The management of patients with advanced carcinoid tumors and islet cell carcinomas

OBJECTIVE

To determine the effectiveness of hepatic artery occlusion alone and with sequenced chemotherapy for patients with hepatic-dominant metastases of islet cell carcinomas and carcinoid tumors.

DESIGN

Nonrandomized, observational study with follow-up from 2.5 to 10 years.

PATIENTS

111 ambulatory patients referred to a multidisciplinary tertiary care center who had histologically proven islet cell carcinoma or carcinoid tumor and symptomatic measurable metastatic lesions in the liver or hormonal abnormalities or both. The patients were ambulatory but were having substantial symptoms because of their endocrine syndromes or their tumors.

INTERVENTION

All patients had hepatic artery occlusion done surgically or by catheterization and embolization. After this procedure, 71 patients were selected for chemotherapy with alternating two-drug regimens of doxorubicin plus dacarbazine and streptozocin plus fluorouracil. Main outcome measures of response to therapy were rates of tumor regression, rates of improvement in endocrine abnormalities, symptomatic improvement, and duration of favorable response.

RESULTS

Objective regressions were observed in 60% of patients treated with occlusion alone and in 80% with chemotherapy added. Regressions were associated with substantial or complete relief from the endocrine syndromes. With occlusion alone, the median duration of regression was 4.0 months and with chemotherapy added, it was 18.0 months. Any comparative inferences about the two treatment regimens must be guarded, because this was not a randomized trial and marked differences occurred in the distribution of prognostic factors between the patient groups. Side effects of arterial occlusion included fever, nausea, pain, and abnormalities in liver function. Side effects of chemotherapy included nausea, vomiting, leukopenia, and alopecia.

CONCLUSIONS

Hepatic arterial occlusion can frequently produce major regression of neuroendocrine tumors with relief from the hormonal syndromes. Sequential chemotherapy may improve the rate and duration of the regression.

A combination of anti-CD15 monoclonal antibody PM-81 and 4-hydroperoxycyclophosphamide augments tumor cytotoxicity while sparing normal progenitor cells

A cyclophosphamide congener, 4-hydroperoxycyclophosphamide (4HC), has been used to purge bone marrow (BM) of residual leukemia cells ex vivo for use in support of high-dose chemotherapy for patients with acute myeloid leukemia (AML) undergoing autologous BM transplantation (ABMT). The efficacy and toxicity of 4HC are dose-related. The maximally tolerated concentration, 60-100 micrograms/ml, is toxic to tumor cells but also to normal committed hematopoietic progenitor cells. The anti-CD15 monoclonal antibody (mAb) PM-81 has also been employed for purging BM in patients with AML. In some patients, all tumor cells may not be lysed due to antigenic heterogeneity. Because the two agents used individually are associated with potential limitations in terms of toxicity to normal cells and efficacy of tumor cell purging, using these agents together might have advantages. In fact, in this study the use of these two agents together in subtherapeutic concentration ranges as single agents revealed killing of cells from the HL60 and NB4 promyelocytic leukemia cell lines in addition to cells from patients with AML while sparing normal progenitor cells. Surprisingly, not only did the combination enhance killing of tumor cells, but the order of addition of the two agents was important in maximizing toxicity to tumor cells. Adding mAb+complement (C') first or simultaneously to 4HC was less effective than adding 4HC first followed by mAb + C'. This combination regimen was toxic to HL60 and NB4 leukemia cells that may not be killed by the mAb alone due to antigen-negative tumor cells or by low concentrations of 4HC.(ABSTRACT TRUNCATED AT 250 WORDS)

Rat osteoblasts and ROS 17/2.8 cells contain a similar protein tyrosine phosphatase

Tyrosine phosphorylation plays a central role in intracellular signaling by many hormones and growth factors. Termination of the signal is thought to involve dephosphorylation of target proteins by phosphotyrosine phosphatases (PTPase). Soluble protein PTPases from neonatal rat osteoblasts (ROBs) and rat osteosarcoma (ROS 17/2.8) cells were chromatographically distinguished and characterized using 32P-labelled glutamate/tyrosine co-polymer as substrate. Two activities from both cell types were chromatographically separable. The dominant PTPase activity in the presence of 60-125 mM salt (E1), was eluted from phosphocellulose by 180-280 mM NaCl, bound weakly to a strong anion exchange column (QAE-trisacryl), had an apparent Km for [32P]glutamate/tyrosine copolymer of 52 micrograms/ml, was enhanced (5-10-fold, ROS; 1.5-3-fold, ROB) by assay in 125 mM NaCl, had no significant alkaline, acid, or serine phosphatase activity and had an M(r) of 53,000. A second activity (E2) was not retained by phosphocellulose but eluted from QAE-trisacryl in a single peak at 90-130 mM NaCl. It had an apparent Km for [32P]glutamate/tyrosine copolymer of 30 micrograms/ml (ROS) and its activity was not enhanced by NaCl in the assay. Activity E1 from both cells was 50% inhibited by 0.05 microM Na3VO4, 20 microM ZnCl2, or 5-10 microM CoCl2, but not by 1 mM NaF; activity E2 had a similar inhibition profile, but was more sensitive to ZnCl2 (IC50, 5 microM). Co2+ is a relatively non-toxic metal which may be a useful tool for investigating the role of phosphotyrosine in osteoblast proliferation and function. The similarity between the E1 activity from ROS cells and ROBs suggests that ROS cells may be useful in studying PTPase regulation by hormones, but molecular approaches will be required to establish the identity of PTPases in ROBs and ROS cells.

Carbamazepine and its metabolites in neuralgias: concentration-effect relations

The aim of this study was to investigate the use of carbamazepine in the treatment of neuralgic pain and to determine a therapeutic plasma concentration range for carbamazepine in neuralgias. The relation between plasma concentration and the response to treatment (reduction in pain) was examined by logistic regression analysis of carbamazepine and its metabolites, the epoxide, the diol, and 2-hydroxycarbamazepine. The plasma concentrations of carbamazepine, the epoxide, and the diol were significantly related to the probability of a 25% reduction in pain. Only carbamazepine was significantly related to the probability of 50% and 75% pain reduction. However, multiple regression analysis with backward elimination of the data showed a significant correlation between both carbamazepine and the epoxide with regard to the probability of 50% and 75% reductions in pain. This confirms the previous finding that the epoxide has antineuralgic properties [Tomson and Bertilsson 1984]. The therapeutic plasma concentration range for carbamazepine in neuralgias, defined as the range of concentrations that would be expected to provide a 25-75% reduction in pain in 50% of patients, was 2-7 micrograms.ml-1 (HPLC) or 5-17 micrograms.ml-1 (EMIT).

Liver fat-storing cell clones obtained from a CCl4-cirrhotic rat are heterogeneous with regard to proliferation, expression of extracellular matrix components, interleukin-6, and connexin 43

BACKGROUND

Immunocytochemical analysis of liver has revealed that fat-storing cells (FSC) are heterogeneous with regard to vitamin A content, staining for cytokeratins, desmin, and vimentin and the cytoskeletal protein alpha-smooth muscle actin. Since fat-storing cells play an important role in collagen deposition in normal and cirrhotic liver, we considered it important to study whether fat-storing cells were heterogeneous with regard to cell proliferation, expression of mRNAs coding for cytokines interleukin-6 (IL-6) and transforming growth factor-beta (TGF-beta), and extracellular matrix components alpha 1(I), alpha 1(III), alpha 1(IV) procollagens, laminin B1 chain and fibronectin.

EXPERIMENTAL DESIGN

We used a FSC line (CFSC) that was developed in our laboratory after spontaneous immortalization of a primary culture of fat-storing cells that were obtained from the liver of a CCl4-cirrhotic rat (Lab. Invest. 65:644-653, 1991). The cells were cloned by limiting dilution and have been maintained in culture for over 3 years without appreciable changes in the parameters investigated.

RESULTS

In this communication we report the characterization of 4 of the clones obtained. We show that they are heterogeneous with regard to proliferation index, expression of alpha 1(I), alpha 1(III) and alpha 1(IV) procollagen, IL-6 and TGF-beta mRNAs. The clones also differ in their response to IL-6. We also showed that clones are coupled through functional gap junctions but that they are heterogeneous with regard to the expression of the gap junction protein connexin 43.

CONCLUSIONS

We suggest that clonal heterogeneity of FSC may occur in vivo. Since each of the clones expresses a unique phenotype, these FSC clones could be excellent models to study the role of defined extracellular matrices on the expression of liver specific genes by cultured hepatocytes.

Definitional issues and neurobiological foundations of selected severe neurodevelopmental disorders

This article reviews current definitional issues, selected neuropsychological findings, and presumed neurobiological underpinnings of two of the more commonly identified severe neurodevelopmental disorders: mental retardation and autistic disorder. Although these disorders represent two of the more common severe neurodevelopmental disorders encountered by child neuropsychologists practicing in clinical and research settings, they have not received the amount of attention from the field of neuropsychology as other kinds of neurodevelopmental disorders. Although there are few definitional controversies surrounding these disorders, findings accrued to date reveal solid evidence for neurological processes underlying each of these disorders. In addition, each of these diagnoses likely represents a heterogeneous group of disorders, suggesting that a syndrome analysis approach would prove beneficial for increasing our understanding of each disorder. Conclusions are drawn for the clinician and researcher, particularly with respect to using a neuropsychological perspective and assessment strategies with children with more severe disorders.

Variability in the oral bioavailability of all-trans-retinoic acid

BACKGROUND

Orally administered all-trans-retinoic acid (all-trans-RA) can induce complete remission in a high proportion of patients with acute promyelocytic leukemia. A previous pharmacokinetic study in patients with acute promyelocytic leukemia raised the possibility that the absorption of orally administered all-trans-RA is a saturable process that would have significant clinical impact on dosing strategies.

PURPOSE

This study was specifically designed to examine the saturability of all-trans-RA absorption by measuring the effect of doubling the oral dose of all-trans-RA on plasma drug concentration in patients receiving long-term oral therapy.

METHODS

Six patients with solid tumors received oral doses of 10-mg gelatin capsules of all-trans-RA. Patients were studied on 2 consecutive days after they received 28 days of all-trans-RA administered as two daily 78-mg/m2 doses. The study assigned the patients to two groups. Three patients took a 156-mg/m2 dose on day 28 and a 78-mg/m2 dose on day 29; the other three patients took the lower dose on day 28 and the double dose on day 29. Blood samples for the determination of all-trans-RA plasma concentration were obtained at 30-minute intervals starting just prior to drug administration and continuing for a total of 7 hours. The plasma concentration of all-trans-RA was measured by high-performance liquid chromatography.

RESULTS

Plasma concentrations following an oral dose of all-trans-RA were highly variable, with peak concentrations ranging from 0.07 to 1.2 microM for the 78-mg/m2 dose level. Doubling the dose from 78 to 156 mg/m2 increased plasma concentration in all six patients, but the increase was unpredictable and not related to dose, ranging from less than a 1.2-fold to more than a 10-fold increase.

CONCLUSION

The current study does not support the hypothesis that the gastrointestinal absorption of all-trans-RA involves a saturable process but instead suggests that absorption is highly variable among patients. This wide interpatient variability suggests that pharmacokinetic drug monitoring may have an important role in the management of patients receiving all-trans-RA.

1,25-Dihydroxyvitamin D3 and phorbol myristate acetate produce divergent phenotypes in a monomyelocytic cell line

The human monomyelocytic HL-60 cell line differentiates along a monocytic lineage when cultured in the presence of phorbol myristate acetate (PMA) or 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3]. The protooncogene c-fms, coding for the macrophage colony-stimulating factor (M-CSF) receptor, is characteristically expressed in cells of monocytic lineage, but is not present in HL-60 cells. Since M-CSF has an undefined role in osteoclast development, we wished to examine the effect of 1,25-(OH)2D3, a strong promoter of osteoclast development, on the induction of M-CSF receptor. Treatment of HL-60 cells with 10-50 ng/ml PMA for 3 days stimulated expression of c-fms, as measured by steady state mRNA levels. Treatment with 10 nM 1,25-(OH)2D3 for 4-72 h did not promote c-fms expression. In fact, 1,25-(OH)2D3 attenuated PMA-stimulated c-fms expression in a dose-dependent manner (ED50, 1 nM). Along with attenuation of c-fms expression, 1,25-(OH)2D3 induced expression of mRNA for the osteoclastic enzyme carbonic anhydrase-II (CA II) almost 2-fold over the level expressed in untreated HL-60 cells. The addition of PMA to the culture diminished the basal expression of CA II mRNA, but did not affect 1,25-(OH)2D3-stimulated CA II induction. PMA and 1,25-(OH)2D3, thus, promote divergent phenotype development in the HL-60 cell. Induction of c-fms mRNA by PMA should ensure further macrophage development. The effect of 1,25-(OH)2D3 to attenuate expression of c-fms mRNA and stimulate CA II mRNA suggests that 1,25-(OH)2D3 activates osteoclast, rather than macrophage, development. 1,25-(OH)2D3-induced phenotypic changes may, therefore, involve modulation of the M-CSF effect.

Ascending afferent regulation of rat midbrain dopamine neurons

Standard, extracellular single-unit recording techniques were used to examine the electrophysiological and pharmacological responsiveness of midbrain dopamine (DA) neurons to selected, ascending afferent inputs. Sciatic nerve stimulation-induced inhibition of nigrostriatal DA (NSDA) neurons was blocked by both PCPA (5-HT synthesis inhibitor) and 5,7-DHT (5-HT neurotoxin), suggesting mediation by a serotonergic (5-HT) system. Direct stimulation of the dorsal raphe (which utilizes 5-HT as a neurotransmitter and inhibits slowly firing NSDA neurons) inhibited all mesoaccumbens DA (MADA) neurons tested. Paradoxically, DPAT, a 5-HT1A agonist which inhibits 5-HT cell firing, enhanced sciatic nerve stimulation-induced inhibition of NSDA neurons. MADA neurons were not inhibited by sciatic nerve stimulation and, therefore, could not be tested in this paradigm. In contrast to the dorsal raphe, electrical stimulation of the pedunculopontine tegmental nucleus preferentially excited slowly firing NSDA and MADA neurons. Thus, both excitatory and inhibitory ascending afferents influence the activity of midbrain DA neurons, and intact 5-HT systems are necessary for sciatic nerve stimulation to alter DA cell activity. However, the role that 5-HT plays in mediating peripheral sensory input remains unclear.

cAMP promotion of osteoclast-like cell development from mouse bone marrow cells requires a permissive action of 1,25-(OH)2D3

Recruitment of osteoclasts from monocytic precursors is modulated by local signals. We previously showed that monoblastic differentiation in U937 cells is stimulated by 1,25-(OH)2D3 and cAMP in series. We investigate here the combined effects of these agents to stimulate differentiation of osteoclast-like cells from mouse marrow. Cells from mouse marrow were harvested and cultured in alpha-MEM with 10% fetal bovine serum. The appearance of tartrate-resistant acid phosphatase-containing multinuclear cells was measured after 8 days in culture by cytochemical staining. Continuous exposure of cultures to 10 nM 1,25-(OH)2D3 positively stimulated development of these cells after 8 days (101 +/- 3 cells per well, n = 74). No osteoclast-like cells were found when 1,25-(OH)2D3 was added for the first 4 days followed by 4 days more with no treatment. PGE2 (1 microM) as a single agent added during the last 4 days of culture was not able to recruit osteoclast-like cells. However, cultures exposed to 1,25-(OH)2D3 during the first 4 days and 1 microM PGE2 during the second 4 days developed osteoclast-like cells at 8 days [66 +/- 8% of the formation seen with 1,25-(OH)2D3 alone, p less than 0.05]. Dibutyryl cAMP (1 microM to 3 mM) was also not effective used as a single agent, but was able to stimulate formation of TRAP-positive multinuclear cells when 1,25-(OH)2D3 preceded its addition to culture medium. cAMP analogs therefore mimicked the effect of 1 microM PGE2, but these experiments do not allow us to assign the PGE2 action entirely to activation of cAMP second messenger.(ABSTRACT TRUNCATED AT 250 WORDS)

A phase II study of intravenous 6-thioguanine (NSC-752) in advanced colorectal carcinoma

Fifteen patients with advanced measurable colorectal carcinoma were treated with intravenous 6-thioguanine (6-TG) at a dosage of 55 mg/m2 for 5 consecutive days every 5 weeks. Only one patient had received prior adjuvant chemotherapy. No responses were detected, and eight patients had stable disease for a medium duration of three treatment cycles. Toxicity was tolerable. We conclude that 6-TG given by this dosage schedule is ineffective in treating metastatic colorectal carcinoma.

Popliteal-to-distal bypass for limb-threatening ischemia

In a subset of patients requiring lower extremity revascularization, the popliteal artery may be used for inflow, thereby minimizing dissection and the length of vein required for bypass. This retrospective study was done to define the risks and benefits of arterial reconstruction in a population of patients having popliteal-to-distal bypass procedures. Between 1986 and 1990, 32 surgical procedures were performed on 29 patients. The patient's ages ranged from 46 to 86 years, with a mean age of 68 years. Twenty-four of 29 (83%) were men and 19 of the 29 (66%) had diabetes. Most patients had multiple indications for surgical intervention, and these included rest pain (54%), nonhealing ulcers (64%), and gangrene (29%). Arterial bypass with use of the popliteal artery for the proximal anastomosis was performed with in situ saphenous vein (50%), reversed saphenous vein (41%), and orthograde autologous vein (9%). Distal anastomoses were to the posterior tibial artery in 11 bypasses (33%), the peroneal artery in 10 (30%), the anterior tibial artery in two (6%), and the dorsal pedal artery in 10 (30%). Two deaths occurred in the perioperative period for an operative mortality rate of 6.9%. With use of life-table analysis, the cumulative graft patency rate was 97% at 1 year, 97% at 2 years, and 63.5% at 4 years. The overall cumulative limb salvage rate was 90.1% at 1 year, 90.1% at 2 years, and 78.8% at 4 years.(ABSTRACT TRUNCATED AT 400 WORDS)

Multifocal inflammatory leukoencephalopathy with 5-fluorouracil and levamisole

A cerebral demyelinating disease developed in 3 patients during adjuvant therapy with 5-fluorouracil and levamisole for adenocarcinoma of the colon. None of the patients had evidence of metastatic disease or prior neurological disease. The duration of chemotherapy before onset of neurological symptoms ranged from 15 to 19 weeks. The total dose of 5-fluorouracil was 9.7 to 15.7 gm. The total dose of levamisole was 2.7 to 3.75 gm. Two patients presented with a subacute (2-3 weeks) progressive decline in mental status and ataxia. The third patient had two unexplained episodes of loss of consciousness. In each, magnetic resonance imaging with gadolinium demonstrated prominent multifocal enhancing white matter lesions. Cerebral biopsy was performed stereotaxically in 2 patients. The morphological features were those of active demyelinating disease. The myelin loss was associated with numerous dispersed as well as vasocentric macrophages, sparing of axons, and perivascular lymphocytic inflammation. Electron microscopy confirmed the light microscopic findings. All 3 patients improved after cessation of chemotherapy and a short course of corticosteroid therapy. Our patients represent the first reported examples of an inflammatory leukoencephalopathy associated with the administration of 5-fluorouracil and levamisole. This syndrome may represent the pathological basis for 5-fluorouracil neurotoxicity, although we cannot completely exclude the role of levamisole.

Radiation therapy as a treatment for benign lymphoepithelial parotid cysts in patients infected with human immunodeficiency virus-1

Patients who are infected with the human immunodeficiency virus (HIV) may develop benign lymphoepithelial cysts within the parotid gland that cause severe facial deformity. Standard treatment for this disorder has been superficial parotidectomy, repeated fine-needle aspirations or observation alone. These approaches are unsatisfactory because elective surgery in immunocompromised patients should be avoided, the cysts recur soon after aspiration, and observation alone for a treatable deforming facial process is unacceptable. Radiotherapy's proven effectiveness in treating other benign disorders of the parotid gland led us to evaluate its usefulness as a treatment for this disorder. Eight patients with parotid enlargement, who were seropositive for HIV, received 8-10 Gy to the parotids in 1 week. Five patients had complete response and three patients had partial response. All were very satisfied with the cosmetic result. Treatment-related toxicity was well tolerated and consisted of mild xerostomia and transient taste loss. In all cases, these side effects resolved within 1 month. Radiation therapy thus appears to be an effective and well-tolerated treatment for AIDS-related parotid enlargement.

Humoral and cell surface interactions during gamma-irradiation leukemogenesis in vitro

Gamma-irradiation of plateau phase cultures of the clonal murine bone marrow stromal cell line D2XRII followed by cocultivation of a clonal interleukin 3 (IL-3) (granulocyte-macrophage colony-stimulating factor (GM-CSF)-dependent hematopoietic progenitor cell line FDC-P1JL26 results in a significant increase in "cobblestone islands" of attachment and emergence of subclonal factor-independent malignant sublines. Biochemical purification of conditioned medium from irradiated D2XRII cells yielded a 75,000-dalton glycoprotein termed leukemogenic stromal factor (LSF) that was neutralized by a polyclonal antiserum to murine macrophage colony-stimulating factor (M-CSF). A monoclonal antibody to the murine M-CSF receptor (c-fms) neutralized the biological activity of this molecule in a manner comparable to its effect on recombinant human or murine M-CSF. FDC-P1JL26 parent cells were positive for Ly5, MEL-14, mGR, VLA-4, PGP-1 (CD44), and Thy1.2. After culture in LSF, Thy1.2, MEL-14, and mGR became undetectable; however, significant cell surface MAC-1 antigen and c-fms (M-CSF receptor) were expressed. Neither line was positive for Ly6, Ly22, I-CAM-1, or B220 antigen. LSF-precultured FDC-P1JL26 cells transferred as single cells to microwell culture with 5000-cGy-irradiated D2XRII cells revealed a 60-fold increase in frequency of cobblestone island formation and evolution of factor-independent subclones compared to the parent line. Both parent and LSF-precultured cells became factor independent at a 100-fold lower frequency if kept in suspension in LSF in the absence of stromal cells. Antiserum to M-CSF or monoclonal antibody to the murine M-CSF receptor (c-fms) did not inhibit or displace cobblestone island formation by either clone of FDC-P1 on irradiated stromal cells indicating a mechanism of binding not involving the M-CSF receptor. However, anti-serum to the M-CSF receptor inhibited growth of one factor-independent subclone. In separate studies, a subclone of IL-3-dependent 32Dc13 cells, expressing the transfected murine c-fms protooncogene but not the parent 32Dc13 cell line or another subclone expressing the transfected gene for the human M-CSF receptor, showed adherence and became factor independent when cocultivated with irradiated D2XRII stromal cells. Thus, irradiated stromal cells bind M-CSF receptor-positive hematopoietic progenitor cells and induce c-fms-dependent factor-independent tumorigenic subclones. The cellular interactions in this model may be relevant to gamma-irradiation leukemogenesis in vivo.

The presence of somatostatin receptors in malignant neuroendocrine tumor tissue predicts responsiveness to octreotide

In 77 percent of patients suffering from a malignant carcinoid syndrome, administration of the somatostatin analog, octreotide (SMS 201-995, Sandostatin) induced clinical improvement coupled with a decrease in 24-hour urinary 5-hydroxyindole acetic acid (5-HIAA). This finding prompted an evaluation to determine the correlation between the presence of somatostatin receptors in tumor tissue and the response to octreotide in patients with advanced, metastatic, neuroendocrine tumors. In tissues of 31 tumors (20 carcinoid, eight islet-cell carcinoma, three medullary thyroid carcinomas), the presence of somatostatin receptors was analyzed by binding of the somatostatin analog 125I-Tyr3-SMS 201-995 and autoradiography. Receptors were detected in 16 of 20 samples of carcinoid tissues; all but one patient with receptor-positive tumors improved clinically after treatment with octreotide, and the urine 5-HIAA level was reduced a median of 63 percent (range, 39-94 percent) compared to values before treatment. Of the receptor-negative carcinoid patients, only one showed clinical improvement, which was minimal, and there was a negligible reduction in 5-HIAA after octreotide therapy. All eight patients with metastatic islet-cell carcinomas were positive for somatostatin receptors. Symptomatic improvement and a > 50 percent decrease in the level of at least one of the pathologically elevated marker hormones was seen in all eight. None of the three patients with medullary carcinoma of the thyroid had a decrease in calcitonin, and all three were initially somatostatin receptor-negative. We conclude that the presence of somatostatin receptors in malignant neuroendocrine tumor tissue appears to correlate with the response to octreotide therapy. Analysis of somatostatin receptors in malignant neuroendocrine carcinoma tissue should be included in future prospective clinical trials of this synthetic peptide.