Submasseteric abscess: report of two cases

Submasseteric abscess is a rare infection with the symptoms of cheek tenderness and marked trismus. Submasseteric abscess is located between the masseter muscle and mandibular ramus with different appearances as sepsis, infection, or tumor. Two cases of submasseteric abscess are reported along with symptoms, causes, and management techniques. Adequate drainage and antibiotic infusion are the treatment of choice. The differential diagnosis of cheek swelling and tenderness that should be considered are parotitis, parotid gland tumor, temporomasseter joint arthritis, and submasseteric abscess.

Molecular markers and their use in animal breeding

The use of DNA markers to define the genetic makeup (genotype) and predict the performance of an animal is a powerful aid to animal breeding. One strategy is known as marker-assisted selection (MAS). MAS facilitates the exploitation of existing genetic diversity in breeding populations and can be used to improve a whole range of desirable traits. DNA markers are, by definition, polymorphic, and the methods used to define DNA markers include restriction fragment length polymorphisms (RFLPs), microsatellites, and single nucleotide polymorphisms (SNPs). Linkage analysis, association analysis and analysis of gene function can be used to determine which polymorphisms are useful markers for desirable traits. Future prospects include the use of high throughput DNA microarray (DNA chip) technology which could revolutionize animal breeding in the next millennium.

Impaired vascular dynamics in normotensive diabetic rats induced by streptozotocin: tapered T-tube model analysis

This study is to explore the changes of arterial mechanical properties in streptozotocin (STZ)-diabetic rats, based on the exponentially tapered T-tube model. Rats given STZ 65 mg kg(-1)i.v. are compared with untreated weight- and age-matched controls. A high-fidelity pressure sensor and electromagnetic flow probe measured pulsatile pressure and flow waves in the ascending aorta, respectively. Diabetic rats exhibit isobaric vasodilatation that is characterized by an increase in cardiac output and no significant changes in aortic pressure. Total peripheral resistance of diabetic rats is lower than that of weight- and age-matched controls. Diabetic rats have higher total peripheral compliance (2.86+/-0.70 microl mm Hg(-1)) than do weight- (1.77+/-0.34 microl mm Hg(-1)) and age-matched (1.87+/-0.69 microl mm Hg(-1)) controls. Aortic characteristic impedance is reduced from 0.017+/-0.003 mm Hg min kg ml(-1)in weight- and 0.020+/-0.004 mm Hg min kg ml(-1)in age-matched controls to 0.010+/-0.004 mm Hg min kg ml(-1)in diabetic rats. Moreover, diabetic rats show shorter wave transit time in lower body circulation (17.86+/-1.91 ms) than do weight- (20.45+/-1.91) and age-matched (23.05+/-2.04 ms) controls. Under isobaric vasodilatation, the decreased resistance and increased compliance in peripheral circulation suggest that the contractile dysfunction of the smooth muscle cells may occur in resistance arterioles in diabetes. With unaltered aortic pressure, an impairment in aortic distensibility of STZ-diabetic rats is manifest on the reduced wave transit time rather than on the diminished aortic characteristic impedance.

Acute effects of methoxamine on left ventricular-arterial coupling in streptozotocin-diabetic rats: a pressure-volume analysis

We determined the acute effects of methoxamine, a specific alpha1-selective adrenoceptor agonist, on the left ventricular-arterial coupling in streptozotocin (STZ)-diabetic rats, using the end-systolic pressure-stroke volume relationships. Rats given STZ 65 mg x kg(-1) iv (n = 8) were compared with untreated age-matched controls (n = 8). A high-fidelity pressure sensor and an electromagnetic flow probe measured left ventricular (LV) pressure and ascending aortic flow, respectively. Both LV end-systolic elastance E(LV,ES) and effective arterial elastance Ea were estimated from the pressure-ejected volume loop. The optimal afterload Q(load) determined by the ratio of Ea to E(LV,ES) was used to measure the optimality of energy transmission from the left ventricle to the arterial system. In comparison with controls, diabetic rats had decreased LV end-systolic elastance E(LV,ES), at 513 +/- 30 vs. 613 +/- 29 mmHg x mL(-1), decreased effective arterial elastance Ea, at 296 +/- 20 vs. 572 +/- 48 mmHg x mL(-1), and decreased optimal afterload Q(load), at 0.938 +/- 0.007 vs. 0.985 +/- 0.009. Methoxamine administration to STZ-diabetic rats significantly increased LV end-systolic elastance E(LV,ES), from 513 +/- 30 to 602 +/- 38 mmHg x mL(-1), and effective arterial elastance Ea, from 296 +/- 20 to 371 +/- 28 mmHg x mL(-1), but did not change optimal afterload Q(load). We conclude that diabetes worsens not only the contractile function of the left ventricle, but also the matching condition for the left ventricular-arterial coupling. In STZ-diabetic rats, administration of methoxamine improves the contractile status of the ventricle and arteries, but not the optimality of energy transmission from the left ventricle to the arterial system.

p53-dependent and -independent pathways of apoptotic cell death in sepsis

Sepsis induces extensive apoptosis of lymphocytes, which may be responsible for the profound immune suppression of the disorder. Two potential pathways of sepsis-induced lymphocyte apoptosis, Fas and p53, were investigated. Lymphocyte apoptosis was evaluated 20-22 h after sepsis by annexin V or DNA nick-end labeling. Fas receptor-deficient mice had no protection against sepsis-induced apoptosis in thymocytes or splenocytes. p53 knockout mice (p53-/-) had complete protection against thymocyte apoptosis but, surprisingly, had no protection in splenocytes. p53-/- mice had no improvement in sepsis survival compared with appropriately matched control mice with sepsis. We conclude that both p53-dependent and p53-independent pathways of cell death exist in sepsis. This differential apoptotic response of thymocytes vs splenocytes in p53-/- mice suggests that either the cellular response or the death-inducing signal is cell-type specific in sepsis. The fact that p53-/- lymphocytes of an identical subtype (CD8-CD4+) were protected in thymi but not in spleens indicates that cell susceptibility to apoptosis differs depending upon other unidentified factors.

Prolonged episodes of persistent asthma: A distinct clinical pattern with characteristic clinical features

STUDY OBJECTIVES

To investigate a clinical pattern of unexplained persistent asthma that is episodic in nature and lasts for months to years. This pattern of prolonged episodes of unexplained, persistent asthma was not defined previously.

DESIGNS

Investigating the clinical features using a retrospective cohort design.

SETTING AND PATIENTS

Eighteen subjects (ages, 13 to 64 years) from an allergy practice in a large prepaid health maintenance organization who had two or more prolonged episodes of unexplained persistent asthma lasting >/= 2 months during a 12-year period.

RESULTS

These subjects accounted for 39 asthmatic episodes lasting from 2 to 74 months (median, 7 months). The duration of the episodes positively correlates with the severity of asthma (p = 0.02) at the initial part of the episodes. All episodes demonstrated a similar pattern, with symptom severity greatest at the onset and gradually diminishing until recovery. The relatively symptom-free intervals between the episodes ranged from 1.5 to 63 months (median, 13 months). Fifty-six percent of the episodes (95% confidence interval [CI], 40% to 72%) were associated with symptoms very suggestive or suggestive of an infection of the upper respiratory tract at the onset of the episodes; 33% of the episodes (95% CI, 19% to 50%) had possible symptoms suggestive of an infection; whereas only 10% of the episodes (95% CI, 3% to 24%) had questionable or no symptoms suggestive of an infection of the upper respiratory tract. Thirty-four episodes had the onset between September and March, whereas only 5 episodes occurred between April and August (p < 0. 001).

CONCLUSIONS

These observations indicate that prolonged episodes of unexplained, persistent asthma lasting for months to years constitute a distinct clinical pattern of asthma with characteristic clinical features.

Arecoline excites rat locus coeruleus neurons by activating the M2-muscarinic receptor

The action of arecoline on rat locus coeruleus neurons was studied by intracellular recording from the in vitro brain slice preparation. Superfusion of arecoline (0.1-100 microM) caused two dose-related effects, an increased firing rate and, in neurons previously hyperpolarized to a constant potential by passing a steady hyperpolarizing current across the membrane, depolarization. Both effects were associated with a reduction in membrane input resistance. Moreover, the arecoline-induced excitatory effects were antagonized by the muscarinic receptor antagonist, atropine, but not by the nicotinic receptor antagonist, hexamethonium. Methoctramine, a selective M2-muscarinic receptor antagonist, was also effective in reversing the arecoline-induced effects, with a dissociation equilibrium constant of 14.2+/-1.2 nM (n=6). These results therefore suggest that arecoline exerts its excitatory actions by binding to M2-muscarinic receptors on the cell membrane of neurons of the locus coeruleus.

Electrophysiologic characteristics and ablation of an atypical atrial flutter in the right atrium

Subeustachian isthmus-dependent typical atrial flutter has been well studied. We demonstrate a case with atypical atrial flutter involving only the base of the right atrium around the inferior vena cava. Entrainment pacing and mapping studies documented a distinct circuit traversing the subeustachian isthmus, propagating through the posterobasal right atrium, and skirting the inferior vena cava. Successful radiofrequency ablation of the arrhythmia was accomplished by creating a linear lesion at the subeustachian isthmus. Mapping of the inferior vena cava region and the demonstration of concealed entrainment are essential steps in establishing the mechanism of the atypical atrial flutter.

Home telecare system using cable television plants--an experimental field trial

To solve the inconvenience of routine transportation of chronically ill and handicapped patients, this paper proposes a platform based on a hybrid fiber coaxial (HFC) network in Taiwan designed to make a home telecare system feasible. The aim of this home telecare system is to combine biomedical data, including three-channel electrocardiogram (ECG) and blood pressure (BP), video, and audio into a National Television Standard Committee (NTSC) channel for communication between the patient and healthcare provider. Digitized biomedical data and output from medical devices can be further modulated to a second audio program (SAP) subchannel which can be used for second-language audio in NTSC television signals. For long-distance transmission, we translate the digital biomedical data into the frequency domain using frequency shift key (FSK) technology and insert this signal into an SAP band. The whole system has been implemented and tested. The results obtained using this system clearly demonstrated that real-time video, audio, and biomedical data transmission are very clear with a carrier-to-noise ratio up to 43 dB.

The 5'-end of the porcine perinatal myosin heavy chain gene shows alternative splicing and is clustered with repeat elements

The porcine perinatal myosin heavy chain (MyHC) is a major isoform in foetal skeletal muscles. We report here on its cDNA and genomic isolation, molecular characterisation and expression. Exon 2 and the first 4 bases of exon 3 of the perinatal MyHC gene. both part of the 5'-end untranslated region, showed differential splicing. About 2% of all perinatal MyHC transcripts of a 50-day-old foetus were without exon 2 and about half were without the 4 bases at the 5'-end of exon 3. Perinatal MyHC mRNA was expressed in all hind limb muscles of a 45-day-old foetus along with the slow and embryonic MyHC isoforms in the same fibres. Unlike other sarcomeric MyHCs reported to date, the porcine perinatal promoter is clustered with repeat elements (4 SINEs and 1 microsatellite) and is without a consensus TATA box at the predicted site upstream of exon 1. Nonetheless, in reporter gene transfections, its promoter was found to be highly muscle-specific. The absence of a TATA box may point to a fundamental difference in the regulatory function between the perinatal and adult MyHC isoforms.

Unexpected loss of bipolar pacing with implanted dual chamber pacemakers

Bipolar leads are most commonly used in the current practice of pacemaker therapy. In our study of 124 patients implanted with Guidant/Cardiac Pacemakers (CPI) Vigor dual chamber pacemakers, 5 patients had unexpectedly abrupt increases in bipolar lead impedance and pacing threshold 2 weeks to 18 months postimplantation without changes in sensing function. With the lead configuration reprogrammed to unipolar, the lead impedance and pacing threshold were restored to appropriate ranges. The changes in bipolar lead parameters can be caused by the CPI's "Quick Connect" (QC1) header lead system incorporated in these pacemakers.

Caspases -2, -3, -6, and -9, but not caspase-1, are activated in sepsis-induced thymocyte apoptosis

Sepsis induces extensive lymphocyte cell death that may contribute to immune depression and morbidity/mortality in the disorder. bcl-2 is a member of a new class of oncogenes that prevents cell death from an array of noxious stimuli. Transgenic mice that overexpress BCL-2 in T lymphocytes are resistant to sepsis-induced T cell apoptosis, and mortality was decreased in sepsis. The purpose of this study was to identify key initiator and executioner "caspases" involved in sepsis-induced lymphocyte apoptosis and to determine if BCL-2 acts prior to caspase activation. Thymi were removed 5-22 h post-cecal ligation and puncture (CLP) or sham surgery. Apoptosis was evaluated in thymocytes by annexin-V FITC labeling and flow cytometry. Caspase-1 activity was determined by western blot analysis of the procaspase protein and p20 subunit of the activated caspase; activities of caspases -2, -6, and -9 were determined by colorimetric assays using specific substrates conjugated to a color reporter molecule. Caspase-3 activity was determined both by western blot and by a fluorogenic assay in which a fluorescent compound was generated. Thymocytes from CLP mice had markedly increased apoptosis and activation of caspases -2, -3, -6, and -9 in comparison with thymocytes of sham-operated mice. Caspase-1 was not activated. BCL-2 prevented sepsis-induced thymocyte apoptosis and inhibited activation of all caspases. We conclude that sepsis causes activation of multiple caspases and that BCL-2 acts upstream as an inhibitor of caspase activation. The pattern of caspase activation suggests a mitochondrial mediated pathway.

Simultaneous alterations of QRS configuration and tachycardia cycle length during radiofrequency ablation of idiopathic left ventricular tachycardia

Idiopathic left ventricular tachycardia is characterized by a QRS morphology of right bundle branch block pattern and left axis deviation. Alterations in the QRS configuration and tachycardia cycle length, as well as shifting of the earliest activation site occurred after eliminating the original tachycardia by radiofrequency current in an 18-year-old man with idiopathic left ventricular tachycardia. Activation mapping and entrainment mapping during tachycardia identified 2 putative tachycardia exits, 15 mm apart. Elimination of both tachycardias was accomplished after applying radiofrequency current to each exit separately. We proposed that the first radiofrequency application might have altered the exit site and the zone of slow conduction adjacent to the exit site, such that the ventricular tachycardia had a different QRS morphology and became slower in this patient.

Oxygen effects on glucose measurements with a reference analyzer and three handheld meters

Oxygen may affect glucose meter and reference analyzer measurements. We evaluated the effects of changes in blood oxygen tension (Po2) on Accu-Chek Comfort Curve (Roche Diagnostics, Indianapolis, IN), Precision G, (Abbott Laboratories, Bedford, MA) and One Touch II (Lifescan, Milpitas, CA) glucose meter measurements, and on Yellow Springs Instruments (YSI) (Yellow Springs, OH) reference analyzer measurements. Venous blood drawn from healthy volunteers was adjusted to three glucose levels of 80, 200, and 400 mg/dL, each tonometered with six different Po2 levels (40, 80, 160, 240, 320, and 400 torr). To quantitate oxygen effects on reference analyzer measurements, glucose differences between test sample (Po2 changed) and control (Po2 80 torr) were calculated (YSItest-YSIcontrol). The threshold for determination of oxygen effects was +/-2 SD, where 2 SD was fro

A cytotoxic 5alpha,8alpha-epidioxysterol from a soft coral Sinularia species

A new sterol, (22R,23R,24R)-5alpha,8alpha-epidioxy-22, 23-methylene-24-methylcholest-6-en-3beta-ol (1), as well as two known sterols, numersterol A (2) and pregnenolone (3), have been isolated from a soft coral Sinularia sp. The structure of metabolite 1 was determined by spectral analysis. Cytotoxicity of sterols 1-3 toward various cancer cell lines is also reported.

Prevention of lymphocyte cell death in sepsis improves survival in mice

Sepsis induces extensive lymphocyte apoptosis, a process which may be beneficial to host survival by down-regulating the inflammatory response or, alternatively, harmful by impairing host defenses. To determine the beneficial vs. adverse effects of lymphocyte apoptosis in sepsis, we blocked lymphocyte apoptosis either by N-benzyloxycarbonyl-Val-Ala-Asp(O-methyl) fluoromethyl ketone (z-VAD), a broad-spectrum caspase inhibitor, or by use of Bcl-2 Ig transgenic mice that selectively overexpress the antiapoptotic protein Bcl-2 in a lymphoid pattern. Both z-VAD and Bcl-2 prevented lymphocyte apoptosis and resulted in a marked improvement in survival. z-VAD did not decrease lymphocyte tumor necrosis factor-alpha production. Considered together, these two studies employing different methods of blocking lymphocyte apoptosis provide compelling evidence that immunodepression resulting from the loss of lymphocytes is a central pathogenic event in sepsis, and they challenge the current paradigm that regards sepsis as a disorder resulting from an uncontrolled inflammatory response. Caspase inhibitors may represent a treatment strategy in this highly lethal disorder.

Effects of food restriction on mechanical properties of arterial system in adult and middle-aged rats

The effects of food restriction on the mechanical properties of the vasculature were determined in Long-Evans male rats with different ages. Rats that began food restriction at the ages of 6 months and 12 months were fed on alternate days for 6 months. Rats at the ages of 12 and 18 months were referred to as adult and middle-aged rats and were anesthetized and thoracotomized. The exponentially tapered T-tube model was employed to relate pulsatile pressure and flow signals measured in the ascending aorta. In each age group, food restriction elicited a decrease in body weight as well as basal heart rate but showed no significant change in cardiac output. Arterial blood pressure, total peripheral resistance, and aortic characteristic impedance were not affected by food restriction in middle-aged rats. However, adult food-restricted rats exhibited lower mean arterial blood pressure (99.1 +/- 3.1 mmHg) than did adult ad libitum-fed rats (110.7 +/- 3.0 mmHg). Total peripheral resistance was reduced from 0.645 +/- 0.045 mmHg-min-kg/ml in adult ad libitum-fed rats to 0.492 +/- 0.030 mmHg-min-kg/ml in adult food-restricted rats. Moreover, aortic characteristic impedance of adult food-restricted rats (0.014 +/- 0.001 mmHg-min-kg/ml) was lower than that of adult ad libitum-fed rats (0.024 +/- 0.002 mmHg-min-kg/ml). Neither age nor diet exerted effects on wave transit time and produced no changes in aortic distensibility. In conclusion, food restriction may elicit significant changes in the mechanical properties of both Windkessel vessels and resistance arterioles in adult rats, but not in middle-aged rats.

Inhibition of activation of nuclear factor kappaB is responsible for inhibition of inducible nitric oxide synthase expression by higenamine, an active component of aconite root

Effects of higenamine on nitric oxide (NO) production and inducible NO synthase (iNOS) mRNA expression (RAW 264.7 cells), on vascular reactivity in vitro and in vivo (rats), and on survival rates (mice) and serum nitrite/nitrate levels (rats) were investigated by using last lipopolysaccharide (LPS) plus interferon (IFN)-gamma. Higenamine concentration-dependently inhibited NO production and inducible NO synthase mRNA in RAW 264.7 cells, in which the IC(50) was 53 microM. Higenamine (10 mg/kg i.p.) administered 90 min before LPS (5 mg/kg i.v.) prevented not only LPS-induced hypotension but also pressor response to norepinephrine (1 microgram/kg) in rats. Incubation of thoracic aorta with LPS (300 ng/ml) for 8 h in vitro resulted in suppression of the vasoconstrictor effects to phenylephrine, which was prevented by coincubation with higenamine. The survival rate to endotoxin in mice was significantly (P <.01) increased by the presence of higenamine in the LPS-treated group up to 48 h. Serum nitrite/nitrate levels were significantly (P <.05) reduced by higenamine in LPS-treated rats. Finally, higenamine inhibited the activation of nuclear factor kappaB in RAW 264.7 cells due to LPS + IFN-gamma by mobility shift assays. Taken together, these data strongly suggest that higenamine inhibits iNOS expression by inhibiting nuclear factor kappaB activation by LPS + IFN-gamma, which may be beneficial in inflammatory diseases in which enhanced formation of NO is the main causative factor. Furthermore, due to positive inotropic action, higenamine may be more effective in a condition where myocardial contractility is likely to depress, such as in septic shock and/or endotoxin-induced inflammatory disorders.

Intracardiac echocardiography via the transvenous approach with use of 8F 10-MHz ultrasound catheters

OBJECTIVE

To study the safety and feasibility of intracardiac imaging using a novel 8F 10-MHz non-over-the-wire ultrasound catheter system.

SUBJECTS AND METHOD

Intracardiac imaging using a transfemoral venous approach was performed in 33 adults, 14 men and 19 women, aged 25 to 66 years (mean, 46 years). Six were normal subjects, 12 had congenital heart diseases (5 atrial septal defects, 3 ventricular septal defects, 1 tetralogy of Fallot, 2 patent ductus arteriosus, and 1 Ebstein anomaly), 14 had valvular heart diseases (12 mitral stenoses and 2 calcific aortic stenoses), and 1 had acute pulmonary embolism.

RESULTS

Ultrasound images were obtained, without any complications, from the right side of the heart in all subjects. The atria and ventricles could be recognized by anatomic relationships to the cardiac chambers and the valves by their characteristic motion during each cardiac cycle. The vessels were verified by their connections to the cardiac chamber and by contrast echocardiography if indicated.

CONCLUSION

Intracardiac imaging using the 8F 10-MHz non-over-the-wire ultrasound catheter system via a transfemoral venous approach is feasible and safe. Intracardiac echocardiography is potentially useful for assessing a variety of cardiac anomalies and in guiding and monitoring certain intervention procedures.

Baseline NIH Stroke Scale score strongly predicts outcome after stroke: A report of the Trial of Org 10172 in Acute Stroke Treatment (TOAST)

OBJECTIVE

To compare the baseline National Institutes of Health Stroke Scale (NIHSS) score and the Trial of Org 10172 in Acute Stroke Treatment (TOAST) stroke subtype as predictors of outcomes at 7 days and 3 months after ischemic stroke.

METHODS

Using data collected from 1,281 patients enrolled in a clinical trial, subtype of stroke was categorized using the TOAST classification, and neurologic impairment at baseline was quantified using the NIHSS. Outcomes were assessed at 7 days and 3 months using the Barthel Index (BI) and the Glasgow Outcome Scale (GOS). An outcome was rated as excellent if the GOS score was 1 and the BI was 19 or 20 (scale of 0 to 20). Analyses were adjusted for age, sex, race, and history of previous stroke.

RESULTS

The baseline NIHSS score strongly predicted outcome, with one additional point on the NIHSS decreasing the likelihood of excellent outcomes at 7 days by 24% and at 3 months by 17%. At 3 months, excellent outcomes were noted in 46% of patients with NIHSS scores of 7 to 10 and in 23% of patients with scores of 11 to 15. After multivariate adjustment, lacunar stroke had an odds ratio of 3.1 (95% CI, 1.5 to 6.4) for an excellent outcome at 3 months.

CONCLUSIONS

The NIHSS score strongly predicts the likelihood of a patient's recovery after stroke. A score of > or =16 forecasts a high probability of death or severe disability whereas a score of < or =6 forecasts a good recovery. Only the TOAST subtype of lacunar stroke predicts outcomes independent of the NIHSS score.

Antithrombotic treatment of ischemic stroke among patients with occlusion or severe stenosis of the internal carotid artery: A report of the Trial of Org 10172 in Acute Stroke Treatment (TOAST)

OBJECTIVE

To examine the responses to early IV administration of an anticoagulant or placebo started within 24 hours of stroke among persons with an ipsilateral occlusion or severe stenosis of the internal carotid artery (ICA) identified by carotid duplex imaging.

BACKGROUND

Patients with ischemic stroke of the cerebral hemisphere secondary to an ipsilateral occlusion or severe stenosis of the ICA generally have a poor prognosis. Early, accurate identification of these patients might permit improved treatment.

METHODS

Exploratory analysis of outcomes at 7 days and 3 months was performed among patients enrolled in the Trial of Org 10172 in Acute Stroke Treatment (TOAST) who had an ischemic stroke in the cerebral hemisphere ipsilateral to an occlusion or a stenosis >50% of the ICA identified by carotid duplex imaging.

RESULTS

Regardless of treatment, patients with duplex evidence of an occlusion of the ICA had more severe strokes and poorer outcomes at 7 days and 3 months than patients who had a stenosis. Favorable outcomes at 7 days were noted in 64 of 119 patients given danaparoid (53.8%) and 41 of 108 patients treated with placebo (38.0%; p = 0.023). By 3 months, favorable outcomes were noted in 82 patients given danaparoid (68.3%) and 58 patients administered placebo (53.2%; p = 0.021).

CONCLUSIONS

Early identification by duplex imaging of an occlusion or severe stenosis of the ICA ipsilateral to a hemispheric ischemic stroke might improve selection of patients who could be treated with emergent anticoagulation. Further testing of this approach is needed.

Isolation of a Helicobacter pylori protein, FldA, associated with mucosa-associated lymphoid tissue lymphoma of the stomach

BACKGROUND & AIMS

The growth of gastric mucosa-associated lymphoid tissue lymphoma (MALToma) seems to depend on the stimulation of Helicobacter pylori. We attempted to identify specific antigen(s) from H. pylori strains associated with MALToma.

METHODS

Membranous and secreted proteins of H. pylori were compared on sodium dodecyl sulfate-polyacrylamide gel electrophoresis by Western blot using sera from patients with MALToma.

RESULTS

A 19-kilodalton protein was seen in all strains isolated from patients with MALToma but uncommonly in other strains. The protein was purified and sequenced. Amino acid sequence comparison showed it was an FldA homologue, a putative flavodoxin protein. DNA sequencing in 26 strains revealed that a nucleotide G insertion at position 481 of the fldA gene was more frequently observed in strains associated with MALToma than other strains (9/9 vs. 6/17; P = 0.002). The mutation caused a short truncation. A recombinant protein with this truncation was expressed and tested. Sera of 12 (70.6%) of 17 patients with MALToma were positive for the antibody to the recombinant protein, and 7 (16.7%) of 42 control patients were positive (12/17 vs. 7/42; P < 0.0001).

CONCLUSIONS

Truncated FldA of H. pylori is associated with gastric MALToma. It may be involved in the pathogenesis of gastric MALToma. Antibody to this antigen could be used as a serological marker of the disease.

Radiofrequency ablation of a right atriofascicular Mahaim fiber and two contralateral left free-wall accessory pathways

We report a rare combination of a right atriofascicular Mahaim fiber and two left-sided atrioventricular accessory pathways in a 57-year-old female presenting with an antidromic atrioventricular reciprocating tachycardia. Radiofrequency ablation was first targeted at the left lateral accessory pathway that served as the retrograde limb of the tachycardia. After elimination of the left lateral pathway, a bystander left posterolateral pathway was detected, and it too was successfully ablated. Although no tachycardia was reinducible, the Mahaim pathway was ablated because of its short effective refractory period. A discrete Mahaim potential recorded at the right atrial free-wall successfully guided the ablation.

Overexpression of Bcl-2 in transgenic mice decreases apoptosis and improves survival in sepsis

In sepsis there is extensive apoptosis of lymphocytes, which may be beneficial by down-regulating the accompanying inflammation. Alternatively, apoptosis may be detrimental by impairing host defense. We studied whether Bcl-2, a potent antiapoptotic protein, could prevent lymphocyte apoptosis in a clinically relevant model of sepsis. Transgenic mice in which Bcl-2 was overexpressed in T cells had complete protection against sepsis-induced T lymphocyte apoptosis in thymus and spleen. Surprisingly, there was also a decrease in splenic B cell apoptosis in septic Bcl-2 overexpressors compared with septic HeJ and HeOuJ mice. There were marked increases in TNF-alpha, IL-1beta, and IL-10 in thymic tissue in sepsis in the three species of mice, and the increase in TNF-alpha and IL-10 in HeOuJ mice was greater than that in Bcl-2 mice. Mitotracker, a mitochondrial membrane potential indicator, demonstrated a sepsis-induced loss of membrane potential in T cells in HeJ and HeOuJ mice but not in Bcl-2 mice. Importantly, Bcl-2 overexpressors also had improved survival in sepsis. To investigate the potential impact of loss of lymphocytes on survival in sepsis, Rag-1-/- mice, which are totally deficient in mature T and B cells, were also studied. Rag-1-/- mice had decreased survival compared with immunologically normal mice with sepsis. We conclude that overexpression of Bcl-2 provides protection against cell death in sepsis. Lymphocyte death may be detrimental in sepsis by compromising host defense.