Uveal and conjunctival melanomas: disease course and outcomes in Chinese patients.

INTRODUCTION: Epidemiological studies of ocular melanomas have largely focused on Caucasian populations. This study reviewed the course and outcomes of uveal melanoma (UM) and conjunctival melanoma (CM) in Chinese patients. METHODS: This retrospective study included patients with UM and CM who received treatment in a tertiary eye centre in Hong Kong from January 1994 to December 2019. Data were recorded concerning patient demographics, tumour laterality, tumour characteristics, investigations performed, treatment regimen, and final outcomes. RESULTS: During the 25-year study period, there were 13 patients with UM and 11 patients with CM who did not display nodal or systemic involvement at diagnosis. The mean ± standard deviation ages at diagnosis of UM and CM were 59 ± 15.8 and 57 ± 13.9 years, respectively. There were more men among patients with UM than among those with CM (P=0.042). Most patients with UM underwent primary enucleation (n=12; 92.3%), whereas most patients with CM underwent orbital exenteration (n=9; 81.8%). The prognosis was significantly worse for CM than for UM. The median disease-free survival were 5.2 years (range, 0.7-20.5) and 2.1 years (range, 0.1-24.9) for UM and CM, respectively. Melanoma-related mortality was significantly higher among patients with CM than among those with UM (P=0.006). CONCLUSION: Compared with UM, CM has higher rates of systemic metastasis and tumour-related mortality in Hong Kong Chinese patients, regardless of prior definitive treatment.

Depressive symptoms among community-dwelling, post-stroke elders in Hong Kong.

BACKGROUND: Depressive symptoms adversely affect functional recovery among post-stroke elders. Such symptoms manifest when elders face difficulties in realistic daily living after being discharged. AIMS: The aim of this study was to examine (1) the prevalence of depressive symptoms among community-dwelling post-stroke elders, (2) the relationship between depressive symptoms and demographic and clinical characteristics among community-dwelling post-stroke elders, and (3) the demographic and clinical factors that differentiate post-stroke elders with and without depressive symptoms. METHODS: A descriptive cross-sectional survey was performed on 50 post-stroke elders from a geriatric day clinic. FINDINGS: Depressive symptoms were highly prevalent (68%) among the community-dwelling post-stroke elders. Depressive symptoms were negatively correlated with social support network, social support satisfaction and functional independence. Lastly, poor social support satisfaction and lower functional independence was found to differentiate those post-stroke elders with and without depressive symptoms. CONCLUSION: The inclusion of psychosocial assessment and delivery of appropriate psychosocial interventions to post-stroke elders are recommended.

Ocular Sebaceous Carcinoma In Situ With Biphenotypic Differentiation: A Reappraisal of the Alternative Origin of the Tumor.

Ocular sebaceous carcinoma is an uncommon, aggressive tumor arising from the Meibomian gland, Zeis gland, or sebaceous glands in the caruncle or eyelashes. We described a rare case of sebaceous carcinoma in situ in a 51-year-old female that was characterized by intraepithelial growth of sebaceous carcinoma cells with no invasive carcinoma in the underlying sebaceous glands. Early stromal invasion was identified that featured 2 distinctive but focally intermixed populations of sebaceous carcinoma cells and squamous carcinoma cells. The 2 populations of cells exhibited their respective distinct immunophenotype but both showed strong overexpression of p53. This case provides evidence to support the hypothesis that some ocular sebaceous carcinoma may arise from intraepithelial pluripotent stem cells.

Comparing mask fit and usability of traditional and nanofibre N95 filtering facepiece respirators before and after nursing procedures.

BACKGROUND: The reliability of N95 filtering facepiece respirators (FFRs) depends on correct fitting. The perceived usability of FFRs is equally important because discomfort during usage may affect compliance. Body movements during nursing procedures may also increase the risk of face seal leakage. AIM: To evaluate the mask fit and usability of the best-fitting 3M N95 FFR and the nanofibre N95 FFR before and after nursing procedures. The physical properties of these FFRs were also examined. METHODS: This experimental study had a one-group multiple comparison design. In total, 104 nursing students participated, and performed nursing procedures for 10 min when wearing the best-fitting 3M FFR and the nanofibre FFR. Mask fit and perceived usability of the FFRs were evaluated. FINDINGS: More participants failed to obtain a fit factor ≥100 when using the best-fitting 3M FFR than when wearing the nanofibre FFR (33.7% vs 21.2%) after the procedures (P=0.417). The nanofibre FFR also demonstrated higher usability than the 3M FFRs in terms of facial heat, breathability, facial pressure, speech intelligibility, itchiness, difficulty of maintaining the mask in place, and comfort level (P<0.001). The nanofibre FFR was also lighter, thinner and had slightly higher bacterial filtration efficiency than the 3M FFRs. CONCLUSION: The nanofibre FFR demonstrated significantly better usability than the 3M FFRs. None of the respirators were able to provide consistent protection for the wearer, as detected by face seal leakage after performing nursing procedures. Further improvement in the prototype design is needed to increase compliance and ensure the respiratory protection of users.

Localization of an Arg-Gly-Asp recognition site within an integrin adhesion receptor.

Many adhesive interactions are mediated by Arg-Gly-Asp (RGD) sequences within adhesive proteins. Such RGD sequences are frequently recognized by structurally related heterodimers that are members of the integrin family of adhesion receptors. A region was found in the platelet RGD receptor, gpIIb/IIIa, to which an RGD peptide becomes chemically cross-linked. This region corresponds to residues 109 to 171 of gpIIIa. This segment is conserved among the beta subunits of the integrins (76 percent identity of sequence), indicating that it may play a role in the adhesive functions of this family of receptors.

Isochromosome 7q in Down syndrome.

Isochromosome 7q is not an uncommon chromosomal abnormality. It has been reported in association with Shwachman-Diamond syndrome, Wilms tumor, and hepatosplenic T-cell lymphoma. In other hematolymphoid malignancies, it occurs almost invariably as a secondary change. A notable example is its association with t(4;11)(q21;q23) in acute lymphoblastic leukemia. It has rarely been described in myelodysplastic syndrome and acute myeloid leukemia. We report the occurrence of i(7q) as the primary abnormality in a 2-year-old boy with Down syndrome and minimally differentiated acute myeloid leukemia.

Comparison of antioxidant activities of different parts from snow chrysanthemum (Coreopsis tinctoria Nutt.) and identification of their natural antioxidants using high performance liquid chromatography coupled with diode array detection and mass spectrometry and 2,2'-azinobis(3-ethylbenzthiazoline-sulfonic acid)diammonium salt-based assay.

Snow chrysanthemum (Coreopsis tinctoria Nutt.), a world-widely well-known flower tea material, has attracted more and more attention because of its beneficial health effects such as antioxidant activity and special flavor. In this study, a high performance liquid chromatography coupled with diode array detection and mass spectrometry (HPLC-DAD-MS) and 2,2'-azinobis(3-ethylbenzthiazoline-sulfonic acid)diammonium salt (ABTS) based assay was employed for comparison and identification of antioxidants in different samples of snow chrysanthemum. The results showed that snow chrysanthemum flowers possessed the highest while stems presented the lowest antioxidant capacities. Fourteen detected peaks with antioxidant activity were temporarily identified as 3,4',5,6,7-pentahydroxyflavanone-O-hexoside, chlorogenic acid, 2R-3',4',8-trihydroxyflavanone-7-O-glucoside, flavanomarein, flavanocorepsin, flavanokanin, quercetagitin-7-O-glucoside, 3',5,5',7-tetrahydroxyflavanone-O-hexoside, marein, maritimein, 1,3-dicaffeoylquinic acid, coreopsin, okanin and acetyl-marein by comparing their UV spectra, retention times and MS data with standards or literature data. Antioxidants existed in snow chrysanthemum are quite different from those reported in Chrysanthemum morifolium, a well-known traditional beverage in China, which indicated that snow chrysanthemum may be a promising herbal tea material with obvious antioxidant activity.

Effect of cellular and receptor activation on the extent of integrin alphaIIbbeta3 internalization.

Previous studies by our laboratory demonstrated that internalization of fibrinogen-bound alphaIIbbeta3 correlated with both a loss of aggregation and a loss of bound fibrinogen from the platelet surface. However, these studies do not address whether cellular activation, receptor activation and/or receptor occupancy are responsible for the observed internalization of alphaIIbbeta3. The present studies were designed to evaluate the roles of cellular and receptor activation states on the alphaIIbbeta3 internalization process. In these studies, washed platelets were allowed to bind FITC-D57, an antialphaIIb monoclonal antibody, and were subsequently treated with ADP, thrombin receptor activation peptide (TRAP) or antiLIBS6 monoclonal antibody. Following flow cytometric analyses for log green fluorescence, rabbit antifluorescein was added, and the samples were re-analyzed for residual/unquenched fluorescence. Because access of the quenching antibody is limited to extracellular/surface-associated fluorescein, protection from quenching by antifluorescein is taken as evidence of internalization. Stimulation of platelets with ADP or TRAP resulted in a significant increase in the percent internalization of alphaIIbbeta3 compared to control (8.7% and 12.8% vs. 2.9%). Addition of cytochalasin E prior to stimulation resulted in a greater than 90% inhibition of both TRAP and ADP-induced internalization, suggesting that activation-dependent internalization is mediated by the actin cytoskeleton. To investigate whether receptor activation increases the extent of alphaIIbbeta3 internalization, platelets were treated with anti-LIBS6, which directly activates alphaIIbbeta3. Stimulation with anti-LIBS6 caused an approximate 8-fold increase in the extent of alphaIIbbeta3 internalization. To evaluate whether the activated pool of alphaIIbbeta3 is preferentially internalized, platelets were incubated with PAC-1, an antibody specific for activated alphaIIbbeta3. Platelets stimulated with TRAP, demonstrated a dose-dependent internalization of PAC-1. However, approximately 29% of total PAC-1 binding was internalized, irrespective of TRAP concentration, suggesting that a constant proportion of activated alphaIIbbeta3 is selectively internalized in platelets. Collectively, these data suggest that alphaIIbbeta3 is internalized to a greater extent in activated platelets in a cytoskeleton-dependent manner. Furthermore, the active conformer of alphaIIbbeta3 is preferentially internalized which may act as a mechanism for downregulating adhesiveness of activated platelets in the circulation.

Effect of cAMP phosphodiesterase inhibitors on ADP-induced shape change, cAMP and nucleoside diphosphokinase activity of rabbit platelets.

The effects of cAMP phosphodiesterase inhibitors on ADP-induced shape change and cAMP concentrations have been studied. Caffeine (10 mM), theophylline (8 mM), dipyridamole (0.2 mM), or papaverine (0,05 mM) prevented the shape change of washed rabbit platelets induced by 0.4 microM ADP. At these concentrations, none of these cAMP phosphodiesterase inhibitors increased 14C-cAMP in platelets in which the cytoplasmic adenine nucleotides had been labelled with 14C-adenine. By a protein binding assay, only papaverine by itself increased platelet cAMP above its basal level. These results indicate that two pools of cAMP may exist in platelets. Both methods showed that stimulation of platelet adenylate cyclase with PGE1 (1 microM) resulted in an increase in platelet cAMP and all these cAMP phosphodiesterase inhibitors potentiated this increase caused by PGE1. By themselves, some of these compounds may act through mechanisms that do not involve platelet cAMP. The effects of these cAMP phosphodiesterase inhibitors on platelet nucleoside diphosphokinase (NDK) activity were also investigated. At concentrations that prevented ADP-induced shape change, papaverine and dipyridamole had no effect on the formation of 14C-ATP from 14C-ADP by washed rabbit platelets. The methylxanthines partially inhibited NDK activity of washed rabbit platelets and of isolated platelet membranes, probably due to the structural similarity between the adenine ring of ADP and these substances. However, adenine (8 mM) inhibited ADP-induced shape change and platelet NDK activity but was a less effective inhibitor of ADP-induced platelet aggregation. Thus it seems unlikely that interference with platelet NDK or the ADP receptor is the major mechanism by which the methylxanthines inhibit platelet functions.

The fibrinogen gamma chain dodecapeptide inhibits agonist-induced aggregation of rabbit platelets and fibrinogen binding to rabbit glycoprotein IIb-IIIa.

The HHLGGAKQAGDV (H12) sequence at the carboxyl termini of the y chains and the RGD sequences in the Aalpha chains of human fibrinogen are potential recognition sites for the binding of soluble fibrinogen to glycoprotein IIb-IIIa (GPIIb-IIIa) on activated human platelets. Thus, addition of either H12 or RGD-containing peptides inhibits aggregation of and fibrinogen binding to human platelets. In contrast, we reported previously that RGDS had relatively little inhibitory effect on these functions of rabbit platelets. In the present study, we found that H12 inhibited ADP- and thrombin-induced aggregation of rabbit platelets in a dose-dependent manner. Specificity was demonstrated by the failure of the variant HHLGGAKQAGEV peptide to inhibit ADP-induced aggregation. Furthermore, flow cytometric analyses demonstrated that H12 inhibited the binding of FITC-fibrinogen to ADP-activated rabbit platelets in a dose-dependent manner. To examine the direct interaction of H12 with rabbit GPIIb-IIIa, we performed affinity chromatography by applying an octylglucoside extract of rabbit platelet proteins onto an affinity matrix containing the fibrinogen gamma chain sequence. Proteins of approximately 135 kDa and approximately 95 kDa were specifically eluted by soluble H12, and the 95 kDa protein band was immunoblotted by anti-LIBS1, a monoclonal antibody against human GPIIIa. In control samples, no detectable protein from rabbit platelet lysates was eluted from an RGD affinity matrix by GRGDSP. Collectively, our results demonstrated that H12 inhibits aggregation of and fibrinogen binding to rabbit platelets by directly interacting with rabbit GPIIb-IIIa. These findings suggest that rabbit platelets would serve as a suitable thrombosis model for testing the efficacy of peptide mimetics derived from H12.

Isolation and kinetic studies of nucleoside diphosphokinase from human platelets and effects of cAMP phosphodiesterase inhibitors.

Nucleoside diphosphokinase (NDK) of human platelets has been purified by chromatography on Blue Sepharose CL-6B gel (purification factor of 950) and shown to be free of adenylate kinase, ATPase and adenylate cyclase. The molecular weight was 70,000 with subunits of 17,000. The pH optimum was 8.0 Km values for ATP and dTDP were determined in two ways using the pyruvate kinase-lactate dehydrogenase coupled enzyme assay. Values of 0.38 and 0.20 mM were obtained for ATP and 0.29 and 0.21 mM for dTDP. Km values for ADP (0.024 mM) and GTP (0.12 mM) were determined with the hexokinase-glucose-6-phosphate dehydrogenase coupled enzyme assay. These values are in agreement with those reported for NDK from other sources. Theophylline, which inhibits the NDK activity of intact platelets and platelet membrane preparations and inhibits the ADP-induced shape change of platelets, was shown to be a competitive inhibitor of both the free and phosphorylated forms of NDK with competitive inhibition constants (Kic) of 9.3 and 9.6 mM respectively. Papaverine, another cAMP phosphodiesterase inhibitor, which also inhibits the ADP-induced shape change of platelets, had no inhibitory effect on platelet NDK. It was concluded that the inhibitory effect of theophylline on the activity of the purified enzyme was due to the structural similarity between the methylxanthine and the adenine moiety of ADP.

Anti-peptide antibodies against the human blood platelet thromboxane A2/prostaglandin H2 receptor. Production, purification and characterization.

Two anti-peptide antibodies have been raised against the human blood platelet thromboxane A2/prostaglandin H2 (TXA2/PGH2) receptor. Based on the published sequence of the placental TXA2/PGH2 receptor, two decapeptide segments were selected as potential antigens: one in the first extracellular loop corresponding to residue 89 through 98, and the other in the C-terminal region of the intracellular domain corresponding to residue 314 through 323. Rabbits were immunized with each peptide, and the antisera were subjected to a two-step purification procedure. The IgG fraction was purified using a DEAE Affi-Gel Blue column, and the peptide-specific IgG was further purified by affinity chromatography employing each peptide as the immobilized ligand. The combined purification factor for both procedures was approximately 60-fold. By ELISA, both antibodies displayed immunoreactivity toward their synthetic antigens, solubilized platelet membranes and affinity-purified TXA2/PGH2 receptor protein. Furthermore, Western blot analysis revealed that: (1) each antibody reacted with the purified platelet TXA2/PGH2 receptor protein (55 kDa); and (2) each antibody recognized a single band (55 kDa) in solubilized platelet membranes. These findings establish antibody specificity for the human platelet TXA2/PGH2 receptor protein. Functional analysis demonstrated that neither antibody interfered with ADP- or U46619-induced platelet aggregation of [3H]SQ29,548 binding to the solubilized receptor. These results suggest that the antibody epitopes are separate from the TXA2/PGH2 binding domain. In summary, two specific anti-peptide antibodies have been raised against the human platelet TXA2/PGH2 receptor. These antibodies should prove to be of value in the further investigation of the platelet TXA2/PGH2 receptor.

Purification of the human blood platelet thromboxane A2/prostaglandin H2 receptor protein.

The human platelet thromboxane A2/prostaglandin H2 receptor has been purified 6100-fold to apparent homogeneity by a three-step chromatographic procedure with an overall yield of 6%. A 6-fold purification of the receptor was first achieved by chromatography of 3-[(3-cholamidopropyl)dimethyl-ammonio]-1-propanesulfonate (CHAPS)-solubilized membrane proteins from human platelets on a diethylaminoethyl (DEAE)-Sepharose column. The DEAE eluate fractions containing receptor activity were then applied to a newly developed affinity column using the cyclohexyl derivative of SQ30,741 (SQ31,491) as the immobilized ligand. Elution of the receptor from the affinity column with BM13.177 yielded a further purification of 1700-fold. An additional 4-fold receptor purification from the affinity column eluate was achieved by HPLC using GPC 500 and GPC 100 columns connected in tandem. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and silver staining of the HPLC eluate containing purified receptor revealed a single, distinct band with a molecular weight of 55,000. The receptor binding activity was detected with [3H]SQ29,548 using a newly developed binding assay which involved immobilization of the receptor on polyethyleneimine-treated glass fiber filters. The binding of [3H]SQ29,548 to the purified receptor was time dependent, saturable, reversible and highly specific. Unlabeled SQ29,548, BM13.505, and U46619 (but not thromboxane B2 or 6-keto prostaglandin F1 alpha) competed for [3H]SQ29,548 binding to the purified receptor in a concentration-dependent manner. Scatchard analysis of [3H]SQ29,548 binding to the purified receptor revealed the presence of a single class of high-affinity binding sites, with a Kd of 4 nM and a Bmax of 17 nmol/mg protein.

Kappa light-chain myeloma with pleural involvement.

A case of kappa light-chain myeloma with pleural involvement is reported. The diagnosis was made by pleural biopsy, pleural fluid cytology, and urine immunoelectrophoresis. A review of the literature on pleural involvement in multiple myeloma revealed that this is the first reported case in patients with light-chain myeloma.

Synchronous laparoscopic-assisted right hemicolectomy and right adrenalectomy.

In recent years, minimally invasive surgery has been increasingly employed for the treatment of colorectal and adrenal tumors. We report an 82-year-old woman with synchronous right-sided colonic tumor and right adrenal tumor requiring resection. Preoperative workup showed a 6-cm primary right adrenal tumor with no evidence of invasion to adjacent structures. Laparoscopic removal of the two tumors was achieved with the use of a hand-port device, which assured safe retraction of the liver and meticulous dissection of the adrenal tumor, as well as port site protection during retrieval of the specimens. The whole operation lasted 270 min and our patient made an uneventful recovery.

Rhabdomyolysis following oral ingestion of the hydrocarbon cyclohexanone in an adolescent.

A 15-year-old boy with no prior medical problems ingested cyclohexanone in a suicide attempt. The patient developed altered mental status, shock, metabolic acidosis, chemical hepatitis, and renal insufficiency. In addition, he developed rhabdomyolysis as evidenced by muscle pain, increased serum creatine phosphokinase levels and myoglobinuria. He was treated successfully with intubation, fluid resuscitation, dopamine, and activated charcoal. The patient was discharged without clinical sequelae. Renal involvement, chemical hepatitis, shock, and metabolic acidosis following oral ingestion of hydrocarbon containing solutions have been well described in the literature. To our knowledge, the development of rhabdomyolysis following an oral ingestion of a hydrocarbon was reported only once in an adult patient and never in an adolescent. We reviewed literature pertaining to the occurrence, pathophysiology, and etiology of rhabdomyolysis in hydrocarbon intoxication.

Feasibility case-controlled study of day-case haemorrhoidectomy.

INTRODUCTION: Haemorrhoidectomy is traditionally an inpatient procedure. With many benefits, the day-surgery arrangement is an attractive alternative. The feasibility of day-surgery haemorrhoidectomy was explored and the hospital days were calculated in a case controlled design. METHODS: A single surgeon's experience of day-surgery haemorrhoidectomy between 1 July 1999 and 31 March 2000 was compared with inpatient haemorrhoidectomy during the same period. The operations were performed at United Christian Hospital Department of Surgery, Hong Kong (a government-funded public hospital). Statistical tests were applied where appropriate. RESULTS: There were 30 day-surgery and 15 inpatient haemorrhoidectomies. The groups were comparable in terms of age, gender, severity of haemorrhoids, method and duration of haemorrhoidectomy, blood loss, residual haemorrhoids, duration of follow up and unplanned readmission rate. Significantly more day-patients received general than spinal anaesthesia. Twenty-six of 30 (87%) patients were successfully discharged after day surgery. Two were admitted for transient fever (< 24 h), one for micturition syncope and one for acute urinary retention. There were four unplanned readmissions after day surgery: one for pain and three for secondary bleeding. All stopped spontaneously. All three unplanned readmissions after inpatient surgery were for secondary bleeding. All stopped spontaneously. Patient stay was significantly shorter for day surgery (1 +/- 1 day) than for the inpatient arrangement (4 +/- 1.6 days). CONCLUSION: Day-surgery haemorrhoidectomy is feasible. The significantly shorter hospital stay implies savings in public medical expenses.