Resistance Training-Induced Acute Hypoalgesia in Women With Persistent Pain After Breast Cancer Treatment.

ABSTRACT: Fogh Rasmussen, GH, Madeleine, P, Arroyo-Morales, M, Voigt, M, and Kristiansen, M. Resistance training-induced acute hypoalgesia in women with persistent pain after breast cancer treatment. J Strength Cond Res 37(3): e16-e24, 2023-The aim of this study was to determine whether a single bout of resistance training (RT) produces acute exercise-induced hypoalgesia (EIH) in breast cancer survivors (BCS) suffering from persistent pain ≥1.5 years after treatment. Twenty individuals with self-reported pain ≥3 on a 0-10 Numerical Rating Scale after treatment for breast cancer completed 3 experimental sessions, (a) familiarization; (b) 1 repetition maximum (1RM) normalization, and (c) training, consisting of 3 sets of 10 repetitions at 60% of 1 repetition maximum. Pressure pain thresholds (PPTs) were measured before and after training for the dorsal and ventral shoulder regions of the affected side. Movement-evoked pain (MEP) and rating of perceived exertion (RPE) were collected immediately after each set. A p -value less than 0.05 was considered statistically significant. The results demonstrated a significant increase in PPTs of the ventral shoulder region after a single bout of RT ( p ≤ 0.05), indicating a localized analgesic response for this area. By contrast, no change was detected in PPTs on the dorsal shoulder region. No significant differences were found in MEP between sessions despite a significant increase in load and RPE during 1RM assessment ( p ≤ 0.05), indicating that MEP was not affected by increase in absolute and relative intensity. In conclusion, a single bout of submaximal RT reduced PPTs for the ventral shoulder region of BCS with persistent pain after treatment and was well tolerated. Hence, RT may be a useful therapeutic tool for managing persistent pain after breast cancer treatment in clinical practice.

Multi-vitamin supplementation blunts the circulating IL-6/IL-10 ratio increase after knee arthroplasty: A randomized, double-blind, placebo controlled study.

Circulating interleukin (IL)-6 and IL-10 concentrations can be elevated following the surgically induced trauma of total knee arthroplasty (TKA). An exaggerated increase in IL-6 relative to IL-10 (i.e., IL-6/IL-10 ratio) associates with trauma severity and indicative of pro-inflammatory predominance. Although various vitamins and minerals alter individual IL-6 and IL-10 concentrations in the blood, surprisingly, it is unknown if a multi-vitamin supplement alters the IL-6/IL-10 ratio during the systemic inflammatory response following TKA. The objective of this study was to identify if a multi-vitamin with mineral supplement taken prior to alters the circulating IL-6/IL-10 ratio following total knee arthroplasty (TKA). This study consisted of a randomized, double-blind, placebo controlled design. Twenty-one subjects undergoing elective, primary, unilateral TKA were randomly assigned to a placebo (PL, n = 11) or multi-vitamin with mineral supplement (MV, n = 10). Supplements were taken daily starting approximately 6-weeks prior to surgery. Supplements were not taken the day of surgery or during inpatient care 2-days after surgery. Circulating IL-6, IL-10, high-sensitivity CRP (hsCRP), vitamin C (ascorbic acid (AA)), vitamin D (25-hydroxyvitamin D (25(OH)D)), and vitamin E (α-tocopherol (αT)) concentrations were measured in fasting blood draw samples obtained ~6-weeks prior to surgery (and before starting supplementation), the morning of surgery, and 24-hours and 48-hours after surgery. MV supplementation tended to increase serum 25(OH)D and significantly increased plasma AA and plasma αT before surgery without mitigating the post-operative IL-6 and hsCRP increases. However, the post-operative increase in the serum IL-6/IL-10 ratio after surgery was significantly blunted in the MV group. Based on these findings, we conclude that a multi-vitamin with mineral supplement taken daily for several weeks before surgery might reduce the pro-inflammatory predominance after TKA. Future research confirming or refuting the novel data presented herein is needed.

Muscular-based and patient-reported outcomes differentially associate with circulating superoxide dismutases and cytokines in knee osteoarthritis.

Muscular (i.e., quadriceps) weakness contributes to disease progression and precedes the appearance of patient-reported symptoms, such as pain and perceived physical dysfunction, in knee osteoarthritis (OA). It is unknown, however, if muscular-based and patient-reported outcomes differentially associate with systemic biomarkers reflective of the local mediators in knee OA. The purpose of this study was to identify if muscular-based and patient-reported outcomes differentially associate with circulating superoxide dismutase (SOD) and cytokines in knee OA. Subjects (n = 29) with pain, muscular weakness, and radiographic evidence (Kellgren-Lawrence grade ≥2) of knee OA in the involved (INV) leg were included in this study. Serum Cu/Zn and Mn SOD and cytokine concentrations were measured in fasting blood samples. Pain and physical dysfunction were subjectively assessed and muscle strength (i.e., peak isometric force and torque, and peak isokinetic-concentric knee-extension and -flexion torques) was determined unilaterally in the INV and non-involved (NI) legs. Peak isometric and peak isokinetic-concentric knee-flexion torques in the INV leg correlated with serum Cu/Zn SOD (both p < 0.05). Peak isometric force and torque and peak isokinetic-concentric knee-extension and -flexion torques in the INV leg correlated with serum Mn SOD (all p < 0.05). Pain and dysfunction inversely associated with serum IL-1ß, IL-4, IL-5, IL-12, IL-13, and/or IFN-γ (p < 0.05). Neither SOD associated with pain or dysfunction, and none of the cytokines associated with muscular-based outcomes. We conclude that common outcome measures used in the clinical evaluation of OA differentially associate with circulating SOD and cytokines.

Tourniquet use during total knee arthroplasty does not modulate the neutrophil-to-lymphocyte ratio, pain, or activity.

The purpose of our study was to identify the influence of tourniquet use during total knee arthroplasty (TKA) on the neutrophil-to-lymphocyte ratio (NLR) shortly after surgery and patient-reported outcomes (pain and physical activity) from outpatient physical therapy. This retrospective study consisted of 104 subjects who underwent primary unilateral TKA (51 subjects with and 53 subjects without tourniquet assistance) between 2010 and 2012. The NLR was calculated from the absolute neutrophil and lymphocyte counts obtained immediately before and after (1 and 2 days) knee arthroplasty. The Knee Outcome Survey (KOS) of Activities of Daily Living and numeric pain scores collected at the first [33.0 (34.2) days after surgery] and last [85.5 (40.7) days after surgery] outpatient physical therapy visits were extracted from an electronic database. The NLR, pain, and KOS score were not significantly (all p > 0.05) different with tourniquet use. Based on these findings, we conclude that tourniquet use during TKA neither increases systemic inflammation shortly after surgery nor impairs patient-reported outcomes obtained during outpatient physical therapy. LEVEL OF EVIDENCE: IV.

Circulating interleukin-6 is not altered while γ-tocopherol is increased in subjects scheduled for knee surgery with low vitamin D.

The purpose of this study was to identify if circulating interleukin (IL)-6 and γ-tocopherol (γT) fluctuate with vitamin D status in subjects with an underlying knee joint injury or disease. We hypothesized that low vitamin D associates with an increase in plasma γT while serum IL-6 remains unchanged in subjects with an underlying knee joint trauma or disease. Fifty-four subjects scheduled to undergo primary, unilateral anterior cruciate ligament reconstructive surgery (ACL; n=27) or total knee arthroplasty (TKA; n=27) were studied. Circulating γT, α-tocopherol (αT), lipids (cholesterol and triglycerides), IL-6, and 25-hydroxyvitamin D (25(OH)D) were measured in fasting blood samples obtained prior to surgery. Subjects were classified as vitamin D deficient, insufficient, or sufficient if they had a serum 25(OH)D concentration <50, 50-75, or >75nM, respectively. The majority (57%) of the subjects possessed a serum 25(OH)D less than 50nM. Circulating cholesterol, triglycerides, and IL-6 were not significantly (all p>0.05) different between vitamin D status groups. However, lipid corrected αT was significantly (p<0.05) decreased and both lipid- and non-lipid-corrected plasma γT concentrations were significantly (both p<0.05) increased with low serum 25(OH)D (i.e., <50nM). A significant (p<0.05) multi-variate analysis revealed that an increase in plasma γT per lipids was significantly (p<0.05) predicted by a decrease in serum 25(OH)D but not by a decrease in plasma αT per lipids. We conclude that low vitamin D associates with an increase in plasma γT but not IL-6 in subjects with an underlying joint injury or disease.

Is there a link between the neutrophil-to-lymphocyte ratio and venous thromboembolic events after knee arthroplasty? A pilot study.

BACKGROUND: This study aimed to identify (1) if the postoperative increase in the neutrophil-to-lymphocyte ratio (NLR) is different between contrasting knee arthroplasty procedures, and (2) if the NLR predicts venous thromboembolism (VTE) after total knee arthroplasty (TKA). MATERIALS AND METHODS: To address the first objective, we retrospectively studied patients who underwent primary unilateral TKA (n = 111) or unicompartmental knee arthroplasty (UKA; n = 74) between 2009 and 2012. Patients who required a blood transfusion, underwent autologous blood salvage, experienced any postoperative complication (such as VTE), or were re-admitted >90 days were excluded from analysis. For the second objective, we retrospectively identified patients (cases, n = 10) who underwent primary unilateral TKA between 2010 and 2012 and developed postoperative VTE (deep venous thrombosis, pulmonary embolism, or both) during inpatient care (postoperative day 1 or day 2). Cases were matched to surgeon, gender, body mass index, age, and date of surgery controls (n = 20) who underwent primary unilateral TKA without developing VTE before patient discharge. The NLR was calculated from the neutrophil and lymphocyte counts extracted from pre- and postoperative (day 1 and day 2) blood chemistry records. RESULTS: On postoperative day 1, the NLR increase was exacerbated (p = 0.02) following TKA compared to UKA and predicted (p = 0.02) the occurrence of VTE in TKA patients prior to hospital discharge. CONCLUSION: We conclude that the NLR increase is greater following TKA compared to UKA and could serve as a matrix to predict or identify a patient susceptible of sustaining VTE after TKA. LEVEL OF EVIDENCE: 3.

Serum cytokines are increased and circulating micronutrients are not altered in subjects with early compared to advanced knee osteoarthritis.

Knee osteoarthritis (OA) is a leading cause of physical disability. At the early stage of knee OA, the increase in synovial fluid cytokine concentrations could contribute to the pathogenesis of OA by degrading articular cartilage. It is unknown, however, if inflammatory cytokines increase systemically at the early or advanced stage of knee OA. The systemic increase of inflammatory cytokines could be detrimental to the endogenous status of micronutrients that protect against excessive inflammation and cytokine-mediated events. The purpose of this study was to test the hypothesis that an increase in serum cytokines associate with a decrease in circulating micronutrients in subjects with early compared to advanced knee OA. Advanced knee OA subjects (n=14) displayed radiographic, pain, and muscular weakness symptoms of knee OA. Early knee OA subjects (n=14) were matched (age, gender, and body mass index) to the advanced OA group and displayed one or two of the aforementioned symptoms of knee OA. Inflammatory cytokines, vitamins C (ascorbic acid), D (25-hydroxyvitamin D), and E (α- and γ-tocopherols), and ß-carotene were measured in fasting blood samples. In the early OA group, serum tumor necrosis factor (TNF)-α, interleukin (IL)-5, IL-6, IL-12, and IL-13 concentrations were significantly (all p<0.05) increased. Circulating ascorbic acid, 25-hydroxyvitamin D, α- and γ-tocopherol's, and ß-carotene concentrations were not significantly different between groups. Based on these preliminary results, we conclude that the systemic increase of inflammatory cytokines is not associated with a decrease in circulating micronutrients in subjects with early compared to advanced knee OA.

Pain sensitivity and shoulder function among breast cancer survivors compared to matched controls: a case-control study.

OBJECTIVE: Persistent pain and loss of shoulder function are common adverse effects to breast cancer treatment, but the extent of these issues in comparison with healthy controls is unclear for survivors beyond 1.5 years after treatment. The purpose of this study was to benchmark differences in pressure pain thresholds (PPT), maximal isokinetic muscle strength (MIMS), and active range of motion (ROM) of females with persistent pain ≥1.5 years after breast cancer treatment (BCS) compared with pain-free matched controls (CON), and examine the presence of movement-evoked pain (MEP) during assessment of MIMS. METHODS: The PPTs of 18 locations were assessed using a pressure algometer and a numeric rating scale was used to assess intensity of MEP. Active ROM and MIMS were measured using a universal goniometer and an isokinetic dynamometer, respectively. RESULTS: A two-way analysis of variance revealed that PPTs across all locations, MIMS for horizontal shoulder extension/flexion and shoulder adduction, active ROM for shoulder flexion, horizontal shoulder extension, shoulder abduction, and external shoulder rotation were significantly lower for BCS compared with CON (P < 0.05). MEP was significantly higher for BCS and MEP intensity had a significant, negative correlation with PPTs (P < 0.01). DISCUSSION/CONCLUSION: BCS with persistent pain ≥1.5 years after treatment demonstrates widespread reductions in PPTs and movement-specific reductions in MIMS and active ROM of the affected shoulder, along with MEP during physical performance assessment. IMPLICATIONS FOR CANCER SURVIVORS: BCS with persistent pain ≥1.5 years after treatment shows signs of central sensitization and may benefit from individualized rehabilitation.

Circulating IL-10 is compromised in patients predisposed to developing and in patients with severe knee osteoarthritis.

The purpose of this investigation was to identify if serum interleukin (IL)-10 and tumor necrosis factor (TNF)-α concentrations and their ratio (IL-10/TNF-α) are altered in subjects predisposed to developing knee osteoarthritis following ligamentous injury and in those with severe knee osteoarthritis. Serum IL-10 and TNF-α concentrations were measured in four groups of subjects (n = 218): (1) reportedly-healthy and non-injured control subjects (CON; n = 92), (2) subjects scheduled to undergo anterior cruciate ligament surgery (ACL; n = 42), (3) non-surgical subjects with knee osteoarthritis (OA; n = 60), and (4) subjects with knee osteoarthritis scheduled to undergo total knee arthroplasty (TKA; n = 24). X-ray images were used to grade the severity of knee osteoarthritis. Serum IL-10 and the serum IL-10/TNF-α ratio were significantly lower while serum TNF-α was not significantly perturbed with severe compared to moderate knee osteoarthritis (i.e., Kellgren-Lawrence grade 4 vs. 3, respectively). Serum IL-10 was significantly lower in the absence of serum TNF-α alterations in the ACL group. We conclude that serum IL-10 concentrations are compromised in subjects predisposed to developing knee osteoarthritis following ligamentous trauma and in subjects with radiographic evidence of severe knee osteoarthritis.

Absolute and relative reliability of pain sensitivity and functional outcomes of the affected shoulder among women with pain after breast cancer treatment.

OBJECTIVE: Breast cancer survivors (BCS) are often characterized by decreased pressure pain thresholds (PPT), range of motion (ROM) and strength in and around the shoulder affected by the treatment. This intra-rater reliability study was to establish the relative and absolute reliability of PPT's, active ROM and maximal isokinetic muscle strength (MIMS) of the affected shoulder in BCS with persistent pain after treatment. METHODS: Twenty-one BCS participated in the study. The PPTs of 17 locations and pain intensity were assessed using a pressure algometer and a numeric rating scale. The ROM was measured using a universal goniometer and MIMS was measured using an isokinetic dynamometer. Relative reliability was estimated using intra class correlation coefficient (ICC), and absolute reliability using standard error of measurement (SEM). Minimum detectable change (MDC) was calculated from SEM. RESULTS: The ICCs for PPTs ranged from 0.88-0.97, with SEM values ranging from 12.0 to 28.2 kPa and MDC ranging from 33.2 to 78.2 kPa. The ICCs for ROM ranged from 0.66-0.97, with SEM values ranging from 3.0 to 7.5° and MDC ranging from 8.4 to 20.8°. Finally, ICCs for MIMS ranged from 0.62-0.92, with SEM values ranging from 0.03 to 0.07 Nm/Kg FFM and MDC ranging from 0.09 to 0.19 Nm/kg FFM. CONCLUSION: The results of this study indicate that PPTs, ROM and MIMS can be measured reliably on the affected shoulder in BCS with pain after treatment. This offer the possibility of using these measures to assess the effectiveness of interventions in this population.

Interaction of the Pseudomonas aeruginosa secretory products pyocyanin and pyochelin generates hydroxyl radical and causes synergistic damage to endothelial cells. Implications for Pseudomonas-associated tissue injury.

Pyocyanin, a secretory product of Pseudomonas aeruginosa, has the capacity to undergo redox cycling under aerobic conditions with resulting generation of superoxide and hydrogen peroxide. By using spin trapping techniques in conjunction with electron paramagnetic resonance spectrometry (EPR), superoxide was detected during the aerobic reduction of pyocyanin by NADH or porcine endothelial cells. No evidence of hydroxyl radical formation was detected. Chromium oxalate eliminated the EPR spectrum of the superoxide-derived spin adduct resulting from endothelial cell exposure to pyocyanin, suggesting superoxide formation close to the endothelial cell plasma membrane. We have previously reported that iron bound to the P. aeruginosa siderophore pyochelin (ferripyochelin) catalyzes the formation of hydroxyl free radical from superoxide and hydrogen peroxide via the Haber-Weiss reaction. In the present study, spin trap evidence of hydroxyl radical formation was detected when NADH and pyocyanin were allowed to react in the presence of ferripyochelin. Similarly, endothelial cell exposure to pyocyanin and ferripyochelin also resulted in hydroxyl radical production which appeared to occur in close proximity to the cell surface. As assessed by 51Cr release, endothelial cells which were treated with pyocyanin or ferripyochelin alone demonstrated minimal injury. However, endothelial cell exposure to the combination of pyochelin and pyocyanin resulted in 55% specific 51Cr release. Injury was not observed with the substitution of iron-free pyochelin and was diminished by the presence of catalase or dimethyl thiourea. These data suggest the possibility that the P. aeruginosa secretory products pyocyanin and pyochelin may act synergistically via the generation of hydroxyl radical to damage local tissues at sites of pseudomonas infection.

Inhibition of G2/M progression in Schizosaccharomyces pombe by a mutant calmodulin kinase II with constitutive activity.

Intracellular signaling by the second messenger Ca2+ through its receptor calmodulin (CaM) regulates cell function via the activation of CaM-dependent enzymes. Previous studies have shown that cell cycle progression at G1/S and G2/M is sensitive to intracellular CaM levels. However, little is known about the CaM-regulated enzymes involved. Protein phosphorylation has been shown to be important for cell-cycle regulation. Because CaM regulates several protein kinases, and at least one protein phosphatase, our studies are focusing on the roles of these enzymes within the cell cycle. As an initial approach to this problem, cDNAs encoding either normal or mutant calcium/calmodulin kinase II (CaMKII) have been expressed in Schizosaccharomyces pombe. The results show that overexpression of a constitutively active mutant CaMKII caused cell-cycle arrest in G2. Arrest was associated with a failure to activate the p34/cdc2 protein kinase. Expression of the mutant CaMKII in strains of S. pombe with altered timing of mitosis revealed that this effect is not mediated either by cdc25+ or wee1+, suggesting that CaMKII may regulate G2/M progression by another mechanism.

Bicarbonate and phosphate ions protect transferrin from myeloperoxidase-mediated damage.

Exposure to hypochlorous acid (HOCl), the main product of the reaction of neutrophil myeloperoxidase (MPO), H2O2, and Cl-, reportedly decreases apotransferrin's iron binding capacity. Optimal transferrin iron binding requires the coexistent binding of anions such as bicarbonate (HCO3-) near the protein's two iron binding sites. Recently, we found that if HCO3- was also present during HOCl exposure, apotransferrin retained its ability to inhibit iron-catalyzed hydroxyl radical generation. Therefore, we examined apotransferrin iron binding capacity after exposure to the MPO/H2O2/I- system in the presence and absence of several anions (HCO3-, H2PO4, SO4(2-), and ClO4-) known to bind to apotransferrin. Although the MPO system decreased apotransferrin iron uptake to only 46% of the untreated apotransferrin control, apotransferrin treated in the presence of 1 mM HCO3- or H2PO4- retained 84 and 74%, respectively, of its iron binding capacity. Similar results were seen when apotransferrin was treated with NaOCl. These results could not be explained on the basis of a loss of MPO activity or scavenging of HOCl. In contrast, SO4(2-) and ClO4- were unable to prevent the MPO-mediated loss of apotransferrin iron binding capacity. NaOCl had no effect on the ability of transferrin to bind any of these anions, as assessed by the anion-induced change in apotransferrin absorbance spectrum. HCO3- but not H2PO4-, SO4(2-), or ClO4- decreased MPO-mediated oxidation (iodination) of apotransferrin. Under some conditions H2PO4- actually increased apotransferrin iodination. HCO3- and H2PO4- may protect apotransferrin from MPO-mediated oxidative damage by preventing selective oxidation of one or both iron binding sites. This process may allow transferrin to retain its iron binding function during MPO exposure in vivo.

Influence of the oral hypoglycemic agent linogliride (McN-3935) on insulin secretion from isolated rat islets of Langerhans.

The influence of a new orally effective hypoglycemic compound, linogliride (McN-3935), on insulin release from isolated perifused rat islets was investigated. At a concentration of 100 microM, linogliride was without effect on insulin secretion in the absence of glucose. While 5.5 mM glucose alone produced a weak secretagogue effect, the secretory response was dramatically (5- to 6-fold) increased by the addition of 100 microM linogliride. This concentration of linogliride did not affect the conversion of [5-3H]glucose to 3H2O, a measure of the rate of glycolysis by the islet. Insulin secretion in response to the combination of 100 microM linogliride and 5.5 mM glucose was abolished by the omission of extracellular calcium. Mannoheptulose (10 mM), an inhibitor of glucose phosphorylation and glucose-stimulated insulin secretion, markedly attenuated the insulinotropic effect of linogliride in parallel with reduced glucose usage. Paradoxically, in the presence of another metabolic inhibitor, 2-deoxyglucose (10 mM), the insulinotropic effect of linogliride (100 microM) in the presence of 5.5 mM glucose was not diminished despite the reduced glucose usage. Linogliride significantly increased the secretory response to other secretagogues, including 2.5 mM D-glyceraldehyde, 15 mM N-acetylglucosamine, 10 mM leucine, and 100 nM of the phorbol ester 12-O-tetradecanoylphorbol-13-acetate. These data suggest that linogliride amplifies a cellular signal generated during beta-cell activation by various stimulants.

An ultrastructural analysis of neurites in the basal lamina of capillaries in the chinchilla cochlear nucleus.

In an ultrastructural study of the chinchilla anteroventral cochlear nucleus (AVCN), we found innervated capillaries in the layer of granule cells that comprises the dorsolateral portion of the AVCN and forms a cap over the principal portion of the nucleus. In 66% of 215 capillaries we examined in the granule cell layer of various levels of the AVCN, we found structures having ultrastructural features of axons that (1) were within the brain parenchyma and were in direct contact with the pericapillary basal lamina, or (2) were separate fro, the adjacent neuropil and, often in the company of astrocytic processes, were completely enveloped by the pericapillary basal lamina. An analysis of serial sections confirmed that neurites within the pericapillary basal lamina were in continuity with neurites in the brain parenchyma. Most neurites within the basal lamina of capillaries were next to pericytes, but some neurites were next to endothelial cells. None of the neurites adjoining capillaries had the abundance of synaptic vesicles typical of autonomic vasomotor nerve endings and synaptic terminals. Consequently, they may be sensory, responding perhaps to changes in hydrostatic pressure or chemical composition of the blood or cerebrospinal fluid. However, we cannot exclude the possibility that neurites which accompany capillaries in the AVCN terminate elsewhere. In the AVCN the innervation of capillaries is restricted to the superficial layer of granule cells. In none of 177 capillaries of the principal portion of the AVCN did we find an example of a neurite in contact with the pericapillary basal lamina, a pericyte, or an endothelial cell, although it was sometimes necessary to examine specimens at various angles of tilt to confirm that the pericapillary glial sleeve was continuous. Furthermore, we found no innervated blood vessels among 266 capillaries examined in the granular and molecular layers of the cerebellar cortex.

Construction of SV40 deletion mutants and delimitation of the binding domain for heat shock protein to the amino terminus of large T-antigen.

SV40 large T-antigen (T-ag) mutants were generated using a cassette mutagenesis strategy and naturally occurring restriction sites. T-ag mutant constructs included internal in-frame deletions, frame-shift deletions that resulted in amino-terminal fragments, and internal initiation mutants that produced carboxy-terminal fragments; no foreign amino acids were introduced. The deletion mutants were stably expressed in BALB/c 3T3E cells and were analyzed for ability to bind heat shock cognate protein 70 using an ATP release assay of T-ag immunoprecipitates. Complex formation between heat shock protein and T-ag was independent of p53 involvement. The heat shock protein binding domain was narrowed to the amino-terminal 97 amino acids of T-ag, with the first 29 residues influencing the interaction. The amino-terminal domain of T-ag is important in both viral replication and cell transformation. We propose that the functional interactions of this highly interactive region of T-ag may be modulated by heat shock cognate protein 70.

Binding of iron and inhibition of iron-dependent oxidative cell injury by the "calcium chelator" 1,2-bis(2-aminophenoxy)ethane N,N,N',N'-tetraacetic acid (BAPTA).

A role for increases in intracellular calcium (Ca2+) has been suggested in the pathophysiology of various forms of oxidant-mediated cell injury. In recent studies, we found that iron bound to the Pseudomonas aeruginosa siderophore, pyochelin, augments oxidant-mediated endothelial cell injury by catalyzing the formation of hydroxyl radical (HO.). To investigate the role of Ca2+ in this process, the effects of two Ca2+ chelating agents, Fura-2 and 1,2-bis(2-aminophenoxy)ethane N,N,N',N'-tetraacetic acid (BAPTA), were assessed. BAPTA, but not Fura-2, was protective against H2O2/ferripyochelin-mediated injury. Subsequent data suggested that chelation of iron rather than Ca2+ by BAPTA was most likely responsible. Spectrophotometry demonstrated that both ferrous (Fe2+) and ferric (Fe3+) iron formed a complex with BAPTA. The affinity of BAPTA for the metals was Fe3+ > Ca2+ > Fe2+. BAPTA was found to decrease markedly iron-catalyzed production of HO. and/or ferryl species when analyzed by spin trapping. Although our results do not definitively prove that BAPTA protects endothelial cells from ferripyochelin-associated damage by chelating iron, these data indicate that caution must be exercised in utilizing protective effects of intracellular "Ca2+ chelating agents" as evidence for a role of alterations in cellular Ca2+ levels in experimental conditions in which iron-mediated oxidant production is also occurring.

An electron microscopic study of clinical Paget's disease of the nipple.

An ultrastructural study of the epidermis from eight patients with clinical Paget's disease of the nipple supports the epidermotropic theory. There was no evidence that the Paget's cells originated from keratinocytes. We propose the hypothesis that Paget's cells represent transformed ductal cells, from the subjacent lactiferous ducts of the nipple, which have migrated into the epidermis, either as neoplastic cells or as normal ductal cells with secondary in situ transformation in the epidermis.

Bronchoscopic airway evaluation facilitated by the laryngeal mask airway in pediatric patients.

The laryngeal mask airway (LMA) was introduced for clinical use in 1988. It represents a new concept in airway management. Its role has been described as filling the gap between tracheal intubation and the anesthesia face mask. It is inserted without direct visualization into the hypopharynx and when properly positioned forms a low pressure seal around the laryngeal inlet, allowing spontaneous as well as gentle positive pressure ventilation. Since its introduction, its indications and applications in anesthesia practice have increased. Although initially used as a means of delivering anesthesia and obviating the need for holding a mask on the patient, its position directly over the laryngeal inlet makes it a useful guide during flexible bronchoscopy. We report our experience in six pediatric patients and describe an anesthetic technique for bronchoscopy using the LMA for general anesthesia with spontaneous ventilation.

Isotopic abundance measurements on solid nuclear-type samples by glow discharge mass spectrometry.

A double-focusing Glow Discharge Mass Spectrometer (GDMS) installed in a glovebox for nuclear sample screening has been employed for isotopic measurements. Isotopic compositions of zirconium, silicon, lithium, boron, uranium and plutonium which are elements of nuclear concern have been determined. Interferences arising from the matrix sample and the discharge gas (Ar) for each of these elements are discussed. The GDMS results are compared with those from Thermal Ionization Mass Spectrometry (TIMS). For boron and lithium at microg/g-ng/g levels, the two methods gave results in good agreement. In samples containing uranium the isotopic composition obtained by GDMS was in agreement with those from TIMS independently of the enrichment. Attempts for the determination of plutonium isotopic composition were also made. In this case, due to the interferences of uranium at mass 238 and americium at mass 241, the GDMS raw data are complementary with those values obtained from physical non-destructive techniques.