Metabolomic analysis of prostate cancer risk in a prospective cohort: The alpha‐tocopherol,beta‐carotene cancer prevention (ATBC) study

Despite decades of concerted epidemiological research, relatively little is known about the etiology of prostate cancer. As genome‐wide association studies have identified numerous genetic variants, so metabolomic profiling of blood and other tissues represents an agnostic, “broad‐spectrum” approach for examining potential metabolic biomarkers of prostate cancer risk. To this end, we conducted a prospective analysis of prostate cancer within the Alpha‐Tocopherol, Beta‐Carotene Cancer Prevention Study cohort based on 200 cases (100 aggressive) and 200 controls (age‐ and blood collection date‐matched) with fasting serum collected up to 20 years prior to case diagnoses. Ultrahigh performance liquid chromatography/mass spectroscopy and gas chromatography/mass spectroscopy identified 626 compounds detected in >95% of the men and the odds ratio per 1‐standard deviation increase in log‐metabolite levels and risk were estimated using conditional logistic regression. We observed strong inverse associations between energy and lipid metabolites and aggressive cancer (p = 0.018 and p = 0.041, respectively, for chemical class over‐representation). Inositol‐1‐phosphate showed the strongest association (OR = 0.56, 95% CI = 0.39–0.81, p = 0.002) and glycerophospholipids and fatty acids were heavily represented; e.g., oleoyl‐linoleoyl‐glycerophosphoinositol (OR = 0.64, p = 0.004), 1‐stearoylglycerophosphoglycerol (OR=0.65, p = 0.025), stearate (OR=0.65, p = 0.010) and docosadienoate (OR = 0.66, p = 0.014). Both alpha‐ketoglutarate and citrate were associated with aggressive disease risk (OR = 0.69, 95% CI = 0.51–0.94, p = 0.02; OR = 0.69, 95% CI = 0.50–0.95, p = 0.02), as were elevated thyroxine and trimethylamine oxide (OR = 1.65, 95% CI = 1.08–2.54, p = 0.021; and OR = 1.36, 95% CI = 1.02–1.81, p = 0.039). Serum PSA adjustment did not alter the findings. Our data reveal several metabolomic leads that may have pathophysiological relevance to prostate carcinogenesis and should be examined through additional research.     

Immunolymphoscintigraphy of pulmonary and mediastinal lymph nodes in dogs: a new approach to lung cancer imaging

Despite improved resolution with new imaging techniques, surgical confirmation of mediastinal lymph node status is often required for reliable staging of patients with non-small cell lung cancer. Recent scintigraphic studies suggest that s.c. administration of radiolabeled antibodies can be more efficient than the i.v. route for targeting regional lymph nodes in animals and humans. To determine if this approach could be applied to the lymphatics of the lung, we injected both specific and irrelevant radiolabeled monoclonal antibodies via a flexible fiberoptic bronchoscope through the mucosa of lobar bronchi in normal dogs. The injected antibodies were expected to drain by way of local lymphatic vessels toward the central lymph nodes, in effect following the same pathway as do cells metastasizing to these nodes during early regional tumor dissemination. To accomplish this, anesthetized dogs were intubated and then coinjected with the two labeled antibodies [600 microCi/100 micrograms (total)] through a fiberoptic bronchoscope. The animals were serially imaged and then autopsied 14-36 h after injection. Individual hilar and carinal nodes contained over 1% of the injected 131I-labeled specific antibody dose and the average selectivity was 2.5:1 with respect to a coinjected irrelevant IgG. Distant organs (mesenteric lymph node, liver, spleen, bone marrow, and lung parenchyma other than the injection site) contained much less radioactivity, and those sites accumulated a greater fraction of the non-specific labeled antibody. The ratio of iodine-131 to iodine-125 counts between hilar/carinal lymph nodes and abdominal lymph nodes ranged from 15:1 to 100:1. These initial studies indicate efficient delivery of antibody to a subset of the regional nodes via pulmonary lymphatics. They suggest the feasibility of this technique which may be of use in the detection and perhaps therapy of human lung cancer metastases in regional lymph nodes.     

Biotransformation of pravastatin sodium in humans.

Pravastatin sodium (PV) is a potent cholesterol-lowering agent that acts by inhibiting 3-hydroxy-3-methylglutaryl-coenzyme A reductase. Biotransformation profiles of PV in pooled human urine, plasma, and feces from healthy male volunteers given single 19.2-mg oral or 9.9-mg iv doses of [14C]PV were determined by HPLC. The predominant drug-related component in urine, plasma, and feces corresponded to intact PV; in the pooled urine samples, PV constituted 29 and 69% of the radioactivity after the po and iv doses, respectively. The delta 4.5-3 alpha-hydroxy isomer of PV constituted 10% (po) and 2% (iv), and 6-epi-PV constituted 3% (po) and 1% (iv) of the urinary radioactivity. Negligible amounts of the lactones of PV or its isomers were detected in urine, plasma, or feces. At least 15 other metabolites were also present; none of these accounted for more than 6% of the total urinary radioactivity. For metabolite isolation, an aliquot of pooled urine samples, obtained after administration of the radioactive dose, was added as a tracer to urine samples obtained from healthy subjects after administration of single nonradiolabeled 40-mg oral doses of PV. Urinary metabolites were concentrated on an XAD-2 column, extracted with ethyl acetate, and purified by extensive preparative HPLC. In addition to isolation and identification of unchanged drug and the two isomeric metabolites described above, eight other metabolites were isolated and structural assignments were made based on HPLC, UV spectra, mass spectral analysis, and proton NMR.(ABSTRACT TRUNCATED AT 250 WORDS)     

Sites of First-Pass Bioactivation (Hydrolysis) of Orally Administered Zofenopril Calcium in Dogs

The relative contribution of the gut, liver, and lungs as sites of first-pass bioactivation (hydrolysis) of the orally administered ester prodrug, zofenopril calcium (SQ 26,991), to the active angiotensin converting enzyme (ACE) inhibitor, SQ 26,333, was determined. With a five-way study design, two dogs each received a single 1.6-mg/kg dose of zofenopril [as its soluble potassium salt (SQ 26,900)] via the following routes of administration: intraarterial, intravenous, intraportal, and oral. Each dog also received an equimolar oral dose of zofenopril calcium (1.5 mg/kg). Concentrations of zofenopril in plasma were quantitated with a GC/MSD assay. Extraction ratios (E) for zofenopril by the gut, liver, and lungs were calculated based on the ratios of the area under the curve (AUC) values of zofenopril in arterial plasma after administration by the various routes. As individual eliminating organs, the gut and liver each had a high intrinsic capability to hydrolyze zofenopril; E values ranged from 45 to 89%. The lungs were found to have low, but measurable, hydrolytic activity with estimated E values that ranged from 5 to 26%. Overall, about 95% of the orally administered dose of zofenopril calcium was hydrolyzed during the first pass. Because the prodrug is sequentially exposed to the gut, liver, and lungs, the contribution of the gut to the overall first-pass hydrolysis (ca. 87%) was estimated to be significantly greater than that of the liver (<10%) or lungs (<2%). Zofenopril was rapidly eliminated after parenteral administration; mean residence time values were 2 min and the elimination half-life values (intraarterial route only) were 9 min. The total-body clearance (Cl_total) of zofenopril, determined after intraarterial injection, was rapid (ca. 25 ml/min/kg) and was similar to the Cl_total value reported previously for fosinopril sodium, another prodrug ACE inhibitor. Although the E _lungs value was relatively low, the lungs receive 100% of cardiac output and were estimated to contribute significantly to systemic bioactivation of zofenopril. The major sites of systemic bioactivation appear to be the lungs (ca. 44 to 65%) and liver (ca. 31%), whereas the hydrolysis of zofenopril by the blood per se does not apparently contribute to Cl_total.     

Laparoscopic reconstruction of gastroesophageal anatomy for the treatment of reflux disease

This paper presents the technique and results of an operation that restores normal anatomical and physiological antireflux mechanisms for the treatment of gastroesophageal reflux disease (GERD). The Hill procedure was modified beginning in 1973, evolving into an operation that has been standard in our practice since 1987. Major changes included total fixation of the abdominal esophagus and elimination of phrenoesophageal bundle plication.We began performing the procedure laparoscopically in 1991 and simultaneously began a study to look at our results. This is the first report of the first 44 patients operated on from October 1991 through March 1994. There was one operative complication. Mean follow-up was 14 months. One patient was lost to follow-up and one patient died. There were no long-term side effects. A Visick grading scale was designed to categorize results. Forty graded satisfactory (95%) and two unsatisfactory.     

Sulindac derivatives inhibit growth and induce apoptosis in human prostate cancer cell lines.

We examined the activity of two metabolites of sulindac (a nonsteroidal anti-inflammatory drug), sulindac sulfide and sulindac sulfone (exisulind, Prevatec), and a novel highly potent analog of exisulind (CP248) on a series of human prostate epithelial cell lines. Marked growth inhibition was seen with the BPH-1, LNCaP, and PC3 cell lines with IC50 values of about 66 microM, 137 microM, and 64 nM for sulindac sulfide, exisulind, and CP248, respectively. DNA flow cytometry and 4',6'-diamido-2-phenylindole (DAPI) staining indicated that these three compounds also induced apoptosis in all of these cell lines. Similar growth inhibition also was seen with the PrEC normal human prostate epithelial cell line, but these cells were resistant to induction of apoptosis at concentrations up to 300 microM, 1 mM, and 750 nM of sulindac sulfide, exisulind, and CP248, respectively. Derivatives of LNCaP cells that stably overexpress bcl-2 remained sensitive to growth inhibition and induction of apoptosis by these compounds. In vitro enzyme assays indicated that despite its high potency in inhibiting growth and inducing apoptosis, CP248, like exisulind, lacked cyclooxygenase (COX-1 and COX-2) inhibitory activity even at concentrations up to 10 mM. Moreover, despite variations of COX-1 and COX-2 expression, the three benign and malignant prostate cell lines showed similar sensitivity to growth inhibition and induction of apoptosis by these three compounds. Therefore, sulindac derivatives can cause growth inhibition and induce apoptosis in human prostate cancer cells by a COX-1 and -2 independent mechanism, and this occurs irrespective of androgen sensitivity or increased expression of bcl-2. These compounds may be useful in the prevention and treatment of human prostate cancer.     

Does ketamine mimic aspects of schizophrenic speech?

Speech disturbances are well-known symptoms contributing to the diagnosis of schizophrenia. Subanesthetic doses of the N-methyl-D-aspartate (NMDA) antagonist ketamine have been reported to produce positive and negative symptoms and cognitive impairments consistent with those seen in schizophrenia. Insofar as this is true, it constitutes evidence that the NMDA system is involved in schizophrenia. It is therefore of interest to know whether ketamine produces speech disturbances like those of schizophrenia. Quantitative computer-aided analysis of apparently normal speech can detect clinically relevant changes and differences that are not noticeable to the human observer. Accordingly, in this study, speech samples were analysed for repetitiousness, idea density, and verb density using software developed by the authors. The samples came from two experiments, a within-subjects study of healthy volunteers given intravenous ketamine versus placebo, and a between-groups study of patients diagnosed with schizophrenia and comparable healthy controls.Our primary hypothesis was that in both schizophrenia and ketamine, repetitiousness would increase, since perserverative speech is a well-known symptom of schizophrenia. Our secondary hypotheses were that in both schizophrenia and ketamine, idea density and verb density would decrease as indicators of cognitive impairment. The primary hypothesis was confirmed in the schizophrenia experiment (between groups) and the ketamine experiment (within subjects).The secondary hypotheses were disconfirmed except that in the ketamine experiment, verb density was significantly lowered. Reduced use of verbs apparently reflects a cognitive impairment of a different type than repetitiousness, and further investigation is needed to determine whether this impairment occurs in psychosis.     

Effects of the antiestrogen LY 117018 on the modulation by ethinyl estradiol of the metabolism of [1-14C]oleic acid by perfused livers from normal and ovariectomized rats

Intact female Sprague-Dawley rats (195-249 g) and rats that had been ovariectomized (210-285 g) were injected subcutaneously for 14 days with ethinyl estradiol (15 micrograms/kg), the antiestrogen LY 117018 (500 micrograms/kg), both drugs simultaneously, or the vehicle (sesame oil) alone. Livers were removed and perfused in vitro in a recycling system. The administration of LY 117018 alone did not affect the secretion of triacylglycerol by livers from normal rats but decreased the secretion of triacylglycerol by livers from ovariectomized rats. When the drugs were administered concurrently to either normal or ovariectomized animals, the increase in the concentration of triacylglycerol and the decrease in the concentration of cholesteryl esters in the plasma produced by ethinyl estradiol were prevented. When administered to either intact or ovariectomized rats, ethinyl estradiol alone stimulated the synthesis and secretion of triacylglycerol and cholesteryl esters by perfused livers isolated from these animals. The simultaneous administration of LY 117018 with ethinyl estradiol prevented this stimulation of the hepatic synthesis and secretion of triacylglycerol and cholesteryl esters. The depression of ketogenesis observed with livers from rats administered ethinyl estradiol alone was reversed by concurrent administration of LY 117018. The concurrent administration of the estrogen and antiestrogen did not result, however, in a complete blockade of the estrogen-induced elevation of hepatic triacylglycerol synthesis and depression of ketogenesis. The incorporation of [1-14C]oleic acid into the triacylglycerol and ketone bodies by livers from ovariectomized rats was less than that of livers from normal rats. It is clear that the antiestrogen antagonizes the actions of ethinyl estradiol on hepatic lipid metabolism. Furthermore, the use of the antiestrogen LY 117018 in these experiments allows the probable conclusion that the modulation of hepatic metabolism of fatty acid by estrogen is mediated by conventional estrogenic receptors.