Messenger RNA (mRNA) molecules encoding proteins related to the presynaptic cholinergic and neurotrophin systems were quantitated in the hippocampus and basal forebrain of Long-Evans rats with spatial learning ability assessed in the Morris water maze. The reverse transcriptase-polymerase chain reaction showed that the mRNAs for the low-affinity neurotrophin receptor (p75-NTR) and the growth-associated protein GAP-43 were decreased in level in the basal forebrain of aged-impaired rats. In the hippocampus of these aged-impaired rats, the mRNA for VGF, another neurotrophin-inducible gene, also was decreased. In situ hybridization histochemistry revealed that mRNAs for nerve growth factor (NGF) and brain-derived neurotrophic factor increased in level in the aged rat hippocampus; when age effects were removed, NGF mRNA level remained significantly correlated with maze performance. Enzyme-linked immunosorbent assay indicated that NGF protein was expressed at normal levels in the aged rat hippocampus. These mRNA and protein alterations may signify that a defect in neurotrophin signaling exists in the brains of aged Long-Evans rats, underlying reduced plasticity responses in the basal forebrain cholinergic system.

Aging↗

PubMedDate not supplied

Dermal exposure to strychnine.

A non-fatal case of strychnine poisoning through dermal exposure is described. About 24 h after cleaning up a strychnine spill, a 50-year-old woman presented to the emergency department with classical signs of strychnine poisoning, consisting of marked pain in the muscles of her lower limbs, dermal sensitivity, and stiffness in her jaw. Her treatment was intravenous fluid replacement and alkalinization in anticipation of potential renal failure due to rhabdomyolysis. Her plasma creatine kinase was elevated to 677 U/L with no rise in the heart specific MB fraction. Serum myoglobin level obtained retrospectively was 195 microg/L. Biological samples were taken approximately 28 h after her exposure. Strychnine was measured in plasma (196 ng/mL) and urine (6,850 ng/mL) by gas chromatography-mass spectrometry. The small amount of pheniramine in the plasma (35 ng/mL) and urine (1,255 ng/mL) is considered an inconsequential finding.

Accidents, Home↗

PubMedDate not supplied

Nuclear scanning with technetium-99m-sestamibi to evaluate ischemia in muscle flaps for cardiomyoplasty.

Mobilization of the latissimus dorsi muscle from the chest wall for cardiomyoplasty interrupts part of its blood supply. The time required for adequate collaterals to develop from the thoracodorsal artery is unknown. In four dogs, the latissimus dorsi muscle was mobilized as for cardiomyoplasty and stimulating electrodes were implanted. The muscle was replaced on the chest wall over a sheet of Gore-Tex (W. L. Gore & Associates, Inc. Flagstaff, AZ) membrane to block growth of collateral vessels from the chest wall. The opposite latissimus dorsi muscle served as the control. After a delay of 2 weeks the latissimus dorsi was burst stimulated at a rate of 80 per min with two 100 msec bursts at 85 Hz and 25 Hz for 30 min. Technetium-99m-sestamibi scans were then done to detect ischemia. Serial studies were done during the next several weeks. Images at 4 weeks demonstrated maximum uptake in the mobilized muscle, which did not subsequently improve. The authors conclude that the mobilized latissimus dorsi muscle can be imaged with technetium-99m-sestamibi and evidence of ischemia resolves at 4 weeks. These findings suggest that collateral flow is adequate as early as 4 weeks after mobilization of the latissimus dorsi muscle for cardiomyoplasty.

Animals↗

PubMedDate not supplied

Computer-assisted coregistration of multislice SPECT and MR brain images by fixed external fiducials.

We have developed and validated in a phantom a method of computer-assisted coregistration using multislice SPECT and MR images. Reusable fiducial markers were fabricated from nylon-based plastic and consist of two parts: a base that remains fixed to the skin with adhesive between scans and a removable, spherical cavity insert that can be filled with contrast agents appropriate for multiple imaging modalities. Markers external and internal to a three-dimensional brain phantom provided a means of quantifying the method's accuracy. A computer algorithm was used to derive transformation matrices for image sets by minimizing the root mean squared deviations obtained for multiple permutations (n = 10) of increasing numbers (range 3-11) of external SPECT/MRI point pairs. As defined by the average +/- SEM mean residual deviations of noncoregistered internal fiducials, the minimal accuracy was 2.4 +/- 0.3 mm (no marker > 3.6 mm) for three coregistration points and did not improve beyond seven to eight fiducials (2.2 +/- 0.1 mm; no marker > 3.2 mm). The method's true accuracy is likely to be better than estimates of minimal accuracy, however, since such measures reflect surmountable random errors in fiducial location. With use of identical MRI (or SPECT) data sets, measures of intraoperator (0.5 +/- 0.1 and 0.5 +/- 0.1 mm, respectively) and interoperator (0.5 +/- 0.3 and 0.8 +/- 0.1 mm) reliability were also obtained, establishing the method as highly reproducible and objective. Preliminary results in a human subject suggest its feasibility for clinical studies.

Brain↗

PubMedDate not supplied

The machine breaks.

Explore the source record for details and available documents.

Burnout, Professional↗

PubMedDate not supplied

Report cards: are they passing or failing? Another New Yorker says they're failing.

Explore the source record for details and available documents.

Cardiac Surgical Procedures↗

PubMedDate not supplied

What do Irish women know about cervical screening?

In anticipation of the launch of the national cervical screening programme, a questionnaire was distributed amongst 200 women on the maternity wards of the Coombe Women's Hospital. The questionnaires revealed that 24% of the women surveyed never had a smear test and 50% of these did not know how the test was performed. The majority of all women did not know what a smear test showed and 26% did not know the meaning of an abnormal smear. Irish women's knowledge of cervical screening is limited, and the success of the proposed programme will depend on an improvement in public information and education.

Adolescent↗

PubMedDate not supplied

Ephedrine as a marker of intravascular injection in laboring parturients.

Thirty healthy laboring parturients were randomly chosen to receive either normal saline (NS), ephedrine 10 mg (EPH-10), or ephedrine 15 mg (EPH-15) intravenously. Changes in maternal heart rate and blood pressure and fetal heart rate were monitored. A clinically useful and statistically significant (less than 0.001) increase in systolic blood pressure of 10 torr or more occurred in all 10 patients in the EPH-15 group. There was no adverse fetal outcome. Transient fetal tachycardia was seen in three fetuses in the EPH-15 group.

Anesthesia, Epidural↗