Reorganization of trigeminal primary afferents following neonatal infraorbital nerve section in hamster

The infraorbital nerve was sectioned and the ipsilateral whisker follicles were cauterized in hamsters within 12 h of birth. Sixty to ninety days later application of HRP to the proximal stumps of the ipsilateral lingual, inferior alveolar, mylohyoid and auriculotemporal nerves resulted in increased numbers of labeled somata in trigeminal ganglion regions which contain primarily infraorbital cell bodies in normal animals. The labeled central processes of mandibular nerves also occupied portions of the brainstem trigeminal complex normally innervated by infraorbital axons. These findings represent the first anatomical demonstration of trigeminal primary afferent plasticity.     

Parvalbumin and calbindin immunocytochemistry reveal functionally distinct cell groups and vibrissa-related patterns in the trigeminal brainstem complex of the adult rat.

Immunocytochemistry for calbindin (CA) and parvalbumin (PA) was combined with retrograde tracing from the thalamus, superior colliculus (SC), and cerebellum to define the ascending projections of neurons in the rat's trigeminal (V) brainstem complex that express immunoreactivity for these calcium binding proteins. Many PA-immunoreactive neurons were observed in trigeminal nucleus principalis (PrV). Many of these cells projected to thalamus and a few sent axons to SC. In ventral PrV, PA-immunoreactive neurons were arranged in a vibrissa-related pattern. A very small number of large CA-immunoreactive neurons were observed in dorsomedial PrV. None of these cells were labeled by our tracer deposits. Small neurons in V subnucleus oralis (SpO) were also immunoreactive for PA, but none were retrogradely labeled. A small percentage of the large neurons in SpO were CA-immunoreactive; many of these were retrogradely labeled by tracer injections in the thalamus and/or SC. In V subnucleus interpolaris (SpI), many small to medium sized cells were PA-positive and they were arrayed in a vibrissae-like pattern. None of these neurons were retrogradely labeled from any of the above-listed targets, but many were retrogradely labeled by tracer injections into ipsilateral PrV. SpI also contained many large CA-immunoreactive cells. Many of these projected to the thalamus and/or SC and some were also retrogradely labeled by tracer injections into ipsilateral PrV. In V subnucleus caudalis (SpC), very dark PA-immunoreactive neurons were located in the inner part of lamina II and less often in laminae I. Lightly labeled cells were located in the magnocellular laminae and formed vibrissa-related aggregates. None of these neurons were retrogradely labeled by our tracer injections. CA-immunoreactive cells were located throughout the depth of lamina II in SpC and smaller numbers were also visible in lamina I and layers III-V. A small percentage of the CA-positive cells in lamina I and in the magnocellular layers were retrogradely labeled from the thalamus. These data indicate that PA and CA antisera identify two cell populations in whisker-related regions of the V brainstem complex and that PA cells are somatotopically patterned in PrV, SpI, and SpC. These markers also distinguish two cell groups in superficial laminae of the medullary dorsal horn.     

Low seminal zinc bound to high molecular weight proteins in asthenozoospermic patients: evidence of increased sperm zinc content in oligoasthenozoospermic patients [published erratum appears in Hum Reprod 1998 Jun;13(6):1750]

Total seminal zinc concentration, seminal zinc fraction bound to high molecular weight proteins (HMW-Zn%) and zinc content in spermatozoa were assayed in the ejaculates of 90 asthenozoospermic patients subdivided into two study groups: normoasthenozoospermics (group I: n = 50) and oligoasthenozoospermics (group II: n = 40). The zinc concentrations of patients were compared with those of a control group of donors showing normal semen parameters. All samples were also investigated for their sperm membrane functional integrity by the hypo- osmotic swelling test (HOS). The results showed normal total zinc concentrations but very low HMW-Zn% values (P < 0.001) in seminal plasma of the two groups of asthenozoospermic patients compared to the controls. Furthermore higher zinc amounts (P < 0.001) were measured in spermatozoa of oligoasthenozoospermic patients compared to group I and to the control group. Oligoasthenozoospermics also displayed a lower HOS score (P < 0.001) compared to the other two groups. These data suggest that the increased unbound seminal zinc could contribute to the decrease of sperm motility in normoasthenozoospermic and oligoasthenozoospermic patients. A further impairment in sperm motility could occur in the oligoasthenozoospermic patients where the increase of seminal free zinc was followed by a major zinc uptake by spermatozoa. The higher intrasperm zinc content in these patients could be a reflection of their low sperm membrane functionality.      

In-111-labeled leukocyte scintigraphy in suspected orthopedic prosthesis infection: comparison with other imaging modalities

When infection of prosthetic orthopedic implants is suspected, optimal management requires accurate confirmation or exclusion of infection. The authors retrospectively studied 98 patients with possible infection who underwent scanning with indium-111-labeled white blood cells (WBCs) and subsequently underwent surgery within 14 days. At surgery, 50 patients had infections, as determined by means of culture or histologic results. The diagnostic accuracy of In-111 scanning was compared with that of plain radiography, arthrography, three-phase bone scanning, and various clinical and laboratory findings classically associated with infection. Positive findings on In-111 WBC scans and elevated erythrocyte sedimentation rates were found to be the most predictive variables in the diagnosis of septic prostheses (P less than or equal to .001 and P less than or equal to .002, respectively). Likelihood ratio analysis more clearly demonstrated the superiority of In-111 WBC scanning, with positive and negative scans yielding likelihood ratios of 5.0 and 0.16, respectively.     

Acute myocardial ischemia: MR imaging with Mn-TP

Cardiac-gated magnetic resonance (MR) imaging was performed in rats to determine the effects of manganese ethylenediaminetetraphosphonate (TP). Ten normal rats received Mn-TP in a dose of 50 mumol/kg through a tail-vein injection. Spin-echo MR images were obtained before and every 10 minutes after Mn-TP injection for 1 hour. Cardiac signal intensity (SI) increased more than 70% after Mn-TP injection and remained nearly unchanged 1 hour after injection. Myocardial T1 was 517 +/- 49 msec in eight control rats and 282 +/- 61 msec (P less than .001) in six rats 81 +/- 0 minutes after injection. Nine rats underwent occlusion of the left anterior descending coronary artery prior to MR imaging. Images were obtained before and 15, 30, and 60 minutes after Mn-TP injection. In normal myocardium, SI increased up to 82% and remained elevated for 1 hour. In ischemic myocardium, SI rose 11%, leading to a marked contrast between the two tissue zones. T1 was also different in the two regions: In normal tissue, it was 206 msec +/- 54; in ischemic tissue, 338 +/- 82 (P less than .001). With T1-weighted MR imaging, Mn-TP showed a potential for delineating the jeopardized area after acute myocardial ischemia.     

Effect of fetal infraorbital nerve transection upon trigeminal primary afferent projections in the rat

Transganglionic tracing with a combination of horseradish peroxidase (HRP) and wheat germ agglutinin-conjugated HRP (WGA-HRP) was employed to compare the trigeminal (V) innervation of the brainstem in adult rats that sustained transection of the infraorbital nerve (ION) on either the day of birth or just prior to the beginning of the 17th embryonic day (E-17). The same methods were also employed to assess the effects of such lesions upon the innervation of the brainstem by the lingual, inferior alveolar, mylohyoid, and auriculotemporal V branches. Previous experiments (Chiaia et al.: Dev. Brain Res. 36:75-88, '87) showed that application of HRP and WGA-HRP to the ION in normal adult rats (N = 3) labelled 12,553 +/- 1,455 (mean +/- s.d.) V ganglion cells while application of these tracers to the regenerated ION after neonatal transection (N = 9) labelled 5,001 +/- 1,287 ganglion cells. Application of HRP and WGA-HRP to the regenerated ION in adulthood (N = 6) after fetal transection labelled 5,476 +/- 3,056 ganglion cells. Thus, the numbers of ganglion cells giving rise to the regenerated ION after fetal and neonatal transection were equivalent (P greater than .05). The central projections of the ION after fetal transection were qualitatively different from those observed after neonatal injury. After neonatal transection, the central terminal field of regenerated ION fibers in adulthood is almost completely restricted to layers I and II of subnucleus caudalis (SpC; Jacquin and Rhoades: Brain Res. 269:137-144, '83; Chiaia et al.: Dev. Brain Res. 36:75-88, '87). After fetal transection, regenerated ION axons terminate heavily in all portions of the V brainstem complex. After neonatal ION transection, we (Jacquin and Rhoades: J. Comp. Neurol. 235:129-143, '85) have been unable to detect central sprouting of undamaged V mandibular axons by means of transganglionic tracing with HRP and WGA-HRP. Such sprouting was evident in both V subnucleus interpolaris (SpI) and SpC after fetal ION transection. We carried out one additional experiment to determine whether ION ganglion cells that survived fetal axotomy were more resistant to axonal damage than the population of neurons that normally contribute to this nerve on the day of birth. Rats (N = 5) sustained transection of the ION on E-17 and again on the day of birth. The regenerated ION was then labelled with HRP and WGA-HRP when the animals reached adulthood.(ABSTRACT TRUNCATED AT 400 WORDS)