Biomedical subjects

K Doi

Publications and source records attributed to K Doi.

At least 217 records · Page 12Linked to original sources

PubMed1999

[Labyrinthine fistulas in cholesteatoma].

The purpose of the present study was to investigate the clinical features of cases of cholesteatoma with labyrinthine fistulas, and in particular the pre and post-operative bone-conduction (BC). Cholestatoma patients with bone erosion or a defect found in the first stage operation were analyzed. The operations were conducted between 1992 and 1996. The patients were classified into four types, I, IIa, IIb, and III, according to Dornhoffer and Milewski's classification, which is based on different stages in the bone defect. A type I fistula is an erosion of the bony labyrinth with an intact endosteum. Type IIa is accompanied by an opened perilymphatic space with undisturbed perilymph while type IIb has a disturbed perilymph. A Type III fistula is an opened perilymphatic space with a disturbance of the underlying membranous labyrinth. Only 24 patients with type II and type III fistulas were included in this study. The location of the fistulas was the semicircular canals (SCCs) or/and the vestibula in 21 patients and in the cochlea in 3 patients. We examined the fistula by high-resolution computed tomography scan (CT scan) with 1 mm slice and 1 mm width axial-sections in 14 patients. A bone defect in the labyrinth was detected in 10 cases (71.5%) pre-operatively. Pre-operative BC was worse in the patients with cochlear fistulas than in those with fistulas located in SCCs or the vestibula. Within this latter group there were 13 type IIa (group IIa), patients and 8 type IIb or III (group IIb or III) patients. However, there was no difference in the pre-operative BC between these two sub-groups Tympanoplasty was conducted in all 24 patients. The postoperative BC of group IIa and group IIb or III were compared. Two of the 13 patients in group II a (15.4%) and 3 of 8 in group IIb or III (37.5%) had a deteriorated postoperative BC. Statistical analysis revealed that the postoperative BC was more inclined to become worse in patients with advanced stage IIb or III fistulas.

Adolescent↗

PubMed1999

[The prognostic value preoperative promontory testing in Japanese cochlear implant patients].

The prognostic value of preoperative promontory testing was evaluated in Japanese cochlear implant patients. Promontory testing consisted of measurement of electrical thresholds (T), uncomfortable level (UCL), dynamic range (DR), gap detection (GAP), and temporal difference limen (TDL). Patients' performances were measured at 3 months (n = 46) and 1 year (n = 20) postoperatively, using a standard Japanese audiologic test battery without lip-reading. This study included only postlingual deaf patients who received the Nucleus multichannel cochlear implant. Wide DRs at low frequencies (50,100,200 Hz) and good GAP detection (< 20 ms) emerged as excellent preoperative predictors of the 3-month postoperative performances (P < 0.05). In contrast, any measurements could not serve as a good predictor of the 1-year performances. These results suggest that the preoperative promontory testing provides useful information only for early postoperative performances but that it could not predict the final language performances.

Adolescent↗

PubMed1999

[Evaluation of 99mTc-MAG3 (mercaptoacetyltriglycine) renography for pediatric patients].

It is difficult to evaluate renal function with 99mTc-MAG3 renography in both adult and pediatric patients. We examined 109 pediatric patients with various renal diseases using 99mTc-MAG3 renography. Tenal diseases were classified as follows: 9 vesicoureteral reflux, 4 ureteropelvic junctional stenosis, 3 double pelvis, 23 hydronephrosis, 4 glomerulonephritis, 4 nephrotic syndrome, 24 hemolytic uremic syndrome, 10 others; and 24 patients without abnormal findings on other examinations. After hydration and sedation, 100-200 MBq of 99mTe-MAG3 was injected intravenously. All patients were placed in the supine position, and dynamic data acquisition at 12 sec/frame x 100 frames was performed from the back. The renograms were prepared with the ROIs (regions of interest) set to include the entire kidney. Tmax and T1/2 of renograms were measured for 26 kidneys with no abnormal findings. The correlations between Tmax or T1/2 and age (days after birth) were determined by a linear or logarithmic function. The logarithmic function (Y = 7.49 - 0.56 logeX, r2 = 0.134) yielded a higher correlation than did the linear function (Y = 5.16 - 0.00194X, r2 = 0.089) between Tmax and age. For T1/2 and age (days after birth), the linear function (Y = 8.07 - 0.00451X, r2 = 0.222) yielded a higher correlation than the logarithmic function (Y = 11.9 - 0.986 logeX, r2 = 0.192). Our findings suggest that prolonged Tmax is normalized more rapidly than T1/2 after birth in infants. A delayed excretion phase is not suggestive of renal dysfunction, but is characteristic of renograms in pediatric patients. Abnormality was detected in all patients with hydronephrosis using 99mTc-MAG3 renography. On the other hand, a quantitative study was required because renography detected no abnormality for some of patients with disorders of renal parenchyma.

Adolescent↗

PubMed1999

[Metastatic endometrial sarcoma of the right ventricular outflow tract associated with disseminated intravascular coagulopathy].

A case of myocardial metastasis of endometrial sarcoma to the right ventricular outflow tract is described. A 56-year-old woman was admitted with ecchymoses of lower limbs in September in 1995. Laboratory findings included thrombocytopenia and an increase of fibrinogen degradation products due to disseminated intravascular coagulopathy (DIC). Transesophageal echocardiography (TEE) demonstrated a large mass both in the right ventricular outflow tract and the proximal pulmonary artery. The mass was excised including base of the stalk. Cryoablation was employed on the endocardium where the stalk was originated. With pathological examination, the mass was identified to be endometrial sarcoma. The patient achieved an uneventful recovery and DIC was improved dramatically in a week after operation. Thirty-three months after the surgery, she has been well and free from local recurrent tumor.

Disseminated Intravascular Coagulation↗

PubMed1999

[Quantitative assessment of 201Tl-SPECT in tumors of bone and soft tissue].

201Tl-SPECT was performed to diagnose the malignancy of bone and soft tissue tumors by visual and quantitative assessment in 48 patients (17 malignant lesions and 31 benign lesions). SPECT images were obtained in the early phase (15 min after injection) and the delayed phase (240 min). By visual assessment a tumor was considered malignant if high accumulation was found in the tumor in the early phase and the accumulation was confirmed in the delayed phase. Tumors which did not meet these criteria were considered benign. For quantitative assessment, the ROI (region of interest) accumulation ratios of the tumor to the contralateral normal tissue in the early phase (ER) and in the delayed phase (DR), the ROI accumulation ratio of the delayed phase to the early phase of the tumor (Td/Te), and the ROI accumulation ratio of the delayed phase to the early phase of the contralateral normal tissue (Nd/Ne) were obtained. Sixteen patients with malignant tumors each had a high accumulation each but 12 of 31 benign lesions had no high accumulation on visual assessment. Furthermore, the accuracy was 85.4%, sensitivity 94.1%, and specificity 80.6%. Quantitative assessment was performed for 36 cases of high accumulation. The ER of malignant and benign lesions was 5.51 +/- 3.73 and 2.75 +/- 2.17, respectively, and the ER of malignant lesions was significantly higher than that of benign lesions. The DR did not demonstrate a significant difference. If the tumor having an ER greater than 3.9 was assumed to be malignant, the accuracy for differentiating malignant lesions from benign lesions was 85.4%. The Td/Te of benign lesions (0.97 +/- 0.28) was higher than that of malignant lesions (0.77 +/- 0.09). The Nd/Ne of normal tissue which contained muscles in both lesions were higher than 1.4. In conclusion, 201Tl-SPECT was very useful for the differential diagnosis of benign or malignant bone and soft tissue tumors. The ER was important for quantitative assessment, but a delayed image was necessary for visual assessment.

Adolescent↗

PubMed1999

[Antinociceptive effects of intrathecally administered GABA agonists at the spinal cord level].

The present study was designed to investigate antinociceptive effect of GABA agonists regarding visceral as well as somatic noxious stimuli. Following the approval by the institutional animal care committee, an intrathecal catheter was implanted in the subarachnoid space at the L 4/5 level in male Sprague-Dawley rats. The tail flick (TF) test and the colorectal distension test (CD) were used to measure responses to somatic and visceral stimuli, respectively. Threshold in TF test and CD test were measured at 5, 10, 15, 20, 30, 60, 90, 120 and 180 min after the intrathecal injection of 0.1, 1, 5, 20 micrograms of muscimol, 0.01, 0.1, 0.3, 1 microgram of baclofen or normal saline. Percent of maximum possible effect (%MPE) and %area under the curve (%AUC) were calculated by transforming response threshold in TF and CD tests. Repeated measure ANOVA followed by Fisher's PLSD test were used for statistical analysis. Muscimol 0.1 microgram increased mean %MPE in TF test at 10 min to 15% but not in CD test. Muscimol 1, 5 and 20 micrograms significantly increased %MPE at 5 min in TF and CD tests. Muscimol 20 micrograms produced 100%MPE for 180 min after drug injection. Baclofen 0.1, 0.3 and 1 microgram significantly increased %MPE at 5 min in TF and CD test. Antinociceptive effect in TF test seems to be greater than that in CD test. Muscimol caused motor disturbance but baclofen did not. It is concluded that intrathecally administered muscimol and baclofen produced somatic and visceral antinociception in a dose dependent fashion.

Analgesics↗

PubMed1999

Tracking RPE transplants labeled by retroviral gene transfer with green fluorescent protein.

PURPOSE: To determine whether human retinal pigment epithelium (RPE) can be modified by retroviral-mediated gene transfer and to monitor the human RPE cells in the subretinal space of living rabbits with scanning laser ophthalmoscopy (SLO). METHODS: Cultured human fetal retinal pigment epithelium (HFRPE) was exposed to green fluorescent protein (GFP)-transducing retroviral vectors, Moloney murine leukemia virus, and lentivirus. The cultured cells were followed by fluorescence microscopy. Suspensions of GFP-expressing HFRPE were transplanted into the subretinal space of pigmented rabbits, and the transplant sites were examined by SLO for fluorescence, including fluorescein and indocyanine green angiography. The rabbits were euthanatized at different times after transplantation, and the retinas were studied histologically. RESULTS: Retroviral gene transfer can introduce a foreign gene such as GFP into cultured HFRPE. Gene expression is maintained in cultured RPE for at least 3 months. The lentiviral vector transduced both nondividing and dividing cells; the Moloney vector only transduced the latter. GFP-expressing cells can be followed in the living retina. Their changes reflect the rejection response followed histologically. CONCLUSIONS: Cultured HFRPE could be transduced to express GFP for long periods of time by retroviral gene transfer. GFP allowed retinal transplants and gene expression to be monitored in vivo. These results provide a model for potential ex vivo gene therapy in the subretinal space.

Animals↗

PubMed1999

[A report of 4 cases of aortic operation using open proximal anastomosis under the hypothermic circulatory arrest and left lateral exposure].

Four cases of aortic operations using open proximal anastomosis (OPA) under the hypothermic circulatory arrest (HCA) and left lateral approach (LLA) are reported. Three of 4 cases had extensive aortic disease from distal arch to descending thoracic aorta (Stanford type B chronic aortic dissection, double false aneurysms, and double true aneurysms). Another one case had ruptured aneurysm of thoracic aorta. LLA should have been selected in all cases, however, aortic proximal cross-clamp was impossible in them, because of giant pseudolumen, diseased lesion of aortic arch, hemothorax followed rupture of aneurysm. Therefore OPA under the HCA was performed. There were no complication associated with HCA, bleeding, neurological deficiency and respiratory dysfunction. We conclude that, although the HCA may have some problems, if there is the proper indication, OPA under the HCA is useful method at aortic operation for difficult aortic disease.

Adult↗

PubMed1999

[A case of pulmonary edema following upper airway obstruction after general anesthesia].

A 30-year-old man underwent tonsillectomy and laryngomicrosurgery under nitrous oxide oxygen-isoflurane anesthesia. Preoperative physical examinations and interview revealed no cardiopulmonary abnormalities. Two minutes after extubation, he showed dyspnea with marked inspiratory efforts and cyanosis due to laryngeal spasm. The SpO2 decreased from 100% to 80%. He was reintubated after administration of suxamethonium 100 mg and ventilated with 100% oxygen. At that time pink frothy sputum came out from his airway. He was diagnosed as pulmonary edema from analysis of arterial blood gases and chest X-ray. He received mechanical ventilation with positive end-expiratory pressure in the ICU. Twenty hours later the pulmonary edema was improved and he was extubated uneventfully. He was discharged from the hospital on the 8th post-operative day. We reported a case of pulmonary edema after laryngeal spasm. It was suggested that a patient after acute upper airway obstruction should be carefully treated considering secondary pulmonary edema.

Adult↗

PubMed1999

Does dilatation of the sinotubular junction cause aortic regurgitation?

BACKGROUND: Some patients develop aortic regurgitation (AR) in association with dilatation of the sinotubular junction (STJ), despite having normal aortic valve. However, the relationship between dilatation of the STJ and AR is unclear. METHODS: Canine hearts and aortas were isolated. A suture was placed in each commissure and in the sinus of Valsalva at the STJ. These interrupted sutures were drawn horizontally, and strain on the sutures was varied. The sites of the retracted sutures were changed to various positions, and the opening and closing of the aortic valve was observed endoscopically. A beating heart model was used to observe changes in aortic valve function during mechanical retraction of the commissures or sinuses. RESULTS: Opening area of the valve increased when strain on all sutures or commissures was increased. When strain was increased on the sinus alone, coaptation of the valve was not affected. CONCLUSION: We observed endoscopically that mechanical dilatation of the STJ causes AR. These findings suggest that the principal cause of AR associated with dilatation of the STJ is outward deviation of the commissure.

Animals↗

PubMed1999

Double muscle transfer for upper extremity reconstruction following complete avulsion of the brachial plexus.

Recent interest in reconstruction of the upper limb following brachial plexus injuries has focused on the restoration of prehension following complete avulsion of the brachial plexus. The authors use free muscle transfers for reconstruction of the upper limb to resolve the difficult problems in complete avulsion of the brachial plexus. This article describes the authors' updated technique--the double free muscle procedure. Reconstruction of prehension to achieve independent voluntary finger and elbow flexion and extension by the use of double free muscle and multiple nerve transfers following complete avulsion of the brachial plexus (nerve roots C5 to T1) is presented. The procedure involves transferring the first free muscle, neurotized by the spinal accessory nerve for elbow flexion and finger extension, a second free muscle transfer reinnervated by the fifth and sixth intercostal nerves for finger flexion, and neurotization of the triceps brachii via its motor nerve by the third and fourth intercostal motor nerves to extend and stabilize the elbow. Restoration of hand sensibility is obtained via the suturing of sensory rami from the intercostal nerves to the median nerve. Secondary reconstruction, including arthrodesis of the carpometacarpal joint of the thumb and glenohumeral joint, and tenolysis of the transferred muscle and distal tendons, improve the functional outcome. Based on the long-term result, selection of the patient, donor muscle, and donor motor nerve were indicated. Most patients were able to achieve prehensile functions such as holding a can and lifting a heavy box. This double free muscle transfer has provided prehension for patients with complete avulsion of the brachial plexus and has given them new hope to be able to use their otherwise useless limbs.

Adult↗

PubMed1999

[Bronchospasm during crush induction with propofol under the Sellick maneuver in a patient for emergency laparotomy].

A 61-year-old man was scheduled for an emergency laparotomy due to ileus. He had a history of asthma, but it was well controlled without medication. Anesthesia was induced with propofol and ketamine under the Sellick maneuver. Following administration of vecuronium, endotracheal intubation was performed. However, he could not be ventilated. We thought that the tube had been inserted into the esophagus, and re-intubation was performed. However he could not be ventilated as in the first trial. At that time, we suspected that bronchospasm had occurred. Bronchospasm improved rapidly using hyperventilation with 100% oxygen and 3-5% sevoflurane, and intravenous aminophylline. Because he had a history of asthma, propofol was relatively indicated from the point of smooth muscle relaxant effects. However we should consider the risk of bronchospasm in a patient with a history of asthma, even if we use propofol.

Anesthesia↗

PubMed1999

A point mutation (W70A) in the rod PDE-gamma gene desensitizing and delaying murine rod photoreceptors.

PURPOSE: To examine the corneal electroretinogram (ERG) of transgenic mice (W70A mice) carrying a point mutation (W70A) in the gene encoding for the gamma-subunit of rod cGMP phosphodiesterase (PDEgamma). METHODS: The ERG of W70A mice was compared with that of normal mice. Cone responses were separated from rod responses by light adaptation, whereas rod sensitivity was assessed by threshold stimulation with dim light. Spectral sensitivity curves of the ERG were obtained using a constant response criterion. RESULTS: The ERG of the W70A mouse has a desensitized, delayed rod b-wave at threshold, and a prolonged rod b-wave at higher flash intensities. The a-wave is absent even at maximal stimulation. The cone ERG of the W70A mouse is indistinguishable from that of normal mice. The spectral sensitivity of the W70A mouse is maximal in the UV spectrum, in contrast to the normal mouse, which is most sensitive in the green region of the spectrum. This supports the interpretation of the results as normal cone and abnormal rod function in the W70A mouse. CONCLUSIONS: The W70A mouse represents new model of stationary nyctalopia that can be recognized by its unusual ERG features.

3',5'-Cyclic-GMP Phosphodiesterases↗

PubMed1999

Sex-related differences in plasminogen activator and plasminogen activator inhibiting activities in young and aged rats.

The purpose of this study was to determine whether aging influences the sex-related differences in fibrinolytic activity in rats. We measured plasminogen activator (PA) activity and plasminogen activator inhibiting (PAI) activity in 5-, 12-, 45-, and 60-week-old male and female rats. We also examined the effects of gonadectomy and sex hormone-treatments in adult male and female rats. The increase in age did not influence the PA activity in the male or female rats. However, the PA activity was higher in the female rats than in the males in all four age groups. Orchidectomy caused a significant increase in PA activity in the male rats. Estradiol treatment induced a significant increase of PA activity in ovariectomized female rats. Testosterone treatment resulted in a decrease of PA activity in orchiectomized male rats. The increase in age had an effect on PAI activity; the activity level in the 45- and 60-week-olds was stronger than that in the 12-week-old rats. The PAI activity was not significantly different between the normal rats of each sex. Gonadectomy did not influence the PAI activity in male or female rats, and testosterone and estradiol treatments also did not affect PAI activity in gonadectomized male and female rats. We found that the increase in age induced a decrease in the fibrinolytic system in the rats, and that there were sex-related differences in the fibrinolytic system in even 60-week-old rats.

Aging↗

PubMed1999

A Greedy Algorithm for Minimizing the Number of Primers in Multiple PCR Experiments.

The selection of a suitable set of primers is very important for polymerase chain reaction (PCR) experiments. Most existing algorithms for primer selection are concerned with producing a primer pair for each DNA sequence. However, when all the DNA sequences of the target objects are already known, like the approximately 6,000 yeast ORFs, we may want to design a small set of primers to PCR amplify all the targets, which can then be resolved electrophoretically in a series of experiments. This would be quite useful, because decreasing the number of primers greatly reduces the cost of an experiment. This paper extends the problem of primer selection for a single experiment presented in Doi and Imai (Genome Informatics, 8:43-52, 1997) to primer selection for multiple PCR experiments, and proposes algorithms for the extended problem. The algorithms design primer sets one at a time. We extend the greedy algorithm for one PCR experiment in (Genome Informatics, 8:43-52, 1997) by handling amplified segments in DNA sequences that have been identified by primer pairs already selected and by changing the priorities in the greedy algorithm. This algorithm is applied to real yeast data. The number of primers equaled 85% of the number of identified DNA sequences, which represented more than 90% of all the target DNA sequences. This is 42% the number of primers needed for multiplex PCR. Furthermore, the length of each primer is less than half the length of multiplex PCR primers so the cost of producing the primers is reduced to 20% of the cost in the multiplex PCR case.

Journal Article↗

PubMed1999

Functioning muscle transplantation after wide excision of sarcomas in the extremity.

Free functioning muscle transplantation was performed after resection of 23 sarcomas in the extremity. There were 21 soft tissue sarcomas and two malignant bone tumors. The tumor resection was performed with a wide margin in all except two patients who had a marginal margin in a limited area. The consequent extensive soft tissue defect received free musculocutaneous flaps, the motor nerve of which was repaired in the recipient site. The most frequent procedure was latissimus dorsi transplantation to replace thigh muscles in 17 cases. The other donors included gracilis, tensor fascia lata, and rectus femoris, which were selected according to the site of defects. Patients were followed up for a mean of 60 months (range, 13-119 months). The grafted muscles showed reinnervation at a mean of 6 months postoperatively in all patients except for a 75-year-old patient. Obtained contraction of the muscles was powerful in 18 patients and fair in four patients. Performance of the salvaged limb significantly improved after recovery of the muscles. Although there were five distant recurrences, local recurrence was seen in one patient with systemic metastases. Because muscle loss could be compensated functionally for by the innervated free muscle transfer, the method encouraged surgeons to perform more radical tumor excisions and this may have contributed to the excellent local tumor control that was achieved. Thus, functioning muscle transplantation was extremely useful in limb salvage surgery from the functional and oncologic viewpoints.

Adolescent↗

PubMed1998

Gene encoding a replication initiator protein and replication origin of conjugative plasmid pSA1.1 of Streptomyces cyaneus ATCC 14921.

pSA1.1 is a 9.1-kb multicopy plasmid originally isolated from Streptomyces cyaneus (formerly S. azureus) ATCC 14921. This plasmid accumulates single-stranded DNA in S. lividans and is therefore considered to replicate by a rolling-circle replication. In the present work, the rep gene encoding the replication initiator protein and the replication origin ori of pSA1.1 were determined. The rep and ori are located on separate regions. The Rep protein of pSA1.1 belongs to superfamily I which includes A proteins of phages. Nucleotide sequence of the surrounding putative nicking site of pSA1.1 shows good agreement with those of the pC194 group plasmids and phages. The direction of replication was also determined.

Amino Acid Sequence↗

PubMed1998

BASH, a novel signaling molecule preferentially expressed in B cells of the bursa of Fabricius.

The bursa of Fabricius is a gut-associated lymphoid organ that is essential for the generation of a diversified B cell repertoire in the chicken. We describe here a novel gene preferentially expressed in bursal B cells. The gene encodes an 85-kDa protein, designated BASH (B cell adaptor containing SH2 domain), that contains N-terminal acidic domains with SH2 domain-binding phosphotyrosine-based motifs, a proline-rich domain, and a C-terminal SH2 domain. BASH shows a substantial sequence similarity to SLP-76, an adaptor protein functioning in TCR-signal transduction. BASH becomes tyrosine-phosphorylated with the B cell Ag receptor (BCR) cross-link or by coexpression with Syk and Lyn and associates with signaling molecules including Syk and a putative chicken Shc homologue. Overexpression of BASH results in suppression of the NF-AT activation induced by BCR-cross-linking. These findings suggest that BASH is involved in BCR-mediated signal transduction and could play a critical role in B cell development in the bursa.

Adaptor Proteins, Signal Transducing↗