Off-pump coronary artery grafting in patients with left main coronary artery disease

BACKGROUND: Left main coronary artery disease (LMCD) is considered a relative contraindication to off-pump coronary artery bypass (OPCAB) grafting. This study evaluates the safety and feasibility of OPCAB in these patients compared to an on-pump group (cardiopulmonary bypass, CPB) with LMCD. METHODS: Between January 2000 and July 2002, 95 patients with left main coronary artery stenosis >50% underwent coronary revascularization. Seventy-three unselected patients underwent OPCAB and 22 underwent revascularization using CPB. The techniques used for OPCAB included the use of deep traction sutures in the posterior pericardium and stabilizers to expose the distal coronary targets. Intraluminal coronary shunts were routinely used during construction of the anastomoses. Variables were analyzed using a Student's paired t-test with statistical significance defined as p < 0.05. RESULTS: The mean age in the OPCAB group was 59.9 years and the CPB group 61.8 years (p = 0.54). There were 56 males (77%) in the OPCAB and 18 (82%) in the CPB groups. Mean preoperative left ventricular ejection fraction (LVEF) was 40.3% in OPCAB and 47.3% in CPB (p = 0.015). Average number of grafts was 3.1 in OPCAB and 4.1 in CPB (p = 0.0038). There were no conversions to CPB in those patients initially chosen to undergo OPCAB. There were no early deaths in OPCAB. There was one death in CPB. Mean hospital length of stay was 6.9 days for OPCAB and 9.1 for CPB (p = 0.0159). CONCLUSIONS: Patients with LMCD can undergo OPCAB grafting safely and effectively despite reduced LVEF. LMCD should no longer be seen as a contraindication to perform OPCAB grafting.     

Calculated DNA damage from gadolinium Auger electrons and relation to dose distributions in a head phantom

PURPOSE: To calculate the number of 157Gadolinium (157Gd) neutron capture induced DNA double strand breaks (DSB) in tumor cells resulting from epithermal neutron irradiation of a human head when the peak tissue dose is 10 Gy. To assess the lethality of these Gd induced DSB. MATRIALS AND METHODS: DNA single and double strand breaks from Auger electrons emitted during 157Gd(n,gamma) events were calculated using an atomistic model of B-DNA with higher-order structure. When combined with gadolinium neutron capture reaction rates and neutron and photon physical dose rates calculated from the radiation transport through a model of the human head with explicit tumors, peak tissue dose can be related to the number of Auger electron induced DSB in tumor cell DNA. The lethality of these DNA DSB were assessed through a comparison with incorporated 125I decay cell survival curves and second comparison with the number of DSB resulting from neutron and photon interactions. RESULTS: These calculations on a molecular scale (microscopic calculations) indicate that for incorporated 157Gd, each neutron capture reaction results in an average of 1.56 +/- 0.16 DNA single strand breaks (SSB) and 0.21 +/- 0.04 DBS in the immediate vicinity (approximately 40 nm) of the neutron capture. In an example case of Gd Neutron Capture Therapy (GdNCT), a 1 cm radius midline tumor, peak normal tissue dose of 10 Gy, and a tumor concentration of 1000 ppm Gd, result in a maximum of 140 +/- 27 DSBs per tumor cell. CONCLUSIONS: The number of DSB from the background radiation components is one order of magnitude lower than the Gd Auger electron induced DSB. The cell survival of mammalian cell lines with a similar amount of complex DSB induced from incorporated 125I decay yield one to two magnitudes of cell killing. These two points indicate that gadolinium auger electrons could significantly contribute to cell killing in GdNCT.     

Correlation of cephalic anthropometric parameters and microsurgical anatomy of the optic nerves: a cadaveric morphometric study

BACKGROUND: This study was designed to elucidate the possible correlation of cranial anthropometric measurements with the chiasm to limbus sphenoidale distance to facilitate preoperative estimation of this distance and to choose a better surgical approach. METHODS: Thirty-three fresh adult cadaver heads (22 males and 11 females) were evaluated for cranial anthropometric measurements. The precraniotomy anthropometric measurements included (A) inion to nasion distance and (B) the longest intermeatal meridian. Subsequently, with a standard craniotomy, the following intervals were measured: (C) optic chiasm to falciform ligament, (D) anterior aspect of optic chiasm to limbus sphenoidale, and (E) limbus sphenoidale to inner nasion. A combined ratio parameter, labeled as (F), was calculated from the following equation: F = B/E x 10. RESULTS: The mean values and standard errors of the mean of parameters A to F were 195.8 +/- 14.53 mm, 374.7 +/- 25.29 mm, 10.47 +/- 1.89 mm, 9.93 +/- 2.01 mm, 38.46 +/- 3.17 mm, and 9.81 +/- 1.11, respectively. The parameter D had significant correlation to the parameters B, C, E, and F. The most significant correlation was seen between parameters D and F (p < 0.001). According to linear regression assessment between parameters D and F, the following regression equation was obtained: D = 4.24 + 0.58F. CONCLUSIONS: Optic nerve topography and dimensions show inter-personal variations that may be anticipated to some extent with cranial anthropometric data. Calculating of F ratio gives us an acceptable estimation of the actual distance of chiasm to limbus sphenoidale, which in turn can help the surgeon to select the approach to tumors of intrasellar region. However, the role of meticulous imaging studies cannot be overemphasized to confirm the anticipated estimations.     

Clinical impact of drug-eluting stents in changing referral practices for coronary surgical revascularization in a tertiary care center

BACKGROUND: The long-term benefits of angioplasty are limited by the occurrence of restenosis. Drug-eluting stents with a projected restenosis rate of close to 0% are soon to become available. The short- and long-term consequences of this advance to the cardiac surgical volume remain unclear. METHODS: A total of 196 consecutive coronary angiograms and medical records of patients referred for coronary bypass surgery were reviewed. Considering the hypothetical premise of having drug-eluting stents with a near zero restenosis rate, we reviewed each case to determine if surgical revascularization was still the preferred option for revascularization. RESULTS: The mean age was 60 (+/-10.6) years. Seventy-two percent of patients were male. Considering the availability of drug-eluting stents 154 (79%) would still have been sent to surgery, representing a 21% decrease in the number of surgical revascularizations. Angiographic characteristics predicting coronary bypass revascularization were the presence of chronic total occlusion (odds ratio [OR]: 9.1; confidence interval [CI]: 2.1 to 39), left main coronary artery stenosis (OR: 9.6; CI: 1.27 to 73), and need for valvular surgery (OR: 7.38; CI: 1.3 to 157). The most common predictors of a change in clinical management from surgical to percutaneous revascularization if drug-eluting stents were available were diffuse coronary narrowing (OR: 15.78), restenotic lesions (OR: 27.86), and small coronary arteries (OR: 26). CONCLUSIONS: Drug-eluting stents may have a significant impact on cardiac surgery volume (approximately a 21% decrease in our center). It may also direct patients with small vessels, diffuse narrowing, or restenotic lesions and diabetic patients to percutaneous therapy.     

Efficacy of Human Adipose Tissue-Derived Stem Cells on Neonatal Bilirubin Encephalopathy in Rats

Kernicterus is a neurological syndrome associated with indirect bilirubin accumulation and damages to the basal ganglia, cerebellum and brain stem nuclei particularly the cochlear nucleus. To mimic haemolysis in a rat model such that it was similar to what is observed in a preterm human, we injected phenylhydrazine in 7-day-old rats to induce haemolysis and then infused sulfisoxazole into the same rats at day 9 to block bilirubin binding sites in the albumin. We have investigated the effectiveness of human adiposity-derived stem cells as a therapeutic paradigm for perinatal neuronal repair in a kernicterus animal model. The level of total bilirubin, indirect bilirubin, brain bilirubin and brain iron was significantly increased in the modelling group. There was a significant decreased in all severity levels of the auditory brainstem response test in the two modelling group. Akinesia, bradykinesia and slip were significantly declined in the experience group. Apoptosis in basal ganglia and cerebellum were significantly decreased in the stem cell-treated group in comparison to the vehicle group. All severity levels of the auditory brainstem response tests were significantly decreased in 2-month-old rats. Transplantation results in the substantial alleviation of walking impairment, apoptosis and auditory dysfunction. This study provides important information for the development of therapeutic strategies using human adiposity-derived stem cells in prenatal brain damage to reduce potential sensori motor deficit.     

Anomalous centre of mass energy fluctuations during treadmill walking in healthy individuals

Motorised treadmills are used to research and rehabilitate gait despite conflicting evidence that treadmill ambulation is equivalent to ground walking. It has been suggested that no mechanical differences should exist between these environments but there is little evidence to support this. During ground walking, the whole body centre of mass (COM) acts like an inverted pendulum recovering energy, thereby reducing the effort of locomotion. The energy recovery has a relationship with speed whereby maximum recovery occurs at intermediate speeds. In order to determine the relationship between energy recovery and speed during treadmill walking, we investigated estimated COM displacement in nine healthy individuals each walking on a treadmill at seven different speeds. In addition, we measured oxygen cost to determine the effort of walking. Our participants formed two distinct groups, those with normal COM energy recovery (N%R) that was similar to ground walking, and those with low COM energy recovery (L%R) that was different from typical ground walking. The low energy recovery in the L%R group was attributed to in-phase potential and kinetic energy fluctuations. Despite the low energy recovery values both groups produced the expected 'U'-shaped oxygen cost speed curve with no significant difference between groups (p<0.05), however, only N%R produced a significant relationship between energy recovery and oxygen cost (p<0.05). Although a useful tool, walking on a treadmill may not be a true representation of ground walking and therefore not the most effective way to research or rehabilitate gait.     

Treatment of cutaneous leishmaniasis with either topical paromomycin or intralesional meglumine antimoniate

Ninety-six patients with a clinical and parasitological diagnosis of cutaneous leishmaniasis were recruited to a comparative randomized clinical trial evaluating the efficacy of topical paromomycin vs. weekly intralesional injections of meglumine antimoniate. The patients were randomly divided into two treatment groups: one group was treated with topical paromomycin ointment and the other with intralesional meglumine antimoniate. Treatment was continued in both groups until complete recovery occurred (defined as healing in less than 2 months with no residual scar or relapse for up to 1 year post treatment). Treatment failure was defined as an increase in the number and size of pre-existing lesions or untoward side-effects. The maximum treatment period was 3 months. The patients were followed up for 1 year. The results showed that intralesional meglumine antimoniate led to 41.7% complete recovery, However, topical paromomycin gave a lower cure rate of 16.6% (P < 0.05). Treatment failure was observed in 39.7% of the group receiving intralesional meglumine and in 72.9% of those on topical paromomycin (P < 0.05). This study indicates that intralesional meglumine antimoniate is superior to topical paromomycin in the treatment of cutaneous leishmaniasis.     

Correlation between cathepsin D serum concentration and carotid intima-media thickness in hemodialysis patients

Aim  

Cardiovascular (CV) disease is the leading cause of death in hemodialysis (HD) patients, and approximately half of mortalities in HD patients are attributed to CV disease. Atherosclerosis is the most frequent cause of CV complications in patients with end-stage renal disease (ESRD). Based on recent studies, cathepsin D has been suggested as a potential marker of atherosclerosis, and we hypothesized that there is an association between serum concentration of cathepsin D and carotid intima-media thickness (CIMT) in hemodialysis patients.