Can the quality of colonic surgery be improved by standardization of surgical technique with complete mesocolic excision?

AIM: we analysed the influence of standardization of colon cancer surgery with complete mesocolic excision (CME) on the quality of surgery measured by the pathological end-points of number of harvested lymph nodes, high tie of supplying vessels, plane of mesocolic resection and rate of R0 resection. METHOD: One hundred and ninety-eight patients with colonic carcinoma who underwent radical surgery between September 2007 and February 2009 were divided into two groups, including those undergoing surgery before (93) or after (105) 1 June 2008, when complete mesocolic excision (CME) was introduced as standard in our hospital. RESULTS: The overall mean high tie increased from 7.1 (CI, 6.5-7.6) to 9.6 (8.9-10.3) cm (P<0.0001) and the mean number of harvested lymph nodes from 24.5 (22.8-26.2) to 26.7 (24.6-28.8) (P=0.0095). There were no significant increases in these end-points in open right hemicolectomy, and in laparoscopic sigmoid resection the number of lymph nodes did not increase significantly. The plane of mesocolic resection, the rate of R0 resection and the risk of complications did not change significantly. The median (range) length of hospital stay increased from 4 (2-62) to 5 (2-71) days (P=0.04). CONCLUSION: Standardization of colonic cancer surgery with CME seems to improve the quality of surgery without increasing the risk of complications.

Immunopathology of in situ seminoma.

In this study of the seminomatous human testis the composition, activity and apoptosis of lymphocytes infiltrating the immune-privileged seminiferous tubules with in situ seminoma were studied by immunohistochemistry and DNA fragmentation detection. Likewise the lymphocytes infiltrating the invasive seminomas were studied. The study showed equal numbers of CD4+ and CD8+ T cells and B cells, about 30% of the cells. Very few T gamma/delta and NK cells were present. The activity in terms of IL-2-R, FasL and perforin expression was low. Apoptosis of the lymphocytic cells was limited. No differences were observed between the lymphocytes in seminiferous tubules with in situ seminoma and the lymphocytes in invasive tumours. The study suggests that either specifically committed lymphocytes are not present or, if present, immune-suppressing mechanisms in addition to FasL may be working.

Validation of ultrasonography of the thyroid gland for epidemiological purposes.

Ultrasonography of the thyroid is often used in epidemiological surveys, thus thorough characterization of the interobserver variation of the different parameters obtained is important. Various methods have been used for measuring thyroid volume, and different formulas have been used for calculation of thyroid volume from the measured dimensions. In this article, two principles of thyroid volume measurement are described in detail: the wellknown method based on the three axes of each lobe and a new principle based on planimetry in two planes. The interobserver variation of the examination and the measuring procedure in itself were tested on 25 participants in a population study. A comparison of postmortem ultrasonography of the thyroid and results of an autopsy was performed. Good correlation and agreement between observers was found for thyroid volume (r = 0.98) and prevalence of thyroid nodules (kappa = 0.72), whereas echogenecity and echopattern showed little agreement. The correlation of thyroid volume by ultrasonography to autopsy results was satisfactory (r = 0.93), but the volume tended to be slightly underestimated even when using the formula pi/6(= 0.52)*length*width*depth. No major differences were found between the performance of the two principles of volume calculation. We conclude that when the measuring procedure is well defined, results of ultrasonography are comparable between observers for thyroid volume and prevalence of thyroid nodules, but not for echogenecity or echopattern. The formula of length*depth*width*pi/6 is suitable for thyroid volume measurement.

Evaluation of pneumonia diagnosis in intensive care patients.

The aims of this study were to investigate the frequency of bronchopneumonia diagnosed by histological criteria among autopsied intensive care unit (ICU) patients and to compare these with rates of pneumonia diagnosed by conventional clinical methods. The study material comprised 141 autopsied ICU patients from 7 ICUs in university hospitals in Copenhagen from a 1-y period. A total of 20 lung tissue specimens were sampled from each patient and the histopathological diagnoses were classified as no, mild, moderate or severe bronchopneumonia. Inter-observer variation was calculated using kappa statistics. Demographic data and diagnoses of pneumonia were registered from the patient files. Twenty-six percent of the patients had pneumonia diagnosed whilst in the ICU. Histological evidence of pneumonia, found for every second patient, was regarded as the gold standard. Diagnosis of pneumonia in the ICU had a sensitivity of 29% and if diagnoses of pneumonia during the month before ICU-admission were included, a sensitivity of 60% was found. Specificity for pneumonia diagnosed in the ICU was 77%. The percentage of all ICU-patients with pneumonia was calculated to be between 36% and 56%, depending on the extent of excess mortality attributable to pneumonia. Pulmonary segments with histologically diagnosed pneumonic lesions were distributed diffusely, although the upper segments tended to be affected less. Nearly all patients had other histopathological findings than bronchopneumonia. The reliability coefficient among the 6 pathologists was found to be moderately good (kappa = 0.45).

Immunohistochemical investigation of p53 and EGFR expression of oligodendrogliomas.

The biological behavior of oligodendrogliomas is somewhat unpredictable. A supplementing prognostic factor is, therefore, desirable. Thirty-two supratentorial pure oligodendrogliomas were studied immunohistochemically by exposing the tumors to a monoclonal antibody towards the p53 protein, and a polyclonal antibody against the epidermal growth factor receptor (EGFR). A mean p53 labeling index (% of tumor cells stained) of 8.6% and a weak EGFR expression in 18 of the oligodendrogliomas were found. Univariate analysis showed no correlation between p53, EGFR expression and prognosis. Multivariate analysis showed that age was a prognostic factor for survival.

Fas and Fas-ligand expression in seminomatous testes.

Sixteen seminomas with surrounding tissue containing normal and precancerous (cis) seminiferous tubules were examined for the expression of Fas (CD95, APO-1) and Fas ligand (FasL) (CD95L). This was done by analyzing frozen specimens using immunohistochemistry with antibodies directed against Fas and FasL. The study showed that varying numbers (mean approx. 20%) of Fas-positive lymphocytes were present among tumor-infiltrating lymphocytes, but very few FasL-positive lymphocytes. Fas was not expressed by normal seminiferous tubules and only occasional Fas-positive epithelial cells were seen in cis tubules. FasL was expressed in 9 out of 10 cases in virtually all normal seminiferous tubules, mainly as a thin layer at the base of the seminiferous epithelium. In precancerous tubules, this layer was discontinuous and less pronounced. Rete testis expressed FasL in 2 out of 2 cases with rete present and Fas in 1 out of 1 case. Invasive tumor cells did not express Fas or FasL. The data are discussed in relation to immune reactions to seminomas and to the concept of the testis being an immunologically privileged area.

Intrinsic radiosensitivity of human pancreatic tumour cells and the radiosensitising potency of the nitric oxide donor sodium nitroprusside.

A panel of eight human pancreatic tumour cell lines displayed high intrinsic radioresistance, with mean inactivation doses between 2.4 and 6.5 Gy, similar to those reported for melanoma and glioblastoma. The radiosensitising potency of sodium nitroprusside, a bioreductive nitric oxide donor, was assessed in a model of metabolism-induced hypoxia in a cell micropellet. Sodium nitroprusside at 0.1 mM revealed a radiosensitising effect with an overall enhancement ratio of 1.9 compared with 2.5 for oxygen. Radiosensitising activity correlated with the enhancement of single-strand DNA breakage caused by radiation. In suspensions with cell densities of between 3% and 30% (v/v), the half-life of sodium nitroprusside decreased from 31 to 3.2 min, suggesting a value of around 1 min for micropellets. Despite this variation, the radiosensitising activity was similar in micropellets and in diluted cell suspensions. S-nitroso-L-glutathione was found to possess radiosensitising activity, consistent with a possible role of natural thiols in the storing of radiobiologically active nitric oxide adducts derived from sodium nitroprusside. As measured by a nitric oxide-specific microsensor, activation of sodium nitroprusside occurred by bioreduction, whereas S-nitroso-L-glutathione showed substantial spontaneous decomposition. Both agents appear to exert radiosensitising action through nitric oxide as its scavenging by carboxy phenyltetramethylimidazolineoxyl N-oxide (carboxy-PTI0) and oxyhaemoglobin resulted in attenuated radiosensitisation. Sodium nitroprusside was at least 10-fold more potent than etanidazole, a 2-nitroimidazole used as a reference. Our data suggest that sodium nitroprusside, a drug currently used for the treatment of hypertension, is a potential tumour radioresponse modifier.

Immortalization of Syrian hamster embryo cells: probabilistic event or deterministic process.

Previous findings on the induction of immortalization in SHE cells have been explained with the activation/alteration hypothesis which postulates that treatment with a carcinogen results in the induction of a so-called "activated state" which enhances the rate of a probabilistic event in the progeny of the treated cells. This event is supposed to be a mutation. Because it has been recently indicated that in mammalian cells the switching on of signal transduction pathways by 12-O-tetradecanoyl-phorbol-13-acetate (TPA) or carcinogens can lead to genetic instability in the progeny of the treated cells, the possibility of an analogy between the induction of genetic instability and induction of immortalization after treatment with TPA was investigated. No effect of TPA was found on the rate of immortalization/cell/generation, not in otherwise untreated cells nor in cells treated with benzo(a)pyrene. TPA was found to enhance the life span of SHE cells. The life span of a culture correlated with its growth rate and its cell density at confluence both in the absence and presence of TPA. These correlations are supposed to reflect a regulation mechanism involved in the program of cellular senescence, and supposedly TPA can partly reverse this program. Treatment with benzo(a)pyrene also interferes with the life span resulting in premature senescence in most of the cells and extension of life span in a small fraction of the cells which subsequently can become immortal. Repeated switching from logarithmic growth to G0 also enhanced life span and rate of immortalization. The findings indicate that the activated state is a disturbance of a differentiation program affecting in SHE cells the program of cellular senescence and that, as an explanation for immortalization, epigenetic alterations causing a deterministic process of dedifferentiation in a subpopulation of the cells appear as plausible or perhaps even more plausible as a probabilistic mutation. This indicates that disturbance of differentiation might be among the causes of genetic instability.

Immortalization of carcinogen-treated Syrian hamster embryo cells occurs indirectly via an induced process.

The hypothesis that rodent cells can be immortalized by the direct induction of a single mutation-like event was tested by initiating cultures of benzo(a)pyrene treated Syrian hamster embryo cells with low inocula and expanding these few cells maximally until senescence prevented further culturing or immortalization took place. According to the mutation hypothesis immortalization is hardly to be expected under these conditions. However, immortalization was frequently observed. Therefore the induction of immortalization appears indirect. The progeny of benzo(a)pyrene treated cells immortalized with a rate of 3.9 x 10(-8)/cell/generation, which is 64 times higher than the spontaneous rate. The results are in line with the probabilistic theory developed in 1980 by both Fernandez et al. (Proc. Natl. Acad. Sci. USA, 77: 7272-7276, 1980) and Kennedy et al. (Proc. Natl. Acad. Sci. USA, 77: 7262-7266, 1980), which states that treatment of cells with a carcinogen can result in a so-called activated state of the treated cells which is transmitted to the progeny and which results in an enhanced rate of transforming events.

Immortalization of Syrian hamster embryo cells is in itself a multistep event.

The hypothesis that induction of immortalization of rodent cells follows one-hit kinetics was tested by the determination of frequencies of immortalization of Syrian hamster embryo cells after treatment with benzo(a)pyrene, X-rays, or ethylnitrosourea. Contrary to expectation, immortalization did not occur in a single step. Full immortalization appeared to be a process which required at least three steps: extension of life span (step 1), increase in cloning efficiency (step 2), and increase in growth rate (step 3). These three steps occur in this fixed sequence. The first step appears to be induced by the carcinogenic treatment, while the two other steps occur spontaneously in the progeny of cells which underwent the first step. The frequency of induction of the first step is in the order of magnitude of mutation induction, which suggests that mutation in one allele of a limited number of loci is sufficient to initiate the process of immortalization. However, the spontaneous frequency of immortalization is below 2.4 x 10(-9)/cell/generation, which appears to be too low for a spontaneous mutation frequency. The frequencies/cell/generation of the second and the third step are in the order of magnitude of spontaneous mutation frequencies.