Biomedical subjects

T M Lin

Publications and source records attributed to T M Lin.

At least 19 recordsLinked to original sources

PubMed2004

Seroprevalence of Chlamydia pneumoniae infection in Taiwan.

OBJECTIVES: To survey the seroprevalence of Chlamydia pneumoniae (C. pneumoniae) infection in healthy subjects in Taiwan. MATERIALS AND METHODS: We used microimmunofluorescence antibody assay to survey the prevalence of antibodies to C. pneumoniae in 620 serum samples from healthy subjects aged 6 months to 86 years in Taiwan. RESULTS: The mean prevalence (+/-SD) of IgG antibodies against C. pneumoniae at titer greater than or equal 1:16 was 55.8% (range 7.8-81.8%). The antibody prevalence was low in children under the age of 10 years (7.8%), and increased rapidly with age. Most individual acquired infection during the second and third decades of life with highest antibody prevalence reached up to 81.8% at fifth decade of life and remained high (70%) thereafter. CONCLUSIONS: Chlamydia pneumoniae infection is highly endemic in Taiwan. These data contribute to the understanding of asymptomatic infections with C. pneumoniae in general population and should serve as a basis for studies on the role of C. pneumoniae infections and their related diseases.

Adolescent↗

PubMed2004

A CD14 promoter polymorphism is associated with CD14 expression and Chlamydia-stimulated TNF alpha production.

CD14, a pattern recognition receptor on monocyte and macrophage, plays a central role in innate immunity through recognition of bacterial lipopolysaccharide and initiation of inflammatory response. Recently, CD14/-260C>T promoter gene polymorphism has been found to be related to a risk of inflammatory diseases. Our results showed that the C allele frequency among Chinese in Taiwan was lower than those in Western countries. The membrane CD14 expression was significantly higher in TT as compared with CT and CC genotypes (P=0.034, 0.044, respectively). There was a higher level of soluble CD14 in TT and CT genotypes than in CC genotypes. In addition, TNFalpha production in whole blood was significantly higher in TT genotype than in CC genotype after stimulation by Chlamydiae. In conclusion, the single base pair polymorphism of CD14 promoter gene is associated with CD14 expression and Chlamydia-stimulated TNFalpha production, and may thus play some role in the chlamydia-induced inflammatory response.

Adult↗

PubMed2001

Role of the aryl hydrocarbon receptor in the development of control and 2,3,7,8-tetrachlorodibenzo-p-dioxin-exposed male mice.

Experiments were conducted to determine the role of the aryl hydrocarbon receptor (AhR) in the development of control and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-exposed C57Bl/6 male mice. Male and female mice heterozygous for the AhR (Ahr+/-) were mated, and pregnant females were dosed orally on gestation day 13 with corn oil vehicle or TCDD (5 microg/kg). Pups were necropsied on postnatal day (PND) 21, 35, and 90. Comparison of vehicle-exposed wild-type (Ahr+/+) pups with vehicle-exposed AhR knockout (AhRKO; Ahr-/-) pups confirmed and extended previous reports that development of the liver, heart, spleen, thymus, and kidney is affected by absence of the AhR. Lung, submandibular gland, testis, and epididymis weights were also affected, indicating that the AhR plays a role in normal development of these organs as well. The presence or absence of the AhR had no effect on the incidence of hydronephrosis, daily sperm production, or cauda epididymal sperm numbers in vehicle-exposed mice. TCDD caused numerous effects in wild-type mice that were absent in AhRKO mice; specifically, hydronephrosis, increases in relative liver and heart weight, decreases in absolute heart and lung weight, and decreases in absolute and relative thymus, submandibular gland, epididymis, and testis weight. In several cases, TCDD produced one effect in wild-type mice (reductions in body weight and absolute thymus, submandibular gland, and epididymis weight on PND 21; and reductions in absolute and relative submandibular gland and absolute testis weight on PND 35) but caused the opposite effect in AhRKO mice. In yet other cases (reduced relative spleen weight on PND 21 and reductions in absolute and relative thymus weight on PND 35), TCDD produced similar effects in wildtype and AhRKO mice. There were also cases in which TCDD significantly affected AhRKO mice without significantly altering the same endpoint in wild-type mice; absolute liver, lung, and kidney weight were increased and relative submandibular gland weight was decreased on PND 21; relative heart weight was reduced and absolute lung weight increased on PND 35; and relative liver weight was decreased on PND 90. Although many effects of TCDD required the presence of the AhR, these results provide evidence either for multiple forms of the AhR in mice (one or more of which are still present in AhRKO mice), or for AhR-independent effects of low-level TCDD exposure.

Animals↗

PubMed2001

Human monocyte-derived insulin-like growth factor-2 enhances the infection of human arterial endothelial cells by Chlamydia pneumoniae.

It has been shown that infection of human endothelial cells by Chlamydia pneumoniae is enhanced by co-culturing endothelial cells with human monocytes and is mediated by monocyte-derived soluble factors. This study was conducted to identify the infectivity-enhancing factor. Serum-free conditioned medium of human monocytic cells was fractionated by ultrafiltration. The enhancing activity was found in the fraction in the molecular mass range between 5000 and 10,000 kDa. Recombinant human insulin-like growth factor (IGF)-1 or -2, with a molecular mass of 7500 kDa, was added to the culture medium of human endothelial cells for growing C. pneumoniae. Only IGF-2 enhanced C. pneumoniae growth. Pretreatment of the conditioned medium with a monoclonal antibody against IGF-2 blocked the enhancing activity. This suggests that the infectivity-enhancing factor is IGF-2 and that paracrine interactions between monocytes and endothelial cells in vivo can induce secretory products and sustain infection with C. pneumoniae within atherosclerotic lesions.

Antibodies, Monoclonal↗

PubMed2001

An alternative dressing for skin graft immobilization: negative pressure dressing.

The key difficulty of skin grafting is keeping the graft immobilized on uneven surfaces involved with motion, such as the nuchal area, axilla, web spaces, and the perineal area. This study reports the development of a new idea of negative pressure dressing (NPD) to maintain good immobilization of the skin graft and, at the same time, not cause any significant distress in the patient's daily life. Furthermore, the components of this dressing are available in ordinary hospitals. In this report, there are eight cases of skin grafts which were applied by this method, and the average success rate was approximately 97%. Therefore, use of negative pressure dressings to safeguard immobilization of the skin graft is an appropriate alternative method for grafts on uneven or mobile surfaces.

Adolescent↗

PubMed2001

Endoscopic excision of benign tumors in the forehead and brow.

Twenty-five cases of benign tumor of the forehead and brow were excised successfully with endoscope-assisted surgery. The access incision was selected strategically behind the front hairline. For tumors in the middle of the forehead, the tumor was approached by subgaleal dissection. For those in the brow or temporal area, the dissection plane was just superficial to the deep temporal fascia. Patient age ranged from 3 to 59 years. The mass varied in size from 1.0 x 0.5 to 2.0 x 2.0 cm. There were 18 lipomas, 6 dermoid cysts, and 1 pilomatricoma. There was no residual mass or recurrence 1 to 24 months postoperatively. There was no paresthesia or numbness in the scalp. Patients and their families were greatly satisfied with this operation and the absence of visible scarring.

Adolescent↗

PubMed2001

Nonendoscopic harvest of the gastrocnemius muscle flap through a small incision.

Traditional gastrocnemius flap harvest requires a long skin incision, starting from the popliteal fossa to the mid leg. The authors designed three instruments to facilitate harvest of this flap through a small incision without the help of an endoscope in 10 patients. All 10 gastrocnemius muscle flaps survived with a 100% success rate.

Adolescent↗

PubMed2001

Abnormalities of sexual development in male rats with in utero and lactational exposure to the antiandrogenic plasticizer Di(2-ethylhexyl) phthalate.

Several members of the phthalate ester family have antiandrogenic properties, yet little is known about how exposure to these ubiquitous environmental contaminants early in development may affect sexual development. We conducted experiments to determine effects of in utero and lactational exposure to the most prevalent phthalate ester, di(2-ethylhexyl) phthalate (DEHP), on male reproductive system development and sexual behavior. Sprague-Dawley rats were dosed with corn oil or DEHP (0, 375, 750, or 1,500 mg/kg/day, per os) from gestation day 3 through postnatal day (PND) 21. Dose-related effects on male offspring included reduced anogenital distance, areola and nipple retention, undescended testes, and permanently incomplete preputial separation. Testis, epididymis, glans penis, ventral prostate, dorsolateral prostate, anterior prostate, and seminal vesicle weights were reduced at PND 21, 63, and/or 105-112. Additional dose-related effects included a high incidence of anterior prostate agenesis, a lower incidence of partial or complete ventral prostate agenesis, occasional dorsolateral prostate and seminal vesicle agenesis, reduced sperm counts, and testicular, epididymal, and penile malformations. Many DEHP-exposed males were sexually inactive in the presence of receptive control females, but sexual inactivity did not correlate with abnormal male reproductive organs. These results suggest that in utero and lactational DEHP exposure also inhibited sexually dimorphic central nervous system development. No major abnormalities were found in any of eight control litters, but DEHP caused severe male reproductive system toxicity in five of eight litters at 375 mg/kg/day, seven of eight litters at 750 mg/kg/day, and five of five litters at 1,500 mg/kg/day. These results demonstrate that the male reproductive system is far more sensitive to DEHP early in development than when animals are exposed as juveniles or adults. The effects of DEHP on male reproductive organs and sexual behaviors and the lack of significant effects on time to vaginal opening and first estrus in their littermates demonstrate that DEHP (and/or its metabolites) affects development of the male reproductive system primarily by acting as an antiandrogen. The pattern of effects of in utero and lactational DEHP exposure differed from patterns caused by other phthalate esters, and the preponderance of anterior prostate agenesis appears to be unique among all chemicals. These results suggest that DEHP acts partly by mechanisms distinct from those of other antiandrogens.

Androgen Antagonists↗

PubMed2001

Tarsal tunnel syndrome secondary to neurilemoma--a case report.

Peripheral nerve entrapment syndromes in the foot include those symptom complexes that are primarily neurologic in origin and result from embarrassment to any of the peripheral nerve trunks or branches of the foot. Tarsal tunnel syndrome usually is precipitated by compression of the tibial nerve posterior and distal to the medial malleolus. A neurilemoma is relatively uncommon in the foot. It is usually a solitary tumor that is almost exclusively benign and can be removed without jeopardizing the integrity of the nerve. Diagnosis is based on a thorough history and clinical pictures. Certain diagnostic modalities, ultrasound and MRI, have been employed to aid in diagnosis. Surgical excision of the tumor remains the treatment of choice.

Female↗

PubMed2001

Congenital multiple plaque-like glomangiomyoma in trunk--a case report.

Congenital glomus tumor is a rare variant of glomus tumor, and glomangiomyoma is the least frequent histological type of glomus tumor. We present a case of congenital multiple plaque-like glomangiomyoma in an 11-year-old child with multiple diffuse plaques on his right lateral trunk. Histopathologic study showed a picture of typical glomus cell undergoing transition to smooth muscle cell. After literature review, this might be the first case report of congenital multiple plaque-like glomus tumor in trunk with histological appearance of a glomangiomyoma.

Child↗

PubMed2001

Endometrioma in a cesarean section scar--a case report.

Scar endometriosis remains quite rare and there is only one case report in the literature of plastic surgery. We present a case of endometrioma appearing on the cesarean section scar. The classic symptom was a painful scar that became swollen and more tender during menstruation. The cause of surgical scar endometriosis is believed to be iatrogenic transplantation of endometrium to the surgical wound. Surgical excision remains the treatment of choice. This entity must be kept in mind by plastic surgeons evaluating patients who present with soft-tissue masses of the abdominal wall in the setting of previous combined hysterectomy and abdominoplasty.

Adult↗

PubMed2000

Experimental infection with bovine herpesvirus-4 enhances atherosclerotic process in rabbits.

An association of herpesvirus and atherosclerosis has been suggested by seroepidemiologic studies and detection of the virus in arterial tissues. To facilitate the studies of the pathogenic role of herpesvirus in atherosclerosis, we established a rabbit model of atherosclerosis with bovine herpesvirus type-4 (BHV-4). Forty New Zealand White rabbits were randomly divided into six groups. Groups 1, 2, and 3 were inoculated iv with BHV-4 and control Groups 4, 5, and 6 with normal saline. Groups 1 and 4 were fed a regular diet throughout the experiment; Groups 2 and 5 were fed a diet supplemented with 2% cholesterol for 3 weeks starting at 3 weeks postinoculation; and Groups 3 and 6 with a diet supplemented with 2% cholesterol for 6 weeks starting at 3 days postinoculation. Extensive atherosclerotic lesions in Groups 2, 3, and 6, and small lesions in two rabbits in Group 1 were observed, but no obvious lesions were observed in Groups 4 and 5. BHV-4 DNA was demonstrated by polymerase chain reaction and liquid hybridization in aortic sections, various tissue samples, and peripheral blood mononuclear cells of all infected rabbits. Our studies demonstrated that BHV-4 can accelerate the atherosclerotic process in rabbits, and that experimental infection of rabbits with BHV-4 can be a useful atherosclerosis model.

Animals↗

PubMed2000

Monocyte-endothelial cell coculture enhances infection of endothelial cells with Chlamydia pneumoniae.

To determine the mechanism(s) by which Chlamydia pneumoniae homes to and establishes persistent infection in atheromatous lesions, the effect of the interaction of monocytes/macrophages (U937 cells) with human umbilical vein endothelial cells (HUVECs) and transformed human arterial endothelial cells (HMEC-1s) on the susceptibility of endothelial cells to infection with C. pneumoniae was investigated. Infection was enhanced 4.7-fold (HUVECs) and 4.4-fold (HMEC-1s) after coculture at monocyte-to-endothelial cell ratios of 5 and 2.5, respectively. U937 cells also directly transmitted infection to the endothelial cells, and addition of U937 cell-conditioned media dose-dependently enhanced the infectivity 2.0- to 2.5-fold. The stimulation of infectivity was specific to endothelial cells, because coculturing of monocytes with epithelial cells did not enhance the susceptibility of epithelial cells to infection. The susceptibility of endothelial cells to infection with C. trachomatis and C. psittaci was not enhanced by the monocyte-derived factor(s).

Cell Communication↗

PubMed2000

Chlamydia, inflammation, and atherogenesis.

Atherosclerotic lesions are initiated and progress largely as a result of a chronic, fibroproliferative, inflammatory response. This review discusses how Chlamydia pneumoniae could conceivably contribute to this chronic inflammatory response and reports on recent in vivo and in vitro studies. In vivo studies in mice demonstrate that C. pneumoniae infection is disseminated to the artery wall following infection in the lung by alveolar macrophages. Recent in vitro studies show that infected U937 cells can directly transfer infection to endothelial cells and can indirectly increase the susceptibility of endothelial cells to C. pneumoniae infection. Loading of RAW 264.7 cells with modified forms of low-density lipoprotein increases the resistance of the cells to C. pneumoniae infection and also increases the susceptibility to the combined toxic effects of modified lipids and C. pneumoniae infection.

Animals↗

PubMed2000

Physiological role of the aryl hydrocarbon receptor in mouse ovary development.

The aryl hydrocarbon receptor (AhR) regulates the toxicity of environmental contaminants such as 2,3,7, 8-tetrachlorodibenzo-p-dioxin (TCDD). As the physiological role of the AhR in the ovary is unknown, the purpose of this study was to test the hypothesis that the AhR regulates the appearance and numbers of ovarian follicles. Ovaries were harvested from AhR-deficient (AhRKO) and wild-type mice on gestational day 18 (GD 18) and postnatal days (PND) 2-3, 8, 32-35, and 53. Complete serial sections of ovaries were evaluated histologically for the presence of germ cells and follicles. On GD 18, there was no difference in the number of germ cells per ovary between AhRKO and wild-type fetuses. However, by PND 2-3, AhRKO mice had significantly more fully formed primordial follicles (AhRKO = 38,440 +/- 3632 versus wild-type = 21,120 +/- 2688) and fewer single germ cells than wild-type mice (AhRKO = 12,696 +/- 1192 vs. wild-type = 18,160 +/- 720). On PND 8 and 32-35, there was no difference in the number of follicles between AhRKO and wild-type mice but by PND 53, AhRKO mice had significantly fewer antral follicles than wild-type (AhRKO = 3416 +/- 480 vs. wild-type = 6776 +/- 1024). Taken together, these results suggest that the AhR may play a role in the formation of primordial follicles and the regulation of antral follicle numbers.

Animals↗

PubMed2000

2,3,7,8-tetrachlorodibenzo-p-dioxin inhibits luminal cell differentiation and androgen responsiveness of the ventral prostate without inhibiting prostatic 5alpha-dihydrotestosterone formation or testicular androgen production in rat offspring.

In utero and lactational exposure to a single maternal dose of 1 microg 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)/kg causes some overt toxicity and impairs prostate growth in male offspring. As similar effects on the ventral prostate can be caused by decreased testosterone production during perinatal development, we determined whether intratesticular testosterone content, testicular responsiveness to gonadotropin stimulation, or plasma testosterone concentrations were reduced in fetal and newborn rats. Because these endpoints were not affected, the ability of TCDD exposure to inhibit synthesis of the proximal androgen in prostate development, 5alpha-dihydrotestosterone (DHT), from the circulating precursor testosterone and 5alpha-androstane-3alpha,17ss-diol (3alpha-Diol), was studied on postnatal days (PNDs) 14, 21, and 32. The ability of the ventral prostate to form DHT from 3alpha-Diol was slightly impaired on PND 14, but this transient effect was not statistically significant, and recovery was evident by PND 21. Subsequent experiments used organ culture to study the effects of in vivo TCDD exposure on androgen metabolism, androgen responsiveness, androgen receptor expression, and luminal epithelial cell differentiation after in vitro exposure to graded androgen concentrations. In utero and lactational TCDD exposure had no effect on DHT formation in organ culture, but transiently reduced the androgen -induced expression of prostatic-binding protein subunit C3, decreased ventral prostate epithelial cell androgen receptor expression, and inhibited the formation of androgen responsive luminal epithelial cells. These results suggest that TCDD exposure impairs prostate growth and androgen responsiveness by inhibiting prostatic epithelial cell differentiation.

3-Hydroxysteroid Dehydrogenases↗

PubMed2000

Endoscope-assisted correction of primary varicose veins.

The purpose of this study is to evaluate the possibilities and results of application of endoscopic surgery in the operation of primary varicose veins. With good illumination and magnified viewing, the varicosities, incompetent perforating veins, and healthy veins were clearly visualized. The incompetent perforating veins were clipped and divided securely. The varicose veins and tributaries were dissected and removed completely after being clipped and divided. The healthy veins were preserved if possible. Primary varicose veins in 43 limbs of 37 patients were operated. The operation was conducted through one access incision in 31 limbs (72%), two incisions in 11 limbs (25%), and three incisions in 1 limb. The mean number of incisions was 1.3 in each limb. Hematoma formation occurred in 1 patient due to the slipping of one clip on the third postoperative day. The other patients had uneventful postoperative courses. All 37 patients were reviewed 4 to 30 months postoperatively. Only one limb had recurrent varices at a new site. Ninety-seven percent of limbs (42 of 43) had no recurrence of varicose veins. Seventy-eight percent of patients (29 of 37) were extremely pleased with this operation. Although the other 22% of patients (8 of 37) appreciated this operation, they were not completely satisfied because some preoperative complaints persisted. In this series, the recurrent rate of varicose veins was low (1 in 43 limbs) and postoperative scarring was minimized, in addition to the advantages of endoscopic surgery. These results demonstrate that endoscopic surgery is a worthy alternative procedure for correcting primary varicose veins.

Adult↗

PubMed2000

Correction of scar contracture deformities of the big toe with a multiplanar distraction device.

A multiplanar distraction device was used in a 65-year-old woman for correction of multiplanar deformities of her right big toe. These deformities were caused by long-standing scar contracture after a crushing injury to the right foot. Without the necessity of other complicated procedures, the dorsal contracture and lateral deviation were corrected from 43 deg to 0 deg and from 22 deg to 0 deg respectively 3 weeks postoperatively. Kirschner wires were inserted temporarily for prevention of recurrence after removal of the frame, and were removed 6 weeks later. In follow-up after 8 months, the position of the big toe was stable and without recurrence of contracture. Application of the multiplanar distraction device simplified the surgical procedure to achieve this correction.

Aged↗