Internal Delensing of Cosmic Microwave Background Polarization B-Modes with the POLARBEAR Experiment.

Using only cosmic microwave background polarization data from the polarbear experiment, we measure B-mode polarization delensing on subdegree scales at more than 5σ significance. We achieve a 14% B-mode power variance reduction, the highest to date for internal delensing, and improve this result to 22% by applying for the first time an iterative maximum a posteriori delensing method. Our analysis demonstrates the capability of internal delensing as a means of improving constraints on inflationary models, paving the way for the optimal analysis of next-generation primordial B-mode experiments.

Eficacia de la aplicación tópica de 0, 3% ciprofloxacina en la reducción de la biota conjuntival de pacientes operados de cataratas / Efficacy of topical 0.3% ciprofloxacin application in reducing the conjunctival biota of patients undergoing cataract extraction

Objetivo: Determinar la eficacia de la ciprofloxacina tópica al 0,3% en la reducción de la biota conjuntival en pacientes operados de cataratas. Pacientes y métodos: Estudio experimental, prospectivo, aleatorizado, controlado a simple ciego. Cuarenta y seis ojos de 46 pacientes fueron distribuidos al azar en dos grupos: el grupo de estudio (n = 23) recibió ciprofloxacina al 0,3% un día antes de la cirugía a razón de una gota cada 6 h y, luego, en el día de la cirugía, una gota cada 15 min, empezando una hora antes de la cirugía hasta completar tres dosis; el grupo control (n = 23) no recibió antibiótico; en ambos grupos para el campo quirúrgico se utilizó iodopovidona al 10%. Se tomaron muestras de la conjuntiva en cuatro momentos diferentes, cultivadas en medios sólidos (agar chocolate, agar sangre) y en caldo de enriquecimiento (tioglicolato). Además se obtuvieron muestras de humor acuoso que fueron cultivadas en tioglicolato. La presencia de bacterias fue identificada cuantitativa y cualitativamente y la frecuencia de contaminación fue medida considerando el desarrollo de microorganismos en los medios de cultivo tanto líquido como sólido, y se contabilizaron los números de colonias (UFC) en el sólido. Resultados: Antes de la administración de ciprofloxacina al 0,3% se obtuvieron cultivos positivos en el 82,6 y 78,3% de los pacientes en los grupos de estudio y control, respectivamente. La administración de ciprofloxacina al 0,3% redujo significativamente las UFC en comparación con el grupo control (p < 0,05); inmediatamente después del uso de la iodopovidona el porcentaje de pacientes con cultivo positivo disminuyó a 21,7% en el grupo de estudio y a 8,7% en el grupo control; al final de la cirugía este porcentaje fue de 26 y 30,4%, respectivamente. El germen más frecuente fue el estafilococo coagulasa-negativo (66,7%) (AU)

Conclusión: La administración de ciprofloxacina al 0,3% reduce la carga bacteriana conjuntival en el período preoperatorio, pero no la erradica de forma significativa. La administración de iodopovidona erradica la biota conjuntival en el 50-70% de los pacientes operados de cataratas (AU)

Objective: To determine the efficacy of topical 0.3% ciprofloxacin in reducing conjunctival biota in patients undergoing cataract surgery. Patients and methods: Experimental, prospective, randomized, controlled and single-blind study. Forty-six eyes of 46 patients were randomized into 2 groups, the study group (n = 23) received topical 0.3% ciprofloxacin one day before surgery for six times, and on the day of the surgery one drop every 15 minutes starting one hour before surgery until 3 doses were completed. The control group (n = 23) did not receive any antibiotics. For both groups for the surgical field 10% povidone-iodine was applied. Samples from the conjunctiva were taken at four different times and then cultured on solid media (chocolate agar, blood agar) and enrichment broth (thioglycolate). The aqueous humor samples were also cultured in thioglycolate. The presence of bacteria was identified quantitatively and qualitatively, and the frequency of contamination was measured by considering the presence of bacteria in liquid and solid culture media. The number of colony forming units (CFU) was counted in the solid culture medium. Results: Positive cultures were obtained in 82.6% and 78.2% of the patients in the study and control groups, respectively, before the administration of 0.3% ciprofloxacin. The administration of 0.3% ciprofloxacin significantly reduced the CFU compared to the control group (P < 0.05). Immediately after the use of povidone-iodine, the proportion of patients with a positive culture decreased to 21.7% in the study group, and 8.7% in the control group. At the end of the surgery, this percentage was 26% and 30.4%, respectively. The most common isolated pathogen was negative-coagulase Staphylococcus (66.7%) (AU)

Conclusion: The administration of 0.3% ciprofloxacin reduces conjunctival bacterial load in the preoperative period. However, it was unable to eradicate the bacteria completely. The administration of povidone-iodine reduced conjunctival biota in 50%-70% of patients undergoing cataract surgery (AU)

[Efficacy of topical 0.3% ciprofloxacin application in reducing the conjunctival biota of patients undergoing cataract extraction]. / Eficacia de la aplicación tópica de 0,3% ciprofloxacina en la reducción de la biota conjuntival de pacientes operados de cataratas.

OBJECTIVE: To determine the efficacy of topical 0.3% ciprofloxacin in reducing conjunctival biota in patients undergoing cataract surgery. PATIENTS AND METHODS: Experimental, prospective, randomized, controlled and single-blind study. Forty-six eyes of 46 patients were randomized into 2 groups, the study group (n=23) received topical 0.3% ciprofloxacin one day before surgery for six times, and on the day of the surgery one drop every 15minutes starting one hour before surgery until 3 doses were completed. The control group (n=23) did not receive any antibiotics. For both groups for the surgical field 10% povidone-iodine was applied. Samples from the conjunctiva were taken at four different times and then cultured on solid media (chocolate agar, blood agar) and enrichment broth (thioglycolate). The aqueous humor samples were also cultured in thioglycolate. The presence of bacteria was identified quantitatively and qualitatively, and the frequency of contamination was measured by considering the presence of bacteria in liquid and solid culture media. The number of colony forming units (CFU) was counted in the solid culture medium. RESULTS: Positive cultures were obtained in 82.6% and 78.2% of the patients in the study and control groups, respectively, before the administration of 0.3% ciprofloxacin. The administration of 0.3% ciprofloxacin significantly reduced the CFU compared to the control group (P<.05). Immediately after the use of povidone-iodine, the proportion of patients with a positive culture decreased to 21.7% in the study group, and 8.7% in the control group. At the end of the surgery, this percentage was 26% and 30.4%, respectively. The most common isolated pathogen was negative-coagulase Staphylococcus (66.7%). CONCLUSION: The administration of 0.3% ciprofloxacin reduces conjunctival bacterial load in the preoperative period. However, it was unable to eradicate the bacteria completely. The administration of povidone-iodine reduced conjunctival biota in 50%-70% of patients undergoing cataract surgery.

Effects of dexamethasone and colostrum feeding on mRNA levels and binding capacities of beta-adrenergic receptors in the liver of neonatal calves.

Glucocorticoids increase plasma glucose concentrations in neonatal calves, but not hepatic gluconeogenic enzyme mRNA levels and activities. Catecholamines, too, enhance plasma glucose levels and regulate hepatic glucose metabolism. We have measured hepatic mRNA levels of beta-adrenergic receptors and beta-adrenergic receptor binding in neonatal calves on day 5 of life. Calves were fed either colostrums (C) or an isoenergetic milk-based formula (F), and in each feeding group, half of the calves were treated with dexamethasone (DEXA; 30 microg/(kg body weightday)). Abundance of mRNA was highest (P < 0.01) for beta2-adrenergic receptors and was higher (P < 0.01) for beta1- than for beta3-adrenergic receptors. DEXA treatment decreased (P < 0.05) beta1- and beta2-adrenergic receptor mRNA levels. Beta3-adrenergic receptor mRNA levels were higher (P < 0.05) in colostrum- than in formula-fed calves. Competitive binding revealed highest affinities for alprenolol, propranolol (both beta1- and beta2-antagonists), and ICI-188,551 (beta2-antagonist), which did not significantly differ from each other. Atenolol (beta1-antagonist) up to 10(-5) M did not displace (3H)-CGP-12177 from receptors. Competitive binding for adrenaline was best fitted by a two-receptor model. DEXA decreased (P < 0.05) (3H)-CGP-12177 binding capacities, whereas binding affinity of (3H)-CGP-12177 was not affected by DEXA or different feeding. Binding sites correlated positively with mRNA levels of beta2-adrenergic receptors (r = 0.56; P < 0.01). In conclusion, beta2-adrenergic receptors were the dominant subtype in the hepatic tissue. Feeding did not significantly affect beta2-adrenergic binding sites. However, DEXA decreased beta2-adrenergic binding sites and this was regulated at the transcriptional level.

Ontogenetic development of mRNA levels and binding sites of hepatic beta-adrenergic receptors in cattle.

Catecholamines regulate glucose metabolism and affect hepatic glucose production mainly through beta2-adrenergic receptors. The hypothesis was tested that gene expression and numbers of hepatic beta-adrenergic receptors in calves are influenced by age. Examined developmental stages included pre-term (P0) and full-term (F0) calves immediately after birth, full-term calves on day 5 of life (F5), and veal calves (VC) at the age of 159 days. Expression of beta1-, beta2-, and beta3-adrenergic receptor mRNA was measured by real-time PCR. Receptor binding was quantified by saturation binding assays using (3H)-CGP-12177 as a ligand. Abundance of mRNA differed among beta-adrenergic subtypes (beta2 > beta1 > beta3; P < 0.01). Beta3-adrenergic receptor mRNA was undetectable in VC. mRNA abundance for beta2-adrenergic receptors was higher (P < 0.05) in VC than P0 and for beta3-adrenergic receptors was higher (P < 0.001) in F5 than P0. Binding studies revealed most binding of (3H)-CGP-12177 to beta2-adrenergic receptors, which were highest in VC (P < 0.001) and higher (P < 0.05) in F5 than P0. Binding sites correlated positively with mRNA levels of beta2-adrenergic receptors (r = 0.67; P < 0.001), with hepatic activities of phosphoenolpyruvate kinase (r = 0.73; P < 0.001) and with pyruvate kinase (r = 0.4; P < 0.05), and with plasma glucose concentrations (r = 0.5; P < 0.01). In conclusion, mRNA of all three beta-adrenergic receptor subtypes were found in liver, with beta2-adrenergic receptors being the dominant subtype. Numbers of beta2-adrenergic receptors increased with age and were mainly regulated at the transcriptional level. Numbers of beta-adrenergic receptors were positively associated with hepatic activities of gluconeogenetic enzymes and with plasma glucose levels, suggesting functional importance.

Fetal rhabdomyoma of the posterior cervical triangle.

Rhabdomyoma is an uncommon benign tumor, with the majority arising from cardiac muscle. Seventy to 90% of extracardiac rhabdomyomas are found in the head and neck region, usually within the upper aerodigestive tract. The case of a 7-month-old boy with an enlarging posterior triangle neck mass found to be fetal rhabdomyoma is presented. This location is quite rare for benign rhabdomyoma, with previous literature search showing overwhelming predilection for the upper aerodigestive tract.

Simulated reflux and laryngotracheal reconstruction: a rabbit model.

OBJECTIVES: (1) To test the feasibility of a rabbit model using a pharyngostomy tube to simulate gastroesophageal reflux and (2) to study the effects of gastroesophageal reflux on laryngotracheal reconstruction using a new rabbit model. DESIGN: Prospective randomized trial. SUBJECTS: Thirty-three New Zealand white rabbits. INTERVENTIONS: Anterior cartilage laryngotracheoplasty and pharyngostomy tube placement into the pyriform sinus were performed in 33 rabbits, 22 of which are included in this analysis. Beginning postoperative day 1, hydrochloric acid at a pH of 1.5 with pepsin (n = 7) or at a pH of 4.0 with pepsin (n = 8) was irrigated twice daily through the pharyngostomy tube to simulate gastroesophageal reflux, and a control group received twice-daily isotonic sodium chloride solution irrigations (n = 7). MAIN OUTCOME MEASURES: Specimens were scored by a pathologist masked to individual groups using a newly modified inflammation scoring system. In addition, cross-sectional areas of the cartilage grafts and subglottic airway lumina were compared. RESULTS: Inflammation scores were significantly higher in rabbits receiving hydrochloric acid and pepsin irrigations at a pH of 4.0 (P =.04) but not in those in the pH 1.5 group. Cartilage necrosis was prominent in all groups, and airway sizes and cross-sectional areas of the grafts were not significantly different among the 3 groups. CONCLUSIONS: Cartilage necrosis is prominent during the early stages after laryngotracheoplasty. Inflammation can be increased using hydrochloric acid and pepsin irrigations but is difficult to predict based on this study. Although we confirmed the feasibility of this model, further modifications of this study are proposed to improve animal survival and data collection.

Potpourri aspiration presenting as tension pneumothorax.

Foreign body aspiration in children is a relatively common occurrence, with peanuts, seeds, or other food particles representing the most common items. Because radiological findings such as mediastinal shift, postobstructive emphysema, and pneumonia are notoriously inconsistent, diagnosis hinges on an accurate history, which may be correlated by physical examination and radiography. We present the case of a 2-year-old girl with delayed treatment of a bronchial foreign body who presented with tension pneumothorax before endoscopy. After chest tube removal, her pneumothorax recurred, thereby bringing about the question of bronchial erosion. Furthermore, an uncommonly reported aspirated object, household potpourri, was encountered.

Parathyroid hormone-related protein (1-34) and urothelial redifferentiation in the neuropathic urinary bladder.

STUDY DESIGN: A comparative study of immunostaining for parathyroid hormone-related protein (1-34) (PTHrP (1-34)) in the vesical epithelium of biopsies obtained from patients with non-neuropathic bladder and those with neuropathic bladder. OBJECTIVES: To investigate the immunostaining for PTHrP (1-34) in the control cases and in neuropathic bladders showing (1) normal transitional epithelium, (2) hyperplastic transitional epithelium, and (3) squamous metaplasia. SETTING: Regional Spinal Injuries Centre, and Department of Cellular Pathology, Southport & Ormskirk Hospitals NHS Trust, Southport, Department of Pathology, Royal Liverpool University Hospital and the Departments of Clinical Chemistry and Cell Biology, The University of Liverpool, Liverpool, England. METHODS: Cold cup biopsies of bladder mucosa were taken from patients suffering from neuropathic urinary bladder when they were undergoing a therapeutic procedure in the urinary tract. Immunohistochemistry was performed on these biopsy specimens using a rabbit polyclonal antibody raised to a synthetic peptide corresponding to human PTHrP (1-34). Control group (n=10) consisted of archival biopsies taken from non-neuropathic bladders. RESULTS: In the control group, the transitional epithelium showed no immunostaining, or at the most, very faint positive staining was seen in the transitional epithelium of non-neuropathic bladder. Positive immunostaining to PTHrP (1-34) was seen in the normal transitional epithelium of neuropathic bladder in nine of 13 cases. Hyperplastic transitional epithelium showed positive immunostaining for PTHrP (1-34) in 11 of 13 biopsies from patients with neuropathic bladder. Immunostaining for PTHrP (1-34) was observed in the metaplastic squamous epithelium in 14 of 17 cases with neuropathic bladder. CONCLUSION: The transitional epithelium of non-neuropathic bladder showed no immunostaining, or at the most, very faint positive staining for PTHrP (1-34). In contrast to this, positive immunostaining for PTHrP (1-34) was observed more frequently in the vesical epithelium of neuropathic bladder. This observation opens up avenues for innovative therapy with PTHrP or its analogues for possible modulation of urothelial differentiation in the neuropathic bladder.

Synthesis of osteonectin by human retinal pigment epithelial cells is modulated by cell density.

PURPOSE: To determine whether human retinal pigment epithelial (HRPE) cells are able to synthesize the antiadhesive protein osteonectin, also known as secreted protein, acidic and rich in cysteine (SPARC). Additionally, because locally produced SPARC may modulate cellular behavior during tissue repair, to ascertain whether HRPE SPARC production and HRPE proliferation, migration, and/or differentiation are associated, in a simple HRPE wound-healing model. METHODS: Immunohistochemical and Western blot analyses of SPARC protein expression by low- and high-density cultured HRPE cells were undertaken. Total RNA extracted from cultures was studied by reverse transcription-polymerase chain reaction (RT-PCR) and Northern blot analysis. Western and Northern blot analyses were evaluated by densitometry. Experiments were repeated with HRPE cells cultured in the presence of 1, 10, or 100 microM of the differentiating agents butyric acid (BA) and retinoic acid (RA). RESULTS: HRPE cell cultures exhibited SPARC immunoreactivity. Western blot analysis of cell lysates and conditioned media showed a 43-kDa protein. RT-PCR and Northern blot analysis confirmed the presence of SPARC mRNA (with transcripts at 2.2 and 3.0 kb). Protein and mRNA transcript band densitometry revealed a higher proportion of SPARC protein and mRNA in high-density HRPE cell culture than in low-density culture. Neither BA nor RA (at the concentrations assessed) had a significant effect on SPARC production by HRPE cells in high- or low-density culture. CONCLUSIONS: HRPE can synthesize SPARC. Although the findings do not support an invariable association between SPARC production by HRPE and HRPE proliferation, migration, or differentiation, they demonstrate that synthesis of SPARC by HRPE is modulated by cell density.

Pediatric tracheotomies: changing indications and outcomes.

OBJECTIVE/HYPOTHESIS: To study the outcomes and complications associated with pediatric tracheotomy, as well as the changing trend in indications and outcomes since 1970. STUDY DESIGN: Retrospective chart review at a major tertiary care children's hospital. METHODS: On children who underwent tracheotomy at Children's Hospital of the King's Daughters (Norfolk, VA) between 1988 and 1998, inpatient and outpatient records were reviewed. Of 218 tracheotomies, sufficient data were available on 204. Indications for tracheotomy were placed into the following six groups: craniofacial abnormalities (13%), upper airway obstruction (19%), prolonged intubation (26%), neurological impairment (27%), trauma (7%), and vocal fold paralysis (7%). RESULTS: The average age at tracheotomy was 3.2 +/- 0.6 years. Although the prolonged intubation group was significantly younger than all others, the neurological impairment and trauma groups were significantly older. Decannulation was accomplished in 41%. Time to decannulation was significantly higher in the neurological impairment and prolonged intubation groups, but was significantly shorter in the craniofacial group. Complications occurred in 44%. Overall mortality was 19%, with a 3.6% tracheotomy-related death rate. Comparison of our series to other published series of pediatric tracheotomies since 1970 shows fewer being performed for airway infections and more for chronic diseases, with a corresponding increase in duration of tracheotomy and decreased decannulation rates. CONCLUSIONS: Tracheotomy is a procedure performed with relative frequency at tertiary care children's hospitals. While children receiving a tracheotomy have a high overall mortality, deaths are usually related to the underlying disease, not the tracheotomy itself.

A CD36-binding peptide from thrombospondin-1 can stimulate resorption by osteoclasts in vitro.

Thrombospondin-1 (TSP-1), purified from platelets, stimulates resorption by avian osteoclasts in an in vitro resorption assay. TSP-1 binds to a number of different cellular receptors via different domains of the molecule and several short receptor-binding sequences have been identified within the TSP-1 molecule. In this study, we have used synthetic peptides representing these various sequences in order to identify the cellular receptor and TSP domain responsible for stimulation of resorption. We show that one peptide CSVTCG, which represents the CD36-binding region of TSP-1, stimulates resorption in a fashion similar to the intact molecule, while the peptides RGDS, RFYVVMWK, and RFYVVM, representing other cell-binding domains of TSP, have no effect on resorption. Using RT-PCR and immunoblotting, we further demonstrate expression of CD36 in human osteoclastoma (giant cell tumour), primary human bone derived cells, and clonal osteoblastic cells. These studies suggest that CD36 is involved in regulation of resorption by osteoclasts and is the receptor responsible for the resorption-promoting effects of TSP-1.

Postsurgical follow-up of children with tympanostomy tubes: results of the American Academy of Otolaryngology-Head and Neck Surgery Pediatric Otolaryngology Committee National Survey.

Postsurgical follow-up of children with tympanostomy tubes is becoming a contentious issue in this era of managed care. Primary care providers believe themselves to be capable of evaluating these children. Otolaryngologists, on the other hand, have more specialized equipment available to them (suction apparatus, otomicroscopes, audiology devices, etc) for treating suppurative infections and monitoring the tympanic membrane for structural changes. In addition, the otolaryngologist is placed in an uncomfortable legal and ethical position if access to the patient with a tube-related complication is denied by the primary care provider. Attempts to develop an American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) policy statement have been hampered by a lack of data on the incidence and severity of tube-related complications and the role that otolaryngologists can play in reducing these sequelae. A survey designed by the AAO-HNS Pediatric Otolaryngology Committee was distributed to 1000 board-certified otolaryngologists and all members of the American Society of Pediatric Otolaryngologists and the American Academy of Pediatrics-Otolaryngology Section regarding current practice patterns and practitioners' experiences with tympanostomy tube complications. Specific information regarding complications that could have been avoided with earlier otolaryngology referral was also obtained. The results of the survey and its implications for AAO-HNS policy are presented.

Cultured human retinal pigment epithelial cells differentially express thrombospondin-1, -2, -3, and -4.

Thrombospondins are a family of at least five proteins (TSP-1 to -4 and cartilage oligomeric matrix protein or COMP) whose functions are indeterminate. Distribution differences between family members suggest each protein may have some distinct functions. The retinal pigment epithelium (RPE) has divers unusual roles for an epithelia and can produce TSP-1. However, the wide range of RPE activities suggests that, if different thrombospondin family members do have different functions, RPE may express thrombospondins additional to TSP-1. Therefore, we analysed expression of thrombospondin isoforms by RPE using reverse-transcription-linked polymerase chain reaction. Cultured cells exhibited differential expression of TSP-1 to -4; TSP-2 and TSP-4 appearing later in culture than TSP-1 and TSP-3. In situ RPE expressed mRNA for TSP-1 to -4. No COMP mRNA was detected in RPE. These observations suggest that thrombospondin isoforms are regulated differently by the cells and that these proteins may have different functions in the RPE.

Immunohistochemical study of parathyroid hormone-related protein in vesical transitional epithelium of patients with spinal cord injury.

INTRODUCTION: Parathyroid hormone-related protein (PTHrP), in addition to the well-established role in endochrondral bone development, is believed to be an important mediator of cellular growth and differentiation in a number of non-bony tissues. OBJECTIVES: To compare the immunohistochemical staining of vesical transitional epithelium to antibodies raised to synthetic peptides of PTHrP composed of amino acid sequences 43 - 52 and 127 - 138 in patients with spinal cord injury (SCI) and neuropathic bladder (n=14), and control patients with intact neuraxis and no history of bladder cancer (n=10). SETTING: Male SCI patients registered with Regional Spinal Injuries Centre, Southport, England. INTERVENTION: Endoscopic cold cup biopsy from the trigone of the urinary bladder was taken from patients with SCI while they were undergoing a therapeutic procedure in the urinary bladder. The control samples of bladder biopsies were taken from the archives of the Department of Histopathology, District General Hospital, Southport. Immunohistochemistry was performed using rabbit antibodies raised against synthetic peptides of human PTHrP (43 - 52) and PTHrP (127 - 138). The biopsies were examined for immunostaining of transitional epithelium. RESULTS: Of the 14 biopsies of SCI patients, positive immunostaining using antibodies to both the PTHrP peptides was found in four cases; five biopsies showed positive immunostaining only to anti-PTHrP (43 - 52); and five biopsies showed no immunostaining with either of the PTHrP peptides. In contrast, transitional epithelium in the biopsy specimens of ten control subjects with no history of bladder cancer showed no immunostaining with either of the PTHrP peptides. CONCLUSION: This study revealed that the transitional epithelium of neuropathic urinary bladder exhibits increased predilection for positive immunohistochemical staining for PTHrP (43 - 52), and to a lesser extent, to PTHrP (127 - 138), as compared to the vesical transitional epithelium of able bodied individuals with no history of vesical malignancy. The possible role of PTHrP in the cellular differentiation of urothelium of neuropathic bladder, and thereby, in the pathogenesis of cystitis in SCI patients, needs to be explored.

Focal parotid necrosis in systemic lupus erythematosus: case report and review of the literature.

Systemic lupus erythematosus (SLE) is a disease that may affect a number of organ systems, particularly the joints, skin, kidneys, heart, lungs, and immune system. Salivary gland involvement is usually associated with Sjögren's syndrome, in which lymphocytic acinar infiltrates predominate histologically. We present the case of a 29-year-old woman with SLE who developed bilateral parotid enlargement with a unilateral focus of parotid necrosis that was consistent with a cystic mass on computerized tomography. A biopsy of this lesion was histologically similar to a cervical lymph node biopsy in the same patient, with both specimens showing loss of architecture and foci of necrosis consisting of nuclear dust, histiocytes, and scattered plasma cells without formation of granulomata or presence of multinucleated giant cells; these findings are classic for SLE lymphadenopathy. We believe this to be the first reported case of focal necrosis in the parotid gland directly associated with SLE.

Expression of members of the thrombospondin family by human skeletal tissues and cultured cells.

We have previously shown that the multifunctional platelet glycoprotein thrombospondin-1 (TSP-1) promotes resorption in an in vitro resorption assay. However, TSP-1 is one of a family of multifunctional TSP molecules, and the current study was undertaken to investigate whether it is TSP-1 or another TSP family member which may be involved in regulation of resorption in vivo. RT-PCR was performed on cultured human bone cells, cultured human chondrocytes, and three separate samples of human osteoclastoma tissue using primers specific for each TSP family member. mRNA for TSP-2 was detected in almost all samples, and significantly in all osteoclastomas in the above tissues, while TSP-1 was detected less frequently and was only seen in one of three osteoclastomas. TSP-3, -4, and COMP were detected only in a minority of cases. These results indicate that TSP-2 is the most common TSP family member found in skeletal tissues and that TSP-2, rather than TSP-1, may be the molecule responsible for promoting resorption in vivo.

Effect of PGE2 on the cell surface molecule expression in PMA treated thymocytes.

PGE2 is produced by cells of the thymic microenvironment. The effects of PGE2 are mediated by cAMP through binding to its intracellular receptor protein kinase A (PKA). Phorbol 12-myristate 13-acetate (PMA) is known to modulate CD molecule expression on thymocytes, probably through activation of protein kinase C (PKC). We have hypothesized that cross-talk between these two signalling pathways may affect modulation of the CD molecules on the cell surface of thymocytes. For this purpose, we compare the effects of PMA alone or combined with PGE2 on CD3, CD4 and CD8 expression on mouse thymocytes by flow-cytometric analysis. PMA treatment almost completely abolished CD4 expression and slightly decreased CD3 and CD8 expression. PGE2 alone did not change the CD3, CD4 and CD8 molecule expression. Combined with PMA, PGE2 can overcome the decrease induced by PMA of the CD3 expression and partially reduced the disappearance of the CD4 molecule. On the other hand PGE2 accelerated the loss of CD8 molecule expression. These events occurred only in CD4+ CD8+ immature thymocytes. An analogue of cAMP (dibutyryl cAMP) mimics the effect of PGE2, but not Br-cGMP. This differential regulation by PGE2 of the CD molecule expression on immature thymocytes may provide additional evidence on the role of PGE2 during the process of thymic differentiation.

Extracellular nucleotides stimulate proliferation in MCF-7 breast cancer cells via P2-purinoceptors.

Nucleotides such as ATP can act as extracellular effector molecules by interaction with specific cellular receptors known as P2-purinoceptors. Recently, we cloned the human P2U purinoceptor from osteoclastoma and demonstrated its expression in skeletal tissues. In the current study we have investigated the expression of P2U purinoceptors in human breast tumour cell lines and examined functional effects of extracellular nucleotides on these cells. By reverse transcription-linked polymerase chain reaction (RT-PCR) the expression of mRNA for P2U purinoceptors was demonstrated in four human breast cancer cell lines, Hs578T, MCF-7, SK-Br3 and T47-D. In MCF-7 cells, extracellular ATP (1-100 microM) elevated intracellular free calcium concentration [Ca2+]i, indicating that these cells express functional P2-purinoceptors. UTP elevated [Ca2+]i in an identical manner to ATP, whereas 2-methylthioATP was completely ineffective, and ADP only partially effective. This pharmacological profile suggests that the P2U subtype may be the only P2-purinoceptor expressed by these cells. The functional significance of P2U purinoceptor expression by MCF-7 cells was investigated by analysing the effects of extracellular ATP on cell proliferation. The slowly hydrolysed analogue of ATP, ATPgammaS (which was also shown to elevate [Ca2+]i), induced proliferation of MCF-7 cells when added daily to serum-free cultures over a period of 3 days. ATPgammaS-induced proliferation was demonstrated by three separate methods, detection by scintillation counting of [3H]thymidine incorporation, immunocytochemical detection of 5-bromo-2-deoxyuridine incorporation and direct counting of cell numbers. These data suggest that ATP, possibly released at sites of tissue injury or inflammation, may be capable of growth factor action in promotion of tumour proliferation or progression.

PTHrP and the PTH/PTHrP receptor are co-expressed in human breast and colon tumours.

Using RNA extracted from human tumour samples removed during surgery, we have analysed expression of mRNA for parathyroid hormone-related protein (PTHrP) and for the PTH/PTHrP receptor by RT-PCR in a panel of human breast and colon tumours. All but 1 of 18 breast tumour samples expressed PTHrP, whereas receptor expression was detected in 11 of these. Expression of the PTH/PTHrP receptor was found in three out of four metastatic lesions, including one sample in which no receptor was detected in the primary tumour. PTHrP expression was also detected in five colon tumours, and receptor expression detected in two of these. These results demonstrate that PTHrP and the PTHrP receptor are also co-expressed in breast tumours in vivo and provide further evidence that PTHrP may be an important autocrine/paracrine growth factor in breast cancer.