A two-generational reproductive study to assess the effects of Juglans regia on reproductive developments in the male and female rats

Environmental pollutants and lifestyle severely threaten human and animal health, leading to disturbances of various functions, including infertility. So, exploring a safe treatment that could effectively reverse infertility remains a challenge. The current study was intended to explore the fertility-enhancing effect of Juglans Regia oil in two successive generations of rats; F0 and F1. J. Regia oil was initially tested for in vitro antioxidant assay via ROS and DPPH, followed by in vivo toxicity testing. In the fertility assessment, eighteen pairs of male and female rats (n=36, 1:1, F0 generation) were divided into three groups and dosed with 1 mL/kg and 2 mL/kg daily of J. Regia oil and saline, respectively, up to pre-cohabitation, cohabitation, gestation and lactation periods. The reproductive performance, including body weight, live birth index, fertility index, and litter size, was assessed. Hormonal and antioxidant markers of F1 generations were assessed with the histopathological evaluation of male and female organs. The oil of J. Regia showed great antioxidant potential (P < 0.05) in DPPH (1,1-diphenyl-2-picrylhydrazyl) and ROS (Reactive Oxygen Species) methods (P<0.05). The continued exposure of the F0 and F1 generations to J. Regia oil did not affect body weight, fertility index, litter size, and survival index. We have found pronounced fertility outcomes in both genders of F0 and F1 generations with J. Regia 2 mL/kg/day in comparison to the control. Results showed that J. Regia significantly increased (P < 0.05) luteinizing hormone (LH), plasma testosterone, follicular stimulating hormone (FSH), glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities in both generations. Histology of both generations reveals improved spermatogenesis and folliculogenesis with enhanced architecture. Altogether, the present results suggest that J. Regia improved fertility in both male and female rats by improving hormonal activities and oxidative stress.

'One Health´ approach to end zoonotic TB

Mycobacterium bovis has a wide host range causing TB in animals, both in wildlife and cattle (bovine TB bTB), and in humans (zoonotic TB zTB). The real burden of bovine and zoonotic TB (b/zTB) remains unknown due to diagnostic challenges. Although progress has been made to reduce the burden of TB, b/zTB has been neglected in low- and middle-income countries (LMICs) with little improvement in prevention, diagnosis or treatment. Using Tanzania as a case study, because of its high TB burden, large wildlife diversity and wide reliance on livestock, we developed an approach to comprehensively estimate the burden and implement multidisciplinary actions against b/zTB. We performed a review of the literature on b/zTB, but there is a lack of available data on the b/zTB burden in Tanzania and, notably, on epidemiological indicators other than incidence. We propose a five-action programme to address b/zTB in Tanzania, and we believe our proposed approach could benefit other LMICs as it operates by implementing and strengthening surveillance and health delivery. The resulting knowledge and system organisation could further prevent and mitigate the effects of such conditions on human and animal health, livestock production, population livelihood and the economy.

Polysaccharide-Drug Conjugates: A Tool for Enhanced Cancer Therapy

Cancer is one of the most widespread deadly diseases, following cardiovascular disease, worldwide. Chemotherapy is widely used in combination with surgery, hormone and radiation therapy to treat various cancers. However, chemotherapeutic drugs can cause severe side effects due to non-specific targeting, poor bioavailability, low therapeutic indices, and high dose requirements. Several drug carriers successfully overcome these issues and deliver drugs to the desired sites, reducing the side effects. Among various drug delivery systems, polysaccharide-based carriers that target only the cancer cells have been developed to overcome the toxicity of chemotherapeutics. Polysaccharides are non-toxic, biodegradable, hydrophilic biopolymers that can be easily modified chemically to improve the bioavailability and stability for delivering therapeutics into cancer tissues. Different polysaccharides, such as chitosan, alginates, cyclodextrin, pullulan, hyaluronic acid, dextran, guar gum, pectin, and cellulose, have been used in anti-cancer drug delivery systems. This review highlights the recent progress made in polysaccharides-based drug carriers in anti-cancer therapy.

Global Guidelines in Dermatology Mapping Project (GUIDEMAP): a scoping review of dermatology clinical practice guidelines

BACKGROUND

Clinical practice guidelines (CPGs) play a critical role in standardizing and improving treatment outcomes based on the available evidence. It is unclear how many CPGs are available globally to assist clinicians in the management of patients with skin disease.

OBJECTIVES

To search for and identify CPGs for dermatological conditions with the highest burden globally.

METHODS

We adapted a list of 12 dermatological conditions with the highest burden from the Global Burden of Disease (GBD) study 2019. A systematic literature search was done to identify CPGs published between October 2014 to October 2019. The scoping review was conducted and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) framework.

RESULTS

A total of 226 CPGs were included. Melanoma had the greatest representation in the CPGs, followed by dermatitis and psoriasis. Skin cancers had a relatively high CPG representation but with lower GBD disease burden ranking. There was an uneven distribution by geographical region, with resource-poor settings being under-represented. The skin disease categories of the CPGs correlated weakly with the GBD disability-adjusted life-years metrics. Eighty-nine CPGs did not have funding disclosures and 34 CPGs were behind a paywall.

CONCLUSIONS

The global production of dermatology CPGs showed wide variation in geographical representation, article accessibility and reporting of funding. The number of skin disease CPGs were not commensurate with its disease burden. Future work will critically appraise the methodology and quality of dermatology CPGs and lead to the production of an accessible online resource summarizing these findings.

Determinants of Pre-Hospital Delay after Myocardial Infarction in Bangladesh: A Rural Center Experience

Determinants of pre-hospital delay after myocardial infarction, strictly among South-Asian rural community, till now is largely unknown. And Bangladesh is not an exception. It is a fact that though around two third of its population still live in villages, we do not know what factors are having influence on such delay. To find out these primers of time consumption before seeking medical help, this is a picture of a medical college hospital situated in a rural precinct. This cross-sectional analytical study was conducted among 98 patients came with Myocardial Infarction (MI) who had met inclusion and exclusion criteria from July 2019 and December 2019. Both STEMI & NSTEMI patients were selected as they have similar attributes. Data was collected in the coronary care unit using a preformed questionnaire. Among 98 MI patients, where 16 female and 82 male patients had average age 53±12 years. Average income rural community was around 100 USD. Almost 50% of sample were illiterate or below 5th grade. On average 6.6 hours (95% CI: 3.5-12.3) were required to reach CCU after symptom onset, whereas distance to first medical contact (FMC) was about 10.2 Km (95% CI: 6.4-16.2). Median distance to nearest PCI-capable hospital was 140 Km (IQR- 20 Km). Only 28% of patients could reach hospital within 2 hours, where 85% had onset of symptom while they were at home. Tertiary level medical college (74.5%) followed by Upazilla (Sub-urban) government health complex (22.4%) were frequent site of FMC. Principle mode of transport to hospital was CNG-three-wheeler (75% of cases). Logistic regression analysis showed only low literacy was as significant predictor about more than 2 hours pre-hospital delay (OR=2.58; p=0.043). Other factors such as low income (OR=2.51; p=0.126), diabetes mellitus (OR=2.99; p=0.059), female sex (OR=1.56; p=0.753), house wife (OR=1.88; p=0.547), previous MI (OR=1.52; p=1.000), symptom ignorance (OR=2.14; p=0.455) increases pre-hospital delay and distance to FMC <10 Km (OR=0.44; p=0.079) no significant prediction of pre-hospital delay after myocardial infarction. As rural community has less access to education low literacy has a significant impact on pre-hospital delay after myocardial infarction. So measures should be taken in rural areas through patient education and social awareness program regarding MI symptom and danger of delayed medical attention.

A skin disease and needs assessment analysis of the displaced Rohingya population in the Kutupalong refugee camp, Bangladesh

The physical, psychological and financial burden of skin disease in low- to middle-income countries, where access to skincare is limited, is poorly understood. A group that we know very little about in this regard are refugees. There are limited data on the range of skin diseases and skincare needs of this group. To better understand the skincare needs of the displaced Rohingya population residing in the Kutupalong refugee camp, Bangladesh, we collected data on demographics, living conditions and range of dermatoses. In the 380 patients assessed, fungal skin infections, predominantly dermatophytes, were by far the most common skin disease seen (n = 215), followed by dermatitis (n = 81). Skin disease can be the presenting feature in many systemic conditions and may cause significant secondary complications itself. Developing a better understanding of the skincare needs of the refugee population is essential for future healthcare planning for this vulnerable group.

Hidden in plain sight: An unusual cause of rapidly progressive renal failure

Hyperoxaluria and resultant oxalate nephropathy are infrequently reported causes of irreversible renal failure. A rapid decline in renal function in an otherwise insidiously progressive oxalate nephropathy may be triggered by various superimposed insults like the use of nephrotoxic drugs. We present the case of a patient with rapidly progressive renal failure due to oxalate nephropathy that lead to a retrospective diagnosis of chronic pancreatitis. This case highlights the importance of timely assessment for enteric hyperoxaluria in patients with unexplained renal failure of tubulointerstitial nature.

Endophthalmitis: magnitude, treatment and visual outcome in northwest frontier province of Pakistan

BACKGROUND

Many cases of post-operative and posttraumatic endophthalmitis are being managed at the Khyber Institute of Ophthalmic Medical Sciences, Peshawar in Pakistan but no study has been done to ascertain the magnitude of the disease and to also evaluate the visual outcome after management.

METHODS

The case notes of 39 patients diagnosed with posttraumatic and postoperative endophthalmitis between May 2006 and April 2007 were analyzed and clinical characteristics obtained were documented and tabulated.

RESULTS

During the study period, 2474 patients were admitted in both the male and female wards. Of these, 39 (1.6%) had endophthalmitis due to surgical and traumatic complications. In all, 6 (12.4%) patients had evisceration, while 21 (53.8%) patients who had topical antibiotics consisting of ofloxacin, 0.1% corticosteroids, fortified cetazoline and 1% atropine along with intravitreal antibiotics, a combination of 0.1 mg vancomycin and 0.4 mg amikacin, were discharged home with a visual acuity of counting fingers to light perception.

CONCLUSION

Endophthalmitis is a serious ocular complication of open globe injury and intraocular surgery. The frequency in this center has been noted to be very high as compared to other places. Its management is very challenging and often leads to devastating structural and functional damage to the eye; causing severe frustration to both the patient and the attending physician. Efforts must be made to prevent the condition.

The role of the thalamus in amnesia: a tractography, high-resolution MRI and neuropsychological study

Although it is well established that thalamic lesions may lead to profound amnesia, the precise contribution of thalamic sub-regions to memory remains unclear. In an influential article Aggleton and Brown proposed that recognition memory depends on two processes supported by distinct thalamic and cortical structures. Familiarity is mediated by the mediodorsal (MD) thalamic nucleus and the entorhinal/perirhinal cortex. Recollection is mediated by the anterior thalamic nucleus (AN), the mamillothalamic tract (MTT) and the hippocampus. The authors also suggested that the lateral dorsal nucleus (LD) may contribute to the thalamic/hippocampus system, thereby implying that the LD may play a role in recollection. Given the finding that material specific amnesia can occur following thalamic lesions, we tested an extension of the Aggleton and Brown model. We predicted that patients with bilateral lesions with a bias to the left or right MD or AN/MTT/LD may exhibit impaired familiarity or recollection on verbal or non-verbal memoranda. We report two patients with highly focal thalamic lesions and profound memory impairments affecting verbal and non-verbal memoranda. For the first time, diffusion-weighted imaging was employed to perform tractography of the MTT along with high-resolution anatomical MRI and detailed assessments of verbal and non-verbal memory. Our data support only some aspects of the Aggleton and Brown model. Both patients had left MD nucleus and AN/MTT lesions and performed poorly on familiarity and recall for verbal memoranda, just as predicted by the model. However, both patients' performance for non-verbal memoranda (human faces and topography) is more difficult to reconcile with the model. Patient 1 had damage to the right AN/MTT/LD with sparing of the MD: familiarity should therefore have been preserved but was not. Patient 2 had damage to the right MD with sparing of AN/MTT: recollection should have been preserved but was not. This finding raises the possibility that fractionation of familiarity and recollection to separate thalamic nuclei may not fully capture the role of thalamic sub-regions in memory function.

Two new trans-clerodane diterpenoids from Otostegia limbata

Two new tricyclic clerodane-type diterpenoids, limbatolide D (1) and limbatolide E (2), have been isolated from the roots of Otostegia limbata. Their structures and the relative configuration were established on the basis of spectral methods, especially two-dimensional (2D) NMR techniques.

Response to cotrimoxazole in the management of childhood pneumonia in first-level health care facilities

BACKGROUND

Reports of high levels of antimicrobial resistance to cotrimoxazole in children with non-severe pneumonia (NSP) have prompted calls for a change to amoxicillin in the therapeutic guidelines at the first-level health care facility (FLHF). FLHFs lack data about the use of World Health Organization (WHO) acute respiratory infection (ARI) standard case management (SCM).

OBJECTIVE

To apply ARI SCM guidelines at the FLHF, assess clinical outcome of NSP with oral cotrimoxazole and determine the risk factors influencing treatment outcome.

DESIGN

Health care workers (HCWs) at 14 health centres managed children aged 2-59 months with NSP according to ARI SCM guidelines. The primary outcome was treatment failure, including change of antibiotic therapy and loss to follow-up.

RESULTS

Of 949 children enrolled, 110 (11.6%) failed therapy with oral cotrimoxazole. Clinical failure was significantly higher among children presenting with a fast respiratory rate of > or = 15 breaths/min above normal for age and wheezing on examination.

CONCLUSIONS

To treat children with NSP at the FLHF, oral cotrimoxazole is an acceptable treatment choice in view of the efficacy, cost and ease of use. In children with wheezing and signs of pneumonia, the decision to use antibiotic therapy should be made after a trial of bronchodilator therapy.

Dyslipidemia in the metabolic syndrome: clinical implications and management

Dyslipidemia is an important component of the metabolic syndrome. Dyslipidemia in the metabolic syndrome is characterized by hypertriglyceridemia, low serum levels of high density lipoprotein cholesterol (HDL-C) and an increase in the serum fraction of small dense low density lipoprotein cholesterol (LDL-C) particles. Serum LDL-C elevation is frequently present, but is not a criterion of the metabolic syndrome. A Medline search was conducted using the terms metabolic syndrome, dyslipidemia, hypertriglyceridemia and HDL cholesterol. The metabolic syndrome is a common and important risk factor for cardiovascular disease and progression to type 2 diabetes mellitus. Dyslipidemia is present in most patients with the metabolic syndrome and is treatable with therapeutic lifestyle changes and pharmacotherapy. Aggressive management of atherogenic dyslipidemia is justified by the very high cardiovascular risk associated with this disorder. Atherogenic dyslipidemia is frequently present in patients with the metabolic syndrome and requires aggressive treatment due to the very high risk for cardiovascular disease and progression to type 2 diabetes mellitus.

Aortic root dilatation in patients with emphysema

BACKGROUND

Abdominal aortic aneurysms have been recognized to occur more frequently in patients with emphysema. However, the prevalence of aortic root dilatation in patients with emphysema and its relationship to risk factors for aortic enlargement have not been previously described.

METHODS

We studied 47 patients, past smokers (aged 67 +/- 6 years, 18 women) with severe emphysema diagnosed by a pulmonary function test and an ultrafast computed tomographic scan. Two-dimensional echocardiography was used to measure the aortic root at the aortic annulus, sinus of Valsalva, sinotubular junction and proximal part of the ascending aorta. Measured mean values were compared with published normal values and age- and sex-matched patients without emphysema. The relationship between aortic root size and cardiac risk factors (hypertension, hypercholesterolemia, and diabetes) was also examined.

RESULTS

In patients with emphysema the mean aortic root dimensions were significantly larger than normal values at each measured site (P <.0001) and those of patients without emphysema (P <.05 to.0001). A substantial percentage of patients with emphysema had larger sinus of Valsalva (43%) and proximal ascending aorta (59%) than the upper limit of normal. In the multivariable regression model, emphysema was a significant determinant of aortic root size at all measured sites and hypertension was associated with additional dilatation at the sinus of Valsalva, sinotubular junction, and proximal ascending aorta.

CONCLUSIONS

(1) In patients with emphysema the aortic root dimension is significantly larger than in patients without emphysema. (2) Systemic hypertension is associated with additional enlargement of the proximal ascending aorta, the sinus of Valsalva, and the sinotubular junction.

Twenty-year comparison of tissue and mechanical valve replacement

OBJECTIVE

We sought to compare outcomes with tissue and St Jude Medical mechanical valves over a 20-year period.

METHODS

Valve-related events and overall survival were analyzed in 2533 patients 18 years of age or older undergoing initial aortic, mitral, or combined aortic and mitral (double) valve replacement with a tissue valve (Hancock, Carpentier-Edwards porcine, or Carpentier-Edwards pericardial) or a St Jude Medical mechanical valve. Total follow-up was 13,390 patient-years. There were 666 St Jude Medical aortic valve replacements, 723 tissue aortic valve replacements, 513 St Jude Medical mitral valve replacements, 402 tissue mitral valve replacements, 161 St Jude Medical double valve replacements, and 68 tissue double valve replacements. The mean age was 68 +/- 13.3 years (St Jude Medical valve, 64.5 +/- 12.9; tissue valve, 72.0 +/- 12.6).

RESULTS

There were no overall differences in survival between tissue and mechanical valves. Multivariable analysis indicated that the type of valve did not affect survival. Analysis by age less than 65 years or 65 years or older and presence or absence of coronary disease revealed similar long-term survival in all subgroups. The risk of hemorrhage was lower in patients receiving tissue aortic valve replacements but was not significantly different in patients receiving mitral valve or double valve replacements. Thromboembolism rates were similar for tissue and mechanical valve recipients. However, reoperation rates were significantly higher in patients receiving both aortic and mitral tissue valves. The reoperation hazard increased progressively with time both in patients receiving aortic and in those receiving mitral tissue valves. Overall valve complications were initially higher with mechanical aortic valves but not with mechanical mitral valves. However, valve complication rates later crossed over, with higher rates in tissue valve recipients after 7 years in patients undergoing mitral valve replacement and 10 years in those undergoing aortic valve replacement.

CONCLUSIONS

Tissue and mechanical valve recipients have similar survival over 20 years of follow-up. The primary tradeoff is an increased risk of hemorrhage in patients receiving mechanical aortic valve replacements and an increased risk of late reoperation in all patients receiving tissue valve replacements. The risk of tissue valve reoperation increases progressively with time.

Twenty-year follow-up of patients with new perioperative Q waves after coronary artery bypass grafting

It is unclear whether the development of new Q waves on the electrocardiogram after coronary artery bypass grafting (CABG) is associated with an adverse prognosis. We analyzed the 20-year survival of 227 patients who underwent CABG, and found that new perioperative Q waves had no impact on long-term survival; therefore, conservative management may be appropriate for uncomplicated patients with new Q waves after CABG.

Neutrophil depletion in rats reduces burn-injury induced intestinal bacterial translocation

OBJECTIVE

To determine whether neutrophil depletion could eradicate intestinal bacterial translocation in bum-injured rats.

DESIGN

Prospective, randomized, controlled study.

SETTING

University research laboratory.

SUBJECTS

Adult male Sprague-Dawley rats.

INTERVENTIONS

The rats were intravenously administered a rabbit anti-rat neutrophil antibody causing profound neutropenia and subjected to a 30% total body surface area scald burn.

MEASUREMENTS AND MAIN RESULTS

The depletion of neutrophils from the intestine was assessed via measurements of myeloperoxidase (MPO) activity in the intestinal homogenates. In addition, the presence of activated/extravasated neutrophils in intact intestines was determined via immunohistochemical localization of neutrophil nicotinamide adenine dinucleotide phosphate (NADPH) oxidase component protein p47phox. Bacterial translocation was measured using agar cultures and by determining Escherichia coli beta-galactosidase gene via polymerase chain reaction/Southern blot analyses of mesenteric lymph node and spleen, liver, lung, and blood. MPO measurements demonstrated a six-fold increase above the control value in the intestinal tissue in rats on day 1 postburn. The presence of activated neutrophils (expression of p47phox protein) was also markedly increased in the intestines of these rats. The increased MPO activity and p47phox expression accompanied a translocation of indigenous E. coli into the mesenteric lymph node without a spread to other organs. The administration of anti-neutrophil antibody to burn animals prevented an increase in MPO activity and bacterial translocation.

CONCLUSION

These studies indicate that enhanced intestinal bacterial translocation caused by burn injury could be related to the increased infiltration of activated neutrophils into the intestinal tissue after bum. The release of neutrophil products such as superoxide anion may effect intestinal tissue damage leading to bacterial translocation of indigenous E. coli.

Regression of hypertrophy after Carpentier-Edwards pericardial aortic valve replacement

BACKGROUND

The purpose of this study was to determine whether significant regression of left ventricular hypertrophy is seen after implantation of small sizes (19 to 23 mm) of the Carpentier-Edwards (CE) pericardial valve, a stented pericardial valve.

METHODS

Echocardiograms and electrocardiograms (ECGs) were performed at least 1 year after surgery (mean 18 months) in patients with 19-, 21-, and 23-mm CE pericardial aortic valves and compared with preoperative echocardiograms and ECGs.

RESULTS

A total of 41 patients, mean age 79 +/- 9 years (range 46 to 93 years), were studied, including 7 19-mm, 22 21-mm, and 12 23-mm patients. The mean postoperative gradient was 22 +/- 7 mm Hg for 19-mm valves, 18 +/- 5 mm Hg for 21-mm valves, and 16 +/- 4 mm Hg for 23-mm valves. The postoperative valve areas were 1.1 +/- 0.3 cm2 for the 19-mm, 1.3 +/- 0.3 cm2 for the 21-mm, and 1.5 +/- 0.4 cm2 for the 23-mm valves. Left ventricular end diastolic diameter, end systolic diameter, septal thickness, and posterior wall thickness all decreased significantly (p <0.05) postoperatively. The proportion of patients with significant left ventricular hypertrophy on ECG decreased from 63% to 47% (p = 0.001). Left ventricular mass decreased significantly by echocardiography from 265 g preoperatively to 208 g postoperatively (p = 0.004). Left ventricular mass decreased for each valve size, and the greatest absolute reduction in mass occurred in the 19-mm valve recipients.

CONCLUSIONS

Implantation of the 19-, 21-, and 23-mm CE pericardial valves results in significant reductions in left ventricular mass. These findings suggest that stented pericardial valves can be used in the small aortic root without the need for aortic root enlargement procedures.

Transesophageal echocardiographic identification of an abdominal aortic pseudoaneurysm complemented by a transpulmonary echo contrast agent

Pseudoaneurysm of the abdominal aorta, a rare complication after traumatic injuries, represents a diagnostic challenge for which sophisticated imaging modalities are often used for its early identification. We describe a case in which transesophageal echocardiographic examination complemented by a transpulmonary echo contrast agent was useful not only in demonstrating the pseudoaneurysm, but in helping to localize the intravascular communication between the aorta and the pseudoaneurysm.

Cardiac reoperations in octogenarians: analysis of outcomes

BACKGROUND

With the rapid growth of the elderly segment of the population, more octogenarians are referred for complex cardiac interventions, including reoperations. Data regarding the outcomes, quality of life, and long-term results after reoperative open-heart surgical procedures in octogenarians are scarce.

METHODS

We retrospectively studied 113 consecutive octogenarians (mean age, 83+/-2.6 years) who underwent reoperative cardiac procedures within a 13-year period. Coronary artery bypass grafting (CABG) was performed in 49 patients (CABG group), valvular procedures (aortic, mitral, or tricuspid valve, alone or in combination) in 35 (valve group), and combined CABG and valve intervention in 29 (combined CABG and valve group).

RESULTS

The 30-day mortality rate was 8% (4 of 49) for the CABG group, 9% (3 of 35) for the valve group, and 17% (5 of 29) for the combined CABG and valve group. One- and 5-year actuarial survival rates were, respectively, 85%+/-5% and 58%+/-10% for the CABG group, 78%+/-7% and 53%+/-12% for the valve group, and 69%+/-9% and 63%+/-10% for the combined CABG and valve group. Sixty-one percent of patients in the CABG group, 40% in the valve group, and 38% in the combined CABG and valve group were in New York Heart Association class I or II postoperatively at a mean follow-up time of 2.1+/-2.4 years. Similarly, 91%, 85%, and 80%, respectively, thought that they had an improved quality of life and were satisfied with their functional status.

CONCLUSIONS

Cardiac reoperations can be performed successfully in most octogenarians, although with an increased risk, particularly in the combined CABG and valve group. Long-term survival is acceptable with improved quality of life and functional status. However, it is possible that these results could be improved in this high-risk group of patients with earlier referral and surgical intervention, for the effective use of health care resources.

A 20-year experience with the Hancock porcine xenograft in the elderly

BACKGROUND

The availability of 20 years of follow-up data on the Hancock porcine valve (Medtronic Inc, Irvine, CA) allows determination of long-term actual and actuarial failure rates in the elderly.

METHODS

We analyzed outcomes after mitral or aortic valve replacement with the Hancock porcine valve in 491 consecutive patients, comparing actual and actuarial valve failure rates in the elderly (age 65 or older) with those in younger patients.

RESULTS

The average age of aortic valve replacement recipients was 68+/-14 years (N = 243) and of mitral valve replacement recipients, 64+/-12 years (N = 248). Average follow-up was 7.0 years (1,673 patient-years) for aortic valve replacement and 7.3 years (1,781 patient years) for mitral valve replacement recipients. The median time to reoperation or structural failure was 15.9 years for aortic valve replacement patients and 14.3 years for mitral valve replacement patients. However, few elderly patients survived to 15 years (22% of the elderly aortic valve replacement and 13% of the older mitral valve replacement patients). The 15-year actual reoperation rate was therefore only 10% in the elderly aortic valve replacement compared to 30% in the younger aortic valve replacement patients. For mitral valve replacement, the 15-year actual reoperation rate was 11% in the elderly and 36% in the younger patients. The lifetime reoperation risk (the maximum potential number of patients who might ever undergo reoperation during their lifetime) is the sum of actual survival and actual reoperation rates. The lifetime reoperation risk was 20% or less for elderly aortic valve replacement patients and 18% or less for elderly mitral valve replacement patients.

CONCLUSION

These data suggest that about 1 in 10 elderly patients (65 years or older) receiving a Hancock valve will require reoperation within 15 years and less than one in five will ever require reoperation in their lifetimes.

Twenty-year, three-institution evaluation of the Hancock Modified Orifice aortic valve durability. Comparison of actual and actuarial estimates

BACKGROUND

Information regarding the incidence of structural valve deterioration (SVD) is used in selecting the type of valve for patients. Standard actuarial statistical techniques have been used widely but do not provide the most appropriate information for patient populations experiencing competing hazards. "Actual," or cumulative incidence, methods may provide a better estimate of the durability of tissue valves for these patients. The purpose of this article is to compare actuarial and actual estimates of the durability of the Hancock Modified Orifice bioprosthesis aortic valve in a multi-institutional study.

METHODS AND RESULTS

Valves were implanted between 1976 and 1985 in 3 institutions. This sample contains follow-up data on 727 patients (42% female) with a mean age of 63 +/- 13 years. The difference between actuarial and actual rates of SVD became more important over time. At 5 years, the difference is significant only in the elderly (aged > or = 65 and > or = 70), whereas at 17 years, the difference was significant for all patients. Similarly, the magnitude of the difference increases over time. Freedom from SVD for patients > 65 at 5 years is estimated at 98 +/- 0.01% by actuarial methods and 100 +/- 0.00% actual methods. The difference between estimates is larger at 10 years, 93 +/- 0.02% versus 96 +/- 0.01%. This difference is greater at 17 years, 78 +/- 0.04% versus 93 +/- 0.01%.

CONCLUSIONS

The results of this study demonstrate that the particular statistical analysis method used to calculate SVD can provide strikingly different conclusions. These observations indicate that the actual method is able to identify the lower risk of SVD in older patients. Generalizability issues must be considered, however, when using actual SVD rates to make decisions regarding valve selection in larger populations.

Cardiac operations in patients 90 years of age and older

BACKGROUND

Growth of the elderly population worldwide, and specifically in the United States, will continue to accelerate and will have a profound impact on the cost and delivery of health care resources in the future. A medical strategy that allows the elderly to live independently is essential to most cost-effective use of our resources. The question remains as to what will be the future of surgical therapy for this increasing population.

METHODS

We retrospectively studied the cases of 30 consecutive nonagenarians (mean age, 92.3 +/- 1.8 years) who underwent a cardiac operation within a 9-year period. All patients were in New York Heart Association class III or IV and underwent operation urgently or emergently.

RESULTS

The 30-day mortality rate was 10%, and the actuarial survival rates were 81% +/- 8% and 75% +/- 9% at 1 year and 2 years, respectively. Seventy-eight percent of survivors were in New York Heart Association class I or II within 2 years after operation and had an improved quality of life. The cost of providing care in this age group was 24% higher than in octogenarians.

CONCLUSIONS

Advanced age in and of itself (>90 years) should not be a contraindication to an open-heart operation, although morbidity, mortality, and cost may be higher. However, selective criteria identifying risks and benefits for individual patients should be applied. The aging of our population will have a profound impact on the cost and delivery of health care resources in the future. This issue must be addressed in the current debate on the provision of expensive procedures under a realigned national health-care system.

Reconstitution of mammalian pyruvate dehydrogenase and 2-oxoglutarate dehydrogenase complexes: analysis of protein X involvement and interaction of homologous and heterologous dihydrolipoamide dehydrogenases

Optimal conditions for rapid and efficient reconstitution of pyruvate dehydrogenase complex (PDC) activity are demonstrated by using an improved method for the dissociation of the multienzyme complex into its constituent E1 (substrate-specific 2-oxoacid decarboxylase) and E3 (dihydrolipoamide dehydrogenase) components and isolated E2/X (where E2 is dihydrolipoamide acyltransferase) core assembly. Selective cleavage of the protein X component of the purified E2/X core with the proteinase arg C decreases the activity of the reconstituted complex to residual levels (i.e. 8-12%); however, significant recovery of reconstitution is achieved on addition of a large excess (i.e. 50-fold) of parent E3. N-terminal sequence analysis of the truncated 35,000-M(r) protein X fragment locates the site of cleavage by arg C at the extreme N-terminal boundary of a putative E3-binding domain and corresponds to the release of a 15,000-M(r) N-terminal fragment comprising both the lipoyl and linker sequences. In native PDC this region of protein X is shown to be partly protected from proteolytic attack by the presence of E3. Recovery of complex activity in the presence of excess E3 after arg C treatment is thought to result from low-affinity interactions with the partly disrupted subunit-binding domain on X and/or the intact analogous subunit binding domain on E2. Contrasting recoveries for arg C-modified E2/X/E1 core, and untreated E2/E1 core of the 2-oxoglutarate dehydrogenase complex, reconstituted with excess bovine heart E3, pig heart E3 or yeast E3 point to subtle differences in subunit interactions with heterologous E3s and offer an explanation for the inability of previous investigators to achieve restoration of PDC function after selective proteolysis of the protein X component.

Adverse 5-year outcome after coronary artery bypass surgery in blacks

BACKGROUND

Coronary heart disease is the leading cause of death among blacks, but little is known about the late results of coronary artery bypass surgery in this population. It is not known whether differences in preoperative medical characteristics or medical health insurance affect outcome. We studied the effects of medical risk factors on survival outcome after coronary artery bypass surgery in a population of medically insured black and white patients.

METHODS

Racial status and outcomes from surgery were determined in 3728 consecutive patients who had coronary artery bypass surgery at the authors' institution from January 1, 1984, to June 30, 1992. Coronary artery bypass surgery (excluding valve replacement) was performed in 115 black and 3113 white patients.

RESULTS

Late survival probability was worse for blacks than whites at 1 year (84% vs 92%) and at 5 years (64% vs 82%, P=.001, Wilcoxon test). Most deaths were due to cardiac events in both groups (68% in blacks vs 67% in whites). Blacks had more hypertension (84% vs 54%), diabetes mellitus (36% vs 23%), and more were current smokers (21% vs 14%) (all P<.05, Fisher's exact test). Medical insurance coverage for blacks and whites was as follows: Medicare (60% vs 57%), private (38% vs 42%), and Medi-Cal (2% vs 2%). Operative mortality (30 days) was similar (5.2% for blacks vs 4.1% for whites; P=.48, Fisher's exact test). In a Cox regression model, race predicted long-term survival and persisted as an important risk factor after adjusting for preoperative factors related to patient survival (adjusted hazard ratio, 2.10; 95% confidence interval, 1.43 to 3.07).

CONCLUSIONS

In this group of predominantly medically insured patients undergoing coronary artery bypass surgery, the risk of death in blacks at 5 years was twice that of whites.

Long-term survival after coronary artery bypass grafting

The most quoted long-term outcome studies from the coronary artery bypass surgery literature were performed in the 1970s, and these trials--the Coronary Artery Surgery Study, the Veterans Administration Study, and the European Cooperative Study--added significantly to our knowledge of the efficacy of bypass surgery. However, important studies are still being performed and are refining our knowledge of long-term outcomes. This review covers early factors that affect long-term outcome, and recent information concerning particular subgroups of patients undergoing bypass surgery. In addition, new information is becoming available about the relative roles of percutaneous transluminal coronary angioplasty and coronary artery bypass grafting, and these studies are also discussed.

Ten-year experience of cardiac surgery in patients aged 80 years and over

Five hundred twenty-eight consecutive patients aged 80 years and over (mean age, 83.1 +/- 2.7 years) underwent cardiac operations with hypothermia (mean, 21.9 degrees +/- 2.2 degrees C), hyperkalemic cardioplegia, and cardiopulmonary bypass in a 10-year period. Fifty-six percent of the patients were male. Preoperatively, 68% of the patients were in New York Heart Association functional class IV, and 31% were in class III. Among them, 303 patients had isolated coronary artery bypass grafting (CABG) (group I), 132 had aortic valve replacement only or combined with CABG (group II), 42 had mitral valve replacement only or combined with CABG (group III), 31 had mitral valve repair and CABG (group IV), and 20 had double-valve procedure only or combined with CABG (group V). The 30-day or in-hospital mortality was 8.3% in group I, 4.5% in group II, 29% in group III, 23% in group IV, and 30% in group V. Total 30-day or in-hospital mortality was 10.6%. One-year and 5-year actuarial survival rates were as follows: group I, 82% and 62%; group II, 85% and 58%; group III, 61% and 37%; group IV, 56% and 19%; and group V, 63% and 15%. Total 1-year and 5-year actuarial survival were 79% and 54%. At follow-up (mean, 2 years), 70% of overall survivors reported that their general health had improved. Our experience demonstrates that for select patients aged 80 years and over with unmanageable cardiac symptoms, CABG and aortic valve replacement groups had better results in improving quality of life as compared with patients having mitral or combined procedures.

Postinfarction ventricular septal defect in the elderly: analysis and results

Fifteen elderly patients (age more than 70 years) underwent surgical repair of postinfarction ventricular septal defects during the years 1980 through 1992. The operative (to discharge or < 30 days) mortality rate was 47%, and the complication rate among survivors was 63%. The probability of survival at 1 year was 47% +/- 13%. Because of the small sample size of our patient population, predictive preoperative risk factors associated with early mortality could not be identified with certainty. However, there is a trend suggesting that high right atrial pressures (p = 0.15) and the need of an intraaortic balloon pump preoperatively (p = 0.12) influence 30-day mortality, as previously described in larger series. Of 5 long-term survivors, 3 are in New York Heart Association functional class I and 2 are in class II. Our experience in this group of patients suggests that in the elderly, a very aggressive approach should be taken in recommending early surgical intervention for postinfarction ventricular septal defect before hemodynamic deterioration ensues and severely compromises chances for survival.

Action potential alternans and irregular dynamics in quinidine-intoxicated ventricular muscle cells. Implications for ventricular proarrhythmia

BACKGROUND

Cardiac cells display rate-dependent beat-to-beat variations in action-potential duration (APD), action potential amplitude (APA), and excitability during periodic stimulation. We hypothesized that quinidine causes a marked increase in the variability of APD, APA, and excitability of ventricular cells isolated from quinidine-toxic, arrhythmic ventricles.

METHODS AND RESULTS

Action potentials were recorded from right ventricular endocardial tissues (2 x 1 cm, < 2 mm thick) isolated from dogs in which ventricular tachycardia and ventricular fibrillation (VT/VF) were induced with intravenous quinidine (80-100 mg/kg) over a 5-hour period in vivo (n = 7). As the basic cycle length (BCL) of stimulation was progressively shortened, rate-dependent variations in APD and APA occurred. The initial dynamic change was alternans of APD and APA that could be either in or out of phase between two cells. The magnitude of alternans was a function of the BCL and the strength of the stimulation current. At critically short BCLs, irregular APD and APA behavior emerged in the quinidine-intoxicated cells. In control cells (n = 16) isolated from three nontreated dogs, APD and APA remained constant at all BCLs tested (2,000-300 msec). Quinidine increased the slope of the APD restitution curve compared with control. The observed quinidine APD restitution curve was fitted with a biexponential equation, and computer simulation using the fitted restitution curve reproduced the aperiodic APD seen in the quinidine toxic cells during periodic stimulation. Thus, the observed irregular APD behavior was predictable from the restitution curve.

CONCLUSIONS

Quinidine toxicity increases the temporal and spatial variability of APD and APA in the ventricle that may promote the initiation of reentrant VT/VF in vivo. The slope of the APD restitution curve provides a method to quantitate inhomogeneities in repolarization time and could be a useful marker for proarrhythmia.

Assessment of prosthetic valve hemodynamics by Doppler: lessons from in vitro studies of the St. Jude valve

Although Doppler assessment of native heart valve hemodynamics is quite accurate, assessment of prosthetic mechanical valve hemodynamics presents more potential problems. These problems arise from the unique geometry of prosthetic valves. Two important prosthetic valve phenomena can violate the basic assumptions underlying Doppler calculations: pressure recovery and localized gradients. When pressure recovery is present, Doppler systematically overestimates the actual net catheter gradient across the valve. In contrast, the presence of localized gradients may cause Doppler to measure differing gradients depending on which part of the valve is interrogated. These phenomena can also affect the calculation of prosthetic valve areas using the continuity equation. When assessing prosthetic valves with Doppler echocardiography, it must be remembered that Doppler measures velocity, not pressure gradients and that the echocardiographer must exercise great care when interpreting Doppler velocities as either pressure gradients or in calculating valve areas for prosthetic valves.

The St. Jude valve. Thrombolysis as the first line of therapy for cardiac valve thrombosis

BACKGROUND

Thrombolytic therapy is a promising alternative to valve replacement in the management of prosthetic valve thrombosis. We sought to determine the short- and long-term results of treating thrombosed St. Jude heart valves with thrombolytic therapy as the primary treatment modality.

METHODS AND RESULTS

Between March 1978 and December 1991, 988 patients underwent implantation of St. Jude prosthetic valves at our medical center, and all patients with thrombosed valves were identified prospectively. During this period, 17 patients (13 women; mean age, 66.8 +/- 19.0 years) developed prosthetic valve thrombosis (11 aortic, six mitral). In six patients, Coumadin was stopped in preparation for elective surgery. The clinical presentation was congestive heart failure in 13, syncope and fatigue in two, and a cerebrovascular accident in one; one patient was asymptomatic. The average duration of symptoms was 11.7 +/- 12.0 days (range, 1-45 days). Anticoagulation was subtherapeutic in all but one patient at the time of presentation. Cinefluoroscopy was the primary method used for diagnosis and was also used to follow the response to therapy. Twelve patients were treated medically (10 with thrombolytic therapy and two with heparin), three were treated surgically, and two were diagnosed at autopsy. Of the 12 medically treated patients, 10 had marked improvement in leaflet movement and symptoms within 12 hours. Thus, 10 of 12 patients (83%) had a satisfactory response to medical therapy alone. No medically treated patient died or had a major complication resulting in permanent damage. However, four of the 12 medically treated patients had minor complications, including a transient episode of facial weakness in one patient, hematomas in two, and epistaxis in one. Late rethrombosis recurred in two patients in the medically treated group and was successfully retreated with thrombolytic therapy. At 3 months, all patients were alive and well.

CONCLUSIONS

Thrombolytic therapy can be used as the first line of therapy for thrombosed St. Jude valves with a low risk of permanent side effects and excellent chances of success. In most cases, surgery can be reserved for patients who do not respond to thrombolytic therapy.

Interaction of age and preoperative risk factors in predicting operative mortality for coronary bypass surgery

BACKGROUND

Models for predicting operative mortality for coronary bypass surgery assume that preoperative risk factors affect mortality to the same extent in all patients groups.

METHODS AND RESULTS

To determine whether certain preoperative risk factors disproportionately increase operative mortality in the elderly, 663 consecutive elderly patients (age 75 years or older) and 1,464 younger patients (age 65 or younger) undergoing isolated coronary bypass surgery between 1982 and 1990 were studied. Hospital mortality was significantly greater in the elderly patients than in younger patients (7.5% versus 1.8%; relative risk, 4.5). Univariate analysis identified age, prior coronary artery bypass grafting, congestive heart failure, left main disease, New York Heart Association functional class, hypertension, prior myocardial infarction (MI), and preoperative atrial fibrillation as associated with mortality. Multivariate analysis was then used to construct a model to describe the risk of operative mortality in terms of selected risk factors. However, comparison of observed mortality rates with those predicted by the model revealed problems with the model's goodness of fit. Further testing revealed that young patients without prior MI had a mortality rate lower by an order of magnitude than either younger patients with prior MI or elderly patient groups with and without MI. Two separate models were therefore constructed stratifying by the presence of prior MI. This resulted in a significant improvement in the fit of the models to the observed data.

CONCLUSIONS

These results suggest that the impact of risk factors on the elderly may be significantly different from the effect of these risk factors on younger patients. Models for predicting outcome after bypass surgery should be tested for potential interactions between age and risk factors.

Phase plane plot of electrograms as a marker of ventricular electrical instability during acute ischemia: initial experimental results and potential clinical applications

We used a phase plane plots method (a plot of voltage [V(t)] vs rate of change of voltage [dV/dt]) derived from nonlinear dynamics to transform a sinus rhythm strip into a geometric form. The geometric form thus obtained detects variations in the ECG over time and therefore may aid in identifying patterns of vulnerability to ventricular fibrillation (VF). The trajectories of consecutive ventricular depolarizations and repolarizations of sinus rhythm in dogs that evolve to VF showed characteristic differential band thickening (inhomogeneities) that were absent in the dogs that did not develop VF. This method of analysis can be a useful complementary tool to detect cardiac electrical instability, and with simple hardware, can easily be displayed in real time.

Results of early repair of ventricular septal defect after an acute myocardial infarction

A 10-year experience with early operation for postinfarction ventricular septal defect is reviewed. Twenty-two patients underwent surgical repair; operative mortality was 36% (< 30 days). The actuarial survival was 64% at 1 month, 59% at 1 year, and 47% at 5 years. Risk factors predictive of operative mortality were diabetes (p = 0.001), elevated preoperative right atrial pressure (p = 0.02), the absence of a preoperative intraaortic balloon pump (p = 0.006), and a short time interval between infarct and operation (p = 0.018). Long-term survival was adversely related to diabetes (p = 0.030), elevated preoperative right atrial pressure (p = 0.005), and, surprisingly, survival was better in patients with a greater extent of coronary artery disease (p = 0.023). There were 14 operative survivors (64%) and 11 long-term survivors (3 months to 10 years, mean 6.0 +/- 3.5 years). Six of eleven survivors were in functional New York Heart Association class I, one was in class II, and four were in class III.

Cellular mechanisms of differential action potential duration restitution in canine ventricular muscle cells during single versus double premature stimuli

BACKGROUND

We tested the hypothesis that action potential duration (APD) restitution of normal ventricular muscle cells is different during double premature stimuli (S3) compared with a single premature stimulus (S2). We propose a possible ionic mechanism for such a difference.

METHODS AND RESULTS

Action potentials and isometric tension were recorded simultaneously from isolated canine right ventricular trabeculae (2 x 2 x 10 mm) (n = 35). APD and tension restitution curves (APD) and peak tension versus diastolic interval [DI] of S2 and S3 were constructed by the extrastimulus method during pacing at 1,500 msec. The following results were obtained. 1) The APD restitution curve of S2 was different from that of S3. During the restitution of S2, an early biphasic upward hump was present at short DIs. In contrast, a smooth exponential rise was consistently seen during S3 restitution. 2) Peak tension remained significantly (p less than 0.001) lower during the restitution of S2 than during S3 restitution at all DIs tested. 3) The variation of APD during the initial 100 msec of DI was significantly longer during S3 than S2 (22 +/- 5 msec versus 41 +/- 5 msec, p less than 0.001). 4) Caffeine (2 mM, n = 5) and ryanodine (10 microM, n = 5) blocked cyclic variations of tension, presumably by blocking cyclic variations of intracellular calcium ion concentrations ([Ca2+]i), and eliminated the differences in APD restitution between S2 and S3. 5) Nisoldipine at high (5 microM) but not at lower (2 microM, n = 5) concentration eliminated the differences in restitution of both APD and tension between S2 and S3. 6) BAY K 8644 (100 nM, n = 5) had no effect on this difference.

CONCLUSIONS

Greater variations of APD occur during the restitution of S3 than during S2 at short DIs. These differences appear to be caused by cyclic variations in tension and thus in [Ca2+]i. Calcium-sensitive outward currents could explain these differences in APD restitution.

Doppler assessment of prosthetic valve orifice area. An in vitro study

BACKGROUND

Although Doppler echocardiography has been shown to be accurate in assessing stenotic orifice areas in native valves, its accuracy in evaluating the prosthetic valve orifice area remains undetermined.

METHODS AND RESULTS

Doppler-estimated valve areas were studied for their agreement with catheter-derived Gorlin effective orifice areas and their flow dependence in five sizes (19/20-27 mm) of St. Jude, Medtronic-Hall, and Hancock aortic valves using a pulsatile flow model. Doppler areas were calculated three ways: using the standard continuity equation; using its simplified modification (peak flow/peak velocity); and using the Gorlin equation with Doppler pressure gradients. The results were compared with Gorlin effective orifice areas derived from direct flow and catheter pressure measurements. Excellent correlation between Gorlin effective orifice areas and the three Doppler approaches was found in all three valve types (r = 0.93-0.99, SEE = 0.07-0.11 cm2). In Medtronic-Hall and Hancock valves, there was only slight underestimation by Doppler (mean difference, 0.003-0.25 cm2). In St. Jude valves, however, all three Doppler methods significantly underestimated effective orifice areas derived from direct flow and pressure measurements (mean difference, 0.40-0.57 cm2) with differences as great as 1.6 cm2. In general, the modified continuity equation calculated the largest Doppler areas. When orifice areas were calculated from the valve geometry using the area determined from the inner valve diameter reduced by the projected area of the opened leaflets, Gorlin effective orifice areas were much closer to the geometric orifice areas than Doppler areas (mean difference, 0.40 +/- 0.31 versus 1.04 +/- 0.20 cm2). In St. Jude and Medtronic-Hall valves, areas calculated by either technique did not show a consistent or clinically significant flow dependence. In Hancock valves, however, areas calculated by both the continuity equation and the Gorlin equation decreased significantly (p less than 0.001) with low flow rates.

CONCLUSIONS

Doppler echocardiography using either the continuity equation or Gorlin formula allows in vitro calculation of Medtronic-Hall and Hancock effective valve orifice areas but underestimates valve areas in St. Jude valves. This phenomenon is due to localized high velocities in St. Jude valves, which do not reflect the mean velocity distribution across the orifice. Valve areas are flow independent in St. Jude and Medtronic-Hall prostheses but decrease significantly with low flow in Hancock valves, suggesting that bioprosthetic leaflets may not open fully at low flow rates.

Case report: liver adenomatosis presenting as multiple calcified masses

Liver adenomatosis is a rare condition with only 14 cases reported. It is considered to be a distinct entity from liver adenoma. This is the first case in which calcification has been described. The differential diagnosis of multiple calcified lesions in the liver is discussed, and other features of liver adenomatosis.

Surgical revascularization in women

Multiple studies have shown that coronary bypass surgery in women clearly has a higher risk of operative death. The reason for this higher risk remain less clear, however. Although earlier studies suggested that women were at higher risk due to their smaller body size, several recent studies have suggested that a significant component of the higher mortality of women may be late referral for bypass surgery. Complication rates and hospital stay also appear to be higher in women. Although operative mortality is higher, women have similar long-term results from bypass surgery. Thus, coronary bypass surgery is a valuable treatment option for women with advanced coronary disease with excellent long-term outcomes. The short-term outcomes of women referred for bypass surgery may be improved with earlier referral of women for revascularization.

Valvular emergencies

Valvular emergencies result from a wide variety of causes, including infectious, inflammatory, ischemic, traumatic, degenerative, and recently iatrogenic processes. In addition, prosthetic valves have brought new valvular emergencies that present unique challenges in diagnosis and therapy. The advent of color Doppler and TEE have provided significant enhancements to our diagnostic armamentarium. Similarly, thrombolytic therapy has also found a place in the treatment of a common prosthetic valve emergency--thrombosed mechanical valves. Because of the likelihood of serious consequences, rapid diagnosis and aggressive management of valvular emergencies are needed, but the results can be very gratifying and lead to excellent short- and long-term outcomes.