Implications of hypertrophic cardiomyopathy transmitted by sperm donation

CONTEXT

Sperm donation is an increasingly common practice for achieving pregnancy in the absence of a male partner or when fertility is problematic. The unintended consequence in which genetic diseases are unwittingly transmitted to offspring is an underrecognized public health issue not previously prioritized by US Food and Drug Administration guidelines.

OBJECTIVE

To report the clinical circumstances and implication of hypertrophic cardiomyopathy (HCM) transmitted by sperm donation to recipients.

SETTING

Voluntary sperm donation through a US Food and Drug Administration-approved tissue bank.

MAIN OUTCOME MEASURE

Incidence of genetically affected offspring and clinical outcomes to date.

RESULTS

An asymptomatic 23-year-old man who had no personal knowledge of underlying heart disease and who underwent standard testing that was negative for infectious diseases, repeatedly donated sperm over a 2-year period (1990-1991). The donor was later shown to be affected (in 2005) by a novel beta-myosin heavy-chain mutation that caused HCM, after an offspring was clinically diagnosed with this disease. Of the 24 children known to be offspring of the donor, including 22 who were products of fertilization via sperm donation and 2 conceived by the donor's wife, a total of 9 genetically affected offspring, 2 to 16 years of age and 6 males, have been identified with HCM (2005-2009). Three of the 9 gene-positive children have currently expressed phenotypic evidence of HCM, including one who died at age 2 years due to progressive and unrelenting heart failure with marked hypertrophy, and also 2 survivors with extreme left ventricular hypertrophy at age 15 years. The latter 2 children and the donor are judged likely to be at increased risk for sudden death.

CONCLUSIONS

This case series underscores the potential risk for transmission of inherited cardiovascular diseases through voluntary sperm donation, a problem largely unappreciated by the medical community and agencies regulating tissue donation. Recommendations include improved screening guidelines for donors to exclude cardiovascular diseases (eg, HCM) such as consideration for 12-lead electrocardiograms.

Transesophageal echocardiographic evaluation of aortitis

Aortitis is an uncommon infection which may occur in patients with preexisting atherosclerotic disease of the aorta. The clinical features in two patients presenting with fever and nonspecific symptoms are reviewed. In these patients, transesophageal echocardiographic features of wall thickening and false aneurysm formation were suggestive of the diagnosis of aortitis. Both patients were taken for surgical excision of the descending aorta and subsequently improved.

Practice variation among cardiovascular physicians in management of patients with mitral regurgitation

Severe mitral regurgitation (MR), whether isolated or with coronary disease, was associated with adverse clinical outcomes. However, clinician practice is characterized by different thresholds for treatment. No data exist that described current practice patterns, factors that affected these patterns, or whether physicians followed American College of Cardiology/American Heart Association guidelines in clinical practice for patients with MR. Cardiovascular specialists were surveyed using e-mail, and 1,076 physicians completed the survey (71% response rate), including adult cardiologists (94%) and cardiac surgeons (5%) who practiced in the United States (78%), Canada (5%), and other nations (17%). Wide variations were noted regarding rates of referral of asymptomatic patients with severe MR for mitral valve repair. There was geographic and specialty-dependent heterogeneity in practice. Most physicians (65%) used medications to delay the progression of MR in the absence of guideline recommendations. A minority (28%) of respondents routinely quantitated MR by calculating the effective regurgitant orifice area. In patients undergoing percutaneous coronary intervention, MR severity was not assessed before the procedure by 1 in 4 providers, and the presence of MR frequently did not affect clinical care decisions. In conclusion, considerable variability existed in the clinical management of MR, particularly regarding referral of asymptomatic patients for mitral valve reparative surgery. Medications were frequently used to treat asymptomatic patients with MR in the absence of evidence of pharmacologic efficacy. MR was frequently not considered a relevant factor before treatment of patients with coexistent coronary artery disease.

Geographic differences in clinical presentation, treatment, and outcomes in type A acute aortic dissection (from the International Registry of Acute Aortic Dissection)

Although several studies have provided robust evidence about global differences for several cardiovascular emergencies, such as myocardial infarction and stroke, data were limited for aortic disease. The aim was to explore geographic variation in type A acute aortic dissection (TA-AAD) in a large group of consecutive patients. Patients (n = 615) from the IRAD with TA-AAD were studied with respect to presenting symptoms and signs, diagnosis, management, and outcomes in Europe versus North America. Compared with Europeans, North Americans were more likely to be older and present with atypical features and without many of the classic chest X-ray findings of AAD. In the North American cohort, electrocardiographic findings showed higher rates of nonspecific ST changes and a trend toward ST-elevation or new myocardial infarction (North Americans vs Europeans 7.9% vs 4.4%; p = 0.09). Use of imaging studies to confirm the diagnosis of AAD varied between North American and European centers. North American centers performed an average of 1.6 imaging studies compared with 1.8 in the European group (p = 0.002). Furthermore, they were significantly less likely to use computed tomography and significantly more likely to use transesophageal examination as part of the overall diagnostic algorithm. Compared with Europeans, TA-AAD occurred at smaller aortic diameters and there was a substantial delay to presentation and diagnosis in North Americans. No significant differences for early mortality rates were observed between the 2 groups. In conclusion, geographic differences in presentation and initial management were highlighted, but this did not translate into a difference in early mortality.

Comparison of outcomes in high-risk patients>70 years of age with aortic valvuloplasty and percutaneous coronary intervention versus aortic valvuloplasty alone

The goal of this study was to compare outcomes of combined balloon aortic valvuloplasty (BAV) plus percutaneous coronary intervention (PCI) with BAV alone in a surgically high risk, older (>70 years) population with both aortic stenosis (AS) and coronary artery disease (CAD). The medical records, coronary angiograms, and procedural reports of 100 consecutive patients who underwent BAV and coronary angiography at our institution from July 2003 to November 2006 were reviewed. Seventeen patients (mean age 86.2+/-6.4 years) underwent combined (nonstaged) BAV and PCI with a calculated Society of Thoracic Surgery risk score of 13.5%+/-6.7; 13 of these underwent coronary stenting before BAV and 4 after BAV. All 17 patients were successfully treated with this combined strategy. The incidence of periprocedural mortality, myocardial infarction, and stroke was zero. An additional 25 patients (mean age 85.9+/-6.9) with CAD were identified who underwent BAV alone with a Society of Thoracic Surgery risk score of 12.6+/-5.7%. PCI in these patients was avoided primarily because of greater lesion complexity or a perceived low probability of symptomatic benefit. There was 1 procedural death, no myocardial infarction, and 1 postprocedural stroke in these 25 patients. The procedural duration and hospital length of stay for the combined BAV and PCI group was 98.8+/-17.6 minutes and 4.1+/-2.8 days, respectively, and for the BAV only group was 86.2+/-27.3 minutes and 3.3+/-2.1 days, respectively. In conclusion, with appropriate selection, BAV plus PCI was safely performed in this retrospective series of elderly, high-risk patients with severe AS and CAD.

International Heterogeneity in Diagnostic Frequency and Clinical Outcomes of Ascending Aortic Intramural Hematoma

BACKGROUND

Differing diagnostic frequencies and management strategies for intramural hematoma (IMH) have been described in North American (NA)/European and Japanese/Korean studies.

METHODS

All publications including type-A aortic IMH were reviewed for details on patient demographics, treatment strategy, and clinical outcomes. Publications were stratified by the geographic region (NA/Europe or Japan/Korea).

RESULTS

IMH, as a percentage of aortic dissection, occurs more frequently in Japan/Korea versus NA/Europe (31.7% vs 10.9%, P < .0001). The proportion of patients treated with early medical therapy is greater in Japanese/Korean studies (77.9% vs 48.8% in NA/Europe, P < .0001). However, the overall mortality is significantly lower in Japan/Korea compared with NA/Europe (9.4% vs 20.6%, odds ratio = 2.80, P = .003) in part because of the lower mortality with early medical therapy (7.8% vs 33.3%, P < .0001).

CONCLUSION

There is significant international heterogeneity in the diagnosis and clinical outcomes of ascending IMH. IMH is diagnosed more frequently and has better overall outcomes in Japan/Korea.

Long-term outcomes of patients with mitral regurgitation undergoing percutaneous coronary intervention

The most appropriate treatment for patients with ischemic mitral regurgitation (MR) remains controversial. MR has prognostic importance in patients after myocardial infarction and those undergoing coronary artery bypass surgery, but the long-term outcomes after percutaneous coronary intervention (PCI) are less well defined. We evaluated patients who underwent PCI and had assessment of MR by left ventriculography and/or echocardiography in the year 2000. We determined effects of MR on 30-day and 5-year survival. The cohort included 711 patients (67% men) with an average age of 64.5 +/- 12.4 years. MR severity was divided into 3 strata: none (n = 420, 59%), mild (n = 209, 29%), and moderate to severe (n = 82, 12%). Patients with more severe MR differed from patients with mild or no MR in that they were older (p <0.001), more frequently women (p <0.001), and more likely to have a coronary artery bypass graft (p <0.001), myocardial infarction (p <0.001), and lower ejection fraction (p <0.001). Decreased survival rates were associated with increasing MR severity (none vs mild vs moderate to severe) at 30 days (100%, 98.7%, and 96.6%, respectively; p <0.0025) and 5 years (97%, 83.3%, and 57.5%; p <0.0001). MR was an important independent predictor of survival (hazard ratio 1.57, p <0.0009). In conclusion, patients with ischemic MR undergoing PCI have significantly decreased survival rates at 5 years, and severity of MR is an independent predictor of survival.

Tolerability and infusion time of an accelerated infusion dobutamine echocardiography protocol

OBJECTIVES

A new, accelerated dobutamine-atropine stress echocardiography (DASE) protocol (baseline 20 mcg/kg/min; 40 mcg/kg/min) was compared with a standard protocol in patients with suspected coronary artery disease (CAD) to evaluate tolerability, length of infusion, and overall test times, as well as safety.

METHODS

Patients received the DASE or the standard protocol on an alternating basis (n = 164).

RESULTS

Total test time, including patient recovery (HR < 100 bpm), dropped from an average of 19:23-12:12 min (p < 0.0001). Average symptom duration decreased from 5:50 to 3:17 min (p < 0.01). Women had shorter total test times in both accelerated and standard protocols compared to that of men.

CONCLUSIONS

The accelerated DASE protocol is a well tolerated alternative to standard dobutamine stress testing allowing practitioners to reduce test times without increasing the incidence of arrhythmias. Patients in the accelerated arm also had shorter duration of symptoms.

Cardiac Magnetic Resonance Imaging for Detection of an Abscess Associated with Prosthetic Valve Endocarditis: A Case Report

Propionibacterium acnes is an organism frequently isolated in cultures and often dismissed as a contaminant. A patient with a febrile illness and prosthetic aortic valve was suspected of having infectious endocarditis. Magnetic resonance imaging was useful in defining a paravalvular abscess associated with prosthetic valve endocarditis due to Propionibacterium acnes that was then successfully surgically repaired.

Feasibility of transcatheter intervention for severe aortic stenosis in patients ≥90 years of age: Aortic valvuloplasty revisited

OBJECTIVES

The goals of this study were to determine the feasibility, safety, and early outcomes of balloon aortic valvuloplasty (BAV) for severe aortic stenosis in a nonagenarian population.

BACKGROUND

This very elderly population is expanding rapidly, has a high incidence of aortic stenosis, and uncommonly undergoes surgical aortic valve replacement. These patients may best be treated with a transcatheter approach due to comorbidities, surgical risk, and personal preference.

METHODS

We reviewed 31 consecutive patients >or=90 years of age who underwent BAV at our institution from July 2003 to August 2006 for data pertinent to patient characteristics, procedural techniques, and 30-day outcomes.

RESULTS

Our patients had a mean age of 93 +/- 3.0 years (90-101). The society of thoracic surgery risk score was 18.5 (+/-10.2) and logistic Euroscore was 35.8 (+/-19.3). Twenty-five patients (81%) underwent retrograde BAV and 6 (19%) antegrade BAV. Five patients (16%) underwent combined BAV and coronary stenting. Overall mean aortic valve area increased from 0.52 cm2 (+/-0.17) to 0.92 cm2 (+/-0.22) and mean New York Heart Association (NYHA) functional class improved from 3.4 to 1.8. Intraprocedural mortality occurred in one patient (3.2%) and 30-day mortality in three patients (9.7%).

CONCLUSIONS

BAV can be carried out in high risk nonagenarian patients with an acceptable complication rate, low perioperative mortality, and early improvement in NYHA functional class.

Brief communication: Cardiovascular screening practices of major North American professional sports teams

BACKGROUND

Customary preparticipation screening strategies to detect heart disease in professional athletes have not been examined systematically.

OBJECTIVE

To describe the current preparticipation cardiovascular screening process for professional athletes.

DESIGN

Screening practices surveyed by questionnaire.

SETTING

The 122 major professional sports teams in North America.

PARTICIPANTS

Athletic trainers and team physicians.

MEASUREMENTS

League recommendations for history taking and physical examination and noninvasive testing were compared with screening recommendations from an American Heart Association consensus panel.

RESULTS

All 122 teams have team physicians perform annual screening, including family and personal history taking (100%), physical examination (100%), and lipid panels (108 of 122 [89%]). Diagnostic testing by using electrocardiography was substantially more common (112 of 122 [92%]) than exercise testing and stress echocardiography (21 of 122 [17%]) or echocardiography (16 of 122 [13%]). League recommendations for history taking and physical examination were most complete for Major League Baseball and the National Hockey League, meeting 10 of 12 and 8 of 12 American Heart Association recommendations, respectively. The most comprehensive cardiovascular screening using echocardiography is confined to selected, elite professional basketball players.

LIMITATIONS

Data were self-reported by team representatives.

CONCLUSIONS

A variety of nonstandardized preparticipation screening strategies for the detection of cardiovascular disease, varying considerably in scope, constitute customary practice among professional sports teams.

Prevalence, clinical profile, and significance of left ventricular remodeling in the end-stage phase of hypertrophic cardiomyopathy

BACKGROUND

End stage (ES) is a recognized part of the hypertrophic cardiomyopathy (HCM) disease spectrum. Frequency, clinical profile and course, and treatment strategies in these patients remain incompletely defined.

METHODS AND RESULTS

Three HCM cohorts comprised 1259 patients, including 44 (3.5%) characterized as ES with systolic dysfunction (ejection fraction <50% at rest; range 15% to 49%). ES developed at a wide age range (14 to 74 years), with 45% of patients < or = 40 years old. Although 29 patients (66%) died of progressive heart failure, had sudden death events, or underwent heart transplantation, 15 (34%) survived with medical management over 3+/-3 years. Duration from onset of HCM symptoms to ES identification was considerable (14+/-10 years), but ES onset to death/transplantation was brief (2.7+/-2 years). ES occurred with similar frequency in patients with or without prior myectomy (P=0.84). Appropriate defibrillator interventions were 10% per year in patients awaiting donor hearts. Most ES patients (n=23; 52%) showed substantial left ventricular (LV) remodeling with cavity dilatation. Less complete remodeling occurred in 21 patients (48%), including 5 with persistence of a nondilated and markedly hypertrophied LV. Pathology and magnetic resonance imaging showed extensive (transmural) fibrosis in 9 of 11 ES patients. At initial evaluation, patients who developed ES were younger with more severe symptoms, had a larger LV cavity, and more frequently had a family history of ES than other HCM patients.

CONCLUSIONS

ES of nonobstructive HCM has an expanded and more diverse clinical expression than previously appreciated, including occurrence in young patients, heterogeneous patterns of remodeling, frequent association with atrial fibrillation, and impaired LV contractility that precedes cavity dilatation, wall thinning, and heart failure symptoms. ES is an unfavorable complication (mortality rate 11% per year) and a sudden death risk factor; it requires vigilance to permit timely recognition and the necessity for defibrillator implantation and heart transplantation.

Dense core vesicles resemble active-zone transport vesicles and are diminished following synaptogenesis in mature hippocampal slices

Large dense core vesicles (approximately 100 nm) contain neuroactive peptides and other co-transmitters. Smaller dense core vesicles (approximately 80 nm) are known to contain components of the presynaptic active zone and thought to transport and deliver these components during developmental synaptogenesis. It is not known whether excitatory axons in area CA1 contain such dense core vesicles, and whether they contribute to synaptic plasticity of mature hippocampus. Serial section electron microscopy was used to identify dense core vesicles in presynaptic axons in s. radiatum of area CA1 in adult rat hippocampus. Comparisons were made among perfusion-fixed hippocampus and hippocampal slices that undergo synaptogenesis during recovery in vitro. Dense core vesicles occurred in 26.1+/-3.6% of axonal boutons in perfusion fixed hippocampus, and in only 17.6+/-4.5% of axonal boutons in hippocampal slices (P<0.01). Most of the dense core vesicle positive boutons contained only one dense core vesicle, and no reconstructed axonal bouton had more than a total of 10 dense core vesicles in either condition. Overall the dense core vesicles had average diameters of 79+/-11 nm. These small dense core vesicles were usually located near nonsynaptic membranes and rarely occurred near the edge of a presynaptic active zone. Their size, low frequency, locations, and decrease following recuperative synaptogenesis in slices are novel findings that merit further study with respect to small dense core vesicle content and possible contributions to synapse assembly and plasticity in the mature hippocampus.

Radiation following percutaneous balloon aortic valvuloplasty to prevent restenosis (RADAR pilot trial)

OBJECTIVES

We wished to determine the feasibility and early safety of external beam radiation therapy (EBRT) used following balloon aortic valvuloplasty (BAV) to prevent restenosis.

BACKGROUND

BAV for calcific aortic stenosis (AS) has been largely abandoned because of high restenosis rates, i.e., > 80% at 1 year. Radiation therapy is useful in preventing restenosis following vascular interventions and treating other benign noncardiovascular disorders.

METHODS

We conducted a 20-patient, pilot study evaluating EBRT to prevent restenosis following BAV in elderly patients with calcific AS. Total doses ranging from 12-18 Gy were delivered in fractions over a 3-5 day post-op period to the aortic valve. Echocardiography was performed pre and 2 days post-op, 1, 6, and 12 months following BAV.

RESULTS

One-year follow-up is completed (age 89 +/- 4). There were no complications related to EBRT. Eight patients died prior to 1 year; 5 of 10 (50%) in the low-dose (12 Gy) group and 3 of 10 (30%) in the high-dose (15-18 Gy) group. None of these 8 patients had restenosis, i.e., > 50% loss of the initial AVA gain, and only three deaths were cardiac in origin. One patient underwent aortic valve replacement and none repeated BAV. By 1 year, 3 of the initial 10 (30%) in the low-dose group and 1 of 9 (11%) in the high-dose group demonstrated restenosis (21% overall).

CONCLUSIONS

EBRT following BAV in elderly patients with AS is feasible, free of early complications, and holds promise in reducing the 1 year restenosis rate in a dose-dependent fashion.

Effects of angiotensin-converting enzyme inhibition on mitral regurgitation severity, left ventricular size, and functional capacity

BACKGROUND

Mitral regurgitation (MR) is a progressive disorder that leads to left ventricular (LV) dilatation and dysfunction. Previous small studies have shown conflicting results regarding the benefits of afterload reduction for MR.

METHODS

We assessed by serial echocardiography the effects of ramipril on MR severity and LV size by a number of quantitative methods in 26 asymptomatic patients with moderate to severe MR at baseline and again after 6 months of ramipril treatment. We also evaluated exercise capacity, neurohormonal levels, and the Minnesota Living With Heart Failure score.

RESULTS

Despite a significant reduction in blood pressure with ramipril, there was no change in MR severity. MR severity, as assessed by effective regurgitant orifice area, was reduced in individuals with baseline systolic blood pressure (SBP) > or = 140 mm Hg (55.1 +/- 26 vs 37.4 +/- 35.4 mm2, P = .03), but not in individuals with SBP < 140 mm Hg (39.7 +/- 37.7 vs 46.1 +/- 34.1 mm2, P = not significant). Neither LV cavity size, exercise capacity, nor the Minnesota Living With Heart Failure score exhibited a significant change.

CONCLUSIONS

Patients with MR do not experience significant changes in MR severity, LV size, or functional status after 6 months of treatment with angiotensin-converting enzyme inhibition. However, patients with SBP > or = 140 mm Hg represent a subgroup that shows reduction in MR. These data are consistent with current American College of Cardiology/American Heart Association guidelines, which reserve the use of afterload reduction for MR patients with systemic hypertension or LV dysfunction.

Relation of electrocardiographic patterns to phenotypic expression and clinical outcome in hypertrophic cardiomyopathy

Twelve-lead electrocardiography, a traditional component in evaluations of patients with hypertrophic cardiomyopathy (HC), is often regarded as a marker for the magnitude of left ventricular (LV) hypertrophy, which in turn has been linked to sudden death risk. To determine whether electrocardiographic (ECG) patterns have clinical utility by accurately reflecting phenotypic expression or predicting clinical outcome, voltages and patterns were compared with LV wall thicknesses assessed by echocardiography and with clinical outcomes in 448 consecutive patients with HC. Significant but relatively weak correlations were evident between maximum LV wall thickness and ECG voltage: r = 0.295 (p <0.01) for the sum of R- and S-wave voltages in all 12 leads, r = 0.254 (p <0.01) for the maximum R or S wave in any lead, and r = 0.210 (p <0.01) for the sum of SV(1) (or SV(2)) and RV(5) (or RV(6)). Of 55 patients with extreme LV hypertrophy (LV wall thickness > or =30 mm), only 24 (44%) showed greatly increased ECG voltage > or =30 mm in any lead. Of 102 patients with outflow gradients > or =30 mm Hg at rest, only 43 (42%) had ECG voltage > or =30 mm in any lead. Normal ECG results were uncommonly associated with HC-related death (1 of 40 patients, 2.5%) but had similar prevalence in surviving patients (17 of 376 patients, 4.5%; p = NS). In conclusion, in HC, 12-lead ECG voltages are not a reliable clinical marker for the magnitude of LV hypertrophy or outflow obstruction. Diverse ECG patterns, consistent with heterogeneous expression of this disease, did not predict HC-related death. Scalar electrocardiography has selective but limited power in routine clinical assessments of patients with HC.

Transseptal technique of percutaneous PFO closure results in persistent interatrial shunting

Our goal was to review the effectiveness of the transseptal and tunnel techniques of patent foramen ovale (PFO) closure. Percutaneous PFO closure is an increasingly common treatment for prevention of paradoxical embolism and is typically performed by passing the device through the defect tunnel itself. The transseptal technique, in which the septum primum is punctured to create a hole through which the device is passed, has been proposed for patients with long-tunnel PFO. From May 2001 to December 2003, 120 patients underwent PFO closure at our institution and were included in this analysis. Defect closure was assessed by transesophageal echocardiography (TEE) with bubble study. Clinical follow-up data were obtained by clinic visits or standardized telephone interviews. Device closure was successfully completed in all patients, with 12 (10%) undergoing transseptal closure and 108 (90%) undergoing tunnel closure. Immediately following the procedure, complete closure occurred in 6 of 12 (50%) of the transseptal group and 88 of 108 (81.5%) of the tunnel group (P = 0.0120). Of the 89 patients (74.2%) who returned for 6-month TEE, complete closure was demonstrated in 4 out of 10 (40%) of the transseptal group and 58 out of 79 (73.4%) of the tunnel group (P = 0.0303). There have been four transient ischemic attacks during a mean follow-up of 11 months. The transseptal technique of PFO closure results in a higher proportion of patients with persistent interatrial shunting when compared with the tunnel technique. Whether this is due to a difference in technique, device, or patient anatomy is unclear.

Initial Report of Off-Pump Coronary Artery Bypass Surgery as Sole Therapy for Moderate Ischemic Mitral Regurgitation: Operative and Intermediate-Term Outcome

Background: Patients undergoing on-pump coronary artery bypass surgery (CAB) with coexistent moderate ischemic mitral regurgitation (IMR) have a significant mortality rate compared to patients without MR. The mortality rate is elevated both perioperatively (0%-12% mortality), as well as over a 1- and 2-year postoperative period (15%-25%). It is thought that some patients are best served by off-pump CAB (OPCAB); however, outcomes have not been reported for such patients with coexistent moderate IMR. Methods: We reviewed the independent database of patients undergoing OPCAB between 1995 and 2002 to find 989 patients, 17 (1.7%) of whom had moderate or moderately severe MR. Patients were contacted and clinical and echocardiographic data were obtained. Results: The patient group consisted of 11 men and 6 women (age, 65 15 years). The study group had a PA pressure of 52 14, creatinine of 1.6 0.7, and left ventricular ejection fraction of 43 18. Nine patients (53%) had advanced New York Heart Association (class III-IV) heart failure. Mortality rates perioperatively and at 1, 2, and 3 years were 0%, 6.25% (1/16), 12.5% (2/16), and 38% (4/8), respectively. At the time of this report, no patient had returned for a reparative procedure. Conclusion: In patients felt to be best served by OPCAB with ischemic MR, operative and intermediate mortality rates are remarkably similar to those previously reported for on-pump series. These data underscore the continued need to understand which patients undergoing CAB require mitral valve problems to be addressed at the time of surgery.

Dendritic spines disappear with chilling but proliferate excessively upon rewarming of mature hippocampus

More dendritic spine synapses occur on mature neurons in hippocampal slices by 2 h of incubation in vitro, than in perfusion-fixed hippocampus. What conditions initiate this spinogenesis and how rapidly do the spines begin to proliferate on mature neurons? To address these questions, CA1 field of the hippocampus neurons expressing green fluorescent protein in living slices from mature mice were imaged with two-photon microscopy. Spines disappeared and dendrites were varicose immediately after slice preparation in ice-cold artificial cerebrospinal fluid (ACSF). Electron microscopy (EM) revealed disrupted dendritic cytoplasm, enlarged or free-floating postsynaptic densities, and excessive axonal endocytosis. Upon warming dendritic varicosities shrank and spines rapidly reappeared within a few minutes illustrating the remarkable resilience of mature hippocampal neurons in slices. When membrane impermeant sucrose was substituted for NaCl in ACSF dendrites remained spiny at ice-cold temperatures and EM revealed less disruption. Nevertheless, spine number and length increased within 30 min in warm ACSF even when the extracellular calcium concentration was zero and synaptic transmission was blocked. When slices were first recovered for several hours and then chilled in 6 degrees C ACSF many spines disappeared and the dendrites became varicose. Upon re-warming varicosities shrank and spines reemerged in the same position from which they disappeared. In addition, new spines formed and spines were longer suggesting that chilling, not the initial injury from slicing, caused the spines to disappear while re-warming triggered the spine proliferation on mature neurons. The new spines might be a substrate for neuronal recovery of function, when neurons have been chilled or exposed to other traumatic conditions that disrupt ionic homeostasis.

Confirmation by DNA analysis that Contarinia maculipennis (Diptera: Cecidomyiidae) is a polyphagous pest of orchids and other unrelated cultivated plants

The cytochrome oxidase subunit I gene in mitochondrial DNA of 53 larvae of Contarinia maculipennis Felt from flower buds of various host plants, collected from Hawaii, Japan and Thailand was analysed. Monophyly of the clade including C. maculipennis from Hawaii, Thailand and Japan was supported. There was no sequential variation within the specimens from Hawaii and Japan, which differed from one another by 6 bp (1.37%). Three haplotypes were recognized in specimens from Thailand but differences from Hawaiian and Japanese specimens were small. Overall, there were no differences in the 146 deduced amino acid residues. It is therefore concluded that C. maculipennis is a polyphagous species that can develop on plant hosts representing at least seven botanical families. This pest of Dendrobium flower buds in glasshouses is considered to have entered Hawaii, Florida and Japan from Southeast Asia, and was recently intercepted in the Netherlands. Infestations have established and spread in orchid glasshouses, causing concern about the possibility of more extensive damage to orchids and to crops, such as bitter gourd, grown in close proximity to orchid glasshouses in Japan. The potential usefulness of DNA analysis in determining host plant ranges of morphologically identical cecidomyiid species that are currently identified solely on differences of host plant is emphasized.