Parasaccharibacter apium, gen. nov., sp. nov., Improves Honey Bee (Hymenoptera: Apidae) Resistance to Nosema.

The honey bee, Apis mellifera L., is host to a variety of microorganisms. The bacterial community that occupies the adult worker gut contains a core group of approximately seven taxa, while the hive environment contains its own distribution of bacteria that is in many ways distinct from the gut. Parasaccharibacter apium, gen. nov., sp. nov., is a hive bacterium found in food stores and in larvae, worker jelly, worker hypopharyngeal glands, and queens. Parasaccharibacter apium increases larval survival under laboratory conditions. To determine if this benefit is extended to colonies in the field, we tested if P. apium 1) survives and reproduces in supplemental pollen patty, 2) is distributed throughout the hive when added to pollen patty, 3) benefits colony health, and 4) increases the ability of bees to resist Nosema. Parasaccharibacter apium survived in supplemental diet and was readily consumed by bees. It was distributed throughout the hive under field conditions, moving from the pollen patty to hive larvae. While P. apium did not significantly increase colony brood production, food stores, or foraging rates, it did increase resistance to Nosema infection. Our data suggest that P. apium may positively impact honey bee health.

Staged resection of bilateral pleuropulmonary blastoma in a two-month old girl.

Pleuropulmonary blastoma is a rare unilateral intrathoracic tumor of childhood. We report an unusual case of bilateral pleuropulmonary blastoma in a two-month old girl who underwent staged thoracotomies for complete wedge resection of both neoplasm. She remains well and tumor free two years after the operation.

Double closed loop obstruction and perforation in a previous Roux-en-Y gastric bypass.

A healthy 45-year-old woman with a previous Roux-en-Y gastric bypass presented with the signs, symptoms and blood analysis results consistent with acute pancreatitis. She was initially treated nonoperatively and subsequently went into circulatory shock. Computerized tomographic scan and exploratory laparotomy revealed a volvulus of the afferent jejunal limb with secondary obstruction, necrosis, and perforation of the bypassed stomach.

The effects of prosthetic cardiac binding and adynamic cardiomyoplasty in a model of dilated cardiomyopathy.

OBJECTIVE: Because adynamic cardiomyoplasty, or wrapping skeletal muscle around the heart, had been shown to provide a girdling effect and delay progressive ventricular dilatation in heart failure, a similar girdling effect by the much simpler procedure of cardiac binding, using a prosthetic membrane to wrap the heart, was studied and compared with that of adynamic cardiomyoplasty. METHODS: Twenty-one dogs were divided into control, adynamic cardiomyoplasty, and cardiac binding groups. Cardiac dimension and hemodynamic studies were carried out before and 4 weeks after rapid pacing at 250 beats/min. For adynamic cardiomyoplasty, the left latissimus dorsi muscle was used for the cardiac wrap; for cardiac binding, a Marlex sheet (C. R. Bard, Inc., Murray Hill, N.J.) was used. Serial two-dimensional echocardiography, right heart catheterization, and in the cardiac binding group, left heart catheterization were performed. RESULTS: Four weeks of rapid pacing induced severe heart failure and cardiac dilatation. The magnitude of ventricular dilatation at the end of rapid pacing was less in the cardiac binding group than in the control group and least in the adynamic cardiomyoplasty group. Left ventricular end-diastolic volume, end-systolic volume, and ejection fraction were 82.1 +/- 21.1 ml, 67.1 +/- 16.0 ml, and 17.5% +/- 5.8%, respectively, in the control group; 61.9. +/- 8.1 ml, 44.1 +/- 7.8 ml, and 30.1% +/- 3.6%, respectively, in the cardiac binding group; and 51.8 +/- 8.7 ml, 30.3 +/- 10.4 ml, and 27.0% +/- 4.0%, respectively, in the adynamic cardiomyoplasty group. CONCLUSIONS: Both adynamic cardiomyoplasty and cardiac binding reduced cardiac enlargement and functional deterioration after rapid pacing, with adynamic cardiomyoplasty appearing to be more effective, perhaps because of the adaptive capabilities of the skeletal muscle wrap. However, cardiac binding is a simpler and less invasive procedure, which may be useful as an adjunct to prevent or delay progressive ventricular dilatation in heart failure.

Mechanisms of cardiomyoplasty: comparative effects of adynamic versus dynamic cardiomyoplasty.

BACKGROUND: The apparent paradox seen in patients who have undergone dynamic cardiomyoplasty and shown substantial clinical and functional improvements with only modest hemodynamic changes may be due to inappropriate end points chosen for study, a result of incomplete understanding of mechanisms involved. The purpose of this study was to compare the relative role of the passive "girdling effect" and the dynamic "systolic squeezing effect" of the wrapped muscle in cardiomyoplasty. METHODS: The control group of 6 dogs underwent 4 weeks of rapid pacing (250 beats/min) to induce severe heart failure followed by 8 weeks of observation without rapid pacing. The trajectory of recovery in hemodynamics and cardiac dimensions was followed with echocardiography and Swan-Ganz catheters. In the "adynamic" cardiomyoplasty group (n=4), the left latissimus dorsi muscle was wrapped around the ventricles and allowed to stabilize and mature for 4 weeks. This was followed by rapid pacing and recovery as in the control group. In the "dynamic" cardiomyoplasty group (n=3), the same protocol for the adynamic group was followed except that a synchronizable cardiomyostimulator was attached to the thoracodorsal nerve of the muscle wrap. This allowed the latter to be transformed during the rapid-pacing phase and permitted dynamic squeezing of the muscle wrap to be generated by burst stimulation synchronized with cardiac contraction in a 1:2 ratio. RESULTS: Baseline data were comparable in all groups prior to rapid pacing. After 4 weeks of rapid pacing, the left ventricular ejection fraction was higher in the adynamic (27.0%+/-3.9%; p < 0.05) and dynamic (33.3%+/-2.3%; p < 0.02) cardiomyoplasty groups compared with controls (18.8%+/-8.3%). Similarly, ventricular dilatation in both systole and diastole was less in the adynamic (51.8+/-8.7 mL, [p < 0.002] and 38.2+/-7.2 mL [p < 0.001], respectively) and dynamic (62.0+/-7.2 [p < 0.02] and 41.3+/-3.5 mL [p < 0.005], respectively) cardiomyoplasty groups compared with controls. In the dynamic group, on and off studies were carried out after cessation of rapid pacing while the heart was still in severe failure, and they demonstrated a systolic squeezing effect in stimulated beats. Only this group recovered fully to baseline after 8 weeks. CONCLUSIONS: By reducing myocardial stress, both the passive girdling effect and the dynamic systolic squeezing effect have complementary roles in the mechanisms of dynamic cardiomyoplasty.

Pathologic findings of latissimus dorsi muscle graft in dynamic cardiomyoplasty: clinical implications.

BACKGROUND: We hypothesize that the integrity of the latissimus dorsi muscle graft used to wrap the heart may affect the clinical outcome of patients undergoing dynamic cardiomyoplasty. METHODS: By correlating the pathologic findings with their clinical course in five patients who died 1 month to 6 years after dynamic cardiomyoplasty operation, we sought to discern findings that might shed light on the pathophysiology of cardiomyoplasty. RESULTS: Of the two patients who had a limited clinical response, one had an atrophic, edematous latissimus dorsi muscle with fatty infiltration resulting from cardiac cachexia, and the other had insufficient length of latissimus dorsi muscle to cover a large heart. The remaining patients responded well clinically without signs of pump failure and died at various intervals, mostly of arrhythmias. Autopsy findings included the following: (1) one patient with ischemic cardiomyopathy as the underlying disease had development of rich vascularity in the interface between the muscle wrap and the epicardium; whereas in four others with idiopathic cardiomyopathy, such evidence of collateralization was far less evident. (2) There was a variation in the skeletal muscle transformation achieved, with the fraction type I fatigue-resistant fiber in the muscle wrap ranging from 60% to 100%, in spite of the identical transformation protocol used. Such variation is believed to be genetically based. (3) In one patient, the skeletal muscle was paced to contract at 30 to 50 times/minute (2:1 ratio) for more than 5 years. Nevertheless, the pathologic specimen of the muscle wrap showed only minimal interstitial fibrosis. (4) Relatively thin muscle wrap around the heart found at autopsy could be atrophy but most likely was related to muscle transformation, which is known to reduce muscle mass and increase capillary density. (5) All skeletal muscle grafts showed geometric conformation to the shape of the epicardium and grossly looked as if they were an additional layer of the ventricular wall. Such conformation may facilitate the modulation of the ventricular remodelling process in the failing heart, as has been described both in clinical and experimental studies. CONCLUSIONS: Our findings are consistent with and support a number of mechanisms proposed for cardiomyoplasty. Thus preservation of latissimus dorsi muscle graft integrity may be important in the success of dynamic cardiomyoplasty.

Characterization of a submillimeter high-angular-resolution camera with a monolithic silicon bolometer array for the Caltech Submillimeter Observatory.

We constructed a 24-pixel bolometer camera operating in the 350- and 450-µm atmospheric windows for the Caltech Submillimeter Observatory (CSO). This instrument uses a monolithic silicon bolometer array that is cooled to approximately 300 mK by a single-shot (3)He refrigerator. First-stage amplification is provided by field-effect transistors at approximately 130 K. The sky is imaged onto the bolometer array by means of several mirrors outside the Dewar and a cold off-axis elliptical mirror inside the cryostat. The beam is defined by cold aperture and field stops, which eliminates the need for any condensing horns. We describe the instrument, present measurements of the physical properties of the bolometer array, describe the performance of the electronics and the data-acquisition system, and demonstrate the sensitivity of the instrument operating at the observatory. Approximate detector noise at 350 µm is 5 × 10(-15) W/√Hz, referenced to the entrance of the Dewar, and the CSO system noise-equivalent flux density is approximately 4 Jy/√Hz. These values are within a factor of 2.5 of the background limit.

Expiratory flow pattern and respiratory mechanics.

During resting breathing, expiration is characterized by the narrowing of the vocal folds which, by increasing the expiratory resistance, raises mean lung volume and airway pressure. This is even more pronounced in the neonatal period, during which expirations with short complete airway closure are commonly occurring. We asked to which extent differences in expiratory flow pattern may modify the inspiratory impedance of the respiratory system. To this aim, newborn puppies, piglets, and adult rats were anesthetized, paralyzed, and ventilated with different expiratory patterns, (a) no expiratory load, (b) expiratory resistive load, and (c) end-inspiratory pause. The stroke volume of the ventilator and inspiratory and expiratory times were maintained constant, and the loads were adjusted in such a way that inflation always started from the resting volume of the respiratory system. After 1 min of each ventilatory pattern, mean inspiratory impedance and compliance of lung and respiratory system were measured. The values were unchanged or minimally altered by changing the type of ventilation. We conclude that the expiratory laryngeal loading is not primarily aimed to decrease the work of breathing. It is conceivable that the expiratory pattern is oriented to increase and control mean airway pressure in the regulation of pulmonary fluid reabsorption, distribution of ventilation, and diffusion of gases.

Four critical areas in governance.

How well hospitals weather today's increasingly stormy environment depends upon the performance of their trustees in handling four essential areas of governance: strategic planning, financing, quality assurance, and community relations.

Four critical areas in governance.

How well hospitals weather today's increasingly stormy environment depends upon the performance of their trustees in handling four essential areas of governance: strategic planning, financing, quality assurance, and community relations. This article considers, for each of these areas, the responsibilities of trustees, the problems they face in meeting their responsibilities, and some ways of dealing with these problems.

Is the hospital beyond our understanding?

For the modern hospital to operate effectively, it is becoming increasingly necessary for trustees, administrators, and clinical staff members to earn how they can function better in unison. Educational programs to help them understand how the unique organizational characteristics of the hospital affect their attitudes and behavior are becoming increasingly important to hospitals' future viability.