Scattered radiation from dental metallic crowns in head and neck radiotherapy.

We aimed to estimate the scattered radiation from dental metallic crowns during head and neck radiotherapy by irradiating a jaw phantom with external photon beams. The phantom was composed of a dental metallic plate and hydroxyapatite embedded in polymethyl methacrylate. We used radiochromic film measurement and Monte Carlo simulation to calculate the radiation dose and dose distribution inside the phantom. To estimate dose variations in scattered radiation under different clinical situations, we altered the incident energy, field size, plate thickness, plate depth and plate material. The simulation results indicated that the dose at the incident side of the metallic dental plate was approximately 140% of that without the plate. The differences between dose distributions calculated with the radiation treatment-planning system (TPS) algorithms and the data simulation, except around the dental metallic plate, were 3% for a 4 MV photon beam. Therefore, we should carefully consider the dose distribution around dental metallic crowns determined by a TPS.

Development and assessment of morphologic criteria for diagnosing gastric cancer using confocal endomicroscopy: an ex vivo and in vivo study.

BACKGROUND AND STUDY AIMS: The Confocal Endomicroscopy System (Optiscan Pty Ltd. and Pentax Corp.) is a newly developed imaging tool that uses laser light and optical technology to visualize living tissue at the cellular level. Digital images of cells magnified 1000-fold appear in real time on a computer screen, which enables immediate detection of changes in cellular structure without the need for a biopsy. The aim of this study was to assess the features of the cellular architecture of cancerous tissue that can be used in the differential diagnosis of cancerous tissue and normal mucosa using this system's image-processing software. PATIENTS AND METHODS: A total of 27 gastric cancers were examined ex vivo using confocal endomicroscopy. A fluorescent contrast agent, acriflavine, was applied topically to normal and to cancerous mucosa. In vivo imaging of the gastric mucosa after intravenous injection of fluorescein sodium was also performed in nine patients with gastritis or gastric cancer. RESULTS: The nuclear area in the ex vivo specimens was calculated using Scion Image software. The mean nuclear area of cancer cells was found to be significantly larger than that of normal cells in 18/27 gastric cancers (67 %). The mean nuclear area of the cancers tended to be larger than that of normal mucosa, especially in cases of differentiated adenocarcinoma. In more than half the cases, it was possible to diagnose malignancy automatically using confocal endomicroscopy and image-processing software without the need for biopsy and pathological examination. In vivo imaging of cancerous lesions showed irregularity in cellularity and vascularity. CONCLUSION: The ability of this imaging device to differentiate between normal tissue and cancerous tissues gives it potential value as a new screening tool for early detection of malignancy.

Near-infrared spectrophotoscopy of finger venules in assessment of autonomic dysfunction.

The authors evaluated morphologic changes in the venules of the finger using near-infrared spectrophotoscopy in patients with autonomic dysfunction, such as familial amyloidotic polyneuropathy and multiple-system atrophy. Abnormalities of the venules, such as tortuosity, irregular venous caliber, and microaneurysm-like change, and a linear negative correlation between the degree of orthostatic hypotension and the degree of vasoconstriction of the venules were observed.

[Perioperative assessment of blood lactate levels in pediatric heart surgery].

Measuring arterial lactate concentration is a prompt, easy and relatively non-invasive way to estimate tissue oxygen metabolism. We evaluated whether perioperative levels of the arterial lactate concentrations can reflect the general severity of a pediatric patient's condition. A consecutive series of 112 patients, aged 5 days to 17 years (median age: 12 months), admitted to our pediatric intensive care unit (PICU) following cardiac surgery under cardiopulmonary bypass were studied. Arterial blood lactate concentration was measured preoperatively, immediately upon termination of the cardiopulmonary bypass (postCPB), immediately following the operation, and 16th hours postoperatively (D1). Trends within arterial lactate concentrations were examined in relation to mortality rates, the duration of PICU stays and the patient's ages. The studied population had a mortality rate of 5.7% (6 patients). Lactate levels increased significantly and exceeded 4.0 mmol.l-1 during postCPB measurements in a majority of the patients. The increases in lactate levels are affected by the changes in interorgan blood flow, blood glucose levels and/or blood pH in addition to the effects of the CPB-priming lactated Ringer's solution. Thus, higher cut off values have to be determined, and lower probabilities assigned, when using postCPB lactate levels to predict the severity of an outcome. Significantly and sustained increases in D1 lactate levels were noted in neonates, patients with longer PICU stays (> 15 days) and those died later. Hyperlactemia greater than 2.2 mmol.l-1 at D1 predicted death with a sensitivity of 82% and a specificity of 72%. The measurement of early postoperative lactate levels, reflecting postoperative ability to eliminate intraoperative hyperlactemia, is a better way of assessing the severity of a pediatric patient's condition following cardiac surgery. The ideal time to measure early postoperative lactate levels should be determined by further research.

Nicorandil affords cardioprotection in patients with acute myocardial infarction treated with primary percutaneous transluminal coronary angioplasty: assessment with thallium-201/iodine-123 BMIPP dual SPECT.

BACKGROUND: It has been reported that nicorandil restores blood flow to reperfused myocardium in patients with acute myocardial infarction. However, whether nicorandil might decrease infarct size remains unclear. The aim of this study was to assess the effect of nicorandil on infarct size with thallium-201/beta-methyl-p-iodophenyl pentadecanoic acid (BMIPP) dual-isotope single photon emission computed tomography. METHODS: A total of 62 patients were randomly assigned to receive intravenous nicorandil (4 mg in 5 minutes at admission, immediately followed by 6 mg/hr over a 24-hour period) or placebo. All patients were divided into 4 groups: Group N-a, 16 patients with preexisting angina treated with nicorandil; N-b, 15 patients without preexisting angina treated with nicorandil; C-a, 14 patients with preexisting angina given placebo; C-b, 17 patients without preexisting angina given placebo. Tl-201/BMIPP imaging was performed in the 62 patients within 7 days after admission. Dual-isotope single photon emission computed tomographic images were quantified by severity index with a polar map. RESULTS: The BMIPP severity index was similar among the 4 groups. Only the thallium severity index in the N-a group was significantly less (P<.05). The ratio of the thallium severity index to that of BMIPP in the N-a group was significantly decreased compared with those of the other groups. CONCLUSION: Nicorandil has a protective effect in patients with acute myocardial infarction and preexisting angina treated with primary balloon angioplasty.

[Economical evaluation for drug consultation at home].

We started drug consultation at patients' homes in October, 1998. The number of drug consultations are 2.65 per month per patient and the consulting time is 2.25 hours per patient. The fee for drug consultation is 550 points twice a month. We evaluate the fee for drug consultation. Our data suggest that this fee needs to be 550 points three times a month.

Assessment of the effects of aging and medication on salivary gland function in patients with xerostomia using 99mTC-scintigraphy.

To examine the effect of aging and medication on xerostomia, the salivary gland function was evaluated in 20 patients with xerostomia using 99mTc-scintigraphy and the measurement of unstimulated whole saliva (USWS). All of the patients showed USWS volume of less than 2ml/10min. The patients were divided into 2 subgroups based on age (under 65 and 65 and older) and medication status (patients who were on medication which reduced salivary secretion and patients who were not on such medication). The scintigraphic results, such as the maximum radioisotope (RI) count, RI secretion velocity and the volume of USWS, were compared between the subgroups. The maximum RI count and the RI secretory velocity in the submandibular gland and the volume of USWS revealed significantly different functional disturbances between relatively younger patients (under 65) and older patients (65 and older). There was no difference when the scintigraphic results and the volume of USWS measurements in medicated patients were compared with the results of similar tests performed on non-medicated patients. When the medicated and non-medicated groups were separated by age, an increase in age still diminished the volume of USWS in medicated patients. This result might be related to an organic change in the submandibular gland in older patients which was suggested by the scintigraphic results.

Preoperative assessment of lymph nodes in the prediction of disease spread and outcome in cancer of the thoracic oesophagus.

Prospective assessment of lymph node status, based on the findings of computed tomography, external ultrasonography and palpation, was compared with clinical results in 179 patients who underwent oesophagectomy with systematic node dissection. Preoperative findings for each node group were classified into four grades: involvement not suspected (-); possible involvement (+/-); probable involvement (+); and definite involvement (++). When only (++) or (+) assessment was categorized as positive, the specificity was more than 94 per cent, although the sensitivity was less than 40 per cent. The preoperative assessment correlated significantly with the incidence of node involvement (P < 0.02), the degree of lymphatic invasion (P < 0.0001) and outcome after operation. For patients with all nodes assessed as (-), the 5-year survival rate was 70 per cent, compared with 26 per cent for those with nodes assessed as (++), P = 0.001. Preoperative assessment provided useful information on nodal status.

Assessment of central visual function after successful retinal detachment surgery by pattern visual evoked cortical potentials.

The pattern of visual recovery after successful surgery by pattern visual evoked cortical potentials (VECP), visual acuity, colour vision, and critical fusion frequency was investigated in 14 eyes with retinal detachment involving the macula. The temporal tuning characteristics in the evoked potentials were measured as based on the P100 amplitude and the frequency necessary for evoking 0 mu V amplitude, which was defined as an objective critical fusion frequency by extrapolating the curve. Significant improvement in visual acuity and colour vision was observed within 2 months postoperatively. A significantly increased P100 peak latency became shorter as the postoperative days increased. In general, a good correlation was noted between the P100 peak latency and subjectively measured visual acuity, colour vision, and critical fusion frequency. The objective critical fusion frequency measured by VECP recovered gradually during the 6 months after surgery. Functional recovery was not related to the length of time the macula was detached before surgery.

Assessment of an EIA for measuring human serum erythropoietin as compared with RIA and an in-vitro bioassay.

A recently developed enzyme-linked immunosorbent assay (EIAZ, ELISA) using two murine monoclonal anti-erythropoietin antibodies was compared with a radioimmunoassay (RIA) and a commercial in-vitro bioassay, EPOS, for measuring serum erythropoietin (Epo) in humans. Specificity and validity for Epo-EIA and the other two assays were examined. The serum Epo in normal subjects was 18 +/- 12 mU/ml (mean +/- SD, n = 80) for EIA compared with 22.5 +/- 18.5 mU/ml (n = 20) for RIA and 136 +/- 132 mU/ml (n = 14) for the bioassay. The serum Epo concentrations in normals and patients were highly comparable between EIA and RIA for Epo (P less than 0.01, r = 0.95). Epo concentrations by the EIA for normal female and male subjects were 20.5 +/- 13 and 16.5 +/- 10 mU/ml, respectively. Epo levels in patients with secondary polycythaemia or autoimmune haemolytic anaemia were significantly higher than normal subjects by the three methods. Epo levels in patients with chronic renal failure were within the normal range. By the EPOS bioassay, the Epo concentrations of normals and patients with renal failure were significantly higher than expected (136 +/- 132 and 447 +/- 273, respectively). Due to its inherent design, the EPOS bioassay possibly measures bone marrow proliferative activity in response to other serum growth regulators besides erythropoietin and was found to be unsuitable for clinical assessment of Epo. We concluded that the new EIA and RIA were similarly sensitive, reliable and accurate for measurement of serum Epo. The EIA method has the advantage of being less time consuming, more convenient and avoids the use of a radioisotope.

[A simplified method for the assessment of C1 esterase inhibitor function].

From the result that the activated form of C1-s(C1-s) prolonged the kinetics of hemolysis via complement, this assay was applied to assess C1 esterase inhibitor (C1INH) function. In the kinetic assay, the complement hemolytic activity was evaluated by the time which required to cause 50% reduction of the initial turbidity of sensitized sheep erythrocytes, and was expressed as T1/2. (1) T1/2 of pooled normal human sera (p-NHS) showed dose-dependent prolongation by the addition of various amounts of C1-s. (2) Preincubation of various amounts of functionally pure C1INH with the constant amounts of C1-s inhibited dose-dependently the prolongation of T1/2 by C1-s. (3) The C1INH activity of NHS was 840 +/- 80 units/ml (n = 6) and that of the C1INH deficient serum was 80 units/ml, which were calculated from the standard curve established by the addition of various amounts of purified C1INH. This test requiring only C1-s and sensitized sheep erythrocytes is simple technically and high in sensitivity, and seems to be useful for the routine assay for C1INH function of human sera.

Assessment of cardiopulmonary baroreflex function in hypertensive and normotensive subjects with or without hypertensive relatives.

1. To investigate whether cardiopulmonary baroreflex control contributes to the pathogenesis and progression of hypertension, we have evaluated the function of the cardiopulmonary baroreflex in 22 patients with essential hypertension and in 17 volunteers with normotension. The normotensive group consisted of 8 subjects with a family history of hypertension and nine with no family history. 2. Forearm vascular resistance (FVR) and central venous pressure (CVP) were measured under control conditions when -10 mmHg lower body negative pressure was applied; the cardiopulmonary slope (CPS = delta FVR/delta CVP) was calculated as an index of the cardiopulmonary baroreflex function. 3. CPS was significantly higher in hypertensives (6.0 +/- 3.93 [s.d.], P less than 0.01) and also tended to be higher in normotensives with a family history of hypertension (3.9 +/- 3.53, P less than 0.05), compared with normotensives without a family history of hypertension (1.7 +/- 0.88). 4. When the hypertensives were divided into two groups, depending on whether CPS was greater or less than 6.0 units, cardiac wall thickness (20 +/- 1.6 mm vs 23 +/- 3.2 mm, P less than 0.05) and the renal vascular resistance (20.9 +/- 6.52 units vs 28.9 +/- 7.32 units, P less than 0.05) were both significantly higher in the Low CPS group. 5. These findings suggest that cardiopulmonary baroreflex function was augmented even in normotensive subjects with hypertensive relatives, as compared with those without hypertensive subjects. Furthermore, cardiopulmonary baroreflex function was augmented in the early stages of hypertension and diminished further with increasing severity.