Mycoplasma pneumoniae Induces Chronic Respiratory Infection, Airway Hyperreactivity, and Pulmonary Inflammation: a Murine Model of Infection-Associated Chronic Reactive Airway Disease

Because chronic Mycoplasma pneumoniae respiratory infection is hypothesized to play a role in asthma, the potential of M. pneumoniae to establish chronic respiratory infection with associated pulmonary disease was investigated in a murine model. BALB/c mice were intranasally inoculated once with M. pneumoniae and examined at 109, 150, 245, 368, and 530 days postinoculation. M. pneumoniae was detected in bronchoalveolar lavage fluid by culture or PCR in 70 and 22% of mice at 109 and 530 days postinoculation, respectively. Lung histopathology was normal up to 368 days postinoculation. At 530 days, however, 78% of the mice inoculated with M. pneumoniae demonstrated abnormal histopathology characterized by peribronchial and perivascular mononuclear infiltrates. A mean histopathologic score (HPS) at 530 days of 5.1 was significantly greater (P < 0.01) than that for controls (HPS score of 0). Serum anti-M. pneumoniae immunoglobulin G was detectable in all of the mice inoculated with M. pneumoniae and was inversely correlated with HPS (r = -0.95, P = 0.01) at 530 days postinoculation. Unrestrained whole-body plethysmography measurement of enhanced pause revealed significantly elevated airway methacholine reactivity in M. pneumoniae-inoculated mice compared with that in controls at 245 days (P = 0.03) and increased airway obstruction at 530 days (P = 0.01). Murine M. pneumoniae respiratory infection can lead to chronic pulmonary disease characterized by airway hyperreactivity, airway obstruction, and histologic inflammation.     

Centrally and locally mediated vasomotor activities in Raynaud's phenomenon

A selective review on the attack of Raynaud's phenomenon in primary Raynaud's phenomenon and vibration-induced white finger is presented with special reference to the location of the primary vasospasm, the nature of the dominant pathophysiological mechanism, and the anatomic location of the abnormal link in this mechanism. It is suggested that the primary vasospasm is a total closure of the main digital arteries, that the arterial spasm is mainly mediated through an exaggerated central sympathetic reflex mechanism, and that the abnormal link in this reflex arch could be the smooth muscle cells of the digital arteries. Other anatomic locations of the abnormal link can however not be excluded as yet.     

The gracilis free flap for reconstruction of parotidectomy defects

Summary Total parotidectomy causes a significant postoperative concave deformity in the retromandibular, preauricular, and infra-auricular regions of the face; many patients are concerned about this defect. Frey's syndrome (gustatory sweating) is also a well-recognized postoperative entity following parotid surgery. The incidence of Frey's syndrome ranges from 10–90%, depending on the type and complexity of the investigation used to diagnose it [5, 11]. Numerous methods have been described to correct these problems. Patients requiring total parotidectomy were recently offered the option of immediate reconstruction of the contour defect with microvascular transfer of a tailored gracilis muscle flap. Four patients are included in this preliminary series; all are extremely satisfied with the postoperative result. The defect following total parotidectomy can be reconstructed immediately with gratifying cosmetic results, a hidden donor site scar, and to date no operative morbidity.     

Controlling for occasion-specific effects when assessing the test–retest reliability of self-report health questionnaires

OBJECTIVE: This study proposes a method for self-report health questionnaires to adjust test-retest reliability for changes during the test-retest interval based on an external measure, and to distinguish such changes from random response errors. METHODS: In our application, eighty participants completed the Symptoms of Illness Checklist (SIC) on two occasions, two weeks apart, immediately before interviews given on each occasion by one of two physicians in a crossover design. The physician interview scores served as external measures, and structural equation modeling was used to estimate the parameters of a model that corrected for the occasion-specific effect of participants' responses using information from the interviews. RESULTS: Correcting for changes in symptoms during the test-retest interval increased SIC test-retest reliability from .744 to .804 and significantly improved model fit (chi2(diff)(1) = 30.78, p < .001). CONCLUSIONS: The results suggest methods that can improve the evaluation of self-report health questionnaire test-retest reliability by identifying changes using an external measure, and distinguishing these from random response errors; these increased the estimated SIC test-retest reliability and indicated that the SIC was indeed able to measure changes over the studied time interval. This method can be applied across a broad range of questionnaires.     

Interobserver variation in the evaluation of neurological signs: observer dependent factors.

Introduction - Interobserver variation among four observers in evaluation of eight selected neurological signs was investigated. Material & methods - Two hundred and two consecutive unselected inpatients were examined by two senior neurologists and two trainees, all without knowledge of the neurological case history. The signs examined were: anisocoria, jerky eye movements, facial palsy, elbow extension force, finger-nose test, Barré sign, knee jerk, and extensor plantar reflex. Observed agreement rates and kappa coefficients were calculated in order to compare the interobserver variability among neurologists and trainees, and to evaluate differences in the interobserver variability between signs. Results - Observed agreement rates varied from 0.80 to 0.95 for neurologists and from 0.65 to 0.98 for trainees. For neurologists kappa coefficients ranged from 0.40 to 0.67 and for trainees from 0.22 to 0.81. The neurologists had higher kappa values than the trainees in 5 signs, but this difference was only statistically significant for jerky eye movements. For the individual signs the observed agreement rates were between 0.50 and 0.93 for all four examiners combined, and overall kappa values varied from 0.32 to 0.71 with highest agreement for facial palsy and lowest for knee jerk. Conclusion - The magnitude of the interobserver and intersign variation indicates that the interpretation of the neurological signs tested, without knowledge of the case history, should be done with some caution.     

An occipito-temporal syndrome in adolescents with optimally controlled hyperphenylalaninaemia

Summary The study included 16 adolescents with optimally controlled hyperphenylalaninaemia (McKusick 26160), of whom six did not require treatment according to conventional criteria. All except the two patients with lowest median serum phenylalanine level throughout childhood (most values at 200–300 µmol/L) had white matter abnormalities detectable with magnetic resonance imaging. The lesions were particularly prominent in the watershed regions between the posterior and middle cerebral arteries. In most patients with moderate or severe hyperphenylalaninaemia frontal white matter lesions were present as well. Normal proton magnetic resonance spectra indicated that the lesions were stable. Occipital EEG abnormalities were frequent, and deficient performance on a pattern-recognition test was a characteristic neuropsychological finding. Serum phenylalanine levels at about 300 µmol/L or below throughout childhood and early adolescence may be required to avoid lesions. The present study demonstrates the limitations of even an optimally controlled dietary regimen in hyperphenylalaninaemia.     

Noninvasive assessment of metabolism in wounded skin by 31P-NMR in vivo.

Phosphorus-31 nuclear magnetic resonance techniques using shallow penetrating coils have been used to noninvasively monitor severity and metabolic changes over time in skin wounds in rats. Ratios of phosphocreatine (PCr) to inorganic phosphate (Pi) indicate energy status in both thermal wounds and surgical flaps. In partial and full-thickness scald wounds, reductions in PCr/Pi ratios correlated with burn depth and improved over time postinjury, suggesting wound revascularization. No decrease in intracellular pH was noted in these wounds; the phosphate shifts may be primarily the result of tissue degradation followed by restoration of the microvasculature. Distal regions of caudally based dorsal 3 x 10 cm full-thickness skin flaps reveal progressively lower PCr/Pi ratios to 3-6 hours after elevation as well as drops in pH up to 0.5 units, presumably as a result of anaerobic glycolysis in these tissues. After 24 hours, the intracellular pH returned to normal (7.1-7.2) and the PCr/Pi ratios approached 70%-90% of the well-perfused proximal regions within 3-7 days. These results indicate the establishment of a microvasculature from the underlying bed as the distal regions survive as free grafts. The data demonstrate the potential usefulness of the technique in noninvasive measurement of the biochemical response to injury and wound healing in living organisms.     

Mediastinitis in heart transplantation.

Between March 1985 and December 1991, mediastinitis developed in 12 of 420 cardiac transplantation patients (2.8%). The mortality rate in this group of patients was 8.3% (1/12). Actuarial survival (1 year, 75%; and 5 years, 65%) was not significantly different from that of the group without mediastinitis (1 year, 88%; and 5 years, 75%). A higher percentage of the patients in the group with mediastinitis were listed as UNOS status 1 (50% versus 35%) and had a history of previous sternotomies (58% versus 44%). The presentation of mediastinitis was typical. Computed tomographic scanning with or without aspiration was a valuable adjunct in the diagnosis of mediastinitis. Induction immunotherapy with minimal steroids in the perioperative period was used in all patients. This may contribute to the patients' ability to mount an appropriate and effective response to infection, permitting earlier diagnosis. The debridement irrigation technique used in 8 of 12 patients had a low success rate of 33%, whereas the debridement muscle flap technique used in 4 of 12 was 100% successful in eliminating infection.     

Influence of bradykinin B1 and B2 receptors in the immune response triggered by renal ischemia–reperfusion injury

Bradykinin B1 receptors are exclusively expressed in inflamed tissues. For this reason, they have been related with the outcomes of several pathologies. Ischemia–reperfusion injury is caused by the activation of inflammatory and cytoprotective genes, such as macrophage chemoattractant protein-1 and heme oxygenase-1, respectively. This study was aimed to analyze the involvement of bradykinin B1 and B2 receptors (B1R and B2R) in tissue response after renal ischemia–reperfusion injury. For that, B1R (B1−/−), B2R (B2−/−) knockout animals and its control (wild-type mice, B1B2+/+) were subjected to renal bilateral ischemia, followed by 24, 48 and 120 h of reperfusion. At these time points, blood serum samples were collected for creatinine and urea dosages. Kidneys were harvested for histology and molecular analyses by real-time PCR. At 24 and 48 h of reperfusion, B1−/− group resulted in the lowest serum creatinine and urea levels, indicating less renal damage, which was proved by renal histology. Renal protection associated with B1−/− mice was also related with higher expression of HO-1 and lower expression of MCP-1. In conclusion, the absence of B1R had a protective role against inflammatory responses developed after renal ischemia–reperfusion injury.