Purine agonists prevent trophic changes caused by sympathetic denervation

Surgical denervation of the lateral saphenous vein of the dog causes marked extraneuronal changes, both of a morphological and functional type. In an attempt to investigate the factor(s) responsible for the trophic effects exerted by the sympathetic innervation on the dog saphenous vein we studied the effects of noradrenaline, adenosine, inosine and N-ethylcarboxamidoadenosine (NECA) on vascular tissue after sympathetic denervation. The saphenous vein was denervated using either surgical or chemical (6-hydroxydopamine, 6-OHDA) methods. Noradrenaline (0.1 microgram/kg per h), adenosine (10 micrograms/kg per h), inosine (10 micrograms/kg per h) or NECA (0.1 microgram/kg per h) were delivered continuously for 5 days through Alzet minipumps connected to the vein. 6-OHDA-induced denervation resulted in morphological changes similar to those described for surgical denervation. Smooth muscle cells and fibroblasts showed ultrastructural signs of increased synthetic activity and their size was significantly increased. In confirmation of earlier studies, constant i.v. infusions of noradrenaline did not prevent the morphological changes induced by denervation. Adenosine prevented the morphological changes induced by chemical or surgical denervation. Similarly to adenosine, infused NECA prevented the structural consequences of denervation. In contrast, inosine did not prevent the changes caused by surgical denervation. The results are compatible with an involvement of purines in the trophic effects of sympathetic innervation. Moreover, the effects of adenosine do not appear to be mediated by inosine.     

IRBP: preparation and characterization of site-specific monoclonal antibodies.

Interstitial retinoid binding protein (IRBP) is a 136,000 molecular weight photoreceptor cell protein which is a highly pathogenic autoantigen for the induction of experimental autoimmune uveitis (EAU). In this study we produced a series of monoclonal antibodies (MAbs) which define different epitopes in the native molecule. These MAbs were further subdivided into three distinct groups based on a radioimmunoassay, and by ELISA assay using native IRBP and synthetic peptides corresponding to its entire amino acid sequence. Group I MAbs (MAbD7-B1 and MAbC6-B4) bound to native IRBP but not to any synthetic peptides, suggesting that their antigenic epitopes are strictly conformation dependent. Group II MAbs (MAbC7-D3 and MAbG8-H4) bound weakly to multiple peptides which shared amino acid sequence similarity located within each of four homology domains indicating that these epitopes are also conformation dependent. In group III (MAbH3-B5, MAbH7-A5, and MAbB6-D12) MAb binding was localized to a specific peptide. The MAbH3-B5 binding site was further refined to amino acid positions 361 to 367 in the native molecule. MAbH3-B5 was also useful in localizing IRBP in the mouse retina by immunohistochemical techniques. The application of these MAbs in the study of EAU and interphotoreceptor transport mechanisms is discussed.     

Treatment of muscle spasticity in patients with cerebral palsy using BTX-A: a pilot study

This study was designed to verify the safety and efficacy of botulinum toxin type A (BTX-A) used as a neuromuscular block on spastic masticatory musculature of children with cerebral palsy. Six patients who had spastic-tetraplegic cerebral-palsy, aged 5 to 20 years were selected. All patients had spasticity of the jaw muscles, bruxism, lower lip trauma, limited mouth opening, and difficulties in cleaning the oral cavity. The patients were sedated under general anesthesia, while the dentist injected the masseter and temporalis muscles bilaterally with 150 and 75 units of BTX-A each. Clinical examinations were conducted at 7, 14, 30, and 90 days after the initial appointment. We found statistically significant decreases in muscle spasticity and bruxism ( p = 0.002), improved inter-incisal opening ( p = 0.002), improved oral hygiene ( p = 0.031), and less lower lip trauma ( p = 0.060) after the neuromuscular blocking.     

Retinoblastoma. A clinical, immunohistochemical, and electron microscopic case report

A 4-year, 9-month-old boy had a history of leukocoria of the right eye for approximately six months prior to admission. The other eye was normal. There was no family history of retinoblastoma. Funduscopy disclosed a large white mass extending from the nasal pars plana to the mid-pupillary zone and the posterior pole with a near total retinal detachment in the superior temporal quadrant. A B-scan ultrasound showed an echo dense area of the anterior portion of the mass. A CT scan showed intraocular tissue densities with no evidence of optic nerve involvement or extraocular extension. Immunohistochemistry of a fresh frozen portion of tumor revealed reactivity with antibodies directed against interphotoreceptor retinoid-binding-protein (IRBP), neuron-specific enolase, glial fibrillary acidic protein, S-antigen, focal reactivity with opsin, and scattered cytoplasmic staining for cyclic GMP and cyclic GMP phosphodiesterase. Biochemical analysis of fresh frozen tissue samples confirmed the presence of IRBP. Transmission electron microscopy disclosed occasional Flexner-Wintersteiner rosettes connected by zonula adherens-like junctions. These showed inner segment-like structures containing prominent mitochondria, portions of cilia and fragments of outer segment material. These data, along with the immunocytochemistry indicates a predominant neuronal nature of the tumor cells with significant photoreceptor-like differentiation.     

Variability in cardiovascular and plasma norepinephrine responses to head-up tilt in healthy human subjects.

Eight healthy, young adult males underwent three separate, 10-min 70 degrees head-up tilts (HUT) over a period of nine days, in order to assess the intra- and inter-individual variability of cardiovascular and plasma norepinephrine (NE) responses to the manoeuvre. Cardiovascular parameters and plasma NE were measured in the basal state and at 2-min intervals during the HUT. The results indicate that: (1) the intra-individual variability is a smaller component of the total variability of both cardiovascular and plasma NE responses to HUT; (2) the variability in cardiovascular parameters is smaller than that in plasma NE levels, both basal and in response to postural stress; (3) there does not appear to be any difference in variability when expressed either as the maximal or the mean response to HUT; and (4) there does not appear to be an increase in the variability of the measured parameters over the duration of the HUT.     

Deep-freezing versus 4 degrees preservation of avascular osteocartilaginous shell allografts in rats

Osteocartilaginous allografts (distal femurs of rats) were stored at 4 degrees for six, 12, 24, and 48 hours and at -80 degrees for five days and then evaluated for viability of the bone and cartilage. Storage at 4 degrees for 12 or 24 hours had little effect on cartilage viability but decreased bone viability to 40% and 10% of controls, respectively. Storage at -80 degrees for five days resulted in nonviable bone in all cases but showed an either/or response of cartilage, with high viability in two cases and nonviability in the other eight cases. In a second set of experiments, femurs from rats were stored in situ at 4 degrees for 12 or 24 hours or were harvested and stored at -80 degrees for five days, after which they were transplanted into rats of a different strain. The antibody response to each set of femurs was measured at two, six, and 12 weeks after operation. The 4 degrees storage resulted in a moderately decreased immunogenicity, whereas the storage at -80 degrees resulted in significantly reduced immunogenicity.     

Clinico-microbiological study of dermatophytoses.

In the present series, 80 cases of dermatophytoses were subjected to mycological examination including microscopy and culture the mycological findings were correlated with clinical presentation of the patients. The isolation rate was 62.5 percent. Fungal culture was successful in 36.25 percent of cases, Trichophyton rubrum being the commonest etiological agent accounting for 55.18 percent of cases.     

Ictal chronology and interictal spikes predict perfusion patterns in temporal lobe epilepsy: a multivariate study.

Typical (TPP) and atypical (APP) perfusion patterns (PP) may be seen in ictal SPECT of patients with temporal lobe epilepsy (TLE). APP may pose problem in the lateralization of the epileptogenic zone (EZ). We aimed to investigate predictive variables for the occurrence of TPP and APP. Fifty-one TLE patients were submitted to successful anterior-mesial temporal lobectomy. Univariate (UVA) and multivariate (MVA) analysis were performed upon clinical data, distribution of interictal spikes, and ictal chronology of seizures. From MVA, a final predictive model (FPM) was determined to better predict TPP and APP. Forty patients showed TPP (78.5%) and 11 patients APP (21.5%). Accuracy of ictal SPECT was higher in the unilateral (UIS) than in the bilateral (BIS) interictal spikes group (P = 0.05). FPM showed that patients exhibiting BIS, with shorter proportion of the electrographic seizure occurring after completion of tracer injection, and longer clinical than EEG seizure duration had more APP (P = 0.003). Generalized tonic-clonic seizures did not result in more APP. We concluded that analysis of ictal SPECT in TLE requires the knowledge of TPP and APP, the distribution of interictal spikes on temporal lobes and the ictal chronology of seizures. BIS showed that beyond a more complex epileptogenicity and seizure propagation, they may also lead to APP.     

Extended pericranial flap and bone graft reconstruction in anterior skull base surgery.

OBJECTIVES: The objectives of this study was to establish a rationale for repairing large anterior skull base defects with an extended pericranial flap and split calvarial bone graft; to define large anterior skull base defects as those spanning the anterior cranial measuring at least 3.0 x 4.0 cm; and to describe the surgical technique and compare it with alternative strategies.Study design Thirty-four patients underwent anterior craniofacial resection of anterior skull-based tumors of varying histology with reconstruction using an extended pericranial flap and split calvarial bone graft. RESULTS: The survival of the pericranial flap and bone graft was maintained in 33 of 34 patients. There was 1 episode of postoperative cerebrospinal fluid leak, 1 episode of osteomyelitis of the bone graft and an epidural abscess, and 1 episode of asymptomatic pneumocephalus. CONCLUSION: Split calvarial bone graft with an extended pericranial flap is an effective technique for reconstructing large anterior skull base defects.