Effect of exogenous surfactant on total respiratory system compliance

We measured total respiratory system compliance (Crs) before and after instilling 25 mg artificial surfactant in 1 ml saline down the endotracheal tube of preterm babies requiring resuscitation at birth, and compared results with data from 6 similar babies receiving saline only. Surfactant did not produce a significant improvement in Crs.     

Apoptosis inhibitor as a suppressor of tumor progression: expression of Bcl-2 eliminates selective advantages for p53-deficient cells in the tumor

Inactivation of p53 and expression of Bcl-2, frequently occurring during tumor progression, have different prognostic value: while inactivation of p53 is generally associated with unfavorable prognosis, expression of Bcl-2 often correlates with better clinical outcome and delays selection of metastatic variants of experimental tumors. To analyze the mechanisms underlying the "anti-progression" function of Bcl-2, we engineered tumor cell variants differing in their p53 status and Bcl-2 expression and compared their expansion in experimental tumors. Although neither p53 suppression nor Bcl-2-expression altered cell growth properties in vitro, both variants showed rapid accumulation in growing tumors in vivo, presumably due to their resistance to hypoxia. However, no expansion of p53-deficient variants occurred in the tumors formed by Bcl-2-overexpressing cells, indicating that p53 deficiency has no selective advantages in the Bcl-2-expressing environment. Importantly, expression of Bcl-2, unlike p53 suppression, did not lead to genomic instability as judged by the frequencies of gene amplification. Thus, acquisition of Bcl-2 expression is as advantageous for tumor cell growth in vivo as is p53 inactivation but does not affect genomic stability and creates the environment restrictive for the expansion of genetically unstable and potentially malignant p53-deficient cells, causing a delay in tumor progression and explaining the different prognostic value of Bcl-2 and p53.     

Noonan's and DiGeorge syndromes with monosomy 22q11

A boy with the dysmorphic features of Noonan's syndrome and pulmonary valve stenosis who had evidence of hypoparathyroidism and abnormal T lymphocyte numbers in the neonatal period is reported. He had a normal karyotype but molecular analysis revealed a submicroscopic deletion within chromosome 22q11, the region deleted in DiGeorge syndrome. Thus this child has both Noonan's syndrome and DiGeorge syndrome; 22q11 is a candidate region for a gene defective in Noonan's syndrome.     

Clinical usefulness of botulinum toxin in the lower extremity

As the literature that pertains to botulinum toxin expands, the scope of treatment options broadens. Although initial uses of botulinum toxin focused around the head and neck, there are many uses for the toxin in the area of the foot and ankle; more possibilities are under investigation every day. We review the uses and techniques for botulinum toxin in the foot and ankle and present results of botulinum toxin treatment in 10 idiopathic toe walkers.     

The acute effect of peripheral nerve transection on digital thermoregulatory function

PURPOSE: This study tests the hypothesis that major peripheral nerves serve as important routes for adrenergic neural fibers and therefore peripheral nerve injury affects cutaneous perfusion within the nerve's sensory innervation territory. The specific aim of the study was to determine whether an acute isolated peripheral nerve injury would result in alteration of blood flow to a specific digit, digital pain, and/or cold sensitivity. METHODS: The influence of peripheral nerves on their dominant area of autonomic vasomotor function was evaluated in 9 patients who had primary neurorrhaphy after a single complete median or ulnar nerve transection. At a mean follow-up of 47 days the response of digital perfusion to a cold stress was examined in these patients by using isolated cold stress testing and laser Doppler fluxmetry. Patients also completed subjective questionnaires to evaluate their symptoms. RESULTS: The affected hands showed a decreased cutaneous perfusion when compared with the contralateral hands during all 3 phases of the cold stress test. In addition cutaneous perfusion patterns evaluated by laser Doppler perfusion imaging showed markedly decreased cutaneous perfusion patterns in the digits within the innervation territory of the injured nerve. There was no notable difference in digital baseline temperatures and temperature changes after an isolated cold stress test between the most affected digits of the injured hands and corresponding digits of the unaffected, contralateral hands. All 9 patients reported mild to severe digital numbness, 8 reported mild to severe pain, and 4 reported mild to moderate cold sensitivity of the upper extremity. CONCLUSIONS: This study documents that cutaneous perfusion and thermoregulatory function is altered after isolated peripheral nerve injury.     

Prolonged Receptor Blockade by Opioid Receptor Probes

Opioid receptor interactions of morphinan-type opioids derivatized at the C-6 carbon were investigated. The compounds, designed as probes for studying opioid receptors, were characterized with regard to affinity for the rat brain mu receptor by competition with tritium-labeled dihydromorphine (³H-DHM). All compounds were also screened for prolonged receptor blockade by preincubation of rat brain membranes with the compounds alone, followed by extensive washing, and incubation with ³H-DHM. The apparent dissociation profiles of congeners with prolonged blockade were further studied in the presence and absence of physiological concentrations of salts. Under conditions that completely dissociate the parent opioids, naltrexone, naloxone, and oxymorphone, the derivative l-(N-fluoresceinyl naltrexone thiosemicarbazone (6-FNX) and the opioid-steroid hybrids naloxone estrone azine (N-EH) and androstene bisoxymorphone azine (O-AD-O) showed more persistent receptor blockade than the bivalent opioid naloxonazine (NAz). Neither chemical reactivity nor a bivalent opioid structure was found to be a prerequisite for prolonged receptor blockade.     

The effect of botulinum toxin type A injections on the natural history of equinus foot deformity in paediatric cerebral palsy patients

Neuromuscular blockade with botulinum toxin type A (BTX-A) injections was employed to manage equinus foot deformity in the lower extremities of paediatric cerebral palsy patients. The patients were followed to evaluate the effect of the blockade on lower extremity function and to determine the effect of treatment on the need for tendo-Achilles lengthening (TAL) surgery. The average length of follow-up was 3.4 years. Of the 48 patients, 17 (35%) responded to treatment witbin 6 months of initiation of therapy, as determined by a Physician Rating Scale of gait. Overall, 25 (52%) of the 48 patients underwent TAL surgery during the follow-up period, including eight patients who responded to the BTX-A treatment. The average age of the patients at the time of surgery was 7 years. This age compares favourably with the age at surgery reported in the recent literature. There were no significant differences by responder status, age, or gender in those patients who did and did not require TAL surgery. No adverse events relating to BTX-A were reported. These results indicate that patients who respond to BTX-A treatment have improved physical functioning and gait, and are able to sustain these results long term.