Continuous application of compressive force induces fusion of osteoclast-like RAW264.7 cells via upregulation of RANK and downregulation of LGR4

AIMS

During orthodontic treatment, facilitating osteoclastic bone resorption in the alveolar bone exposed to the compressive force (CF) is an important factor for tooth movement. The present study investigated the effect of CF stimulation on the differentiation of RAW264.7 cells from precursors to mature osteoclasts.

MAIN METHODS

The cells were continuously stimulated with 0.3, 0.6, or 1.1 g/cm² CF-which was generated by increasing the volume of culture medium in the wells of a 96-well plate-in the presence or absence of receptor activator of nuclear factor κB (RANK) ligand (RANKL) for 4 days.

KEY FINDINGS

In the presence of RANKL, the number of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells and the mRNA levels of dendritic cell-specific transmembrane protein (DC-STAMP) and osteoclast-stimulatory transmembrane protein (OC-STAMP) were increased by application of 0.6 and 1.1 g/cm² CF as compared to 0.3 g/cm² CF. The mRNA level of RANK was upregulated whereas that of leucine-rich repeat-containing G-protein-coupled receptor (LGR)4-another RANKL receptor was downregulated by 0.6 and 1.1 g/cm² CF as compared to 0.3 g/cm² CF in the absence of RANKL. The proportion of cells with nuclear translocation of the nuclear translocation of nuclear factor of activated T cells (NFAT)c1 was increased by 0.6 and 1.1 g/cm² CF in the presence of RANKL.

SIGNIFICANCE

Continuous application of CF induced the differentiation of RAW264.7 cells into TRAP-positive multinuclear cells by enhancing the expression of DC- and OC-STAMP and the nuclear translocation of NFATc1. This may result from the CF-induced increase in RANK and decrease in LGR4 expression.

Effects of C-reactive protein on the expression of matrix metalloproteinases and their inhibitors via Fcγ receptors on 3T3-L1 adipocytes

The association between obesity and inflammation is well documented in epidemiological studies. Proteolysis of extracellular matrix (ECM) proteins is involved in adipose tissue enlargement, and matrix metalloproteinases (MMPs) collectively cleave all ECM proteins. Here, we examined the effects of C-reactive protein (CRP), an inflammatory biomarker, on the expression of MMPs and tissue inhibitors of metalloproteinases (TIMPs), which are natural inhibitors of MMPs, in adipocyte-differentiated 3T3-L1 cells. We analyzed the expression of Fcγ receptor (FcγR) IIb and FcγRIII, which are candidates for CRP receptors, and the effects of anti-CD16/CD32 antibodies, which can act as FcγRII and FcγRIII blockers on CRP-induced alteration of MMP and TIMP expression. Moreover, we examined the effects of CRP on the activation of mitogen-activated protein kinase (MAPK) signaling, which is involved in MMP and TIMP expression, in the presence or absence of anti-CD16/CD32 antibodies. Stimulation with CRP increased MMP-1, MMP-3, MMP-9, MMP-11, MMP-14, and TIMP-1 expression but did not affect MMP-2, TIMP-2, and TIMP-4 expression; TIMP-3 expression was not detected. Adipocyte-differentiated 3T3-L1cells expressed FcγRIIb and FcγRIII; this expression was upregulated on stimulation with CRP. Anti-CD16/CD32 antibodies inhibited CRP-induced expression of MMPs, except MMP-11, and TIMP-1. CRP induced the phosphorylation of extracellular signal-regulated kinase (ERK) 1/2 and p38 MAPK but did not affect SAPK/JNK phosphorylation, and Anti-CD16/CD32 attenuated the CRP-induced phosphorylation of p38 MAPK, but not that of ERK1/2. These results suggest that CRP facilitates ECM turnover in adipose tissue by increasing the production of multiple MMPs and TIMP-1 in adipocytes. Moreover, FcγRIIb and FcγRIII are involved in the CRP-induced expression of MMPs and TIMP-1 and the CRP-induced phosphorylation of p38, whereas the FcγR-independent pathway may regulate the CRP-induced MMP-11 expression and the CRP-induced ERK1/2 phosphorylation.

Effective treatment for infantile hemangioma with long-pulsed dye laser with oral propranolol medication: a preliminary report

PURPOSE

To investigate the efficacy of our treatment of infantile hemangioma (IH)s retrospectively presenting as disfiguring or functionally threatening lesions.

MATERIALS AND METHODS

25 infants with IH treated with long-pulsed dye laser or laser with or without propranolol. Tumor fading after treatment was evaluated using both color and size rating scales, before, during and after treatment.

RESULTS

6 infants were treated by laser, 11, oral propranolol and 8 using both treatments. Each treatment was effective for most IH with a median treatment duration of 7.7 months for laser, and 13.3 months for the latter two. Combination therapy was the most effective in both color-fading and size reduction by the 3rd month. Laser alone was most effective in color-fading with almost complete disappearance of most tumors. Oral propranolol to the three site-specific IHs was effective with disappearance of tumors. There were no apparent side effects related to laser treatment, but one infant suffered from allergy and another from bronchial asthma due to propranolol medication.

CONCLUSIONS

Most IHs discolored and regressed considerably with these treatments, including complete disappearance of the three functionally threatening lesions. This combined approach is quite useful for accelerating tumor regression.

The control of precerebellar neuron migration by RNA-binding protein Csde1

Neuronal migration during brain development sets the position of neurons for the subsequent wiring of neural circuits. To understand the molecular mechanism regulating the migrating process, we considered the migration of mouse precerebellar neurons. Precerebellar neurons originate in the rhombic lip of the hindbrain and show stereotypic, long-distance tangential migration along the circumference of the hindbrain to form precerebellar nuclei at discrete locations. To identify the molecular components underlying this navigation, we screened for genes expressed in the migrating precerebellar neurons. As a result, we identified the following three genes through the screening; Calm1, Septin 11, and Csde1. We report here functional analysis of one of these genes, Csde1, an RNA-binding protein implicated in the post-transcriptional regulation of a subset of cellular mRNA, by examining its participation in precerebellar neuronal migration. We found that shRNA-mediated inhibition of Csde1 expression resulted in a failure of precerebellar neurons to complete their migration into their prospective target regions, with many neurons remaining in migratory paths. Furthermore, those that did reach their destination failed to invade the depth of the hindbrain via radial migration. These results have uncovered a crucial role of Csde1 in the proper control of both radial and tangential migration of precerebellar neurons.

Lysozyme stimulates immunoglobulin production by human-human hybridoma and human peripheral blood lymphocytes

Lysozyme [EC 3.2.1.17] derived from hen egg white stimulated immunoglobulin production by human-human hybridoma, HB4C5 cells producing human lung cancer specific monoclonal IgM. IgM production by HB4C5 cells was enhanced more than 13-fold by the addition of lysozyme at 380 μg/ml in a serum-free medium. The immunoglobulin production stimulating effect of lysozyme was observed immediately after inoculation and maintained for 5 days. Lysozyme enhanced immunoglobulin production by the hybridoma line without growth promotion. This enzyme also accelerated IgM and IgG production of human peripheral blood lymphocytes 5.3-fold and 2.3-fold, respectively. These results suggest that lysozyme stimulates immunoglobuling production of not only specific hybridoma line, but also non-specific immunoglobulin producers. However, although the enzymatic activity of lysozyme was almost lost by heat-treatment at 100 °C for 30 min, the IPSF activity was retained. This fact suggests that IPSF activity of lysozyme does not come from its enzymatic activity or reaction products. All these findings clearly indicate that lysozyme has a novel function as an immunoglobulin production stimulating factor. GAPDH - glyceraldehyde-3-phosphate dehydrogenase; Ig - immunoglobulin; IPSF - immunoglobulin production stimulating factor; PBL - peripheral blood lymphocytes; HPLC - high-performance liquid chromatography.

Evaluation of preoperative positron emission tomography with computed tomography (PET-CT) for detecting lymph node metastasis in gynecologic carcinoma

5593

Background: To evaluate the sensitivety, specificity, and accuracy of PET-CT for detecting lymph node metastasis in gynecologic carcinoma. Methods: Between May 2007 to August 2008, 36 consecutive patients (pts) with cervical carcinoma, endometrial carcinoma and epithelial ovarian carcinoma were enrolled. All pts underwent PET-CT prior to the surgery of systematic pelvic and paraaortic lymphadenectomy. For pathological metastatic lymph nodes, the size of intranodal tumor deposits (maximum diameter of metastatic foci in each lymph node) were recorded. Results: The total number of pelvic lymph nodes (PLNs) plus paraaortic lymph nodes (PANs) removed was 2426. The median number of removed lymph nodes (LNs) was 67 each pts (range: 25 to 102). The number of involvement LNs was 79 (3.5%). The sensitivity, specificity and accuracy of preoperative PET-CT to detect LN metastasis were 24%, 99.9%, and 97.5%, respectively. The sensitivity of PLNs and PANs were 39.5% and 7.3%, respectively. The sensitivity of squamous cell carcinoma (SCC) were 35.7%, that of adenocarcinoma were 8.1%. FDG-PET detected 100% of intranodal tumor deposits > or =10 mm, whereas tumor deposits smaller than 5 mm were not detected. Conclusions: The results of our study revealed 76% underdiagnosis (overlooking) in evaluation of preoperative PET-CT in LN metastasis. Particularly, tumor deposits smaller than 5 mm were not detected at all. Using PET-CT for detecting small LN metastasis in gynecologic carcinoma may be unreliable so far. However we found that PLNs are comparatively easy to be detected than PANs, and SCC are comparatively easy to be detected than adenocarcinoma. The improved usability and application of PET-CT for detecting LN metastasis in gynecologic carcinoma have to keep researching constructively.

No significant financial relationships to disclose.

The histological subtype and grade work as prognostic indicators for platinum-based chemotherapy (CTX) of advanced ovarian carcinoma (AOC)

16015

Background: We previously reported the new histopathologic grading system applicable for all histological types of ovarian carcinoma (Cancer 82:893–901, 1998), which thereafter was reappraised by several investigators. The aim of the present study is to investigate the relationship of the histopathologic type and grade with the effect of CTX for AOC. Methods: Between 1/89 and 12/05, 272 consecutive patients (pts) with pT3 (FIGO stage III or IV) AOC pts received 6 cycles or more of cisplatin (70 mg/m2 for 1 cycle)-based CTX combined with aggressive debulking surgery consisting of hysterectomy, bilateral adnectomy, omentectomy, pelvic to paraaortic lymphadenectomy, with or without more extensive surgery including intestinal resections. Histological types and grade were diagnosed according to the WHO classification system and our system reported method, respectively. Results: Of the eligible 261 pts, response was achieved in 67% (CR: 21.8%, PR: 45.2%) of the pts. Response (CR+PR/total) by histological type was 86% (36+91/148) for serous, 97% (16+13/30) for transitional cell, 67% (5+13/27) for endometrioid, 4% (0+1/29) for mucinous, and 0% (0+0/27) for clear cell, respectively. Response (overall/CR) for chemo-sensitive histological types (serous/transitional cell/endometrioid) by grade (G) was 86%/52% for 21 G1, 90%/31% for 64 G2, and 83%/28% for 118 G3 (CR rate: G3 vs G1 + G2: p=0.02). Response duration (CR/PR) by G was not reached/30 months (mo) for G1, 85 mo/23 mo for G2, 40 mo/16 mo for G3. Response (overall/CR) to 2nd line CTX was 75%/38% for G1, 73%/17% for G2, and 47%/10% for G3. Conclusions: Histological type correlated with platinum-CTX sensitivity. CTX regimens should be designed based on the histological subtypes. New “non-platinum” regimens should be considered for both mucinous and clear cell carcinoma. Histological grade worked as an indicator for CR rate, response duration (thus, progression rate), and response rate to 2nd line CTX. Thus, the grade is considered to be a significant prognostic factor for platinum-sensitive AOC.

No significant financial relationships to disclose.

Combination chemotherapy with consecutive low-dose cisplatin with ifosfamide and epirubicin (CLD-IEP) in uterine sarcoma

10057

Background: To evaluate the efficacy and toxicity of CLD-IEP for patients (pts) with sarcoma uteri. Methods: Eligible criteria were: a histologic proof of advanced or recurrent sarcoma uteri; measurable lesions; age between 18 and 80 yrs; WHO PS 0–3; WBC = 3,000/μL; platelet count = 100,000/μL; hemoglobin level = 9 g/dL; adequate liver function; C-Cr = 40 mL/min; no lung, heart, or brain disease; no previous neoplastic disease; no prior chemotherapy; and informed consent. The CLD-IEP regimen was ifosfamide 700 mg/m2 infused over 2 hrs days 1 through 3; epirubicin 50 mg/m2 bolus day 5; and cisplatin 15 mg/m2 infused over 4 hrs days 1 through 5. The treatment was repeated at 4-week intervals. Results: To date, forty eligible pts (16 leiomyosarcoma [LMS], 4 endometrial stromal sarcoma, and 20 carcinosarcoma) were enrolled in this study and all pts were assessable for response, toxicity, and survival. The median age was 52 yrs (range, 28–77). Thirteen pts received CLD-IEP in the neoadjuvant setting. Nine pts had prior radiotherapy. After a median of 4 cycles (range, 2–13), we observed objective responses in 24 pts (60%), with 5 (13%) CRs and 19 (48%) PRs (95% CI, 42% to 78%, 4% to 22%, 30% to 66%, respectively). Of 16 pts with LMS, 1 CR and 7 PRs (1 pt with good PR surviving more than 48 months after the start of CLD-IEP) were observed. Median overall survival time (MOS) after the start of CLD-IEP for all 40 pts was 17 months (range, 3 to 62). MOS was 20.5 months in the responders versus 9 months in the non-responders (Log-rank, p=0.023). The median progression-free survival time of the responders was 10.5 months. NCI-CTC grade 3 or 4 leucopoenia, neutropenia, thrombocytopenia, and anemia occurred in 63%, 75%, 12%, and 18%, respectively. There was no significant nausea/vomiting, nephrotoxicity, or CNS toxicity. Conclusions: CLD-IEP regimen has significant to moderate anti-tumor activity with acceptable toxicity in pts with sarcoma uteri including LMS.

No significant financial relationships to disclose.

Acquired symmetrical dermal melanocytosis (naevus of Hori) developing after aggravated atopic dermatitis

BACKGROUND

Acquired symmetrical dermal melanocytosis (ASDM) is a pigmentary disorder characterized by blue-brown macules most frequently seen on the face of young and middle-aged Asian women. ASDM developing after other skin diseases has not been previously reported.

OBJECTIVES

To characterize the clinical and histopathological features of ASDM associated with atopic dermatitis (AD) and to elucidate the differences between AD-associated ASDM and idiopathic ASDM.

METHODS

Sixteen patients with ASDM associated with AD were examined clinically and histopathologically and were compared with 69 patients with idiopathic ASDM.

RESULTS

The AD patients associated with ASDM consisted of four men and 12 women with a mean age of 32.8 +/- 13.1 years. Most patients remembered that the pigmented macules appeared in places where refractory eczema had existed for a long time. The marked preponderance in females and the appearance in the early reproductive period were common features of AD-associated ASDM and idiopathic ASDM. AD-associated ASDM was most commonly observed on the forehead (68.8%) and on the backs of the hands (50.0%), whereas 89.9% of idiopathic ASDM was seen on the cheeks. There was no significant difference in the number of dermal melanocytes between AD-associated ASDM and idiopathic ASDM. Electron microscopic studies demonstrated many mature melanocytes and smaller numbers of immature melanocytes in the dermis. Some melanocytes were seen adjacent to mast cells.

CONCLUSIONS

AD-associated ASDM does not appear to be rare in Japan. ASDM may be triggered in AD patients by sunlight exposure, some alterations in sex hormones and/or persistent cutaneous inflammation. Histamine and stem cell factor produced by mast cells may play crucial roles in the pathogenesis of AD-associated ASDM.

Effects of Ultraviolet Light on Melanocyte Differentiation: Studies with Mouse Neural Crest Cells and Neural Crest-derived Cell Lines

To evaluate the etiologic role of ultraviolet (UV) radiation in acquired dermal melanocytosis (ADM), we investigated the effects of UVA and UVB irradiation on the development and differentiation of melanocytes in primary cultures of mouse neural crest cells (NCC) by counting the numbers of cells positive for KIT (the receptor for stem cell factor) and for the L-3,4-dihydroxyphenylalanine (DOPA) oxidase reaction. No significant differences were found in the number of KIT- or DOPA-positive cells between the UV-irradiated cultures and the non-irradiated cultures. We then examined the effects of UV light on KIT-positive cell lines derived from mouse NCC cultures. Irradiation with UVA but not with UVB inhibited the tyrosinase activity in a tyrosinase-positive cell line (NCCmelan5). Tyrosinase activity in the cells was markedly enhanced by treatment with alpha-melanocyte-stimulating hormone (alpha-MSH), but that stimulation was inhibited by UVA or by UVB irradiation. Irradiation with UVA or UVB did not induce tyrosinase activity in a tyrosinase-negative cell line (NCCmelb4). Levels of KIT expression in NCCmelan5 cells and in NCCmelb4 cells were significantly decreased after UV irradiation. Phosphorylation levels of extracellular signal-regulated kinase 1/2 in cells stimulated with stem cell factor were also diminished after UV irradiation. These results suggest that UV irradiation does not stimulate but rather suppresses mouse NCC. Thus if UV irradiation is a causative factor for ADM lesions, it would not act directly on dermal melanocytes but may act in indirect manners, for instance, via the overproduction of melanogenic cytokines such as alpha-MSH and/or endothelin-1.

Effective treatment of pruritus in atopic dermatitis using H1 antihistamines (second-generation antihistamines): changes in blood histamine and tryptase levels

BACKGROUND

Atopic dermatitis (AD) is a common chronic inflammatory and allergic skin disease that almost always begins in childhood and follows a course of remittance and flare-up. AD is characterized by intense pruritus and itchiness that can be triggered by an interplay of genetic, immunologic and environmental factors. Of the mediators, histamine is one of the most potent inducers of pruritus. Serum tryptase, which is also a mediator, may be used to examine allergic disease as well. The development of minimal sedation H1 antihistamines (second-generation antihistamines) has revolutionized treatment of allergic diseases.

OBJECTIVE

The present study examines the efficacy of second-generation antihistamines in relieving pruritus due to AD. In addition, the relationship between AD pruritus and antihistamine therapy was analyzed by measuring the blood histamine and tryptase levels.

METHODS

Thirty-two AD patients were recruited and underwent second-generation antihistamine therapy for 2 weeks. Seventeen received combined topical corticosteroid treatment (Group 1) and the other 15 did not receive steroid treatment (Group 2). The Severity Index and Pruritus Score were assessed as an AD clinical activity index and compared with baseline data.

RESULTS

Both the Severity Index and Pruritus Score improved significantly in Group 1 (P<0.001, P<0.05). Group 2 demonstrated a significant improvement in Pruritus Score (P<0.05), but not in the Severity Index. Plasma histamine levels were significantly higher in AD at baseline compared with healthy controls.

CONCLUSION

Following antihistamine therapy, these levels decreased significantly in both AD groups (P<0.05). There was a significant correlation between baseline blood histamine and typtase levels. However, this correlation was not evident following treatment. This may reflect insufficient detection capabilities of the measuring assay. The present results suggest that second-generation antihistamine therapy provides an effective clinical treatment for AD, with a notable improvement in pruritus. Furthermore, antihistamine therapy reduced plasma histamine levels in AD patients. These findings further suggest that high blood histamine and tryptase levels in AD patients contribute to the pathogenesis of this disorder, including the onset of pruritus.

Light and electron microscopic study of corticorubral synapses in adult cat: evidence for extensive synaptic remodeling during postnatal development

Spine-like dendritic protrusions (SLDPs) emanating from developing dendrites have been proposed to play an important role in early synaptogenesis. We previously analyzed synaptic termination sites on soma-dendritic membrane of newborn cats and found that corticorubral (CR) axons form synapses preferentially on SLDPs (Saito et al., 1997). In the present study, we examined CR synapses in adult cats to elucidate the maturation process of CR synapses in relation to SLDPs. Electron microscopic observation of serial thin sections of Phaseolus vulgaris-leucoagglutinin-labeled axons revealed that approximately 60% of CR terminals in adult cats formed synapses on dendritic spines. We also found that CR axons terminate on dendritic spines originating from the intermediate or distal dendrites of rubrospinal cells (more than 200 microm apart from the soma), in contrast to kittens in which CR fibers terminate on SLDPs originating from the proximal dendrites (less than 100 microm apart from the soma) of rubrospinal cells (Saito et al. [1997] J. Neurosci. 17:8792-8803). These results suggest that CR synapses undergo remarkable remodeling after initial termination on SLDP during postnatal development.

Excitatory postsynaptic potentials trigger a plateau potential in rat subthalamic neurons at hyperpolarized states

The subthalamic nucleus (STN) directly innervates the output structures of the basal ganglia, playing a key role in basal ganglia function. It is therefore important to understand the regulatory mechanisms for the activity of STN neurons. In the present study, we aimed to investigate how the intrinsic membrane properties of STN neurons interact with their synaptic inputs, focusing on their generation and the properties of the long-lasting, plateau potential. Whole cell recordings were obtained from STN neurons in slices prepared from postnatal day 14 (P14) to P20 rats. We found that activation of glutamate receptor-mediated excitatory synaptic potentials (EPSPs) evoked a plateau potential in a subpopulation of STN neurons (n = 13/22), in a voltage-dependent manner. Plateau potentials could be induced only when the cell was hyperpolarized to more negative than about -75 mV. Plateau potentials, evoked with a depolarizing current pulse, again only from a hyperpolarized state, were observed in about half of STN neurons tested (n = 162/327). Only in neurons in which a plateau potential could be evoked by current injection did EPSPs evoke plateau potentials. L-type Ca(2+) channels, Ca(2+)-dependent K(+) channels, and TEA-sensitive K(+) channels were found to be involved in the generation of the potential. The stability of the plateau potential, tested by the injection of a negative pulse current during the plateau phase, was found to be robust at the early phase of the potential, but decreased toward the end. As a result the early part of the plateau potential was resistant to membrane potential perturbations and would be able to support a train of action potentials. We conclude that excitatory postsynaptic potentials, evoked in a subpopulation of STN neurons at a hyperpolarized state, activate L-type Ca(2+) and other channels, leading to the generation of a plateau potential. Thus about half of STN neurons can transform short-lasting synaptic excitation into a long train of output spikes by voltage-dependent generation of a plateau potential.

Crossing the floor plate triggers sharp turning of commissural axons

During development of the vertebrate CNS, commissural axons initially grow circumferentially toward the ventral midline floor plate. After crossing the floor plate, they abruptly change their trajectory from the circumferential to the longitudinal axis. Although recent studies have unraveled the mechanisms that control navigation of these axons along the circumferential axis, those that result in the transition from circumferential to longitudinal trajectory remain unknown. Here, we examined whether an interaction with the floor plate is a prerequisite for the initiation of trajectory transition of commissural axons, using in vitro preparations of the rat metencephalon. We found that commissural axons in the metencephalon, once having crossed the floor plate, turned sharply to grow longitudinally. In contrast, axons extending in floor plate-deleted preparations, continued to grow circumferentially, ignoring the hypothetical turning point. These results suggest that a prior interaction of commissural axons with floor plate cells is a key step for these axons to activate a navigation program required for their change in axonal trajectory from the circumferential to the longitudinal axis.

Visualization, direct isolation, and transplantation of midbrain dopaminergic neurons

To visualize and isolate live dopamine (DA)-producing neurons in the embryonic ventral mesencephalon, we generated transgenic mice expressing green fluorescent protein (GFP) under the control of the rat tyrosine hydroxylase gene promoter. In the transgenic mice, GFP expression was observed in the developing DA neurons containing tyrosine hydroxylase. The outgrowth and cue-dependent guidance of GFP-labeled axons was monitored in vitro with brain culture systems. To isolate DA neurons expressing GFP from brain tissue, cells with GFP fluorescence were sorted by fluorescence-activated cell sorting. More than 60% of the sorted GFP(+) cells were positive for tyrosine hydroxylase, confirming that the population had been successfully enriched with DA neurons. The sorted GFP(+) cells were transplanted into a rat model of Parkinson's disease. Some of these cells survived and innervated the host striatum, resulting in a recovery from Parkinsonian behavioral defects. This strategy for isolating an enriched population of DA neurons should be useful for cellular and molecular studies of these neurons and for clinical applications in the treatment of Parkinson's disease.

HBV-related fulminant hepatic failure: successful intensive medical therapy in a candidate for liver transplantation

Fulminant hepatic failure (FHF) usually has a fatal prognosis without liver transplantation. We describe the case of a woman who developed FHF, and was evaluated as a candidate for liver transplantation, but who was cured without transplantation through intensive medical care that included glucagon-insulin therapy, methylprednisolone pulse therapy, interferon beta and lamivudine administration, cyclosporine administration, and high-volume hemodiafiltration and plasma exchange. In a patient with FHF who is a candidate for liver transplantation but for whom the transplantation cannot be performed for some reason, intensive medical therapy, including regeneration-promoting therapy, immunosuppressive therapy, antiviral therapy, and vigorous hepatic support, should be carried out.

Local nonpermissive and oriented permissive cues guide vestibular axons to the cerebellum

Information that originates from peripheral sensory organs is conveyed by axons of cephalic sensory cranial ganglia connecting the sensory organs to appropriate central targets in the brain. Thus, the establishment of correct axonal projections by sensory afferents is one of the most important issues in neural development. Previously, we examined the development of the vestibular nerve that originates from the VIIIth ganglion using a flat whole-mount preparation of the rat hindbrain and developed an in vitro, culture preparation that can recapitulate vestibular nerve development (Tashiro, Y., Endo, T., Shirasaki, R., Miyahara, M., Heizmann, C. W. and Murakami, F. (2000) J. Comp. Neurol. 417, 491–500). Both in vivo and in vitro, the ascending branch of the VIIIth ganglion projecting to the cerebellum reaches the base of the cerebellar primordium and starts to splay out towards the rhombic lip, apparently avoiding the ventral metencephalon. We now examine the nature of cues that guide vestibulocerebellar axons by applying various manipulations to the flat whole-mount in vitro preparation. Our observations suggest that local nonpermissive cues and oriented cues play a pivotal role in the guidance of vestibular axons to their central target.

The release of the substrate for xanthine oxidase in hypertensive patients was suppressed by angiotensin converting enzyme inhibitors and alpha1-blockers

OBJECTIVE

Hyperuricemia is associated with the vascular injury of hypertension, and purine oxidation may play a pivotal role in this association, but the pathophysiology is not fully understood. We tested the hypothesis that in hypertensive patients, the excess amount of the purine metabolite, hypoxanthine, derived from skeletal muscles, would be oxidized by xanthine oxidase, leading to myogenic hyperuricemia as well as to impaired vascular resistance caused by oxygen radicals.

METHODS

We investigated the production of hypoxanthione, the precursor of uric acid and substrate for xanthine oxidase, in hypertensive patients and found that skeletal muscles produced hypoxanthine in excess. We used the semi-ischemic forearm test to examine the release of hypoxanthine (deltaHX), ammonium (deltaAmm) and lactate (deltaLAC) from skeletal muscles in essential hypertensive patients before (UHT: n = 88) and after treatment with antihypertensive agents (THT: n = 37) in comparison to normotensive subjects (NT: n = 14).

RESULTS

deltaHX, as well as deltaAmm and deltaLAC, were significantly higher in UHT and THT (P< 0.01) than in NT. This release of deltaHX from exercising skeletal muscles correlated significantly with the elevation of lactate in NT, UHT and THT (y = 0.209 + 0.031x; R2 = 0.222, n = 139: P < 0.01). Administration of doxazosin (n = 4), bevantolol (n = 5) and alacepil (n = 8) for 1 month significantly suppressed the ratio of percentage changes in deltaHX by -38.4 +/- 55.3%, -51.3 +/- 47.3% and -76.3 +/- 52.2%, respectively (P< 0.05) but losartan (n = 3), atenolol (n = 7) and manidipine (n = 10) did not reduce the ratio of changes; on the contrary, they increased it in deltaHX by +188.2 +/- 331%, +96.2 +/- 192.2% and +42.6 +/- 137.3%, respectively. The elevation of deltaHX after exercise correlated significantly with the serum concentration of uric acid at rest in untreated hypertensive patients (y = 0.194 - 0.255x; R2 = 0.185, n = 30: P < 0.05). The prevalence of reduction of both deltaHX and serum uric acid was significantly higher in the patients treated with alacepril, bevantolol and doxazosin (67%: P < 0.02) than in the patients treated with losartan, atenolol and manidipine (12%).

CONCLUSIONS

It is concluded that the skeletal muscles of hypertensive patients released deltaHX in excess by activation of muscle-type adenosine monophosphate (AMP) deaminase, depending on the degree of hypoxia. The modification of deltaHX by angiotensin-converting enzyme inhibitors and alpha1-blockers influenced the level of serum uric acid, suggesting that the skeletal muscles may be an important source of uric acid as well as of the substrate of xanthine oxidase in hypertension.

Inhibitory mechanism by polysialic acid for lamina-specific branch formation of thalamocortical axons

During development, thalamocortical axons form arbors primarily in layer 4 of the neocortex. This lamina-specific branch formation was studied in cultures of rat thalamic explants grown next to chemically fixed cortical slices. After a week in vitro, thalamic axons formed branches specifically in the target layer of fixed cortical slices, regardless of the orientation of the ingrowth. This in vitro system permits a direct assessment of contributions of membrane-associated molecules to thalamic axon branch formation. To this end, the present study uses three enzymatic perturbations: chondroitinase, phosphatidylinositol phospholipase C, or the polysialic acid (PSA)-specific endoneuraminidase (endo N). With endo N pretreatment of cortex, the number of branch points was increased significantly, whereas branch tip length was decreased. In addition, the localization of branch points to the target layer was weakened considerably. These features of branch formation were not altered by the other two enzymatic treatments, except that branch tips were shortened by chondroitinase treatment to the same extent as in endo N treatment. These results suggest that membrane-bound components are involved in lamina-specific branch formation of thalamocortical axons, and in particular that PSA moieties contribute to laminar specificity by inhibiting branch emergence in inappropriate layers.

Mixed connective tissue disease with multiple organ damage: successful treatment with plasmapheresis

A 24-year-old-woman with mixed connective tissue disease (MCTD) developed multiple organ failure, disseminated intravascular coagulation (DIC), metabolic acidosis, and respiratory and renal failure resulting from visceral vasospasm, so-called visceral Raynaud's phenomenon. After plasmapheresis, the condition of multiple organ failure was markedly improved. The successful treatment with plasmapheresis was dependent upon the removal of immune complexes in serum and improvement of visceral circulation. Thus plasma exchange is recommended as a possible a treatment for multiple organ damage in MCTD.

Dorsal spinal cord inhibits oligodendrocyte development

Oligodendrocytes are the myelinating cells of the mammalian central nervous system. In the mouse spinal cord, oligodendrocytes are generated from strictly restricted regions of the ventral ventricular zone. To investigate how they originate from these specific regions, we used an explant culture system of the E12 mouse cervical spinal cord and hindbrain. In this culture system O4(+) cells were first detected along the ventral midline of the explant and were subsequently expanded to the dorsal region similar to in vivo. When we cultured the ventral and dorsal spinal cords separately, a robust increase in the number of O4(+) cells was observed in the ventral fragment. The number of both progenitor cells and mature cells also increased in the ventral fragment. This phenomenon suggests the presence of inhibitory factor for oligodendrocyte development from dorsal spinal cord. BMP4, a strong candidate for this factor that is secreted from the dorsal spinal cord, did not affect oligodendrocyte development. Previous studies demonstrated that signals from the notochord and ventral spinal cord, such as sonic hedgehog and neuregulin, promote the ventral region-specific development of oligodendrocytes. Our present study demonstrates that the dorsal spinal cord negatively regulates oligodendrocyte development.

Characterization of Ca(2+) channels in rat subthalamic nucleus neurons

The subthalamic nucleus (STN) plays a key role in motor control. Although previous studies have suggested that Ca(2+) conductances may be involved in regulating the activity of STN neurons, Ca(2+) channels in this region have not yet been characterized. We have therefore investigated the subtypes and functional characteristics of Ca(2+) conductances in STN neurons, in both acutely isolated and slice preparations. Acutely isolated STN cells were identified by retrograde filling with the fluorescent dye, Fluoro-Gold. In acutely isolated STN neurons, Cd(2+)-sensitive, depolarization-activated Ba(2+) currents were observed in all cells studied. The current-voltage relationship and current kinetics were characteristic of high-voltage-activated Ca(2+) channels. The steady-state voltage-dependent activation curves and inactivation curves could both be fitted with a single Boltzmann function. Currents evoked with a prolonged pulse, however, inactivated with multiple time constants, suggesting either the presence of more than one Ca(2+) channel subtype or multiple inactivation processes with a single channel type in STN neurons. Experiments using organic Ca(2+) channel blockers revealed that on average, 21% of the current was nifedipine sensitive, 52% was sensitive to omega-conotoxin GVIA, 16% was blocked by a high concentration of omega-agatoxin IVA (200 nM), and the remainder of the current (9%) was resistant to the co-application of all blockers. These currents had similar voltage dependencies, but the nifedipine-sensitive current and the resistant current activated at slightly lower voltages. omega-Agatoxin IVA at 20 nM was ineffective in blocking the current. Together, the above results suggest that acutely isolated STN neurons have all subtypes of high-voltage-activated Ca(2+) channels except for P-type, but have no low-voltage-activated channels. Although acutely isolated neurons provide a good preparation for whole cell voltage-clamp study, dendritic processes are lost during dissociation. To gain information on Ca(2+) channels in dendrites, we thus studied Ca(2+) channels of STN neurons in a slice preparation, focusing on low-voltage-activated channels. In current-clamp recordings, a slow spike was always observed following termination of an injected hyperpolarizing current. The slow spike occurred at resting membrane potentials and was sensitive to micromolar concentrations of Ni(2+), suggesting that it is a low-threshold Ca(2+) spike. Together, our results suggest that STN neurons express low-voltage-activated Ca(2+) channels and several high-voltage-activated subtypes. Our results also suggest the possibility that the low-voltage-activated channels have a preferential distribution to the dendritic processes.

A factor XI deficiency associated with a nonsense mutation (Trp501stop) in the catalytic domain

We identified a novel mutation in an asymptomatic 65-year-old Japanese man with severe factor XI deficiency. Sequence analysis after polymerase chain reaction single-stranded conformation polymorphism (PCR-SSCP) analysis of his factor XI gene revealed a G-->A transition in codon 501 of exon 13, resulting in a substitution of Trp501 (TGG) by a stop codon (TAG) in the catalytic domain. This mutation abolished a FokI restriction site. The PCR product from normal subjects was digested with FokI and yielded two fragments, one of 223 bp and one of 47 bp. The PCR product from the patient gave a single 270-bp fragment, demonstrating possible homozygosity.

'Epitope fingerprinting' using overlapping 20-mer peptides of the MUC1 tandem repeat sequence

The ISOBM TD-4 Workshop antibodies 122-177 were tested for reactivity with 20 overlapping MUC1 tandem repeat 20-mer peptides by an ELISA, in order to determine the complete amino acid sequences of the epitopes. Of the 56 antibodies studied, 30 showed specific binding and thus the epitopes were characterized. The epitopes appear to be 'broader' when compared to those deduced from studies using smaller peptides. Interassay variation is remarkably small, allowing for precise grouping of clusters with very similar epitope patterns. Five groups of antibodies show remarkable similarity: BC3 and VU-4-H5; BC4W154, C595 and Mc5; MF06 and B27.29; VU-11-D1 and VU-11-E2; Ma552, VU-3-C6, 7540MR and BC4E549. We have used the term 'epitope fingerprinting' to refer to the 'fine structure' of the epitope with all its essential and flanking amino acids. We believe this method is more precise than the usual epitope mapping with short peptides.

[Significance of interferon alpha therapy for advanced renal cell carcinoma. Fukushima Renal Cancer Study Group]

We ranked prognostic factors to retrospectively evaluate the clinical significance of interferon alpha (IFN-alpha) therapy in patients with Robson stage IVB renal cell carcinoma. A total of 44 Robson stage IVB renal cancer patients were divided into 2 groups, one with more than 6 months administration of IFN-alpha (3-7 times a week: group A) and another without any IFN-alpha administration. The distribution of these 2 groups was not randomized. In addition to IFN-alpha therapy, survival was analyzed with respect to performance status (PS), mass reductive nephrectomy, concomitant use of other cytotoxic therapies, the number of metastatic organs, growth type, site of metastasis and the period of diagnosis, using a multivariate method with Cox proportional hazards regression. The multivariate analysis showed administration of IFN-alpha to be the most significant factor influencing a good prognosis. Improved survival was also significantly correlated with slow growing type and good PS. Among group A, a significant favorable prognosis was obtained in patients with the responses of no change (NC), partial response (PR) and complete remission (CR) 6 months after initiating administration of IFN-alpha, as well as with good PS and a slow growing type carcinoma. We conclude that IFN-alpha therapy might improve the prognosis of patients with Robson stage IVB renal cell carcinoma, especially, in cases when a greater than NC response is obtained after 6 months administration of IFN-alpha.

Levels of interleukin (IL)-6, IL-8, and IL-1 receptor antagonist in the hepatic vein following liver surgery

BACKGROUND/AIMS

The liver produces various cytokines, but local changes in the concentrations of these reaction products after liver surgery are unknown. We investigated the local changes of interleukin-6, interleukin-8 and interleukin-1 receptor antagonist after liver surgery.

METHODOLOGY

We determined levels of interleukin-6, interleukin-8, and interleukin-1 receptor antagonist in the hepatic vein and radial artery after liver resection in 13 patients. These cytokine levels in the portal vein were also measured in 6 patients.

RESULTS

Interleukin-6, interleukin-8, and interleukin-1 receptor antagonist levels were significantly increased during liver surgery (P < 0.05). The level of interleukin-6 was significantly lower in the hepatic vein than in the radial artery as well as in the portal vein at the end of the operation (P < 0.05, < 0.03). The level of interleukin-8 and interleukin-1 receptor antagonist was significantly higher in the hepatic vein than in the artery (P < 0.05).

CONCLUSIONS

Interleukin-6 may be taken up by the liver after liver surgery, and the difference between hepatic venous and peripheral arterial interleukin-6 levels may be an indicator of liver regeneration after liver resection. Interleukin-8 and interleukin-1 receptor antagonist appear to be produced in the remaining liver.

Allele frequency of human endothelial nitric oxide synthase gene polymorphism in abdominal aortic aneurysm

OBJECTIVE

This study was performed to examine the role of the endothelial constitutive NO synthase (ecNOS) gene in patients with abdominal aortic aneurysm (AAA).

METHODS

We determined the distributions of polymorphism in intron 4 of the ecNOS (ecNOS4) gene, amplified by polymerase chain reaction, and compared the allele frequencies between subjects with abdominal aortic aneurysms (AAAs) and healthy individuals.

PATIENTS

Fifty-eight patients with AAAs and 410 race-matched healthy controls were studied.

RESULTS

Two alleles of the ecNOS4 gene, containing 4 (a-allele) and 5 (b-allele) repeats, were identified. We found that the a-allele frequency of this gene was significantly higher in the surgical than in the non-surgical group.

CONCLUSION

The results of this study suggest that the a-allele of the ecNOS4 gene is indicative of the need for surgery for AAA. Analysis of the alleles of the ecNOS4 gene polymorphism could provide useful information concerning the clinical course of AAA progression.

The mode of actions of lysozyme as an immunoglobulin production stimulating factor

As we demonstrated before, hen egg white lysozyme stimulates immunoglobulin production by a human-human hybridoma line, HB4C5 cells and human peripheral blood lymphocytes. Then, the mode of actions of lysozyme as an immunoglobulin production stimulating factor was investigated. The immunoglobulin production stimulating activity of lysozyme was inactivated by trypsin digestion, even though the enzymatic activity was completely preserved. This fact suggests that the immunoglobulin production stimulating effect of lysozyme is irrelevant to its enzymatic function. Furthermore, this means that the effect is a novel function of this enzyme. Lysozyme enhanced IgM production by transcription-suppressed HB4C5 cells treated with actinomycin D. However, the enzyme was ineffective to accelerate IgM production by translation-suppressed HB4C5 cells treated with cycloheximide or sodium fluoride. In addition, the intracellular IgM content of HB4C5 cells treated with monensin for suppression of the post-transcription activity was obviously increased by lysozyme, although the secretion of IgM was inhibited. These findings suggest that lysozyme accelerates the translation process to enhance immunoglobulin productivity.

Local directional cues control growth polarity of dopaminergic axons along the rostrocaudal axis

The vertebrate CNS is composed of a variety of longitudinal axonal tracts extending rostrally and caudally. Although recent studies have demonstrated that chemoattraction and chemorepulsion play key roles in axon guidance along the circumferential axis in the neural tube of the vertebrate, mechanisms of axonal elongation along the longitudinal axis, and most importantly, what determines rostrocaudal polarity of axonal growth, remains unknown. Here, we examined the mechanism that guides midbrain dopaminergic axons rostrally, using flat whole-mount preparations of embryonic rat brain both in vivo and in vitro. At embryonic day 11 (E11) and early stage E12, dopaminergic neurons in the ventral midbrain extended short axons dorsally. By middle stage E12, these axons had increased in number, some deflecting rostrally and others caudally. At E13, almost all axons showed rostrally oriented growth heading toward the forebrain targets. In in vitro whole-mount preparations prepared from an E12 embryo and cultured for 24 hr, these axons showed rostrally oriented growth, but when they were forced to grow on substratum of reversed rostrocaudal polarity, they turned abruptly and grew following the polarity of the reversed midbrain substratum. These results suggest that local directional cues in the midbrain guide these axons rostrally and support the idea that substratum-associated polarized cues play an important role in axon guidance along the longitudinal axis.

[Coronary artery bypass grafting by warm blood cardioplegia and normothermic cardiopulmonary bypass]

Warm blood cardioplegia and normothermic cardiopulmonary bypass (CPB) have been used in coronary artery bypass grafting (CABG). The method of myocardial protection was intermittent combined antegrade and retrograde warm blood cardioplegia with terminal warm blood cardioplegia. We performed elective CABG in 30 patients above the age of 70 years (elderly group). These patients were compared with 30 patients below 70 years who underwent elective CABG (young group). No significant differences were observed about the preoperative data between two groups. No significant differences were obtained in the postoperative cardiac function, cerebral or renal complication between two groups. Warm blood cardioplegia and normothermic CPB were not associated with adverse effects on postoperative recovery in elderly as well as young patients. We may conclude that warm blood cardioplegia with normothermic CPB is a safe procedure for CABG in elderly as well as young patients.

Afferents of cranial sensory ganglia pathfind to their target independent of the site of entry into the hindbrain

In vertebrates, sensory neurons interconnect a variety of peripheral tissues and central targets, conveying sensory information from different types of sensory receptors to appropriate second-order neurons in the central nervous system (CNS). To explore the possibility that the different rhombomere environments where sensory neurons enter into the hindbrain affect the pathfinding capability of growth cones, we studied the development of the VIIIth ganglion afferent both in vivo and in vitro. We focused on the vestibular nerve because it is the only cranial nerve projecting to the cerebellum, allowing for ready identification from its pattern of projection. Embryonic rat brain was cut along the dorsal midline and, with the VIIIth and Vth ganglia still attached, flat mounted and visualized with antibodies specific for sensory ganglia. Axons reached the cerebellar primordium at embryonic day (E) 13, then splayed out towards the edges of the rhombic lip of rostral hindbrain. In vitro, the VIIIth ganglion showed development similar to that in vivo and innervated the cerebellum, an appropriate target, indicating that mechanisms for axon guidance and target recognition are preserved in vitro. When the VIIIth ganglion was transplanted to the position of the Vth ganglion, axons from the transplanted ganglion entered the cerebellar primordium with a trajectory characteristic of the VIIIth nerve. These results indicate that the central projection pattern of the VIIIth nerve is not affected by the environment of nerve entry into the brainstem, suggesting that axons of sensory cranial ganglion intrinsically possess the capacity to find their target correctly.

Coronary artery bypass grafting for spontaneous coronary artery dissection: a case report and a review of the literature

A 37 year-old woman underwent coronary angiography because of chest pain at rest. Selective coronary angiography demonstrated dissection and stenosis with a filling delay from the left main trunk to the left anterior descending coronary artery. The patient was successfully managed with urgent coronary artery bypass grafting. Spontaneous coronary artery dissection is relatively rare and threatens both elderly and young patients with acute coronary disturbances. Patients can be divided etiologically into three groups. The first was comprised of those in the postpartum period. The second was those with atherosclerotic coronary artery disease, and the third was those associated with coronary vasospasm. Dissections are frequently fatal and most of the known cases have been diagnosed at autopsy. Only a few cases have been documented by coronary angiography, and operative cases of spontaneous coronary artery dissection have rarely been reported.

Characterization of factors regulating lamina-specific growth of thalamocortical axons

During development, most thalamocortical axons extend through the deep layers to terminate in layer 4 of neocortex. To elucidate the molecular mechanisms that underlie the formation of layer-specific thalamocortical projections, axon outgrowth from embryonic rat thalamus onto postnatal neocortical slices which had been fixed chemically was used as an experimental model system. When the thalamic explant was juxtaposed to the lateral edge of fixed cortical slice, thalamic axons extended farther in the deep layers than the upper layers. Correspondingly, thalamic axons entering from the ventricular side extended farther than those from the pial side. In contrast, axons from cortical explants cultured next to fixed cortical slices tended to grow nearly as well in the upper as in the deep layers. Biochemical aspects of lamina-specific thalamic axon growth were studied by applying several enzymatic treatments to the cortical slices prior to culturing. Phosphatidylinositol phospholipase C treatment increased elongation of thalamic axons in the upper layers without influencing growth in the deep layers. Neither chondroitinase, heparitinase, nor neuraminidase treatment influenced the overall projection pattern, although neuraminidase slightly decreased axonal elongation in the deep layers. These findings suggest that glycosylphosphatidylinositol-linked molecules in the cortex may contribute to the laminar specificity of thalamocortical projections by suppressing thalamic axon growth in the upper cortical layers.

[Preoperative autologous blood donation in coronary artery bypass grafting in elderly patients]

Allogeneic blood transfusion still carries risks of transfusion reaction and infection. We examined the effect of a preoperative autologous blood donation (800-1,200 g) by subcutaneous epoetin alpha injection on a series of patients undergoing elective coronary artery bypass grafting (CABG). CABG was being performed with increased frequency in elderly patients. We have performed CABG in 18 patients over 65 years of age (elderly group). These patients were compared with 20 patients under 64 years of age (younger group). Postoperative bleeding and allogeneic blood transfusion were significantly larger in quantity in the elderly group than the younger group (p < 0.05). The incidence of allogeneic blood usage was significantly higher in the elderly group than the younger group (p < 0.05). Therefore, a preoperative autologous blood donation in CABG was considered to be not so effective for saving allogeneic blood transfusion and preventing transfusion reaction or infection in elderly patients.

Protective effect of nisoldipine on myocardial ischemia during coronary bypass surgery

BACKGROUND

Nisoldipine, a calcium antagonist, was assessed for myocardial protection and the prevention of reperfusion injury in patients undergoing CABG.

METHODS

Of the 34 subjects undergoing CABG in this study, 20 were given nisoldipine orally at 10 mg/day for 2 weeks before surgery (N group) and the other 14 untreated controls (C group). Myocardial protection was conducted via ante-grade cold blood cardioplegia at 20-minute intervals.

RESULTS

Myocardial blood flow was significantly higher in the N group (67.8 +/- 21.8 ml/100 g vs. 47.2 +/- 14.4 ml/100 g, p < 0.05) after cardiopulmonary bypass. Serum interleukin-6 levels were significantly lower in the N group 1 hour after reperfusion (116 +/- 58 vs. 409 +/- 362 pg/ml, p < 0.05), as were serum lactate dehydrogenase levels immediately after surgery (888 +/- 268 vs. 1350 +/- 486 IU/L, p < 0.05). The N Group showed a better left ventricle stroke work index 6 hours after surgery (43 +/- 8 vs. 36 +/- 9 g.m/m2). Dopamine dosage in the N group on postoperative day 1 was lower than in controls (5.3 +/- 1.9 vs. 3.0 +/- 2.4 micrograms/kg/min).

CONCLUSIONS

Preoperative nisoldipine treatment increased blood flow in the postischemic myocardium and prevented myocardial damage and reperfusion injury to some extent.

Valvulotomy of calcified aortic valves using the neodymium: yttrium-aluminum-garnet (Nd:YAG) laser

The neodymium: yttrium-aluminum-garnet (Nd:YAG, wavelength; 1064 nm) laser knife was used for valvulotomy of severely calcified aortic valves in 12 patients. The fibrous layer enveloping the calcium deposits was peeled off the valvular annulus and the native valvular leaflet. The underlying calcium deposits were then resected. The average aortic cross-clamp time was 69 +/- 21 minutes. The cardiopulmonary bypass time averaged 118 +/- 32 minutes. All of the patients were discharged from the hospital without complications. Laser valvulotomy can be used to resect severely calcified aortic valves without mechanical crushing, reducing the risk of embolization.

Non-mycotic pseudoaneurysm in the ascending aorta following cardiac surgery

Cannulation of the ascending aorta is the recognized method to achieve arterial return during cardiopulmonary bypass. Mediastinal infection after cardiac surgery can cause disruption at the point of insertion, and give rise to a pseudoaneurysm in the ascending aorta. Although rare, a pseudoaneurysm can occur without clear evidence of infection. Here we report two cases that received aortic valve replacement and that developed ascending aortic aneurysms after surgery. Based on our clinical findings, these aneurysms were related to the arterial cannulation into the aorta and not to any infection.

Platelet nitric oxide metabolites in migraine

Nitric oxide (NO) is a candidate as a causative molecule in migraine. We determined nitrite, total nitrate/nitrite, and cyclic guanosine 3',5'-monophosphate (cGMP) concentrations in platelets from 30 migraine without aura (MwoA) patients and 17 migraine with aura (MwA) patients. All migraine patients were studied during their migraine attacks. The control group consisted of 28 healthy volunteers. Concentrations of platelet nitrite and total nitrate/nitrite were determined using simple and sensitive nitrate/nitrite fluorometric assay techniques. High concentrations of platelet nitrite and total nitrate/nitrite were found in patients with MwoA and MwA when compared with healthy controls. High concentrations of platelet cGMP were also found in patients with MwoA and MwA. The levels of platelet total nitrate/nitrite significantly decreased in headache-free periods after treatment with oral propranolol. These findings suggest that NO is produced in platelets during migraine attacks. It may also be related to the migrainous pain and the changes in cerebral blood flow experienced during migraine attacks. These data may provide new strategies for the treatment of migraine.