Mechanism of Action of p-Chlorobiphenyl on the Inhibition of Platelet Aggregation

p-Chlorobiphenyl (1–50 μm ) concentration-dependently inhibited the aggregation and release reaction of rabbit washed platelets induced by arachidonic acid and collagen, but not those induced by platelet-activating factor (PAF), U46619 and thrombin. The IC50 values of p-chlorobiphenyl on the arachidonic acid and collagen-induced platelet aggregation were 2.9 ± 0.5 and 12.8 ± 2.3 μm , respectively. The formation of both platelet thromboxane B₂ and prostaglandin D₂ caused by arachidonic acid was inhibited by p-chlorobiphenyl concentration-dependently. In myo-[³H]inositol-labeled and fura-2-loaded platelets, [³H]inositol monophosphate generation and the rise in intracellular Ca²⁺ stimulated by arachidonic acid were inhibited by p-chlorobiphenyl. In human platelet-rich plasma, p-chlorobiphenyl and indomethacin prevented the secondary aggregation and blocked ATP release from platelets induced by adenosine 5′-diphosphate and adrenaline without affecting the primary aggregation. It is concluded that p-chlorobiphenyl may be a cyclo-oxygenase inhibitor and its antiplatelet action is mainly due to the inhibition of thromboxane formation.     

Role of amino and carboxyl groups of cobrotoxin in the conformational stability and the interaction with acetylcholine receptor

To study the functional involvements of the common interaction of the Leu-1 α-amino group and Asp-58 in cobrotoxin, the lysine ε-amino groups of cobrotoxin were initially guanidinated with o-methylisourea. The α-amino group of Leu-I was then modified with TNBS after the guanidination of cobrotoxin. Both modified derivatives displayed no significant changes in the secondary structure and antigenicity of cobrotoxin, whereas the binding affinity for nicotinic acetylcholine receptor (nAChR) was pronouncedly decreased when Leu-1 was modified. Six out of seven free carboxyl groups and the remaining buried Glu-21 carboxyl group of cobrotoxin were modified with glycine methyl ester in the absence and presence of guanidine HCl, respectively. Alternation in the β-sheet secondary structure of cobrotoxin was observed with the carboxyl-group modified derivatives, which caused a decrease in the binding activity of the toxin molecule to the antibody and nAChR. Moreover, modification of the Glu-21 carboxyl group of cobrotoxin further reduced the nAChR binding activity, while the antigenicity remained unchange. Thus, our results conclude that the Glu-21 residue and the common interaction of the terminal Leu-1 α-amino group and the Asp-58 carboxyl group are related to the nAChR-binding activity of cobrotoxin, and the free carboxyl groups in cobrotoxin are conformation-essential. © Munksgaard 1995.     

Temporal changes in the humoral immune response of cattle during experimental infections with Onchocerca lienalis

In order to gain insights into the immune response in onchocerciasis during early infection, laboratory-reared calves were infected with 1000 Onchocerca lienalis infective larvae and examined serologically over a period of 508 days. Levels of serum antibodies measured by ELISA against adult worm extract revealed a multiphasic response, characterized by a broadly similar profile of peaks in individual animals arising at 15–30, 79 and >266 days after infection. Timings of these changes in responsiveness closely mirrored parasite development, coinciding with larval moults and with the onset of a patent infection. The levels of individual antibody isotypes directed against parasite antigens was strongly skewed. The dominant response was of IgG1, although limited reactivities were also found for IgG2 and IgM: No parasite-specific IgA antibodies were detected. Immuno-blots of adult worms extracts revealed a pattern of antigen recognition over time that matched the results obtained by ELISA. Again, the IgGl response was strongest, although certain lgG2 and IgM specificities were well represented. In general, there was a steady increase in the number of individual antigens recognized as the infection progressed, with a striking expansion of antibody specificities from day 79 following the fourth larval moult. Antibodies to a 16kDa component were a prominent feature of the response following development of a patent infection. These data reveal the strong influence of parasite biology on the development of the immune response in onchocerciasis.     

Prolonged Ventricular Asystole, Sinus Arrest, and Paroxysmal Atrial Flutter-Fibrillation:

CHOU, H.-H., et al.: Prolonged Ventricular Asystole, Sinus Arrest, and Paroxysmal Atrial Flutter-Fibrillation: An Uncommon Presentation of Vasovagal Syncope. We described a 55-year-old woman with recurrent syncope, complete atrioventricular (AV) block, sparsely scattered idioventricular beats lasting for 56 seconds, and long sinus arrest recorded during the syncopal episode. Paroxysmal atrial flutter-fibrillation was also presented during Holter electrocardiograph (ECG) monitoring without clinical symptom. During tilt test, atrial flutter with variable AV block was induced and the patient suddenly passed out. The vasovagal syncope was successfully treated with a DDD permanent pacemaker with a rate drop response algorithm. Vasovagal syncope with concomitant ventricular asystole and sinus arrest is rare. Aggressive management with permanent pacemaker is strongly advocated in malignant vasovagal syncope. (PACE 2003; 26[Pt. I]:914–917)     

Depletion of stratum corneum intercellular lipid lamellae and barrier function abnormalities after long-term topical corticosteroids

The intercellular lipid lamellae of the stratum corneum (SC) is believed to provide the permeability barrier of the epidermis. Previous functional studies have demonstrated an increase in the transepidermal water loss (TEWL) after long-term use of topical corticosteroids (TCS); however, direct morphological confirmation of this barrier abnormality is still lacking. The aim of this study was to determine whether any abnormality could be detected in the structure of the SC intercellular lipid lamellae in patients after long-term TCS. Atrophic skin and untreated normal skin of 10 patients after long-term TCS were examined by transmission electron microscopy using ruthenium tetroxide- fixed tissue for the multilamellar lipid sheets of SC, and oil red O stain for neutral lipids of the SC. Layers of the SC were evaluated by 0·1% methylene blue stain after alkaline expansion, and TEWL was measured by Evaporimeter EPI. The TCS-treated atrophic skin had fewer layers of horny cells, mean 9–4 layers, than the normal control skin, 18 layers (P<0·001) and increased TEWL of 21·3g/m² compared with the control skin TEWL of 6·7 g/m²(P<0·01). The mean neutral lipid content of the SC was also significantly lower (P<0·001). Moreover, ultrastructural studies revealed a marked decrease in both the numbers of intercellular lipid lamellae of SC and membrane-coating granules of stratum granulosum in the atrophic skin. These results suggest that the diminution in the SC intercellular lipid lamellae and SC cell layers play an important part in the pathogenesis of barrier dysfunction after long-term use of TCS.     

Vacuolating Toxin Gene Polymorphism among Helicobacter pylori Clinical Isolates and Its Association with m1, m2, or Chimeric vacA Middle Types

Background: Helicobacter pylori vacuolating cytotoxin encoded by vacA plays an essential role in H. pylori-related pathogenesis. Specific vacA alleles are believed to be associated with increased virulence. Association among vacA polymorphism, vacA middle genotypes, and various H. pylori-related diseases was thus investigated. Methods: Eighty-nine isolates from patients with various gastrointestinal diseases were examined for restriction fragment length polymorphism (RFLP) of the 2.0-kb polymerase chain reaction-amplified vacA middle region. Further genetic heterogeneity was assessed with ureA-ureB RFLP. Results: Twenty-eight distinct vacA RFLPs were seen among 89 isolates. Each pattern was associated with one specific vacA middle genotype. The association of specific RFLPs with certain clinical manifestations was noted among six common groups. Further RFLP analysis of the 2.4-kb ureA-ureB segment from isolates in four popular vacA RFLPs showed high genetic variation. Conclusions: The vacA genetic polymorphism may be associated with different gastrointestinal diseases.     

Correlation between white blood cell count and metabolic syndrome in adolescence

BACKGROUND: Metabolic syndrome (MetS) is associated with increased risk for diabetes and coronary heart disease. Data suggest that MetS starts even in children. Thus, it is important to understand the role of MetS and the risks related to it. Furthermore, white blood cell count (WBCC) is available in routine examination and it has been proved to be related to risks of MetS. METHODS: A total of 1657 subjects aged 14-19 years were enrolled, with normal WBCC (< or =10 x 10(9) cells/L). The subjects were divided into four quartiles according to WBCC (WBCC1-4, from the lowest to highest WBCC) in both genders. RESULTS: The female subjects had significantly lower systolic blood pressure, fasting plasma glucose (FPG), triglyceride (TG), body mass index (BMI) and higher high-density lipoprotein-cholesterol (HDL-C) than the male subjects. When comparing the risks of the quartiles of WBCC, WBCC4 had significant higher BMI than WBCC1 and WBCC2 in both genders; and lower HDL-C than WBCC3 in male subjects. On multiple regression WBCC was positively related with BMI and TG and negatively related to HDL-C in male subjects. In female subjects only BMI was positively correlated with WBCC. Subjects with MetS did not have significant higher WBCC than those without MetS. CONCLUSIONS: In adolescents with normal WBCC, BMI is significantly related to the levels of WBCC and is the earliest component of MetS to be noted in adolescents. Elevated TG and decreased HDL-C could also be important markers for future risk factors only in male subjects.     

The Association between health-related quality of life and prosthetic status and prosthetic needs in Taiwanese adults

Summary  The objective of this study was to describe aspects of prosthetic statuses and needs and to evaluate their relationship with health-related quality of life in Taiwan. The study participants, aged 18 years and above, were recruited from a community survey, and each of the total 2469 participants received a dental examination and completed a questionnaire. Multivariable analysis was used to assess the adjusted means of health-related quality of life (SF-36) in both prosthetic status and need. The results showed that 12·6% of those aged 65 years and above were edentulous. The proportion of prosthetic need increased as age increased (39·7% to 61·3%). Multivariate analysis revealed that participants with 'removable prosthesis' had higher physical health scores than those with 'non-removable prosthesis'. The scores of mental health measurement decreased in people with need for full prostheses in relation to people without need for any prosthesis. Therefore, fulfilling prosthetic needs is not only about recovering oral masticatory function, but also concerns improvement of both physical and mental health-related quality of life.     

The use of topical 5% lignocaine ointment for the relief of pain associated with post-operative nasal packing

Packing of the nasal cavity remains a common routine precautionary measure following septal surgery. The nasal pack and its removal 24 h later are often cited by patients as the most painful aspects of septal surgery. We present the results of a randomized, prospective controlled trial of the use of topical 5% lignocaine ointment as a method of pain relief following post-operative nasal packing. Post-operative pain as measured using a visual analogue scale at 3 h post-operatively was halved in patients receiving a lignocaine impregnated nasal pack compared with those having a standard vaseline gauze pack (P < 0.05). Pain scores at 6 h post-operatively and at pack removal were also reduced, but these failed to reach significance. No patients suffered reactionary haemorrhage. The use of topical lignocaine ointment is safe and may have a place in the relief of pain due to post-operative nasal packing.     

Prospective, Randomized, Blinded Study of a New Wound Closure Film Versus Cutaneous Suture for Surgical Wound Closure

BACKGROUND Wound closure devices include sutures, tissue adhesives, adhesive strips, and staples. Recent studies suggest no differences between various tissue adhesives and sutures for dehiscence, infection, and satisfaction when assessed by patients or surgeons. To date, no studies have investigated ClozeX (Clozex Medical LLC, Wellesley, MA, USA), a novel adhesive strip, for closure of surgical incisions.
OBJECTIVE To compare surgical wounds repaired with ClozeX versus suture.
METHODS A prospective, randomized study was conducted, in which 15 patients with surgical incisions were allocated to closure with ClozeX on half of the wound and monofilament suture on the other half. Physician satisfaction with blinded assessment, patient satisfaction, complication rates, and closure times were recorded.
RESULTS Application with ClozeX was faster than with suture ( p =.007). There were no complications in either group. Sixty-nine percent of the patients gave ClozeX a higher satisfaction score ( p =.02). More physicians were satisfied with the ClozeX half than with the suture half ( p =.007).
CONCLUSIONS This pilot study demonstrates ClozeX to be a safe and effective closure device. The cosmetic outcome seems to be at least as good as simple running suture. Physicians and patients were generally more satisfied with ClozeX. No difference was found in the rate of dehiscence or infection between the groups.