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Biomedical subjects

Yoshiaki Okada

Publications and source records attributed to Yoshiaki Okada.

At least 37 records · Page 2Linked to original sources
PubMed2005

Cerebral density on CT immediately after a successful resuscitation of cardiopulmonary arrest correlates with outcome.

PURPOSE: To evaluate whether cerebral CT findings taken immediately after successful resuscitation from cardiopulmonary arrest (CPA) correlate with the outcome or not. MATERIAL AND METHODS: We analyzed retrospectively brain sections with the Housfield unit (CT number). Between May 2001 and March 2004, 16 consecutive patients, who recovered from CPA, were included as subjects in this study. They satisfied all of the following criteria: (a) a helical multislice head CT was performed within 1 h of the return of the spontaneous circulation (ROSC); (b) patients died within 24 h after ROSC, and any patients with trauma or cerebral vascular disease were excluded. The subjects were divided into two groups; those with a cerebral performance category of 1-3 (GR group) and those with a cerebral performance category of 4-5 (VD group). RESULTS: There were no significant differences between the two groups except for age. The average ventricle size on the brain CT showed no significant difference between the two groups. The average CT number of the putamen and cerebral cortex, and the corticomedullary contrast in the GR group were higher than those in the VD group. CONCLUSION: Although the influence of age cannot be disregarded, the CT number of the putamen and cortex, and also the corticomedullary contrast correlated with outcome of hypoxic encephalopathy even when cerebral CT was performed within 1 h after ROSC following CPA.

Aged↗
PubMed2005

Therapeutic hypothermia limited to the resuscitation period does not prolong survival after severe hemorrhagic shock in rats.

OBJECTIVE: Controlled hypothermia induced during hemorrhagic shock (HS) has been shown previously to improve survival in HS rat outcome models. We hypothesized that hypothermia (34 degrees C) induced immediately with reperfusion would also improve survival. METHODS: Twenty-four rats were lightly anesthetized with halothane and maintained spontaneous breathing. The rats underwent: an HS phase I of 75 min, with an initial blood withdrawal of 2.5 mL/100 g over 15 min, followed by either additional blood withdrawal or re-infusion in order to maintain a mean arterial pressure (MAP) of 30 mmHg over 60 min; a resuscitation phase II of 60 min with return of shed blood and infusion of lactated Ringer's solution to maintain a MAP of 75 mmHg; and an observation phase III without anesthesia for 72 h. Five minutes before the start of phase II, 12 rats were randomized into either a normothermia (38 degrees C) group or hypothermia (34 degrees C) group. The rectal temperature in each group was carefully maintained during the 60-min period of phase II. Survival at 72 h, as well as gut damage were assessed. RESULTS: All 24 rats survived beyond phases I and II. At 72 h, 8 of 12 rats survived in the hypothermia group, while and 6 of 12 survived in the normothermia group (p=0.64). Intestines of the 72 h survivors were macroscopically normal. In rats that died during phase III, total gut scores did not differ statistically between the groups (1.2+/-0.6 versus 1.0+/-0.9). CONCLUSION: Brief resuscitative hypothermia of 60 min duration induced immediately with reperfusion after HS did not improve survival in this model.

Animals↗
PubMed2005

Early diagnosis of hypovolemic shock by sonographic measurement of inferior vena cava in trauma patients.

BACKGROUND: The diameter of the inferior vena cava in trauma patients may be useful for evaluating hypovolemia. METHODS: Between June 2003 and September 2003, 35 injured patients transferred to the authors' hospital were prospectively investigated. They were divided into two groups: a shock group (n = 10) and a control group (n = 25). The maximum anteroposterior diameter of the inferior vena cava was measured using a sonography at arrival and on hospital day 5. RESULTS: The average diameter of the inferior vena cava in the shock group was significantly smaller than in the control group. There was no significant change in the diameter of the inferior vena cava in the control group, but significant change was seen in the shock group between arrival and hospital day 5. CONCLUSION: The diameter of the inferior vena cava was found to correlate with hypovolemia in trauma patients.

Adult↗
PubMed2005

Ionized magnesium in the cerebrospinal fluid of patients with head injuries.

BACKGROUND: In head injury patients, a decrease in the serum ionized magnesium (iMg) concentration is considered to be related to the severity of the injury, however, this phenomenon is still not completely understood. The cerebrospinal fluid (CSF) iMg concentration has not been well documented under such conditions and, moreover, its normal value has not yet been established. We hereby intended to investigate the role of the iMg concentration and other parameters in both the serum and CSF of head injury patients and identify any relationship with other parameters. MATERIALS AND METHODS: The subjects consisted of head injury patients without any other serious injuries. Ten healthy volunteers were selected as control subjects. Arterial blood and CSF specimens were simultaneously obtained and measured. We measured the Glasgow Coma Scale scores (GCS), the intracranial pressure (ICP), pH, po2, pco2, sodium, potassium, iCa, iMg, glucose, lactate, urea nitrogen. All data are expressed as the mean+/-SD and the units of iMg and iCa (corrected under pH 7.40) are given in mmol/L. RESULTS: In the healthy subjects, the iMg concentration in the serum/CSF was 0.48 +/- 0.02 / 0.66 +/- 0.14, and iCa was 1.14 +/- 0.05 / 0.94 +/- 0.07. The GCS of the 15 head injury subjects at examination was 8.7 +/- 4.5. When the subjects were divided into 3 groups according to the GCS level (3 and 4, 5-8, and > or =9) at the time of examination, the serum iMg concentration was thus found to be related to the severity of injury based on the GCS level (p = 0.028), but not the CSF iMg concentration (p = 0.89). No relationship was observed between the iMg concentration in the serum and CSF when all specimens were compared, but an extremely close correlation was seen in the group with GCS 3 and 4 (p < 0.0001, r = 0.995), although no such correlation was seen in the other 2 groups (p = 0.12, r = -0.56 in the group with GCS 5-8, and p = 0.26, r = -0.35 in the group with GCS > or = 9). There was a significant correlation between the serum iMg and iCa (p = 0.0093, r = 0.47), and also between the CSF iMg and iCa concentrations (p < 0.0001, r = 0.67). CONCLUSION: The serum iMg concentration has been suggested to possibly affect the neurologic state through CSF iMg in patients with the most severe head injury. In patients with moderate or mild head injuries, however, the ionized magnesium concentration is also probably associated with the degree of neurologic deficit based on the ionized calcium level. The CSF and serum ionized magnesium dissociation may thus result from the slow movement of ionized magnesium through the blood brain barrier.

Adolescent↗
PubMed2005

Photoacoustic diagnosis of burns in rats.

BACKGROUND: Accurate burn depth assessment is important for determining the appropriate treatment plan for severe burn patients. However, conventional methods of diagnoses, such as visual observation and pinprick test, are often inaccurate. We previously proposed a new method for burn diagnosis in which photoacoustic signals originating from the blood in healthy tissue under the injured tissue are measured. In this study, we investigated the validity of this method by an experiment using rat scald burn models. METHODS: Superficial dermal burns (SDBs), deep dermal burns (DDBs), and deep burns (DBs) were made in the dorsal skin of rats by using a Walker-Mason template. Wounds were irradiated with low-energy, 550-nm, nanosecond pulsed light, and photoacoustic signals induced were measured with a piezoelectric film as a function of postburn time. Measurement in normal skin as a control was also performed. Temporal profiles of the photoacoustic signals were converted into depth profiles using sound velocity of tissue, and for each profile, a peak showing highest signal intensity was selected. For this peak, the depth at which the signal rose (signal rise depth) and the depth that gave a peak value (signal peak depth) were recorded. Statistical analysis was performed to clarify the difference in depth information of signals between burn groups. RESULTS: Depth profiles of photoacoustic signals showed unique features depending on the degree of burn; pronounced peaks shifted to deeper tissue as the burn severity increased. This indicates that the zone of stasis formed due to injuries can be monitored. There were significant differences in both the signal rise depth and the peak depth between the control and SDB groups, SDB and DDB groups, and DDB and DB groups (p < 0.001). CONCLUSION: SDBs, DDBs, and DBs can be differentiated by photoacoustic signals, suggesting that the method proposed is useful for diagnosing burn injuries.

Acoustics↗
PubMed2005

Unfavorable outcome of burn patients with neuropsychiatric disorders.

To assess the outcome of burn patients with neuropsychiatric disorders, we performed a 7-year retrospective review of burn patients admitted to the National Defense Medical College. Seventy-seven skin burn patients over 10 years of age were included in this study and divided into two groups, neuropsychiatry and control groups. The neuropsychiatry group consisted of self-inflicted burn patients (n=21) and burn patients with a neurological disorder (n=18), who could not move away from burning source due to neurological problems. The control subjects (n=38) had been healthy before burn. No significant differences in the age, gender or causes of burn were observed between the two groups. Notably, total burned surface area, area of full-thickness burn, and mortality are greater in the neuropsychiatry group than those in the control. However, after matching the patients for the severity of burn injuries, the above parameters show no significant differences between the two groups. Therefore, the outcome of the burned patients depends on the patients' will and ability to move away from the burning source. Whenever we treat severe burn patients, we should assess their neuropsychiatric conditions.

Accidents, Home↗
PubMed2005

Differences in the outcomes and treatments of extensively burned patients between a Chinese hospital and a Japanese hospital.

To know the therapeutic level at one's own institute is important and contributes to improving the treatment of patients. We compared the outcomes of extensively burned patients between a Chinese hospital and a Japanese hospital in order to identify the differences in the clinical treatment of severe burn patients. Thirty-four burn patients who were admitted to the National Defense Medical College Hospital (NDMC) in Japan and 95 burn patients who were admitted to the Changhai Hospital of the Second Military Medical University (SMMU) in China from January 1999 to December 2003 were studied. All patients were transported to the respective hospitals within 3 days after suffering burns and their total body surface area of burns was greater than 20%. Fourteen of the 34 patients (41.2%) at NDMC hospital and 1 of the 95 patients (1.1%) at SMMU hospital were injured by attempted suicide; namely, the suicide rate was significantly higher in the patients at NDMC hospital (p < 0.001). Moreover, the age (p = 0.005) and inhalation rate (p = 0.013) were significantly higher at NDMC hospital than those at SMMU hospital. Consequently, the survival rate at SMMU was higher than at NDMC in the patients with a burn surface area of greater than 80% or with a burn index of greater than 60. The excellent outcomes of the extensively burned patients at SMMU were in part due to the fact that Chinese doctors tend to perform an immediate tracheostomy and a traditional Chinese operation with alloskin, called microskin grafting or intermingled skin grafting.

Adolescent↗
PubMed2005

Type I odontoid fracture--case report.

A 17-year-old man presented with sleeping tendency, tenderness of the back of the neck, and left upper monoplegia after a motorcycle accident. Three-dimensional computed tomography on the 2nd hospital day clearly revealed a type I odontoid fracture. His injuries were treated conservatively and he was discharged on the 60th hospital day, with sequelae due to the cervical root avulsion injuries. Type I odontoid fracture is rare and may be caused by coronal distraction of the head and neck area.

Adolescent↗
PubMed2005

[Case of suicide by hanging complicated by cerebral sinus thrombosis].

A 43-year-old male with respiratory arrest due to neck hanging was resuscitated at the scene. The head CT on arrival showed diffuse brain swelling predominantly in the right cerebral hemisphere. The swelling improved but right transverse sinus thrombosis was recognized on the 4th hospital day. His conscious state gradually recovered and recanalization of the sinus was confirmed on a subsequent MR venography. He was discharged without neurological deficit. A sinus thrombosis should be considered as a differential diagnosis of brain swelling after hanging.

Adult↗
PubMed2005

[A case of catatonia associated with the ingestion of hydroxyzine].

A twenty-six-year male who presented with a consciousness disturbance induced by the ingestion of an estimated 7g of hydroxyzine. He demonstrated bipolar symptoms which consisted of both stupor and excitement, and both an increase in muscle tension and apnea, however, these symptoms improved after the infusion of diazepam. He was diagnosed to demonstrate catatonia. After treatment composing three days of mechanical ventilation in combination with the administration of sedatives and muscle relaxatants, his symptoms improved. Hydroxyzine is thus considered to be able to induce catatonia and this mechanism of this condition is discussed.

Adult↗
PubMed2005

Reactivity of genotypically distinct hepatitis B virus surface antigens in 10 commercial diagnostic kits available in Japan.

Hepatitis B virus (HBV) surface antigen (HBsAg) is one of the most important serological markers of current HBV infection. However, there are significant antigenic variations of HBsAg caused by genotypic diversity as well as mutation of the HBV genome. It is predictable that amino acid substitutions occurring in the HBsAg "a" determinant of a particular HBV genotype will affect the sensitivity of some diagnostic kits, since all the diagnostic kits currently available utilize monoclonal and/or polyclonal antibodies against the "a" determinant. One possible concern is that there may be a significant variation in the sensitivity of HBsAg diagnostic kits to HBsAg encoded by HBV of different genotypes, which might result in a failure to detect HBsAg of a particular HBV genotype. In this study, we assessed the reactivity of HBsAg specimens derived from three different HBV genotypes (A, B, and C) that are prevalent in Japan by 10 commercially available EIA (enzyme immunoassay), CLIA (chemiluminescent immunoassay), and CLEIA (chemiluminescent enzyme immunoassay) diagnostic kits. Specimens included both clinical samples and recombinant HBsAg. Our results showed that all the diagnostic kits evaluated were able to detect HBsAg irrespective of HBV genotypes. At the same time, it is apparent that some, but not all of the kits showed clear differences in sensitivity to the three HBV genotypes.

Genotype↗
PubMed2005

[A case of a dramatic recovery of hypertensive hemorrhage in the mid-pons].

A 50-year-old female who had a past history of non-treated hypertension, demonstrated a coma on arrival. CT revealed a high density lesion measuring 23 mm in transverse diameter and 15 mm in height at the ventral mid pons without breaking into a fourth ventricle or extending to the midbrain. She required mechanical ventilation support. Her consciousness improved on the 2nd hospital day. She showed tetra-plegia, which was especially dominant on her right side. Her symptoms gradually improved until she could stand and she was eventually discharged on the 41st hospital day. At 90 days after the initial presentation, an enhanced head MRI showed the absorption of the hematoma and no existence of any vascular malformation was observed. We herein report a case who dramatically recovered from a hypertensive pontine hemorrhage, despite the fact that she demonstrated several risk factors for a poor prognosis. The fact that the size of the hematoma was not so huge, and the location of the hematoma spared both the ascending reticular activating system and the nuclei, may explain the favorable outcome in this case.

Cerebral Hemorrhage↗
PubMed2005

[Clinical feature of organophosphate poisoning patients requiring prolonged mechanical ventilation].

OBJECTIVE: To clarify the clinical characteristics in organophosphate poisoning patients who require prolonged mechanical ventilation (PMV). MATERIAL AND METHODS: We reviewed the medical records of 15 adults organophsophate poisoning patients who admitted to our intensive care unit between Junuary, 1995, and December, 2004. The patients were divided into two groups: a PMV group requiring mechanical ventilation for more than 1 week (n=7) and a non PMV group (n=8), and various factors relating to PMV were compared between the two groups. RESULTS: The mean value of mechanical ventilation days was 16 +/- 6 days for the PMV group, which was significantly greater than 1 +/- 1 days for the non PMV group (p < 0.01). There were no statistical differences in the physical findings such as Japan Coma Scale, vital signs, and salivation and/or diarrhea, and in the treatments such as gastric lavage, administration of activated charcoal, and intravenous administration of pralidoxim and/or atropine on admission between the groups. The intermediate syndrome developed in 5 patients of the PMV group during their hospital course, whereas in no patient of the non-PMV group (p < 0.05). Hospital length of stay was 35 +/- 7 days in the PMV group, comparing with 11 +/- 11 days in the non-PMV group (p < 0.01). All patients of both groups survived and all but one patient returned to pre-hospital activities of daily living. CONCLUSIONS: Organophosphate poisoning patients requiring PMV had a higher incidence of the intermediate syndrome, but had similar mortality and morbidity compared with patients without PMV.

Adult↗
PubMed2004

Upstream stimulatory factors stimulate transcription through E-box motifs in the PF4 gene in megakaryocytes.

Platelet factor 4 (PF4) is expressed during megakaryocytic differentiation. We previously demonstrated that the homeodomain proteins (myeloid ecotropic integration site 1 [MEIS1], Pbx-regulating protein 1 [PREP1], and pre-B-cell leukemia transcription factors [PBXs]) bind to the novel regulatory element tandem repeat of MEIS1 binding element [TME] and transactivate the rat PF4 promoter. In the present study, we investigated and identified other TME binding proteins in megakaryocytic HEL cells using mass spectrometry. Among identified proteins, we focused on upstream stimulatory factor (USF1) and USF2 and investigated their effects on the PF4 promoter. USF1 and 2 bound to the E-box motif in the TME and strongly transactivated the PF4 promoter. Furthermore, physiologic bindings of USF1 and 2 to the TME in rat megakaryocytes were demonstrated by the chromatin immunoprecipitation (ChIP) assay. Interestingly, the E-box motif in the TME was conserved in TME-like sequences of both the human and mouse PF4 promoters. USF1 and 2 also bound to the human TME-like sequence and transactivated the human PF4 promoter. Expressions of USF1 and 2 were detected by reverse-transcriptase-polymerase chain reaction (RT-PCR) in the human megakaryocytes derived from CD34+ cells. Thus, these studies demonstrate that the novel TME binding transcription factors, USF1 and 2, transactivate rat and human PF4 promoters and may play an important role in megakaryocytic gene expression.

Amino Acid Motifs↗
PubMed2004

Serum cortisol as a predictive marker of the outcome in patients resuscitated after cardiopulmonary arrest.

OBJECTS: To analyze the relationship between stress hormones (arginine vasopressin (ADH), adrenocorticotropic hormone (ACTH) and cortisol and the outcome of patients resuscitated after cardiopulmonary arrest (CPA). METHODS: Thirty-six patients were enrolled in this study. In 36 of the resuscitated cases, 27 were non-survivors and 9 survived. The survival group was defined as cases either in a persistent vegetative state, with some disability or good recovery 1 month after return of spontaneous circulation (ROSC). The non-survival group was defined as cases who died within 1 month. RESULTS: The plasma ADH and ACTH levels and the serum cortisol levels in both the surviving and the non-surviving patients were 82.3+/-74.5 and 149.6+/-135.4 (pg/ml), 239.7+/-327.4 and 282.4+/-553.0 (pg/ml), 34.1+/-11.2 and 19.0+/-12.8 (g/ml) (mean+/-S.D., respectively). The plasma ADH and ACTH levels showed no significant difference between the two groups. The serum cortisol levels were significantly higher in survivors than in the non-survivors (P=0.029). We also used the receiving-operating characteristics (ROC) curves to evaluate the optimal cutoff value of the concentration of serum cortisol as a predictive maker of non-surviving patients. The cutoff value of 16.7 g/ml for the concentrations of serum cortisol was a 1.00 positive predictive value and a 1.00 specificity at a 0.519 negative predictive and a 0.409 sensitivity for predicting non-surviving patients. The area under the ROC curve was calculated to be 0.858 at a prevalence of 0.58. The plasma ADH levels correlated significantly and positively with the plasma ACTH levels (r=0.516, P<0.0010). CONCLUSIONS: We concluded that the serum cortisol levels were significantly higher in survivors than in non-survivors resuscitated after CPA.

Adrenocorticotropic Hormone↗
PubMed2004

Reversible blindness associated with alcoholic ketoacidosis.

PURPOSE: To report a case of reversible blindness associated with severe alcoholic ketoacidosis. DESIGN: Observational case report. METHODS: A 44-year-old male presented with gradual bilateral blindness that developed within a 24-hour period. He suffered from ethanol-induced severe ketoacidosis and shock and was resuscitated with epinephrine and sodium bicarbonate. RESULTS: The treatment of acidosis led to a rapid resolution of the patient's blindness. CONCLUSIONS: It is important to understand the role of severe acidosis as the sole causative factor of reversible bilateral blindness.

Adult↗
PubMed2004

Surgical treatment of liver injury with microwave tissue coagulation: an experimental study.

OBJECTIVE: The purpose of this study was to examine whether microwave tissue coagulation (MTC) therapy is capable of stopping bleeding from severe liver injury in pigs. METHODS: Ten pigs (38 +/- 4 kg) underwent a 30-mL/kg isovolemic exchange transfusion with 3% low-molecular-weight dextran to produce dilutional coagulopathy, and then a through-and-through laceration injury measuring approximately 8 cm in length was induced in the right hepatic lobe. Immediately after inflicting the injury, the animals were randomly divided into two groups: Group A (n = 5, MTC was repeated along the liver laceration at intervals of 2.0 cm with manual compression) or Group B (n = 5, the injured lobe was manually compressed without MTC therapy for 1 minute). All animals received lactated Ringer's solution to maintain the mean arterial pressure at 75 mm Hg for 1 hour after the abdominal closure. The intraperitoneal blood loss, mean arterial pressure, volume of lactated Ringer's solution, and hematologic variables were compared between the groups. For further laboratory evaluation, three additional experimental animals were treated with the MTC therapy after inflicting the injury and then were allowed to survive for 14 days. RESULTS: Mean arterial pressure declined from a mean value of 88 +/- 10 mm Hg (range, 75-107 mm Hg) to 62 +/- 3 mm Hg (range, 50-75 mm Hg) after the induction of liver injury. The total blood loss in Group A was 192 +/- 58 g (range, 120-250 g), which was lower (p < 0.01) than that of 448 +/- 138 g (range, 260-650 g) in Group B. The resuscitation fluid volume of Group A animals was 304 +/- 204 mL (range, 100-600 mL), which was smaller (p < 0.01) than that of 1,320 +/- 654 mL (range, 900-2,250 mL) in Group B. At 14 days, all three animals that were treated in the additional study were found to be in good health. Their necropsies showed no evidence of an intrahepatic abscess, hematoma, or biloma. CONCLUSION: MTC therapy was thus found to provide simple, rapid, and definitive hemorrhage control in cases of severe liver injury without the need for reoperation.

Animals↗