The treatment of epulis fissuratum of the oral cavity by CO 2 laser surgery

A clinical study was conducted on a group of 20 patients who presented with epulis fissuratum caused by denture wearing. CO 2 laser surgery was used to treat these patients and the cases were followed up over a two-year period. The advantage of CO 2 laser surgery on oral tissues was evident by the good response to healing four weeks postoperatively and beyond. No sutures or packing of any kind were used and the wound was allowed to granulate. Re-epithelialization occurred in all patients within 14 days and was complete after about 4 weeks. The lack of wound contraction, scarring, and good re-epithelialization combined with precise tissue destruction make CO 2 laser surgery ideal for this procedure when compared with conventional surgical techniques. The advantage of using CO 2 laser surgery has been demonstrated clinically in the patients treated in this study.     

Tyrosine phosphatase-like protein (IA-2) and glutamic acid decarboxylase (GAD65) autoantibodies: a study of Chinese patients with diabetes mellitus

Type 1 diabetes in most Asian populations may not have a salient autoimmune basis when assessed with single determinations of the major markers, islet cell antibodies (ICAs) and glutamic acid decarboxylase antibodies (GAD65ab). With the inclusion of antibodies to tyrosine phosphatase-like protein IA-2 (IA-2ab) as an additional major marker, we re-examined autoimmune diabetes in a group of Chinese patients. We studied 272 subjects at various stages of disease with blood samples procured for biochemical analysis. ICAs were measured by immunofluorescence, GAD65ab and IA-2ab by radioimmunoassay. Sixty-seven patients fulfilled clinical diagnosis of type 1 diabetes and the remaining 205 patients were type 2. Prevalence of single autoantibody type in recent-onset type 1 diabetes ( < 1 year duration; n = 47) showed 10.6% with ICAs, 44.7% GAD65ab and 36.2% IA-2ab. GAD65ab account for more than two-thirds of the markers found in type 1 diabetes. Combined analysis further showed that 51.1% had at least one antibody type, 31.9% with two or more antibodies and 8.5% with all three antibodies. Islet autoimmunity presence in childhood-onset type 1 diabetes improved with the addition of IA-2ab, though less impact was seen in the adult-onset. Similarly, combined analysis for type 2 patients with recent diabetes showed a modest increase to 13% with islet autoimmunity compared to 8% when assessed by GAD65ab alone. Combining IA-2ab and GAD65ab assays results detected slightly more immune-mediated diabetes, compared to using a single GAD65ab determination. Non-autoimmune causes need to be considered in the pathogenesis of type 1 diabetes in Chinese, particularly in adults.     

Human micro-insemination by injection of single or multiple sperm: ultrastructure

The process of micro-insemination by single or muhiple spermtransfer into the perivitelline space (PVS) or by direct sperminjection into oocytes was examined by transmission electronmicroscopy. Spermatozoa from normal and oligozoospermic menwere injected into oocytes, obtained from consenting IVF patients,mostly by zona-puncture using micromanipulators. Spermatozoawere washed by the Percoll or Ficoll methods and capacitatedusing Whittingham's T₆ or modified Tyrode's medium or incubatedin strontium medium before injection. The women were stimulatedby three IVF methods and oocytes were recovered by laparoscopyor ultrasonography. Sixty-one oocytes were cultured in T₆ orHam's F-10 media (3–24 h) and were subjected to micromanipulation.Four oocytes were also studied after zona-drilling. Normal 2-pronuclearova were developed after single-sperm transfer satisfying allmorphological criteria of fertilization. Both monospermic andpolyspermic fertilization resulted after multiple sperm transfer,indicating that a vitelline block to polyspermy may exist inhumans. The majority of oocytes examined were unfertilized.Spermatozoa with intact or reacted acrosomes and those undergoingthe acrosome reaction were found in the PVS and in the ooplasm.Abnormal spermatozoa were also seen in these locations. Quantitatlonof acrosomal status in 16 oocytes after multiple-sperm transfer,revealed that 24% of spermatozoa were acrosome reacted or reactingin the PVS following Ficoll entrapment, while 76% of spermatozoawere intact (33% of these abnormal). Sperm transfer seemed tobe the least invasive, while direct sperm injection was comparativelydestructive to oocytes. Drilling with acid made larger breachesin the zona when compared with mechanical perforation and spermatozoaoccasionally escaped through breaches. Three 2-pronuclear ovaobtained after multiple sperm transfer have resulted in twopregnancies, in cases of severe oligozoo spermia, during thecourse of this study.     

Involvement of microtubules in Kunjin virus replication

Summary Induction of microtubulin paracrystals (Pc) by Kunjin (KUN) virus occurred after 15 hours post-infection and were often associated with convoluted membranes (cm) and virus particles. Vinblastine sulphate which disrupts microtubulin, had an inhibitory effect on the virus production when added during the viral latent period. When infected samples were extracted with Triton X-100 and analysed by SDS-PAGE, four viral proteins were observed.     

Biocompatible nanofiber matrices for the engineering of a dermal substitute for skin regeneration

Natural and synthetic biodegradable nanofibers are extensively used for biomedical applications and tissue engineering. Biocompatibility and a well-established safety profile for polycaprolactone (PCL) and collagen represent a favorable matrix for preparing a dermal substitute for engineering skin. Collagen synthesized by fibroblasts is a good surface active agent and demonstrates its ability to penetrate a lipid-free interface. During granulation tissue formation, fibronectin provides a temporary substratum for migration and proliferation of cells and provides a template for collagen deposition, which increases stiffness and tensile strength of this healing tissues. The objective of this study was to fabricate nanofiber matrices from novel biodegradable PCL and collagen to mimic natural extracellular matrix (ECM) and to examine the cell behavior, cell attachment, and interaction between cells and nanofiber matrices. Collagen nanofiber matrices show a significant (p < 0.001) level of fibroblast proliferation and increase up to 54% compared with control tissue culture plate (TCP) after 72 h. The present investigation shows that PCL-coated collagen matrices are suitable for fibroblast growth, proliferation, and migration inside the matrices. This novel biodegradable PCL and collagen nanofiber matrices support the attachment and proliferation of human dermal fibroblasts and might have potential in tissue engineering as a dermal substitute for skin regeneration.     

Discordant quantitative detection of putative biomarkers in nodal micrometastases of colorectal cancer: biological and clinical implications

AIMS: Nodal expression of the carcinoembryonic antigen (CEA), cytokeratin 20 (CK20), and guanylyl cyclase C (GCC) genes was measured in tandem in patients with colorectal cancer (CRC) to assess whether there would be sufficient agreement between these markers in their ability to detect micrometastasis to qualify one of them as a universal marker, and whether frozen and paraffin wax embedded tissues would yield similar results. METHODS: One hundred and seventy five frozen lymph nodes (FT) and 158 formalin fixed, paraffin wax embedded lymph nodes (PET) from 28 CRC cases were analysed using gene specific quantitative real time polymerase chain reaction, carried out on the LightCycler system with SYBR Green chemistry. RESULTS: There was significant disparity in positive detection of the three biomarkers in FT versus PET, with notable agreement achieved only for CEA (66.6%) in FT versus PET in Dukes' B disease, and between CK20 and GCC (44.6%) in FT, also in Dukes' B disease. One patient with full concordance in all three tumour markers with both tissue types suffered a relapse and died within two years of follow up. CONCLUSIONS: There was considerable discordance in the positive detection of the three tumour markers in both tissue types (FT versus PET). This brings into question whether using a single tumour marker to detect micrometastasis in one tissue type (FT or PET) is adequately representative, and challenges the concept of universal markers for molecular CRC metastatic detection. Multiple tumour markers would predict more accurately the metastatic potential of Dukes' B CRCs.     

Electrospun P(LLA-CL) nanofiber: a biomimetic extracellular matrix for smooth muscle cell and endothelial cell proliferation

Poly(L-lactide-co-epsilon-caprolactone) [P(LLA-CL)] with L-lactide to epsilon-caprolactone ratio of 75 to 25 has been electrospun into nanofibers. The relationship between electrospinning parameters and fiber diameter has been investigated. The fiber diameter decreased with decreasing polymer concentration and with increasing electrospinning voltage. The X-ray diffractometer and differential scanning colorimeter results suggested that the electrospun nanofibers developed highly oriented structure in CL-unit sequences during the electrospinning process. The biocompatibility of the nanofiber scaffold has been investigated by culturing cells on the nanofiber scaffold. Both smooth muscle cell and endothelial cell adhered and proliferated well on the P(LLA-CL) nanofiber scaffolds.     

Development of a Western Blot Assay for Detection of Antibodies against Coronavirus Causing Severe Acute Respiratory Syndrome

To identify a major antigenic determinant for use in the development of a rapid serological diagnostic test for severe acute respiratory syndrome (SARS) coronavirus infection and to study the immune response during SARS coronavirus infection in humans, we cloned the full length and six truncated fragments of the nucleocapsid gene, expressed them, and purified them as glutathione S-transferase-tagged recombinant proteins. The reactivities of the recombinant proteins to a panel of antibodies containing 33 SARS coronavirus-positive sera and 66 negative sera and to antibodies against other animal coronaviruses were screened. A truncated 195-amino-acid fragment from the C terminus of the nucleocapsid protein (N195) was identified that had a strong ability to detect antibodies against SARS coronavirus. No cross-reaction was found between the N195 protein and antibodies against chicken, pig, and canine coronaviruses. The N195 protein was used to develop a Western blot assay to detect antibodies against SARS coronavirus in 274 clinically blinded samples. The specificity and sensitivity of this test were 98.3 and 90.9%, respectively. The correlation between our Western blotting assay and an immunofluorescence assay (IFA) was also analyzed. The results of our Western blot assay and IFA for the detection of SARS coronavirus-positive sera were the same. Thus, the N195 protein was identified as a suitable protein to be used as an antigen in Western blot and other possible assays for the detection of SARS coronavirus infection.