Esophageal lung with multiple congenital anomalies: conundrums in diagnosis and management.

BACKGROUND/PURPOSE: Communicating bronchopulmonary foregut malformations (CBPFM) are a diverse group of potentially devastating congenital anomalies with anatomy that may be difficult to delineate. The authors present a case that illustrates conundrums in the diagnosis and management of these complex disorders. METHODS: A term baby had esophageal atresia (EA), tracheoesophageal fistula (TEF), and tetralogy of Fallot. Initially, a gastrostomy was performed, and a balloon catheter was inserted through the endotracheal tube to occlude the fistula until the patient was hemodynamically stable. Subsequently, the fistula was ligated. Postoperatively, the left lung collapsed, and bronchoscopy showed an atretic left mainstem bronchus. Repeat thoracotomy showed that the fistula ligation was intact. Air was introduced through the gastrostomy tube, and, surprisingly, the left lung inflated, indicating the left mainstem bronchus arose from the esophagus distal to the ligated TEF. RESULTS: Despite reopening this fistula, ventilation remained poor, and support was withdrawn. Autopsy findings confirmed a unilobed left lung arising from the esophagus, EA, TEF, an atretic left mainstem bronchus, tetralogy of Fallot, and DiGeorge syndrome. CONCLUSIONS: This is the first report of a combination of EA and distal TEF with a second CBPFM involving the esophagus and the entire left lung. Successful correction of these anomalies will require extensive delineation of the anatomy to plan an operative strategy.

Overexpression of the glucose transporter gene with a herpes simplex viral vector protects striatal neurons against stroke.

Herpes simplex virus vectors bearing a glucose transporter (GT) gene and a marker gene were found to protect neurons against a 1-h focal ischemic insult. Rats receiving the GT vector v alpha22beta gal alpha4GT exhibited a 67.4 +/- 35.3% survival of virally targeted neurons in the ischemic hemisphere compared with the contralateral control (n = 7), whereas rats receiving a control vector exhibited only 32.8 +/- 17.9% survival (n = 9). This significant improvement in survival (105%, p=0.022) suggests that energy failure is an important contributor to the neuropathology of ischemic damage in the striatum, and that it can be alleviated by gene transfer. This is the first demonstration of protection against ischemic cerebral injury by the direct transfer of GT genes to neurons.

Defective herpes simplex virus vectors expressing the rat brain glucose transporter protect cultured neurons from necrotic insults.

Because neurons are postmitotic, they are irreplaceable once they succumb to necrotic insults such as hypoglycemia, ischemia, and seizure. A paucity of energy can exacerbate the toxicities of these insults; thus, a plausible route to protect neurons from necrotic injury would be to enhance their glucose uptake capability. We have demonstrated previously that defective herpes simplex virus (HSV) vectors overexpressing the rat brain glucose transporter (GT) gene (gt) can enhance glucose uptake in adult rat hippocampus and in hippocampal cultures. Furthermore, we have observed that such vectors can maintain neuronal metabolism during hypoglycemia and reduce kainic acid-induced seizure damage. In this study, we have developed bicistronic vectors that coexpressed gt and Escherichia coli lacZ as a reporter gene, which allows us to identify directly neurons that are infected with the vectors. Overexpression of GT from these vectors protected cultured hippocampal, spinal cord, and septal neurons against various necrotic insults, including hypoglycemia, glutamate, and 3-nitropropionic acid. Our observations demonstrate the feasibility of using HSV vectors to protect neurons from necrotic insults. Although this study has concentrated on the delivery of gt, other genes with therapeutic or protective capability might also be used.

Herpes simplex virus vector system: analysis of its in vivo and in vitro cytopathic effects.

With its natural propensity to infect and establish life-long latency in neurons, herpes simplex virus type 1 (HSV-1) has been successfully employed by various laboratories as vectors for gene transfer into neurons. However, analysis of its cytopathic effects in vivo and in vitro has been limited. In this study, we examined the cytopathic effects of 2 HSV-1 alpha 4 mutants (ts756 and d120) on adult rat hippocampus and striatum and of d120 on hippocampal neurons in culture. We assessed damage by stringent counting of surviving neurons after infection and demonstrated that while neither ts756 nor d120 infection resulted in any gross anatomical or behavioral changes of the animals, ts756, but not d120, produced a significant amount of damage in the CA4 cell field and dentate gyrus of the hippocampus. Thus, since crude examination is insufficient to detect subtle but significant degrees of neuron loss, the cytopathic effects of HSV or any vector system must be carefully analyzed. Furthermore, we also observed that uninfected cell lysates damaged neurons, both in vivo and in vitro. This cytotoxicity occurred within the first 24 h post-inoculation and probably arose through the activation of glutamate receptors. For the preparation of HSV vectors, purification of the virus from soluble cellular components by a simple pelleting step can significantly decrease such acute toxicity.