Endotoxin-induced mortality is related to increased oxidative stress and end-organ dysfunction, not refractory hypotension, in heme oxygenase-1-deficient mice

BACKGROUND

Heme oxygenase (HO)-1 is an enzyme that degrades heme to generate CO (a vasodilatory gas), iron, and the potent antioxidant bilirubin. A disease process characterized by decreases in vascular tone and increases in oxidative stress is endotoxic shock. Moreover, HO-1 is markedly induced in multiple organs after the administration of endotoxin (lipopolysaccharide [LPS]) to mice.

METHODS AND RESULTS

To determine the role of HO-1 in endotoxemia, we administered LPS to mice that were wild-type (+/+), heterozygous (+/-), or homozygous null (-/-) for targeted disruption of HO-1. LPS produced a similar induction of HO-1 mRNA and protein in HO-1(+/+) and HO-1(+/-) mice, whereas HO-1(-/-) mice showed no HO-1 expression. Four hours after LPS, systolic blood pressure (SBP) decreased in all the groups. However, SBP was significantly higher in HO-1(-/-) mice (121+/-5 mm Hg) after 24 hours, compared with HO-1(+/+) (96+/-7 mm Hg) and HO-1(+/-) (89+/-13 mm Hg) mice. A sustained increase in endothelin-1 contributed to this SBP response. Even though SBP was higher, mortality was increased in HO-1(-/-) mice, and they exhibited hepatic and renal dysfunction that was not present in HO-1(+/+) and HO-1(+/-) mice. The end-organ damage and death in HO-1(-/-) mice was related to increased oxidative stress.

CONCLUSIONS

These data suggest that the increased mortality during endotoxemia in HO-1(-/-) mice is related to increased oxidative stress and end-organ (renal and hepatic) damage, not to refractory hypotension.

Strand displacement amplification and homogeneous real-time detection incorporated in a second-generation DNA probe system, BDProbeTecET

BACKGROUND

Amplified DNA probes provide powerful tools for the detection of infectious diseases, cancer, and genetic diseases. Commercially available amplification systems suffer from low throughput and require decontamination schemes, significant hands-on time, and specially trained laboratory staff. Our objective was to develop a DNA probe system to overcome these limitations.

METHODS

We developed a DNA probe system, the BDProbeTecTMET, based on simultaneous strand displacement amplification and real-time fluorescence detection. The system uses sealed microwells to minimize the release of amplicons to the environment. To avoid the need for specially trained labor, the system uses a simple workflow with predispensed reagent devices; a programmable, expandable-spacing pipettor; and the 96-microwell format. Amplification and detection time was 1 h, with potential throughput up to 564 patient results per shift. We tested 122 total patient specimens obtained from a family practice clinic with the BD ProbeTecET and the Abbott LCx(R) amplified system for the detection of Chlamydia trachomatis and Neisseria gonorrhoeae.

RESULTS

Based on reportable results, the BDProbeTecET results for both organisms were 100% sensitive and 100% specific relative to the LCx.

CONCLUSIONS

The BDProbeTecET is an easy-to-use, high-throughput, closed amplification system for the detection of nucleic acid from C. trachomatis and N. gonorrhoeae and other organisms.

[The protrusion of thoracic intervertebral disc-thoracic spondylosis (author's transl)]

The protrusion of cervical intervertebral discs was divided into three pathological entities by Spurling; soft disc, hard disc and spondylosis. We applied these concept to the dorsal intervertebral disc disease and treated two cases of thoracic spondylosis. Case 1. A 41-year-old male entered the hospital because of the gradual progression of weakness of both legs of two months' duration. Since ten days before admission he had not had an errection and had not been to able to walk and micturate. He also complained of paresthesia radiating down the abdomen into both legs. There were no visceral complaints. Neurological examination revealed severe weakness of both legs with bilateral impairment of deep sensations and hypalgesia up to the level of T6. Reflexes in both legs were hyperactive with sustained clonus. Plantar responses were extensor bilaterally. Though plain X-rays showed no changes, tomography revealed a calcified intervertebral spur formation at the T5-6 interspace. A myelogram showed a complete block of the contrast medium at the level of the upper part of T6. The patient underwent a complete laminectomy from T3 through T6 and extradural anterior decompression with the removal of the calcified disc at the T5-6 interspace using an air drill. Postoperatively, he demonstrated an immediate improvement in sensation and a gradual recovery in motor power. At his follow-up examination 14 months after surgery he could walk without assistance. Case 2. A 47-year-old dwarfish woman (130 cm) with a low back pain and difficulty in walking for a few years duration was admitted. A few months before admission she felt pain at her left lateral abdomen. There was weakness of both legs, greater in the left. Reflexes in her left lower extremity were hyperactive with sustained clonus. Plantar responces were flexor bilaterally. Palin X-rays showed scoliosis of thoracic spine with the top at T7 level and calcified intervertebral masses at T10-11, T11-12 and T12-L1, extending into the canal that were confirmed more clearly by tomography. Myelography by a cisternal puncture disclosed a complete block at the level of T10. The patient underwent total laminectomy of T9 through L2 and extradural anterior decompression with the removal of calcified discs. At her follow-up examination 12 months after surgery she could walk for herself with some residual neurological signs, minimal weakness in the right leg and hypesthesia up to the level of T12 in the left. We have discussed the incidental, related diagnostic and operative problems of this disease.