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Masanori Tamura

Publications and source records attributed to Masanori Tamura.

15 recordsLinked to original sources
PubMed2006

Neonatal management of trisomy 18: clinical details of 24 patients receiving intensive treatment.

Management of neonates with trisomy 18 is controversial, supposedly due to the prognosis and the lack of precise clinical information concerning efficacy of treatment. To delineate the natural history of trisomy 18 managed under intensive treatment, we reviewed detailed clinical data of 24 patients with full trisomy 18 admitted to the neonatal intensive care unit of Nagano Children's Hospital, providing intensive treatment to those with trisomy 18, from 1994 to 2003. Cesarean, resuscitation by intubation, and surgical operations were performed on 16 (67%), 15 (63%), and 10 (42%) of the patients, respectively. Mechanical ventilation was required by 21 (88%), and 6 (29%) of them were extubated. Survival rate at age 1 week, 1 month, and 1 year was 88%, 83%, and 25%, respectively. Median survival time was 152.5 days. Respiration was not stabilized in two patients with left diaphragmatic eventration and hypoplasia accompanied by lung hypoplasia, even with maximal ventilation. The common underlying factors associated with death were congenital heart defects and heart failure (96%), followed by pulmonary hypertension (78%). The common final modes of death were sudden cardiac or cardiopulmonary arrest (26%) and possible progressive pulmonary hypertension-related events (26%). These data of improved survival, through neonatal intensive treatment, are helpful for clinicians to offer the best information on treatment options to families of patients with trisomy 18.

Birth Weight↗
PubMed2006

Liquid incubator with perfluorochemicals for extremely premature infants.

OBJECTIVES: Maintenance of appropriate body temperature, humidification and prevention of skin injury are very important in the management of extremely premature infants with immature skin. We have developed a new closed liquid incubator, utilising the characteristics of perfluorochemical (PFC) liquids, i.e., high specific gravity and chemical and biological inertness. The potential of this incubator to control body temperature was evaluated in rats. METHODS: PFC liquid (FC43; 3M Company, Tokyo, Japan) within the incubator was heated or cooled and the rectal temperature of each rat and the PFC temperature were monitored. RESULTS: The rectal temperature of rats floating on the PFC liquid surface changed almost in parallel to the temperature of PFC within the incubator, indicating that this technique can be used to warm or cool adults rats in a stable manner. The relative humidity of air within the incubator was maintained constant at 100%. CONCLUSIONS: The liquid incubator used in the present study maintained an environment with a relative humidity of 100% and allowed stable maintenance of temperature in adult rats. We also demonstrated that heating and cooling the PFC liquid allowed control of body temperature. Although further studies are required, this new incubator may be useful for the clinical management of extremely premature infants.

Animals↗
PubMed2005

Partial liquid ventilation with low-dose perfluorochemical and high-frequency oscillation improves oxygenation and lung compliance in a rabbit model of surfactant depletion.

BACKGROUND: Partial liquid ventilation (PLV) with perfluorochemical (PFC) has been advocated as a new therapy for acute respiratory distress syndrome in both clinical and animal studies, meconium aspiration syndrome, and RDS. PFC is referred to as liquid PEEP because it gets distributed to the most gravity-dependent regions of the lung due to its density. High-frequency oscillation (HFO) has been shown to prevent both acute and chronic lung injury in the management of very low birth weight infants with RDS, with gentle ventilation approach. Specifically, HFO with aggressive and adequate lung volume recruitment has been shown to reduce the incidence of chronic lung disease in very low birth weight infants. We hypothesized that PLV along with HFO might be effective in ARDS in an adult rabbit model. OBJECTIVES: To examine the efficiency of low-dose PLV with with HFO on pulmonary gas exchange and lung compliance in a surfactant-depleted rabbit model. METHODS: After induction of severe lung injury by repeated saline lung lavage, 19 adult white Japanese rabbits were randomized into two groups that received PLV with HFO (n=9) or HFO gas ventilation (n=10). Physiological and blood gas data were compared between the two groups by analysis of variance. RESULTS: The HFO-PLV group showed improved total lung compliance with maintenance of significantly lower mean airway pressure as compared with the HFO-GAS group so as to keep SpO2>90%. CONCLUSIONS: The addition of a low dose of PFC with HFO was effective in achieving adequate oxygenation, with a reduction in further lung injury in neonates.

Animals↗
PubMed2005

Chest wall mesenchymal hamartoma associated with a massive fetal pleural effusion: a case report.

Abstract We report on an extremely rare chest wall mesenchymal hamartoma associated with a massive fetal pleural effusion. Prenatal ultrasound examination demonstrated a heterogeneous mass in the right thorax associated with a massive pleural effusion and right lung compression at 29 weeks of gestation. The patient underwent pleuroamniotic shunting at 30 weeks and was delivered at 33 weeks by cesarean delivery secondary to fetal distress. After management of the respiratory distress and evaluation of the mass, surgery was performed at day of life 8. Histological examination confirmed the diagnosis of a chest wall mesenchymal hamartoma.

Adult↗
PubMed2005

[Interleukin 12 measurement in the cerebrospinal fluid of infants with purulent meningitis].

We measured IL-12 concentrations in the CSF of patients with purulent meningitis. Twenty-three infants who were admitted between 1997 and 2003 and diagnosed as having purulent meningitis were included in this study. All patients in this study were admitted by the 3rd day of illness. After admission, appropriate antibiotics were administered to all infants. Two infants died and two other infants developed cerebral palsy and mental retardation (adverse outcome group). None of the other patients showed any neurologic abnormalities at discharge (good outcome group). As a control group, 16 infants who were diagnosed with diseases other than purulent meningitis were also investigated. The CSF IL-12 p40 concentrations in meningitis infants on admission (median [range], 1,890 [< 15-7,770] pg/ml) were significantly higher compared with those in the control group (p < 0.001). Among infants with meningitis, there were no significant differences on admission between patients with adverse outcome group and those with good outcome group. Consecutive measurements were performed in 17 infants with meningitis including the 2 infants with adverse outcome group. The concentration in the infants with adverse outcome group seemed to decrease more gradually than that in those with good outcome group. IL-12 induces production of interferon-gamma, which enhances the function of polymorphonuclear leukocytes. IL-12 may contribute to local host defenses in the subarachnoid space.

Cerebral Palsy↗
PubMed2004

Periventricular low intensities on fluid attenuated inversion recovery imaging in the newborn infant: relationships to the clinical data and long-term outcome.

BACKGROUND: The author's previous study showed that it is possible to predict the severity of white matter injury in early infancy by using fluid attenuated inversion recovery (FLAIR) imaging. A follow-up study was performed in order to assess the correlation between the incidence of periventricular low intensities on FLAIR imaging (F-PVLI) and the clinical data including the physiological variables at birth and the long-term outcome of the infant. METHODS: The authors reviewed MRI of 328 newborn infants, which were obtained before 2 months corrected age. Abnormal findings in the periventricular white matter and other part of the brain were recorded. Periventricular abnormal intensities were sorted into four groups according to the FLAIR grade, which comprised normal, F-PVLI 1 (focal), F-PVLI 2 (extensive), cystic periventricular leukomalacia (C-PVL), and diffused leukomalacia. RESULTS: Significantly more periventricular abnormal intensities were detected by FLAIR imaging than by conventional T1 and T2 weighted imaging. In the groups of F-PVLI 2 and C-PVL, the birth weight (BW), gestational age (GA), blood pH and base excess at birth were significantly lower than in the normal group. However, when the study population was defined into very low birth weight infants, F-PVLI 2 had significantly larger BW and GA than normal. The FLAIR grade had a strong correlation with the developmental outcome at 12 and 36 months corrected age. CONCLUSIONS: F-PVLI is a silent but very important white matter injury, which has many features in common with C-PVL. FLAIR imaging could be a strong tool in screening newborn infants at high risk of neurological impairment.

Cerebral Ventricles↗
PubMed2004

Periventricular low intensities on fluid attenuated inversion recovery imaging in the newborn infant: Relationships to chronic white matter lesions.

BACKGROUND: Neurological disadvantages due to hypoxic ischemic encephalopathy (HIE) are still very serious problems. In order to support the infant with HIE, it is important to evaluate the severity of the brain injury early. The authors performed a magnetic resonance imaging (MRI) study of the neonatal brain in order to assess the clinical value of periventricular low intensities (PVLI) detected on fluid attenuated inversion recovery (FLAIR) imaging. METHODS: A total of 451 MRI from 167 preterm and 113 term infants were sorted into groups according to the corrected age at the time of scanning. Intensities in the white matter were then divided into five grades according to the severity of the finding on FLAIR imaging. Chronic abnormalities such as periventricular hyperintensities (PVHI) were also analyzed. RESULTS: In early MRI, which was obtained before 2 months corrected age, the incidence of PVLI was 63%, while it was only 3% and 0% in the middle (2-8 months) and the late (8-18 months) scans, respectively. Instead of PVLI, PVHI were commonly observed both on late FLAIR imaging (89%) and late T2-weighted imaging (72%). The severity of the white matter damage diagnosed on early FLAIR imaging had a significant correlation with that of late FLAIR imaging. CONCLUSIONS: F-PVLI on early FLAIR imaging would be a good predictor of chronic white matter damage. FLAIR imaging would be also useful in follow-up of infants because of its high sensitivity to the chronic white matter lesion.

Cerebral Ventricles↗
PubMed2003

Brain temperature in newborn piglets under selective head cooling with minimal systemic hypothermia.

BACKGROUND: Although selective brain hypothermia is expected to be a promising neuroprotective treatment, the thermal distribution under hypothermia is not fully investigated. We applied selective head cooling to seven newborn piglets under general anesthesia in order to investigate the mechanism of cooling. METHODS: Seven healthy, large white piglets aged within 5 days after birth were studied. Temperatures were monitored at the superficial brain (0.5 cm), deep brain (2.0 cm), scalp skin, nasopharynx, tympanum, esophagus, and rectum. A radiant heater and a warmer blanket were used to maintain the normal rectal temperature (38.5-39 degrees C). For the first piglet, the coolant temperature was widely changed from 15 degree C to - 20 degree C in order to define the practical range. Subsequently, the coolant temperature was set at 10 degree C, 0 degree C, and - 10 degree C for the remaining six piglets. The target deep brain temperature was set at 35 degree C, as the same reduction of brain temperature might provide moderate brain hypothermia in the human neonate. RESULTS: With 0 degree C coolant temperature, the deep brain temperature was cooled to 35 degree C; however, the scalp skin attached to the cooling cap became broadly blotchy and injured in all animals. When we induced minimal systemic hypothermia by 1C for a cohort of three piglets, the deep brain temperature decreased in parallel with the rectal temperature, which enabled us to achieve the target temperature with 10 degrees C coolant without injuring the scalp skin. The scalp skin and nasopharyngeal temperatures were good predictors of both superficial and deep-brain temperatures throughout the experiment. CONCLUSIONS: Our results suggest that moderate brain hypothermia may be applied to newborn infants without inducing moderate systemic hypothermia.

Animals↗
PubMed2003

Early head cooling in newborn piglets is neuroprotective even in the absence of profound systemic hypothermia.

BACKGROUND: Selective head cooling in the newborn infant has been proposed as a neuroprotective treatment with a lower level of systemic adverse effect than that of systemic hypothermia. However, the efficacy is not confirmed as well as that of systemic hypothermia. In order to analyze the safety and efficacy of selective head cooling, 25 newborn piglets were randomly selected for either normothermic or hypothermic treatment. METHODS: Global hypoxic insult was induced by lowering the oxygen concentration to the maximal level to maintain the background electroencephalogram (EEG) voltage under 7 microV for 45 min. The core temperature of normothermic piglets was maintained between 38.5 degrees C and 39 degrees C, while prophylactic cooling was applied to the hypothermic piglets at the same time of the insult. Very mild systemic hypothermia by 1 degrees C was induced in addition to selective head cooling with 10 degrees C coolant temperature. Animals were killed for histopathological examination seven hours after the end of the insult. RESULTS: Two normothermic piglets died while all hypothermic piglets survived. Neuropathological findings were significantly severer in the normothermic group than in the hypothermic group. Intracranial pressure was significantly lower, and EEG recovery was significantly better in the hypothermic piglets. There was no significant difference in the lowest oxygen concentration, degrees of acidosis, blood lactate, and blood pressure between the groups, although heart rate was significantly lower in the hypothermic group. CONCLUSIONS: We have demonstrated that early head cooling was effective in preventing some of the earliest brain damage due to hypoxic insult even in the absence of profound systemic hypothermia.

Animals↗
PubMed2002

Continuous venovenous hemodiafiltration in neonatal onset hyperammonemia.

We report on four cases of neonatal-onset hyperammonemia due to metabolic disorders treated with continuous hemodiafiltration (CHDF). CHDF accomplished prompt removal of serum ammonia under very stable circulation. To overcome the various difficulties of blood purification procedures to the neonate, we used: (1) a 7-Fr double lumen catheter from the internal jugular vein to the atrium to perform the procedure veno-venously, (2) a special circuit for neonates, (3) nafamostat mesilate as an anticoagulant, and (4) a circuit warmer. The serum ammonium level decreased under 200 microg/dL within 30 hours and lactic acidosis were corrected immediately. We conclude that CHDF is an extremely effective and safe treatment for fluminant neonatal-onset hyperammonemia due to metabolic disorders.

Adult↗
PubMed2002

Partial liquid ventilation with low dose of perflubron and a low stretch ventilation strategy improves oxygenation in a rabbit model of surfactant depletion.

To demonstrate the efficacy of partial liquid ventilation (PLV) with a low dose of perflubron (PFB), severe lung injury model followed surfactant-depleted rabbits underwent PLV with either moderate tidal volume (V(T)) and high positive end-expiratory pressure (PEEP) or high V(T) and low PEEP. PLV with low-dose PFB was effective in alleviating hypoxia in a severe lung injury model if adequate PEEP was applied. We concluded that the addition of a low dose of PFB might be beneficial to a low stretch ventilation strategy, which allows a less aggressive approach to achieve adequate oxygenation with a possible reduction in further lung injury.

Animals↗