Pulmonary vascular permeability and resistance measurements in control and ANTU-injured dog lungs

Because questions have arisen regarding pulmonary vascular permeability and resistance measurements in isolated, perfused lungs, we sought to determine the 1) stability of repeated measurements of permeability and resistance in control lungs; and 2) magnitude of change in these measurements when permeability was greatly increased. Using blood-perfused dog lungs, we measured filtration coefficient (Kf) and isogravimetric capillary pressure (Pci) as indexes of vascular permeability, and we also determined total vascular resistance (Rt) as well as the segmental resistances using the double-occlusion pressure (Pdo). In a control group (n = 8), the base-line measurement of Kf (0.21 +/- 0.02 ml.min-1.cmH2O-1.100 g-1) and Pci (10.2 +/- 0.9 cmH2O) did not change over 4 h, indicating no changes in endothelial barrier function. Base-line Rt (13.9 +/- 2.6 cmH2O.l-1.min.100 g) also did not significantly increase. In a second group (n = 5), alpha-naphthylthiourea (ANTU) increased the initial Kf more than eight times (from 0.17 +/- 0.03 to 1.40 +/- 0.32 ml.min-1.cmH2O-1.100 g-1) and decreased Pci by 56% (from 9.4 +/- 0.6 to 4.1 +/- 0.4 cmH2O) at 1 h, indicating severely damaged endothelium. In addition, the Pdo determined during isogravimetric conditions correlated very well with Pci not only in control lungs (observed previously) but also in very permeable lungs (not previously reported). We conclude that this experimental model provides an excellent means of assessing changes in pulmonary microvascular permeability, with a spectrum ranging from no changes in hourly measurements for 4 h to obvious changes in permeability by 1 h.

Chest wall restriction limits high airway pressure-induced lung injury in young rabbits

High peak inspiratory pressures (PIP) during mechanical ventilation can induce lung injury. In the present study we compare the respective roles of high tidal volume with high PIP in intact immature rabbits to determine whether the increase in capillary permeability is the result of overdistension of the lung or direct pressure effects. New Zealand White rabbits were assigned to one of three protocols, which produced different degrees of inspiratory volume limitation: intact closed-chest animals (CC), closed-chest animals with a full-body plaster cast (C), and isolated excised lungs (IL). The intact animals were ventilated at 15, 30, or 45 cmH2O PIP for 1 h, and the lungs of the CC and C groups were placed in an isolated lung perfusion system. Microvascular permeability was evaluated using the capillary filtration coefficient (Kfc). Base-line Kfc for isolated lungs before ventilation was 0.33 +/- 0.31 ml.min-1.cmH2O-1.100g-1 and was not different from the Kfc in the CC group ventilated with 15 cmH2O PIP. Kfc increased by 850% after ventilation with only 15 cmH2O PIP in the unrestricted IL group, and in the CC group Kfc increased by 31% after 30 cmH2O PIP and 430% after 45 cmH2O PIP. Inspiratory volume limitation by the plaster cast in the C group prevented any significant increase in Kfc at the PIP values used. These data indicate that volume distension of the lung rather than high PIP per se produces microvascular damage in the immature rabbit lung.

Lung edema increases transvascular filtration rate but not filtration coefficient

To determine whether the accelerated rate of lobe weight gain during severe pulmonary edema is attributed to increased permeability of the microvascular barrier or a loss of tissue forces opposing filtration, the effect of edema on capillary filtration coefficient (Kf,C), interstitial compliance (Ci), and the volume of fluid filtered after a step increase in microvascular pressure (delta Vi) were determined in eight isolated left lower lobes of dog lungs perfused at 37 degrees C with autologous blood. After attaining a base-line isogravimetric state, the capillary pressure (Pc) was increased in successive steps of 2, 5, and 10 cmH2O. This sequence of vascular pressure increases was repeated three times. Edema accumulation was expressed as weight gained as a percent of initial lobe weight (% delta Wt), and Kf,C was measured by time 0 extrapolation of the weight gain curve. An exponential rate constant for the decrease in the rate of weight gain with time (K) was calculated for each curve. Ci was then calculated by assuming that the capillary wall and interstitium constitute a resistance-capacitance network. Kf,C was not increased by edema formation in any group. Between mild (% delta Wt less than 30%) and severe edema states (% delta Wt greater than 50%) respective mean Ci increased significantly from 3.54 to 9.12 ml.cmH2O-1.100 g-1, K decreased from 0.089 to 0.036 min-1, and delta Vi increased from 1.28 to 2.4 ml.cmH2O-1.100 g-1. The delta Vi during each Pc increase was highly correlated with Kf,C and Ci when used together as independent variables (r = 0.99) but less well correlated when used separately.(ABSTRACT TRUNCATED AT 250 WORDS)

Pulmonary embolism: analysis of endothelial pore sizes in canine lung

The effect of glass-bead microemboli (diameter 100 micron, range 77-125 micron) in the absence of fibrinolysis inhibition on pulmonary hemodynamics and microvascular permeability was determined in anesthetized, microfilaria-free dogs acutely prepared for the collection of lung lymph. Pulmonary vascular resistance, pulmonary capillary pressure (Pc), lymph flow (QL), and the ratio of lymph (CL) to plasma (Cp) protein concentrations were measured after 0.2 (n = 4), 0.4 (n = 6), or 0.6 (n = 3) g/kg beads. In all cases, emboli increased resistance and QL severalfold (P less than 0.05), while CL/Cp remained unchanged. In part, the increase in QL could be attributed to an increase in Pc compared with control (12.4 +/- 2.2 vs. 6.7 +/- 0.6 mmHg, P less than 0.05). Furthermore, since the solvent-drag reflection coefficient (sigma f) for total proteins approaches the osmotic reflection coefficient (sigma d) at high QL, sigma d was estimated under these conditions with sigma f approximately equal to sigma d approximately equal to 1 - (CL/Cp)min. The sigma d was decreased (P less than 0.05) after 0.4 and 0.6 g/kg beads to 0.55 +/- 0.03 and 0.50 +/- 0.07, respectively, when compared with that in control lungs (sigma d = 0.62 +/- 0.02; Parker et al., Circ. Res. 48: 549-561, 1981). A pore-stripping analysis demonstrated that after emboli the pulmonary endothelial barrier could be described by a population of small (80 A) and large (350 A) pores. However, the number of large to small pores was 1:1,195, compared with 1:195 in control lungs, suggesting an increased contribution of extra-alveolar vessels upstream of the emboli.(ABSTRACT TRUNCATED AT 250 WORDS)

Control of glucose metabolism in pancreatic beta-cells by glucokinase, hexokinase, and phosphofructokinase. Model study with cell lines derived from beta-cells

Glucose usage by soluble fractions of cell extracts from two insulin-producing cell lines, RINm5F and HIT, was investigated. Analysis of enzyme activities indicated that glucose phosphorylation and phosphofructokinase are likely to be the rate-limiting steps of glycolysis in both RINm5F and HIT cell extracts. RINm5F extracts, which lack glucokinase, exhibited relatively flat concentration-dependency curves of glucose usage and showed substantial inhibition of hexokinase. HIT cell extracts, which contain glucokinase but lack hexokinase, exhibited sigmoidal concentration-dependency curves of glucose usage, reflecting almost fully expressed glucokinase activity. A reconstituted system prepared from RINm5F and HIT cell extracts exhibited a composite concentration-dependency curve of glucose usage and showed substantial inhibition of hexokinase and almost fully expressed glucokinase. However, conditions that activate phosphofructokinase, such as addition of ammonium sulfate or fructose 2,6-bisphosphate or alkalization, removed the inhibition of hexokinase without noticeably affecting the glucokinase component of usage. Results obtained with a reconstituted system containing RINm5F cell extract and purified glucokinase were consistent with these findings. The data presented here indicate that this reconstituted cell-free system serves as a valid model for the study of aspects of glycolytic control in the islet. This model illustrates the preeminent role of glucokinase in the control of glycolysis, consistent with its glucose-sensor function in the islet. In addition, these studies help to define the contribution of phosphofructokinase to the control of glycolysis and the mechanism whereby changes in phosphofructokinase activity could modulate, via changes in the glucose 6-phosphate concentration, the activity of hexokinase and hence the net glycolytic flux.

Lymph flow during increases in pulmonary blood flow and microvascular pressure in dogs

We studied the effects of an increase in pulmonary blood flow (PBF) on steady-state lung lymph flow (QL) and protein transport in anesthetized dogs (n = 7) to estimate the effect of vascular recruitment in zone 3 on transvascular filtration. At the end of each experiment, we increased left atrial pressure to 25-30 mmHg using a balloon catheter and obtained a washdown of the lymph protein concentration. PBF was increased with an extracorporeal circuit, which pumped blood from the left to the right atrium, and increases in pulmonary capillary pressure (Pc) were minimized by lowering left atrial pressure. PBF was measured by thermodilution, and Pc was measured by transient analysis of arterial occlusion pressure with a Swan-Ganz catheter. PBF increases averaged 78% with increases ranging from 36 to 118%. Pc increases ranged from 0.5 to 6.3 mmHg, and QL increases averaged 31% with changes ranging from -2 to +138%. We observed a 16% increase in QL for each 1-mmHg increase in Pc during increased PBF, which was comparable to the relationship previously observed after an increased left atrial pressure. Lymph-to-plasma total protein concentration ratios (CL/CP) decreased from 0.71 +/- 0.04 to 0.625 +/- 0.06 during increased PBF. The relationship between CL/CP, QL, and Pc for both increased blood flow and increased left atrial pressure were within the expected range for increased pressure alone. These data suggest that there was minimal vascular recruitment for transvascular filtration in zone 3 when pulmonary blood flow was increased. Microvascular filtration pressure was the main determinant of fluid and protein transvascular filtration under these conditions.

Pulmonary and systemic blood flow contributions to upper airways in canine lung

The blood flow contributions and drainage patterns of the pulmonary and systemic circulations in the upper airways (trachea and main bronchi) were assessed in anesthetized dogs by injecting 15-micron radiolabeled microspheres into the right and left heart, respectively. After the animals were killed, the tracheal cartilage, tracheal muscle-mucosa, and main bronchi were excised. The tracheal cartilage and tracheal muscle-mucosa were divided into lower, middle, and upper segments for blood flow determinations. The pulmonary contribution to tracheal blood flow was very small, averaging only 0.6 +/- 0.3 ml.min-1.100 g-1 (means +/- SE), being higher in the lower segments. The systemic contribution to these same tracheal regions was significantly (P less than 0.05) higher, averaging 20.9 +/- 5.5 ml.min-1.100 g-1 (means +/- SE) and higher in the upper segments. The pulmonary and systemic circulations each contributed approximately 50% to the main bronchi blood flow, which averaged 11.2 +/- 4.2 ml.min-1.100 g-1 (means +/- SE). The pulmonary blood flow contribution alone to the trachea and main bronchi was also determined in subsequent experiments that utilized the isolated lung, and these blood flows were not significantly different from the pulmonary contribution measured in the intact lungs. The present results indicate that the systemic (bronchial) circulation is the primary source of tracheal blood flow and that both the pulmonary and systemic circulations may contribute approximately 50% of the blood flow to the main bronchi in dog lungs.

Antidepressant analgesia in rheumatoid arthritis

Forty-seven patients with definite rheumatoid arthritis (RA) were treated in a 32 week, double blind, crossover trial of amitriptyline, desipramine, trazodone, and placebo. All drug regimens produced significant changes on pain measures relative to baseline, but only amitriptyline exceeded placebo. Amitriptyline was associated with a significant reduction in the number of painful/tender joints. Our study supports the efficacy of a moderate dose of amitriptyline as an adjunct drug for the treatment of pain in both depressed and nondepressed patients with RA.

An anatomical and clinical investigation of spinal meningeal nerves

Anatomical studies on nerve roots obtained from autopsied subjects indicated that meningeal innervations of the dura surrounding spinal nerves are more numerous in the lumbar and cervical regions. They are most abundant near the surface of the dura, and on the ventral, lateral and ventro-lateral aspects of the spinal nerve root dura. A denervation procedure was conceived and carried out on 28 patients, 8 of which were failed discs. The results indicated that these nerves subserve the function of pain and their denervation may ameliorate such pain.

Stimulation of calcium-sodium exchange in dog red blood cells by hemolysis and resealing

Osmotic hemolysis and resealing greatly increase calcium influx in dog red blood cells. The resealed ghosts show a saturable calcium entry pathway with complex kinetics. As expected for a calcium-sodium exchanger, calcium uptake is stimulated by internal sodium and inhibited by external sodium. Compared to fresh, intact red cells the resealed ghost calcium-sodium exchanger is less responsive to quinidine and to alterations in medium tonicity. The differences in calcium uptake rate among cells from different donors are minimized in the ghost preparation. There are several ways to stimulate sodium-dependent calcium movements in these cells, of which hemolysis-resealing is the most potent. The results of these and previous studies suggest that dog red blood cells have a latent capacity for calcium-sodium exchange.

Reabsorption kinetics of albumin from pleural space of dogs

The reabsorption of albumin from the pleural space was measured in eight dogs receiving 0.5 ml intrapleural injection of 131I-labeled albumin and a simultaneous intravenous injection of 125I-labeled albumin. Plasma curves for both tracers were obtained over 24 h. The 125I-albumin curve served as input function of albumin for interstitial spaces, including pleura, whereas the 131I-albumin curve represented the output function from pleural space. The frequency function of albumin transit times from pleural space to plasma was obtained by deconvolution of input-output plasma curves. Plasma recovery of 131I-albumin was complete by 24 h, and the mean transit time from pleura to plasma averaged 7.95 +/- 1.57 (SD) h. Albumin reabsorption occurred mainly via lymphatics as indicated by experiments in 16 additional dogs in which their right lymph ducts or thoracic ducts were ligated before intrapleural injection. A pleural lymph flow of 0.020 +/- 0.003 (SD) ml.kg-1.h-1 was estimated, which is balanced by a comparable filtration of fluid into the pleural space. This suggests that, under physiological conditions, the subpleural lymphatics represent an important control mechanism of pleural liquid pressure.

Patients with rheumatoid arthritis at high risk for noncompliance with salicylate treatment regimens

Recent studies indicate the adherence of many patients with rheumatoid arthritis (RA) to their treatment regimens is poor. Management of this problem depends on identification of noncompliant patients, followed by interventions to increase their level of adherence. In this study, 63 patients with RA receiving salicylate drugs completed a questionnaire during an outpatient visit. The questionnaire contained items believed to be predictive of future compliance, including patient self-predictions regarding future compliance, ratings of behavior in similar situations and barriers to compliance, such as ease of transportation to the clinic. Compliance was estimated via a salicylate assay that was taken during a subsequent outpatient appointment. Multivariate analyses of our data revealed that significant predictions could be made regarding future compliance, with 75% of the noncompliant patients correctly identified. Variables contributing significantly included behavioral self-predictions and a measure of current behavior in similar situations, as assessed by a salicylate assay that was collected during the 1st outpatient visit.

Fixation of transporters in the active or inactive state

A strategy is presented for fixing regulated transport systems in the functional or non-functional state. The advantages of this approach include the ability to distinguish between sensor and effector systems, the capacity to study transporters independently of their activating mechanisms, and the possibility of identifying membrane polypeptides that participate in the regulatory process.

Depression in rheumatoid arthritis

Operationalized diagnostic criteria for depression were used to assess 137 (76% male, 24% female) patients with rheumatoid arthritis (RA). Forty-two percent met criteria for some form of depression. Discriminant function analysis revealed a significant relationship between the presence or history of depression and higher levels of pain, but not between current depression and common indicators of RA activity or severity. These results suggest that depression is a frequent disorder among persons with RA. The importance of patient appraisal of disease and assessment of repeated depressive episodes is discussed. Attention to specific interventions for depression in conjunction with the treatment of the RA is suggested.

Pain management in rheumatoid arthritis patients. A cognitive-behavioral approach

To examine the effectiveness of a cognitive-behavioral pain management program for patients with rheumatoid arthritis, three patient groups were studied: a cognitive-behavioral group (CB), an attention-placebo group, and a control group. The CB group received a comprehensive, 12-month pain management program that taught coping strategies such as problem-solving techniques, relaxation training, strategies for attention diversion, and training in family dynamics and communication. Dependent measures included pain, coping strategies, psychological status, functional status, and disease status. Data analysis at 12 months revealed benefits for the CB group in the area of enhanced coping strategies. Specifically, the CB subjects showed significantly greater use of coping strategies and significantly more confidence in their ability to manage pain. The findings are discussed in terms of the importance of enhanced self-efficacy and personal control for patients with rheumatoid arthritis.

Linked oscillations of free Ca2+ and the ATP/ADP ratio in permeabilized RINm5F insulinoma cells supplemented with a glycolyzing cell-free muscle extract

We show in the accompanying paper that the steady-state level of free Ca2+ maintained by the organelles of permeabilized RINm5F insulinoma cells varies inversely with the ATP/ADP ratio when this ratio is set by addition of creatine phosphokinase and fixed ratios of creatine to creatine phosphate. We, therefore, asked whether acute cyclic alterations in the cytosolic ATP/ADP ratio in the range known to modulate O2 consumption might be involved in regulating the physiological activity of Ca2+ -ATPases and the cytosolic free Ca2+ level. To explore this hypothesis we combined two experimental systems: 1) permeabilized RINm5F insulinoma cells that can maintain a low medium Ca2+ concentration and 2) a cell-free extract of rat skeletal muscle that spontaneously exhibits oscillatory behavior of glycolysis and linked oscillations in the ATP/ADP ratio, when provided with glucose. The free Ca2+ level maintained by the permeabilized cells oscillated in phase with the glycolytic oscillations and correlated closely with the ATP/ADP ratio but not with glucose 6-phosphate, fructose 6-phosphate, orthophosphate, or pH. When glucokinase replaced hexokinase as the glucose phosphorylating enzyme, Ca2+ oscillations were induced by increasing the glucose concentration from 2 to 8 mM. The results demonstrate a link between metabolite changes and free Ca2+ levels in a reconstituted physiological system. They support a model in which oscillations in glycolysis and the ATP/ADP ratio may cause oscillations in cytosolic free Ca2+, beta-cell electrical activity, and insulin release.

Volume-activated transport systems in dog red blood cells

1. When dog red blood cells are shrunken or swollen, transport pathways are activated that do not function discernibly when the cell is at normal volume. Swelling the cells turns on two pathways, a Ca-Na exchanger and a Cl-dependent K pathway. 2. Shrinking the cells activates a Na-H antiporter. 3. The passive net flow of ions through these transporters is in such a direction as to correct the perturbation of cell volume: when the cell water content has returned to normal, the transporters turn off. 4. Recently we have investigated agents that can lock or fix the volume-responsive transporters in the activated state. Na-H exchange, for example, can be fixed in the on position with either glutaraldehyde or N-phenylmaleimide. 5. Ca-Na exchange can be locked on by the sulfhydryl-oxidizing agent, diamide. We have used these effects to investigate the relationships between cell volume and the transport mechanisms. 6. It is possible, for instance, to distinguish whether certain inhibitors act on the transporters per se or on the apparatus that perceives cell volume and communicates with the transporters. 7. Furthermore, in the case of the Ca-Na exchanger some indication of the membrane polypeptides involved in volume regulation has been possible, using radioactive compounds that bind covalently to sulfhydryl groups.

Neuronal intranuclear hyaline inclusion disease associated with premature coronary atherosclerosis

Neuronal intranuclear hyaline inclusion disease (NIHID) has been recognized in 14 patients. It usually occurs in the first and second decades but has been seen in the sixth. Both sexes are affected by this sporadic multisystem degenerative disorder that has involved the central and peripheral nervous systems with fibrillar and granular intranuclear inclusions. NIHID appears to be several variants of a multisystem degenerative disease as illustrated by the combination of a spontaneous, degenerative central and peripheral nervous system disorder with neuronal intranuclear inclusions and severe atherosclerotic coronary artery disease in a 23-year-old white man. Beginning at 11 years of age, this patient had experienced diffuse muscle spasms, dysarthria, dysphagia, tremors, ataxia, oculogyric crises, progressive muscle weakness, and atrophy. At autopsy, neuronal intranuclear hyaline inclusions and neuronal loss were seen in his brain, brainstem, cerebellum, spinal cord, bowel, bladder, and esophagus. These fibrillary and granular Cowdry type A and B intraneuronal inclusions were consistent with the diagnosis of NIHID associated with severe coronary atherosclerosis.