Characterization and identification of microbial communities in bovine necrotic vulvovaginitis.

Bovine necrotic vulvovaginitis (BNVV) is a severe and potentially fatal disease of post-partum cows that emerged in Israel after large dairy herds were merged. While post-partum cows are commonly affected by mild vulvovaginitis (BVV), in BNVV these benign mucosal abrasions develop into progressive deep necrotic lesions leading to sepsis and death if untreated. The etiology of BNVV is still unknown and a single pathogenic agent has not been found. We hypothesized that BNVV is a polymicrobial disease where the normally benign vaginal microbiome is remodeled and affects the local immune response. To this end, we compared the histopathological changes and the microbial communities using 16S rDNA metagenetic technique in biopsies taken from vaginal lesions in post-partum cows affected by BVV and BNVV. The hallmark of BNVV was the formation of complex polymicrobial communities in the submucosal fascia and abrogation of neutrophil recruitment in these lesions. Additionally, there was a marked difference in the composition of bacterial communities in the BNVV lesions in comparison to the benign BVV lesions. This difference was characterized by the abundance of Bacteroidetes and lower total community membership in BNVV. Indicator taxa for BNVV were Parvimonas, Porphyromonas, unclassified Veillonellaceae, Mycoplasma and Bacteroidetes, whereas unclassified Clostridiales was an indicator for BVV. The results support a polymicrobial etiology for BNVV.

Bloodless lung transplantation in Jehovah's Witnesses: impact on perioperative parameters and outcome compared with a matched control group.

BACKGROUND: Jehovah's Witnesses (JW) refuse to receive blood products due to their religious beliefs. Bloodless transplantation programs have made the successful transplantation of solid organs like heart, liver, kidney, and pancreas in JW feasible. In this study we present the third and fourth case of a successful bloodless lung transplantation and analyze perioperative parameters and outcome with a strictly selected matched control group (CG). METHODS: Two JW patients suffering from idiopathic pulmonary fibrosis had single lung transplantation in the transfusion-free program. Ten of 113 patients (8.8%) undergoing lung transplantation fulfilled the matching criteria and served as CG. Perioperative parameters including blood loss and transfusions were collected from the charts. Regarding outcome parameters arterial blood gas, lung function testing, length of stay, and survival were analyzed. RESULTS: Concerning perioperative parameters no significant differences could be found between both groups except for the creatinine level, which was significantly lower in the JW group on postoperative day 0 (P = .037), and the hemoglobin and hematocrit levels, which were significantly higher in the JW group on postoperative day 3 (P = .032 and P = .041, respectively). The analysis of the outcome parameters revealed significantly higher postoperative lung functional testing values forced expiratory volume after 1 second (FEV1) and forced vital capacity (FVC) in the JW group compared with the CG (P = .037 and P = .036, respectively). CONCLUSION: Bloodless lung transplantation is feasible in carefully selected JW recipients. Comparing JW to CG, no statistically significant difference in the perioperative course and a trend towards a favorable postoperative lung function outcome were detected.

Esophageal perforation in a sword swallower.

We present the case of a 59-year-old man who sustained an esophageal perforation as a result of sword swallowing. An esophagogram established the diagnosis, and surgical repair was attempted. However, 19 days later, a persistent leak and deterioration of the patient's condition necessitated a transhiatal esophagectomy with a left cervical esophagogastrostomy. The patient recovered and has resumed his daily activities at the circus, with the exception of sword swallowing. This case report presents an unusual mechanism for a potentially lethal injury. Our search of the English-language medical literature revealed no other report of esophageal perforation resulting from sword swallowing. Management of such an injury is often difficult, and a favorable outcome is dependent on prompt diagnosis and treatment.

Extracorporeal membrane oxygenation for early graft dysfunction in lung transplantation: a case report.

Although extracorporeal membrane oxygenation (ECMO) has become standard treatment for neonatal respiratory failure, the results of ECMO in adults have been less encouraging. With technical improvements in membrane oxygenators and revised ECMO protocols, there has been renewed interest in ECMO for adults with severe acute respiratory failure. However, few cases of ECMO as an adjunct to adult lung transplantation have been reported. We present the case of a 20-year-old woman with cystic fibrosis who underwent bilateral single lung transplantation. She had development of severe graft dysfunction in the immediate postoperative period requiring support with ECMO for stabilization.

Effect of IgM-positive crossmatches on survival in heart transplant recipients.

To determine whether an IgM-positive crossmatch adversely affects the results of heart transplantation, we conducted a retrospective study of 125 orthotopic heart transplant recipients. A direct donor-recipient crossmatch was performed retrospectively on sera from all patients by the standard National Institutes of Health (NIH) method and the antihuman globulin (AHG) procedure. The patients were then divided into 3 groups as follows. Group 1 comprised 110 patients with a negative NIH and AHG crossmatch (control group). Group 2 comprised 5 patients with a positive NIH crossmatch and a negative AHG crossmatch. Group 3 comprised 10 patients with positive NIH and AHG crossmatches. All positive crossmatches in group 3 patients converted to negative after treatment of sera with dithioerythritol, indicating that the initial result was due to IgM antibodies. All patients received standard immunosuppressive treatment. An IgM-positive crossmatch did not affect the number or severity of rejection episodes among the 3 groups, nor did it have an effect on the incidence of infection. Whereas coronary artery disease was detected by angiography in 16 of 110 patients (14.6%) in group 1 and in 1 of 10 patients (10%) in group 3 (P = NS), no patient in group 2 was affected. Actuarial survival at 1 and 2 years post-transplant was significantly better for patients with an IgM-positive crossmatch (group 2) (100% survival at 2 years) than for patients with a negative crossmatch (group 1) (73% at 1 year and 71% at 2 years, P < 0.05). Based on our study, the effect of an IgM-positive crossmatch on survival is difficult to interpret because of the small sample size. An IgM-positive crossmatch, however;did not appear to have a deleterious effect on survival. It may be that the IgM antibody has an immunoregulatory role. A larger series of patients with positive crossmatches and longer follow-up will be necessary to evaluate the importance of these results.

Graft replacement of the descending thoracic aorta: results of "open" distal anastomosis.

With the advent of rapid autotransfusion, we began to repair aneurysms of the descending thoracic and thoracoabdominal aorta by using an "open" technique, in which a single cross-clamp is placed proximal to the aneurysm to exsanguinate the lower body. To determine whether open distal anastomosis effectively protects against spinal cord injury, we studied 71 consecutive patients (50 men, 21 women) who underwent this procedure beginning in April 1989. The patients ranged in age from 31 to 83 years (mean, 63.3 years). Most patients were hypertensive (n = 61; 86%) and symptomatic (n = 54; 76%). Most had been diagnosed with medial degeneration (n = 45; 63.4%) or aortic dissection (n = 16; 22.5%). Five patients (7.0%) were admitted with aortic rupture. We replaced the entire descending thoracic aorta in 31 (43.7%), the thoracoabdominal aorta in 21 (29.6%), and a segment of the descending thoracic aorta in 19 (26.7%). The average distal ischemic time was 22.4 minutes (range, 11 to 42 minutes). The amount of blood returned through the autotransfusion device averaged 2,099 mL. Eight patients (11.3%) died within 30 days (multiple organ failure, 3; hemorrhage, 2; coexisting ischemic heart disease, 3). Spinal cord dysfunction occurred in 6 patients (8.5%) (lower extremity paraparesis, 4; paraplegia, 2). Renal insufficiency requiring dialysis occurred in 4 patients (5.6%). We believe that the low incidence of spinal cord injury and renal insufficiency in this series may have resulted from the free draining of the intercostal and lumbar arteries during aortic occlusion, which decreases cerebrospinal fluid and central venous pressures.(ABSTRACT TRUNCATED AT 250 WORDS)

Mechanical circulatory support in children.

Nine children (aged 1.2-15 years) have been treated with mechanical circulatory support devices at our institution. Indications for treatment were acute cardiac allograft rejection (n = 4), postcardiotomy cardiogenic shock (n = 4), and bridge to cardiac transplantation (n = 1). Eight patients required left ventricular support, and one required biventricular support. A BioMedicus centrifugal pump was used in eight patients, and a Hemopump intra-aortic axial flow device was used in one patient. In two patients, an intra-aortic balloon pump was in place at the time that circulatory support was instituted. Mechanical support time ranged from 2 to 139 h, and the average flow index was 2.31 l/min per m2. Three patients required hemodialysis during support, and one patient required re-exploration because of mediastinal hemorrhage. Recovery of native ventricular function was assessed by transthoracic or transesophageal echocardiography, and weaning from the device was achieved by gradually decreasing pump flow in increments of 0.1 to 0.5 l/min. Seven patients were successfully weaned from support. Two hospital deaths occurred after circulatory support had been discontinued: one patient died of respiratory failure and the other of gram-negative pneumonia and sepsis. The five surviving patients experienced no significant complications, and their hemodynamic indices were normal at the time of discharge. At a mean follow-up of 28.8 months, these patients are leading active unrestricted lives, with no long-term device-related sequelae. Based on this experience, mechanical circulatory support is feasible in children who experience profound circulatory failure from a variety of causes.

Postcardiotomy LVAD support and transesophageal echocardiography in a child.

A case of postcardiotomy cardiogenic shock after repair of a congenital ventricular septal defect in a 5-year-old boy is reported. Mechanical circulatory support, instituted with a centrifugal left ventricular assist device, adequately supported the patient for 50 hours until recovery of native left ventricular function occurred. Transesophageal echocardiography proved to be useful in assessment of left ventricular function, allowing for timely institution and withdrawal of mechanical circulatory support.

The effect of prolonged left ventricular support on myocardial histopathology in patients with end-stage cardiomyopathy.

To determine the histopathologic effect of prolonged (> 30 days) left ventricular unloading on the myocardium, the authors studied myocardial tissue specimens from eight men (mean age, 40.8 years) with end-stage cardiomyopathy (six idiopathic, two ischemic) who were supported with the HeartMate (Thermo Cardiosystems, Inc., Woburn, MA) left ventricular assist device (LVAD) as a bridge to cardiac transplantation. The average length of support was 79.6 days (range, 31-136 days). Before left ventricular support was instituted, transthoracic echocardiography revealed that all patients had significantly dilated left ventricular cavities (average left ventricular diastolic dimension, 7.2 cm). Tissue specimens from the core of the left ventricular apex, which is removed at the time of LVAD implantation, were compared through pathologic examination with specimens from the explanted hearts at the time of cardiac transplantation. Apical core specimens from all patients exhibited extensive areas of attenuated myocardial fibers, combined with wavy patterns in some areas. In these regions, the nuclei of the cardiac myocytes from idiopathic cardiomyopathy specimens were neither pyknotic nor disappearing, as was noted in an infarcted area of a specimen from one patient with ischemic cardiomyopathy. At the time of heart transplantation, myocardial tissue specimens from the explanted hearts had a significant decrease or disappearance of stretched fibers. There was also a slight increase in interstitial replacement fibrosis, as well as an increase in the diameter of the myocardial fibers. These findings appear to correlate with the clinical impression of improved native ventricular function and with radiographic findings and decreased chamber size during prolonged ventricular support.

Acoustic distortion products in rabbit ear canal. II. Sites of origin revealed by suppression contours and pure-tone exposures.

Previous work on acoustic distortion products (DPs) recorded from the ear canal has not established unequivocally whether emitted DPs principally reflect basilar-membrane nonlinearities at the frequency sites of the primary tones, f1 and f2, or if the DP-frequency place itself makes a significant contribution to the emitted response. Results from some studies on acoustic emissions attribute generation of the emitted DP almost exclusively to the regions of maximum primary-tone interaction, while the findings of other investigations implicate reemission of the response from the DP locus as a significant contributor to response magnitude. Using suppression, interfering tones, and temporary threshold shift (TTS) procedures, the work reported here was designed to establish more definitively the precise contributions of the basilar-membrane regions involved in generating acoustic DPs in rabbits. Suppression tuning curves and interfering-tone experiments indicated that for the DP at 2f1-f2, regions near the f1 or f2 frequencies were the major contributors to the emitted response. However, for the higher-frequency DP at 2f2-f1, the basilar-membrane region just basal to the DP site was implicated as the generator. Following brief episodes of TTS at frequencies related to either the DP or the primary tones, the locus of the exposure stimulus that most effectively reduced the magnitude of the 2f1-f2 response also implicated the region of maximal primary-tone interaction in the generation of the acoustic DP. In contrast, for the DP at 2f2-f1, basilar-membrane sites nearer the DP were identified as the primary contributors to the emitted response. Both sets of results imply that different DPs recorded from the ear canal may originate from unique regions of primary-tone interaction along the basilar membrane.