed for use in this geographic area; however, DS occurring on remote islands highlights the wider issue of the centralization of health services.

In vitro evaluation of cashew nut shell liquid as a methane-inhibiting and propionate-enhancing agent for ruminants.

Cashew nut shell liquid (CNSL) containing antibacterial phenolic compounds was evaluated for its potency as a feed additive for ruminants. In experiment 1, ruminal responses to CNSL supplementation were assessed using a batch culture system. Rumen fluid from cattle was diluted with artificial saliva and incubated for 18h in a batch culture with a mixed diet containing a 30:70 hay:concentrate diet to which raw or heated CNSL was added at a final concentration of 500 µg/mL. In experiment 2, a Rusitec, using rumen fluid from the same cattle, was operated over a period of 7 d during which only raw CNSL was tested at concentrations of 0, 50, 100, or 200 µg/mL, and variations in fermentation and bacterial population were assessed. In experiment 3, a pure culture study was conducted using selected bacteria to determine their susceptibility to CNSL. In experiment 1, methane production was inhibited by raw CNSL (56.9% inhibition) but not by heated CNSL. Total volatile fatty acid concentration was not affected, whereas increased concentrations of propionate and decreased concentrations of acetate and butyrate were observed using either raw or heated CNSL. These changes were more obvious when raw CNSL was tested. In experiment 2, raw CNSL inhibited methanogenesis and increased propionate production in a dose-dependent manner, showing maximum methane inhibition (70.1%) and propionate enhancement (44.4%) at 200 µg/mL supplementation. Raw CNSL increased total volatile fatty acid concentration and dry matter digestibility. Raw CNSL also appeared to induce a dramatic shift in the population of rumen microbiota, based on decreased protozoa numbers and changes in quantitative PCR assay values for representative bacterial species. In experiment 3, using pure cultures, raw CNSL prevented the growth of hydrogen-, formate-, and butyrate-producing rumen bacteria, but not the growth of bacteria involved in propionate production. Based on these data, raw CNSL, rich in the antibacterial phenolic compound anacardic acid, is a potential candidate feed additive with selective activity against rumen microbes, leading to fermentation that results in decreased methane and enhanced propionate production.

Fos activation in hypothalamic neurons during cold or warm exposure: projections to periaqueductal gray matter.

The hypothalamus, especially the preoptic area, plays a crucial role in thermoregulation, and our previous studies showed that the periaqueductal gray matter is important for transmitting efferent signals to thermoregulatory effectors in rats. Neurons responsible for skin vasodilation are located in the lateral portion of the rostral periaqueductal gray matter, and neurons that mediate non-shivering thermogenesis are located in the ventrolateral part of the caudal periaqueductal gray matter. We investigated the distribution of neurons in the rat hypothalamus that are activated by exposure to neutral (26 degrees C), warm (33 degrees C), or cold (10 degrees C) ambient temperature and project to the rostral periaqueductal gray matter or caudal periaqueductal gray matter, by using the immunohistochemical analysis of Fos and a retrograde tracer, cholera toxin-b. When cholera toxin-b was injected into the rostral periaqueductal gray matter, many double-labeled cells were observed in the median preoptic nucleus in warm-exposed rats, but few were seen in cold-exposed rats. On the other hand, when cholera toxin-b was injected into the caudal periaqueductal gray matter, many double-labeled cells were seen in a cell group extending from the dorsomedial nucleus through the dorsal hypothalamic area in cold-exposed rats but few were seen in warm-exposed rats. These results suggest that the rostral periaqueductal gray matter receives input from the median preoptic nucleus neurons activated by warm exposure, and the caudal periaqueductal gray matter receives input from neurons in the dorsomedial nucleus/dorsal hypothalamic area region activated by cold exposure. These efferent pathways provide a substrate for thermoregulatory skin vasomotor response and non-shivering thermogenesis, respectively.

Effect of local hyperthermia on metastases in oral squamous cell carcinoma.

In this experimental study, hamsters with oral squamous cell carcinoma (O-1N), which has a high potential for lymph node metastasis, received treatment with local hyperthermia. The effect of hyperthermia on regional lymph node metastases was examined pathologically. O-1N was heated twice, each session consisting of radiofrequency capacitive heating (13.56 MHz) for 40 min at 43 degrees C. Cervical lymph nodes were excised 14, 17, 21, and 28 days after heating and were examined histologically. Hamsters in the sham and control groups were killed on the same days and specimens were examined in a same manner. The incidence of lymph node metastasis was significantly lower in the hyperthermia group (36.4%) than in the sham (68.5%) and control (65.0%) groups (both P=0.02). The patterns of lymph node metastasis in the sham and control groups were more advanced than that in the hyperthermia group. The incidence of lymph node metastasis was very low (7.7%) in hamsters with no evidence of tumour after hyperthermia. On multivariate analysis, hyperthermia correlated with inhibition of cervical lymph node metastasis (P=0.02). Our findings suggest that local hyperthermia inhibits lymph node metastasis when the primary tumour responds histologically to treatment.

Hypothalamic region facilitating shivering in rats.

Although the posterior part of the hypothalamus has long been considered important for thermoregulatory shivering, it is unknown whether the neurons there or the passing fibers are implicated in the response. Exposure of urethane-anesthetized rats to cold (15-21 degrees C) elicits shivering. An injection of muscimol (0.5 mM), a GABA(A) receptor agonist, into the medial part of the hypothalamus, including the dorsomedial and posterior nuclei, suppressed the cold-induced shivering. This result suggests that neurons having an excitatory effect on shivering are in this region of the hypothalamus.

MM-1, a c-Myc-binding protein, is a candidate for a tumor suppressor in leukemia/lymphoma and tongue cancer.

The c-myc oncogene product (c-Myc) is a transcription factor that dimerizes with Max and recognizes the E-box sequence, and it plays key functions in cell proliferation, differentiation, and apoptosis. We previously showed that MM-1 bound to myc box II within the transactivation domain of c-Myc and repressed the E-box-dependent transcriptional activity of c-Myc. Here we report that MM-1 showed features of a tumor suppressor. In an EST data base search for cDNAs homologous to MM-1, we found a frequent substitution of amino acid 157 of MM-1, from alanine to arginine (A157R), and the substitution was observed more in tumor cells than in normal cells. A survey of the A157R mutation of MM-1 in 57 cultured cancer cells and 90 tissues from cancer patients showed that the A157R was present in about 50-60% of leukemia/lymphoma cells and in more than 75% of squamous cell carcinoma of tongue cancer. Although both the A157R and the wild-type MM-1 bound to c-Myc, only A157R lost the activities to repress both the E-box-dependent transcriptional activity of c-Myc and the myc/ras cooperative transforming activity in rat 3Y1 cells. Furthermore, the wild-type MM-1, but not A157R, arrested the growth of 3Y1 cells. The human MM-1 gene was mapped at chromosome 12q12-12q13, where many chromosome abnormalities in cancer cells have been reported. The results suggest that MM-1 is a novel candidate for a tumor suppressor that controls the transcriptional activity of c-Myc.

A method for detection of a cytokine and its mRNA in the central nervous system of the developing rat.

We report here an effective and concise method to determine the localization of macrophage migration inhibitory factor (MIF), a proinflammatory cytokine, and its mRNA in the central nervous system of pre- and postnatal rats. This method allows for double staining to demonstrate localization of different molecules on the same tissue specimen at the levels of mRNA and proteins by in situ hybridization and immunohistochemistry, respectively. Additionally, the present method gives results more quickly than the conventional isotopic techniques. By use of this method, we carried out immunohistochemistry with an anti-rat MIF polyclonal antibody and demonstrated positive staining using the avidin-biotin complex method (ABC method). To detect its mRNA, we performed nonradioactive in situ hybridization using a digoxigenin (DIG)-labeled RNA probe prepared from a full length fragment of rat MIF cDNA. MIF was strongly expressed in the telencephalon on embryonic day 16. Non-radioactive in situ hybridization with a DIG-labeled RNA probe as well as the immunohistochemistry described here could be applicable to characterize localization of mRNA and proteins of different molecules on the same tissue specimen.

PKA-mediated phosphorylation of the human K(ATP) channel: separate roles of Kir6.2 and SUR1 subunit phosphorylation.

ATP-sensitive potassium (K(ATP)) channels play important roles in many cellular functions such as hormone secretion and excitability of muscles and neurons. Classical ATP-sensitive potassium (K(ATP)) channels are heteromultimeric membrane proteins comprising the pore-forming Kir6.2 subunits and the sulfonylurea receptor subunits (SUR1 or SUR2). The molecular mechanism by which hormones and neurotransmitters modulate K(ATP) channels via protein kinase A (PKA) is poorly understood. We mutated the PKA consensus sequences of the human SUR1 and Kir6.2 subunits and tested their phosphorylation capacities in Xenopus oocyte homogenates and in intact cells. We identified the sites responsible for PKA phosphorylation in the C-terminus of Kir6.2 (S372) and SUR1 (S1571). Kir6.2 can be phosphorylated at its PKA phosphorylation site in intact cells after G-protein (Gs)-coupled receptor or direct PKA stimulation. While the phosphorylation of Kir6.2 increases channel activity, the phosphorylation of SUR1 contributes to the basal channel properties by decreasing burst duration, interburst interval and open probability, and also increasing the number of functional channels at the cell surface. Moreover, the effect of PKA could be mimicked by introducing negative charges in the PKA phosphorylation sites. These data demonstrate direct phosphorylation by PKA of the K(ATP) channel, and may explain the mechanism by which Gs-coupled receptors stimulate channel activity. Importantly, they also describe a model of heteromultimeric ion channels in which there are functionally distinct roles of the phosphorylation of the different subunits.

Glial cell line-derived neurotrophic factor protects against delayed neuronal death after transient forebrain ischemia in rats.

Glial cell line-derived neurotrophic factor, a member of the transforming growth factor-beta superfamily, is a potent neurotrophic factor, which has a variety of biological activities that affect several types of neurons in both the central and peripheral nervous systems. In this study, we examined the effects of glial cell line-derived neurotrophic factor on delayed neuronal death in the hippocampal CA1 region of rats after transient forebrain ischemia. In the control rats pretreated with the vehicle, transient forebrain ischemia-induced delayed neuronal death in the hippocampal CA1 region was observed seven days after reperfusion. Pretreatment with glial cell line-derived neurotrophic factor (1.0 microg), which was directly microinjected into the right hippocampal CA1 region, gave significant protection against the delayed hippocampal neuronal death. On the contralateral side of the hippocampus, which was not injected with glial cell line-derived neurotrophic factor, delayed neuronal death similar to that seen in vehicle-treated control animals was observed. Intracerebroventricular glial cell line-derived neurotrophic factor (2.5 microg) injection also protected against delayed neuronal death. In addition, pretreatment with glial cell line-derived neurotrophic factor gave significant protection against apoptotic cell death induced by brain ischemia in the hippocampal CA1 region, as determined by in situ staining for DNA fragmentation. These findings suggest that glial cell line-derived neurotrophic factor plays an important role in delayed neuronal death induced by brain ischemia.

Antiproliferative activity in vitro and in vivo of the spicamycin analogue KRN5500 with altered glycoprotein expression in vitro.

The spicamycin analogue KRN5500 (NSC 650426; SPA) is derived from Streptomyces alanosinicus. The unique structure contains a purine, an aminoheptose sugar, glycine, and a tetradecadiene fatty acid. SPA potently inhibits the growth of certain human tumor cell lines in vitro (IC50 for growth <100 nM) and displays marked activity in vivo in Colo 205 colon carcinoma xenografts. Selective inhibition of labeled precursor incorporation was not evident at 1 or 4 h of exposure to the drug, but at 8 h, [3H] leucine incorporation was inhibited by approximately 40% at or below the IC50 for cell growth. Because of the structural similarity of SPA to inhibitors of glycoprotein processing, we examined the effect of SPA on indicators of glycoprotein synthesis and processing in HL60TB promyelocytic leukemia and Colo 205 colon carcinoma cells. Brief periods of exposure ( approximately 30 min) to SPA at the IC50 for growth increased incorporation of [3H]mannose. When examined by Western blotting after prolonged (40-48 h) incubation with lectins that target mannose-containing carbohydrates, Galanthus nivalis agglutinin and concanavalin A, a qualitative change in the pattern of mannose-containing glycoproteins was observed in HL60TB cells. Significant changes in the pattern of surface glycoprotein expression in intact cells were demonstrated by flow cytometry using fluorescence-labeled lectins. An increase in the number of cells binding G. nivalis agglutinin (indicating terminal mannose) was noted, but a decrease in the amount of lectin bound per cell was noted for wheat germ agglutinin (detecting sialic acid and terminal beta-N-acetyl glucosamine residues). Electron microscopy revealed loss of microvilli, and the Golgi apparatus appeared inflated. Our findings, therefore, raise the possibility that cells exposed to SPA have altered glycoprotein processing after exposure to low concentrations of drug, prior to the occurrence of overt cytotoxicity. These effects are consistent with a prominent early effect of SPA on the enzymatic machinery or organelles important for proper glycoprotein processing and emphasize the novelty of this agent's likely mechanism of action.

Purification and characterization of two lectins from calllus of Helianthus tuberosus.

Two lectins were purified from Helianthus tuberosus callus by maltose affinity chromatography and subsequent preparative electrophoresis. The lectins were designated HTA I and HTA II and their molecular masses were about 34 kDa by gel-filtration chromatography. A single band of 17 kDa and bands of 17 kDa and 18 kDa were detected after SDS-PAGE of HTA I and HTA II, respectively, indicating that HTA I is a homodimer while HTA II is a heterodimer. The amino acid compositions of the two lectins were very similar; they were rich in glycine residues, lacking detectable amounts of methionine, cysteine, and histidine. A hapten-inhibition assay showed that HTA I and HTA II had identical saccharide-binding specificity to the extent tested and belonged to the group of so-called mannose/glucose-binding lectins. They had high affinity for alpha-linked manno-oligosaccharides. Each HTA completely lost its hemagglutinating activity at pH 5.0, as a result of its dissociation to monomers, but it did not lose its ability to bind to oligosaccharides.

Protective effects of KW-3902, an adenosine A1-receptor antagonist, against cisplatin-induced acute renal failure in rats.

We investigated possible renal protective and therapeutic effects of KW-3902 (8-(noradamantan-3-yl)-1,3-dipropylxanthine), a novel and potent adenosine A1-receptor antagonist, on cisplatin-induced acute renal failure (ARF). ARF was induced in rats by a single injection of cisplatin-induced acute renal failure (ARF). ARF was induced in rats by a single injection of cisplatin (5 mg/kg, i.v.). Prophylactic treatment with KW-3902 (0.01-1 mg/kg, p.o., twice a day) significantly attenuated the increases of serum creatinine (S-CRE) and urea nitrogen (S-UN) induced by cisplatin. On the other hand, neither furosemide nor trichlormethiazide showed any ameliorating effects against the cisplatin-induced ARF. In the clearance study, the cisplatin-treatment induced marked decreases of glomerular filtration rate (GFR), renal plasma flow (RPF), and reabsorptions of water, sodium and potassium at tubular sites, in comparison with those in untreated normal rats. KW-3902 (0.1 mg/kg, p.o., twice a day) significantly improved these deteriorated glomerular and tubular functions. In the rats with established cisplatin-induced ARF, KW-3902 ameliorated the cisplatin-induced reductions of GFR, RPF, and reabsorptions of water, sodium and potassium at tubular sites. These results suggest that activation of adenosine A1-receptors is involved in the pathogenesis of cisplatin-induced ARF. The adenosine A1-receptor antagonist may be useful for the treatment of cisplatin-induced ARF.

[Intermittent hepatic arterial infusion of high-dose 5-FU for liver metastases from colorectal cancer].

A phase II study of weekly intermittent hepatic arterial infusion of high dose 5-FU for liver metastases from colorectal cancer was carried out. Thirty-two patients with unresectable liver metastases from colorectal cancer were entered in this study. Nausea (< or = grade 2) was observed in 31% of the cases, mild elevation of rGTP in 13%, biloma in 9%, and hepatic arterial occlusion in 22%. However, no major toxicity occurred. The response rate evaluated by CT-scans was 75% (4 CR + 20 PR/32), and the overall median survival was 22 months. Significant differences of median survival were observed in the extra-hepatic lesions [extrahepatic lesions: (-) 16 months vs (+) 22 months]. This regimen showed high activity without major toxicity and the reduction of pts' QOLs caused by pumps. It confirmed by a study involving a large number of cases, this regimen will become a standard regimen for unresectable liver metastases from colorectal cancer.

A new point mutation in the deoxyribonucleic acid-binding domain of the vitamin D receptor in a kindred with hereditary 1,25-dihydroxyvitamin D-resistant rickets.

Hereditary 1,25-dihydroxyvitamin D [1,25-(OH)2D]-resistant rickets (HVDRR) is a rare disorder characterized by rickets, alopecia, hypocalcemia, secondary hyperparathyroidism, and normal or elevated serum 1,25-dihydroxyvitamin D levels. We describe a patient with typical clinical characteristics of HVDRR, except that elevated levels of serum phosphorus were present coincident with increased levels of serum intact PTH. The patient was treated with high dose calcium infusion after an ineffective treatment with 1 alpha-hydroxyvitamin D3; serum calcium and phosphorus as well as intact PTH and alkaline phosphatase levels were normalized. Evaluation of phytohemagglutinin-activated lymphocytes derived from this patient revealed that 1,25-(OH)2D3 was unable to inhibit thymidine incooperation, a result that contrasts with the capacity of 1,25-(OH)2D3 to inhibit uptake into normal activated lymphocytes. 1,25-(OH)2D3 did not induce human osteocalcin promoter activity after transfection of this DNA linked to a reporter gene into patient cells. Cointroduction of a human vitamin D receptor (VDR) cDNA expression vector with the reporter plasmid, however, restored the hormone response. Evaluation of extracts from the patient cells for VDR DNA binding revealed a defect in DNA binding. Analysis of genomic DNA from the patient's cells by PCR confirmed the presence of a point mutation in exon 2 of the VDR. This exon directs synthesis of a portion of the DNA-binding domain of the receptor. We conclude that the genetic basis for 1,25-(OH)2D3 resistance in this kindred with VDR-positive HVDRR is due to a single base mutation in the VDR that leads to production of a receptor unable to interact appropriately with DNA.

Virus-induced obesity in mice: association with a hypothalamic lesion.

In an earlier study we found that a substantial percentage of mice surviving infection with canine distemper virus (CDV) slowly developed a morbid obesity syndrome. In the present study we wished to explore the role of the virus in the development of this syndrome. The distribution of viral antigen(s) in brains of pre-obese animals shortly after intracerebral infection was mapped using immunocytochemical procedures. A distinctive pattern of cell labeling was found, extending from the anterior periventricular hypothalamus ventrally and caudally toward the posterior hypothalamus. The heaviest concentration of labeled cells was found in the arcuate-ventromedial area. Viral antigen-containing cells were not found in obese brain specimens. However, the latter revealed, by glial fibrillary acidic protein immunostaining, a gliotic lesion of the hypothalamus that approximated topographically the pattern of virus tropism. Examination of the arcuate area revealed a significant reduction in tyrosine hydroxylase immunoreactive and pro-opiomelanocortin mRNA positive perikarya. We suggest that the loss of critical populations of hypothalamic neurons as a result of an antecedent viral infection led ultimately to the development of morbid obesity.

[An unresectable colon cancer with a diffuse metastases that turned resectable following thermotherapy with chemoimmunotherapy].

Reported is the case of a 66-year-old woman who complained of a pain in the upper abdomen. A barium enema revealed a stenosis in the transverse and sigmoid colon and since her ileus worsened, an emergency operation was performed, which revealed an unresectable transverse colon cancer with a diffuse peritoneal metastases. After closing the wound, the patient was treated with local thermotherapy of the abdomen using an RF wave in combination with chemotherapy and immunotherapy. Later, since the tumor could not be palpated and the tumor markers dissipated, a reoperation was performed, and it was found that diffuse metastases had completely disappeared from the peritoneum. Further, a histopathological study did not disclose any tumor cells. Therefore, as the cancer was remarkably reduced, a partial transverse and descending colon colectomy was performed.

[Curability of multidisciplinary treatment including combined hyperthermia, radiotherapy and chemotherapy].

Reported are the results in 311 patients who received a multidisciplinary treatment for their cancers, said treatment combining hyperthermia, radiotherapy, and chemtherapy. Of his number, 266 patients were in the advance stage of their disease while another 42 still had localized cancers. According to the criteria of Koyama and Saitoh for evaluating solid tumors that had received chemotherapy, of 298 evaluable patients, 64 showed a complete response (CR), 94 showed a partial response (PR), 89 showed no change (NC), and 57 showed a progressive disease (PD), for an overall response of 53.0% (158 cases). A multidisciplinary treatment combining radiotherapy and hyperthermochemotherapy was used for cases involving localized tumors of the vulva, the skin, the thyroid gland, the prostate gland, the uterus, the rectum, the soft tissue bone, and the ovary, though our treatment regimen could not be continued in cases of tumors involving the stomach, the esophagus, the lung, the mediastinum, the liver, and the pancreas. Our data has shown that a high overall rate of curability was achieved in cases involving the stomach, the bladder, the blood, the skin, the head, and neck, and the esophagus.

Pediatric total colonoscopy.

One hundred fifty-one total colonoscopies were performed in 105 children ranging from 1 month to 15 years of age. The cecum was reached successfully in 136 examinations without complications, generally within 30 minutes. Our major indications for total colonoscopy were abnormal findings in a contrast enema, undiagnosed rectal bleeding, and possible organic lesion causing intussusception. All procedures were performed using sedation only. The pediatric gastroscope was employed for total colonoscopy on infants less than 6 years of age; the cecum was reached successfully in 98 of 106 procedures with this instrument. Our total colonoscopy series contributed to the diagnosis of various disorders in 86 children and of normality in the 19 remaining children. The results suggest that, if performed with proper precautions and techniques, total colonoscopy is a safe and useful procedure with which to examine the entire colon of infants and children.

Levels of growth hormone and growth-hormone-releasing factor in cord blood.

In order to evaluate the mechanism of high growth hormone (GH) secretion in perinatal life, the levels of GH and growth-hormone-releasing factor (GRF) in cord blood were determined. Plasma-immunoreactive GRF was measured by a double antibody RIA method. The levels (mean +/- SD) of GH, GRF and somatostatin (SRIF) were 23.4 +/- 10.2 ng/ml, 49.5 +/- 11.7 and 41.5 +/- 10.4 pg/ml, respectively; they were remarkably higher than those of healthy adults. In statistical analysis, there were no significant relationships among the levels of GH, GRF or SRIF. We speculate that a high GRF release from the hypothalamus might increase the secretion of GH in the perinatal period.

Infantile neuroaxonal dystrophy: perinatal onset with symptoms of diencephalic syndrome.

In a neonatal case of infantile neuroaxonal dystrophy, there was emaciation, nystagmus, and endocrinologic disorder suggesting the diencephalic syndrome. At autopsy, spheroid bodies were widely disseminated, particularly in the hypothalamus, infundibulum, and neurohypophysis. The pathologic process may have started in utero.