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Biomedical subjects

T M Lin

Publications and source records attributed to T M Lin.

At least 37 records · Page 2Linked to original sources

Continuous intra-arterial infusion therapy in hydrofluoric acid burns.

To determine the effect of continuous intra-arterial calcium gluconate infusion therapy on patients suffering from hydrofluoric acid dermal burns of the digits, clinical treatment was performed prospectively on 10 patients from January 1997 to December 1998 at the burn care unit of Kaohsiung Medical University Hospital. An arterial catheter was inserted transcutaneously through the radial artery of the involved hand. After confirmation of the proper position of the catheter, calcium gluconate was infused continuously with an ambulatory infusion pump. Rapid pain relief was achieved immediately after infusion. The rate of infusion was then tapered down gradually, and treatment was completed with no major therapeutic complication. All injured digits of these 10 patients were successfully salvaged with good cosmetic appearance and complete functional preservation. Compared with other conventional therapies, continuous intra-arterial calcium gluconate infusion therapy proved to be a safe, rapid, simple, portable, and effective method for treating hydrofluoric acid dermal burns.

Adult↗

Chlamydia pneumoniae induces inflammatory changes in the heart and aorta of normocholesterolemic C57BL/6J mice.

Chlamydia pneumoniae infection induces inflammatory changes in blood vessels in normocholesterolemic rabbits, but it is not known whether the same phenomenon occurs in other animal models. Thus, in this study, C57BL/6J mice were inoculated with C. pneumoniae. Inflammatory changes in the heart or aorta were observed in a small number of chronically infected mice. No evidence of atherosclerotic lesions was found in any of the mice. These findings suggest that chronic C. pneumoniae infection can induce inflammatory changes in the heart and aorta of C57BL/6J mice, but does not initiate definitive atherosclerosis.

Animals↗

Computed tomography findings of bony regeneration after radiotherapy for nasopharyngeal carcinoma with skull base destruction: implications for local control.

PURPOSE: To evaluate the response of bony destruction (BD) of the skull base following radiotherapy in nasopharyngeal carcinoma (NPC) and investigate the implications of bony regeneration (BR) on local control and its related factors. METHODS AND MATERIALS: Ninety patients with NPC with skull base destruction clearly demonstrated on computed tomography (CT) were reviewed. These patients have completed the prescribed treatment and received regular CT follow-up. A total of 338 sets of CT images of the head and neck were reviewed. The tumor response and the appearance of BR in the previous destructive part of the skull base were recorded and analyzed. The tumor response was divided into complete, partial, or no response. BR was defined as recalcification or sclerotic change with partial or complete healing in the previous osteolytic bony defect. Local failure was confirmed either by pathological or merely by imaging studies showing progression of tumor in consecutive radiological pictures. RESULTS: The distribution of specific sites of bony destruction (BD) in these patients included the sphenoid bone (68%), paracavernous sinus area (48%), petrous apex (47%), clivus (44%), pterygoid plates (20%), and others (7%). The CT showed 57 patients (63%) had BR. All were observed within 1 year after treatment. Sixty-two patients (69%) had complete tumor response after treatment. Analyzed by logistic regression method, tumor response after treatment was found to have a statistically significant correlation with BR (p = 0.0004). Most BR (55/57) was demonstrated in patients with complete tumor response. The 3-year actuarial local control rate was 54 % in these patients. The local control was quite different in the comparison of patients with BR versus those with persistent BD (77% vs. 21%, p < 0.0001). Multivariate analysis showed that patients with complete tumor response or with BR on imaging had statistically better local control than those without either of the two findings (p < 0.05). CONCLUSION: Appearance of BR at previous destructive skull base following radiotherapy for NPC patients could be clearly demonstrated on CT. Bony regeneration significantly correlated with treatment response and local control. Although the underlying significance of BR was unknown, to predict the outcome after treatment, the appearance of BR shown on CT may imply the complete eradication of tumor in this area.

Adolescent↗

Persistent infection of bovine herpesvirus type 4 in bovine endothelial cell cultures.

Herpesviruses can establish a persistent infection in the cells and tissues of their natural hosts and thus may produce diseases due to cytolytic infections. We have isolated a herpesvirus from a bovine vascular endothelial cell culture after continuous subculturing. Typical cytopathic changes were observed in bovine endothelial cell cultures 2 days after inoculation of the virus. The virus had an icosahedral nucleocapsid of 100-150 nm in diameter and an envelope. The sequences of some DNA fragments of the virus were highly homologous to those of the bovine herpesvirus type 4 (BHV-4) strains. The DNA restriction maps of the virus and the reference strains of BHV-4, DN 599 and Movar 33/63 were very similar but not identical. Therefore, the newly isolated virus has been designated Taiwan strain. The presence of BHV-4 DNA in apparently normal bovine endothelial cell cultures was shown by Southern blot hybridization with the BamHI fragment of the newly isolated BHV-4 and was further confirmed by digestion of the DNA with BamHI plus AccI. In conclusion, we have demonstrated that BHV-4 persisted in the bovine endothelial cell cultures and continuous subcultures could lead to the production of infectious viral particles.

Animals↗

Bilateral gluteal dystrophic calcification--a case report.

Abnormal deposits of calcium in the injured and necrotic tissue (dystrophic calcification) are not considered to be rare conditions in human pathologic records. We report a severe case of bilateral gluteal calcification that has not often been found in the literature. It was caused by multiple intramuscular and/or subcutaneous injections. The multiple lumps along with the chronic unhealed fistula over the gluteal regions were successfully treated by carbon dioxide laser without recurrence. The pathogenesis of variable possibilities were reviewed and discussed.

Calcinosis↗

The use of composite acellular allodermis-ultrathin autograft on joint area in major burn patients--one year follow-up.

Scar contracture is a major long-term sequelae of meshed split-thickness skin grafts in the case of full-thickness burn injuries, and especially in joint areas. Severe contracture around joints may lead to loss of mobility. The thickness of the dermis in the autograft plays a major role in the functional and cosmetic outcomes of the third degree burn. How to replace lost dermis is a major problem in skin restoration following severe burns. The human allograft skin (AlloDerm) is an acellular dermal matrix with normal collagen bundling organization and intact basement membrane complex. We present 12 cases of clinical application of a composite grafting technique in which the allogeneic skin (AlloDerm) provided source of dermis, and an ultrathin autograft (0.004-0.006 inch in thickness) provided epidermis. In these patients, The composite grafts were applied to full-thickness burn wounds over various articular skin surfaces. The average skin graft take rate was 91.5%. These ultrathin autografts allow the donor sites to heal faster. The mean time of donor site reepithelization was 6 days. All patients had a nearly normal range of joint motion (average 95% of normal) after one year's follow up. Wound assessment over time has shown supple skin that has been resistant to trauma and infection. The cosmetic results were judged to be fair to good by surgeons and patients after one year's follow up.

Adult↗

A piezoelectric quartz crystal sensor for the determination of coagulation time in plasma and whole blood.

A Peizoelectric Quartz Crystal (PQC) system possessing an adequate sensitivity to a slight viscosity change is employed to monitor the blood coagulation. In the case of an anticoagulated plasma specimen, prothrombin time (PT) was determined by the PQC sensor on the basis of the introduction of tissue thromboplastin (TF) and calcium ion. Discussing the PQC data statistically, we found that at 90% of the total frequency shift (delta f) the best linear relationship in a double-logarithmic plot of PT versus TF concentration in the range of 5.466-22.311 unit/ml is shown. The PQC result was compared with commercial optical coagulometry and showed a good linear correlation (ca. 0.98). The clotting and recalcification of whole blood were also studied by the PQC system. The testing time for one measurement could be completed within 20 min. and had a good agreement with that obtained conventionally.

Biosensing Techniques↗

The distally based lateral adipofascial flap.

The distally based lateral adipofascial flap can be based either on the lowermost perforator or the anterior perforating branch of the peroneal artery avoiding sacrifice of the main peroneal artery. It has been used successfully to resurface soft tissue defects either on the lateral or medial aspect of the lower third of the leg in 13 cases. The size of these flaps varied from 2.0 cm x 5.0 cm to 4.5 cm x 15.0 cm in size. These cases had minimal donor site morbidity and had positive aesthetic results. The advantages were: 1. Choice of either the lowermost perforator or the anterior perforating branch giving a wide arc of rotation; 2. Preservation of the superficial peroneal nerve; 3. Primary closure of the donor site.

Adult↗

The role of CD8+ cells and CD11a in the rejection-reaction of the allogeneic microskin grafting.

By using histological tissue sections and immunohistochemical stains, the rejection-reaction of the allogeneic microskin grafting of rabbit-skin wounds was studied. The results revealed that the rejection started early in the days following transplantation. In the second week following transplantation, severe graft rejection with epithelial destruction was noted. In addition, an increase of CD8+ cells and expression of the adhesion molecule-CD11a-were also noticed and persisted throughout the days following transplantation. These findings suggest that the CD8+ cells and CD11a may play a major role in the rejection of allogeneic skin grafting.

Animals↗

Cloning and characterization of TDD5, an androgen target gene that is differentially repressed by testosterone and dihydrotestosterone.

By using mRNA polymerase chain reaction differential display technique (DDPCR), we have identified one early responsive cDNA fragment, TDD5, from a 5alpha-reductase-deficient T cell hybridoma. The DDPCR profiles of TDD5 suggest that its expression can be repressed by testosterone (T) within 2 hr. More importantly, both DDPCR and Northern blot analysis further demonstrated that the expression of TDD5 was differentially repressed by T and dihydrotestosterone (DHT) at the mRNA level. To our knowledge, this is the first androgen target gene to show a preference in response to T over DHT in cell culture. TDD5 is expressed in several tissues with particular abundance in kidney. Full-length TDD5 cDNA (2,916 bp) encodes a protein with a calculated molecular weight of 42,000. Finally, our animal studies further confirm that TDD5 mRNA levels can be repressed to the basal level 8 hr after DHT administration. The isolation and characterization of the early-responsive androgen target gene TDD5 and the fact that TDD5 mRNA level can be differentially regulated by T and DHT may provide a useful tool to study the molecular mechanism of androgen preference on target gene regulation.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗

Uromodulin and Tamm-Horsfall protein induce human monocytes to secrete TNF and express tissue factor.

Effects of uromodulin (URO) and Tamm-Horsfall protein (THP), the most abundant proteins in the urine of pregnant and normal women, respectively, on the induction of TNF-alpha secretion and tissue factor (TF) expression of human monocytes were studied. THP, URO, and its fragments stimulated human mononuclear cells to proliferate and secrete TNF-alpha. The release of URO and THP-induced TNF-alpha in monocytes was dependent upon protein tyrosine kinase activation that results in tyrosine phosphorylation. URO and THP also induced TF expression of human monocytes and monocytic cell line U937 in a dose-dependent manner. TF expression was transient, reached its peak at 6 h and declined toward basal levels by 24 h. Reverse transcriptase-PCR and dot-blot analysis confirmed the induction of TF mRNA synthesis. URO and THP-induced TF expression were inhibited by actinomycin D and pentoxifylline further supporting the requirement of de novo TF mRNA synthesis. The possibility of LPS contamination of URO and THP was excluded because: 1) URO and THP-induced TF expression were inhibited by specific Ab; 2) URO was less capable of inducing TF in HUVEC as compared with LPS; 3) polymyxin B blocked the induction of Limulus clotting by LPS but not by URO and THP; 4) both LPS-sensitive (C3H/HeN) and -resistant (C3H/HeJ) mice produced little or no TNF-alpha after URO challenge. Therefore, our findings suggest that URO and THP play a significant role in the innate immunity of the urinary system and that the immunostimulatory activity of URO is potentially useful for immunotherapy.

Animals↗

Susceptibility of endothelial cells to bovine herpesvirus type 4 (BHV-4).

The sensitivity of two different types of cells to bovine herpesvirus type 4 (BHV-4) was compared by median tissue culture infectious dose (TCID50) assays. The bovine arterial endothelial (BAE) cell culture derived from bovine carotid arteries was 100-1000 times more sensitive to two strains of BHV-4, Movar 33/63 and DN 599, than Madin Darby bovine kidney (MDBK) cell line commonly used for the propagation of these viruses. BAE cell cultures infected with BHV-4 displayed cytopathic effects (CPE) earlier and more prominently than the MDBK cells infected with the same viruses. BAE cells were also more sensitive than MDBK cells in conventional plaque assays in that the former developed well characterized and easily recognized plaques after infection with the viruses. BAE cells, which are proved to be exceptionally susceptible to BHV-4, can be used in the detection and quantitation of BHV-4.

Animals↗

Adipofascial flap of the lower leg based on the saphenous artery.

The adipofascial flap of the lower leg based on the saphenous artery is a modification of the saphenous artery flap. It has been used successfully in 5 patients for reconstruction of soft tissue defects around the knee and superior third of the tibia. The size of these flaps ranged from 5 x 12 cm to 5 x 18 cm. All flaps survived completely. These cases had minimal donor site morbidity because their donor sites were closed primarily with the preserved overlying skin.

Adolescent↗

The lateral calcaneal artery adipofascial flap.

The lateral calcaneal artery adipofascial flap is a modification of the lateral calcaneal artery skin flap. It has been used successfully in five patients. In comparison to the skin flap, it has the advantages of more versatile clinical applications, better aesthetic result of the donor site and sural nerve preservation.

Adipose Tissue↗

The expression of locomotor circadian rhythm in female German cockroach, Blattella germanica (L.).

Fifteen percent of intact female German cockroaches (n = 13), Blattella germanica (L.) (Dictyoptera: Blattellidae), had weak free-running locomotor rhythmicity under 28 degrees C and constant darkness conditions. However, 86% of ovariectomized females (n = 14) showed a strong free-running rhythm under the same conditions with a circadian period of 23.60 +/- 0.15 h, similar to the male's period of 23.45 +/- 0.03 h. In addition, the locomotory activities occurred mainly during the subjective night under DD conditions as was the case in males. These results indicated that female locomotion was under the control of a circadian oscillator, which was masked by the existence of ovaries. This internal masking effect could be removed by the existence of males, but females had no effect on the locomotor pattern of another female. Since the male failed to entrain female locomotion, its role as a zeitgeber was excluded. That the locomotory pattern of the females still coincided with their reproductive cycle when exposed to male odor suggests that exposure to a male only partially removed the internal masking effects.

Animals↗

Multiple functions of the TR2-11 orphan receptor in modulating activation of two key cis-acting elements involved in the retinoic acid signal transduction system.

The testicular receptor 2 (TR2) orphan receptor binds to hormone response elements (HREs) consisting of two AGGTCA half-site direct repeat consensus sequences (DR) with various spacing in the following order: DR1 > DR2 > DR5 DR4 DR6 > DR3. When binding to natural HREs, TR2 orphan receptor remains flexible with higher binding affinities to (a) cellular retinol-binding protein II promoter region (CRBPIIp) (DR1), SV40 +55 region (DR2), and retinoic acid response element beta (RARE beta) (DR5) than to (b) NGFI-B response element (NBRE) and also to (c) the palindromic thyroid hormone response element (TREpal). This wide spectrum of HRE recognition sequences suggests possible versatility of the TR2 orphan receptor in cross-talking with other signal transduction systems. Chloramphenicol acetyltransferase (CAT) assay demonstrates that the TR2 orphan receptor competes with CRBPIIp- and RARE beta-CAT gene expression activated by retinoid X receptor alpha (RXR alpha) and retinoic acid receptor alpha (RAR alpha)/RXR alpha heterodimers, respectively. In addition, this suppression may not be mediated by the formation of heterodimers between TR2 orphan receptor and either RXR alpha or RAR alpha. Instead, a minimum of 100-fold higher affinity of the TR2 orphan receptor for CRBPIIp than RXR alpha may explain why the TR2 orphan receptor dominates RXR alpha in CRBPIIp-CAT activation. Together, our data suggest that the TR2 orphan receptor may be a master regulator in modulating the activation of two key HREs, RARE beta and CRBPIIp, involved in the retinoic acid signal transduction pathway.

Animals↗

Reconstruction of the upper leg and knee with a reversed flow saphenous island flap based on the medial inferior genicular artery.

Soft-tissue defects around the knees and below-the-knee amputation stumps are difficult to reconstruct. We present an option for reconstruction of these defects. Reversed flow saphenous island flaps, based on the medial inferior genicular artery, were successfully transferred in 6 patients. All wounds healed well postoperatively. The donor defect can be closed directly when the width is less than 7 cm. This is a thin and reliable fasciocutaneous flap that is useful in covering defects around the knee joint, popliteal fossa, upper half of the leg, and below-the-knee amputation stump.

Adult↗

Variants of the human prostate LNCaP cell line as tools to study discrete components of the androgen-mediated proliferative response.

Androgens regulate the proliferation of their target cells through a sequential two-step mechanism. In the first step, androgens increase proliferation rates; following this proliferative response, a second step of proliferative shutoff ensues. Human prostate LNCaP cell variants were used to assess whether the proliferative and shutoff effects of androgens could be segregated selectively by manipulating the hormonal milieu. The LNCaP-FGC and LNCaP-LNO cell lines were derived from the same biopsy specimen but exhibited different proliferative responses. Cell proliferation was inhibited by treatment with 10% charcoal-dextran stripped human serum in the LNCaP-FGC variant but not in LNCaP-LNO cells. Physiological androgen concentrations induced a proliferative shutoff in LNCaP-LNO cells (G1 arrest), an effect also expressed by LNCaP-FGC cells. This G1 arrest was irreversible in the LNCaP-FGC variant but was reversed upon androgen withdrawal in LNCaP-LNO cells. A new variant (LNCaP-TJA) was selected from LNCaP-LNO cells treated with 30 nM methyltrienolone for 4 months; these cells proliferated maximally regardless of the presence of androgens. All three cell variants had functional androgen receptors, and androgens induced prostate-specific antigen secretion. The androgen-induced proliferative shutoff in LNCaP-FGC and LNO cells was partially antagonized by antiandrogens and was not mediated by autocrine factors. Finally, the variant LNCaP cell lines described herein are probably representative of phenotypes present in prostate cancer patients during the course of this disease and may arise from selective pressure imposed by therapeutic protocols aimed at modifying the hormonal milieu of the host.

Androgen Antagonists↗