Biomedical subjects

H M Lee

Publications and source records attributed to H M Lee.

At least 73 records · Page 4Linked to original sources

PubMed2000

Thin film of low-crystalline calcium phosphate apatite formed at low temperature.

Surface modification of biomaterials to improve biocompatibility without changing their bulk properties is desired for many clinical applications and has become an emerging technology in biomaterial research and industry. In the present study, a simple method of coating the solid surfaces of metals, organic tissue matrices, glasses, inorganic ceramics as well as organic polymers with a thin film of low-crystalline apatite crystals (LCA) was developed. Acidic solution containing calcium and phosphate ions was neutralized with alkaline solution to form calcium phosphate precipitates at low temperature. Precipitates of solid calcium phosphate particles were, then, removed by filtration. Concentration of free ions in the filtered ion solution which were not involved in the formation of calcium phosphate precipitate was high enough to induce the heterogeneous nucleation on the solid surfaces at low temperature. Thin layers of calcium phosphate crystals were formed on the surfaces of metals, glasses, inorganic ceramics, organic polymers including hydrophobic ones, and biological tissue matrices with this solution. The thin layer of crystals consisted of poorly crystalline calcium phosphate apatite crystals which contain high amount of labile ions like bone crystals and did not dissolve in the physiologic solutions. Various cells attached to this crystal layer and proliferated well.

Biocompatible Materials↗

PubMed2000

Endogenous bacterial endophthalmitis: an east Asian experience and a reappraisal of a severe ocular affliction.

PURPOSE: To report 32 eyes of 27 patients with endogenous bacterial endophthalmitis seen over a 4 year period. Features and outcomes of this condition in the current series and the cases reported in the literature from 1986-1998 were reviewed. DESIGN: Retrospective noncomparative case series. PARTICIPANTS: All patients with this condition seen at the three participating general hospitals were included. INTERVENTION: A review of the systemic and ocular characteristics, therapeutic methods, and final outcomes in patients afflicted with this condition. MAIN OUTCOME MEASURES: Features studied included patients' demographic characteristics, microbiology, source of infection, ocular features, therapeutic interventions, final visual and anatomic outcomes. RESULTS: Nineteen (70%) of the 27 incriminating organisms in this case series were gram negative microbes, with Klebsiella pneumoniae infections alone being responsible in 16 (60%) cases. Hepatobiliary tract infection was the source of bacteremia in 13 (48%) patients. Only nine (28%) eyes obtained good final visual acuity (20/120 or better), and two eyes were enucleated/eviscerated. A literature review of 209 patients with endogenous endophthalmitis over a 12 year period showed a similar increase in the frequency of gram negative microbes as the responsible organism, especially among the East Asian population. Overall, 22% had bilateral involvement; two thirds of patients had predisposing factor(s) or underlying illness(es), and diabetes mellitus was present in 46%. Thirty-four percent of all eyes obtained counting finger or better final vision, and 16% had their eyes eviscerated or enucleated. Infections with virulent organisms (gram negative rods, Serratia, Bacillus) usually denoted a grave visual prognosis; however, a media that was not opaque on presentation was usually associated with a good prognosis. CONCLUSION: Metastatic ocular infection is not uncommon despite the availability of modern antibiotic therapy. Among the East Asian population, the patient at highest risk is a diabetic patient with Klebsiella pneumoniae hepatobiliary infection. In contrast, in the Caucasian population, this condition occurs in predisposed patients with gram-positive bacteremia arising from endocarditis or skin/joint infections. The final visual outcome in patients with endogenous bacterial endophthalmitis in the recent 12 years has not differed significantly from five decades ago.

Adult↗

PubMed2000

Subjective visual experience during phacoemulsification and intraocular lens implantation using retrobulbar anesthesia.

PURPOSE: To investigate the subjective visual experience of patients during phacoemulsification and intraocular lens (IOL) implantation using retrobulbar anesthesia. SETTING: Department of Ophthalmology, Tan Tock Seng Hospital, Singapore. METHODS: Seventy cataract patients who had routine phacoemulsification and posterior chamber IOL implantation under retrobulbar anesthesia were interviewed on the day of their surgery regarding their visual experience in the operated eye during surgery. Thirty-nine men (55.7%) and 31 women (44.3%) were included in the study. Their mean age was 65.1 years (range 37 to 87 years). Preoperative best corrected visual acuity ranged from 6/12 to counting fingers. Sixty eyes (85.7%) had no ocular pathology other than cataract. Eleven patients (15.7%) reported no light perception during the surgery. The rest reported they could see light (59 patients, 84.3%), 1 or more colors (39 patients, 55.7%), flashes (35 patients, 50.0%), movements (34 patients, 48.6%), instruments (12 patients, 17.1%), and the surgeon's fingers or hands (11 patients, 15.7%). The colors seen included red (23 patients, 32.9%), blue (17 patients, 24.3%), yellow (12 patients, 17.1%), green (7 patients, 10. 0%), and orange (1 patient, 1.4%). Eight patients (11.4%) saw a spectrum of colors similar to a rainbow. Thirty-one patients (44.3%) reported that the brightness of light changed during surgery. Five patients (7.1%) found their visual experience frightening. Patients who reported seeing colors (P =.048, Fisher exact test) and flashes of light (P =.027, Fisher exact test) were more likely to find the experience frightening. There was no statistically significant correlation between those who found the experience frightening and patient sex or age, length of surgery, or history of cataract surgery in the fellow eye. CONCLUSIONS: Many patients having phacoemulsification and IOL implantation under retrobulbar anesthesia experienced a variety of visual sensations that were frightening in a small proportion of cases.

Adult↗

PubMed2000

Time-course analysis of stretch reflexes in hemiparetic subjects using an on-line spasticity measurement system.

Spasticity after a stroke is usually assessed in a score form by subjectively determining the resistance of a joint to an externally imposed passive movement. This work presents a spasticity measurement system for on-line quantifying the stretch reflex of paretic limbs. Four different constant stretch velocities in a ramp-and-hold mode are used to elicit the stretch reflex of the elbow joint in spastic subjects. The subjects are tested at supine position with the upper limb stretched towards the ground, in contrast with the horizontally stretched movement used in other studies. By subtracting the baseline torque, reflex torque measured at a selected low stretch velocity of 5 deg/sec, the influence of gravity torque and inertial in vertical stretching mode can be minimized. The averaged speed-dependent reflex torque (ASRT), defined as the measured torque deviated from the baseline torque, is used for quantifying the spastic hypertonia. Four subjects having incurred cerebrovascular accident (CVA) are recruited for time-course study in which the measurements are taken at 72 hours, one week, one month, three months, and six months after onset of stroke. During the development of spasticity, the changes of ASRT and velocity sensitivity of ASRT of the involved and the intact elbow joints are discussed.

Elbow Joint↗

PubMed2000

Dietary 4-HPR suppresses the development of bone metastasis in vivo in a mouse model of prostate cancer progression.

The effects of the synthetic retinoid N-(4-hydroxyphenyl) retinamide (4-HPR) on prostate cancer metastasis in vivo were evaluated in the mouse prostate reconstitution (MPR) model. MPRs were produced by infection of either heterozygous (+/-) or nullizygous (-/-) p53-mutant fetal prostatic epithelial cells with the recombinant retrovirus Zipras/myc 9. Previous studies have documented that loss of p53 function potentiates metastasis in this model system. MPRs were grafted into homozygous (+/+) p53 male mice, fed a 4-HPR containing diet or a control diet and maintained until the status of tumor progression dictated sacrifice. Under these experimental conditions, treatment with 4-HPR did not have a significant effect on primary tumor wet weight for either p53 +/- or p53 -/- MPRs. For, p53 +/- MPRs the animals fed the 4-HPR diet had a slight improvement in survival and a significant reduction in the number of mesenteric metastases (P = 0.0477, t-test). Notably, in p53 +/- MPRs the incidence of metastasis to lumbar spine and sternum was 92% in the control animals compared to 54% in the 4-HPR treated animals (P = 0.035, chi2-test). In p53 -/- MPRs there was a trend toward a reduction in the number of soft tissue metastases to lung and liver in the 4-HPR group relative to the control diet group and a statistically significant reduction in the incidence of metastasis to bone was demonstrated in that 50% of control animals versus 30% of 4-HPR treated p53 -/- animals harbored bone metastases (P = 0 < 0.05, chi2-test). Cell lines were established from portions of the primary tumor and from selected metastatic deposits in each experimental group. Clonal analysis, by retroviral integration pattern, indicated increased clonal diversity in both the primary tumors and metastasis-derived cell lines from 4-HPR treated animals relative to the control animals. In vitro treatment with 4-HPR did not reveal discriminating differences between cell lines derived from primary tumors and bone metastases or control and treatment groups in regard to growth arrest or apoptotic responses. Overall these studies indicate limited anti-tumor and anti-metastatic activity in this highly aggressive in vivo mouse model of prostate cancer, yet 4-HPR treatment significantly suppressed the development of bone metastases in p53 +/- and p53 -/- MPRs revealing a novel and potentially clinically useful activity of this retinoid.

Animals↗

PubMed2000

Endogenous Klebsiella endophthalmitis.

PURPOSE: To report 4 cases of endogenous Klebsiella endophthalmitis. This disease is a rare but devastating complication of Klebsiella sepsis. Familiarity with its varied clinical presentations would aid in early diagnosis and institution of appropriate therapy. METHODS: We report 5 eyes of 4 patients with endogenous Klebsiella endophthalmitis from December 1995 to September 1996 and review the literature regarding previously successfully treated cases. RESULTS: The mean age of the patients was 67.5 years (range 37-85 years). One patient had bilateral involvement. At presentation, 3 eyes had a visual acuity of no perception of light (NPL) and the 1 patient with bilateral involvement had an acuity of counting fingers in one eye and 20/40 in the other. The primary source of sepsis was the pulmonary system in 2 patients, the hepatobiliary system in 1 patient and the urinary tract in 1 patient. One patient had coexisting diabetes mellitus. Two patients had a pupillary hypopyon. Local and systemic treatment with an aminoglycoside and cephalosporin was initiated. Despite treatment, 2 eyes remained NPL. One eye developed a globe perforation and was eviscerated. The patient with bilateral involvement was treated within 8 h and recovered fully with a final visual acuity of 20/20 in both eyes. CONCLUSION: It is important to have a high index of suspicion in patients with septicaemia presenting with intraocular inflammation, especially in diabetics with suppurative liver disease, urinary tract infection or pulmonary infection. As the visual prognosis for patients with Klebsiella endophthalmitis is generally poor, early diagnosis and treatment with intravenous and intravitreal antibiotics may improve the visual outcome.

Adult↗

PubMed2000

Caudal ropivacaine and ketamine for postoperative analgesia in children.

In a prospective, randomised, double-blind clinical study, we studied 32 ASA grade I and II boys aged 18 months to 12 years, scheduled for circumcision under general anaesthesia on an outpatient basis. They were randomly allocated to one of two groups: those in the ropivacaine group received caudal ropivacaine 0.2% 1 ml. kg-1 for postoperative analgesia and those in the ketamine/ropivacaine group received caudal ropivacaine 0.2% 1 ml. kg-1 plus caudal ketamine 0.25 mg.kg-1. Postoperative pain was assessed using a modified 10-cm visual analogue scale and analgesia was administered if the pain score exceeded a value of 3. The median duration of analgesia was significantly longer in the ketamine/ropivacaine group (12 h) than in the ropivacaine group (3 h, p < 0.0001), and subjects in the ropivacaine group required significantly more doses of postoperative analgesia than those in the ketamine/ropivacaine group (p < 0.0001). There were no differences between the groups in the incidence of postoperative nausea, vomiting, sedation, emergence delirium, nightmares, hallucinations, motor block and urinary retention.

Amides↗

PubMed2000

Phosphorylation of the signal transducer PII protein and an additional effector are required for the PII-mediated regulation of nitrate and nitrite uptake in the Cyanobacterium synechococcus sp. PCC 7942.

In the cyanobacterium Synechococcus sp. strain PCC 7942, the phosphorylation states of the signal transducer PII protein (GlnB) can change rapidly depending on the nitrogen and carbon supply. A PII-null mutant (MP2) shows no ammonium-dependent inhibition of the nitrate and nitrite uptake, in contrast to the wild-type. New mutants with different types of PII, which may mimic either the phosphorylated (GlnBS49E or GlnBS49D) or unphosphorylated (GlnBS49A) form of the protein, were constructed using site-directed in vitro mutagenesis. Mutant MP2-A (GlnBS49A) grew poorly using nitrate as a nitrogen source and was unable to take up nitrate supplied at 100 microM, even in the absence of externally added ammonium. Mutants MP2-D and MP2-E (GlnBS49D and GlnBS49E, respectively), however, showed nitrate-dependent growth and regulation of nitrate uptake by ammonium, as in the wild-type. Characterization of the mutants also included an analysis of nitrite uptake and of the levels of the nir (nitrate/nitrite assimilation) operon transcripts, the presence of NrtA (nitrate/nitrite transport binding protein), and nitrate and nitrite reductase activities. In vitro, no significant difference was observed in the cooperative binding of ATP and 2-oxoglutarate between the wild-type and the unphosphorylated or phosphorylated-like forms of the mutant PII proteins. The results obtained indicate that both unphosphorylated and phosphorylated-like forms of PII are able to inhibit nitrate uptake in the presence of ammonium, but the unphosphorylated form also has a negative effect in the absence of this nitrogen source. Therefore, an additional effector, possibly 2-oxoglutarate, is required for the PII protein to relieve inhibition of nitrate uptake in the absence of ammonium.

Adenosine Triphosphate↗

PubMed2000

Expression of human beta-defensin 1 mRNA in human nasal mucosa.

Antimicrobial peptides are cationic proteins that are found in a wide range of organisms. Recent reports suggested that human beta-defensin 1 (hBD-1), a prominent group of antimicrobial peptides, is an important component of the innate immune response, particularly at mucosal surfaces that are vulnerable to colonization by potential pathogens. Therefore, hBD-1 may participate in providing intrinsic nasal mucosal defence against microbial infections. The present study aimed to look for hBD-1 mRNA in human nasal mucosa without obvious signs of inflammation. Total RNA was isolated from human inferior turbinate mucosa and hBD-1 mRNA was detected in these tissues by using reverse transcription and polymerase chain reaction (RT-PCR). By in situ hybridization, hBD-1 mRNA was predominantly localized in superficial epithelial cells and submucosal glandular epithelium of human inferior turbinate mucosa. These data suggest that nasal epithelia and submucosal glands may secrete hBD-1, contributing to the mucosal defences of the nose.

Defensins↗

PubMed2000

Three decades of corneal transplantation: indications and patient characteristics.

PURPOSE: To review the indications and patient characteristics for penetrating keratoplasty (PKP). METHODS: Retrospective review of records at the Pathology Service, Department of Ophthalmology, University of Toronto from 1964 to 1997. RESULTS: The 6,222 records were reviewed. The leading indications for PKP were regraft, keratoconus (KC), pseudophakic bullous keratopathy (PBK), Fuchs' dystrophy, viral infections, and trauma, in that order. During the second half of the 1980s, PBK replaced KC as the leading indication for transplantation. The average age of patients increased from 49 (+/-19) years during the second half of the 1960s to 63 (+/-20) years at the first half of the 1990s. Gender differences (M/F ratio) were significant for KC, viral keratopathy, trauma, PBK, aphakic bullous keratopathy (ABK), edema of unspecified etiology, interstitial keratitis, rheumatoid arthritis, and Fuchs' dystrophy. Diagnostic category differences between all patients for PKPs and regrafts were significant for autoimmune keratolysis, congenital opacities, PBK, ABK, edema of unspecified etiology, scarring, Fuchs' dystrophy, and KC. CONCLUSION: Indications are in accordance with the literature with the exception of regraft, which was higher. An increase in the average age of patients corresponded with the PBK epidemic. The high male-to-female ratio among patients with KC was different from that previously reported for the prevalence of this condition. Sex distribution among patients with PBK and ABK showed a female predominance. Differences in the underlying disease distributions between regrafted patients and the rest of the series coincide with prognostic classifications for PKP.

Adult↗

PubMed2000

Association of the cytoplasmic membrane protein XpsN with the outer membrane protein XpsD in the type II protein secretion apparatus of Xanthomonas campestris pv. campestris.

An xps gene cluster composed of 11 open reading frames is required for the type II protein secretion in Xanthomonas campestris pv. campestris. Immediately upstream of the xpsD gene, which encodes an outer membrane protein that serves as the secretion channel by forming multimers, there exists an open reading frame (previously designated ORF2) that could encode a protein of 261 amino acid residues. Its N-terminal hydrophobic region is a likely membrane-anchoring sequence. Antibody raised against this protein could detect in the wild-type strain of X. campestris pv. campestris a protein band with an apparent molecular mass of 36 kDa by Western blotting. Its aberrant slow migration in sodium dodecyl sulfate-polyacrylamide gels might be due to its high proline content. We designated this protein XpsN. By constructing a mutant strain with an in-frame deletion of the chromosomal xpsN gene, we demonstrated that it is required for the secretion of extracellular enzyme by X. campestris pv. campestris. Subcellular fractionation studies indicated that the XpsN protein was tightly associated with the membrane. Sucrose gradient sedimentation followed by immunoblot analysis revealed that it primarily appeared in the cytoplasmic membrane fractions. Immune precipitation experiments indicated that the XpsN protein was coprecipitated with the XpsD protein. In addition, the XpsN protein was co-eluted with the (His)(6)-tagged XpsD protein from the metal affinity chromatography column. All observations suggested that the XpsN protein forms a stable complex with the XpsD protein. In addition, immune precipitation analysis of the XpsN protein with various truncated XpsD proteins revealed that the C-terminal region of the XpsD protein between residues 650 and 759 was likely to be involved in complex formation between the two.

Amino Acid Sequence↗

PubMed2000

Breath-hold three-dimensional contrast-enhanced coronary MR angiography: motion-matched k-space sampling for reducing cardiac motion effects.

A view order that matches k-space sampling to cardiac motion within the acquisition window was developed for breath-hold three-dimensional contrast material-enhanced coronary magnetic resonance angiography. In vivo experiments in seven volunteers demonstrated that blurring was substantially reduced with this motion-matched view order as compared with the standard centric view order. Coronary arteries were well delineated.

Adult↗

PubMed2000

Agarose plug instillation causes goblet cell metaplasia by activating EGF receptors in rat airways.

We hypothesized that foreign bodies in airways cause inflammation leading to goblet cell metaplasia. Instilled agarose plugs lodged in the bronchi of pathogen-free rats caused a time-dependent increase in Alcian blue-periodic acid-Schiff staining that was detected within 24 h and markedly increased at 72 h. Control bronchi contained no pregoblet or goblet cells, but plugged bronchi contained many pregoblet and goblet cells and a decrease in nongranulated secretory cells. In situ hybridization showed no expression of MUC5AC in control airways, but plugged airways showed a marked expression. Control bronchi showed sparse staining for epidermal growth factor receptor (EGFR) protein, but plugged bronchi showed intense EGFR staining in the epithelium. Pretreatment with an EGFR tyrosine kinase inhibitor (BIBX1522) prevented Alcian blue-periodic acid-Schiff staining and MUC5AC gene expression in plugged bronchi. Pretreatment with tumor necrosis factor-alpha neutralizing antibody or pretreatment with cyclophosphamide abolished plug-induced EGFR protein expression and goblet cell metaplasia. Thus instillation of agarose plugs induces profound goblet cell metaplasia by causing EGFR expression and activation.

Animals↗

PubMed2000

Olfactory mucosal findings in patients with persistent anosmia after endoscopic sinus surgery.

Sixty-three biopsy specimens were obtained from the olfactory region of 15 patients with persistent anosmia and 6 patients with normosmia after sinus surgery. Immunohistochemical examination of all specimens with microtubule-associated protein 5 (MAP5) antisera demonstrated olfactory epithelium in 11 of 18 specimens from normosmic patients and in 12 of 45 samples from anosmic patients. There was a significant difference in the proportion of specimens containing olfactory epithelium between the two groups of patients. In normosmic patients, most of the biopsy samples contained normal-appearing olfactory tissue. However, 2 main patterns of histologic findings were noted in the olfactory mucosa of anosmic patients. First, the olfactory receptor cells were remarkably decreased in number. Second, the orderly arrangement of cells characteristic of normal olfactory epithelium was lost, demonstrating a degenerative appearance. These data suggest that olfactory epithelium can be degenerated even in chronic sinusitis and thereafter extensively replaced with respiratory epithelium, resulting in increased sampling error. Moreover, an unimproved olfactory deficit after sinus surgery may be due to the abnormalities observed at the olfactory epithelium level.

Adolescent↗

PubMed2000

Endocrine disruptive effects of polychlorinated aromatic hydrocarbons on intestinal cholecystokinin in rats.

The ubiquitous and persistent nature of polychlorinated aromatic hydrocarbons (PCAHs) in our environment and the risk of exposure to PCAHs have provoked concern over their potential toxicity. In humans, exposure to PCAHs is aimed chiefly at epithelial cells residing in the intestinal mucosa, because oral intake of contaminated food is a major source of PCAHs. The purpose of this study, therefore, was to examine the effects of chronic exposure to various PCAHs [i.e. 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 2,3,4,7,8-pentachlorodibenzofuran (PeCDF), 3,3',4,4',5-pentachlorobiphenyl (PCB-126), and 2,2'4,4'5,5'-hexachlorobiphenyl (PCB-153)], given alone or as mixtures, on intestinal cholecystokinin (CCK) peptide and messenger RNA levels. We show that chronic PCAH treatment significantly lowers intestinal levels of stored CCK peptide. Intestinal CCK messenger RNA levels are not affected. In addition, 3,3',4,4',5-pentachlorobiphenyl treatment increased intestinal insulin-like growth factor-binding protein-3 levels in a dose-related manner. Acute 2,3,7,8-tetrachlorodibenzo-p-dioxin treatment of intestinal CCK cells lowered levels of CCK-processing enzymes (i.e. prohormone convertase-1 and -2). Together, these data indicate that PCAHs may decrease intestinal levels of stored CCK peptide by affecting the intestinal insulin-like growth factor system and CCK processing.

Animals↗

PubMed2000

Detection of porcine epidemic diarrhea virus by immunohistochemistry with recombinant antibody produced in phages.

Several diagnostic methods including immunofluorescence, enzyme-linked immunosorbent assay, polymerase chain reaction and immunohistochemistry have been developed for the detection of porcine epidemic diarrhea virus (PEDV). An immunohistochemical method using a new recombinant antibody produced by a phage antibody system (PAS16) kit was investigated and compared with that using a monoclonal antibody for PEDV detection in PEDV-infected piglets. In both the immunohistochemical methods, PEDV antigens were detected in the cytoplasm of villous enterocytes and in the macrophages infiltrated in the lamina propria at 18 to 110 hr post inoculation. The positive signals with the recombinant PAS16 antibody were similar to those with the monoclonal antibody. This result suggests that the recombinant PAS16 antibody can be applicable for the rapid immunohistochemical diagnosis of PEDV infection.

Animals↗

PubMed2000

Involvement of protein kinase C-gamma in IL-1beta-induced cyclooxygenase-2 expression in human pulmonary epithelial cells.

The signaling pathway of protein kinase C (PKC) is known to play a role in mediating the action of various cytokines. Here we examined the signal transduction pathway of PKC activation and the role of PKC isoforms in interleukin-1beta (IL-1beta)-mediated cyclooxygenase-2 (COX-2) expression in human pulmonary epithelial cell line (A549). The tyrosine kinase inhibitors (genistein and tyrphostin AG126) and phosphatidylcholine-phospholipase C inhibitor (D-609) prevented IL-1beta-induced prostaglandin E(2) (PGE(2)) release and COX-2 expression, whereas U-73122 (a phosphatidylinositol-phospholipase C inhibitor) and propranolol (a phosphatidate phosphohydrolase inhibitor) had no effect. The PKC inhibitors (Go 6976 and Ro 31-8220) and NF-kappaB inhibitor, pyrrolidine dithiocarbamate, also attenuated IL-1beta-induced PGE(2) release and COX-2 expression. Western blot analysis using PKC isoenzyme-specific antibodies indicated that A549 cells expressed PKC-alpha, -gamma, -iota, -lambda, -zeta, and -micro. IL-1beta caused the translocation of PKC-gamma but not other isoforms from cytosol to the membrane fraction. Moreover, the translocation of PKC-gamma was inhibited by genistein or D-609, but not by U-73122. IL-1beta caused the translocation of p65 NF-kappaB from cytosol to the nucleus as well as the degradation of IkappaB-alpha in cytosol. Furthermore, the translocation of p65 NF-kappaB was inhibited by genistein, Go 6976, Ro 31-8220, or pyrrolidine dithiocarbamate. These results indicate that in human pulmonary epithelial cells, IL-1beta might activate phosphatidylcholine-phospholipase C through an upstream tyrosine phosphorylation to elicit PKC activation, which in turn initiates NF-kappaB activation, and finally induces COX-2 expression and PGE(2) release. Of the PKC isoforms present in A549 cells, only activation of PKC-gamma is involved in regulating IL-1beta-induced responses.

Cyclooxygenase 2↗

PubMed2000

Collagen-to-smooth muscle ratio helps prediction of prognosis after pyeloplasty.

PURPOSE: We quantitatively evaluated the collagen-to-smooth muscle tissue matrix ratio in ureteropelvic junction obstruction, and compared the ratio with the degree of obstruction, patient age and postoperative renal recovery. MATERIALS AND METHODS: We analyzed histological sections from 65 patients with ureteropelvic junction obstruction and 6 normal controls. Morphological and functional grading systems were adapted to determine the degree of renal obstruction. To examine smooth muscle and collagen tissue, sections were stained using Masson's trichrome. Two distinct populations of collagen versus smooth muscle were identified and the tissue matrix ratio was calculated by color image analysis. RESULTS: The mean tissue matrix ratio plus or minus standard deviation was 1.32+/-0.79 in all patients with ureteropelvic junction obstruction but only 0.30+/-0.10 in normal controls (p <0.0001). It appeared that the lower the tissue matrix ratio, the better the improvement in postoperative hydronephrosis (r = -0.50, p = 0.0001). Better recovery of renal function after pyeloplasty was observed with a decrease in the tissue matrix ratio (r = -0.43, p = 0.0004). We divided patients according to the tissue matrix ratio into groups 1--ratio 1 or less, 2--greater than 1 to 1.5 and 3--greater than 1.5 to determine a more detailed and clinically applicable correlation of tissue matrix ratio with postoperative renal functional changes. Better improvement in postoperative renal function was observed in group 1 than in group 3 (p = 0.002). Also, the tissue matrix ratio increased with patient age (r = 0.33, p = 0.007). CONCLUSIONS: Since our data represent an objective and quantitative parameter associated with ureteropelvic junction obstruction, we believe that our findings may help to predict the prognosis after pyeloplasty.

Child↗