Effect of preoperative chemotherapy on the outcome of women with operable breast cancer.

PURPOSE: To determine, in women with primary operable breast cancer, if preoperative doxorubicin (Adriamycin) and cyclophosphamide (Cytoxan; AC) therapy yields a better outcome than postoperative AC therapy, if a relationship exists between outcome and tumor response to preoperative chemotherapy, and if such therapy results in the performance of more lumpectomies. PATIENTS AND METHODS: Women (1,523) enrolled onto National Surgical Adjuvant Breast and Bowel Project (NSABP) B-18 were randomly assigned to preoperative or postoperative AC therapy. Clinical tumor response to preoperative therapy was graded as complete (cCR), partial (cPR), or no response (cNR). Tumors with a cCR were further categorized as either pathologic complete response (pCR) or invasive cells (pINV). Disease-free survival (DFS), distant disease-free survival (DDFS), and survival were estimated through 5 years and compared between treatment groups. In the preoperative arm, proportional-hazards models were used to investigate the relationship between outcome and tumor response. RESULTS: There was no significant difference in DFS, DDFS, or survival (P = .99, .70, and .83, respectively) among patients in either group. More patients treated preoperatively than postoperatively underwent lumpectomy and radiation therapy (67.8% v 59.8%, respectively). Rates of ipsilateral breast tumor recurrence (IBTR) after lumpectomy were similar in both groups (7.9% and 5.8%, respectively; P = .23). Outcome was better in women whose tumors showed a pCR than in those with a pINV, cPR, or cNR (relapse-free survival [RFS] rates, 85.7%, 76.9%, 68.1%, and 63.9%, respectively; P < .0001), even when baseline prognostic variables were controlled. When prognostic models were compared for each treatment group, the preoperative model, which included breast tumor response as a variable, discriminated outcome among patients to about the same degree as the postoperative model. CONCLUSION: Preoperative chemotherapy is as effective as postoperative chemotherapy, permits more lumpectomies, is appropriate for the treatment of certain patients with stages I and II disease, and can be used to study breast cancer biology. Tumor response to preoperative chemotherapy correlates with outcome and could be a surrogate for evaluating the effect of chemotherapy on micrometastases; however, knowledge of such a response provided little prognostic information beyond that which resulted from postoperative therapy.

Further evaluation of intensified and increased total dose of cyclophosphamide for the treatment of primary breast cancer: findings from National Surgical Adjuvant Breast and Bowel Project B-25.

PURPOSE: In 1989, the National Surgical Adjuvant Breast and Bowel Project initiated the B-22 trial to determine whether intensifying or intensifying and increasing the total dose of cyclophosphamide in a doxorubicin-cyclophosphamide combination would benefit women with primary breast cancer and positive axillary nodes. B-25 was initiated to determine whether further intensifying and increasing the cyclophosphamide dose would yield more favorable results. PATIENTS AND METHODS: Patients (n = 2,548) were randomly assigned to three groups. The dose and intensity of doxorubicin were similar in all groups. Group 1 received four courses, ie, double the dose and intensity of cyclophosphamide given in the B-22 standard therapy group; group 2 received the same dose of cyclophosphamide as in group 1, administered in two courses (intensified); group 3 received double the dose of cyclophosphamide (intensified and increased) given in group 1. All patients received recombinant human granulocyte colony-stimulating factor. Life-table estimates were used to determine disease-free survival (DFS) and overall survival. RESULTS: No significant difference was observed in DFS (P =.20), distant DFS (P =.31), or survival (P =.76) among the three groups. At 5 years, the DFS in groups 1 and 2 (61% v 64%, respectively; P =. 29) was similar to but slightly lower than that in group 3 (61% v 66%, respectively; P = 08). Survival in group 1 was concordant with that in groups 2 (78% v 77%, respectively; P =.71) and 3 (78% v 79%, respectively; P =.86). Grade 4 toxicity was 20%, 34%, and 49% in groups 1, 2, and 3, respectively. Severe infection and septic episodes increased in group 3. The decrease in the amount and intensity of cyclophosphamide and delays in therapy were greatest in courses 3 and 4 in group 3. The incidence of acute myeloid leukemia increased in all groups. CONCLUSION: Because intensifying and increasing cyclophosphamide two or four times that given in standard clinical practice did not substantively improve outcome, such therapy should be reserved for the clinical trial setting.

Tamoxifen in treatment of intraductal breast cancer: National Surgical Adjuvant Breast and Bowel Project B-24 randomised controlled trial.

BACKGROUND: We have shown previously that lumpectomy with radiation therapy was more effective than lumpectomy alone for the treatment of ductal carcinoma in situ (DCIS). We did a double-blind randomised controlled trial to find out whether lumpectomy, radiation therapy, and tamoxifen was of more benefit than lumpectomy and radiation therapy alone for DCIS. METHODS: 1804 women with DCIS, including those whose resected sample margins were involved with tumour, were randomly assigned lumpectomy, radiation therapy (50 Gy), and placebo (n=902), or lumpectomy, radiation therapy, and tamoxifen (20 mg daily for 5 years, n=902). Median follow-up was 74 months (range 57-93). We compared annual event rates and cumulative probability of invasive or non-invasive ipsilateral and contralateral tumours over 5 years. FINDINGS: Women in the tamoxifen group had fewer breast-cancer events at 5 years than did those on placebo (8.2 vs 13.4%, p=0.0009). The cumulative incidence of all invasive breast-cancer events in the tamoxifen group was 4.1% at 5 years: 2.1% in the ipsilateral breast, 1.8% in the contralateral breast, and 0.2% at regional or distant sites. The risk of ipsilateral-breast cancer was lower in the tamoxifen group even when sample margins contained tumour and when DCIS was associated with comedonecrosis. INTERPRETATION: The combination of lumpectomy, radiation therapy, and tamoxifen was effective in the prevention of invasive cancer.

Blood usage during wartime: the Sarajevo blood bank experience.

By this retrospective analysis about blood usage in the treatment of civilians and soldiers, we want to contribute to better understanding of the duties of hospital blood bank during the war. We have analysed medical files of 3055 wounded and non-wounded patients (1732 civilians and 1323 soldiers) hospitalised at State Hospital Sarajevo in the period from May 11th 1992 to May 11th 1993 while Sarajevo was under siege. The frequency of blood transfusion among wounded patients (31.3%) and non-wounded patients (22.1%) was significantly different (p < 0.001). The wounded patients received 1.92 blood units (modus) while non-wounded received 1.66 blood units. The difference in blood quantity per recipient between wounded and non-wounded patients was significant (D = 0.267; p < 0.001). Out of the total number of wounded patients 48.8% were civilians. There was no significant difference in the frequency of blood transfusion among wounded civilians and wounded soldiers (30.1%: 32.5%; p > 0.20) and the same can be said for transfused blood quantity (D = 0.062; p > 0.05). The difference in frequency of transfusions among civilians and soldiers (26.7%: 30.3%; p > 0.05) are due to higher rate of wounded patients in the group of soldiers than in the group of civilians (79.2%: 57.6%; p < 0.001). In the treatment of 100 hospitalised patients, regarding to which group they belonged to (civilians/soldiers and wounded/non-wounded) an average of 61-153 blood units were used. The results of this analysis may help in the preparation of hospital blood banks for a successful functioning during the war which is characterised with massive injuries of the civilian population and may serve for a future comparison.

Effect of preoperative chemotherapy on the outcome of women with operable breast cancer.

PURPOSE: To determine, in women with primary operable breast cancer, if preoperative doxorubicin (Adriamycin) and cyclophosphamide (Cytoxan; AC) therapy yields a better outcome than postoperative AC therapy, if a relationship exists between outcome and tumor response to preoperative chemotherapy, and if such therapy results in the performance of more lumpectomies. PATIENTS AND METHODS: Women (1,523) enrolled onto National Surgical Adjuvant Breast and Bowel Project (NSABP) B-18 were randomly assigned to preoperative or postoperative AC therapy. Clinical tumor response to preoperative therapy was graded as complete (cCR), partial (cPR), or no response (cNR). Tumors with a cCR were further categorized as either pathologic complete response (pCR) or invasive cells (pINV). Disease-free survival (DFS), distant disease-free survival (DDFS), and survival were estimated through 5 years and compared between treatment groups. In the preoperative arm, proportional-hazards models were used to investigate the relationship between outcome and tumor response. RESULTS: There was no significant difference in DFS, DDFS, or survival (P = .99, .70, and .83, respectively) among patients in either group. More patients treated preoperatively than postoperatively underwent lumpectomy and radiation therapy (67.8% v 59.8%, respectively). Rates of ipsilateral breast tumor recurrence (IBTR) after lumpectomy were similar in both groups (7.9% and 5.8%, respectively; P = .23). Outcome was better in women whose tumors showed a pCR than in those with a pINV, cPR, or cNR (relapse-free survival [RFS] rates, 85.7%, 76.9%, 68.1%, and 63.9%, respectively; P < .0001), even when baseline prognostic variables were controlled. When prognostic models were compared for each treatment group, the preoperative model, which included breast tumor response as a variable, discriminated outcome among patients to about the same degree as the postoperative model. CONCLUSION: Preoperative chemotherapy is as effective as postoperative chemotherapy, permits more lumpectomies, is appropriate for the treatment of certain patients with stages I and II disease, and can be used to study breast cancer biology. Tumor response to preoperative chemotherapy correlates with outcome and could be a surrogate for evaluating the effect of chemotherapy on micrometastases; however, knowledge of such a response provided little prognostic information beyond that which resulted from postoperative therapy.

Comparative audit of blood transfusion during war and peace in Sarajevo.

A comparative study was made between 146 patients receiving blood transfusion at the State Hospital, Sarajevo, in a 3-month period of peace (group 1) and 250 patients receiving transfusions in a 3-month period of war (group 2). In group 1, trauma accounted for only 7% of transfusions while it accounted for 99% in group 2. The threshold for transfusion was increased in war and the mean pretransfusion haematocrit in group 2 was 21%, compared with 27% in group 1 (P < 0.001). Less blood was also transfused per patient in war with a mean transfusion volume of 1.1 units in group 2 compared with 2.6 units in group 1 (P < 0.001). The reasons and justification for such a conservative transfusion practice in a besieged city are discussed.

[The blood transfusion service during war: how can sufficient blood be provided?]. / Funkcioniranje sluzbe za transfuziju krvi u odbrambenom ratu: kako obezbijediti dovoljno krvi?

The basic task of the Division for Blood Transfusion (DBT) during a defensive war is delivery of adequate quantity of blood in time to all medical units where the wounded and the sick are given specialistic aid. The experiences acquired in previous wars and in the war in Bosnia and Herzegovina shows that this task can be implemented by a DBT organised on a regional principle. In that case, it can and should provide 1.43 blood units (BU) for the wounded and 0.66 BU for the sick being in hospital. The study represents the strategy and tactics in using blood during defensive war. The aim of them is storing of blood reserves and superseding its shortage, in order to enable a smooth progress and good results of curing. Studying of problems of function of DBS during war must be continued in order to find most favourable solutions.

Transfusion therapy during war and peace in Sarajevo.

OBJECTIVE: To investigate surgical blood usage during the siege of Sarajevo. METHODS: Data on blood usage and pre-transfusion hematocrit (Hct) values from blood transfusion request forms in 250 wartime emergency surgical procedures during August through October 1992 (experimental group), and in 146 peacetime elective surgical procedures (control group) during April through June 1991 at the State Hospital of Sarajevo, were reviewed. RESULTS: The mean number of blood units transfused per patient (blood usage rate) was 1.13 in the experimental group versus 2.56 in the control group (p < 0.001). During the war, for blood conservation, normovolemic hemodilution was practiced widely. A significantly lower mean pre-transfusion Hct value of 0.21 was observed in the experimental group versus 0.27 in the control group (p < 0.001). CONCLUSION: Blood-usage rate was lower during emergency surgical procedures in war than during elective surgical procedures in peacetime without apparent adverse patient outcome. This decrease in blood-usage rate in the face of increased numbers of trauma victims was the result of a planned blood-conservation program which included: stringent blood-usage criteria, and widespread implementation of casualty resuscitation using normovolemic hemodilution with colloid and crystalloid plasma substitutes.

Blood transfusion requirements among war casualties in Sarajevo.

INTRODUCTION: The safe and timely provision of blood is of crucial importance in the prevention and mitigation of morbidity and mortality due to trauma. The use of blood in the treatment of war casualties, soldiers as well as civilians, was analyzed retrospectively and the impact of massive blood transfusion on blood banking services and reserves of blood during the war in Sarajevo was assessed. METHODS: A retrospective analysis of 3,215 war casualties (1,815 civilians plus 1,400 military) who arrived to the casualty reception center of the State Hospital of Sarajevo during the period 11 May through 31 October 1992 was performed. Blood usage was reviewed in three stages: within 24 hours (h) of admission, after seven days of hospitalization, and after 30 days of hospitalization. The types of injury, survival rate, and blood-usage rate in a sample of 37 war casualties who required massive blood transfusions (MBT) during the period 11 May through 31 December 1992 was examined. RESULTS: The civilian casualty rate in this series of patients was 56.5%. A total of 1,217/3,215 (37.9%) casualties were hospitalized. In this study, 16% (504/3,215) of total number of persons wounded received blood transfusion. Of these patients, 504/1,217 (41.4%) were transfused. A total of 971.1 liters of blood were transfused through 31 October 1992; 68% within 24 h of admission, 91% within the first seven days, and 100% within the first 30 days. From a total of 37 MBT recipients, 36 (97%) were injured by firearms. Survival rate among MBT patients was 30%. The MBT recipients comprised 2% of total hospitalized patients and 6% of total number of patients transfused. The amount of blood needed during episodes of MBT was 15% of total blood used through 31 December 1992. CONCLUSIONS: Based on these data, prospective requirements for blood usage should take into account casualty triage, as follows: for each casualty transported to the hospital, hospitalized, or transfused, 0.302, 0.796, and 1.912 liters of blood respectively, will be needed for the first 30 days of treatment. Recipients of massive blood transfusions are a significant drain on blood reserves in war. This experience can be utilized in the development of revised guidelines for blood usage for an entire population affected by war.

Emergency medical services during the siege of Sarajevo, Bosnia and Herzegovina: a preliminary report.

BACKGROUND: The siege of Sarajevo is a long-term, human-made, medical disaster of international significance. The delivery of emergency health care provided to the large civilian population held captive in that war zone for an extended time was studied. METHODS: In May 1993, a humanitarian and fact-finding visit to Sarajevo was conducted. Physicians, administrators, and public health officials were interviewed; epidemiological data were acquired--the resuscitation of war casualties at the two largest hospitals were observed; and local published reports and videotaped footage on the organization and delivery of prehospital and hospital care were reviewed. The videotapes also served to document war crimes. RESULTS: Daily bombardment and sniper fire directed at civilians have caused a steady stream of casualties (64,130, or an average of 119 killed or injured per day in 18 months). Eighty percent of the victims were civilian. Despite hazardous conditions from direct shelling, disruption of vital lifelines, and shortage of supplies, medicines, oxygen, and anesthetics, the physicians continue to provide at least a minimum standard of resuscitative care. Seventy percent of all war victims were transported to hospitals in private vehicles. Most casualties (93%) received some form of prehospital, basic first-aid from lay bystanders or first responders. From November 1992 to February 1993, 27,733 patients were treated in hospitals, resulting in 2,139 major surgical procedures. The primary cause of death in 71 of 273 victims was prolonged hemorrhagic, hypovolemic shock. Sixty-one percent of these victims died within 24 hours of injury. CONCLUSIONS: Continuous needs assessment of a civilian population in a war zone should be accompanied by rapid delivery of outside aid. International "peacekeeping" forces should protect hospitals and their staffs, and ensure the entry of supplies and evacuation of some patients. A public trained in life-supporting first-aid, and physicians and paramedics with experience in advanced life support may have enhanced lifesaving efforts in Sarajevo.

Effect of UV light on tumor cell sensitivity to NK and NC cell-mediated lysis.

The effect of UV light irradiation on the immunobiological properties of murine tumor cells was studied. In vitro irradiation of MCA 102 and MCA 105 fibrosarcomas with a short-wavelength UVC light rendered them highly immunogenic and sensitive to natural cell-mediated cytotoxicity (NCMC). Analysis of the effector cells involved in NCMC revealed that UV irradiation stably increased tumor cell sensitivity to both NK and NC cell lysis. Studies of the mechanisms responsible for increased sensitivity to NK cells indicate that UV treatment did not affect tumor-cell recognition by NK cells but increased their susceptibility to NK-derived lytic granules. Augmentation of UV-treated tumor cell sensitivity to NC cell-mediated lysis was found to be due to their increase in sensitivity to the effector-cell-released TNF. In parallel, UV-treated cells showed high sensitivity to human recombinant TNF whereas untreated parental cells were resistant to rTNF. UV irradiation did not affect rTNF binding, internalization and degradation but increased tumor cell vulnerability to TNF-induced DNA fragmentation. Thus, UV light appears as a potent modulator of tumor cell sensitivity to T cell- and natural cell-mediated immunity.

Ultraviolet light-induced increase in tumor cell susceptibility to TNF-dependent and TNF-independent natural cell-mediated cytotoxicity.

Previously we demonstrated that two consecutive in vitro irradiations of MCA 102 cells with high doses of UVC light (610 and 457 J/m2) resulted in a selection of a permanent line MCA 102UV that manifested high sensitivity to natural cell-mediated cytotoxicity (NCMC). In the present study analysis of the effector cells involved in lysis of these tumor cells was performed by comparing the cytotoxicity of normal spleen cells which mediated both NK and NC cell activity with (a) normal spleen cells in which NC activity was neutralized by anti-TNF Abs (NK+,NC-), (b) NK-depleted or NK-deficient spleen cells (NK-,NC+), and (c) NK-deficient or -depleted spleen cells with NC activity neutralized by anti-TNF Abs (NK-,NC-). Results of these studies indicate that lysis of the original MCA 102 tumor cells was relatively low and was mediated by NC cells. UV irradiation significantly increased MCA 102 tumor cell sensitivity to lysis by both NK and NC cells. Analysis of the mechanisms involved in UV-induced NK sensitivity revealed that UV irradiation increased tumor cell susceptibility to lytic NK-derived granules. NC sensitivity of MCA 102UV tumor cells was associated with their increase in sensitivity to TNF and selection of MCA 102UV cells for resistance to rTNF resulted in a decrease in their susceptibility to NC cells. To determine how fast UV-induced sensitivity to NCMC and rTNF can be established, 51Cr-labeled MCA 102 cells were irradiated in vitro with 38-304 J/m2 of UVC light and their sensitivity to lysis by spleen cells and rTNF was tested immediately in an 18-hr cytotoxicity assay. UV treatment with the same doses was repeated 12 days later. The data obtained showed that tumor cell sensitivity to NCMC and TNF appeared shortly after UV irradiation, was stable, and was further substantially augmented by the second round of UV treatment. Thus, in vitro UV irradiation of tumor cells could be an effective modulator of tumor cell sensitivity to TNF-dependent and TNF-independent cell-mediated cytotoxicity.

Increase in immunogenicity and sensitivity to natural cell-mediated cytotoxicity following in vitro exposure of MCA105 tumor cells to ultraviolet radiation.

The effect of short wave length ultraviolet C (UVC) light irradiation on tumor cell immunogenicity and sensitivity to natural cell-mediated cytotoxicity was studied. Two consecutive courses of UVC irradiation of 3LL Lewis lung carcinoma and MCA105 fibrosarcoma increased their immunogenicity and sensitivity to lysis by normal spleen cells. Analysis of the effector cells involved in lysis of the parental MCA105 and UV-treated MCA105UV tumor cells was performed by comparing the cytotoxic activity of normal spleen cells containing both natural killer (NK) and natural cytotoxicity (NC) cell activity (NK+, NC+) with: (a) normal spleen cells in which NC activity was neutralized by anti-tumor necrosis factor (TNF) antibodies (NK+, NC-); (b) NK-depleted or NK-deficient spleen cells (NK-, NC+); and (c) NK-depleted or -deficient spleen cells with NC activity blocked by anti-TNF antibodies (NK-, NC-). In addition, the ability of polyinosinic-polycytidylic acid or interleukin 2-stimulated spleen cells to lyse UV-treated and untreated tumor cells in the presence or absence of anti-TNF antibodies was also investigated. Lysis of MCA105 cells was shown to be mediated mostly by NC cells, since it was inhibited in the presence of anti-TNF antibodies and was not significantly affected by depletion or stimulation of NK cells. UV irradiation of MCA105 tumor cells substantially increased their sensitivity to both NK and NC effector cells. Augmentation of NK sensitivity of MCA105UV cells was associated with an increase in their lysability by large granular lymphocyte-derived cytolytic granules. UVC treatment of tumor cells also increased their sensitivity to lysis by recombinant TNF-alpha, pointing to the possible mechanism responsible for the increase in their sensitivity to NC cell-mediated cytotoxicity. Indeed, selection of MCA105UV cells for resistance to TNF led to resistance to spleen cell-mediated NC cytotoxicity. UVC irradiation did not affect internalization and degradation of TNF by MCA105UV cells but substantially increased sensitivity to TNF-induced DNA fragmentation. The results of this study indicate that UV irradiation can be a potent and stable modulator of the immunobiological properties of tumor cells.

New potent alpha-glucohydrolase inhibitor MDL 73945 with long duration of action in rats.

Inhibition of intestinal alpha-glucohydrolase activity is one approach for reducing the glycemic response from dietary carbohydrate and may prove useful for the treatment of diabetes mellitus. In this article, we describe the pharmacological properties of a time-dependent intestinal alpha-glucohydrolase inhibitor, MDL 73945. When preincubated 2 h with a rat intestinal mucosa preparation before substrate addition, MDL 73945 was a potent inhibitor of sucrase, maltase, glucoamylase, and isomaltase activities (MDL 73945 concentrations required to cause a 50% decrease in enzyme activity, 2 x 10(-7), 1 x 10(-6), 5 x 10(-6), and 8 x 10(-6) M, respectively); without preincubation, it was 10- to 500-fold less potent. In rats, a single oral dose of MDL 73945 administered simultaneously with 2 g/kg body wt sucrose resulted in a dose-dependent reduction in the area under the 0- to 3-h glycemic response curve, which was significant at 1 (45% reduction) and 3 (65% reduction) mg/kg. When administered 1 h before sucrose, the compound was more potent, with 0.3 mg/kg MDL 73945 significantly reducing the glycemic response to sucrose by 62%. A reduction in the glycemic response to sucrose was accompanied by reduced insulin secretion. MDL 73945 was slightly less effective against a starch load, with 3 and 10 mg/kg MDL 73945 administered 0.5 h before starch reducing the glycemic response by 39 and 52%, respectively. MDL 73945 was more effective against a sucrose load in streptozocin-administered rats than in control rats and was as effective after 16 daily doses as after a single dose.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of ultraviolet irradiation on MCA102 tumor cell immunogenicity and sensitivity to tumor necrosis factor.

The ability of UV irradiation to induce immunogenicity of the nonimmunogenic major histocompatibility complex-negative MCA102 fibrosarcoma was studied. In parallel, the effect of short wavelength UVC light on the sensitivity of tumor cells to natural cell-mediated cytotoxicity and tumor necrosis factor (TNF) was also investigated. MCA102 fibrosarcoma cells were irradiated in vitro twice with UVC light (610 and 457 J/m2). Surviving cells were expanded and maintained in vitro as the MCA102UV subline. UV treatment changed tumor cell morphology and increased their in vitro rate of proliferation. However, after inoculation of 1 x 10(5) to 2 x 10(6) MCA102UV cells into C57BL/6 mice, growth of these cells was completely prevented. Lyt2.2 and not L3T4 lymphocytes were responsible for the rejection of these tumor cells. To determine the minimal and optimal dose of UV irradiation capable of increasing tumor cell immunogenicity, MCA102 cells were irradiated once or twice with different doses (76 to 610 J/m2) of UV light. After a single dose of UV treatment, tumor growth in C57BL/6 mice was inhibited, particularly with lines irradiated at the highest doses (610 or 457 J/m2). After a second round of irradiation, tumor cells became more immunogenic, and the level of tumor growth inhibition increased with higher doses of UV irradiation. Thus, cells irradiated twice with 610 and 457 J/m2 became rejectable in all immunocompetent C57BL/6 mice. The increase in tumor cell immunogenicity induced by UV light was not associated with the appearance of Class I H-2 antigens. In parallel with the induction of tumor cell immunogenicity, UV irradiation made tumor cells more sensitive to natural cell-mediated cytotoxicity and to lysis by TNF. An increase in sensitivity to natural cell-mediated cytotoxicity and TNF was observed after single or double doses (152 to 610 J/m2) of UV irradiation. The cells that showed the highest levels of immunogenicity were found also to be most sensitive to lysis by TNF. MCA102UV cells cultured in the presence of increased doses of recombinant TNF became resistant to its cytotoxicity without losing their immunogenicity, suggesting that immunogenicity and TNF sensitivity are two independent UV-induced properties. Thus, UV irradiation appears to be an effective modality for altering tumor cell immunobiological properties, including increased tumor cell sensitivity to T-cell and/or natural cell-mediated immunity.

Quantitative relationship of lysosomal glycogen accumulation to lysosomal alpha-glucosidase inhibition in castanospermine-treated rats.

To quantitatively examine the relationship between lysosomal acid alpha-glucosidase (LAAG, alpha-D-glucoside glucohydrolase, EC 3.2.1.20) inhibition and glycogen accumulation, rats were treated with castanospermine (CS), and liver lysosomal/mitochondrial fractions were analyzed for glycogen content and LAAG activity. Liver lysosomal glycogen accumulation positively correlated (r = 0.90) with the amount of LAAG inhibition when inhibition was about 50% or greater. Glycogen did not accumulate when LAAG inhibition was less than 50%. The route of CS administration had little effect on the amount of LAAG inhibition observed. In rats killed 17 hr after CS administration, the doses estimated to cause 50% LAAG inhibition were 0.77, 0.11, and 0.22 mg/kg for i.p., i.v., and oral administration respectively. After 89% inhibition of LAAG activity with a single oral dose of 10 mg CS/kg, LAAG activity returned to 50% of normal value in about 2.5 days. Accumulated glycogen disappeared as LAAG activity recovered. Surprisingly, twelve daily CS doses of 1 mg/kg had only a small cumulative effect on LAAG inhibition and did not cause more glycogen accumulation than a single dose.

Quantitative relationship between intestinal sucrase inhibition and reduction of the glycemic response to sucrose in rats.

We have investigated the quantitative relationship between sucrase inhibition and reduction in the 0-3 h glycemic response to an oral dose of sucrose in rats. Castanospermine is a quasi-irreversible sucrase inhibitor that did not dissociate from sucrase during tissue preparation or assay for sucrase activity. An oral dose of castanospermine (0.1-3.0 mg/kg body wt) dose-dependently reduced sucrase activity of intestinal segments by 15-90%; 0.4 mg/kg body wt reduced total sucrase activity about 50%. The lower doses inhibited sucrase much more extensively in the proximal than in the distal segments. Castanospermine also dose-dependently reduced the 0-3 h glycemic response to sucrose; 1.5 mg/kg body wt reduced the glycemic response about 50%. Each submaximal castanospermine dose inhibited total sucrase activity more than it reduced the glycemic response. We conclude that intestinal sucrase activity in the rat is in modest excess relative to the rate-determining step of glucose absorption following sucrose administration. Fourteen days of castanospermine treatment (0.2 mg.kg body wt-1.d-1) resulted in sucrase inhibition that was similar to a single castanospermine treatment, suggesting that castanospermine treatment resulted in neither cumulative sucrase inhibition nor induction of sucrase activity.