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.     

Risk of Respiratory Complications and Wound Infection in Patients Undergoing Ambulatory Surgery: Smokers versus Nonsmokers

Background: Smoking is considered to be a risk factor for patients undergoing surgery and anesthesia, but it is unclear whether this is applicable to patients undergoing ambulatory surgery. The aim of this study was to determine the risk of respiratory complications and wound infection among smokers.

Methods: The authors studied a random selection of 489 adult patients undergoing ambulatory surgery. Smoking status was determined by self-report and confirmed with end-expired carbon monoxide analysis. The risk of respiratory complications (i.e., desaturation, cough, laryngospasm, bronchospasm, breath-holding, or apnea) and wound infection (i.e., wound redness or discharge +/- positive microbial culture, requiring antibiotic therapy) in smokers versus nonsmokers was ascertained. Odds ratios were estimated from multivariable logistic regression and adjusted for age, gender, body mass index, partner's smoking status, domiciliary smoking exposure, and extent and duration of surgery.

Results: Most smokers continued to smoke up until the day of surgery. Smokers had a higher rate of respiratory complications (32.8%vs. 25.9%; adjusted odds ratio, 1.71; 95% confidence interval, 1.03-2.84;P = 0.038) and wound infection (3.6%vs. 0.6%; odds ratio, 16.3; 95% confidence interval, 1.58-175;P = 0.019). Odds ratios comparing current plus ex-smokers with nonsmokers were of similar magnitude for most of these complications.     

Negative symptoms,defect state and Huber's basic symptoms: A comparison of the concepts

Comparing Crow's schizophrenia model with the defect state and Huber's basic symptoms shows that this model is an oversimplification of the complex reality of schizophrenic outcomes. The concept of negative symptoms is undermined by several factors, such as differing definitions, other confounding cross-sectional variables (e.g., akinesia and depression), short follow-ups and lack of confirmation by factorial analysis. The longitudinal concept of a defect state, which has been used in long-term follow-up studies, includes enduring symptoms currently classified as positive and negative. Huber's conceptualization of basic symptoms describes prodromal and enduring residual symptoms of schizophrenia associated with structural brain abnormalities. The overlap and lack of equivalence of these concepts and the limited empirical evidence does not allow firm conclusions. New longitudinal studies using clinical, psychosocial, and neuropsychological measures are needed to understand the natural history and etiology of the defect state.The authors are affiliated with the Medical College of Pennsylvania/EPPI, Philadelphia, PA. William H. Wilson, M.D., is currently at Oregon Health Sciences University, Portland, OR.     

Same-Day Upper and Lower Inpatient Endoscopy: A Trend for the Future

Performance of same-day upper and lower endoscopy has many potential advantages, as it may reduce costs, shorten hospital stay, and expedite patient care, but its feasibility, efficacy, and potential have not been carefully defined. We report here our experience with a group of 87 patients who underwent same-day upper and lower endoscopy (174 procedures) over a 2-yr period at a tertiary care VA Hospital, compared with an alternate-day upper and lower endoscopy group of 50 patients (100 procedures) over the same time period. Most patients were elderly males. Common indications for endoscopy were occult or overt gastrointestinal bleeding, previous or concomitant history of pertinent pathology (i.e., polyps, ulcers), abdominal pain, diarrhea, or other symptoms, abnormal radiological studies, and iron deficiency anemia. Both groups required similar amounts of intravenous sedation. There were no complications in either group. In both groups, common positive findings were inflammation (i.e., colitis, esophagitis), benign neoplasms, diverticulae, peptic ulcer, and cancer. In both groups, only 2-6% had negative upper and lower endoscopy, whereas either one procedure was negative in 25% and 18% of cases, respectively. We conclude that the practice of same-day inpatient upper and lower endoscopy is feasible, has excellent diagnostic yield, even in the elderly, and carries no increased risks. When indicated, the practice of same-day upper and lower endoscopy should be encouraged.     

Impact of Retrograde Cerebral Perfusion on Ascending Aortic and Arch Aneurysm Repair

Purpose. The effect of retrograde cerebral perfusion on the incidence of stroke and death among patients undergoing repair of aneurysms of the ascending aorta and transverse arch was determined.

Material and Methods. Between January 1991 and March 1995, 161 patients were operated on for aneurysms of the ascending aorta and transverse arch. Thirty-three of the patients (20%) had an aneurysm of the ascending aorta only and 128 (80%) had aneurysms of both the ascending aorta and the transverse arch. All the patients underwent cardiopulmonary bypass, profound hypothermia, and circulatory arrest, and 120 (74%) also underwent retrograde cerebral perfusion. Median pump time was 143 minutes (range, 21 to 461 minutes). Median circulatory arrest time was 42 minutes (range, 8 to 111 minutes), and median myocardial ischemic time was 71 minutes (range, 14 to 306 minutes).

Results. The overall 30-day mortality rate was 6% (9 patients) and the incidence of stroke was 4% (7 patients). The use of retrograde cerebral perfusion demonstrated a protective effect against stroke (3 of 120 patients, or 3%) compared with no retrograde cerebral perfusion (4 of 41 patients, or 9%; odds ratio, 0.24; confidence interval, 0.06 to 0.99; p < 0.049). This was most significant in patients more than 70 years of age; none of the 36 elderly patients who received retrograde cerebral perfusion had a stroke, compared with 3 of the 13 (23%) who did not (p < 0.003). Only pump time was associated with an increased risk of stroke (odds ratio, 1.01; 95% confidence interval, 1.00 to 1.02; p < 0.005). Pump time also was associated with increased mortality (odds ratio, 1.01; 95% confidence interval, 1.00 to 1.02; p < 0.008).

Conclusion. Retrograde cerebral perfusion decreased the incidence of stroke in patients undergoing repair of aneurysms of the ascending aorta and transverse arch.     

Functional anatomy and biomechanics of the meniscus

The meniscus is no longer considered the evolutionary remnant in the knee joint.Rather, it is now well established as an important structure that is integral to the complex biomechanics and proper functioning of the knee. The medial and lateral menisci form two crescent-shaped wedges of fibrocartilage between the femoral condyles and tibial plateaus.The knee joint biomechanics are based on a complex interaction of these intra-articular structures. The functions ascribed to the menisci include load transmission, shock absorption, stability, proprioception, joint lubrication, and joint nutrition. Load transmission generally is accepted as one of its primary functions. The menisci transmit a portion of the axial forces across the knee joint by converting this load into “hoop stresses.” This is accomplished by their unique shape, composition, and anatomic attachments. The menisci are relatively mobile structures and their motion during knee flexion also is determined by their shape and soft tissue attachments/constraints. Preservation of the meniscal functions is essential, and the authors review the basic anatomic and biomechanical concepts necessary to understand techniques for repair and restoration of these functions.     

Mucopolysaccharidosis VII as cause of fetal hydrops in early pregnancy

We report on fetal hydrops presenting at 18 weeks of gestation and diagnosed as β-glucuronidase deficiency. The parents were first cousins and there were 2 previous similar fetal deaths. β-Glucuronidase was absent in cultured fetal fibroblasts and lymphoblasts but was normal in the tested relatives. The activities of other lysosomal enzymes were normal. © 1992 Wiley-Liss, Inc.