Effects of Peak Inspiratory Flow on Development of Ventilator-induced Lung Injury in Rabbits

Background: A lung-protecting strategy is essential when ventilating acute lung injury/acute respiratory distress syndrome patients. Current emphasis is on limiting inspiratory pressure and volume. This study was designed to investigate the effect of peak inspiratory flow on lung injury.

Methods: Twenty-four rabbits were anesthetized, tracheostomized, ventilated with a Siemens Servo 300, and randomly assigned to three groups as follows: 1) the pressure regulated volume control group received pressure-regulated volume control mode with inspiratory time set at 20% of total cycle time, 2) the volume control with 20% inspiratory time group received volume-control mode with inspiratory time of 20% of total cycle time, and 3) the volume control with 50% inspiratory time group received volume-control mode with inspiratory time of 50% of total cycle time. Tidal volume was 30 ml/kg, respiratory rate was 20 breaths/min, and positive end-expiratory pressure was 0 cm H2O. After 6 h mechanical ventilation, the lungs were removed for histologic examination.

Results: When mechanical ventilation started, peak inspiratory flow was 28.8 +/- 1.4 l/min in the pressure regulated volume control group, 7.5 +/- 0.5 l/min in the volume control with 20% inspiratory time group, and 2.6 +/- 0.3 l/min in the volume control with 50% inspiratory time group. Plateau pressure did not differ significantly among the groups. Gradually during 6 h, Pao2 in the pressure regulated volume control group decreased from 688 +/- 39 to a significantly lower 304 +/- 199 mm Hg (P < 0.05) (mean +/- SD). The static compliance of the respiratory system for the pressure regulated volume control group also ended significantly lower after 6 h (P < 0.05). Wet to dry ratio for the pressure regulated volume control group was larger than for other groups (P < 0.05). Macroscopically and histologically, the lungs of the pressure regulated volume control group showed more injury than the other groups.     

A case of bilateral panophthalmoplegia caused by paranasal malignant lymphoma extending into the skull base]

A case of bilateral panophthalmoplegia developed after paranasal malignant lymphoma is described, and previously reported cases are reviewed. A 74-year-old female was hospitalized with the chief complaints of bilateral ptosis and bilateral deep orbital pain that had developed over a 10-day period. Neurological examination revealed bilateral dilated pupils, panophthalmoplegia, and hypalgesia in the area of the ophthalmic nerve on both sides. Laboratory studies and endocrinological examination were free from abnormal findings. Skull X-ray films showed a soft tissue lesion in the sphenoidal and ethmoidal sinus and this was associated with bony structure destruction in the surrounding area. Computed tomography demonstrated a heterogeneously enhanced mass lesion in the paranasal sinus extending into the intrasellar region and bilateral cavernous sinus. Meticulous investigation has so far revealed no distant lesions either in the thoracic or abdominal lesions. Subtotal tumor resection was undergone via the transsphenoidal route at which time tumor extension into the nasal cavity and sellar floor destruction were confirmed. Diffuse and mixed B-cell type malignant lymphoma was the pathological diagnosis. Postoperatively, improvement of abnormalities of pupils, panophthalmoplegia, and ptosis was achieved but this was only transient. Despite focal radiation therapy and repeated chemotherapy, the patient died 14-months after the diagnosis was made. On reviewing the literature, it is shown that the incidence of bilateral panophthalmoplegia among patients who develop disturbance of ocular movement is extremely low (0.4%).(ABSTRACT TRUNCATED AT 250 WORDS)     

Evaluation of therapeutic interventions of sustained monomorphic ventricular tachycardia guided by an electrophysiologic study: a case report

Therapeutic evaluation of sustained monomorphic ventricular tachycardia (VT) using electrophysiologic study (EPS) is presented in a case of refractory VT. A 54-year-old man with a history of recurring syncope underwent coronary angiography which revealed total occlusion of the posterior descending branch of the right coronary artery. Left ventriculography showed a left ventricular aneurysm at the cardiac apex. Ejection fraction of the left ventricle was 36%. He had four VTs of different QRS morphologies in 12 lead electrocardiograms. According to our programmed ventricular stimulations, single or double, and rarely triple, extra stimuli were administered after eight basic stimuli at two basic cycle lengths. Rapid ventricular pacing, up to 210 bpm, was then added. The stimuli were delivered to two different sites in the right ventricle and to at least one site in the left ventricle. When the entire protocol could not induce VT, isoproterenol was given intravenously, and the same protocol was repeated. No drug could prevent VT attacks, even after the surgical resection of two VT foci, VT was still inducible. Postoperative drug therapy could not prevent VT induction in EPS. However, changes in the mode required for VT induction were observed. Among 47 patients with sustained monomorphic VT treated in our hospital, 24 had EPS to evaluate the efficacies of therapeutic interventions, such as drugs and surgery. In 14 patients, no VT was induced by the entire VT induction protocol. Among the remaining 10 patients, four showed changes in the VT induction mode, but VT recurred in their clinical courses even after their treatments.(ABSTRACT TRUNCATED AT 250 WORDS)     

Measurement of free and total hydroxyproline by automated flow injection of serum or urine samples from maintenance hemodialysis patients with renal osteodystrophy

An automated measurement of total and free hydroxyproline in serum or urine is presented that uses flow injection analysis. After exclusion of nonspecific substances, hydroxyproline was oxidized by chloramine- T and L-cysteine with Ehrlich's reagent. The linearity obtained was from 3.8μmole/ L to 1.22 mmole/L with good precision (CV <3%). Comparison of the proposed method with HPLC yielded r = 0.939 as the correlation coefficient. Reference intervals of free and total hydroxyproline are 1.4–9.7 μmole/L, 3.8–27.2 μmole/L for serum, and 10.0–72.5 μmole/L, 25.2–303.6 μmole/L for urine, respectively. Serum free and total hydroxyproline levels in renal osteodystrophy patients on maintenance hemodialysis (N = 71) were significantly higher than in controls (P<0.0001). This method is superior to the use of HPLC with regard to stability of the color reaction. The measurement of serum free and total hydroxyproline is a useful marker for therapeutic observation of renal osteodystrophy patients. © 1994 Wiley-Liss, Inc.     

In vivo observation of crystalline lens changes in the early post-vitrectomy stage]

Crystalline lens changes of 17 cases of eye undergoing simple vitrectomy were observed from the post-operative 1st to 21st month. Changes in the crystalline lenses were detected through a slitlamp microscope or by methods of image analysis, the Opacity Lensmeter and the laser scattering spectroscopy. Increases of the scattering light intensity of the anterior and posterior deep cortical layers were observed from the early post-operative stage in 9 cases. Seven cases progressed to nuclear opacification during the observation period, however, one case showed no nuclear changes even at the 12 post-operative month. No relationships were observed between the early cortical changes and surgical invasion, patient age, or cause of vitreous opacification. Quantitative evaluation by image analysis revealed early post-operative crystalline lens changes in cases undergoing vitreous surgery.     

Fecal stream is essential for adaptive induction of glucose-coupled sodium transport in the remnant ileum after total proctocolectomy

Our previous studies demonstrated that sodium glucose cotransporter 1 (SGLT-1) was induced in the remnant ileum of total colectomized rats via the action of factors other than hyperaldosteronism. The aim of the present study was to clarify whether fecal stream is required for the enhancement of SGLT-1-mediated sodium transport. Twenty-seven pairs of ileal tissues were obtained from the proximal and distal side, respectively, of loop ileostomy after total proctocolectomy. Mucosae were mounted in an Ussing chamber to evaluate glucose-coupled sodium transport. Levels of SGLT-1 mRNA in proximal and distal mucosae were compared by Northern blotting. Villous height and crypt depth were measured to test for correlations between mucosal structure and SGLT-1-mediated sodium transport or mRNA expression levels. Both glucose-coupled sodium transport and expression of SGLT-1 mRNA were significantly lower in distal mucosae relative to proximal mucosae. In distal mucosae, villous height, but not crypt depth, was significantly lower than in proximal mucosae, demonstrating a positive correlation between villous height and SGLT-1 function and expression. Comparative studies of proximal and distal mucosae demonstrated that in addition to hormonal changes, fecal stream is required for full induction of the sodium transport system (which includes SGLT-1-mediated transport) in the remnant ileum following total proctocolectomy. Presented in part at the Forty-Sixth Annual Meeting of The Society for Surgery of the Alimentary Tract, Chicago, Illinois, May 14–19, 2005 (poster presentation). This work was supported by Grants-in-Aid for Scientific Research 10557118 and 14657295 from the Ministry of Education, Science and Culture of Japan to K. Fukushima, and by Kanae Foundation to K. Fukushima.     

Xamoterol in patients with dilated cardiomyopathy: an increase in beta-receptors in lymphocytes

Xamoterol, a partial-beta 1 agonist, was administered orally (100 mg, twice daily) to healthy volunteers (n = 8) and to patients with heart failure (n = 8) for one week. The density (Bmax) and affinity (Kd) of lymphocyte beta-receptors were lower in the patients with heart failure than in the healthy volunteers (Bmax = 931 +/- 214 vs 1466 +/- 373 sites/cell, and Kd = 0.60 +/- 0.11 vs 1.07 +/- 0.14 nM). During treatment with xamoterol, Bmax (7169 +/- 3768 and 7749 +/- 3807 sites/cell) and Kd (6.01 +/- 3.84 and 9.06 +/- 4.66 nM) increased strikingly (p less than 0.01) in both groups. For 12 months, xamoterol (100 mg bd) was given in the same manner to 10 patients with dilated cardiomyopathy. The long-term effects after three and 12 months were assessed. Xamoterol reduced the cardiothoracic ratio from 57 +/- 6% to 55 +/- 5% after three months and 54 +/- 5% after 12 months of treatment (both p less than 0.05), and increased exercise tolerance from 5 +/- 2 min to 7 +/- 2 min and to 7 +/- 2 min (p less than 0.01, p less than 0.05). Echocardiographic fractional shortening increased from 13 +/- 6% to 20 +/- 8% (p less than 0.01) and to 20 +/- 10% (p less than 0.05). Pulmonary wedge pressure during exercise at the same work load decreased from 40 +/- 12 mmHg to 25 +/- 9 mmHg (p less than 0.01) in three months; whereas pulmonary wedge pressures during exercise or at rest in 12 months were unchanged. Exercise heart rate decreased from 118 +/- 9 beats/min to 106 +/- 6 beats/min in three months (p less than 0.01), but was unchanged in 12 months. Bmax and Kd of the beta-receptors increased from 1024 +/- 413 sites/cell and 0.67 +/- 0.27 nM to 1976 +/- 497 sites/cell and 1.60 +/- 0.42 nM (both p less than 0.01), respectively, in three months, and 1584 +/- 650 sites/cell (NS) and 1.21 +/- 0.54 nM (p less than 0.05), respectively, in 12 months. It is concluded that xamoterol improves exercise tolerance, hemodynamics and resolves subjective symptoms for certain patients with dilated cardiomyopathy by its actions as a beta-agonist and beta-antagonist during longterm treatment.