Experimental study of epithelialization of the muscle-only flap in the oral cavity

PURPOSE: The purpose of this study was to observe the epithelialization process of the muscle-only flap used for reconstruction of the oral mucosal defects. MATERIALS AND METHODS:Forty-three male adult Japanese rabbits were used. A superiorly based cleidomastoid muscle flap was designed after vascular assessment. The flap was transferred into the oral cavity to cover a mucoperiosteal defect made in the mandibular alveolus. Epithelialization of the flap was histologically evaluated at designated intervals. RESULTS: The flaps survived without ischemic necrosis. By 8 days postoperation, the flap was infiltrated by acute inflammatory cells and being replaced by granulation tissue originating from the adjacent tissues. The oral epithelial cells advanced onto this granulating muscle flap, with eventual coverage by 21 days. The granulation tissue matured to fibrous tissue with significant contraction by 2 months. At 6 months postoperation, abnormally hyperkeratinized epithelium was seen on the flap. This differed from the surrounding parakeratinized oral epithelium. CONCLUSIONS: The muscle-only flap in the oral cavity epithelializes after the granulation process.     

Diagnosis of lymphoma in the new millennium

Finally, it may be that if there were a complete understanding of lymphoid neoplasms, with tools and methods to dissect precisely each patient's cell of origin, genetic abnormality and level of differentiation or proliferation, every patient's lymphoma might be different, one from the other. One wonders whether such complete knowledge would be helpful. Each patient, given enough time and advanced technology, might prove to have a unique defect. Currently flow cytometry allows us to characterize patients into a reasonable number of subgroups for therapy. DNA and molecular biology techniques in the future may allow for gene replacement, gene piece insertion, antisense DNA inhibition and other exciting and as yet undreamed of miracles.     

Crystal structure of the actin-binding protein actophorin from Acanthamoeba

Tertiary butyl alcohol and trichloroacetic acid are known to be contaminants in drinking water. In order to evaluate the interactive toxicity of t-butyl alcohol with trichloroacetic acid, young male Wistar rats were dosed through water at a dose level of t-butyl alcohol (TBA)-0.5% (v/v), trichloroacetic acid (TCA)-25 ppm and a combined dose of TBA + TCA (0.5% v/v TBA-25 ppm TCA) for a period of 10 weeks ad libitum and were maintained on normal diet. The control animals received plain water and normal diet. The liver and kidney histology was undertaken to see whether subtoxic administration of TBA and TCA individually as well as combined administration for a period of 10 weeks would bring about any histological alterations. It was observed that TBA, TCA and TBA + TCA caused histological alterations in the liver such as centrilobular necrosis, vacuolation in hepatocytes and loss of hepatic architecture. TBA and TBA + TCA caused periportal proliferation and lymphocytic infiltration. Hypertrophy of hepatocytes in the periportal area was a characteristic feature in the liver of TCA treated rats. Moreover, in the histology of the kidney, in the three treated groups, degeneration of renal tubules, with syncitial arrangements of the nucleus of renal tubular epithelial cells was evident. In addition to this, degeneration of the basement membrane of the Bowmans capsule, diffused glomeruli and vacuolation of glomeruli was also evident in the three treated rat kidneys. Renal tubular proliferation in certain areas was also evident in certain areas of the kidney in TCA treated rats. The results indicate that, TBA and TCA do bring about alterations in histology of liver and kidney, but on combined administration, do not show enhanced toxicity in the form of increased hepatic and renal injury.     

Investigation of oxidant stress and vasodepression to glyceryl trinitrate in the obese Zucker rat in vivo

OBJECTIVE: To describe risk factors and explore mechanisms of ischemic strokes after general surgery. BACKGROUND: Strokes follow general surgery in about 0.08% to 2.9% of cases. Patients with previous cerebrovascular disease, atrial fibrillation, hypertension, advanced age, or atherosclerosis were found to have an increased risk. Knowledge of factors involved may guide physicians in determining the overall risk of surgery. METHODS: This case-control study was performed in a referral center. A total of 61 patients identified through a computerized database with ischemic strokes after surgical procedures-excluding heart, brain, vessels, or neck-between July 1986 and July 1996 were studied. Procedures included 11 urogenital, 16 gastrointestinal, 17 orthopedic, 12 pulmonary, and 5 other. A total of 122 randomly selected controls were matched for age, sex, procedure, and year of procedure. Main outcome measures included arterial territory, timing, risk factors, and perioperative events. Differences were expressed as adjusted odds ratios (AOR) with 95% confidence limits (CL), using multivariate conditional logistic analyses for matched case-control design. RESULTS: Arterial territory included 37 middle cerebral artery, 11 posterior circulation, 7 borderzone, and 6 multiple. Median procedure to stroke interval was 2 days (range, 0 to 16); 10 patients had intraoperative strokes. Three major risk factors emerged: previous cerebrovascular disease (AOR 12.57, 95% CL 2.14/73.70), chronic obstructive pulmonary disease (COPD) (7.51, 1.87/30.12), and peripheral vascular disease (PVD) (5.35, 1.25/22.94). After adding stroke-related factors, PVD (14.70, 2.01/107.71) and COPD (10.04, 1.90/53.14) remained the strongest variables; blood pressure (1.05, 1.01/1.10) and urea (1.04, 1.01/1.07) contributed slightly. Hypotension did not contribute. Four patients (6.6%) and no controls had diffuse intravascular coagulation (p = 0.01). Four stroke patients had myocardial infarction (6.6% versus 0%; p = 0.01). CONCLUSIONS: Ischemic strokes after general surgery most commonly occur after an asymptomatic interval. Previous cerebrovascular disease, COPD, and PVD greatly increase the risk. Hypotension rarely accounts for postoperative strokes. Major comorbidity of the patient at risk seems more important than complicating events during surgery.     

Clinical evaluation of a continuous intra-arterial blood gas system in critically ill patients

OBJECTIVE: To evaluate the clinical performance of a new, continuous intra-arterial blood gas monitoring system (CIABG) in abnormal ranges of blood gases, and during episodes of low blood pressure, in critically ill patients. DESIGN: Prospective study. SETTINGS: Medical ICU, University Hospital. METHODS: The CIABG system, based on fluorescent dyes, consists of a fiber-optic sensor introduced through an arterial catheter. Twenty-one sensors were evaluated in 15 acutely ill patients. A high failure rate (6/21) was found, due to the brittleness of the fibers. The bias, between CIABG and standard method, and precision were determined for each fiber and for the overall values. Analysis focused on the data collected in patients with arterial oxygen tension (PaO2) values below 75 mmHg, pH lower than 7.35 and arterial carbon dioxide partial pressure (PaCO2) values exceeding 50 mmHg and during episodes of low blood pressure. The accuracy of the CIABG to follow sequential changes in blood gases was studied among the abnormal values. RESULTS: Measurements with CIABG among the abnormal values showed biases of +2mmHg, +0.1mmHg and +0.005 for PaO2, PaCO2 and pH, respectively, and precisions of 9.0mmHg, 3.5mmHg and 0.027, respectively. Bias and precision were not influenced by hemodynamic instability. A substantial difference in the performance of individual CIABG was observed for PaO2 analysis, with 30% of the fibers having a much poorer performance than the others. The sensors were kept in place for 5 +/- 2 days and the drift rate per day was 0.005 for pH, 0.6mmHg for PaCO2 and -1.2mmHg for PaO2. CONCLUSION: In situations of severe hypoxemia, hypercapnia and acidosis, the agreement between CIABG and arterial blood sampling (ABS) is better for PaCO2 and pH than for PaO2, and is not influenced by episodes of low blood pressure.     

Basic principles of photobiology and photochemistry for nurse phototherapists and phototechnicians

Phototherapy administration requires a team approach to be safe and effective. Implementing the treatment plan requires the knowledge, skills, and expertise of the entire health care team. Understanding the relationship between natural light, artificial light sources, administration of phototherapy, and the short and long-term consequences of the therapy can enhance the experience for the patient and provide an increase in employment satisfaction for the therapist.     

Coexpression of hepatocyte growth factor and receptor (Met) in human breast carcinoma

Expression of hepatocyte growth factor (HGF) and HGF receptor (HGFR, product of the met proto-oncogene) mRNA were examined by nonisotopic in situ hybridization in a spectrum of benign and malignant human breast tissues. mRNA for both HGFR and HGF was detected in benign ductal epithelium. Epithelial expression of HGF mRNA was particularly intense in regions of ductal epithelial hyperplasia. Positive expression of HGF (but not HGFR) mRNA was also found in adipocytes, endothelial cells, and to varying degrees in stromal fibroblasts. In 12 of 12 cases of ductal carcinoma in situ and infiltrating ductal carcinoma, carcinoma cells showed a heterogeneous pattern of expression for both HGFR and HGF mRNA. In infiltrating ductal carcinomas, intense expression of HGFR mRNA was not restricted to ductular structures but as also seen in non-duct-forming carcinoma cells. The same zones of the tumors (most commonly at the advancing margins) that expressed strongly HGFR mRNA often were also strongly positive for HGF mRNA, suggesting a possible autocrine effect. The expression pattern of HGFR protein in 25 cases including the same series of tissues used for in situ hybridization analysis was similar to that of HGFR mRNA, as determined by an immunoperoxidase technique. The finding that HGFR is expressed by both benign and malignant epithelium, and its not restricted to duct-forming structures, suggests that, although the potential for HGF/HGFR binding is maintained in malignancy, the response to ligand binding at the level of the receptor or the cellular response to receptor activation may change at some point during progression.     

An amebic liver abscess; early suspicion, late detection

Two men aged 38 and 26 years developed symptoms including pain in the (upper) abdomen, malaise and fever 1.5-5 months after visiting the Caribbean. It was only after repeated ultrasonography that liver abscesses were observed. Adequate treatment was instituted and the patients recovered. The diagnosis of 'amoebic abscess of the liver' is usually based on the clinical presentation, the serological findings and characteristic observations at ultrasonography. However, if patients are seen at an early stage of development of the abscess, the serological findings may be negative and the ultrasonographic findings normal; consequently these findings do not justify exclusion of the diagnosis.