Optically stimulated luminescence in vivo dosimetry for radiotherapy: physical characterization and clinical measurements in (60)Co beams.

A commercial optically stimulated luminescence (OSL) dosimetry system was investigated for in vivo dosimetry in radiation therapy. Dosimetric characteristics of InLight dot dosimeters and a microStar reader (Landauer Inc.) were tested in (60)Co beams. The reading uncertainty of a single dosimeter was 0.6%. The reproducibility of a set of dosimeters after a single irradiation was 1.6%, while in repeated irradiations of the same dosimeters it was found to be 3.5%. When OSL dosimeters were optically bleached between exposures, the reproducibility of repeated measurements improved to 1.0%. Dosimeters were calibrated for the entrance dose measurements and a full set of correction factors was determined. A pilot patient study that followed phantom validation testing included more than 100 measured fields with a mean relative difference of the measured entrance dose from the expected dose of 0.8% and the standard deviation of 2.5%. In conclusion, these results demonstrate that OSL dot dosimeters represent a valid alternative to already established in vivo dosimetry systems.

Comparison of doses calculated by the Monte Carlo method and measured by LiF TLD in the buildup region for a 60Co photon beam.

This work studied the percent depth doses of (60)Co photon beams in the buildup region of a plastic phantom by LiF TLD measurements and by Monte Carlo calculations. An agreement within +/-1.5% was found between PDDs measured by TLD and calculated by the Monte Carlo method with the TLD in a plastic phantom. The dose in the plastic phantom was scored in voxels, with thickness scaled by physical and electron density. PDDs calculated by electron density scaling showed a better match with PDD(TLD)(MC); the difference is within +/-1.5% in the buildup region for square and rectangular field sizes.

Galectin-3 and CD44v6 positivity by RT-PCR method in fine needle aspirates of benign thyroid lesions.

OBJECTIVE: To investigate whether the presence of macrophages and Hürthle cells (HC) in benign thyroid lesions could explain the false-positive expression of galectin-3 and CD44v6 detected by reverse transcriptase-polymerase chain reaction (RT-PCR). METHODS: For galectin-3 and CD44v6, RT-PCR was performed on RNA isolated from aspirates obtained by ultrasound guided fine needle aspiration cytology (FNAC) from 123 patients with benign thyroid lesions. The results of RT-PCR analysis were evaluated against the definitive FNAC diagnosis. RESULTS: Galectin-3 expression was found in 29% follicular adenoma (FA), 26% Hashimoto thyroiditis (HT), and in 24% nodular goitre (NG). We found a statistically significant relationship between the presence of macrophages and galectin-3 positivity in NG and HT samples (P < 0.0001 and P = 0.0087 respectively). We found a statistically significant (P = 0.0219) relationship between the presence of HC and galectin-3 positivity in HT and a tendency of such a relationship (P = 0.0838) in NG. CD44v6 expression was found in 29% FA, 33% HT and in 18% NG. We found a statistically significant relationship between the presence of HC and positive expression of CD44v6 in NG (P = 0.0003) and a strong tendency of such a relationship in HT (P = 0.0571). We did not find a statistically significant relationship between the presence of macrophages and CD44v6 positivity. In FA, we did not find a statistically significant relationship between the presence of macrophages or HC and galectin-3 or CD44v6 positivity. CONCLUSION: Our results suggest that the presence of macrophages and/or HC may explain the positive expression of galectin-3 and CD44v6 detected by RT-PCR in HT and NG cytological samples.

Croatia has reached iodine sufficiency.

This study was performed in 2002, 6 yr after the introduction of a new regulation on salt iodination with 25 mg KI/kg of salt. The aim of the study was to evaluate whether further significant positive results of improved iodine intake could be observed among schoolchildren in Croatia. A total of 927 schoolchildren of both sexes, aged 6-12 yr, were included in the study. In Croatia, with a population of 4,437,460 the research was implemented in four major geographical regions: the Northwestern, Slavonia, Northern Adriatic and Dalmatian regions. Investigations included randomly selected pupils from regional centers and neighboring smaller towns or villages. The results have revealed that thyroid volumes were within the normal range according to the provisional WHO/ICCIDD reference values for sonographic thyroid volume in iodine-replete school-age children, updated in 2001. A significant improvement in medians of urinary iodine excretion was detected in 2002: from 9 microg/dl in 1991 to 14.6 microg/dl in Zagreb, from 4.3 microg/dl in 1995 to 13.1 microg/dl in Split, from 9.4 microg/dl in 1997 to 14.2 microg/dl in Rijeka and from 13.4 microg/dl in 1997 to 14.7 microg/dl in Osijek. An overall median of 14.0 microg/dl of urinary iodine excretion was detected in Croatian schoolchildren. The control of salt at different levels, from production to consumption, including salt produced in all three Croatian salt plants and imported salt, revealed that Croatian salt is adequately iodized. From severe iodine deficiency before the 1950s, through mild-to-moderate iodine deficiency in the 1990s, Croatia has now reached iodine sufficiency.

Phagocytic functions of salivary neutrophils in oral mucous membrane diseases.

BACKGROUND AND PURPOSE: Phagocytic functions of salivary polymorphonuclear neutrophils (sPMNs) have not been comprehensively studied in patients with oral mucous membrane diseases, although available data suggest the role of immunity in their pathogenesis. SUBJECTS AND METHODS: Phagocytic functions of sPMN were determined in 15 patients with acute recurrent aphthous ulceration (RAU), 11 patients with oral lichen planus (OLP) and 20 healthy volunteers. In healthy subjects, the same parameters were also determined in peripheral blood polymorphonuclear neutrophils (bPMNs). Phagocytic activity (proportion of ingesting cells, PA), ingestion ability (number of ingested targets per 100 phagocytes, IA) and intracellular microbicidity (proportion of killed targets, IM) of PMNs separated from peripheral blood and the whole unstimulated saliva were determined by acridine orange method with living yeast cells as targets. RESULTS: Salivary PMNs in healthy individuals showed significant reduction in PA (33% vs. 76%; P < 0.009) and IA (0.47% vs. 2.93%; P < 0.009) and significant increase in IM (12.0% vs. 5.5%; P = 0.011) in comparison with bPMNs. In RAU patients, reduced PA (27% vs. 37%; P = 0.035) and IA (0.25% vs. 0.47%; P = 0.05) were detected, while in OLP patients enhanced IM was detected (12% vs. 19%; P = 0.033) in comparison with healthy controls. CONCLUSION: Salivary PMNs present functional features distinct from those in peripheral blood. Some phagocytic functions of sPMNs are reduced in RAU and enhanced in OLP, indicating their role in pathogenesis or reflecting clinical changes in these conditions.

Salivary immunoglobulin A and G subclasses in HIV positive patients.

Many of the opportunistic infections in HIV are related to the mucous membranes, but the protection of oral mucosal compartment mediated by IgA and IgG subclasses in saliva is still not well documented. Therefore, the aim of this study was to investigate the status of salivary IgA and IgG subclass in HIV positive patients. Levels of IgG1, IgG2, IgG3 and IgG4 were determined by ELISA and IgA1 and IgA2 by radial immunodiffusion in the resting whole saliva of 33 HIV patients and 21 HIV-seronegative healthy controls and were expressed in mg/L (IgA) and ug/L (IgG) of saliva. Salivary IgA2 was significantly reduced in the HIV positive patients (p<0.0009) when compared to the healthy controls, but no differences in salivary IgA1 level between HIV patients and healthy controls were found. On the other hand, salivary IgG1, IgG2, IgG3 and IgG4 subclasses were increased (p<0.0009) in HIV patients in comparison to the healthy controls. We can conclude that inspite of IgA2 deficiency which was found in studied HIV positive patients, mucosal antibody responses are quite normal and might not predispose development of oral opportunistic infections.

Salivary IgA and IgG subclasses in oral mucosal diseases.

OBJECTIVE: It was hypothesized that serum levels of immunoglobulins may play a role in the pathogenesis of oral mucosal diseases, or reflect clinical changes in these conditions, but little is known about the role of salivary immunoglobulins in the pathogenesis of these diseases. The aim of this study was to investigate possible alterations in salivary immunoglobulin A (IgA) and IgG subclasses in patients with oral mucosal inflammatory diseases. SUBJECTS AND METHODS: Levels of IgG1, IgG2, IgG3 and IgG4 were determined by enzyme-linked immunosorbent assay (ELISA), and IgA1 and IgA2 by radial immunodiffusion in the resting whole saliva of 31 patients with acute recurrent aphthous ulceration (RAU) (and followed in remission), 11 patients with chronic hyperplastic candidal infection (CHC), 12 patients with Sjogren's syndrome (SS), six patients with oral lichen planus (OLP), and 18 healthy volunteers using the normal saliva as a comparison point for all. RESULTS: IgG and IgA subclasses were increased in OLP. In CHC all IgG subclasses were increased while IgA1 was decreased, IgG1, IgG3 and IgG4 levels were increased in SS, while all IgG subclasses as well as IgA2 were increased in acute RAU in comparison with healthy controls. No differences in any immunoglobulin subclasses between major and minor acute RAU were found. In remission, IgG1 and IgG4 returned to normal values while IgG2, IgG3, and IgA2 remained increased in patients with RAU. CONCLUSION: Salivary immunoglobulin subclasses vary in different oral mucosal conditions and may play a role in oral mucosal inflammatory diseases and/or reflect clinical changes in these conditions.

Redundant thyroid laboratory diagnostic modules in laboratory information system--a way to improve the performance.

In this paper, we introduced an idea of using redundant thyroid laboratory diagnostic modules integrated in laboratory information system. The first module was based on decision tree which was the result of Assistant algorithm applied to thyroid laboratory test results. Instead of improving decision rules, the "second opinion" module was designed based on Spad-S software. Diagnosis obtained with both modules were compared with results before introducing the "second opinion" module. From the first results it was clear that introducing the "second opinion" module decreased the number of misclassified records from the first module. With three or more modules, the final diagnosis could be obtained by voting or more complex procedures.

First beneficial results of the implementation of Croatian new law on salt iodination.

Presented pilot-study on urinary iodine excretion among schoolchildren in main geographic regions of Croatia indicates a significant improvement in iodine excretion only 12 months after introduction of a new mandatory salt iodination with 25 mg KI/kg of salt. Measurements of urine iodine excretion in 663 schoolchildren of both sexes, aged 9-16 years, from Zagreb, Rude, Bednja, Osijek, Dakovo, Rijeka, Pazin and Dubrovnik showed that from 77.9% to 94.8% of subjects have had urinary iodine above 5 microg/dl. Also from 41.2% to 70.8% of children have had urinary iodine excretion above 10 microg/dl. Before introduction of a new law mostly borderline values of urinary iodine excretion were recorded; therefore recent values present significant positive shift and actually they are the best signs of almost adequate iodine intake in Croatian youth. Nevertheless, further measures for improvement of iodine intake are recommendable because still 31% of controlled table-salt samples from households and 15.7% of imported salt samples have had KI level below 20 mg/kg of NaCl. Salt produced in Croatia was (Pag and Nin salt plants) completely in accordance with iodination regulations. On the other hand, as recent increase in urinary iodine excretion could not be simultaneously followed by reduction in goiter prevalence, in the following years further epidemiological surveys of iodine deficiency disorders shall be warranted.

Immunoscintigraphy with 99Tcm-labelled monoclonal anti-CEA BW 431/26 antibodies in patients with suspected recurrent and metastatic colorectal carcinoma: two-year follow-up.

The aim of this study was to evaluate immunoscintigraphy with BW 431/26 anti-CEA antibody in the follow-up of 15 patients with colorectal carcinoma. A whole-body scan followed by SPET imaging of the abdomen and pelvis was performed 4-6 and 20-24 h after the intravenous infusion of 0.6-1.0 mg of intact anti-CEA monoclonal BW 431/26 antibody labelled with 814-1110 MBq of 99Tcm. The HAMA response and serum CEA levels were determined. Immunoscintigraphic findings were verified by biopsy, radiologically and/or by 2 year follow-up. On an individual patient basis, immunoscintigraphy demonstrated an overall sensitivity of 83%, specificity of 100%, accuracy of 87%, positive predictive value of 100% and negative predictive value of 60%. Better results were achieved in the pelvic region than in the liver or in the extra-hepatic abdominal region. We evaluated 40 lesions; on an individual lesion basis, immuno-scintigraphy gave a sensitivity of 80% and an accuracy of 80%. SPET images detected significantly more lesions than whole-body planar images (P < 0.05). SPET at 20-24 h detected significantly more 'hot' lesions than at 4-6 h (P < 0.01). No correlation between CEA serum levels and immunoscintigraphy was observed (r = 0.376, P > 0.05). One of nine patients (11%) developed HAMA after immunoscintigraphy. We conclude that immunoscintigraphy with BW 431/26 antibody appears able to differentiate between tumour recurrence and scar tissue, and to evaluate liver metastases of colorectal carcinoma. Serum CEA levels appear not to influence the result of immunoscintigraphy and the HAMA response is minimal. A delayed SPET scan should be part of an immunoscintigraphic imaging protocol when 99Tcm-labelled BW 431/26 monoclonal antibody is used.

Bone marrow immunoscintigraphy for the detection of skeletal metastases in patients with breast cancer.

In this study, we evaluated the efficacy of bone marrow immunoscintigraphy (BMIS) for the detection of skeletal metastases in 23 patients with histologically confirmed breast cancer. All patients underwent whole-body BMIS 3-6 h after the intravenous injection of 0.20-0.33 mg of the intact anti-NCA 95 MAb BW 250/183 labelled with 259-555 MBq 99Tcm and a whole-body 99Tcm-MDP bone scan. In four patients, BMIS SPET of the lumbar spine was also performed. Serum alkaline phosphatase was determined in all patients and the level of human anti-mouse antibody (HAMA) in 16. Final diagnosis was confirmed by radiology and 2 years follow-up. Compared with the 99Tcm-MDP bone scan, BMIS demonstrated better specificity (88% vs 75%) and a better positive predictive value (92% vs 85%). There were no significant differences between BMIS and the bone scan in the detection of skeletal metastases (P > 0.05). In one patient with normal planar BMIS of the lumbar spine, SPET disclosed a metastatic lesion in the bone marrow. The correlation coefficient between BMIS and bone scan and between BMIS and serum alkaline phosphatase was r = 0.688 and r = 0.483 respectively. One patient developed a minor HAMA response after BMIS. Patients with diffuse increased activity of the skull on the bone scan had a significantly higher skull to whole body ratio on BMIS (P < 0.01). Thus BMIS can improve the specificity and positive predictive value of bone scanning in the detection of skeletal metastases, with a low HAMA response. Diffuse increased activity of the skull on bone scans could be explained by bone marrow extension. SPET scanning of the spine may improve the sensitivity of BMIS.

Endemic goitre and plasmatic levels of vitamins A and E in the school-children on the island of Krk, Croatia.

A total of 1975 school-children on the island of Krk aged 7-19 years of life were included in this study. The purpose was to establish the goitre status and plasmatic level of vitamins A and E in the examined children with the enlarged thyroid gland. The goitre prevalence was 29.8%. The average plasmatic values of vitamins A and E in the children with enlarged thyroids were statistically significantly lower from the reference values. Mentioned goitre prevalence at the level of moderate and heavier endemic goitre speaks on behalf of alimentary iodine deficiency. But the goiter examinations suggested the idoine deficiency not to be the only etiological factor of goitre on the island of Krk. Lower average plasmatic values of vitamins A and E in the examined with the enlarged thyroids referred to this fact to a certain degree.

The expression and role of insulin-like growth factor II in malignant hemangiopericytomas.

Hemangiopericytoma is a rare soft tissue tumor originating from contractile pericapillary pericytes. To address the issue of molecular genetic events that participate in genesis and progression of hemangiopericytoma we analyzed insulin-like growth factor (IGF) II and IGF I receptor in 29 tumors collected from a human tumor bank network. Seven of these tumors were associated with severe hypoglycemia; six were retroperitoneal and one was located in the leg. Of 22 tumors tested 12 (54.5%) exhibited IGF II mRNA, while almost 90% (17 of 19) of hemangiopericytomas exhibited IGF I receptor mRNA. Sera from some patients whose tumors expressed IGF II mRNA contained elevated levels of IGF II. Removal of the tumor eliminated most of the IGF II immunoreactivity from the sera. The potential role of IGF II as a growth-promoting factor was examined on three malignant primary hemangiopericytoma cell cultures. Extracellular addition of IGF II significantly enhanced cell proliferation in a dose-dependent manner. Antisense oligodeoxynucleotides that specifically inhibit IGF II mRNA, at a concentration of 40 or 80 micrograms/ml, inhibited the growth of hemangiopericytoma cells significantly, by 40%. Simultaneous administration of antisense deoxyoligonucleotides to both IGF II and IGF I receptor inhibited tumor cell proliferation by even 80%. Our data suggest that tumor cells produce IGF II, and that this in turn stimulates their proliferation by autocrine mechanisms.

Detection of Helicobacter pylori in various oral lesions by nested polymerase chain reaction (PCR).

Nested PCR was used for the detection of Helicobacter pylori DNA in specimens collected from seven different topographic sites in the oral cavity. Out of 161 patients, only 21 (13.04%) were positive. There was no correlation between H. pylori status and patient diagnosis and age. No preferential site for bacterial colonization was found in the oral cavity, nor was an association established between a bacterial presence and ulcerated versus non-ulcerated lesions. The results indicate that the oral mucosa does not appear to represent a preferred site of colonization for H. pylori. Furthermore, the evidence presented in this paper suggests that H. pylori is not pathogenic in the oral cavity, nor is it associated with common oral pathologic processes.

Detection and typing of human papillomaviruses by polymerase chain reaction in cervical scrapes of Croatian women with abnormal cytology.

The association between certain human papillomaviruses (HPV) and cervical intraepithelial neoplasia (CIN) is well documented, but still unknown among Croatian women. In 1995, women between the age of 17 and 64 with cytomorphologically abnormal smears (CIN I-IV) were tested for the presence of HPV. Consensus and specific primers were used in the polymerase chain reaction (PCR) to detect the most common types: 6, 11, 16, 18, 31 and 33, as well as the unknown-risk HPV types (HPV X). Out of 379 specimens, 163 (43%) contained one or more HPV types. Coinfection with different HPV types in the same sample was observed in 16 cases. Beside low-risk HPV 6/11 (25.8%) the most frequently observed types were high-risk HPV types 16 (20.2%) and 31 (17.8%). Globally, the HPV positivity rate declines with age. The presence of HPV DNA significantly increased from 35.5 to 61.1% along with the severity of the cervical intraepithelial neoplasia (CIN I-IV). HPV type 6/11 was strongly associated with CIN I (33.8%), HPV type 31 with CIN II (22.9%), and HPV type 16 with CIN III (50%).

[Initial experience with ventilation-perfusion scintigraphy in patients with a suspected pulmonary embolism]. / Nasa prva iskustva s ventilacijsko-perfuzijskim scintigramom u bolesnika sa sumnjom na plucnu emboliju.

Ventilation-perfusion (V/P) scintigraphy was performed 62 times in 57 patients suspected of having pulmonary embolism (PE). The aim of this study was to present the results and our first experiences in V/P scintigraphy, as well as to point out some specificities of the study. Perfusion scintigraphy was performed following i.v. administration of 99mTc MAA. If the finding was positive, ventilation scan was performed directly after the inhalation of 99mTc DTPA aerosol. Based on the comparison of both findings the patients were divided into four groups: normal finding (8.1% of patients), low (54.8%), medium (22.6%), and high level of PE probability (14.5%). As V/P scintigraphy is a very sensitive and non-aggressive method, it is our opinion that it should be included in PE diagnosing as a "screening" method, because the scanning results greatly influence further therapeutical and diagnostic treatment of the patient.

Follow-up of patients with gastrointestinal cancer by tumor marker determination.

In addition to clinical examination and various diagnostic procedures, patients with gastrointestinal cancer (GIC) were also monitored by tumor marker (TM) determination. In total, 202 patients with GIC were postoperatively followed-up. According to in vivo diagnostic procedures, there were 133 (66%) patients without metastases, 63 (31%) patients with distant metastases, 48 (76%) of them with liver metastases, and six (3%) patients with local recurrences. During the 1990-1995 period, they were followed-up by serum TM concentration measurements on 1-8 occasions. At the time of initial diagnosis, TM were determined in a varying percent of the patients: CA 19-9 (100%), TPA (54%), CA 72-4 (49%), IAP (41%), CEA (41%) and AFP (25%). In the group of patients without metastases, the percentage of normal TM values ranged between 73%-100%, and TM sensitivity between 0%-86%. No ideal TM has as yet been discovered either for any malignant disease or for patients with GIC. Therefore, in the follow-up of patients with GIC we suggest the concentrations of at least two instead of only one TM (CA 19-9 and TPA or CEA) to be determined. It is also difficult to choose the best TM among numerous TM kits available on the market and to keep using it during a longitudinal follow-up study.