Effect of pre-operative oral paracetamol on gastric residual volume and pH in young children in the context of a 1-hour clear fluid fast: a randomised controlled trial.

High gastric residual volume and low pH are associated with increased mortality following pulmonary aspiration in animal studies. The use of pre-operative oral paracetamol has not been investigated in younger children and infants in the context of a prescriptive 1-h clear fluid fast aimed at reducing the risk of pulmonary aspiration while improving patient experience. Children aged 1 month up to a weight of 25 kg and scheduled for elective surgery were randomly allocated to receive a prescribed 3.6 ml.kg-1 drink of water alone (water group) or 3 ml.kg-1 water and oral Infant Calpol® syrup (24 mg.ml-1 concentration, equivalent volume 0.6 ml.kg-1 , paracetamol group) 1 h before the induction of anaesthesia. Following induction, a nasogastric tube was used to aspirate gastric contents and the volume and pH were recorded. Ninety-seven children, median (IQR [range]) age 24 (12-45 [1-96]) months and weight 12.4 (9.7-16.0 [2.9-27.0]) kg, were analysed. Median time from drink to induction was 54 (45-60 [21-113]) min. There was no significant difference in gastric residual volume (p = 1) or pH (p = 0.99) between the water and the paracetamol groups. Sub-group analysis revealed no significant difference in gastric residual volume or pH for 29 children who weighed < 10 kg compared with > 10 kg. Using a prescriptive fluid regime of 3 ml.kg-1 of water, the addition of oral paracetamol syrup did not significantly alter gastric residual volume or pH in the context of a 1-h fast in infants and young children.

Further observations on the inhibition of tumor growth by Corynebacterium parvum with cyclophosphamide. I. Variation in administration of both agents.

Studies from this laboratory have indicated that the administration of cyclophosphamide (CY) and Corynebacterium parvum (CP) over a prolonged time to C3H mice with established measurable tumors resulted in complete arrest of tumor growth as well as partial and complete regressions in many instances. The present investigations on optimal dosage, route, frequency, and sequence of administration of CY and CP in the model system were performed to obtain information that could be useful in the design of chemotherapeutic and immunotherapeutic regimens for the treatment of human tumors. Findings have suggested the need for administration of CP in more than one instance. Although a single dose of CP in combination with weekly injections of CY had a significantly prolonged inhibitory effect, weekly doses of CP and CY were more effective. We also concluded that the time between doses of an immunostimulating agent (I-I interval) as well as between administration of chemotherapy (C-C interval) may be critical for an optimal result. In this model system, C-C and I-I intervals of 7 days inhibited tumor growth most effectively. The time between administration of chemotherapy and immunotherapy (C-I interval) has been considered critical. Whereas slightly better results were achieved in these studies when the immunotherapy was administered 4 days after the CY or when the C-I interval was +4 days, almost equally good results were obtained when both agents were given on the same day, which signified that the C-I interval may not be as critical as other investigators have reported. The present findings confirmed and extended our prior observations and indicated that the iv and ip routes of administration were superior to the im and sc routes in our model. The observed tumor growth inhibition was a result of both chemotherapeutic and immunotherapeutic modalities; also, the inhibitory properties of the regimen were more related to the chemotherapeutic component. Finally, almost identical tumor growth inhibition was observed when CP obtained from two different laboratories was used in conjunction with CY.

Further observations on the inhibition of tumor growth by Corynebacterium parvum with cyclophosphamide. II. Effect of cortisone acetate.

Studies from this laboratory have demonstrated that the administration of cyclophosphamide (CY) and Corynebacterium parvum (CP) over a prolonged time to C3H mice with established measurable tumors resulted in complete arrest of tumor growth as well as partial and complete regressions in many instances. A study of the effect of two different doses of cortisone acetate (CA), administered two or five times weekly, on the tumor inhibitory properties of this chemoimmunotherapeutic regimen indicated that the addition of a corticosteroid to the CY-CP combination did not alter its tumor-inhibitory properties. There was no significant change when CA was administered with CP; however, tumor inhibition was enhanced to a degree approaching statistical significance when CA was added to CY at dose levels of 1.5 and 2.5 mg twice weekly. These results demonstrated that it may be possible in treatment of humans to administer a steroid in combination with a chemoimmunotherapeutic regimen without inhibition of the regimen's antitumor effects.

Cellular cytotoxicity in tumor-bearing mice after transfer of normal or tumor-sensitized lymphoid cells.

The present investigations are a continuation of those indicating that the administration to normal inbred C3HeB/-FeJ mice of syngeneic tumor-sensitized cells or cells from F344 Mai rats (xenogeneic) sensitized to mouse tumor imparted "information" that resulted in the production of tumor-specific cytotoxic cells by recipients. Current findings revealed that normal but not tumor-sensitized spleen cells when transferred to syngeneic tumor-bearing recipients enhanced the cytotoxicity ofrom F344 Mai rats (xenogeneic) sensitized to mouse tumor imparted "information" that resulted in the production of tumor-specific cytotoxic cells by recipients. Current findings revealed that normal but not tumor-sensitized spleen cells when transferred to syngeneic tumor-bearing recipients enhanced the cytotoxicity of lymphoid cells in the recipients. This enhanced cytotoxicity was specific for the immunizing tumor. Inoculation of normal or tumor-sensitized lymph node cells failed to produce such an effect. Our present and previous findings suggested that in the presence of a tumor, uncommitted cells that reside in the spleen and that are available for recruitment and "instruction" may become depleted, whereas no comparable deficit may exist in cells that are capable of information transfer.

Cellular cytotoxicity and serum inhibition in normal mice following transfer of syngeneic tumor-sensitized cells.

Investigations were performed to elucidate changes in normal syngeneic recipients after they received tumor-sensitized cells. Transfer of regional or nonregional lymph node cells or spleen cells from tumor-bearing inbred C3HeB/FeJ mice to normal syngeneic recipients caused the recipients to produced bone marrow, which mediated in vitro cytolysis of immunizing tumor target cells. This finding was not entirely limited to transfer of lymphoid cells. The transfer of myeloid cells, granulocytes, and cultured macrophages from tumor-bearing mice also produced cytotoxic cells. The extent of cytotoxicity following cell transfer was related to the duration of tumor growth in cell donors, to the degree of cytotoxicity, and to the number of cells transferred. Both the iv and ip routes were equally effective. Treatment of cells before transfer with trypsin or pronase, mitomycin C, or sublethal irradiation failed to prevent development of cytotoxicity in cells of the recipient, whereas freeze-thawing abolished this event. Serum from the cell recipient could inhibit the cytotoxicity demonstrated by lymphoid cells derived from the recipient or from a tumor-bearing animal. The findings indicate that "information" transferred to normal animals not previously exposed to a tumor results in production of tumor-specific cytotoxic cells in these animals.

Interrelation between tumor cell proliferation and 17-fluoresceinated estrone binding following primary tumor removal, radiation, cyclophosphamide, or tamoxifen.

The proportion of single intact viable mouse mammary tumor cells containing estrogen receptor (ER) as determined by 17-fluoresceinated estrone binding and the proportion labeled with [3H]thymidine (LI) have been assessed in the same cell population after either primary tumor removal, radiation, cyclophosphamide, or tamoxifen administration. Subsequent to tumor removal, the increase in LI occurring in a cell population from a residual tumor focus was associated with a concomitant decrease in the proportion of cells demonstrating 17-fluoresceinated estrone binding (fluorescence). As the level of LI in the tumor focus returned to that observed prior to tumor removal, the proportion of ER-containing cells simultaneously reverted to its original value. Following cyclophosphamide administration, there was a decrease in tumor LI and a concomitant elevation in the proportion of fluorescent cells which were dose related. The prolonged depression in LI following radiation was accompanied by a sustained increase in the proportion of ER-containing cells. Thus, the change in ER-containing cells was related to the alteration of the proliferating cell population by the various therapies. The findings support the thesis that fewer cells in the growth fraction of the tumor studied contain ER than in the nonproliferating cell pool. Following tamoxifen administration, a decrease occurred in the proportion of fluorescing cells due to competitive binding. There was no alteration in LI. This observation is not in conflict with the thesis that there is a correlation between ER and LI since the mechanism for reduction in detectable ER is different. These studies provide additional support to the credibility of the use of 17-fluoresceinated estrone binding for the determination of ER in individual tumor cells. They also indicate the usefulness of the method for obtaining biological information regarding tumor ER which cannot be obtained with the use of conventional biochemical analyses.

Influence of the interval between primary tumor removal and chemotherapy on kinetics and growth of metastases.

In many animal models, primary tumor removal produces increased proliferation of cells in metastatic foci. The present investigations using a murine mammary tumor were carried out to determine how a variation in the time interval between primary tumor removal and administration of a single dose of cyclophosphamide (CY) affected labeling indices of residual tumor cells, their growth, and animal survival. The CY (240 mg/kg) had a more favorable effect when given on the day of tumor removal than 3 days after, a time when the labeling index (LI) of metastases was at a peak. It was least effective if given at 7 days following primary tumor excision, when the LI had returned to the preoperative level. The greatest effect occurred when the CY was given prior to operation. It completely prevented the increase in LI resulting from tumor removal, more effectively suppressed the growth of residual tumor, and prolonged survival to a greater extent than was noted under any other circumstance. The interval between tumor removal and administration of a relatively small amount of CY (60 mg/kg) was critical. When given on the day of tumor removal, an increase in LI of the residual focus occurred which was greater than that occurring as a result of tumor removal. When given 3 days after tumor removal, the smaller dose was almost as effective in suppressing LI as was the larger. From a kinetic standpoint, there was no advantage in reducing the tumor burden prior to the use of chemotherapy. The tumor response in this model suggests that, for the most effective control of metastases, the largest tolerable dose of chemotherapy would best be used at the time of or before primary tumor removal. The results provide a biological rationale for the use of perioperative adjuvant chemotherapy.

Relation of estrogen and its receptor to rat liver growth and regeneration.

A variety of hormones have been implicated in the process of liver regeneration. Despite the demonstration of specific estrogen receptors (ER) in mammalian liver and the identification of responses to estrogen which occur in liver, there has been little or no investigation of the relation of that hormone or its receptor to liver regeneration or liver growth. This report provides information which indicates: (a) the effect of 17 beta-estradiol on the mass of both intact and regenerating rat liver; (b) the percentage of hepatocytes in neonatal and adult normal intact livers which contain ER, i.e., the estrogen receptor index (ERI); (c) changes in ERI and in nuclear ER occurring in that cell population following partial hepatectomy (PH) and/or 17 beta-estradiol administration; and (d) the temporal relation of the changes in ER with those related to DNA synthesis and liver regeneration and to liver growth. Approximately 55 to 60% of parenchymal cells from intact livers in adult rats were found to contain ER which was entirely located in the cytoplasm. No nuclear ER was evident in such cells. By 1 hr, and subsequently following 17 beta-estradiol administration to such animals, there resulted a depletion in the number of ER-containing cells and the identification of nuclear ER. These changes were followed by the onset of increased DNA synthesis and an increase in liver weight (p less than 0.001). Subsequent to 70% PH, a similar series of events occurred in liver remnants. Not only was there a decrease in the ERI from 60% at the time of PH to 40% 3 hr later and 30% after 72 hr, there was a decrease in cytosol ER as well. Accompanying the decrease was an increase in the number of cells with nuclear ER. By 24 hr post-PH, 29% of the cells with ER displayed that receptor in their nuclei. At that time, DNA synthesis was at its peak, and liver regeneration was taking place. When 17 beta-estradiol was administered at the time of PH, there was a more rapid onset of translocation of ER to the nuclei of parenchymal cells. At PH, when 17 beta-estradiol was given, no cells displayed nuclear ER. One hr later, 18% of cells with ER had nuclear ER, in contrast to the finding that only 3% of cells had nuclear ER 1 hr post-PH when 17 beta-estradiol was not administered. Regeneration was greater (59 versus 73%; p = 0.003) when animals received 17 beta-estradiol prior to PH.(ABSTRACT TRUNCATED AT 400 WORDS)

The effect of a growing tumor and its removal on the cytotoxicity of macrophages from cultured bone marrow cells.

Previous investigations by us have demonstrated that there is a significant but transient (4 to 14 days) increase of colony-forming cells (CFC) in bone marrow following implanation of a syngeneic mammary tumor in C3H mice. Those CFC gave rise to enhanced macrophage colony production when cultured in semisolid medium. The present studies have for the first time demonstrated that macrophages from the colonies were cytotoxic to cells from the immunizing tumor, and they continued to possess that characteristic for as long as a tumor was present in the animal from which bone marrow was derived. By 21 days after tumor removal cytotoxicity was no longer evident. The findings provide evidence to suggest that the cytotoxicity displayed by the macrophage originates in its ancestral CFC or in the antecedent stem cell. They also suggest that receptor sites of the CFC (or stem cell) that respond to a stimulus for self-replication are probably different from those sites that, when activated, result in cytotoxic properties of their progeny. The present findings also indicate not only that quantitation of macrophage production is of relevance in determining the efficacy of a therapeutic regimen but also that knowledge concerning the specific properties, i.e., ctytotoxicity, of such cells is of equal or greater importance.

The effect of Corynebacterium parvum in combination with 5-fluorouracil, L-phenylalanine mustard, or methotrexate on the inhibition of tumor growth.

Previous reports from this laboratory have demonstrated conclusively that cyclophosphamide administered asynchronously with Corynebacterium parvum (CP) results in greater C3H mammary tumor inhibition than that observed with either agent alone. An analysis of this combination has revelaed that the chemotherapeutic component contributes more significantly to tumor inhibition than does the immunotherapeutic one. This study was conducted to investigate the inhibition of C3H mammary tumors by other chemotherapeutic agents when used with CP. The results have demonstrated that 60 mg of cyclophosphamide per kg, 90 mg of 5-fluorouracil per kg, and 10 mg of L-phenylalanine mustard per kg administrated weekly have similar tumor-inhibiting properties. The addition of CP enhanced the tumor-inhibiting properties of each agent but to differing degrees. The effect of the immunopotentiator when used in combination with alkylating agents was greater than that seen when it was used with the antimetabolite 5-fluorouracil. The tumor inhibition observed when cyclophosphamide was administered asynchronously with CP was significantly greater than that observed when L-phenylalanine mustard was similarly used. Of particular interest was the finding that the addition of CP to a combination of chemotherapeutic agents resulted in no greater tumor growth inhibition than that which occurred when CP was used along with the most effective single agent in the combination. The data have indicated that, contrary to clinical impression, there is no evidence that CP through its toxicity-sparing effect permits the utilization of larger doses of chemotherapy. Consideration has been given to the mechanisms that might account for the differences in tumor growth inhibition encountered when CP was used with different chemotherapeutic agents.

Effect of surgical removal on the growth and kinetics of residual tumor.

Findings from this study using a transplantable C3H mammary tumor failed to indicate interaction relative to growth parameters between two foci present in the same host. Whether they were growing alone or in the presence of a second focus, tumor growth rates were similar until the combined mass of multiple tumors approached that which was incompatible with survival. Only then was a difference in growth observed. Cytokinetic parameters, i.e., labeling index, primer-dependent DNA polymerase index or growth fraction, DNA synthesis time, tumor doubling time, and cell cycle time, were also similar whether tumors grew alone or in the presence of a second focus. Following removal of a tumor, changes were observed within 24 hr in the kinetics of the residual focus. There was an increase in labeling index (duration approximately equal to 10 days) and primer-dependent DNA polymerase index with a decrease in the tumor doubling time. Minimal change was noted in DNA synthesis time and cell cycle time. The kinetic changes observed were reflected in a measureable increase in tumor size approximately equal to a week following tumor removal. Absence of an alteration in DNA synthesis time and cell cycle time indicates that the increase in tumor growth was probably due to a conversion of noncycling cells in G0 phase into proliferation. Relationship of the findings to the use of adjuvant chemotherapy is considered.

Correlation of antitumor chemoimmunotherapy with serum inhibition of tumor cell destruction.

The administration of cyclophosphamide and Corynebacterium parvum in combination results in tumor growth inhibition greater than that resulting from the use of either agent alone. The precise mechanism(s) by which this chemoimmunotherapy combination results in a synergistic inhibiting effect is not known. The possibility was entertained that the tumor effect might be related to a greater decrease in serum-mediated interference with cellular cytotoxicity, i.e., "blocking" activity, by both agents in combination rather than by either alone. The present findings fail to support such an explanation. C. parvum by itself failed to decrease serum inhibition and in conjunction with cyclophosphamide resulted in an effect that was no greater than that produced by cyclophosphamide alone.

Presence of a growth-stimulating factor in serum following primary tumor removal in mice.

The effect of removal of a primary tumor on the kinetics of cells in a metastasis was evaluated using six different tumors (C3H, MXTa, MXTb, MC54, CD8, and 3LL) which varied relative to their origin, histology, and the strain of mice in which they were carried. There was an increase in the labeling index (LI) of distant tumor focus ("metastasis") associated with the removal of each of the tumor types and unrelated to operative and anesthetic trauma. Information presented supports the presence of a serum growth factor as being responsible for the phenomenon. Serum obtained from mice following removal of a tumor, when transferred to a recipient with the same type of tumor as in the donor, resulted in an increase in the LI of the tumor. Multiple injections of serum failed to add to the increase but did prolong its presence, suggesting that there is a finite population of cells, most likely in the G1-G0 phase, which are capable of responding to the stimulating factor. The transfer of serum obtained following removal of a tumor type different from that in recipients resulted in findings which indicate that tumors producing a stimulating growth factor are those capable of responding to it. Serum obtained from animals with unremoved tumors or less than 18 h after removal failed to substantially augment the LI of tumors in recipients. It is postulated that the growth factor released by a tumor is in an inactive form which becomes activated over time. Observations indicate that medium conditioned by the growth of C3H tumor contains a growth-stimulating factor which is capable of increasing the LI of a C3H tumor in a recipient in a fashion similar to that obtained following tumor removal. That finding indicates the capability of the tumor to elaborate growth-stimulating material which may be similar to that found in serum. The findings presented refute the premise that removal of a primary tumor is a local phenomenon with no other biological consequences. They indicate that, following primary tumor removal, metastatic behavior may be affected by an interplay of growth factor(s) which can influence the outcome of a host to its tumor.

Effect of local or systemic treatment prior to primary tumor removal on the production and response to a serum growth-stimulating factor in mice.

This report indicates that not only does the preoperative administration of cyclophosphamide or radiation prevent the kinetic changes observed in a distant tumor focus following tumor removal but that the preoperative administration of the antiestrogen tamoxifen and the luteinizing hormone-releasing hormone analogue Zoladex are equally effective in that regard. It also provides evidence indicating that serum obtained from mice treated with those therapies when transferred to a recipient bearing a tumor of a similar type to that in the donor fails to stimulate DNA synthesis in the tumor of the recipient. In contrast, an increase in labeling index occurs following transfer of serum obtained following tumor removal from untreated mice. Moreover, when tumor-bearing mice were treated by each of the four modalities prior to receiving serum obtained from untreated donors following removal of a tumor, no kinetic changes were observed in the tumor of the serum recipient.

Influence of irradiation of a primary tumor on the labeling index and estrogen receptor index in a distant tumor focus.

The present investigation reaffirms our observation that removal of a C3H mouse mammary adenocarcinoma results in a perturbation of tumor cells in a metastatic focus. An increase occurs in the proportion of cells undergoing DNA synthesis (labeling index, LI), and a decrease occurs in the proportion demonstrating estrogen receptor (ER index; ERI). The changes are transient but of sufficient duration and magnitude to produce an increase in the size of a distant tumor. This study was conducted to determine whether cytoreduction of a primary tumor by irradiation would produce a similar change in metastatic tumor cells and whether preoperative radiation would obtund the effect of primary tumor removal. The administration of a maximum tolerated dose of radiation (50 Gy) to a primary tumor produced a significant (p less than 0.001) increase in LI and decrease in ERI of a lesser magnitude than that observed following surgical removal of the primary tumor, but still sufficient to enhance the growth of a metastatic focus. Whereas, there was almost a 50% increase in LI in a metastasis 1 and 3 days following removal of a primary tumor the increase was only 13% three days after radiation. There was a 20% decrease in ERI 3 days following radiation and a 37% decrease at that time following tumor removal. Preoperative irradiation of a primary tumor 1, 3, or 5 days prior to tumor removal, obtunds the increase in LI and decrease in ERI following operation. Radiation the day before surgery was most effective because the changes in a distant focus occurring as a result of the radiation and of the surgery were prevented. The clinical relevance of these observations deserves further consideration.

The regional lymph node in cancer. Relationship of nodal histologic findings to cytotoxicity and immunity.

Although regional lymph nodes showed increased numbers of pyroninophilic cells for at least six weeks after the implantation of a C3H mammary tumor, a decrease in the number of these cells was noted four weeks after amputation of a tumor-bearing limb. These observations appear paradoxical, since such animals have repeatedly demonstrated so-called sinecomitant tumor immunity. However, the lack of pyroninophilia coincided with prior observations that cells obtained from the regional nodes after amputation of a tumor-bearing limb-showed decreased in vitro cytotoxicity. This suggested that the pyroninophilic elements, vis a vis immunoblasts, may have been more closely related to cytotoxicity rather than to tumor immunity per se. The possible importance of nodal lymph follicle formation in the latter was suggested by their increased presence in such regional nodes.