Progress towards discovery of antifibrotic drugs targeting synthesis of type I collagen.

Type I collagen is the most abundant protein in human body. Fibrosis is characterized by excessive synthesis of type I collagen in parenchymal organs. It is a leading cause of morbidity and mortality worldwide, about 45% of all natural deaths are attributable to some fibroproliferative disease. There is no cure for fibrosis. To find specific antifibrotic therapy targeting type I collagen, critical molecular interactions regulating its synthesis must be elucidated. Type I and type III collagen mRNAs have a unique sequence element at the 5' end, the 5' stem-loop. This stem-loop is not found in any other mRNA. We cloned LARP6 as the protein which binds collagen 5' stem-loop with high affinity and specificity. Mutation of the 5' stem-loop or knock down of LARP6 greatly diminishes collagen expression. Mice with mutation of the 5' stem-loop are resistant to development of liver fibrosis. LARP6 associates collagen mRNAs with filaments composed of nonmuscle myosin; disruption of these filaments abolishes synthesis of type I collagen. Thus, LARP6 dependent collagen synthesis is the specific mechanism of high collagen expression seen in fibrosis. We developed fluorescence polarization (FP) method to screen for drugs that can inhibit binding of LARP6 to 5' stem-loop RNA. FP is high when LARP6 is bound, but decreases to low levels when the binding is competed out. Thus, by measuring decrease in FP it is possible to identify chemical compounds that can dissociate LARP6 from the 5' stem-loop. The method is simple, fast and suitable for high throughput screening.

Isolation and characterization of point mutations in mismatch repair genes that destabilize microsatellites in yeast.

The stability of simple repetitive DNA sequences (microsatellites) is a sensitive indicator of the ability of a cell to repair DNA mismatches. In a genetic screen for yeast mutants with elevated microsatellite instability, we identified strains containing point mutations in the yeast mismatch repair genes, MSH2, MSH3, MLH1, and PMS1. Some of these mutations conferred phenotypes significantly different from those of null mutations in these genes. One semidominant MSH2 mutation was identified. Finally we showed that strains heterozygous for null mutations of mismatch repair genes in diploid strains in yeast confer subtle defects in the repair of small DNA loops.

[The beginnings and development of diagnostic imaging in nuclear medicine]. / Poceci i razvoj vizualizacione dijagnostike u nuklearnoj medicini.

INTRODUCTION: The phenomenon of radioactivity was discovered in 1896 by Antoin Henri Becquerel, but its application in visual diagnostics started about fifty years later. RECTILINEAR SCANNER: It was constructed by B. Cassen and ass. in 1949, when first scintiscans were obtained. Technical improvements have been made 1950-1956 (B. Cassen and ass., R. Newall and ass., P. Bell, D. Kuhl). Soon after appearance of the first Cassen's scanner, commercial production began. GAMMA CAMERA: It was invented and constructed by H. Anger in 1957, improvements being made from 1958 to 1963. Gamma cameras are being commercially produced and sold since 1962; about ten years later they become widely used, and soon they pushed out the scanner from visual diagnostics. COMPUTER: Its use in scintigraphic diagnostics started in 1964 (H. Shepers, D. Wincler, D. Brown). From 1965 to 1974 various centers developed their own computer programs; after 1974 computers with incorporated nuclear medicine software packages became commercially available. TOMOSCINTIGRAPHY (SPET) AND POSITRON TOMOGRAPHY (PET): Numerous attempts to obtain tomographic images of organs using scanners and gamma cameras were made between 1963 and 1973 (D. Kuhl and R. Edwards, H. Anger, N. Charkes and R. Somburanasin et al.). The concept of contemporary single photon emission tomography (SPET) device was developed between 1974 and 1977 (J. Keyes and ass. and R. Jaszczak and ass.), while commercial production started in 1982. First cyclotrons for production of positron emitters, a prerequisite for positron emission tomography (PET) diagnostics, emerged in hospitals in 1955, and in last ten years they are being commercially made for these purposes. H. Anger (1959), M. Phelps, E. Hoffman and M. Ter-Pogossian (1975) set the grounds of PET; commercial production of PET systems started thereafter. CONCLUSION: Visual diagnostics in nuclear medicine reached its zenith in clinical practice during 1970-1980. It is partly pushed into the background by new imaging techniques (US, CT, MRI), but it only initiated further improvements (SPET, PET).

[131-I-lipiodol in therapy of liver carcinoma--methods and case report]. / 131-J-lipiodol u lecenju karcinoma jetre--metodologija i prikaz slucaja.

INTRODUCTION: Primary malignant liver tumors are successfully treated only by means of surgery, but no more than 10% of patients are candidates for surgical intervention. The rest receive only palliative treatment which is, as a rule, unsuccessful. 131I-Lipiodol therapy (commercial label LIPIOCISTM) applied to the hepatic artery through a catheter has been used since 1984, primarily for treatment of hepatocellular carcinoma (HCC). The aim of this paper is to review the methodology of 131J-Lipiodol treatment of primary liver carcinomas. This treatment was applied for the first time in Yugoslavia. CASE REPORT: A female patient, 46 years of age had an inoperable primary liver carcinoma. Since progression of the disease couldn't be controlled by chemotherapy, treatment with 131I-Lipiodol was indicated. After blocking the thyroid with Lugol, Sol. 2.22 GBq of 131I-Lipiodol was injected into hepatic artery via catheter, and the patient was isolated in a designated facility until discharged. Around 5 months later, second therapeutic dose of 1.11 GBq was administered. Early post-therapy complications were severe, but transient. After 131I-Lipiodol therapy, the tumor growth was stopped, but the patient's general condition slowly deteriorated. The patient died 7 months after receiving the first therapeutic dose. CONCLUSION: In the reported patient, 131I-Lipiodol therapy stopped the tumor growth within the liver and significantly prolonged survival compared to the expected, but no improvement in quality of life was achieved. This treatment methodology is very complex. Medical staff providing care for these patients is exposed to substantial irradiation.

Increased rates of genomic deletions generated by mutations in the yeast gene encoding DNA polymerase delta or by decreases in the cellular levels of DNA polymerase delta.

In Saccharomyces cerevisiae, POL3 encodes the catalytic subunit of DNA polymerase delta. While yeast POL3 mutant strains that lack the proofreading exonuclease activity of the polymerase have a strong mutator phenotype, little is known regarding the role of other Pol3p domains in mutation avoidance. We identified a number of pol3 mutations in regions outside of the exonuclease domain that have a mutator phenotype, substantially elevating the frequency of deletions. These deletions appear to reflect an increased frequency of DNA polymerase slippage. In addition, we demonstrate that reduction in the level of wild-type DNA polymerase results in a similar mutator phenotype. Lowered levels of DNA polymerase also result in increased sensitivity to the DNA-damaging agent methyl methane sulfonate. We conclude that both the quantity and the quality of DNA polymerase delta is important in ensuring genome stability.

[Radiologic follow-up and prognosis of efficiency of systemic Sr-89 Cl-2 therapy of bone metastases in prostate cancer]. / Kompleksnaia luchevaia otsenka i prognozirovanie éffektivnosti sistemnoi radioterapii 89SrCl2 pri kostnykh metastazakhraka predstatel'noi zhelezy.

We evaluated possibilities of bone scintigraphy with 99mTc-methylendiphosphonate (99mTc-MDP) and magnetic resonance imaging (MRI) in follow-up and prediction of effect in patients with extensive bone metastatic disease treated with betha-emitter 89SrCl2. 24 patients with prostate cancer and extensive metastatic involvement of skeleton were referred for the study. 89SrCl2 was injected as single injection of 150 MBq (4 mCi), in eighteen from Amersham plc., England, as Metastron, in six--from Medradiopreparat, Russia). In all patients bone scintigraphy with 99mTc-MDP and MRI study of metastatic regions were performed before and in 3 months after 89SrCl2 injection. Patients treated with Metsatron were also studied in 6 months after injection. Quantitative analysis of data comprised count and anatomic dimensions of metastatic areas and calculation of indices [metastasis/intact bone] both for scintillation count of 99mTc-MDP bone scans and signal intensity of T1-weighted MRI scan. Henceforth, we conclude the data of bone scanning with 99mTc-MDP and of MRI give evidencies for significant regress of bone metastases in patients treated with 89SrCl2 besides symptomatic suppression of pain syndrome. 99mTc-MDP bone scanning is also of predictive value for the prognosis of therapeutic effect of systemic radiotherapy with 89SrCl2 in prostate cancer.

Core body temperature and sleep of older female insomniacs before and after passive body heating.

The purpose of this study was to investigate the relationship between core body temperature and sleep in older female insomniacs and changes in that relationship as a result of passive body heating (PBH). An increase in body temperature early in the evening by way of PBH in older female insomniacs increased SWS in the early part of the sleep period and improved sleep continuity. Fourteen older female insomniacs (60-73 years old) participated in at least two consecutive nights of PBH involving hot (40-40.5 degrees C) baths 1.5-2 hours before bedtime. Hot baths resulted in a significant delay in the phase of the core body temperature rhythm compared to baseline nights. This delay in temperature phase paralleled the improvements in sleep quality.

A mutation of the yeast gene encoding PCNA destabilizes both microsatellite and minisatellite DNA sequences.

The POL30 gene of the yeast Saccharomyces cerevisiae encodes the proliferating cell nuclear antigen (PCNA), a protein required for processive DNA synthesis by DNA polymerase delta and epsilon. We examined the effects of the pol30-52 mutation on the stability of microsatellite (1- to 8-bp repeat units) and minisatellite (20-bp repeat units) DNA sequences. It had previously been shown that this mutation destabilizes dinucleotide repeats 150-fold and that this effect is primarily due to defects in DNA mismatch repair. From our analysis of the effects of pol30-52 on classes of repetitive DNA with longer repeat unit lengths, we conclude that this mutation may also elevate the rate of DNA polymerase slippage. The effect of pol30-52 on tracts of repetitive DNA with large repeat unit lengths was similar, but not identical, to that observed previously for pol3-t, a temperature-sensitive mutation affecting DNA polymerase delta. Strains with both pol30-52 and pol3-t mutations grew extremely slowly and had minisatellite mutation rates considerably greater than those observed in either single mutant strain.

Destabilization of yeast micro- and minisatellite DNA sequences by mutations affecting a nuclease involved in Okazaki fragment processing (rad27) and DNA polymerase delta (pol3-t).

We examined the effects of mutations in the Saccharomyces cerevisiae RAD27 (encoding a nuclease involved in the processing of Okazaki fragments) and POL3 (encoding DNA polymerase delta) genes on the stability of a minisatellite sequence (20-bp repeats) and microsatellites (1- to 8-bp repeat units). Both the rad27 and pol3-t mutations destabilized both classes of repeats, although the types of tract alterations observed in the two mutant strains were different. The tract alterations observed in rad27 strains were primarily additions, and those observed in pol3-t strains were primarily deletions. Measurements of the rates of repetitive tract alterations in strains with both rad27 and pol3-t indicated that the stimulation of microsatellite instability by rad27 was reduced by the effects of the pol3-t mutation. We also found that rad27 and pol3-01 (an allele carrying a mutation in the "proofreading" exonuclease domain of DNA polymerase delta) mutations were synthetically lethal.

[Goals and scientific achievements of the Institute of Oncology]. / Stremljenja i strucno-naucna dostignuca Instituta za onkologiju.

The Institute of oncology represents an oncological center which renders the measures of prevention, early detection and diagnostic of tumours and multidisciplinary strategy for antitumour treatment, including rehabilitation of patients suffering from tumours. To fulfil the above mentioned aims the Institute is organized in ten completely operative units and several functional centres and committees. The paper presents only few aspects of diagnostic and treatment of tumour, and the implementation of the programmes and targets of individual organizational units within the Institute. This orientation is particularly actual now when epidemiological studies show an increase of disease and mortality incidence in the region of Vojvodina.

[Use and efficacy of radioiodine therapy in the treatment of hyperthyroidism]. / Primena i efikasnost radiojodne terapije kao nacin lecenja hipertireoze.

Radioiodine (131J) therapy is a method of radical treatment for hyperthyroidism. In our study in the period 1971-1993, we administered radioiodine therapy in 163 patients with hyperthyroidism. We performed a long-term follow-up, from one month, to 21 years after the radioiodine therapy. The cured rate was 83.4%: euthyroid state was found in 43.6% of patients and hypothyroidism appeared in 39.9% of patients. After the radioiodine therapy hyperthyroidism was found in 16.6% of cases. Radioiodine therapy is very efficient, non-invasive, radical treatment of hyperthyroidism, not expensive and easy to administer. It has practically no immediate or long-term complications, except hypothyroidism.

Myocardial perfusion imaging using 99mTc-MIBI in patients with dilated cardiomyopathy--methodology and its clinical use.

The aim of the study was to demonstrate the methodology of investigation of myocardial perfusion and viability using 99mTc-MIBI in patients with dilated cardiomyopathy and to estimate its clinical use. Myocardial perfusion and viability were investigated by using the planar and SPECT scintigraphy and by estimating the wall motion of the myocardium. The foci of decreased myocardial viability were found in 7 patients. One patient had perfusion defect only at stress. Analyzing the patients data, by using the gated studies, we found various degrees of wall motion myocardial abnormalities.

Correlation between the blood pool tomoscintigraphy (SPECT) and planar scintigraphy in the diagnostic of the liver hemangioma.

The aim of the study was the estimation of diagnostic importance of the hepatic blood pool tomoscintigraphy (SPECT) and planar scintigraphy in patients investigated under suspicion of the liver hemangioma. In the diagnostic procedure the correlation between radiocolloidal scintigraphy, blood pool planar scintigraphy (early and late) and SPECT was made. Sixty-seven patients with focal lesions in the liver were investigated. The blood pool scintigraphy was made after application of traser dose of 99mTc and equilibration of tagged red blood cells in circulation. The planar scintigraphy was made 20 min after the red cells tagging and again 2 hours later (early and late scintigrams). SPECT was also applied to make the diagnostic procedure more accurate. From 31 hemangiomas detected by SPECT only 19.4% were clearly visible by planar scintigraphy. The diagnostic of very small hemangiomas is enabled by SPECT too.

Protocol of the diagnostic, therapy and follow-up of differentiated thyroid cancer.

The Protocol of the multidisciplinary diagnostic treatment and follow-up of differentiated thyroid cancers, made in the Institute of Oncology in Sremska Kamenica, is described. It is in use in this institution from 1990. It is in concordance with general oncology principles and follows the guidelines of the International Union Against Cancer (UICC) concerning this problem.

[Scintigraphy of the vascular supply of the liver in the differential diagnosis of hemangioma, in malignant processes and cystic formations in the liver]. / Scintigrafija vaskularnih prostora jetre u diferencijalno-dijagnostickom postupku hemangioma, u malignim procesima i cisticnim formacijama u jetri.

The aim of the research is to establish and confirm the diagnoses of patients with suspected haemangioma of the liver with completed ultrasonography. A group of 92 patients were checked by scintigraphy after the equilibration of marked eritrocytes in the circulation. After the marking dose of 99mTc-Sn-PYP in a dose of 555 MBq scintigraphy and static scintigram of the liver (early and late, after 3 hours) were done. During the clinical studies the classic scintigraphy of the liver by 99mTc-S-coloid was done in all the patients. After the study it was concluded that there was a partial gathering of the radioisotopes in early scintigrams which was more evident in the late ones especially in the areas which represented focal-cold zones in the classic scintigrams.

[Dosimetric measurements and early complications in patients with differentiated thyroid carcinomas treated with radioactive iodine]. / Dozimetrijska merenja i rane komplikacije kod bolesnika sa diferenciranim karcinomom stitaste zlezde lecenih radioaktivnim jodom.

The aim of the study was to determine the exposure dose rate during the application of radioiodine therapy (ablative or tumoral dose) given in order to treat the differentiated thyroid carcinoma, during the medical visit and examinations of those patients, to establish the safety distance from patients both for population and for medical staff and to perceive early complications after the therapy. The dosimetric measurements were performed in 10 patients. The exposure dose rate during the application of the therapy ranged from 2000 to 10000 pC/kg.s, during the visit from 528 to 15 pC/kg.s and during the examinations of patients from 5500 to 200 pC/kg.s. The average safety distance from patients for population was about 8.5 m on the day O (the very day of the therapy) and 2.0 m on the day 4, while for the medical staff it amounted to 5.0 m on the day 0 and 0.5 m on the day 4. The early complications perceived were as follows: radiation thyroiditis in 5/10 patients, stomach problems in 1/10 patients and transitorial leucopeny, forty days after the therapy, in 2/10 patients.

[Inhalation scintigraphy in the diagnosis of pulmonary thromboembolism]. / Doprinos inhalacione scintigrafije u dijagnostici plucnog tromboembolizma.

The purpose of this report is to realize the role of inhalation scintigraphy in the diagnostics of the pulmonary thromboembolic disease, as an addition to perfusion lung scintigraphy in the assessment of the nature of perfusion disturbances discovered by the perfusion scintigram. Perfusion lung scintigraphy, in itself, is a very sensitive indicator of a recent pulmonary thromboembolism but it is not sufficiently specific. The combining of perfusion and inhalation lung scintigraphy increases the specific quality of scintigraphic examinations in the diagnostics of lung thromboembolism.

[Inhalation scintigraphy of the lungs and its clinical aspects]. / Inhalaciona scintigrafija pluca i njeni klinicki aspekti.

The aim of the work was to examine the new Taplin's system for the production and inhalation of radioactive aerosol in routine diagnostic application. For that purpose a new commercially produced system of the firm CADEMA was used with a small modification which made possible its repeated application. The advantage of this system is a high level of aerosol particles of optimal size from 0.7-0.8 micron and inhalation is carried out only on the basis of air circulation caused by natural breathing. Total of 125 inhalation scintigrams was made. The results show that one can get aerosol of a high quality the distribution of which does not depend significantly on the sort of material marked with 99mTc. The distribution itself is even and scintigrams of high quality can be obtained. Inhalation scintigram of high quality combined with a perfusion scintigram enables reliable estimation of regional relationship between ventilation and perfusion of the lungs which is of special interest in the diagnostic of lung thromboembolism.