Effect of Testosterone on Neuronal Morphology and Neuritic Growth of Fetal Lamb Hypothalamus-Preoptic Area and Cerebral Cortex in Primary Culture

Testosterone plays an essential role in sexual differentiation of the male sheep brain. The ovine sexually dimorphic nucleus (oSDN), is 2 to 3 times larger in males than in females, and this sex difference is under the control of testosterone. The effect of testosterone on oSDN volume may result from enhanced expansion of soma areas and/or dendritic fields. To test this hypothesis, cells derived from the hypothalamus-preoptic area (HPOA) and cerebral cortex (CTX) of lamb fetuses were grown in primary culture to examine the direct morphological effects of testosterone on these cellular components. We found that within two days of plating, neurons derived from both the HPOA and CTX extend neuritic processes and express androgen receptors and aromatase immunoreactivity. Both treated and control neurites continue to grow and branch with increasing time in culture. Treatment with testosterone (10 nM) for 3 days significantly (P < 0.05) increased both total neurite outgrowth (35%) and soma size (8%) in the HPOA and outgrowth (21%) and number of branch points (33%) in the CTX. These findings indicate that testosterone-induced somal enlargement and neurite outgrowth in fetal lamb neurons may contribute to the development of a fully masculine sheep brain.

Prenatal influence of an androgen agonist and antagonist on the differentiation of the ovine sexually dimorphic nucleus in male and female lamb fetuses

The ovine sexually dimorphic nucleus (oSDN) is 2 times larger in rams than in ewes. Sexual differentiation of the oSDN is produced by testosterone exposure during the critical period occurring between gestational day (GD)60 and GD90 (term, 147 d). We tested the hypothesis that testosterone acts through the androgen receptor to control development of the male-typical oSDN. In experiment 1, pregnant ewes received injections of vehicle, androgen receptor antagonist flutamide, or nonaromatizable androgen dihydrotestosterone (DHT) propionate during the critical period. Fetuses were delivered at GD135. Both antagonist and agonist treatments significantly reduced mean oSDN volume in males but had no effects in females. Experiment 2, we analyzed the effect of treatments on the fetal hypothalamic-pituitary-gonadal axis to determine whether compensatory changes in hormone secretion occurred that could explain the effect of DHT. Pregnant ewes were injected with vehicle, flutamide, or DHT propionate from GD60 to GD84, and fetuses were delivered on GD85. Flutamide significantly increased LH and testosterone in males, whereas DHT significantly decreased both hormones. In females, LH was unaffected by flutamide but significantly reduced by DHT exposure. DHT significantly decreased pituitary gonadotropin and hypothalamic kisspeptin mRNA expression in males and females. These results suggest that androgen receptor mediates the effect of testosterone on oSDN masculinization, because this process was blocked by the androgen receptor antagonist flutamide in eugonadal males. In contrast, the reduction of oSDN volume observed after DHT exposure appears to be mediated by a negative feedback mechanism exerted on the hypothalamus to reduce LH and testosterone secretion. The reduced androgen exposure most likely accounted for the decreased oSDN volume. We conclude that, during the critical period, the male reproductive axis in long gestation species, such as sheep, is sufficiently developed to react to perturbations in serum androgens and mitigate disruptions in brain masculinization.

Cell death in the central division of the medial preoptic nucleus of male and female lamb fetuses

The medial preoptic area of the adult sheep contains an ovine sexually dimorphic nucleus (oSDN) that is larger and has more neurons in males than in females. In the lamb fetus, the nascent oSDN occupies the central division of the medial preoptic nucleus (MPNc) and consists of a cluster of cells that is organized by the action of testosterone during gestational days 60-90 of a 147 day term pregnancy. The current study sought to determine whether programmed cell death contributes to the emergence of the oSDN. Male and female lamb fetuses were euthanized at different ages spanning the period during which the oSDN is organized. The expression of the pro- and anti-apoptotic genes bcl-2 and bax, respectively, was measured by quantitative RT-PCR to assess possible sex differences in neuron vulnerability to programmed cell death. The appearance of DNA-fragmentation was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and used to estimate the occurrence of apoptotic cell death. We found that bcl-2 and bax mRNA expression in the medial preoptic area of the developing lamb fetus decreased during the last half of the 147-day gestation. The ratio of bcl-2/bax gene expression was highest at gestational day 85 but was equivalent between males and females. TUNEL staining in the MPNc was very low and although it decreased significantly with age, it was not significantly different between sexes. These results using two different methods to assess cell death indicate that a sex difference in the incidence of cell death is not a primary mechanism leading to sexual differentiation of the oSDN.

Inhaled corticosteroids for asthma: are they all the same?

OBJECTIVES

To assess similarities and differences among currently available inhaled corticosteroids (ICS) for treatment of asthma, with special emphasis on factors that may affect the relative safety of these medications.

METHODS

PubMed was searched for relevant reviews and original articles. Information from these studies was synthesized and critically assessed.

RESULTS

Differences in corticosteroid formulations and delivery systems can create variations in therapeutic efficacy. Chemical properties of the various corticosteroids may also affect their relative safety. Ciclesonide and beclomethasone dipropionate are administered as prodrugs activated by enzymes present in the lungs but not the oropharynx. Corticosteroid-specific adverse effects in the oropharynx are thus avoided, although formulation-specific effects may remain. Other adverse effects require systemic availability, either via the gastrointestinal tract or the lung. Once they enter the systemic circulation, all ICS are rapidly metabolized by the liver. Oral bioavailability of ICS such as fluticasone, ciclesonide and mometasone is minimal, as a result of their essentially complete first-pass metabolism in the liver. Ciclesonide also undergoes extrahepatic metabolism that eliminates it even more rapidly. Additionally, ciclesonide and mometasone exhibit very high levels of binding to serum proteins that reduces their ability to stimulate glucocorticoid receptors outside the lung.

CONCLUSIONS

Despite acting by similar mechanisms, currently available ICS and their delivery systems differ in ways that can potentially affect both safety and therapeutic effectiveness for individual patients.

Severe asthma: approach and management

Management of severe asthma remains a significant challenge. Patients with this condition do not respond adequately to inhaled corticosteroids and bronchodilators, forcing a search for alternative strategies. The clinician's initial priority is to firmly establish the diagnosis of severe asthma, as many conditions can mimic and/or aggravate this disease. Once the diagnosis is confirmed and confounding variables addressed, a variety of pharmacological and non-pharmacological approaches must be considered. Continuous use of oral corticosteroids carries a risk of significant adverse effects. Leukotriene modifiers and antibodies to IgE are effective for some patients but not for many others. Alternative anti-inflammatory drugs and novel or unconventional modalities may also be used. Although severe asthma remains a clinical dilemma, a rational diagnostic and therapeutic strategy can be used to improve patient outcomes.

mGluR1/5-dependent long-term depression requires the regulated ectodomain cleavage of neuronal pentraxin NPR by TACE

Matrix metalloproteases (MMPs) play a role in remodeling the extracellular matrix during brain development and have been implicated in synaptic plasticity. Here, we report that a member of the neuronal pentraxin (NP) family, neuronal pentraxin receptor (NPR), undergoes regulated cleavage by the MMP tumor necrosis factor-alpha converting enzyme (TACE). NPR is enriched at excitatory synapses where it associates with AMPA-type glutamate receptors (AMPAR) and enhances synaptogenesis. However, in response to activation of group 1 mGluRs (mGluR1/5), TACE cleaves NPR and releases the pentraxin domain from its N-terminal transmembrane domain. Cleaved NPR rapidly accumulates in endosomes where it colocalizes with AMPAR. This process is necessary for mGluR1/5-dependent LTD in hippocampal and cerebellar synapses. These observations suggest that cleaved NPR functions to "capture" AMPAR for endocytosis and reveal a bifunctional role of NPs in both synapse strengthening and weakening.

Indoor air quality at Salarjung Museum, Hyderabad, India

Deterioration of art objects at Salarjung Museum has been noticed such as blackening of white and pink pigments of Indian miniature paintings and other objects like pigments, paints, varnishes, coatings, silver ware, zari works, textiles, which are displayed in museum galleries. The cause of deterioration of the artifacts is attributed to air pollution. The outdoor air pollution levels with respect to suspended particulate matter, sulphur dioxide, oxides of nitrogen, ammonia, aldehydes and oxidants are observed to be high when compared with background environment and ambient air quality standards for sensitive areas. The indoor air quality levels in terms of various parameters including temperature and relative humidity (RH) observed to be more than the threshold limits. The climatic conditions coupled with polluted indoor air are the main causes for the deterioration of art objects. Hence remedial measures are suggested to avoid further deterioration of objects.

Polycyclic aromatic hydrocarbons in the ambient air of Jeedimetla Industrial Development Area-Hyderabad

Polycyclic aromatic hydrocarbons (PAHs) have received increased attention in recent years in air pollution studies, as some of these compounds are highly carcinogenic or mutagenic. PAHs are mainly associated with respirable suspended particulate matter (RSPM) (diameter <10 m in size). Hence, it is important to determine the concentration of PAHs adsorbed on RSPM to know the extent of human exposure to these potentially carcinogenic substances. The study was carried out at 10 locations in and around the Jeedimetla industrial development area, Hyderabad during April 2000. Higher concentrations of B(a)A and B(b)F were observed at Nandanagar, Py and B(a)P at Kukatpally while, F1 concentrations at Allwyn Colony. These variations in the concentration can be attributed to their source and climatic conditions during sampling.

Acute toxicity of lake water to fishes

The present study investigates the acute toxicity of Hussainsagar lake water to fishes. In this context, experiments were conducted on three species of fishes (Cyprinus carpio, Tilapia mozambica and Lebistus reticularis), using 5, 10 and 20% volume of Jeedimetla nallah wastewater and were observed for the signs of survival within the specified period of time. The TLm value for 96 hours test period was found to be 17%. Similarly Toxicity studies were carried out on Hussainsagar lake water with dilutions varying from 10-100%. Absence of mortality during 96 hours of test period indicates that there is no acute toxicity of Hussainsagar lake water to fishes.

Assessment of slow sand filtration system for rural water supply schemes--a case study

In India, water supply programmes form a part of National Development Plans and are implemented in a phased manner under the Five-Year Plans. A number of departments and ministries of the Central and State Governments have been vested with the responsibility for water supply and sanitation. Due to inherent advantages of slow sand filters over conventional rapid sand filters, the Panchayat Raj Engineering Department (PRED), Government of Andhra Pradesh has designed and constructed a number of slow sand filter plants for rural water supply schemes in the state. At the instance of Netherland Assisted Project (NAP) Office, Hyderabad, NEERI undertook a critical evaluation of the functioning of three slow sand filter plants in Andhra Pradesh and suggested improvements in construction, operation and maintenance (O&M) including a review of design criteria followed by PRED. The paper presents the outcome of these studies along with suggestions needed to bring about improvements in source protection, design, construction, O&M of slow sand filter and training programme to improve the quality of supervision.

Sepsis-induced immunosuppression: from bad to worse

The sepsis syndrome is characterized by the acute release of a variety of inflammatory mediators, which often result in detrimental effects to the host. The release of these mediators is regulated and counterbalanced by the coordinated expression of antiinflammatory molecules. It is the balance between the expression of pro- and antiinflammatory mediators that often determines the magnitude of early tissue injury and subsequent risk of infectious complications. As our understanding of the pathophysiology of sepsis continues to evolve, we have gained a greater appreciation for the effects that sepsis and similar states of overwhelming stress have on host antimicrobial immunity. A number of functional defects in leukocytes isolated from sepsis patients have been characterized. These defects include diminished expression of important cell surface antigens, dysregulated cytokine production, alterations in antigen-presenting ability, and accelerated apoptosis. Impaired leukocyte function has important clinical ramifications, as high mortality rates have been observed in patients displaying evidence of sepsis-induced immune deactivation. In this article, we review the current literature supporting evidence of dysregulation of host immunity occurring during sepsis syndrome, characterize the underlying pathophysiology, and describe novel therapeutic interventions directed at augmenting host immunity during sepsis.

Performance evaluation of water treatment plants based on microfilter technology for rural water supply

Panchayat Raj Engineering Department (PRED), Government of Andhra Pradesh installed package water treatment plants on a trial basis, in some villages in Krishna district of Andhra Pradesh. These plants with a design capacity of 6000-12000 lph were supplied and erected by a firm in Hyderabad. These plants consist of three stage treatment comprising of pulverized quartz filter bed, activated carbon bed and micro filter unit followed by disinfection. At the request of PRED, comprehensive studies were carried on individual plants which includes a detailed appraisal of the performance of the individual components of the plant, infrastructure at the village level for routine O&M of the plants as also views of the community regarding their acceptability of the system. This paper presents the findings and conclusions of the performance evaluation study.

Selective inhibition of COX-2 improves early survival in murine endotoxemia but not in bacterial peritonitis

Prostaglandins of the E series are believed to act as important mediators of several pathophysiological events that occur in sepsis. Studies were performed to evaluate the effect of cyclooxygenase (COX)-2-specific inhibition on the outcome in murine endotoxemia and cecal ligation and puncture (CLP). We observed a significant time-dependent upregulation of PGE(2) production in both blood and lung homogenates of mice administered lipopolysaccharide intraperitoneally, which was nearly completely suppressed by the administration of the COX-2 inhibitor NS-398. Treatment with NS-398 significantly improved early but not late survival in lipopolysaccharide-challenged mice. On the contrary, elevated PGE(2) levels were found in bronchoalveolar lavage fluid but not in plasma of mice subjected to CLP (21 gauge). Pretreatment with NS-398 failed to significantly improve survival in CLP mice. No significant differences were noted in plasma or lung homogenate proinflammatory cytokine levels or lung neutrophil sequestration between the NS-398-treated and control groups. These results demonstrate that selective COX-2 inhibition confers early but not long-term benefits without affecting the expression of proinflammatory cytokines or the development of lung inflammation.

Alveolar macrophage deactivation in murine septic peritonitis: role of interleukin 10

Sepsis predisposes the host to a number of infectious sequelae, particularly the development of nosocomial pneumonia. Mechanisms by which sepsis results in impairment of lung antibacterial host defense have not been well defined. Alveolar macrophages (AM) represent important immune effector cells of the lung airspace. In this study, we examined the effects of cecal ligation and puncture (CLP) on murine AM function ex vivo, including the expression of proinflammatory cytokines and AM phagocytic activity. AM were harvested from mice subjected to a sham operation and CLP 24 h after laparotomy, adherence purified, and challenged with lipopolysaccharide (LPS) or left unstimulated. Both unstimulated and LPS-stimulated AM from mice subjected to CLP (CLP mice) produced significantly smaller amounts of proinflammatory cytokines tumor necrosis factor alpha and interleukin (IL-12) and C-X-C chemokines KC and macrophage inflammatory protein 2 than similarly treated AM from animals subjected to a sham operation. Furthermore, AM isolated from CLP mice displayed a marked impairment in phagocytic activity, as determined by flow cytometry, with this defect persisting to 48 h post-CLP. Induction of peritoneal sepsis syndrome resulted in a time-dependent increase in IL-10 in plasma and peritoneal fluid. Interestingly, the impairment in AM proinflammatory-cytokine production and phagocytic activity observed in AM from CLP mice was partially reversed by the in vivo neutralization of IL-10 prior to AM harvest. These observations suggest that abdominal sepsis syndrome results in significant impairment in AM effector cell function, which is mediated, in part, by sepsis-induced expression of IL-10.

Intrapulmonary TNF gene therapy reverses sepsis-induced suppression of lung antibacterial host defense

Sepsis syndrome is frequently complicated by the development of nosocomial infections, particularly Gram-negative pneumonia. Although TNF-alpha (TNF) has been shown to mediate many of the pathophysiologic events in sepsis, this cytokine is a critical component of innate immune response within the lung. Therefore, we hypothesized that the transient transgenic expression of TNF within the lung during the postseptic period could augment host immunity against nosocomial pathogens. To test this, mice underwent 26-gauge cecal ligation and puncture (CLP) as a model of abdominal sepsis, followed 24 h later by intratracheal (i.t.) administration of Pseudomonas aeruginosa. In animals undergoing sham surgery followed by bacterial challenge, Pseudomonas were nearly completely cleared from the lungs by 24 h. In contrast, mice undergoing CLP were unable to clear P. aeruginosa and rapidly developed bacteremia. Alveolar macrophages (AM) recovered from mice 24 h after CLP produced significantly less TNF ex vivo, as compared with AM from sham animals. Furthermore, the adenoviral mediated transgenic expression of TNF within the lung increased survival in CLP animals challenged with Pseudomonas from 25% in animals receiving control vector to 91% in animals administered recombinant murine TNF adenoviral vector. Improved survival in recombinant murine TNF adenoviral vector-treated mice was associated with enhanced lung bacterial clearance and proinflammatory cytokine expression, as well as enhanced AM phagocytic activity and cytokine expression when cultured ex vivo. These observations suggest that intrapulmonary immunostimulation with TNF can reverse sepsis-induced impairment in antibacterial host defense.

Hemodynamic effects of carbon dioxide insufflation during endoscopic vein harvesting

BACKGROUND

A prospective study was performed assessing the hemodynamic effects of carbon dioxide (CO2) insufflation during endoscopic vein harvesting (EVH) using the Guidant Vasoview Uniport system.

METHODS

Five hemodynamic and respiratory parameters (end-tidal carbon dioxide, arterial partial pressure of carbon dioxide, mean arterial pressure, mean pulmonary arterial pressure, and cardiac output), were measured in 100 consecutive patients undergoing EVH with CO2 insufflation. Data were obtained prior to commencement of EVH, 15 minutes after commencement, and 5 minutes after completion of the vein harvesting.

RESULTS

No adverse hemodynamic effects were observed during CO2 insufflation. Specifically, average mean arterial pressure went from 88.77+/-9.64 to 89.13+/-8.60 to 88.24+/-8.71 mm Hg before, during, and after endoscopic vein harvesting (p = 0.291). Likewise, average mean pulmonary artery pressures were 19.76+/-4.75, 20.05+/-4.48, and 20.05+/-4.62 mm Hg (p = 0.547); and average cardiac output was 4.25+/-0.74, 4.22+/-0.73, and 4.23+/-0.69 L/min (p = 0.109) at those three intervals. Additionally, there was no evidence of significant systemic absorption of CO2 as reflected in average arterial PCO2, which remained steady at 37.42+/-5.19, 37.51+/-4.59, and 38.10+/-4.80 mm Hg (p = 0.217); and average end-tidal CO2, which was 32.10+/-3.66, 32.50+/-3.47, and 32.38+/-3.33 mm Hg (p = 0.335). In a subset of 20 patients with elevated pulmonary arterial pressure (more than 32 mm Hg), there was also no significant change in any of the parameters.

CONCLUSIONS

Carbon dioxide insufflation during EVH leads to no adverse hemodynamic consequences or systemic CO2 absorption. The technique appears to be safe and well tolerated.

Vasoseal after intra-aortic balloon pump removal: a pilot study

Vascular complications after removal of an intra-aortic balloon pump (IABP) have been reported to occur in up to 15% of patients. Vasoseal, a vascular hemostasis device (VHD), has been shown to be safe and effective in rapidly achieving hemostasis after a cardiac catheterization or percutaneous coronary intervention. We propose that similar results can be obtained with the VHD when removing an IABP. However, it is necessary to first gain first the experience of deploying the VHD without insertion of a guidewire. We studied 10 patients in whom Vasoseal was utilized after an IABP was removed. The primary endpoint was a composite of major or minor bleeding, infection, and any vascular complication at 7 days. The time to achieve hemostasis was also assessed. There was not a single episode of bleeding, infection, or vascular injury at 7 days. The time to hemostasis ranged between 8 and 17 min (mean, 12.9 min). This VHD can be utilized safely and efficaciously when removing an IABP.

Pneumonia in acute respiratory distress syndrome. A prospective evaluation of bilateral bronchoscopic sampling

We evaluated the diagnostic yield of bilateral bronchoalveolar lavage (BAL) in patients with acute respiratory distress syndrome (ARDS) with suspected ventilator-associated pneumonia (VAP) and compared BAL results from contralateral sites. Ninety-four ARDS patients with suspected VAP underwent 172 bronchoscopies (344 BALs). BAL was processed for quantitative cultures, total cell count and subjected to microscopic analysis for cell differential, presence of intracellular organisms (ICO), and Gram stain. The diagnostic threshold for VAP was a growth of >= 10(4) cfu/ml in BAL culture. Most episodes (68%) had bilateral insignificant bacterial growth. Forty (43%) patients had one or more episodes of VAP. Thirty-three of the 55 (60%) positive bronchoscopies had significant growth in only one side, 18 were right BAL, and 15 were left BAL. Episodes with bilateral significant growth were more likely to be polymicrobial, to have a bacterial growth >= 10(5) cfu/ml in the BAL, and to possess a higher percentage of neutrophils and ICO. Among 65 microorganisms recovered in significant concentration, Pseudomonas aeruginosa occurred in 43% and S. aureus in 15%. Overall, Gram stain had a sensitivity of 54% and a specificity of 87%; and Giemsa stain (> 2% ICO) had a sensitivity of 46% and a specificity of 93%. Antibiotic treatment was modified by the results of BAL cultures in 50 (91%) episodes of pneumonia. In patients with ARDS and suspected VAP, bilateral BAL quantitative bacterial cultures had significant growth on one side only in 19% and in both sides in 13%.

Traditional fish intake and fatty acid composition in fish consuming and non-fish consuming populations

To evaluate the validity of habitual marine fish intake, the relation between fatty acid composition of serum phospholipids and dietary patterns were investigated. Dietary intake and serum fatty acid concentrations were measured in healthy subjects of coastal fish consuming and non-fish consuming populations. Amongst fish consumers, the intake of total energy (p<0.01) and carbohydrate (p<0.05) is significantly lower and protein intake higher than in non-fish consumers. The mean percentages of saturated and monounsaturated fatty acids do not show significant variation. However, in the ω-6 fatty acid series, the percent of linoleic acid, 22:4 ω-6 and 22:5 ω-6 is significantly lower in fish consumers, whereas dihomo-gamma linolenic acid is higher than in the non-fish consumers. The percentage of w-3 fatty acids in fish consumers, eicosapentaenoic acid, docosapentaenoic acid and docosahexaenoic acid are significantly greater (p<0.01) than those in non-fish consumers probably attributable to differences in fish intake. These differences in fatty acid profiles, particularly in the long-chain ω-3 series, are highlighted with the consumption of fish being a possible explanation between fish consuming and non-fish populations. The findings of this study suggest that the therapeutic efficacy of fish consumption is worthy of further study.

Review: the effects of antihypertensive agents on serum lipids

Because various antihypertensive drugs adversely affect lipid metabolism, these drugs may increase associated risks for coronary artery disease and thus offset some of the beneficial effects of blood pressure reduction. In this paper the current literature regarding the effects of antihypertensive agents on serum lipids is reviewed. Differing effects of various classes of antihypertensives are assessed to further our understanding of this very important subject.

End organ function with prolonged nonpulsatile circulatory support

The hypothesis tested in these studies was that long-term circulatory support with a nonpulsatile device is safe and causes no end organ dysfunction. An inexpensive, small centrifugal pump with a 7 L/min capacity was implanted in 6 sheep (15 acute implants have previously been reported). The inlet cannula was placed in the left atrium and the outlet graft anastomosed to the descending aorta. A percutaneous cable supplied DC power and heparinized saline (10 ml/hr) for lubrication. Outputs of pump flow, stator, animal core temperature, pump power consumption, and RPM were monitored throughout the course of each experiment. The sheep moved freely within a large pen using an overhead swivel/tether system that carried all input and output lines. Four sheep survived longer than 4 weeks, and the indices of end organ function were analyzed at 28 days. No animal revealed any neurologic dysfunction. Hemoglobin was 9.075 +/- 0.78 g/dl at 28 days, as opposed to 7.475 +/- 0.68 (p = 0.002) before surgery. The blood urea nitrogen was 9.250 +/- 4.57 versus 14 +/- 5.72 mg/dl (p = 0.041), creatinine was 0.775 +/- .10 versus 0.775 +/- 0.05 mg/dl (p > or = 0.999), total bilirubin was 0.425 +/- 0.2 versus 0.225 +/- 0.05 mg/dl (p = 0.092), serum glutamic oxaloacetic transaminase was 74.75 +/- 24 versus 106.25 +/- 15.84 IU/L (p = 0.015), serum glutamic pyruvic transaminase was 36 +/- 28.7 versus 28.3 +/- 5.7 IU/L (p = 0.25), and total protein was 6.675 +/- 0.49 versus 5.47 +/- 0.15 g/dl (p = 0.025). It is concluded that these animals adapted very well to pulseless circulatory support. The results of these studies support the concept of an inexpensive, implantable, centrifugal pump as a ventricular assist device.

Alternatives to human heart replacement

The continuing and increasing discrepancy between the number of available donor hearts and the number of patients who might benefit from cardiac transplantation has prompted efforts in the development of xenotransplantation, mechanical assist devices, and cardiomyoplasty techniques. We briefly review recent work in these three fields. The results of experimental xenotransplantation between closely related species are improving slowly with currently available drugs, and clinical trials in this field may be possible in the near future. Implantable ventricular assist devices are also at a stage of development where permanent implantation is likely to be followed by a reasonable and worthwhile period of patient survival. With regard to cardiomyoplasty, steady progress is being made in clarifying exact indications and patient selection, as well as confirming the potential benefits.

Electrocardiographic normalization after cerebral vascular accident

A 59 year old female sustained an anterior subendocardial infarction with deep T wave inversions in leads I, AVL and V2-V6. She subsequently developed a cerebral vascular accident. The ECG now revealed upright T waves in the leads that previously showed deep T wave inversions. A review of the literature failed to reveal a similar case of normalization of the ECG after a cerebral vascular accident.