Personal exposure to nitrogen dioxide from indoor heaters and cooking stoves

The personal exposure to NO₂ generated from various heaters and cooking stoves were studied, using 85 university students. The students attached NO₂ filter badges to their chests or collars and wrote down the period of time for heating and cooking for 1 week. Types of heaters and smoking habits were described through a questionnaire. The urinary hydroxyproline/creatinine ratio (HOP/C) was examined as a biomarker for health effects. The outdoor NO₂ concentration during the study period was 13.5–13.7 g/m³. Smoking and the usage of electric heaters did not affect the exposure to NO₂. Exposure increased according to the length of time kerosene heaters or oil fan heaters were used. The NO₂ concentration during the heating by a kerosene heater and an oil fan heater was calculated to be 219 and 474 g/m³, respectively. The correlation between the period of cooking and personal exposure was also observed. The NO₂ levels during cooking were calculated to be 290 g/m³. Using these calculated values of NO₂ concentration, it is possible to presume the personal exposure levels from the length of time heaters and cooking stoves are used even if the subjects do not attach the filter badges. Neither smoking nor exposure to NO₂ were associated with the increase of urinary HOP/C.     

Anti-thrombotic effects and bleeding risk of AJvW-2, a monoclonal antibody against human von Willebrand factor

1. A murine anti-human vWF monoclonal antibody, AJvW-2, was developed that inhibited the interaction between platelet glycoprotein Ib (GPIb) and von Willebrand factor (vWF) during the ristocetin- (IC₅₀=0.7±0.1 μg ml⁻¹) and botrocetin- (IC₅₀=1.8±0.3 μg ml⁻¹) induced aggregation of human platelets.
2. AJvW-2 inhibited the high shear stress (10.8 N m⁻²) induced aggregation of human platelets dose-dependently with an IC₅₀=2.4±0.3 μg ml⁻¹, but had no effect on low shear stress induced platelet aggregation (1.2 N m⁻²) up to 100 μg ml⁻¹.
3. AJvW-2 also inhibited the high shear stress (5.0 N m⁻²) induced adhesion of human platelets to collagen I with the same efficacy (IC₅₀=2.4±0.3 μg ml⁻¹), but had no effect at low shear conditions (1.5 N m⁻²).
4. AJvW-2 inhibited the botrocetin-induced aggregation of platelets from guinea-pig, rat, rabbit, dog and pig at the same concentration range as human platelets; it likewise also inhibited the high shear stress induced aggregation and adhesion to collagen I of guinea-pig platelets.
5. AJvW-2 prevented arterial thrombus formation in guinea-pigs at a dose of 100 μg kg⁻¹ without prolonging the template bleeding time, whereas the GPIIb/IIIa antagonist lamifiban mediated inhibition of thrombosis at 1000 μg kg⁻¹ was accompanied by a significant prolongation of the bleeding time.
6. These results suggest that AJvW-2 is a potent inhibitor of the GPIb-vWF interaction and a potential novel antithrombotic agent with lower bleeding risk than GPIIb/IIIa antagonists.

     

Proliferation and differentiation of transplanted embryonic diencephalon in the brain of adult rats

The survival, proliferation potential, differentiation, and host tissue reaction of allografts of undifferentiated embryonal diencephalic tissue (E12.5, E17.5) transplanted into or around the third ventricle of adult rats were investigated. Rats harboring grafts were sacrificed at three, six, and nine weeks after transplantation. The proliferative activity of the grafts was assessed by injection of 5'-bromo-2'-deoxyuridine (BrdU) into pregnant rats before the removal of fetuses for transplantation, and staining the grafts using an anti-BrdU antibody. The proliferative activity of the transplanted grafts was evaluated by immunostaining using an anti-proliferating cell nuclear antigen (PCNA) antibody. The differentiation of the grafts into neurons was estimated by double immunostaining using anti-BrdU and anti-neuron-specific enolase (NSE) antibodies. The survival rate of the grafts was strongly related to the proliferative activity of the graft. Surviving E17.5 grafts contained immunoreactive BrdU cells. E12.5 grafts could survive without immunoreactive BrdU cells. Undifferentiated El2.5 grafts proliferated up to six weeks after transplantation. Thereafter, most graft cells differentiated into mature neurons. E12.5 diencephalic allografts survived well with minimal rejection reactions and resulted in substantial neurite ingrowth into the host brain, while El7.5 allografts caused substantial reactive gliosis and little ingrowth.     

Clinical application of18F-FUdR in glioma patients — PET study of nucleic acid metabolism

Summary Positron emission tomography was used to investigate the metabolism of nucleic acids by¹⁸F-fluoro-2-deoxyuridine (¹⁸F-FUdR) in 22 patients with gliomas. Sixteen cases of high grade glioma clearly demonstrated a region of high activity with a differential absorption rate (DAR) of 0.64 ± 0.34. Six cases of low grade glioma failed to reveal a positive image of the tumor and the DAR in tumor was 0.21 ± 0.042 (p < 0.01). This PET-¹⁸F-FUdR study succeeded in differentiating high and low grade gliomas from the view point of nucleic acid metabolism.     

Finger bougie method compared with pyloroplasty in the gastric replacement of the esophagus

To elucidate the necessity of pyloroplasty for the gastric tube through the posterior mediastinum in esophageal surgery, gastric emptying and duodenogastric reflux (DGR) were evaluated in 16 cases undergoing an anterior pylorectomy (group P) and in 16 cases treated by the finger bougie method (group F). First, the obstruction and reflux symptoms were examined based on a patient questionnaire using a brief scoring system. The median value of the symptom score showed the patients in P to have more symptoms than those in F; however, the difference was not significant (8.0 vs 6.0). Secondly, the swallowed Tc O₄ ⁻ (85 MBq) was counted using a gamma camera at three sites on the sternal bone in the upright position based on a gastric transit scintigram. Both the descending time of the RI peak and the clearance rates were similar between the two groups. Thirdly, intragastric 24-h pH monitoring was carried out. Antimony pH sensors were anchored 5 and 15 cm below the esophagogastrostomy. We could not find any difference between the two groups in both the % time pH>4 and %time pH>7. These findings thus revealed no big difference between groups P and F. The finger bougie method to drain the vagotomized posterior mediastinal stomach was found to achieve results similar to conventional pyloroplasty, while it was also simpler and safer.     

Lewy body-type degeneration in cardiac plexus in Parkinson's and incidental Lewy body diseases

Heart tissues of patients with PD or incidental Lewy body (LB) disease (ILBD) were examined by light and electron microscopy. LBs and alpha-synuclein-positive neurites were identified in the hearts from 9 of 11 patients with PD and from 7 of 7 patients with ILBD. LBs were present in both tyrosine hydroxylase-positive and -negative nerve processes, which are nerves of extrinsic sympathetic and intrinsic origin, respectively. These findings provide histologic evidence that the postganglionic sympathetic and intrinsic neurons in the heart are involved in the PD disease process.     

Sonic motor nucleus and its connections with octaval and lateral line nuclei of the medulla in a rockfish, Sebastiscus marmoratus

The sonic motor nucleus and its fiber connections were examined in a rockfish, Sebastiscus marmoratus by means of tracer methods using horseradish peroxidase (HRP), biocytin, and carbocyanine dye (DiI). Sebastiscus has a swimbladder and a pair of extrinsic sonic/drumming muscles. The sonic muscle is ipsilaterally innervated by the occipital nerve which is composed of two ventral roots arising from the sonic motor nucleus. The sonic motor neurons are distributed in the most ventral part of the ventral column from the caudal medulla to the rostral spinal cord, and form a ventrally located columnar nucleus. Each neuron in this nucleus possesses a long thick dendrite and several short dendrites. The long dendrite extends dorsolaterally and branches in the lateral funiculus, whereas the short dendrites branch around their cell bodies. After biocytin injections into the sonic motor nucleus, two groups of premotor neurons were retrogradely labeled bilaterally, one in the dorsomedial portion of the descending octaval nucleus (DO) and the other in the medial zone of the reticular formation (RF) in the medulla. The DO premotor neurons were multipolar with several dendrites branching near the cell bodies, and the RF premotor neurons were bipolar. One of the two dendrites of the RF premotor neurons extends laterally into the ventral portion of the DO, and the other dendrite extends into the ventromedial area in the medulla. In the ventromedial dendritic field of the RF premotor neurons, descending fibers arising from the optic tectum (TO) and torus semicircularis (TS) traverse in the tractus tectobulbaris and terminate bilaterally. After DiI insertion into the ventromedial dendritic field, retrogradely labeled neurons were found bilaterally in the TS and TO. The majority of tectal neurons were located in the stratum griseum centrale. These neurons had two short basal dendrites branching in the cell layer and a long apical dendrite extending to the stratum fibrosum et griseum superficiale and stratum opticum. The toral neurons were bipolar and were distributed throughout the TS. Furthermore, biocytin injections into the medial nucleus of the lateral line system revealed that the nucleus projects bilaterally to the RF premotor neurons. These results show that premotor neurons for the sonic motor nucleus are located in the dorsomedial portion of the DO and the medial zone of the RF in the medulla. It is suggested that the sonic motor nucleus receives auditory input via the DO premotor neurons and input from RF premotor neurons which receive lateral line input via the medial nucleus, vestibular input through the lateral dendrite extending into the ventral portion of the DO, and information from the TO and TS via the tractus tectobulbaris.     

Dynamic changes in glucose metabolism of living rat brain slices induced by hypoxia and neurotoxic chemical-loading revealed by positron autoradiography

Fresh rat brain slices were incubated with 2-deoxy-2-[18F]-fluoro-D-glucose ([18F]FDG) in oxygenated Krebs-Ringer solution at 36 degrees C, and serial two-dimensional time-resolved images of [18F]FDG uptake were obtained from these specimens on imaging plates. The fractional rate constant (= k3*) of [18F]FDG proportional to the cerebral glucose metabolic rate (CMRglc) was evaluated by applying the Gjedde-Patlak graphical method to the image data. With hypoxia loading (oxygen deprivation) or glucose metabolism inhibitors acting on oxidative phosphorylation, the k3* value increased dramatically suggesting enhanced glycolysis. After relieving hypoxia < or = 10-min, the k3* value returned to the pre-loading level. In contrast, with > or = 20-min hypoxia only partial or no recovery was observed, indicating that irreversible neuronal damage had been induced. However, after loading with tetrodotoxin (TTX), the k3* value also decreased but returned to the pre-loading level even after 70-min TTX-loading, reflecting a transient inhibition of neuronal activity. This technique provides a new means of quantifying dynamic changes in the regional CMRglc in living brain slices in response to various interventions such as hypoxia and neurotoxic chemical-loading as well as determining the viability and prognosis of brain tissues.     

A case of unruptured cerebral aneurysm treated by intra-aneurysmal embolization during outpatient hemodialysis for chronic renal failure

A 70-year-old woman, who had been receiving hemodialysis in a local hospital every other day for 2 years, complained of occasional headaches. Magnetic resonance imaging showed a large middle cerebral artery (MCA) aneurysm. Angiography in the midterm day of hemodialysis demonstrated a large aneurysm on the right MCA bifurcation. Her chronic renal failure made us hesitate to perform craniotomy. Intra-aneurysmal Guglielmi detachable coil (GDC) embolization was performed also in the midterm day of hemodialysis. She was admitted to our hospital after hemodialysis on the day before the embolization. The embolization was carried out under local anesthesia and systemic heparinization. The aneurysm was almost completely embolized with five GDCs. She was transferred to the local hospital to receive the next hemodialysis on the day after the embolization. Patients with chronic renal failure are not suitable for neurosurgical therapy because mortality of patients undergoing dialysis is 45-80%, which is mainly due to disequilibrium syndrome and a hemorrhagic tendency. We propose that some cases like this case should be treated with an intra-vascular neurosurgical technique. In conclusion, this report demonstrates that intra-aneurysmal embolization is less invasive and is a more suitable treatment for patients who are considered to be at high risk for surgery and general anesthesia.