The Site of Vascular Response to the α-Toxin of Clostridium Perfringens Type A in Skeletal Muscle

The vascular response to the α-toxin of Clostridium perfringens type A, was observed topographically in the cremaster muscle of the rat, in terms of exudation, labelling of damaged vessels by circulating carbon, and in addition histologically for patency of the vascular plexus.It was confirmed that the permeability response is biphasic. The short-lived immediate phase corresponds to that of venular labelling, and the delayed phase reaches its peak rather later than the corresponding phase of capillary labelling. The intensity and extent of these responses are determined by the degree of injury, but their shape and timing, especially in the immediate phase, vary almost as consistently with the duration of exposure to circulating dye or carbon.After the standard dose of toxin, vascular patency is largely unaffected until 24 hours. Apparently irreversible vascular occlusion occurs rather earlier with larger doses. A three-fold reduction of the standard dose proportionately reduces both exudation and capillary labelling but leaves immediate venular labelling unaffected, suggesting that the latter is not dose dependent and therefore non-specific. Prolongation of moderate venular labelling into the middle of the delayed phase may occur at this dosage. Its absence after the standard dose suggests that delayed inhibition of venular reactivity may be occurring.Irregular labelling of venules and small veins persists throughout the delayed phase with doses 2·4 or more times the standard dose. A brief ultramicroscopic survey revealed appearances in both venules and capillaries at 1-2 hours after injury closely comparable to those which have been described for Cl. oedematiens toxin at 6-24 hours.In rats given carbon during the delayed phase, the effective vascular patency 10 minutes later includes half of the labelled capillaries up to 10 μm in diameter. This proportion is little affected by toxin dose, but intensely so when the carbon clearance time is increased, suggesting that such injured microvessels may be a major source of plasma protein exudation.     

Effects of concurrent inspiratory and expiratory muscle training on respiratory and exercise performance in competitive swimmers

The efficiency of the respiratory system presents significant limitations on the bodys ability to perform exercise due to the effects of the increased work of breathing, respiratory muscle fatigue, and dyspnoea. Respiratory muscle training is an intervention that may be able to address these limitations, but the impact of respiratory muscle training on exercise performance remains controversial. Therefore, in this study we evaluated the effects of a 12-week (10 sessions week^–1) concurrent inspiratory and expiratory muscle training (CRMT) program in 34 adolescent competitive swimmers. The CRMT program consisted of 6 weeks during which the experimental group (E, n=17) performed CRMT and the sham group (S, n=17) performed sham CRMT, followed by 6 weeks when the E and S groups performed CRMT of differing intensities. CRMT training resulted in a significant improvement in forced inspiratory volume in 1 s (FIV_1.0) (P=0.050) and forced expiratory volume in 1 s (FEV_1.0) (P=0.045) in the E group, which exceeded the S groups results. Significant improvements in pulmonary function, breathing power, and chemoreflex ventilation threshold were observed in both groups, and there was a trend toward an improvement in swimming critical speed after 12 weeks of training (P=0.08). We concluded that although swim training results in attenuation of the ventilatory response to hypercapnia and in improvements in pulmonary function and sustainable breathing power, supplemental respiratory muscle training has no additional effect except on dynamic pulmonary function variables.     

Primary low-grade B-cell lymphoma of mucosa-associated lymphoid tissue type arising in the urinary bladder: report of 4 cases with molecular genetic analysis

CONTEXT: Primary lymphoma of the urinary bladder is rare. Only 84 cases have been reported in the English literature to date, and none of these cases has had molecular confirmation of clonal immunoglobulin gene rearrangement. OBJECTIVES: To review all cases with primary urinary bladder lymphoma in our records, to classify them using the REAL classification, to confirm their immunophenotype and genotype, and to determine their outcome. DESIGN: We identified 4 cases of primary urinary bladder lymphoma in our medical records from a 30-year period. Immunohistochemical detection of immunoglobulin light chains and molecular analysis of immunoglobulin heavy-chain genes using the polymerase chain reaction were performed on paraffin-embedded material. RESULTS: All patients were older than 60 years. The male-female ratio was 1:3. All patients had a history of chronic cystitis. Histologic features of mucosa-associated lymphoid tissue lymphoma with centrocyte-like cells, plasmacytoid B cells, or both were observed in all cases. Monoclonality of B cells was demonstrated by immunohistochemistry, polymerase chain reaction, or both methods in every case. All patients presented with stage IAE disease, were treated with radiotherapy alone, and have been in continuous complete remission for 2 to 13 years. CONCLUSIONS: Primary bladder lymphomas are usually of low-grade mucosa-associated lymphoid tissue type. They are more common in females and are associated with a history of chronic cystitis. Lymphoepithelial lesions are seen only in association with areas of cystitis glandularis. B-cell clonality is readily demonstrable by immunohistochemistry and/or polymerase chain reaction analysis. Local radiotherapy appears to confer long-term control.     

A comparison of three months of anticoagulation with extended anticoagulation for a first episode of idiopathic venous thromboembolism

BACKGROUND: Patients who have a first episode of venous thromboembolism in the absence of known risk factors for thrombosis (idiopathic thrombosis) are often treated with anticoagulant therapy for three months. Such patients may benefit from longer treatment, however, because they appear to have an increased risk of recurrence after anticoagulant therapy is stopped. METHODS: In this double-blind study, we randomly assigned patients who had completed 3 months of anticoagulant therapy for a first episode of idiopathic venous thromboembolism to continue receiving warfarin, with the dose adjusted to achieve an international normalized ratio of 2.0 to 3.0, or to receive placebo for a further 24 months. Our goal was to determine the effects of extended anticoagulant therapy on rates of recurrent symptomatic venous thromboembolism and bleeding. RESULTS: A prespecified interim analysis of efficacy led to the early termination of the trial after 162 patients had been enrolled and followed for an average of 10 months. Of 83 patients assigned to continue to receive placebo, 17 had a recurrent episode of venous thromboembolism (27.4 percent per patient-year), as compared with 1 of 79 patients assigned to receive warfarin (1.3 percent per patient-year, P<0.001). Warfarin resulted in a 95 percent reduction in the risk of recurrent venous thromboembolism (95 percent confidence interval, 63 to 99 percent). Three patients assigned to the warfarin group had nonfatal major bleeding (two had gastrointestinal bleeding and one genitourinary bleeding), as compared with none of those assigned to the placebo group (3.8 vs. 0 percent per patient-year, P=0.09). CONCLUSIONS: Patients with a first episode of idiopathic venous thromboembolism should be treated with anticoagulant agents for longer than three months.     

Occurrence of schizotypal and borderline symptoms in parasuicide patients: comparison between subjective and objective indices

Seventy-six patients were interviewed within a week of admission following a parasuicide episode. Axis II diagnosis on DSM-III was made for schizotypal, borderline, histrionic, and antisocial personality disorder. In addition patients completed a self-rating questionnaire, the Schizotypy Questionnaire of Claridge & Broks (1984), which assesses schizotypal and borderline personality traits. The objective and subjective indices of schizotypal and borderline symptoms correlated significantly but allocation of patients to a diagnosis missed several patients who nevertheless rated themselves as having a high frequency of these symptoms. There was an asymmetry of symptom pattern reminiscent of Foulds & Bedford's (1975) hierarchy model. The presence of schizotypal symptoms appeared to be higher in the hierarchy: they predicted borderline symptoms, but a high frequency of borderline symptoms did not necessarily predict schizotypy. We suggest that the occurrence of schizotypal symptoms should become a more explicit focus of clinical assessment and treatment of these patients, especially those who repeatedly harm themselves and we suggest ways in which cognitive therapies may be adapted to do this.