Hyperfractionated Reirradiation for Locally Recurrent Thoracic Tumors

PURPOSE/OBJECTIVE(S)

For patients with locally recurrent thoracic tumors or second primaries within previously irradiated volumes, hyperfractionated reirradiation (re-RT) may mitigate late toxicity compared to conventional fractionation, but clinical outcomes have not been extensively studied. We herein report our institutional experience with thoracic hyperfractionated reirradiation.

MATERIALS/METHODS

We identified 26 cases among 23 patients treated with re-RT to either primary or metastatic thoracic tumors, 60 Gy in 50 fractions, twice daily over 5 weeks using highly conformal image guided RT with motion management. Nineteen patients had dosimetry data available. The primary outcome was Grade (G2) or higher toxicity rates per CTCAEv5.0. Secondary endpoints were 12-month local control (LC), progression free survival (PFS)-determined by treating physician and/or multidisciplinary tumor board-and overall survival (OS).

RESULTS

Median follow-up was 13 months. Half had non-small cell lung cancer, 95.8% had ultracentral tumors, 57.7% had single prior thoracic RT course; 38.5%, 11.5% and 11.5% received concurrent chemotherapy, immunotherapy, and targeted agents, respectively. Minimum and median intervals between RT courses were 10 and 39.5 months, respectively; 94.7% of re-irradiation plans had overlapping 80% isodose volumes. Median OS and PFS were 13 and 10 months, respectively. Crude 12-month LC was 73.1%. Of those with a recurrence, the first recurrence occurred locally in 6 (54.6%), regionally in 3 (27.3%), and distantly in 8 (72.7%) patients. ≥G2 and ≥G3 toxicity rates were 30.8% and 7.69%, respectively (one G3 atrial fibrillation; one G5 pneumonitis). Using the American Radium Society guidelines for thoracic reirradiation, only 10.5% met all dose volume constraint recommendations.

CONCLUSION

Definitive hyperfractionated thoracic re-RT was well tolerated with promising local control. ≥G3 toxicities were rare. Patients should be counseled on the low but potential risk of life-threatening toxicity. Consensus guidelines for dose constraints may be difficult to meet in reirradiation setting; in this cohort, rates of severe toxicity were low despite exceeding putative constraints in most patients.

Comparison of Plan Quality Metrics after Left Anterior Descending Coronary Artery Sparing in VMAT Esophageal Radiotherapy

PURPOSE/OBJECTIVE(S)

Cardiotoxicity is a significant late effect of esophageal radiotherapy (RT). Mean heart dose has been implicated with major adverse cardiac events (MACE) and emerging evidence increases MACE association with left anterior descending (LAD) coronary artery specific dose. This retrospective planning study investigates the dosimetric impact of including the LAD as an OAR-sparing objective for VMAT-based plan optimization in patients previously treated for esophageal cancers.

MATERIALS/METHODS

A retrospective cohort was identified of patients who underwent neoadjuvant RT for esophageal cancers between 2017-2020 without intentional LAD sparing. Treatment planning was performed using Eclipse™ treatment planning system. Doses were calculated using Acuros® XB algorithm or anisotropic analytical algorithm with a 2-2.5mm calculation grid. For each patient, the LAD was delineated and the treated VMAT plan was re-optimized to reduce the dose to the LAD receiving 15 Gy to less than 10%, when possible. Re-plans were performed such that 95% of the PTV received the prescription dose. Institutional constraints were used to minimize the dose to the heart, lung, and spinal cord (Table 1). A paired t-test was used to compare the dose between the original VMAT plan used for treatment (Esophagus Original) against those re-optimized (Esophagus + LAD), with significance of p<0.05.

RESULTS

A total of 19 patients were identified. Of those treated, 12 of 19 original plans (63%) exceeded the LAD constraint (V15<10%) with a mean V15 Gy of 47.1%. Plan re-optimization accounting for the LAD allowed for 66.7% (9/12) of cases to meet LAD V15 constraints. Aside from increased sparing of the mean heart dose, there were no statistically significant impacts on target coverage and OAR doses otherwise, including to that of the lung and spinal cord (Table 1).

CONCLUSION

Accounting for LAD dose in treatment planning may help reduce future MACE risks. LAD dose can be significantly reduced without compromising PTV coverage or having significant effects on other OAR dose sparing.

O-261 In-vitro supplementation of vitamin B12 to improve post-thaw viability and DNA integrity

Study question

Does the supplementation of vitamin B12 protect the spermatozoa against damage caused by the freeze-thaw process further improving the overall post-thaw survival and DNA integrity?

Summary answer

The antioxidant property of vitamin B12 protects the spermatozoa and improves the post thaw motility, vitality, and reduces DNA damage caused by freeze-thaw process.

What is known already

Cryopreservation of spermatozoa is an effective way of fertility preservation in humans, often used in Assisted Reproductive Technology(ART). Despite the refinement in cryopreservation, the salvage of post-thaw sperms remains poor. The reactive oxygen species(ROS), that is formed as a result of freeze-thaw process is known to decrease the motility, plasma membrane integrity and increase the DNA fragmentation. Most vitamins have antioxidant properties, that protect the mammalian cells from oxidative stress one such vitamin is cyanocobalamin(vitamin B12). Vitamin B12 modulates oxidative stress through methionine synthase activity and also acts as a scavenger of ROS. Thus protecting the DNA against free radicals.

Study design, size, duration

This prospective observational study was performed for a period of 6 months in 111 men, who attended the fertility clinic. The study population included all semen samples except men with azoospermia, surgically retrieved samples and men on vitamin supplements. The study population contained men ageing between 21-40 years.

Participants/materials, setting, methods

Semen samples were analysed according to WHO 5th edition and were assessed for DNA fragmentation index (DFI) using sperm chromatin dispersion assay (SCD). The ejaculates were split into two as group A: semen samples with equal amount of cryoprotectant and group B: semen samples with equal amount of cryoprotectant supplemented with Vitamin B12 (2mg/ml). They were frozen for a minimum of 24 hrs. Post-thaw motility, vitality and DFI were assessed and compared.

Main results and the role of chance

The mean age of patients in our study was 34.26±4.7yrs. 58.5% of the study population had primary infertility. 37.8% of the study population had male factor infertility, 32.4% had oligoasthenoteratozoospermia(OAT), 31.1% had normozoospermia 16.2% had asthenoteratozoospermia, 13.5% had teratozoospermia, 3.6% had oligozoospermia and rest 2.7% had asthenozoospermia.

There was an overall increase in post thaw motility (41.59±18.09 vs 32.3±18.8,p=0.0005), progressive motility (21.54±13.02 vs 15.91±11.80,p=0.0005), vitality (57.14±15.09 vs 46.76±16.45,p=0.0005) and a significant decrease in DFI (26.69±10.03 vs 32.09±10.00,p=0.0005) in group B compared to group A.

Our study also demonstrated that, Normozoospermia patients had a significant increase in vitality (67.17±13.8 vs 58.51±12.0, p = 0.007) and lower DFI (22.68±9.3 vs 27.6±8.9, p = 0.02) in group B than in group A.

OAT patients had a significant increase in total motility (26.25±12.15 vs 15.7±11.4,p=0.0003), progressive motility (11.69±8.8 vs 6.14±5.8,p=0.0028), vitality (46.06±11.34 vs 34.31±12.99,p=0.0001) and significantly lower DFI (30.22±9.87 vs 36.08±9.7,p=0.012) in group B.

Teratozoospermia patients showed significant increase in progressive motility in group B (27.87±8.81 vs 19.33±10.69,p=0.02) and

Asthenoteratozoospermia patients showed significant increase in total motility (40.72± 13.14 vs 30.89±13.06,p=0.02) and vitality (54.39±12.28 vs 43.78±14.14,p=0.02) in group B.

However, in asthenozoospermic patients the parameters were comparable in both the groups.

Limitations, reasons for caution

Due to ethical reasons the samples were not used for in vitro procedures such as intrauterine insemination(IUI), in vitro fertilization (IVF) and intracytoplasmic sperm injection(ICSI). Hence, no inference was obtained regarding the fertilization rates/ pregnancy rates.

Wider implications of the findings

Our study demonstrated that with supplementation of vitamin B12 the recovery rate significantly increased and also preserved the DNA content. Among the various categories, supplementation of vitamin B12 to OAT samples was more beneficial as it improved the overall viability of the sperms.

Trial registration number

CSP/21/JUL/96/389

P–077 Performance of the postwash total motile sperm count as a predictor of pregnancy at the time of intrauterine insemination

Study question

Is the performance of the postwash total motile sperm count a predictor of pregnancy at the time of intrauterine insemination?

Summary answer

The number of motile spermatozoa inseminated (NMSI) in IUI can be used to define clear range of pre /postwash sperm parameters.

What is known already

There is no consensus about the optimal number of motile spermatozoa inseminated (NMSI) required for a reasonable chance of pregnancy after IUI. A meta-analysis of 16 studies assessing NMSI and IUI outcomes, concluded that at cut-off levels between 0.8 and 5 million, defined as the ability to predict failure to become pregnant. The purpose of this study is to determine the range of NMSI as a predictor of success in IUI.

Study design, size, duration

This prospective study includes 60 patients who underwent semen analysis at an academic infertility centre (SRIHER) during the month of December 2020 and January 2021.

Participants/materials, setting, methods

A total of 60 infertile couples who underwent IUI at our academic centre were enrolled in our study. A detailed history and infertility work up was done before proceeding for IUI, as per the department protocol. The semen was prepared by discontinuous 2 layered density gradient method. The results were analyzed by patient factors including age, BMI, semen parameters, NMSI. The NMSI were divided into 4 groups: A (&lt;1), B (1–4), C (5–9), D (&gt;10).

Main results and the role of chance

The mean age of the infertile couples who underwent IUI was (28.2 ± 3.8) in females and (31.8 ± 3.8) in males respectively. The sperm parameters such as concentration (21.8 ± 14.8), motility (53.15 ± 13.22), morphology (2.43 ± 1.33) respectively. When the NMSI was group C (5–9 x 10 6) the pregnancy rate was 38.5% whereas the pregnancy rate was 37.5% in group D ( &gt;10 x 10 6). In the other sub groups such as group A(&lt;1 x 10 6) and group C (1–4 x 10 6) the pregnancy rate was 14.2% and 12.5% respectively.

Limitations, reasons for caution

Infertile men with Azoospermia, Men with Retrograde ejaculation, Testicular samples, Epididymal samples, Infected samples. All of the above samples were avoided. It cannot be used for counselling during the initial infertility workup, but only during/after the IUI procedure.

Wider implications of the findings: The results suggest that NMSI can be a predictor of success in IUI in patients who are &lt; 30 years of age & ≥35 years, NMSI does not appear to be a useful. The effect of NMSI on pregnancy rate needs to evaluated on a larger scale .

Trial registration number

Not applicable

P–301 Intrauterine instillation of autologous platelet rich plasma for thin endometrium improves the outcome of frozen embryo transfer cycles

Study question

How does the intrauterine instillation of autologous platelet rich plasma (PRP) affect the endometrial thickness and live birth rate in frozen embryo transfer cycles?

Summary answer

Intrauterine instillation of autologous PRP resulted in significant improvement in endometrial thickness. The live birth rates were satisfactory post-PRP instillation.

What is known already

Autologous Platelet rich plasma (PRP) had resulted in significant improvement in endometrial thickness, when instilled intrauterine in women with thin endometrium in FET cycles.

Study design, size, duration

A retrospective observational study was performed at a tertiary care university teaching hospital in South India. 35 women who received intrauterine autologous PRP during endometrial preparation for frozen embryo transfer from June 2017 to December 2020, were included. Patients who underwent donor oocyte recipent cycles, those with a history of tubercular endometritis, Asherman syndrome, previous intrauterine manipulations such as manual removal of placenta, and uterine anomalies were excluded.

Participants/materials, setting, methods

All the women underwent endometrial preparation in artificial cycles by depot GnRH agonist suppression and HRT (Hormone replacement therapy) was initiated by 4–6 mg of estradiol valerate and stepped up as required. Autologous PRP was offered to all women who had endometrial thickness &lt; 7 mm on day 16 of HRT. PRP was prepared by the two-step centrifugation method and administered intrauterine by IUI catheter. The patients underwent repeat evaluation after 5 days post-PRP instillation.

Main results and the role of chance

Optimal response to PRP was considered as the attainment of an endometrial thickness (ET) ≥ 7mm after 5 days of post-PRP. 25 (71.4%) had an optimal response to PRP. There was a significant improvement in the endometrial thickness(mm) in the study participants following PRP instillation: 6.3 ± 0.6 vs. 7.1 ± 1.2; P = 0.0001.The study participants were divided into two groups based on their response to intrauterine PRP instillation. Those who optimally responded to PRP were categorized as Group A and those who didn’t were categorized as Group B. The study participants of both the groups were comparable by their demographic characteristics such as age, cause of infertility, indications for ART, and the dose of estradiol valerate before PRP. The dose of estradiol valerate (mg) after PRP was significantly higher in Group B compared to Group A: 19.9 ± 4.9 vs. 15.6 ± 3.9; P = 0.014. A total of 26 women underwent embryo transfer and 9 (25.7%) women had cycle cancellation. Of these 22 were from Group A and 4 from Group B. The pregnancy, clinical pregnancy, miscarriage and live birth rates were 36.3%(8/22) and 25% (1/4); 31.8% (7/22) and 25% (1/4); and 31.8% (7/22) and 25% (1/4), respectively.

Limitations, reasons for caution

As the study was retrospective in nature and the PRP was offered only in patients who had consented, there was a significant bias. Hence the results of the study should be interpreted with caution. Further large prospective RCTs (Randomised controlled trials) are required to confirm our findings.

Wider implications of the findings: Autologous PRP may enhance the response to the estrogen preparations. It may produce satisfactory live birth rates and reduce cycle cancellations in a reasonable proportion of patients with thin endometrium in FET cycles. However, these findings should be confirmed by dose finding clinical trials, and studies involving a comparison group.

Trial registration number

Not applicable

Mid-Term Follow-Up of Neonatal Neochordal Reconstruction of Tricuspid Valve for Perinatal Chordal Rupture Causing Severe Tricuspid Valve Regurgitation

BACKGROUND

Papillary muscle rupture in the perinatal period is a rare event that leads to severe mitral or tricuspid insufficiency due to a flail leaflet. Neonatal tricuspid chordal reconstruction for this condition is rarely reported. Early recognition and treatment have the potential to be lifesaving. We present our surgical experience with five such patients, along with their midterm follow-up.

METHODS

Between August 2010 and November 2012, five neonates (aged 1-30 days) underwent surgery for severe atrioventricular valve regurgitation. All neonates had severe tricuspid regurgitation due to ruptured chordae. In addition, two had moderate mitral regurgitation; one due to ruptured chordae of the posterior mitral leaflet and the other due to prolapse of the anterior mitral leaflet. All underwent emergent surgery where the ruptured chordae to the anterior tricuspid leaflet were replaced with neochordae made with expanded polytetrafluoroethylene (ePTFE) suture. The mitral valve was repaired in two patients.

RESULTS

All patients survived surgery without the need for postoperative mechanical circulatory assist. Predischarge echocardiograms showed good coaptation of tricuspid and mitral leaflets with minimal regurgitation in all. At follow-up between 75 months to 102 months, four patients had excellent outcomes with less than mild tricuspid regurgitation. One child with flail tricuspid and mitral leaflets developed progressive tricuspid and mitral regurgitation requiring surgical re-repair at 20 months following the initial surgery.

CONCLUSION

Repair of chordal rupture of the tricuspid valve in neonates using ePTFE neo-chordae can provide acute salvage and gratifying midterm results in the management of this potentially fatal condition.

Pulmonary Valve Replacement in Repaired Tetralogy of Fallot Through Limited Left Anterolateral Thoracotomy: An Alternative to Repeat Sternotomy

We report two patients with repaired tetralogy of Fallot who underwent pulmonary valve replacement through a limited left anterolateral thoracotomy. We describe the technique in detail. Both patients were at risk of cardiac injury during repeat sternotomy. This approach reliably avoids the risk of cardiac injury during repeat sternotomy and appears to be safe, simple, and reproducible.

First principles calculations of the thermodynamic stability of Ba, Zr, and O vacancies in BaZrO3

The temperature dependence of the stability of bulk BaZrO3 (BZO) and of the vacancies in this material are investigated by considering phonon contributions to the free energy. The stability diagram of BZO is determined for different chemical environments. With increasing temperature the stability region becomes smaller which is particularly caused by the strong temperature dependence of the chemical potential of gaseous oxygen. The free formation energy of Ba, Zr, and O vacancies in BZO is calculated for all possible charge states and for different atomic reservoirs. While the free formation energy of Zr vacancies is strongly influenced by temperature a weaker dependence is found for Ba and O vacancies. This also has an effect on the charge transition levels at different temperatures. The present results demonstrate that O poor reservoir conditions and a Fermi level close to the valence band maximum favour a high concentration of doubly positively charged O vacancies which is a prerequisite to get a large number of protonic defects and good proton conductivity. In such a chemical environment the number of Ba and Zr vacancies is low so that Ba and Zr deficiencies are not an important issue and BZO remains sufficiently stable.

Extracorporeal shock wave lithotripsy versus ureteroscopy for management of pediatric nephrolithiasis in upper urinary tract stones: multi-institutional outcomes of efficacy and morbidity

INTRODUCTION

As the incidence of pediatric nephrolithiasis rises, understanding the efficacy and morbidity of surgical treatment options is critical. Currently, there are limited comparative data assessing shock wave lithotripsy (SWL) and ureteroscopy (URS) outcomes in children.

OBJECTIVE

The objective of this study was to compare stone clearance, 30-day emergency department visits, and the number of general anesthetics required per stone treatment for both modalities.

STUDY DESIGN

A multi-institutional retrospective review of children presenting for either URS or SWL between 2000 and 2017 was performed. Stone clearance, need for retreatment, the number of anesthetics, as well as the number and reason for emergency room visit were captured and compared between groups. Multivariate statistical analysis accounting for age, stone location, stone diameter, pre-intervention stent, and provider volume was performed for adjusted analysis.

RESULTS

A total of 84 SWL and 175 URS procedures were included. Complete stone clearance and rates of residual stone fragments <4 mm after final procedure for SWL were 77.0% and 90.8% and for URS were 78.5% and 91.7%, respectively. Retreatment rates for both procedures were not significantly different (17.9% SWL vs. 18.9% URS, P = 0.85). Children who underwent SWL had lower rates of emergency room visits for infections (0% vs. 5.1%, P = 0.03) and flank pain (3.6% vs. 10.9%, P = 0.05) and required fewer general anesthetics per treatment (1.2 vs. 2.0, P < 0.01) than those who underwent URS (Figure).

DISCUSSION

Stone clearance after both the initial and final treatments and need for repeat interventions were similar between surgical modalities. However, SWL carries less morbidity than URS. Specifically, patients who underwent SWL experienced lower rates of ED visits for urinary tract infection and for flank pain, parallel to conclusions in current comparative literature. In addition, SWL requires less general anesthetics (2.0 vs. 1.2), secondary to lower rates of ureteral stent placement and removal. Data on the potential risk of general anesthetics to neurodevelopment support thoughtful utilization of these medications. Limitations of this study include its retrospective nature and the prolonged 20-year time period over which data were collected.

CONCLUSIONS

When adjusting for confounders, SWL and URS achieve similar stone clearance. In the setting of equivalent efficacy, considerations regarding necessity of repeat interventions, morbidity of anesthesia, and complications should be integrated into clinical practice.

Pulmonary artery-to-left atrial fistula discovered after the closure of atrial septal defect: A rare clinical scenario

A case of the right pulmonary artery-to- left atrial fistula with atrial septal defect (ASD) is presented. The fistula was detected after the patient developed desaturation following surgical closure of the ASD. It was managed with a transcatheter (trans-RPA route) closure of the fistula using a 12-mm Amplatzer ventricular septal defect closure device.

Effect of direct loading of phytoestrogens into the calcium phosphate scaffold on osteoporotic bone tissue regeneration

3D porous calcium deficient hydroxyapatite scaffolds with phytoestrogens were fabricated for osteoporotic bone tissue regeneration through a combination of 3D printing techniques and cement chemistry as a room temperature process.

Testicular abscess caused by Salmonella para-typhi

This case is the first report of a bacteriologically proven testicular abscess in a child caused by Salmonella paratyphi 'A' in Pakistan that clinically simulates a testicular tumour. The case also emphasises that a course of 2 weeks antibiotic is sufficient for testicular abscess if complete surgical debridement is done.

Mononuclear ruthenium(III) complexes containing chelating thiosemicarbazones: synthesis, characterization and catalytic property

Mononuclear ruthenium(III) complexes of the type [RuX(EPh(3))(2)(L)] (E=P or As; X=Cl or Br; L=dibasic terdentate dehydroacetic acid thiosemicarbazones) have been synthesized from the reaction of thiosemicarbazone ligands with ruthenium(III) precursors, [RuX(3)(EPh(3))(3)] (where E=P, X=Cl; E=As, X=Cl or Br) and [RuBr(3)(PPh(3))(2)(CH(3)OH)] in benzene. The compositions of the complexes have been established by elemental analysis, magnetic susceptibility measurement, FT-IR, UV-vis and EPR spectral data. These complexes are paramagnetic and show intense d-d and charge transfer transitions in dichloromethane. The complexes show rhombic EPR spectra at LNT which are typical of low-spin distorted octahedral ruthenium(III) species. All the complexes are redox active and display an irreversible metal centered redox processes. Complex [RuCl(PPh(3))(2)(DHA-PTSC)] (5) was used as catalyst for transfer hydrogenation of ketones in the presence of isopropanol/KOH and was found to be the active species.

Binuclear ruthenium(III) Schiff base complexes bearing N(4)O(4) donors and their catalytic oxidation of alcohols

An interesting series of binuclear ruthenium(III) Schiff base complexes bearing bis-salophen/bis-naphophen units of the general composition [(EPh(3))(X)Ru-L-Ru(X)(EPh(3))] (where E=P or As; X=Cl or Br; L=binucleating dianionic tetradentate ligands) have been synthesized and characterized by analytical (elemental analysis, magnetic susceptibility measurements), spectral (FT-IR, UV-vis and EPR) and electrochemical methods. These ruthenium(III) complexes have two N(2)O(2) metal binding sites, which are linked to each other with a biphenyl bridge and acts as potential catalyst for oxidation of wide range of primary and secondary alcohols to corresponding aldehydes or ketones with moderate to high conversion in the presence of N-methylmorpholine-N-oxide (NMO). The formation of high-valent Ru(V)=O species as a catalytic active intermediate is proposed for the catalytic processes.

Chest radiographs in uveitis patients

This is an article regarding a patient presented with bilateral uveitis who was subsequently found to have lung carcinoma on further investigations. We recommend doing a CXR especially in uveitis patients who have a history of smoking.

Effects of depth of incision on final outcome in radial keratotomy

OBJECTIVE

To assess the effect of depth of incision on the final outcome of radial keratotomy for correction of myopia.

METHODS

Sixty-five eyes with preoperative uncorrected myopia between 2.5-6.0D in subjects with a mean age of 29.2 (+/-7) years underwent radial keratotomy between Sept 1999-July 2002 in department of Ophthalmology, Military Hospital, Rawalpindi. Based on their preoperative depth of incision the eyes were divided into group-A (twenty-five eyes), with an incision depth of 500-530 microm, and Group-B (forty eyes), with an incision depth of 531-560 microm. The comparison between the postoperative visual acuity of two groups was made at the end of study after one years' follow up.

RESULTS

A total of Sixteen eyes in Group-A (64%) that were within one diopter of emmetropia at first follow-up reverted back to their preoperative myopic state after one year of surgery as compared to only two eyes (5%) in Group-B (p<0.05). Hyperopic shift occurred in two eyes (8%) in Group-A, as compared to four eyes (10%) of Group-B (p>0.05). After one year, refraction showed that only 24% cases of Group-A were within 1 diopter of emmetropia as compared to 85% cases in Group-B. Similarly, 40% cases of Group-A were within 2 diopters of emmetropia as compared to 90% cases of Group-B. Glare and variation of vision in the initial four weeks were the most frequently reported complications in both groups.

CONCLUSION

Depth of corneal incision significantly affects the outcome of surgery, if central optical zone is kept the same in cases of low to moderate degrees of myopia.

Minimal impairment of myocardial blood flow responses to exercise in the remodeled left ventricle early after myocardial infarction, despite significant hemodynamic and neurohumoral alterations

OBJECTIVES

Previous studies have demonstrated a decreased flow reserve in the surviving hypertrophied left ventricle (LV) early after myocardial infarction. We hypothesized that exacerbation of hemodynamic abnormalities and neurohumoral activation during exercise could exhaust coronary flow reserve and thereby impair myocardial O(2) supply. Consequently, we studied hemodynamic, neurohumoral and regional myocardial perfusion and metabolic responses to exercise in pigs with LV hypertrophic remodeling 3 weeks after a myocardial infarction produced by permanent left circumflex coronary artery ligation.

METHODS

Chronically instrumented pigs were exercised on a treadmill up to 85% of maximum heart rate. Pigs with a myocardial infarction (MI) had a lower cardiac output (21%), stroke volume (28%), LVdP/dt(max) (18%), systemic (22%) and pulmonary (20%) vascular conductance, and increased left atrial (225%) and pulmonary artery (75%) pressures, compared to normal pigs. In MI, the exercise-induced increases in cardiac pump function, and systemic and pulmonary vasodilation were blunted compared to normals. Consequently, perfusion of visceral organs became impaired during strenuous exercise, but cerebral and skeletal muscle blood flows were maintained. Exercise-induced increases in norepinephrine and endothelin levels were exacerbated and, while relative sympathetic drive was maintained, cardiac responsiveness to norepinephrine was blunted. Despite lower capillary densities in the hypertrophied non-infarcted LV and relative subendocardial hypoperfusion during strenuous exercise, which necessitated a slight increase in O(2) extraction, there was no metabolic evidence of overt myocardial ischemia during strenuous exercise as indicated by the arterio-coronary venous pH difference.

CONCLUSIONS

LV dysfunction and neurohumoral activation were present in pigs with a 3-week-old infarction, particularly during exercise. However, although myocardial perfusion and O(2) supply were slightly impaired, myocardial ischemia did not occur even during exercise up to 85% of maximum heart rate, suggesting that perfusion abnormalities do not contribute to LV dysfunction early after infarction.

Effect of plant volatile oils in protecting stored cowpea Vigna unguiculata (L.) Walpers against Callosobruchus maculatus (F.) (Coleoptera: Bruchidae) infestation

Adult Callosobruchus maculatus (F.) were introduced into cowpea seeds which were stored in containers with volatile oils derived from Mentha arvensis, M. piperata, M. spicata and Cymbopogon nardus. The numbers of eggs laid, adult mortality, adult emergence and subsequent seed damage were studied for four months. All oils significantly influenced all parameters (P<0.05) and results with different parameters were generally parallel. Significant differences for at least some time/parameters combinations indicated an order of potency of M. spicata>M. piperata>M. arvensis>C. nardus.

Detection and molecular characterization of the zot gene in Vibrio cholerae and V. alginolyticus isolates

A total of 11 Vibrio cholerae isolates from 1996-1998 outbreaks in Malaysia and 4 V. alginolyticus were analyzed. Isolates were characterized by polymerase chain reaction (PCR) and Southern hybridization for the presence of the gene encoding zonula occludens toxin (zot). Screening of zot gene by PCR revealed the presence of this gene in V. cholerae and V. alginolyticus. The zot gene from one V. cholerae Ogawa isolate that was cloned in a pCR 2.1 TOPO vector was sequenced. The sequences obtained were 99% homologous to the zot gene sequence from the Gene Bank.

Changes of haemolymph protein profile in the larva of Pericallia ricini (Fabricius) parasitised by the Braconid Wasp, Apanteles taragamae Viereck (Hymenoptera: Braconidae)

Parasitism by the braconid wasp, A. taragamae caused alterations in the haemolymph polypeptides of woolly bear larvae of P. ricini. Analysis of haemolymph proteins by SDS-PAGE and densitometry showed that the quantities of haemolymph proteins were reduced dramatically in the parasitised larvae. Simultaneously, parasitism induced large amount of 95 kDa polypeptides in the haemolymph of the parasitised larvae. Also, a remarkable induction of 43 and 45 kDa polypeptides which are not detectable in non-parasitised larvae appeared in the parasitised larvae.

Effect of solvent residues of Vitex negundo Linn. and Cassia fistula Linn. on pulse beetle, Callosobruchus maculatus Fab. and its larval parasitoid, Dinarmus vagabundus (Timberlake)

Effect of solvent residues of Vitex negundo L. and Cassia fistula L. leaves (0.5 and 1%) was studied on egg laying and adult emergence of Callosobruchus maculatus Fab. and on percentage of larval parasitism by Dinarmus vagabundus (Timberlake). Cowpea seeds treated with methanol and aqueous extract of Vitex, at these concentrations (0.5 and 1%), significantly reduced the number of eggs and emergence of F1 adults of C. maculatus. Both Vitex and Cassia extracts did not affect the percentage of parasitism by D. vagabundus on C. maculatus grubs.

Ciprofloxacin-associated acute renal failure in patients undergoing high-dose chemotherapy and autologous stem cell rescue

The broad spectrum of activity of ciprofloxacin makes it an ideal drug for the prophylaxis of bacterial infections in patients undergoing high-dose chemotherapy (HDC) with autologous stem cell rescue. We present two cases of ciprofloxacin-associated acute renal failure (ARF) in patients undergoing HDC. Maintaining a high index of suspicion for this complication will allow a prompt diagnosis, with discontinuation of the drug usually resulting in a reversal of renal failure. Renal biopsy usually reveals changes compatible with interstitial nephritis, but is not always possible in these patients due to severe thrombocytopenia following HDC. A brief course of steroid therapy may be beneficial although the role of glucocorticoids is difficult to ascertain in the absence of data regarding its efficiency in this clinical setting.

Mutational analysis of the human immunodeficiency virus type 1 Vpu transmembrane domain that promotes the enhanced release of virus-like particles from the plasma membrane of mammalian cells

Human immunodeficiency virus type 1 Vpu is a multifunctional phosphoprotein composed of the N-terminal transmembrane (VpuTM) and C-terminal cytoplasmic domains. Each of these domains regulates a distinct function of the protein; the transmembrane domain is critical in virus release, and phosphorylation of the cytoplasmic domain is necessary for CD4 proteolysis. We carried our experiments to identify amino acids in the VpuTM domain that are important in the process of virus-like particle (VLP) release from HeLa cells. VLPs are released from the plasma membrane of HeLa cells at constitutive levels, and Vpu expression enhanced the release of VLPs by a factor of 10 to 15. Deletion of two to five amino acids from both N- and C-terminal ends or the middle of the VpuTM domain generated mutant Vpu proteins that have lost the ability to enhance VLP release. These deletion mutants have not lost the ability to associate with the wild-type or mutant Vpu proteins and formed complexes with equal efficiency. They were also transported normally to the Golgi complex. Furthermore, a Vpu protein having the CD4 transmembrane and Vpu cytoplasmic domains was completely inactive, and Vpu proteins harboring hybrid Vpu-CD4 TM domains were also defective in the ability to enhance the release of VLPs. When tested for functional complementation in cotransfected cells, two inactive proteins were not able to reconstitute Vpu activity that enhances the release of Gag particles. Coexpression of functional CD4/Vpu hybrids or wild-type Vpu with inactive mutant CD4/Vpu proteins revealed that mutations in the VpuTM domain could dominantly interfere with Vpu activity in Gag release. Taken together, these results demonstrated that the structural integrity of the VpuTM domain is critical for Vpu activity in the release of VLPs from the plasma membrane of mammalian cells.

Decreased DNA damage by acid and increased repair of acid-damaged DNA in acid-habituated Escherichia coli

A study of the conjugal transfer of ColV,I-K94 tn 10 from acid-treated donors suggested that acid-habituated recipients repair acid-damaged plasmid DNA better than those that are not habituated. The presence of an increased repair activity for acid-damaged DNA in habituated cells was confirmed by isolating pBR322 from acid-treated organisms; habituated cells produced more transformants when transformed by it than did non-habituated ones. Additionally, agarose gel electrophoretic studies of pBR322 DNA isolated from acid-damaged cells and tests of its transforming activity both indicated that plasmid DNA in habituated cells is less damaged by extreme acidity than is that in non-habituated organisms.

Habituation to acid in Escherichia coli: conditions for habituation and its effects on plasmid transfer

Induction of acid resistance (habituation) in Escherichia coli at pH 5.0 took ca 5 min in broth at 37 degrees C and 30-60 min in minimal medium. Induction occurred at a range of pH values from 4.0 to 6.0; it was dependent on continuing protein and RNA synthesis but substantial acid resistance appeared in the presence of nalidixic acid. Acid resistance was long-lasting; organisms grown at pH 5.0 retained most of their resistance after 2 h growth at pH 7.0. Organisms grown at pH 5.0 showed increased synthesis of a number of cytoplasmic proteins compared with the level in cells grown at pH 7.0. DNA repair-deficient strains carrying recA, uvrA or polA1 mutations were more acid-sensitive than the repair-proficient parents but were able to habituate at pH 5.0. Organisms grown at pH 5.0 transferred the ColV plasmid much more effectively at acid pH than did those grown at pH 7.0 and habituated recipients appeared better able to repair incoming acid-damaged plasmid DNA than did those that were non-habituated. Induction of acid resistance at pH 5.0 may be significant for the survival of organisms exposed to periodic discharges of acid effluent in the aquatic environment and habituation may also allow plasmid transfer and repair of acid-damaged plasmid DNA during or after such exposure.

A rapid micro radial electrophoretic method of protein separation on cellulose acetate membranes

A new rapid micromethod for protein separation under a radial electric field is described. As many as 12 rabbit serum samples could be separated in 4--6 min.