[A study on the pulmonary amine imaging in asthmatic patients and guinea pig asthma models]

Scintigraphic technique (SPECT) with intravenous injection of 131I-HIPDM was used to study pulmonary amine imaging in asthmatic patients and Guinea pig animal models. The results showed that the patients and animals had similar characteristic changes of amine imaging: the amine scanning pictures were not well-distributed, pulmonary amine uptake was significantly decreased but the clearance speed significantly increased as compared with those in healthy controls (P < 0.05-0.01). The only difference between the patients and the animals was that the amine imaging parameters in animals during remission recovered practically to normal, while that in patients during remission did not. The mechanism and clinical significance of the above changes were discussed.

Conformation of a biologically active C-terminal hexapeptide analog of the pheromone biosynthesis activating neuropeptide by NMR spectroscopy

The solution conformation of a biologically active C-terminal hexapeptide analog of the pheromone biosynthesis activating neuropeptide Tyr-D-Phe-Ser-Pro-Arg-Leu-NH2 has been studied by NMR spectroscopy. A beta-turn conformation was identified from the NOE connectivities observed for the peptide in a mixed solvent of water and DMSO, indicating that this is the biologically active conformation of the peptide. This study also suggests that the use of such an aqueous-like solvent mixture allows the observation of a preferred conformation for small linear peptides in the presence of conformational averaging.

Ventricular septal summit stimulation in atrioventricular nodal reentrant tachycardia

In all, 18 consecutive patients with atrioventricular nodal reentry tachycardia (AVNRT) underwent right ventricular (RV) stimulation during AVNRT from either the RV apex or summit. Stimulation from the RV apex advanced the tachycardia with the same atrial sequence in 6 of 18 patients (33%), but never conclusively excluded the presence of a low atrial tachycardia. RV summit stimulation resulted in direct stimulation of the low septal right atrium in 6 patients. RV summit stimulation advanced the tachycardia in 4 patients, delayed it in 2 and terminated it in 3 without an atrial electrogram. The latter 2 findings exclude the presence of a low atrial tachycardia. Thus, in patients with AVNRT, application of extrastimuli closer to the putative reentrant site enables greater efficacy in tachycardia resetting and in excluding a low septal atrial tachycardia.

Effects of pulsatile reperfusion on globally ischemic myocardium

To evaluate the effects of pulsatile reperfusion on the post ischemic myocardium, two categories of sheep were put on cardiopulmonary bypass (CPB). In Category I, the hearts of 23 sheep were arrested by global ischemia for 30 min, reperfused with pulsatile flow in 10 animals (P group), and non pulsatile flow in 13 animals (NP group), and then defibrillated. The incidence of ventricular fibrillation was much higher in the NP group than the P group, 77% versus 40% (p < 0.05). The lipoperoxide products and creatinine kinase from coronary sinus blood were elevated, but there were no significant differences between the two groups during 2 hour reperfusion. In the P group, less ultrastructural damage was observed, and Na+ and H2O accumulations in the subendomyocardium were significantly less than in the NP group, at 7.11 +/- 0.60 versus 9.98 +/- 1.10 mg/g dry weight (p < 0.05) and 82.58 +/- 0.47% versus 84.3 +/- 0.38% (p < 0.05), respectively. In Category II, the ischemic time of 17 sheep (eight in the P group, nine in the NP group) was prolonged to 45 min, and animals were supported by CPB after defibrillation. Myocardial energy phosphates were measured with high-performance liquid chromatography, and triphenyltetrazolium chloride was used to delineate the infarct size. After 2 hour of reperfusion, there were no significant differences in myocardial AMP and ADP between the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Hepatitis D virus infection among prostitutes in Taiwan

Two hundred and sixty-three adult licensed, 233 adult and 157 teenage unlicensed prostitutes from Taiwan were studied for prevalence and risk factors of hepatitis D virus (HDV) infection. The hepatitis B carrier rate among the three groups was 21, 15 and 20%, respectively, not significantly different from that of the general population in this area. However, the prevalence of HDV infection among carrier prostitutes was 55, 36 and 16%, respectively, much higher than that in general hepatitis B carriers. Univariate analysis revealed that the history of conducting paid sex for more than 12 months (P < 0.03), ear-piercing (P < 0.02), tattooing (P < 0.02), and gonorrhoea or syphilis (P < 0.005) were significant factors associated with HDV infection among these subjects. Multivariate analysis revealed that the history of ear-piercing and venereal diseases (P < 0.001) were still significant. In summary, genital ulcers caused by venereal diseases due to frequent sexual contact with multiple partners, and use of unsterilized needles in ear-piercing or tattooing play important roles in the high prevalence of HDV infection in prostitutes.

[Effect of anhydrous glycerol injection into the mental foramen of rabbit on inferior nerve:An experimental study]

In this experiment anhydrous glycerol was injected into the mental foramen of rabbits to determine neurolytic effects on the peripheral trigeminal nerve by electrohysiologic and morphologic methods.The rabbits underwent unilateral injection of anhydrous glycerol and the control side was injected with normal saline.The results show that partial fibers are effected (myelinated and unmyelinated fibers at random).Glycerol injection increased the average latencies and reduced the average amplitudes of compound action potentials.Morphologic examination disclosed myelin swelling,disintergrationan d axonal shrinking,axonolysis.One week after the injection,eletrophysiologic and morphologic changes were most severe and signs of regeneration were noted in the fifth week,By 16 weeks after injection,the nerve fibers appeared almost normal.

Electrocardiographic and electrophysiologic characteristics of anterior, midseptal and right anterior free wall accessory pathways

OBJECTIVES

The objective of this study was to define the electrocardiographic (ECG) and electrophysiologic characteristics of midseptal, anteroseptal and right anterior free wall accessory pathways.

METHODS

The fully pre-excited 12-lead surface ECGs and ECGs during orthodromic atrioventricular (AV) reentrant tachycardia were compared for 13 patients with an anteroseptal, 7 with a midseptal and 7 with a right free wall accessory pathway. Routine electrophysiologic studies were performed in all and stimulation of the right ventricular summit during tachycardia was accomplished in 10 patients.

RESULTS

Differences in the surface ECGs were not sufficiently sensitive to distinguish among accessory pathway locations. Premature ventricular complexes induced from the right ventricular septal summit during ventricular activation either advanced the succeeding atrial depolarization or terminated the tachycardia in three of six patients with a septal pathway and in none of the four with a right anterior pathway. The change in ventriculoatrial (VA) interval with the development of right bundle branch block during orthodromic AV tachycardia proved most helpful in distinguishing these pathways. Patients with a right anterior free wall pathway showed a change in VA interval > or = 40 ms, whereas those with an anteroseptal pathway showed changes of 20 to 30 ms and those with a midseptal pathway showed no change.

CONCLUSIONS

Anteroseptal, midseptal and right anterior free wall pathways may be distinguished by using programmed stimulation of the summit of the right ventricular septum and especially with changes in the VA interval with development of right bundle branch block during orthodromic AV reentrant tachycardia.

Insular cistern hematoma. A special type of subarachnoid hemorrhage

The clinical manifestations of 20 cases of insular cistern hematoma were characterized by sudden onset violent headache, vomiting, bloody CSF, and subhyaloid hemorrhage (1/3 cases). CT scan showed semilunar high density image centering on the insular cistern with serrate internal edge. The average volume of the hematoma was 20 ml. By means of cerebral angiography, operation and/or autopsy, 7 cases were identified as aneurysm of middle cerebral artery, 6 as aneurysm of posterior communicating artery, and 2 as amyloid angiopathy. In the other 5 cases, the etiology was unknown.

Use of suppressor analysis to identify DNA polymerase mutations in herpes simplex virus which affect deoxynucleoside triphosphate substrate specificity

Herpes simplex virus DNA polymerase mutations which map in the N-terminal part of the protein and appear to alter deoxynucleoside triphosphate (dNTP) substrate specificity are described. These mutations suppress a drug hypersensitivity associated with the downstream mutation, Aphr10. We suggest that the mutant residues form part of the dNTP-binding site, a site previously thought to be confined to the C terminus.

Radiofrequency catheter ablation for treatment of bundle branch reentrant ventricular tachycardia: results and long-term follow-up

Seven of 120 consecutive patients with inducible sustained ventricular tachycardia (from September 1, 1988 to January 1, 1991) had bundle branch reentrant tachycardia and underwent percutaneous radiofrequency ablation of the right bundle branch. The seven patients had been unsuccessfully treated with a mean of 3 +/- 1 drugs. Four patients presented with syncope and three with aborted sudden death. The baseline electrocardiogram revealed a left bundle branch block pattern in three patients and an intraventricular conduction defect in four. The baseline HV interval was prolonged in each case (79 +/- 2 ms). With use of programmed ventricular extrastimuli, sustained bundle branch reentrant tachycardia was inducible in all patients at a mean cycle length of 283 +/- 17 ms (range 230 to 350). Bundle branch reentrant tachycardia characteristics included atrioventricular dissociation, a His deflection that preceded each QRS complex and spontaneous His to His variation that preceded changes in ventricular tachycardia cycle length. A quadripolar catheter was positioned across the tricuspid valve with the distal electrode tip of the catheter near the right bundle branch. One to three applications of continuous unmodulated radiofrequency current at 300 kHz between the distal electrode and a large posterior skin patch resulted in complete right bundle branch block in all patients, after which none had inducible bundle branch reentrant tachycardia on restudy. On restudy, three of the seven patients had ventricular tachycardia of myocardial origin (not bundle branch reentry). One patient required no therapy; drug or defibrillator therapy was used in the others.(ABSTRACT TRUNCATED AT 250 WORDS)

Patients with supraventricular tachycardia presenting with aborted sudden death: incidence, mechanism and long-term follow-up

A total of 13 (4.5%) of 290 patients with aborted sudden death had either documented (7; 54%) or strong presumptive evidence of supraventricular tachycardia that deteriorated into ventricular fibrillation. Six (46%) of the 13 had an accessory conduction pathway and either atrial fibrillation (5 patients) or paroxysmal atrioventricular (AV) reentrant tachycardia (1 patient) that deteriorated into ventricular fibrillation. Three patients with AV node reentrant tachycardia and four with atrial fibrillation and enhanced AV node conduction presented with supraventricular arrhythmias that deteriorated into ventricular fibrillation. Patients were treated with medical, surgical or catheter ablative procedures designed to prevent recurrences of supraventricular arrhythmias. Four patients received an implanted automatic defibrillator, but none had an appropriate device discharge. Over a follow-up period of 41.6 +/- 33.6 months, 12 patients are alive without symptomatic arrhythmias. One patient died because of severe chronic lung disease and heart failure. Supraventricular tachycardia was the cause of aborted sudden death in approximately 5% of patients referred for evaluation of sudden cardiac death. Treatment directed at prevention of supraventricular tachycardia was associated with an excellent prognosis. Current treatment techniques appear to obviate the need for automatic defibrillator therapy in these patients.

Parkinson's disease in China. Coordinational Group of Neuroepidemiology, PLA

An epidemiological study on the incidence and prevalence of Parkinson's disease (PD) was carried out in 29 provinces, cities and autonomous regions in this country in 1986. The survey was conducted in 117 areas, and 566 patients with PD were found among 3,869,162 persons examined, giving a point prevalence for men and women of 16.9/10(5) and 12.4/10(5), with the highest prevalence after the fifth decade of age. The disease was most prevalent in the southern part of China, especially in Hunan and Guangxi provinces. The incidence was 1.5/10(5)/yr in 1986. Both the prevalence and incidence of PD in China are lower than those in the white race and Japanese.

Influences of Polyactin A on activities of human monocytes in vitro

Effects of Polyactin A (PAA) on abilities of human monocytes to synthesize and secrete interleukin-1 (IL-1) and to modulate natural killer (NK) cell activity in large granular lymphocytes (LGL) were investigated in vitro. Over a wide range of concentrations (0.01-100 micrograms.ml-1), PAA directly induced IL-1 synthesis and secretion, showing the maximal effect at 10 micrograms.ml-1, and evidently synergized with lipopolysaccharides (LPS) of E coli in stimulation of IL-1 production by human monocytes. The manifestation of PAA pretreated autologous monocytes in modulation of NK cell activity was closely related to PAA concentration. A boosting effect of PAA-treated monocytes on NK activity was observed when PAA 10-100 micrograms.ml-1 were used for pretreatment of monocytes, while an inhibitory influence of monocytes was found when PAA 0.01-0.1 microgram.ml-1 were used. These results demonstrate significant effects of PAA on functions of human monocytes, enhancing IL-1 production and affecting their regulative activity on NK cell cytotoxicity.

Comparison of class I- and II-restricted T cell recognition of the identical peptide

There is structural and functional evidence that both class I- and II-restricted T cells recognize short processed peptides bound to MHC molecules. Although the structural conformation of bound peptides remains unknown, no evidence of distinct structural motifs of class I- or class II-restricted peptides has been described. Conversely, two algorithms proposed to predict T cell epitopes, and based on primary amino acid sequence or tertiary structure, are both compatible with many observed class I- and class II-restricted peptides. We previously identified eight class I-restricted peptides which were also recognized by class II-restricted T cells. Based on functional and direct binding studies, additional examples of peptides with both class I and II restrictions have been identified. In this study, we have directly compared the fine specificity of T cell recognition of a single epitope in a single mouse strain in the context of both class I- and class II-restricted responses. Based on a panel of analogue peptides with amino acid substitutions and peptides of various lengths, we observed several striking similarities in the recognition patterns of both class I- and class II-restricted T cells. In addition, some characteristics of recognition were different in the two systems indicating that the recognition processes were similar but not identical.

Pathological study on cerebral amyloid angiopathy

The cerebral amyloid angiopathy (CAA) was pathologically confirmed in 26 cases in which there were 20 cerebral hemorrhages, 2 subarachnoid hemorrhages, 3 cerebral infarctions, and 1 subdural hematoma. The CAA mainly involved the media and extima of small and medium-sized arteries as well as the capillaries of the brain tissue. Half of all cases in our series had the CAA associated vasculopathies (CAA-AV), including microaneurysms, "double barreling", onion skin-like intima, fibrinoid necrosis, clusters of arterioles and perivascular lymphocytic infiltrations. The CAA was often accompanied with the senile plaques and neurofibrillary tangles.

Modified Wicomb's apparatus for preservation of heart for 24 hours

To prolong the time of heart preservation, we modified the Wicomb's perfusion apparatus, in which oxygen flow acts as the source of power and provides oxygenation for the perfused myocardium. Ten adult porcine hearts which had been preserved for 24 hours were resuscitated successfully and continued to beat steadily for more than 1.5-3 hours after reperfusion. Myocardial ultrastructure was observed at the end of preservation and 15-120 minutes after reperfusion. The damages of the myocardial ultrastructure at the end of preservation were reversible.

Characterization of autoreactive T cells. Relative importance of self-peptides versus MHC

The degree to which processed self-peptides contribute to the stimulation of autoreactive T cells has not been determined. In this study we have analyzed a panel of autoreactive T cell hybridomas from normal C57BL/26 mice produced by fusing peripheral lymph node cells with a variant of the BW5147 thymoma line, which does not express endogenous TCR alpha- and beta-chains. All of the autoreactive hybridomas responded to spleen cells expressing the syngeneic I-Ab allele, but not to allogeneic spleen cells. Although all hybridomas were I-Ab restricted, they demonstrated different patterns of reactivity to a panel of APC expressing I-Ab but derived from different genetic backgrounds. In a panel of APC expressing recombinant I-A molecules, changes in the second half of the first domain, which encodes alpha-helix segments that flank the Ag binding site and directly contact the TCR V regions in proposed models, eliminated reactivity of all hybridomas tested. In addition, most of the autoreactive hybridomas also demonstrated inhibition of reactivity to mutations in the amino half of the first domain of the I-A alpha- and beta-chains, which encodes the beta-pleated sheet of the floor of the Ag-binding groove. To confirm the role of processed peptides in the different patterns of reactivity, APC were incubated with competitor Ag and fixed by glutaraldehyde cross-linking before incubation with the autoreactive T hybridomas. The hybridomas were effectively inhibited by exogenous protein and peptide Ag. These results indicate that processed self-peptides are required to activate the autoreactive T cells.

Characterization of autoreactive T cells. Relative importance of self-peptides versus MHC

The degree to which processed self-peptides contribute to the stimulation of autoreactive T cells has not been determined. In this study we have analyzed a panel of autoreactive T cell hybridomas from normal C57BL/26 mice produced by fusing peripheral lymph node cells with a variant of the BW5147 thymoma line, which does not express endogenous TCR alpha- and beta-chains. All of the autoreactive hybridomas responded to spleen cells expressing the syngeneic I-Ab allele, but not to allogeneic spleen cells. Although all hybridomas were I-Ab restricted, they demonstrated different patterns of reactivity to a panel of APC expressing I-Ab but derived from different genetic backgrounds. In a panel of APC expressing recombinant I-A molecules, changes in the second half of the first domain, which encodes alpha-helix segments that flank the Ag binding site and directly contact the TCR V regions in proposed models, eliminated reactivity of all hybridomas tested. In addition, most of the autoreactive hybridomas also demonstrated inhibition of reactivity to mutations in the amino half of the first domain of the I-A alpha- and beta-chains, which encodes the beta-pleated sheet of the floor of the Ag-binding groove. To confirm the role of processed peptides in the different patterns of reactivity, APC were incubated with competitor Ag and fixed by glutaraldehyde cross-linking before incubation with the autoreactive T hybridomas. The hybridomas were effectively inhibited by exogenous protein and peptide Ag. These results indicate that processed self-peptides are required to activate the autoreactive T cells.

Effect of pulsatile reperfusion on myocardial high energy phosphates following global ischemia

To evaluate the effects of pulsatile reperfusion (PR) on the postischemic myocardial phosphometabolites, 17 sheep were put on cardiopulmonary bypass (CPB) and randomly divided into a pulsatile group (P group) and nonpulsatile group (NP group). The heart was arrested by global ischemia for 45 minutes, then defibrillated and reperfused for 2 hours while the circulation was supported by CPB. Myocardial needle biopsies were obtained, and ATP, ADP, and AMP were measured with high performance liquid chromatography. There were no significant differences between the two groups in myocardial ADP and AMP. However, after 120 minutes of reperfusion, the myocardial ATP was restored in the P group, but continued to decrease further in the NP group. Experimental results imply that PR might reduce reperfusion injury and promote recovery of the ischemic myocardium.

Reduction of granulocyte-mediated lung injury in canine cardiopulmonary bypass by anisodamine infusion

The effect of infusing the M-cholinergic receptor blocker anisodamine during cardiopulmonary bypass (CPB) on granulocyte-mediated lung injury was evaluated in sixteen dogs undergoing CPB for 120 min with the aorta crossclamped for 90 min. The treated dogs (n = 8) received a total dose of 15 mg/kg anisodamine hydrochloride before and during CPB whereas the controls (n = 8) received saline only. A significantly reduced sequestration of granulocytes in the lungs was found in the treated dogs as indicated by a lower right-to-left atrium granulocyte gradient 15 minutes after pulmonary recirculation during CPB (p less than 0.05) and less granulocyte accumulation in the lung capillaries after CPB, as shown by histological examination (p less than 0.01). Moreover, oxygen free radical release as indicated by plasma malondialdehyde concentrations was significantly lower (p less than 0.05) in the treated dogs than in the controls towards the end of CPB. Finally, a significantly reduced lung-water content was found 30 min after CPB in the treated dogs as compared with the controls (p less than 0.01). These results suggest that anisodamine administration in this experimental model significantly inhibits pulmonary granulocyte sequestration in CPB and the consequent lung injury induced.

Immunodominance is altered in T cell receptor (beta-chain) transgenic mice without the generation of a hole in the repertoire

Despite the tremendous plasticity of the TCR repertoire, T cells recognize a limited number of antigenic sites (frequently a single site, or immunodominant epitope) on a complex protein Ag. Current models suggest that the immunodominant epitope of a complex protein is the processed peptide that binds to the MHC molecule with the highest affinity. Conversely, the inability of the T cell population to recognize a specific epitope, termed a "hole" in the repertoire, can prevent the immunodominance of a peptide despite efficient processing and MHC binding of the peptide. The role of specific TCR alpha- or beta-chains in determining MHC restriction and recognizing specific epitopes is complex and incompletely understood. To evaluate the contribution of each TCR chain to the functional diversity of the T cell repertoire, we investigated in vivo the T cell response to phage lambda-repressor protein in transgenic mice expressing a single rearranged beta-chain gene (C57L beta mice) in association with the complete germline alpha-chain repertoire. Our results demonstrate that expression of the TCR beta-chain transgene alters the immunodominant epitope recognized by T cells. However, after immunization with the appropriate peptide the transgenic mice can also respond to the nonimmunodominant epitope; thus, the expression of the TCR beta-chain transgene does not create a hole in the repertoire. These data indicate that the primary site, or immunodominant epitope, of an Ag recognized by T cells can be altered by the preimmune TCR repertoire independent of antigen processing and MHC affinity.

Immunodominance is altered in T cell receptor (beta-chain) transgenic mice without the generation of a hole in the repertoire

Despite the tremendous plasticity of the TCR repertoire, T cells recognize a limited number of antigenic sites (frequently a single site, or immunodominant epitope) on a complex protein Ag. Current models suggest that the immunodominant epitope of a complex protein is the processed peptide that binds to the MHC molecule with the highest affinity. Conversely, the inability of the T cell population to recognize a specific epitope, termed a "hole" in the repertoire, can prevent the immunodominance of a peptide despite efficient processing and MHC binding of the peptide. The role of specific TCR alpha- or beta-chains in determining MHC restriction and recognizing specific epitopes is complex and incompletely understood. To evaluate the contribution of each TCR chain to the functional diversity of the T cell repertoire, we investigated in vivo the T cell response to phage lambda-repressor protein in transgenic mice expressing a single rearranged beta-chain gene (C57L beta mice) in association with the complete germline alpha-chain repertoire. Our results demonstrate that expression of the TCR beta-chain transgene alters the immunodominant epitope recognized by T cells. However, after immunization with the appropriate peptide the transgenic mice can also respond to the nonimmunodominant epitope; thus, the expression of the TCR beta-chain transgene does not create a hole in the repertoire. These data indicate that the primary site, or immunodominant epitope, of an Ag recognized by T cells can be altered by the preimmune TCR repertoire independent of antigen processing and MHC affinity.

Membrane oxygenator prevents lung reperfusion injury in canine cardiopulmonary bypass

The effect of blood activation on lung reperfusion injury during cardiopulmonary bypass was investigated in 20 dogs with the use of a bubble oxygenator (n = 10) or a membrane oxygenator (n = 10). In the bubble oxygenator group, significant leukocyte and platelet right to left atrium gradients were found 15 minutes after lung reperfusion (p less than 0.05, p less than 0.01) accompanied by a sharp increase in plasma malondialdehyde concentration 5 minutes after lung reperfusion, whereas no significant right to left atrium gradient of leukocytes or platelets nor significant increase in plasma malondialdehyde concentration was observed in the membrane oxygenator group. In both the bubble oxygenator and membrane oxygenator group, similar mild to moderate lung histological changes were found before lung reperfusion. After lung reperfusion, however, more endothelial cell swelling (p less than 0.05), leukocyte (p less than 0.01) and platelet (p less than 0.01) accumulation in lung capillaries, leakage of erythrocytes into the alveolar space (p less than 0.05), and type I cell damage (p less than 0.05) were found only in the bubble oxygenator group. Eventually, a significantly higher lung water content was found in the bubble oxygenator group than in the membrane oxygenator group (p less than 0.01) after cardiopulmonary bypass. This study indicated that lung injury during cardiopulmonary bypass starts mainly after lung reperfusion, which was correlated with lung leukocyte and platelet sequestration associated with different types of oxygenators.