Spinal surgery for gallstones disease - Case report of a rare differential diagnosis.

INTRODUCTION AND IMPORTANCE: Abdominal pain in the right upper quadrant is very common for patients to present in the emergency department. Finding the correct diagnosis seems straightforward in most cases but can be challenging. CASE PRESENTATION: We present the case of a 75-year-old male with a rare differential diagnosis for right upper quadrant and back pain, initially diagnosed as symptomatic cholelithiasis. After referral to an abdominal surgeon, detailed history taking prior to planned cholecystectomy revealed a record of back pain due to spinal degeneration and fusion surgery, as well as a bulb of the right abdominal wall with hypesthesia in a dermatomal area in the right upper quadrant. Considering these "new" facts, a spinal surgeon was consulted and a foraminal disc hernia of the thoracic vertebrae 11/12 was identified as the cause of symptoms. Instead of the initially planned cholecystectomy, a right-sided facetectomy Th11/12, sequestrectomy and unilateral transpedicular stabilization to decompress the nerve root was successfully performed. CLINICAL DISCUSSION: Although, symptomatic cholelithiasis is one of the most common diagnoses for patients presenting with right upper quadrant pain in the presence of gallstones, other differential diagnoses have to be considered. Thoracic disc herniations can present with atypical symptoms that mimic other non-spinal causes and may pose a diagnostic challenge, sometimes even leading to unnecessary surgery. CONCLUSION: This case highlights a rare differential diagnosis for one of the most common diseases seen by emergency physicians. It emphasizes the risk of working under time pressure, especially in an emergency setting, which may lead to premature diagnostic error and treatment, endangering patient's care and safety.

Evaluation and classification of right ventricular wall motion abnormalities in healthy subjects by 3-tesla cardiovascular magnetic resonance imaging.

BACKGROUND: Right ventricular (RV) shape and function serves as an indicator in several types of heart disease such as arrhythmogenic right ventricular dysplasia (ARVD). However, there is no in-depth knowledge of RV motion, even in healthy subjects. The aim of our study was to provide a quantitative analysis of normal variations in RV wall motion in healthy subjects by cardiac magnetic resonance imaging (CMRI). MATERIAL AND METHODS: The study population consisted of 65 consecutive patients referred for the evaluation of cardiac function by 3 Tesla CMR. Balanced steady-state free-precession images were obtained and areas of disordered RV wall motion were evaluated and classified based on a standardised segmental model for the right ventricle. RESULTS: In 59 patients (90.8 %) wall motion abnormalities (WMA) of the right ventricle were evident. WMA were predominately detected in the apicolateral segments (72 %) compared with mediolateral (24 %, P < 0.001) and inferolateral segments (4 %, P < 0.001). Dyskinesia was the most frequent wall motion disorder (62.4 %), followed by hypokinesia (20.8 %) and bulging (16.8 %). The mean WMA diameter in the transverse plane (6.4 ± 1.9 mm) was significantly shorter compared with the diameter in the horizontal long-axis (8.1 ± 3.6 mm, P = 0.002) and short-axis plane (10.7 ± 4.6 mm). CONCLUSION: WMA of the right ventricle are common. Therefore, one should be aware that these nonpathological wall motion disorders can easily be mistaken for a pathological regional wall motion contraction, particularly in ARVD where to date, clear wall motion criteria are lacking.

Intra-aortic balloon pump (IABP) counterpulsation improves cerebral perfusion in patients with decreased left ventricular function.

BACKGROUND: The current goal of treatment after acute ischemic stroke is the increase of cerebral blood flow (CBF) in ischemic brain tissue. Intra-aortic balloon pump (IABP) counterpulsation in the setting of cardiogenic shock is able to reduce left ventricular afterload and increase coronary blood flow. The effects of an IABP on CBF have not been sufficiently examined. We hypothesize that the use of an IABP especially enhances cerebral blood flow in patients with pre-existing heart failure. METHODS: In this pilot study, 36 subjects were examined to investigate the effect of an IABP on middle cerebral artery (MCA) transcranial Doppler (TCD) flow velocity change and relative CBF augmentation by determining velocity time integral changes (ΔVTI) in a constant caliber of the MCA compared to a baseline measurement without an IABP. Subjects were divided into two groups according to their left ventricular ejection fraction (LVEF): Group 1 LVEF >30% and Group 2 LVEF ≤30%. RESULTS: Both groups showed an increase in CBF using an IABP. Patients with a LVEF ≤30% showed a significantly higher increase of ΔVTI in the MCA under IABP augmentation compared to patients with a LVEF >30% (20.9% ± 3.9% Group 2 vs.10.5% ± 2.2% Group 1, p<0,05). The mean arterial pressure (MAP) increased only marginally in both groups under IABP augmentation. CONCLUSIONS: IABP improves cerebral blood flow, particularly in patients with pre-existing heart failure and highly impaired LVEF. Hence, an IABP might be a treatment option to improve cerebral perfusion in selected patients with cerebral misperfusion and simultaneously existing severe heart failure.

Latent pulmonary hypertension in atrial septal defect: Dynamic stress echocardiography reveals unapparent pulmonary hypertension and confirms rapid normalisation after ASD closure.

OBJECTIVE: Closure of atrial septal defects (ASD) prevents pulmonary hypertension, right heart failure and thromboembolic stroke. The exact timing for ASD closure is controversial. METHODS: In a prospective study to address the question whether unapparent pulmonary hypertension can be revealed prior to right ventricular (RV) remodelling, patients were investigated before and 6, 12, and 24 months after ASD closure using exercise stress echocardiography (ESE) and ergospirometry (n = 24). RESULTS: At rest, RV systolic pressure (RVSP) was normal in 58.8 %, slightly elevated in 26.5 %, and moderately elevated in 11.8 %. One patient showed severe pulmonary hypertension. During ESE, all patients with normal RVSP at rest exhibited an increase (25.7 ± 1.2 mmHg vs. 45.3 ± 2.3 mmHg, p < 0.001). After closure the RVSP was lower, both at rest and ESE. RV diameters decreased too. Tricuspid annulus plane systolic excursion (TAPSE) at rest remained lower after closure (24.0 ± 0.9 vs. 22.0 ± 0.9 mm, p < 0.05). TAPSE in ESE was elevated, and stayed stable after closure (30.1 ± 1.8 mm vs. 29.3 ± 1.6 mm). Before closure, RV systolic tissue velocities (s(a)) at rest were normal and decreased after closure (14.0 ± 1.0 cm/s vs. 11.5 ± 0.7 (6 month) vs. 10.6 ± 0.5 cm/s (12 month), p < 0.05). During ESE, s(a) velocity was similar before and after closure (23.0 ± 1.3 cm/s vs. 23.3 ± 1.9 cm/s). Maximal oxygen uptake (VO2/kg) did not differ between baseline and follow-ups. CONCLUSION: Latent pulmonary hypertension may become apparent in ESE. ASD closure leads to a significant reduction in this stress-induced pulmonary hypertension and to a decrease in the right heart diameters indicating reverse RV remodelling. RV functional parameters at rest did not improve. The VO2/kg did not change after ASD closure.

Tricuspid annular plane systolic excursion assessed using MRI for semi-quantification of right ventricular ejection fraction.

OBJECTIVE: Accurate determination of right ventricular volume and ejection fraction (RVEF) is established using MRI. Automatic contour detection of the right ventricular endocardial border is not established in clinical practice, resulting in considerable manual efforts to quantify RVEF. Using transthoracic echocardiography (TTE), the tricuspid annular plane systolic excursion (TAPSE) has proved its worth for quantification of RVEF and risk prediction. Therefore, the aim of this study was to clarify whether TAPSE assessed with MRI as a fast and easily obtainable parameter correlated with volumetric quantification of RVEF. METHODS: Right ventricular volumes and RVEF were measured with the standardised slice-summation method at MRI. MRI-TAPSE was defined as maximum apical excursion of lateral tricuspid annular plane and measured in a four-chamber view using steady-state free precession sequences. Additionally, MRI-TAPSE was compared with TAPSE assessed using TTE. RESULTS: 76 consecutive patients (aged 58±17 years) were examined. At MRI, right end-diastolic volumes were 97±36 ml, right end-systolic volumes were 57±27 ml and the mean RVEF was 42±14%. MRI-TAPSE was determined with 19±6 mm and correlated well at linear regression analysis with volumetric RVEF (r=0.72, p<0.001). Furthermore, MRI-TAPSE discriminated sufficiently between patients with impaired and normal RVEF. Multiplying MRI-TAPSE by 2.5 led to values close to the RVEF by volumetry. Additionally, MRI-TAPSE correlated well with TAPSE determined using TTE. The inter- and intra-observer variabilities of MRI-TAPSE determination were low (3.1% and 1.8%). CONCLUSION: TAPSE assessed with MRI is a fast and easily obtainable parameter which correlates well with volumetric quantification of RVEF.

Ropinirole improves depressive symptoms and restless legs syndrome severity in RLS patients: a multicentre, randomized, placebo-controlled study.

Comorbid depressive symptoms in restless legs syndrome (RLS) remain a treatment challenge, as some antidepressants aggravate RLS symptoms. Preliminary data in depressive patients suggest antidepressant properties of ropinirole. The present study investigates the effects of ropinirole immediate release (IR) on depressive symptoms and RLS severity. A multicenter, placebo-controlled, double-blind randomized (3:1) study was performed including patients with moderate to severe idiopathic RLS and at least mild depressive symptoms. Ropinirole IR (in flexible doses up to 4 mg/day) or placebo was given for 12 weeks including an uptitration phase of 7 weeks. Visits were scheduled at screening, baseline, and weeks 1, 4, and 12 with additional telephone contacts for dosing decisions. The modified intent to treat population comprised 231 patients (171 ropinirole, 60 placebo). The MADRS (Montgomery-Asberg Depression Rating Scale) scores decreased from baseline to week 12 from 18.8 to 8.7 in the ropinirole group and from 18.4 to 12.1 in the placebo group (primary endpoint, adjusted mean treatment difference -3.6 (95% CI: -5.6 to -1.6, significance in favor of ropinirole: P < 0.001). The superiority of ropinirole compared to placebo was confirmed by the Hamilton Scale for Depression and Beck Depression Inventory-II scores. RLS severity scores (IRLS) decreased by 14.7 (ropinirole) and by 9.9 (placebo, P < 0.001) points. Three out of four subdomains of the Medical Outcomes Study Sleep Scale improved significantly. The findings indicate that mild to moderate depressive symptoms should not be treated before sufficient therapy for RLS. Antidepressant medication can be necessary if depression symptoms still persist even if RLS symptoms are ameliorated.

Elevation of left-sided diaphragm leading to myocardial infarction by compression of the left circumflex artery.

A previously healthy 46-year-old male presented to our emergency department with severe thoracic pain, dyspnea and vomiting, which had suddenly started 2 hours before. He had no history of unusual features and no cardiovascular risk factors. The 12-lead electrocardiogram indicated a posterolateral myocardial infarction. Immediate coronary catheterization revealed occlusion of the proximal left circumflex artery (LCX). Recanalization and coronary stent implantation were successful. No other coronary lesions were detectable that could have indicated coronary artery disease. During catheterization, superposed intestinal loops in the left thorax were striking. The chest X-ray revealed crass cranial displacement of the left-sided diaphragm with intestinal loops beneath, leading to compression of the ipsilateral lung and to a mediastinal shift to the right. Thoracic computed tomography showed compression by the elevated diaphragm of the posterior atrioventricular groove and the left circumflex (LCX) artery embedded in this. Clinical workup revealed no muscular disorder or central dysfunction responsible for diaphragm elevation; no reason for a phrenic nerve lesion was found. The patient subsequently developed ventilatory failure, necessitating intermittent noninvasive bilevel positive airway pressure. After 5 days of intermittent ventilation, the elevation of the diaphragm reduced noticeably and respiratory assistance could be stopped. The cause of this reversible unilateral diaphragm elevation remained unknown.

Receptor-independent sensitization of the adenylyl cylase after chronic treatment with cyclosporine A.

Chronic treatment with cyclosporine A (CyA) is often complicated by severe hypertension. If activation of the beta-adrenergic-receptor-linked adenylyl cyclase (AC) system contributes to hypertension is unresolved. Rats were treated with CyA (20 mg kg(-1) day(-1)) for 7 days. beta-adrenergic, muscarinic, and alpha-adrenergic receptors, G-proteins, and the activity of AC were determined in cardiac and pulmonary plasma membranes. The density of cardiac beta-adrenergic receptors, muscarinic receptors, alpha-adrenergic receptors, G(alphas) and, G(alphai) remained unchanged after treatment with CyA. However, CyA increased the responsiveness of AC to different stimulators. The responsiveness of AC was even more pronounced after solubilization and partial purification, suggesting a direct modulation of the enzyme. These data suggest that CyA modulates the activity of the sympathoadrenergic system by a direct, receptor-independent sensitization of AC, suggesting that this pathway contributes to hypertension in patients treated with CyA.

Incidence of aortic valve regurgitation and outcome after percutaneous closure of atrial septal defects and patent foramen ovale.

BACKGROUND: In recent years percutaneous, transcatheter closure of atrial septal defects (ASD) or patent foramen ovale (PFO) was introduced into clinical practice. OBJECTIVE: To investigate the functional effects on heart valves caused by an interatrial closure device. METHODS AND RESULTS: Between 2001 and 2006, 240 consecutive patients underwent percutaneous closure of an ASD or a PFO. Heart valve functions were defined by transoesophageal echocardiography before implantation and 3, 6 and 12 months after defect closure. A successful implantation procedure was performed in 98% of patients. Sufficient closure without residual shunt was achieved in 89% of patients with ASD and in 92% of patients with PFO. An overall major complication rate of 0.8% was apparent during the observation time (mean (SD) 27 (15) months). Long-term follow-up disclosed newly developed or worsened aortic valve regurgitation (AR) in 9% of patients with ASD and in 10% of patients with PFO. A potential cause for developing AR may be overgrowth of the device by tissue, leading to changes in interatrial septal geometry and traction on the root of the non-coronary aortic cusp. CONCLUSION: AR occurred in 9% of patients with closed ASD and in 10% of patients with closed PFO. Indication for closure should consider this potential complication despite an otherwise safe interventional procedure.

Breastfeeding habits in families with Type 1 diabetes.

AIMS: Breastfeeding is acknowledged to be beneficial for child development. Women with diabetes may be more likely not to breastfeed their children because of neonatal morbidity and instability in diabetes control. The aim of this study was to assess the effect of maternal Type 1 diabetes on breastfeeding habits. METHODS: Full breastfeeding and any breastfeeding were reported in the first year of life in 1560 children born in Germany between 1989 and 2004. Of those, 997 children had a mother with Type 1 diabetes, and the remaining 563 children had a father or sibling with Type 1 diabetes. RESULTS: Fewer children of mothers with Type 1 diabetes were breastfed than children of non-diabetic mothers (77 vs. 86%; P < 0.0001) and, amongst breastfed children, there was a shorter duration of full breastfeeding (12 vs. 17 weeks; P < 0.0001) and any breastfeeding (20 vs. 26 weeks, P < 0.0001) in children of mothers with Type 1 diabetes compared with children of non-diabetic mothers. Other factors associated with reduced frequency and duration of breastfeeding were pre-term delivery (P < 0.0001), young maternal age (P < 0.0001), and firstborn children (P < 0.0001). After stratification for each of these factors, breastfeeding remained significantly less frequent and of less duration in children of mothers with Type 1 diabetes as compared with children of non-diabetic mothers. CONCLUSIONS: Mothers with Type 1 diabetes breastfeed their children less than international recommendations. Counselling to increase frequency and duration of breastfeeding may be warranted in this population.

NT-proBNP correlates with right heart haemodynamic parameters and volumes in patients with atrial septal defects.

BACKGROUND: To investigate the role of N-terminal pro-BNP (NT-proBNP) for the estimation of right heart failure and pulmonary pressure in patients with atrial septal defects (ASD) before and after percutaneous defect closure. METHODS: We performed correlation analysis for NT-proBNP and right ventricular systolic pressure (RVSP) as well as right ventricular enddiastolic and endsystolic volume (RVEDV, RVESV) determined by cardiac magnetic resonance imaging (MRI) before and up to one year following ASD closure. Additionally NT-proBNP concentrations were correlated with right atrial (RA) and RV enddiastolic pressure (RVEDP), ASD size and interatrial left-to-right shunt. RESULTS: Baseline RVSP was 33+/-8 mmHg, which decreased significantly during follow-up. Initially, NT-proBNP levels were 240+/-93 pg/ml. After closure, a reduction to 116+/-62 pg/ml was obvious (p<0.01). Baseline MRI showed enlarged RV volumes in all individuals. At six and twelve months follow-up a significant reduction of RVEDV and RVESV was apparent. A positive correlation was noted between RV volumes and NT-proBNP (r=0.65, p<0.05). Furthermore RA pressure, RVEDP, RVSP and left-to-right shunt significantly correlated to peptide levels. No correlation was seen between ASD size and NT-proBNP. CONCLUSION: NT-proBNP correlates to right ventricular dilatation, pulmonary pressure and left-to-right shunt in volume load of the right heart caused by an underlying ASD.

Transcatheter closure of atrial septal defects improves right ventricular volume, mass, function, pulmonary pressure, and functional class: a magnetic resonance imaging study.

OBJECTIVE: To characterise prospectively by magnetic resonance imaging (MRI) changes in right ventricular (RV) volume, function, and mass after transcatheter closure of atrial septal defects (ASDs) and to evaluate the course of pulmonary pressure and functional class criteria. METHODS: In 20 patients with secundum-type ASD and dilated RV diameter, MRI was performed to quantify RV end diastolic (RVEDV) and end systolic volumes (RVESV), RV mass, tricuspid annular diameter, and RV ejection fraction before and 6 and 12 months after transcatheter closure of the ASD. RV systolic pressure was measured during follow up by transthoracic echocardiography. RESULTS: Functional class improved in the majority of patients after ASD closure. RVESV (from 81 (18) ml/m2 to 53 (15) ml/m2, p < 0.001), RVEDV (from 127 (17) ml/m2 to 99 (18) ml/m2, p < 0.001), and RV mass (from 79 (10) g to 63 (8) g, p < 0.01) decreased significantly during follow up, although tricuspid annular diameter did not. RV ejection fraction improved (by 9% compared with baseline, p < 0.05) and RV systolic pressure decreased significantly (from 33 (8) mm Hg to 24 (6) mm Hg, p < 0.001) after closure. CONCLUSION: MRI studies showed significant improvement of RV volumes, mass, and function after transcatheter closure of ASDs. Restoration of the RV leads to decreased pulmonary pressure resulting in a better functional class in the majority of patients.

[Bacterial pericarditis]. / Bakterielle Perikarditis.

HISTORY AND CLINICAL FINDINGS: A 65-year-old previously healthy man was referred because of high fever, progressive dyspnea and retrosternal pain for 2 days. On admission, the patient was already in a reduced general condition, blood pressure was 120/70 mmHg, heart rate irregular at 75/min and temperature at 39.7 degrees C. Auscultation of the heart revealed distant heart sounds, murmurs were not present, but mild rales were heard over both lung bases. Jugular veins were congested. INVESTIGATIONS: ECG showed a generalized ST-segment elevation with preserved R-waves, slightly depressed PR-segment and atrial bigemini. Chest X-ray revealed an enlarged cardiac silhouette with signs of a pneumopericardium. Transthoracic echocardiography showed a circular pericardial effusion and haemodynamic impairment. Percutaneous pericardiocentesis revealed a purulent effusion with microbiological proof of pneumococci. The primary infectious focus was a maxillary sinusitis caused by pneumococci. DIAGNOSIS: Bacterial pericarditis due to by haematogenous spread of pneumococci. TREATMENT AND COURSE: Antibiotic therapy consisted of intravenous ceftriaxon and gentamicin. To rinse the pericardial space and drain the thick, purulent effusion subxiphoidal, pericardiocentesis and insertion of a drainage tube were done. Physiological saline was put into the pericardial space several times a day, drained and analysed microbiologically. In the meantime rinsing of the infected maxillary sinus was performed. Transthoracic echocardiography was done repeatedly to rule out complications of bacterial pericarditis, especially constrictive pericarditis. The pericardial tube was removed after proof of a sterile drainage 9 days after insertion. The patient was discharged after 4 weeks of hospitalization without clinical or echocardiographic signs of diastolic dysfunction. CONCLUSION: Suspected bacterial pericarditis must be treated as an emergency and confirmed or ruled out by percutaneous pericardiocentesis.

Transcatheter closure of patent foramen ovale (PFO) in patients with paradoxical embolism. Periprocedural safety and mid-term follow-up results of three different device occluder systems.

AIMS: Interventional PFO closure has previously been reported to reduce the risk for recurrent thromboembolic events. The aim of the present study was to evaluate three different occluder systems in respect to (a) the safety and practicability and (b) the mid-term risk of recurrent thromboembolic events. METHODS AND RESULTS: Since 08/98 until 12/02, 307 consecutive patients (138 women, 169 men, mean age 43 years) with a symptomatic PFO underwent PFO closure using the PFO-Star ( n=177), Amplatzer PFO occluder ( n=69) and CardioSeal/Starflex ( n=61 ). Implantation was successful in all patients. Periinterventional complications occurred in 9 patients (5x ST-segment elevations, 1x arteriovenous fistula, 2x TIA, 1x device dislodgement). All of them were reversible and not associated with a specific type of device. During the median follow-up of 24 months (25/75th percentiles: 14/37 months), the annual risk of recurrence was 0.6% for TIA, 0% for stroke and 0.2% for peripheral embolism (PFO-Star: 0.8%, Amplatzer PFO occluder: 0.7% and CardioSeal/Starflex: 1.0%). CONCLUSION: Interventional PFO closure appears to be safe and a promising technique in symptomatic PFO patients with a low incidence of periinterventional complications and recurrent thromboembolic events using three different devices (PFO-Star, Amplatzer PFO occluder or the CardioSeal/Starflex).

Evaluation of standard methods for the analysis of methyl tert-butyl ether and related oxygenates in gasoline-contaminated groundwater.

The U.S. Environmental Protection Agency (EPA) now requires monitoring of oxygenate compounds in groundwater at leaking underground storage tank (LUST) sites nationwide. Three purge-and-trap gas chromatography methods most commonly employed for this purpose were tested, and their performance as a function of total petroleum hydrocarbon (TPH) content of the sample matrix was determined. Tests included a formal method evaluation, a round-robin study, and a split-sample study (424 groundwater samples). Consistently good results were achieved with EPA Method 8240B/60B (mass spectrometry) and ASTM Method D4815 (flame ionization detection) when five oxygenates were monitored in reagent water and gasoline. However, one protocol routinely employed for analysis of LUST samples had serious limitations: EPA Method 8020A/21B (photoiozination detection) was unfit for monitoring of tert-butyl alcohol (TBA) and frequently yielded false-positive (12-50% of samples) and inaccurate results when ether oxygenates were monitored in aqueous samples containing high concentrations of TPH (> 1,000 microg/ L). Thus, care should be taken in the analysis of LUST databases populated with EPA Method 8020/21 data because results reported for methyl tert-butyl ether (MTBE) in samples containing high levels of TPH have a high likelihood of being inaccurate or false-positive. For all three methods, detection limits determined in reagent water were sufficiently low for monitoring MTBE at the stringent primary (13 microg/L) and secondary (5 microg/L) action levels set by the state of California.

Nitrergic neurons make synapses on dual-input dendritic spines of neurons in the cerebral cortex and the striatum of the rat: implication for a postsynaptic action of nitric oxide.

Pre-embedding electron microscopic immunocytochemistry was used to examine the ultrastructure of neurons containing nitric oxide synthase and to evaluate their synaptic relationships with target neurons in the striatum and sensorimotor cerebral cortex. Intense nitric oxide synthase immunoreactivity was found by light and electron microscopy in a type of aspiny neuron scattered in these two regions. The intensity of the labeling was uniform in the soma, dendrites and axon terminals of these neurons. In both forebrain regions, nitric oxide synthase-immunoreactive neurons received synaptic contacts from unlabeled terminals, which were mostly apposed to small-caliber dendrites. The unlabeled symmetric contacts were generally about four times as abundant as the unlabeled asymmetric contacts on the nitric oxide synthase-immunoreactive neurons. Terminals labeled for nitric oxide synthase were filled with synaptic vesicles and were observed to contact unlabeled neurons. Only 54% (in the cerebral cortex) and 44.3% (in the striatum) of the nitric oxide synthase-immunoreactive terminals making apposition with the target structures were observed to form synaptic membrane specializations within the plane of the randomly sampled sections. The most common targets of nitric oxide synthase-immunoreactive terminals were thin dendritic shafts (54% of the immunoreactive terminals in the cortex and 75.7% of the immunoreactive terminals in the striatum), while dendritic spines were a common secondary target (42% of the immunoreactive terminals in the cortex and 20.6% of the immunoreactive terminals in the striatum). The spines contacted by nitric oxide synthase-immunoreactive terminals typically also received an asymmetric synaptic contact from an unlabeled axon terminal. These findings suggest that: (i) nitric oxide synthase-immunoreactive neurons in the cortex and striatum preponderantly receive inhibitory input; (ii) nitric oxide synthase-containing terminals commonly make synaptic contact with target structures in the cortex and striatum; (iii) spines targeted by nitric oxide synthase-containing terminals in the cortex and striatum commonly receive an asymmetric contact as well, which may provide a basis for a synaptic interaction of nitric oxide with excitatory input to individual spines.

The interaction of bacteriophage P2 B protein with Escherichia coli DnaB helicase.

Bacteriophage P2 requires several host proteins for lytic replication, including helicase DnaB but not the helicase loader, DnaC. Some genetic studies have suggested that the loading is done by a phage-encoded protein, P2 B. However, a P2 minichromosome containing only the P2 initiator gene A and a marker gene can be established as a plasmid without requiring the P2 B gene. Here we demonstrate that P2 B associates with DnaB. This was done by using the yeast two-hybrid system in vivo and was confirmed in vitro, where (35)S-labeled P2 B bound specifically to DnaB adsorbed to Q Sepharose beads and monoclonal antibodies directed against the His-tagged P2 B protein were shown to coprecipitate the DnaB protein. Finally, P2 B was shown to stabilize the opening of a reporter origin, a reaction that is facilitated by the inactivation of DnaB. In this respect, P2 B was comparable to lambda P protein, which is known to be capable of binding and inactivating the helicase while acting as a helicase loader. Even though P2 B has little similarity to other known or predicted helicase loaders, we suggest that P2 B is required for efficient loading of DnaB and that this role, although dispensable for P2 plasmid replication, becomes essential for P2 lytic replication.

S-1 radiculopathy as a possible predisposing factor in focal myositis with unilateral hypertrophy of the calf muscles.

Associated with chronic S-1 radiculopathy, a 44-year-old man developed unilateral hypertrophy of the calf muscles. Electromyography revealed neurogenic alterations in the corresponding limb compatible with S-1 radiculopathy. In addition, MR-tomographic and bioptic findings were consistent with a focal inflammatory myopathy of the enlarged right gastrocnemius muscle. Predisposing factors for the localisation of a focal myositis are unknown. This case report highlights the diagnostic difficulties in distinguishing focal myositis and denervation hypertrophy following S-1 radiculopathy or secondary inflammation related to denervation. We consider the possibility that in our case the inflammatory process might have been triggered by electromyographically proven chronic denervation related to radiculopathy.