Biomedical subjects
Publications and source records attributed to Y Ushijima.
We report a case of small pulmonary arteriovenous fistulae precisely diagnosed by a combination of selective pulmonary arteriography and scintigraphy during (99)Tc(m)-macroaggregated albumin injection via the peripheral pulmonary artery.
Partial mitochondrial 16S ribosomal ribonucleic acid gene sequences in the ticks Carios capensis collected from black-footed albatross. Diomedea nigripes, colonies on Torishima Island, Japan (30 degrees 28'N, 140 degrees 18'E), were examined. The sequence was compared with those of C. capensis from Hawaii, South Carolina, and Texas. The sequences were all identical in ticks from Torishima and 2 from Hawaii. There were 2-3 transitions between the other Hawaiian and Texas ticks and Torishima specimens. Two transitions were also observed when compared with the ticks from South Carolina. The results suggest the possibility of gene flow between tick populations at each of the 2 geographic sites, which probably was accomplished by tick-infested migratory seabirds at their breeding sites. Sequence comparison analysis indicated that the C. capensis ticks are on the branch with C. marginatus and C. mexicanus ticks and not with Ornithodoros. This supports the revision suggested by Klompen and Oliver (1993).
PURPOSE: To determine whether the location and size of sentinel lymph nodes (SLN) on CT are predictive of the axillary lymph node status in patients with breast cancer. MATERIAL AND METHODS: Forty patients with confirmed breast cancer underwent 5-mm CT of both breasts and axillae and the most inferior lymph node in the affected axilla was designated the SLN. Based on CT assessment of the axillary lymph node status, 22 (55%) patients then underwent dye- and gamma probe (DGP)-guided SLN biopsy followed by axillary dissection; 18 (45%) underwent dissection without prior SLN biopsy. The localization and status of the SLN determined on CT and by DGP-guided biopsy were compared. Biopsied and excised nodes were subjected to histopathologic examinations. RESULTS: All SLN identified on CT were close to the lateral thoracic artery and their localization corresponded well with SLN identified by the DGP-guided method. The positive predictive value of CT diagnosis was 100%. Histopathologic examination of excised nodes confirmed that none of the SLN biopsies was false-negative. CONCLUSION: Our CT criteria were highly accurate for identification and diagnostic assessment of SLN and useful for evaluating the axillary status in patients with breast cancer.
Neuroblastomas sometimes recur after the initial disappearance of the tumour. We evaluated the utility of meta-[123I]iodobenzylguanidine (123I-MIBG) scintigraphy for the detection of recurrent neuroblastomas by comparing with the measurement of biochemical markers and clinical findings. Forty patients who had received treatment for neuroblastomas were included in the study. After the disappearance of the initial tumours, periodic measurements of urinary vanillyl mandelic acid, homovanillic acid and serum neuron specific enolase values, and an 123I-MIBG scintigraphy were performed. Whenever an abnormal finding was observed, other appropriate examinations and/or follow-up examinations were performed to elucidate the true state of the patient. Eleven recurrent episodes in eight patients were observed. Most of them occurred in the bone marrow or bone. Corresponding symptoms were observed in only two episodes; the other episodes were asymptomatic, and discovered by the periodic examinations. 123I-MIBG scintigrams visualized the recurrent tumours in 10 (91%) episodes. Elevated tumour markers were observed in only three episodes. 123I-MIBG scintigrams visualized most of the recurrent tumours, unless they were accompanied by any symptoms or elevations in biochemical tumour markers. Periodic examinations with 123I-MIBG scintigraphy appears to be a useful technique for the detection of the recurrences.
OBJECTIVE: To deepen understanding of hemodynamics in the femoral head, i.e., the essential factor in clarifying pathogenesis of hip disorders, this study examined blood flow and blood volume in the femoral heads of healthy adults, and their changes with age, by using positron emission tomography (PET). METHODS: In 16 healthy adult males (age: 20-78 years old, mean age: 42 years), blood flow was measured by means of the H2(15)O dynamic study method, and blood volume was measured by means of the (15)O-labeled carbon monoxide bolus inhalation method. RESULTS: Blood flow was 1.68-6.47 ml/min/100 g (mean +/- SD: 3.52 +/- 1.2), and blood volume was 1.67-6.03 ml/100 g (mean +/- SD: 3.00 +/- 1.27). Blood flow significantly decreased (p < 0.01) with age, and blood volume significantly increased (p < 0.05). CONCLUSION: PET was useful in the measurement of blood flow and blood volume in the femoral heads. With age, physiological hemodynamic changes also increased in femoral heads.
We have developed new software which can evaluate left ventricular (LV) diastolic functional parameters from a quantitative gated SPET (QGS) program. To examine its accuracy, we compared these findings with the LV diastolic functional indices obtained from gated radionuclide ventriculography (RNV). Twenty-four patients were selected for this study. Gated SPET with technetium-99m tetrofosmin was performed and the QGS program was used with a temporal resolution of 32 frames per R-R interval. The LV volume of each frame was calculated and four harmonics of Fourier series were retained for the analysis of the LV volume curve. From this fitted curve and its first derivative curve, we derived LV systolic functional indices, e.g. ejection fraction (EF), peak ejection rate (PER) and time to PER (TPER), as well as LV diastolic functional variables, e.g. 1/3 filling fraction (1/3 FF), peak filling rate (PFR) and time to PFR (TPFR). Within 5+/-2 days, gated RNV was performed and diastolic functional parameters were determined by the same method. No significant difference was observed between the variables calculated by gated SPET and by gated RNV. There was a good correlation between EF, PER, TPER, 1/3 FF, PFR and TPFR determined by these two methods (EF: r=0.95, P<0.0001; PER: r=0.87, P<0.0001; TPER: r=0.84, P<0.0001; 1/3 FF: r=0.87, P<0.0001; PFR: r=0.92, P<0.0001; TPFR: r=0.89, P<0.0001). Bland-Altman plots did not reveal any significant degree of directional measurement bias in any of the comparisons of gated SPET data and RNV data. It is concluded that, in addition to the conventional LV systolic functional indices, our program accurately provides LV diastolic functional parameters from gated SPET. Also, this program will be useful for detecting LV diastolic dysfunction in various cardiac diseases before LV systolic dysfunction becomes evident.
Argasid ticks collected in the site near Mvumi Hospital, Dodoma, Tanzania, were subjected to flagellin gene-based nested polymerase chain reaction (PCR) amplification for examination of borrelial infections. Eight of 13 ticks gave a strong 350-bp signal; three had a weak signal at the same size, and the rest were negative. Sequence determination of eight of the positive samples resulted in three types of flagellin gene sequences. The first type of sequence (shown by three individuals) was identical to that of Borrelia duttonii strain Ly. The second type of sequence from PCR products from four individual ticks had only one base substitution without amino acid alteration in deduced protein sequence. The third type of sequence was different from that of any other Old World relapsing fever borreliae, and the tick was thought to be infected with an unknown Borrelia species. Ticks were also examined to determine the nucleotide sequence of the mitochondrial 16S rRNA gene. The partial sequence of approximately 470 bases was aligned for comparison with previously published sequences to identify the species. The sequences of 13 individual ticks were all identical, and the sequence similarity analysis revealed the ticks should be classified as members of the Ornithodoros porcinus species. The PCR method described in this report appears to be a reliable tool for the detection of borreliae and epidemiological study of tick-borne relapsing fever.
Iodine-131 uptake was seen in the right upper abdominal quadrant of a patient with postoperative differentiated thyroid cancer that corresponded with a large liver cyst.
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UNLABELLED: Nontraumatic osteonecrosis of the femoral head (ONF) is a complication of renal transplantation. The pathogenic mechanism of ONF is thought to be an ischemic event. The purpose of this study was to investigate whether 3-phase bone scintigraphy can reveal early hemodynamic changes associated with ONF after renal transplantation. METHODS: We performed 3-phase bone scintigraphy on 19 renal allograft recipients between 3 and 9 wk after they underwent renal transplantation. Regions of interest (ROI) were assigned bilaterally in the femoral heads, diaphyses, and soft tissue. The head-to-diaphysis ratio (HD) in each phase was then calculated. RESULTS: ONF occurred in 8 femoral heads of 4 patients. Three of the 4 ONF patients had no abnormal MRI findings at the time of bone scintigraphy. In phase 1, no significant difference in HDs was observed between the ONF patients (mean HD +/- SD, 0.62 +/- 0.44) and the non-ONF patients (0.31 +/- 1.40). The difference between the mean counts for bone and soft tissue was small in both instances, and the HD had a large dispersion. In phase 2, the HDs for the ONF patients (0.70 +/- 0.27) and the non-ONF patients (1.31 +/- 0.43) were significantly different (P = 0.0005). The HD was <1.00 in all femoral heads of the ONF patients, whereas 9 non-ONF heads had an HD that was <1.00. In phase 3, the HD of the ONF patients was significantly lower than that of the non-ONF patients (ONF patients, 0.92 +/- 0.17; non-ONF patients, 1.62 +/- 0.46; P = 0.0002). CONCLUSION: All ONF patients were in the group with a low HD in phase 2, suggesting a reduction in blood flow or blood pool. Phase 2 accumulation in 3-phase bone scintigraphy can be used to estimate early hemodynamic changes in patients with ONF after renal transplantation.
The annual multicenter studies on isolated bacteria from infections in general surgery and their antimicrobial susceptibility have been conducted in Japan since July 1982. This paper describes the results obtained in fiscal 1998 (from April 1998 to March 1999). The number of cases investigated as objectives was 225 for one year. A total of 429 strains (121 strains from primary infections and 308 strains from postoperative infections) were isolated from 183 cases (81.3% of total cases). In primary infections, the isolation rates of anaerobes and Escherichia coli were higher than in postoperative infections, while in postoperative infections, those of Gram-positive aerobes and Pseudomonas aeruginosa were higher than in primary infections. On the whole, among Gram-positive aerobes, the isolation rate of Enterococcus faecalis was the highest, followed by Staphylococcus aureus with high frequency in isolation from postoperative infections. Among Gram-positive anaerobes, Peptostreptococcus spp. and Streptococcus spp. were predominantly isolated. Among Gram-negative aerobes, E. coli, P. aeruginosa, Klebsiella pneumoniae and Enterobacter cloacae were frequently isolated. Among Gram-negative anaerobes, Bacteroides fragilis group was the majority of isolates. In primary infections, the percentage of Gram-negative aerobes has gradually increased since fiscal 1995 or 1996 with these years as the turning point, while those of Gram-positive and Gram-negative anaerobes have gradually declined. In postoperative infections, the percentage of Gram-negative anaerobes has increased continuously since the mid-1980s. The percentage of MRSA among S. aureus rose to 89.7%, which was the highest level since the beginning of this study. The susceptibilities of B. fragilis, which did not show apparent changes, were recognized to have decreased against cephems in fiscal 1998. Among other bacteria in B. fragilis group, development of resistance to cephems has continued on a long-term basis since the mid-1980s. E. coli and K. pneuminiae have obviously not changed in susceptibilities, however, the susceptibilities of isolated strains in fiscal 1998 against high-generation cephems, oxacephems and monobactams have declined. We found neither vancomycin-resistant nor teicoplanin-resistant strains of S. aureus and Enterococcus spp.
The UL37 gene of herpes simplex virus (HSV) encodes a 120-kDa phosphoprotein associated with the virion. In this study, we have generated a rabbit polyclonal antiserum against HSV-2 UL37 protein, and examined its intracellular localization by immunofluorescence study. In infected cells, specific fluorescence was detectable in the perinuclear region. In transfected cells, UL37 protein was observed mainly in the cytoplasm. Transfection assays of deletion mutants of UL37 protein suggested that the leucine rich region (LRR) containing amino acids 263-273 may be important for cytoplasmic localization. Deletion of the LRR or substitution of the leucine residues resulted in nuclear remaining of UL37 protein. Moreover, the LRR could export green fluorescent protein (GFP) to the cytoplasm as a fusion protein and this export was blocked by leptomycin B treatment, indicating that the LRR acted as a nuclear export signal. These results suggest that UL37 protein fulfills a role as a shuttle between the nucleus and the cytoplasm through the LRR.
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HIV-1 enters cells through interacting with cell surface molecules such as CD4 and chemokine receptors. We generated recombinant soluble gp120s derived from T-cell line-tropic (T-tropic) and macrophage-tropic (M-tropic) HIV-1 strains using a baculovirus expression system and investigated the association of CD4-gp120 complex with the chemokine receptor and/or other surface molecule(s). For monitoring the co-down-modulations of the CD4-gp120 complex, a cytoplasmic domain deletion mutant (tailless CD4), which is not capable of undergoing down-modulation by itself in response to phorbol ester PMA, was used. Our studies revealed both cell-type and HIV-1 strain-specific differences. We found that T-tropic gp120s were capable of priming co-down-modulation with tailless CD4 by interacting with CXCR4, whereas M-tropic SF162 gp120 could not after PMA treatment even in the presence of CCR5. Among the T-tropic HIV-1 envelopes, IIIB gp120 was the most potent. Furthermore, the ability of gp120 to prime the PMA induced co-down-modulation of tailless CD4 appeared to be dependent on the concentration of the principal coreceptor CXCR4. Nevertheless, the observation that IIIB gp120 strongly primed tailless CD4 co-down-modulation on human osteosarcoma HOS cells that express undetectable levels of surface CXCR4 raised the possibility that membrane component(s) other than those recently identified can be involved in down-modulation of the CD4/gp120 complexes.
The annual multicenter studies on isolated bacteria from infections in general surgery and their antimicrobial susceptibility have been conducted in 19 facilities in Japan since July 1982. This paper describes the results obtained during the period from April 1997 to March 1998. The number of cases investigated as objectives was 215 for one year. A total of 420 strains (170 strains from primary infections and 250 strains from postoperative infections) were isolated from 174 cases (80.9% of total cases). In primary infections, the isolation rate of anaerobic bacteria was higher than in postoperative infections, while in postoperative infections, those of aerobic Gram-positive bacteria and Pseudomonas aeruginosa were higher than in primary infections. Among aerobic Gram-positive bacteria, the isolation rate of Enterococcus faecalis was the highest, followed by Staphylococcus aureus, which was frequently isolated from postoperative infections. Among anaerobic Gram-positive bacteria, Peptostreptococcus spp. and Streptococcus spp. were commonly isolated from both types of infections. Among aerobic Gram-negative bacteria, Escherichia coli was most predominantly isolated from primary infections, followed by P. aeruginosa, Klebsiella pneumoniae in this order, and from postoperative infections, P. aeruginosa was most predominantly isolated, followed by E. coli and K. pneumoniae. Among anaerobic Gram-negative bacteria, Bacteroides fragilis group was the majority of isolates from both types of infections. We found neither vancomycin nor arbekacin resistant strains of S. aureus, and found no vancomycin resistant strains of Enterococcus spp. The susceptibility of P. aeruginosa against carbapenems did not decline in the year 1997, while resistance of B. fragilis group against cephems advanced increasingly.
Electrolysis or horseradish peroxidase (HRP)-catalyzed oxidation of tyrosine and bityrosine in aqueous solution at pH 7.4 resulted in light emission in the visible region. Electrolysis of tyrosine emitted light which peaked at 490 nm and was almost completely quenched by superoxide dismutase (SOD), while emission by bityrosine peaked at 530 nm. In the HRP-H(2)O(2)-tyrosine system the oxidation-reduction of tyrosine emitted light with two prominent peaks, 490 and 530 nm, and was not quenched by SOD. The phenoxyl neutral radical of the tyrosine in HRP-H(2)O(2)-tyrosine system was detected by electron spin resonance (ESR) spectrometry using tert-nitrosobutane as a spin trap; the spin adduct was found to adhere to the HRP molecule during the enzymatic reaction. Further, bityrosine was detected in the HRP-H(2)O(2)-tyrosine reaction system. Changes in absorption spectra of HRP and chemiluminescence intensities during HRP-catalyzed oxidation of tyrosine suggest that for photon emission compound III is a candidate superoxide donor to the phenoxyl cation radical of tyrosine on the enzyme molecule. The luminescence observed in this study might be originated from at least two exciplexes involved with the tyrosine cation radical (Tyr(*+)) and the bityrosine cation radical (BT(*+))
We examined reverse redistribution (RR) of Tc-99m-tetrofosmin after a single injection in patients with acute myocardial infarction (AMI). Tc-99m-tetrofosmin myocardial SPECT was performed in 28 patients with AMI 10-14 days after the onset. Myocardial images were obtained 30 min and 180 min after the injection of 740 MBq of Tc-99m-tetrofosmin. The left ventricular wall was divided into 9 segments. Regional myocardial uptakes of Tc-99m-tetrofosmin were scored by 4-point scoring (0 = normal, 1 = mildly reduced, 2 = moderately reduced, and 3 = defect). RR was defined as an increase of more than 1 in the regional score in images at 180 min. RR of Tc-99m-tetrofosmin was observed in 17 of 20 patients with direct PTCA and 3 of 8 patients without reperfused therapy. RR was observed in 61 of all 252 segments. Coronary angiography performed 1 month later revealed that the infarct-related artery was patent in 19 of 20 patients (95%) with RR and in 3 of 8 patients (37.5%) with persistent defects (PD) (p < 0.05). In segment-by-segment analysis, the incidence of regional wall motion abnormality I month later was reduced in regions with RR compared to those with PD (p < 0.0001). In conclusion, RR of Tc-99m-tetrofosmin was frequently observed in patients with successful direct PTCA. As the segments with RR showed signs of preserved function 1 month later, this phenomenon may reflect a salvaged myocardium in AMI.