Catalysis of ACAT may be completed within the plane of the membrane: a working hypothesis

Two ACAT sharing protein sequence homology near their C termini have been identified. Both proteins may span the endoplasmic reticulum (ER) membrane several times. There is good evidence implicating the role of ACAT1 in macrophage foam cell formation, and ACAT2 in intestinal cholesterol absorption. On the other hand, the functional roles of ACAT1 and ACAT2 in the VLDL or chylomicron assembly process are less clear. It is possible that both enzymes are able to form lipid droplets (which are present in the cytoplasm), and participate in lipoprotein assembly (which occurs in the ER lumen). To link the site of ACAT catalysis with its function, we propose that part of the ACAT catalytic site may reside within the lipid bilayer, allowing catalysis to be completed within the plane of the membrane. Cholesteryl esters (CE) produced in situ may burst into cytoplasmic lipid droplets, carrying phospholipid monolayers as their outer coats. In cells engaged in lipoprotein assembly and secretion, CE in the bilayer may be recognized by the specific protein microsomal triacylglycerol transfer protein (MTP), reaching out from the lumenal side of the membrane. MTP then lipidates the growing apolipoprotein B (apoB) chain with CE and TG during the early stages of apoB lipoprotein assembly.

Endoscopic mucosal resection with a cap-fitted endoscope for early gastric carcinoma with focal submucosal invasion in a patient with decompensated liver cirrhosis

Prognosis for patients with early gastric cancer who undergo gastric resection is far better than that for patients with advanced disease. However, patients with advanced liver cirrhosis may not be suitable for general anesthesia and major surgery. We used a less invasive endoscopic mucosal resection (EMR) with a cap-fitted endoscope to resect an early gastric cancer in a 58-year-old male with decompensated liver cirrhosis. Although postoperative pathology revealed that the tumor had focal invasion to the submucosa, the patient had an uneventful course and was well during 4 years' follow-up. This method may be effective for the treatment of early gastric cancer with focal submucosal invasion when patients are not suitable for major surgery.

Transvenous permanent pacemaker implantation in children and adolescent

In pediatric patients cardiac pacing has been traditionally carried out by the epicardial approach in Taiwan. This study was to define the long-term results of transvenous endocardial pacemaker therapy in growing children. From 1994 to 1997, patients with sympatomatic bradycardia referred for permanent pacemaker were enrolled. Permanent pacemaker was implanted under propofol anesthesia and direct puncture of subclavian vein and creation of prepectoral pocket. A total of 10 patients ( 5 male, 5 female) aged from 5 to 17 years (13 +/- 4 yrs), constituted the study population. Follow-up period ranged from 14 to 48 months (29 +/- 14 months) . Underlying rhythm disturbances and pacemaker type implanted were: complete atrioventricular (AV) block 5 (VDD pacemaker in 3 and VVIR in 2), sick sinus syndrome 2 (DDDR pacemaker in both), sick sinus syndrome with abnormal AV conduction 1 (WIR), long QT syndrome 1 (VVIR) and hypertrophic cardiomyopathy 1 (DDDR). Pacemaker dysfunction occurred in only one patient in whom the endocardial lead was fixed by absorbable thread with an aim to have more flexibility of the lead. The endocardial lead was dislodged but properly reimplanted about 3 months after the initial implantation. All patients had satisfactory lead sensing and pacing threshold during the long-term follow-up. The pacing threshold was much better than that usually neededfor epicardial leads. With growing, none have the problems of lead length. Quality of life was reported to be improved in all. Tranvenous permanent pacemaker implantation is feasible in children aged 5 or older The long-term efficacy is satisfactory. Physiological pacing using a single lead (VDD) is recommended for younger patients with impaired AV conduction.

Methimazole-induced pulmonary hemorrhage associated with antimyeloperoxidase-antineutrophil cytoplasmic antibody: a case report

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis has been recently recognized in Graves' disease patients treated with antithyroid drugs. We describe the case of an 18-year-old girl who developed antimyeloperoxidase ANCA (MPO-ANCA)-positive vasculitis manifesting as a skin lesion and hemoptysis with hypoxic respiratory failure after taking methimazole. An open lung biopsy was consistent with acute capillaritis. Both skin and sural nerve biopsy showed lymphocytic vasculitis. Administration of steroid and plasmapheresis produced a good clinical response.

Large-volume liposuction: a review of 631 consecutive cases over 12 years

Since the advent of epinephrine-containing wetting solutions and sophisticated fluid management techniques, increasingly larger and larger volumes of liposuction aspirations have been reported. Unfortunately, with these larger volumes of liposuction being routinely performed, greater rates of complications have also been reported, with the worst of these resulting in deaths. In a response to the increasing concerns over the safety of large-volume liposuction, a critical review of the senior author's own series has been performed to evaluate risks and benefits and to recommend guidelines for safe and effective large-volume liposuction. A retrospective chart review was performed on 631 consecutive patients who underwent liposuction procedures of at least 3000 cc total aspirate. All procedures were performed by the same senior surgeon between January of 1986 and March of 1998. Before September of 1996, traditional liposuction techniques were used. After September of 1996, ultrasound-assisted liposuction was performed. The superwet technique of fluid management was employed for all procedures performed after 1991. The particulars of the surgical and anesthetic techniques used are reviewed in the article. Data collection included preoperative patient demographics, preoperative and postoperative weights and measurements, and preoperative and postoperative photographs. Total aspirate volumes, fluid intakes, and fluid outputs were measured, and all complications were tallied. Average follow-up was 1 year. Results showed the majority of patients to be women, aged 17 to 74 years old. Of the preoperative weights, 98.7 percent were within 50 pounds of ideal chart weight. Total aspirate volumes ranged from 3 to 17 liters, with 94.5 percent of these under 10 liters. Fluid balance measurements showed an average of 120 cc/kg positive fluid balance at the end of the procedure, with none of these patients experiencing any significant fluid balance abnormalities. Cosmetic results were good, with a 2- to 6-inch drop from preoperative measurements, depending on the area treated. Ten percent of patients experienced minor skin contour irregularities, with most of these patients not requiring any additional surgical procedures. One year after surgery, 80 percent of patients maintained stable postoperative weights. No serious complications were experienced in this series. The majority of the complications consisted of minor skin injuries and burns, allergic reactions to garments, and postoperative seromas. The more serious complications included four patients who developed mild pulmonary edema and one patient who developed pneumonia postoperatively. These patients were treated appropriately and went on to have uneventful recoveries. The results show that large-volume liposuction can be a safe and effective procedure when patients are carefully selected and when anesthetic and surgical techniques are properly performed. Meticulous fluid balance calculations are necessary to avoid volume abnormalities, and experience is mandatory when performing the largest aspirations. Cosmetic benefits are excellent, and overall complication rates are low.

The significance of human papillomavirus viral load in prediction of histologic severity and size of squamous intraepithelial lesions of uterine cervix

OBJECTIVES

Persistence of high-risk types of human papillomavirus (HPV) in cervical scrapes is responsible for the development, maintenance, and progression of squamous intraepithelial lesions (SILs). Previous studies of viral load and histologic severity have ended with controversial results. This study evaluated the relationships of HPV viral load with size and histologic severity of cervical lesions, which has not been reported previously.

METHODS

By using Hybrid Capture II, DNA level of high-risk HPVs was determined in cervical scrapes and correlated with lesion size and histologic confirmation for 73 women referred for colposcopy. The lesion size was classified as nonvisible (n = 12), small (< or =2/5 of the 12x colposcopic visual filed, n = 36), and large (>2/5 of the 12x field, n = 25) lesions. The final disease status was categorized as high-grade SIL (HSIL)/squamous cell carcinoma (SCC) (designated HSIL+) (n = 32), low-grade SIL (LSIL) (n = 19), and no detectable SIL (n = 22).

RESULTS

A distinct upward trend of high-risk HPV DNA levels paralleled increasing size and histologic severity of cervical lesions (P = 0.003 and 0.001, respectively). With respect to relative risk, women who had high viral load of HPV were at significantly greater risk for large lesion size (odds ratio [OR] = 5.3, 95% confidence interval [CI] = 1.1-24.9) and HSIL+ (OR = 35.0, 95% CI = 4.2-294.5). Of particular note, the risk of developing large lesion size and HSIL+ significantly increased with increasing viral load of HPV (P values for trend test were 0.008 and 0.0004, respectively). In contrast, there were no significant associations of trend in viral load with risk in small lesion size and LSIL.

CONCLUSIONS

The present study revealed that the effect of HPV infection on SIL development is highly influenced by high viral load and highlighted a potential application of viral load testing in predicting the size and severity of lesions of the uterine cervix.

Cerebrovascular reactivity to acetazolamide in alert patients with cerebral infarction: usefulness of first-pass radionuclide angiography using 99m Tc-HMPAO in monitoring cerebral haemodynamics

Cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) were studied in 75 patients with cerebral infarction. All patients were alert with the symptoms of hemiparesis and/or aphasia, and were divided into two groups: 42 patients had occlusion or stenosis of >75% at the internal carotid artery or main trunk of middle cerebral artery; and 33 patients did not. Hemispheric mean CBF was measured by performing first-pass radionuclide angiography using 99mTc-hexamethylpropylene amine oxime. CVR was measured as the percentage change from the baseline mean CBF value after the administration of 500 mg acetazolamide. The CVR in both groups was significantly impaired (5.2+/-6.3%, P<0.001 and 7.7+/-6.1%, P<0.01, respectively) compared with normal controls (14.7+/-3.3%), although the mean CBF was not significantly reduced compared with age-matched controls. In the 12 patients with unilateral carotid occlusion, five patients with good collateral flow via the anterior communicating artery showed preserved CVR (11.0+/-7.8%), but those without did not (1.6+/-7.0%). CVR is impaired in alert patients with cerebral infarction, although the mean CBF is not reduced, and good collateral flow via the anterior communicating artery in patients with carotid occlusion may be a sign of well-preserved haemodynamic status.

A novel multiparametric approach for analysis of cytoplasmic immunoglobulin light chains by flow cytometry

We describe a novel flow cytometric approach using a two-step acquisition technique to determine the cytoplasmic immunoglobulin light chains (LC) expression. Samples were prepared by a lysed-whole-blood technique and incubated with CD38-PE (phycoerythrin) and CD45-FITC (fluorescein isothiocyanate). The cells were fixed and acquired on an FACSCalibur flow cytometer (first acquisition). The cells were then permeabilized, incubated with either kappa-FITC or lambda-FITC and reacquired (second acquisition). Analysis of the data was performed by gating on the differing intensities of CD38 and evaluating them for the presence of a shifting FITC-positive population from the first acquisition to the second acquisition. The FITC fluorescence intensity of the second acquisition was equal to the sum of surface CD45 expression obtained during the first acquisition and the cytoplasmic LC expression obtained during the second acquisition. Thus, the shifting (increase) of FITC fluorescence intensity during the second acquisition is specifically due to the cytoplasmic expression of either the kappa or lambda LC. We studied 15 multiple myeloma (MM) patients and 10 controls (samples from patients without plasma cell dyscrasias). None of the controls showed evidence of any clonal populations. Thirteen of 15 MM patients exhibited clonal plasma cells (CD38 bright), ranging from 0.01% to 34% of total events collected. In addition, we identified another minute clonal population of lymphocytes (CD38 dim, CD45 bright, low forward and side scatter) in 12 of 13 MM patients with clonal plasma cells. This population, ranging from 0.01% to 0.6% of total events collected, had the same LC restriction as the clonal plasma cells. Patients with a ratio of minor clonal population to clonal plasma cells less than 0.07 tended to remain in partial or complete remission than those with a ratio > or =0.07 (4/5 versus 1/4, P <.1, chi(2)). We conclude that this method is highly sensitive and permits us to identify the minute clonal population of lymphocytes in MM patients. Our preliminary observations with a small cohort of patients imply that this minute clonal population may have important prognostic significance. The prognostic significance should be confirmed by further studies.

Aortic valve endocarditis in a dog due to Bartonella clarridgeiae

We report the first documented case of endocarditis associated with Bartonella clarridgeiae in any species. B. clarridgeiae was identified as a possible etiological agent of human cat scratch disease. Infective vegetative valvular aortic endocarditis was diagnosed in a 2.5-year-old male neutered boxer. Historically, the dog had been diagnosed with a systolic murmur at 16 months of age and underwent balloon valvuloplasty for severe valvular aortic stenosis. Six months later, the dog was brought to a veterinary hospital with an acute third-degree atrioventricular block and was diagnosed with infective endocarditis. The dog died of cardiopulmonary arrest prior to pacemaker implantation. Necropsy confirmed severe aortic vegetative endocarditis. Blood culture grew a fastidious, gram-negative organism 8 days after being plated. Phenotypic and genotypic characterization of the isolate, including partial sequencing of the citrate synthase (gltA) and 16S rRNA genes indicated that this organism was B. clarridgeiae. DNA extraction from the deformed aortic valve and the healthy pulmonic valve revealed the presence of B. clarridgeiae DNA only from the diseased valve. No Borrelia burgdorferi or Ehrlichia sp. DNA could be identified. Using indirect immunofluorescence tests, the dog was seropositive for B. clarridgeiae and had antibodies against Ehrlichia phagocytophila but not against Ehrlichia canis, Ehrlichia ewingii, B. burgdorferi, or Coxiella burnetii.

Endoscopic thoracic sympathetic block by clipping for palmar and axillary hyperhidrosis in children and adolescents

Endoscopic thoracic sympathectomy or sympathicotomy is a safe and effective method of treating primary hyperhidrosis (PH), but postoperative compensatory sweating may be a problem. There are few reports of sympathetic blockade by clipping for PH. We present our experience of endoscopic thoracic sympathetic block (ETSB) by clipping in treating palmar (PAH) and axillary hyperhidrosis (AH) in children and adolescents. Between May 1997 and June 1998, a total of 78 patients with PAH or AH underwent ETSB by clipping using an 8-mm, 0 degrees thoracoscope. There were 33 males and 45 females with a mean age of 14.1 years (range 9-16 y). All patients were placed in a semi-sitting position under single-lumen intubation anesthesia; 52 patients with PAH underwent T2 sympathetic block by clipping at the 2nd and 3rd rib beds, and T3 and T4 sympathetic block was performed at the 3rd, 4th and 5th rib beds in 26 patients with AH. A total of 156 sympathetic blocks by clipping were achieved. The operation was usually accomplished within 20 min (range 16-30 min). Most patients were discharged within 4 h after the operation. There were neither surgical complications nor mortality. The mean postoperative follow-up period was 32.7 months (range 26-40). Improvement of PAH or AH could be obtained in all cases; 70 patients (85.4%) developed compensatory sweating of the trunk and lower limbs. One patient with PAH underwent a reverse operation with improvement of the sweating 14 days after removal of the endo-clips. ETSB by clipping is thus a safe and effective method for treating PH in children and adolescents; compensatory sweating may be improved after a reverse operation with removal of the endo-clip.

What factors influence physicians' decisions to switch from intravenous to oral antibiotics for community-acquired pneumonia?

OBJECTIVE

One of the major factors influencing length of stay for patients with community-acquired pneumonia is the timing of conversion from intravenous to oral antibiotics. We measured physician attitudes and beliefs about the antibiotic switch decision and assessed physician characteristics associated with practice beliefs.

DESIGN

Written survey assessing attitudes about the antibiotic conversion decision.

SETTING

Seven teaching and non-teaching hospitals in Pittsburgh, Pa.

PARTICIPANTS

Three hundred forty-five generalist and specialist attending physicians who manage pneumonia in 7 hospitals.

MEASUREMENTS AND RESULTS

Factors rated as "very important" to the antibiotic conversion decision were: absence of suppurative infection (93%), ability to maintain oral intake (79%), respiratory rate at baseline (64%), no positive blood cultures (63%), normal temperature (62%), oxygenation at baseline (55%), and mental status at baseline (50%). The median thresholds at which physicians believed a typical patient could be converted to oral therapy were: temperature < or =100 degrees F (37.8 degrees C), respiratory rate < or =20 breaths/minute, heart rate < or =100 beats/minute, systolic blood pressure > or =100 mm Hg, and room air oxygen saturation > or =90%. Fifty-eight percent of physicians felt that "patients should be afebrile for 24 hours before conversion to oral antibiotics," and 19% said, "patients should receive a standard duration of intravenous antibiotics." In univariate analyses, pulmonary and infectious diseases physicians were the most predisposed towards early conversion to oral antibiotics, and other medical specialists were the least predisposed, with generalists being intermediate (P <.019). In multivariate analyses, practice beliefs were associated with age, inpatient care activities, attitudes about guidelines, and agreeableness on a personality inventory scale.

CONCLUSIONS

Physicians believed that patients could be switched to oral antibiotics once vital signs and mental status had stabilized and oral intake was possible. However, there was considerable variation in several antibiotic practice beliefs. Guidelines and pathways to streamline antibiotic therapy should include educational strategies to address some of these differences in attitudes.

Zona-free oocyte fertilized with intracytoplasmic sperm injection and underwent further division: case report and literature review

The zona pellucida (ZP) plays a protective role during fertilization and early embryonic development. It is related to sperm binding, the acrosome reaction, prevention of polyspermic fertilization, and holding blastomeres together before the morular stage. Zona-free oocytes are accidentally encountered. If these oocytes are healthy, they can be fertilized normally by intracytoplasmic sperm injection (ICSI). We reported on a couple with male infertility undergoing oocyte retrieval after ovarian hyperstimulation. Before the ICSI procedure, cumulus cells surrounding the oocytes were removed, which resulted in one oocyte escaping from its ZP. The zona-free oocyte was fertilized normally with ICSI and developed to the 8-cell stage. We observed that the zona-free zygote had the ability to further divide, despite its loose contact. The zona-free embryo was transferred with other zona-intact embryos, but the implantation failed. We conclude that zona-free oocytes can be rescued, fertilized with ICSI, and cultured for further transfer or cryopreservation.

Preoperative diagnosis and localization of aldosterone-producing adenoma by adrenal venous sampling after administration of metoclopramide

BACKGROUND AND PURPOSE

Adrenal venous sampling is the most reliable test to distinguish aldosterone-producing adenoma (APA) from idiopathic hyperaldosteronism (IHA). The diagnostic accuracy can be improved by administration of adrenocorticotropin to minimize pulsatile secretion of aldosterone. Metoclopramide (MCP), a dopamine antagonist, can increase aldosterone secretion promptly without affecting cortisol secretion. This study investigated the diagnostic accuracy of adrenal venous sampling after MCP injection for the preoperative diagnosis and localization of APA.

METHODS

Prospective diagnosis and adrenalectomy was based on adrenal venous sampling in 23 patients with a diagnosis of primary aldosteronism. Plasma aldosterone concentrations from adrenal veins and the inferior vena cava were measured before and 30 minutes after intravenous administration of 10 mg MCP. The ratio of bilateral adrenal venous aldosterone concentrations after MCP was used for diagnosis as follows: a ratio greater than 5 indicated APA, less than 3 indicated IHA, and 3-5 indicated an intermediate diagnosis.

RESULTS

Catheterization of the right adrenal vein was unsuccessful in three patients. Twelve of 13 patients with an aldosterone ratio greater than 5 after MCP underwent unilateral adrenalectomy, and APA was confirmed in 11 of these patients. One patient with an intermediate diagnosis also had surgically confirmed APA. Six patients had a ratio less than 3. Before MCP administration, 10 of 13 patients with APA had a ratio greater than 5, and three patients had a ratio between 3 and 5; one patient with IHA had a ratio greater than 5. MCP improved the diagnosis of APA to an accuracy of 92% (12/13). Correct diagnosis of APA based on computerized tomography (CT) was 85% (11/13). There was discordance between the findings of adrenal venous sampling and CT in four of 20 patients.

CONCLUSIONS

Administration of MCP to stimulate aldosterone secretion during adrenal venous sampling can improve the accuracy of differential diagnosis between APA and IHA.

Mechanism of up-regulated gap junctional intercellular communication during chemoprevention and chemotherapy of cancer

To develop a strategy for efficacious intervention in order to prevent or treat various cancers, one must understand the basic mechanism(s) by which various anticancer dietary factors prevent or reverse the tumor promotion or progression phases. Carcinogenesis is a multistage, multimechanism process, involving the irreversible alteration of a stem cell (the "initiation" phase), followed by the clonal proliferation of the initiated stem cell (the "promotion" phase), from which the acquisition of the invasive and metastatic phenotypes are generated (the "progression" phase). While intervention to prevent or treat cancer could occur at each step, the objective of this presentation will focus on the rate limiting step, the promotion phase.Gap junctional intercellular communication (GJIC) has been hypothesized to regulate growth control, differentiation and apoptosis. Most normal, contact-inhibited cells have functional GJIC, while most, if not all, tumor cells have dysfunctional homologous or heterologous GJIC. Cancer cells are characterized by the lack of growth control, by the inability to terminally differentiate and by resistance to apoptosis. Chemical tumor promoters (phorbol esters, DDT, phenobarbital, unsaturated fatty acids, saccharin, etc.) inhibit GJIC in a reversible fashion and at doses above particular chemical thresholds. Various oncogenes (e.g. ras, raf, neu, src, mos) down-regulate GJIC while several tumor suppressor genes can up-regulate GJIC. Antitumor promoters (retinoids, carotenoids, green tea components) and antioncogene drugs (i.e. lovastatin) can up-regulate GJIC. Transfection of gap junction genes ("connexins") into GJIC-deficient tumor cells can restore GJIC, growth control and reduce tumorigenicity. On the other hand, antisense gap junction genes can convert the phenotype of a non-tumorigenic cell to that of a tumorigenic one. Recently, a specific connexin knockout mouse was shown to have a higher frequency of spontaneous and induced liver cancers. Evidence from these studies clearly suggests that dietary factors can modulate GJIC by inducing various signal transducing systems. The modulation can either down-regulate GJIC and lead to tumor promotion or it can up-regulate GJIC and lead to suppression of the initiated cells. Multiple mechanisms of up- or down-regulation of GJIC exist, as well as multiple types of pre-malignant and malignant tumor cells that are unable able to have functional GJIC. GJIC can be down-regulated by mutations and by epigenetic means. Alteration of gene expression at the transcriptional, translational or post-translational levels would require specific dietary prevention or treatment of cancer. In conclusion, if dietary prevention or treatment of cancer is to occur, it must ameliorate the growth-stimulatory effects, above threshold levels, of chemicals, growth factors or hormones, that trigger various mitogenic/antiapoptotic signal transducing systems that block GJIC.

Training nu-support vector classifiers: theory and algorithms

The nu-support vector machine (nu-SVM) for classification proposed by Schölkopf, Smola, Williamson, and Bartlett (2000) has the advantage of using a parameter nu on controlling the number of support vectors. In this article, we investigate the relation between nu-SVM and C-SVM in detail. We show that in general they are two different problems with the same optimal solution set. Hence, we may expect that many numerical aspects of solving them are similar. However, compared to regular C-SVM, the formulation of nu-SVM is more complicated, so up to now there have been no effective methods for solving large-scale nu-SVM. We propose a decomposition method for nu-SVM that is competitive with existing methods for C-SVM. We also discuss the behavior of nu-SVM by some numerical experiments.

Establishment and characterization of a cell line, MT-213-VGH, isolated from a mixed müllerian tumor of the uterus

OBJECTIVE

To establish a cell line from a woman with malignant mixed müllerian tumor of the uterus and to examine the biologic properties of this cell line (MT-213-VGH).

STUDY DESIGN

Cells were cloned by the limiting dilution method. Histologic staining of mixed müllerian (mesodermal) tumor (MMMT) cells was performed with May-Grünwald-Giemsa and hematoxylin and eosin stain. After more than 20 passages, cells were used to estimate the population-doubling time and colony-forming efficiency of MMMT cells. The cell line exhibited considerable variation in the degree of sensitivity to diverse chemotherapy drugs in vitro.

RESULTS

MMMT cells containing antigens for vimentin and myoglobin were detected, but those for CA-125, carcinoembryonic antigen, cytoskeleton, desmin, epithelial membrane antigen and fibronectin were not found. In addition, MT-213-VGH cells contained a mucinous substance; its chromosome model number is 45. This cell line showed differential sensitivities to chemotherapeutic agents, such as bleomycin, cisplatin, 5-fluorouracil and vinblastine.

CONCLUSION

The establishment and availability of the number cell line MT-213-VGH for a malignant mixed müllerian tumor of the uterus should assist in research on new methods of managing this type of gynecologic cancer.

Concentration variability of halocarbons over an electronics industrial park and its implication in compliance with the Montreal protocol

This work investigated fugitive emissions of anthropogenic halocarbons in a semiconductor and electronics industrial park in Taiwan using both flask and in-situ measurement methods. Large concentration variabilities in methylchloroform, trichloroethene, and tetrachloroethene suggested substantial usage and emissions in the industrial park. While the variability of CFC-113, CCl4, and CFC-11 was rather small using the flask sampling technique, the in-situ method with its higher frequency, however, showed significantly larger variability arising from observing periodic emission episodes, which were highly correlated with wind direction and topography of the park.

Evaluation of micrometastases in sentinel lymph nodes of cutaneous melanoma: higher diagnostic accuracy with Melan-A and MART-1 compared with S-100 protein and HMB-45

Accurate diagnosis of micrometastases in sentinel lymph nodes of cutaneous melanoma is critical for proper clinical management. S-100 protein and HMB-45 are the traditional immunomarkers widely used for this purpose. However, the interpretation of micrometastases by these markers is difficult with significant reduction in the diagnostic accuracy. S-100 protein demonstrates immunoreactivity for other nonmelanoma cells and obscures nuclear details, which are crucial for the interpretation of single cell metastases. We compared the new melanoma markers, Melan-A (clone A103) and MART-1 (clone M2-7C10), with S-100 protein and HMB-45, by examining 77 formalin-fixed paraffin-embedded sections of sentinel lymph nodes from 13 cases of primary cutaneous melanoma. CD68 (PG-M1) and hematoxylin-eosin-stained sections were also studied. Four pathologists interpreted the staining pattern after concealing the identity of each immunomarker. Az values (area under receiver operating characteristic curve) with receiver operating characteristic curve were higher with Melan-A (0.9742) and MART-1 (0.9779) compared with S-100 protein (0.8034) and HMB-45 (0.8651), demonstrating a higher diagnostic accuracy with Melan-A and MART-1 with superior detection of melanoma micrometastases. Melan-A and MART-1 showed sharp cytoplasmic immunoreactivity, almost exclusively restricted to the melanoma cells. Therefore, Melan-A and MART-1 are recommended for the evaluation of micrometastases in sentinel lymph nodes of cutaneous melanoma as a routine alternative to S-100 protein and HMB-45.

Primary tumour volume delineation in nasopharyngeal carcinoma and correlation with 1997 AJCC tumour stage classification

OBJECTIVE

To investigate the variability in primary tumour volume in nasopharyngeal carcinoma and compare it with the tumour staging of the 1997 American Joint Committee on Cancer.

DESIGN

Prospective study.

SETTING

Tertiary care centre.

METHOD

A series of 33 newly diagnosed patients who were treated with high-dose radiotherapy participated in the study.

MAIN OUTCOME MEASURES

Using computed tomographic scans, primary tumour volumes were measured using the summation-of-areas technique, and the variability in tumour volume was determined. The Mann-Whitney test was used for statistical analysis.

RESULTS

A large variation in primary tumour volume was observed, especially in advanced-stage cases.

CONCLUSIONS

Nasopharyngeal carcinoma shows considerable variability in primary tumour volume. Incorporation of primary tumour volume may lead to further refinement of the 1997 tumour staging system.

In vitro study of ultrasound based real-time tracking of renal stones for shock wave lithotripsy: part 1

PURPOSE

We developed a real-time tracking system for renal stones that decreases the number of shock waves and treatment time of shock wave lithotripsy.

MATERIALS AND METHODS

Ultrasound images were analyzed to identify the renal stones. A computer software module for ultrasound image processing was developed to monitor stone location instantaneously. Another computer software module controlled generator movement in real time for tracking the stone. We used 13 ultrasound stone trajectories recorded from patients to test the system in vitro. Two tests were established to verify tracking system reliability. One test focused on improvement in the coincidence ratio, which denotes the matching extent of the stone within the effective focal area. The other test focused on improvement in the efficiency ratio, that is a decrease in the number of shocks for stone fragmentation. For each recorded stone trajectory 2 experiments were done under tracking and nontracking conditions.

RESULTS

The average coincidence and efficiency ratios plus or minus standard deviation were 79.6% +/- 9.8% and 45.0% +/- 12.7% without tracking, and 97.0% +/- 3.0% and 85.5 +/- 6.8% with tracking, respectively. All tests were statistically significant (paired t test p <0.01).

CONCLUSIONS

An ultrasound based real-time tracking system proved to be significantly helpful for in vitro lithotripsy. It appears that the tracking system may greatly decrease the number of shocks and treatment time for renal stones.

Investigation of the extent of gastric metaplasia in the duodenal bulb by using methylene blue staining

BACKGROUND AND AIMS

The existence of gastric metaplasia (GM) of the duodenal mucosa has been considered to be highly related to the recurrence of duodenal ulcers (DU). The aims of this study are to evaluate the usefulness of methylene blue staining in the detection of GM, and to clarify the relationship between GM and the deformity of the duodenal bulb.

METHODS

Fifteen patients with healed DU and four patients with symptoms of dyspepsia without evidence of ulcers were enrolled into this endoscopic study. During each endoscopy, methylene blue was sprayed evenly on the duodenal bulb, and biopsies were taken from blue-stained and unstained areas. The existence and extent of GM were assessed histologically and grossly. The correlation between duodenal bulb deformity and the extent of GM was also studied.

RESULTS

The mean score of methylene blue non-staining (MBNS) was 0, 1.30 +/- 0.15, and 3.00 +/- 0.00 in group A (non-ulcer patients), group B (patients with healed DU and with normal-shaped bulb) and C (patients with healed DU and with deformed duodenal bulb), respectively; showing significant differences among the groups (P < 0.05 in each). Both the existence and the grading of GM were higher in unstained specimens than in blue-stained specimens (100 vs 16.6%, P < 0.0001 and 3.62 +/- 0.09 vs 0.19 +/- 0.06, P < 0.001, respectively).

CONCLUSIONS

Methylene blue non-staining can be applied to investigate the existence and extent of GM in the duodenal bulb accurately. The incidence of GM in the duodenal bulb was higher in patients with healed ulcers than in non-ulcer patients. Patients with deformed duodenal bulbs have a higher extent of GM than those without deformed duodenal bulbs.

Diabetic ketoacidosis and hypogonadotropic hypogonadism in association with transfusional hemochromatosis in a man with beta-thalassemia major

We report a 23-year-old man with beta-thalassemia major and transfusional hemochromatosis, which manifested as diabetic ketoacidosis and hypogonadotropic hypogonadism. This unusual presentation of diabetic ketoacidosis in hemochromatosis has rarely been reported. Magnetic resonance imaging of the abdomen showed decreased signal intensity in the liver, spleen, and pancreas. In addition, the pituitary gland also showed heterogeneous low signal intensity, compatible with hemochromatosis. He was treated with insulin supplements and pulsatile human chorionic gonadotropin administration. Clinical improvement was noted after hormone replacement. Intensive iron chelation therapy was given to prevent cardiac complications, and to restore his gonadal function. During follow-up, the patient experienced improvement in libido and sexual potency.

Doppler study of the fetal middle cerebral artery at three locations: preliminary report

BACKGROUND

Middle cerebral artery (MCA) detection is useful in monitoring fetal well-being. Knowledge of Doppler flow velocity of the fetal MCA may assist in prenatal diagnosis and management of complicated pregnancies. The aim of this study was to compare the pulsatility index (PI) and resistance index (RI) of the MCA at different locations throughout pregnancy.

METHODS

Uncomplicated singleton pregnancies accepted Doppler surveys of the bilateral MCA. PI and RI values of the proximal, middle, and distal 1/3 of the MCA were measured. The gestation periods for Doppler surveys were (1) 15 to 19 weeks; (2) 20 to 24 weeks; (3) 25 to 29 weeks; (4) 30 to 34 weeks; and (5) 35 to 40 weeks. The MCA flows at different locations and at different gestational aged were compared.

RESULTS

There were 21 patients included. Average PI/RI values of the proximal, middle and distal MCA were 1.62/0.80, 1.69/0.81, and 1.71/0.83, which were non-significantly different. The PI/RI values of MCA in each gestational phase were also non-significantly different: (1) 1.70/0.84; (2) 1.72/0.82; (3) 1.68/0.83; (4) 1.65/0.81; (5) 1.62/0.77.

CONCLUSIONS

The PI and RI values of the proximal MCA were non-significantly lower than those of middle and distal MCA. Middle MCA could represent three locations of MCA. A trend of lower PI/RI values with advancing gestation was noted.