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Biomedical subjects

J Lin

Publications and source records attributed to J Lin.

At least 235 records · Page 13Linked to original sources
PubMed2000

Accuracy, utility, and cost of frozen section margins in head and neck cancer surgery.

OBJECTIVES: Intraoperative frozen section analysis of surgical margins is widely used in head and neck cancer surgery. This study evaluates frozen section accuracy relative to permanent controls and final margins from the entire specimen, the rate at which frozen sections impact intraoperative management, and the resultant cost. STUDY DESIGN: Retrospective. METHODS: From 1997 to 1999 the frozen section results, permanent controls, and final tumor margins from 80 consecutive patients undergoing 420 intraoperative frozen section margins for head and neck malignancy were reviewed. RESULTS: A 98.3% accuracy rate (sensitivity, 88.8%; specificity, 98.9%) was found compared with permanent sections of the same tissue. However, 40% (8 of 20) of patients with positive final margins on the resection specimen, and 100% (15 of 15) with close (<5 mm) margins were not detected by frozen section analysis. The overall accuracy of frozen section in the evaluation of close or positive final margins was 71.3% (sensitivity, 34.3%; specificity, 100%). In addition, 5% (4 of 80) of patients potentially benefited from intraoperative frozen section by virtue of immediate margin revision. The estimated cost of intraoperative frozen section averaged as much as $3,123 per patient, with a cost-benefit ratio of 20:1. CONCLUSIONS: Intraoperative frozen section margins are accurate, but they are costly and cannot reliably eradicate positive final margins. Patients with early-stage lesions and those undergoing re-resection for recurrence or salvage surgery after radiation failure derived the greatest potential benefit from frozen section margins.

Cost-Benefit Analysis↗
PubMed2000

Interleukin-8 as a predictor of the severity of bacteremia and infectious disease.

The relationship between cytokines and sepsis has been studied frequently in the intensive care unit (ICU). However, the determination of cytokines in patients as they enter the emergency department (ED) would be more meaningful in predicting the outcome of infection. This study investigated plasma interleukin-8 in the ED as the predictor of bacteremia and sepsis. One hundred patients admitted through the ED with signs of systemic inflammatory response syndrome were studied. Plasma IL-8, IL-6, and tumor necrosis factor (TNF) were assayed by enzyme-linked immunosorbent assay. Patient's data were evaluated using the APACHE II scoring system as predictive factors of morbidity and mortality. Plasma IL-8 (149 pg/mL) detected bacteremia with a positive predictive value of 90.9% and a specificity of 98.7%. Results indicated that the odds ratios (ORs) of bacteremia were 24.78 (P < 0.01, CI = 2.27-270.8), 5.42 (P < 0.05, CI = 1.37-21.4), and 6.05 (P < 0.05, CI = 1.36-26.8) for IL-8, IL-6, and APACHE II, respectively. Occurrence of bacteremia was highly correlated with increases in plasma IL-8 (P < 0.01). IL-8 (OR = 8.25, CI = 1.03-65.9) and APACHE II scores (OR = 12.6, CI = 2.24-70.4) were found to be significantly better predictive factors of mortality (P < 0.01) than IL-6 (OR = 3.60, CI = 0.57-22.7), TNF (OR = 0.24, CI = 0.01-11.0) and age (OR = 1.02, CI = 0.98-1.06). During bacteremia, IL-8 also correlated well with patient use of a ventilator (P < 0.01, OR = 2.43, CI = 2.41-311.19), use of vasopressors (P < 0.05, OR = 2.67, CI = 1.79-370.78), length of stay in the hospital (P < 0.01, OR = 3.14, CI = 1.87-988.31), and stay in the ICU (P < 0.01, OR = 2.51, CI = 2.98-449.80). Measuring IL-8 on patients in the ED with apparent bacterial infections appears to be a reliable predictor of bacteremia and the severity of disease.

APACHE↗
PubMed2000

Whole-genome trees based on the occurrence of folds and orthologs: implications for comparing genomes on different levels.

We built whole-genome trees based on the presence or absence of particular molecular features, either orthologs or folds, in the genomes of a number of recently sequenced microorganisms. To put these genomic trees into perspective, we compared them to the traditional ribosomal phylogeny and also to trees based on the sequence similarity of individual orthologous proteins. We found that our genomic trees based on the overall occurrence of orthologs did not agree well with the traditional tree. This discrepancy, however, vanished when one restricted the tree to proteins involved in transcription and translation, not including problematic proteins involved in metabolism. Protein folds unite superficially unrelated sequence families and represent a most fundamental molecular unit described by genomes. We found that our genomic occurrence tree based on folds agreed fairly well with the traditional ribosomal phylogeny. Surprisingly, despite this overall agreement, certain classes of folds, particularly all-beta ones, had a somewhat different phylogenetic distribution. We also compared our occurrence trees to whole-genome clusters based on the composition of amino acids and di-nucleotides. Finally, we analyzed some technical aspects of genomic trees-e.g., comparing parsimony versus distance-based approaches and examining the effects of increasing numbers of organisms. Additional information (e.g. clickable trees) is available from http://bioinfo.mbb.yale.edu/genome/trees.

Computational Biology↗
PubMed2000

Protein folds in the worm genome.

We survey the protein folds in the worm genome, using pairwise and multiple-sequence comparison methods (i.e. FASTA and PSI-blast). Overall, we find that approximately 250 folds match approximately 8000 domains in approximately 4500 ORFs, about 32 matches per fold involving a quarter of the total worm ORFs. We compare the folds in the worm genome to those in other model organisms, in particular yeast and E. coli, and find that the worm shares more folds with the phylogenetically closer yeast than with E. coli. There appear to be 36 folds unique to the worm compared to these two model organisms, and many of these are obviously implicated in aspects of multicellularity. The most common fold in the worm genome is the immunoglobulin fold, and many of the common folds are repeated in various combinations and permutations in multidomain proteins. In addition, an approach is presented for the identification of "sure" and "marginal" membrane proteins. When applied to the worm genome, this reveals a much greater relative prevalence of proteins with seven transmembrane helices in comparison to the other completely sequenced genomes, which are not of metazoans. Combining these analyses with some other simple filters allows one to identify ORFs that potentially code for soluble proteins of unknown fold, which may be promising targets for experimental investigation in structural genomics. A regularly updated worm fold analysis will be available from bioinfo.mbb.yale.edu/genome/worm.

Animals↗
PubMed2000

Alterations in fetal adipose tissue leptin expression correlate with the development of adipose tissue.

Control pig fetuses and fetuses hypophysectomized (hypox) at 70 days of gestation were treated with hormones on day 90. At 105 days of gestation, subcutaneous adipose tissue was prepared for morphological studies, leptin Northern blot and Western blot analysis. Fetal ontogeny studies showed that leptin mRNA in adipose tissue increased with morphological development, and the highest level of leptin mRNA was observed in 105-day fetal pigs. In hypox fetuses, levels of leptin mRNA were similar to those in controls. Treatment with either hydrocortisone (HC) or thyroxine (T(4)) resulted in a slight increase in leptin mRNA levels in hypox fetuses but not in intact fetuses. Supplementation with both HC and T(4) markedly stimulated leptin mRNA expression in both hypox and intact fetuses. Morphological data showed that hypox slightly enhanced lipid accretion and treatment of hypox fetuses with HC and T(4) increased lipid accretion to a greater degree than did either HC or T(4) alone. However, serum leptin levels were not influenced by age, hypox or hormone treatment. Leptin protein expression was not detected in adipose tissue of hypox or intact fetuses regardless of hormone treatment. Leptin protein was detected in adipose tissue of 7-day-old pigs and placenta. As compared to 7-day postnatal adipose tissue, placenta showed a higher level of leptin protein expression. Leptin mRNA expression in fetal adipose tissue was not correlated with body weight and organ weight. The expression of long-form leptin receptor mRNA was detected in fetal adipose tissue. Our results indicate that adipose tissue leptin may not be the main source of serum leptin in the fetus and may not be involved in general prenatal growth and development. But adipose tissue leptin may act as an autocrine or paracrine factor in the development of fetal adipose tissue.

Adipose Tissue↗
PubMed2000

MR imaging of anterior cruciate ligament reconstruction graft.

OBJECTIVE: The objective was to determine the MR imaging findings that differentiate intact anterior cruciate ligament reconstruction graft, partial-thickness tear, and full-thickness tear, using arthroscopy as the gold standard. MATERIALS AND METHODS: Sixteen consecutive MR imaging examinations were retrospectively and independently evaluated by two musculoskeletal radiologists for primary signs (graft signal, orientation, fiber continuity, complete discontinuity, and thickness) and secondary signs (anterior tibial translation, uncovered posterior horn lateral meniscus, posterior cruciate ligament hyperbuckling, and abnormal posterior cruciate ligament line) of anterior cruciate ligament reconstruction graft tear in 15 patients with follow-up arthroscopy. Results were compared with arthroscopy, and both receiver operating characteristic curves and kappa values for interobserver variability were calculated. RESULTS: Arthroscopy revealed four full-thickness graft tears, seven partial-thickness tears, and five intact grafts. Of the primary signs, graft fiber continuity in the coronal plane and 100% graft thickness in the sagittal or coronal plane were most valuable in excluding full-thickness tear. Complete discontinuous graft in the coronal plane also was valuable in diagnosis of full-thickness tear. Of the secondary signs, anterior tibial translation and uncovered posterior horn lateral meniscus assisted in differentiating graft tear (partial or full thickness) from intact graft. The other primary and secondary signs were less valuable. Kappa values were highest for graft fiber continuity and graft discontinuity in the coronal plane. CONCLUSION: Full-thickness anterior cruciate ligament graft tear can be differentiated from partial-thickness tear or intact graft by evaluating for graft fiber continuity (coronal plane), complete graft discontinuity (coronal plane), and graft thickness (coronal or sagittal plane).

Adolescent↗
PubMed2000

Elevated phosphorylation of AKT and Stat3 in prostate, breast, and cervical cancer cells.

We examined whether the persistent activation of AKT or Stat3 oncogene product is present in prostate, breast, and cervical cancer cells. We found that some prostate and breast cancer cell lines express high levels of phosphorylated AKT. Interestingly, the cancer cells, which only express low levels of phosphorylated AKT express high levels of phosphorylated Stat3. AKT or Stat3 is also highly phosphorylated in human papilloma virus-negative cervical cancer cells. Therefore, these results indicate that AKT and Stat3 are highly phosphorylated in some breast, prostate and cervical cancer cells, which may play a role in tumorigenesis of these cancers.

Breast Neoplasms↗
PubMed2000

[The relationship of polymorphism of angiotensinogen and angiotensin converting enzyme with essential hypertension].

OBJECTIVE: In order to investigate the candidate genes for essential hypertension(EH), the authors determined the frequencies of M235T allele variation in exon 2 of angiotensinogen(AGT) gene and angiotensin converting enzyme (ACE) gene in 95 normotensives and 87 hypertensives in Chinese. METHODS: Polymerase chain reaction combined with restriction enzyme digestion was used to detect the variation AGT gene while PCR was used to determine ACE gene polymorphism. RESULTS: T235 allele frequency was significantly higher in hypertensive patients than in controls (0.45 vs 0.33, P<0. 05) and it was noticeably higher in male hypertensives. The frequency of ACE D allele in the EH patients with family history was higher than that in controls(0.59 vs 0.41,P<0.05). CONCLUSION: The variation of AGT gene was involved in the pathogenesis of hypertension, especially in male. The ACE D allele was associated with EH with family history.

Alleles↗
PubMed2000

[Preparation of biological bone carrier].

A series of studies on biological bone carrier (BBC), including preparation methods, components analysis, animal implantation test, biomechanical strength, ultrastructure, cross antigenicity and clinical application are reported in this article. Comprehensive process was adopted to reduce the antigen of BBC. As a substitute for bone, BBC has the following merits: (1) good biocompatibility; (2) suitable mechanical strength; (3) natural porous structure and porosity; (4) absorbability and replaceability in host; (5) unlimited sources, ready availability and simplicity in process and storage; (6) both functions of osteoconductability and osteoinductability can be developed after BBC combined with BMP.

Animals↗
PubMed2000

[Study on women with abnormal uterine bleeding treated by hysteroscopic electric resection].

OBJECTIVE: To evaluate the efficacy, prognosis and influences of hysteroscopic electrosurgery in treating abnormal uterine bleeding (AUB). METHODS: Eighty two women with AUB were treated by hysteroscopic electric resection. Among them, 48 cases had submucous myomas, 29 cases endometrial polyps, 4 cases dysfunctional uterine bleeding, and 1 case had submucous myoma and endometrial polyps. RESULTS: The mean time of follow-up was 25.5 months. The effective rate of menstrual flow ameliorated was in 91.5% of the patients. Yet, the percentage of the effective rate was decreased gradually with time. The improved effective rates of dysmenorrhea, midcycle pain, premenstrual symptoms and perimenstrual symptoms were 83.3%, 60.0%, 60.0% and 62.7% respectively. The effective rate of total symptoms improved in endometrial thickness with < or = 5 mm was 91.3%, and that in endometrial thickness with > 5 mm was 63.6%. There is a significant difference between in endometrial thickness with < 5 mm and in endometrial thickness with < 5 mm (P < 0.05). The effective rate of total symptoms improved with drugs suppressing endometrium used in perioperation was 93.8%, and that with no drug used was 72.0%. There is also a significant difference between drug used and no drug used groups (P < 0.05). CONCLUSIONS: Hysteroscopic electric resection in treating AUB improves not only menstrual flow but also perimenstrual symptoms. The effectiveness and prognosis of this operation may be related to endometrial thickness and medical treatment.

Adult↗
PubMed2000

[The effect of estrogen on new bone formation in the implanted bone matrix in aged male rats].

OBJECTIVE: To study the effect of estrogen on new bone formation in the implanted bone matrix in aged male rats and on general bone metabolism. METHODS: The aged male rats were implanted with slices of bone matrix and subcutaneously injected with estrogen, androgen or the solvent for five weeks. The changes in bone histomorphometry, bio-mechanical parameters and urine deoxypyridinoline (Dpd) levels were observed as indexes of bone reabsorption. Calcium, organic phosphate, and alkalphophatase levels in serum and urine were also studied. RESULTS: (1) The areas of new bone formation were significantly larger in estrogen and androgen groups than in the control but without difference between estrogen and androgen groups. (2) The number of osteoclasts was higher in estrogen and androgen groups than in the control (P < or = 0.002) but without difference between estrogen and androgen groups. (3) Urine Dpd/Cr ratio was lower in estrogen and androgen groups than in the control and higher in the control than that obtained 5 weeks ago but without difference between estrogen and androgen groups. CONCLUSION: Estrogen and androgen are able to stimulate new bone formation in the implanted bone matrix and inhibit the reabsorption rate of systemic bones in aged male rats, but there was no difference between estrogen and androgen in these two respects under the conditions of this experiment.

Androgens↗