Two Cases of Bronchial Artery Racemose Hemangioma Successfully Treated with Bronchial Artery Embolization

Rupture of a racemose hemangioma causing dilatation and tortuosity of the bronchial artery can result in massive bleeding and respiratory failure. Bronchial artery embolization (BAE) can treat this life-threatening condition, as we show in two cases. The first case was of an 89-year-old female complaining of sudden-onset chest and back pain. Bronchial artery angiography demonstrated a racemose hemangioma with a 2 cm aneurysm. The second case was of a 50-year-old male with hemoptysis and dyspnea, eventually requiring intubation. Bronchial arteriography showed a racemose hemangioma and a bronchial artery-pulmonary arterial fistula. BAE was successfully performed in both cases, with no recurrent hemorrhage. Therapeutic interventions in bronchial artery racemose hemangiomas include lobectomy or segmentectomy, bronchial arterial ligation, and BAE. BAE should be considered as first-line therapy for bleeding racemose hemangiomas of the bronchial artery because of its low risk of adverse effects on respiratory status, minimal invasiveness, and faster patient recovery.

Treatment of Geriatric Traumatic Brain Injury: A Nationwide Cohort Study

BACKGROUND

Because of the aging of the Japanese population, traumatic brain injuries (TBI) have increased in elderly adults. However, the effectiveness and prognosis of intensive treatment for geriatric TBI have not yet been determined. Thus, we used nationwide data from the Japan Neurotrauma Data Bank (JNTDB) projects to analyze prognostic factors for intensive and aggressive treatments.

METHODS

We analyzed 1,879 geriatric TBI cases (age ≥65 years) registered in four JNTDB projects: Project 1998 (P1998) to Project 2015 (P2015). Clinical features, use of aggressive treatment, and 6-month outcomes on the Glasgow Outcome Scale (GOS) were compared among study projects. Logistic regression was used to identify prognostic factors in aggressively treated patients.

RESULTS

The percentage of geriatric TBI cases significantly increased with time-P1998: 30.1%; Project 2004 (P2004): 34.6%; Project 2009 (P2009): 43.9%; P2015: 53.6%, p<0.0001). Use of aggressive treatment also significantly increased, from 67.0% in P1998 to 69.3% in P2015 (p<0.0001). Less invasive methods, such as trepanation and normothermic targeted temperature management, were more often chosen for geriatric patients. These efforts resulted in a significant decrease in the 6-month mortality rate, from 76.2% in P1998 to 63.1% in P2015 (p=0.0003), although the percentage of severely disabled patients increased, from 8.9% in P1998 to 11.1% in P2015 (p=0.0003). Intraventricular hemorrhage was the factor most strongly associated with unfavorable 6-month outcomes (OR 3.79, 95% CI 1.78-8.06, p<0.0001).

CONCLUSIONS

Less invasive treatments reduced mortality in geriatric TBI but did not improve functional outcomes. Patient age was not the strongest prognostic factor; thus, physicians should consider characteristics other than age.

Feasibility of Human Neural Stem Cell Transplantation for the Treatment of Acute Subdural Hematoma in a Rat Model: A Pilot Study

Human neural stem cells (hNSCs) transplantation in several brain injury models has established their therapeutic potential. However, the feasibility of hNSCs transplantation is still not clear for acute subdural hematoma (ASDH) brain injury that needs external decompression. Thus, the aim of this pilot study was to test feasibility using a rat ASDH decompression model with two clinically relevant transplantation methods. Two different methods, in situ stereotactic injection and hNSC-embedded matrix seating on the brain surface, were attempted. Athymic rats were randomized to uninjured or ASDH groups (F344/NJcl-rnu/rnu, n = 7-10/group). Animals in injury group were subjected to ASDH, and received decompressive craniectomy and 1-week after decompression surgery were transplanted with green fluorescent protein (GFP)-transduced hNSCs using one of two approaches. Histopathological examinations at 4 and 8 weeks showed that the GFP-positive hNSCs survived in injured brain tissue, extended neurite-like projections resembling neural dendrites. The in situ transplantation group had greater engraftment of hNSCs than matrix embedding approach. Immunohistochemistry with doublecortin, NeuN, and GFAP at 8 weeks after transplantation showed that transplanted hNSCs remained as immature neurons and did not differentiate toward to glial cell lines. Motor function was assessed with rotarod, compared to control group (n = 10). The latency to fall from the rotarod in hNSC in situ transplanted rats was significantly higher than in control rats (median, 113 s in hNSC vs. 69 s in control, P = 0.02). This study first demonstrates the robust engraftment of in situ transplanted hNSCs in a clinically-relevant ASDH decompression rat model. Further preclinical studies with longer study duration are warranted to verify the effectiveness of hNSC transplantation in amelioration of TBI induced deficits.

Quantitative pupillometry and neuron-specific enolase independently predict return of spontaneous circulation following cardiogenic out-of-hospital cardiac arrest: a prospective pilot study

This study aimed to identify neurological and pathophysiological factors that predicted return of spontaneous circulation (ROSC) among patients with out-of-hospital cardiac arrest (OHCA). This prospective 1-year observational study evaluated patients with cardiogenic OHCA who were admitted to a tertiary medical center, Nippon Medical School Hospital. Physiological and neurological examinations were performed at admission for quantitative infrared pupillometry (measured with NPi-200, NeurOptics, CA, USA), arterial blood gas, and blood chemistry. Simultaneous blood samples were also collected to determine levels of neuron-specific enolase (NSE), S-100b, phosphorylated neurofilament heavy subunit, and interleukin-6. In-hospital standard advanced cardiac life support was performed for 30 minutes.The ROSC (n = 26) and non-ROSC (n = 26) groups were compared, which a revealed significantly higher pupillary light reflex ratio, which was defined as the percent change between maximum pupil diameter before light stimuli and minimum pupil diameter after light stimuli, in the ROSC group (median: 1.3% [interquartile range (IQR): 0.0–2.0%] vs. non-ROSC: (median: 0%), (Cut-off: 0.63%). Furthermore, NSE provided the great sensitivity and specificity for predicting ROSC, with an area under the receiver operating characteristic curve of 0.86, which was created by plotting sensitivity and 1-specificity. Multivariable logistic regression analyses revealed that the independent predictors of ROSC were maximum pupillary diameter (odds ratio: 0.25, 95% confidence interval: 0.07–0.94, P = 0.04) and NSE at admission (odds ratio: 0.96, 95% confidence interval: 0.93–0.99, P = 0.04). Pupillary diameter was also significantly correlated with NSE concentrations (r = 0.31, P = 0.027). Conclusively, the strongest predictors of ROSC among patients with OHCA were accurate pupillary diameter and a neuronal biomarker, NSE. Quantitative pupillometry may help guide the decision to terminate resuscitation in emergency departments using a neuropathological rationale. Further large-scale studies are needed.

Relation between extracellular Chemistry and Patient Outcome for Severe Traumatic Brain Injury within the First 24 hours: A Microdialysis Study

Object Many studies have reported that extracellular chemistry is related to the outcome of patients with traumatic brain injury (TBI). No study has reported that extracellular chemistry predicts outcome in less than 3 days. Moreover, in other studies, both focal brain and diffuse brain injuries have been often discussed. The authors focused on the relationship between extracellular chemistry in a shorter period and the outcome of patients with focal brain injury.

Methods By using intracerebral microdialysis monitoring, extracellular fluid concentrations of glucose, lactate, glycerol, glutamate, lactate/pyruvate (L/P), and lactate/glucose (L/G) were determined in 30 patients with severe TBI for initial 24 hours. The results were analyzed between favorable and unfavorable, and between survival and mortality.

Results The medians of glycerol and L/P in the favorable group were significantly lower than those in the unfavorable group (124 µmol/L vs. 808 µmol/L, p = 0.002; 31 vs. 48, p = 0.021, respectively). All parameters apart from glutamate differed significantly between the survival and mortality groups (glucose, 25 mmol/L vs. 77 mmol/L, p = 0.035; lactate, 38 mmol/L vs. 73 mmol/L, p = 0.018; glycerol, 168 µmol/L vs. 1462 µmol/L, p = 0.002; glutamate, 14 µmol/L vs. 95 µmol/L, p = 0.019; L/P, 32 vs. 124, p < 0.001; L/G, 1.46 vs. 4.52, p = 0.004).

Conclusion Cerebral extracellular glycerol and L/P was the most reliable predictor of outcomes in patients with focal brain injury and can discriminate between favorable and unfavorable outcomes for the first 24 hours, using the threshold of 200 and 40, respectively.

Treatment Strategies of Subarachnoid Hemorrhage from Bilateral Vertebral Artery Dissection: A Case Report and Literature Review Focusing on the Availability of Stent Placement

BACKGROUND

Bilateral vertebral artery dissection (VAD) may result in subarachnoid hemorrhage (SAH). However, a variety of factors contribute to the difficulties with treating SAH. We report a case of bilateral VAD with SAH, as well as a literature review.

CASE DESCRIPTION

A 32-year-old woman developed headache. Computed tomography demonstrated diffuse SAH, and 3-dimensional computed tomography indicated bilateral VAD. Her left vertebral artery was severely stenosed, and the basilar artery retrogradely flowed via the posterior communicating artery. Her bilateral VAD was trapped with the use of staged craniotomy. The postoperative course was uneventful for 13 days; however, severe neurologic deterioration remained in the area of the cerebral infarction, due to vasospasm of the internal carotid artery. This is the first report of hemorrhagic bilateral VAD treated with bilateral trapping and aggressive spasm treatment in the acute phase. However, the treatment was not successful.

CONCLUSIONS

Because of the increasing use of stent therapy, there has been a shift toward this treatment choice. For cases in which stents cannot be used, treatment methods based on prestenting protocols are helpful. A literature review indicated that conservative treatment for 2 weeks, in which vasospasm and rebleeding are controlled, may be considered compared with acute-stage stent treatment. Following our literature review, in situations in which stents cannot be used, only the ruptured side should be trapped with strict blood pressure control and detailed radiological images should be observed for 2 weeks. In conclusion, patient selection is essential to subject the patient to open surgery in such cases.

Outcome and Refractory Factor of Intensive Treatment for Geriatric Traumatic Brain Injury: Analysis of 1165 Cases Registered in the Japan Neurotrauma Data Bank

OBJECTIVE

With the increase in the aged population, geriatric traumatic brain injury (gTBI) is also rapidly increasing in Japan. There is thus a need to review the effect of intensive treatments for gTBIs. The aim of this study was 1) to assess how intensive treatments influenced patient outcome and 2) to identify the refractory factor against these intensive treatments in gTBI, from the Japan Neurotrauma Data Bank (JNTDB).

METHODS

Of all 3194 patients in the JNTDB, 1165 (≥ 65 years old) with severe gTBIs were enrolled in this study. The clinical features and their outcomes based on the Glasgow Outcome Scale on discharge and 6 months after injury were compared.

RESULTS

Intensive treatments were administered to 71.4% of all patients with severe gTBI showing a significant increase over 15 years. Accordingly, mortality decreased significantly (from 62.7% to 51.1%, P = 0.001). On the other hand, severely disabled dependent survivors, who need daily help from others for living, increased accordingly (from 63.2% to 68.4%). The existence of intraventricular hemorrhage (IVH) rather than the patient's age was identified as the strongest refractory factor (odds ratio, 5.762; 95% confidence interval, 1.317-25.216) against intensive treatment.

CONCLUSIONS

This study clarified that 1) intensive treatments are associated with higher survival rates (however, they also increase the incidence of severely disabled survivors) and 2) the strongest refractory factor for intensive treatment in cases of severe gTBI was not age but the existence of IVH. These results warrant further establishment of a seamless strategy for both the acute and the chronic phase of gTBI.

Association between serum lactate levels and early neurogenic pulmonary edema after nontraumatic subarachnoid hemorrhage

BACKGROUND AND PURPOSE

Few studies have described the risk factors associated with the development of neurological pulmonary edema (NPE) after subarachnoid hemorrhage (SAH). We have hypothesized that acute-phase increases in serum lactate levels are associated with the early development of NPE following SAH. The aim of this study was to clarify the association between lactic acidosis and NPE in patients with nontraumatic SAH.

METHODS

We retrospectively evaluated 140 patients with nontraumatic SAH who were directly transported to the Nippon Medical School Hospital emergency room by the emergency medical services. We compared patients in whom NPE developed (NPE group) and those in whom it did not (non-NPE group).

RESULTS

The median (quartiles 1-3) arrival time at the hospital was 32 minutes (28-38 minutes) after the emergency call was received. Although the characteristics of the NPE and non-NPE groups, including mean arterial pressure (121.3 [109.0-144.5] and 124.6 [108.7-142.6] mm Hg, respectively; P=0.96), were similar, the median pH and the bicarbonate ion (HCO3(-)) concentrations were significantly lower in the NPE group than in the non-NPE group (pH, 7.33 [7.28-7.37] vs. 7.39 [7.35-7.43]); P=0.002; HCO3(-), 20.8 [18.6-22.6] vs. 22.8 [20.9-24.7] mmol/L; P=0.01). The lactate concentration was significantly higher in the NPE group (54.0 [40.3-61.0] mg/dL) than in the non-NPE group (28.0 [17.0-37.5] mg/dL; P<0.001). Multivariable regression analysis indicated that younger age and higher glucose and lactate levels were significantly associated with the early onset of NPE in patients with SAH.

CONCLUSION

The present findings indicate that an increased serum lactate level, occurring within 1 hour of the ictus, is an independent factor associated with the early onset of NPE. Multicenter prospective studies are required to confirm our results.

Traumatic cerebrovascular injury following severe head injury: proper diagnostic timetable and examination methods

Traumatic cerebrovascular injury (TCVI) is a serious complication of severe head injury, with a high mortality rate. To establish a proper treatment strategy for TCVI, we investigated patients with a high risk of TCVI according to the Guidelines for the Management of Severe Head Injury (hereafter "the Guidelines") to elucidate the validity of the criteria for TCVI in the Guidelines and the appropriate screening timing and methods. Of those transported to our facility between December 2008 and June 2012, 67 individuals with a high risk of TCVI were evaluated to reveal the proper timing and methods of vascular evaluation. Of the 67 patients, 21 had a diagnosis of TCVI based on cerebral angiography, three-dimensional computed tomography angiography (3DCTA), or magnetic resonance imaging (MRI), accounting for 6.4% of all patients with severe head injury and as high as 31.3% of patients with a high risk of TCVI according to the Guidelines. In addition, according to the Glasgow Outcome Scale (GOS), outcomes were three deaths due to primary brain injury, six cases of persistent vegetative state, five cases of severe disability, three cases of moderate disability, and four cases of good recovery. Although 3DCTA is a simple and convenient diagnostic method, cerebral angiography is necessary to evaluate dissecting lesions. If patients have any signs or symptoms of TCVI, as described in the Guidelines, cerebral angiography or 3DCTA should be performed as an initial screening method within 72 hours of admission, followed by cerebral angiography on postadmission Day 14 ± 2 to prevent failed diagnosis.

Measurement of inflammatory cytokines and thrombomodulin in chronic subdural hematoma

Inflammation and the coagulation system may influence the genesis of chronic subdural hematoma (CSDH). The appearance of CSDH on computed tomography (CT) varies with the stage of the hematoma. This study investigated the pathogenesis and the recurrence of CSDH by comparing cytokine levels with the CT features of CSDH in 26 patients with 34 CSDHs who underwent single burr-hole surgery at our hospital between October 2004 and November 2006. The hematoma components removed during the procedure were examined, and the hematoma serum levels of cytokines measured such as thrombomodulin (TM), interleukin-6 (IL-6), tumor necrosis factor-α (TNFα), and interleukin-10 (IL-10). Using CT, mixed density hematomas were distinguished from other homogeneous hematomas, and found that the TM level was significantly higher in mixed density hematomas than in homogeneous hematomas (p = 0.043). Mixed density hematomas were classified into three subtypes (laminar, separated, and trabecular hematomas). The TM level was significantly higher in laminar and separated hematomas than in other hematomas (p = 0.01). The levels of IL-6, TNFα, and IL-10 were extremely high, but showed no significant differences in relation to the CT features. Mixed density hematomas had high recurrence rate, as reported previously, and TM level was high in mixed density hematomas such as laminar and separated mixed density hematomas. The present findings suggest that the types of CSDH associated with high TM levels tend to have higher recurrence rate.

[Risk factors of heatstroke]

In recent years, there has been an increased tendency for heatstroke to occur. A rise in mean temperature and the occurrence of extreme high temperatures and fine weather are environmental factors of risk. The prevalence of heatstroke characteristically increases before the passing of the rainy season, and approximately three times more men than women are susceptible. The age-specific distribution of heatstroke is bimodal and peaks at 10-20 and 50-60 years of age. For effective heatstroke prevention, however, many factors such as work environment and everyday life environment must be taken into account.

Medical relief activities conducted by Nippon Medical School in the acute phase of the Great East Japan Earthquake 2011

At 14:46 on March 11, 2011, the Great East Japan Earthquake and tsunami occurred off the coast of Honshu, Japan. In the acute phase of this catastrophe, one of our teams was deployed as a Tokyo Disaster Medical Assistance Team (DMAT) to Kudan Kaikan in Tokyo, where the ceiling of a large hall had partially collapsed as the result of the earthquake, to conduct triage at the scene: 6 casualties were assigned to the red category (immediate), which included 1 case of cardiopulmonary arrest and 1 of flail chest; 8 casualties in the yellow category (delayed); and 22 casualties in the green category (minor). One severely injured person was transported to our hospital. Separately, our medical team was deployed to Miyagi 2 hours after the earthquake in our multipurpose medical vehicle as part of Japan DMAT (J-DMAT). We were the first DMAT from the metropolitan area to arrive, but we were unable to start medical relief activities because the information infrastructure had been destroyed and no specific information had yet reached the local headquarters. Early next morning, J-DMAT decided to support Sendai Medical Center and search and rescue efforts in the affected area and to establish a staging care unit at Camp Kasuminome of the Japan Self-Defense Force. Our team joined others to establish the staging care unit. Because information was still confused until day 3 of the disaster and we could not adequately grasp onsite medical needs, our J-DMAT decided to provide onsite support at Ishinomaki Red Cross Hospital, a disaster base hospital, and relay information about its needs to the local J-DMAT headquarters. Although our medical relief teams were deployed as quickly as possible, we could not begin medical relief activities immediately owing to the severely damaged information infrastructure. Only satellite mobile phones could be operated, and information on the number of casualties and the severity of shortages of lifeline services could be obtained only through a "go and see" approach. Because there was no way to transmit or receive this vital information, disaster workers in the affected areas faced many challenges. For the future, network data links need to be made more resistant to infrastructure damage, and redundant or reach-back systems involving multitiered satellite, wireless, and radio frequency data links would provide definitive solutions. Such integrated systems should be designed around seamless connectivity based on an "always best connected" principle for maintaining communication quality.

Lower extracellular glucose level prolonged in elderly patients with severe traumatic brain injury: a microdialysis study

Age may be an independent predictor of outcomes in traumatic brain injury (TBI), but the causes of the poor outcomes in elderly patients remain unclear. To clarify the differences between elderly and young patients with TBI, brain metabolism parameters were monitored with the microdialysis method in 30 patients with severe TBI (Glasgow Coma Scale scores 3-8). The microdialysis probe was inserted in the penumbra area of the brain and extracellular levels of glucose, glutamate, glycerol, lactate, and pyruvate were measured hourly for the initial 168 hours (7 days) after operation. The lactate/pyruvate ratio, which is considered to be a good indicator of neuronal ischemia, was also calculated. The patients were divided into the elderly group aged 65 years or older and the young group aged less than 65 years, and the biochemical markers were compared daily between these two groups. The value of extracellular glucose concentration was significantly lower in the elderly group than in the young group, and continued until the 7th day after injury. Moreover, the lactate/pyruvate ratio peaked on the 5th day after injury in the elderly group, later than in the young group. We concluded that neural vulnerability persisted longer in elderly patients than in young patients with TBI, and this should be considered to prevent the occurrence of additional secondary brain injury.

Clinical analysis of spinal cord injury with or without cervical ossification of the posterior longitudinal ligament, spondylosis, and canal stenosis in elderly head injury patients

Patients with degenerative diseases of the cervical spine, such as ossification of the posterior longitudinal ligament, spondylosis, and canal stenosis, sometimes present with acute spinal cord injury caused by minor trauma. However, the relative risk of cervical cord injury with these diseases is unknown. The clinical and radiological features of 94 elderly patients with head injury, 57 men and 37 women aged from 65 to 98 years (mean 76.6 years), were retrospectively analyzed to assess the association of spinal cord injury with degenerative cervical diseases. Degenerative cervical diseases were present in 25 patients, and spinal cord injury was more common in the patients with degenerative diseases (11/25 patients) than in the patients without such diseases (3/69 patients; relative risk = 10.2). The incidence of degenerative cervical diseases seems to be increasing in Japan because life expectancy has increased and the elderly are a rapidly growing part of the population. A fall while walking or cycling is a common mechanism of head injury and/or cervical cord injury in the elderly. To decrease the occurrence of cervical myelopathy, prevention by increasing social awareness and avoiding traffic accidents and falls is important.

Cerebral vasospasms after intraventricular hemorrhage from an arteriovenous malformation: case report

A 33-year-old female presented with a rare case of severe vasospasm following the rupture of an arteriovenous malformation (AVM) without subarachnoid hemorrhage. Initial computed tomography (CT) revealed a subcutaneous hematoma and cast formation of intraventricular clots without the deposition of subarachnoid blood in any basal cistern. Cerebral angiography revealed a small AVM located in the right parietal lobe without aneurysmal formations. Repeat CT demonstrated no evidence of subarachnoid clots expected with the presence of intraventricular clots and she was transferred to a general ward. She suffered sudden onset of motor aphasia and disturbance of consciousness on Day 17 after the hemorrhage. Magnetic resonance imaging indicated diffuse cortical infarction and subsequent magnetic resonance angiography revealed severe narrowing of the bilateral internal carotid arteries. Three-dimensional CT angiography on the same day indicated similar findings. She was transferred back to the intensive care unit for critical treatment. However, she suffered persistent mild right hemiparesis and motor aphasia. The characteristic features of vasospasm after intraventricular hemorrhage from AVMs are delayed onset, acute deterioration of consciousness, female predominance, and localization to the bilateral internal carotid arteries. Treatment of patients with AVM rupture should consider the risk of severe vasospasm, even if there is no subarachnoid clot.

[Symmetrical bilateral epidural hematoma after head injury in the mid parietooccipital region: case report]

The authors presented a patient with acute symmetrical bilateral epidural hematomas, which are rare but life threatening. A 72-year-old male accidentally fell from the roof at a height of about 3 meters and hit his head against the ground. He was transferred to the emergency ward in our hospital. On admission, he was alert and had no neurological deficits. Skull X-ray film revealed a depressed fracture in the mid parietoocipital region and bilateral linear fractures extending from the parietal regions to the temporal regions. CT scan showed symmetrical bilateral epidural hematomas in the both parietotemporal regions. His consciousness deteriorated to be drowsiness about one hour after admission. An additional CT scan revealed enlargement of the both epidural hematomas and impending tentorial herniation. Therefore, an emergency operation was called for. For rapid decompression of the brain, bilateral craniotomies were carried out simultaneously by the two neurosurgeon-groups involved and bilateral epidural hematomas were also simultaneously removed. Injury of both of the middle meningeal arteries was revealed to be the cause of the bilateral epidural hematomas. Clinical course after operation was uneventful and the patient was discharged without any neurological deficit. Simultaneous bilateral craniotomies and removal of the epidural hematomas would have contributed to obtaining the good result in this patient.

LIGHT, a member of the TNF superfamily, induces morphological changes and delays proliferation in the human rhabdomyosarcoma cell line RD

LIGHT is a member of the tumor necrosis factor (TNF) superfamily, which binds two known receptors, lymphotoxin-beta receptor (LTbetaR) and the herpesvirus entry mediator (HVEM)/TR2. We investigated the effects of LIGHT on the human rhabdmyosarcoma cell line RD. LIGHT delayed cell proliferation and induced morphological changes of the cells. These effects were not shown by other TNF family ligands such as TNFalpha and LTalpha, which induced the transcriptional activity of nuclear factor-kappaB (NF-kappaB) and NF-kappaB-responsible chemokine productions in the same manner as did LIGHT. LTalpha1beta2, another TNF family ligand for LTbetaR, was shown to have similar activities in RD cells as LIGHT. Both LIGHT and LTalpha1beta2 induced the expression of muscle-specific genes such as smooth muscle (SM) alpha-actin, while TNFalpha and LTalpha did not. These findings indicate that LIGHT may be a novel inducer of RD cell differentiation associated with SM alpha-actin expression through the LTbetaR.

Evaluation of posttreatment response of hepatocellular carcinoma with contrast-enhanced coded phase-inversion harmonic US: comparison with dynamic CT

PURPOSE

To assess the reliability of contrast material-enhanced real-time gray-scale ultrasonography (US) in evaluating posttreatment response of hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Fifty HCC nodules were examined with contrast-enhanced coded phase-inversion harmonic US before and after treatment. Intratumoral vascularity was assessed with continuous imaging in the early arterial phase and with interval-delay scanning to depict tumor parenchymal flow during the blood pool phase. Vascular findings at US were compared with those at dynamic computed tomography (CT).

RESULTS

In 50 HCC nodules before treatment, positive enhancement of tumor vessels and tumor parenchymal flow (stain) were observed in 47 (94%) and 46 (92%), respectively. Either tumor vessel or stain was visualized with coded harmonic US in 49 of 50 nodules. Eighty-one coded harmonic US studies were performed in 49 posttreatment HCC nodules. Compared with dynamic CT, the sensitivity, specificity, and accuracy of coded harmonic US in helping to detect positive enhancement in pretreatment HCC were 98% (49 of 50), 100% (50 of 50), and 98% (49 of 50), respectively. After treatment, positive enhancement of tumor vascularity was observed in 39 (48%) of 81 posttreatment studies, and no enhancement was observed in others (52%). Coded harmonic US demonstrated partial and no enhancement of tumor vascularity in four and one nodule, respectively; after transcatheter arterial embolization with iodized oil, evaluation of tumor vascularity with dynamic CT was difficult because of the presence of oil.

CONCLUSION

With enhancement, coded harmonic US depicted tumor vascularity by showing tumor vessels in a real-time fashion at continuous imaging and tumor parenchymal flow at interval-delay scanning.

Characteristics and distribution of endogenous RFamide-related peptide-1

We have recently identified RFamide-related peptide (RFRP) gene that would encode three peptides (i.e., RFRP-1, -2, and -3) in human and bovine, and demonstrated that synthetic RFRP-1 and -3 act as specific agonists for a G protein-coupled receptor OT7T022. However, molecular characteristics and tissue distribution of endogenous RFRPs have not been determined yet. In this study, we prepared a monoclonal antibody for the C-terminal portion of rat RFRP-1. As this antibody could recognize a consensus sequence among the C-terminal portions of rat, human, and bovine RFRP-1, we purified endogenous RFRP-1 from bovine hypothalamus on the basis of immunoreactivity to the antibody. The purified bovine endogenous RFRP-1 was found to have 35-amino-acid length that corresponds to 37-amino-acid length in human and rat. We subsequently constructed a sandwich enzyme immunoassay using the monoclonal antibody and a polyclonal antibody for the N-terminal portion of rat RFRP-1, and analyzed the tissue distribution of endogenous RFRP-1 in rats. Significant levels of RFRP-1 were detected only in the central nervous system, and the highest concentration of RFRP-1 was detected in the hypothalamus. RFRP-1-positive nerve cells were detected in the rat hypothalamus by immunohistochemical analyses using the monoclonal antibody. In culture, RFRP-1 lowered cAMP production in Chinese hamster ovary cells expressing OT7T022 and it was abolished by pre-treatment with pertussis toxin, suggesting that OT7T022 couples G(i)/G(o) in the signal transduction pathway.

Establishment of an optimized set of 406 microsatellite markers covering the whole genome for the Japanese population

Microsatellites, an essential tool for genetic linkage analyses, are selected in genetic studies on the basis of both informativeness and their positions with respect to one another on the genetic map. In order to establish a microsatellite marker set useful for linkage studies in the Japanese population, we first genotyped 64 unrelated Japanese subjects, using 400 microsatellite markers from a commercially available set (ABI PRISM Linkage Mapping Set-MD10) and then determined the allelic frequencies and heterozygosities for these marker loci in the population. In order to optimize the set, we replaced 41 markers having a heterozygosity lower than 0.6 with as many informative markers in the corresponding loci, and newly added six markers in the set to minimize the several gaps found at intervals of over 20 cM. We finally established a set comprising 406 microsatellites with average intervals of 9cM (maximum, 17 cM) and minimum heterozygosities of over 0.6 (mean, 0.76). All data generated in this study, including the specific polymerase chain reaction (PCR) primer sequences of the newly added markers, are freely available to all researchers at our web site. The genetic tool established here should facilitate genetic linkage studies of various hereditary diseases, especially in the Japanese.

Metastin suppresses the motility and growth of CHO cells transfected with its receptor

We recently reported having identified of the ligand for an orphan G-protein-coupled receptor, hOT7T175, as the gene product (68-121)-amide of the metastasis suppressor gene KiSS-1. We further showed that the ligand, which we named "metastin," inhibits chemotaxis and invasion of Chinese hamster ovary (CHO) cells transfected with hOT7T175 cDNA (CHO/h175) in vitro, and pulmonary metastasis of hOT7T175-transfected B16-BL6 melanomas in vivo. In the present study, we investigated the activity of metastin in CHO/h175 cells in greater detail. Metastin significantly suppressed motility in a chemotaxis assay and wound healing assay at 10-100 nM order concentrations. Two N-terminally truncated peptides, metastin(40-54) and metastin(45-54) inhibited the migration of CHO/h175 cells as potently as metastin itself. Metastin also inhibited the spreading, monolayer growth and colony formation in agar (0.8%) of CHO/h175 cells at 10-100 nM concentrations. These results indicate that metastin is a potent inhibitor of cell motility, leading to suppression of cell growth and antimetastatic activity, and suggest that low molecular chemical compounds could replace its activity as a novel antimetastatic agent.

Sonographic diagnosis of pancreatic islet cell tumor: value of intermittent harmonic imaging

We describe a case of nonfunctioning islet cell tumor of the pancreas diagnosed preoperatively by intermittent harmonic power Doppler imaging and digital subtraction gray-scale harmonic imaging and the use of the contrast agent SH U 508A (Levovist). Hypervascularity and tumor perfusion were clearly demonstrated with both harmonic imaging techniques in the early arterial phase. Sonographic findings were confirmed by other modalities and by histopathologic examination.

In vitro activity of linezolid against Gram-positive uropathogens of hospitalized patients with complicated urinary tract infections

The antimicrobial activity of linezolid, a recently developed antibiotic agent active against Gram-positive bacteria, was tested against pathogens from three different collections. (1) Uropathogens from hospitalized urological patients (1990/1991) with complicated and/or hospital-acquired UTIs; Urologic Clinic, Hospital St. Elisabeth, Straubing. (2) Uropathogens from a multi-centre study (1995/1996) comprising 37 urological centres throughout Germany. (3) MRSA isolates of patients and staff (1999/2000) within the Hospital St. Elisabeth, Straubing. Genotyping of the latter isolates was performed by pulsed-field-electrophoresis. The minimal inhibitory concentrations (MIC) of linezolid determined by an agar (Isosensitest) dilution method using a multipoint inoculator and an inoculum of 10(4) cfu per point ranged for methicillin susceptible Staphylococcus aureus (MSSA) (n=27) between 2 and 4 mg/l, for methicillin resistant S. aureus (MRSA) (n=35) between 1 and 2 mg/l, for methicillin susceptible coagulase-negative staphylococci (CNS) (MSSE) (n=67) between 0.5 and 4 mg/l, for methicillin resistant CNS (MRSE) (n=19) between 0.25 and 2 mg/l, for Enterococcus. faecalis (n=184) between 0.5 and 4 mg/l, for E. faecium (n=3) 2 mg/l and for Streptococcus spp. (n=4) between 0.25 and 1 mg/l, indicating that all strains were susceptible. According to the in vitro activity, linezolid may be considered a promising antibacterial agent for the treatment of complicated UTI caused by Gram-positive uropathogens. Thus, linezolid should be evaluated in a clinical study.

Hepatocellular carcinoma: depiction of tumor parenchymal flow with intermittent harmonic power Doppler US during the early arterial phase in dual-display mode

PURPOSE

To assess the effectiveness of contrast material-enhanced intermittent harmonic Doppler ultrasonography (US) in depicting tumor vessels and tumor parenchymal flow (stain) in hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Fifty-eight patients with 65 HCC nodules were examined by using intermittent harmonic power Doppler US and digital subtraction harmonic B-mode US, both with intravenous administration of SH U 508A. Vascular findings at early arterial phase harmonic US were classified as positive enhancement or nonenhancement, depending on the tumor vascularity relative to the surrounding liver parenchyma. These results were compared with those of three-phase helical dynamic computed tomography (CT).

RESULTS

For hypervascular HCCs, there was excellent depiction of tumor vessels and tumor stain with the two intermittent harmonic US methods. The sensitivity and specificity for depiction of tumor vascularity were 93% (41 of 44 nodules) and 100% (21 of 21), respectively, with intermittent harmonic power Doppler US and 86% (38 of 44) and 100% (21 of 21), respectively, with subtraction US, as compared with these values at dynamic CT. Attenuation was an important factor in the depictability of tumor vascularity at harmonic US.

CONCLUSION

Contrast-enhanced intermittent harmonic US enables noninvasive demonstration of tumor vessels and especially tumor stain in HCC.

Stimulation effect of galanin-like peptide (GALP) on luteinizing hormone-releasing hormone-mediated luteinizing hormone (LH) secretion in male rats

Galanin-like peptide (GALP) is a recently isolated hypothalamic peptide which has sequence homology to galanin and binds to galanin receptors with high affinity. It has been shown that GALP neurons are localized in the arcuate nucleus and that GALP-immunoreactive fibers are in close apposition with LHRH neurons in the medial preoptic area (MPA). In the present study, we found that intracerebroventricular (icv) administration of GALP increased the plasma LH level but did not change the levels of other hormones. Concomitantly, accumulation of c-Fos protein was dramatically increased in the nuclei of LHRH-positive cells in the MPA by icv GALP administration. Furthermore, the GALP-induced plasma LH response was completely abolished by pretreatment with Cetrorelix, a LHRH receptor antagonist. On the other hand, GALP did not affect the release of LH, FSH, TSH, ACTH, GH or PRL directly from dispersed rat pituitary cells in vitro. These results strongly suggest a role for GALP in the control of gonadotropin secretion through a hypothalamic mechanism involving the release of LHRH.

The generation and characterization of a cell line derived from a sporadic renal angiomyolipoma: use of telomerase to obtain stable populations of cells from benign neoplasms

Angiomyolipomas are benign tumors of the kidney derived from putative perivascular epithelioid cells, that may undergo differentiation into cells with features of melanocytes, smooth muscle, and fat. To gain further insight into angiomyolipomas, we have generated the first human angiomyolipoma cell line by sequential introduction of SV40 large T antigen and human telomerase into human angiomyolipoma cells. These cells show phenotypic characteristics of angiomyolipomas, namely differentiation markers of smooth muscle (smooth muscle actin), adipose tissue (peroxisome proliferator-activator receptor gamma, PPARgamma), and melanocytes (microophthalmia, MITF), thus demonstrating that a single cell type can exhibit all of these phenotypes. These cells should serve as a valuable tool to elucidate signal transduction pathways underlying renal angiomyolipomas.

A novel secreted tumor antigen with a glycosylphosphatidylinositol-anchored structure ubiquitously expressed in human cancers

In a search for novel genes expressed in human cancers, we identified one gene from an assembled expressed sequence tag database. Northern blot analysis revealed that the gene, termed alcan, was expressed in various types of human cancer cell lines and in the fetus, but not in normal tissues. The alcan gene is located on chromosome 6 and is encoded on a 246-amino-acid protein with weak homology to classical major histocompatibility complex class I. Its gene product, ALCAN, had hydrophobic amino acid clusters at both the N- and C-terminal regions and was predicted to be a glycosylphosphatidylinositol (GPI)-anchored membrane protein. Flow cytometric analysis revealed that ALCAN was detected on the surface of human cancer cells and on alcan-transfected CHO-K1 cells. ALCAN was also secreted from these cells, suggesting that some portion of the molecules was secreted by enzymatic cleavage by, for example, phospholipases. Mutational analysis of ALCAN suggested that the GPI-anchored position was the Ser(216) residue. These findings indicate that ALCAN may be a potential target for cancer diagnosis or therapy.

Cloning of a novel G protein-coupled receptor, SLT, a subtype of the melanin-concentrating hormone receptor

A DNA fragment encoding an amino acid sequence possessing common features to the G protein-coupled receptor (GPCR) superfamily was found in the human genomic sequence, and from this information, the full-length cDNA of a novel GPCR, designated SLT, was cloned from the human hippocampus cDNA library. SLT showed the highest homology to the melanin-concentrating hormone (MCH) receptor, SLC-1 (31.5% identity), and to a lesser extent, to the somatostatin (SST) receptor subtypes. MCH exhibited agonistic behavior when applied to the SLT-expressing CHO cells at subnanomolar doses whereas more than 200 known peptides, including SST and cortistatin, did not. These results indicated that MCH is the cognate ligand of the SLT receptor and that this newly cloned GPCR is the second subtype of the MCH receptor. Quantitative polymerase chain reaction analysis of the SLT gene expression in human tissues showed that the SLT receptor is expressed mainly in brain areas including the cerebral cortex, amygdala, hippocampus, and corpus callosum, as well as in a limited number of peripheral tissues. The distribution of the SLT nearly overlapped that of SLC-1, suggesting that some of the neural functions of MCH may be mediated by both of these receptor subtypes.

Metastasis suppressor gene KiSS-1 encodes peptide ligand of a G-protein-coupled receptor

Metastasis is a major cause of death in cancer patients and involves a multistep process including detachment of cancer cells from a primary cancer, invasion of surrounding tissue, spread through circulation, re-invasion and proliferation in distant organs. KiSS-1 is a human metastasis suppressor gene, that suppresses metastases of human melanomas and breast carcinomas without affecting tumorigenicity. However, its gene product and functional mechanisms have not been elucidated. Here we show that KiSS-1 (refs 1, 4) encodes a carboxy-terminally amidated peptide with 54 amino-acid residues, which we have isolated from human placenta as the endogenous ligand of an orphan G-protein-coupled receptor (hOT7T175) and have named 'metastin'. Metastin inhibits chemotaxis and invasion of hOT7T175-transfected CHO cells in vitro and attenuates pulmonary metastasis of hOT7T175-transfected B16-BL6 melanomas in vivo. The results suggest possible mechanisms of action for KiSS-1 and a potential new therapeutic approach.

Possible risk reduction in esophageal cancer associated with MPO -463 A allele

Myeloperoxidase (MPO), an enzyme found in lysosomes of phagocytes, causes hydroxy radicals linked to DNA damage and activation of smoking related carcinogens. A -463 G/A polymorphism in the promoter region of the MPO gene results in reduced gene expression, which would imply lower susceptibility of esophageal cancer in mutant carriers. We conducted case-control study to test this hypothesis. Cases were 91 patients with esophageal cancer and controls were 241 non-cancer outpatients. MPO genotypes were examined by PCR-RFLP. The allele frequency for MPO -463A was found to be 8.2% for cases and 10.5% for controls. The age, sex, smoking and drinking status adjusted odds ratio for all subjects for MPO -463 GG/GA as compared to the AA was 0.61 (95% CI: 0.28-1.32). The adjusted odds ratio for the GG/GA genotype was significantly low (0.15; 0.03-0.76, P=0.022) for those aged 61 years or older who had a significantly higher odds ratio for smoking than younger subjects. No difference was observed in disease risk when prevalent and incident cases were compared. Although there are limitations for interpretation of this study because of prevalent case-control study and partial statistical significance, these results suggest that MPO -463 A allele reduce the risk of esophageal cancer.

Molecular properties of apelin: tissue distribution and receptor binding

We analyzed the tissue distribution of apelin mRNA in rats by a quantitative reverse transcription-polymerase chain reaction and that of immunoreactive apelin (ir-apelin) by an enzyme immunoassay (EIA) using a monoclonal antibody. The expression levels of apelin mRNA and ir-apelin seemed to be consistent among tissues: they were highly expressed in the lung and mammary gland. By the combination of gel filtration and EIA, we found that the molecular forms of apelin differ among respective tissues: apelin molecules with sizes close to apelin-36 (long forms) were major components in the lung, testis, and uterus, but both long and short (whose sizes were close to [<Glu(65)]apelin-13) forms were detected in the mammary gland. In Scatchard analyses, the radioiodinated apelin-36 analogue bound to the receptor, APJ, with high affinity. In competitive binding assays, apelin-36 and apelin-19 far more efficiently inhibited the binding of the labeled apelin-36 analogue with APJ than [<Glu(65)]apelin-13. In analyses for the dissociation of apelin from APJ, unlabeled apelin-36 replaced more rapidly the labeled apelin-36 analogue bound with APJ than [<Glu(65)]apelin-13. Our results demonstrate that the long and short forms of apelin differently interact with APJ.

Distribution of galanin-like peptide in the rat brain

Galanin-like peptide (GALP) is a novel galanin-like peptide isolated from the porcine hypothalamus. To determine the distribution of GALP in the rat brain, we performed immunohistochemical studies using a monoclonal antibody toward the N-terminal sequence of GALP. GALP-immunoreactive neuronal cell bodies were observed only in the arcuate nucleus (Arc), which was further confirmed by in situ hybridization studies using digoxigenin-labeled antisense GALP riboprobe. Additional immunostained cells were found in the median eminence and infundibular stalk. The GALP neurons found in the Arc were further characterized by double label immunohistochemistry. More than 85% of the GALP neurons were immunostained with leptin receptor antibody. However, the GALP neurons and fibers found in the Arc were not labeled with alpha-MSH, somatostatin, neuropeptide Y, agouti-related protein, or galanin antibodies, indicating that GALP is found in neurons other than these known Arc neurons. Dense staining of GALP-containing fibers was found in the anterior parvicellular part of the paraventricular hypothalamic nucleus, in the ventral part of the lateral septal nucleus, and in the bed nucleus of the stria terminalis. Relatively dense staining was noted in the medial preoptic area (MPA), and weak staining was noted in the periventricular hypothalamic nucleus. Detailed double labeling studies in the paraventricular hypothalamic nucleus demonstrated that GALP-containing fibers converged in a more rostral direction than did agouti-related protein-containing fibers. Furthermore, GALP-immunoreactive fibers were in close apposition with GnRH-immunoreactive fibers in the MPA and bed nucleus of the stria terminalis, and about 6% of GnRH-positive neurons in the MPA showed close contact with the GALP-immunoreactive fibers. Our findings indicate that GALP neurons, as leptin-responsive neurons, may participate in the regulation of feeding behavior and/or reproductive functions.

Contrast-enhanced subtraction harmonic sonography for evaluating treatment response in patients with hepatocellular carcinoma

OBJECTIVE

Our objective was to assess the usefulness of contrast-enhanced subtraction harmonic sonography in evaluating the treatment response of patients with hepatocellular carcinoma.

SUBJECTS AND METHODS

Thirty-two hepatocellular carcinoma lesions in 26 patients (age range, 44-85 years; mean age, 66 years) were examined with Levovist-enhanced intermittent harmonic imaging before and after therapy. A Toshiba Powervision 8000 was used. A subtraction image was obtained by digitally subtracting the last-frame harmonic image from the first-frame image when multishot mode was preset. Results of contrast-enhanced CT were compared with the results of subtraction harmonic imaging.

RESULTS

Before therapy, an enhancement pattern of tumor vascularity was seen for 93.8% (30/32) of hepatocellular carcinoma nodules on subtraction harmonic imaging. After therapy, subtraction harmonic imaging showed 46.7% (14/30) enhancement (incomplete tumor necrosis) and 53.3% (16/30) no enhancement (complete tumor necrosis). When dynamic CT was the gold standard, the sensitivity, specificity, and accuracy of subtraction harmonic imaging were 93.3%, 100%, and 96.7%, respectively. Intratumoral flow signals in hepatocellular carcinoma after therapy on harmonic imaging were used as a guide to target additional percutaneous therapy.

CONCLUSION

Digital subtraction contrast-enhanced harmonic imaging can depict tumor vascularity in hepatocellular carcinoma after therapy sensitively and accurately. Because it is easy to perform and provides real-time needle insertion guidance, it may be preferable to perform after localized therapy to monitor treatment response, which will reduce unnecessary CT scanning.

Conformation of a peptide ligand bound to its G-protein coupled receptor

Many peptide hormones elicit a wide array of physiological effects by binding to G-protein coupled receptors. We have determined the conformation of pituitary adenylate cyclase activating polypeptide, PACAP(1--21)NH(2), bound to a PACAP-specific receptor by NMR spectroscopy. Residues 3--7 form a unique beta-coil structure that is preceded by an N-terminal extended tail. This beta-coil creates a patch of hydrophobic residues that is important for receptor binding. In contrast, the C-terminal region (residues 8--21) forms an alpha-helix, similar to that in the micelle-bound PACAP. Thus, the conformational difference between PACAP in the receptor-bound and the micelle-bound states is limited to the N-terminal seven residues. This observation is consistent with the two-step ligand transportation model in which PACAP first binds to the membrane nonspecifically and then diffuses two-dimensionally in search of its receptor; a conformational change at the N-terminal region then allows specific interactions between the ligand and the receptor.

Quantitative analysis of gene expressions related to inflammation in canine spastic artery after subarachnoid hemorrhage

BACKGROUND AND PURPOSE

The possible role of inflammatory reaction of the cerebral artery in the pathogenesis of cerebral vasospasm has been noted in recent studies. We quantitatively measured the levels of expression of genes related to inflammation in the spastic artery in a canine double-hemorrhage model.

METHODS

Twenty dogs were assigned to 4 groups: group D0, control; group D2, dogs killed 2 days after cisternal injection of blood; group D7, dogs given double cisternal injections of blood and killed 7 days after the first injection; and group D14. Angiography was performed twice: on the first day and before the animals were killed. Total RNA was extracted from the basilar artery. The expressions of interleukin (IL)-1alpha, IL-6, IL-8, IL-10, tumor necrosis factor-alpha, E-secretin, fibronectin, intercellular adhesion molecule (ICAM)-1, vascular cell adhesion molecule-1, transforming growth factor-ss, basic fibroblast growth factor, and collagen types I, III, and IV were examined with TaqMan real-time quantitative reverse transcription-polymerase chain reaction.

RESULTS

Prolonged arterial narrowing peaking on 7 day was observed. There was a significant difference in vessel caliber between D0, D2, D7, and D14 groups (P:<0.0001). There were significant differences in mRNA expression in the basilar artery for IL-1alpha, IL-6, IL-8, ICAM-1, and collagen type I between D0, D2, D7, and D14 groups (P:=0.0079, 0. 0196, 0.0040, 0.0017, and <0.0001, respectively). The average level of mRNA was highest in D7 for IL-1alpha, IL-6, IL-8, and ICAM-1 (17-, 16-, 131-, and 1.7-fold compared with those of D0, respectively) and in D14 for collagen type I (10.9-fold).

CONCLUSIONS

Increased expression of genes related to inflammation in the spastic artery suggests that inflammatory reaction of the cerebral artery is associated with sustained contraction.

Methicillin-resistant coagulase-negative staphylococci isolated from healthy horses in Japan

OBJECTIVE

To determine patterns of methicillin-resistant staphylococci isolated from apparently healthy horses.

SAMPLE POPULATION

44 horses from 8 riding clubs in Japan.

PROCEDURE

Methicill in-resistant staphylococci were isolated from the skin or nares, using a selective medium containing a beta-(symboric) lactam antibiotic, ceftizoxime. Clonality of isolates was determined by use of pulsed-field gel electrophoresis. Detection of mecA, mecl, and mecR1 genes was accomplished by use of polymerase chain reactions.

RESULT

Of the 44 horses, 13 (29.5%) yielded 15 isolates of methicillin-resistant staphylococci. The 15 isolates were identified as 6 species (Staphylococcus epidermidis, S lentus, S saprophyticus, S xylosus, S sciuri, and S haemolyticus). However, methicillin-resistant S aureus was seldom isolated. Each isolate contained the mecA gene and had a high resistance to beta-lactam antibiotics. Some isolates also were resistant to other antibiotics such as erythromycin and kanamycin.

CONCLUSIONS AND CLINICAL RELEVANCE

Methicillin-resistant coagulase-negative staphylococci that were highly resistant to various antibiotics were isolated from apparently healthy horses in Japan. These organisms must be considered a potential threat to horses and veterinarians who care for them.

New neuropeptides containing carboxy-terminal RFamide and their receptor in mammals

Only a few RFamide peptides have been identified in mammals, although they have been abundantly found in invertebrates. Here we report the identification of a human gene that encodes at least three RFamide-related peptides, hRFRP-1-3. Cells transfected with a seven-transmembrane-domain receptor, OT7T022, specifically respond to synthetic hRFRP-1 and hRFRP-3 but not to hRFRP-2. RFRP and OT7T022 mRNAs are expressed in particular regions of the rat hypothalamus, and intracerebroventricular administration of hRFRP-1 increases prolactin secretion in rats. Our results indicate that a variety of RFamide-related peptides may exist and function in mammals.

Identification and functional characterization of a novel subtype of neuromedin U receptor

Neuromedin U is a bioactive peptide isolated originally from the porcine spinal cord. We recently identified neuromedin U as the cognate ligand for the orphan G protein-coupled receptor FM-3. In this study, we isolated cDNA coding for a novel G protein-coupled receptor, TGR-1, which was highly homologous with FM-3. We found that neuromedin U specifically and clearly elevated the extracellular acidification rates, arachidonic acid metabolite release, and intracellular Ca(2+) mobilization in Chinese hamster ovary cells expressing TGR-1. Radiolabeled neuromedin U specifically bound with high affinity to membrane fractions prepared from these cells. These results show that TGR-1, like FM-3, is a specific and functional receptor for neuromedin U. We analyzed TGR-1 mRNA tissue distribution in rats using quantitative reverse transcription-polymerase chain reaction and found it to considerably differ from that of FM-3 mRNA. TGR-1 mRNA was primarily expressed in the uterus, suggesting that TGR-1 mediates the contractile activity of neuromedin U in this tissue. The identification of specific and functional receptor subtypes for neuromedin U will facilitate the study of their physiological roles and the search for their specific agonists and antagonists.

Molecular and functional characteristics of APJ. Tissue distribution of mRNA and interaction with the endogenous ligand apelin

We have recently identified apelin as the endogenous ligand for human APJ. In rats, the highest expression of APJ mRNA was detected in the lung, suggesting that APJ and its ligand play an important role in the pulmonary system. When apelin-36 and its pyroglutamylated C-terminal peptide, [<Glu(65)]apelin-13, were compared in microphysiometric analyses, the elevation of extracellular acidification induced in cells expressing APJ by [<Glu(65)]apelin-13 was transient, whereas that by apelin-36 was sustained. These responses were almost completely inhibited by a specific inhibitor for G(i) or that for Na(+)/H(+) exchanger. (125)I -Labeled [<Glu(65)]apelin-13 analogue specifically bound to APJ with a high affinity, and [<Glu(65)]apelin-13 was more potent than apelin-36 in competitive inhibition assays. Because pretreatment with apelin-36 but not [<Glu(65)]apelin-13 drastically reduced the binding of the labeled apelin to APJ, the different patterns of acidification induced by these two peptides appeared to reflect their dissociation rather than association with APJ. Apelin elicited the migration of APJ-expressing cells, and [<Glu(65)]apelin-13 was more potent than apelin-36 in this activity. Heterogeneous molecular forms of apelin corresponding to apelin-36 and [<Glu(65)]apelin-13 were produced in bovine colostrum. Apelin-36 and [<Glu(65)]apelin-13 might have different functions in vivo and in vitro.

Identification of neuromedin U as the cognate ligand of the orphan G protein-coupled receptor FM-3

Neuromedin U is a bioactive peptide first isolated from porcine spinal cord. In this paper, we demonstrate that neuromedin U is the cognate ligand for the orphan G protein-coupled receptor, FM-3, isolated originally as a homologue of neurotensin and growth hormone secretogogue receptors. Neuromedin U induced specific and evident elevation of extracellular acidification rates, arachidonic acid metabolite release, and intracellular Ca(2+) mobilization in Chinese hamster ovary cells expressing human FM-3. In addition, radiolabeled neuromedin U specifically bound to membrane fractions prepared from these cells with high affinity. We subsequently analyzed the tissue distribution of neuromedin U and FM-3 mRNAs in rats using quantitative reverse transcription-polymerase chain reaction. Neuromedin U mRNA was highly expressed in the gastrointestinal tract, and the highest expression was detected in the pituitary gland. On the other hand, FM-3 mRNA was highly expressed in the small intestine and lung, suggesting that neuromedin U plays important roles in these tissues. The identification of a specific and functional receptor for neuromedin U will facilitate studies on their physiological roles and the search for receptor agonists and antagonists.

Molecular cloning of a novel brain-type Na(+)-dependent inorganic phosphate cotransporter

We have isolated a human cDNA encoding a protein, designated DNPI, that shows 82% amino acid identity and 92% similarity to the human brain-specific Na(+)-dependent inorganic phosphate (Na(+)/P(i)) cotransporter (BNPI), which is localized exclusively to neuron-rich regions. Expression of DNPI mRNA in Xenopus oocytes resulted in a significant increase in Na(+)-dependent P(i) transport, indicating that DNPI is a novel Na(+)/P(i) cotransporter. Northern blot analysis shows that DNPI mRNA is expressed predominantly in brain, where the highest levels are observed in medulla, substantia nigra, subthalamic nucleus, and thalamus, all of which express BNPI mRNA at low levels. In contrast, DNPI mRNA is expressed at low levels in cerebellum and hippocampus, where BNPI mRNA is expressed at high levels. No hybridizing signal for DNPI mRNA is observed in the glia-rich region of corpus callosum. In other regions examined, both mRNAs are moderately or highly expressed. These results indicate that BNPI and DNPI, which coordinate Na(+)-dependent P(i) transport in the neuron-rich regions of the brain, may form a new class within the Na(+)/P(i) cotransporter family.

Analyses for susceptibility of rat anterior pituitary cells to prolactin-releasing peptide

We validated the effect of prolactin-releasing peptide (PrRP) on prolactin (PRL) secretion from rat anterior pituitary cells in in vitro culture. We found that culture conditions considerably influenced the response of the anterior pituitary cells to PrRP. Longer culture term (4 d) was required to obtain better responses of the anterior pituitary cells to PrRP in comparison to thyrotropin-releasing hormone (TRH). Under the culture conditions employed here, PrRP was comparable to TRH in the potency promoting PRL secretion, and the action of PrRP was very specific for PRL secretion. The susceptibility of the anterior pituitary cells to PrRP varied in female rats depending on the process of reproduction: the cells prepared from lactating rats were the most sensitive to PrRP compared with those from random-cycle and pregnant rats. Because the expression levels of PrRP receptor mRNA in the pituitary varied during the reproductive process, we speculated that the susceptibility of the anterior pituitary cells would reflect cellular changes including the expression level of PrRP receptors. In addition, treatment with estrogen in vivo enhanced the susceptibility of the cultured anterior pituitary cells in male rats. Our results indicate that the susceptibility of the rat anterior pituitary cells to PrRP is regulated by physiological mechanisms.

Clinical features of intracranial aneurysms in siblings

OBJECTIVE

Among the family members of patients with aneurysmal subarachnoid hemorrhage (SAH), siblings have been documented to be at high risk of SAH and to have a high prevalence of unruptured aneurysms. We studied the distinctive features of aneurysms in siblings and attempted to determine the risk of rupture.

METHODS

We analyzed detailed data on 159 patients with siblings who had ruptured and unruptured aneurysms in 77 families from throughout Japan.

RESULTS

Seventy-three percent of the patients were female, and the mean age at the time of rupture was 55.6 years. In 39 families, two or more siblings had SAH. Eighty of 107 patients with ruptured aneurysms and 28 of 52 with unruptured aneurysms had a family history of SAH in siblings (P = 0.0082). Multiple and mirror-image aneurysms were found in 42 and 21 patients, respectively. Among 218 aneurysms, middle cerebral artery aneurysms were the most common type (43%). Anterior communicating artery aneurysms were underrepresented (15%). There were significantly more ruptured than unruptured anterior communicating artery aneurysms, compared with other aneurysms (P = 0.01).

CONCLUSION

The clinical features of aneurysms in siblings in this population agreed well with those reported for familial intracranial aneurysms and SAH, except for the age at the time of rupture. It is suggested that the risk of rupture is greater when patients with unruptured aneurysms have siblings with aneurysmal SAH and/or anterior communicating artery aneurysms.

Stimulation of corticotropin-releasing hormone-mediated adrenocorticotropin secretion by central administration of prolactin-releasing peptide in rats

Prolactin-releasing peptide (PrRP) is a recently isolated hypothalamic peptide which is an endogenous ligand to an orphan receptor. We previously demonstrated that PrRP neurons are widely distributed throughout the rat brain and suggested that PrRP may have important functions in the central nervous system. To analyze the function of PrRP, we studied the effect of intracerebroventricular (i.c.v.) PrRP administration on c-Fos protein accumulation in the rat brain. The results clearly indicated that c-Fos protein accumulation was dramatically increased in the nuclei of corticotropin-releasing hormone (CRH)-positive parvocellular neurosecretory cells in the paraventricular nucleus (PVN). We also demonstrated synapse-like contact between PrRP neurons and CRH cell bodies in the PVN, which suggests that PrRP31 has some effect on CRH secretion. We therefore investigated the effect of i.c.v. administration of PrRP31 on the CRH-mediated increase in adrenocorticotropin (ACTH) levels, and found that plasma ACTH levels were indeed increased by i.c.v. PrRP31. In addition, animals pre-treated with intravenous alpha-helical CRH, a potent CRH antagonist, showed attenuated plasma ACTH responses after i.c.v. PrRP31 administration. These results strongly suggest that PrRP affects the hypothalamic-pituitary-adrenal axis.

Cloning of cDNA and the gene encoding human hepatocyte nuclear factor (HNF)-3 beta and mutation screening in Japanese subjects with maturity-onset diabetes of the young

AIMS/HYPOTHESIS

Molecular defects of the genes for transcription factors, hepatocyte nuclear factor (HNF)-4 alpha, HNF-1 alpha, HNF-1 beta and insulin promoter factor-1 cause maturity-onset diabetes of the young (MODY1, 3, 5, and 4, respectively). This suggests the HNF-related transcription cascade is important in insulin secretion which is induced by glucose. These genes and the gene encoding glycolytic enzyme glucokinase (MODY2) are, however, responsible for only 15-20% of cases of MODY in the Japanese. Searching for a novel form of MODY in this population, we cloned a new candidate gene encoding human HNF-3 beta, a winged helix transcription factor, which also belongs to the same HNF-transcription cascade.

METHODS

The cDNA clone for human HNF-3 beta was isolated from a liver cDNA library. The gene was also cloned from a genomic library and its organization and chromosomal localization were determined. We screened 68 Japanese subjects with MODY/early-onset diabetes for mutations in this gene.

RESULTS

Human HNF-3 beta is composed of 457 amino acids. The human gene, which was mapped to the segment 30 cR from SHGC-37039 on chromosome 20p by radiation hybrid mapping, spans approximately 4.5 kb and consists of three exons. Direct sequencing of the exons and flanking regions identified one missense mutation A328 V and seven polymorphisms, although the functional significance of the mutation in the pathogenesis of diabetes is not known.

CONCLUSION/INTERPRETATION

The characterization of the structure of the HNF-3 beta gene and its mapping in the framework of markers will be helpful in genetic studies of the various forms of diabetes mellitus.