Comparative Analysis of Learning Effect for Students who Experienced both Lecture-based Learning and Problem-based Learning in a Complete Denture Course

PURPOSE

The purpose of this study was to analyze the difference in educational effect on students who experienced both lecture-based learning (LBL) and problem-based learning (PBL) in a complete denture course. The analysis focused on differences between the two methods concerning self study, ability to understand clinical inference, and appraisal of class contents and tutors.

METHODS

In the complete denture preclinical course, the class of 2003 received LBL in 3rd grade and PBL in 4th grade. PBL was planned to present five cases in five consecutive classes. Group discussion was carried out for each case, and a summary was required to be produced two times as a group, two times as an individual report and one time by group presentation. A questionnaire regarding the educational effect of LBL and PBL and assessment of tutors was administered. Factor analysis was carried out to classify the questionnaire items and each item was analyzed between LBL and PBL (Paired-t test).

RESULTS

Factor analysis revealed that the questionnaire items could be classified into four components. Comparing lecture type and PBL: "study attitude" (4 out of 7 items), "clinical inference ability" (all items), "class contents" (5 out of 7 items) and "tutor appraisal" (2 out of 5 items) showed significant assessment with PBL. Eighteen of 27 items (66.6%) indicated the significant usefulness of PBL.

CONCLUSION

PBL improves the educational effect of self study and clinical inference ability, in comparison with LBL. However, since students are passive about taking the same system class repeatedly, a strategy to improve their attitude needs to be considered.

Randomized controlled clinical trial for verifying the effect of silicone-based resilient denture liner on the masticatory function of complete denture wearers

PURPOSE

The purpose of this study was to investigate whether application of permanent silicone-based resilient denture liner (SR) to mandibular complete dentures significantly improves patients' masticatory ability compared to conventional heat-activated acrylic resin (AR).

MATERIALS AND METHODS

Twenty-eight edentulous patients were randomly placed into 1 of 2 crossover groups (AR-SR/SR-AR) by using a random permuted block within strata method. The AR-SR group received AR denture treatments followed by SR denture treatments. The SR-AR group received treatments in the reverse sequence. The outcomes were classified by matiscatory performance, mandibular movement, electromyographic activity, and maximum occlusal force.

RESULTS

No significant differences were observed in any of the baseline characteristic measurements between groups. SR denture wearers exhibited significantly higher masticatory performance than AR denture wearers. SR denture wearers exhibited a longer early-stage occluding period than AR denture wearers. There were no differences in electromyographic activity between the AR and SR groups. There were no significant differences in maximum occlusal force between the AR and SR groups.

CONCLUSION

This study showed that the application of SR to mandibular complete dentures resulted in significant improvements to the patients' masticatory ability compared to AR.

Influence of occlusal contact on cervical muscle activity during submaximal clenching

The aim of this study was to clarify the relationship between changes in the occlusal contact area and cervical muscle activity. A decreases in the occlusal contact area using bite planes (stage 1: full contact bite plane, stage 2: bilateral molar removed from contact, and stage 3: bilateral molar and premolar removed from contact) was experimentally simulated in seven subjects (aged 23-25 years) with normal dentition, and muscle activity of the sternocleidomastoid muscle (SCM) and trapezius muscle (TRM) during 50 and 10% of maximum voluntary contraction (MVC) was measured by surface electromyography. The SCM activity during 50% MVC was stage 1: 31.2 +/- 9.4 microV and stage 3: 35.3 +/- 12.3 microV. The TRM activity during 50% MVC was stage 1: 15.2 +/- 0.7 microV and stage 3: 18.3 +/- 2.9 microV. At the 50% MVC, stage 3 showed significant differences in comparison with stage 1 (P < 0.05, anova). These findings suggested that the sternocleidomastoid and TRM play roles in the exertion of occlusal force, and decreases in the occlusal contact area influence the amount of SCM and TRM activity.

[Standard values of inter-inner canthal, inter-outer canthal, and inter-pupillary distances in normal Japanese infants and children]

PURPOSE AND MATERIALS: We studied inter-inner canthal distance(DIC), inter-outer canthal distance (DOC), and inter-pupillary distance (PD) in 1,006 normal Japanese infants and children to establish the normal ratio of DIC/PD and DOC/DIC for the diagnosis of congenital anomalies such as Waardenburg syndrome.

RESULTS

DIC, DOC, and PD increased significantly from one month after birth to 12 years of age. DIC and DOC were stable but PD increased from 13 years of age to 15 years of age in junior high school. The DIC/PD and DOC/DIC averages were 0.61 and 2.73, respectively, one month after birth and 0.63 and 2.69 at three months after birth. On the other hand, DIC/PD and DOC/DIC were stable at 0.55-0.59 and 2.45 from 8 to 15 years of age.

CONCLUSION

Since there have been no reports on standard values of DIC, DOC and PD in infants, we established the standard values in this study. These values are expected to be very useful in the diagnosis of neural crest cell migration anomalies, such as Waardenburg syndrome.

Direct medical costs of chronic obstructive pulmonary disease: chronic bronchitis and emphysema

In this study we aimed to estimate direct medical costs of Chronic Obstructive Pulmonary Disease (COPD) by disease type; chronic bronchitis and emphysema. This study estimates direct costs in 1996 dollars using a prevalence approach and both aggregate and microcosting. A societal perspective is taken using prevalence, and multiple national, state and local data sources are used to estimate health-care utilization and costs. Chronic bronchitis and emphysema together account for $14.5 billion in annual direct costs. Inpatient costs are greater than outpatient and emergency costs ($8.3 vs. $7.8 billion) and hospital and medication costs account for most resources spent. The high prevalence of chronic bronchitis accounts for its larger total costs ($11.7 billion) compared with emphysema ($2.8 billion). Emphysema, which is more severe, has higher costs per prevalent case ($1341 vs. $816). Hospital stays account for the highest costs, $6.0 billion for chronic bronchitis and $1.9 billion for emphysema. The hospitalization rate, length of stay and average cost per prevalent case are higher for emphysema than for chronic bronchitis. Medication costs are the second highest cost category ($4.4 billion for chronic bronchitis, $0.693 billion for emphysema). The high hospitalization and low home care costs (0.2% of total) suggest underuse of home care and room to shift from acute to preventive care. More attention to healthcare management of chronic bronchitis and emphysema is suggested, and improving inhaler and anti-smoking compliance might be important targets.

Immunohistochemistry for hMLH1 and hMSH2: a practical test for DNA mismatch repair-deficient tumors

Inactivation of deoxyribonucleic acid (DNA) mismatch repair genes, most commonly human mutL homologue 1 (hMLH1) or human mutS homologue 2 (hMSH2), is a recently described alternate pathway in cancer development and progression. The resulting genetic instability is characterized by widespread somatic mutations in tumor DNA, and is termed high-frequency microsatellite instability (MSI-H). Although described in a variety of tumors, mismatch repair deficiency has been studied predominantly in colorectal carcinoma. Most MSI-H colorectal carcinomas are sporadic, but some occur in patients with hereditary nonpolyposis colorectal cancer (HNPCC), and are associated with germline mutations in mismatch repair genes. Until now, the identification of MSI-H cancers has required molecular testing. To evaluate the role of immunohistochemistry as a new screening tool for mismatch repair-deficient neoplasms, the authors studied the expression of hMLH1 and hMSH2, using commercially available monoclonal antibodies, in 72 formalin-fixed, paraffin-embedded tumors that had been tested previously for microsatellite instability. They compared immunohistochemical patterns of 38 MSI-H neoplasms, including 16 cases from HNPCC patients with known germline mutations in hMLH1 or hMSH2, with 34 neoplasms that did not show microsatellite instability. Thirty-seven of 38 MSI-H neoplasms were predicted to have a mismatch repair gene defect, as demonstrated by the absence of hMLH1 and/or hMSH2 expression. This included correspondence with all 16 cases with germline mutations. All 34 microsatellite-stable cancers had intact staining with both antibodies. These findings clearly demonstrate that immunohistochemistry can discriminate accurately between MSI-H and microsatellite-stable tumors, providing a practical new technique with important clinical and research applications.

[A study of hypertriglyceridemia occurring in patients with chronic hepatitis C during administration of interferon beta]

The prevalence and risk factors of hypertriglyceridemia during the administration of interferon (IFN) were examined in 78 patients with chronic hepatitis C who were treated with 6 MU of IFN-beta once or 3 MU of IFN-beta twice a day for 6 weeks. Hypertriglyceridemia (serum triglyceride (TG) above 150 mg/dl) was found before the start of IFN treatment in 9% of the patients. During the administration of IFN, elevation of serum TG above 150 mg/dl was found in 82% of patients. In addition, serum TG level exceeded 500 mg/dl at least once during the administration of IFN in 13% of patients. On stepwise multiple regression analysis, three risk factors, high serum TG value before the administration of IFN, high ALT value before the administration of IFN, and divided administration of IFN-beta twice daily were found to be associated with hypertriglyceridemia during IFN administration.

Cervical myelocystocele with Chiari II malformation: magnetic resonance imaging and surgical treatment

BACKGROUND

The myelocystocele is a rare clinical entity, and there have only been six case reports concerning the cervical myelocystocele, including ours.

METHODS

The case of a female neonate with cervical myelocystocele, who presented with respiratory distress beginning at birth is reported.

RESULTS

Magnetic resonance (MR) imaging disclosed a cystic lesion surrounded by two layers of membrane, which were recognized to be the dural and arachnoid layer and the ependymal lining layer, respectively, during operation and on histopathologic examination. Hydromyelia at C2-C7 with Chiari II malformation was also observed. After a thorough repair and untethering surgery, the hydromyelia was diminished on a follow-up MR examination. The patient's respiratory status normalized several days postoperatively, and her growth and development were within normal limits at the 2-year follow-up.

CONCLUSIONS

In cases of cervical myelocystocele with Chiari II malformation, untethering through intradural exploration to treat the tethered cord and outer decompression of the foramen magnum are needed. MR imaging is the best modality for preoperative determination of anatomic relationships.

[Percutaneous microwave coagulation therapy for hepatocellular carcinoma--study on its therapeutic effect in surgical cases]

Six patients with hepatocellular carcinoma were subjected to percutaneous microwave coagulation therapy (PMCT) by ultrasonic guiding. The size of the main tumor in the present cases was limited to not more than 2 cm. From 18 to 48 days after PMCT, each patient was subjected to surgery and pathological examination. By macroscopic observation, the PMCT area including both non-tumor and tumor regions looked yellowish white, and the boundary was clearly recognized. In the histological examination, the coagulation area surrounded by fibrous capsule was found, and deletion of nuclei and changes in stainability were observed in the marginal region. These changes indicated obvious coagulation necrosis, but the changes became less intense toward the center in the area, and in some portions, the tissue was indistinguishable from viable cells by light microscopy. In 2 cases out of the 6, part of the tumor remained outside the coagulation area. Since only the area determined by the microwave electrode is coagulated to cause necrosis on PMCT, sufficient safety margin should be required.

[Angiographical frequency of unruptured incidental intracranial aneurysms]

We reviewed cerebral angiograms studied between May 1985 and December 1992 focusing on unruptured incidental intracranial aneurysms. In a total of 605 cases of cerebral angiograms except for patients with SAH, 43 patients (7.1%) were found to have unruptured aneurysms. In the 72 patients with headache, 11 patients (15.3%) were found to have unruptured aneurysms. This high frequency of unruptured aneurysms in headache patients is significant as a factor showing that headache may be due to unruptured aneurysms. The result of this observation is that as a screening study for headache patients, cerebral angiography may be required in spite of the invasive and high-risk method. But we think that MR angiography is, at present, a useful screening study only for detecting cerebral aneurysms with a diameter of over 5mm, and which are considered to need an operation.

Duodenal adenomas in familial adenomatous polyposis: relation of cell differentiation and mucin histochemical features to growth pattern

We performed a clinicopathologic analysis of 74 periampullary and duodenal adenomas from 30 patients with familial adenomatous polyposis to evaluate the growth pattern, mucin histochemical profile, and degree and significance of Paneth cell and endocrine cell differentiation in these lesions. A trend toward more numerous adenomas was seen in patients with the longest intervals since their previous colectomies. Adenomas were most often clustered in the periampullary region and were numerous (> 20) in 40% of patients. Periampullary and duodenal adenomas were morphologically similar; both exhibited the same size-villous shape-dysplasia relationship as sporadic and familial adenomatous polyposis-associated colonic adenomas. Adenomas showed a heterogenous pattern of mucin production (mixed small intestinal-large intestinal types), with a shift toward the colonic type (sulfomucin) in lesions that were larger, villous, or severely dysplastic. Ninety-two percent of adenomas showed Paneth cell differentiation (average n Paneth cells/high power field = 24.5), and 99% showed endocrine cell differentiation (average n endocrine cells/high power field = 64.4). In general, the proportion of these specialized cell types was inversely related to size, villous shape, and degree of epithelial dysplasia. These results suggest that periampullary and duodenal adenomas in familial adenomatous polyposis arise from the neoplastic transformation of an undifferentiated stem cell that retains its ability for multidirectional differentiation.

Studies on prostaglandin and luteolysis in the pseudopregnant rabbit

The ability of pulsatile infusion of prostaglandin F2 alpha (PGF2 alpha) or 13, 14-dihydro prostaglandin F2 alpha to induce corpus luteum regression was examined in the pseudopregnant rabbit. Each prostaglandin was infused in 5, 1-hour pulses (1 per 6 hours) during a 25-hour period starting day 9 or 10 of pseudopregnancy. Although both prostaglandins were capable of inhibiting progesterone secretion, pulse administration was no more effective than continuous infusion. To determine if PGF2 alpha was released into the systemic circulation during spontaneous luteolysis, starting day 12 of pseudopregnancy serial blood samples were collected every 90 minutes from the jugular vein. Prostaglandin F levels remained steady (1-2 ng/ml over the collection period with no apparent increase associated with functional luteolysis. Although prostaglandins may be involved in luteolysis in the rabbit, the present results suggest that it is unlikely that PGF2 alpha by itself is responsible for the sustained fall in progesterone secretion at the end of the pseudopregnancy.

[The clinical examination for posttransfusion hepatitis]

We studied viral hepatitis, type A, type B, type D and type non A non B. Type A hepatitis was diagnosed by the serological examination for IgM type anti-HA and total anti-HA. Several cases were negative for IgM type anti-HA within 2 weeks after the onset of type A hepatitis. Type B hepatitis was diagnosed by RIA for serum HBs antigen. Several cases of type B hepatitis were negative for serum HBs antigen but positive for IgM type anti-HBc, or hepatocytes were positive for HBs antigen. These cases had high titer of total anti-HBc. Type D hepatitis was diagnosed by RIA for anti-delta in serum and by PAP stain for delta antigen in hepatocytes. All cases of type D hepatitis were positive for anti-delta in their serum and positive for delta antigen in their hepatocytes, they were positive for HBs antigen. Incidence of HDV infection was 0.7% in HBV carrier. The incidence of non A non B hepatitis was 27.6% in 105 recipients and the incidence of its progression to the chronicity was 20.0%.

[A case of cerebral embolism caused by atrial myxoma--superselective fibrinolytic therapy]

A 37-year-old man was admitted to our clinic 3 hours after the onset of cerebrovascular accident with right hemiparesis and total aphasia. On admission, we started combined administration of mannitol, vitamin E, phenytoin (Sendai Cocktail) and perfluorochemicals to protect ischemic brain. Left cerebral angiography revealed occlusion of the left middle cerebral artery involving its perforating arteries. Following the performance of angiography, vascular balloon catheter was introduced into the embolus, and fibrinolytic agent (urokinase) was continuously injected. Soon after the injection of 240,000 unit urokinase, recanalization of left middle cerebral artery was shown by repeated cerebral angiography performed 5.5 hours after the onset. On his clinical course, left hemiparesis and aphasia were improved step by step, and 1 week later, he could walk by himself with minor neurological deficits. Further examination revealed that myxoma was located on left atrium by echocardiography. Within 1 week, the patient was transferred to cardio-surgical unit, and myxoma was successfully removed. Now he is in good health and has returned to his job. Usually cerebral embolisms result from atrial myxoma cause severe cerebral infarction. Here we reported a case of cerebral embolism by myxoma and recanalized using fibrinolytic agent by balloon catheter injection. The damage will be reduced if the duration of occlusion is limited, so this method will be helpful to treat cerebral embolism.

[A new superselective balloon catheter--all-silicone catheter with a floppy tip]

We have introduced concept of "chemical" embolization and have tried to develop a new agent which would enable us to embolize the lesion with one-shot injection. Such an agent must be able to occlude diffusely the lesion distal to the catheter. This has made it mandatory to develop a new catheter which can be introduced into the vessel as close to the lesion as possible with fewer risks of clot formation and/or vessel damage. A new superselective balloon catheter for angiography and infusion of liquid embolizing materials has been developed. This catheter consists of a proximal relatively stiff silicone catheter, a short distal thin-walled flexible silicone catheter and silicone balloon. These three silicone components are connected by silicone adhesives. The distal catheter allows us to catheterize fine arteries such as lenticulostriates, while the proximal catheter assures easy manipulation. This balloon catheter can be used for superselective angiography and infusion of liquid embolizing materials. It has been used on nine patients; one with a dural arterio-venous malformation (AVM), four with meningiomas, and four with brain and spinal cord AVMs. In the case of dural AVM and meningiomas, it was possible to easily introduce into the middle meningeal artery distal to the foramen spinosum. In addition, in one of the cases of meningioma, we were able to catheterize one of the main feeding pedicles beyond the pterion. Chemical embolization was carried out in 5 cases with good results. In the case of brain and spinal cord AVM, useful information was obtained from the superselective angiography.(ABSTRACT TRUNCATED AT 250 WORDS)