Differences in the laminar origin of projections from the medial prefrontal cortex to the nucleus accumbens shell and core regions in the rat

The medial prefrontal cortex (mPFC) projects to the nucleus accumbens shell, core and rostral pole. In this retrograde tract-tracing study of rat mPFC to nucleus accumbens projection neurons, the advantages of Neurobiotin are utilised in order to reveal the detailed morphology of labelled projection cells, and to permit an examination of the laminar projections to shell and core compartments The retrogradely transported Neurobiotin was found in somata, proximal and distal dendrites of neurons that project from the mPFC to the nucleus accumbens. The morphology of these projection neurons was revealed in great detail and confirmed that the projection arises wholly from pyramidal cells. Interestingly, it was also found that retrogradely labelled neurons were exclusively located in prelimbic and infralimbic regions in layers V and VI, after shell injections, but also in layer II following core sites. This observation may reflect possibly different roles for cortical laminae on the nucleus accumbens.

Effects of four methods of sperm preparation on motion characteristics and nitric oxide concentration in laboratory-prepared oligospermia

BACKGROUND

To compare four different spermatozoa preparation methods in semen samples with respect to recovery rate, percent motility, path and progressive velocity, and nitric oxide (NO) production before and after centrifugation.

METHODS

Each of 36 semen specimens was diluted to 1 x 10(6)/ml and divided into four 1-ml aliquots for sperm processing using four methods: swim-up, two (Percoll II) and three (Percoll III) layer Percoll (Pharmacia Biotech AB, Uppsala, Sweden) gradients and albumin columns. The motile sperm recovery rate, percent motility and motion parameters were measured for each semen specimen (n = 36) before and after processing using the four methods. NO was measured with the use of a chemiluminescence method before and after centrifugation (n = 17).

RESULTS

The sperm recovery rate was higher using both Percoll gradients than with the other two methods (Percoll II, 68 +/- 20.5%, Percoll III, 75.3 +/- 22.2% vs swim-up, 25.8 +/- 9.9% and albumin, 33.1 +/- 20.7%). The results were similar for total motile cells (Percoll II, 3.55 +/- 1.72 x 10(6)/ml, Percoll III, 4.25 +/- 1.29 x 10(6)/ml vs swim-up, 1.19 +/- 0.71 x 10(6)/ml and albumin, 1.89 +/- 1.36 x 10(6)/ml). Both Percoll methods and the albumin method produced a statistically significant improvement over the swim-up method in motility. The albumin column method resulted in the least path and progressive velocities (51.3 +/- 15.4 microns/s and 46.2 +/- 16.5 microns/s, respectively). NO produced during sperm processing did not differ significantly among the four processing methods (swim-up, 4,531 +/- 1,626 nM, Percoll II, 5,119 +/- 3,969 nM, Percoll III, 6,060 +/- 5,512 nM, albumin 4,838 +/- 2,462 nM).

CONCLUSIONS

Our data suggest that Percoll methods are superior to swim-up and albumin columns for sperm preparation, yielding good sperm recovery, motility and motion characteristics. The trend toward lower NO levels among samples prepared using albumin columns did not reach statistical significance.

[Clinical multivariate statistical analysis of nephrotoxicity induced by cisplatin]

Nephrotoxicity was studied in 47 patients who received combined chemotherapy with cisplatin (DDP, 50-100 mg/m2) as the chief agent. The treatment was given every 3-4 weeks with vigorous hydration and forced diuresis. The renal tubular toxicity was evaluated by urinary beta 2 microglobulin (beta 2-MG). It was found that the nephrotoxicity secondary to DDP was dose-dependent. Hypertonic saline was able to decrease the renal damage without any significant difference among the first, second and third course. The nephrotoxicity of DDP administered in one day was more severe than that given in two days. beta 2-MG was a good parameter of DDP nephrotoxicity. By multivariate statistical analysis, metoclopramid and chlorpromazine were found to alleviate DDP nephrotoxicity. Classification, examination and management of DDP nephrotoxicity is proposed.