Evaluation of photo-crosslinked fibrinogen as a rapid and strong tissue adhesive.

Tissue adhesives and sealants are commonly used in surgery either as an adjunct to, or replacement for, sutures. Previously, we have shown that fibrinogen can be crosslinked rapidly to give a high-strength bond in the presence of a ruthenium(II) complex, a persulfate and irradiation with visible light, and that the crosslinked fibrinogen is nontoxic to cells in vitro. This approach addresses limitations to current fibrin sealants that typically have relatively slow curing times and low bond strengths. In the present study, we have evaluated the efficacy and safety of this new biological scaffold sealant in various animal models. When placed as solid implants into rats, the crosslinked fibrinogen persisted for at least 8 weeks but was fully resorbed by 18 weeks with minimal inflammatory responses. When used as a tissue adhesive for repair of skin incisions in rats or as an arterial haemostat in pig, the photo-crosslinked fibrinogen sealed tissue or arrested bleeding within 20 s of application. For the skin incisions, the fibrinogen sealant promoted rapid tissue vascularization and cellular infiltration with no adverse foreign body cell generation. New collagen deposition occurred and with time the matrix had remodelled to acquire large mature collagen fiber bundles which were accompanied by maximum regenerated tensile strength. This biomaterial system may find useful applications in surgical procedures where rapid curing and/or high strength tissue sealing is required.

Five-year overall survival and prognostic factors in patients with cervical cancer in Bulgaria.

PURPOSE: To perform a population-based analysis on the 5-year survival rate and to analyse the significance of various prognostic factors for survival in patients with cervical cancer in Bulgaria for the period 1993-2002. PATIENTS AND METHODS: A total of 9,457 women were analyzed using the data of the National Cancer Registry. Their mean age was 51.41 years. Survival analysis was performed using the life table method. Analysis of factors affecting survival was performed by the Cox proportional hazards regression model. The statistical processing was carried out with the SPSS program/PC+v.11.01 for Windows. RESULTS: The overall cumulative 5-year survival was 47.12%. According to age, higher survival was observed in women younger than 35 years. Women in towns had better survival than those in villages. Significant difference was observed between squamous cell carcinoma and adenocarcinoma and some rare histological types. According to stage, survival was higher for stages I and II and was decreasing with advancing disease stage. Better survival was achieved with surgical treatment. In the Cox regression analysis, the highest relative risk was associated with advanced clinical stage, with symptomatic therapy only, with rare histological types, age over 65 years, and village residents. CONCLUSION: According to these results, Bulgaria is among the countries with low 5-year cervical cancer survival. Survival at the population level depends on several factors. The most important among them could be attributed to the absence of organized cervical screening.

[Results of the operative treatment of primary pulmonary sarcomas].

OBJECTIVE: To study and evaluate clinic, diagnostics and operative treatment of patients with primary pulmonary sarcomas (PPS). MATERIAL AND METHODS: During 24 years period, a total of 49 patients underwent surgery for PPS. There were 29 male and 20 female with a mean age of 52.6 years. Main presenting complaints were shortness of breath, cough, chest pain, weight loss and haemoptysis. Correct preoperative diagnosis was obtained in 12 (24.48%) of the patients by bronchoscopy or percutaneous core biopsy. Carcinoma was diagnosed in 14 (28.6%) of them. Almost half of the cases were operated on without histological confirmation for suspected malignancy. The histological diagnoses were fibrosarcoma (16), fibroleiomyosarcoma (10), leiomyosarcoma (6), rhabdomyosarcoma (7), hemangiopericytoma (3), epitheloid hemangioendothelioma (3), undifferentiated sarcoma (2), malignant schwannoma (1) and liposarcoma (2). Only 2 of the tumors were scored in grade 1. The rest were classified in higher grades of malignancy. The following operations were carried out: lobectomy--30 (59.2%), including 2 sleeve lobectomies; pneumonectomy--10 (20.4%), polysegmental resections--3 (6.2%) and atypical resection--1 (2%). The resections were extended to the thoracic wall, diaphragm or pericardium in 4 patients. Endoscopic laser resection was applied in 1 (2%) case. Exploratory thoracotomy was performed on 3 (6.1%) patients. There were 2 (4.1%) stage I A; 26 (53.1%) stage I B; 11 (22.4) stage II B; 5 stage III A; 4 stage III B and 1 stage IV. RESULTS: No postoperative death occurred. Postoperative empyema was observed in 2 cases (4.1%) and 1 patient (2%) was reoperated on for local recurrence 18 months after surgery. Adjuvant therapy was administered to 20 of the patients. Follow-up (range, 6 to 160 months) was available for 41 patients. The actuarial 5-year postoperative survival was 51.8% with mean survival of 40.8 months. CONCLUSION: The correct preoperative diagnosis of PPS still presents a challenge. There are no specific clinical, imaging and other signs for this tumor evaluation. Surgery with systematic lymphnode dissection is a treatment of choice with an acceptable 5-year survival rate. Only the complete resection and the low stages of the tumor significantly influence survival.

Hodgkin's disease incidence and survival in European children and adolescents (1978-1997): report from the Automated Cancer Information System project.

This paper reports the geographical patterns and time trends of incidence and survival of Hodgkin's disease (HD) in children and adolescents in Europe over the period 1978-1997. Data on 4230 HD cases were gathered from 62 paediatric or general cancer registries in 19 European countries by the Automated Cancer Information System (ACCIS). European annual incidence rates in 1988-1997 were estimated at 5.8 per million in children (world age-standardised) and at 29.7 per million in adolescents, with higher rates in the East and South. Incidence rates increased steeply with age, while the male predominance, marked for the youngest children, vanished in the highest age groups. Over the period 1978-1997 incidence rates increased in age groups 10-14 years (+1% per year) and 15-19 years (+3.5% per year), mainly due to the nodular sclerosis subtype. Age and sex distribution of cases remained unchanged with time. The overall 5-year survival rate was higher in children (93%, 95% confidence interval (CI) 92-94) than in adolescents (89% (95% CI 87-91)) for the period 1988-1997. Five-year survival increased significantly in all regions from 87% to 93% in children and from 80% to 88% in adolescents between 1978-1982 and 1993-1997. In future, detailed documentation of cases in the cancer registries with respect to standardised diagnostic subtypes, stage of extension, and treatments, will help to refine interpretation of international and temporal variations in incidence and survival.

Cancer incidence and survival in European adolescents (1978-1997). Report from the Automated Childhood Cancer Information System project.

Data on 15,399 adolescents diagnosed with cancer at age 15-19 years during 1978-1997 in Europe were extracted from the database of the Automated Childhood Cancer Information System (ACCIS). Total incidence in Europe as a whole was 186 per million in 1988-1997. Incidence among males was 1.2 times that among females. Lymphomas had the highest incidence of any diagnostic group, 46 per million, followed by epithelial tumours, 41 per million; central nervous system (CNS) tumours, 24; germ cell and gonadal tumours, 23; leukaemias, 23; bone tumours, 14; and soft tissue sarcomas, 13 per million. Total incidence varied widely between regions, from 169 per million in the East to 210 per million in the North, but lymphomas were the most frequent diagnostic group in all regions. Cancer incidence among adolescents increased significantly at a rate of 2% per year during 1978-1997. Five-year survival for all cancers combined in 1988-1997 was 73% in Europe as a whole. Survival was highest in the North, 78%, and lowest in the East, 57%. Five-year survival was generally comparable with that in the Surveillance, Epidemiology, and End Results (SEER) registries of the United States of America (USA), but for Ewing's sarcoma it was below 45% in all European regions compared with 56% in the USA. Survival increased significantly during 1978-1997 for all cancers combined and for all diagnostic groups with sufficient registrations for analysis.

Primary pulmonary sarcomas and carcinosarcomas--postoperative results and comparative survival analysis.

OBJECTIVE: To evaluate the early and long-term results after surgery for primary pulmonary sarcomas (PPS) and to compare them with those of patients with pulmonary carcinosarcomas (PCaSa). METHODS: During a 20-year period, 48 patients with PPS and 15 patients with PCaSa underwent surgery. There were 40 males and 23 females with a mean age of 52.1 years (range 13-78). The histologic diagnoses in PPS group were fibrosarcoma (15), fibroleiomyosarcoma (10), leiomyosarcoma (6), rhabdomyosarcoma (6), hemangiopericytoma (3), epitheloid hemangioendothelioma (3), malignant schwannoma (1), liposarcoma (1) and undifferentiated sarcoma (3). The following curative resections were carried out: lobectomy (36), including two sleeve lobectomies (in PPS group), pneumonectomy (15) and polysegmental resections (4). In four PPS cases, these procedures were extended to the thoracic wall, diaphragm or pericardium. An atypical resection was applied in one PPS patient (the tumor was falsely classified as benign on frozen section examination). Exploratory thoracotomy was performed in five of PPS patients (11%) and in two of those with PCaSa (13%). The majority of PPS patients were with low stages I and II (76%). The PCaSa patients were predominantly with stage IIIA (39%). RESULTS: No postoperative death was registered. Major complications included two localized empyemas (4.2%) in PPS and one reoperation for bronchial stump fistula (6.7%) in PCaSa groups. Local recurrences were operated on in one patient per group (2.1 and 6.7%, respectively). Follow-up was available on 57 patients and ranged from 4 to 148 months. The overall cumulative 5-year survival was 48.81% for PPS and 49.38% for PCaSa patients (P=0.9035). It was better in low vs. higher stage cases, statistically significant in PPS group (P=0.0005) and without significant difference in PCaSa cohort (P=0.11). CONCLUSIONS: Complete resection of PPS and PCaSa favors an acceptable survival, especially in low stages. There is no significant difference in the survival rates between PPS and PCaSa patients, despite the greater number of cases with higher stages in PCaSa group.

Diagnostic possibilities of the electroexcision and cold knife conization for precancerous lesions of the uterine cervix.

PURPOSE: The aim of the present study was to assess and compare the diagnostic possibilities of the loop electroexcision procedure (LEEP) and of conventional surgical conization of the uterine cervix in women with cervical precancerous lesions. PATIENTS AND METHODS: The study involved 80 women aged between 22 and 63 years (mean age 38.75 years), with cytological findings indicating various degrees of dyscaryosis. The patients were subjected to colposcopic targeted biopsy with subsequent (within 3 months) wide excision (40 patients with LEEP and 40 with cold knife conization). RESULTS: In both groups of women coincidence of the results to 1 degree of difference was found in 34 (85%) women. Analysis of the results obtained showed no statistically significant difference (p >0.05), both in the cases of full agreement as well as in the cases with 1 degree of difference, between the findings obtained by LEEP and surgical conizations on the one hand, and targeted biopsies on the other hand, as well as between the two excisional procedures. Also, no statistically significant difference between LEEP and surgical conization was found in comparing the frequencies of resection lines in healthy tissues and in the cases with visible squamous/ columnar junction (p= 0.418). At the same time, such a difference was found in comparing the cases with invisible junction (p= 0.0003), which was due to the cases with positive edges after LEEP. CONCLUSION: The results of the present study have evidenced the good possibilities of the LEEP and surgical conization as precision diagnostic tools in precancerous lesions of the uterine cervix. Based on the results obtained we think that LEEP has advantages in lower-grade lesions with visible boundary between squamous and columnar epithelium. In all other cases the method of choice should be surgical conization.

Epidemiological prognosis of cervical cancer in Bulgaria for the period 1997-2010.

PURPOSE: The aim of this study was to make a prognosis for the expected levels of the basic epidemiological indicators (incidence and mortality) of cervical cancer for the period 1997 through 2010, based on the surveillance data and the disease trends obtained during the screening activities performed so far (1970-1996). MATERIALS AND METHODS: The data we studied came from the National Cancer Registry and the Central Institute of Statistics. The statistical processing of all data was performed using the software package SPSS / + v.501 for Windows and the prognosis for the expected levels of incidence and mortality of invasive cervical cancer, and incidence of carcinoma in situ (CIS) were derived through extrapolation analysis. RESULTS: Based on these data, and on the assumption that all factors affecting the incidence and mortality rates will preserve their intensity and the direction of their impact, a fairly unfavourable prognosis of increase of these indicators was obtained, with levels of about 23.7 and 9.3 per 100,000 women yearly for incidence and mortality, respectively, at the end of the prognostic period, i.e. in 2010. For comparison, the actual incidence and mortality at the start (1970) of the screening program in our country were 12.1 and 3.9 per 100,000/year women, respectively. On the contrary, further decline of the CIS incidence rate (ranging between 3.1 to 6.6 per 100,000 women for the period 1970- 1996) is expected for the period 1997-2010, and the predicted level of this indicator at the end of the prognostic period was 2.15 per 100,000 women yearly. CONCLUSION: Based on the results of this study we conclude that an aggravating unfavourable tendency of both incidence and mortality for invasive cancer and of incidence for CIS can be expected for the period 1997-2010 should the situation of lack of cervical screening programs persists.

Bone marrow micrometastases as a prognostic factor in early breast cancer patients.

PURPOSE: To assess the prognostic significance of bone marrow micrometastases (BMMM) in patients with early breast cancer. PATIENTS AND METHODS: Cytological and cytochemical assessments of bone marrow aspirates were carried out on 100 patients with early breast cancer. The bone marrow was obtained by trephine biopsy or aspiration from both upper iliac crests during general anesthesia. The median follow-up period after surgery was 72 months. The statistical analysis of the data was carried out using the x(2) test and Kaplan-Meier univariate methodology. RESULTS: BMMM were found in 28 (28%) of all studied women. Bone metastases were proved in 13 (46.4%) of the 28 cases with BMMM within a period of 21 to 50 months after surgery (median 41.3 months). In the patients without BMMM, disease dissemination was diagnosed in 6 (8.3%) of them. In 3 (4.1%) cases bone metastases were proved, while in the other 3 (4.1%) pulmonary metastases were found. A significant relative risk (RR=11.43) of skeletal metastases occurrence with 95% confidence interval (95% CI) from 3.48 to 36.16 was established in patients with BMMM. Survival analysis of all 100 women showed an average survival period of 6.34 years for 95% of the patients (95% CI 6.20- 6.48). The difference in survival between the 2 groups with or without BMMM was not statistically significant. CONCLUSIONS: 1) The information of bone marrow status could be used as an additional prognostic criterion to identify a subgroup of early breast cancer patients with a high risk for development of bone metastases. 2) The detection of BMMM is an additional adverse prognostic factor, irrespective of tumour size and axillary node status and might be used to define the need of preventive therapy to reduce the incidence of bone metastases.

A study on the cervical epithelium of women in early pregnancy - histological findings and human papillomavirus characterization.

PURPOSE: To study the histological findings of the uterine cervix of women in early pregnancy and to compare them to a control group of nonpregnant women. In cases with morphology compatible with human papillomavirus (HPV) infection, DNA in situ hybridization (ISH) for the types 6, 11, 16, 18, 31 and 33 was performed. PATIENTS AND METHODS: The study involved 250 women, aged between 14 and 45 years (mean 26.5 years), of whom 166 were pregnant (up to 12 weeks of gestation, admitted for abortion), and 84 were nonpregnant. Target cervical biopsy was taken from all of them, and the biopsy spot was defined according to the presence of atypical colposcopic findings or from a preliminary chosen part. In the cases with histological results showing the presence of HPV infection (according to Reid criteria), DNA-ISH was carried out. The statistical processing of the obtained results was performed with the SPSS/PC + v.5.01 for Windows, the selected level for statistical significance being at p= 0.05. RESULTS: The histological findings from the material suitable for assessment showed morphology compatible for HPV infection in 29 (17.7%) pregnant and 11 (13.1%) nonpregnant women. At the same time, precancerous lesions with or without HPV infection were found in 43 pregnant women, of whom 40 (24.4%) with CIN I-II and 3 (1.8%) with CIN III, and in the group of nonpregnant women in 20, of whom 17 (20.2%) with CIN I-II and 3 (3.6%) with CIN III. Microinvasive cancer was detected in one patient of the control group. DNA-ISH was performed to all 54 women with histology compatible with HPV infection (33 pregnant and 21 nonpregnant). CONCLUSION: We believe that the significant difference of the histological findings between pregnant and nonpregnant women is basically due to the 4-fold higher incidence of normal findings in nonpregnant women and, to a lesser extent, to the higher frequency of HPV lesions and low grade CIN (I and II) in pregnant women. The distribution of the investigated viral types with DNA-ISH did not show any difference between the two investigated groups.

Nonmelanoma skin cancers and risk of subsequent malignancies: a cancer registry-based study in Bulgaria.

Analysis of new primary tumors following nonmelanoma skin cancers (NMSC) has a public health and risk assessment interest, as well as potential implications for etiologic inference. The aim of this study is to evaluate the risk of the second primary tumors occurrence after NMSC development. A cohort of 2620 cases (1335 males and 1285 females) with nonmelanoma skin cancers registered in Bulgarian National Cancer Registry in 1993 was examined. The follow-up period represented a total of 15,856 person-years at risk. Over this period 128 (83 in men, 45 in women) new secondary tumors were established. After NMSC appearance, both genders show higher risk for the second primary tumors occurrence. This risk is greater for men. For both sexes after NMSC development there is increased risk for occurrence of second primary cancers of head and neck, thyroid, lung, larynx, bladder, colon, as well as cutaneous malignant melanoma, non-Hodgkin's lymphoma and leukemias. The results of considering only basal cell carcinomas show an elevated risk in patients of both sexes for appearance of second primary tumors of head and neck, bladder, larynx, lung and colon as well as non-Hodgkin's lymphoma and cutaneous malignant melanoma. The results of considering only squamous cell carcinomas show an increased risk in persons of both sexes for development of second primary cancers of head and neck, skin, thyroid, lung, stomach, as well as leukemias, non-Hodgkin's lymphoma and cutaneous malignant melanoma. The association between NMSC and subsequent increased risk for appearance of second primary skin and visceral tumors determine the necessity of monitoring the patients with NMSC.

Control of acute emesis in repeated courses of moderately emetogenic chemotherapy.

PURPOSE: Cyclophosphamide (CY)-containing chemotherapy is usually characterized as moderately emetogenic. The aim of this study was to evaluate the efficacy of different antiemetics in the control of acute emesis in repeated cycles of moderately emetogenic chemotherapy. PATIENTS AND METHODS: A total of 101 patients with breast cancer (41, 40.6%), Hodgkin's disease (46, 45.5%) and non-Hodgkin's lymphoma (14, 13.9%) were studied. These patients received standard protocols of CY-based (>/=750 mg/m(2)) moderately emetogenic chemotherapy. Intravenous (i.v.) bolus metoclopramide (MCL), ondansetron (OND) and their combinations with corticosteroids (CS) were administered to the patients. The MCL-alone group of patients was used as control group. Emesis was evaluated during the first 3 courses of chemotherapy according to the internationally accepted criteria. All calculations were performed using the SPSS-5.0 statistical computing package. RESULTS: During the first course of chemotherapy no differences in the efficacy between the control group and the other groups were noted (p >0.05). On the contrary, during the next 2 courses the efficacy of MCL progressively decreased and OND, OND plus CS and MCL plus CS showed significantly higher efficacy compared with MCL alone (p <0.05). Excluding MCL alone, the other antiemetics showed similar efficacy in the 2nd and 3rd course of chemotherapy (p >0.05). Patients aged over 35 years had more severe emesis. CONCLUSION: The combination of MCL plus CS showed similar efficacy compared with OND and OND plus CS, and is cost-effective. The control of acute emesis in the first course and the patients' age are significant factors, influencing the efficacy of the antiemetic therapy in repeated courses of moderately emetogenic chemotherapy.

Post-immunisation gastritis and Helicobacter infection in the mouse: a long term study.

BACKGROUND AND AIMS: Helicobacter pylori is a major cause of peptic ulcers and gastric cancer. Vaccine development is progressing but there is concern that immunisation may exacerbate Helicobacter induced gastritis: prophylactic immunisation followed by challenge with H felis or H pylori can induce a more severe gastritis in mice than seen with infection alone. The aim of this study was to investigate the relationship between immunity to Helicobacter infection and post-immunisation gastritis. METHODS: (1) C57BL/6 mice were prophylactically immunised before challenge with either H felis or H pylori. Histopathology and colonisation were assessed one month post-challenge. (2) C57BL/6 mice were prophylactically immunised against H felis infection and gastritis assessed up to 18 months post-challenge. RESULTS: Prophylactic immunisation induced a reduction in bacterial colonisation following H felis challenge which was associated with increased severity of active gastritis with neutrophil infiltration and atrophy. However, immunised mice challenged with H pylori SS1 had little evidence of pathology. Long term follow up showed that post-immunisation gastritis was evident at three months. However, from six months onwards, although immunised/challenged mice still developed gastritis, there was no significant difference between inflammation in these mice and infected controls. Post-immunisation gastritis was not associated with the serum antibody response. Immunisation prevented the formation of secondary lymphoid aggregates in the gastric tissue. CONCLUSION: The H felis mouse model of post-immunisation gastritis is the most extreme example of this type of pathology. We have shown in this model that post-immunisation gastritis is a transient event which does not produce long term exacerbation of pathology.

Clinical stages of cutaneous malignant melanoma in Bulgaria.

The aim of the study was to investigate the distribution of the newly diagnosed cases with cutaneous malignant melanoma by clinical stages in Bulgaria over the period 1993-1995 as a reason for improving both mclanoma prevention and control. Over the period 827 new cases with cutaneous malignant melanoma are registered in the country. A representative sample of 671 cases has been taken. The cases with a localized melanoma (Stage I and II) were prevalent - 509 (75.8% of all studied cases). The thick melanomas (Stage IIB) were most frequently encountered among the primary lesions. They were 207 cases (30.8%). The thin melanomas (Stage IA) were only 41 (6.1%). The proportion of the cases with nodal and in-transit metastases (Stage III) -122 (18.2%) and the proportion of the cases with distant metastases (Stage IV) -40 (6.0%) were quite high. The analysis of the results shows that the cases with cutaneous malignant melanoma in Bulgaria are detected quite late. The cases with early-diagnosed melanoma are prevalent among women, young persons and urban population, and the cases with advanced melanoma are more frequent among men, persons older than 50 and rural population.

Dominant nonresponsiveness to Helicobacter pylori infection is associated with production of interleukin 10 but not gamma interferon.

Helicobacter pylori-induced gastritis is an essential precursor lesion for the development of peptic ulcers or gastric adenocarcinoma. We demonstrate that nonresponsiveness to H. pylori SS1 infection is dominantly inherited in mice. F(1) hybrid crosses between a nonresponder mouse and three responder strains all possessed the nonresponder phenotype. Secretion of interleukin-10 but not gamma interferon was associated with nonresponsiveness to infection.

Tolerance of half-body irradiation as systemic therapy for patients with locally advanced breast cancer.

BACKGROUND: Locally advanced breast cancer (LABC) is one of the main causes of cancer death among women in Bulgaria. In 1988, when this study started, there was still controversy about the role of chemotherapy in controlling systemic disease. There were encouraging results from the Radiation Therapy Oncology Group (RTOG) 82-06 study suggesting that half-body irradiation (HBI) should be used earlier in the disease course to prevent the development of metastases. There were many patients with LABC requiring treatment, but there was a problem with obtaining the drugs needed; they were expensive and not consistently available. PROCEDURE: Taking into account the medical contraindications to chemo-therapy treatment, its toxicity, and the possibility of chemoresistance, we initiated this study to look at the effects of HBI given as two fractions of 4 Gy to the upper and then lower parts of the body, after surgery and before local radiotherapy. RESULTS: The acute tolerance of this regimen in 36 patients with LABC was as good as it was in 4 additional LABC patients with M1 disease, and hematologic recovery was satisfactory. CONCLUSIONS: We conclude that systemic treatment with HBI is tolerable. It therefore may be a convenient and cost-effective treatment for LABC, although better treatments are still needed.

Murine splenocytes induce severe gastritis and delayed-type hypersensitivity and suppress bacterial colonization in Helicobacter pylori-infected SCID mice.

The goal of this study was to evaluate the role of host immunity in gastritis and epithelial damage due to Helicobacter pylori. Splenocytes from H. pylori-infected and uninfected C57BL/6 mice were adoptively transferred to H. pylori-infected and uninfected severe combined immunodeficient (SCID) mice. Transfer was verified by flow cytometry, and all mice were evaluated for the presence of delayed-type hypersensitivity (DTH) by footpad inoculation with sterile H. pylori sonicate and for humoral immunity by enzyme-linked immunosorbent assay. The severity of gastritis and gastric epithelial damage was quantified histologically, epithelial proliferation was determined by proliferating cell nuclear antigen staining, and colonization was quantified by culture. C57BL/6 mice, but not nonrecipient SCID mice, developed moderate gastritis in response to H. pylori. In contrast, recipient SCID mice developed severe gastritis involving 50 to 100% of the gastric mucosa and strong DTH responses not present in C57BL/6 mice. DTH, but not serum anti-H. pylori immunoglobulin G, correlated with adoptive transfer, gastritis, and bacterial clearance. Severe gastritis, but not bacterial colonization, was associated with epithelial metaplasia, erosions, and an elevated labeling index. This study demonstrates that (i) adaptive immunity is essential for development of gastritis due to H. pylori in mice, (ii) T-cell-enriched lymphocytes in SCID mice induce DTH and gastritis, which is more severe than donor gastritis, and (iii) the host inflammatory response, not direct bacterial contact, causes epithelial damage. The greater severity of gastritis in recipient SCID mice than in donor C57BL/6 mice suggests that gastritis is due to specific T-cell subsets and/or the absence of regulatory cell subsets in the transferred splenocytes.

Cancer incidence in Republic of Bulgaria aircrew, 1964-1994.

BACKGROUND: This study includes all cases of cancer among Republic of Bulgaria Air Force and civil aviation aircrew. Cancer incidence, Standardized Incidence Ratios (SIRs) and 95% confidential intervals were calculated for the pilots, using data about cancer incidence in the same age groups of the male population of the Republic of Bulgaria for the same period of time, taken from the National Cancer Register. RESULTS: The results show a considerable difference in the structure of cancer among males in Bulgaria, as compared to male pilots (r<0.0001). While cancer of the respiratory system has the greatest incidence among the civil population, cancer of the bladder has the greatest incidence among pilots, followed by testicular and skin cancer. For the period under consideration there is a lower risk of malignant diseases in pilots as compared to the rest of the population. There is a higher risk of testicular cancer only in civil aviation pilots. For Air Force aircrew there is a 10-fold higher risk of bladder cancer as compared to the rest of the population. CONCLUSION: We established an interdependence between age and cancer incidence, cancer incidence being higher among pilots in the age group from 20-40 yr. For the remaining age groups, cancer incidence among the civil population is approximately 2.5 times higher. Of the pilots with cancer, 73.53% returned to a flying career after an average of 7 mo treatment.

The role of gastric Helicobacter and N-methyl-N'-nitro- N-nitrosoguanidine in carcinogenesis of mice.

BACKGROUND: The aim of this study was to determine whether gastric epithelial proliferation due to gastric Helicobacter infection in mice represents a preneoplastic lesion. MATERIALS AND METHODS: Helicobacter heilmannii infected and uninfected mice were treated with 150 microg/ml N-methyl-N'-nitro-N-nitrosoguanidine in drinking water for either 20 or 38 weeks. Mice were killed 12 or 18 months after bacterial inoculation. RESULTS: All infected mice developed lymphoplasmocytic gastritis and epithelial hyperplasia. Proliferative gastric lesions were characterised by nodular hypertrophy of the glandular mucosa, multifocal epithelial hyperplasia, and elevated BrdU labeling index. Intestinal metaplasia and true atrophy were not present but proliferative glands were poorly differentiated, lined by mucus-type epithelial cells with no parietal, chief or other specialized cell types. Neoplasms developed only in MNNG-treated mice. of the 180 treated mice the following neoplasms developed: 14 squamous cell carcinomas of mouth and forestomach; 37 hemangiosarcomas of the intestinal serosa; and 15 splenic lymphomas. No tumors were present in the glandular gastric mucosa, and infection did not affect tumor incidence. p53 overexpression occurred in 79% of hemangiosarcomas and 71% of squamous cell carcinomas but not in normal or proliferative gastric glandular mucosa. CONCLUSIONS: Gastric proliferative lesions in Helicobacter-infected mice are not preneoplastic, and the combination of an alkylating agent and non-neoplastic proliferation does not result in gastric carcinogenesis in mice.