Host range of poliovirus is restricted to simians because of a rapid sequence change of the poliovirus receptor gene during evolution

The host range of most poliovirus (PV) strains is restricted to simians. This host range specificity is believed to be determined by the interaction between PV and its receptor molecule. To elucidate the molecular basis of this species-specific infection of PV, we cloned orthologs of the PV receptor (PVR) gene ( pvr) as well as those of PV receptor-related genes 1 and 2 ( prr1 and prr2) from various mammalian species. These three genes are widely present in mammalian genomes including those of non-susceptible species. Comparison of the deduced amino acid sequences of PVR orthologs revealed that the NH(2)-terminal immunoglobulin-like domain (domain 1), which is the virus binding site in the human PVR, is highly variable among species, whereas that of PRR1 is highly conserved. Domain 1 of the PVR orthologs for the ring-tailed lemur and rabbit, which are not susceptible to PV, show only 51 and 61% amino acid sequence identity to that of human PVR, respectively. Chimeric PVR proteins that have the domain 1 of the ring-tailed lemur and rabbit PVRs failed to serve as receptors for PV. These results suggest that rapid changes in the domain 1 sequence during mammalian evolution determined the host range restriction of PV.

Pharmacokinetics, toxicokinetics, distribution, metabolism and excretion of linezolid in mouse, rat and dog

1. Linezolid (ZYVOX), the first of a new class of antibiotics, the oxazolidinones, is approved for treatment of Gram-positive bacterial infections. 2. The aim was to determine the absorption, distribution, metabolism and excretion (ADME) of linezolid in mouse, rat and dog in support of preclinical safety studies and clinical development. 3. Conventional replicate study designs were employed in animal experiments, and biofluids were assayed by HPLC or HPLC-MS. 4. Linezolid was rapidly absorbed after p.o. dosing with an p.o. bioavailability of > 95% in rat and dog, and > 70% in mouse. Twenty-eight-day i.v./p.o. toxicokinetic studies in rat (20-200mg kg(-1) day(-1)) and dog (10-80 mg kg(-1) day(-1)) revealed neither a meaningful increase in clearance nor accumulation upon multiple dosing. 5. Linezolid had limited protein binding (<35%) and was very well distributed to most extravascular sites, with a volume of distribution at steady-state (V(ss)) approximately equal to total body water. 6. Linezolid circulated mainly as parent drug and was excreted mainly as parent drug and two inactive carboxylic acids, PNU-142586 and PNU-142300. Minor secondary metabolites were also characterized. In all species, the clearance rate was determined by metabolism. 7. Radioactivity recovery was essentially complete within 24-48 h. Renal excretion of parent drug and metabolites was a major elimination route. Parent drug underwent renal tubular reabsorption, significantly slowing parent drug excretion and allowing a slow metabolic process to become rate-limiting in overall clearance. 8. It is concluded that ADME data were relatively consistent across species and supported the rat and dog as the principal non-clinical safety species.

Significance of fractionated irradiation for the biological therapeutic gain of carbon ions

It is well established that the RBE (relative biological effectiveness) for cell killing depends on LET (linear energy transfer), and that a maximum RBE is observed at approximately 150 keV.micron-1. However, the therapeutic gain depends on the ratio of the RBEs for the effects on the cancer cell population and the effects on normal tissues. The RBE of a given radiation quality depends not only on LET but also on dose, biological system and effect, and irradiation conditions. There is no data available to answer the question: which LET is suitable to improve the biological therapeutic gain of carbon ions? Here, three different LET values of 290 MeV/u carbon ions were selected, and the relative biological effectiveness was compared between tumour-growth retardation and skin damage using a murine transplantable tumour. Larger RBE values for tumours after than the skin type were obtained when carbon ions of intermediate LET were delivered daily for 2 to 5 fractions. The biological therapeutic gain would be high for the carbon ion SOBP if the number of fractions were correctly selected in clinical trials.

Development and use of competitive PCR assays for the rumen cellulolytic bacteria: Fibrobacter succinogenes, Ruminococcus albus and Ruminococcus flavefaciens

Competitive PCR assays were developed for the enumeration of the rumen cellulolytic bacterial species: Fibrobacter succinogenes, Ruminococcus albus and Ruminococcus flavefaciens. The assays, targeting species-specific regions of 16S rDNA, were evaluated using DNA from pure culture and rumen digesta spiked with the relevant cellulolytic species. Minimum detection levels for F. succinogenes, R. albus and R. flavefaciens were 1-10 cells in pure culture and 10(3-4) cells per ml in mixed culture. The assays were reproducible and 11-13% inter- and intra-assay variations were observed. Enumeration of the cellulolytic species in the rumen and alimentary tract of sheep found F. succinogenes dominant (10(7) per ml of rumen digesta) compared to the Ruminococcus spp. (10(4-6) per ml). The population size of the three species did not change after the proportion of dietary alfalfa hay was increased. All three species were detected in the rumen, omasum, caecum, colon and rectum. Numbers of the cellulolytic species at these sites varied within and between animals.

Development and use of competitive PCR assays for the rumen cellulolytic bacteria: Fibrobacter succinogenes, Ruminococcus albus and Ruminococcus flavefaciens

Competitive PCR assays were developed for the enumeration of the rumen cellulolytic bacterial species: Fibrobacter succinogenes, Ruminococcus albus and Ruminococcus flavefaciens. The assays, targeting species-specific regions of 16S rDNA, were evaluated using DNA from pure culture and rumen digesta spiked with the relevant cellulolytic species. Minimum detection levels for F. succinogenes, R. albus and R. flavefaciens were 1-10 cells in pure culture and 10(3-4) cells per ml in mixed culture. The assays were reproducible and 11-13% inter- and intra-assay variations were observed. Enumeration of the cellulolytic species in the rumen and alimentary tract of sheep found F. succinogenes dominant (10(7) per ml of rumen digesta) compared to the Ruminococcus spp. (10(4-6) per ml). The population size of the three species did not change after the proportion of dietary alfalfa hay was increased. All three species were detected in the rumen, omasum, caecum, colon and rectum. Numbers of the cellulolytic species at these sites varied within and between animals.

Electroretinogram analysis of relative spectral sensitivity in genetically identified dichromatic macaques

The retinas of macaque monkeys usually contain three types of photopigment, providing them with trichromatic color vision homologous to that of humans. However, we recently used molecular genetic analysis to identify several macaques with a dichromatic genotype. The affected X chromosome of these animals contains a hybrid gene of long-wavelength-sensitive (L) and middle-wavelength-sensitive (M) photopigments instead of separate genes encoding L and M photopigments. The product of the hybrid gene exhibits a spectral sensitivity close to that of M photopigment; consequently, male monkeys carrying the hybrid gene are genetic protanopes, effectively lacking L photopigment. In the present study, we assessed retinal expression of L photopigment in monkeys carrying the hybrid gene. The relative sensitivities to middle-wavelength (green) and long-wavelength (red) light were measured by electroretinogram flicker photometry. We found the sensitivity to red light to be extremely low in protanopic male monkeys compared with monkeys with the normal genotype. In female heterozygotes, sensitivity to red light was intermediate between the genetic protanopes and normal monkeys. Decreased sensitivity to long wavelengths was thus consistent with genetic loss of L photopigment.

Time course of reoxygenation in experimental murine tumors after carbon-beam and X-ray irradiation

We compared the tumor reoxygenation patterns in three different murine tumor cell lines after X-irradiation with those after carbon-beam irradiation using a heavy-ion medical accelerator (HIMAC) system. The tumors of the cell lines SCCVII, SCCVII-variant-1 and EMT6 on the hind legs of mice received local priming irradiation with a carbon-beam (8 Gy, 73 keV/microm in LET, 290 MeV/u, 6 cm SOBP) or X-rays (13 Gy, 250 kVp). After various intervals, the mice were given whole-body test irradiation (16 Gy. 250 kVp X-ray) either in air or after they were killed. The hypoxic fractions were estimated as the proportions of the surviving fractions of the tumors in killed mice to those in air-breathing mice. In the SCCVII tumors, the hypoxic fractions at 0.5 h were 50% and 21% (p < 0.05) after the priming X-irradiation and carbon-beam irradiation, respectively. In the SCCVII-variant-1 tumors, the hypoxic fractions were 85% and 82% at 0.5 h, 84% and 20% at 12 h (p < 0.01), and 21% and 31% at 24 h after X-ray and after carbon-beam irradiation, respectively. In the EMT6 tumors, the reoxygenation patterns after X-irradiation and carbon-beam irradiation were quite similar. We concluded that the reoxygenation pattern differed among the three tumor cell lines, and that reoxygenation tended to occur more rapidly after carbon-beam irradiation than after X-irradiation for SCCVII and SCCVII-variant-1 tumors.

MR imaging of pancreatic diseases

This article presents current MR imaging techniques for the pancreas, and review a spectrum of MR imaging features of various pancreatic diseases. These include: 1) congenital anomalies such as anomalous union of pancreatobiliary ducts, divisum, and annular pancreas, 2) inflammatory diseases, including acute or chronic pancreatitis with complications, groove pancreatitis, and autoimmune pancreatitis, tumor-forming pancreatitis, 3) pancreatic neoplasms, including adenocarcinoma, islet cell tumors, and cystic neoplasms (microcystic adenoma, mucinous cystic neoplasms, and intraductal mucin-producing pancreatic tumor). Particular attention is paid to technical advances in MR imaging of the pancreas such as fat-suppression, MR pancreatography (single- or multi-slice HASTE), and thin-section 3D multiphasic contrast-enhanced dynamic sequences. Imaging characteristics that may lead to a specific diagnosis or narrow the differential diagnosis are also discussed.

Measurement of B(0)(d)-B_(0)(d) mixing rate from the time evolution of dilepton events at the upsilon(4S)

We report a determination of the B(0)(d)-&B_(0)(d) mixing parameter Deltam(d) based on the time evolution of dilepton yields in Upsilon(4S) decays. The measurement is based on a 5.9 fb(-1) data sample collected by the Belle detector at KEKB. The proper-time difference distributions for same-sign and opposite-sign dilepton events are simultaneously fitted to an expression containing Deltam(d) as a free parameter. Using both muons and electrons, we obtain Deltam(d) = 0.463+/-0.008 (stat)+/-0.016 (syst) ps(-1). This is the first determination of Deltam(d) from time evolution measurements at the Upsilon(4S). We also place limits on possible CPT violations.

Measurement of the CP violation parameter sin2 phi(1) in B(0)(d) meson decays

We present a measurement of the standard model CP violation parameter sin2 phi(1) (also known as sin2beta) based on a 10.5 fb(-1) data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric e(+)e(-) collider. One neutral B meson is reconstructed in the J/psiK(S), psi(2S)K(S), chi(c1)K(S), eta(c)K(S), J/psiK(L), or J/psipi(0) CP-eigenstate decay channel and the flavor of the accompanying B meson is identified from its charged particle decay products. From the asymmetry in the distribution of the time interval between the two B-meson decay points, we determine sin2 phi(1) = 0.58(+0.32)(-0.34)(stat)+0.09-0.10(syst).

Relative biological effectiveness of the 235 MeV proton beams at the National Cancer Center Hospital East

A therapy-dedicated cyclotron was installed in the National Cancer Center Hospital East (NCCHE) at Kashiwa in 1997. Prior to the start of clinical use, we investigated the biological effectiveness of therapeutic proton beams for cell lethality. The proton beams accelerated up to 235 MeV were horizontally extracted from the cyclotron, and scattered by a bar-ridge filter to produce a Spread-Out-Bragg-Peak (SOBP) of 10-cm width. The biological systems used here were mouse intestinal crypt cells and three in vitro cell lines, including SCC61 human squamous cell carcinoma, NB1RGB human fibroblasts and V79 Chinese hamster cells. The dose responses after irradiation at either the entrance plateau or the middle portion of SOBP were compared with those after linac 6 MV X-ray irradiation. The fit of a linear quadratic model to survival curves showed that proton irradiation increased the alpha value of SCC61 and the beta value of V79 cells with a least change for alpha/beta ratio of NB1RGB cells. The isoeffect dose that reduces either cell survivals to 10% or mouse jejunum crypts to 10 per circumference was termed D10. The relative biological effectiveness (RBE) of protons obtained by comparing the D10 values between protons and X-rays ranged from 0.9 to 1.2. The depth distribution of cell lethality was measured by replating V79 cells after irradiation from a "cell stack chamber" that received a single dose of 7 Gy at the middle position of SOBP. The thus-obtained cell survivals at various depths coincided well with the estimated survivals, but tended to decrease at the distal end of SOBP. We conclude that an RBE of 1.1 would be appropriate for 235 MeV proton beams at the NCCHE.

Endovascular stent grafting for the treatment of blunt thoracic aortic injury

OBJECTIVE

Recent advances of endovascular stent-grafting (ESG) provide a new therapeutic option with minimum surgical damage for blunt aortic injury (BAI) during its acute phase. To clarify the effectiveness of ESG for BAI, a prospective clinical study at a university hospital was conducted.

METHODS

All patients with blunt thoracic injury underwent thoracic contrast-enhanced computed tomographic (CT) scan. Six patients age 48.8 +/- 19.8 years, with Injury Severity Scores of 35.8 +/- 8.1, and with BAI were treated according to our protocol. The stent-graft covered by woven Dacron was placed at the injury site. Endoleakage was then checked by aortography and CT scan was again performed once a day on days 7 through 14.

RESULTS

All patients had injury of the aortic isthmus. ESG placement was performed within 8 hours after injury except in one (48 hours). The operating time was 159.5 +/- 21.1 minutes and bleeding volume was 105 +/- 26.6 mL. No endoleakage was found. Repeat CT scan revealed disappearance of hematoma. All patients except one had an event-free clinical course. One patient died because of rupture of the ascending aorta on day 6; however, autopsy revealed evidence of the healing process at the injury site sealed by ESG.

CONCLUSION

An ESG is a valid therapeutic option with minimal surgical invasion for patients with acute-phase aortic injury.

Localization of heme oxygenase-2 in the canine larynx

The localization of heme oxygenase-2 (HO-2) in the larynx of the dog was investigated using immunohistochemistry. HO-2-positive cells were seen among neurons in intralaryngeal ganglia. Nerve fibers positive to HO-2 immunohistochemistry were seen surrounding laryngeal glands and arterioles and also in the adventitia of arterioles. HO-2-positive fibers were also seen running parallel to the mucosa in the lamina propria but no positive fibers were seen in the epithelium. Some of the intramuscular neurons found in the intrinsic laryngeal muscles were HO-2-positive, although no positive motor fibers were seen, and the neuromuscular junctions were also HO-2-negative. The results implicate the participation of HO-2-in the parasympathetic innervation of the larynx.

[Use of passing intestine pump (EN) from home ingredient nutrition passing pipe nutrition method (HEN) in home medical treatment support]

Introducing the passing intestine pump (EN) into home medical treatment from October 1999 for passing intestine nutrition management, and to the passing intestine nutrition management to the management is thought to increase the quality of life (QOL) of the patient and the family. The life style of the patient broadens and this seems to be an effective piece of home support equipment. We here in report the actual general management of the passing intestine pump in home medical treatment.

Discrimination of alcoholic from virus-induced cirrhosis on MR imaging

OBJECTIVE

The purpose of this study was to determine whether MR features help to differentiate virus-induced cirrhosis from alcoholic cirrhosis.

MATERIALS AND METHODS

The MR examinations of 53 patients with cirrhosis (38 men and 15 women; age range, 28-73 years) caused by hepatitis B (n = 16), hepatitis C (n = 18), or alcohol abuse (n = 19) were retrospectively reviewed independently by two radiologists. The following MR features were assessed by each radiologist independently: volume indexes of the spleen and of each liver segment (based on 3-axis measurements), the nodularity of the surface, and the presence of regenerative nodules, ascites, iron or fat deposition, varices or collateral veins, the right posterior hepatic notch, and an expanded gallbladder fossa.

RESULTS

The mean values of the volume index of the caudate lobe were significantly greater (p < 0.0001) in the group with alcoholic cirrhosis than those in the group with viral cirrhosis. The frequency of visualization of the right posterior hepatic notch in the patients with alcoholic cirrhosis was significantly greater (p < 0.05) than that in the patients with viral cirrhosis. The size of regenerative nodules of the liver in the patients with cirrhosis caused by hepatitis B was significantly greater (p < 0.02) than that in the patients with alcoholic cirrhosis.

CONCLUSION

Enlargement of the caudate lobe and the presence of the right posterior hepatic notch on MR imaging are more frequent findings of alcoholic cirrhosis than of virus-induced cirrhosis.

Gastric seromuscular and omental pedicle flap for bronchopleural fistula after pneumonectomy

We report a case of postpneumonectomy bronchopleural fistula treated using a gastric seromuscular and omental pedicle flap and maintaining good postoperative respiratory function. A 76-year-old man underwent right pneumonectomy with regional lymph node dissection for squamous cell carcimoma of the lung. Five weeks later, a bronchopleural fistula occurred. Empyema with the bronchopleural fistula was diagnosed and chest tube drainage implemented immediately. Despite the drainage, signs of inflammation persisted and the patient's nutrition did not improve leading to surgery, on August 18, 1997. The bronchopleural fistula was closed by horizontal suture proximal to the stapling sutured line. A gastric seromuscular and omental pedicle flap was sutured as a cover over the bronchial stump. Postoperative analysis of respiratory function and arterial blood gas showed good results.

Changes in cardiopulmonary parameters during upper gastrointestinal endoscopy in patients with heart disease: towards safer endoscopy

BACKGROUND AND STUDY AIMS

Gastrointestinal endoscopy is an invasive examination. The aims of this study were to elucidate the effects and risks of upper gastrointestinal endoscopy with regard to cardiopulmonary functions in patients with heart disease, and to establish safety guidelines for use during endoscopy in this particular group of patients.

PATIENTS AND METHODS

The patients involved were 53 inpatients in whom upper gastrointestinal endoscopy was carried out before cardiac surgery. Their cardiac functions had been evaluated previously. Electrocardiography with two leads (II, V5) was used, and blood pressure and peripheral oxygen saturation (SpO2) were monitored throughout the procedure. The relationship between the changes in cardiopulmonary parameters during endoscopy and the cardiac functions was analyzed.

RESULTS

Heart rate increased immediately after insertion of the endoscope (P < 0.01). There was a significantly higher incidence of ventricular and supraventricular extrasystoles during observation of the second portion of the duodenum (P < 0.05). A lower cardiac index (P < 0.05) and a higher New York Heart Association (NYHA) functional classification (P < 0.05) were found in patients with oxygen desaturation than in patients without it. Two patients with severe coronary artery lesions showed marked ST-T depression, and these ischemic changes were thought to be due to increase in cardiac work during endoscopy.

CONCLUSIONS

Upper gastrointestinal endoscopy has many adverse effects on cardiopulmonary functions in patients with heart disease. In our study, the clinical value of very close monitoring and administration of oxygen for patients with heart disease was confirmed by objective data.

Induction of nitric oxide synthase activity in nucleus ambiguus motoneurons after injury to the rat recurrent laryngeal nerve

Recent studies have implicated nitric oxide (NO) in neuronal degeneration and plasticity in the motor nervous system. In the present study, we investigated the induction of nitric oxide synthase (NOS) in the motoneurons in the nucleus ambiguus (NA) after injury to the rat recurrent laryngeal nerve (RLN) using nicotinamide-adenine-dinucleotide-phosphate-diaphorase (NADPH-d) histochemistry. NADPH-d reactivity was clearly induced in motoneurons in the ipsilateral NA after transection or avulsion of the RLN, compared with control animals. This finding suggests that NO may play an important role in the pathogenesis of RLN paralysis. Another interesting finding in the present study was the induction of NADPH-d reactivity in nerve terminals of the NA after RLN injury. This finding suggests that RLN injury has some effect on nitrergic input to the NA and a direct effect on the motoneurons.

[Endoscopic transnasal transsphenoidal surgery for pituitary tumors--intranasal procedures]

We have been performing intranasal procedures and postoperative nasal treatments in patients undergoing microscopic transseptal pituitary surgery for the past twenty years. This surgery is safe and minimally invasive and has become the standard procedure for removing pituitary adenomas. Recent advances in optical technology have increased the use of endoscopy in endonasal sinus surgery. Several methods for endoscopic transnasal pituitary surgery have been reported. Here, we report the results for 31 patients (34 operations) who were treated with endoscopic transnasal pituitary surgery. This technique enables the area of surgery to be visualized without requiring a sublabial incision or septal ablation to be performed. Five of the cases were for recurrences after microscopic surgery. A transsphenoidal surgical approach via a unilateral nasal cavity was used in 32 cases. For the remaining two cases, a transsphenoidal surgical approach via bilateral nasal cavities was used in 1 case, and a transethmoidal-transsphenoidal surgical approach via a unilateral nasal cavity was used in 1 case. Excellent results comparable to those of microscopic transseptal surgery were obtained. Endoscopic transnasal transsphenoidal surgery was found to have the following advantages: low-invasiveness, a wide and clear surgical view, and a relatively short operating time in the nose and sinus, especially for recurrent cases. This endoscopic procedure should therefore be considered as the first choice for pituitary surgery.

Oddi sphincter and common channel: evaluation with pharmacodynamic MR cholangiopancreatography using fatty meal and secretin stimulation

PURPOSE

This study was performed to assess the usefulness of pharmacodynamic MR cholangiopancreatography (MRCP) in depicting the segment covered by the Oddi sphincter.

MATERIALS AND METHODS

Twelve volunteers were studied by pharmacodynamic MRCP. After stimulation by the oral intake of a fatty meal and an intravenous injection of secretin, a single-shot rapid acquisition relaxation enhancement (RARE) sequence was used to obtain consecutive images of the segment covered by the Oddi sphincter. The contraction range of the Oddi sphincter and the lengths of the common channel were measured on the MR console by comparing the most contracted image of the sphincter with the most relaxed image.

RESULTS

Pharmacodynamic MRCP showed periodic contraction of the Oddi sphincter in all cases. The range of sphincteric contraction over the biliary duct was 8-19 mm (11.8+/-3.2 mm, mean +/- standard deviation) and over the pancreatic duct 8-23 mm (10.0+/-1.5 mm). In 11 of the 12 cases, the common channel was depicted and its length ranged from 3-8 mm (5.2+/-1.3 mm).

CONCLUSION

Pharmacodynamic MRCP clearly depicted the range of contraction of the Oddi sphincter and the common channel, which are not usually revealed by conventional MRCP.

Involvement of carbon monoxide in the innervation of the canine cervical esophagus and trachea

We investigated the involvement of carbon monoxide (CO) in the innervation of the canine cervical esophagus and trachea by means of immunohistochemistry using an antiserum against heme oxygenase-2 (HO-2). We detected HO-2-immunoreactive nerve fibers around the blood vessels and submucosal glands of the esophagus and trachea. We found HO-2-immunoreactive neurons in ganglia in the trachea and in the myenteric plexus of the esophagus. These results suggest that CO is involved as a neurotransmitter in the innervation of the canine esophagus and trachea.