Alterations in hemodynamics and Kf,c during lung mass resection

The effects of progressive lung mass reduction on total pulmonary vascular resistance (RT), compliance (CT), arterial (Pa), venous (PV), and capillary (Pc) pressures, and the capillary filtration coefficient (Kf,c) were evaluated in whole isolated dog lungs perfused with autologous blood. RT increased (P less than 0.05) in a nonlinear fashion when mass was reduced by greater than 35% in zone 3 lungs (Pa greater than PV greater than airway pressure) perfused at constant pressure (CP, n = 9), a finding predicted by a model of rigid parallel flow channels subjected to loss of cross-sectional area. Furthermore, these findings were not altered by pretreatment with ibuprofen or diphenhydramine (n = 7). In contrast, in zone 3 lungs perfused with constant flow (CF, n = 4), RT did not increase until at least 60-75% of mass was removed. Since Pa and Pc were constant in the former group, but increased in the latter group (P less than 0.05), the attenuation of RT by CF is best explained by vascular distension. This is supported by the finding that microvascular C, as a fraction of CT, decreased significantly with CF, but not with CP. Kf,c and CT (referenced to the initial lung mass) decreased linearly with reductions in lung mass % delta Kf,c = 1.26-0.98% mass removed (r = 0.90, P less than 0.01) and % delta CT = -3.99-0.98% mass removed (r = 0.82, P less than 0.01) relationships that were not altered by blocker pretreatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Diamide stimulates calcium-sodium exchange in dog red blood cells

Calcium influx can be stimulated in dog red blood cells by preexposure to diamide under certain conditions. Diamide-activated calcium influx resembles swelling-induced Ca2+-Na+ exchange in several respects. These include saturation of calcium influx at external calcium levels greater than 0.5 mM, suppression of calcium influx by external sodium, and inhibition by quinidine. The ability of diamide to stimulate this transport pathway depends critically on the ionic composition of the medium in which the cells are bathed at the time of diamide exposure. The effect is greatest if the diamide preincubation is conducted in a hypotonic lithium chloride medium containing at least 1 microM calcium. Stimulation of Ca2+-Na+ exchange is seen at diamide concentrations (0.10-0.33 mM) that are lower than those reported to cause major spectrin cross-linking, glutathione depletion, Ca2+-ATPase inhibition, or ion channel formation. The results suggest that dog red cells have a large latent capacity for Ca2+-Na+ exchange.

Risk assessment and oncodynamics of ethylene oxide as related to occupational exposure

Two rat inhalation bioassays have been integrated into the risk assessment on the carcinogenicity of ethylene oxide (EO). The carcinogenic findings as well as relevant metabolism and pharmacokinetic data are reviewed. Brain tumors were selected as the endpoint for the assessment of risk because of the indication that adverse effects on the nervous system, related to EO exposure, were consistent across species. Two methods, time-exposure concentration product and area under the plasma concentration-time curve (AUC) are used as a basis for calculating effective dose. Scaling of the dose to man from both rat and dog is explored based on pharmacokinetic studies. Two different mathematical risk extrapolation models, the probit and the multi-stage, are used to estimate the cancer risk for daily exposures to EO of 1.8 microgram/liter over a working lifetime. The use of AUC as a basis for dose from a daily exposure of 1.8 microgram/liter over a working lifetime gives the higher risk rates (90-142/10,000 workers). The implication of the simulated dose using plasma concentrations versus the time-concentration product approach is discussed in relation to threshold effects.

Nontraumatic clavicle lesions in children

Sixteen children (average age 7.4 years) with nontraumatic lesions of the clavicle were reviewed. There were six cases of neoplasms, six cases of infection, and four developmental anomalies. The patients with infections all had pain at presentation, with elevated white blood cell counts and erythrocyte sedimentation rates. Tissue biopsy was an important diagnostic tool.

Band 3 tyrosine kinase in avian erythrocyte plasma membrane is immunologically related to pp60c-src

We have identified in the plasma membrane of the chicken erythrocyte a 60-kDa tyrosine-specific protein kinase immunologically related to the transforming protein pp60v-src of Rous sarcoma virus. The erythrocyte protein kinase phosphorylated heavy chains of tumor-bearing rabbit (TBR) antibodies reactive with pp60c-src at tyrosine in immune complex protein kinase assays. The kinase was identified as a 60-kDa protein by [35S]methionine labeling of erythrocytes and by autophosphorylation in immune complexes. The kinase migrated on two-dimensional gel electrophoresis with an apparent pI and molecular mass similar to pp60c-src. A plasma membrane-enriched fraction isolated from chicken red cells contained the majority of the kinase activity. The kinase was solubilized from the plasma membrane by the detergents 0.5% (wt/vol) Na-deoxycholate and 1% (vol/vol) Nonidet P-40. One molar NaCl was much less effective, indicating a strong association of the kinase with the plasma membrane. Incubation of the plasma membrane fraction with [32P]ATP resulted in tyrosine phosphorylation of the anion transport protein band 3. Band 3 phosphorylation was blocked by TBR antibodies, indicating that the kinase recognized by pp60c-src antibodies was responsible for band 3 phosphorylation. These results demonstrate that the avian erythrocyte plasma membrane contains a tightly bound tyrosine-specific protein kinase identical or closely related to pp60c-src and that this kinase is responsible for band 3 phosphorylation in vitro.

Interactions of sodium-proton exchange mechanism in dog red blood cells with N-phenylmaleimide

Dog red blood cells (RBC) have a Na-H exchanger that is reversibly activated by cell shrinkage. The Na-H exchanger can be fixed in the on or off mode by treating the cells with N-phenylmaleimide. This action depends on the volume of the cells at the time of exposure to N-phenylmaleimide and also on the concentration of the reagent per number of cells. If the cells are swollen in hypotonic media during N-phenylmaleimide exposure, the Na-H exchanger becomes irreversibly inactivated, so that on subsequent shrinkage of the cells, no amiloride-sensitive Na flux is seen. This effect is maximal at N-phenylmaleimide concentrations of greater than 20 mumol/g hemoglobin. If the cells are shrunken in hypertonic media during N-phenylmaleimide exposure, the response of the Na-H exchanger depends critically on the concentration of the reagent. At N-phenylmaleimide concentrations of less than 20 mumol/g hemoglobin, the Na-H exchanger is fixed in the activated state, so that even when the volume stimulus is removed by subsequent cell swelling, an amiloride-sensitive flux is seen. Higher concentrations of N-phenylmaleimide applied to shrunken cells inhibit the Na-H exchanger. The results are accounted for in a model that envisions a volume-responsive switching mechanism for Na-H exchange that has two functional groups capable of reacting with N-phenylmaleimide. The accessibility of these groups is determined by cell volume.

Analysis of altered capillary pressure and permeability after thermal injury

In order to investigate the effects of thermal injury on microvascular hemodynamics and permeability, hindpaw arterial (PA), venous (PV), and capillary (PC) pressures, blood (QB) and lymph (QL) flows, and lymph (CL) and plasma (CP) total protein concentrations were measured before and for 3 hr after a 10-sec 100 degrees C scald burn in 11 dogs. Prior to injury in eight experiments (Group I--permeability analysis) venous pressure was elevated by outflow restriction until the minimal CL/CP was obtained. In three experiments (Group II--hemodynamic analysis) outflow was not restricted. Lymph and plasma protein fractions ranging in size from 37 to 120 A were measured using gradient gel electrophoresis and capillary equivalent pore sizes were calculated. In the early postburn period, PC increased from 24 +/- 2 (mean +/- SE) to 47 +/- 5 mm Hg (P less than 0.05) and precapillary resistance (RA) decreased from 6.6 +/- 0.2 to 2.5 +/- 0.2 mm Hg/ml/min/100 g (P less than 0.05) while postcapillary resistance (RV) remained unchanged. Pre- to postcapillary resistance (RA/RV) fell by 74%. The reflection coefficient for total proteins (calculated as sigma = 1 - CL/CP) decreased from 0.87 +/- 0.01 to 0.45 +/- 0.02 (P less than 0.01). Permeability of the postburn capillary endothelium was described by using two populations of equivalent pores. Preburn pore radii were 50 and 300 A with 13% of the capillary filtrate passing through the large pores. Pore radii increased after injury to 70 and 400 A with 49% of the filtrate passing through the large pores. The postburn total tissue filtration coefficient (Kf) increased to 2.4 times the control. Over the first 3 hr postburn, 53% of the increase in capillary filtration was attributable to increased capillary pressure and 47% to increased permeability. We conclude that the early rapid edema formation following thermal injury is the result of marked increases in both capillary filtration pressure and filtration through large nonsieving pores.

Further evidence for coupling of sodium and proton movements in dog red blood cells

Using 4,4'-diisothiocyanostilbene-2,2'-disulfonate (DIDS) and tributyltin the sodium transport pathway activated by shrinkage in dog red blood cells is shown to behave as expected for an electroneutral Na+/H+ exchanger. When the driving forces for sodium and protons are equal, flow through the pathway stops. Amiloride inhibits the shrinkage-induced Na+/H+ exchange.

Interstitial distribution of charged macromolecules in the dog lung: a kinetic model

A mathematic model was constructed to investigate conflicting physiologic data concerning the charge effect of continuous capillaries to macromolecules in the lung. We simulated the equilibration kinetics of lactate dehydrogenase (MR 4.2 nM) isozymes LDH 1 (pI = 5.0) and LDH 5 (pI = 7.9) between plasma and lymph using previously measured permeability coefficients, lung tissue distribution volumes (VA) and plasma concentrations (CP) in lung tissue. Our hypothesis is that the fixed anionic charges in interstitium, basement membrane, and cell surfaces determine equilibration rather than charged membrane effects at the capillary barrier, so the same capillary permeability coefficients were used for both isozymes. Capillary filtration rates and protein fluxes were calculated using conventional flux equations. Initial conditions at baseline and increased left atrial pressures (PLA) were those measured in animal studies. Simulated equilibration of isozymes over 30 h in the model at baseline capillary pressures accurately predicted the observed differences in lymph/plasma concentration ratios (CL/CP) between isotopes at 4 h and equilibration of these ratios at 24 h. Quantitative prediction of isozyme CL/CP ratios was also obtained at increased PLA. However, an additional cation selective compartment representing the surface glycocalyx was required to accurately simulate the initial higher transcapillary clearances of cationic LDH 5. Thus experimental data supporting the negative barrier, positive barrier, and no charge barrier hypotheses were accurately reproduced by the model using only the observed differences in interstitial partitioning of isozymes without differences in capillary selectivity.

Segmental vascular resistances and compliances in dog lung

The segmental distribution of vascular resistances and compliances were evaluated in isolated blood perfused lung lobes using arterial, venous, and double-occlusion pressures and were compared with filtration midpoint capillary pressures (Pc,f). We separated total vascular resistance (RT) and compliance (CT) into large artery (Ra, Ca), large vein (Rv, Cv), and microvascular compartments (Rmc, Cmc) at base-line and increased vascular pressures and during infusions of histamine, serotonin, and norepinephrine. In control lobes, double-occlusion pressure (Pdo) closely approximated Pc,f at all vascular pressures. Pre- and postcapillary resistance were approximately equal when referenced to either Pc,f or Pdo. Although Rmc comprised 42% of RT and Cmc constituted 76% of CT, a twofold increase in base-line Pc,f caused RT to decrease to 67% and Rmc/RT to 29% of control values, whereas CT decreased to 87% and Cmc/CT decreased to 88% of control values over the same Pc,f range. Mean static CT was 2.25 +/- 0.09 ml X cmH2O-1. 100 g-1, whereas dynamic CT was 1.54 +/- 0.08 ml X cmH2O-1. 100 g-1, or only 68% of static vascular compliance. Drug infusions increased mean RT from 4.2- to 5.3-fold and significantly decreased both static and dynamic CT. Although all vascular segments were constricted, histamine affected primarily large veins, serotonin increased Ra greater than Rv, and norepinephrine constricted upstream and downstream vessels about equally. Increased Pc,f in the presence of these drugs decreased RT significantly in every case primarily through attenuation of the drug vasoconstrictor effect on Rmc and decreased CT primarily due to a decrease in Cmc, but increased Cmc/(Ca + Cv). Thus the microvascular compartment appears to be the major site of both fluid filtration and vascular compliance and contributes significantly to total vascular resistance. Drug infusions constricted large and small vessel compartments as defined here, but increased Pc,f attenuated microvascular vasoconstriction and to a lesser extent large vessel vasoconstriction resulting in a reduced microvascular resistance in both drug-treated and control lobes. This effect can be attributed to recruitment and/or distension of microvessels and distension of larger vessels.

Biological basis for extrapolation across mammalian species

The rationale for extrapolation or "scaling" across species is founded in the commonality of anatomic characteristics and the universality of physiologic functions and biochemical reactions. The development of the allometric equation, Y = aWn, relating species body size (W) with various morphological, physiological, biochemical, pharmacological, and toxicological characteristics, as the fundamental basis for extrapolation of biological data from laboratory animals to man is outlined. The familiar methods of extrapolation on the basis of "milligrams per kilogram body weight" and "body surface area" are simply examples, W1.0 and W0.67, respectively, of this equation. The experimental observations used to support these two, and other extrapolation bases, are reviewed. Criteria for the selection of an appropriate base for transfer of specific biologic data from laboratory animals to man, and the expected reliability of the extrapolation, are discussed with the enunciation of four guiding principles. The application of these principles to the extrapolation to man of dose-tumor incidence data from carcinogenicity bioassays of laboratory animals is discussed. The components are identified, and illustrative examples are given.

Paralytic hip instability in poliomyelitis

A retrospective study was made of the results of surgical treatment of subluxation or dislocation of the hip in patients who had suffered from poliomyelitis. Good results were achieved in 46% and satisfactory results in 24%. The key factors for success are muscle balance, the femoral neck-shaft and anteversion angles, and the acetabular geometry. Iliopsoas transfer can augment the hip abductor power by an average of one MRC grade. Varus derotation femoral osteotomy is important to re-establish a normal neck-shaft angle and anteversion. The results of pelvic osteotomy are variable and the importance of a posterior acetabular defect is emphasised.

Validation of double vascular occlusion method for Pc,i in lung and skeletal muscle

Capillary pressures in isogravimetric lung and skeletal muscle measured with the double vascular occlusion technique (Pdo) were compared to those measured using the traditional gravimetric technique (Pc,i). Pressures were measured using both techniques in isolated blood-perfused canine lungs (n = 18), blood-perfused rat hindquarters before (n = 8) and after (n = 6) maximal dilatation with papaverine and in rat hindquarters perfused with an artificial plasma (n = 6). In both organs, regardless of vascular tone, the double vascular occlusion isogravimetric pressure was the same as the gravimetric Pc,i, and the two measurements were highly correlated. Lung: Pdo = -0.22 + 1.06 Pc,i (r = 0.85, P less than 0.01); hindquarter: Pdo = -1.03 + 0.99 Pc,i (r = 0.91, P less than 0.01). In addition, Pdo was the same at every combination of isogravimetric arterial and venous pressures tested. The results indicate that the more rapidly applied double vascular occlusion pressure yields an accurate measure of isogravimetric capillary pressure in isolated organs over a wide range of isogravimetric pressures.

Transvascular clearance and distribution of charged macromolecules in ANTU lung injury

Tissue uptake, extravascular distribution volumes, and plasma-lymph equilibration of two isozymes of lactate dehydrogenase (LDH) were labeled with radioiodine and studied in dogs with either normal or injured lungs. Cationic LDH 5 [isoelectric point (pI) = 7.9] was initially cleared from plasma by lung tissue at a rate 1.61 times higher (9.3 vs. 5.8 X 10(-3) ml X min-1 X g-1 extravascular wet wt) than anionic LDH 1 (pI = 5.0). LDH 5 also had a significantly higher extravascular distribution volume but equilibrated more slowly between plasma and pulmonary lymph (t1/2 = 120 min) than LDH 1 (t1/2 = 78 min) in normal lungs. Respective lymph-to-plasma ratios were 0.53 and 0.43 for LDH 1 and LDH 5 after 4 h of infusion. Infusion of the isozymes 2 h after injection of alpha-naphthylthiourea (ANTU) resulted in larger initial tissue plasma clearances for both isozymes compared with control, but greater relative tissue plasma clearances and extravascular distribution volumes for LDH 5 compared with LDH 1. Plasma-lymph equilibration half times of LDH 5 and LDH 1 were reduced after ANTU to 50 min and 41 min, respectively, whereas the respective alveolar fluid-to-plasma ratios of the two isozymes at termination of the ANTU experiments were 0.56 and 0.84. These data suggest that the fixed anionic charges on endothelial cell surfaces, intercellular junctions, basement membranes, and interstitial structures act much like a cation exchange gel to rapidly take up cationic proteins and retard the plasma-lymph equilibration of these proteins relative to anionic proteins of the same size.(ABSTRACT TRUNCATED AT 250 WORDS)

Interactions of lithium and protons with the sodium-proton exchanger of dog red blood cells

Passive movements of Li in dog red blood cells (RBC) ar like those of Na and protons in being stimulated by osmotic cell shrinkage and inhibited by amiloride. Li and protons have similar asymmetrical effects on Na-H exchange. When the intracellular fluid is made rich in Li or protons, Na-H exchange is stimulated. When the extracellular fluid is enriched in Li or protons, Na-H exchange is inhibited. In the case of protons, these effects can override alterations in driving force that are created by the experimental conditions. For example, acidification of the cytoplasm stimulates outward Na movements, while acidification of the medium inhibits Na efflux. Thus, protons (and, by analogy, Li) can interact with the Na-H exchanger not only as substrates but also as modulators. In previous experiments, the only way to activate the Na-H exchanger in dog RBC was to shrink the cells in hypertonic media. The influences of Li or protons, however, are so strong as to preempt the volume effects, so that the pathway can be activated even in swollen cells and deactivated in shrunken ones.

Empirically derived pain-patient MMPI subgroups: prediction of treatment outcome

Fifty-seven male chronic pain patients admitted to an inpatient multimodal pain treatment program at a Midwestern Veterans Administration hospital completed the MMPI, Profile of Mood States (POMS), Tennessee Self-Concept Scale (TSCS), Rathus Assertiveness Schedule (RAS), activity diaries, and an extensive pain questionnaire. All patients were assessed both before and after treatment, and most also were assessed 2-5 months prior to treatment. No significant changes occurred during the baseline period, but significant improvements were evident at posttreatment on most variables: MMPI, POMS, TSCS, RAS, pain severity, sexual functioning, and activity diaries. MMPI subgroup membership, based on a hierarchical cluster analysis in a larger sample, was not predictive of differential treatment outcome. Possible reasons for comparable treatment gains among these subgroups, which previously have been shown to differ on many psychological and behavioral factors, are discussed.

Fluid filtration and protein clearances through large and small pore populations in dog lung capillaries

Solvent drag reflection coefficients (sigma f) for six protein fractions with hydrodynamic radii ranging from 37 to 120 A were determined using dog lung lymph CL/CP data over a range of lung lymph flows (QL). Two equivalent pore populations with effective radii of 75-85 A and 200-325 A were determined for the pulmonary capillaries over a range of mean lymph flows for 1.8 to 6.3 times control. Fractional fluid clearance through the large pore population was observed to decrease from 0.28 to 0.16 as QL increased. These data indicate that lymph flow (filtration) increased primarily by an increased filtration through small pores with relatively little increase in filtration through the large pore population. The shift to small pore filtration at high filtration rates accounts for the dependence of the homoporous estimate of total protein sigma f on lymph flow previously observed using lung lymph (Parker et al., 1981). If capillary membrane heteroporosity is present then there should be a net convective clearance of protein across the capillary caused by a volume circulation between large and small pore populations. Minimal estimates of 6-10% of protein clearance are attributed to this mechanism even in the absence of net fluid movement across the capillary. The optimal solute radius for clearance due to volume circulation is about 60 A, based on the membrane pore sizes determined for lung capillaries. Although convective transport of macromolecules is generally acknowledged to account for most transcapillary protein clearance at high filtration rates, the inclusion of a volume circulation component suggests that convection may also be the dominant mode of macromolecular transport at low filtration rates.

Postmortem evaluation of Alzheimer's disease

Postmortem evaluation of ten individuals with a diagnosis of Alzheimer's disease (AD) confirmed the clinical diagnostic accuracy at our institution and showed significant ventricular dilatation with reduced brain mass, increased neuritic plaques, neurofibrillary tangles, vascular amyloid, and Lewy bodies in these individuals. A matched control group had no or fewer cortical neuritic plaques and neurofibrillary tangles, and two of the four control patients with rare neuritic plaques had terminal dementia. Cancer and cardiovascular disease occurred more often in the control group, but pneumonia and respiratory failure were more prevalent in the patients with AD. Thorough clinical assessment can accurately indicate Alzheimer's disease, as shown in this study.

Plasma-lymph exchange and interstitial distribution volumes of charged macromolecules in the lung

The plasma-lymph exchange of two lactate dehydrogenase (LDH) isozymes (4.2 nM) of different molecular charge between plasma (CP) and lung lymph (CL), their initial clearances across the capillary wall, and their extravascular distribution volumes were studied in dog lungs at control and increased left atrial pressures (Pla = 23.3 +/- 2.1 cmH2O). The anionic LDH 1 [isoelectric point (pI) = 5.0] exhibited a more rapid plasma decay compared with cationic LDH 5 (pI = 7.9) after bolus injection but was maintained relatively constant in several experiments using a constant infusion. The mean 10- to 12-min lung tissue clearances were 40% higher for LDH 5 than LDH 1 at control Pla and 120% higher at increased Pla. The CL/CP ratios of the anionic LDH 1 were consistently higher at 4-5 h after simultaneous injection than those of cationic LDH 5. However, the extravascular distribution volumes of LDH 5 were significantly higher in lymph equivalents than those of LDH 1 at 4 h in both Pla groups. Fixed negative charges located on endothelial cells, basement membrane, and interstitial matrix could explain the observed differences between LDH isozymes in CL/CP ratios, tissue uptake, and extra-vascular distribution volumes by the ionic interaction of LDH 5 with these negative change sites which would retard the plasma-lymph transport and enhance the extravascular distribution volume and initial clearance of these cationic macromolecules.

Exclusion of charged macromolecules in the pulmonary interstitium

The polyanionic glycosaminoglycans and glycoproteins of the interstitial ground substance could influence the interstitial distribution volumes (VA) of plasma proteins filtered across the pulmonary capillaries depending upon the molecular charge of the proteins. To determine if such differences occur, two isozymes of lactate dehydrogenase (LDH) were selectively labeled with either 125I or 131I and infused simultaneously at a rate sufficient to maintain constant plasma concentrations for 24 hr. The isoelectric points of LDH 1 and LDH 5 are 5.0 and 7.9, respectively, but they have the same mol wt (140,000) and hydrodynamic radius (42 A). VA values were calculated in lymph equivalents based on the respective activities in prenodal tracheobronchial lymph. We corrected the residual blood in the tissue using either 99mTc-labeled red cells or Dextran 70 washout of blood. At 24 hr the VA for cationic LDH 5 was significantly greater than that of anionic LDH 1 (0.299 vs 0.197 ml/g wet wt) in the lung. Lymph/plasma ratios for LDH 1 and 5 were not significantly different (0.63 vs 0.58) and total extravascular lung water was not significantly different from normal. This indicates the LDH 1 was excluded from a significantly greater portion (47%) of interstitial fluid than LDH 5 (21%), and suggests an interaction of the fixed negative charges on interstitial polysaccharides with cationic proteins.

Ovarian cancer complicated by cerebellar degeneration: a paraneoplastic syndrome

A patient with ovarian carcinoma who subsequently developed the paraneoplastic syndrome of cerebellar degeneration is presented. The literature is reviewed and possible explanations of the phenomenon are discussed.

Infantile hematomyelia complicating electrocardioversion

A premature male infant survived for eight months with significant cardiorespiratory problems. He developed a sudden, unexplained cardiorespiratory arrest that required vigorous resuscitation with apparent electrical cardioversion. Subsequent postmortem examination demonstrated focal and confluent hemorrhages in the thoracic and lumbar cord. Care is advised in administering electrical cardioversion due to the potential hazard of hematomyelia.

Osmotic reflection coefficient for total plasma protein in lung microvessels

The osmotic reflection coefficient (sigma) for total plasma proteins was estimated in 11 isolated blood-perfused canine lungs. Sigma's were determined by first measuring the capillary filtration coefficient (Kf,C in ml X min-1 X 100g-1 X cmH2O-1) using increased hydrostatic pressures and time 0 extrapolation of the slope of the weight gain curve. Kf,C averaged 0.19 +/- 0.05 (mean +/- SD) for 14 separate determinations in the 11 lungs. Following a Kf,C determination, the isogravimetric capillary pressure (Pc,i) was determined and averaged 9.9 +/- 0.5 cmH2O for all controls reported in this study. Then the blood colloids in the perfusate were either diluted or concentrated. The lung either gained or lost weight, respectively, and an initial slope of the weight gain curve (delta W/delta t)0 was estimated. The change in plasma protein colloid osmotic pressure (delta IIP) was measured using a membrane osmometer. The measured delta IIP was related to the effective colloid osmotic pressure (delta IIM) by delta IIM = (delta W/delta t)0/Kf,C = sigma delta IIP. Using this relationship, sigma averaged 0.65 +/- 0.06, and the least-squares linear regression equation relating Pc,i and the measured IIP was Pc,i = -3.1 + 0.67 IIP. The mean estimate of sigma (0.65) for total plasma proteins is similar to that reported for dog lung using lymphatic protein flux analyses, although lower than estimates made in skeletal muscle using the present methods (approximately 0.95).

Insulin mediator stimulates pyruvate dehydrogenase of intact liver mitochondria

The effects of putative insulin mediators on the pyruvate dehydrogenase (PDH) activity of intact mitochondria isolated from rat liver were investigated. The mitochondria were judged intact on the basis of electron microscopic examination and demonstrated respiratory control. Only mitochondria having respiratory control ratios of greater than 4, using succinate as a substrate, were used in these studies. Addition of physiologic concentrations of insulin to these mitochondria caused stimulation of PDH activity, attributed to generation of an insulin mediator from plasma membranes contaminating the mitochondrial preparation. Exogenous plasma membranes from rat adipocytes or liver caused further stimulation of PDH activity, which was proportional to the amount of plasma membranes added. Addition of insulin to the mixture of mitochondria and plasma membranes stimulated PDH still further. The stimulation was proportional to the insulin concentration, with maximal effects observed at 50 microU/ml insulin. Partially purified mediators from liver, muscle, H4-II-E hepatoma cells, and IM9 lymphocytes also stimulated PDH activity in intact mitochondria. Mediators prepared from insulin-treated liver, muscle, and cultured hepatoma cells stimulated PDH more than did mediators from the corresponding untreated source. Mediator from insulin-treated IM9 lymphocytes stimulated PDH less than did mediator from untreated IM9 lymphocytes. These findings are consistent with the known effects of insulin on these tissues and with the reported effects of the various mediators on PDH activity in non-intact mitochondria. These observations support the proposal that these mediators are physiologically significant modulators of insulin's effects on PDH activity.

Cecocentral scotomas in gliomatosis cerebri

A previously healthy 69-year-old white male presented with slowly progressive, painless loss of vision in both eyes. Bilateral cecocentral scotomas were found, and this was his only chief complaint for 9 months. Signs of progressive neurologic dysfunction ensued, and the patient was followed through a complete neuropathologic study at postmortem examination. To our knowledge, this is the only reported instance of pathologically confirmed gliomatosis cerebri with an initial presentation of bilateral chronic cecocentral scotomas.

Increased microvascular permeability in dog lungs due to high peak airway pressures

The effect of peak airway pressure (Paw) on vascular permeability and the "safety factor" against edema formation was determined in isolated blood-perfused lower lobes of dog lungs. Microvascular permeability was evaluated using the measured filtration coefficient (Kf,C), isogravimetric capillary pressure (Pc,i), and critical capillary pressure (Pcrit) for exhaustion of tissue safety factors. Airway pressure was maintained constant at -3 cmH2O except for the test period of 20 min when the lungs were ventilated at 6/min with sufficient volume to generate a peak inflation pressure ranging from 5 to 60 cmH2O. Mean Kf,C (in ml X min-1 X cmH2O X 100 g-1) were measured before and immediately after the period of peak airway pressures. Kf,C was significantly increased in all lungs where Paw exceeded 42 cmH2O, but in only two experiments at a lower Paw. Mean Pc,i was significantly reduced from control in the 45-55 and 55-65 cmH2O Paw groups, and both Pc,i and Pcrit were found to be inversely related to Kf,C measured after Paw ventilation. These data indicate that ventilation with Paw above 42 cmH2O (30.9 Torr) and in some cases lower pressures for 20 min significantly increased capillary hydraulic conductivity, reduced the effective osmotic effect of plasma proteins at the capillary wall, and reduced the total tissue safety factor against edema formation.

Cl- permeabilities in red blood cells and peripheral blood lymphocytes from cystic fibrosis and control subjects

Recent studies have identified abnormalities in Cl- permeation across two target cystic fibrosis (CF) epithelia (sweat duct and respiratory epithelium). In the present study, anion conductances of red blood cells (RBCs) and peripheral blood lymphocytes (PBLs) from CF and normal subjects were estimated and compared. For RBCs, the valinomycin-induced rate constant for K+ loss (PK+) was taken as an index of PCl-. For PBLs, the secondary volume increase after gramicidin pretreatment and hypotonic (0.67 X isotonic) stress was used to estimate PCl-. The Cl- permeabilities of RBCs and PBLs from CF and control subjects were comparable. These findings suggest that the abnormality in PCl- reported for CF sweat ductal and respiratory epithelia is not expressed in circulating blood elements.

Educating patients with rheumatoid arthritis: a prospective analysis

Twenty-two men with rheumatoid arthritis were randomly assigned to either a patient education group, receiving standard inpatient medical care in addition to a formal education program, or a control group receiving only the inpatient medical care. Members of the groups were not significantly different in terms of age, degree of life stress, socioeconomic status, educational level, or years since onset of rheumatoid arthritis. Dependent measures included the Arthritis Knowledge Inventory (AKI), the Arthritis Impact Measurement Scales (AIMS), and the Beck Depression Inventory (BDI), and they were collected preeducation, posteducation, and at a three-month followup. Results from the AIMS revealed improvement in dexterity, social role, depression, and overall health status for both groups. The BDI also revealed significantly less depression for both groups, reflecting a general improvement following medical intervention. Although the patient education group revealed significantly higher scores on the knowledge measure, they also revealed significantly more impairment of activity levels and significantly higher pain scores. Education was effective for increasing rheumatoid arthritis knowledge, but such topics as joint protection and disease process may adversely affect how patients view their physical capacities and interpret their pain.

Glutaraldehyde fixation of sodium transport in dog red blood cells

The large increase in passive Na flux that occurs when dog red blood cells are caused to shrink is amiloride sensitive and inhibited when Cl is replaced by nitrate or thiocyanate. Activation and deactivation of this transport pathway by manipulation of cell volume is reversible. Brief treatment of the cells with 0.01-0.03% glutaraldehyde can cause the shrinkage-activated transporter to become irreversibly activated or inactivated, depending on the volume of the cells at the time of glutaraldehyde exposure. Thus, if glutaraldehyde is applied when the cells are shrunken, the amiloride-sensitive Na transporter is activated and remains so regardless of subsequent alterations in cell volume. If the fixative is applied to swollen cells, no amount of subsequent shrinkage will turn on the Na pathway. In its fixed state, the activated transporter is fully amiloride sensitive, but it is no longer inhibited when Cl is replaced by thiocyanate. The action of glutaraldehyde thus allows one to dissect the response to cell shrinkage into two phases. Activation of the pathway is affected by anions and is not prevented by amiloride. Once activated and fixed, the anion requirement disappears. Amiloride inhibits movement of Na through the activated transporter. These experiments demonstrate how a chemical cross-linking agent may be used to study the functional properties of a regulable transport pathway.

Plasma-lymph albumin kinetics, total lymph flow, and tissue hematocrit in normally hydrated dog lungs

Lung lymph flow was normalized for lung weight and total lung lymph flows were calculated in five mongrel dogs using a kinetic analysis of albumin distribution between the pulmonary capillaries, interstitial fluid, and pulmonary lymph. Using prenodal tracheobronchial lymph an intravenous bolus of 125I-labeled albumin equilibrated between plasma and lymph with mean T1/2 of 2 hr 22 min. The mean volume of interstitial fluid drained by the cannulated lymphatics was 9.9 ml which corresponded to the extravascular albumin distribution volume of 31% of the total lung weight. Lung tissue hematocrit was determined using 51Cr-labeled red cells and 125I-albumin and averaged 92% of the simultaneous mixed venous hematocrit. The extravascular albumin and 99mTc-DTPA (diethylenetriamine pentacetic acid) spaces in lung were corrected for differences between tissue and mixed venous hematocrit and were 18.5 and 33.0 ml/100 g, respectively. This indicated that albumin distributed in 57% of the interstitial volume at 4 hr after injection. Lung lymph flow normalized to postmortem lung mass during baseline conditions was 0.060 ml/min/100 g after correction for tissue hematocrit differences. Normalized lymph flows are used for quantitative comparisons of lung lymph protein flux data between different types of experiments.

Volume-responsive sodium and proton movements in dog red blood cells

Shrinkage of dog red blood cells (RBC) activates a Na transport pathway that is Cl dependent, amiloride sensitive, and capable of conducting Na-proton counterflow. It is possible to establish transmembrane gradients for either Na or protons and to demonstrate that each cation species can drive reciprocal movements of the other. The nature of the coupling between Na and proton movements was investigated using the fluorescent probe diS-C3(5) and also by an indirect method in which K movements through valinomycin channels were used to draw inferences about the membrane potential. No evidence was found to suggest that the Na-proton pathway activated by shrinkage of dog RBC is a conductive one. By exclusion, it is presumed that the coupling between the counterflow of Na and protons is electroneutral. The volume-activated Na-proton fluxes in dog RBC have certain properties that distinguish them from similar transport pathways in other cell types.

Effects of histamine, serotonin, and norepinephrine on circulation of dog lungs

The action of histamine (H), serotonin (5-HT), and norepinephrine (NE) on the lung vasculature was evaluated in isolated blood-perfused dog lung lobes using isogravimetric techniques. Pre- and postcapillary resistances, isogravimetric capillary pressure (Pc,i), capillary filtration pressure (Pc,f), capillary filtration coefficient (Kf,c), and vascular pressure-volume relationships were measured. For constant-flow conditions, all drugs induced marked increases in both pre- and postcapillary resistances and increased Pc,f. The rise in Pc,f was most pronounced for H and least marked for NE and 5-HT. For constant-pressure perfusion, Pc,f increased slightly for H but not for NE and 5-HT, while total vascular resistance increased 4-5 times for all drugs. Vascular distensibility and volumes decreased markedly for NE and 5-HT but only slightly for H. None of the drugs appeared to alter capillary permeability because Kf,c and Pc,i measured during the infusions were not different from control.

Effects of vascular pressure on the pulmonary microvasculature in isolated dog lungs

The effects of short periods of high pulmonary vascular pressures on the filtration characteristics of the lung's microcirculation have been studied in isolated dog lungs. When left atrial pressures (Pla) were less than 30 cmH2O, the capillary filtration coefficient (Kf,c) was not different from that of controls (0.192 +/- 0.009 ml X min-1 X cmH2O-1 X 100 g-1). In 17 of 23 observations, where Pla exceeded 55 cmH2O, Kf,c was at least 1.5 times control. In 10 of 13 lungs, Kf,c returned to control values within 2 h after the Pla increase. However, in the other three experiments, Kf,c did not return to control values. These findings indicate that the filtration coefficient of pulmonary microvessels increases at high left atrial pressures (greater than 55 cmH2O) and may represent either a "stretching" of existing pores or opening of a few large pores.

High-frequency ventilation: lymph flow, lymph protein flux, and lung water

The effects of high-frequency oscillatory (HFV) ventilation on lung fluid balance and microvascular permeability to macromolecules were measured in open-chest dog lungs. Prenodal lung lymph flow, concentration of total plasma proteins in lymph and plasma, pulmonary arterial and left atrial pressure, cardiac output, and blood-free lung wet-to-dry weight ratios were measured for conventional mechanical ventilation (CMV, 12/min, 200-300 ml tidal volume) and HFV of 15 Hz and a stroke volume of 40-50 ml for normal and elevated left atrial pressures. HFV increased both lymph flow and lung water (68 and 20%, respectively), and lymph-to-plasma ratios of total plasma proteins remained unchanged. When left atrial pressure was increased, an analysis of lymph protein flux indicates that the lung microvascular permeability was not altered by HFV. The increase in lymph flow and lung water associated with HFV may reflect an increased microvascular exchange surface area or a change in interstitial fluid pressure.

Evaluation of transected spinal cord regeneration in the rat

Rat spinal cords were subjected to a 200 g/cm force acceleration injury at T10. Ten days later, the cords were totally transected at T10 and the rats separated into two groups: group C (controls) had the spinal cord realigned end-to-end; group X had 3 mm trimmed from proximal and distal cord stumps and a semifluid collagen matrix (CM) bioimplant was inserted in the gap. The CM polymerized to a firm gel at body temperature within 2 h. All rats were maintained 90 days posttransection (dpt). At 90 dpt, they were examined for local spinal cord blood flows, somatosensory evoked potentials, and a neurological evaluation. After killing, the cords were processed for electron and light microscopy and monoamine histofluorescence. The results indicated that CM can support the growth of central neurites, fibroblasts, and an adequate anastomotic network of blood vessels. Control scar tissue does not promote the presence of nerve fibers and blood vessels to the extent observed in the CM. Somatosensory evoked potential early waveforms were present in CM-bioimplanted rats but not in controls. No rat regained walking ability at 90 dpt but muscle tone and strength appeared better in CM-implanted than in control rats. We conclude that a CM bridge can provide a well vascularized, relatively nonhostile environment for central neurites and catecholaminergic axons extending from the proximal spinal cord tissue across the CM bridge and into the distal stump.

Fluid balance in ANTU-injured lungs during crystalloid and colloid infusions

A controversy exists as to the preferred solution for plasma volume replacement and cardiac output maintenance in the presence of lung injury. To evaluate these responses, crystalloid and colloid infusions were compared in dogs treated with 5 mg/kg of alpha-naphthylthiourea (ANTU), which produces a predictable increase in vascular permeability and extravascular water (QW) in the lung. A tracheobronchial lymphatic from the left lung was cannulated and left atrial (Pla) pressure, lymph flow, lymph-to-plasma protein concentration ratios, and thermal dilution cardiac output were monitored. Test infusions were either 15 ml/kg of 6% dextran 70 (DX) or 60 ml/kg of normal saline (NS) infused over 20 min. Solutions were infused 3 h after ANTU as follows: group I (DX); group II (NS), group III (DX, constant Pla); and group IV (NS, constant Pla). In groups III and IV, Pla was maintained constant by bleeding into a reservoir during an exchange transfusion. Postinfusion QW increased to 9.01 and 9.14 g/g blood-free dry wt for groups I and II, respectively, but there was no significant postinfusion increase in QW for groups III and IV compared with the 3-h preinfusion values. However, cardiac output was significantly higher at 5 h in group III compared with group IV. These studies indicate that capillary hydrostatic pressure was the major determinant of QW during the infusions but that DX maintained cardiac output significantly higher because of vascular retention of the colloids.

Failure of myocardial ischemia to increase pulmonary microvascular permeability in dogs

Increased extravascular lung water has been reported following periods of myocardial ischemia. To determine whether increased pulmonary microvascular permeability was produced by ischemia, total protein lymph-to-plasma concentration ratios (CL/CP) were obtained at mechanically increased left atrial pressures (Pla) before and after ligation of the left anterior descending coronary artery in dogs. Pulmonary and systemic vascular pressures and cardiac output were monitored and lymph flow was measured from an afferent tracheobronchial lymphatic. Osmotic reflection coefficients (sigma) for total protein were estimated using CL/CP = 1-sigma at high filtration rates, and permeability-surface area (PSf) products were fit to the data. The postischemic lung lymph data best fit average values of sigma = 0.68 and PSf = 0.073 ml X min-1 X 100 g-1 wet weight. There were no significant differences in lymph protein or water clearances between the pre- and postischemic increased Pla states or for myocardial ischemia compared with control values for the experimental preparation. Levels of 6-ketoprostaglandin F1 alpha, a degradation product of prostacyclin, increased by 10- to 14-fold above preischemic values in pulmonary lymph, and there was a significant increase in pulmonary vascular resistance during ischemia. Extravascular lung water was not increased above that attributed to the increased Pla alone. These data indicate no significant increase in pulmonary microvascular permeability to plasma proteins during myocardial ischemia.

Mental status outcomes following carotid endarterectomy: a six-month analysis

Fifty-one male and two female patients were divided into the following three groups: (a) patients with symptomatic carotid artery disease who received carotid endarterectomies, (b) patients with symptomatic carotid artery disease who either declined or were not candidates for carotid endarterectomies, and (c) patients who received a surgical procedure unrelated to cerebral functioning. The three groups were not significantly different in terms of age or educational level. The subjects were examined using the WAIS, Wechsler Memory Scale, Halstead-Reitan Neuropsychological Battery, Sickness Impact Profile, and Profile of Mood States. The assessments were conducted presurgery and repeated at a 6 month follow-up. The results of two-way analyses of variance revealed a significant trials effect for a majority of the variables, including the average impairment rating and the full scale WAIS IQ. However, significant group x trials interactions were not found for either the neuropsychological measures or the quality of life indices. The results did not support the conclusion of improved mental status or increased psychosocial well-being in patients who received carotid endarterectomies.

Neuronal ceroid lipofuscinosis. Diagnosis from peripheral blood smear

Neuronal ceroid lipofuscinosis (NCL), or Batten-Vogt's disease, is a disorder of young children who manifest visual, neurologic, and mental problems. The ophthalmologist can provide helpful diagnostic information by examining the fundus and performing an electroretinogram. In addition, diagnostic markers can be identified by examining circulating lymphocytes from a peripheral blood specimen with light and electron microscopy.

A kinetic investigation of the effects of adrenaline on 45Ca2+ exchange in isolated hepatocytes at different Ca2+ concentrations, at 20 degrees C and in the presence of inhibitors of mitochondrial Ca2+ transport

The effects of adrenaline on 45Ca2+-exchange curves for isolated hepatocytes incubated under various steady-state conditions were investigated. Kinetic analysis showed that the simplest compartment configuration consistent with each set of data was a series configuration of a three-compartment closed system comprising compartment 1 (C1), the extracellular medium, and two kinetically distinct compartments of cellular exchangeable Ca2+, C2 and C3 (C1 = C2 = C3). Subcellular fractionation of hepatocytes labelled with 45Ca2+ at 0.1 mM-Ca2+ indicated that C3 includes exchangeable Ca2+ in the mitochondria and endoplasmic reticulum. The following results were obtained from experiments conducted at 37 degrees C at five different extracellular Ca2+ concentrations. For both untreated and adrenaline-treated cells, plots of the flux from C1 to C2 as a function of the extracellular Ca2+ concentration were best described by straight lines consistent with Ca2+ influx across the plasma membrane being a diffusion process. Adrenaline increased the value of the permeability constant for Ca2+ influx by 40%. For untreated cells, plots of the flux between C2 and C3 as a function of the concentrations of Ca2+ in these compartments approached a plateau at high Ca2+ concentrations. Adrenaline caused a 3-fold increase in the concentration of Ca2+ that gives half-maximal rate of Ca2+ transport from C2 to C3. At 1.3 mM extracellular Ca2+, a decrease in incubation temperature from 37 degrees C to 20 degrees C decreased the quantity of Ca2+ in C3 and the flux and fractional transfer rates for the transport of Ca2+ between C2 and C3. At 20 degrees C adrenaline increased the quantity of Ca2+ in C3 and the fractional transfer rates for the transfer of Ca2+ from C1 to C2, and from C2 to C3. At 37 degrees C and 2.4 mM extracellular Ca2+, antimycin A plus oligomycin decreased the quantity of Ca2+ in C3 and increased the fractional transfer rate for the transport of Ca2+ from C3 to C2. In the presence of antimycin A and oligomycin, adrenaline did not increase the quantity of Ca2+ in C2 or the flux and fractional transfer rate for the transport of Ca2+ from C1 to C2, whereas these parameters were increased in the absence of the inhibitors.

The effects of oxygen radicals on pulmonary edema formation

This article is a review of the current literature concerning the possible involvement of oxygen radicals in the development of pulmonary edema. The article focuses on changes in capillary endothelium caused by many different imposed experimental conditions that may be related to the generation of O2, OH. or H2O2. Data from our laboratory show that scavengers such as superoxide dismutase, dimethylsulfoxide, and catalase as well as leukocyte depletion provide partial protection to the very caustic alpha-naphthylthiourea. The literature concerning the possible involvement of leukocyte or tissue generation of oxygen radicals in the various forms of pulmonary edema is combined into a simple model that may explain why pathologic tissues show variable responses to compounds that should either scavenge the oxygen radicals or prevent leukocyte involvement.

Comparison of isogravimetric and venous occlusion capillary pressures in isolated dog lungs

Venous occlusion capillary pressures (Pcv) were simultaneously compared with isogravimetric capillary pressures (PcI) in the same isolated perfused dog lung preparations. For 26 determinations, PcI averaged 1.23 +/- 0.22 (SE) mmHg higher than Pcv. However, the two measurements of capillary pressure were highly correlated (r = 0.99), and the following regression equation was obtained: Pcv = 1.12 PcI - 2.1. Pcv could be easily measured several times in the same preparation, either by total venous occlusion or regional venous occlusion using a Swan-Ganz balloon catheter. In addition, Pcv did not require an isogravimetric state for its determination. These data suggest that the major sites of filtration and vascular capacitance in the pulmonary circulation reside in the microvessels and that the more easily determined Pcv is an adequate measure of the average capillary filtration pressure in the lungs.

Perturbation of sodium-lithium countertransport in red cells

The rate of sodium-lithium countertransport in red cells is thought to be determined by inheritance and to be constant over years in a given person. We have found that the rate is influenced acutely by ultrafiltration and by hemodialysis. In seven patients with endstage renal disease secondary to essential hypertension, the mean rate of sodium-lithium countertransport (+/- S.E.M.) was reduced from 0.18 +/- 0.02 to 0.09 +/- 0.01 mmol per liter of cells per hour (P less than 0.02) by ultrafiltration and from 0.22 +/- 0.03 to 0.12 +/- 0.03 mmol per liter per hour (P less than 0.001) by hemodialysis. When patients' red cells obtained before dialysis were incubated with plasma obtained afterward, the rate of countertransport fell, and when red cells obtained after dialysis were incubated with plasma obtained beforehand, the rate returned to normal. Whereas the rate in red cells from normal subjects was reduced after incubation in post-dialysis plasma from patients, predialysis plasma from the same patients had no such effect. We conclude that the rate of the countertransport system of red cells is dependent on a dialyzable plasma factor.

Volume-responsive sodium movements in dog red blood cells

As dog red blood cells are shrunken in vitro, their sodium permeability increases progressively. Some new features of this volume-responsive transport process are described. Retardation of sodium movements in shrunken cells occurs when chloride is replaced by the more conductive anions: nitrate or thiocyanate. Micromolar concentrations of amiloride or quinidine inhibit the increment of sodium flux associated with a reduction in cell volume. In the presence of a large outwardly directed sodium gradient, dog red blood cells can progressively alkalinize the medium in which they are suspended. This pH change is stimulated by cell shrinkage, reversed by cell swelling, retarded when chloride is replaced by nitrate or thiocyanate, and inhibited by micromolar concentrations of amiloride or quinidine. The similarities between the shrinkage-associated sodium flux and the alkalinization phenomenon suggest that the mechanism responsible for increased sodium permeability in shrunken cells can be made to operate as a sodium-hydrogen exchanger.