Transport of Dissolved Amino Acids by the Mussel, Mytilus edulis: Demonstration of Net Uptake from Natural Seawater.

High-performance liquid chromatography provides direct evidence for substantial removal of naturally occurring specific free amino acids during a single passage of water through the mantle cavity of mussels. This occurs during the few seconds required for passage of the water across the gill, and removal proceeds unabated at ambient substrate concentrations as low as 38 nanomoles per liter.

The microRNA-23b/-27b cluster suppresses prostate cancer metastasis via Huntingtin-interacting protein 1-related.

Deregulation of microRNAs (miRs) contributes to progression and metastasis of prostate and other cancers. miR-23b and -27b, encoded in the same miR cluster (miR-23b/-27b), are downregulated in human metastatic prostate cancer compared with primary tumors and benign tissue. Expression of miR-23b/-27b decreases prostate cancer cell migration, invasion and results in anoikis resistance. Conversely, antagomiR-mediated miR-23b and -27b silencing produces the opposite result in a more indolent prostate cancer cell line. However, neither miR-23b/-27b expression or inhibition impacts prostate cancer cell proliferation suggesting that miR-23b/-27b selectively suppresses metastasis. To examine the effects of miR-23b/-27b on prostate cancer metastasis in vivo, orthotopic prostate xenografts were established using aggressive prostate cancer cells transduced with miR-23b/-27b or non-targeting control miRNA. Although primary tumor formation was similar between miR-23b/-27b-transduced cells and controls, miR-23b/-27b expression in prostate cancer cells decreased seminal vesicle invasion and distant metastases. Gene-expression profiling identified the endocytic adaptor, Huntingtin-interacting protein 1-related (HIP1R) as being downregulated by miR-23b/-27b. Increased HIP1R expression in prostate cancer cells inversely phenocopied the effects of miR-23b/-27b overexpression on migration, invasion and anchorage-independent growth. HIP1R rescued miR-23b/-27b-mediated repression of migration in prostate cancer cells. HIP1R mRNA levels were decreased in seminal vesicle tissue from mice bearing miR-23b/-27b-transduced prostate cancer cell xenografts compared with scrambled controls, suggesting HIP1R is a key functional target of miR-23b/-27b. In addition, depletion of HIP1R led to a more rounded, less mesenchymal-like cell morphology, consistent with decreased metastatic properties. Together, these data demonstrate that the miR-23b/-27b cluster functions as a metastasis-suppressor by decreasing HIP1R levels in pre-clinical models of prostate cancer.

Arterial thrombosis associated with adjuvant chemotherapy for breast carcinoma: a Cancer and Leukemia Group B Study.

PURPOSE: Multiagent chemotherapy and chemohormonal therapy for breast cancer are associated with an increased risk for venous thromboembolic complications. We observed instances of arterial thrombosis in two studies of breast cancer involving multiagent chemotherapy for stages II and III disease. Our purpose in this study was to determine the incidence of this complication and whether it appeared to be related to the chemotherapy or was a random event. PATIENTS AND METHODS: Episodes of arterial thrombotic events were identified from record reviews of 1,014 assessable patients with breast cancer entered on two Cancer and Leukemia Group B protocols. Details of the kind of arterial event, when it occurred, the outcome, and the occurrence of metastases were analyzed. RESULTS: Thirteen (1.3%) patients had an arterial thrombosis: six (5.3%) of 113 patients with stage III disease and seven (0.8%) of 901 patients with stage II disease. Four of these patients had a peripheral arterial thrombosis and nine had strokes (four were fatal). All these events occurred while the patients were receiving adjuvant chemotherapy. Only one additional arterial event (a stroke approximately four years later) has occurred in this patient group after chemotherapy was completed. CONCLUSION: Arterial thrombosis is also associated with multiagent chemotherapy in patients with breast cancer. The mechanism is unknown.

A GABA cardiovascular mechanism in the dorsal raphe of the rat.

An injection of gamma-aminobutyric acid (GABA) and the GABA agonist, muscimol, into the dorsal raphe reduced both heart rate and blood pressure in the urethane-anesthetized rat. Picrotoxinin (3.4 nmol) did not affect blood pressure and slightly reduced the heart rate when injected into the dorsal raphe, but it blocked the decrease in both cardiovascular responses produced by GABA. These decreases in heart rate and blood pressure most likely result from stimulation of a GABAA receptor, as the GABAB agonist, baclofen, appeared to elevate heart rate and blood pressure by a mechanism occurring outside the dorsal raphe area. The changes in blood pressure and heart rate induced by muscimol occurred whether or not respiration was supported. Finally, it can be inferred that these GABAergic actions on blood pressure and heart rate probably involve both an inhibition of central sympathetic outflow and an excitation of parasympathetic outflow, as the quaternary muscarinic blocker, atropine methyl nitrate, blocked the decrease in heart rate induced by muscimol, but not the decrease in blood pressure.

Neuropeptide modulation of muscarinic receptors and function in cerebral cortex of young and senescent rats.

The possible influence of several neuropeptides on muscarinic receptor binding and function in fronto-parietal cortex of young and senescent Fischer 344 rats was examined. Low concentrations (100 nM) of cholecystokinin, neurotensin and vasoactive intestinal polypeptide (VIP), added in vitro, enhanced carbachol-stimulated phosphoinositide metabolism in cortical miniprisms from both young and senescent rats, while somatostatin was ineffective. Interestingly, the VIP receptor antagonist [d-parachloro-Phe6,Leu17[VIP shifted the dose-response curve for carbachol significantly to the right, indicating inhibition of phosphoinositide hydrolysis. No direct actions of neuropeptides on the number or affinity of [3H]l-quinuclidinyl benzilate binding sites nor on agonist conformation states of the muscarinic receptor were noted in cortex from young animals. The neuropeptide modulation of phosphoinositide metabolism was selective for muscarinic systems, as norepinephrine-stimulated phosphoinositide hydrolysis was not altered. Pretreatment with hemicholinium-3, an inhibitor of high-affinity choline uptake, did not prevent the neuropeptide effects, indicating the interaction was probably postsynaptic. It is possible that pharmacologic manipulation of peptidergic processes could improve cholinergic neurotransmission in brain.

Dissociation of locomotor depression and ChE activity after DFP, soman and sarin.

The effect of direct intrastriatal injection of three organophosphate cholinesterase inhibitors, DFP (diisopropylphosphorofluoridate), soman (pinacolyl methylphosphonofluoridate) and sarin (isopropyl methylphosphonofluoridate) has been studied on locomotor activity in the rat. The degree of ChE inhibition has been monitored in the striatum, as well as in surrounding brain areas and blood, in order to verify the selectivity of the treatment and rule out effects attributable to actions in these areas and/or the periphery. It has been determined that while enzyme activity is inhibited in the striatum by all three compounds, only DFP significantly reduces locomotor activity at doses that produce no other observable behavioral deficits, or significant leakage into the periphery. Behavioral recovery occurs before enzyme activity returns to control levels. Possible contributions of DFP's action on other neurotransmitters and on ChE in other brain areas to the inhibition of locomotor activity are discussed.

The nutritional aspects of Rett syndrome.

Nutrition is a major problem for the Rett patient. We have studied 21 girls with Rett syndrome (19 typical, two atypical). We report our experience in this population with the nutritional aspects of Rett syndrome, the typical dietary habits, and various nutritional deficiencies. Further experience with the use of high fat diets is reported.

Hyperglycemic complications associated with adjuvant chemotherapy of breast cancer. A cancer and leukemia group B (CALGB) study.

Many adjuvant chemotherapy regimens used for breast cancer include prednisone, which has the potential to cause hyperglycemia. We reviewed the results of three CALGB studies employing prednisone as part of adjuvant therapy to determine the incidence and severity of hyperglycemic complications. All treatment regimens included cyclophosphamide, methotrexate or doxorubicin, 5-fluorouracil, and vincristine in addition to prednisone. Among 1,237 evaluable patients receiving a five-drug regimen including prednisone, there were 98 patients (7.9%) who experienced any degree of hyperglycemia. Thirty patients (2.4% overall; 30.6% of those having any hyperglycemia) had severe or life-threatening degrees of hyperglycemia, including two patients whose hyperglycemia contributed directly to death. We conclude that prednisone administration as part of adjuvant chemotherapy regimens in breast cancer produces an appreciable incidence of hyperglycemia. Serum glucose levels should be monitored during therapy to help prevent the occasional severe or life-threatening episode of hyperglycemia in these patients.

Esorubicin (4'-deoxydoxorubicin, NSC 267469) in advanced breast cancer. A phase II study of the CALGB.

Forty-six eligible women with advanced metastatic breast cancer were entered on a Phase II trial utilizing esorubicin (4'-deoxydoxorubicin) given in a dosage of 30 mg/m2 intravenously every 3 weeks. No patient had received anthracyclines or cytotoxic therapy for metastatic disease. Twenty-three (50% of patients) had prior adjuvant chemotherapy, 21 (46%) had prior hormonal therapy, and 32 (70%) were postmenopausal. Dominant site of disease was visceral in 26 (57%), bone in 14 (30%), and soft tissue in 6 (13%). There were 3 complete and 13 partial responders observed, for a 35% response rate; 95% confidence interval for response was 21-49%. Median response duration was 4.0 months (range 2-21 months), and one partial responder remains on study at 6.3 months. Thirty-nine of 46 patients have died; median survival was 10.1 months. Toxicity was primarily hematologic, with 2 drug-related septic deaths. In addition, 2 patients developed severe congestive heart failure secondary to esorubicin cardiotoxicity (at 687 and 770 mg/m2, respectively), which resulted in one patient death. Nausea and vomiting were severe in 16% of patients, but total alopecia was only noted in 4 (9%). Esorubicin is an active agent in metastatic breast cancer; its role in treatment remains undefined.

Effects of directed gel degradation and collagenase digestion on the integration of neocartilage produced by chondrocytes encapsulated in hydrogel carriers.

Chondrocytes were encapsulated in non-degrading and partially degrading poly(ethylene glycol) (PEG) gels in apposition to native cartilage layers in order to examine the effects of gel degradation on the integration of regenerated cartilaginous matrix with native tissue. In addition, the effect of collagenase predigestion of the native cartilage surfaces on this integration was examined in studies with partially degrading co-polymer gels. Integration was quantitatively assessed by mechanical measurements of adhesive strength, and visualized by histological staining and non-destructive ultrasound analysis. Constructs with encapsulated chondrocytes and a non-degrading gel layer had significantly higher adhesive strength than partially degrading gel constructs and non-degrading gel constructs without cells. In addition, better maintenance of proper cell morphology was observed near the gel-cartilage interface in non-degrading gel constructs than in partially degrading gel constructs after 8 weeks of in vitro culture. Facile collagen distribution in the degrading gels appeared to have a significant effect on mechanical adhesion measurements only when the native cartilage surface was predigested with collagenase. Ultrasound analysis provided qualitative evidence of cartilaginous matrix evolution and non-destructive imaging of developing constructs and the interface between newly formed matrix and existing cartilage tissue.

Effect of intrastriatal injection of diisopropylfluorophosphate on acetylcholine, dopamine, and serotonin metabolism.

Diisopropylfluorophosphate (81.5 nmol) was injected directly into the striata of rats to study changes in striatal metabolism of acetylcholine (ACh), 3,4-dihydroxyphenylethylamine (dopamine), and 5-hydroxytryptamine (serotonin) at early time points following acute irreversible inhibition of cholinesterase. Twenty minutes following the intrastriatal injection of diisopropylfluorophosphate, levels of striatal acetylcholine were elevated by 50%, but a decrease in KACh compensated for this change. At 1 h, levels of ACh were still elevated, but not significantly different from control values. However, KACh and, hence, ACh turnover were greatly enhanced at this time. Finally, at 24 h, striatal ACh content was only slightly elevated and KACh and the turnover rate of ACh had returned to control values. Striatal cholinesterase activity remained significantly inhibited at all three times. At none of these times was ACh content or turnover affected in the parietal cortex, hippocampus, hypothalamus, or medulla/pons. Neither dopamine and its metabolites 3,4-dihydroxyphenylacetic acid and homovanillic acid nor serotonin and its metabolite 5-hydroxyindoleacetic acid were significantly affected at any of the three times by intrastriatal diisopropylfluorophosphate treatment. Possible mechanisms of the changes in cholinergic parameters are discussed.

Therapeutic effects of a ketogenic diet in Rett syndrome.

Seven girls (age 5 to 10 years) with Rett syndrome were investigated extensively. In 6 patients elevations of blood pyruvate were found. Blood lactate levels were marginally elevated. Two patients had variably elevated blood glucose levels. Metabolic studies were otherwise normal apart from minimally elevated blood ammonia levels in 3 of 5 patients tested, 2 of whom were on valproic acid. All 7 patients had anticonvulsant resistant seizures. EEG changes included generalized slowing and multifocal spike wave discharges, and pseudo-periodic burst-suppression patterns during sleep. Respiratory monitoring revealed apneic episodes only during the waking record. Six patients were below the 5th centile for weight despite normal caloric intake. Treatment with ketogenic diets, using medium chain triglyceride (MCT) oil when possible, has improved seizure control in the 5 patients who could tolerate the diet. Slight behavioral and motor improvement has occurred in these 5 patients and 6 of 7 patients on high fat diets have gained weight. With a possible defect in carbohydrate metabolism and a difficult seizure disorder, use of a ketogenic diet is logical and appears to produce clinical benefit in patients with Rett Syndrome.

Responses to chemotherapy or chemohormonal therapy in advanced breast cancer patients treated previously with adjuvant chemotherapy. A subset analysis of CALGB Study 8081.

The Cancer and Leukemia Group B (CALGB) evaluated the response to subsequent chemotherapy or chemohormonal therapy in 46 patients with advanced breast cancer treated previously with adjuvant chemotherapy that had been completed 6 months or more before protocol entry. The results were compared with 379 patients in the same study who had not received prior adjuvant chemotherapy. The patients were treated with cyclophosphamide, Adriamycin (Adria Laboratories, Columbus, OH), and 5-fluorouracil (CAF), with or without tamoxifen. There was no difference in response rate, response duration, time to treatment failure, or survival between patients who had received prior adjuvant chemotherapy and those who had not. The addition of tamoxifen to CAF failed to enhance response rates or response durations in all subgroups. Women who relapsed 6 months or more after completion of adjuvant chemotherapy did not have inherently drug-resistant tumors. They responded to standard CAF chemotherapy with the same response rate and survival as patients untreated previously with chemotherapy.

Comparison of induction chemotherapies for metastatic breast cancer. An Eastern Cooperative Oncology Group Trial.

Patients with advanced breast carcinoma and no prior chemotherapy were prospectively evaluated to assess the induction capabilities of cyclophosphamide, methotrexate and 5-fluorouracil (CMF), Adriamycin and vincristine (AV), and CMF plus prednisone (CMFP). The crossover responsiveness from CMF or CMFP to AV and of AV to CMF were also assessed. A disproportionate randomization led to 166 analyzable cases on AV, 79 on CMF were also assessed. A disproportionate randomization led to 166 analyzable cases on AV, 79 on CMF and 86 on CMFP induction. One hundred and twelve patients were evaluated on crossover. Induction response rates were similar with 56% on AV, 57% on CMF and 63% on CMFP. Crossover response rates ranged from 32% to 41%. CMFP and AV were superior to CMF in terms of response duration (P = 0.05), and CMFP was superior to either in terms of time to treatment failure (P = 0.04), and survival (P = 0.03). Treatment failures occurred in only the on-study organ sites of disease in 73% of the patients and did not appear to be related to the response achieved. CMF was associated with more thrombocytopenia than either AV or CMFP (P = 0.03). AV was associated with fewer infections than CMFP (P = 0.02), less diarrhea than CMFP (P = 0.04), more emesis than CMF (P = 0.02), and more neurologic toxicity than either CMF or CMFP (P less than 0.0001). There was also more emesis with CMF than with CMFP (P = 0.006). CMFP was associated with greater delivery of CMF than was the CMF regimen despite a similar day 1 leukocyte distribution. These results strongly suggest that CMF(P) and AV are clinically noncross-resistant regimens, that AV and CMF are essentially equivalently active induction regimens, and that CMFP is superior to CMF and AV.

A feasibility study of intensive CAF as outpatient adjuvant therapy for stage II breast cancer in a cooperative group: CALGB 8443.

In preparation for a national Phase III study of dose and dose intensity in the treatment of node-positive, Stage II adenocarcinoma of the female breast, CALGB instituted a pilot study of intensive intravenous outpatient CAF (cyclophosphamide, Adriamycin, 5-fluorouracil) for four months. This study was designed to give full doses of drugs without dose reduction for hematologic toxicity. In order to evaluate the feasibility of physician and patient compliance with a potentially toxic therapy, a multi-institution pilot study was performed. This protocol demonstrated that a cooperative group could deliver toxic drug doses to outpatients with a median of 98% of cyclophosphamide, 97% of Adriamycin (doxorubicin), and 91% of 5-fluorouracil administered on schedule. Major side effects, as expected, were leukopenia, nausea, and vomiting. Disease-free survival is at least equivalent to that observed in previous studies.