Biomedical subjects

M Petrovecki

Publications and source records attributed to M Petrovecki.

At least 19 recordsLinked to original sources

PubMed2006

Age estimation methods using anthropological parameters on human teeth-(A0736).

The research was conducted on the 160 intact extracted human teeth with one and two roots of the known age and sex. The teeth were disinfected, dried and X-rayed. After that the section of the longitudinal cut through the teeth was performed in order to facilitate monitoring of all tissues and morphological characteristics of the teeth. The age was determined in three ways: Method 1 [G.Bang, E. Ramm, Determination of age in humans from root dentin transparency, Acta Odontol. Scand. 28 (1970) 3-35]--analysis of the translucency of the root dentine, Method 2 [S. Kvaal, T. Solheim, A non-destructive dental method for age estimation, J. Forensic Odonto-stomatol. 12 (1994) 6-11]--analysis of the root and the root canal from the X-ray, Method 3 [G. Johanson, Age determination from human teeth, Odontol. Revy. 22 (1971) 1-126]--analysis of six parameters on each teeth. All data were subject to the correlation and regression analysis which showed the following: all of the three applied methods were in the significant correlation with the real age, and the best of them proved to be Method 3 where the coefficient of correlation was 0.85, p<0.001. The teeth of the maxilla are more convenient for the age determination than the teeth of mandible. They are in the significant strong correlation with the known real age, and in Method 3, the coefficient of correlation is 0.78, p<0.001. Age determination of the teeth with two roots is in significant correlation with the known real age p<0.001 in relation to the determined age on the teeth with one root. The results show that sex too, is in significant correlation with the real age, p<0.001. In practice, the methods used and the results achieved in this research have been enabling the dental age estimation of human remains from mass graves after the 1991 war in Croatia.

Adolescent↗

PubMed2005

Peptic ulcer disease in dyspeptic patients with ischemic heart disease: search and treat?

OBJECTIVE: The aim of this study was to determine the prevalence and risk factors for peptic ulcer disease (PUD) in dyspeptic patients with ischemic heart disease (IHD), and to assess whether the healing of PUD before coronary artery bypass grafting (CABG) could reduce the need for urgent postoperative endoscopy. PATIENTS AND METHODS: A series of 894 patients referred to Dubrava University Hospital in Zagreb for elective CABG during the period from May 1998 until April 2001 was prospectively analysed. Dyspepsia was assessed by a questionnaire, PUD by upper gastrointestinal endoscopy, and H. pylori status by histology/Giemsa staining and the rapid urease test. The need for urgent postoperative endoscopy (hematemesis and/or melena, sudden onset of anemia or unexplained epigastric pain) was compared between the prospective study group of 894 patients and a series of 463 patients referred for CABG to Dubrava University Hospital during the period from January 1997 until April 1998. RESULTS: Gastroduodenal dyspepsia predominated in 184 (20.6 %) patients, 142 (77.2 %) of them with Helicobacter (H.) pylori infection and 69 (37.5 %) with verified PUD. Univariate analysis indicated the increased risk of multiple PUD to be related to a previous diagnosis of PUD (OR 3.61, 95 % CI 1.32 - 9.82), H. pylori infection (OR 18.86, 95 % CI 2.31 - 153.98), use of aspirin (OR 5.70; 95 % CI 1.80 - 18.03) and left coronary artery occlusions (3.10, 95 % CI 1.00 - 9.59). Multivariate analysis pointed to H. pylori infection (OR 16.30, 95 % CI 1.57 - 168.53) and left coronary artery occlusions (OR 4.84, 95 % CI 1.05 - 22.30) as independent risk factors for multiple PUD. The OR for urgent postoperative endoscopy due to a major gastrointestinal event was 9.9 (95 % CI 2.2 - 45.1) and the OR for active peptic ulcer with stigmata of recent bleeding was 6.9 (95 % CI 1.4 - 33.1) in the group of patients with IHD who were not submitted to evaluation for dyspepsia prior to elective heart surgery. CONCLUSIONS: In areas with a high prevalence of H. pylori infection, endoscopy and a "search and treat" strategy for IHD patients with dyspepsia before elective cardiac surgery should significantly reduce the need for urgent postoperative endoscopy due to major gastrointestinal events.

Comorbidity↗

PubMed2003

Comparison of colonoscopies performed under sedation with propofol or with midazolam or without sedation.

BACKGROUND: Previous studies have shown that some patients are not able to tolerate colonoscopy without sedation because of low pain threshold, anxiety, colonic sensitivity and anatomical variations. Benzodiazepines are most commonly used, often in combination with pethidine. Our study compares sedation with propofol to midazolam and colonoscopy without sedation. METHODS: In this study 147 patients were examined. The patients were divided into three groups: The first group included patients in whom propofol was used for sedation, the second group included patients sedated with midazolam, and the third group was comprised of patients who received no sedation. Oxygen saturation and heart rate were recorded continuously by pulse oxymetry. Arterial blood pressure (BP) was monitored at 3-min intervals. RESULTS: A decrease in blood pressure and heart rate was documented in the first two groups (P < 0.001), whereas in group 3 we found an increase in both BP and heart rate (P < 0.001). Oxygen saturation dropped below 90 % in 11/102 patients sedated with propofol and in 9/23 sedated with midazolam. Two of 22 patients in whom no sedation was used were found to have oxygen saturation below 90 %. The recovery time was shorter (7 min) in group 1 (propofol) than in group 2 (midazolam), in which it was found to be 20 min. CONCLUSIONS: Our results showed that propofol provided good sedation with excellent pain control, a short recovery time and no significant haemodynamic side effects.

Adolescent↗

PubMed2001

Alterations in lymphocyte phenotype of infected preterm newborns.

The cord blood lymphocytes from 44 premature newborns were analyzed using two-color monoclonal antibodies and flow cytometry. Depending on whether or not there was an infection at birth, the newborns were divided into two groups and the immunophenotypes of infected and uninfected newborns were compared. The percentage of T lymphocytes (CD3+) was significantly lower in the infected prematures. The percentage of both helper and cytotoxic T lymphocytes was lower. The proportion of activated T lymphocytes, cytotoxic non-MHC-restricted T lymphocytes, NK cells and B lymphocytes did not differ between the group of infected and the group of uninfected prematures. The percentage of memory helper T lymphocytes (CD45RO+CD4+) was very low in premature newborns regardless of whether or not they were infected and could not be used as a marker of bacterial infection at this age.

B-Lymphocytes↗

PubMed2001

Croatian Medical Journal introduces culture, control, and the study of research integrity.

Culture, control, and the study of research integrity represents the future goals of the Croatian Medical Journal. This article will highlight research integrity as experienced in the USA by the Office of Research Integrity (ORI) and discuss the framework being developed in Croatia. First, the Croatian Medical Journal seeks to promote a research culture that is aware of research integrity. This will be accomplished through the education and training of Croatian researchers interested in publishing their results in international scientific journals. To facilitate this goal, the Croatian Medical Journal introduces, what it believes to be, the first Research Integrity Editor. Second, the Croatian Medical Journal intends to facilitate the development of an Office of Research Integrity based on ORI model. The Croatian office of research integrity would be authorized to develop regulations to define scientific misconduct, investigate, and develop administrative actions against those found to have committed scientific misconduct. Furthermore, the office would be responsible for developing national education standards for promoting research integrity and the responsible conduct of research. Third, the Croatian Medical Journal is developing a science-based research agenda. This new research agenda will examine topics similar to those presented recently at the first Research Conference on Research Integrity held in Bethesda, Maryland, USA (November, 2000). The initial research topics would include studying those variables and mechanisms that help to promote research integrity and honorable research practices. This Editorial represents the first step towards achieving this goals, by establishing a collaborative relationship between ORI and the Croatian Medical Journal.

Clinical Trials as Topic↗

PubMed2001

Opinions of Zagreb University students on professor-student dating.

AIM: To investigate what Zagreb University students think about professor-student dating. METHODS: We surveyed 500 students from ten different Zagreb University schools using anonymous questionnaires. Twenty-five female and 25 male students from each school were asked to assess professor-student dating as either acceptable, reckless, unethical, or shameful, and decide how severely such behavior should be punished, if it should be punished at all. Sex of the professor and student was irrelevant. RESULTS: Students were equally strict towards the student and the professor. They judged professor-student dating more strictly if dating started before the student passed the exam in the subject taught by the professor than if it started afterwards. More female than male students had no opinion on whether the professor should be punished. When dating started after the student passed the exam, male students judged the student's behavior more strictly than female students; if the dating started before, the Economics students were stricter and the Music Academy students milder than average in their judgements. In the case when dating started after the student passed the exam, students of the Faculty of Physical Education judged both dating parties more strictly, Political Sciences students were milder toward a professor, whereas more students of the Faculty of Philosophy thought that it should be punished. Most students with no opinion on punishing dating were found among Agronomy students. CONCLUSION: Most Zagreb University students think that professor-student dating should not be punished and that both dating parties take equal responsibility for such behavior.

Attitude↗

PubMed2001

Changes of cytolytic cells and perforin expression in patients with posttraumatic stress disorder.

AIM: To define phenotypic characteristics of cytotoxic T lymphocytes (CTL) and natural killer cells (NK) in peripheral blood, frequency of somatic symptoms, and level of anxiety and depression in 25 patients clinically diagnosed with chronic post-traumatic stress disorder (PTSD). METHODS: Patients were divided into two sub-groups according to the stressor: 18 PTSD patients with the battlefield experience and 7 PTSD patients with battlefield experience who were tortured as the prisoners of war (POW) in Bosnian-Serbian camps. The control group consisted of 15 healthy volunteers matched to the patients by sex and age. We tested all patients using Becks depression inventory, Spielberger anxiety test, and somatic disturbance list, and analyzed their peripheral blood lymphocytes using flow cytometry with the double fluorescence staining of cell surface antigens (CD3, CD4, CD8, CD16, and CD56) and intracellular cytolytic molecule perforin (P), a mediator of cytolytic action at the molecular level. RESULTS: All PTSD patients showed a significant level of anxiety, depression, and numerous somatic symptoms. The only significant difference between PTSD patients with and without POW experience was in the anxiety level (median, 71; range 61-79; vs median, 65; range, 49-77). PTSD patients with POW experience had significantly higher levels of CD16+ cells (median, 37%; range, 16-55%) than those without it (median, 12%; range, 5-37%). Double labeling for intracellular P antigen and cell surface antigens showed the highest levels of CD16+P+ (median, 33%; range, 15-40%; vs median, 10%; range, 3-29%) and CD56+P+ (median, 21%; range, 11-40%; vs median 8%; range, 1-30%) cells in PTSD-POW patients. CONCLUSION: Chronic PTSD patients who survived concentration camps show the most numerous alterations in PBL phenotype, the highest number of perforin-containing cells, and a significantly higher level of anxiety.

Adult↗

PubMed2000

Clinical, histopathological and flow-cytometric properties of incidental renal cell carcinomas.

Medical records of 63 patients operated on for renal cell carcinoma (RCC) between 1986 and 1996 in the Karlovac General Hospital were studied retrospectively. In 23 (36.5%) patients, the tumor was incidentally detected. The median patient age was 62 in the incidental group and 64 years in the symptomatic group (P > 0.05). Ultrasonography was the leading technique for incidental detection of RCC. The median tumor diameter was 6 cm in the incidental group and 9 cm in the symptomatic group (P < 0.001). Incidental carcinomas had a lower stage (P = 0.022) and a lower nuclear grade (P < 0.001) than the symptomatic ones. The incidental cases were associated with a more favorable ploidy status (P = 0.027) and a lower proliferative activity (P = 0.005). The 5-year survival rate was significantly higher in incidental (81.4%) than in symptomatic cases (44.3%) (P = 0.020). Univariate analysis showed that tumor stage, ploidy status, and proliferative activity were good prognostic parameters, while patient age, tumor size, and nuclear grade were not. Tumor stage was the only independent prognostic parameter in multivariate analysis. In conclusion, the incidentally detected RCC show more favorable clinical, histopathological, and flow-cytometric characteristics and their prognosis is significantly better than in symptomatic cases.

Adult↗

PubMed2000

Two-color flow cytometric analysis of preterm and term newborn lymphocytes.

Immune system maturation proceeds postnatally in humans. Therefore, newborns, especially those of a lower gestational age, are not fully immunocompetent and are more likely to acquire perinatal infections. In order to investigate the neonatal immune system status, the major lymphocyte subpopulations were studied in newborns of different gestational age, comparing term newborns and adults. The cord blood from 66 newborns and the peripheral blood from 23 adults were analyzed using fluorochrome labelled monoclonal antibodies and two-color flow cytometry. The newborns were divided into three groups according to their gestational age. Ten prematures were under 32 weeks of gestation, 35 were of 32-37 weeks and there were 21 term newborns. The percentage of cytotoxic T lymphocytes (CD4 CD8+) was lower in term newborns as compared to the adult controls (17.8 versus 30.3%), and so were the percentages of activated T lymphocytes (CD3+Ia+; 0.3 versus 3.7%), cytotoxic non-MHC restricted T lymphocytes (CD3+CD16+CD56+; 0.2 versus 1.8%) and NK cells (CD3-CD16+CD56+; 4.8 versus 15.5%). On the contrary, the proportions of unlabelled cells were increased in term cord blood. The expression of CD45R0 marker on neonatal lymphocytes was very low (1%). In comparison to the higher-gestation newborns, the lower gestation prematures had reduced percentages of T lymphocytes (CD3+; 43 versus 65%), mostly helper T lymphocytes (CD4+CD8-; 35 versus 50%), and increased percentages of unlabelled cells. The percentages of NK cells (CD3+CD16+CD56+) and B lymphocytes (CD3-CD19+; CD3-Ia+) did not differ among the tested newborn groups. There were no significant differences in major lymphocyte subpopulations between the group of highest-gestation prematures and the group of term newborns that differed significantly when compared to adults. The lowest-gestation newborns showed the most immature lymphocyte phenotype with the highest percentages of unlabelled cells.

Antigens, CD19↗

PubMed2000

Effects of a membrane-metallopeptidase blocking agent thiorphan in long-term cultures of human bone marrow.

Thiorphan [(DL-3-mercapto-2-benzylpropanoyl)-glycine], a drug blocking the activity of membrane metalloendopeptidase EC 3.4.24.11 (CD10, CALLA), was added to long-term cultures of human bone marrow. Progression of the cultures was assessed by cell counts, cytology and clonogenic (GM-CFU) ability of the non-adherent cells in the supernatant and by morphology of the adherent stromal layer. A stimulatory effect on hematopoiesis was noted.

Bone Marrow Cells↗

PubMed2000

Thiorphan, an inhibitor of neutral endopeptidase/enkephalinase (CD10/CALLA) enhances cell proliferation in bone marrow cultures of patients with acute leukemia in remission.

Thiorphan, (DL-mercapto-2-benzylpropanoyl)-glycine is a potent and specific inhibitor of membrane metallo-endopeptidase (EC 3.4.24.11, CD10). We explored its effects in short-term clonal cultures of the bone marrow from 10 patients with acute leukemia in remission. The cell suspensions were incubated with thiorphan (10(-13) to 10(-5) M) and seeded for the granulocyte/macrophage-colony forming unit (GM-CFU) assay. In normal bone marrow samples the median seeding efficiency was 119 colonies and clusters per 10(5) cells and thiorphan caused slight stimulation of the clonal growth in concentrations above 10(-9) M. In the leukemic samples, the median seeding efficiency varied from 10 to 366 colonies and clusters per 10(5) seeded cells. Meaningful alterations of the clonal growth were noted in 32 out of 83 thiorphan-treated cultures (39%). In those 32 cultures the stimulatory effects outnumbered the inhibitory effects (24 versus 8). Thus, thiorphan stimulated the progenitor cell proliferation in bone marrow samples from the normal donor and from the patients with acute leukemia in remission. Thiorphan binding to CD10 might interfere with the processing of neuropeptide hemoregulatory factors and thus influence the progenitor cell proliferation.

Acute Disease↗

PubMed2000

Prognostic significance of DNA ploidy pattern and nucleolar organizer regions (AgNOR) in colorectal carcinoma.

AIM: To investigate the prognostic significance of DNA ploidy and silver stained nucleolar organizer regions (AgNOR), as well as their relation to the histological grade and Dukes' stages of colorectal carcinomas, and the relation of tumor cells proportion in the S-phase and Dukes' stage, histologic grade, DNA ploidy, or AgNOR count. METHODS: DNA flow cytometric analysis and AgNOR were performed on 94 surgically removed colorectal carcinomas. The mean AgNOR count was calculated in 200 tumor cells for each case. Survival rates and tests for significance were evaluated using the log-rank test and Cox regression model. RESULTS: There were no significant correlations between the ploidy pattern, histological grade, and Dukes' stage. Diploid tumors had a significantly lower AgNOR count (median 2.5, range 2.1-7.7) than aneuploid (median 6.2, range 2.0-7.9). Dukes' C stage tumors exhibited higher AgNOR count than Dukes' A or B stages. The proportion of tumor cells in S-phase did not correlate with any other parameter. Each of these parameters failed to show any correlation with survival. After dividing the tumors into those with high (>5) and low AgNOR count (<5), no correlation was found in the latter group between AgNOR and any other studied parameters, whereas in the group with high AgNOR count correlations to Dukes' stage, DNA ploidy, and histological grade were established.Conclusions. The difference in survival between well, moderately, and poorly differentiated tumors were significant in the group with high AgNOR counts. Dukes' C stage and aneuploid tumors had the worst prognosis.

Adult↗

PubMed2000

Effect of opioid peptide methionine-enkephalin in long-term cultures of human bone marrow.

Methionine enkephalin, an opioid peptide belonging to the family of neuropeptides, has been shown to function as a neurotransmitter, hormone and growth factor. The present work explored its effects in long-term culture of bone marrow cells, harvested from a patient with acute lymphoid leukemia (ALL-L3) in the second complete remission. Nine cultivation flasks were established and maintained for five weeks, with medium renewal once a week. At each re-feeding, methionine-enkephalin was added to the cultures in final concentrations 10(-8), 10(-10) or 10(-12) M, and granulocyte-macrophage progenitor cells (GM-CFU) were determined among the harvested, nonadherent cell populations. The total number of nonadherent cells was 8% to 42% higher in the treated cultures than in the control, nontreated cultures, and the GM-CFU counts were three to four times higher. Those changes, although evident, did not reach statistical significance because of the small group sizes. In 1 of 9 cultures the adherent cell layer was atypical, the cell population consisted of small cells resembling the lymphoblasts, and the cell count was 2-8 times higher than in the controls. That aberrant culture has presumably arisen from residual leukemic cells remaining in the bone marrow after chemotherapy. The findings support the idea that opioid peptides, including methionine-enkephalin, participate in regulation of hematopoiesis. Two mechanisms may have accounted for the observed effects of enkephalin on cultured bone marrow cells: an indirect action, via interleukins secreted from the stromal cells upon stimulation of the opioid receptors, or a direct action on hematopoietic precursors.

Bone Marrow Cells↗

PubMed1999

Effects of tamoxifen on steroid hormone receptors and hormone concentration and the results of DNA analysis by flow cytometry in endometrial carcinoma.

OBJECTIVES: Tamoxifen is a nonsteroidal triphenylethylene derivate with a predominant antiestrogen activity, used in the endocrine treatment of breast and endometrial cancer. It is not known which endometrial carcinomas will respond favorably to tamoxifen and which ones will not. The aim of this study was to find out whether tamoxifen has an effect on hormone steroid receptors, hormone concentration, DNA content, and proliferative activity in endometrial cancer and to correlate the tamoxifen-induced changes with pathologic parameters such as clinical stage, tumor differentiation, depth of invasion, and histologic type. METHODS: Thirty postmenopausal women with endometrial carcinoma were treated with 30 mg of tamoxifen daily for 7-10 days after curettage. Steroid hormone receptors (estrogen and progesterone receptors), levels of follicle-stimulating hormone, luteinizing hormone, prolactin, estradiol, progesterone, testosterone, dehydroepiandrosterone sulfate, sex hormone binding globulin, and DNA ploidy and proliferative activity were determined before and after therapy. The patients were also divided into favorable and unfavorable prognosis groups according to classical histological parameters. The patients in the favorable group consisted of patients with stage I disease, well and moderately differentiated tumors, favorable histologic type, and a depth of myometrial invasion of less than (1/3). The patients with only one of the unfavorable parameters (clinical stage II or III, poorly differentiated tumors, unfavorable histologic types, and deeper invasion of myometrium) were included in the unfavorable prognosis group. RESULTS: After the treatment, there was a net increase in the progesterone receptors and sex hormone binding globulin and a significant decrease in the estrogen receptors. The increase in progesterone receptors and decrease in estrogen receptors occurred in the patient group with favorable prognosis regarding histologic type, degree of differentiation, and clinical stage, but also in the unfavorable prognosis group regarding the depth of myometrial invasion. Statistically significant decrease in the follicle-stimulating hormone concentration was observed in the groups with favorable prognosis regarding histologic type, depth of myometrial invasion, and grade of differentiation. Concentration of sex hormone binding globulin was significantly increased in groups with favorable prognosis if histologic type and grade of differentiation were taken into account. On the other hand, there was a significant decrease in the concentration of luteinizing hormone in the group with unfavorable histologic type and also a decrease in progesterone concentration in patients with unfavorable prognosis regarding the grade of differentiation. There was no statistical significance either in the concentrations of other hormones measured or in the DNA analysis by flow cytometry. CONCLUSIONS: Our results revealed that tamoxifen can increase progesterone receptors and decrease estrogen receptors in endometrial cancer. The effect was most pronounced in tumors with favorable clinicopathologic parameters. We conclude that tamoxifen therapy can induce progesterone receptor synthesis even in tumors with low initial progesterone receptor levels, making such tumors potentially responsive to additional hormonal therapy with progesterone.

Adenocarcinoma↗

PubMed1999

Double immunoenzymatic APAAP staining for the detection of leukemia-associated immunophenotypes.

Detection of unusual or aberrant cell immunophenotype with flow cytometry is the basis for the immunologic recognition of minimal residual disease (MRD) in patients with acute leukemia (AL). In this study, we have shown that the double immunocytochemical alkaline phosphatase antialkaline phosphatase (APAAP) staining technique also makes possible the detection of leukemic cells with unusual (leukemic) combinations of antigens (ULCA) both at diagnosis and during follow-up of patients with ULCA+ AL. The applicability of double APAAP was analyzed on bone marrow (BM) samples obtained from 12 patients (8 with AML, 3 with ALL, and 1 with undifferentiated acute leukemia [AUL]) randomly chosen from a larger group of 22 ULCA+ patients treated at our center in a 3-year period (22% observed ULCA+ AL frequency). The percentages of ULCA+ BM cells before chemotherapy were in the range of 5%-60%, which dropped to 0%-7% in 10 patients who achieved remission (range 0%-7%, p < 0.01). However, these cells could also be found 60 days after the initiation of therapy, ranging from 0%-2% of all nucleated cells. In 2 of 10 patients who achieved remission, 2% ULCA+ BM cells were found on days 35 and 60 after initiation of chemotherapy, and this finding was followed by relapse on days 110 and 270. However, the other 8 patients remained in remission despite positive finding of ULCA+ BM cells ranging from 0.2%-2% on at least one occasion. In 2 patients with AML FAB-M3 and cytomorphologic remission, the finding of ULCA+ cells by double APAAP correlated with the molecular finding of PML/RARalpha junction. These results indicate that double APAAP staining can identify leukemic cells in samples with a cytomorphologic pattern consistent with remission, but its applicability in detection of MRD awaits additional studies on a larger number of patients with ULCA+ AL.

Acute Disease↗

PubMed1999

Quantity and origin of transplanted autologous blood cells are independent factors associated with speed of postransplant hematological reconstitution.

AIM: Multivariate analysis of the prognostic significance of clinical and laboratory parameters on hematological recovery after autologous hematopoietic stem cell transplantation. METHODS: Sixty-two patients suffering from hematological and non-hematological malignancies entered the study. After conditioning therapy, 28 patients received bone marrow stem cells, 21 received peripheral blood stem cells, and 13 received both. The dynamic of hematological engraftment was calculated as recovery probability of leukocytes and neutrophils. Statistics was done using Kaplan-Meier method and multivariate Cox's proportional regression. RESULTS: Numerous clinical and laboratory parameters correlated with hematological recovery, but only two variables were found to be independently associated. Faster reconstitution correlated with greater number of progenitors and patients who received bone marrow cells recovered significantly later than others. Faster recovery could be expected in patient s receiving >13x10(4) CFU-GM/kg body weight, and significantly slower in those receiving <8.5x10(4) CFU-GM/kg. CONCLUSION: The quantity of progenitor cells and transplant type are variables significantly associated with the speed of postransplant engraftment, but these two parameters are mutually independent. The number of stem cells estimated by CFU-GM assay is a good and reliable routine test for predicting hematopoietic recovery.

Acute Disease↗

PubMed1998

Thiorphan stimulates clonal growth of GM-CFU in short-term cultures of bone marrow from a healthy donor and from patients with non-Hodgkin lymphoma.

Thiorphan, a specific inhibitor of membrane neutral endopeptidase (NEP, EC 3.4.24.11) also known as the common acute lymphoblastic leukemia antigen (CALLA, CD10) was added into short-term clonal cultures of the buffy coat concentrates of human bone marrow obtained from a healthy donor (six experiments) and from ten patients with non-Hodgkin lymphoma (NHL) (eight in complete remission, one in partial remission and one in relapse). Thiorphan concentrations ranged from 10(-5) to 10(-13) M. Nanomolar and higher concentrations of the drug mildly stimulated the granulocyte-macrophage colony-forming unit (GM-CFU) counts in the cultures of normal bone marrow, reaching the significance at 10(-7) M. Meaningful alterations of the GM-CFU counts were noted in 31 of 79 thiorphan-treated cultures of NHL bone marrow (39%). In those cultures the stimulatory effects (33%) outnumbered the inhibitory ones (6%). The stimulatory effects occurred mainly in the bone marrow samples of the patients with highly malignant NHL. The observations are compatible with the idea that the membrane endopeptidase (CALLA, CD10) participates in processes controlling the proliferation and differentiation of hematopoetic cells by cleaving the neuropeptides and related hemoregulatory peptides.

Bone Marrow↗

PubMed1998

Indirect demonstration of the lifetime function of human thymus.

The aim of this study was to test the hypothesis that human thymus maintains its function as the site of early T cell development throughout life, but to a progressively diminishing extent. Mononuclear cell suspensions prepared from the samples of 39 human thymuses were analysed for the total number of cells per gram of thymus tissue, percentage of single marker-positive CD2, CD4 and CD8 cells, percentages of double-positive CD4CD8 and CD2CD8 cells, double-negative CD4CD8 cells, absolute numbers of these cells per gram of tissue, and extent of the in vitro proliferation upon stimulation with concanavalin A (Con A), phytohaemagglutinin (PHA) and pokeweed mitogen (PWM) mitogens. The main outcome measures were flow cytometric data on thymus lymphoid cell composition (according to CD classification), expressed as percentages and numbers of cells per gram of thymus tissue. The total number of mononuclear cells expressed per gram of thymus tissue exponentially decreased with age. The slope of none of the analysed cell subpopulations differed from the slope of the line constructed for age-related decline of the total number of mononuclear cells (-0.024 on a semilogarithmic scale). The thymuses of all ages contained all analysed cell subpopulations in approximately the same proportions: percentages of these cell subpopulations did not change with age, except for all CD4+ (P=0.017) and double-positive CD4+CD8+ (P=0.016) cells, which tended to decrease with age. The extent of proliferation of thymus cells upon stimulation with T and B cell mitogens was unrelated to age. We conclude that the thymus retains its function as the site of differentiation of T lymphocytes throughout life. With respect to the number of involved lymphoid cells, the function exponentially decreases with age.

Adolescent↗