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Purpose of review This review explores trends in the United States (US) transplant surgery workforce with a focus on historical demographics, post-fellowship job market, and quality of life reported by transplant surgeons. Ongoing efforts to improve women and racial/ethnic minority representation in transplant surgery are highlighted. Future directions to create a transplant workforce that reflects the diversity of the US population are discussed. Recent findings Representation of women and racial and ethnic minorities among transplant surgeons is minimal. Although recent data shows an improvement in the number of Black transplant surgeons from 2% to 5.5% and an increase in women to 12%, the White to Non-White transplant workforce ratio has increased 35% from 2000 to 2013. Transplant surgeons report an average of 4.3 call nights per week and less than five leisure days a month. Transplant ranks 1st among surgical sub-specialties in the prevalence of three well-studied facets of burnout. Concerns about lifestyle may contribute to the decreasing demand for advanced training in abdominal transplantation by US graduates. Summary Minimal improvements have been made in transplant surgery workforce diversity. Sustained and intentional recruitment and promotion efforts are needed to improve the representation of women and minority physicians and advanced practice providers in the field.

Thirty-day (30-day) mortality, a common posttreatment quality metric, is yet to be described following surgery for head and neck squamous cell carcinoma (HNSCC). This study aimed to measure 30-day postoperative mortality in HNSCC and describe clinical/nonclinical factors associated with 30-day mortality.In this retrospective cohort study, the National Cancer Database (2004 to 2013) was queried for eligible cases of HNSCC (n=91,858). Adult patients were included who were treated surgically with curative intent for the primary HNSCC, not missing first treatment, survival, and follow-up information. The outcome of interest was all-cause mortality within 30 days of definitive surgery. Clinical and nonclinical factors associated with all-cause 30-day postoperative mortality were estimated using a fully adjusted, multivariable logistic regression, which accounted for time-varying nature of adjuvant therapy.A total of 775 patients died within 30 days of definitive surgery for HNSCC (30-day mortality rate of 0.84%). Thirty-day mortality rate was however up to 2.33% (95% confidence interval [CI], 1.91%-2.75%) depending on comorbidity. In the fully adjusted model, increasing severity of comorbidity was associated with greater odds of 30-day mortality (Charlson-Deyo comorbidity scores of 1: adjusted odds ratio [aOR], 1.43; 95% CI, 1.21-1.69, and of 2+ aOR, 2.55; 95% CI, 2.07-3.14). Odds of 30-day mortality were greater among Medicaid patients (aOR, 1.77; 95% CI, 1.30-2.41), and in patients in neighborhoods with little education (≥ 29% missing high school diploma: aOR, 1.35; 95% CI, 1.02-1.78).Patients with higher 30-day mortality were those with a greater burden of comorbidities, with little education, and covered by Medicaid.

Supplemental Digital Content is available in the text., Rationale: In chronic heart failure, increased adrenergic activation contributes to structural remodeling and altered gene expression. Although adrenergic signaling alters histone modifications, it is unknown, whether it also affects other epigenetic processes, including DNA methylation and its recognition. Objective: The aim of this study was to identify the mechanism of regulation of the methyl-CpG–binding protein 2 (MeCP2) and its functional significance during cardiac pressure overload and unloading. Methods and Results: MeCP2 was identified as a reversibly repressed gene in mouse hearts after transverse aortic constriction and was normalized after removal of the constriction. Similarly, MeCP2 repression in human failing hearts resolved after unloading by a left ventricular assist device. The cluster miR-212/132 was upregulated after transverse aortic constriction or on activation of α1- and β1-adrenoceptors and miR-212/132 led to repression of MeCP2. Prevention of MeCP2 repression by a cardiomyocyte-specific, doxycycline-regulatable transgenic mouse model aggravated cardiac hypertrophy, fibrosis, and contractile dysfunction after transverse aortic constriction. Ablation of MeCP2 in cardiomyocytes facilitated recovery of failing hearts after reversible transverse aortic constriction. Genome-wide expression analysis, chromatin immunoprecipitation experiments, and DNA methylation analysis identified mitochondrial genes and their transcriptional regulators as MeCP2 target genes. Coincident with its repression, MeCP2 was removed from its target genes, whereas DNA methylation of MeCP2 target genes remained stable during pressure overload. Conclusions: These data connect adrenergic activation with a microRNA—MeCP2 epigenetic pathway that is important for cardiac adaptation during the development and recovery from heart failure.

Background— α1-adrenergic receptors (α1-ARs) play adaptive roles in the heart and protect against the development of heart failure. The 3 α1-AR subtypes, α1A, α1B, and α1D, have distinct physiological roles in mouse heart, but very little is known about α1 subtypes in human heart. Here, we test the hypothesis that the α1A and α1B subtypes are present in human myocardium, similar to the mouse, and are not downregulated in heart failure. Methods and Results— Hearts from transplant recipients and unused donors were failing (n=12; mean ejection fraction, 24%) or nonfailing (n=9; mean ejection fraction, 59%) and similar in age (≈44 years) and sex (≈70% male). We measured the α1-AR subtypes in multiple regions of both ventricles by quantitative real-time reverse-transcription polymerase chain reaction and radioligand binding. All 3 α1-AR subtype mRNAs were present, and α1A mRNA was most abundant (≈65% of total α1-AR mRNA). However, only α1A and α1B binding were present, and the α1B was most abundant (60% of total). In failing hearts, α1A and α1B binding was not downregulated, in contrast with β1-ARs. Conclusions— Our data show for the first time that the α1A and α1B subtypes are both present in human myocardium, but α1D binding is not, and the α1 subtypes are not downregulated in heart failure. Because α1 subtypes in the human heart are similar to those in the mouse, where adaptive and protective effects of α1 subtypes are most convincing, it might become feasible to treat heart failure with a drug targeting the α1A and/or α1B.

Background— Epinephrine (EPI) is an important neurotransmitter and hormone. Its role in regulating cardiovascular function at rest and with stress is unclear, however. Methods and Results— An epinephrine-deficient mouse model was generated in which the epinephrine-synthesizing enzyme phenylethanolamine N-methyltransferase was knocked out (KO). Blood pressure and heart rate were monitored by telemetry at rest and during graded treadmill exercise. Cardiac structure and function were evaluated by echocardiography in mice under 1 of 2 conditions: unstressed and lightly anesthetized or restrained and awake. In KO mice, resting cardiovascular function, including blood pressure, heart rate, and cardiac output, was the same as that in wild-type mice, and the basal norepinephrine plasma level was normal. However, inhibition of sympathetic innervation with the ganglion blocker hexamethonium caused a 54% smaller decrease in blood pressure in KO mice, and treadmill exercise caused an 11% higher increase in blood pressure, both suggesting impaired vasodilation in KO mice. Interestingly, phenylethanolamine N-methyltransferase KO did not change the heart rate response to ganglionic blockade and exercise. By echocardiography, KO mice had an increased ratio of left ventricular posterior wall thickness to internal dimensions but did not have cardiac hypertrophy, suggesting concentric remodeling in the KO heart. Finally, in restrained, awake KO mice, heart rate and ejection fraction remained normal, but cardiac output was significantly reduced because of diminished end-diastolic volume. Conclusion— Our data suggest that epinephrine is required for normal blood pressure and cardiac filling responses to stress but is not required for tachycardia during stress or normal cardiovascular function at rest.

Background— In α1-AR knockout (α1ABKO) mice that lacked cardiac myocyte α1-adrenergic receptor (α1-AR) binding, aortic constriction induced apoptosis, dilated cardiomyopathy, and death. However, it was unclear whether these effects were attributable to a lack of cardiac myocyte α1-ARs and whether the α1A, α1B, or both subtypes mediated protection. Therefore, we investigated α1A and α1B subtype–specific survival signaling in cultured cardiac myocytes to test for a direct protective effect of α1-ARs in cardiac myocytes. Methods and Results— We cultured α1ABKO myocytes and reconstituted α1-AR signaling with adenoviruses expressing α1-GFP fusion proteins. Myocyte death was induced by norepinephrine, doxorubicin, or H 2 O 2 and was measured by annexin V/propidium iodide staining. In α1ABKO myocytes, all 3 stimuli significantly increased apoptosis and necrosis. Reconstitution of the α1A subtype, but not the α1B, rescued α1ABKO myocytes from cell death induced by each stimulus. To address the mechanism, we examined α1-AR activation of extracellular signal-regulated kinase (ERK). In α1ABKO hearts, aortic constriction failed to activate ERK, and in α1ABKO myocytes, expression of a constitutively active MEK1 rescued α1ABKO myocytes from norepinephrine-induced death. In addition, only the α1A-AR activated ERK in α1ABKO myocytes, and expression of a dominant-negative MEK1 completely blocked α1A survival signaling in α1ABKO myocytes. Conclusions— Our results demonstrate a direct protective effect of the α1A subtype in cardiac myocytes and define an α1A-ERK signaling pathway that is required for myocyte survival. Absence of the α1A-ERK pathway can explain the failure to activate ERK after aortic constriction in α1ABKO mice and can contribute to the development of apoptosis, dilated cardiomyopathy, and death.

In this issue of Circulation , Bowling et al1 present important data on protein kinase C (PKC) in human heart failure. PKC is a candidate rate-limiting molecular switch in what has come to be known as “hypertrophic signaling,” the molecular mechanisms whereby surface and nuclear receptors and their intracellular transducers convert mechanical and soluble growth stimuli into the end product of a bigger cardiac myocyte. Cardiac myocyte hypertrophy is an essential chronic adaptation but is believed to become maladaptive in the so-called “transition from hypertrophy to failure.” Thus, hypertrophic signaling has become a research area of intense interest, with the hope that targeting specific signaling molecules by drugs or even gene therapy might be useful in heart failure. This editorial summarizes the present study in the context of recent data on PKC, particularly the β-isoform of PKC, and considers some unresolved issues and future directions. Recent editorials in this journal have presented variations on the general theme of hypertrophic signaling.2 3 4 Bowling et al1 studied PKC proteins, mRNAs, and activity in a dozen explanted hearts with end-stage dilated cardiomyopathy, both ischemic and idiopathic, and a similar number of nonfailing control hearts. Using left ventricular free wall samples from failing hearts, they showed by immunoblot that 2 Ca2+-sensitive PKC isoform proteins, α and β (both the β1 and β2 forms), are substantially elevated, by 40% to 70%, in particulate or “membrane” fractions. Furthermore, the α- and β-PKC proteins are increased in cardiac myocytes by immunostaining in tissue sections, and β1- and β2-PKC mRNAs are also higher in failing myocytes by in situ hybridization. Selectivity in upregulation is suggested by unchanged levels of a Ca2+-insensitive PKC isoform, e-PKC. Finally, PKC enzyme activity in failing membranes in vitro is …

In 1987, Ontario's physicians conducted a strike, ultimately not successful, over the issue of "extra billing." The fact that the Ontario public did not support this action reflected a major gap between the profession's view of itself and the public's view of the profession. In 1990, the province's five medical schools launched a collaborative project to determine more specifically what the people of Ontario expect of their physicians, and how the programs that prepare future physicians should be changed in response. The authors report on the first five years of that ongoing project. Consumer groups were asked to state their views concerning the current roles of physicians, future trends that would affect these roles, changes in roles they wished to see, and suggestions for changes in medical education. Methods used included focus groups, key informant interviews, an extensive literature review, and surveys, including a survey of health professionals. Concurrently, inter-university working groups prepared tools and strategies for strengthening faculty development, assessing student performance, and preparing future leadership for Ontario's medical education system. Eight specific physician roles were identified: medical expert, communicator, collaborator, health advocate, learner, manager ("gatekeeper"), scholar, and "physician as person." Educational strategies to help medical students learn to assume these eight roles were then incorporated into the curricula of the five participating medical schools. The authors conclude that the project shows that it is feasible to learn specifically what society expects of its physicians, to integrate this knowledge into the process of medical education reform, and to implement major curriculum changes through a collaborative, multi-institutional consortium within a single geopolitical jurisdiction.

Historic releases of key radionuclides were estimated as a first step in determining the radiation doses that resulted from Hanford Site operations. The Hanford Site was built in southcentral Washington State during World War II to provide plutonium for the U.S. nuclear weapons program. As part of the Hanford Environmental Dose Reconstruction (HEDR) Project, releases to the Columbia River of 24Na, 32P, 46Sc, 51Cr, 56Mn, 65Zn, 72Ga, 76As, 90Y, 131I, 239Np, and nonvolatile gross beta activity from operation of eight Hanford single-pass production reactors were estimated. Releases of 90Sr, 103Ru, 106Ru, 131I, 144Ce, and 239Pu to the atmosphere from operation of chemical separation facilities were also estimated. These radionuclides and the atmospheric and Columbia River pathways were selected for study because scoping studies showed them to be the largest contributors to dose from Hanford operations. The highest doses resulted from releases to the atmosphere of 131I from chemical separations plants in the pre-1950 period. Prior to 1950, the technology for limiting iodine releases had not been developed. Hence, a very detailed reconstruction of the hourly 131I release history was achieved for 1944-1949 using Monte Carlo methods. Atmospheric releases of the other radionuclides were estimated on a monthly basis for 1944-1972 using deterministic calculations. Monthly releases to the Columbia River for 1944-1971 were based on Monte Carlo methods.

alpha 1-Adrenergic receptor (AR) activation in cardiac muscle has several different physiological effects that might be mediated through different alpha 1-AR subtypes. Two alpha 1-AR subtypes have been cloned from the rat, the alpha 1B and the alpha 1D; both are present in adult rat heart. A third subtype, the alpha 1C, cloned from the cow and human, was reported to be absent in the rat. However, we recently found alpha 1C mRNA in adult rat heart by using a partial alpha 1C cDNA. Thus, all three cloned alpha 1-AR subtypes are present in the heart, but it is unknown whether each is expressed in cardiac myocytes or in cardiac fibroblasts. In the present study, the full-length rat alpha 1C-AR was cloned from cultured neonatal cardiac myocytes. alpha 1C mRNA transcripts of 3, 9.5, and 11 kb were present in adult rat heart by Northern blot analysis. alpha 1B-, alpha 1C-, and alpha 1D-subtype mRNAs were each present in isolated adult and neonatal cardiac myocytes by RNase protection assay. In addition, cultured neonatal cardiac myocytes expressed the three alpha 1-AR subtype mRNAs. In contrast, none of the alpha 1-AR mRNAs was detected in cultured neonatal cardiac fibroblasts. In addition, alpha 1-ARs were absent in fibroblasts by [3H]prazosin binding and norepinephrine-stimulated [3H]inositol phosphate production. The absence of alpha 1-ARs in cardiac fibroblasts differs from beta-adrenergic and angiotensin II receptors, which are present in both cardiac fibroblasts and cardiac myocytes.(ABSTRACT TRUNCATED AT 250 WORDS)

Alpha-1 adrenergic receptors (α1-ARs) have beneficial effects in the heart and cardiac myocytes. In pilot studies in vivo , a sub-hypertensive dose of the α1A subtype-selective agonist A61603 has cardioprotective signaling and prevents and rescues cardiomyopathy in mouse models. These studies give a possible explanation for adverse cardiac effects of α1-antagonists in clinical trials and are a rationale to test α1-agonists in heart failure. Our objective was to establish models to screen α1-agonists for beneficial cardiac signaling. We tested the hypothesis that different α1-AR agonists have distinct beneficial cardiac effects at very low doses. To test this, we studied α1-AR-mediated cardioprotective and adaptive hypertrophic signaling in isolated neonatal rat ventricular myocytes (NRVM) and adult mouse ventricular myocytes (AMVM). We compared A61603 to all clinically approved α1-agonists: epinephrine (EPI), norepinephrine (NE), phenylephrine (PE), dobutamine (DOB), methoxamine (MET), and midodrine (MID) at 5 doses, all in the presence of the beta-blocker propranolol (200 nM). Cardioprotective signaling was measured by α1-AR-ERK survival pathway activation and cell viability by MTT assay after doxorubicin (20 μM)-induced toxicity. Cellular adaptive hypertrophy was measured by protein synthesis in NRVM and fetal gene protein expression in AMVM. In NRVM, A61603 was the most potent (EC 50 = 4 nM) and efficacious agonist for ERK activation. The rank-order potency was: A61603 > NE > EPI > PE > MET > DOB > MID. For protein synthesis, A61603 had high efficacy and potency (EC 50 = 12 nM). The rank-order potency was: A61603 > NE > DOB > PE > EPI > MET > MID. In AMVM, A61603 was potent for ERK (EC 50 = 58 nM) and increased cell viability 48% (1.48 vs. 1.00 control) with doxorubicin toxicity. A61603 (200 nM) increased the number of myocytes expressing beta-myosin heavy chain and atrial natriuretic factor by immunocytochemistry. We conclude that myocyte culture models are predictive of α1-agonist efficacy and potency in adaptive and protective cardiac effects. A61603 , an imidazoline with high affinity for the α1A-AR, is more potent and efficacious in myocyte models than are clinically available α1-agonists, and is a promising candidate for therapeutic testing in vivo .

The mechanisms regulating myocardial hypertrophy are largely unknown. Furthermore, the hypertrophic phenotype can be associated with either normal or abnormal function. To study the molecular mechanisms involved in myocardial hypertrophy, we have established a cell culture system in which stimulation of the alpha 1-adrenergic receptor leads to the development of myocardial cell hypertrophy. In addition to producing a generalized twofold increase in both cell size, total protein, and total RNA, activation of the alpha 1-receptor produces specific alterations in gene expression that are reflected by changes at both the mRNA and protein levels. In particular, alpha 1 stimulation leads to an increase in the expression of the c-myc oncogene as well as a selective increase in skeletal alpha-actin and beta-myosin heavy-chain isogene expression, isoforms normally found only in fetal/neonatal hearts. Similar changes in gene expression are seen in pressure-load hypertrophy in vivo. Skeletal alpha-actin gene expression is induced preferentially to that of the cardiac actin isogene resulting from a specific preferential increase in gene transcription. Work with subtype-specific inhibitors indicates that it is a particular alpha 1-receptor subtype that is responsible for the development of hypertrophy in culture. The finding that alpha 1 stimulation leads to an increase in protein kinase C activity is suggestive of a potential second messenger involving the phosphorylation of a transcriptional factor or factors.

Heart failure caused by anthracycline chemotherapy, e.g. doxorubicin (DOX), is preceded by significant cell apoptosis. Early, non-invasive detection of cardiac cell death may improve patient outcomes by enabling real-time adjustment of chemotherapy. To this end, Annexin V protein (ANX) binds to membrane-bound phosphatidylserine, which is externalized in early apoptosis. We tested whether ANX conjugated to superparamagnetic iron oxide (SPIO) could detect and quantify apoptosis via T2-weighted magnetic resonance imaging (MRI). ANX was purified and conjugated to SPIO. Cultured, neonatal rat cardiac myocytes (CMs) and fibroblasts (FBs), and mouse mesenchymal stem cells (mMSCs) were exposed to DOX (1uM) for varying times, then stained with ANX-SPIO, or with fluorescent ANX (ANX-FLUOS, Roche) or TUNEL as controls. In vitro MRI (3 Tesla, GE Excite, WI) was performed on plated cells using a gradient echo (GRE) sequence (see Table ). MRI signal after ANX-SPIO incubation correlated highly with the number of ANX-FLUOS or TUNEL positive cells after exposure to varying durations of DOX (R=0.91 ANX-FLUOS vs. ANX-SPIO, n=5; R=0.80 TUNEL vs. ANX-SPIO, n=4; p ), with peak apoptosis after 30 minutes of DOX exposure. Conversely, cardiac FBs were resistant to DOX for 22 hours, and mMSCs showed intermediate susceptibility to DOX. Competition binding between ANX-SPIO and ANX-FLUOS confirmed the specificity of ANX-SPIO for apoptotic cells in culture. In vitro MRI of a magnetically-labeled marker of apoptosis (ANX-SPIO) can accurately detect cell death in culture with high sensitivity. MRI of ANX-SPIO can also resolve differential susceptibility to DOX in CMs, FBs, and mMSCs. This compound may hold promise for in vivo MRI detection of early anthracycline-induced cell death in the myocardium. This research has received full or partial funding support from the American Heart Association, AHA Western States Affiliate (California, Nevada & Utah). Cell-Type Specific Susceptibility to Doxorubicin Assessed by MRI

Background: Alpha-1-adrenergic receptor (AR) agonists classically increase blood pressure (BP). Among the 3 alpha-1-AR subtypes, A, B, and D, the alpha-1A is required for cardiac protection in a knockout (KO) mouse, and is sufficient for protection of cultured cardiac myocytes, via ERK activation. However, it is unknown if activation of the alpha-1A-subtype by a drug can protect the heart in vivo. Hypothesis: At a dose that does not increase BP, an agonist selective for the alpha-1A-AR subtype can prevent cardiomyopathy. Methods: We gave the alpha-1A agonist A61603 (A6) to 11 week-old wild type (WT) male C57Bl6J mice by osmotic minipump. We induced cardiomyopathy with a single dose of doxorubicin (DOX) (25 mg/kg IP), a cardiotoxic cancer drug. We measured BP by tail cuff, activated (phosphorylated, P)-ERK by immunoblot, heart mRNAs by RT-qPCR, fractional shortening (FS) by echocardiog-raphy (ECHO), myocyte necrosis by serum creatine kinase (CK), apoptosis by TUNEL stain, and fibrosis by sirius red stain. Results : In dose-finding experiments (0.01–100 ug/kg/d), A6 at 10 ng/kg/d over 7 days had no effect on daily tail cuff BP (average mmHg Vehicle 115 ± 4; A6 119 ± 4), but increased heart P-ERK (1.7-fold) and the mRNAs for beta-MyHC and ANF (5-fold). A6 at higher doses increased BP. Next, A6 at the non-hypertensive dose (10 ng/kg/d) or vehicle was infused over 7 days after a single DOX injection. The TABLE shows that DOX caused cardiomyopathy, with reduced survival and FS, and increased necrosis, apoptosis, and fibrosis (data are mean ± SE). A6 prevented all of these abnormalities. In alpha-1A-subtype KO mice, DOX caused increased apoptosis and mortality compared with WT mice, and A6 had no beneficial effect (not shown), indicating specificity of A6. Conclusions: A very low dose of an agonist selective for the alpha-1A-AR subtype can activate cardiac survival signaling (P-ERK), induce cardiac fetal genes, and prevent DOX-induced cardiomyopathy, all without increasing BP.

Background: Alpha-1-adrenergic receptors (ARs) play an adaptive role in the heart and protect against the development of HF. There are three alpha-1-AR subtypes: A, B, and D. Limited prior studies find that the human heart contains primarily the A subtype mRNA. Alpha-1-AR subtype proteins have never been measured in human heart. Hypothesis: This study tests the hypothesis that all three alpha-1-AR subtypes are present in both the failing (F) and non-failing (NF) human heart. Methods: F human hearts [n =6, mean EF 26%, mean age 47, 3 males (M), 3 females (Fe)] were obtained after cardioplegia during heart transplant. NF controls were unused donor hearts (n =6, mean EF 58%, mean age 41, 4 M, 2 Fe). Left (LV) and right ventricular (RV) tissue from the mid free wall was flash frozen in liquid nitrogen. mRNA was purified and treated with DNase. Quantitative real time reverse transcription PCR results were normalized to beta-actin and TATA binding protein. Saturation binding used tritiated prazosin and competition binding used 5-methylurapidil, an alpha-1A-specific antagonist. Results: All three alpha-1-AR subtype mRNAs were identified, and the A subtype was the most abundant in both LV and RV (p . Arbitrary Units ±SEM (% of total alpha-1-AR mRNA )]. Mean alpha-1-AR protein density was unchanged in HF by saturation binding (NF: 4.6 ±0.7 fmol/mg vs. F: 3.9 ±0.8 fmol/mg). Competition binding in NF LV tissue (n =6) showed a classic two-site binding curve with 38% high affinity (alpha-1A) binding sites and 62% low affinity (alpha-1B/D) sites. Conclusions: These results are the first to measure alpha-1-AR subtype proteins in the human heart. At the protein level, alpha-1A is less abundant than the sum of alpha-1B and D, even though alpha-1A mRNA is most abundant. Given that alpha-1-ARs protect against HF in animal models, specific activation of cardiac alpha-1-AR subtypes might be feasible.

Rates of NO3- disappearance under anaerobic conditions, from six widely differing soils, gradually increased and then became relatively constant when glucose was added in increments supplying 0.04 to 1.5 mg of C/g of soil. Maximum rates of NO3- loss ranged from approximately 9.3 to 13.7 percent/hr. Increased production of NH4+ accompanied glucose additions in all soils. Results based on 13N-labeled Ca(NO3)2 showed that substantial amounts of NO3- were reduced to NH4+ after 4 hr of anaerobic incubation, and 15NH4+ continued to increase until all or most of the 15NO3- had been converted to NH4+, organic N, and gaseous forms (N2 and N2O). Results seriously challenge the prevalent view that denitrification accounts for essentially all NO3- dissimilation in anaerobic soils.

The role of hormones and other humoral factors in the regulation of myocardial hypertrophy has been difficult to evaluate. We asked whether myocardial cell hypertrophy could be demonstrated in cultures from the day-old rat ventricle and evaluated the effect of serum concentration and catecholamines on the growth process. Two single-cell preparations were used: serum-supplemented, bromodeoxyuridine-treated cultures and serum-free cultures with transferrin and insulin. Both preparations were characterized by myocardial cell predominance (about 75--80% of total cells) and constant cell numbers. Myocardial cell size was documented by photomicroscopy and quantified by volume (microscopic diameter of suspended cells), surface area (planimetry of attached cells), and total cell protein concentration (Lowry method and cell counts). Growth was also evaluated in pure nonmyocardial cell cultures. In cultures with 5% (vol/vol) serum, myocardial cell size increased 2- to 3-fold over 11 days in culture. Final volume, surface area, and protein concentration were about 3000 micrometer3/cell, 5000 micrometer2/cell, and 1500 pg/cell, respectively. Serum had a dose-related effect on myocardial cell hypertrophy; myocardial cell size increased about 4-fold when serum concentration was increased from 0% to 5% or 10%. Cells maintained in serum-free medium with transferrin and insulin (each 10 microgram/ml) did not hypertrophy, but did remain responsive to the growth-promoting activity of serum. Chronic exposure to isoproterenol or norepinephrine (1 microM) significantly stimulated myocardial cell hypertrophy. This stimulation was dose-related, was not blocked by equimolar propranolol, was not associated with a sustained chronotropic effect, and was more pronounced in the serum-free preparation. In pure cultures of nonproliferating (bromodeoxyuridine-treated) nonmyocardial cells, cell size also increased with time in culture, but variation in serum concentration and addition of norepinephrine had no significant effect on cell size. Myocardial cell hypertrophy occurs in culture and is regulated by variations in the culture medium, including serum, with its contained hormones and growth factors, and catecholamines. The culture preparation can be used to explore the regulation of myocardial cell hypertrophy by nonhemodynamic factors.

An unsuspected metastasis of liposarcoma of the heart was detected on a computed tomographic (CT) examination of the chest. Further CT study with i.v. contrast administration gave excellent delineation of the tumor. Compared with two-dimensional echocardiography and angiocardiography, CT was best at showing the myocardial and intrapericardial extension of the tumor, but did not show movement of the tumor during the cardiac cycle. CT is a useful noninvasive method for evaluating cardiac metastasis. Its advantages and disadvantages with respect to echocardiography and angiocardiography are discussed.

Catecholamines may be one of the molecular signals linking increased circulatory demand to myocardial hypertrophy, and I have found previously that norepinephrine stimulates hypertrophy of cultured neonatal rat heart muscle cells through an alpha 1-adrenergic receptor. Since catecholamine stimulation of contractility is believed to be under beta-adrenergic control, I asked whether these cultured heart cells had dual pathways regulating growth and contractility through alpha- and beta-adrenergic receptors, respectively. I examined the effect of adrenergic agents on hypertrophy and beating of myocytes in serum-free cultures. Hypertrophy was defined as an increase in myocyte surface area and in cell protein content, measured by a radioisotopic method, and chronotropic activity was examined visually. Norepinephrine and epinephrine were equipotent stimulants of hypertrophy and beating, increasing cell protein and area 1.5- to 2-fold, and the proportion of beating cells from 5% or less to 95%. Response maxima occurred 24-48 hours after exposure, and EC50 were 20-200 nM. Studies with other agonists (phenylephrine, methoxamine, clonidine, isoproterenol, dopamine) and antagonists (prazosin, terazosin, yohimbine, propranolol, betaxolol, ICI 118,551) indicated that hypertrophy was mediated through an alpha 1-adrenergic receptor, whereas the induction of beating required both alpha 1- and beta 1-receptor activation. Hypertrophied cells with minimal beating were produced by alpha-stimulation, alone. In contrast, alpha-plus beta-stimulation in the presence of cycloheximide to inhibit protein synthesis resulted in maximum beating but no hypertrophy. These findings imply that growth and beating can be regulated independently through separate cellular pathways.

Female schizophrenics have been reported to have a better prognosis than male schizophrenics. However, earlier reports rarely used either operational criteria for schizophrenia or appropriate comparison groups. Using data collected as part of a long-term follow-up and family study, the authors examined outcome by sex of 186 schizophrenics, 212 depressives, 86 manics, and 145 surgical controls. When the authors controlled for differences in the age and sex distributions of the diagnostic groups, sex did not make a significant contribution to the explanation of outcome differences between diagnoses or within diagnoses. Examination of outcomes within diagnoses revealed only a nonsignificant trend for female manics to have a better long-term outcome than male manics.