Activation of RMTg projections to the VTA reverse cocaine-induced molecular adaptation in the reward system

The rostromedial tegmental nucleus (RMTg) plays a crucial role in regulating reward-related behavior by exerting inhibitory control over the ventral tegmental area (VTA). This modulation of dopamine neuron activity within the VTA is essential for maintaining homeostasis in the reward system. Recently we have shown that activation of RMTg projections to the VTA during the acquisition of cocaine-conditioned place preference (CPP) reduces the rewarding properties of cocaine and decreases VTA dopamine neuron activity. By inhibiting dopamine neurons in the VTA, we hypothesized that RMTg projections hold the potential to restore reward system homeostasis disrupted by repeated cocaine use, and attenuate molecular adaptations in the reward system, including alterations in signaling pathways. Our study demonstrates that enhancing the GABAergic inputs from the RMTg to the VTA can mitigate cocaine-induced molecular changes in key regions, namely the VTA, nucleus accumbens (NAc), and prefrontal cortex (PFC). Specifically, we found that cocaine-induced alteration in the phosphorylation state of ERK (pERK) and GluA1 on serine 845 (S845) and serine 831 (S831), that play a major role in plasticity by controlling the activity and trafficking of AMPA receptors, were significantly reversed following optic stimulation of RMTg afferents to the VTA. These findings highlight the therapeutic potential of targeting the RMTg-VTA circuitry for mitigating cocaine reward. Ultimately, this research may pave the way for novel therapeutic interventions that restore balance in the reward system and alleviate the detrimental effects of cocaine.

Mutational Signature and Integrative Genomic Analysis of Human Papillomavirus-Associated Penile Squamous Cell Carcinomas from Latin American Patients

Simple Summary

DNA sequencing has been crucial to comprehending cancer mutational patterns, leading to the identification of driver genes and altered signaling pathways. Thus, identifying new pathogenic variants and their impact on tumor onset, progression, and treatment response has fueled tumor biology research. Here, we present novel findings addressing the first whole-exome sequencing (WES) of human papillomavirus (HPV)-associated penile squamous cell carcinoma (PSCC) from Latin Americans and its association with pathogenesis. We also compared the molecular profile of the tumors to that of three previous studies from populations with different genetic and socioeconomic backgrounds, the majority of which was HPV-negative. We describe the most altered genes and the main pathogenic variants found in the Latin Americans, ten of which are exclusive to our study sample. The data allowed us to identify molecular pathways and druggable targets with potential treatment value for this still-neglected HPV-associated carcinoma.

Abstract

High-throughput DNA sequencing has allowed for the identification of genomic alterations and their impact on tumor development, progression, and therapeutic responses. In PSCC, for which the incidence has progressively increased worldwide, there are still limited data on the molecular mechanisms involved in the disease pathogenesis. In this study, we characterized the mutational signature of 30 human papillomavirus (HPV)-associated PSCC cases from Latin Americans, using whole-exome sequencing. Copy number variations (CNVs) were also identified and compared to previous array-generated data. Enrichment analyses were performed to reveal disrupted pathways and to identify alterations mapped to HPV integration sites (HPVis) and miRNA–mRNA hybridization regions. Among the most frequently mutated genes were NOTCH1, TERT, TTN, FAT1, TP53, CDKN2A, RYR2, CASP8, FBXW7, HMCN2, and ITGA8. Of note, 92% of these altered genes were localized at HPVis. We also found mutations in ten novel genes (KMT2C, SMARCA4, PTPRB, AJUBA, CR1, KMT2D, NBEA, FAM135B, GTF2I, and CIC), thus increasing our understanding of the potential HPV-disrupted pathways. Therefore, our study reveals innovative targets with potential therapeutic benefits for HPV-associated PSCCs. The CNV analysis by sequencing (CNV-seq) revealed five cancer-associated genes as the most frequent with gains (NOTCH1, MYC, NUMA1, PLAG1, and RAD21), while 30% of the tumors showed SMARCA4 with loss. Additionally, four cancer-associated genes (CARD11, CSMD3, KDR, and TLX3) carried untranslated regions (UTRs) variants, which may impact gene regulation by affecting the miRNAs hybridization regions. Altogether, these data contribute to the characterization of the mutational spectrum and its impact on cellular signaling pathways in PSCC, thus reinforcing the pivotal role of HPV infection in the molecular pathogenesis of these tumors.

HPV-associated penile cancer: Impact of copy number alterations in miRNA/mRNA interactions and potential druggable targets

BACKGROUND

Penile cancer (PeCa) is a rare disease, but its incidence has increased worldwide, mostly in HPV+ patients. Nevertheless, there is still no targeted treatment for this carcinoma.

OBJECTIVE

To predict the main signaling pathways involved in penile tumorigenesis and its potential drug targets.

METHODS

Genome-wide copy number profiling was performed in 28 PeCa. Integration analysis of CNAs and miRNAs and mRNA targets was performed by DIANA-TarBase v.8. The potential impact of the miRNAs/target genes on biological pathways was assessed by DIANA-miRPath v.3.0. For each miRNA, KEGG pathways were generated based on the tarbase and microT-CDS algorithms. Pharmaco-miR was used to identify associations between miRNAs and their target genes to predict druggable targets.

RESULTS

269 miRNAs and 2,395 genes were mapped in cytobands with CNAs. The comparison of the miRNAs mapped at these cytobands and the miRNAs that were predicted to regulate the genes also mapped in these regions, resulted in a set of common 35 miRNAs and 292 genes. Enrichment pathway revealed their involvement in five top signaling pathways. EGFR and COX2 were identified as potential druggable targets.

CONCLUSION

Our data indicate the potential use of EGFR and COX2 inhibitors as a target treatment for PeCa patients.

Hereditary gastric cancer: Three rules to reduce missed diagnoses

Gastric cancer remains one of the most lethal cancers. The incidence and mortality rates are quite similar. The main reason for the high mortality is diagnosis at advanced stages of disease, when treatment options are poor. One of the supposed strategies to overcome late-stage diagnosis is identifying people at high risk with the aim of establishing rigorous clinical control, including routine endoscopy and biopsies. Hereditary gastric cancer (HGC) syndromes, though representing a sizeable group to monitor for prevention or, at least, for early diagnosis, are apparently extremely rare. The low rate of HGC diagnosis might be related to the low rates of suspicion, insufficient familiarity about clinical diagnosis criteria, and the supposed conditional necessity of a molecular diagnosis. In this review, we will discuss simple measures to increase HGC diagnosis by applying three rules that might provide an opportunity for precision care to benefit the families affected by this disease.

Genomic profiling reveals the pivotal role of hrHPV driving copy number and gene expression alterations, including mRNA downregulation of TP53 and RB1 in penile cancer

The incidence of penile cancer (PeCa) is increasing worldwide, however, the highest rates are reported in underdeveloped countries. The molecular mechanisms that underly the onset and progression of these tumors are still unclear. Therefore, our goal was to determine the genome-wide copy number alterations and the involvement of human papiloma virus (HPV) (TP53 and RB1), inflammatory (COX2 and EGFR), and PI3K/AKT pathway (AKT1, AKT2, EGFR, ERBB3, ERBB4, PIK3CA, and PTEN) associated genes in patients with PeCa from a high incidence region in Brazil (Maranhão). HPV genotyping was performed by nest-PCR and genome sequencing, copy number alterations (CNAs) by array comparative genomic hybridization and gene copy number status, gene, and protein expression by quantitative polymerase chain reaction, reverse transcriptase-quantitative polymerase chain reaction, and immunohistochemistry, respectively. HPV genotyping revealed one of the highest frequencies of HPV reported in PeCa, affecting 96.4% of the cases. The most common CNAs observed were located at the HPV integration sites, such as 2p12-p11.2 and 14q32.33, where ADAM 6, KIAA0125, LINC00226, LINC00221, and miR7641-2, are mapped. Increased copy number of ERBB3 and EGFR genes were observed in association with COX2 and EGFR overexpression, reinforcing the role of the inflammatory pathway in PeCa, and suggesting anti-EGFR and anti-COX2 inhibitors as promising therapies for PeCa. Additionally, TP53 and RB1 messenger RNA downregulation was observed, suggesting the occurrence of other mechanisms for repression of these oncoproteins, in addition to the canonical HPV/TP53/RB1 signaling pathway. Our data reinforce the role of epigenetic events in abnormal gene expression in HPV-associated carcinomas and suggest the pivotal role of HPV driving CNAs and controlling gene expression in PeCa.

Genomics and epidemiology for gastric adenocarcinomas (GE4GAC): a Brazilian initiative to study gastric cancer

Gastric cancer (GC) is the fifth most common type of cancer worldwide with high incidences in Asia, Central, and South American countries. This patchy distribution means that GC studies are neglected by large research centers from developed countries. The need for further understanding of this complex disease, including the local importance of epidemiological factors and the rich ancestral admixture found in Brazil, stimulated the implementation of the GE4GAC project. GE4GAC aims to embrace epidemiological, clinical, molecular and microbiological data from Brazilian controls and patients with malignant and pre-malignant gastric disease. In this letter, we summarize the main goals of the project, including subject and sample accrual and current findings.

The Small Bowel Cancer Incidence Enigma

Although the small bowel is a vast organ with a highly proliferative epithelium, the incidence of small bowel cancers is surprisingly low. Many factors could be involved in this unexpected cancer incidence, including difficult access to the exploration of the small bowel mucosa, which might lead to missed diagnoses of non-obstructive and non-bleeding small tumours. Moreover, possible factors that influence the low incidence include more efficient machinery of DNA replication and DNA repair enzymes, peculiarities in microbiota components, competence of the immune system, and the speed of intestinal transit. Importantly, the answer for the enigmatic risk of driver mutations caused by replication errors may be hidden in the small bowel, which is an obscure part of digestive tract that is usually inaccessible by endoscopic or colonoscopic conventional investigations. These observations warrant the necessity of an urgent exploration of small bowel features, including the evaluation of DNA replication controls and expression of DNA repair genes, in order to shed light on these obscure events.

Piwi like RNA-mediated gene silencing 1 gene as a possible major player in gastric cancer

AIM

To establish a permanent piwi like RNA-mediated gene silencing 1 (PIWIL1) gene knockout in AGP01 gastric cancer cell line using CRISPR-Cas9 system and analyze phenotypic modifications as well as gene expression alterations.

METHODS

CRISPR-Cas9 system used was purchased from Dharmacon GE Life Sciences (Lafayette, CO, United States) and permanent knockout was performed according to manufacturer’s recommendations. Wound-healing assay was performed to investigate the effect of PIWIL1 knockout on migration capability of cells and Boyden chamber invasion assay was performed to investigate the effect on invasion capability. For the gene expression analysis, a one-color microarray-based gene expression analysis kit (Agilent Technologies, Santa Clara, CA, United States) was used according to the protocol provided by the manufacturer.

RESULTS

PIWIL1 gene knockout caused a significant decrease in AGP01 migration capacity as well as a significant decrease in cell invasiveness. Moreover, functional analysis based on grouping of all differentially expressed mRNAs identified a total of 35 genes (5 up-regulated and 30 down-regulated) encoding proteins involved in cellular invasion and migration. According to current literature, 9 of these 35 genes (DOCK2, ZNF503, PDE4D, ABL1, ABL2, LPAR1, SMAD2, WASF3 and DACH1) are possibly related to the mechanisms used by PIWIL1 to promote carcinogenic effects related to migration and invasion, since their functions are consistent with the changes observed (being up- or down-regulated after knockout).

CONCLUSION

Taken together, these data reinforce the idea that PIWIL1 plays a crucial role in the signaling pathway of gastric cancer, regulating several genes involved in migration and invasion processes; therefore, its use as a therapeutic target may generate promising results in the treatment of gastric cancer.

An animal model for the evaluation of graft thrombosis in the acute phase on carbon-lined PTFE prosthesis

Fortyfive carbon-lined (CL) and 45 standard (ST) 4 mm internal diameter polytetra-fluoroethylene (PTFE) grafts were implanted as aortic interposition in 90 rabbits. A pilot study of 20 animals: 10 CL and 10 ST grafts were used to develop microsurgical techniques, then 60 grafts were placed in 60 New Zealand rabbits with lower morbidity. The two hours graft patency (Doppler and angiographic studies) showed better patency rate in CL group (93% versus 80%). In 10 animals, platelet accumulation was investigated in vivo using gammacamera imaging after injection of autologous platelets labeled with Indium111. In vitro, radioactivity counting of the explanted midgraft sections at 2 hours revealed 6 times greater activity in ST grafts (6.60 ± 1.98 x 103platelets/mm2 versus 0.82 ± 0.25 x 103 platelets/mm2; p<0.05). Light microscopy found platelet and fibrin deposition (PFD) in nearly all ST grafts whereas PFD were found in only 13% of the CL grafts corresponding to those thrombosed (chi2: 61.117, p<0.001). Carbon-lining decreases platelet accumulation on PTFE grafts in the acute phase of a new experimental model.

GelMA-Encapsulated hDPSCs and HUVECs for Dental Pulp Regeneration

Pulpal revascularization is commonly used in the dental clinic to obtain apical closure of immature permanent teeth with thin dentinal walls. Although sometimes successful, stimulating bleeding from the periapical area of the tooth can be challenging and in turn may deleteriously affect tooth root maturation. Our objective here was to define reliable methods to regenerate pulp-like tissues in tooth root segments (RSs). G1 RSs were injected with human dental pulp stem cells (hDPSCs) and human umbilical vein endothelial cells (HUVECs) encapsulated in 5% gelatin methacrylate (GelMA) hydrogel. G2 RSs injected with acellular GelMA alone, and G3 empty RSs were used as controls. White mineral trioxide aggregate was used to seal one end of the tooth root segment, while the other was left open. Samples were cultured in vitro in osteogenic media (OM) for 13 d and then implanted subcutaneously in nude rats for 4 and 8 wk. At least 5 sample replicates were used for each experimental group. Analyses of harvested samples found that robust pulp-like tissues formed in G1, GelMA encapsulated hDPSC/HUVEC-filled RSs, and less cellularized host cell-derived pulp-like tissue was observed in the G2 acellular GelMA and G3 empty RS groups. Of importance, only the G1, hDPSC/HUVEC-encapsulated GelMA constructs formed pulp cells that attached to the inner dentin surface of the RS and infiltrated into the dentin tubules. Immunofluorescent (IF) histochemical analysis showed that GelMA supported hDPSC/HUVEC cell attachment and proliferation and also provided attachment for infiltrating host cells. Human cell-seeded GelMA hydrogels promoted the establishment of well-organized neovasculature formation. In contrast, acellular GelMA and empty RS constructs supported the formation of less organized host-derived vasculature formation. Together, these results identify GelMA hydrogel combined with hDPSC/HUVECs as a promising new clinically relevant pulpal revascularization treatment to regenerate human dental pulp tissues.

High-Throughput miRNA Sequencing Reveals a Field Effect in Gastric Cancer and Suggests an Epigenetic Network Mechanism

Field effect in cancer, also called "field cancerization", attempts to explain the development of multiple primary tumors and locally recurrent cancer. The concept of field effect in cancer has been reinforced, since molecular alterations were found in tumor-adjacent tissues with normal histopatho-logical appearances. With the aim of investigating field effects in gastric cancer (GC), we conducted a high-throughput sequencing of the miRnome of four GC samples and their respective tumor-adjacent tissues and compared them with the miRnome of a gastric antrum sample from patients without GC, assuming that tumor-adjacent tissues could not be considered as normal tissues. The global number of miRNAs and read counts was highest in tumor samples, followed by tumor-adjacent and normal samples. Analyzing the miRNA expression profile of tumor-adjacent miRNA, hsa-miR-3131, hsa-miR-664, hsa-miR-483, and hsa-miR-150 were significantly downregulated compared with the antrum without tumor tissue (P-value < 0.01; fold-change <5). Additionally, hsa-miR-3131, hsa-miR-664, and hsa-miR-150 were downregulated (P-value < 0.001) in all paired samples of tumor and tumor-adjacent tissues, compared with antrum without tumor mucosa. The field effect was clearly demonstrated in gastric carcinogenesis by an epigenetics-based approach, and potential biomarkers of the GC field effect were identified. The elevated expression of miRNAs in adjacent tissues and tumors tissues may indicate that a cascade of events takes place during gastric carcinogenesis, reinforcing the notion of field effects. This phenomenon seems to be linked to DNA methylation patterns in cancer and suggests the involvement of an epigenetic network mechanism.

High-Throughput Sequencing of miRNAs Reveals a Tissue Signature in Gastric Cancer and Suggests Novel Potential Biomarkers

Gastric cancer has a high incidence and mortality rate worldwide; however, the use of biomarkers for its clinical diagnosis remains limited. The microRNAs (miRNAs) are biomarkers with the potential to identify the risk and prognosis as well as therapeutic targets. We performed the ultradeep miRnomes sequencing of gastric adenocarcinoma and gastric antrum without tumor samples. We observed that a small set of those samples were responsible for approximately 80% of the total miRNAs expression, which might represent a miRNA tissue signature. Additionally, we identified seven miRNAs exhibiting significant differences, and, of these, hsa-miR-135b and hsa-miR-29c were able to discriminate antrum without tumor from gastric cancer regardless of the histological type. These findings were validated by quantitative real-time polymerase chain reaction. The results revealed that hsa-miR-135b and hsa-miR-29c are potential gastric adenocarcinoma occurrence biomarkers with the ability to identify individuals at a higher risk of developing this cancer, and could even be used as therapeutic targets to allow individualized clinical management.

Strong water isotopic anomalies in the martian atmosphere: probing current and ancient reservoirs

We measured maps of atmospheric water (H2O) and its deuterated form (HDO) across the martian globe, showing strong isotopic anomalies and a significant high deuterium/hydrogen (D/H) enrichment indicative of great water loss. The maps sample the evolution of sublimation from the north polar cap, revealing that the released water has a representative D/H value enriched by a factor of about 7 relative to Earth's ocean [Vienna standard mean ocean water (VSMOW)]. Certain basins and orographic depressions show even higher enrichment, whereas high-altitude regions show much lower values (1 to 3 VSMOW). Our atmospheric maps indicate that water ice in the polar reservoirs is enriched in deuterium to at least 8 VSMOW, which would mean that early Mars (4.5 billion years ago) had a global equivalent water layer at least 137 meters deep.

MiRNA expression profile for the human gastric antrum region using ultra-deep sequencing

Background

MicroRNAs are small non-coding nucleotide sequences that regulate gene expression. These structures are fundamental to several biological processes, including cell proliferation, development, differentiation and apoptosis. Identifying the expression profile of microRNAs in healthy human gastric antrum mucosa may help elucidate the miRNA regulatory mechanisms of the human stomach.

Methodology/Principal Findings

A small RNA library of stomach antrum tissue was sequenced using high-throughput SOLiD sequencing technology. The total read count for the gastric mucosa antrum region was greater than 618,000. After filtering and aligning using with MirBase, 148 mature miRNAs were identified in the gastric antrum tissue, totaling 3,181 quality reads; 63.5% (2,021) of the reads were concentrated in the eight most highly expressed miRNAs (hsa-mir-145, hsa-mir-29a, hsa-mir-29c, hsa-mir-21, hsa-mir-451a, hsa-mir-192, hsa-mir-191 and hsa-mir-148a). RT-PCR validated the expression profiles of seven of these highly expressed miRNAs and confirmed the sequencing results obtained using the SOLiD platform.

Conclusions/Significance

In comparison with other tissues, the antrum’s expression profile was unique with respect to the most highly expressed miRNAs, suggesting that this expression profile is specific to stomach antrum tissue. The current study provides a starting point for a more comprehensive understanding of the role of miRNAs in the regulation of the molecular processes of the human stomach.

Etomidate has no effect on hypoxia reoxygenation and hypoxic preconditioning in isolated human right atrial myocardium

BACKGROUND

We examined the effects of etomidate on recovery of contractile function after hypoxia reoxygenation and hypoxic preconditioning in vitro using isolated human myocardium.

METHODS

Human right atrial myocardium were obtained at the time of cardiac surgery from 38 adults patients. We recorded isometric force of contraction (FoC) of atrial trabeculae suspended in an oxygenated Tyrode's solution (34 degrees C, stimulation frequency 1 Hz). In all groups, a 30-min hypoxic period was followed by 60 min of reoxygenation (HR). In separate groups, muscles were exposed to etomidate (10(-7), 10(-6), 10(-5) M) 10 min before and throughout the HR periods. Hypoxic preconditioning was induced by 4-min hypoxia followed by 7-min reoxygenation applied before HR periods. Etomidate 10(-5) M was administered before, throughout, and after the hypoxic preconditioning stimulus. Recovery of FoC (expressed as % of baseline value) at the end of HR was compared among groups.

RESULTS

Compared with the control group (FoC: 52%+/-10%), etomidate 10(-7) M (FoC: 57%+/-9%; P=0.24), 10(-6) M (FoC: 61%+/-11%; P=0.10), and 10(-5) M (FoC: 54%+/-9%; P=0.29) did not modify the recovery of FoC after HR. Hypoxic preconditioning-induced increase in the recovery of FoC (87%+/-5%; P<0.001 vs control group) was not modified in the presence of etomidate 10(-5) M (FoC: 86%+/-7%; P=0.74 vs hypoxic preconditioning group).

CONCLUSIONS

Etomidate did not modify the in vitro FoC of human myocardium exposed to HR. Furthermore, etomidate did not modify the protective effect of hypoxic preconditioning.

Le phéochromocytome comme cause inhabituelle de choc cardiogénique

The authors reported a case involving a young patient with a cardiogenic shock associated to an acute pulmonary oedema. According to the seriousness of the shock, an external ventricular assist device (VAD) was initially inserted and replaced thereafter because of the cardiovascular instability, by an external pneumatic biventricular assist device. A cardiogenic shock induced by an acute adrenergic myocarditis due to a phaeochromocytoma was diagnosed. The patient was weaned from the VAD on day 84 and was scheduled for elective surgery of the phaeochromocytoma on day 93. The authors discussed the time of the surgery according to the anticoagulation therapy necessary to the VAD and the necessary caution taken if a cardiogenic shock appeared around surgery.

Ketamine preconditions isolated human right atrial myocardium: roles of adenosine triphosphate-sensitive potassium channels and adrenoceptors

BACKGROUND

The authors examined the effect of ketamine and its S(+) isomer on isolated human myocardium submitted to hypoxia-reoxygenation in vitro.

METHODS

The authors studied isometric contraction of human right atrial trabeculae suspended in an oxygenated Tyrode's modified solution at 34 degrees C. Ten minutes before a 30-min hypoxic period followed by a 60-min reoxygenation, muscles were exposed for 15 min to racemic ketamine and its S(+) isomer at 10, 10, and 10 m alone or in the presence of 8.10 m 5-hydroxydecanoate, 10 m HMR 1098 (sarcolemmal adenosine triphosphate-sensitive potassium channel antagonist), 10 m phentolamine (alpha-adrenoceptor antagonist), and 10 m propranolol (beta-adrenoceptor antagonist). Force of contraction at the end of the 60-min reoxygenation period was compared between groups (mean +/- SD).

RESULTS

Ketamine (10 m: 85 +/- 4%; 10 m: 95 +/- 10%; 10 m: 94 +/- 14% of baseline) and S(+)-ketamine (10-6 m: 85 +/- 4%; 10 m: 91 +/- 16%; 10 m: 93 +/- 14% of baseline) enhanced recovery of force of contraction at the end of the reoxygenation period as compared with the control group (47 +/- 10% of baseline; P < 0.001). Ketamine-induced preconditioning at 10 m was inhibited by 5-hydroxydecanoate (60 +/- 16%; P < 0.001), HMR 1098 (60 +/- 14%; P < 0.001), phentolamine (56 +/- 12%; P < 0.001), and propranolol (60 +/- 7%; P < 0.001).

CONCLUSIONS

In vitro, ketamine preconditions isolated human myocardium, at least in part, via activation of adenosine triphosphate-sensitive potassium channels and stimulation of alpha- and beta-adrenergic receptors.

Liver Transplant Combined With Heart Transplant in Severe Heterozygous Hypercholesterolemia: Report of the First Case and Review of the Literature

Familial hypercholesterolemia (FH) is a dominant inherited disease of low-density lipoprotein (LDL) metabolism caused by mutations of LDL receptors mainly located in the liver. This metabolic disorder is responsible for severe cardiovascular disease, from coronary lesions to chronic heart failure (CHF). Liver transplantation in homozygous FH provides the missing functional LDL receptors and thus partially restores LDL receptor activity to more than 50% of normal. Combined heart and liver transplantation was successfully performed in a homozygous FH patient with end-stage heart failure. Herein we report our experience with a heterozygous male patient with terminal CHF, and review data from the literature on short- and long-term results of such procedures.

Repair of Aortic Leaflet Prolapse: The “Sliding Leaflet Technique”

Valve-preserving aortic replacement has become an accepted therapeutic option for aortic dilatation with normal valve leaflets. The presence of a leaflet prolapse often induces the choice of a composite graft repair. In these cases, however, the repair of a leaflet prolapse is possible and represents a valuable alternative to a prosthetic valve. The conventional techniques of repair of a cusp prolapse are designed to restore coaptation through a reduction of free margin length. The sliding leaflet technique is an alternative procedure conceived to repair the prolapsed valve cusp by remodeling both the free margin and the annular insertion.

Back from Irreversibility: Extracorporeal Life Support for Prolonged Cardiac Arrest

BACKGROUND

The survival of patients after prolonged cardiac arrest is still inadequate. Extracorporeal life support (ECLS) represents an alternative therapeutic method for patients who do not respond to conventional cardiopulmonary cerebral resuscitation. This technology is used to support the circulation of a patient with severe cardiac failure.

METHODS

Between June 1997 and January 2003, 40 ECLS procedures were performed in patients who presented with refractory cardiac arrest. During external cardiac massage, the patient was connected to an extracorporeal circuit by the insertion of an arterial and venous cannula through the femoral vessels. The extracorporeal circuit included a centrifugal pump and an oxygenator. Mean age was 42 +/- 15 years; the average time of external cardiac massage was 105 +/- 44 minutes.

RESULTS

Once the circulation was restored, 22 patients were disconnected from the extracorporeal circulation because of brain death or multiorgan failure; after 24 hours, among the 18 survivors, 6 were weaned off the pump, 9 were bridged to a ventricular assist device, and 2 patients were directly bridged to cardiac transplantation. Eight patients are alive and without any sequelae at 18 month's follow-up.

CONCLUSIONS

In prolonged cardiac arrest with failing conventional measures, rescue by extracorporeal support provides an ultimate therapeutic option with a good outcome in survivors. Our results encourage the wider application of ECLS for refractory cardiocirculatory arrest in selected patients. The high rate of neurologic death needs further improvements in the early phase of resuscitation maneuvers.

The Inotropic and Lusitropic Effects of Ketamine in Isolated Human Atrial Myocardium: The Effect of Adrenoceptor Blockade

We studied the direct myocardial effects of racemic ketamine, in the presence of alpha- and beta-adrenoceptor blockade, on isolated human right atrial myocardium. Isometric force of contraction (FoC), its first derivative with time (+dF/dt), the contraction relaxation coupling parameter R2 = (+dF/dt) / (-dF/dt), and time to half relaxation (T(1/2)) were recorded before and after addition of 10(-6), 10(-5) and 10(-4) M racemic ketamine alone and in the presence of alpha-adrenoceptor blockade (phentolamine 10(-6) M) and beta-adrenoceptor blockade (propranolol at 10(-6) M). Ketamine had a moderate positive inotropic effect at 10(-5) M (FoC, 104% +/- 5% of baseline value; P = 0.03) and 10(-4) M (FoC, 107% +/- 11% of baseline value; P = 0.09). Racemic ketamine had a negative inotropic effect in the presence of propranolol (FoC, ketamine 10(-6) M, 77% +/- 11%; ketamine 10(-5) M, 63% +/- 16%; ketamine 10(-4) M, 62% +/- 17% of baseline; P < 0.001) but not phentolamine (FoC, ketamine at 10(-6) M, 94% +/- 6%; ketamine 10(-5) M, 96% +/- 5%; and ketamine 10(-4) M, 98% +/- 15% of baseline). Ketamine decreased T(1/2) (ketamine 10(-5) M, 94% +/- 3% of baseline value; P < 0.001 and ketamine 10(-4) M, 90% +/- 9% of baseline value; P = 0.007) but did not modify R2. In human right atrial myocardium, racemic ketamine induced a moderate positive inotropic effect and hastened isometric relaxation. In the presence of beta-adrenoceptor blockade it induced a direct negative inotropic effect.

Less invasive radial artery harvest

BACKGROUND

Recent studies have sparked a renewed interest in the use of autogenous radial arteries in coronary operations. Some concerns have been found about sequelae of conventional harvesting. A less invasive technique for radial artery harvesting has been proposed by others using endoscopic devices. This technique is time consuming, needs expensive instrumentation and an important learning curve.

METHODS

A new less invasive approach for radial harvesting has been developed with a light assisted retractor under direct vision. A small skin incision, median in the forearm, is followed by dissection of the proper plane of the artery. A subcutaneous tunnel is created around the vessel and all the branches are ligated or clipped. The dissection of the pedicle under the skin is completed with the aid of a modified light assisted retractor, originally designed for the saphenous vein harvesting. The incision is closed after heparin reversal with a small redon as drainage.

RESULTS

A preliminary serie of 15 patients have been operated with this technique. In all patients the radial artery was patent and functional at the postoperative angiography. Morbidity included only a light hematoma at the beginning of our experience.

CONCLUSION

This less invasive technique for the radial artery harvesting appears to be an excellent surgical compromise between the open technique and the endoscopic procedure; it is easy to perform, the learning curve is acceptable and it offers an excellent aesthetic result.

Mechanisms of sevoflurane-induced myocardial preconditioning in isolated human right atria in vitro

BACKGROUND

The authors examined the role of adenosine triphosphate-sensitive potassium channels and adenosine A(1) receptors in sevoflurane-induced preconditioning on isolated human myocardium.

METHODS

The authors recorded isometric contraction of human right atrial trabeculae suspended in oxygenated Tyrode's solution (34 degrees C; stimulation frequency, 1 Hz). In all groups, a 30-min hypoxic period was followed by 60 min of reoxygenation. Seven minutes before hypoxia reoxygenation, muscles were exposed to 4 min of hypoxia and 7 min of reoxygenation or 15 min of sevoflurane at concentrations of 1, 2, and 3%. In separate groups, sevoflurane 2% was administered in the presence of 10 microm HMR 1098, a sarcolemmal adenosine triphosphate-sensitive potassium channel antagonist; 800 microm 5-hydroxy-decanoate, a mitochondrial adenosine triphosphate-sensitive potassium channel antagonist; and 100 nm 8-cyclopentyl-1,3-dipropylxanthine, an adenosine A(1) receptor antagonist. Recovery of force at the end of the 60-min reoxygenation period was compared between groups (mean +/- SD).

RESULTS

Hypoxic preconditioning (90 +/- 4% of baseline) and sevoflurane 1% (82 +/- 3% of baseline), 2% (92 +/- 5% of baseline), and 3% (85 +/- 7% of baseline) enhanced the recovery of force after 60 min of reoxygenation compared with the control groups (52 +/- 9% of baseline). This effect was abolished in the presence of 5-hydroxy-decanoate (55 +/- 14% of baseline) and 8-cyclopentyl-1,3-dipropylxanthine (58 +/- 16% of baseline) but was attenuated in the presence of HMR 1098 (73 +/- 10% of baseline).

CONCLUSIONS

In vitro, sevoflurane preconditions human myocardium against hypoxia through activation of adenosine triphosphate-sensitive potassium channels and stimulation of adenosine A(1) receptors.

Pre-operative balloon counterpulsation and off-pump coronary surgery for high-risk patients

Coronary artery bypass surgery (CABG) can be performed less invasively without cardiopulmonary bypass (CPB). Multivessel off-pump CABG (OPCAB) is challenging in patients with critical left main stenosis (> 70%) and/or severe ventricular dysfunction (ejection fraction < 0.35) Our objective was the evaluation of efficiency of intra aortic balloon pump (IABP) preoperatively in this high-risk group in order to perform OPCABG safely.

MATERIAL AND METHOD

In a consecutive 10-month period (out of 88 OPCABG patients) 23 high-risk patients were treated and were compared with 15 on-pump patients (out of 69) with the same criteria.

RESULTS

Preoperative implantation of IABP was significantly higher in the OPCABG group (70% vs 46%, p < 0.05). No conversion to CPB was required in the OPCABG group. Post-operative angiography was systematically performed and demonstrated 97.5% patency of anastomosis. No device-related complications occurred. No difference was found concerning age, risk factors, emergency surgery, ejection fraction, mean number of grafts per patient (2.64 versus 2.75) and average operating time. In contrast, OPCABG demonstrated a trend toward reduced morbidity in terms of atrial fibrillation, reexploration for bleeding and prolonged ventilator requirement > 12 h. Mortality was less in the OPCABG group (p < 0.05).

CONCLUSION

More randomized controlled trials are needed to evaluate the true efficacy of elective IABP in OPCABG high-risk patients. Until such studies are evaluated, and therefore because older and sicker patients now constitute a greater percentage of candidates for OPCABG, the timing of application of the IABP is warranted. These results may further justify preoperative use of the IABP in a large proportion of this group of patients.

Mechanisms of desflurane-induced preconditioning in isolated human right atria in vitro

BACKGROUND

The authors examined the role of adenosine triphosphate-sensitive potassium (K(ATP)) channels, adenosine A1 receptor, and alpha and beta adrenoceptors in desflurane-induced preconditioning in human myocardium, in vitro.

METHODS

The authors recorded isometric contraction of human right atrial trabeculae suspended in oxygenated Tyrode's solution (34 degrees C; stimulation frequency, 1 Hz). Before a 30-min anoxic period, 3, 6, and 9% desflurane was administered during 15 min. Desflurane, 6%, was also administered in the presence of 10 microm glibenclamide, a K(ATP) channels antagonist; 10 microm HMR 1098, a sarcolemmal K(ATP) channel antagonist; 800 microm 5-hydroxy-decanoate (5-HD), a mitochondrial K(ATP) channel antagonist; 1 microm phentolamine, an alpha-adrenoceptor antagonist; 1 microm propranolol, a beta-adrenoceptor antagonist; and 100 nm 8-cyclopentyl-1,3-dipropylxanthine (DPX), the adenosine A1 receptor antagonist. Developed force at the end of a 60-min reoxygenation period was compared (mean +/- SD).

RESULTS

Desflurane at 3% (95 +/- 13% of baseline), 6% (86 +/- 6% of baseline), and 9% (82 +/- 6% of baseline) enhanced the recovery of force after 60 min of reoxygenation as compared with the control group (50 +/- 11% of baseline). Glibenclamide (60 +/- 12% of baseline), 5-HD (57 +/- 21% of baseline), DPX (63 +/- 19% of baseline), phentolamine (56 +/- 20% of baseline), and propranolol (63 +/- 13% of baseline) abolished desflurane-induced preconditioning. In contrast, HMR 1098 (85 +/- 12% of baseline) did not modify desflurane-induced preconditioning.

CONCLUSIONS

In vitro, desflurane preconditions human myocardium against simulated ischemia through activation of mitochondrial K(ATP) channels, adenosine A1 receptor, and alpha and beta adrenoceptors.

[Severe intoxication with cardiotoxic drugs: value of emergency percutaneous cardiocirculatory assistance]

Acute severe self-administration of an overdose of betablockers, calcium antagonists or antiarrhythmic drugs is rare but carries a mortality of 10-15%. Between May 1997 and March 2000, 6 patients with an average age of 34 years (range 17-55 years) had a cardiac arrest on admission requiring emergency cardiac massage and emergency intubation with ventilatory assistance following massive ingestion of cardiotoxic drugs. Echocardiography confirmed complete biventricular akinesia. The surgical team implanted a cardiovascular assist device (ECMO: Extra Corporeal Membrane Oxygenation) by the femoral approach with pre-heparinated percutaneous cannula. The first two patients died of multi-organ failure due to a delay in the installation of the assistance. The 4 other patients survived without sequellae or recurrences. The average time on ECMO was 59.25 +/- 2 hours (range 48-71 hours). The early recognition of the indication for ECMO was one of the most important predictive factors for morbidity and mortality. The strategy of patient management should be determined in the emergency room: in cases of cardiocirculatory arrest resistant to symptomatic treatment (stomach washout, intravenous fluids, isoprenaline, inotropic agents) an echocardiogram should be obtained and the cardiac surgical team alerted to the problem. The introduction of pre-heparinated circuits, percutaneous cannula and peripheral shunts has widened the indications, efficacy (detoxification, restoration of peripheral tissue perfusion) and accessibility to this material, while limiting its duration. The collaboration of experienced multidisciplinary teams (emergency room staff, cardiologists, anaesthetists and surgeons) should optimise the timing of implantation and the monitoring of these systems and improve the results of resuscitation of these patients.

The in vitro effects of remifentanil, sufentanil, fentanyl, and alfentanil on isolated human right atria

Because some clinical studies have suggested that opioids used in anesthesia may have different deleterious hemodynamic effects, we compared the direct myocardial effects of cumulative concentrations of remifentanil, sufentanil, fentanyl, and alfentanil on inotropic and lusitropic variables of isolated human myocardium in vitro. Human right atrial trabeculae, obtained from patients scheduled for coronary bypass surgery or aortic valve replacement, were suspended vertically in an oxygenated (95% oxygen/5% CO(2)) Tyrode's modified solution ([Ca(2+)](o) = 2.0 mM, 37 degrees C, pH 7.40, stimulation frequency 1 Hz). The effects of cumulative concentrations (10(-11), 10(-10), 10(-9), 10(-8), 10(-7), and 10(-6) M) of remifentanil (n = 8), sufentanil (n = 8), fentanyl (n = 8), and alfentanil (n = 8) on inotropic and lusitropic variables of isometric twitches were measured. Remifentanil, sufentanil, and fentanyl did not modify active isometric force and peak of the positive force derivative as compared with the Control group. Alfentanil induced a dose-dependent decrease in active isometric force and peak of the positive force derivative. This effect was abolished in the presence of [Ca(2+)](o) = 4.0 mM. None of these opioids altered lusitropic variables.

The in vitro effects of remifentanil, sufentanil, fentanyl, and alfentanil on isolated human right atria

Because some clinical studies have suggested that opioids used in anesthesia may have different deleterious hemodynamic effects, we compared the direct myocardial effects of cumulative concentrations of remifentanil, sufentanil, fentanyl, and alfentanil on inotropic and lusitropic variables of isolated human myocardium in vitro. Human right atrial trabeculae, obtained from patients scheduled for coronary bypass surgery or aortic valve replacement, were suspended vertically in an oxygenated (95% oxygen/5% CO(2)) Tyrode's modified solution ([Ca(2+)](o) = 2.0 mM, 37 degrees C, pH 7.40, stimulation frequency 1 Hz). The effects of cumulative concentrations (10(-11), 10(-10), 10(-9), 10(-8), 10(-7), and 10(-6) M) of remifentanil (n = 8), sufentanil (n = 8), fentanyl (n = 8), and alfentanil (n = 8) on inotropic and lusitropic variables of isometric twitches were measured. Remifentanil, sufentanil, and fentanyl did not modify active isometric force and peak of the positive force derivative as compared with the Control group. Alfentanil induced a dose-dependent decrease in active isometric force and peak of the positive force derivative. This effect was abolished in the presence of [Ca(2+)](o) = 4.0 mM. None of these opioids altered lusitropic variables.

Analysis of arylsulfatases A and B, acid phosphatase, lactate dehydrogenase, and aspartate transaminase in chronic periapical lesions of endodontic origin

Attempts were made to detect and measure the activities of arylsulfatases. A&B acid phosphatase, lactate dehydrogenase, and glutamate oxaloacetate transaminase (aspartate transaminase) enzymes in human chronic lesions of endodontic origin. Thirteen periapical lesions of endodontic origin and 11 noninflamed control periapical tissues were obtained. The specimens were carried to the laboratory on liquid nitrogen and kept at -70 degrees C. Samples were thawed, homogenized, and then assayed for enzyme activities. The specific activities of arylsulfatase A (nmol/hr/mg protein) were 55.0+/-10.7 (chronic lesions) vs. 3.4+/-2.2 (controls) (p < 0.01). Arylsulfatase B specific activities (nmol/hr/mg protein) were 50.3+/-6.4 (chronic lesions) vs 91.8+/-18.4 (controls). Total acid phosphatase activities (mU/mg protein) were 45.8+/-6.6 (chronic lesions) vs. 26.8+/-3.1 (controls). Lactate dehydrogenase activities (Berger-Broida units/mg protein) of the chronic periapical lesions were significantly higher than the control group (362+/-63.2) vs. (140+/-46.0) (p < 0.05). There was no significant difference between the specific activities of aspartate transaminase in chronic lesions and the control group (68.0+/-14.5) vs. (53.0+/-10.4) mU/mg protein).

Aortic root remodeling with the "cuff" technique for stentless valve implantation

Aortic root and sinotubular junction dilatation and aneurysm of ascending aorta are considered relative contra-indications to implantation of a stentless valve prosthesis, because the modified aortic geometry leads to aortic incompetence and early failure of the prosthesis. Aortic root reconstruction can be performed according to various techniques. We present a surgical technique in which a tubular graft, replacing an ascending aortic aneurysm, allows sinotubular remodeling and satisfactory implantation of a stentless prosthesis. The native aorta is inserted into the vascular prosthesis at the level of the sinotubular junction which is wrapped in order to prevent commissure spreading. Sizing of the vascular and valve prosthesis is made according to annular diameter. Since October 1999, 6 patients have been operated using this technique with good results.

Catastrophic consequences of a free floating thrombus in ascending aorta

Floating masses in ascending aorta are an uncommon source of embolism. We report the case of a 46-year-old woman, smoker, on synthetic progestagen, with no previous history of thrombotic events, who was admitted to our emergency department for an acute anterior myocardial infarction. Coronary angiogram showed occlusion of left main coronary trunk. Recanalization of the artery was obtained. Ascending aorta angiogram revealed a free floating mass attached to the aortic wall without evidence of aortic dissection. Transesophageal echocardiography confirmed the presence of a pedunculated mobile mass attached to the aortic wall superior to the left coronary ostium. The patient underwent urgent surgery. Intraoperatively a floating thrombus was localized in the posterior wall of ascending aorta. At macroscopical examination aortic wall and leaflets were normal. Post-operative low cardiac output refractory to inotropic drugs and intraaortic balloon counterpulsation required a circulatory assist device. Consequences for the patient were catastrophic in terms of outcome.

Necrotizing granulomata of the aortic valve in Wegener's disease

Wegener's disease is an inflammatory disease of unknown etiology, characterized by a granulomatous-necrotizing general vasculitis. Cardiac involvement in the form of aortic pathology is not frequent. We report a case of Wegener's granulomatosis which required prosthetic aortic valve replacement for aortic valve insufficiency. Microscopic examination of the valve demonstrated histopathology typical of Wegener's disease.

Surgical treatment of pulmonary aspergilloma: current outcome

OBJECTIVE

This retrospective study was designed to confirm that aggressive pulmonary resection can provide effective long-term palliation of disease for patients with pulmonary aspergilloma.

METHODS AND RESULTS

From 1959 to 1998, 84 patients underwent a total of 90 operations for treatment of pulmonary aspergilloma in the Marie-Lannelongue Hospital. The mean follow-up period was 9 years, and 83% of the patients were followed up for 5 years or until death, if the latter occurred earlier. The median age was 44 years. The most common indications were hemoptysis (66%) and sputum production (15%). Fifteen patients (18%) had no symptoms. Tuberculosis and lung abscess were the most common underlying causes of lung disease (65%). The procedures were 70 lobar or segmental resections, 8 cavernostomies, and 7 pneumonectomies. Five thoracoplasties were required after lobectomy (3 patients) or pneumonectomy (2 patients). The operative mortality rate was 4%. The major complications were bleeding (23 patients), prolonged air leak (31 patients), respiratory failure (10 patients), and empyema (5 patients). The actuarial survival curve showed 84% survival at 5 years and 74% survival at 10 years. During the first 2 years, death was related to the surgical procedure and the underlying disease. In contrast, 85% of the survivors had a good late result.

CONCLUSION

Lobar resection in both the symptomatic and the asymptomatic patients was conducted in low-risk settings. For patients whose condition is unfit for pulmonary resection, cavernostomy may need to be undertaken despite the high operative risk. The better survival rate in this study may have been due to the selection of patients with better lung function and localized pulmonary disease.

Postinfarction ventricular septal rupture: early repair through the right atrial approach

OBJECTIVE

Early repair of posterior ventricular septal rupture associated with myocardial infarction by means of transinfarct ventriculotomy is technically challenging and can be associated with significant mortality and morbidity. An alternative route of exposing the septum is through the right atrium. This technique, which avoids direct incision of the ventricle in select patients, reduces postrepair bleeding and impairment of ventricular contractile function.

METHODS

The results of 12 patients operated on over a 20-year period were reviewed and analyzed. Late follow-up was obtained in all patients who survived the operation. There were 9 men and 3 women, with a mean age of 69.9 years. The mean time between acute myocardial infarction and surgery was 7.3 days (range, 2-16 days). Six patients were in New York Heart Association class IV, and 3 patients presented for surgery in cardiogenic shock. One patient had previously undergone a coronary artery bypass. The surgical technique included a standard sternotomy approach with a transatrial approach to the septal rupture. In all patients the septal rupture was repaired with a Dacron patch.

RESULTS

There were 3 early deaths and 1 late death; one patient was reoperated on for a residual shunt. Postoperative complications included low cardiac output, acute renal tubular necrosis, and supraventricular arrhythmia. Eight patients are alive and undergoing echocardiographic investigation, and only 1 patient had a small residual shunt.

CONCLUSION

Our experience shows that a posterior ventricular septal rupture can be safely repaired through a transatrial approach. Avoiding additional damage to the ventricle, it reduces the risks of the postoperative bleeding and enhances survival.

In vitro effects of desflurane, sevoflurane, isoflurane, and halothane in isolated human right atria

BACKGROUND

Direct myocardial effects of volatile anesthetics have been studied in various animal species in vitro. This study evaluated the effects of equianesthetic concentrations of desflurane, sevoflurane, isoflurane, and halothane on contractile parameters of isolated human atria in vitro.

METHODS

Human right atrial trabeculae, obtained from patients undergoing coronary bypass surgery, were studied in an oxygenated (95% O2-5% CO2) Tyrode's modified solution ([Ca2+]o = 2.0 mM, 30 degrees C, stimulation frequency 0.5 Hz). The effects of equianesthetic concentrations (0.5, 1, 1.5, 2, and 2.5 minimum alveolar concentration [MAC]) of desflurane, sevoflurane, isoflurane, and halothane on inotropic and lusitropic parameters of isometric twitches were measured.

RESULTS

Isoflurane, sevoflurane, and desflurane induced a moderate concentration-dependent decrease in active isometric force, which was significantly lower than that induced by halothane. In the presence of adrenoceptor blockade, the desflurane-induced decrease in peak of the positive force derivative and time to peak force became comparable to those induced by isoflurane. Halothane induced a concentration-dependent decrease in time to half-relaxation and a contraction-relaxation coupling parameter significantly greater than those induced by isoflurane, sevoflurane and desflurane.

CONCLUSIONS

In isolated human atrial myocardium, desflurane, sevoflurane, and isoflurane induced a moderate concentration-dependent negative inotropic effect. The effect of desflurane on time to peak force and peak of the positive force derivative could be related to intramyocardial catecholamine release. At clinically relevant concentrations, desflurane, sevoflurane, and isoflurane did not modify isometric relaxation.

Cosmetic aspects in minimally invasive cardiac surgery

The initial focus of the pioneering cardiac surgeons was appropriately centered on survival as opposed to cosmetic results. A variety of minimally invasive techniques have been introduced to perform cardiac operations through a limited incision. As the results in cardiac surgery improved, cosmetic and psychological implications of surgery become more important in the evaluation of the morbidity of these procedures. Future comparative studies will be mandatory to show whether these small incisions have an actual advantage on recovery or morbidity or whether their interest is entirely aesthetic.

Aortic balloon entrapment complicating intra-aortic balloon counterpulsation

Short-term balloon counterpulsation may be complicated by aortic balloon entrapment. We report a patient in whom video-coronary surgery was performed using beating heart anastomosis. This patient developed intra-aortic balloon (IAB) entrapment 4 days after initiation of the counterpulsation previously implanted for a preoperative low ejection fraction. No limb ischaemia was detected, but urgent removal of the balloon catheter is mandatory if blood is detected in the tubing connecting the balloon to the console, even in the presence of adequate function of the IAB assistance.