Essential research projects of oral health science in Tokyo Dental College for the 21st century

In this era of an aging society, no longer will it be sufficient for us to sit in small research units and concentrate on individual experiments. Tokyo Dental College must expand its abilities and develop new attitudes to meet society's evolving needs. The Search Eye 21 will provide us with new opportunities to identify such research goals and to unite coordinated efforts for the advancement of oral health science.

Abdominal actinomycosis: barium enema and computed tomography findings

A case of abdominal actinomycosis is described in a woman with recurrent right lower abdominal pain and low-grade fever without history of appendectomy. Past history included the use of an intrauterine device (IUD) until 10 years before manifestation of these symptoms. We followed up the patient, via diagnostic imaging, for 7 months. On initial barium enema, a polypoid lesion was visualized at the bottom of the cecum and there was constriction of the sigmoid colon; the appendix was not seen. Seven months later, poor extension at the cecum, severe constriction in the sigmoid colon, and narrowing of the terminal ileum were also visualized. On computed tomography (CT), the lesion was initially localized only in the ileocecal region adjacent to the sigmoid colon. After 7 months, the lesion had infiltrated adjacent anatomic components and showed direct infiltration of the pelvic space. Differential diagnosis was difficult, as it was not obvious whether this was a pelvic abscess due to inflammation or appendiceal carcinoma. Laparotomy was performed. Macroscopically, the lesion was not limited to the ileocecal region, but involved the right ureter, tubes the Fallopian and ovary, bladder, psoas muscle, and abdominal wall. Pathology findings showed, chronic inflammatory tissue with evidence of actinomycosis. Although previous reports have described a lack of specific findings in this disease. When actinomycosis is suspected, CT is recommended to define its extent.

Mothers' low care in the development of alexithymia: a preliminary study in Japanese college students

We examined the influences of perceived parental bonding on scores on alexithymia in a sample of 232 college students. Ratings on mothers' care, a scale of the Parental Bonding Inventory were significantly and negatively correlated with scores on the Toronto Alexithymia Scale, and also with ratings on Difficulty Describing Feelings but not Difficulty Identifying Feelings and Externally Oriented Thinking. These results were replicated in another sample of 156 college students. Although our findings were based on simple correlations, they suggest that perceived mothers' low care is related to adults' scores on alexithymia, in particular, the construct, Difficulty Describing Feelings.

Pathological consideration of a "blister-like" aneurysm at the superior wall of the internal carotid artery: case report

OBJECTIVE AND IMPORTANCE

Although the incidence is low, a very small aneurysm with a thin wall and no neck arises at the superior wall of the supraclinoid portion of the internal carotid artery and is called a "blister-like" aneurysm. However, the pathogenesis of such a vascular lesion remains uncertain.

CLINICAL PRESENTATION

A 57-year-old man developed a fatal subarachnoid hemorrhage caused by the rupture of a blister-like aneurysm at the superior wall of the internal carotid artery. An autopsy was performed, and the lesion was pathologically examined.

RESULTS

The internal elastic lamina and media had disappeared at the border between the eccentrically sclerotic and normal carotid wall. The gap in the internal elastica was covered with normal adventitia and fibrinous tissue. This portion was not composed of collagenous tissue as ordinarily seen in an aneurysmal wall. Neither infiltration of inflammatory cells nor dissection of the artery were observed.

CONCLUSION

The blister-like aneurysm appeared to be a laceration of the carotid wall based on degeneration of the internal elastic lamina.

Changes in the immunoreactivity of protein gene product (PGP) 9.5 in the cochlea of spontaneously diabetic WBN/Kob rats

The mechanism of hearing impairment due to diabetes mellitus was examined in relation to changes in the level of the immunoreaction for the protein gene product 9.5 in the cochlea of spontaneously diabetic WBN/Kob rats. At 7 months (33 weeks) of age, when half of the males of this strain manifest diabetes, male WBN/Kob rats were divided into two groups as follows: one group consisted of prediabetic animals showing slightly decreased tolerance to glucose with a normal plasma concentration of glucose, normal urinary excretion of glucose, and functional hearing impairment (assessed in terms of elevation of hearing threshold). The second group consisted of diabetic animals with glucose intolerance, high plasma glucose level, polyuria, urinary glucose excretion, and more apparent elevation of hearing threshold. According to morphometric analysis of the spiral ganglion, the number of ganglion cells was significantly smaller in both the prediabetic and the diabetic animals than in the age-matched control Wistar rats. The staining intensity for protein gene product 9.5 was increased in some spiral ganglion cells of diabetic animals, but decreased in others according to quantitative immunohistochemical analysis. On the other hand, the immunoreactivity for protein gene product 9.5 was similar in the prediabetic animals to that in the control Wistar rats. These results suggest that numerical and immunohistochemical changes in the spiral ganglion cells reflect the onset and degree of the diabetic hearing impairment.

[A successful removal of T4 lung cancer with its left atrial extension using cardiopulmonary bypass]

A 42-year-old man presented with cough, chest pain and dyspnea. The chest roentgenogram revealed a large mass shadow in the right upper and middle lobes with atelectasis and pleural effusion. Massive polypoid tumor extending into the left atrium was diagnosed by computed tomography and two dimensional echocardiography. In order to prevent sudden death and cardiac failure, surgery was performed. At first, the polypoid tumor in the left atrium was removed with a partial resection of the left atrial wall under cardiac arrest using cardiopulmonary bypass. Then, a right pneumonectomy was performed. Episodes of embolism were not observed during surgery. His postoperative course was almost favorable. The size of the tumor in the right lung was 18 x 15 x 8 cm and the one in the left atrium was 6.5 x 4.5 x 3 cm, respectively. Pathological examination of the resected specimen revealed the evidences of large cell carcinoma extending into the left atrium. Local recurrence with S9 metastasis of the left lung were detected 6 months after surgery, and he died 6 months later. It is emphasized that the extended surgery using cardiopulmonary bypass was useful for both prevention of embolism and improvement of quality of life.

Development of anterior cranial fossa dural arteriovenous malformation following head trauma. Case report

Dural arteriovenous malformations (AVMs) are considered to be acquired lesions that develop secondary to venous obstruction, which sometimes happens in head trauma. However, there has been a report of an anterior cranial fossa dural AVM that occurred independently of a history of head trauma, and there has been speculation that these malformations are congenital. The authors recount their experience with a patient who had an anterior cranial fossa dural AVM that was discovered incidentally. The lesion was fed by the bilateral anterior ethmoidal arteries and drained into the superior sagittal sinus via frontal cortical veins. The patient had a history of severe head trauma that had occurred 30 years earlier. This is the first case report in which a previous head trauma is strongly believed to be the cause of an anterior cranial fossa dural AVM. The authors postulate that anterior cranial fossa dural AVMs can develop secondary to a head trauma.

Serial analysis of hepatitis B virus core nucleotide sequence of patients with acute exacerbation during chronic infection

Recent studies suggest that hepatitis B virus (HBV) core region could be an immunological target and that amino acid (aa) substitutions are mostly restricted to a small segment located in the middle of the core region. We sequenced the middle portion of HBV core gene during the course of acute exacerbation of chronic hepatitis B, and compared aa variations between the region including ideal HLA-A2 binding motifs and the nonbinding region. Five HBeAg+ chronic hepatitis patients with subtype adr (three with HLA-A2 and two without HLA-A2) were selected and using polymerase chain reaction (PCR) and cloning system, the central part of core region (nt 2063 to 2365, 303 bp) was sequenced in sera from each patient at three time points; before, at the peak of, and after exacerbation of hepatitis. The second set of sera showed higher aa substitution rates in five and in three out of five patients compared with those of the first and third sera, respectively. No significant difference was found in the aa substitution rates for the region with ideal HLA-A2 binding motifs between patients with and without HLA-A2. In asymptomatic HBV carriers with persistently normal aminotransferase values, alterations of the aa sequence were not observed within the same time frame. The results suggest that aa substitutions often occur at some particular positions in the middle of HBV core region during acute exacerbation of the disease under possible host immune pressures. Furthermore, unidentified epitopes appear to exist in the central part of HBV core region and HLA-unrestricted lymphocytes may play a role in the immune response of chronic HBV carriers.

Endothelin-converting enzyme expression in the rat vascular injury model and human coronary atherosclerosis

BACKGROUND

Endothelin 1 has been implicated in various human diseases, including atherosclerosis. In this study, we examined the expression and localization of endothelin-converting enzyme-1 (ECE-1), the final key enzyme of endothelin 1 processing, in rat carotid arteries after balloon injury and in human coronary atherosclerotic lesions.

METHODS AND RESULTS

ECE-1 mRNA levels and ECE activity in rat balloon-injured arteries started to increase between 2 and 5 days after injury. The endothelin 1 content of tissue in injured arteries was concomitantly increased. Immunohistochemical staining located ECE-1 signals in endothelial cells in uninjured arteries, whereas ECE-1 immunoreactivity was detected in neointimal smooth muscle cells in injured arteries 5 to 14 days after balloon denudation. The size of the neointima was effectively reduced by phosphoramidon, an inhibitor of neutral metalloproteases, including ECE-1. In human coronary atherosclerotic lesions, intense ECE-1 immunoreactivity was detected in subsets of cells embedded in atheromatous plaque that correspond to smooth muscle cells and macrophages, as identified by staining for smooth muscle alpha-actin and CD68 surface marker, respectively.

CONCLUSIONS

The present study ascertained that ECE-1 is expressed in neointimal smooth muscle cells in rat balloon-injured arteries and in both smooth muscle cells and macrophages in human coronary atherosclerotic lesions. Blockade of ECE-1 was effective in reducing neointimal formation after balloon injury. Thus, ECE-1 may contribute to the process of injury-induced neointimal formation and atherosclerosis through the autocrine/paracrine effects of endothelin 1.

Unilateral meningoencephalitis with hemispheric slowing on EEG

We report a 12-year-old boy with unilateral meningoencephalitis due to non-herpes simplex virus. He experienced secondarily generalized partial seizures of the left extremities with loss of consciousness. In contrast with normal neuroimaging findings, interictal electroencephalograms (EEGs) showed prolonged slowing in the right hemisphere. This laterality agreed with the right brain dysfunction verified on neuropsychological examination. Follow-up EEG is important in such a subtle case with normal neuroimaging.

Differential binding of peptides substituted at putative C-terminal anchor residue to HLA-DQ8 and DQ9 differing only at beta 57

HLA-DQ8 (DQA1*0302-DQB1*0302: DQ beta 57 Ala) and (DQA1*0302-DQB1*0303: DQ beta 57 Asp) differ only at beta 57, at which polymorphism reportedly confers distinct susceptibility to insulin-dependent diabetes mellitus (IDDM). To identify the differential peptide binding affected by beta 57, we determined DQ9-binding peptides by affinity-based selection of a phage random peptide library using the biotinylated DQ9 complex. Nonconservative single-residue substitution of high-affinity DQ8- and DQ9-binding peptide (1KLPDYVLWSSSTVVGLGAAGA21) at the underlined residues significantly decreased the peptide binding to DQ8 and DQ9. Affinities of the wild-type 21-mer K4DYVLWSSSTV13 and K4AYAAWAAATA13 to DQ8 and DQ9 were practically the same. The K4DYVLWSSSTV13-based analogue peptides with substitutions at 12T showed that residues R, K, H, E, D, Q, N, T, S, V, L, I, F, M, W, and Y permitted binding to DQ8, whereas only R, T, V, L, I, F, M, W, and Y did so to DQ9. Thus, significant differences exist between DQ9 and DQ8, in that the majority of polar residues, regardless of their static charges at the residue 12, permitted binding to IDDM-susceptible DQ8, which is not the case for DQ9. The affinities of K4DYVLWSSSXV13 AND K4AYAAWAAAAX13 (where X is T, A, K, D, or I) were almost equal to DQ8 and DQ9, suggesting the DQ8- and DQ9-binding peptide motifs could accept both the 8-mer and 9-mer frames depending on intervening sequences between N- and C-terminal anchor residues. The biochemical basis of peptide-HLA interactions determined by DQ beta 57 is discussed.

[Diagnostic imaging of renal pedicle injury]

We reviewed the radiological findings of 8 patients with renal pedicle injury admitted to our emergency center from January 1986 through September 1995 and compared them with the previously reported findings. The patients included 3 with renal artery occlusion and 5 with avulsion or disruption of renal pedicle vasculature. Extended retroperitoneal hematoma such as contralateral pararenal or central parahilar hematoma was visualized in all 5 cases with avulsion or disruption of renal pedicle vasculature. Although lack of contrast enhancement of injured renal parenchyma is a hall-mark of renal pedicle injury, three cases did not demonstrate this typical finding. In these three cases, one showed partial and the others showed total enhancement of the injured renal parenchyma on contrast enhanced CT. Partial enhancement in one case was found to represent total occlusion of the main renal artery and an intact accessory polar branch on angiography. The other two cases showed total enhancement of the renal parenchyma, with renal vein perforation done and complete disruption of the main renal artery and vein in the other. The latter findings were thought to be due to the maintenance of vascular flow surrounded by hematoma. In conclusion, when central parahilar hematoma is identified, the possibility of renal pedicle injury should be considered even if the renal parenchyma is well enhanced.

[Clinical efficacy of silver sulfadiazine (AgSD: Geben cream) for ulcerative skin lesions infected with MRSA]

The clinical efficacy was evaluated on 1% silver sulfadiazine (AgSD) cream (Geben cream) for the treatment of ulcerative skin lesions infected with MRSA (methicillin-resistant Staphylococcus aureus). 1% AgSD cream was applied once a day to cutaneous ulcers such as burns or decubitus or various other ulcers, infected with MRSA, in 13 patients. MRSA was eradicated in 45.5% of 11 evaluable patients. The clinical efficacy rate of 1% AgSD cream was 72.7% in this series of treatment. No side effects were noted in any of the patients, either locally or systemically. The results of the present study have indicated that 1% AgSD cream is useful for cutaneous ulcers such as burns or decubitus, infected with MRSA.

Usefulness of self made introducer for laryngeal mask airway in paediatric anaesthesia

The usefulness of a self made introducer for laryngeal mask airway (LMA) placement was investigated in 251 paediatric patients. Adequate success rate on the first attempt and atraumatic insertions were achieved by the introducer with minimum experience. The authors concluded that the introducer has significant advantages for easy and safe insertions of the LMA in paediatric anaesthesia.

Cyclosporine therapy affects aminotransferase activity but not hepatitis C virus RNA levels in chronic hepatitis C

Interferon (IFN) therapy is of proven efficacy in chronic hepatitis C, but it is not universally effective and is often limited by side effects. Cyclosporine A (CsA) is a potent immunosuppressant widely used in organ transplantation. We conducted a pilot study to determine whether CsA therapy could affect aminotransferase activity and hepatitis C virus RNA levels in patients with chronic hepatitis C. Cyclosporine A was administered to 10 patients (mean age of 59 years; male:female = 9:1) who did not respond to IFN therapy previously and who had elevated serum alanine aminotransferase (ALT) values for at least 6 months. All patients were positive for HCV-RNA by RT-PCR with genotype 1b. Their mean duration of hepatitis was 15 years. Oral CsA was given for 3 months in a dose that was increased at 1 month intervals from 1.5-2.0 to 2.0-3.0 and 3.0-4.0 mg/kg per day. All patients completed the treatment schedule, although two patients developed mild non-symptomatic hypertension. Serum ALT levels gradually decreased in all but one patient. The mean percentage decrease was 59.5% at the end of therapy (from 153 +/- 82 to 62 +/- 48 IU/L; P < 0.02). The ALT levels fell to the normal range in five patients, although once therapy was discontinued the enzyme levels tended to return to pretreatment levels. Serum aspartate aminotransferase and g-glutamyl transpeptidase levels similarly decreased. The serum HCV-RNA titre, determined by competitive RT-PCR, did not change in any patient throughout the study period. There were no appreciable alterations in other laboratory tests, such as serum creatinine levels and lymphocyte subsets, except for an increase in serum alkaline phosphatase levels. These findings suggest that CsA, even in a relatively low dose, reduces serum aminotransferase levels without serious side effects in patients with chronic hepatitis C, although an antiviral effect was not noted.

Temporal lobe epilepsy: correlation of proton magnetic resonance spectroscopy and 18F-fluorodeoxyglucose positron emission tomography

Proton magnetic resonance spectroscopy (MRS) has demonstrated reduction of N-acetylaspartate (NAA) in the epileptogenic temporal lobe. However, the correlation of NAA reduction with cerebral metabolic abnormalities is unknown in temporal lobe epilepsy (TLE). Proton MRS and 18F-fluorodeoxyglucose positron emission tomography (FDG/PET) were used to study 12 unilateral TLE patients with medically intractable seizures and 26 age-matched healthy volunteers. The epileptogenic temporal lobe of each patient was determined by both electroencephalography and FDG/PET. The NAA/choline-plus-creatine (NAA/(Cho+Cr)) ratio correlated significantly with the interictal glucose metabolism (r = 0.54, P < 0.01) in 12 TLE patients. The mean NAA/(Cho+Cr) ratio in the epileptogenic temporal lobe was significantly less than that in the contralateral side (P < 0.01), and less than that in normal control temporal lobes (P < 0.0001). These results suggest that quantitative MRS abnormalities reflect underlying metabolic pathology in TLE.