Mitofusin-2 mediates cannabidiol-induced neuroprotection against cerebral ischemia in rats

Cannabidiol (CBD) reportedly exerts protective effects against many psychiatric disorders and neurodegenerative diseases, but the mechanisms are poorly understood. In this study, we explored the molecular mechanism of CBD against cerebral ischemia. HT-22 cells or primary cortical neurons were subjected to oxygen-glucose deprivation insult followed by reoxygenation (OGD/R). In both HT-22 cells and primary cortical neurons, CBD pretreatment (0.1, 0.3, 1 μM) dose-dependently attenuated OGD/R-induced cell death and mitochondrial dysfunction, ameliorated OGD/R-induced endoplasmic reticulum (ER) stress, and increased the mitofusin-2 (MFN2) protein level in HT-22 cells and primary cortical neurons. Knockdown of MFN2 abolished the protective effects of CBD. CBD pretreatment also suppressed OGD/R-induced binding of Parkin to MFN2 and subsequent ubiquitination of MFN2. Overexpression of Parkin blocked the effects of CBD in reducing MFN2 ubiquitination and reduced cell viability, whereas overexpressing MFN2 abolished Parkin's detrimental effects. In vivo experiments were conducted on male rats subjected to middle cerebral artery occlusion (MCAO) insult, and administration of CBD (2.5, 5 mg · kg-1, i.p.) dose-dependently reduced the infarct volume and ER stress in the brains. Moreover, the level of MFN2 within the ischemic penumbra of rats was increased by CBD treatment, while the binding of Parkin to MFN2 and the ubiquitination of MFN2 was decreased. Finally, short hairpin RNA against MFN2 reversed CBD's protective effects. Together, these results demonstrate that CBD protects brain neurons against cerebral ischemia by reducing MFN2 degradation via disrupting Parkin's binding to MFN2, indicating that MFN2 is a potential target for the treatment of cerebral ischemia.

COVID-19 associated Brugada pattern electrocardiogram: systematic review of case reports

Objective

To summarize published case reports of patients diagnosed with COVID-19 infection and Brugada pattern electrocardiogram (ECG).

Background

Fever is a common clinical manifestation of COVID-19 infection. Fever has also been associated with unmasking Brugada pattern ECG in patients and may result in life-threatening arrhythmia. Little is known regarding COVID-19 associated Brugada pattern ECG. There is paucity of data and guidance in how to manage these patients.

Methods

To identify all published case reports, the latest Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist was followed. A literature search was conducted using PubMed, EMBASE, and Scopus through September 2021. A systematic review was performed to identify the incidence, clinical characteristics, and management outcomes of COVID-19 patients with a Brugada pattern ECG.

Results

A total of 18 cases were collected. The mean age was 47.1 years and 11.1% were women. No patient had prior confirmed diagnosis of Brugada syndrome. The most common presenting clinical symptoms were fever (83.3%), chest pain (38.8%), shortness of breath (38.8%), and syncope (16.6%). All 18 patients presented with type 1 Brugada pattern ECG. Four patients (22.2%) underwent left heart catheterization, and none demonstrated the presence of obstructive coronary disease. The most common reported therapies included antipyretics (55.5%), hydroxychloroquine (27.7%), and antibiotics (16.6%). One patient (5.5%) died during hospitalization. Three patients (16.6%) who presented with syncope received either an implantable cardioverter defibrillator or wearable cardioverter defibrillator at discharge. At follow up, thirteen patients (72.2%) had resolution of type 1 Brugada pattern ECG.

Conclusion

COVID-19 associated Brugada pattern ECG is rare. Most patients may see resolution of the ECG pattern once their symptoms have improved. Increased awareness and timely use of antipyretics is warranted in this population.

Funding Acknowledgement

Type of funding sources: None.

Clinical and health status outcomes in nonagenarians undergoing transcatheter mitral valve repair

Background

Transcatheter mitral valve repair (TMVR) has emerged as an effective treatment in patients with mitral regurgitation due to degenerative valve disease and increased surgical risk. However, nonagenarians were excluded from the original TMVR trials and there is paucity of data.

Purpose

The aim of this study was to investigate the clinical and health status outcomes in nonagenarians undergoing TMVR.

Methods

This is a retrospective observational study of patients who underwent TMVR at a community hospital between June 2012 and December 2019. Baseline clinical characteristics and post-operative outcomes were collected and compared. This cohort of patients was stratified into three groups, age <80 (n=57), 80–89 (n=150) and ≥90 (n=40). Clinical outcomes assessed were procedural complications and 30-day and 1-year mortality. Health status was assessed using the 12-item Kansas City Cardiomyopathy Questionnaire overall summary score (KCCQ-OS) at baseline and at 1-month and 12-month follow-up.

Results

Overall there was no significant difference in procedural complications between the three groups (Table 1). Although not statistically significant, nonagenarians had higher rates of stroke (0% vs 0.6% vs 5%, p=0.053). 30-day and 1-year mortality were similar (p=0.796 and p=0.599). At baseline, there was significance difference in KCCQ-OS between three groups (27.0±20.8 vs 45.3±26.4 vs 41.1±26.2, p=0.ehab724.16483). However, there were no difference in KCCQ-OS at 1-month or 12-months (p=0.731 and p=0.561).

Conclusion

In our single center retrospective study, nonagenarians who underwent TMVR had similar clinical and health status outcomes compared to other age groups. TMVR appeared to be a safe and effective procedure in this patient population.

Funding Acknowledgement

Type of funding sources: None.

Early experience utilizing bivalirudin as anticoagulation in extracorporeal membrane oxygen in coronavirus disease 2019

Background

Extracorporeal membrane oxygenation (ECMO) is utilized as rescue therapy in patients diagnosed with coronavirus disease 2019 (COVID-19) with refractory respiratory or cardiogenic failure. Systemic anticoagulation with heparin remains the initial choice for thromboembolism prophylaxis in ECMO-treated patients. However, heparin carries the risk of severe complications, such as heparin-induced thrombocytopenia (HIT), and acquired antithrombin deficiency. Bivalirudin has been suggested as an alternative anticoagulant since it neither requires anti-thrombin III monitoring nor triggers HIT.

Purpose

There is very limited data on the utilization of bivalirudin in patients with COVID-19 treated with ECMO. We report the clinical safety and efficacy of using bivalirudin at our institution.

Methods

We retrospectively reviewed 17 patients diagnosed with COVID-19, who were treated with ECMO from 7/31/2020 to 12/20/2020. All patients received bivalirudin for thromboprophylaxis while on ECMO support.

Results

The mean age of our study cohort was forty-five years. Thirteen patients (76.4%) were of either Hispanic or African American descent. Of the seventeen patients, six (35.3%) patients developed deep venous thrombosis and one (5.9%) patient developed pulmonary embolism. Two (11.8%) patients developed a clotted circuit that required exchange. Fifteen (88.2%) patients had hemorrhage requiring transfusion with the gastrointestinal tract as the most common bleeding site. Nine (52.9%) patients developed thrombocytopenia. Six (35.3%) patients were discharged home or to a long-term acute care center; eleven (64.7%) patients died. The average length of stay was thirty-seven days.

Conclusion

In our small case series, the rates of complications and mortality remained high while using bivalirudin as anticoagulation of choice in patients diagnosed with COVID-19 and treated with ECMO. Further studies are needed to investigate the optimal anticoagulant in this population.

Funding Acknowledgement

Type of funding sources: None.

[Study on characteristics and microscopic identification of fruits of Notopterygium franchetii and N. forrestii]

Rhizoma et Radix Notopterygii is a rare and endangered Chinese medicine. In the collection of Notopterygium franchetii fruits, we collected a sample of N. forrestii , which is a spurious breed. Fruits of N. franchetii and N. forrestii are very similar in morphology and can be easily confused. Until now the morphological identification of the fruits of Notopterygium has not been reported. To provide a scientific basis for the identification of N. franchetii and N. forrestii fruits, the morphology and microscopic identification were studied in this paper. In this study, stereomicroscope and paraffin sections were used to compare the morphological characteristics and microscopic characteristics of these two fruits. Our results showed that these two fruits were different in size, surface texture and the number of vertical edges on the back. These traits can be used as diagnostic characteristic of these two fruits. The difference between the number of tubing and the endosperm cell contents can be used as microscopic identification features. The above discriminative characteristics can distinguish the two fruits and provide scientific basis for the identification and germplasm evaluation of Notopterygium fruits.

Transoral vertical ramus osteotomy fixed with Kirschner pins

Transoral vertical ramus osteotomy (VRO) has been condemned because the condyle has the potential to sag, and because it needs lengthy maxillomandibular fixation. We have therefore introduced a simple method of fixation, and examined its effectiveness and complications. After the osteotomy, the proximal and distal segments are trimmed to adapt to each other. Four Kirschner (K) pins 0.9mm in diameter are inserted percutaneously from the proximal to the distal segment while the condyle is positioned in the glenoid fossa. This is followed by a brief period of maxillomandibular fixation. We have reviewed the records of 95 patients who had unilateral or bilateral vertical ramus osteotomy fixed with K pins, after which the mean (SD) period of fixation was 19 (11) days. Fixation failed in two patients because excursion of the jaw was either too heavy or too early. The fixations were redone. All other fixations remained stable, including the 20 dual-jaw procedures in which VRO preceded maxillary osteotomy. The mean (SD) maximal mouth opening at final follow-up was 44 (7) mm, and in only one patient was it less than 30mm. Numbness of the lip or chin developed in seven patients, five of whom had other anterior mandibular procedures. Four patients had discomfort on palpation of the site of the pins, and one required removal. The new method was effective, and resulted in few complications within its limitations.

Differential Gene Expression Profiles Reflecting Macrophage Polarization in Aging and Periodontitis Gingival Tissues

Recent evidence has determined a phenotypic and functional heterogeneity for macrophage populations. This plasticity of macrophage function has been related to specific properties of subsets (M1 and M2) of these cells in inflammation, adaptive immune responses and resolution of tissue destructive processes. This investigation hypothesized that targeted alterations in the distribution of macrophage phenotypes in aged individuals, and with periodontitis would be skewed towards M1 inflammatory macrophages in gingival tissues. The study used a non-human primate model to evaluate gene expression profiles as footprints of macrophage variation in healthy and periodontitis gingival tissues from animals 3-23 years of age and in periodontitis tissues in adult and aged animals. Significant increases in multiple genes reflecting overall increases in macrophage activities were observed in healthy aged tissues, and were significantly increased in periodontitis tissues from both adults and aged animals. Generally, gene expression patterns for M2 macrophages were similar in healthy young, adolescent and adult tissues. However, modest increases were noted in healthy aged tissues, similar to those seen in periodontitis tissues from both age groups. M1 macrophage gene transcription patterns increased significantly over the age range in healthy tissues, with multiple genes (e.g. CCL13, CCL19, CCR7 and TLR4) significantly increased in aged animals. Additionally, gene expression patterns for M1 macrophages were significantly increased in adult health versus periodontitis and aged healthy versus periodontitis. The findings supported a significant increase in macrophages with aging and in periodontitis. The primary increases in both healthy aged tissues and, particularly periodontitis tissues appeared in the M1 phenotype.

Quantifying midbrain serotonin transporter in depression: a preliminary study of diagnosis and naturalistic treatment outcome

INTRODUCTION

Serotonin may play an important role in the pathology of major depressive disorder (MDD). However, the relationship between serotonin transporter (SERT) availability and the medical outcome of antidepressant treatment is uncertain.

METHODS

In this naturalistic study, SERT availability (expressed as the specific uptake ratio, SUR) in the midbrain of 17 drug-free patients with MDD and 17 controls matched for age and gender was measured using SPECT with [(123)I]ADAM. The severity of MDD was measured by the Hamilton Depression Rating Scale before, and after 6 weeks of non-standardized antidepressant treatment.

RESULTS

A total of 12 patients completed the study. The SUR of the patients with MDD was significantly lower than that of the healthy controls. The SUR of SERT was not found to have a linear relationship with the treatment outcome; however, supplemental analysis found a curvilinear relationship between treatment outcome and the SUR of SERT.

DISCUSSION

The findings indicate that the SUR of SERT is lower in patients with MDD; however it did not predict treatment outcome in a linear fashion. Studies with larger sample sizes are required.

Experimental and numerical insights into isotropic spreading and deterministic dewetting of dielectrowetted films

Dielectrowetting effects of surface wrinkling, isotropic vs anisotropic spreading, electrode geometry, and deterministic dewetting are presented both experimentally and by 3D numerical modeling. The numerical results are generated by COMSOL in conjunction with the phase-field and electrohydrodynamic methods, including comparisons to experimental data. The dynamic behavior of the two-phase system has been accurately characterized on both the macro- and microscopic level. This work provides a deeper theoretical insight into the operating physics of dielectrowetting superspreading devices.

P300 waveform and dopamine transporter availability: a controlled EEG and SPECT study in medication-naive patients with schizophrenia and a meta-analysis

BACKGROUND

Reduced P300 event-related potential (ERP) amplitude and latency prolongation have been reported in patients with schizophrenia compared to healthy controls. However, the influence of antipsychotics (and dopamine) on ERP measures are poorly understood and medication confounding remains a possibility.

METHOD

We explored ERP differences between 36 drug-naive patients with schizophrenia and 138 healthy controls and examined whether P300 performance was related to dopamine transporter (DAT) availability, both without the confounding effects of medication. We also conducted a random effects meta-analysis of the available literature, synthesizing the results of three comparable published articles and our local study.

RESULTS

No overall significant difference was found in mean P300 ERP between patients and controls in latency or in amplitude. There was a significant gender effect, with females showing greater P300 amplitude than males. A difference between patients and controls in P300 latency was evident with ageing, with latency increasing faster in patients. No effect of DAT availability on P300 latency or amplitude was detected. The meta-analysis computed the latency pooled standardized effect size (PSES; Cohen's d) of -0.13 and the amplitude PSES (Cohen's d) of 0.48, with patients showing a significant reduction in amplitude.

CONCLUSIONS

Our findings suggest the P300 ERP is not altered in the early stages of schizophrenia before medication is introduced, and the DAT availability does not influence the P300 ERP amplitude or latency. P300 ERP amplitude reduction could be an indicator of the progression of illness and chronicity.

Efficient spin-light emitting diodes based on InGaN/GaN quantum disks at room temperature: a new self-polarized paradigm

A well-behaved spin-light emitting diode (LED) composed of InGaN/GaN multiple quantum disks (MQDs), ferromagnetic contact, and Fe3O4 nanoparticles has been designed, fabricated, and characterized. The degree of circular polarization of electroluminescence (EL) can reach up to a high value of 10.9% at room temperature in a low magnetic field of 0.35 T, which overcomes a very low degree of spin polarization in nitride semiconductors due to the weak spin-orbit interaction. Several underlying mechanisms play significant roles simultaneously in this newly designed device for the achievement of such a high performance. Most of all, the vacancy between nanodisks can be filled by half-metal nanoparticles with suitable energy band alignment, which enables selective transfer of spin polarized electrons and holes and leads to the enhanced output spin polarization of LED. Unlike previously reported mechanisms, this new process leads to a weak dependence of spin relaxation on temperature. Additionally, the internal strain in planar InGaN/GaN multiple quantum wells can be relaxed in the nanodisk formation process, which leads to the disappearance of Rashba Hamiltonian and enhances the spin relaxation time. Our approach therefore opens up a new route for the further research and development of semiconductor spintronics.

Lower availability of midbrain serotonin transporter between healthy subjects with and without a family history of major depressive disorder - a preliminary two-ligand SPECT study

PURPOSE

Serotonin transporter (SERT) and dopamine transporter (DAT) levels differ in patients with major depressive disorder (MDD) who are in a depressed state in comparison with healthy controls. In addition, a family history of depression is a potent risk factor for developing depression, and inherited vulnerability to serotonergic and dopaminergic dysfunction is suspected in this. The aim of this study was to examine the availabilities of midbrain SERT and striatal DAT in healthy subjects with and without a first-degree family history of MDD.

METHODS

Eight healthy subjects with first-degree relatives with MDD and 16 sex- and age-matched healthy controls were recruited. The availabilities of SERT and DAT were approximated using SPECT, employing [¹²³I] 2-((2-((dimethylamino) methyl) phenyl)thio)-5-iodophenylamine (ADAM) and [(⁹⁹m)Tc] TRODAT-1 as the ligands, respectively. There are missing data for one participant with a first-degree family history of MDD from the ADAM study, due to a lack of the radio-ligand at the time of experiment.

RESULTS

SERT availability in the midbrain was significantly lower in subjects with a first-degree family history of MDD than in healthy subjects. However, DAT availability was no different between two groups.

CONCLUSIONS

The results with regard to the midbrain SERT level suggest the heritability of MDD.

Treadmill exercise improved adriamycin-induced nephropathy

Adriamycin nephropathy (AN) or doxorubicin-induced chronic kidney disease (DRCKD) has several strengths as an experimental model of renal diseases involving glomerulosclerosis, tubulointerstitial inflammation and fibrosis. Exercise has shown to be beneficial to many chronic diseases. We hypothesize that treadmill exercise may improve AN, and an investigation was carried out with the AN SD rat model. Treadmill exercise was conducted three times per week, each time for 30 and 60 min. DR induced swelling of glomeruli, collagen deposition in the interstitium and renal cortex, and increased the serum levels of MDA, IL-6, PDGF-BB, MMP-2, MMP-9, TGF-beta, p-PDGFR, uric acid, serum cholesterol, triglycerides, BUN, creatinine, blood platelet count, ratio of kidney to body weight, glomerular volume, and urinary BUN and protein. Conversely, levels of serum SOD, TNF-alpha, p-PI3K, p-Akt, albumin, WBC, RBC, and urinary creatinine were decreased. Treadmill exercise ameliorated most of these damaging effects, better outcome was found for the 60-min exercise training. Conclusively, the endurance exercise is more associated with the normalization of signaling expressions involving TGF-beta, PDGF-BB, p-PDGFR, p-PI3K, and p-Akt, which may help CKD patients to restore cell survival, proliferation, and growth. As rehabilitation is a personalized medicine, an appropriate design to fit individual feasibility has to be well figured out.

Ileocolorectal intussusception due to caecal hamartoma

Although 75% of intussusceptions occur within the first two years of life, they can also develop in teenage years. This is a case report of a 13-year old boy with an ileocolorectal intussusception from a large caecal hamartoma (10 x 6 x 2 cm3) adjacent to the ileocaecal valve. Partial resection of the ascending colon and terminal ileum was performed, and the pathology of the resected mass revealed a hamartoma. Ileocolorectal intussusception secondary to hamartoma represents a particularly rare event in the paediatric population. With early surgical intervention, this patient's outcome was uneventful.

Poly[diaqua-(μ(2)-oxalato-κO,O:O,O)(μ(2)-pyrazine-2-carboxyl-ato-κN,O:O,O')neodymium(III)]

In the title complex, [Nd(C(5)H(3)N(2)O(2))(C(2)O(4))(H(2)O)(2)](n), the Nd(III) atom is ten-coordinated by one N atom and three O atoms from two pyrazine-2-carboxyl-ate ligands, four O atoms from two oxalate ligands and two water mol-ecules in a distorted bicapped square-anti-prismatic geometry. The two crystallographically independent oxalate ligands, each lying on an inversion center, act as bridging ligands, linking Nd atoms into an extended zigzag chain. Neighboring chains are linked by the pyrazine-2-carboxyl-ate ligands into a two-dimensional layerlike network in the (10) plane. The layers are further connected by O-H⋯O and O-H⋯N hydrogen bonds, forming a three-dimensional supra-molecular network.

Clustering and phases of compartmentalized granular gases

This paper experimentally investigates the clustering conditions for compartmentalized monodisperse granular gases, determining the critical particle number and condensation granular temperature at the gas-clustering transition. When one heavier intruding particle is added to a monodisperse gas, it is found that the condensation temperature decreases with the ratio of the mass of the intruding particle to that of the background particle. This phenomenon can be mathematically characterized by a proposed linear relation, which is reminiscent of a relation between the freezing point depression for a solvent and the concentration of an added solute. Finally we perform various tests by changing the numbers of two types of particles in bidisperse granular mixtures to construct the phase diagrams, which present the range of the five different states, namely, homogeneous gas, unstable-gas, one-clustering, two-clustering, and granular oscillation states.

A large chest wall tumour in an asymptomatic 15-year-old girl

A 15-year-old asymptomatic girl was found to have a large left lower chest wall mass associated with chest wall invasion on an opportunistic chest radiograph. The tumour was excised and shown to be a clear cell sarcoma. Adjuvant chemotherapy was administered and she was disease free at her 10 month follow up.

Computer evaluation of network dynamics models with application to cell cycle control in budding yeast

Cellular processes are governed by complex networks of interacting genes and proteins. Theoretical molecular biologists attempt to describe these processes via mathematical models by writing biochemical reaction equations. Modellers are building increasingly larger and complex mathematical models to describe these cellular processes, making model evaluation a time consuming and difficult task. The authors describe an automatable process for model evaluation and a software system that implements this process. The software is adaptable to many types of models and is freely available along with all needed data files. The cell cycle control system for budding yeast is known in fine detail and constrained by more than 100 phenotypic observations in mutant strains. As an example, the authors apply their process to a model of cell cycle control in budding yeast containing dozens of regulatory equations and explaining nearly all of the known mutant phenotypes.

Cloning and expression of the genes associated with lipid metabolism in Tsaiya ducks

Sterol regulatory element binding protein 1 (SREBP1) drives the expression of several lipogenic genes, whereas SREBP2 dictates the expression of every gene involved in cholesterolgenesis in mammals. In the current study, we cloned the cDNA fragments for SREBP1, SREBP2, fatty acid synthase (FAS), 3-hydroxy-3-methylglutaryl-CoA reductase (HMG-CoA reductase), and very low density apolipoprotein-II (apoVLDL-II), the genes associated with lipid metabolism. Fifteen ducks immediately before the first egg was laid (18 wk old) and 15 ducks from the same population at an egg production rate of 80% were killed. Total RNA was extracted from liver and used to amplify the targeted genes by reverse transcription-PCR and screening of a cDNA library. The sequence data showed that Tsaiya duck SREBP1, SREBP2, FAS, and HMG-CoA reductase were highly homologous to that of chicken. Tsaiya duck SREBP1 mRNA was expressed in adipose tissue, cardiac muscle, skeletal muscle, liver, and ovary. The SREBP2 mRNA concentration was highest in liver and ovary. Concentrations of FAS and HMG-CoA reductase mRNA were high in liver and lower in other tissues. The apoVLDL-II mRNA was specifically expressed in the liver. The differences between mRNA concentrations of SREBP1, SREBP2, and FAS in the livers of laying and prelay ducks were not significant. However, the concentrations of hepatic HMG-CoA reductase and apoVLDL-II mRNA were higher in the laying ducks than in prelay ducks. Therefore, laying may affect particular aspects of lipid metabolism, especially biochemical pathways that involved apoVLDL-II and HMG-CoA reductase.

Neurotrophic effects of vascular endothelial growth factor and neurotrophins on cultured major pelvic ganglia

OBJECTIVE

To investigate the feasibility of using a ganglial culture system to screen various growth factors as potential therapeutic agents for pelvic nerve injuries.

MATERIALS AND METHODS

The major pelvic ganglia (MPG) were isolated from male rats and attached to culture dishes with the aid of Matrigel (Becton Dickinson, Mountain View, CA, USA). Alternatively, the dorso-caudal region (DCR) of MPG, from which the cavernous nerves originate, was dissected and then attached to a Matrigel-coated coverslip. The MPG or DCR was cultured in serum-free medium supplemented with phosphate-buffered saline (PBS, control), 50 ng/mL of vascular endothelial growth factor (VEGF), 20 ng/mL of a neurotrophin (BDNF, NT3, or NT4), or combinations of these growth factors. After 2 days of incubation, the ganglial tissues with their outgrowing nerve fibres were stained for the expression of NADPH-diaphorase, tyrosine hydroxylase (TH) and acetylcholinesterase (AChE). The length and staining intensity of nerve fibres were analysed.

RESULTS

The outgrowing fibres were significantly longer in MPG treated with any of the four tested growth factors than in PBS-treated MPG. The combination of VEGF and NT3 induced the best fibre growth. Improvements to the culturing conditions allowed a histological examination of the outgrowing fibres for the expression of nitric oxide synthase (NOS), TH and AChE. VEGF and BDNF were equally capable of inducing NOS- and TH-expressing fibres. BDNF was much weaker than VEGF for inducing AChE-expressing fibres.

CONCLUSIONS

This improved culturing system is potentially useful for screening nerve-regenerating factors; VEGF had neurotrophic effects comparable with BDNF, NT3, or NT4.

Ductal adenocarcinoma of the prostate with endometrioid features in a 69-year-old man

We describe a case of ductal adenocarcinoma of the prostate with endometrioid characteristics presenting as painless hematuria and intraurethral tumor. A 69-year-old man had intermittent painless hematuria for 2 months. The serum prostate-specific antigen concentration was elevated (22.0 ng/mL). An enlarged prostate with a necrotic tumor was noted in the right lobe of the prostate on computerized tomography and magnetic resonance imaging studies. A polypoid and worm-like tumor was found within the prostatic urethra near the verumontanum. The tumor had a distinctly papillary configuration with a focal glandular structure on microscopy. Radical prostatectomy was performed and histology of the tumor specimen revealed it to be composed of a closely packed glandular structure lined by single layers of high columnar cells with focal stratification. Frequent papillary projections of glandular epithelium and intraglandular bridging were noted, with a histopathologic appearance similar to endometrioid carcinoma of the uterus. Androgen deprivation therapy was started immediately following surgery. No evidence of recurrence or metastasis was found at follow-up 27 months postoperatively. Distinct features of ductal adenocarcinoma of the prostate include intraurethral papillary tumor close to the verumontanum, urethral obstruction, and easy bleeding of the tumor. Its more aggressive behavior than classical microacinar adenocarcinoma of the prostate makes early recognition of this type of prostatic malignancy important.

Gene expression profiling of an arteriogenic impotence model

Penile arterial insufficiency is one of the most common causes of ED. We have established a traumatic arteriogenic insufficiency rat model by the ligation of the pudendal arteries. To simulate both acute and chronic traumatic injuries, five ligation periods (6 h, 3 days, 7 days, 3 weeks, and 6 weeks) were chosen. By electrostimulation of the cavernous nerve, the intracavernous pressure was determined to be between 20 and 40-cm H(2)O for the ligated rats compared to around 100-cm H(2)O for the control rats. The erectile tissue in the corpus cavernosum of these rats was then subjected to microarray analysis, in which an array that contains cDNA fragments representing 1176 rat genes was used. The results demonstrated that normal rat corpus cavernosum expressed approximately 200 genes at detectable levels and that ligation produced differential expression of approximately 25 genes, depending on the duration of ligation. The most highly ligation-induced gene was apolipoprotein D (ApoD), with peak expression in the 3- and 7-day ligated rats. Three of the insulin-like growth factor binding proteins (IGFBP-1, 3, and 5) were upregulated in all ligated rats. IGFBP-6, which was one of the most highly expressed genes in the normal corpus cavernosum, was down-regulated in all ligated rats. Cysteine proteases of the cathepsin family were also differentially expressed between control and ligated rats, with cathepsin K being down-regulated most. A few genes were upregulated only in the 6-week ligated rats, including angiotensin-converting enzyme. Finally, VEGF, whose induction has been identified in many other ischemic tissues, was not induced in corpus cavernous tissue of ligated rats.

Duodenojejunal intussusception secondary to hamartomatous polyps of duodenum surrounding the ampulla of Vater

Duodenojejunal intussusception is a rare pediatric emergency. A case of duodenojejunal intussusception secondary to hamartomatous polyps of the second portion of duodenum in a 10-month-old boy is reported. Surgical excision of the polyps and reduction of the intussusception were performed. Pathologic examination found hamartomatous polyps. This is the third case report of children in literature, but this is the first case of a child with intussusception surrounding the ampulla of Vater and a successful excision performed without damaging the ampulla of Vater.

Purification and characterization of isoforms of beta-galactosidases in mung bean seedlings

Five isoforms of beta-galactosidase (EC 3.2.1.23), designated as beta-galactosidases I-V, were isolated from five-day-old mung bean (Vigna radiata) seedlings. Beta-galactosidases II and III were purified to electrophoretic homogeneity by a procedure involving acid precipitation, ammonium sulfate fractionation, chromatography on diethylaminoethyl-cellulose (DEAE-Cellulose) and con A-Sepharose. and chromatofocusing. Beta-galactosidases I, II and III have the same molecular mass of 87 kDa. comprising two nonidentical subunits with molecular masses of 38 and 48 kDa, while beta-galactosidases IV and V have molecular masses of 45 and 73 kDa, respectively. All the enzymes were active against p-nitrophenyl-beta-D-galactoside, and to a lesser extent, p-nitrophenyl-alpha-L-arabinoside and p-nitrophenyl-beta-D-fucoside. The enzymes were inhibited by D-galactono-1,4-lactone, D-galactose, Hg2+, Ag+ and sodium dodecyl sulfate (SDS). Beta-galactosidases I, II and III were shown to be competitively inhibited by either D-galactono-1, 4-lactone or D-galactose. Isoforms I, II and III have a common optimal pH of 3.6, while isoforms IV and V have pH optima at 3.8 and 4.0, respectively. Isoelectric points of isoforms I, II and III were 7.7, 7.5 and 7.3, respectively. Double immunodiffusion analysis indicated that beta-galactosidases I, II, III and V are immunologically similar to each other, while beta-galactosidase IV shares partially identical antigenic determinants with the other four isoforms. The purified beta-galactosidases II and III were capable of releasing D-galactose residue from the hemicellulose fraction isolated from mung bean seeds.

Dynamics of changes in micronucleus frequencies in subjects post cessation of chronic low-dose radiation exposure

To assess DNA damage remaining in peripheral lymphocytes, 48 individuals were evaluated twice for lymphocyte micronucleus frequencies by the cytokinesis-blocking cytochalasin B (CBMN) analysis post relocation from radio-contaminated apartments after various periods of time. The frequencies of CBMN at the first evaluation were significantly higher than those at the second examination (Chang et al., 1999c). These individuals were categorized into three groups: those with cumulative exposure of >300 mSv (defined as high exposure, HDose), those with 100-300 mSv (MDose) and those with <100 mSv (LDose). Using the Poisson mixed-effect model (Little et al., 1996), the estimated mean CBMN frequencies ( per thousand) for individuals in HDose, MDose and LDose exposure categories when they had only recently relocated were 21.8, 17.6 and 15.4, respectively. The estimated mean duration post relocation for the CBMN frequencies of these individuals to reduce to 10.2, the second CBMN frequency, on average, was 47.5, 37.2 and 28.3 months in the three exposure groups, respectively. The rates of change in CBMN frequencies were shown to be significantly higher in the HDose group than in the MDose and LDose groups. The results suggested a characteristic dose-dependent decline in the CBMN frequencies in the exposed population post cessation of chronic low-dose ionizing radiation exposure.

Legal and ethical considerations of assisted reproductive technology and surrogate motherhood in AOFOG countries

With increasing use of assisted reproductive technologies (ART) and its related issues, the Ethics Committee of the Asia-Oceania Federation of Obstetrics and Gynecology (AOFOG), after discussion at its council meeting, took up the mission to understand the current legal and ethical aspects of this special subject in Asia-Oceania area before making proper recommendations. This Committee drafted a questionnaire to all 22 country member societies in 1995, and again conducted the same survey in 2000 to track changes in each country/region's laws and regulations. The results show that the current attitude and status of country member societies vary in a wide range and do not have formal legal codes in majority regulating the ethical aspects of ART. The use of ART and surrogacy is obviously affected by local traditions, popularity in the use of such techniques and cultural/religious concerns. The changes in 5 years are not major. Three countries do not as yet practice such techniques. However, liberalization of surrogate motherhood has become a trend. Five countries, compared with two only in 1995, are now available for surrogate motherhood, though regulated by strict criteria. Based on the data collected and issues discussed, a detailed guideline may not be generally applicable as each region has its own rules, reflecting differences in the management of ART, especially in the surrogate motherhood. This Committee therefore recommends that ART must be performed by a board certified gynecologist in a certification laboratory and surrogate motherhood must be used only for medical reasons and not be commercialized. The patients of this special group must be treated individually, based on this recommendation and the regulations of their own country/region.

Juvenile papillomatosis of the breast in a 9-year-old girl

Juvenile papillomatosis (JP) is a rare benign, proliferative breast tumor in children. We observed a 9-year-old girl with a large soft-tissue mass at the lower outer quadrant of the left breast. Ultrasonography showed an ill-defined, inhomogeneous mass with numerous small, hypoechoic areas. The tumor was completely excised. Histopathology revealed JP of the breast. The case is presented and the literature is reviewed.

Epilepsy-induced decrease of L-type Ca2+ channel activity and coordinate regulation of subunit mRNA in single neurons of rat hippocampal 'zipper' slices

L-type voltage-sensitive Ca2+ channels (VSCCs) preferentially modulate several neuronal processes that are thought to be important in epileptogenesis, including the slow afterhyperpolarization (AHP), LTP, and trophic factor gene expression. However, little is yet known about the roles of L-type VSCCs in the epileptogenic process. Here, we used cell-attached patch recording techniques and single cell mRNA analyses to study L-type VSCCs in CA1 neurons from partially dissociated (zipper) hippocampal slices from entorhinally-kindled rats. L-type Ca2+-channel activity was reduced by >50% at 1.5-3 months after kindling. Following recording, the same single neurons were extracted and collected for mRNA analysis using a recently developed method that does not amputate major dendritic processes. Therefore, neurons contained essentially full complements of mRNA. For each collected neuron, mRNA contents for the L-type pore-forming alpha1D/Ca(v)1.3-subunit and for calmodulin were then analyzed by semiquantitative kinetic RT-PCR. L-type alpha1D-subunit mRNA was correlated with L-type Ca2+-channel activity across single cells, whereas calmodulin mRNA was not. Thus, these results appear to provide the first direct evidence at the single channel and gene expression levels that chronic expression of an identified Ca2+-channel type is modulated by epileptiform activity. Moreover, the present data suggest the hypothesis that down regulation of alpha1D-gene expression by kindling may contribute to the long-term maintenance of epileptiform activity, possibly through reduced Ca2+-dependent AHP and/or altered expression of other relevant genes.

Diffusion of molecules in brain extracellular space: theory and experiment

Volume transmission depends on the migration of informational substances through brain extracellular space (ECS) and almost always involves diffusion; basic concepts of diffusion are outlined from both the microscopic viewpoint based on random walks and the macroscopic viewpoint based on the solution of equations embodying Fick's Laws. In a complex medium like the brain, diffusing molecules are constrained by the local volume fraction of the ECS and tortuosity, a measure of the hindrance imposed by cellular obstacles. Molecules can also experience varying degrees of uptake or clearance. Bulk flow and the extracellular matrix may also play a role. Examples of recent work on diffusion of tetramethylammonium (molecular weight, 74) in brain slices, using iontophoretic application and ion-selective microelectrodes, are reviewed. In slices, the volume fraction is about 20% and tortuosity about 1.6, both similar to values found in the intact brain. Using integrative optical imaging, results obtained with dextrans and albumins up to a molecular weight of 70,000 are summarized, for such large molecules the tortuosity is about 2.3. Experiments using synthetic long-chain PHPMA polymers up to 1,000,000 molecular weight show that these molecules also diffuse in the ECS but with a tortuosity of about 1.6. Studies with osmotic challenge show that volume fraction and tortuosity do not vary together as expected when the size of the ECS changes; a model is presented that explains the osmotic-challenge on the basis of changes in cell shape. Finally, new analytical insights are provided into the complex movement of potassium in the brain.

Effects of Nd:YAG laser irradiation on cultured human gingival fibroblasts

BACKGROUND AND OBJECTIVE

The Nd:YAG laser has been proposed to apply in minor soft tissue surgery, including various periodontal procedures. However, little information is available regarding the direct effect of Nd:YAG laser on gingival fibroblasts, which play an important role in the early healing processes of periodontal repair.

STUDY DESIGN/MATERIALS AND METHODS

Nd:YAG laser irradiation was performed in pulsed mode on human gingival fibroblasts, which was derived from healthy human gingiva by an explant method. The size of laser diode was 400 microm in diameter. The parameters in laser delivery were pulse energy (50-150 mJ), power output (1.0-3.0 W), pulse rate (10-30 pps), and fixed duration of irradiation (10 seconds). The cell cultures were analysed by cytomorphologic examination under phase-contrast and scanning electron microscope. The vitality was also examined with the help of MTT staining.

RESULTS

The area of laser damage on cell culture was circular in shape, with diameter beyond the size of laser diode. By scanning electron microscopy, we observed the cellular damage of cultured gingival fibroblasts induced by Nd:YAG laser irradiation, comparable with the progressive increased power settings. The cytomorphologic changes ranged from disappearance of cellular boundary, loss of identifiable cellular nucleus, and finally cell contraction and vacuolization. Significant decrease in cellular vitality (14% approximately 44%) after laser treatment with irradiation distance of nearly contact was noted. However, 2 mm defocusing irradiation with the same power settings did not significantly decrease cellular vitality.

CONCLUSION

Our study demonstrated the cell damaging effects of Nd:YAG laser, ranging from degeneratively cytomorphologic change to cell death, on the cultured human gingival fibroblasts. It provided the dentist a chance to understand the potential hazard of laser application in periodontal treatment. If the energy output is enough for the clinical purposes, Nd:YAG laser with lower pulse energy and corresponding pulse rate should be selected to minimize the damage on adjacent soft tissue.

Measurement of the size and orientation of human masseter and medial pterygoid muscles

To gain a better understanding of biting and chewing performance, the size and orientation of the masseter and medial pterygoid muscles in living humans were studied. Twenty-seven young males having complete dentition, class I dental occlusion and normal muscle and jaw function were examined using magnetic resonance images of the head between the zygomatic arch and hyoid bone. The sections were parallel to the palatal plane, and the thickness was 3 mm without a gap. A computer software program (Medical Dental Image, MDI) was developed to identify and calculate the area of each cross section of the muscle, and the volume of the muscle was then estimated. The axis of the muscle was determined by connecting the centroids of the sections in the lower and upper 1/3 of the whole muscle. The effective muscle cross section area was then calculated by resectioning the muscle perpendicularly to the muscle axis. It was found that the mean masseter muscle volume was around 31 cm3, and that the mean medial pterygoid muscle volume was 11 cm3. Their mean effective cross section areas were around 6.2 cm2 and 3.5 cm2, respectively. The axis of the masseter muscle was more perpendicular to the palatal plane and parallel to the sagittal plane than was the medial pterygoid muscle. The results suggest that the use of magnetic resonance images (MRI) is an effective noninvasive measurement technique for determining the size and orientation of masseter and medial pterygoid muscles. This technique can be employed in future studies on human bite force evaluation and masticatory function.

Vitamin D hormone confers neuroprotection in parallel with downregulation of L-type calcium channel expression in hippocampal neurons

Although vitamin D hormone (VDH; 1,25-dihydroxyvitamin D(3)), the active metabolite of vitamin D, is the major Ca(2+)-regulatory steroid hormone in the periphery, it is not known whether it also modulates Ca(2+) homeostasis in brain neurons. Recently, chronic treatment with VDH was reported to protect brain neurons in both aging and animal models of stroke. However, it is unclear whether those actions were attributable to direct effects on brain cells or indirect effects mediated via peripheral pathways. VDH modulates L-type voltage-sensitive Ca(2+) channels (L-VSCCs) in peripheral tissues, and an increase in L-VSCCs appears linked to both brain aging and neuronal vulnerability. Therefore, we tested the hypothesis that VDH has direct neuroprotective actions and, in parallel, targets L-VSCCs in hippocampal neurons. Primary rat hippocampal cultures, treated for several days with VDH, exhibited a U-shaped concentration-response curve for neuroprotection against excitotoxic insults: lower concentrations of VDH (1-100 nm) were protective, but higher, nonphysiological concentrations (500-1000 nm) were not. Parallel studies using patch-clamp techniques found a similar U-shaped curve in which L-VSCC current was reduced at lower VDH concentrations and increased at higher (500 nm) concentrations. Real-time PCR studies demonstrated that VDH monotonically downregulated mRNA expression for the alpha(1C) and alpha(1D) pore-forming subunits of L-VSCCs. However, 500 nm VDH also nonspecifically reduced a range of other mRNA species. Thus, these studies provide the first evidence of (1) direct neuroprotective actions of VDH at relatively low concentrations, and (2) selective downregulation of L-VSCC expression in brain neurons at the same, lower concentrations.

Correlation of cervical vertebra maturation with hand-wrist maturation in children

The purpose of this study was to evaluate the reliability of cervical vertebra maturation as an indicator of skeletal age during the circumpubertal period. This was determined by correlating cervical vertebra maturation to hand-wrist maturation. The vertebral skeletal age was assessed using lateral cephalometric radiographs according to maturity indicators modified from Lamparski. The hand-wrist skeletal age was evaluated in radiographs with the system developed by Fishman. The sample consisted of 503 subjects (244 boys and 259 girls), aged 8 through 18 years. The Spearman rank correlation coefficients and Wilcoxon sign rank test showed that a statistically significant relationship existed between the two assessments. Both the intra- and inter-judge tests of reliability displayed no significant differences. The results of this study indicate that skeletal age assessment made from the maturational changes of cervical vertebrae were reliable, reproducible and valid.

Perinatal outcome of oligohydramnios without associated premature rupture of membranes and fetal anomalies

To investigate the perinatal outcome of patients with oligohydramnios (amniotic fluid index < or = 5 cm), but without premature rupture of membranes and fetal congenital anomalies, data from 245 singleton pregnancies were analyzed and compared to those with normal amniotic fluid volumes (5 < amniotic fluid index < 24 cm, n=27,261). Significantly higher incidences of primiparity, pregnancy-induced hypertension, premature separation of placenta, past history of intrauterine fetal death, past history of preterm delivery, postterm pregnancy, and advanced maternal age were noted to be associated with the occurrence of oligohydramnios. Pregnancies complicated by a markedly diminished amniotic fluid volume assessed antenatally by ultrasound were significantly more frequently associated with adverse perinatal outcomes such as preterm delivery, low or very low birth weight, low Apgar scores, intrauterine fetal death, small-for-gestational-age newborns, meconium staining, cesarean delivery, neonatal intensive care, and neonatal death.

Comparison of landmark identification in traditional versus computer-aided digital cephalometry

The aim of this study was to assess landmark identification on digital images in comparison with those obtained from original radiographs. Ten cephalometric radiographs were selected randomly. Seven orthodontic residents identified 19 cephalometric landmarks on both the original radiographs and the digital images. To assess the concordance between landmarks identified on the original radiographs and on their digital counterparts, the x, y coordinates for each landmark in the 2 modalities were transformed with the identical references. The placement differences for 19 landmarks between 2 methods were calculated and their components in horizontal and vertical directions were analyzed respectively. Multivariate analysis of variance showed that the "cephalometric radiograph" and "landmark" variation had greater influence than that from "method" (landmark identification on digital / original radiograph). It was also noted that the differences of landmark identification between original radiographs and their digital counterparts were statistically significant. The landmarks with significant differences of horizontal component on the x-axis were Me, Gn, ANS, PNS, LIA. The differences were generally under 1 mm with the exception of Or, Me, PNS, LIA. The landmarks with significant differences of vertical component on the y-axis were Po, Or, Gn. The inter-observer error for each landmark in digital images was generally larger than that in the original radiographs. However, statistically significant differences of inter-observer errors between 2 modalities were only found for 4 of the 19 landmarks. These 4 landmarks, Po, Ar, ANS, and UM, should be scrutinized more carefully during potential applications of digital cephalometry.

Expression of functional type 1 protease-activated thrombin receptors by mouse primary palatal mesenchymal cells in vitro

Development of the primary palate involves a series of processes including cell growth, differentiation, and morphogenesis. To study the molecular and cellular processes during mouse primary palatogenesis, mesenchymal cells were isolated from the primary palate of BALB/cBy embryos (day-11, hour 20). Most of the primary palatal mesenchymal (PPM) cells were morphologically similar to fibroblasts. The population doubling time was about 36 h. At concentrations of 5 and 10 unit/ml, alpha-thrombin significantly stimulated the proliferation of these palatal cells by 2- to 2. 4-fold compared to untreated controls over a 72 hour incubation period. Reverse transcriptase-polymerase chain reaction using primers based on the mouse type 1 protease-activated thrombin receptor (PAR1) detected PAR1 mRNA in the PPM cells, the authenticity of which was confirmed by partial DNA sequencing. Blocking of the alpha-thrombin proteolytic site with the highly specific inhibitor D-phenylalanyl-prolyl-arginyl chloromethyl ketone significantly suppressed the mitogenic effect of thrombin on the PPM cells by 71%. These results suggest that PAR1 is present on PPM cells in the mouse embryo and that serine protease activity is important for the receptor activation.

Dissection of the XChk1 signaling pathway in Xenopus laevis embryos

Checkpoint pathways inhibit cyclin-dependent kinases (Cdks) to arrest cell cycles when DNA is damaged or unreplicated. Early embryonic cell cycles of Xenopus laevis lack these checkpoints. Completion of 12 divisions marks the midblastula transition (MBT), when the cell cycle lengthens, acquiring gap phases and checkpoints of a somatic cell cycle. Although Xenopus embryos lack checkpoints prior to the MBT, checkpoints are observed in cell-free egg extracts supplemented with sperm nuclei. These checkpoints depend upon the Xenopus Chk1 (XChk1)-signaling pathway. To understand why Xenopus embryos lack checkpoints, xchk1 was cloned, and its expression was examined and manipulated in Xenopus embryos. Although XChk1 mRNA is degraded at the MBT, XChk1 protein persists throughout development, including pre-MBT cell cycles that lack checkpoints. However, when DNA replication is blocked, XChk1 is activated only after stage 7, two cell cycles prior to the MBT. Likewise, DNA damage activates XChk1 only after the MBT. Furthermore, overexpression of XChk1 in Xenopus embryos creates a checkpoint in which cell division arrests, and both Cdc2 and Cdk2 are phosphorylated on tyrosine 15 and inhibited in catalytic activity. These data indicate that XChk1 signaling is intact but blocked upstream of XChk1 until the MBT.

Risk factors for pre-eclampsia in an Asian population

OBJECTIVE

To identify the risk factors for pre-eclampsia in an Asian population.

METHOD

We conducted a retrospective cohort study involving 29375 Taiwanese women who delivered between July 1990 and September 1998, excluding pregnancies complicated by chronic hypertension or fetal malformations.

RESULT

Four hundred and fifteen women had pre-eclampsia (1.4%). Women who had a history of pre-eclampsia (OR 6.3, 95% CI 4.4, 9.2), multiple gestation (OR 3.6, 95% CI 2.4, 5.5), a prepregnancy BMI > 24.2 kg/m(2) (OR 2.4, 95% CI 1. 8, 3.1), were > 34 years of age (OR 1.8, 95% CI 1.4, 2.4), nulliparous (OR 1.3, 95% CI 1.2, 1.5), had urinary tract infection (OR 4.8, 95% CI 1.5, 15.8), or worked during pregnancy (OR 1.9, 95% CI 1.4, 2.4) were at increased risk of pre-eclampsia.

CONCLUSION

Some of the risk factors for pre-eclampsia among Asian women are the same as those of other ethnic groups, whereas some of the risk factors are different.

Changes in brain cell shape create residual extracellular space volume and explain tortuosity behavior during osmotic challenge

Diffusion of molecules in brain extracellular space is constrained by two macroscopic parameters, tortuosity factor lambda and volume fraction alpha. Recent studies in brain slices show that when osmolarity is reduced, lambda increases while alpha decreases. In contrast, with increased osmolarity, alpha increases, but lambda attains a plateau. Using homogenization theory and a variety of lattice models, we found that the plateau behavior of lambda can be explained if the shape of brain cells changes nonuniformly during the shrinking or swelling induced by osmotic challenge. The nonuniform cellular shrinkage creates residual extracellular space that temporarily traps diffusing molecules, thus impeding the macroscopic diffusion. The paper also discusses the definition of tortuosity and its independence of the measurement frame of reference.

Spatial buffering of potassium ions in brain extracellular space

It has long been assumed that one important mechanism for the dissipation of local potassium gradients in the brain extracellular space is the so-called spatial buffer, generally associated with glial cells. To date, however, there has been no analytical description of the characteristic patterns of K(+) clearance mediated by such a mechanism. This study reanalyzed a mathematical model of Gardner-Medwin (1983, J. Physiol. (Lond.). 335:393-426) that had previously been solved numerically. Under suitable approximations, the transient solutions for the potassium concentrations and the corresponding membrane potentials of glial cells in a finite, parallel domain were derived. The analytic results were substantiated by numerical simulations of a detailed two-compartment model. This simulation explored the dependence of spatial buffer current and extracellular K(+) on the distribution of inward rectifier K(+) channels in the glial endfoot and nonendfoot membranes, the glial geometric length, and the effect of passive KCl uptake. Regarding the glial cells as an equivalent leaky cable, the analyses indicated that a maximum endfoot current occurs when the glial geometric length is equal to the corresponding electrotonic space constant. Consequently, a long glial process is unsuitable for spatial buffering, unless the axial space constant can match the length of the process. Finally, this study discussed whether the spatial buffer mechanism is able to efficiently transport K(+) over distances of more than several glial space constants.

Expression of alpha 1D subunit mRNA is correlated with L-type Ca2+ channel activity in single neurons of hippocampal "zipper" slices

L-type voltage-sensitive Ca(2+) channels (L-VSCCs) play an important role in developmental and aging processes, as well as during normal function of brain neurons. Here, we tested a prediction of the hypothesis that membrane density of functional L-VSCCs is regulated by the level of gene expression for its alpha(1D) pore-forming subunit. If so, alpha(1D) mRNA and L-VSCC activity should be positively correlated within individual neurons. Conventional methods of aspiration and/or acute cell dissociation used in prior single-cell studies have generally yielded variable and incomplete recovery of intracellular mRNA. Thus, quantitative relationships between channel function and expression have been difficult to define. In this study, we used the partially dissociated ("zipper") hippocampal slice preparation as a method for collecting a single neuron's mRNA complement. This preparation, developed to expose neuronal somata for recording, also enables the extraction of a neuron with major processes largely intact. Thus, single-cell measures of gene/mRNA expression can be based on approximately the cell's full set of mRNA transcripts. In adult and aged rat hippocampal zipper slices, L-VSCC activity was first recorded in CA1 neurons in cell-attached patch mode. The same neurons were then extracted and collected for semiquantitative reverse transcriptase-PCR analysis of alpha(1D) and calmodulin A (CaM) mRNA content. Across multiple single neurons, a significant, positive correlation was found between the rank orders of L-VSCC activity and of alpha(1D), but not CaM, mRNA expression. Thus, these studies support the possibility that the level of alpha(1D) gene expression regulates the density of functional L-VSCCs.

Concurrent quantification and pharmacokinetic analysis of cefotaxime in rat blood and brain by microdialysis and microbore liquid chromatography

A simple but effective coupling of microdialysis and microbore liquid chromatograph with UV detection technique was applied to the simultaneous studying of the pharmacokinetics of cefotaxime in both the peripheral compartment and central nervous system. The mobile phase consisted of methanol-100 mM monosodium phosphoric acid (25:75, v/v, pH 5.5) pumped through a C18 microbore column at a flow-rate of 0.05 ml/min. Detection of cefotaxime was set at a UV wavelength of 254 nm. Microdialysis probes were inserted into the jugular vein and striatum of the rat. Following stabilization of microdialysate levels, rats received cefotaxime (20 mg/kg, i.v., n=6) via the femoral vein, and complete concentration versus time profiles for blood and striatum were constructed. The results indicated that cefotaxime rapidly (within 10 min) entered the extracellular fluid of brain striatum following intravenous administration. Noncompartmental pharmacokinetics analysis indicated that the area under the concentration versus time ratio of cefotaxime in rat brain and blood was 6.9%, suggesting appreciable blood-brain barrier penetration. The method was relatively simple, imposed minimal physiological perturbance as it involved no body fluid consumption and sampled in particular protein-unbound drugs, generally believed to be the active fraction.

Transverse testicular ectopia: preoperative diagnosis by ultrasonography

Transverse testicular ectopia (TTE) is a rare anomaly. We report the first case of TTE described in Taiwan. The physical examination, ultrasonography (US), and laparoscopy revealed both testes in the left hemiscrotum, and surgical correction was performed. This case was diagnosed preoperatively by US, which can offer an easy, safe, and convenient alternative in the preoperative diagnosis of TTE. The possible mechanism for this anomaly and the literature are reviewed.

Gel-filtrated fractions of alveolar bone extract contain factors promoting cell attachment and a mitogenic effect on periodontal ligament fibroblasts

The purpose of this study was to investigate the effect of acetic acid-extracted bone proteins on human periodontal ligament fibroblasts (hPF) with respect to mitogenic and cell attachment promoting activity. Alveolar bone was harvested from healthy donors and subjected to 0.5 M acetic acid extraction, dialysis and lyophilization, and gel filtration. Promotion of cell attachment and stimulation of DNA synthesis by the crude extract and gel-filtrated fractions were studied in cultured hPE Many protein components, varying in molecular weight from 10-14 to 120 kDa, were detectable in 10% SDS-PAGE of the extract. Gel filtration of bone extract disclosed four fractions with molecular weights of 55, 34, 29 and 19-20 kDa. Both the 34 and 55 kDa fractions at a concentration of 5 microg/ml, but not the 29- or 19-20 kDa fractions, were found to promote cell attachment while only the 55 kDa fraction (5 microg/ml) stimulated DNA synthesis of hPF, Both mitogenic activity and the promotion of the cell attachment by gel-filtrated active fractions were resistant to thermal treatment (70 degrees C) and pH (4 to approximately 8) changes. These findings suggest that acetic acid extract of alveolar bone may contain components which are capable of modulating cell attachment and mitogenesis of hPF.

Kinetic analysis of a molecular model of the budding yeast cell cycle

The molecular machinery of cell cycle control is known in more detail for budding yeast, Saccharomyces cerevisiae, than for any other eukaryotic organism. In recent years, many elegant experiments on budding yeast have dissected the roles of cyclin molecules (Cln1-3 and Clb1-6) in coordinating the events of DNA synthesis, bud emergence, spindle formation, nuclear division, and cell separation. These experimental clues suggest a mechanism for the principal molecular interactions controlling cyclin synthesis and degradation. Using standard techniques of biochemical kinetics, we convert the mechanism into a set of differential equations, which describe the time courses of three major classes of cyclin-dependent kinase activities. Model in hand, we examine the molecular events controlling "Start" (the commitment step to a new round of chromosome replication, bud formation, and mitosis) and "Finish" (the transition from metaphase to anaphase, when sister chromatids are pulled apart and the bud separates from the mother cell) in wild-type cells and 50 mutants. The model accounts for many details of the physiology, biochemistry, and genetics of cell cycle control in budding yeast.

Simultaneous measurement of cefuroxime in rat blood and brain by microdialysis and microbore liquid chromatography. Application to pharmacokinetics

To characterize the pharmacokinetics of cefuroxime in rat blood and brain, microdialysis probes were inserted into the jugular vein and brain striatum, respectively. Cefuroxime (20 mg/kg, i.v.) was administered via the femoral vein. Blood microdialysates were automatic injected onto microbore liquid chromatography via an on-line injectors. The mobile phase consisted of methanol-100 mM monosodium phosphoric acid (25:75, v/v, pH 5.0) with a flow-rate of 0.05 ml/min. Ultraviolet detector was set at a wavelength of 280 nm for cefuroxime. The present assay enhanced the detection sensitivity and enabled the determination of cefuroxime down to 5 ng/ml. The pharmacokinetic data demonstrated that the area under the concentration curve (AUC) ratio of unbound cefuroxime in rat brain and blood was about 4.2% after cefuroxime (20 mg/kg, i.v.) administration. These results provided further evidence that cefuroxime could penetrate the blood-brain barrier.

Expression and mutagenesis studies of cobrotoxin from Taiwan cobra

The cDNA encoding cobrotoxin was constructed from the cellular RNA isolated from the venom glands of Naja naja atra (Taiwan cobra). The cDNA was subcloned into the expression vector pET20b(+) and transformed into BL21(DE3) Escherichia coli strain. Expressed cobrotoxin was isolated from inclusion bodies of E. coli and subjected to refolding into its folded structure. The refolded cobrotoxin was purified by high-performance liquid chromatography and exhibited a neurotoxicity in inhibiting acetylcholine-induced muscle contractions. Recombinant cobrotoxin showed a tendency to isomerize its disulfide bonds as that observed with native cobrotoxin. An appreciable decrease in the rate of isomerization reaction was observed when Glu-38 was replaced with Gln-38 or Lys-47 was replaced with Glu-47 or Gln-47. These results reflect that the element in controlling the disulfide isomerization of cobrotoxin is closely associated with the charged side chains in the cobrotoxin molecule.

Topical steroid treatment of phimosis in boys

PURPOSE

We evaluate whether steroid application alone or retraction and hygiene are responsible for successful results in boys treated with topical steroids for phimosis.

MATERIALS AND METHODS

A prospective study was performed, which included a control group of 42 patients with phimosis seen at our outpatient department from January to June 1997. During that time we trained the parent to retract and clean the foreskin only. From July 1997 to June 1998 topical steroid cream was prescribed in addition to retraction and hygiene in 276 boys with phimosis. All cases were divided into 3 subgroups of asymptomatic, symptomatic and buried penis.

RESULTS

The response rate was greater than 95% in patients who received topical steroid treatment in addition to improved hygiene. Only 13 boys (less than 5%) had no response to steroid treatment. Of the control patients 23 (55%) had no response to gentle retraction and personal hygiene. There was a significant difference (p<0.001) in response rate between the study and control groups. However, the subgroup with a buried penis responded poorly to steroid, retraction and hygiene treatment. There was significant difference (p<0.001) in response rate between the buried penis and other steroid groups but no significant difference (p>0.05) in the control group.

CONCLUSIONS

Phimosis is a physiological condition in neonates due to natural adhesion between the foreskin and the glans. Chronic infection due to poor hygiene is responsible for most cases of childhood phimosis. Circumcision is the traditional treatment of choice for phimosis or unretractable foreskin, although it is not always desired by parents or surgeons. Topical steroid cream is an easy, safe and nonsurgical alternative for phimosis. However, boys with a buried penis are not good candidates for steroid treatment.