Application of a biomagnetic measurement system (BMS) to the evaluation of gastrointestinal transit of intestinal pressure-controlled colon delivery capsules (PCDCs) in human subjects.

PURPOSE: For determination of the transit time through various parts of the gastrointestinal (GI) tract, we developed a method that provides the location of disintegration and drug release. This method involves GI magnetomarkergraphy (GIMG) using a 129-channel Shimadzu vector biomagnetic measurement system (BMS). METHODS: To magnetically label the pressure-controlled colon delivery capsule (PCDC) containing 75.0 +/- 0.5 mg of caffeine as a tracer drug, small capsule caps containing 90 mg of ferric oxide powdered magnetite (Fe2O3) were attached to PCDCs. After orally administration to fasted human volunteers, saliva samples were collected hourly and salivary caffeine concentration was measured. At the same time, locations of the magnetic PCDC were detected by BMS just after the PCDCs were magnetized with the coils of a magnetic resonance imaging (MRI) system. The magnetic field distributions were analyzed and the estimated positions were shown on the MRI picture of the same subject's abdominal structure. RESULTS: We magnetized PCDC with permanent magnets or an electromagnet before ingestion and the estimated locations of PCDC in the GI tract exhibited high estimation error. In order to increase the precision of estimated localization of PCDCs, PCDCs were magnetized within the coils of the MRI. As a result, these PCDCs had strong magnetic dipoles that were parallel to the sensor unit of BMS in every measurement, and therefore the spatial resolution of the PCDC's two-dimensional positions in the organs of the GI tract was within a range of several millimeters. CONCLUSIONS: GIMG is a powerful tool for the study of colon delivery efficiencies of PCDCs. The main advantage of GIMG is the capability to obtain even more detailed knowledge of the behavior and fate of solid pharmaceutical formulations during GI passage.

Arterial and mixed venous oxygen desaturation during incremental exercise in patients with chronic pulmonary disease.

We evaluated arterial and mixed venous oxygen desaturation during symptom-limited exercise in patients with chronic pulmonary disease. Patients were divided into five groups according to disease: [chronic pulmonary emphysema (CPE), chronic bronchitis (CB), pulmonary tuberculosis sequalae (TB-seq), fibrosing lung disease (FLD), and pulmonary vascular disease (PVD)]. There were no significant difference in the values of arterial (PaO2) and mixed venous (PvO2) oxygen tension before and at the end of exercise among the five groups, whereas absolute decreases in PvO2 were significantly larger in PVD and FLD. The changes in PvO2 were similar to the changes in the coefficient of oxygen delivery (COD) which is equal to oxygen transport divided by oxygen consumption. These results suggest that the relative decrease in oxygen transport during exercise due to the high ratio of oxygen extraction by tissues is an important factor to determine decreases in PvO2 in pulmonary hypertensive disease and fibrosing lung disease.

[A case of type B chronic hepatitis showing rapid progression to liver cirrhosis with prolonged positive IgM anti-HBc].

We reported a case of type B chronic hepatitis with high titer of IgM anti-HBc continuously, which progressed to liver cirrhosis rapidly. The patient was a 37-years-old man, and was diagnosed as chronic type B hepatitis with severe activity by laparoscopy and liver biopsy. The titer of IgM anti-HBc persisted high level for more than 2 years. Then the second liver biopsy showed the progression to liver cirrhosis within only about 2 years. It is a very rare case to prolong positive IgM anti-HBc for such a long time. Anti-HBc production of PBMC was enhanced remarkably in this case. We considered that HBc antigens released into serum from hepatocytes with severe exacerbations had enhanced the anti-HBc producing activity of B lymphocytes. And the rapid progression in this case would be due to the episodes of severe exacerbations.

[Evaluation of masticatory efficiency and the analysis of occlusal pattern factors using computer image processing method].

The purpose of this study was to evaluate the newly developed computer-assisted image processing method. We applied this method for the evaluation of masticatory efficiency and the analysis of occlusal pattern factors: the number and the size of occlusal contact areas, the number of and the size of the projected facets. We compared this new method with our conventional one which is the simplified particle counting method using a sieve and measuring the occlusal pattern factors with a planimeter. The results were as follows: 1. It is possible to count the number of particles within an optional range of size with the new method. 2. The new method may be used with minimum error for the measurement of occlusal pattern factors. We believe that this newly developed computer-assisted image processing method can be put to practical use for clinical evaluation of masticatory efficiency and analysis of occlusal pattern factors.