Effect of oxaliplatin-based chemotherapy on chemosensitivity in patients with peritoneal metastasis from colorectal cancer treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy: proof-of-concept study

Background

Chemosensitivity testing, including collagen gel droplet‐embedded culture drug sensitivity test, has proven to be a useful tool in therapeutic decision‐making. This retrospective analysis investigated chemosensitivity testing of peritoneal metastases collected during cytoreductive surgery (CRS), and its impact on survival in patients with colorectal cancer.

Methods

All patients with peritoneal metastasis from colorectal cancer who underwent CRS with or without hyperthermic intraperitoneal chemotherapy (HIPEC) between November 2008 and October 2014 were included. The growth inhibition rate was expressed as the ratio between the image density after treatment (T) and that before treatment (control, C). Tumours with a reduction in T/C ratio of less than 20 per cent were defined as resistant and those with a reduction of 20 per cent or more as sensitive. Groups were compared for overall (OS) and disease‐free (DFS) survival.

Results

Of 84 eligible patients, 81 received neoadjuvant chemotherapy (NACT), including 56 patients with an oxaliplatin‐based regimen. Mean(s.d.) follow‐up was 23·4(22·9) months. The median overall survival of all patients was 19·0 (i.q.r. 5·7–36·1) months, with a progression‐free survival time of 10·1 (4·5–17·0) months. Patients who received oxaliplatin‐based NACT had significantly altered chemosensitivity to oxaliplatin; only 20 of 51 such patients showed chemosensitivity to oxaliplatin compared with 16 of 24 who did not undergo oxaliplatin‐based NACT (P = 0·046). However, patients who showed chemoresistance to oxaliplatin had similar OS to those with chemosensitivity (18·8 versus 18·1 months; P = 0·835). The choice of HIPEC agents in patients who received oxaliplatin‐based NACT did not significantly influence survival (oxaliplatin versus mitomycin C: median OS 20·6 (10·9–24·8) versus 19·0 (10·5–34·6) months, P = 0·811; DFS 6·6 (2·8–25·7) versus 9·3 (4·1–13·9) months, P = 0·191).

Conclusion

Patients who had oxaliplatin‐based NACT showed a higher rate of chemoresistance to oxaliplatin at the time of CRS and HIPEC. The impact of chemosensitivity testing on OS remains unclear and needs further investigation.

Evaluation of international normalized ratios by a controlled field survey with 4 different thromboplastin reagents

A nationwide survey has been performed in Japan involving 75 laboratories to assess the relative reliability of different methods of reporting prothrombin time results in anticoagulant control. The interchangeability of results using prothrombin time, prothrombin activity percentage, prothrombin ratio and international normalized ratios (INR) were compared with four different thromboplastin reagents and a range of coagulometers. A secondary batch of reference thromboplastin of human brain origin (BCT/454) was used to calibrate the local thromboplastins and for comparison of methods of reporting. The study revealed the closest agreement of the results between BCT and the other reagents, and the regression lines of these reagents were almost identical, when the results were reported as INR. Box-Whisker plot analysis showed that the distribution of the results was large with the more deficient plasmas with all methods of reporting. It was found by this analysis that the interchangeability of the results was greatest when the results were expressed by INR, because the mean values obtained of each plasma using different thromboplastin reagents gave the lowest CV and the frequency of the far-out data was least, compared with the other methods of expression. On the other hand, the type of coagulometer had almost as much effect as the thromboplastin reagent on the prothrombin time, even if INR was used. Interchangeability of INR would be further improved by providing ISI values for each reagent/instrument combination.

Studies on B-cell memory. IV. Effects of lipopolysaccharide on primary and secondary antibody responses to T-independent type-2 (TI-2) antigen in mice

Effects of LPS on primary and secondary antibody responses to typical TI-2 antigens were investigated in mice. Simultaneous injection of LPS with a TI-2 antigen showed only little adjuvant effect on the following primary antibody response to the antigen. In contrast, either a single or multiple injections of LPS, prior to the immunization with a TI-2 antigen, significantly augmented the following primary antibody response to the antigen. LPS, however, inhibited the development of B-cell memory to a TI-2 antigen when administered together with the antigen. Moreover, an injection of LPS in mice, which had strong IgM and IgG B-cell memories to a TI-2 antigen, caused disappearance or profound reduction of the memories. The results suggest that LPS produced by gram-negative bacteria exerts inhibitory effects on the development and continuation of B-cell memory to bacterial infections.

Effects of different sample preparations on enumeration of large granular lymphocytes (LGLs), and demonstration of a sex difference of LGLs

Peripheral natural killer (NK) cells were identified by their morphologic appearance as large granular lymphocytes (LGLs) in a cytocentrifuged or spun blood film but not in thin wedge blood film. The authors studied the effect of different methods of sample preparation and staining on the enumeration of peripheral human LGLs as a routine test. In the blood film made from anticoagulated venous blood, LGLs were scattered in a field and sometimes deformed by compression of erythrocytes. In a blood film made from mononuclear cells, LGLs were shrunken, rendering it difficult to always identify cytoplasmic granules. In contrast, LGLs were easily and accurately identified in a blood film made from leukocyte-rich plasma, displaying none of the above artifacts. As well, the percentage of LGLs obtained was similar to that obtained from a blood film made from anticoagulated venous blood. In addition, May-Grünwald-Giemsa (MGG) stained azurophilic granules more clearly than did Giemsa above. As a result of these observations, a blood film that was made from leukocyte-rich plasma and that was stained by MGG was considered to be most suitable for the routine enumeration of LGL. Using this method, the authors found a significant correlation between the percentages of LGLs and Leu-7+ cells in the same subjects (r = 0.71; n = 22; P less than 0.001) and also a significant sex difference in the percentages of peripheral LGLs, which were significantly lower in women (17.0 +/- 3.6%; n = 35; P less than 0.05) than in men (19.5 +/- 5.3%; n = 20). Furthermore, the percentage of LGLs with abundant cytoplasmic granules, which might have greater NK activity, was also significantly lower in women (15.9 +/- 3.1%; n = 35; P less than 0.01) than in men (17.9 +/- 4.0%; n = 20).

Protein C in human plasma determined by homogeneous enzyme immunoassay with use of a centrifugal analyzer

We describe the simple and rapid enzyme immunoassay of protein C in human plasma with use of a Cobas Fara centrifugal analyzer. The antibody, labeled with horseradish peroxidase, is reacted with antigen (protein C) for 15 min. The peroxidase activity of the resulting antigen-antibody conjugate is measured at 500 nm for 5 min in the presence of excess H2O2, phenol, and 4-aminoantipyrine, as compared with that of free conjugates. Results are calculated from a stored standard curve and expressed as a percentage of the value determined for a pooled specimen of normal adult plasma. The standard curve is linear from 0% to 200%. The CV is generally less than 4% for different concentrations of protein C. In liver cirrhosis, hepatocellular carcinoma, therapy with warfarin, thrombosis, and disseminated intravascular coagulation, protein C concentrations are about 40-70% of normal. Results obtained with the present homogeneous enzyme immunoassay correlated well with those by enzyme-labeled immunosorbent assay (r = 0.97).

Protein C in human plasma determined by homogeneous enzyme immunoassay with use of a centrifugal analyzer

We describe the simple and rapid enzyme immunoassay of protein C in human plasma with use of a Cobas Fara centrifugal analyzer. The antibody, labeled with horseradish peroxidase, is reacted with antigen (protein C) for 15 min. The peroxidase activity of the resulting antigen-antibody conjugate is measured at 500 nm for 5 min in the presence of excess H2O2, phenol, and 4-aminoantipyrine, as compared with that of free conjugates. Results are calculated from a stored standard curve and expressed as a percentage of the value determined for a pooled specimen of normal adult plasma. The standard curve is linear from 0% to 200%. The CV is generally less than 4% for different concentrations of protein C. In liver cirrhosis, hepatocellular carcinoma, therapy with warfarin, thrombosis, and disseminated intravascular coagulation, protein C concentrations are about 40-70% of normal. Results obtained with the present homogeneous enzyme immunoassay correlated well with those by enzyme-labeled immunosorbent assay (r = 0.97).

Effect of aging on immunological memory in gastrointestinal tract induced by sheep red blood cells in mice

Tolerance induction by oral administration of sheep red blood cells (SRBC) was investigated in young and aged mice. Two-month old C3H/He mice receiving oral administration of 8 X 10(9) SRBC a day for two weeks became tolerant to a subsequent SRBC challenge in the systemic immune system. In contrast, older C3H/He mice aged about 1 year old receiving the same treatment did not become tolerant but resisted tolerance induction and produced a prominent IgG memory in the systemic immune system. Autoimmune-prone NZB mice showed a similar resistance to tolerance induction even at 3 months of age. To investigate a possible role of the liver in the oral tolerance induction, young (2-month old) C3H/He mice received an injection of 1 X 10(8) SRBC via portal vein. The mice thus treated, were not tolerized at all but immunized. The results suggest that gut-associated local immune system play a key role in the induction of the oral tolerance and that the tolerance inducing function of the local immune system declines with aging. Antigens in the gut including denatured self antigens may immunize the systemic immune system of aged animals.

Decrease of peripheral large granular lymphocytes in Graves' disease

Peripheral large granular lymphocytes (LGL) were enumerated in normal subjects and patients with autoimmune thyroid diseases. In normal subjects, the percentage of LGL was significantly lower in women (mean +/- s.d., 17.0 +/- 3.6%; n = 35; P less than 0.05) than in men (19.5 +/- 5.3%; n = 20). In untreated patients with thyrotoxic Graves' disease (GD), both the percentage (11.5 +/- 2.7%; n = 12; P less than 0.001) and the absolute count (244 +/- 102/mm3; P less than 0.01) of LGL were significantly lower than those in normal women (17.0 +/- 3.6% and 334 +/- 122/mm3; n = 35). No significant differences from normal controls were observed in the percentages or absolute counts of LGL in patients with euthyroid GD under treatment or in euthyroid or hypothyroid patients with Hashimoto's disease (HD). The percentage of LGL was inversely correlated with the serum levels of T4 and T3 and the free T4 index, but not with the titre of anti-thyroid antibodies, the size of goitre or the degree of proptosis in the group of untreated patients with GD and HD. The decreased levels of LGL in thyrotoxic patients with GD may be related to the self-perpetuation of thyrotoxicosis in patients with this disease.

Detection of DR antigen on leukemic cells from a patient suffering from adult T-cell leukemia and progressive systemic sclerosis

This report concerns an unusual case of adult T cell leukemia (ATL) complicated with progressive systemic sclerosis (PSS). The surface markers of peripheral blood mononuclear cells (PBM) and lymph node cells, both of which mainly consisted of leukemic cells, were examined. The effect of these cells on the pokeweed mitogen (PWM)-induced IgG synthesis by normal PBM also was studied. The leukemic cells formed rosettes with sheep red blood cells (SRBC; E) and expressed T cell antigen, Leu-1, and DR antigen. The detection of cell surface antigens was carried out by employing monoclonal antibodies against these antigens. We diagnosed this case as DR positive ATL. In terms of the immunoregulatory function of these leukemic cells, the co-culture experiments showed that these cells had some suppressive effect on the PWM-induced IgG production by allogeneic normal PBM.

Human cytotoxic T lymphocytes (CTL) induced by phytohemagglutinin: conditions for CTL generation and effect of interferon

The present study demonstrates that human peripheral blood mononuclear cells (PMC) can be stimulated in vitro to become cytotoxic T lymphocytes (CTL) by PHA. A significant cytotoxic activity of PMC was detected 48 hr after the culture initiation in the presence of 5 micrograms/ml of PHA and the peak level of the activity was obtained by culturing PMC for 72 hr. The cytotoxic cells require the presence of PHA as a cell agglutinin for the expression of their cytotoxic activity. The effector cells mediating the activity were identified as T lymphocytes by E-rosette fractionation of PMC. In this system, removal of carbonyl iron phagocytosed or attached cells from PMC did not abrogate CTL generation of PMC. In addition, human alpha-interferon did not augment CTL generation or expression of their activity. Although the target cells employed were sensitive to natural killer (NK) cells, the effector cells induced by PHA did not seem to have any relation to the NK cells. The present study may provide a useful tool to analyze for precursors of killer T cells.

Increase of peripheral B lymphocytes in Graves' disease

Peripheral T and B lymphocytes were examined in autoimmune thyroid diseases. The percentages of T and B lymphocytes were calculated from the proportions of E and EAC rosette-forming cells and peroxidase-positive cells determined by micromethods. In thyrotoxic Graves' disease, the percentage of T cells was significantly lower, and the percentage of B cells was higher than in normal controls. The absolute count of B lymphocytes was also markedly increased. The serum levels of thyroid hormones showed a significant correlation with the percentage of B cells and an inverse correlation with that of T cells in untreated cases of Graves' disease. Similar abnormalities of lymphocyte subpopulations were observed in patients with thyrotoxic Graves' disease under drug therapy, but the proportions and absolute counts of T and B lymphocytes were normal in euthyroid patients with Graves' disease, either under drug therapy or in remission. No abnormalities in T and B cells were found in Hashimoto's disease. The data indicate that the main feature of the abnormality of the lymphocyte subpopulations in thyrotoxic Graves' disease is an increase of B lymphocytes. The reasons for the discrepancy between our results and those of earlier reports and for the B cell abnormality in Graves' disease are discussed.

Endoscopic studies on the minute structures of colonic mucosa in the follow-up observation of ulcerative colitis

Thirty cases of ulcerative colitis were examined endoscopically by means of magnifying colonoscope with dye spraying method (the combined method), and their minute mucosal structures were classified into four categories endoscopically, which correlated well with the histological findings. By this procedure, it was easy to detect the subsidence of inflammation of the mucosa in the quiescent phase or to reveal the active inflammatory involvement of the bowel. Moreover, inspecting the minute changes of the colonic mucosa detected by the combined method, remission was more correctly decided and rigid control is contributing to the decrease in the recent rate of recurrence of ulcerative colitis.