Phenotypic Heterogeneity in Patients with Mutations in the Mitochondrial Complex I Assembly Gene NDUFAF5

BACKGROUND

Rare mutations in NADH:ubiquinone oxidoreductase complex assembly factor 5 (NDUFAF5) are linked to Leigh syndrome.

OBJECTIVE

We aimed to describe clinical characteristics and functional findings in a patient cohort with NDUFAF5 mutations.

METHODS

Patients with biallelic NDUFAF5 mutations were recruited from multi-centers in Taiwan. Clinical, laboratory, radiological, and follow-up features were recorded and mitochondrial assays were performed in patients' skin fibroblasts.

RESULTS

Nine patients from seven unrelated pedigrees were enrolled, eight homozygous for c.836 T > G (p.Met279Arg) in NDUFAF5 and one compound heterozygous for p.Met279Arg. Onset age had a bimodal distribution. The early-onset group (age <3 years) presented with psychomotor delay, seizure, respiratory failure, and hyponatremia. The late-onset group (age ≥5 years) presented with normal development, but slowly progressive dystonia. Combing 25 previously described patients, the p.Met279Arg variant was exclusively identified in Chinese ancestry. Compared with other groups, patients with late-onset homozygous p.Met279Arg were older at onset (P = 0.008), had less developmental delay (P = 0.01), less hyponatremia (P = 0.01), and better prognosis with preserved ambulatory function into early adulthood (P = 0.01). Bilateral basal ganglia necrosis was a common radiological feature, but brainstem and spinal cord involvement was more common with early-onset patients (P = 0.02). A modifier gene analysis showed higher concomitant mutation burden in early-versus late-onset p.Met279Arg homozygous cases (P = 0.04), consistent with more impaired mitochondrial function in fibroblasts from an early-onset case than a late-onset patient.

CONCLUSIONS

The p.Met279Arg variant is a common mutation in our population with phenotypic heterogeneity and divergent prognosis based on age at onset. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Case report: Vaccine-induced immune thrombotic thrombocytopenia complicated by acute cerebral venous thrombosis and hemorrhage after AstraZeneca vaccines followed by Moderna COVID-19 vaccine booster and surgery

Vaccine-induced thrombotic thrombocytopenia (VITT) is a well-known complication of adenoviral vector COVID-19 vaccines including ChAdOx1 nCoV-19 (AstraZeneca) and Ad26. COV2.S (Janssen, Johnson & Johnson). To date, only a few cases of mRNA COVID-19 vaccine such as mRNA-1273 (Moderna) or BNT162b2 (Pfizer-BioNTech)-induced VITT have been reported. We report a case of VITT with acute cerebral venous thrombosis and hemorrhage after a booster of mRNA-1273 (Moderna) vaccine in a patient previously vaccinated with two doses of the AstraZeneca vaccine. A 42-year-old woman presented with sudden onset of weakness of the right upper limb with focal seizure. She had received two doses of AstraZeneca vaccines and a booster with Moderna vaccine 32 days before presentation. She had also undergone a laparoscopic myomectomy 12 days previously. Laboratory examinations revealed anemia (9.5 g/dl), thrombocytopenia (31 × 10³/μl), and markedly elevated d-dimer (>20.0 mg/L; reference value < 0.5 mg/L). The initial brain computed tomography (CT) was normal, but a repeated scan 10 h later revealed hemorrhage at the left cerebrum. Before the results of the blood smear were received, on suspicion of thrombotic microangiopathy with thrombocytopenia and thrombosis, plasmapheresis and pulse steroid therapy were initiated, followed by intravenous immunoglobulin (1 g/kg/day for two consecutive days) due to refractory thrombocytopenia. VITT was confirmed by positive anti-PF4 antibody and both heparin-induced and PF4-induced platelet activation testing. Clinicians should be aware that mRNA-1273 Moderna, an mRNA-based vaccine, may be associated with VITT with catastrophic complications. Additionally, prior exposure to the AstraZeneca vaccine and surgical procedure could also have precipitated or aggravated autoimmune heparin-induced thrombocytopenia/VITT-like presentation.

Genetic Variants Associated With Subjective Cognitive Decline in Patients With Migraine

The genetic association between subjective cognitive decline (SCD) and migraine comorbidity remains unclear. Furthermore, single nucleotide polymorphisms (SNP) associated with SCD have not been identified previously. Migraineurs were genotyped using an Affymetrix array. The correlation between different SNP variants in migraineurs with or without SCD and non-migraine controls was investigated. Migraineurs with or without SCD were further divided for the analysis of relevant SNP variants linked to migraine with aura (MA), migraine without aura (MoA), episodic migraine (EM), and chronic migraine (CM). Significant connectivity between SNPs and clinical indices in migraineurs and non-migraine controls with SCD were assessed using multivariate regression analysis. The rs144191744 SNP was found in migraineurs (p = 3.19E-08), EM (p = 1.34E-07), and MoA(p = 7.69E-07) with and without SCD. The T allele frequency for rs144191744 in TGFBR3 was 0.0054 and 0.0445 in migraineurs with and without SCD (odds ratio, 0.12), respectively. rs2352564, rs6089473 in CDH4, rs112400385 in ST18, rs4488224 and rs17111203 in ARHGAP29 SNPs were found, respectively, in non-migraineurs (p = 4.85E-06, p = 8.28E-06), MoA (p = 3.13E-07), and CM subgroups (p = 1.05E-07, 6.24E-07) with and without SCD. Rs144191744 closely relates to SCD with the all-migraine group and the EM and MoA subgroups. In conclusion, rs144191744 in TGFBR3 was significantly associated with SCD in migraineurs, especially in the EM, MoA, and female patient subgroups. Furthermore, three SNPs (rs112400385, rs4488224, and rs17111203) were associated with SCD in migraineurs but not in non-migraine controls.

Recurrent umbilical varix rupture with hemoperitoneum: a case report and review of literature

Background

Non-traumatic hemoperitoneum was a rare event with the risk of sudden death. Spontaneous rupture of hepatocellular carcinoma is the most intuitive diagnosis when hemoperitoneum occurs in cirrhotic patients who are not regularly followed up. However, other etiologies of hemoperitoneum, such as intra-abdominal varix rupture, should be kept in mind.

Case presentation

A 44-year-old man with alcoholic liver cirrhosis, Child–Pugh B was sent to our emergency department (ED) because of recurrent abdominal pain and hypovolemic shock. He had similar symptoms one month ago and was diagnosed as hepatocellular carcinoma (HCC) rupture with hemoperitoneum, therefore he underwent trans-arterial embolization (TAE). However, the follow-up magnetic resonance imaging (MRI) showed less possibility of hepatocellular carcinoma. Contrast enhanced abdominal computed tomography (CT) showed possible umbilical vein contrast agent extravasation. Exploratory laparotomy confirmed the diagnosis of rupture umbilical varix with hemoperitoneum.

Conclusion

Although umbilical varix rupture is a rare cause of hemoperitoneum, it should be kept in mind in cirrhotic patients with unexplained hemoperitoneum.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02167-3.

Primary Familial Brain Calcification Caused by a Novel Compound Heterozygous Mutation in the MYORG Gene

BACKGROUND PURPOSE

To demonstrate a novel compound heterozygous mutation in MYORG-related recessive primary familial brain calcification.

CASE REPORT

We report a case of primary familial brain calcification with newly-discovered compound heterozygous mutation in the MYORG gene presenting with progressive parkinsonism, cerebellar signs, and typical diffuse brain calcifications.

CONCLUSION

Clinicians should consider MYORG testing in patients who have primary brain calcifications with either a negative or recessive family history.

Novel and Efficient Quantitative Posterior-Circulation-Structure-Based Scale via Noncontrast CT to Predict Ischemic Stroke Prognosis: A Retrospective Study

(1) Background: Posterior circulation ischemic stroke has high mortality and disability rates and requires an early prediction prognosis to provide the basis for an interventional approach. Current quantitative measures are only able to accurately assess the prognosis of patients using magnetic resonance imaging (MRI). However, it is difficult to obtain MRI images in critically urgent cases. Therefore, the development of a noncontrast CT-based rapid-assist tool is needed to enhance the value of the clinical application. (2) Objective: This study aimed to develop an auxiliary-annotating noncontrast CT-efficient tool, which is based on a deep learning model, to provide a quantitative scale and the prognosis of posterior circulation ischemic stroke patients. (3) Methods: A total of 31 patients with posterior circulation ischemic stroke, diagnosed in the stroke registry at the Tri-Service General Hospital from November 2019 to July 2020, were included in the study, with a total of 578 CT images collected from noncontrast CT and MRI that were ≤ 3 days apart. A 5-fold cross validation was used to develop an image segmentation model to identify nine posterior circulation structures, and intersection over union (IoU) was used to assess the ability of the model to identify each structure. A quantitative score was integrated to assess the importance of the proportion of ischemic lesions in each posterior circulation structure, and the ROC curve was compared with the semiquantitative score for prognostic power. The prognoses of the patients were defined into two groups of 18 patients. An mRS score of 0–2 at discharge was defined as a good prognosis, while an mRS score of 3–6 was deemed to be a poor prognosis. (4) Results: The performance of the image segmentation model for identifying the nine posterior circulation structures in noncontrast CT images was evaluated. The IoU of the left cerebellum was 0.78, the IoU of the right cerebellum was 0.79, the IoU of the left occipital lobe was 0.74, the IoU of the right occipital lobe was 0.68, the IoU of the left thalamus was 0.73, the IoU of the right thalamus was 0.75, the IoU of the medulla oblongata was 0.82, and the IoU of the midbrain was 0.83. The prognostic AUC of posterior circulation patients predicted using a quantitative integrated score was 0.74, which was significantly higher than that of the pc-ASPECTS (AUC = 0.63, p = 0.035), with a sensitivity of 0.67 and a specificity of 0.72. (5) Conclusions: In this study, a deep learning model was used to develop a noncontrast CT-based quantitative integrated score tool, which is an effective tool for clinicians to assess the prognosis of posterior circulation ischemic stroke.

Identification of genetic risk loci for depression and migraine comorbidity in Han Chinese residing in Taiwan

INTRODUCTION

The genetic association between depression and migraine has not been well investigated in Asian populations. Furthermore, the genetic basis of depression and comorbid migraine subtypes remains nebulous. Hence, in the current study we investigate the susceptibility loci associated with depression and migraine comorbidity in the Han Chinese population in Taiwan.

METHODS

We perform a genome-wide association study involving 966 migraine patients, with or without comorbid depression. Genotyping is performed using participant genomic DNA. Association analyses are performed for the entire migraine cohort (subgroups: episodic migraine, chronic migraine, and migraine with or without aura).

RESULTS

Results show that the single nucleotide polymorphism variants of the CDH4 intron region (rs78063755), NTRK3-AS1 downstream region (rs57729223), and between LINC01918 and GPR45 (rs2679891) are suggestively associated with depression. Twenty additional susceptibility loci occur within the subgroups. A multivariate association study demonstrated that a variant in the intron region of CDH4 rs78063755 was associated with Beck Depression Inventory and Migraine Disability Assessment scores.

DISCUSSION

The findings of this study identify several genetic loci suggestively associated with depression among migraine patients in the Han Chinese population. Moreover, a potential genetic basis has been characterized for depression and migraine comorbidity, thus providing genetic candidates for further investigation.

Treatable Rapid Progressive Dementia: A First Case Report of Anti-dipeptidyl-peptidase-like Protein 6 Encephalitis in Taiwan

PURPOSE

Anti-dipeptidyl-peptidase-like protein 6 (DPPX) encephalitis is a rare but treatable autoimmune disorder, characterized by gastrointestinal symptoms, cognitive dysfunction, and central nervous system hyperexcitability.

CASE REPORT

Herein, we report a case of an 80-year-old male patient who presented with unexplained diarrhea, weight loss, rapidly progressive dementia, tremors, and myoclonus. His serum tested positive for anti-DPPX antibodies. He was treated with plasma exchange, oral prednisolone, and azathioprine. All his symptoms improved substantially after treatment.

CONCLUSION

Early recognition of anti-DPPX encephalitis is important because it can be treated with immunotherapy. To the best of our knowledge, this is the first reported case of anti-DPPX encephalitis in Taiwan.

Original article: Validity of measuring wheelchair kinematics using one inertial measurement unit during commonly used testing protocols in elite wheelchair court sports

Wheelchair court sports can measure both continuous and discrete wheelchair kinematics using Inertial Measurement Units (IMU) during testing and games. A method involving three IMU (3IMU) shows good validity with motion capture systems, but the hardware cost and the need for multiple sensors may make it a barrier for implementation in a sport context. A method using only one wheel mounted IMU (1IMU) has been developed that may reduce this cost, but further validation is required. This study assessed the validity of 1IMU compared to 3IMU, across a variety of continuous and discrete measurements during common on-court testing protocols, using national team athletes. Subjects recruited from national Wheelchair Basketball and Wheelchair Rugby programs performed a series of sprint, agility, and pivot testing protocols. Continuous wheel speed, frame rotation, and wheelchair speed data as well as a number of important discrete metrics including peak linear and rotational speeds, were compared between 3IMU and 1IMU. Low error (RMSE < 0.15 m s^-1) and high linearity (R² > 0.99) were seen in continuous measurements for wheel speed. Similar observations were made for frame rotational speed (RMSE < 11° s^-1 and R² < 0.97) during continuous measurements. Good to excellent intraclass correlations (ICC) were observed for peak linear speeds (ICC > 0.86) and frame rotational speeds (ICC > 0.94). Overall, 1IMU offers a lower cost solution that provides valid information for pertinent outcomes in wheelchair sports to use in the field.

Alterations of plant architecture and phase transition by the phytoplasma virulence factor SAP11

As key mediators linking developmental processes with plant immunity, TCP (TEOSINTE-BRANCHED, CYCLOIDEA, PROLIFERATION FACTOR 1 and 2) transcription factors have been increasingly shown to be targets of pathogenic effectors. We report here that TB/CYC (TEOSINTE-BRANCHED/CYCLOIDEA)-TCPs are destabilized by phytoplasma SAP11 effectors, leading to the proliferation of axillary meristems. Although a high degree of sequence diversity was observed among putative SAP11 effectors identified from evolutionarily distinct clusters of phytoplasmas, these effectors acquired fundamental activity in destabilizing TB/CYC-TCPs. In addition, we demonstrate that miR156/SPLs and miR172/AP2 modules, which represent key regulatory hubs involved in plant phase transition, were modulated by Aster Yellows phytoplasma strain Witches' Broom (AY-WB) protein SAP11. A late-flowering phenotype with significant changes in the expression of flowering-related genes was observed in transgenic Arabidopsis plants expressing SAP11AYWB. These morphological and molecular alterations were correlated with the ability of SAP11 effectors to destabilize CIN (CINCINNATA)-TCPs. Although not all putative SAP11 effectors display broad-spectrum activities in modulating morphological and physiological changes in host plants, they serve as core virulence factors responsible for the witches' broom symptom caused by phytoplasmas.

Do iatrogenic serosal injuries result in small bowel perforation in a rabbit model?

BACKGROUND

Surgical dogma dictates that serosal injuries should be repaired during laparotomy as these injuries may result in localised areas of bowel ischaemia and may perforate. No study has investigated whether there is a correlation between the extent of serosal injuries and the risk for perforation under normal physiological conditions. We hypothesized that small bowel serosal injuries do not result in early or late perforation at physiological intraluminal pressures regardless of their size.

METHOD

An in-vivo rabbit small bowel serosal injury model was developed and two experiments were conducted. The first - to determine whether and at which pressures various lengths and circumferences of serosal injuries in small bowel result in immediate bowel perforation - was performed infusing saline into isolated bowel segments with or without a variety of serosal injuries. In the second study - to determine whether or not serosal injuries result in delayed perforation - a range of injuries was created in rabbits and the effect assessed at re-laparotomy 5 days after the creation of the injury.

RESULTS

No perforations were observed at the site of serosal injuries at physiological intraluminal pressures. Perforations occurred at 43.7+ 18.6 cmH₂O, 23.3+ 14.4 cmH₂O, and 24.4+ 23.9 cmH₂O for controls, 4 cm long and 100% circumference serosal injuries respectively (p-value = 0.18 for various lengths and 0.71 for various circumferences). No serosal injuries perforated within 72 or 120 hours after creation.

CONCLUSION

Small bowel serosal injuries do not perforate or leak at physiological intraluminal pressures, either at the time of creation or up to 120 hours thereafter.

False-positive finding of retropharyngeal lymph node recurrence in both fluorine (18)FDG PET and MRI in a patient with nasopharyngeal carcinoma

BACKGROUND

Biopsy of the retropharyngeal node is not routinely accessible. The diagnosis of retropharyngeal lymph node recurrence in patients with nasopharyngeal carcinoma (NPC) is often based on an imaging study.

METHODS

We reported a patient with NPC who was incorrectly diagnosed with left retropharyngeal lymph node recurrence by both MRI and positron emission tomography (PET)/CT.

RESULTS

A woman who was treated for stage IVA NPC 2 years previously was found to have a nodal lesion in the left retropharyngeal space on MRI together with focal fluorodeoxyglucose (FDG) uptake on PET/CT. Locoregional recurrence was suspected, and surgery was performed. Subsequent pathology results showed reactive lymphoid hyperplasia.

CONCLUSION

Although tissue biopsy for the retropharyngeal node is technically difficult, this case demonstrates that tumor recurrence cannot be diagnosed even based on both positive findings on MRI and PET/CT in patients with NPC.

Dementia is associated with open-angle glaucoma: a population-based study

PURPOSE

Previous epidemiologic studies that focused on the association between open-angle glaucoma (OAG) and dementia showed inconsistent results. In the present study, we explored the association between OAG and dementia in an ethnic Chinese (i.e., Taiwanese) population using a population-based data set.

METHODS

We retrieved data on study subjects for this case-control study from the Longitudinal Health Insurance Database 2000. We identified 7770 patients who had a diagnosis of dementia as cases, and 7770 subjects matched in terms of sex and age, which were randomly extracted as controls. A conditional logistic regression conditioned on age group, sex, and index year was used to assess the association of dementia with previously diagnosed OAG among the sampled patients.

RESULTS

Of 15,540 patients, 1.70% had prior OAG, including 2.02% of the dementia group and 1.38% of the controls. After adjusting for patient socioeconomic characteristics and comorbid medical disorders, dementia patients were more likely to have had prior OAG than controls (odds ratio (OR): 1.44; 95% confidence interval (CI): 1.12-1.85; P<0.01). In addition, female dementia patients were more likely to have had prior OAG than controls (OR: 1.93; 95% CI: 1.35-2.77; P<0.001), whereas no statistical difference in prior OAG between male dementia patients and controls was found.

CONCLUSIONS

Female dementia patients were associated with a higher proportion of prior OAG than were the controls.

Heparin protects BALB/c mice from mite-induced airway allergic inflammation

More and more studies have demonstrated the anti-inflammatory effects of heparin. However, in the aspect of allergic airway inflammation, data about its daily use in animal model is scarce. To evaluate the efficacy of 22-day intranasal heparin administration in mite-induced airway allergic inflammation in BALB/c mice, the murine model of house dust-mite allergen-induced asthma was used to assess the effect of heparin (h) and low molecular weight heparin (l mwh) administered intra-nasally (IN) throughout the full study period (22 days). Effects were monitored by histopathology, cell counts in broncho-alveolar lavage fluid (BALF), local cytokine production, serum, specific antibody levels, and airway resistance measurements. Compared to the positive control group, both hIN and lmwhIN groups had lower peri-bronchiolar/alveolar inflammatory pathology score and lower goblet cell scores (p less than 0.01); lower eosinophil and neutrophil counts in BALF (p less than 0.0001); and lower cytokine levels including IL-17A/F, IL-5, IL-13, IL-8 and eotaxin in lung tissue (p less than 0.001). Serum Der p-specific IgE level was also lower in heparin-treated groups (p less than 0.004). The two heparin-treated groups also revealed lower value of Penh after Mch stimulation. In conclusion, heparin and lmw heparin decrease serum Der p-specific IgE level and possess anti-inflammatory effects on mite-induced airway allergic inflammation model in BALB/c mice.

Spontaneous uterine rupture in a nulligravida female presenting with unexplained recurrent hematometra

Spontaneous rupture of an unscarred uterus in reproductive-age women is exceedingly rare, especially in the context of dysfunctional bleeding and a patent cervical canal. A 25-year-old nulligravida female, who reported recent onset of metromenorrhagia and anemia, was initially admitted for surgical management of unexplained hematometra requiring dilation and curettage. The patient remained with intermittent vaginal bleeding for the following six months on continuous progestin therapy. She then re-presented with enlarged hematometra and uterine rupture, which was surgically repaired. Despite exhaustive conservative treatment to preserve fertility, hysterectomy was eventually required due to recurrent uterine rupture. Idiopathic recurrent hematometra can result from the rare combination of uncontrolled dysfunctional bleeding and absence of outflow obstruction.

Effects of nano-SiO(2) and different ash particle sizes on sludge ash-cement mortar

The effects of nano-SiO(2) on three ash particle sizes in mortar were studied by replacing a portion of the cement with incinerated sewage sludge ash. Results indicate that the amount of water needed at standard consistency increased as more nano-SiO(2) was added. Moreover, a reduction in setting time became noticeable for smaller ash particle sizes. The compressive strength of the ash-cement mortar increased as more nano-SiO(2) was added. Additionally, with 2% nano-SiO(2) added and a cure length of 7 days, the compressive strength of the ash-cement mortar with 1 microm ash particle size was about 1.5 times better that of 75microm particle size. Further, nano-SiO(2) functioned to fill pores for ash-cement mortar with different ash particle sizes. However, the effects of this pore-filling varied with ash particle size. Higher amounts of nano-SiO(2) better influenced the ash-cement mortar with larger ash particle sizes.

How messengers modulate the shifting of spontaneously generated action potential into bursts of potentials in central snail neuron?

How messengers modulate the shifting of spontaneously generated action potential into bursts of potentials (BoP) is studied electrophysiologically and biochemically in RP 1 and 4 neurons of the African snail, Achatina fulica Ferussac using d- and l-amphetamine (Amp) as modulator. The stereospecific effects, extracellular and intracellular ionic effects, messenger related to enzymatic effects and membrane ionic currents effects on BoP elicited by Amp are studied. The roles of organelles, such as mitochondria, protein syntheis related endoplasmic-reticulum, on the BoP are also tested. The messengers modulated the BoP are discussed.

A survey of emergency medicine in 36 countries

OBJECTIVE

To assess the current level of development of emergency medicine (EM) systems in the world.

DESIGN

Survey of EM professionals from 36 countries during a 90-day period from Aug. 25 to Nov. 24, 1998.

PARTICIPANTS

Thirty-six EM professionals from 36 countries and 6 continents completed the survey. Thirty-five (97%) were physicians, of whom 25 (69%) gave presentations at 1 of 4 international EM conferences during the study period. Three potential participants from 3 countries were excluded because of language barriers. Five additional participants from 5 other countries did not respond within the study period and were excluded.

MEASUREMENTS

Respondents completed a 103-question questionnaire about the presence of EM specialty, academic, patient care, information and management systems and the factors influencing the future of EM in their countries.

RESULTS

The overall response rate was 88%. Nearly all respondents (97%) stated that their countries had hospital-based emergency departments (EDs). More than 80% of respondents reported that their countries have emergency medical services (EMS), national EMS activation phone numbers and ED systems for pediatric emergency care. More than 70% stated that their countries had national EM organizations, EM research, ED systems for patient transfer and peer review and emergency physician (EP) training in Advanced Cardiac Life Support (ACLS) and the ability to perform rapid sequence intubation. More than 60% reported ED systems for trauma care and triage and EP training in Advanced Trauma Life Support (ATLS) and the ability to perform thrombolysis for acute myocardial infarction. Fifty percent reported EM residency training programs, official recognition of EM as an independent specialty, and EM journals.

CONCLUSIONS

Basic emergency medicine components now exist in the majority of countries surveyed. These include many specialty, academic, patient care and administrative systems. The foundation for further EM development is widely established throughout the world.

Effect of ropivacaine on endothelium-dependent phenylephrine-induced contraction in guinea pig aorta

BACKGROUND

Previous studies have shown that ropivacaine has biphasic vascular effects, causing vasoconstriction at low concentrations and vasorelaxation at high concentrations. This study was designed to examine the role of the endothelium during accidental intravascular absorption of ropivacaine, and to elucidate the mechanisms responsible.

METHODS

Isolated guinea pig aortic rings were suspended for isometric tension recording. The effects of ropivacaine on endothelium-intact and endothelium-denuded aortic rings were assessed. Endothelium-intact aortic rings were pre-contracted with phenylephrine before being exposed to ropivacaine and acetylcholine, in order to generate and compare concentration-response curves. In the absence and presence of yohimbine, propranolol, atropine, indometacin, N(G)-nitro-l-arginine methyl ester (l-NAME), 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) or methylene blue, the contractile response induced by ropivacaine was assessed on endothelium-intact aortic rings pre-contracted with phenylephrine.

RESULTS

Ropivacaine (3 x 10(-4) to 10(-2) mol/l) produced vasoconstriction in endothelium-denuded aortic rings, whereas no such response was observed in aortic rings with intact endothelium. In phenylephrine pre-contracted intact aortic rings, ropivacaine induced a greater degree of vasorelaxation than did acetylcholine. Yohimbine, propranolol and atropine all failed to affect the relaxation responses induced by ropivacaine. However, pre-treatment with indometacin (cyclo-oxygenase inhibitor), l-NAME (nitric oxide synthase inhibitor), methylene blue (soluble guanylyl cyclase inhibitor) or ODQ (soluble guanylyl cyclase inhibitor), significantly decreased the ropivacaine-induced relaxation of endothelium-intact aortic rings (3 x 10(-4) to 10(-2) mol/l).

CONCLUSIONS

Ropivacaine elicits an endothelium-dependent vasorelaxation in phenylephrine pre-contracted aortic rings via the nitric oxide-cyclic guanosine 3',5'-monophosphate pathway and the prostaglandin system.

Unusual pox lesions found in Chinese jungle mynahs (Acridotheres cristatellus)

Pox lesions involving feathered and unfeathered skin, the oral cavity and the uropygial gland were found in Chinese jungle mynahs. Characteristic intracytoplasmic inclusions were detected in the proliferative cells of all lesions. Ultrastructurally, the virus particles consisted of a convoluted outer membrane enclosing lateral bodies and a biconcave central core, typical for poxvirus. The nucleotide sequences of the amplicon obtained with a set of primers for the 4b core protein of fowl poxvirus revealed that the mynah poxvirus was phylogenetically related to wood pigeon poxvirus. This is the first report of poxvirus infection affecting the uropygial gland.

Impact of an outbreak of severe acute respiratory syndrome on a hospital in Taiwan, ROC

STUDY OBJECTIVE

To estimate the impact of the severe acute respiratory syndrome (SARS) outbreak in early 2003 on a tertiary care hospital in Taiwan, ROC.

METHODS

The study estimated the utilisation of resources related to infection control, SARS related medical services, and routine medical services, and SARS related medical outcomes at National Cheng Kung University Hospital (NCKUH) from 25 March to 16 June 2003 through a cross sectional survey of hospital records.

RESULTS

A mean of 5100 persons per day (95%CI 4580 to 5610) underwent fever screening at the outpatient and emergency department (ED) entrances to the hospital, of which 35 per day (95% CI 30 to 40) were referred for further evaluation for suspected or probable SARS. ED isolation surge capacity was created via 12 new beds outside the ED: eight for SARS assessment, three for patients awaiting in hospital bed assignment, and one for resuscitation. A total of 382 patients were fully evaluated for suspected or probable SARS outside the ED, of which 27 were admitted. The mean numbers of outpatient clinic patient visits, ED visits, ED trauma patient visits, ED admissions, hospital admissions, and operative procedures decreased during the outbreak. Thirty eight patients were hospitalised with suspected SARS, of which three received the final diagnosis of probable SARS. Two patients with probable SARS died. No cases of nosocomial SARS transmission occurred.

CONCLUSIONS

This SARS outbreak was associated with substantial use of hospital and ED resources aimed at infection control, comparatively less use of resources related to the medical care of patients with suspected or probable SARS, and decreased use of routine medical services.

Adsorption characteristics of benzene on biosolid adsorbent

This study selected biosolids from a petrochemical wastewater treatment plant as the raw material. The sludge was immersed in 0 to 5 mol l(-1) of ZnCl2 solutions and pyrolyzed at different temperatures. When the sludge was pyrolyzed for 30 min at temperatures of 400, 500, 600, and 700 degrees C, the corresponding surface area of the biosolid adsorbent was 46, 401, 921, and 727 m2/g, respectively. Pore size analysis indicated that the mesopore (20 to 500 A) contributed more than the macropore and micropore in the sludge pyrolytic residue. When the benzene influent concentration was 800 ppmv, the adsorption capacity ranged from 59 to 164 mg/g for different biosolid adsorbents. A larger BET surface area and smaller average pore diameter yielded a larger benzene adsorption capacity.

Arterial blood pressure and blood lipids as cardiovascular risk factors and occupational stress in Taiwan

BACKGROUND

This study is to determine whether occupational stress (defined as high psychological demands and low decision latitude on the job) is associated with increased blood pressure and abnormal level of blood lipids as cardiovascular risk factors.

METHODS

We conducted a cross-sectional study at three work sites of 526 white-collar male workers aged 20 to 66 years without evidence of cardiovascular disease. Systolic, diastolic blood pressure, serum total, high-density lipoprotein cholesterol and plasma triglyceride were measured. Occupational stress index was derived from data collected in the job strain questionnaire.

RESULTS

In multiple linear regression models, occupational stress index was significantly related to diastolic blood pressure and plasma triglyceride, after adjusting for age, education, smoking, and alcohol consumption. A higher occupational stress index was directly associated with higher systolic, diastolic blood pressure and higher level of plasma triglyceride.

CONCLUSIONS

These data from a white-collar working population confirm independent relations between occupational stress defined in the job demand-control model and diastolic blood pressure observed in predominantly Western populations and extend the range of associations to plasma triglyceride than do previous studies.

C. elegans CED-12 acts in the conserved crkII/DOCK180/Rac pathway to control cell migration and cell corpse engulfment

We have identified and characterized a novel C. elegans gene, ced-12, that functions in the conserved GTPase signaling pathway mediated by CED-2/Crkll, CED-5/DOCK180, and CED-10/Rac to control cell migration and phagocytosis of apoptotic cells. We provide evidence that ced-12 likely acts upstream of ced-10 during cell migration and phagocytosis and that CED-12 physically interacts with CED-5 and forms a ternary complex with CED-2 in vitro. We propose that the formation and localization of a CED-2-CED-5-CED-12 ternary complex to the plasma membrane activates CED-10, leading to the cytoskeletal reorganization that occurs in the polarized extension of cell surfaces in engulfing cells and migrating cells. We suggest that CED-12 counterparts in higher organisms regulate cytoskeleton dynamics, as CED-12 does in C. elegans.

Intravenous gamma-globulin therapy in myocarditis complicated with complete heart block: Report of one case

Myocarditis complicated with complete heart block is rare in childhood. We report a case of 4-year-old child presented with complete heart block which may have been caused by Mycoplasma pneumoniae. Under emergent temporal pacing, patient experienced cardiogenic shock with pulmonary edema eventually. The cardiopulmonary function was improved with atrial rhythm at the 6th hour later after intravenous infusion with high-dose gamma-globulin (IVIG). The IVIG therapy may have immunomodulatory effects and serve as a potential adjunctive therapy for fulminant myocarditis.

Emergency medical technicians' disaster training by tabletop exercise

The objective of this study was to assess the attitudes of emergency medical technicians (EMTs) toward tabletop drills to determine the effect of tabletop simulation on the EMT student perception of disaster preparedness and management. In November 1998 and April 1999, 59 firefighters underwent 260 hours of EMT intermediate level training at the National Cheng Kung University Hospital in Tainan, Taiwan. All participants had experience in field disaster exercise training before they attended this EMT training course. The EMT courses included a disaster and mass-casuality incident program. A 9-item questionnaire was completed by the 59 EMTs before (for field exercise) and after undergoing the tabletop drills. The results of the survey revealed that the field operation exercise could not provide adequate provisions to link the results of disaster exercises to appropriate changes in terms of training, equipment, supplies, and plans. Field operation failed to show the ability of others to fill in during the absence of key officials. Tabletop drilling provided better performance for these 2 issues. Tabletop exercise also provided a better chance than field exercise to evaluate the response without the use of telephones, which are not always reliable in real emergency situation. For disaster exercises, limitations of field operation drills such as communications, coordination, assignment of responsibilities, and postevent mitigation priorities were noted, and tabletop drills provided additional benefits for these settings. Large-scale effect evaluation of different drills may be necessary to design future disaster preparedness programs.

Resveratrol reduction of infarct size in Long-Evans rats subjected to focal cerebral ischemia

Resveratrol is found in a wide variety of plant species. It is present in the seeds and skin of grapes and constitutes one of the major components of red wine. This study was undertaken to evaluate whether resveratrol could effectively suppress infarct size from the damaging effects of focal cerebral ischemia. The middle cerebral artery was occluded for 1 hr and 24 hr reperfusion in anesthetized Long-Evans rats. In pretreatment or treatment groups, resveratrol, at dosages of 10(-6), 10(-7), 10(-8) and 10(-9) g/kg, was intravenous injected 15 minutes before middle cerebral artery (MCA) occlusion or when the common carotid arteries clips were removed respectively. Pretreatment or treatment of resveratrol (10(-6), 10(-7), 10(-8) and 10(-9) g/kg) did not produce any changes in pH, blood gases, heart rate or mean arterial blood pressure, but it significantly reduced the total volume of infarction at the doses 10(-6) and 10(-7) g/kg. Our study suggests resveratrol is a potent neuroprotective agent in focal cerebral ischemia. Its beneficial effects may be related to its anti-platelet aggregation activity, vasodilating effect, antioxidant property or by all mechanisms together.

Attenuation of paraquat-induced dopaminergic toxicity on the substantia nigra by (-)-deprenyl in vivo

(-)-Deprenyl (DEP) had been shown to slow of progression of Parkinson's disease (PD). The present study sought to determine whether DEP would attenuate the nigrostriatal system damage induced by intranigral administration of the herbicide paraquat (PQ) as a model of parkinsonism in vivo. Neurochemical and behavioral observations of Wistar rats were the focus of our study. In the neurochemical observation, the PQ injected in the rats caused dose-dependent depletion of dopamine (DA) in the ipsilateral striata. The coadministration of DEP with PQ partially increased the striatal DA level. The prediction of the striatal DA levels was calculated by regression coefficients obtained from multiple linear regression (r(2) = 0.82): DA level (% of control) = 103.34 - 9.58 PQ (nmol) + 0.79 DEP (nmol). It was demonstrated that the high dose of 20 nmol DEP could significant attenuate the PQ (5 nmol)-elicited dopaminergic toxicity (p < 0.05). In the behavioral observation, the intranigral injection of PQ into the rats caused a rotation behavior contralateral to the lesioned side in response to apomorphine administration (0.5 mg/kg, sc). This apomorphine-induced rotational behavior could also be attenuated significantly by coadministration of DEP (20 nmol) and PQ (5 nmol) compared with PQ-treated (5 nmol) animals (p < 0.05). The above observations indicate that DEP could provide a protective effect on the moderate injury elicited by PQ toxicity of the nigrostriatal dopaminergic system. DEP might be a useful therapeutic agent in treating patients with early-stage PD.

Extreme metabolic alkalosis treated with normal bicarbonate hemodialysis

Metabolic alkalosis (MA), defined as a primary increment in plasma bicarbonate concentration, is a common complication in hospitalized patients and is associated with high morbidity and mortality in severe cases. One of the major routes of compensation for MA (ie, the secretion of an alkaline urine) is lost in renal failure patients. We report three cases involving four episodes of extreme MA with an arterial pH value greater than 7.60, serum bicarbonate concentration greater than 55 mmol/L, and stupor or seizure. Profound vomiting or massive gastric drainage combined with concurrent oliguric renal failure was the underlying mechanism for severe MA. Hydration and normal central venous pressure failed to improve the MA. The extreme MA was reversed quickly and safely by conventional hemodialysis with normal bicarbonate dialysate of 25 to 28 mmol/L. To our knowledge, this is the first reported successful use of normal bicarbonate dialysate in the treatment of severe MA. We also found that either H(2) blockers or proton-pump inhibitors have a prophylactic effect on the formation of MA.

Neuroprotective effect of hexasulfobutylated C60 on rats subjected to focal cerebral ischemia

The effects of hexasulfobutylated C60 (FC4S), a free radical remover, on the total volume infarct size elicited by the damaging effects of focal cerebral ischemia were studied on Long-Evans rats in vivo. FC4S was administered intravenously either 15 min before middle cerebral artery (MCA) occlusion (pretreatment groups) or it was injected when the common carotid arteries clips were removed (treatment groups). FC4S did not alter the pH, blood gases, heart rate, or mean arterial blood pressure in either pretreatment or treatment groups of the rats. However, after administration of FC4S at dosages of 10 and 100 microg/kg, the total volume of infarction was significantly reduced in both pretreatment and treatment groups. In addition, after FC4S administration, the nitric oxide (NO) content in plasma was increased and the lactate dehydrogenase (LDH) levels was decreased. It is concluded that FC4S may be used as a neuroprotective agent on focal cerebral ischemia. The beneficial effects may be partly related to its antioxidant property and to the upregulation of NO production of the compound.

Amphetamine elicited potential changes in vertebrate and invertebrate central neurons

The effects of amphetamine on potential changes in both vertebrate and invertebrate central neurons and factors affecting the potential changes were tested. The animals studied included mice, newborn rat and African snail. Seizure was elicited after lethal doses of d-amphetamine (75 mg/kg, i.p.) administration in mice. Repetitive firing of the action potentials were elicited after d-amphetamine (1-30 microM) administration in thin thalamic brain slices of newborn rat. Bursting firing of action potentials in the giant African central RP4 neuron were also elicited after d-amphetamine or l-amphetamine (0.27 mM) administration. The amphetamine elicited bursting firing of action potentials was not blocked even after high concentrations of d-tubocurarine, atropine, haloperidol, hexamethonium administration. Therefore, the amphetamine elicited potential changes may not be directly related to the activation of the receptors of the neuron. The bursting firing of action potentials elicited by amphetamine occurred 20-30 min after amphetamine administration extracellularly, even after high concentrations of d-amphetamine administration (0.27, 1 mM). However, the bursting firing of potentials occurred immediately if amphetamine was administrated intracellularly at lower concentration. Extracellular application of ruthenium red, the calcium antagonist, abolished the amphetamine elicited bursting firing of action potentials. If intracellular injection of EGTA, a calcium ion chelator, or injection with high concentrations of magnesium, the bursting firing of potentials were immediately abolished. These results suggested that the active site of amphetamine may be inside of the neuron and the calcium ion in the neuron played an important role on the bursting of potentials. In two-electrode voltage clamped RP4 neuron, amphetamine, at 0.27 mM, decreased the total inward and steady outward currents of the RP4 neuron. d-Amphetamine also decreased the calcium, Ia and the steady-state outward currents of the RP4 neuron. Besides, amphetamine elicited a negative slope resistance (NSR) if membrane potential was in the range of -50 to -10 mV. The NSR was decreased in cobalt substituted calcium free and sodium free solution. The effects of secondary messengers on the amphetamine elicited potential changes were tested. The bursting firing of action potentials elicited by amphetamine in central snail neurons decreased following extracellular application of H8 (N-(2-methyl-amino) ethyl-3-isoquinoline sulphonamide dihydrochloride), a specific protein kinase A inhibitor and anisomycin, a protein synthesis inhibitor. However, the bursting firing of action potentials were not affected after extracellular application of H7 (1,(5-isoquinolinesulphonyl)-2-methylpiperasine dihydrochloride), a specific protein kinase C (PKC) inhibitor, or intracellular application of GDPbetaS, a G protein inhibitor. The oscillation of membrane potential of the bursting activity was blocked after intracellular injection of 3'-deoxyadenosine, an adenylyl-cyclase inhibitor. These results suggested that the bursting firing of action potentials elicited by d-amphetamine in snail neuron may be associated with the cyclic AMP second messenger system; on the other hand, it may not be associated with the G protein and protein kinase C activity. It is concluded that amphetamine elicited potential changes in both vertebrate and invertebrate central neurons. The changes are closely related to the ionic currents and second messengers of the neurons.

N-Acyl-1,2,3,4a,5,10b-hexahydro-[1]benzopyrano-[3,4-b][1,4]oxazine-9-carbonitriles as bladder-selective potassium channel openers

Optically active N-acyl-5,5-dimethyl-1,2,3,4a,5,10b-hexahydro-[1]benzopyrano[3,4-b][1,4]oxazine-9-carbonitriles 2-22 were synthesized as rigid analogues of cromakalim. The (4aR, 10bR)-N-benzoyl derivative (-)-11 was identified as a bladder-selective KCO (IC50, bladder = 8.2 microM, C50, portal vein = 34.5 microM). Among the analogues of 11 with substitution on the benzoyl moiety, the 3-methyl analogue (-)-14 showed highly potent and selective activity at portal vein (IC50, bladder = 279 microM, IC50, portal vein = 0.54 microM). The 4-bromo analogue (-)-19 (IC50, bladder = 2.0 microM, IC50, portal vein = 8.1 microM) and the 4-hydroxy analogue (-)-21 (IC50, bladder = 3.8 microM, IC50, portal vein = 75 microM) showed enhanced activity at the bladder, while maintaining unprecedented bladder selectivity in vitro. The N-benzenesulfonyl analogue (-)-22, a bioisoster of (-)-11, showed similar activity at the bladder with enhanced selectivity (IC50, bladder = 11.6 microM, IC50, portal vein = 120 microM).

Primary staphylococcal infection and toxic shock syndrome diagnosed by polymerase chain reaction

Primary staphylococcal pneumonia complicated with toxic shock syndrome (TSS) is relatively uncommon in children. Staphylococcus aureus exotoxins are thought to function as superantigens, and seem to promote disease manifestations. The identification of staphylococcal toxin genes by polymerase chain reaction (PCR) offers a specific and rapid diagnostic method for TSS. We describe a 7-year-old child with TSS resulting from staphylococcal pneumonia. S. aureus enterotoxins A and B were detected in the sputum of this patient by PCR.

Burst firing of action potentials in central snail neurons elicited by d-amphetamine: effect of anticonvulsants

The effect of anticonvulsants on the burst firing of action potentials in snail central neuron elicited by d-amphetamine was studied in the identified RP4 neuron of the African snail, Achatina fulica Ferussac. Oscillation of membrane potential and burst firing of action potentials were elicited by d-amphetamine in a concentration-dependent manner. Voltage clamped studies revealed that d-amphetamine elicited a negative slope resistance (NSR) in steady-state I-V curve between - 40 and - 10 mV. The burst firing of action potentials was alleviated following extracellular application of phenytoin, but was not affected after ethosuximide, carbamazepine, and valproic acid. The NSR elicited by d-amphetamine was blocked by phenytoin. However, the NSR was not altered if carbamazepine was added. These results suggest that of the four anticonvulsants tested, only phenytoin could alleviate the burst firing of action potentials elicited by d-amphetamine in snail neuron.

In vitro metabolism of (S)-(-)-[2'-14C]nicotine, using various tissue preparations of marmoset

The nicotine metabolite profile produced by marmoset liver, lung and kidney preparations was investigated after 30 minutes incubation of (S)-(-)-[2'-14C]nicotine. Cation-exchange high performance liquid radiochromatography was employed to separate and quantify nicotine and its metabolites. Cotinine-N-oxide (CNO, 0.7%), 3'-hydroxy-cotinine (3'-OH-C, 0.2%), norcotinine (NORC, 0.9%) and nornicotine (NORN, 0.4%) were formed in the incubates of marmoset lung homogenates; when marmoset kidney homogenates were used, CNO, 0.4%; 3'-OH-C, 0.2%; NORC, 0.7%; NORN, 0.7%; and cotinine (COT, 0.4%) were detected in the incubates. These nicotine metabolites constituted only approximately 2.2% and 2.4% of the original nicotine substrate used by lung and kidney homogenates respectively. When marmoset hepatic homogenates and microsomes were used, both COT and NORN were detected as the major nicotine metabolites. In addition, traces of CNO and 3'-OH-C were also detected in both incubates. The amounts of COT (6.4%) and NORN (1.8%) in the hepatic homogenates were approximately twice that of those formed by hepatic microsomes (3.8% and 0.9%, respectively). Nicotine-1'-N-oxide (NNO, 1.1%) was only detected in the latter preparation. Under the experimental conditions, these nicotine metabolites constituted only 8.2% and 5.8% of the substrate nicotine used in the respective incubates. The present results showed that both primary C-oxidation pathways, i.e. cotinine formation and N-demethylation of nicotine, occurred in the lung, kidney and liver of marmoset in vitro. However, N-oxidation of nicotine was only observed when a marmoset hepatic microsomal preparation was used.

Xenogeneic transplantation of human spermatogonia

In the last 3 years, several studies have shown that xenogeneic transplantation of rodent spermatogonia is feasible. The treatment of infertile patients with spermatogenic arrest using the injection of immature germ cells has yielded only poor results. We attempted to establish a complete spermatogenetic line in the testes of mutant aspermatogenic (W/Wv) and severe combined immunodeficient mice (SCID) transplanted with germ cells from azoospermic men. Spermatogenic cells were obtained from testicular biopsy specimens of men (average age of 34.3 +/- 9 years) undergoing infertility treatment because of obstructive and non-obstructive azoospermia. Testicular tissue was digested with collagenase to promote separation of individual spermatogenic cells. The germ cells were injected into mouse testicular seminiferous tubules using a microneedle (40 microm inner diameter) on a 10 ml syringe. To assess the penetration of the cell suspension into the tubules, trypan blue was used as an indicator. Mice were maintained for 50 to 150 days to allow time for germ cell colonisation and development prior to them being killed. Testes were then fixed for histological examination and approximately 100 cross-sectioned tubules were examined for human spermatogenic cells. A total of 26 testicular cell samples, 16 frozen and 10 fresh, were obtained from 24 men. The origin of the azoospermia was obstructive (OA) in 16 patients and non-obstructive (NOA) in 8 patients. The concentration of spermatogenic cells in the OA group was 6.6 x 10(6) cells/ml, and 1.3 x 10(6) cells/ml in the NOA group (p < 0.01). The different spermatogenic cell types were distributed equally in the OA samples, ranging from spermatogenia to fully developed spermatozoa, but in the NOA group the majority of cells were spermatogonia and spermatocytes. A total of 23 testes from 14 W/Wv mice and 24 testes from 12 SCID mice were injected successfully, as judged by the presence of spermatogenic cells in histological sections of testes removed immediately after the injection. However, sections from the remaining testes examined up to 150 days after injection showed tubules lined with Sertoli cells and xenogeneic germ cells were not found. The reason why the two strains of mouse used as recipients did not allow the implantation of human germ cells is probably due to interspecies specificity involving non-compatible cell adhesion molecules and/or immunological rejection.

Alternative sources of gametes: reality or science fiction?

Although great progress has been made in both the investigation and treatment of infertility, a considerable number of patients still fail to conceive. Spermatogenic failure and/or oocyte ageing appear to be responsible for a large proportion of cases. The use of donor gametes may bring legal, ethical and even social problems of acceptance that can discourage infertile couples from the donor route. Fortunately, emerging reproductive technologies and preliminary results from animal experiments provide some hope for alternative sources of gametes through which these infertile patients can finally conceive their own genetic child. In conjunction with intracytoplasmic sperm injection (ICSI), fertilization of human oocytes with immature sperm precursors, e.g. spermatids and even secondary spermatocytes, has resulted in healthy babies. Pregnancies have also resulted from the use of spermatids derived from in-vitro spermatogenesis. In the mouse, even primary spermatocytes appear able to participate in normal embryogenesis. In view of the possibility for transplantation and even xenotransplantation of spermatogonia to a host testis in animals, a similar use of human male stem cells might provide an attractive source for the treatment of males with arrested spermatogenesis, as well as male cancer patients. Transplantation of somatic cell nuclei and their haploidization within oocytes may prove to be a practical way of eradicating age-related aneuploidy and so constitute an innovative source of healthy oocytes. Most importantly, however, the safety of the procedures described here needs to be proven before their application to the human arena. Finally, we discuss the implications of cytoplasmic quality and of genetic imprinting in the context of these manipulations.

Action potential bursts in central snail neurons elicited by d-amphetamine: roles of ionic currents

The roles of the ionic currents in the firing of potential bursts elicited by d-amphetamine in central snail neurons were studied in the identified RP4 neuron of the African snail, Achatina fulica Ferussac, using the two-electrode voltage-clamp method. Oscillations of membrane potential bursts were elicited by d-amphetamine. The action potential bursts elicited by d-amphetamine decreased following intracellular injection of either EDTA or magnesium, or extracellular application of lanthanum. Voltage-clamped studies revealed that d-amphetamine decreased the fast Na(+), Ca(2+) and transient outward K(+) currents of the RP4 neuron. It also decreased the steady-state K(+) current and elicited a negative slope resistance in the steady-state I-V curve between -50 and -10 mV. The amplitude of negative slope resistance was decreased if either Na(+)-free saline or Co(2+)-substituted Ca(2+)-free saline was perfused. d-Amphetamine did not increase the amplitude of the slowly inactivating Ca(2+) current or the persistent Na(+) currents of RP4 neuron. Tetraethylammonium, a blocker of the delayed outward K(+) current, elicited action potential bursts and negative slope resistance in the RP4 neuron, while 4-aminopyridine, an inhibitor of transient outward K(+) current (I(A)), did not. These results demonstrate that the delayed outward K(+) current and the negative slope resistance in steady-state I-V curve elicited by d-amphetamine may be responsible for the action potential bursts in central snail neurons elicited by d-amphetamine.

Evidence for the biosynthesis of A glucuronide conjugate of (S)-(-)-nicotine, but not (S)-(-)-cotinine or (+/-)-trans-3'-hydroxycotinine by marmoset hepatic microsomes

Recently, the detection of urinary glucuronide conjugates of nicotine and its two major metabolites, trans-3'-hydroxycotinine and cotinine, showed that glucuronidation is an important pathway of nicotine metabolism in humans. (S)-(-)-Nicotine-N(+)-1-beta-glucuronide (quaternary N-glucuronide with linkage through the pyridino-nitrogen of nicotine) was shown to be an important nicotine metabolite of humans in vivo. The present study was undertaken to develop an animal model for this process, in order to ascertain the factors influencing quaternary N-glucuronide formation. (S)-(-)-Nicotine-N(+)-1-beta-glucuronide was formed in vitro when [2'-14C]-nicotine was incubated with Triton X-100 activated marmoset hepatic microsomes in the presence of uridine diphosphoglucuronic acid; it was not formed when activated microsomal preparations of rabbit, guinea-pig, or rat were used as enzyme source. The glucuronide was characterised by comparison with authentic synthetic (S)-(-)-nicotine-N(+)-1-beta-glucuronide using HPLC. The rate of formation of the glucuronide was almost linear during up to four hours of incubation, but still only accounted for a maximum of 6.0% of the available substrate at the end of five hours incubation. The synthetic and biosynthetic (S)-(-)-nicotine-N(+)-1-beta-glucuronides were hydrolysed by beta-glucuronidase and alkali, but were resistant to acid hydrolysis. The results support the concept that the marmoset may be a good animal species to mimic man in studies of nicotine metabolism during exposure to tobacco smoke. In vitro studies using (+/-)-trans-3'-hydroxycotinine or (S)-(-)-cotinine (as potential substrate) and [14C]-uridine diphospho-glucuronic acid (as cofactor) failed to produce any new radiolabelled glucuronide when the above microsomal preparations were used.

Effect of the mandatory helmet law in Taiwan

OBJECTIVE

To estimate the impact of a mandatory motorcycle helmet law in Taiwan.

METHODS

Taiwan passed a mandatory helmet law in June 1997. Data were collected retrospectively from police reports, which include hospital data, to compare six months pre-law June to November 1996) with the same six months post-law (June to November 1997).

RESULTS

Motorcycle fatalities decreased 14% after the introduction of the helmet law. Head injury fatalities fell 22% while fatalities from injuries to other bodily areas rose 20%. Non-fatal motorcycle injuries fell 31%. Non-fatal head injuries fell 44%; non-fatal injuries to other body parts fell 23%.

CONCLUSION

This study indicates that large, immediate public health benefits resulted from the mandatory motorcycle helmet law in Taiwan.

Incidence of sperm aneuploidy in relation to semen characteristics and assisted reproductive outcome

OBJECTIVE

To evaluate the incidence of sperm aneuploidy in men screened for infertility and identify any eventual relation with assisted reproductive outcome.

DESIGN

Controlled prospective study.

SETTING

University hospital-based IVF program.

PATIENT(S)

Infertile couples who were screened for sperm aneuploidy and evaluated for IVF treatment.

INTERVENTION(S)

Fluorescence in situ hybridization was used to identify chromosomes 18, 21, X, and Y. The assisted reproductive techniques of IVF and intracytoplasmic sperm injection were used for infertility treatment.

MAIN OUTCOME MEASURE(S)

The incidence of sperm aneuploidy, semen parameters, fertilization rate, pregnancy characteristics, and rate of neonatal malformations were determined.

RESULT(S)

Oligozoospermic and teratozoospermic men had a significantly higher incidence of chromosomal abnormalities than men with normal semen parameters (2.7% vs. 1.8%). The increased frequency of sperm aneuploidy did not appear to affect pregnancy losses or the occurrence of neonatal malformations.

CONCLUSION(S)

Suboptimal semen samples had a higher incidence of aneuploidy. In this study, the increased frequency of chromosomal abnormalities did not have a direct effect on the fertilization rate, pregnancy characteristics, or neonatal outcome.