Development and testing of an endoscopic pseudo-viewpoint alternating system

Purpose

   An endoscopic system is needed that presents informative images irrespective of the surgical situation and the number of degrees of freedom in endoscopic manipulation. This goal may be achieved with a virtual reality view for a region of interest from an arbitrary viewpoint. An endoscopic pseudo-viewpoint alternation system for this purpose was developed and tested.

Method

   Surgical experts and trainees from an endoscopic surgery training course at the minimally invasive surgery training center of Kyushu University were enrolled in a trial of a virtual reality system. The initial viewpoint was positioned to approximate the horizontal view often seen in laparoscopic surgery, with \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$20^{\circ }$$\end{document}20∘ between the optical axis of the endoscope and the task surface. A right-to-left suturing task with right hand, based on a task from the endoscopic surgery training course, was selected for testing. We compared task outcomes with and without use of a new virtual reality-viewing system.

Result

   There was a 0.37 mm reduction in total error (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$p = 0.02$$\end{document}p=0.02) with use of the proposed system. Error reduction was composed of 0.1 mm reduction on the y-axis and 0.27 mm reduction on the x-axis. Experts benefited more than novices from use of the proposed system. Most subjects worked at a pseudo-viewpoint of around 34\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^\circ $$\end{document}∘.

Discussion

   Suturing performance improved with the new virtual reality endoscopic display system. Viewpoint alternation resulted in an overview that improved depth perception and allowed subjects to better aim the marker. This suggests the proposed method offers users better visualization and control in endoscopic surgery.

Isolation and characterisation of dipeptidyl peptidase IV from Prevotella loescheii ATCC 15930

A proline-specific dipeptidyl aminopeptidase, dipeptidyl peptidase IV (EC 3.4.14.5), was purified from a cell sonicate soluble fraction of Prevotella loescheii ATCC 15930 by sequential column chromatography. The molecular mass of the native enzyme was estimated as 160 kDa by high-pressure liquid gel filtration column chromatography and unheated sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The subunit molecular mass was 80 kDa when the enzyme was heated to 100 degrees C in the presence of 2-mercaptoethanol before SDS-PAGE, suggesting that the native enzyme consists of two identical subunits and is folded in 2% SDS. The optimum pH, with glycyl-prolyl-4-methyl-coumaryl-7-amide as the substrate, was 8.0; the isoelectric point was 5.2. Purified enzyme showed a strong preference for dipeptide substrates containing proline and, less efficiently, alanine in the P1 position. The enzyme was markedly inhibited by Cd(2+), Zn(2+), Hg(2+), Co(2+), and serine proteinase inhibitor di-isopropylfluorophosphate.

Axonal damage revealed by accumulation of beta-amyloid precursor protein in HTLV-I-associated myelopathy

We investigated the localization and extent of beta-amyloid precursor protein (APP) immunoreactivity as a sensitive marker for impairment of fast axonal transport in the spinal cords of patients with HTLV-I-associated myelopathy (HAM)/tropical spastic paraparesis (TSP). The results from this study show that APP, used as a marker of early axonal damage in HAM/TSP lesions, is more intensively expressed in areas of active-inflammatory lesions than those of inactive-chronic lesions. The close localization to the areas containing inflammation (activation of macrophage/microglia) is striking and suggests that axonal damage is closely associated with inflammation in active-chronic lesions. Although inflammatory cell infiltration in the central nervous system (CNS) is rarely found in inactive-chronic lesions, a few clusters of APP+ axons are found in the spinal cord white matter in some cases. The presence of APP+ axons without relation to inflammatory cells in inactive-chronic lesions, suggest that soluble neurotoxic factors might induce axonal changes in the CNS of HAM/TSP. The occasional myelinated fibers in the anterior and posterior spinal roots in lower thoracic to lumbar levels had APP+ axons, suggesting that spinal nerve roots can be affected in HAM/TSP, especially in lower thoracic to lumbar levels. Impairment of fast axonal transport may contribute to the development of disability in patients with HAM/TSP.

Clinical investigation of pulmonary Mycobacterium avium complex infection in human T lymphotrophic virus type I carriers

BACKGROUND

Little is known about pulmonary Mycobacterium avium complex (MAC) infection in human T lymphotrophic virus type I (HTLV-I) carriers. A study was undertaken to investigate and clarify the characteristics of pulmonary MAC infection in these subjects.

METHODS

Twenty nine patients with pulmonary MAC infection without any underlying pulmonary disorder were investigated. The clinical features and radiographic appearance of HTLV-I carriers and non-carriers were compared and the bronchoalveolar lavage (BAL) fluid of these 29 patients and eight normal female control subjects was analysed.

RESULTS

The prevalence of the HTLV-I carrier state in patients with pulmonary MAC infection was 34.5% (10/29) compared with 16.7% (529/3169) among all patients admitted to our department between 1994 and 1998 (odds ratio (OR) 2.63, 95% confidence interval (CI) 1.21 to 5.68). The HTLV-I carriers were all women and all had clinical symptoms, but they did not show systemic dissemination. Peripheral multifocal bronchiectasis with nodular shadowing was seen frequently on the chest computed tomographic (CT) scans of HTLV-I carriers. The area of the pulmonary lesions was more extensive than in non-carriers (p<0.05). White blood cell (WBC) counts and C reactive protein (CRP) levels on admission were significantly lower in HTLV-I carriers than in non-carriers (WBC: difference (D) = 1565/microl, 95% CI -68.9 to 3198.4/microl; CRP: D = 1.8 mg/dl, 95% CI -0.35 to 3.89 mg/dl). The concentrations of neutrophil elastase (NE) and interleukin (IL)-8 in BAL fluid were significantly higher in HTLV-I carriers than in non-carriers (NE: D = 1342 microg/l, 95% CI 704 to 1980.3 microg/l; IL-8: D = 304.5 pg/ml, 95% CI 89.7 to 519. 4 pg/ml).

CONCLUSIONS

Pulmonary MAC infection causes more diffuse and widespread lesions in HTLV-I carriers than in non-carriers.

Eosinophilic pneumonia with eosinophilic gastroenteritis

A 48-year-old man was admitted to our hospital with cough, fever and dysphagia. He had a past history of bronchial asthma and surgery for nasal polyp. Chest radiograph and computed tomography showed atelectasis in the right lower field and infiltrative shadow in the left lower field and overall thickening of the esophageal wall. Transbronchial lung biopsy (TBLB) specimens revealed infiltration of eosinophils and lymphocytes under the bronchial mucosa. Gastrointestinal tract biopsy specimens showed submucosal infiltration of eosinophils. These findings led to a definite diagnosis of eosinophilic pneumonia associated with eosinophilic gastroenteritis, a disease which has been rarely reported.

[Clinical investigation of 15 patients with pulmonary cryptococcosis--clinical comparison of HTLV-I carriers and non-carriers]

We investigated 15 pulmonary cryptococcosis patients. The group had a mean age of 51.7 years, and 6 (40%) of the patients were women. Cryptococcosis was primary in 13 patients and secondary in 2 (diabetes mellitus and smoldering adult T-cell leukemia). Eight patients were asymptomatic and 9 patients were detected by medical examinations. Dry cough was the most common symptoms. On chest radiographs, 5 patients showed solitary nodules, 4 patients showed infiltrative shadows, and 4 patients showed multiple nodules. The right lower lobe was the predominant location of solitary nodules, and the left upper and middle lung fields were the predominant locations of infiltrative shadows. Transbronchial lung biopsy was the method of diagnosis for 9 patients, and open lung biopsy for the others. Eleven patients were treated with fluconazole, and the mean treatment period was 7 months. Four patients underwent, resection procedures only, and experienced no recurrence. Five patients were positive for HTLV-I (one had smoldering ATL) and 5 were negative. Eighty percent of the HTLV-I positive patients had some symptoms and 80% of the HTLV-I negative patients were asymptomatic. HTLV-I positive patients showed various pulmonary shadows and 80% of the HTLV-I negative patients showed solitary nodules. The pulmonary lesions in HTLV-I positive patients were more extensive than those in HTLV-I negative patients (p < 0.05). We postulate the possible existence of subtle immunological abnormalities, including abnormalities of cellular immunity, in HTLV-I carriers.

Mushroom worker's lung resulting from indoor cultivation of Pleurotus osteatus

Indoor cultivation of oyster mushroom Pleurotus osteatus lead to an outbreak of extrinsic allergic alveolitis in two workers. High titer of indirect fluorescent antibody and positive precipitins against basidiospores of P. osteatus were demonstrated in sera of the patients. Mushroom workers should protect themselves from the basidiospores, being aware of their pathogenicity.

[A case of tuberculous abscess in the chest wall close to the thickening pleural lesion following tuberculous pleuritis]

A 33-year-old woman with a history of right tuberculous pleuritis was successfully treated in December 1992 by administration of anti-tuberculous drugs, she demonstrated residual localized pleural thickening on chest computed tomography (CT) and gradually developed a subcutaneous mass in the right chest which became apparent in March 1993. In September, chest CT revealed a periocostal abscess in the right anterior chest wall close to the localized pleural thickening. The patient was diagnosed with tuberculous abscess in the right chest wall on confirmation of acid-fast bacilli in a needle aspiration material of the abscess, and was referred to our hospital. Anti-tuberculous chemotherapy was continued but the chest abscess grew, so on January 28, 1994 she underwent a resection of the abscess, the third costal cartilage and bone, and the parietal pleural lesion connected to the abscess. Histopathological examination showed that the abscess and parietal pleural lesion were compatible with tuberculosis, i.e. both lesions consisted of caseous necrosis and epitheloid cell granuloma, but acid-fast bacilli were not demonstrated in both lesions. After one year of postoperative anti-tuberculous chemotherapy, she was followed without any therapy for 3 years and there has been no recurrence to date. When a localized thickening pleural lesion remains after tuberculous pleuritis, complication of tuberculous abscess in the chest wall should be considered.

[Chronic interstitial pneumonia and crescentic glomerulonephritis associated with perinuclear antineutrophil cytoplasmic antibodies]

We examined a 72-year-old man suffering from chronic interstitial pneumonia with crescentic glomerulonephritis associated with perinuclear antineutrophil cytoplasmic antibodies (P-ANCA). Ten years before admission, he was given a diagnosis of interstitial pneumonia, but received no medication. He was admitted to our hospital because of a high fever and back pain. Antibiotics were used, but without success. The serum P-ANCA titer was high, and examination of a kidney biopsy specimen showed crescentic glomerulonephritis. Computed tomography of the chest showed that the lungs had a honecomblike appearance, and examination of a specimen obtained by transbronchial lung biopsy showed interstitial fibrosis. This case shows that interstitial pneumonia can be associated with P-ANCA. It is important to be a wore that crescentic glomerulonephritis associated with P-ANCA can develop in patients with interstitial pneumonia.

[Clinical features of allergic granulomatosis and angiitis (Churg-Strauss syndrome). Association with asthma symptoms]

We reported clinical and laboratory findings of 5 patients with Churg-Strauss syndrome (CSS), especially association with asthma symptoms. Subjects included 3 males and 2 females with a mean age of 53.8 year-old. In all 5 patients symptoms of neuropathy; mononeuritis multiplex and in some patients, other vasculitic symptoms; fever, diarrhea, abdominal pain and skin eruptions, were noted. These clinical features and laboratory findings; marked peripheral eosinophilia and elevation of serum ECP were normalized after steroid therapy. We investigated the relation between the occurrence of CSS and the symptoms of asthma. The mean duration of asthma in this series was 17.2 years, and 4 cases were atopic and one was non-atopic asthma. In previous publications, asthmatic symptoms were severe at the onset of the disease and progressed thereafter. In our 5 cases, however, the severities of bronchial asthma were mild of two cases, moderate of two and severe of only one, moreover severe asthmatic attacks were shown in only 2 cases when the manifestation of systemic vasculitis occurred. In conclusion, although CSS has been thought that one of complications of bronchial asthma, the occurrence of CSS are not necessarily correlated with symptoms of bronchial asthma.

[Idiopathic interstitial pneumonia that responded to intermittent intravenous administration of high-dose cyclophosphamide]

A 78-year-old man was admitted to the hospital with exertional dyspnea and fever. Chronic idiopathic interstitial pneumonia (IIP) had been diagnosed a year before. Follow-up chest X-ray examination showed diffuse reticular shadows and progressive shrinkage of both lower lobes. Chest CT scan revealed honeycomb appearance of both lower lung fields. Moderate hypoxemia was found by arterial blood gas analysis. The patient responded to an orally administered corticosteroid. Because tapering of the medicine caused exacerbation of the hypoxemia, methylprednisolone pulse therapy was given with poor response. Then high-dose (750 mg) of cyclophosphamide (CPM) were given intravenously 6 times, every 3 or 4 weeks. After the second administration of CPM, decreases in hypoxemia and in blood LDH levels were observed. This treatment allowed as to taper the dose of oral corticosteroid from 60 mg/day to 15 mg/day. This case suggests that intravenous administration of high-dose CPM may be effective against IIP.

[Detection of HTLV-I proviral DNA by PCR method from bronchoalveolar lavage cells of HTLV-I carriers]

To elucidate whether or not human T-lymphotropic virus type I (HTLV-I) infected cells exist in the lungs of HTLV-I carriers, we examined bronchoalveolar lavage (BAL) cells for the presence of HTLV-I proviral DNA by the polymerase chain reaction (PCR) method. The cells were harvested from HTLV-I seropositive individuals with or without various respiratory diseases. The HTLV-I pX region was detected from separated BAL cells by dot blot hybridization after PCR in all 14 HTLV-I seropositive individuals tested. Four out of these 14 individuals were asymptomatic HTLV-I carriers, while the other ten had symptoms, including those of bacterial pneumonia, chronic respiratory tract infection, interstitial pneumonia, atypical mycobacterial infection, bronchitis, mediastinal lymphadenitis and bronchial asthma. HTLV-I proviral DAN was detected in BAL cells from patients with a normal proportion of lavage lymphocytes and a normal CD4/CD8 ratio. These findings suggest that HTLV-I infected cells may commonly exist in the lower respiratory tract and alveolar space without producing characteristic symptoms/signs, and that any causal relation to the pulmonary lesion must therefore be carefully elucidated, in HTLV-I carriers.

Urinary excretion of parathyroid hormone-related protein as a predictor of hypercalcemia in patients with adult T-cell leukemia

Hypercalcemia with adult T-cell leukemia (ATL) is chiefly caused by an excessive production by tumor cells of parathyroid hormone-related protein (PTHrP). We have previously reported hypercalcemic patients with solid tumors to excrete a large amount of the C-terminal fragments of PTHrP (C-PTHrP) into their urine. To elucidate whether PTHrP production correlates with or predicts the development of hypercalcemia, we studied the urinary excretion of C-PTHrP in 36 ATL patients. The urinary excretion of C-PTHrP was in the normal range (< 0.40 nmol equivalent to PTHrP (109-141)/g creatinine) in HTLV-1-positive carriers (n 3), ATL patients in complete remission (n 2) and chronic type ATL patients (n 2). It was marginally increased in seven patients in partial remission, and gradually increased as the disease progressed. In 20 patients who died without or with hypercalcemia, it was increased to 1.98 +/- 0.69 (n 9) and 7.6 +/- 2.1 nmol/g creatinine (mean +/- SD, n 11, P < 0.01), respectively. Urinary C-PTHrP excretion was significantly correlated with serum calcium and LDH levels as well as with CD25-positive cells in the peripheral blood. In four patients whose urinary excretion had been serially determined, it increased prior to the development of hypercalcemia. The findings suggest the urinary excretion of C-PTHrP to be of use as a predictor of the development of hypercalcemia in ATL patients. In ATL patients whose urinary excretion of C-PTHrP is progressively increasing, the serum calcium concentration should be carefully monitored to prevent hypercalcemic crisis.

[Dynamics of atmospheric pressure under the maxillary complete denture. 1. Relations between the denture retention and the atmospheric pressure]

Dynamics of atmospheric pressure under the maxillary complete denture, and their relations with the denture retention influenced by the factors such as the denture seating force, the saliva viscosity and the postdamming, were investigated on the simulation models. The following results were obtained. 1. The atmospheric pressure under the denture became higher than the external one by the denture insertion, and increased during the denture seating, and decreased by the removing force of denture and furthermore became lower than external one by continuous application of its force, and at all became equal to the external one when the denture separated from the basal seat. 2. Greater seating force brought about greater positive pressure and less negative pressure. 3. Higher viscosity of saliva and the postdamming brought about greater positive and negative pressures. 4. Both of greater seating force and higher viscosity of saliva brought about greater retentive force. 5. The postdamming was useful for the maxillary posterior border seal. 6. The atmospheric pressure under the denture base seems not to relate directly to the maxillary denture retention in the static condition but to reveal the status of peripheral seal.