[A Case of Philadelphia Chromosome-Positive Acute Myeloid Leukemia Extramedullary Recurrence in a Patient Undergoing Thoracoscopy for Massive Pleural Effusion]

A man in his early 70s visited a previous hospital because of pancytopenia and was diagnosed with acute myeloid leukemia based on a bone marrowexamination. The karyotype was 46,XY, t(9;22)(q34;q11.2)[2/20], and real-time polymerase chain reaction(PCR)revealed minor bcr-abl chimeric mRNA. Finally, the patient was judged as having Philadelphia chromosome- positive acute myeloid leukemia, and remission induction chemotherapy with the JALSG AML 201 protocol was initiated in combination with dasatinib to achieve complete remission. After 3 courses of consolidation chemotherapy, the anticancer drugs were discontinued because of deterioration of his general condition and renal insufficiency. Six months after the initial treatment, he was referred to our department, and no evidence of recurrence was confirmed on bone marrow examination. However, 2 months later, right massive pleural effusion was detected, and he was admitted to the department of pneumology at our hospital. Thoracoscopic pleural biopsy was performed at the time of chest tube insertion, and he was diagnosed with acute myeloid leukemia extramedullary recurrence. Peripheral myeloblasts appeared and increased rapidly, accompanied by further exacerbation of renal function; thus, he received palliative care at the department of hematology and oncology.

[Case of Primary Mediastinal Non-Seminomatous Germ Cell Tumor with Pathological Complete Response after Induction Chemotherapy and Residual Tumor Resection Accompanied by Late-Onset Bilateral Pneumothorax]

A man in his late teens presented to our hospital with left-sided chest pain. CT showed a 12 cm sized anterior mediastinal tumor and tiny nodules in the bilateral lower lobe of the lungs. The patient also had elevated serum AFP and hCG levels. Pathological findings of the CT-guided biopsy specimen suggested a yolk sac tumor, and no testicular abnormality was seen on ultrasound. Following whole body examination, he was diagnosed with primary mediastinal non-seminomatous germ cell tumor. After sperm cryopreservation, 4 courses of BEP(bleomycin[BLM]plus etoposide[ETP]plus cisplatin[CDDP]) chemotherapy were administered to normalize the tumor markers. The mediastinal tumor shrank but was still widely in contact with the left pulmonary artery. He underwent mediastinal tumor resection and segmentectomy of the left upper lobe via a median sternotomy. The maximum tumor size was 9 cm in diameter, and pathological examination of the specimen revealed only an immature teratoma with no malignant findings. At the same time, both the lower lung nodules were resected and pathologically identified as intrapulmonary lymph nodes. No recurrence was observed, but 6 months after surgery, he made an emergency visit to our department due to dyspnea. Bilateral pneumothorax was detected, and chest tube insertion was rapidly performed that improved with only right chest drainage. Cytology of the right hemorrhagic pleural effusion showed no evidence of malignancy. It was possible that a postoperative right-to-left shunt of the anterior mediastinum was present, leading to bilateral pneumothorax.

Focal Fatty Masses of the Pancreas

Five patients with solitary fatty mass of the pancreas examined with CT and ultrasound (US) were evaluated. The areas of fat replacement were located in the pancreatic neck, body or tail. The size ranged from 4 to 30 mm in the longest diameter. The shape varied from roundish, to ovoid to semicircular, and the contour was universally well defined. The internal structure was homogeneous in 3 patients, but in one case there were thin septa and, in another, a slightly hyperdense part in the peripheral portion. All the masses except the smallest one were in part contact with pancreatic fat. CT showed fat with the same density as the peripancreatic fat and low HU units. The mass was hypoechoic in 2 cases and hyperechoic in one. The masses in the tail of the pancreas were not detected by US.

[Two cases of pulmonary Mycobacterium avium complex disease with resistance to clarithromycin]

We encountered 2 patients with pulmonary Mycobacterium avium complex disease in whom resistance to clarithromycin (CAM) was confirmed after treatment with rifampicin, ethambutol, and CAM. We evaluated the disease course in both patients. The deterioration of radiological findings was preceded by the acquisition of resistance to CAM in both cases. When symptoms of pulmonary MAC disease exacerbate, and radiological findings deteriorate, we should reconsider the type of treatment after determination of the minimal inhibitory concentration (MIC) of CAM for culture positive MAC strains.

[A case with double primary cancers in both lung and nasal cavity]

Our patient, a 77-year-old male, underwent a medical examination for lower back pain. A careful investigation revealed two large tumors both in his lung and nose. The diagnosis was well-differentiated squamous cell carcinoma by biopsy in both sides. Radiation therapy(36 Gy)was performed on his nasal cavity, and nasal tumor volume was reduced considerably. Because the primary lesion could not be determined we used docetaxel chemotherapy which can be applied for both lung cancer and head and neck cancer. As a result, dissociation of the treatment's effect was seen, and we suspected the presence of overlapping cancer in both lung and nasal cavity. We could not use immunostaining to identify the primary lesion in squamous cell carcinoma as we did for adenocarcinoma. In this case we could infer the presence of overlapping cancer over the course of treatment with chemotherapy.

Electrical measurement of antiferromagnetic moments in exchange-coupled IrMn/NiFe stacks

We employ antiferromagnetic tunneling anisotropic magnetoresistance to study the behavior of antiferromagnetically ordered moments in IrMn exchange coupled to NiFe. Experiments performed by common laboratory tools for magnetization and electrical transport measurements allow us to directly link the broadening of the NiFe hysteresis loop and its shift (exchange bias) to the rotation and pinning of antiferromagnetic moments in IrMn. At higher temperatures, the broadened loops show zero shift, which correlates with the observation of fully rotating antiferromagnetic moments inside the IrMn film. The onset of exchange bias at lower temperatures is linked to a partial rotation between distinct metastable states and pinning of the IrMn antiferromagnetic moments in these states. The observation complements common pictures of exchange bias and reveals an electrically measurable memory effect in an antiferromagnet.

A spin-valve-like magnetoresistance of an antiferromagnet-based tunnel junction

A spin valve is a microelectronic device in which high- and low-resistance states are realized by using both the charge and spin of carriers. Spin-valve structures used in modern hard-drive read heads and magnetic random access memoriescomprise two ferromagnetic electrodes whose relative magnetization orientations can be switched between parallel and antiparallel configurations, yielding the desired giant or tunnelling magnetoresistance effect. Here we demonstrate more than 100% spin-valve-like signal in a NiFe/IrMn/MgO/Pt stack with an antiferromagnet on one side and a non-magnetic metal on the other side of the tunnel barrier. Ferromagneticmoments in NiFe are reversed by external fields of approximately 50  mT or less, and the exchange-spring effect of NiFe on IrMn induces rotation of antiferromagnetic moments in IrMn, which is detected by the measured tunnelling anisotropic magnetoresistance. Our work demonstrates a spintronic element whose transport characteristics are governed by an antiferromagnet. It demonstrates that sensitivity to low magnetic fields can be combined with large, spin-orbit-coupling-induced magnetotransport anisotropy using a single magnetic electrode. The antiferromagnetic tunnelling anisotropic magnetoresistance provides a means to study magnetic characteristics of antiferromagnetic films by an electronic-transport measurement.

A case of acute eosinophilic pneumonia following short-term passive smoking: an evidence of very high level of urinary cotinine

Acute eosinophilic pneumonia (AEP) is characterized by febrile illness, diffuse pulmonary infiltrates with eosinophilia. The pathogenesis is not well understood. We report a case of 22-year-old men who never smoke presented with AEP 2 days after acute passive smoke exposure. He developed acute respiratory failure despite having no history of the disease. Computed tomography of the lung revealed diffuse bilateral pulmonary infiltrates. Lung biopsy specimens revealed marked eosinophil infiltration in the alveolar septa without signs of vasculitis. Two days prior to the disease, he was exposed to cigarette smoke for 2 hours in a closed area. In the absence of other causes, passive smoking may cause lung inflammatory responses. The level of urinary cotinine, which is a biomarker of smoke exposure, was considerably higher (0.198 μg/ml [201 ng/mg Creatinine]) than that in nonsmokers, but never detected following period. This case suggests that short-term passive smoking may cause AEP.

Organizing pneumonia with a positive result for anti-CCP antibodies as the first clinical presentation of rheumatoid arthritis

We report an 86-year-old woman who presented with organizing pneumonia (OP) with a positive anti-cyclic citrullinated peptide (anti-CCP) antibodies as the first manifestation of rheumatoid arthritis (RA). She experienced dyspnea, chest X-ray showed diffuse alveolar exudates indicated OP histologically. Although she did not present with articular symptoms initially, anti-CCP antibodies measured for differentiation of RA were positive. Eight months later, she showed representative manifestations of RA. Even though OP following joint involvement is frequent in RA, in rare cases it could be the first manifestation. This is the first case showing OP with a positive result for anti-CCP antibodies as the first manifestation of RA.

A simple and sensitive method for detection of Bacillus anthracis by loop-mediated isothermal amplification

AIMS

To develop a rapid and simple system for detection of Bacillus anthracis using a loop-mediated isothermal amplification (LAMP) method and determine the suitability of LAMP for rapid identification of B. anthracis infection.

METHODS AND RESULTS

A specific LAMP assay targeting unique gene sequences in the bacterial chromosome and two virulence plasmids, pXO1 and pXO2, was designed. With this assay, it was possible to detect more than 10 fg of bacterial DNA per reaction and obtain results within 30-40 min under isothermal conditions at 63 degrees C. No cross-reactivity was observed among Bacillus cereus group and other Bacillus species. Furthermore, in tests using blood specimens from mice inoculated intranasally with B. anthracis spores, the sensitivity of the LAMP assay following DNA extraction methods using a Qiagen DNeasy kit or boiling protocol was examined. Samples prepared by both methods showed almost equivalent sensitivities in LAMP assay. The detection limit was 3.6 CFU per test.

CONCLUSIONS

The LAMP assay is a simple, rapid and sensitive method for detecting B. anthracis.

SIGNIFICANCE AND IMPACT OF THE STUDY

The LAMP assay combined with boiling extraction could be used as a simple diagnostic method for identification of B. anthracis infection.

Rapid and simple detection of Clostridium botulinum types A and B by loop-mediated isothermal amplification

AIMS

To develop a convenient and rapid detection method for toxigenic Clostridium botulinum types A and B using a loop-mediated isothermal amplification (LAMP) method.

METHODS AND RESULTS

The LAMP primer sets for the type A or B botulinum neurotoxin gene, BoNT/A or BoNT/B, were designed. To determine the specificity of the LAMP assay, a total of 14 C. botulinum strains and 17 other Clostridium strains were tested. The assays for the BoNT/A or BoNT/B gene detected only type A or B C. botulinum strains, respectively, but not other types of C. botulinum or strains of other Clostridium species. Using purified chromosomal DNA, the sensitivity of LAMP for the BoNT/A or BoNT/B gene was 1 pg or 10 pg of DNA per assay, respectively. The assay times needed to detect 1 ng of DNA were only 23 and 22 min for types A and B, respectively. In food samples, the detection limit per reaction was one cell for type A and 10 cells for type B.

CONCLUSIONS

The LAMP is a sensitive, specific and rapid detection method for C. botulinum types A and B.

SIGNIFICANCE AND IMPACT OF THE STUDY

The LAMP assay would be useful for detection of C. botulinum in environmental samples.

Characterization of non-linear relationship between total and unbound serum concentrations of valproic acid in epileptic children

OBJECTIVE

To establish a regression equation to properly estimate the unbound serum concentration of valproic acid (VPA) from its total serum concentration; the relationship between total and unbound serum VPA concentrations was retrospectively characterized.

METHODS

Data were obtained from the clinical examination records that were routinely archived during therapeutic drug monitoring. The screening encompassed 342 records of 108 paediatric patients whose total and unbound VPA concentrations had been determined. The relationship between total and unbound VPA concentrations was characterized according to the Langmuir equation by taking account of inter-individual variability with the nonmem program.

RESULTS

The total VPA concentration (C(t)) in the screened patients ranged from 5.5 to 179.8 microg/mL, and the unbound VPA concentration (C(f)) increased in a non-linear manner as the total VPA concentration increased. Taking account of the effects of antiepileptics concurrently administered, the VPA dissociation constant (K(d)) and maximum binding site concentration (B(m)) were 7.8 +/- 0.7 and 130 +/- 4.5 microg/mL respectively, for the regression equation, C(t) = C(f) + B(m) x C(f)/(K(d) + C(f)). An alteration in the unbound concentration was seen in patients who were treated with the combination of VPA and ethosuximide and in those who received two additional antiepileptics.

CONCLUSIONS

A regression equation for estimation of the unbound VPA concentration, based on total VPA concentration collected during routine therapeutic drug monitoring was established. Use of two additional antiepileptics and ethosuximide treatment was considered as potential factors affecting unbound VPA concentration.

Superconducting state of the organic conductor (TMTSF)2ClO4

(TMTSF)2ClO4 is a quasi-one-dimensional organic conductor and superconductor with Tc=1.4 K, and one of at least two Bechgaard salts observed to have upper critical fields far exceeding the paramagnetic limit. Nevertheless, the 77Se NMR Knight shift at low fields reveals a decrease in spin susceptibility chi(s) consistent with singlet spin pairing. The field dependence of the spin-lattice relaxation rate at 100 mK exhibits a sharp crossover (or phase transition) at a field Hs approximately 15 kOe, to a regime where chi(s) is close to the normal state value, even though Hc2>> Hs.

Mott transition from a spin liquid to a Fermi liquid in the spin-frustrated organic conductor kappa-(ET)2Cu2(CN)3

The pressure-temperature phase diagram of the organic Mott insulator kappa-(ET)2Cu2(CN)3, a model system of the spin liquid on triangular lattice, has been investigated by 1H NMR and resistivity measurements. The spin-liquid phase is persistent before the Mott transition to the metal or superconducting phase under pressure. At the Mott transition, the spin fluctuations are rapidly suppressed and the Fermi-liquid features are observed in the temperature dependence of the spin-lattice relaxation rate and resistivity. The characteristic curvature of the Mott boundary in the phase diagram highlights a crucial effect of the spin frustration on the Mott transition.

Spontaneous subacute intratumoral hemorrhage of hepatic cavernous hemangioma

We report a case of giant hepatic cavernous hemangioma associated with spontaneous subacute intratumoral hemorrhage. Magnetic resonance imaging showed an oval, homogeneous, high-intensity lesion with a low-intensity rim in the original high-intensity tumor on T2-weighted images. On T1-weighted images, this oval lesion showed heterogeneous high intensity with peripheral higher intensity. The histologic specimen confirmed hepatic hemangioma with intratumoral hemorrhage.

Diffusion-weighted MR imaging of Carmofur-induced leukoencephalopathy

Carmofur (1-hexylcarbamyl-5-fluorouracil), a derivative of 5-fluorouracil (5-FU), has been widely used in Japan as a postoperative adjuvant chemotherapy agent for colorectal and breast cancer. Periventricular hyperintensity on T2-weighted MR images in carmofur-induced leukoencephalopathy confront the physician with a broad range of differential diagnoses. We describe two cases of carmofur-induced leukoencephalopathy in which diffusion-weighted MR imaging revealed periventricular hyperintensity. We compared their findings with those of age-related periventricular hyperintensity in five patients and found discrepancies in signal intensity of periventricular areas. Our results suggest that diffusion-weighted MR imaging may be useful to differentiate carmofur-induced leukoencephalopathy from age-related periventricular hyperintensity.

Triphasic vascular responses to bradykinin in the mesenteric resistance artery of the rat

The vascular effects of bradykinin were studied in rat perfused mesenteric vascular beds with active tone. Bolus injections of bradykinin (1-1000 pmol) but not des-Arg(9)-bradykinin (bradykinin B(1) receptor agonist) induced triphasic vascular responses: the initial sharp vasodilation followed by transient vasoconstriction and subsequent gradual vasodilation. The triphasic vascular responses to bradykinin were abolished by FR 172357 (3-bromo-8-[2,6-dichloro-3-[N-[(E)-4-(N,N-dimethylcarbamoyl) cinnamidoacetyl]-N-methylamino]benzyloxy]-2-metylimidazo[1,2-a]pyridine) (bradykinin B(2) receptor antagonist, 0.1 microM). Endothelium removal with sodium deoxycholate and N(w)-nitro-L-arginine (300 microM) abolished the bradykinin-induced initial sharp vasodilation. Indomethacin (0.5 microM) and seratrodast (thromboxane A(2) receptor antagonist, 0.5 and 5 microM) abolished the bradykinin-induced second vasoconstriction. The bradykinin-induced third vasodilation was abolished by capsaicin (1 microM) and calcitonin gene-related peptide (CGRP)-(8-37) (CGRP receptor antagonist, 0.5 microM). These findings suggest that the bradykinin-induced initial sharp vasodilation is endothelium dependent, that endogenous thromboxane A(2) is involved in the second vasoconstriction, and that the third slow vasodilation is produced by activation of capsaicin-sensitive CGRP-containing nerves.

Application of 4-hydroxyantipyrine and acetaminophen O-sulfate as biodistribution promoter

The effects of 4-hydroxyantipyrine (4-OH), a major metabolite of antipyrine and its sulfate, 4-hydroxyantipyrine O-sulfate (4-S), on the pharmacokinetics of citicoline and thiopental sodium were investigated in rats. The concomitant use of 4-OH increased significantly the tissue-to-plasma concentration ratio (Kp) of citicoline in the brain and liver and that of thiopental sodium in the brain, liver, and heart, while 4-S did not affect them. The permeability clearance of blood-brain barrier (BBB) (Kin) and the total distribution volume (Vdbr) of citicoline were not affected by either 4-OH or 4-S. However, those of thiopental sodium were significantly increased by not only 4-OH but also by 4-S. On the other hand, the plasma concentration of antipyrine was significantly decreased by the intravenous bolus coadministration of N-acetyl-p-aminophenyl O-sulfate (APAPS) at steady-state plasma concentration of antipyrine. A similar reduction was not observed with the intravenous coadministration of acetaminophen (APAP). The Kp value of antipyrine was significantly increased in the brain by the coadministration of APAPS, but was not affected by APAP. The increment in the drug distribution to the brain with the concomitant use of 4-OH (or APAPS) observed in this study is useful information for the application of drug combinations as biodistribution promoters.

Papillonodular type of cystic partially differentiated nephroblastoma: a case report

We report a case of the papillonodular type of cystic partially differentiated nephroblastoma (CPDN), an extremely rare renal neoplasm that occurs in newborns and infants. The papillonodular type of CPDN is a variant of the conventional form of CPDN. MRI clearly demonstrated the gross pathologic features, distinguishing it from other renal multilocular cystic tumors.

Adrenomedullin inhibits neurotransmission of calcitonin gene-related peptide (CGRP)-containing vasodilator nerves in rat mesenteric resistance arteries

We have reported that the rat mesenteric resistance artery has innervation of calcitonin gene-related peptide (CGRP)-containing vasodilator nerves (CGRPergic nerves). We also demonstrated that adrenomedullin (AM) causes mesenteric vasodilation through activation of CGRP receptors. The present study was designed to examine the effect of AM on neurotransmission of CGRPergic nerves in rat mesenteric arteries. In preconstricted preparations without endothelium, periarterial nerve stimulation (PNS, 1 and 2 Hz) induced a frequency-dependent vasodilation. A bolus injection of CGRP (10 pmol) into the perfusate also caused a vasodilation. AM (0.1 to 10 nM) concentration-dependently caused 40% to 60% inhibition of the PNS-induced vasodilation, but AM did not attenuate vasodilation induced by exogenous CGRP injection. The inhibitory effect of AM (10 nM) on PNS-induced vasodilation was further potentiated by CGRP [8-37] (CGRP receptor antagonist, 50 nM), which attenuated the vasodilator response to the CGRP injection. Combined perfusion of AM [22-52] (AM receptor antagonist, 10 to 100 nM) resulted in further inhibition of PNS-induced neurogenic vasodilation without affecting the vasodilator response to the CGRP injection. CGRP [8-37] but not AM [22-52] antagonized vasodilation induced by AM perfusion. These findings suggest that AM presynaptically inhibits neurotransmission of CGRPergic nerves, probably decreasing CGRP release, via receptors different from CGRP receptors.

Age-Related decrease in calcitonin gene-related peptide mRNA in the dorsal root ganglia of spontaneously hypertensive rats

Age-related changes in levels of calcitonin gene-related peptide (CGRP) mRNA of the dorsal root ganglia was studied in 8-, 12- and 15-week-old spontaneously hypertensive rats (SHR) and age-matched normotensive Wistar Kyoto rats (WKY). CGRP mRNA levels in SHR but not in WKY decreased with age. The contents of CGRP-like immunoreactivities in the atrium and mesenteric artery of 15-week-old SHR were greater than those in age-matched WKY. These results suggest that the outflow of CGRP-containing nerves from the spinal cord and CGRP release from CGRP nerve terminals decreases in SHR.

Regional variation in oral mucosal drug permeability

The purpose of this article is to review regional variation in oral mucosal drug permeability. The structure and composition of the mucosa at different sites in the oral cavity, factors affecting mucosal permeability, selection of appropriate experimental systems for studying mucosal permeability, and formulation factors including penetration enhancement relevant to the design of systems for oral mucosal delivery are reviewed.

Adrenergic nerves mediate acetylcholine-induced endothelium-independent vasodilation in the rat mesenteric resistance artery

Mechanisms underlying acetylcholine-induced endothelium-independent vasodilation were studied in the rat mesenteric vascular bed isolated from Wistar rats. In preparations without endothelium, and contracted by perfusion with Krebs solution containing methoxamine (2-7 microM), perfusion of acetylcholine (1-100 microM) for 1 min produced a concentration-dependent vasodilation. Denervation of denuded preparations by cold storage (4 degrees C for 72 h) abolished the acetylcholine-induced vasodilation; 10 and 100 nM atropine abolished 1 and 10 microM acetylcholine-induced vasodilation, but it inhibited only 20% of vasodilation by 100 microM acetylcholine. The acetylcholine-induced atropine-resistant vasodilation was inhibited by 10 and 100 microM hexamethonium, 5 microM guanethidine, 50 microM bretylium, in vitro 6-hydroxydopamine (2 mM for 20 min, twice), 1 microM capsaicin and 0.5 microM calcitonin gene-related peptide (CGRP)-(8-37) (CGRP receptor antagonist). These findings suggest that the acetylcholine-induced endothelium-independent nicotinic vasodilation requires the presence of intact adrenergic nerves, and is mediated by endogenous CGRP released from CGRP-containing nerves.

Effects of 4-hydroxyantipyrine and its 4-O-sulfate on antipyrine as biodistribution promoter

The effects of 4-hydroxyantipyrine (4-OH), a major metabolite of antipyrine, and its 4-O-sulfate (4-S) on the pharmacokinetics of antipyrine were investigated in rats. Plasma elimination of intravenously administered antipyrine was significantly decelerated under a steady-state concentration of 4-OH but not under that of 4-S. Tissue-to-plasma concentration ratio (Kp) of antipyrine under its steady-state concentration was significantly increased in the brain and heart by the concomitant use of 4-OH, while similar use of 4-S had no effect. The enhancement of the blood-brain barrier (BBB) permeability of antipyrine caused by the concomitant use of 4-OH was believed to be concerned with the increase of the Kp value of antipyrine in the brain. These results suggested that 4-OH could be used as a biodistribution promoter.

Decreased depressor response mediated by calcitonin gene-related peptide (CGRP)-containing vasodilator nerves to spinal cord stimulation and levels of CGRP mRNA of the dorsal root ganglia in spontaneously hypertensive rats

The depressor response to electrical stimulation of the spinal cord and the level of calcitonin gene-related peptide (CGRP) mRNA in the dorsal root ganglion (DRG) in the spontaneously hypertensive rat (SHR) was compared with the normotensive Wistar Kyoto rat (WKY) and Wistar rat (WR). The animals were pithed by inserting a stainless-steel rod into the spinal cord. Pithed rats were treated with hexamethonium (2 mg/kg/min i.v.) to block autonomic outflow, and mean arterial blood pressure (MBP) was maintained at approximately 100 mmHg with continuous infusion of methoxamine (10 to 15 microg/kg/min i.v.). Electrical stimulation (2 and 4 Hz for 30 s) of the lower thoracic spinal cord (T9-12) via the pithing rod caused a frequency-dependent depressor response without a change in heart rate. The depressor response to spinal cord stimulation was significantly smaller in SHR than in WKY and WR. Long-term treatment of 8 week-old SHR with captopril (0.1% in drinking water) for 7 weeks restored the reduced depressor response to spinal cord stimulation. The level of CGRP mRNA in DRG of SHR was significantly lower than that in WKY. These results suggest that the function of CGRP-containing nerves from the spinal cord decreases in SHR and captopril treatment prevents its reduction.

Effects of long-term treatment with calcium antagonists on periarterial nerve function in the mesenteric artery of spontaneously hypertensive rats

The effect of long-term treatment with dihydropyridine calcium antagonists (amlodipine, pranidipine, nicardipine) on the periarterial nerve function was investigated in the perfused mesenteric vascular bed isolated from spontaneously hypertensive rat (SHR). Male 8-week-old SHR received amlodipine (0.01% and 0.02%) and nicardipine (0.1%) in drinking water and pranidipine (0.0035% and 0.035%) in rat chow for 7 weeks. Mean blood pressure in SHR was significantly lowered by long-term treatment with each calcium antagonist. In mesenteric vascular preparations treated with each calcium antagonist, vasoconstriction induced by periarterial nerve stimulation (PNS; 4, 8 and 12 Hz) was significantly smaller than that in non-treated SHR. The PNS (8 Hz)-evoked norepinephrine (NE) overflow in the perfusate was significantly decreased by amlodipine and pranidipine treatment, whereas nicardipine-treatment significantly enhanced the overflow of NE. In preparations with active tone produced by methoxamine and guanethidine, the PNS-induced vasodilation mediated by calcitonin gene-related peptide (CGRP)-containing (CGRPergic) vasodilator nerves was not affected by these drugs. These results suggest that long-term treatment of SHR with long-acting drugs, amlodipine and pranidipine, reduces sympathetic adrenergic nerve function but calcium antagonists have no effect on CGRPergic nerve function.

Endogenous calcitonin gene-related peptide (CGRP) mediates adrenergic-dependent vasodilation induced by nicotine in mesenteric resistance arteries of the rat

1. The mechanisms underlying vasodilator effect of nicotine on mesenteric resistance blood vessels and the role of calcitonin gene-related peptide (CGRP)-containing (CGRPergic) vasodilator nerves were studied in the rat. 2. Mesenteric vascular beds isolated from Wistar rats were perfused with Krebs solution, and perfusion pressure was measured with a pressure transducer. 3. In preparations with intact endothelium and contracted by perfusion with Krebs solution containing methoxamine, perfusion of nicotine (1 - 100 microM) for 1 min caused a concentration-dependent vasodilator response without vasoconstriction. 4. The nicotine-induced vasodilation was markedly inhibited by hexamethonium (nicotinic cholinoceptor antagonist, 10 microM) and blocked by guanethidine (adrenergic neuron blocker, 5 microM). 5. Either denervation by cold storage (4 degrees C for 72 h) or adrenergic denervation by 6-hydroxydopamine (toxin for adrenergic neurons, 2 mM for 20 min incubation, twice) blocked the nicotine-induced vasodilation. 6. Neither endothelium removal with perfusion of sodium deoxycholate (1.80 mg ml(-1), for 30 s) nor treatment with N(omega)-nitro-L-arginine (nitric oxide synthase inhibitor, 100 microM), atropine (muscarinic cholinoceptor antagonist, 10 nM) or propranolol (beta-adrenoceptor antagonist, 100 nM) affected the nicotine-induced vasodilation. 7. In preparations without endothelium, treatment with capsaicin (depleting CGRP-containing sensory nerves, 1 microM) or human CGRP[8 - 37] (CGRP receptor antagonist, 0.5 microM) markedly inhibited the nicotine-induced vasodilation. 8. These results suggest that, in the mesenteric resistanc artery of the rat, nicotine induces vasodilation, which is independent of the function of the endothelium and is involved in activation of CGRPergic nerves. It is also suggested that nicotine stimulates presynaptic nicotinic cholinoceptors on adrenergic nerves to release adrenergic neurotransmitters, which then act on CGRPergic nerves to release endogenous CGRP from the nerve.

Metastatic lymph-node clearance from head and neck epidermoid carcinomas following radiotherapy

Although tumor clearance is a common criterion in assessing the impact of radiotherapy (RT), it is not always reliable. Patterns of tumor clearance were determined using 91 metastatic lymph nodes (LNs) from 51 patients with head and neck tumors treated by definitive RT (61-80 Gy) or preoperative RT (43-65 Gy). Clearance rate (CR) was estimated as a daily volume decrement expressed as a ratio to the pre-RT LN volume. CR was greater for the so-called radioresponsive nasopharyngeal subgroups and more poorly differentiated than those of oral cavity and well-differentiated, respectively. Histologically, LNs that were removed following RT consisted mainly of fibrous tissues, necrotic tissues, and few cancer cells. There was no difference in CR between the cancer-cell-positive group (n = 21) and the cancer-cell-negative group (n = 31). Although the CR may reflect inherent radiosensitivity of tumor cells, tumor persistence predicts the amount of oncologically inactive materials rather than that of remaining cancer cells.

A modified fluorescence polarization immunoassay method incorporating fat emulsion (FE-FPIA) to determine cyclosporin A concentrations in rat skin

We have developed a simple, sensitive and reliable assay procedure for cyclosporin A (CyA), a modified fluorescence polarization immunoassay method incorporating fat emulsion (FE-FPIA), to determine the CyA content in rat skin. The conventional fluorescence polarization immunoassay (FPIA) method for CyA using a commercially available FPIA kit, TDX cyclosporine monoclonal whole blood, was modified. A fat emulsion for intravenous infusion, Intralipos, was incorporated for dissolving the CyA extracted from the skin tissue, and a mixture of MeOH/purified water was used as the sample pretreatment medium instead of the precipitation reagent in the conventional FPIA kit intended for whole blood samples. These modifications enabled us to produce a reliable and the sensitive assay of CyA in skin tissue. The reproducibility (coefficient of variation), detection limit, and assay time for FE-FPIA were below 2%, 25 ng/ml, and about 24 min/24 samples, respectively, and were comparable with those for the whole blood samples determined by the conventional FPIA. Pre-purification of samples required by the HPLC assay is not needed in the FE-FPIA method. The usefulness of the FE-FPIA method in evaluating the topical pharmacokinetics of CyA in skin is discussed.

Differential diagnosis of gynaecological "stained glass" tumours on MRI

Although multilocular cystic gynaecological masses in which the loculi show variable signal intensity on both T1 and T2 weighted images have been considered to be mucinous cystadenoma or adenocarcinoma, other gynaecological tumours can demonstrate this "stained glass" appearance. These include mature cystic teratoma, fibrothecoma, endometrioma, Brenner's tumour of the ovary and degenerated leiomyoma of the uterus, all of which may mimic mucinous tumours of the ovaries.

Testicular feminization: role of MRI in diagnosing this rare male pseudohermaphroditism

PURPOSE

The purpose of our study was to assess the role of MR in the diagnosis and follow-up of patients with testicular feminization (TF).

METHOD

MR scans of seven patients with TF were retrospectively reviewed.

RESULTS

MR could diagnose uterus agenesis in all cases. Undescended testes were depicted within or just below the inguinal canal in four cases. They were smaller and more hypointense than those in normal males. Testes that we could not find by MR were found during surgery in two cases. They were just below the inguinal canal where we had not scanned caudally enough in one and they were too small to be detected in the other.

CONCLUSION

MR can demonstrate both uterine agenesis and undescended testes in TF. The latter tend to be missed because they are small and can be anywhere in the abdomen and inguinal canal. Radiologists should perform careful MR examination to detect testes in patients suspected having TF, as these organs are more likely to undergo malignant neoplasia.

Gamna-gandy bodies of the spleen depicted by unenhanced CT: report of two cases

We report two cases of Gamna-Gandy bodies (GGB) of the spleen, confirmed by MRI, in which unenhanced CT depicted multiple faint high-attenuation spots in the spleens. These spots were considered to represent the calcifications in GGB. CT and MRI reflect the different compositions of GGB. In a very limited number of patients with portal hypertension, unenhanced CT may detect GGB, and this entity should be included in the differential diagnosis of calcified foci of the spleen.

Factors determining drug residence in skin during transdermal absorption: studies on beta-blocking agents

The factors determining drug residence in skin during penetration across rat abdominal skin were investigated using five beta-blocking agents with different lipophilicities as model drugs in vivo and in vitro. The amount of beta-blocking agent in the skin at steady state correlated well with lipophilicity. The distribution of beta-blocking agents to the stratum corneum and the contribution of intercellular lipids in the stratum corneum to their skin distribution were also correlated with their lipophilicity, suggesting that the stratum corneum, especially intercellular lipids in the stratum corneum, would be responsible for the residence of beta-blocking agents in the skin. Furthermore, cholesterol-3-sulfate, palmitic acid, stearic acid and oleic acid were found to interact with the beta-blocking agents, which are cationized under the physiological condition, and were assumed to play an important role in the skin accumulation. On the other hand, the binding to keratinocyte was so small that keratinocyte might have little effect on the skin accumulation of the beta-blocking agents. Drug transport from the stratum corneum to viable skin was suggested to be regulated by the lipophilicity of these agents. To investigate the residence of these drugs in viable skin, in vitro transport studies using stripped skin were performed. The transport rate constant across viable skin to receptor cells (k23) was inversely correlated with the lipophilicity of the drugs. The elimination rate constants from viable skin (k(vs)) obtained in the in vivo study were much smaller than the values of k23 obtained in the in vitro study, and they were inversely correlated with the binding to cytosol components of viable skin but not the lipophilicity. The viable skin-to-muscle concentration ratio of these drugs, obtained at the beta-phase of the plasma concentration-time curve after intravenous administration, was also inversely correlated with the binding to the cytosol components of viable skin. These results suggest that k(vs) reflects the transport from viable skin to muscle rather than to blood circulation and that the binding of drugs to cytosol components in viable skin would be one of the important factors determining the residence in viable skin.

Malleus bar as a rare cause of congenital malleus fixation: CT demonstration

Among congenital ossicular anomalies without external ear atresia, malleus fixation is least common. We report a case of congenital malleus fixation by a bony bar connecting the malleus neck to the posterior tympanic wall, which was depicted on thin-section CT scans.

Uterus didelphys associated with obstructed hemivagina and ipsilateral renal agenesis: MR findings in seven cases

BACKGROUND

Although a specific syndrome of the uterus didelphys, obstructive hemivagina, and ipsilateral renal agenesis had been reported in gynecologic literatures, it is not familiar to radiologists. We introduce this syndrome with radiological, especially MR findings.

METHODS

Imaging findings and medical records of seven patients with this syndrome were retrospectively reviewed.

RESULTS

MR clearly demonstrated uterus didelphys with obstructed hemivagina in six of the seven patients. A remaining one showed uterus didelphys with left-sided hematometra and hematosalpinx who had undergone vaginal septum incision prior to the MR. We could also recognize ipsilateral renal agenesis in all five patients, in whom renal areas were examined on MR. After vaginal septum resection, symptoms disappeared in six patients. We could observe the disappearance of the obstructive complications with MR in three patients.

CONCLUSIONS

MR can do much for the early diagnosis and the prevention against further complications of this condition because it can demonstrate the müllerian duct anomaly complicated with obstructed hemivagina in detail and even ipsilateral renal agenesis.

Well-differentiated liposarcoma of the retroperitoneum with a fat-fluid level: US, CT, and MR appearance

We report a case of retroperitoneal liposarcoma with a fat-fluid level that has not been previously described. A 36-year-old man presented with abdominal distension. Ultrasonography, CT, and MR imaging showed a tumor with a fat-fluid level; nondependent fluid was characteristic of fat. Liposarcoma should be included in the differential diagnosis of tumors exhibiting a fat-fluid level.

Von Meyenburg complexes of the liver: imaging findings

PURPOSE

Our purpose was to present imaging findings of six cases proven or supposed to be von Meyenburg complexes (VMCs) with a basis of reviewing the pathologic literature and to describe imaging points for the diagnosis of typical VMC along with its differential diagnosis.

METHOD

Six cases were diagnosed as VMC of the liver with imaging modalities (one had histopathologic proof). Both ultrasound (US) and CT were available for all cases, and MRI was used for three cases. Follow-up with US, CT and/or MRI was performed in five cases.

RESULTS

US detected varying abnormalities of the livers in four cases. CT and MRI revealed multiple or numerous intrahepatic tiny (usually < 5 mm) cystoid lesions in all of the cases. The lesions were scattered throughout the livers, and some of them were located more frequently adjacent to the medium-sized portal veins than to the hepatic veins of similar size on CT. Moreover, some lesions were apparently located in the subcapsular areas (up to the hepatic capsules). They were usually irregular in shape and showed no enhancement but increased in number by approximately 80-150% after administration of intravenous contrast medium. The T2-weighted MR images and MR cholangiopancreatography showed the lesions to be much more apparent and to be more numerous than T1-weighted images did. Follow-up of five cases with imaging modalities did not show remarkable change of the lesions.

CONCLUSION

Despite our limited experience, VMC lesions seem to show some CT and MR features different from those of other multiple small hepatic lesions. They presented as multiple or numerous intrahepatic tiny cystoid lesions usually with irregular contour, scattered throughout the liver up to the subcapsular areas, and were detected in far greater number by enhanced CT or T2-weighted MR images than by unenhanced CT or T1-weighted images. They showed no remarkable change on long term follow-up imaging. We propose that a diagnosis of typical VMC could be made after analyzing CT or MR images carefully with good understanding of its pathologic basis, but imaging follow-up is necessary in oncology patients.

Perfusion cells for studying regional variation in oral mucosal permeability in humans. 2. A specialized transport mechanism in D-glucose absorption exists in dorsum of tongue

To clarify the site of d-glucose absorption in human oral cavity, newly designed perfusion cells were applied to five different sites in the human oral cavity, i.e., the dorsum of the tongue, the ventral surface of the tongue, the labial mucosa, the floor of the mouth, and the buccal mucosa. The solution of D-glucose was perfused for 1 h and the rate of absorption was calculated from the amount that disappeared from the perfusate. D-Glucose was absorbed rapidly from the dorsum of the tongue and the absorption was saturable. The saturable absorption was also observed in the ventral surface of the tongue, but not in the other three sites. The rate of D-glucose absorption in the dorsum and the ventral surface of the tongue was significantly larger than that of L-glucose, while in the other sites they were not significantly different. The presence of a specialized transport system for D-glucose absorption in the dorsum of human tongue was suggested.

Mature teratoma of the posterior mediastinum

The vast majority of germ cell tumors in the thorax arise at or near the thymus. We report a case of a 41-year-old man with mature teratoma of the posterior mediastinum. He was asymptomatic and was incidentally found to have a posterior mediastinal mass. Computed tomography was helpful in suggesting a diagnosis of mature teratoma by demonstrating the presence of fat and calcification. The differential diagnosis included neurogenic tumors, liposarcoma, and extramedullary hematopoiesis.

Lipo-microdialysis: a new microdialysis method for studying the pharmacokinetics of lipophilic substances

A new microdialysis method (Lipo-MD) using a lipid emulsion as the perfusate instead of Ringer's solution as in conventional microdialysis (MD) was designed. Recovery profiles of the alkylparabens (APBs) dissolved in Ringer' s solution by Lipo-MD were compared with those by MD in vitro. Recovery of APBs in the perfusate in MD decreased with the increasing lipophilicity of APBs, whereas that in Lipo-MD increased. The enhancement of the relative recovery of APBs by Lipo-MD to MD for methyl-, ethyl-, propyl-, and butylparaben were 2.03, 5.24, 77.0, and 390.7, respectively. The utility of Lipo-MD for determination of lipophilic substances to perform pharmacokinetic study was suggested.