Estrogen Regulates Local Cysteine Metabolism in Mouse Myometrium

Sulfur amino acid metabolism influences reproductive physiology, and transsulfuration in particular may be critical for normal cellular function. The sex hormone estrogen (E2) modulates gene expression and redox balance in some tissues by inducing the transsulfuration enzymes cystathionine β-synthase (CBS) and cystathionine γ-lyase (CSE). The role of sex hormones in sulfur amino acid metabolism by uterine smooth muscle is not known. Here, we show that CBS and CSE proteins increase in the mouse myometrium during estrus and diestrus, respectively, suggesting that E2 reciprocally regulates myometrial CBS and CSE expression. In ovariectomized mice, exogenous E2 upregulates CBS and downregulates CSE levels. E2 promotes CBS mRNA and protein expression but attenuates CSE protein expression without affecting CSE mRNA. This pattern of E2-stimulated changes in transsulfuration enzyme expression is specific to the uterine smooth muscle. E2 does not change vaginal or cervical expression of CBS or CSE significantly, and E2 decreases expression of CSE in the liver without affecting CBS. E2 also downregulates myometrial cysteinesulfinic acid decarboxylase (CSAD) and decreases myometrial biochemical synthesis of the gaso-transmitter hydrogen sulfide (H2S). These findings suggest that myometrial sulfur amino acid metabolism may regulate uterine redox homeostasis, with implications for the source and metabolism of myometrial cysteine in high E2 states such as estrus and pregnancy.

Cystathionine γ-lyase promotes estrogen-stimulated uterine artery blood flow via glutathione homeostasis

During pregnancy, estrogen (E₂) stimulates uterine artery blood flow (UBF) by enhancing nitric oxide (NO)-dependent vasodilation. Cystathionine γ-lyase (CSE) promotes vascular NO signaling by producing hydrogen sulfide (H₂S) and by maintaining the ratio of reduced-to-oxidized intracellular glutathione (GSH/GSSG) through l-cysteine production. Because redox homeostasis can influence NO signaling, we hypothesized that CSE mediates E₂ stimulation of UBF by modulating local intracellular cysteine metabolism and GSH/GSSG levels to promote redox homeostasis. Using non-pregnant ovariectomized WT and CSE-null (CSE KO) mice, we performed micro-ultrasound of mouse uterine and renal arteries to assess changes in blood flow upon exogenous E₂ stimulation. We quantified serum and uterine artery NO metabolites (NO_x), serum amino acids, and uterine and renal artery GSH/GSSG. WT and CSE KO mice exhibited similar baseline uterine and renal blood flow. Unlike WT, CSE KO mice did not exhibit expected E₂ stimulation of UBF. Renal blood flow was E₂-insensitive for both genotypes. While serum and uterine artery NO_x were similar between genotypes at baseline, E₂ decreased NO_x in CSE KO serum. Cysteine was also lower in CSE KO serum, while citrulline and homocysteine levels were elevated. E₂ and CSE deletion additively decreased GSH/GSSG in uterine arteries. In contrast, renal artery GSH/GSSG was insensitive to E₂ or CSE deletion. Together, these findings suggest that CSE maintenance of uterine artery GSH/GSSG facilitates nitrergic signaling in uterine arteries and is required for normal E₂ stimulation of UBF. These data have implications for pregnancy pathophysiology and the selective hormone responses of specific vascular beds.

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CSE-null mice exhibit abnormal estrogen augmentation of uterine artery blood flow.

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Estrogen lowers uterine artery nitric oxide metabolites in CSE null mice.

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CSE loss and estrogen additively impair uterine artery glutathione homeostasis.

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Neither CSE loss nor estrogen influences renal artery blood flow or glutathione.

Effects of resveratrol or estradiol on postexercise endothelial function in estrogen-deficient postmenopausal women

Regular exercise enhances endothelial function in older men, but not consistently in estrogen-deficient postmenopausal women. Estradiol treatment improves basal endothelial function and restores improvements in endothelial function (flow-mediated dilation, FMD) to aerobic exercise training in postmenopausal women; however, estradiol treatment is controversial. Resveratrol, an estrogen receptor ligand, enhances exercise training effects on cardiovascular function and nitric oxide (NO) release in animal models, but impairs exercise training effects in men. We conducted a randomized cross-over, double-blinded, placebo-controlled pilot study to determine whether acute (single dose) resveratrol (250-mg tablet) or estradiol (0.05 mg/day transdermal patch) treatment enhances FMD at rest and after a single bout of moderate-intensity aerobic exercise in healthy estrogen-deficient postmenopausal women (n = 15, 58.1 ± 3.2 yr). FMD was measured before and after (30, 60, and 120 min) a 40-min bout of moderate-intensity treadmill exercise (60-75% peak heart rate) under the respective conditions (separated by 1-2 wk). FMD was higher (P < 0.05) before exercise and at all post-exercise time points in the resveratrol and estradiol conditions compared to placebo. FMD was increased from baseline by 120 min postexercise in the estradiol condition (P < 0.001), but not resveratrol or PL conditions. Consistent with our previous findings, estradiol also enhances endothelial function in response to acute endurance exercise. Although resveratrol improved basal FMD, there was no apparent enhancement of FMD to acute exercise and, therefore, may not act as an estradiol mimetic.NEW & NOTEWORTHY The benefits of endurance exercise training on endothelial function are diminished in estrogen-deficient postmenopausal women, but estradiol treatment appears to restore improvements in endothelial function in this group. We show that basal endothelial function is enhanced with both acute estradiol and resveratrol treatments in estrogen-deficient postmenopausal women, but endothelial function is only enhanced following acute endurance exercise with estradiol treatment.

Effect of neuronal nitric oxide synthase serine-1412 phosphorylation on hypothalamic-pituitary-ovarian function and leptin response

Hypothalamic neuronal nitric oxide synthase (nNOS) potentiates adult female fertility in rodents by stimulating gonadotropin releasing hormone (GnRH) secretion, which in turn promotes luteinizing hormone (LH) release and ovulation. The mechanism of hypothalamic nNOS activation is not clear but could be via nNOS serine1412 (S1412) phosphorylation, which increases nNOS activity and physiologic NO effects in other organ systems. In female rodents, hypothalamic nNOS S1412 phosphorylation reportedly increases during proestrus or upon acute leptin exposure during diestrus. To determine if nNOS S1412 regulates female reproduction in mice, we compared the reproductive anatomy, estrous cycle duration and phase proportion, and fecundity of wild-type and nNOS serine1412➔alanine (nNOSS1412A) knock-in female mice. We also measured hypothalamic GnRH and serum LH, follicle stimulating hormone (FSH), estradiol, and progesterone in diestrus mice after intraperitoneal leptin injection. Organ weights and histology were not different by genotype. Ovarian primordial follicles, antral follicles, and corpora lutea were similar for wild-type and nNOSS1412A mice. Likewise, estrous cycle duration and phase length were not different, and fecundity was unremarkable. There were no differences among genotypes for LH, FSH, estradiol, or progesterone. In contrast to prior studies, our work suggests that nNOS S1412 phosphorylation is dispensable for normal hypothalamic-pituitary-ovarian function and regular estrous cycling. These findings have important implications for current models of fertility regulation by nNOS phosphorylation.

Protein kinase A facilitates relaxation of mouse ileum via phosphorylation of neuronal nitric oxide synthase

BACKGROUND AND PURPOSE

The enteric neurotransmitter nitric oxide (NO) regulates gastrointestinal motility by relaxing smooth muscle. Pharmacological cAMP induction also relaxes gastrointestinal smooth muscle, but it is uncertain whether cAMP augments or suppresses enteric NO signalling. In other organ systems, cAMP can increase neuronal NO production by stimulating protein kinase A (PKA) to phosphorylate neuronal NOS (nNOS) Serine-1412 (S1412). We hypothesized that cAMP also increases nNOS S1412 phosphorylation by PKA in enteric neurons to augment nitrergic relaxation of mouse ileum.

EXPERIMENTAL APPROACH

We measured contractile force and nNOS S1412 phosphorylation in ileal rings suspended in an organ bath. We used forskolin to induce cAMP-dependent relaxation of wild type, nNOS^S1412A knock-in and nNOSα-null ileal rings in the presence or absence of PKA, protein kinase B (Akt) and NOS inhibitors.

KEY RESULTS

Forskolin stimulated phosphorylation of nNOS S1412 in mouse ileum. Forskolin relaxed nNOSα-null and nNOS^S1412A ileal rings less than wild-type ileal rings. PKA inhibition blocked forskolin-induced nNOS phosphorylation and attenuated relaxation of wild type but not nNOS^S1412A ileum. Akt inhibition did not alter nNOS phosphorylation with forskolin but did attenuate relaxation of wild type and nNOS^S1412A . NOS inhibition with L-NAME eliminated the effects of PKA and Akt inhibitors on relaxation.

CONCLUSION AND IMPLICATIONS

PKA phosphorylation of nNOS S1412 augments forskolin-induced nitrergic ileal relaxation. The relationship between cAMP/PKA and NO is therefore synergistic in enteric nitrergic neurons. Because NO regulates gut motility, selective modulation of enteric neuronal cAMP synthesis may be useful for the treatment of gastrointestinal motility disorders.

Adiponectin links maternal metabolism to uterine contractility

Adiponectin is secreted by adipose tissue and promotes insulin sensitivity. Low circulating adiponectin is associated with increased risk for preterm labor, but the influence of adiponectin on uterine myometrial physiology is unknown. We hypothesized that adiponectin receptors (AdipoRs) decrease myometrial contractility via AMPK to promote uterine quiescence in pregnancy. Using quantitative RT-PCR, we found that nonpregnant or pregnant human and mouse myometrium express AdipoR1 and AdipoR2 mRNAs. We confirmed AdipoR2 protein expression in human and mouse myometrium, with increased abundance in late mouse pregnancy. Both recombinant adiponectin and a pharmacologic AdipoR agonist, AdipoRon, potently inhibited uterine myometrial strip contractions in physiologic organ bath. The relaxation was independent of contractile stimulus (oxytocin, KCl, U46619). AdipoR agonists increased AMPK phosphorylation in pregnant mouse myometrium, and the direct AMPK activator A769662 also relaxed myometrial strips. However, the AMPK inhibitor dorsomorphin (compound C) blocked AMPK phosphorylation but did not abolish relaxation with either AdipoRon or A769662. In summary, adiponectin inhibits myometrial contractility consistent with the possibility that it is a previously unrecognized link between maternal metabolism and pregnancy maintenance. We also identify a separate role for AMPK regulating myometrial contractions that may influence labor onset.-Vyas, V., Guerra, D. D., Bok, R., Powell, T., Jansson, T., Hurt, K. J. Adiponectin links maternal metabolism to uterine contractility.

Na+-Leak Channel, Non-Selective (NALCN) Regulates Myometrial Excitability and Facilitates Successful Parturition

BACKGROUND/AIMS

Uterine contractility is controlled by electrical signals generated by myometrial smooth muscle cells. Because aberrant electrical signaling may cause inefficient uterine contractions and poor reproductive outcomes, there is great interest in defining the ion channels that regulate uterine excitability. In human myometrium, the Na+ leak channel, non-selective (NALCN) contributes to a gadolinium-sensitive, Na+-dependent leak current. The aim of this study was to determine the role of NALCN in regulating uterine excitability and examine its involvement in parturition.

METHODS

Wildtype C57BL/6J mice underwent timed-mating and NALCN uterine expression was measured at several time points across pregnancy including pregnancy days 7, 10, 14, 18 and 19. Sharp electrode current clamp was used to measure uterine excitability at these same time points. To determine NALCN's contribution to myometrial excitability and pregnancy outcomes, we created smooth-muscle-specific NALCN knockout mice by crossing NALCNfx/fx mice with myosin heavy chain Cre (MHCCreeGFP) mice. Parturition outcomes were assessed by observation via surveillance video recording cre control, flox control, smNALCN+/-, and smNALCN-/- mice. Myometrial excitability was compared between pregnancy day 19 flox controls and smNALCN-/- mice.

RESULTS

We found that in the mouse uterus, NALCN protein levels were high early in pregnancy, decreased in mid and late pregnancy, and then increased in labor and postpartum. Sharp electrode current clamp recordings of mouse longitudinal myometrial samples from pregnancy days 7, 10, 14, 18, and 19 revealed day-dependent increases in burst duration and interval and decreases in spike density. NALCN smooth muscle knockout mice had reduced myometrial excitability exemplified by shortened action potential bursts, and an increased rate of abnormal labor, including prolonged and dysfunctional labor.

CONCLUSIONS

Together, our findings demonstrate that the Na+ conducting channel NALCN contributes to the myometrial action potential waveform and is important for successful labor outcomes.

Perinatal Endotoxemia Induces Sustained Hepatic COX-2 Expression through an NFκB-Dependent Mechanism

BACKGROUND

Exposure to perinatal infection is associated with the multiple morbidities complicating preterm birth. How a relatively immature innate immune response contributes to this is unknown.

OBJECTIVE

We sought to determine if the perinatal innate immune response to endotoxemia induces a unique pattern of cyclooxygenase-2 (COX-2) expression via an NFκB-dependent mechanism.

METHODS

Hepatic and pulmonary COX-2 mRNA expression was assessed following perinatal (at embryonic days 15 and 19 and after birth) or adult endotoxemia. Hepatic NFκB activity was assessed by cytosolic inhibitory protein degradation and subunit nuclear translocation. Immunohistochemistry and isolated cell preparations determined hepatic macrophage COX-2 expression, and the effect of pharmacologic and genetic inhibition of NFκB activity was tested.

RESULTS

Perinatal endotoxemia induced sustained hepatic macrophage COX-2 expression and NFκB activity compared to in exposed adults. Isolated hepatic macrophages and immunohistochemistry demonstrated enriched LPS-induced COX-2 expression that was sensitive to pharmacologic and genetic approaches to attenuate NFκB activity. Finally, pharmacologic inhibition of endotoxemia-induced NFκB activity in neonatal mice prevented hepatic NFκB activity and attenuated COX-2 expression.

CONCLUSION

Our findings of sustained neonatal hepatic NFκB activity and COX-2 expression in response to endotoxemia support a robust perinatal innate immune response. This may represent a link between the innate immune response and the pathogenesis of diseases associated with preterm birth.

Imaging considerations for in vivo 13C metabolic mapping using hyperpolarized 13C-pyruvate

One of the challenges of optimizing signal-to-noise ratio (SNR) and image quality in (13)C metabolic imaging using hyperpolarized (13)C-pyruvate is associated with the different MR signal time-courses for pyruvate and its metabolic products, lactate and alanine. The impact of the acquisition time window, variation of flip angles, and order of phase encoding on SNR and image quality were evaluated in mathematical simulations and rat experiments, based on multishot fast chemical shift imaging (CSI) and three-dimensional echo-planar spectroscopic imaging (3DEPSI) sequences. The image timing was set to coincide with the peak production of lactate. The strategy of combining variable flip angles and centric phase encoding (cPE) improved image quality while retaining good SNR. In addition, two aspects of EPSI sampling strategies were explored: waveform design (flyback vs. symmetric EPSI) and spectral bandwidth (BW = 500 Hz vs. 267 Hz). Both symmetric EPSI and reduced BW trended toward increased SNR. The imaging strategies reported here can serve as guidance to other multishot spectroscopic imaging protocols for (13)C metabolic imaging applications.

DNP-Hyperpolarized C Magnetic Resonance Metabolic Imaging for Cancer Applications

Critical factors in characterizing the aggressiveness and response to therapy for tumors are the availability of noninvasive biomarkers that can be combined with other clinical parameters to tailor treatment regimens to each individual patient. While conventional magnetic resonance (MR) images are widely used to estimate changes in tumor size, they do not provide the rapid readout that is required to make an early decision on whether a change in therapy is required. The use of hyperpolarized (13)C agents to obtain metabolic imaging data is of great interest for in vivo assessment of tumors. One of the first agents being considered for in vivo studies with dynamic nuclear polarization (DNP) is 1-(13)C-labeled pyruvate, which is converted to lactate or alanine, dependent upon the needs of the tissue in question. The development of this new technology and its implementation in preclinical cancer model systems has clearly demonstrated the potential for highlighting tumor aggressiveness and for monitoring changes associated with disease progression. While there is further work to do in terms of studying new agents, improving the DNP process itself and developing efficient MR methods for acquiring and analyzing the data, the preliminary results are extremely promising and provide strong motivation for considering cancer as one of the first applications of the technology.

In vivo 13 carbon metabolic imaging at 3T with hyperpolarized 13C-1-pyruvate

We present for the first time dynamic spectra and spectroscopic images acquired in normal rats at 3T following the injection of (13)C-1-pyruvate that was hyperpolarized by the dynamic nuclear polarization (DNP) method. Spectroscopic sampling was optimized for signal-to-noise ratio (SNR) and for spectral resolution of (13)C-1-pyruvate and its metabolic products (13)C-1-alanine, (13)C-1-lactate, and (13)C-bicarbonate. Dynamic spectra in rats were collected with a temporal resolution of 3 s from a 90-mm axial slab using a dual (1)H-(13)C quadrature birdcage coil to observe the combined effects of metabolism, flow, and T(1) relaxation. In separate experiments, spectroscopic imaging data were obtained during a 17-s acquisition of a 20-mm axial slice centered on the rat kidney region to provide information on the spatial distribution of the metabolites. Conversion of pyruvate to lactate, alanine, and bicarbonate occurred within a minute of injection. Alanine was observed primarily in skeletal muscle and liver, while pyruvate, lactate, and bicarbonate concentrations were relatively high in the vasculature and kidneys. In contrast to earlier work at 1.5 T, bicarbonate was routinely observed in skeletal muscle as well as the kidney and vasculature.

[Complications after ERCP and their treatment]

The aim of this article is to evaluate the occurrence of complications following diagnostic and therapeutic ERCP's and their treatment. It is based on data collected between January 1, 1998 and December 31, 2002, during which time period the Surgical Clinic in Pardubice completed 18 surgical procedures on patients experiencing post-ERCP complications. The article also provides an analysis of the individual types of complications, their specific surgical procedures, and the results. The discussion passage deals with the theoretical possibility of applying conservative treatment that is applicable in certain types of perforation occurrences, with special concern focused on the occurrence of fatal retroperitoneal phlegmona.

Urokinase plasminogen activator amino-terminal peptides inhibit development of the rat ventral prostate

The plasma membrane urokinase plasminogen activator receptor (uPAR) localizes and enhances activation of pro-uPA. Active uPA, in turn, promotes increased degradation of the extracellular matrix (ECM) by activation of plasminogen. uPAR binds to ECM molecules and integrins, which can affect cellular adhesion, signal transduction, and gene regulation. The current study examines the expression and function of uPAR in developing rat ventral prostates (VPs). We report that newborn VPs express uPAR mRNA and protein. In addition, the function of uPAR-bound uPA during in vitro prostatic development was studied by adding recombinant peptide competitive inhibitors of uPA-uPAR binding. Newborn VP explants were cultured in serum-free media for one week with 10(-8) M testosterone plus chimeric peptides containing a human immunoglobulin G Fc domain and either human uPA amino acids 1-138 (hu-uPA 1-138) as a control or mouse uPA amino acids 1-138 (mo-uPA 1-138) or 1-48 (mo-uPA 1-48). Hu-uPA 1-138-treated VPs underwent normal ductal branching morphogenesis and tissue differentiation. In contrast, VPs treated with mo-uPA 1-138 or mo-uPA 1-48 displayed a dose-dependent perturbation of ductal branching. Differentiation of both epithelial and mesenchymal tissues was also impaired. Mo-uPA 1-48-treated VPs contained significantly more apoptotic cells. These observations suggest that disruption of uPA binding to uPAR results in a retardation of the development of newborn VPs.

Docetaxel, estramustine, plus trastuzumab in patients with metastatic androgen-independent prostate cancer

The incidence of human epidermal growth factor receptor 2 (HER2) protein overexpression and its prognostic value are not well characterized in patients with prostate cancer. A phase I study was designed to evaluate docetaxel/estramustine plus trastuzumab, a humanized monoclonal antibody that binds to the HER2 receptor, in patients with metastatic androgen-independent prostate cancer (AIPC). HER2 positivity was not required because safety was the primary endpoint. Patients received oral estramustine 280 mg three times daily (days 1 to 5); docetaxel, 70 mg/m(2) intravenously (day 2); and trastuzumab, 2 mg/kg intravenously (days 2, 9, and 19), every 21 days until the disease progressed or toxicity became unacceptable. This regimen was well tolerated among the first 13 treated patients. Grade 4 neutropenia was seen in 10% of administered cycles. There were two episodes of febrile neutropenia and two thrombembolic events. Of the 13 patients evaluable for prostate-specific antigen (PSA) response, nine (69%) experienced a decrease in PSA level of >50%. Two (33%) of six patients with measurable disease had objective responses, and one complete response was seen on bone scan. Docetaxel/estramustine/trastuzumab appears to be a safe combination when used in the treatment of metastatic AIPC. The response data are too preliminary for speculation about the relative benefits of this 3-drug regimen compared with the combination of only docetaxel and estramustine in this clinical setting.

Prospective trial of the herbal supplement PC-SPES in patients with progressive prostate cancer

PURPOSE

PC-SPES is an herbal supplement for which there are anecdotal reports of anti-prostate cancer activity. This phase II study was undertaken to assess the efficacy and toxicity of PC-SPES in prostate cancer patients.

PATIENTS AND METHODS

Thirty-three patients with androgen-dependent prostate cancer (ADPCa) and 37 patients with androgen-independent prostate cancer (AIPCa) were treated with PC-SPES at a dose of nine capsules daily. Clinical outcome was assessed with serial serum prostate-specific androgen (PSA) level measurement and imaging studies.

RESULTS

One hundred percent of ADPCa patients experienced a PSA decline of >/= 80%, with a median duration of 57+ weeks. No patient has developed PSA progression. Thirty-one patients (97%) had declines of testosterone to the anorchid range. Two ADPCa patients had positive bone scans; both improved. One patient with a bladder mass measurable on computed tomography scan experienced disappearance of this mass. Nineteen (54%) of 35 AIPCa patients had a PSA decline of >/= 50%, including eight (50%) of 16 patients who had received prior ketoconazole therapy. Median time to PSA progression was 16 weeks (range, 2 to 69+ weeks). Of 25 patients with positive bone scans, two had improvement, seven had stable disease, 11 had progressive disease, and five did not have a repeat bone scan because of PSA progression. Severe toxicities included thromboembolic events (n = 3) and allergic reactions (n = 3). Other frequent toxicities included gynecomastia/gynecodynia, leg cramps, and grade 1 or 2 diarrhea.

CONCLUSION

PC-SPES seems to have activity in the treatment of both ADPCa and AIPCa and has acceptable toxicity. Further study is required to determine whether its effects exceed those expected with estrogen therapy.

Simultaneous antiandrogen withdrawal and treatment with ketoconazole and hydrocortisone in patients with advanced prostate carcinoma

BACKGROUND

Although antiandrogen withdrawal has moderate efficacy in patients with hormone refractory prostate carcinoma (HRPC), the effect of the simultaneous suppression of adrenal androgens with ketoconazole at the time of antiandrogen withdrawal is not known.

METHODS

Twenty consecutive patients with HRPC who had developed progressive disease despite combined androgen blockade were treated with antiandrogen withdrawal and simultaneous ketoconazole as a means of inhibiting adrenal steroid production. Prostate specific antigen (PSA) response was defined as a > 50% fall in PSA from baseline that was maintained for at least 8 weeks.

RESULTS

Ten patients had established metastatic disease, 2 had high PSAs and no imaging studies (PSA of 70 and 160 ng/mL, respectively), 3 had microscopically positive lymph nodes and serologic progression, and 5 had serologic progression alone. Overall, of 20 evaluable patients, 11 (55%) had a > 50% fall in PSA (95% confidence interval [CI], 31.5-76.9%). The median PSA response duration was 8.5 months (95% CI, 7-17 months). The median survival was 19 months. Toxicity was mild, with Grade 1 and 2 nausea and emesis in 15% of patients, Grade 1 fatigue in 10% of patients, and reversible Grade 1 or 2 hepatotoxicity in 10% of patients. Mild skin toxicity was observed in 20% of patients.

CONCLUSIONS

The addition of ketoconazole and hydrocortisone to antiandrogen withdrawal appears to increase the PSA response proportion observed with antiandrogen withdrawal alone. Toxicity is mild.

Hepatic metastases: comparative study of diagnostic ultrasound, CT, nuclear scintigraphy and laboratory tests

Computed tomography, ultrasound, nuclear scintigraphy, and laboratory tests (lactic dehydrogenase, alkaline phosphatase, and 5-nucleotidase) were compared in 135 patients with gastro-intestinal carcinoma to define the most useful test to detect hepatic metastases. Thirty-six patients (26.7 per cent) had hepatic metastases at laparotomy. Sensitivities were low: 46.2 per cent for nuclear scintigraphy, 57.6 per cent for ultrasound, 67.7 per cent for computed tomography and 62.9 per cent for lactic dehydrogenase. Accuracies ranged from 62.9 (lactic dehydrogenase) to 77.6 per cent (nuclear scintigraphy). No significant differences were found. Accurate and efficient detection of hepatic metastases is hampered by relatively low sensitivity, specificity and accuracy of the conventional imaging tests and laboratory tests.

Prospective comparative study of ultrasound, CT-scan, scintigraphy and laboratory tests to detect hepatic metastases

The conventional methods of CT scan (CT), ultrasound (US), scintigraphy (SC), and laboratory tests (LDH, AP, 5-Nt) were prospectively compared in 135 patients with gastrointestinal carcinoma to define the most useful test to detect hepatic metastases. Thirty-six patients (26.7%) had hepatic metastases at laparotomy. Sensitivities were low: 46% for SC, 58% for US, 68% for CT and 63% for LDH. Accuracies ranged from 62% (LDH) to 78% (SC). No significant differences were found. Accurate and efficient detection of hepatic metastases is hampered by the relatively low sensitivity, specificity and accuracy of conventional imaging and laboratory tests.