Deep-AVPpred: Artificial Intelligence Driven Discovery of Peptide Drugs for Viral Infections.

Rapid increase in viral outbreaks has resulted in the spread of viral diseases in diverse species and across geographical boundaries. The zoonotic viral diseases have greatly affected the well-being of humans, and the COVID-19 pandemic is a burning example. The existing antivirals have low efficacy, severe side effects, high toxicity, and limited market availability. As a result, natural substances have been tested for antiviral activity. The host defense molecules like antiviral peptides (AVPs) are present in plants and animals and protect them from invading viruses. However, obtaining AVPs from natural sources for preparing synthetic peptide drugs is expensive and time-consuming. As a result, an in-silico model is required for identifying new AVPs. We proposed Deep-AVPpred, a deep learning classifier for discovering AVPs in protein sequences, which utilises the concept of transfer learning with a deep learning algorithm. The proposed classifier outperformed state-of-the-art classifiers and achieved approximately 94% and 93% precision on validation and test sets, respectively. The high precision indicates that Deep-AVPpred can be used to propose new AVPs for synthesis and experimentation. By utilising Deep-AVPpred, we identified novel AVPs in human interferons- α family proteins. These AVPs can be chemically synthesised and experimentally verified for their antiviral activity against different viruses. The Deep-AVPpred is deployed as a web server and is made freely available at https://deep-avppred.anvil.app, which can be utilised to predict novel AVPs for developing antiviral compounds for use in human and veterinary medicine.

StaBle-ABPpred: a stacked ensemble predictor based on biLSTM and attention mechanism for accelerated discovery of antibacterial peptides.

Due to the rapid emergence of multi-drug resistant (MDR) bacteria, existing antibiotics are becoming ineffective. So, researchers are looking for alternatives in the form of antibacterial peptides (ABPs) based medicines. The discovery of novel ABPs using wet-lab experiments is time-consuming and expensive. Many machine learning models have been proposed to search for new ABPs, but there is still scope to develop a robust model that has high accuracy and precision. In this work, we present StaBle-ABPpred, a stacked ensemble technique-based deep learning classifier that uses bidirectional long-short term memory (biLSTM) and attention mechanism at base-level and an ensemble of random forest, gradient boosting and logistic regression at meta-level to classify peptides as antibacterial or otherwise. The performance of our model has been compared with several state-of-the-art classifiers, and results were subjected to analysis of variance (ANOVA) test and its post hoc analysis, which proves that our model performs better than existing classifiers. Furthermore, a web app has been developed and deployed at https://stable-abppred.anvil.app to identify novel ABPs in protein sequences. Using this app, we identified novel ABPs in all the proteins of the Streptococcus phage T12 genome. These ABPs have shown amino acid similarities with experimentally tested antimicrobial peptides (AMPs) of other organisms. Hence, they could be chemically synthesized and experimentally validated for their activity against different bacteria. The model and app developed in this work can be further utilized to explore the protein diversity for identifying novel ABPs with broad-spectrum activity, especially against MDR bacterial pathogens.

Deep-AFPpred: identifying novel antifungal peptides using pretrained embeddings from seq2vec with 1DCNN-BiLSTM.

Fungal infections or mycosis cause a wide range of diseases in humans and animals. The incidences of community acquired; nosocomial fungal infections have increased dramatically after the emergence of COVID-19 pandemic. The increase in number of patients with immunodeficiency / immunosuppression related diseases, resistance to existing antifungal compounds and availability of limited therapeutic options has triggered the search for alternative antifungal molecules. In this direction, antifungal peptides (AFPs) have received a lot of interest as an alternative to currently available antifungal drugs. Although the AFPs are produced by diverse population of living organisms, identifying effective AFPs from natural sources is time-consuming and expensive. Therefore, there is a need to develop a robust in silico model capable of identifying novel AFPs in protein sequences. In this paper, we propose Deep-AFPpred, a deep learning classifier that can identify AFPs in protein sequences. We developed Deep-AFPpred using the concept of transfer learning with 1DCNN-BiLSTM deep learning algorithm. The findings reveal that Deep-AFPpred beats other state-of-the-art AFP classifiers by a wide margin and achieved approximately 96% and 94% precision on validation and test data, respectively. Based on the proposed approach, an online prediction server is created and made publicly available at https://afppred.anvil.app/. Using this server, one can identify novel AFPs in protein sequences and the results are provided as a report that includes predicted peptides, their physicochemical properties and motifs. By utilizing this model, we identified AFPs in different proteins, which can be chemically synthesized in lab and experimentally validated for their antifungal activity.

Deep-ABPpred: identifying antibacterial peptides in protein sequences using bidirectional LSTM with word2vec.

The overuse of antibiotics has led to emergence of antimicrobial resistance, and as a result, antibacterial peptides (ABPs) are receiving significant attention as an alternative. Identification of effective ABPs in lab from natural sources is a cost-intensive and time-consuming process. Therefore, there is a need for the development of in silico models, which can identify novel ABPs in protein sequences for chemical synthesis and testing. In this study, we propose a deep learning classifier named Deep-ABPpred that can identify ABPs in protein sequences. We developed Deep-ABPpred using bidirectional long short-term memory algorithm with amino acid level features from word2vec. The results show that Deep-ABPpred outperforms other state-of-the-art ABP classifiers on both test and independent datasets. Our proposed model achieved the precision of approximately 97 and 94% on test dataset and independent dataset, respectively. The high precision suggests applicability of Deep-ABPpred in proposing novel ABPs for synthesis and experimentation. By utilizing Deep-ABPpred, we identified ABPs in the tail protein sequences of Streptococcus bacteriophages, chemically synthesized identified peptides in lab and tested their activity in vitro. These ABPs showed potent antibacterial activity against selected Gram-positive and Gram-negative bacteria, which confirms the capability of Deep-ABPpred in identifying novel ABPs in protein sequences. Based on the proposed approach, an online prediction server is also developed, which is freely accessible at https://abppred.anvil.app/. This web server takes the protein sequence as input and provides ABPs with high probability (>0.95) as output.

Mesenchymal stem cell tailored bioengineered scaffolds derived from bubaline diaphragm and aortic matrices for reconstruction of abdominal wall defects.

Bioengineered scaffolds derived from the decellularized extracellular matrix (ECM) obtained from discarded animal organs and tissues are attractive candidates for regenerative medicine applications. Tailoring these scaffolds with stem cells enhances their regeneration potential making them a suitable platform for regenerating damaged tissues. Thus, the study was designed to investigate the potential of mesenchymal stem cells tailored acellular bubaline diaphragm and aortic ECM for the repair of full-thickness abdominal wall defects in a rabbit model. Tissues obtained from bubaline diaphragm and aorta were decellularized and bioengineered by seeding with rabbit bone marrow derived mesenchymal stem cells (r-BMSC). Full-thickness abdominal wall defects of 3 cm × 4 cm size were created in a rabbit model and repaired using five different prostheses, namely, polypropylene sheet, nonseeded diaphragm ECM, nonseeded aorta ECM, r-BMSC bioengineered diaphragm ECM, and r-BMSC bioengineered aorta ECM. Results from the study revealed that biological scaffolds are superior in comparison to synthetic polymer mesh for regeneration in terms of collagen deposition, maturation, neovascularization, and lack of any significant (P > 0.05) adhesions with the abdominal viscera. Seeding with r-BMSC significantly increased (P < 0.05) the collagen deposition and biomechanical strength of the scaffolds. The bioengineered r-BMSC seeded acellular bubaline diaphragm showed even superior biomechanical strength as compared to synthetic polymer mesh. Tailoring of the scaffolds with the r-BMSC also resulted in significant reduction (P < 0.01) in antibody and cell mediated immune reactions to the xenogeneic scaffolds in rabbit model.

Surface plasmon resonance immunosensor for label-free detection of BIRC5 biomarker in spontaneously occurring canine mammary tumours.

We report detection of Baculoviral inhibitor of apoptosis repeat containing-5 (BIRC5) protein biomarker in dog serum by label-free surface plasmon resonance (SPR) immunosensor. Initially, overexpression of BIRC5 in canine mammary tumour (CMT) tissues was confirmed by real-time PCR. Recombinant BIRC5 was produced and protein specific antibodies developed in guinea pig specifically reacted with native protein in immunohistochemistry and immunocytochemistry. SPR immunosensor was developed by fabricating anti-BIRC5 antibodies on gold sensor disc. The equilibrium dissociation constant, (KD = kd/ka) was 12.1 × 10-12 M; which indicates that antibodies are of high affinity with sensitivity in picomolar range. The SPR assay could detect as low as 6.25 pg/ml of BIRC5 protein in a calibration experiment (r2 = 0.9964). On testing real clinical samples, 95% specificity and 73.33% sensitivity were recorded. The average amount of serum BIRC5 in dogs with CMT was 110.02 ± 9.77 pg/ml; whereas, in non-cancerous disease conditions, 44.79 ± 4.28 pg/ml and in healthy dog sera 30.28 ± 2.99 pg/ml protein was detected. The SPR immunosensor for detection of BIRC5 in dog sera is reported for the first time and this may find prognostic and diagnostic applications in management of CMT. In future, 'on-site' sensors can be developed using this technique for near-patient testing.

Gene expression profiling of spontaneously occurring canine mammary tumours: Insight into gene networks and pathways linked to cancer pathogenesis.

Spontaneously occurring canine mammary tumours (CMTs) are the most common neoplasms of unspayed female dogs leading to thrice higher mortality rates than human breast cancer. These are also attractive models for human breast cancer studies owing to clinical and molecular similarities. Thus, they are important candidates for biomarker studies and understanding cancer pathobiology. The study was designed to explore underlying molecular networks and pathways in CMTs for deciphering new prognostic factors and therapeutic targets. To gain an insight into various pathways and networks associated with the development and pathogenesis of CMTs, comparative cDNA microarray expression profiling was performed using CMT tissues and healthy mammary gland tissues. Upon analysis, 1700 and 1287 differentially expressed genes (DEGs, P ≤ 0.05) were identified in malignant and benign tissues, respectively. DEGs identified from microarray analysis were further annotated using the Ingenuity Systems Pathway Analysis (IPA) tool for detection of deregulated canonical pathways, upstream regulators, and networks associated with malignant, as well as, benign disease. Top scoring key networks in benign and malignant mammary tumours were having central nodes of VEGF and BUB1B, respectively. Cyclins & cell cycle regulation and TREM1 signalling were amongst the top activated canonical pathways in CMTs. Other cancer related significant pathways like apoptosis signalling, dendritic cell maturation, DNA recombination and repair, Wnt/ß-catenin signalling, etc. were also found to be altered. Furthermore, seven proteins (ANXA2, APOCII, CDK6, GATC, GDI2, GNAQ and MYH9) highly up-regulated in malignant tissues were identified by two-dimensional gel electrophoresis (2DE) and MALDI-TOF PMF studies which were in concordance with microarray data. Thus, the study has uncovered ample number of candidate genes associated with CMTs which need to be further validated as therapeutic targets and prognostic markers.

Multiplexed Autoantibody Signature for Serological Detection of Canine Mammary Tumours.

Spontaneously occurring canine mammary tumours (CMTs) are the most common neoplasms of female unspayed dogs and are of potential importance as models for human breast cancer as well. Mortality rates are thrice higher in dogs as compared to humans with breast cancer, which can partly be attributed to lack of diagnostic techniques for their early detection. Human breast cancer studies reveal role of autoantibodies in early cancer diagnosis and also the usefulness of autoantibody panels in increasing the sensitivity, as well as, specificity of diagnostic assays. Therefore, in this study, we took advantage of high-throughput Luminex technique for developing a multiplex assay to detect autoantibody signatures against 5 canine mammary tumour-associated autoantigens (TAAs). These TAAs were expressed separately as fusion proteins with halo tag at the N-terminus, which allows easy and specific covalent coupling with magnetic microspheres. The multiplex assay, comprising a panel of candidate autoantigens (TPI, PGAM1, MNSOD, CMYC & MUC1) was used for screening circulating autoantibodies in 125 dog sera samples, including 75 mammary tumour sera and 50 healthy dog sera. The area under curve (AUC) of the combined panel of biomarkers is 0.931 (p < 0.0001), which validates the discriminative potential of the panel in differentiating tumour patients from healthy controls. The assay could be conducted in 3hrs using only 1ul of serum sample and could detect clinical cases of canine mammary tumour with sensitivity and specificity of 78.6% and 90%, respectively. In this study, we report for the first time a multiplexed assay for detection of autoantibodies in canine tumours, utilizing luminex technology and halo-tag coupling strategy. Further to the best of our knowledge, autoantibodies to CMYC and MUC1 have been reported for the first time in canines in this study.

Polypropylene mesh seeded with fibroblasts: A new approach for the repair of abdominal wall defects in rats.

PURPOSE: The purpose of study was to develop bioengineered scaffolds by seeding primary mouse embryo fibroblast cells (p-MEF) on polypropylene mesh and to test its efficacy for the repair of abdominal wall defects in rats. METHODS: The study was conducted on 18 clinically healthy adult Wistar rats of either sex. The animals were randomly divided into two equal groups having nine animals in each group. In both the groups a 20mm×20mm size full thickness muscle defect was created under xylazine and ketamine anesthesia in the mid-ventral abdominal wall. In group I the defect was repaired with polypropylene mesh alone and in group II it was repaired with p-MEF seeded polypropylene mesh. Matrices were implanted by synthetic absorbable suture material (polyglycolic acid) in continuous suture pattern. The efficacy of the bio-engineered matrices in the reconstruction of full thickness abdominal wall defects was evaluated on the basis of macro and histopathological observations. RESULTS: Macroscopic observations revealed that adhesions with skin and abdominal viscera were minimum in group II as compared to group I. Histopathological observations confirmed better fibroplasia and collagen fiber arrangement in group II. No recurrence of hernia was found in both the groups. CONCLUSION: Hernias are effectively repaired by implanting polypropylene mesh. However, this work demonstrates that in vitro seeding of mesh with fibroblasts resulted in earlier subsidization of pain, angiogenesis and deposition of collagen, increased thickness of matrices with lesser adhesions with underlying viscera. On the basis of the results p-MEF seeded mesh was better than non-seeded mesh for repair of abdominal wall defects in rats.

Cardiac hydatid cyst in left ventricular free wall.

UNLABELLED: We report a rare case of a cardiac hydatid cyst that was incidentally found during routine work up for a redo-CABG and was picked up on echocardiography and confirmed by magnetic resonance imaging and, after successful removal, further confirmed by histopathology. The report emphasizes the importance of early and urgent surgery for such cardiac hydatid cysts whenever discovered to prevent fatal and unexpected death. Cardiac hydatidosis is a most infrequent type, in comparison with hydatidosis of the liver (65%) and lung (25%). LEARNING POINTS: Hydatidosis or cystic echinococcosis is caused by infection with the metacestode stage of the tapeworm Echinococcus (family Taeniidae). The adult tapeworm is usually found in dogs or other canines; the tapeworm eggs are expelled in the animal's feces and humans become infected after ingestion of the eggs. The initial phase of primary infection is asymptomatic.Cardiac hydatidosis is extremely rare, more commonly the liver and lungs are affected.Morbidity from heart echinococcosis in men is three times higher than that in women. Solitary cysts occur in almost 60% of the cases; the most frequent location is the ventricular myocardium and they are usually subepicardially located, hence they rarely rupture in the pericardial space. The left ventricle is damaged twofold to threefold more frequently than the right one.The diagnosis of echinococcosis in heart can be divided into two steps: detection of the cyst and its identification as echinococcus. It is based on serological reactions, echocardiography, X-ray, computerized tomography, and/or magnetic resonance imaging.The most dangerous complication of cardiac echinococcosis is cyst perforation. After cyst perforation three quarters of the patients die from septic shock or embolic complications.It is very important to understand that chemotherapy may lead to cyst death, and destruction of its wall and result in cyst rupture. Therefore, no germicide must be administered before surgical removal.

Functionalizing gold nanoparticles with bluetongue virus multiple peptide antigens utilizing gold-thiol interaction: a novel approach to develop pen side test.

Bluetongue is an economically important viral disease of small ruminants. The present/current diagnostic kits and methods to diagnose BTV are laborious, time consuming and expensive. In the present study, we have attempted to develop a novel approach to detect BTV antibodies in sera that in future can be harnessed for developing a pen side diagnostic test. Briefly, we identified the immunodominant regions of the VP7 protein of BTV and synthesized them in the multiple antigenic peptide (MAP) format with cysteine at C-terminal of the lysine mosaic, which elicited highly ordered conformation as well as ELISA reactivity. Finally, we coated the MAP peptides on the gold nanoparticles that can be used to detect BTV specific antibodies in the sera using a spot test.

Requirement of pharmacological treatment for primary prevention of cardiovascular disease in asymptomatic office-executives in north-India.

BACKGROUND: Recently, a concept of multi-drug treatment of all individuals in the form of a polypill, irrespective of their risk factor profile, has been proposed with a view to provide an effective means for prevention of cardiovascular disease (CVD). While the rationale, benefits and ethicality of such an approach continue to remain a matter ofdebate, it is not known what proportion of asymptomatic adult population does actually require pharmacological therapy for primary prevention of CVD according to the existing guidelines. METHODS: 1927 consecutive office executives, free of any CVD, undergoing routine health check-up at a tertiary care centre in North-India during the year 2005 were included in the study. For all subjects, information was collected based on their case-records comprising of comprehensive clinical evaluation and the results of biochemical investigations. Requirement of treatment with three anti-atherosclerotic drugs- aspirin, statin and an anti-hypertensive agent was estimated as per the current guidelines. RESULTS: Mean age of the subjects was 45.2 +/- 10.3 years and 71.6% were males. Diabetes was present in 14.3%, hypertension in 46.3% and dyslipidemia in 76.0%. Metabolic syndrome was diagnosed in 47.5% subjects. According to the currently accepted guidelines, 47.0% of all the individuals were candidates for at least one of the three aforementioned drugs--22.9% needed only one drug, 17.8% needed only two drugs and 6.3% needed all the three drugs. Requirement of the treatment was much higher in the highest age-tertile (>50 years of age) with 78.0% needing at least one medication, 45.1% needing at least two medications and 12.6% needing all the three drugs (p value < 0.001). Of the different drugs, aspirin was the most commonly required medicine (38.3% of all) and a combination of aspirin and statin was the most commonly required two-drug combination. CONCLUSIONS: The present study shows that, in spite of high prevalence of CV risk factors, a majority of office-executives who are free of CVD do not require multi-drug therapy for primary prevention of CVD as per the current recommendations. Though a greater proportion of the individuals > 50 years of age require drug therapy, even among them, a triple-drug combination is warranted only in a small proportion of subjects. When needed, a combination of statin and aspirin is the most commonly required combination.

Time-trends in prevalence and awareness of cardiovascular risk factors in an asymptomatic North Indian urban population.

OBJECTIVE: To determine temporal changes in the prevalence and level of awareness of cardiovascular risk factors (CVRFs) in an asymptomatic North-Indian urban population. METHODS: All asymptomatic office executives who underwent routine health check-up at a tertiary care centre in India during the year 2000 (n=2226) and the year 2005 (n=2684) were included in the study. Clinical evaluation including history of CVRFs, anthropometry, blood pressure measurement and biochemical investigations (fasting and postprandial blood glucose and fasting lipid profile) were performed in all the subjects. RESULTS: Mean age of the subjects was 51.3 +/- 9.8 years in the year 2000 and 40.1 +/- 12.2 years in the year 2005 (p<0.001). Of all the subjects, 83.2% in the year 2000 were males compared to 76.8% in the year 2005 (p<0.001). Age- and sex-adjusted prevalence of hypertension, diabetes, impaired fasting glucose and metabolic syndrome was higher in the year 2005 as compared to 2000 (odds ratios--1.3, 1.82, 6.55 and 1.82 respectively; all p values <0.05). In contrast, prevalence of low HDL-cholesterol, smoking and family history of premature coronary artery disease decreased by the year 2005 (odds ratios--0.54, 0.60 and 0.67; all p-values <0.001), whereas prevalence of dyslipidemia remained same (odds ratio--0.89, p-value 0.11) during the same period. As compared to year 2000, in the year 2005 there was significant improvement in the awareness of hypertension (46.9% vs 56.7%, p value <0.001) and dyslipidemia (5.4% vs 9.6%, p value <0.001) but not of diabetes (67.0% vs 71.3%, p- NS). CONCLUSIONS: The present study shows that in the office-executives belonging to urban North-Indian region, prevalence of most of CVRFs is markedly high and is increasing with time. In addition, a significant proportion of these individuals are not aware of their risk status though there has been an improvement in awareness level of hypertension and dyslipidemia over the five-year period from the year 2000 to 2005.

Novel Rath peptide for intracellular delivery of protein and nucleic acids.

In the present study, a novel cell penetrating peptide (CPP) named as Rath, has been identified from the avian infectious bursal disease virus. It has the potential to penetrate and translocate cargo molecules into cells independent of temperature. Additionally, it can deliver oligonucleotide in 30min and antibodies within an hour intracellular to chicken embryonic fibroblast primary cells. As an ideal delivery vehicle, it has the ability to protect the cargo molecules in the presence of serum, nucleases and has minimal or no cytotoxicity at even higher peptide concentrations studied. The biophysical characterizations showed that Rath has a dominant beta structure with a small alpha helix and has remarkable binding ability with protein and DNA. Thus, the characterization of unique Rath peptide to deliver protein or nucleic acid into the cells with non-covalent interaction could be used as an effective delivery method for various cell based assays.

Coronary calcium and coronary artery disease: an Indian perspective.

BACKGROUND: Coronary artery calcification is a part of the development of atherosclerosis. It occurs exclusively in atherosclerotic arteries and can be used as a noninvasive marker of coronary atherosclerosis. As there is no large-scale study on coronary calcium score reported in the Indian population till date, this study was undertaken for calculating the score in Indians at intermediate-to-high risk of coronary artery disease, and to correlate it with angiographically proven coronary artery disease. METHODS AND RESULTS: A total of 388 consecutive patients who underwent coronary calcium scoring and coronary angiography were included in the study. Calcium scoring was performed based on a modification of the Agatston Score using a high-speed computed tomography scanner (GE CT/i scanner). Coronary calcium scores were correlated with the presence or absence of significant coronary artery disease (defined as > or = 70% stenosis of at least one major epicardial coronary artery) on angiography. Out of 388 patients who underwent coronary angiography, 298 were found to have significant coronary artery disease. Mean coronary calcium score was significantly higher in patients with angiographically proven coronary artery disease (226.7+/-65.2) as compared to those who had normal angiograms (20.29+/-56.7; p value<0.0001). All the 72 patients who had a score > 400 had an abnormal angiogram (sensitivity 23.1%, specificity 100%, positive predictive value 100%, and negative predictive value 24.1%). On the other hand, among the patients who had a score > 0, 298 were found to have abnormal angiograms, while 16 had normal angiograms (sensitivity 95.5%, specificity 78.9%, positive predictive value 94.9%, and negative predictive value 81.1%). CONCLUSIONS: Detection of coronary calcium score by a helical computed tomography scanner is a useful tool for predicting the presence of significant coronary artery disease in intermediate-to-high risk patients. An absolute score of 0 has a high negative predictive value for the presence of coronary artery disease, and may obviate the need to perform coronary angiogram in intermediate-risk patients. On the other extreme, score > 400 is highly predictive of the presence of coronary artery disease, and virtually confirms the presence of significant coronary artery disease in intermediate-to-high risk patients.

Transesophageal echocardiography in hypotensive post-coronary bypass patients.

The utility of transesophageal echocardiography in the evaluation of hypotension in the postoperative period after coronary artery bypass was assessed in 126 patients in the intensive care unit. There were 86 men and 40 women, with a mean age of 58.3 years. The indication for transesophageal echocardiography was hypotension refractory to conventional treatment. Valuable diagnostic information was obtained in 103 patients (82%). Based on the echocardiographic findings, 24 patients (19%) underwent urgent surgical intervention. The mean time required to obtain a diagnosis was 9.6 +/- 2.8 min. No significant complications were noted. Our experience suggests that transesophageal echocardiography is highly specific in diagnosing the cause of postoperative hypotension, thus preventing unnecessary surgical intervention and facilitating decision making in cardiac surgical emergencies.

Multimodality targeted approach in redo off-pump coronary artery bypass surgery.

Records of 86 patients who underwent off-pump redo coronary revascularization between December 1997 and December 2000, were analyzed. Approaches included median sternotomy (47), anterolateral thoracotomy for left anterior descending artery and diagonal targets (35), posterolateral thoracotomy for the obtuse marginal with proximal anastomosis on descending aorta (3), and a combined subxiphoid-anterior thoracotomy approach (1) for right gastroepiploic artery-to-left anterior descending artery anastomosis. The mean age was 61.82 years. There were 2 (2.3%) operative deaths. Complications included perioperative myocardial infarction in 4 patients and reexploration for bleeding in one. Blood transfusion was required in 12 patients. The mean length of hospital stay was 5 +/- 2 days. A multimodality targeted approach for off-pump redo coronary artery bypass offers a less invasive but safer method of myocardial revascularization, with decreased complications, lower blood product requirement, and early hospital discharge.

Minimally invasive mitral valve surgery.

BACKGROUND: To reduce surgical trauma and the drawbacks associated with sternotomy, we performed robotically controlled, video-assisted mitral valve surgery, using either the port-access or the transthoracic clamp technique. METHODS AND RESULTS: Between September 1997 and September 2000, 221 patients (78 males, 143 females) underwent mitral valve surgery through a small right minithoracotomy using the port-access endovascular cardiopulmonary bypass system. Mitral valve exposure was facilitated with an endoscope attached to a voice-controlled robotic arm (AESOP 3000) allowing stabilization and voice-activated camera positioning. Twenty-six patients underwent mitral valve repair and 195 had valve replacement. In 197 patients, mitral valve surgery was the primary operation, while 24 were redo cases. Skin-to-skin mean operating time was 3.5 +/- 1.2 hours and aortic cross-clamp time was 58 +/- 16 min, mean intensive care unit stay was 22 +/- 7 hours and hospital stay 6.4 +/- 1.2 days. There was no re-exploration for bleeding. There was no late death or re-operation on mean follow-up of 16.4 +/- 12.2 months. Patients showed improvement in their NYHA functional class from 2.6 +/- 0.5 to 1.4 +/- 0.8 postoperatively. Outcomes were compared with those of our previous 220 patients who underwent mitral valve surgery with the median sternotomy approach. CONCLUSIONS: The use of video and robotic assistance in port-access mitral valve surgery not only minimizes the length of the incision, but also gives full visualization of the entire mitral valve apparatus. This approach provides comparable results with the sternotomy approach, as well as marked advantages of reduced intensive care unit stay. ,ower blood transfusion requirement, better cosmesis and earlier hospital discharge.

Redo mitral valve surgery using the port-access system.

Redo mitral valve surgery is hazardous, hence we explored an alternative approach using a port-access system that avoids reentry. Between October 1997 and December 2000, 32 patients underwent mitral reoperation using the system. All patients had previous cardiac operations. This procedure consisted of a right anterolateral minithoracotomy and femorofemoral cannulation using special port-access instruments and endoaortic clamping in 24 patients or direct transthoracic sliding-rod aortic clamping in 8. The valve disease was of rheumatic etiology in 28 patients and degenerative in 4. The valve was replaced in 31 cases and a paravalvular leak after mitral valve replacement was closed in 1. In 2 cases, the tricuspid valve was repaired along with mitral valve replacement. Mean total operating time was 4.5 +/- 1.2 hours, cardiopulmonary bypass time 162 +/- 72 minutes, and aortic crossclamp time 62 +/- 21 minutes. There was no mortality, and mean stay in the intensive care unit was 22 +/- 7 hours and hospital stay 6.4 +/- 1.2 days. Postoperative blood transfusion was required in 12 patients. In view of the favorable results, we recommend using the port-access system as a standard approach for mitral reoperation.

Robotically controlled video-assisted port-access mitral valve surgery.

From 1997 to 2000, 221 patients underwent mitral valve surgery through a mini-thoracotomy, using a port-access endovascular cardiopulmonary bypass system in 38 and a transthoracic clamp in 183. In 120 patients, exposure of the mitral valve was facilitated by an endoscope attached to a voice-controlled robotic arm (AESOP 3000). The mitral valve was repaired in 26 patients and replaced in 195; 24 were redo cases. Operating time was 3.5 +/- 1.2 hours, aortic crossclamp time was 58 +/- 16 minutes, intensive care unit stay was 22 +/- 7 hours, and hospital stay was 6.4 +/- 1.2 days. Median postoperative blood loss was 332 +/- 104 mL. There was 1 hospital death. On follow-up at 16.4 +/- 12.2 months, there was no late death or reoperation. New York Heart Association functional class improved from 2.6 +/- 0.5 to 1.4 +/- 0.8. Use of video and robotic assistance minimized incision length and allowed visualization of the whole mitral valve apparatus. The transthoracic clamp facilitated aortic crossclamping and injection of cardioplegia. These findings indicate that the procedure is safe and effective and suggest advantages over conventional surgery in terms of cost, cosmesis, blood loss, postoperative discomfort, intensive care unit and hospital stay.