Malignant rhabdoid tumor of the uterine corpus

Malignant rhabdoid tumor (MRT) was first described as a variant of Wilms' tumor but was subsequently found to be a highly malignant tumor composed of primitive cells that resemble rhabdomyoblasts. In the past decade, extrarenal MRTs were reported in different locations and organs throughout the body including the female genital tract. We here report an MRT that arose in the corpus uteri, the second such case reported.

Reproducibility of the amniotic fluid index: its effect on clinical practice

Two methods of measuring the amniotic fluid index (AFI) were subjected to tests of intra- and interobserver reproducibility. In the first method, amniotic fluid in each quadrant was measured by using the deepest pool perpendicular to the floor; in the second method, amniotic fluid in each quadrant was measured by using the deepest pool perpendicular to the uterine contour. Intraobserver and interobserver variability were assessed by using one-way analysis of variance and limits of agreement, respectively. Intraobserver standard deviations were all < 9 mm. When the AFI was measured using the first method, there was an inverse relationship between the interobserver difference and mean values of AFI. Plots of the differences between observers against their means showed that the lower the AFI, the greater the interobserver variability. No such correlation was noted when the AFI was measured by the second method. The limits of agreement (within which 95% of interobserver differences lie) were comparable for the two methods [(-42 mm to 29.4 mm) and (-46.4 mm to 41.6 mm), respectively]. The results suggest that the amniotic fluid index measured by the second method is more reproducible, especially in the presence of reduced amniotic fluid.

Preoperative thyroid ultrasonography and fine-needle aspiration cytology in ectopic thyroid

Ectopic thyroid tissue is a rare entity. The occurrence of a thyroid carcinoma in such aberrant thyroid tissue has been reported, but is very rare. Surgical excision is considered the treatment of choice in managing the lesions associated with ectopic thyroid. If the ectopic thyroid is excised, all the thyroid may have been ablated, resulting in permanent hypothyroidism. We report two cases of ectopic thyroid in emphasizing the importance of thyroid ultrasonography and fine-needle aspiration (FNA) cytology in evaluating ectopic thyroid before surgery.

Prevalence of goiters in children residing in Tung-Lo Township, Taiwan

This study investigated school children in the Tung-Lo Township in central Taiwan to determine the prevalence of goiters compared to other areas of Taiwan and to elucidate the possible etiology. All children attending elementary schools in Tung-Lo were examined for thyroid enlargement by neck palpation, as recommended by the World Health Organization. Thyroid antibodies and thyroid hormones were determined in children with goiters, and in normal age- and sex-matched controls. Additionally, analysis of drinking water for humic substances was done by fluorospectrophotometry. In total, 1,823 school children were examined (965 boys and 858 girls). Of these, 174 (9.5%) were found to have a goiter of grade I or above. The prevalence was higher than our recent surveys in other areas of Taiwan (2.6%-8.8%). Goiter prevalence in school children residing in hill regions (12.9%), mainly dependent on underground water for drinking, was higher than that of school children residing in plain regions (8.2%), who depend on tap water for drinking. The quality of drinking water bore a close relationship to the prevalence of goiter. From the ratio of T3/T4 in this study, and a study of urinary iodine excretion done by others, it is concluded that goiters in Tung-Lo are not related to iodine deficiency. There was no statistically significant correlation between the relative fluorescence intensity of humic substances and the prevalence of goiter. The results of this study suggest that the higher prevalence of goiter in children living in Tung-Lo, an oil-bearing area, may be related to the quality of drinking water.

Third trimester fetal growth and umbilical venous blood concentrations of IGF-1, IGFBP-1, and growth hormone at term

Insulin-like growth factor-1 (IGF-1), insulin-like growth factor binding protein-1 (IGFBP-1) and growth hormone (GH) concentrations were measured in umbilical venous blood after delivery of 78 term newborn infants. Three groups of pregnancies were prospectively identified during the third trimester, according to fetal size and subsequent fetal growth, assessed by repeated ultrasound scans. Fetal size was considered either appropriate for gestational age (AGA) or small for gestational age (SGA), according to whether the first ultrasound measurement of abdominal circumference was equal to or above, or below the tenth centile for gestational age, respectively. Subsequent fetal growth was quantified by the change in the standard deviation score of abdominal circumference measurements between the first and last scans before delivery. Fetal growth retardation (FGR) was defined as a (negative) change in SD score of greater than -1.5. Eighteen SGA fetuses with evidence of FGR had significantly lower IGF-1 (median 0.05 (range 0.0-0.24) U/ml) at delivery than 35 SGA fetuses with normal growth (median 0.13 (range 0.0-0.94) U/ml; P < 0.05) and 25 AGA fetuses with normal growth (median 0.31 (range 0.0-0.84) U/ml; P < 0.05). The median concentration in the SGA group with normal growth was also significantly lower than that of the AGA group with normal growth. There were no significant differences in IGFBP-1 or GH concentrations between the three groups. These observations indicate that umbilical blood concentrations at birth of IGF-1, but not IGFBP-1 or GH, relate to both fetal size and fetal growth during the third trimester of pregnancies reaching term.

Evaluation of four commercial rapid diagnostic kits for identifying Staphylococcus aureus

Three rapid latex agglutination kits (Aureus Test, Pastorex Staph-Plus, and StaphAurex) and one hemagglutination test kit (SlidexStaph) were compared with the conventional coagulase test for the identification of Staphyloccus aureus. A total of 192 methicillin-resistant S. aureus (MRSA), 75 methicillin-susceptible S. aureus (MSSA) and 86 coagulase-negative staphylococci and Micrococcus spp. were tested. The sensitivities of Aureus Test, Pastorex Staph-Plus, StaphAurex and SlidexStaph were 98.6, 99.4, 90.8 and 97.3%, respectively. Capsular serotypes of 27 strains of MRSA were also determined, in which 15 (55.6%) were capsular serotype 5, 11 (40.7%) were capsular serotype 8, and 1 (3.7%) was nontypeable. All the commercial agglutination kits showed 100% specificity except StaphAurex which had a specificity of only 96.5%. False-positive reactions were found in the strains of S. hominis, S. warneri and unidentified coagulase-negative staphylococci. These results suggest that Aureus Test, Pastorex Staph-Plus, and SlidexStaph are better than StaphAurex for rapid identification of S. aureus.

Thyroid peroxidase autoantibodies and their effects on enzyme activity in patients with systemic lupus erythematosus

Thyroid microsomal antibodies (Ms-Ab) are recently proved to be directed to thyroid peroxidase (TPO). The aim of this study was to investigate whether the sera of patients with systemic lupus erythematosus (SLE) contain anti-TPO antibodies (TPO-Ab) and whether these antibodies influence enzyme activity. Sera from patient with Hashimoto's thyroiditis was also studied. Serum samples were obtained from 37 patients with SLE, 20 patients with Hashimoto's thyroiditis and 20 healthy subjects. TPO-Ab were detected by immunoprecipitation using crude microsomal preparations or enzyme-linked immunoabsorbent assay (ELISA) with recombinant TPO. Positive TPO-Ab by ELISA were found in 11 (61%) of 18 patients with lupus whose serum contained Ms-Ab. Low levels of TPO-Ab also were found in three (16%) of 19 lupus sera that did not contain Ms-Ab. All patients with Hashimoto's thyroiditis had high levels of TPO-Ab in serum. When measured by ELISA, TPO-Ab were highly correlated with the results of a TPO immunoprecipitation assay and with the titers of Ms-Ab in patients with lupus (r = 0.83, n = 18, P < 0.01; r = 0.63, n = 18, P < 0.01) and in Hashimoto's thyroiditis (r = 0.89, n = 20, P < 0.01; r = 0.75, n = 20, P < 0.01). When evaluating the direct influence of TPO-Ab on the activity of TPO, we found no significant inhibition of enzymatic activity in both guaiacol and iodide assays by lupus sera in contrast with sera from Hashimoto's thyroiditis.(ABSTRACT TRUNCATED AT 250 WORDS)

Second trimester colour Doppler imaging of the uterine artery: reproducibility of the resistance index

Second trimester assessment of uterine blood flow has been advocated as a predictor of subsequent adverse perinatal outcome. The reproducibility of uterine artery resistance index, as assessed using colour Doppler imaging, was investigated. Two observers, both of whom were experienced in colour Doppler assessment of uterine artery flow velocity waveforms, performed the measurements. One-way analysis of variance was used to evaluate intraobserver variability and the limits of agreement method was used to determine the 95% prediction interval for interobserver differences. The intraobserver standard deviation was small for both observers. The limits of agreement for interobserver differences were wide (-0.24, 0.16), similar in magnitude to those reported by other workers who assessed the uterine vessel using continuous wave Doppler. The poor reproducibility of the resistance index suggests that second trimester Doppler assessment of uterine artery flow velocity waveforms may be better described using other semiquantitative methods such as the presence or absence of a diastolic notch.

Correlation between tumor angiogenesis and metastasis in breast cancer

New vessel formation (angiogenesis) plays an important role in the metastasis of cancer cells. To investigate the correlation between tumor angiogenesis and metastatic potential in breast cancer, the microvessel counts of tumor specimens from 81 women with primary infiltrating ductal carcinomas were examined. Histologic parameters (nodal status, tumor size and tumor grade) and hormone receptor status were also analyzed. We found that axillary node metastasis correlated significantly with the microvessel counts per 200x field and with tumor size, but not with age, tumor grade or hormone receptor status. Tumors without axillary node involvement had a lower microvessel count, irrespective of age, tumor size, tumor grade or hormone receptor status. Logistic regression demonstrated that the microvessel count provided the most important estimate of the relative risk of metastasis. These results suggest that, in invasive breast carcinoma, angiogenesis is closely related to metastatic potential.

Fetal size and growth in Bangladeshi pregnancies

A longitudinal study of 20 uncomplicated pregnancies in Bangladeshi women was undertaken. Fetal growth was investigated by serial ultrasound scans performed between 26 and 38 weeks of pregnancy. Repeated measurements of abdominal circumference and estimates of fetal weight were best described by a log quadratic equation. The coefficients were not significantly different from those obtained from a previously reported study of fetal growth in 67 uncomplicated pregnancies with healthy outcomes in white Anglo-Saxon women. Further comparison between the two groups showed that the mean abdominal circumference and estimates of fetal weight of the Bangladeshi fetuses were smaller at 28, 32 and 36 weeks' gestation. These results suggest that, although Bangladeshi fetuses appear to be smaller than Anglo-Saxon fetuses, they grow at a similar rate during the third trimester.

Value of immunoperoxidase staining of thyroglobulin in fine needle aspiration cytology of thyroid diseases

To elucidate the value of thyroglobulin staining by the immunoperoxidase method in fine needle aspiration cytology of thyroid diseases, it was performed on fine needle aspiration smears of 57 cases of various thyroid diseases. Thirteen of 22 cases (59%) with benign nodular goiter were positive. Eight of 14 cases (57%) with papillary thyroid carcinoma were positive. Among these eight cases with positive staining, seven were at clinical stage II or less. Among the other six cases with negative staining, five cases were in clinical stage III or more. There was a significant relationship between clinical stage and thyroglobulin staining (P < .05). One of 10 cases with thyroid cysts was positive. One of four cases with anaplastic carcinoma was positive. One of two cases with follicular thyroid carcinoma was positive. Two cases of subacute thyroiditis were positive. One case of Hashimoto's thyroiditis was positive. Two cases of metastatic thyroid cancer from the ovary were negative. These results reveal that positive thyroglobulin staining was helpful in defining the source of tissue from the thyroid. However, negative staining could not definitively exclude a thyroid origin. Positive thyroglobulin staining in papillary thyroid carcinoma correlated with less advanced clinical stages.

Prevalence of goiter in Taiwanese adults: a preliminary study

Although there have been many studies on the prevalence of goiters in Taiwanese school children, the goiter prevalence in Taiwanese adults is unknown. This is a preliminary study of the prevalence of goiter in adults admitted for health examinations to the National Taiwan University Hospital. The thyroid glands of 1,020 adults were palpated. Thyroid ultrasonography was also performed on all adults to confirm the palpation findings and to check goiter nodularity. Fine-needle aspiration cytology was done in nodular goiters with or without ultrasound guidance, depending on whether or not the thyroid nodules were easily located by palpation. The adult goiter prevalence was found to be 19.4% in males, 33.6% in females and 25% in total. Seven out of 1,020 adults (0.7%) had thyroid cancers diagnosed by aspiration cytology and confirmed by surgery and pathology. Of the seven adults with thyroid cancer one did not have a palpable goiter. The results show a high prevalence of goiter in these adults. Thyroid ultrasonography is useful for screening thyroid malignancy in adults. If thyroid nodules are detected, fine-needle aspiration cytology can be done with or without ultrasound guidance to confirm the malignancy.

Prevalence of goiter in school children in the Wan-Hwa district of Taipei

Salt has been iodized in Taiwan since 1967. To understand goiter status after salt iodization, we studied the prevalence of goiter in school children in rural areas where tap water or underground water are used. To further elucidate the prevalence of goiter in urban areas where tap water is used, we studied school children from the Tong-Yuan and Lao-Song elementary schools located in the Wan-Hwa District of Taipei. Thyroid enlargement was examined by palpation as recommended by the World Health Organization. Thyroid antibodies and hormones were determined in school children with goiter and in age- and sex-matched normal control children using particle agglutination methods and radioimmunoassay. A total of 4,623 school children were examined. Of these, 129 children (2.8%) had goiters of grade I or above, or nodular goiters. The prevalence of goiter was similar to that of Putai and Peimen in southern Taiwan where tap water is used, but less than that of Tachia and Chingshuei in middle Taiwan where underground water is used. The prevalence of goiter was much lower than recent studies in Tung-Lo, an oil-bearing area in middle Taiwan, where there was a 12.9% prevalence in school children residing in hill districts who relied on underground water for drinking purposes, and 8.2% in school children residing on lower plains, who depended upon tap water for drinking purposes. The prevalence of goiter is highly related to the quality of drinking water.(ABSTRACT TRUNCATED AT 250 WORDS)

Malignant mixed müllerian tumor of the uterine corpus--analysis of 12 cases

Clinical and histopathological features of 12 patients with malignant mixed müllerian tumor of the uterine corpus presenting to Chang Gung Memorial Hospital from January 1988 to September 1993 were retrospectively investigated. The age distribution ranged from 43 to 76 years with a median of 56, and post-menopausal bleeding was the most common symptom in these patients. There was 60% (6/10) of discrepancy in histologic diagnosis between the specimens of dilatation and curettage and that of hysterectomy. All patients received total hysterectomy and bilateral salpingo-oophorectomy, and 10 with retroperitoneal lymph node dissection. Nine patients received cisplatin based chemotherapy, one received radiation only, one received sequential chemotherapy and irradiation, and one underwent concurrent chemoradiation as adjuvant. Two-year survival in patients with stage I-II was 70% (95% C.I.: 34%, 100%) and that of stage III, 25% (95% C.I.: 0.67%). There was 42% (5 of 12) progression/recurrence rate, all developed within 2 years. An effective adjuvant chemotherapy after comprehensive surgery including a total abdominal hysterectomy, bilateral salpingo-oophorectomy and lymph node dissection may be needed for a satisfactory improvement in the patients' survival.

Congenital malformation in newborns. Analysis of 501 cases

Over a 14-year period in Chang Gung Memorial Hospital, 510 out of 44, 362 newborns were found to have birth defects. Maternal age, gestational age, parity, infant sex and birth weight were analyzed for each anomaly and compared to normal newborns. The average maternal age and parity for newborns with congenital anomalies were not significantly different from normal newborns. Mothers giving birth to babies with chromosomal aberrations, however, had a significantly older maternal age than the normal population. The gestational age at delivery was significantly shorter for all except craniofacial anomaly. In addition, there was a high percentage of intrauterine growth retardation in congenital anomalies. The central nervous system, the musculoskeletal system and craniofacial systems were the most commonly involved. The leading anomalies included cleft lip, cleft palate, anencephaly, polydactyly, hydrops fetalis, trisomy 21 and cystic hygroma. With improved ultrasound equipment and other prenatal diagnostic procedures, many defects of the fetus can now be identified. If the fetus is diagnosed with a surgically correctable lesion like cleft lip, it can be kept to term, delivered, then managed postnatally. If life-incompatible malformations have been detected before the 24th week, physicians are in a good position to counsel the parents. After the 24th week termination is proscribed by law. Therefore, physicians must take special care to detect fetal abnormalities early.

Sonographic lenticulostriate vasculopathy in infants: some associations and a hypothesis

PURPOSE

To describe the causes of infantile lenticulostriate vasculopathy (LSV) as demonstrated by sonography and propose the pathogenesis of these findings.

METHODS

Five hundred eighty-six infants were examined via echoencephalography because of seizures, psychomotor retardation, dysmorphism, congenital malformation, microcephaly, macrocephaly, bulging of anterior fontanel, consciousness disturbance, or prematurity. We directed our attention on the sonographic study to the basal ganglionic and thalamic areas. Twenty-eight of the 586 patients underwent color Doppler studies.

RESULTS

In 34 infants with gray-scale neurosonographic findings of LSV, 16 were associated with various causes that have been reported before. In 8 patients entities not previously associated with LSV were found: neonatal lupus, neonatal hypoglycemia, uncomplicated prematurity, encephalitis, and head injury. In the remaining 10 cases, a specific cause could not be found. The LSV was found in 16 (40%), 5 (14%), and 13 (3%) patients with perinatal, acquired, and nonspecific causes, respectively. Generally, this is an uncommon finding because it was observed in only 34 (5.8%) of the study infants; 24 of these 34 had a documented cause of the vasculopathy. With LSV associated with perinatal causes there was a greater chance of sonographic LSV's developing than with that of acquired causes.

CONCLUSIONS

We suggest that sonographic LSV is a nonspecific marker of a previous insult to the developing brain, and the special hemodynamics of the fetal brain plays an important role in its pathogenesis.

Growth regulation by all-trans-retinoic acid and retinoic acid receptor messenger ribonucleic acids expression in gastric cancer cells

Retinoic acid has been recognised as a pivotal compound in cell differentiation, proliferation and malignant transformation. We investigated the effects of all-trans-retinoic acid on cell growth and the expression of retinoid nuclear receptor mRNAs in gastric cancer cells in vitro. Cell growth was quantified by measuring total cellular DNA. The growth of two of the five gastric cancer cell lines tested (SC-M1 and TSGH9201) was inhibited by all-trans-retinoic acid at concentrations ranging from 1 x 10(-8) M to 1 x 10(-6) M. Growth inhibition was associated with G0/G1 phase arrest as determined by flow cytometric analysis. Northern blot analysis showed that all five cell lines expressed mRNA for retinoic acid receptors alpha and retinoic x receptor alpha and beta. Retinoic acid receptor beta mRNA was only expressed in TSGH9201 and TMK-1 gastric cancer cell lines. Two RAR gamma mRNA transcripts (3.2 and 3.0 kb) were detected in SC-M1 and TSGH9201 cells. RA-resistant cells had markedly decreased levels of the 3.2 kb RAR gamma transcript. All-trans-retinoic acid had a cytostatic effect on the growth of some gastric cancer cells, which may be associated with the expression of retinoic acid receptors.

Comparison of the efficacy of tropisetron versus a metoclopramide cocktail based on the intensity of cisplatin-induced emesis

Cisplatin-induced emesis is one of the most feared side effects in cancer treatment. High-dose metoclopramide may prevent only 30-40% of cases of acute emesis. Investigations to test the efficacy of new antiemetics are mandatory. We compared the efficacy, toxicity, and patients' preference for tropisetron, a new 5-hydroxytryptamine3 (HT3) receptor antagonist, with those of a combination of high-dose metoclopramide, dexamethasone, diphenhydramine, and lorazepam (metoclopramide cocktail) in a randomized crossover study for the control of nausea and vomiting during cisplatin-containing chemotherapy. A total of 62 chemotherapy-naive women were included and followed over 3 consecutive courses. Detailed analysis comparing the incidence of acute emesis for each 4 h period following cisplatin infusion was also performed. Complete protection from acute emesis was obtained in 48% of patients receiving tropisetron and 29% of patients receiving the metoclopramide cocktail over the first two courses of chemotherapy (P = 0.029). When the frequency of acute emesis in all patients was compared on a daily basis, no significant difference was found. When emesis frequency was compared over each 4 h period following infusion of cisplatin, tropisetron was superior to the metoclopramide cocktail during the first, the second, and the first and second periods (P = 0.0001, P = 0.01 and P = 0.0006, respectively). This superiority reversed after 12 h but did not reach statistical significance (P = 0.112). Tropisetron was more effective in controlling acute nausea, but metoclopramide provided better control of delayed emesis. A drop in efficacy over successive courses was observed in patients receiving metoclopramide first but was not seen in tropisetron-first patients. A tendency for tropisetron preference was observed. Tropisetron is more effective than the metoclopramide cocktail in the control of chemotherapy-induced vomiting within 8 h of the implementation of cisplatin and in the control of nausea on the 1st day. To improve the control of chemotherapy-induced emesis, further investigations on the additional tropisetron dosing at 8 h after cisplatin infusion or the combination use of tropisetron and other antiemetics by a continuous 4 h period of observation and comparison are mandatory.

The role of maternal serum alpha-fetoprotein, human chorionic gonadotrophin and oestriol in the antenatal screening of Down's syndrome

The use of maternal age alone to identify pregnant mothers at risk of a fetus with Down's syndrome has recently been supplemented by maternal serum screening using biochemical markers such as alpha-protein, human chorionic gonadotrophin and oestriol. These tests have been reported to increase the sensitivity of antenatal detection of such fetuses from 35% to 67% with a false positive rate of 5%. However, these maternal serum markers may be affected by maternal weight, the smoking history of mothers and diabetes mellitus. Furthermore, such sensitivities are achieved only when gestational age is assessed accurately by ultrasound. Many further studies need to be carried out before the introduction of maternal serum screening into routine obstetric practice in Singapore. These include studies on the incidence of Down's syndrome in the local population, studies on the distribution of these serum markers in the second trimester of pregnancy, sensitivities and positive predictive values of such a test in the local population as well as the socio-economic implications of implementing such a screening test in the local obstetric population.

Ultrasonographic findings of papillary thyroid carcinoma and their relation to pathologic changes

To elucidate the ultrasonographic findings in papillary thyroid carcinoma and their relation to pathologic changes, 47 patients on whom thyroid ultrasonography had been performed and whose thyroid tissues were pathologically proven to be papillary thyroid carcinoma were studied. The ultrasonographic findings were reviewed and correlated with the pathologic changes. Fifty-three out of 94 thyroid lobes had papillary carcinoma. The ultrasonographic features of the affected thyroid lobes were hypoechoic in 46, isoechoic in 6 and hyperechoic in 1. The ultrasonographic texture of all 53 lesions was heterogeneous. The margin was clear in 11 lesions and unclear in 42. Cystic degeneration was found in 15 lesions. Discrete particles representative of microcalcifications were found in 25 lesions. Halo signs were found in 7 lesions. Lymph node enlargement was detected in 4 cases. The sensitivity and specificity of each ultrasonic finding in predicting the respective pathologic feature were: unclear margin for tumor invasion, 84% and 31%; cystic degeneration for cysts, 42% and 79%; discrete particles for microcalcification, 50% and 52%; halo sign for total encapsulation, 42% and 88%; and lymph node enlargement for lymph node metastasis, 18% and 100%, respectively. These data suggest that ultrasonographic findings in papillary carcinoma were usually hypoechoic and heterogeneous. An unclear margin in sonography is fairly sensitive for the prediction of tumor invasion.

Regulation of the expression of alkaline phosphatase in a human breast-cancer cell line

Treatment of the cultured human breast-cancer cells BC-M1 with dexamethasone induced a placental-type alkaline phosphatase (ALP). Both the ALP activity and the mRNA level in the cells were increased. The induction of ALP activity by dexamethasone was time- and dose-dependent. The accumulation of ALP mRNA was inhibited by both actinomycin D and cycloheximide, indicating that its induction is a complex event and may involve other regulatory proteins. Retinoic acid showed opposing effects with dexamethasone on the expression of alkaline phosphatase. Retinoic acid (RA) and phorbol 12-myristate 13-acetate also substantially reduced the dexamethasone-induced expression of ALP. Studies on thermostability and sensitivity to various amino acid inhibitors indicated that the BC-M1 ALP is most similar to the placental form. Northern hybridization analysis also revealed that ALP mRNA transcripts in BC-M1 and term placenta are similar in size and are distinct from that of the placental-like mRNA transcript in choriocarcinoma cells. Analysis of the degradation of BC-M1 ALP mRNA showed a similar half-life of 27 h in the untreated and in dexamethasone- or RA-treated cells. These findings demonstrated that the induction of ALP in BC-M1 cells by dexamethasone is mainly due to the increase in the transcription of the ALP gene.

Effect of grinding and fluoride-gel exposure on strength of ion-exchanged porcelain

Strengthening of dental porcelain through a diffusion heat treatment at 450 degrees C of a potassium-enriched, ion-exchange surface coating has been demonstrated in several recent studies. However, little attention has been focused on the potential strength reduction of these materials when the treated surfaces are ground or etched under clinically simulated conditions. The objective of this study was to test the hypothesis that partial removal of the surface layers of ion-exchanged porcelains by grinding or exposure to acidulated fluoride gel will significantly reduce their flexure strength. Nine groups of body porcelain disks were ion-exchanged at 450 degrees C for 30 min. One of these groups was subjected to ion exchange and no further surface treatment. Eight specimen groups were subjected to the following procedures after ion exchange: grinding to depths of 50 microns, 100 microns, 150 microns, 200 microns, and 250 microns, and exposure to acidulated fluoride for 30 min, 60 min, and 300 min. A tenth group (FC) was fired at 960 degrees C and fast-cooled in air, but the disks were not subjected to the ion-exchange treatment. Surface stress was calculated from measured values of cracks induced in the treated surfaces. Fluoride exposure for up to 60 min resulted in a significant decrease in surface compression (P < or = 0.05), although this treatment had no effect on strength. Grinding to a depth of from 100 microns to 250 microns caused a significant decrease in strength, while removal of a 50-microns layer caused no significant change (P > 0.05).

Relationship of eye movement to computed tomographic findings in patients with Graves' ophthalmopathy

To elucidate the relationship between eye movement and computed tomographic findings, 101 patients with Graves' ophthalmology were studied. Eye movements were scaled 0 to 3 according to movability. Extraocular muscle width and area were calculated from the largest portion of each muscle from the orbital coronal CT sections. Muscle widths were measured manually and muscle areas were calculated by a digitizer. The width and area of each rectus muscle were significantly correlated with limitation of eye movement. The muscle widths and areas were also significantly correlated to each other (r = 0.91 to 0.77, p < 0.001). Limitations of supraduction and abduction from enlargement of the inferior and medial rectus muscles were the most common clinical findings (46.5% and 39.6%, respectively). In conclusion, this study establishes a relationship between limitation of eye movement and extraocular muscle enlargement. Calculation of the width from the largest portion of the muscle manually from orbital coronal section is a simple method for clinical assessment of the severity of extraocular muscle involvement.