Biomedical subjects

S E Jordan

Publications and source records attributed to S E Jordan.

At least 19 recordsLinked to original sources

PubMed2001

Heading and head injuries in soccer.

In the world of sports, soccer is unique because of the purposeful use of the unprotected head for controlling and advancing the ball. This skill obviously places the player at risk of head injury and the game does carry some risk. Head injury can be a result of contact of the head with another head (or other body parts), ground, goal post, other unknown objects or even the ball. Such impacts can lead to contusions, fractures, eye injuries, concussions or even, in rare cases, death. Coaches, players, parents and physicians are rightly concerned about the risk of head injury in soccer. Current research shows that selected soccer players have some degree of cognitive dysfunction. It is important to determine the reasons behind such deficits. Purposeful heading has been blamed, but a closer look at the studies that focus on heading has revealed methodological concerns that question the validity of blaming purposeful heading of the ball. The player's history and age (did they play when the ball was leather and could absorb significant amounts of water), alcohol intake, drug intake, learning disabilities, concussion definition and control group use/composition are all factors that cloud the ability to blame purposeful heading. What does seem clear is that a player's history of concussive episodes is a more likely explanation for cognitive deficits. While it is likely that the subconcussive impact of purposeful heading is a doubtful factor in the noted deficits, it is unknown whether multiple subconcussive impacts might have some lingering effects. In addition, it is unknown whether the noted deficits have any affect on daily life. Proper instruction in the technique is critical because if the ball contacts an unprepared head (as in accidental head-ball contacts), the potential for serious injury is possible. To further our understanding of the relationship of heading, head injury and cognitive deficits, we need to: learn more about the actual impact of a ball on the head, verify the exposure to heading at all ages and competitive levels, determine stable estimates of concussive injury rates across the soccer spectrum, conduct prospective longitudinal studies on soccer players focusing on exposure, injury and cognition, and determine the minimum safe age to begin instruction on the skill of heading. Only then will we be able to speak with some authority on the issue of heading and head injuries in soccer.

Biomechanical Phenomena↗

PubMed2000

Selective botulinum chemodenervation of the scalene muscles for treatment of neurogenic thoracic outlet syndrome.

Patients with thoracic outlet syndrome (TOS) who improve temporarily after anesthetic blockade of the anterior scalene muscles have been shown to improve after ultimate surgical decompressions at the interscalene triangle. Anesthetic blockade of the scalene muscles, even with the addition of steroids, however, rarely produces any prolonged relief as patients are awaiting definitive surgery. The present study was undertaken to determine if more effective and prolonged relief might be obtained with electrophysiologically and fluoroscopically guided selective injection of the scalene muscles with botulinum toxin, which has been used in the past for treating conditions associated with spasm of cervical muscles. In 14 of 22 patients (64%) with a clinical diagnosis of TOS, there was more than a 50% reduction of symptoms measured by a 101-point scale for at least 1 month after botulinum chemodenervation of the scalene muscles. Only 4 of the 22 patients (18%) had a 50% reduction of symptoms for at least 1 month after injection with lidocaine and steroids. In no patient were the results of lidocaine and steroid injection superior to botulinum chemodenervation. Chemodenervation had a mean duration of effect of 88 days. No significant side effects were encountered with botulinum chemodenervation except for mild transient dysphagia in two cases. These results appear to demonstrate that botulinum chemodenervation of the scalene muscles may be helpful in alleviating symptoms in patients with TOS awaiting definitive surgical decompression.

Botulinum Toxins, Type A↗

PubMed1999

Intracellular calcium puffs in osteoclasts.

We studied intracellular calcium ([Ca(2+)](i)) in acid-secreting bone-attached osteoclasts, which produce a high-calcium acidic extracellular compartment. Acid secretion and [Ca(2+)](i) were followed using H(+)-restricted dyes and fura-2 or fluo-3. Whole cell calcium of acid-secreting osteoclasts was approximately 100 nM, similar to cells on inert substrate that do not secrete acid. However, measurements in restricted areas of the cell showed [Ca(2+)](i) transients to 500-1000 nM consistent with calcium puffs, transient (millisecond) localized calcium elevations reported in other cells. Spot measurements at 50-ms intervals indicated that puffs were typically less than 400 ms. Transients did not propagate in waves across the cell in scanning confocal measurements. Calcium puffs occurred mainly over regions of acid secretion as determined using lysotracker red DND99 and occurred at irregular periods averaging 5-15 s in acid secreting cells, but were rare in lysotracker-negative nonsecretory cells. The calmodulin antagonist trifluoperazine, cell-surface calcium transport inhibitors lanthanum or barium, and the endoplasmic reticulum ATPase inhibitor thapsigargin had variable acute effects on the mean [Ca(2+)](i) and puff frequency. However, none of these agents prevented calcium puff activity, suggesting that the mechanism producing the puffs is independent of these processes. We conclude that [Ca(2+)](i) transients in osteoclasts are increased in acid-secreting osteoclasts, and that the puffs occur mainly near the acid-transporting membrane. Cell membrane acid transport requires calcium, suggesting that calcium puffs function to maintain acid secretion. However, membrane H(+)-ATPase activity was insensitive to calcium in the 100 nM-1 microM range. Thus, any effects of calcium puffs on osteoclastic acid transport must be indirect.

Adenosine Triphosphate↗

PubMed1999

Nitric oxide regulation of cGMP production in osteoclasts.

Bone resorption by osteoclasts is modified by agents that affect cyclic guanosine monophosphate (cGMP), but their relative physiological roles, and what components of the process are present in osteoclasts or require accessory cells such as osteoblasts, are unclear. We studied cGMP regulation in avian osteoclasts, and in particular the roles of nitric oxide and natriuretic peptides, to clarify the mechanisms involved. C-type natriuretic peptide drives a membrane guanylate cyclase, and increased cGMP production in mixed bone cells. However, C-type natriuretic peptide did not increase cGMP in purified osteoclasts. By contrast, osteoclasts did produce cGMP in response to nitric oxide (NO) generators, sodium nitroprusside or 1-hydroxy-2-oxo-3,3-bis(3-aminoethyl)-1-triazene. These findings indicate that C-type natriuretic peptide and NO modulate cGMP in different types of bone cells. The activity of the osteoclast centers on HCI secretion that dissolves bone mineral, and both NO generators and hydrolysis-resistant cGMP analogues reduced bone degradation, while cGMP antagonists increased activity. NO synthase agonists did not affect activity, arguing against autocrine NO production. Osteoclasts express NO-activated guanylate cyclase and cGMP-dependent protein kinase (G-kinase). G-kinase reduced membrane HCI transport activity in a concentration-dependent manner, and phosphorylated a 60-kD osteoclast membrane protein, which immunoprecipitation showed is not an H+-ATPase subunit. We conclude that cGMP is a negative regulator of osteoclast activity. cGMP is produced in response to NO made by other cells, but not in response to C-type natriuretic peptide. G-kinase modulates osteoclast membrane HCI transport via intermediate protein(s) and may mediate cGMP effects in osteoclasts.

Acids↗

PubMed1999

Parathyroid hormone-regulated production of stem cell factor in human osteoblasts and osteoblast-like cells.

We investigated stem cell factor (SCF) expression in osteoblasts because mast cells, which occur ectopically in hyperparathyroid bone, are induced by SCF. Nontransformed osteoblasts and Saos2 or MG63 cells expressed SCF in response to PTH. Western analysis showed only large, cell-associated isoforms, Mrs approximately 40-48 kD. Transfection of MG63 cells with plasmids expressing antisense SCF mRNA eliminated immunoreactive SCF. Sequencing osteoblast SCF cDNAs showed that exon 6 was omitted. mRNAs without exon 6 produce membrane-associated SCF isoforms in rodents, suggesting that human SCFs are processed similarly. The major osteoblastic SCF mRNA, approximately 5 kB, was augmented by PTH. Neither protein or mRNA was increased by vitamin D, however, 6-7 kB transcripts were predominant in other tissues but not detectable in osteoblasts. We conclude that osteoblasts express SCF in response to PTH, with mRNA and protein processing differences relative to other cells. SCF stimulates osteoclasts, suggesting that PTH-induced osteoblastic SCF functions to accelerate bone turnover. Mast cells may occur due to SCF overexpression at extreme PTH levels.

Amino Acid Sequence↗

PubMed1998

Diagnosis of thoracic outlet syndrome using electrophysiologically guided anterior scalene blocks.

There is no "gold standard" for diagnosing thoracic outlet compression syndrome (TOS), however, anesthetic blocks of the anterior scalene muscle (ASM) have been used as a means of predicting which patients may benefit from surgical decompression. The standard technique of using surface landmarks often results in inadvertent somatic block and sympathetic block because there is no reliable verification of needle tip localization. The present study was undertaken to determine if needle tip localization can be improved by using electrophysiological guidance. ASM blocks were performed for patients with a diagnosis of possible TOS. An insulated hypodermic needle was inserted into the ASM which was identified during electromyogram (EMG) activation maneuvers. Stimulation was performed to make sure that the needle tip was not in the brachial plexus. Local anesthetic was instilled and the intensity of pain induced by TOS stress maneuvers was compared to pain ratings obtained after control injections. The ASM could be identified electromyographically in all 122 cases. There were no instances of inadvertent somatic block nor sympathetic block. Of 38 patients who underwent surgical decompression of the thoracic outlet, 30 of 32 (94%) with a positive block had a good outcome compared with 3 of 6 (50%) who underwent surgery in spite of a negative block. Electrophysiological guidance facilitates accurate needle tip placement in the performance of ASM blocks; the results of these blocks appear to correlate with surgical outcomes.

Adult↗

PubMed1998

Are brain injuries a significant problem in soccer?

This article examines the types of forces that the brain is subjected to in soccer, secondary to both acute brain injury and repetitive heading of the ball. The incidence of acute brain injury is reviewed, as well as studies documenting the effects of heading the ball. Finally, 10 actions are proposed that would make soccer a safer sport with respect to brain injuries and provide avenues for further study in this area.

Athletic Injuries↗

PubMed1998

Tyrosine kinase inhibitor effects on avian osteoclastic acid transport.

We found that tyrosine kinase pp60(c-src) coisolates with acid-transporting osteoclast membranes and hypothesized that this kinase regulates hydrochloric acid transport. We assayed the membrane acid transport and bone degradation effects of tyrosine kinase inhibitors in avian osteoclasts. Isoflavone, tyrphostin, and benzoquinonoid inhibitors were compared with inactive analogues to determine nonspecific effects. Acid-secreting membranes, isolated by nitrogen cavitation, were assayed as reconstituted vesicles by using acridine orange to indicate ATP-dependent hydrogen ion transport. The soy isoflavone genistein and the benzoquinonoid antibiotic herbimycin inhibited hydrochloric acid transport with 50% inhibition at approximately 10 and approximately 2 micromol/L, respectively; effects appeared in <2 min and were reversible. In membrane incubated with inhibitors, the herbimycin effect also inhibited Cl- transport by variable amounts, suggesting that this compound affects Cl- channel activity. However, genistein and tyrphostins did not produce chloride dependent effects. After 30 min with ATP, tyrphostin A47 irreversibly inhibited hydrochloric acid transport with 50% inhibition at approximately 10 micromol/L. Tyrphostin A25 and controls, tyrphostin A1 and daidzein (a genistein congener), were inactive despite preincubation. Osteoclastic bone resorption was more sensitive to the inhibitors over 3-5-d assays than was membrane acid transport, except for tyrphostins. Herbimycin and genistein inhibited bone resorption with half maximal effects at 0.5 and 10 micromol/L and complete inhibition at 3 d in 1 and 20 micromol/L, respectively. None of the tyrphostins, including A47, nor daidzein inhibited resorption to >20 micromol/L. We conclude that tyrosine kinase inhibition directly inhibits osteoclast membrane hydrochloric acid transport; differences among inhibitors may reflect chemical reactivity and permeability.

Animals↗

PubMed1997

Differential effects of tamoxifen-like compounds on osteoclastic bone degradation, H(+)-ATPase activity, calmodulin-dependent cyclic nucleotide phosphodiesterase activity, and calmodulin binding.

We studied effects of calmodulin antagonists on osteoclastic activity and calmodulin-dependent HCl transport. The results were compared to effects on the calmodulin-dependent phosphodiesterase and antagonist-calmodulin binding affinity. Avian osteoclast degradation of labeled bone was inhibited approximately 40% by trifluoperazine or tamoxifen with half-maximal effects at 1-3 microM. Four benzopyrans structurally resembling tamoxifen were compared: d-centchroman inhibited resorption 30%, with half-maximal effect at approximately 100 nM, cischroman and CDRI 85/287 gave 15-20% inhibition, and l-centchroman was ineffective. No benzopyran inhibited cell attachment or protein synthesis below 10 microM. However, ATP-dependent membrane vesicle acridine transport showed that H(+)-ATPase activity was abolished by all compounds with 50% effects at 0.25-1 microM. All compounds also inhibited calmodulin-dependent cyclic nucleotide phosphodiesterase at micromolar calcium. Relative potency varied with assay type, but d- and l-centchroman, surprisingly, inhibited both H(+)-ATPase and phosphodiesterase activity at similar concentrations. However, d- and l-centchroman effects in either assay diverged at nanomolar calcium. Of benzopyrans tested, only the d-centchroman effects were calcium-dependent. Interaction of compounds with calmodulin at similar concentrations were confirmed by displacement of labeled calmodulin from immobilized trifluoperazine. Thus, the compounds tested all interact with calmodulin directly to varying degrees, and the observed osteoclast inhibition is consistent with calmodulin-mediated effects. However, calmodulin antagonist activity varies between specific reactions, and free calcium regulates specificity of some interactions. Effects on whole cells probably also reflect other properties, including transport into cells.

Animals↗

PubMed1997

Regulation of osteoclastic bone resorption by glucose.

Osteoclasts degrade bone by pumping molar quantities of HCl to dissolve the calcium salts of bone, an energy intensive process evidently supported by abundant mitochondria. This is the first study to directly examine the ability of various metabolites to serve as potential energy sources for osteoclastic bone resorption. Glucose, and to a lesser extent lactate, supported osteoclastic bone degradation. However, fatty acids (palmitate, myristate and stearate), essential amino acids plus 20 mM alanine, or ketone bodies (acetoacetate, beta-hydroxybutyrate and alpha-ketoglutarate) did not support bone degradation. Resorption declined to 10-30% of glucose controls when fatty acids or ketoacids were substituted for glucose. Resorption was glucose concentration dependent, with maximal activity at approximately 7 mM (K(M) approximately 3 mM). Glucose transport was linear for approximately 15 minutes, specific for D-glucose, and inhibited by cytochalasin B. Osteoclasts cultured on bone transported glucose at almost twice the rate of those off bone (Vmax 23 versus 13 nmols/mg/min, respectively) and medium acid accumulation paralleled glucose uptake, while the K(M) was unchanged. We conclude that glucose is the principal energy source required for bone degradation. Further, characteristics of glucose transport are consistent with the hypothesis that fluctuations in serum glucose concentration are an important component in regulation of osteoclastic bone degradation.

Alanine↗

PubMed1996

Variable effects of tyrosine kinase inhibitors on avian osteoclastic activity and reduction of bone loss in ovariectomized rats.

We compared the effects of the tyrosine kinase inhibitor genistein, a naturally occurring isoflavone, to those of tyrphostin A25, tyrphostin A47, and herbimycin on avian osteoclasts in vitro. Inactive analogs daidzein and tyrphostin A1 were used to control for nonspecific effects. None of the tyrosine kinase inhibitors inhibited bone attachment. However, bone resorption was inhibited by genistein and herbimycin with ID50s of 3 microM and 0.1 microM, respectively; tyrphostins and daidzein were inactive at concentrations below 30 microM, where nonspecific effects were noted. Genistein and herbimycin thus inhibit osteoclastic activity via a mechanism independent of cellular attachment, and at doses approximating those inhibiting tyrosine kinase autophosphorylation in vitro; the tyrphostins were inactive at meaningful doses. Because tyrosine kinase inhibitors vary widely in activity spectrum, effects of genistein on cellular metabolic processes were compared to herbimycin. Unlike previously reported osteoclast metabolic inhibitors which achieve a measure of selectivity by concentrating on bone, neither genistein nor herbimycin bound significantly to bone. Osteoclastic protein synthesis, measured as incorporation of 3H-leucine, was significantly inhibited at 10 microM genistein, a concentration greater than that inhibiting bone degradation, while herbimycin reduced protein synthesis at 10 nM. These data suggested that genistein may reduce osteoclastic activity at pharmacologically attainable levels, and that toxic potential was lower than that of herbimycin. To test this hypothesis in a mammalian system, bone mass was measured in 200 g ovariectomized rats treated with 44 mumol/day genistein, relative to untreated controls. During 30 d of treatment, weights of treated and control group animals were indistinguishable, indicating no toxicity, but femoral weight in the treated group was 12% greater than controls (P < 0.05). Our data indicate that the isoflavone inhibitor genistein suppresses osteoclastic activity in vitro and in vivo at concentrations consistent with its ID50s on tyrosine kinases, with a low potential for toxicity.

Animals↗

PubMed1996

Regulation of avian osteoclastic H+ -ATPase and bone resorption by tamoxifen and calmodulin antagonists. Effects independent of steroid receptors.

We used highly purified avian osteoclasts and isolated membranes from osteoclasts to study effects of tamoxifen, 4-hydroxytamoxifen, calmodulin antagonists, estrogen, diethylstilbestrol, and the anti-estrogen ICI 182780 on cellular degradation of 3H-labeled bone in vitro and on membrane HCl transport. Bone resorption was reversibly inhibited by tamoxifen, 4-hydroxytamoxifen, and trifluoperazine with IC50 values of approximately 1 microM. Diethylstilbestrol and 17-beta-stradiol had no effects on bone resorption at receptor-saturating concentrations, while ICI 182780 inhibited bone resorption at concentrations greater than 1 microM. At these concentrations ICI 182780, like tamoxifen, inhibits calmodulin-stimulated cyclic nucleotide phosphodiesterase activity. Membrane HCl transport, assessed by ATP-dependent acridine orange uptake, was unaffected by 17-beta-estradiol and diethylstilbestrol at concentrations up to 10 microM, while ICI greater than 1 microM. In contrast HCl transport was inhibited by tamoxifen, 4-hydroxytamoxifen, and the calmodulin antagonists, trifluoperazine and the calmidazolium, with IC50 values of 0.25-1.5 microM. These results suggested the presence of a membrane-associated non-steroid receptor for tamoxifen in osteoclasts. Tamoxifen binding studies demonstrated saturable binding in the osteoclast particulate fraction, but not in the nuclear or cytosolic fractions. Membranes enriched in ruffled border by differential centrifugation following nitrogen cavitation showed binding consistent with one site, Kd approximately microM. Our findings indicate that tamoxifen inhibits osteoclastic HCl transport by binding membrane-associated target(s), probably similar or related to calmodulin antagonist targets. Further, effects of estrogens or highly specific anti-estrogens on bone turnover do not support the hypothesis of a direct effect on osteoclasts by these compounds in this species.

Animals↗

PubMed1996

Effects of cell culture time and bone matrix exposure on calmodulin content and ATP-dependent cell membrane acid transport in avian osteoclasts and macrophages.

Osteoclasts mediate bone resorption by secretion at the site of bone attachment. This process depends on calmodulin concentrated at a specialized acid-secreting membrane. We hypothesized that increased calmodulin and bone attachment were required for acid secretion. We tested this by studying calmodulin, bone attachment, and membrane acid transport in osteoclasts and their precursor mononuclear cells. Osteoclasts and macrophages were isolated from medullary bone of hens; cell fractions were prepared after culturing cells with or without bone. Calmodulin was visualized by Western analysis; calmodulin mRNA was determined by Northern hybridization, and ATP-dependent membrane acid transport was assayed by acridine orange uptake. Calmodulin decreased in osteoclasts cultured without bone. Calmodulin in isolated macrophages was approximately 25% of osteoclast levels, but increased several fold by 5 days. Bone had no effect. Calmodulin mRNA was similar in osteoclasts with or without bone. However, only osteoclasts cultured with bone retained acid transport capacity. Macrophage calmodulin mRNA was not affected by bone, but increased three fold by day 5, paralleling protein production. Macrophages developed acid transport capacity at 3-5 days, but at lower levels than osteoclasts, and bone had no measurable effect. Chicken cells express 1.6 kb and inducible 1.9 kb calmodulin transcripts; in macrophages and osteoclasts, the 1.9 kb transcript predominated. We conclude that, following isolation, calmodulin levels decline in osteoclasts via a post-transcriptional mechanism. In cultured macrophages, by contrast, calmodulin mRNA, protein, and acid secretion increase with time independently of bone substrate, possibly reflecting differentiation in vitro. Increased calmodulin correlated with membrane acid transport capacity in both cell types. The macrophage findings indicate that stimuli other than bone influence acid transport capacity in this family of cells.

Animals↗

PubMed1996

Integrin expression in breast cancer cytology: a novel predictor of axillary metastasis.

The integrins are heterodimeric transmembrane receptors of varying alpha and beta subunits that modulate cell adhesion to each other and to the extracellular matrix. Loss of integrin expression on primary breast cancer frozen sections measured by immunohistochemistry may be related to the presence of axillary metastasis. The clinical application of this finding would be increased if integrin expression could also be shown to be reliably measured on breast cancer cells obtained by fine needle aspiration cytology. Axillary operations may be planned as a single stage procedure from outpatients, and neoadjuvant therapy protocols may be developed without surgery to the axilla. Expression of the alpha 1, alpha 2, alpha 3, alpha 6, alpha v, beta 1, beta 3 and beta 5 integrin subunits were measured by immunohistochemistry and immunocytochemistry in 58 patients. Integrin measurement by both these methods were found to be closely associated using the kappa-test. Loss of expression of the alpha 1, alpha 2, alpha 3, alpha 6, alpha v, beta 1 and beta 5 integrin subunits measured by cytology and histology were each related to positive nodal status (chi(2) test). Measuring integrin expression on cytology is of clinical value and may prove to have prognostic significance.

Adult↗

PubMed1995

Avian cathepsin B cDNA: sequence and demonstration that mRNAs of two sizes are produced in cell types producing large quantities of the enzyme.

Overlapping cDNA fragments encoding avian cathepsin B were cloned from an osteoclast cDNA library and sequenced. The primary structure of the prepro enzyme deduced from this sequence has 340 amino acids. The mature portion of the enzyme is 80% identical with murine cathepsin B; regions found in other papain superfamily enzymes are conserved. In osteoclasts and cultured macrophages, which produce large quantities of cathepsin B, mRNAs of 1.8 and 2.4 kb are produced in approximately equal quantities, while cells producing smaller quantities of the enzyme produce predominantly the 2.4 kb form. This variation in mRNAs suggests transcriptional differences related to production of large quantities of the enzyme.

Amino Acid Sequence↗

PubMed1994

Placebo-controlled immunopathologic study of four months of inhaled corticosteroids in asthma.

The effect of prolonged inhaled corticosteroid treatment on bronchial immunopathology was assessed in 25 nonsmoking mildly asthmatic subjects previously receiving intermittent inhaled beta 2-agonist alone. Inhaled beclomethasone dipropionate (BDP), 500 micrograms twice per day or placebo was administered for 4 mo in a double-blind parallel group study. Histamine bronchial provocation, fiberoptic bronchoscopic biopsy, and bronchoalveolar lavage (BAL) were performed before and after treatment. There was no difference in bronchial responsiveness or lung function between groups. In patients treated with BDP compared with placebo, there was a significant reduction in toluidine blue-staining mast cells (p = 0.028) and total (p = 0.005) and activated eosinophils (p = 0.05) in biopsies but no difference in eosinophils or eosinophil cationic protein in BAL. Granulocyte-macrophage colony-stimulating factor expression was significantly reduced in the bronchial epithelium, and the thickness of Type III collagen deposition in the bronchial lamina reticularis reduced from 29.7 +/- 4.4 to 19.8 +/- 3.4 microns (mean +/- 95% confidence interval) (p = 0.04). No change in helper or activated helper T cells occurred. Prolonged BDP treatment reduces inflammatory infiltration, proinflammatory cytokine expression, and subepithelial collagen deposition, a recognized abnormality in asthma.

Administration, Inhalation↗

PubMed1994

The expression of intercellular adhesion molecule-1 and the beta 1-integrins in asthma.

Expression of intercellular adhesion molecule-1 (ICAM-1) appears to be important to the development of bronchial hyperresponsiveness and eosinophilia in Ascaris sensitized monkeys. Beta 1-integrins are expressed on epithelial cells, and may contribute to adherence of epithelial cells to the basement membrane. The aim of this study was to determine whether adhesion receptor expression was altered in human asthmatic bronchial epithelium. Using monoclonal antibody staining, we have examined the expression of ICAM-1 and the alpha 1-alpha 6-subunits of the beta 1-integrin family in bronchial mucosal biopsies from 33 asthmatic and 13 nonasthmatic subjects. The epithelium was positive for ICAM-1 in 26 out of 33 asthmatics, although negative in all 13 nonasthmatics. ICAM-1 expression was not associated with bronchial responsiveness or with medication requirements. Beta 1-integrin staining showed that alpha 2-, alpha 3- and alpha 6-subunits stained the epithelium in all cases. Alpha 4 staining was weakly positive in the epithelium in five asthmatics. Alpha 5 staining was weak in asthmatics and normals. Alpha 4 and alpha 6-subunits also stained inflammatory cells. Epithelial upregulation of ICAM-1 is present in asthma. Beta 1-integrins with alpha 2-, alpha 3- and alpha 6-subunits appear to be constitutively expressed in bronchial epithelium.

Adult↗

PubMed1991

Granular cell tumor of a digital nerve.

Granular cell tumor is an infrequently encountered albeit not rare neoplasm considered to be of neuroectodermal origin. An example of a benign granular cell tumor originating within a digital nerve is presented. The authors employed routine light microscopic techniques and immunostaining which demonstrate features of the granular cells reflecting structural and functional characteristics of Schwann's cells and support neuroectodermal derivation. Granular cell tumor is ubiquitous in location but occurs more frequently in tongue, skin and subcutaneous tissue. Clinical features are not specific, and a histologic evaluation is required for diagnosis. Circumscription and lack of cellular pleomorphism define a benign process. However, irrespective of its histologic appearance, the biologic potential is uncertain. Complete excision suffices as treatment for benign tumors.

Adult↗