Dendrosome-based delivery of siRNA against E6 and E7 oncogenes in cervical cancer

Although small interfering RNA (siRNA) treatment holds great promise for the treatment of cancers, the field has been held back by the availability of suitable delivery vehicles. For cervical cancer the E6 and E7 oncogenes are ideal siRNA targets for treatment. The purpose of the present study was to explore the potential of dendrosomes for the delivery of siRNA targeting E6 and E7 proteins of cervical cancer cells in vitro. Optimization of dendrimer generation and nitrogen-to-phosphate (N/P) ratio was carried out using dendrimer–fluorescein isothiocyanate oligo complexes. The optimized N/P ratios were used in formulating complexes between dendrimers and siRNA targeting green fluorescence protein (siGFP). Although formulation 4D100 (dendrimer-siRNA complex) displayed the highest GFP knockdown, it was also found to be highly toxic to cells. In the final formulation 4D100 was encapsulated into dendrosomes so as to mask these toxic effects. The optimized dendrosomal formulation (DF), DF3 was found to possess a siGFP-entrapment efficiency of 49.76% ± 1.62%, vesicle size of 154 ± 1.73 nm, and zeta potential of +3.21 ± 0.07 mV. The GFP knockdown efficiency of DF3 (dendrosome) was found to be almost identical to that of 4D100, but the former was completely nontoxic to the cells. DF3 containing siRNA against E6 and E7 was found to knock down the target genes considerably, as compared with the other formulations tested. Our results imply that dendrosomes hold potential for the delivery of siRNA and that a suitable targeting strategy could be useful for applications in vivo.From the Clinical EditorsiRNA treatment holds great promise for the treatment of cancers, but overall, the availability of suitable delivery vehicles remains a major issue. The purpose of this study was to explore the potential of dendrosomes for the delivery of siRNA targeting specific proteins in cervical cancer cells in vitro. The results suggest that dendrosomes hold potential for the delivery of siRNA and a suitable targeting strategy could be useful for applications in vivo.     

An External Aortic Root Device for Decreasing Aortic Regurgitation: In Vitro and In Vivo Animal Studies

Objectives: The purpose of this study was to determine if a device placed externally around the aortic root decreases regurgitant flow in acute aortic regurgitation. Background: Aortic regurgitant flow is dependent on central aortic pressure and the aortic root and leaflet geometry. It may be possible to decrease aortic regurgitant severity by reducing aortic root size or dimension changes. Methods: Aortic regurgitation was created in eight calf heart specimens suspended in a continuous flow system. Retrograde and antegrade aortic flow and distending aortic pressure were measured at baseline and after placement of an external aortic device at the level of the aortic annulus. In two additional specimens, the incompetent aortic valve was visualized fiberoptically before and after placement of the external device. Acute aortic regurgitation was created surgically in four live calves by excising a portion of the aortic leaflets. Antegrade and retrograde flow, left ventricular pressure, and central aortic pressure were measured at baseline, after creation of aortic regurgitation, and after placement of the external device. Results: In the in vitro calf specimens, regurgitant flow decreased from 46.9 cc/sec to 15.1 cc/sec (66.0%± 21.8% decrease) after placement of the external device (p < 0.001). The regurgitant orifice area decreased from 0.13 ± 0.04 cm² to 0.04 ± 0.02 cm² after device placement (p < 0.001). Antegrade flow was reduced to a smaller extent (20.0%± 19.2% decrease) by the device (p < 0.05). Placement of the device around the aorta resulted in improved coaptation of the leaflets with a marked reduction in defect size by endoscopic visualization. Use of the external aortic device was associated with improvement in aortic regurgitant severity in three of four calves with surgically created aortic regurgitation. Concluslons: In these preliminary studies, acute experimental aortic regurgitant severity is decreased by the use of an external aortic device, probably due to reduction in aortic annular dimension changes and improved aortic leaflet apposition. Further studies are needed to determine the effectiveness of this device in chronic aortic regurgitation. (J Card Surg 1994;9:304–313)     

A new syndrome with features of the Smith-Lemli-Opitz and Meckel-Gruber syndromes in a sibship with cerebellar defects

The Smith-Lemli-Opitz syndrome (SLOS) and the Meckel syndrome (MS) have been regarded as separate autosomal recessive entities. Recently, overlap of these two syndromes has been discussed. A sibship containing a probable new syndrome with features reminiscent of the SLOS and the MS is presented. The literature is reviewed with regard to the frequency of various malformations in these syndromes. Clinical manifestations and cerebellar abnormalities in these sibs are similar to those described in the Joubert syndrome (JS). These three cases may represent a new syndrome with features in common with SLOS, MS, and JS resulting from the same mutant gene, which exhibits considerable pleiotropy.     

Community service utilization by youths hospitalized in a state psychiatric facility

A majority of a cohort of 62 children and adolescents who had been hospitalized in a state psychiatric facility was found to have received less restrictive services such as outpatient mental health services prior to their index admission. Also, a number had been involved with the juvenile justice system and almost two-thirds had been placed out-of-home. Ninety percent had at least one prior psychiatric hospitalization. Just over half of the cohort received case management and individual counseling post release. About a third received family counseling, and a few received other types of services. At least a third were rehospitalized within a year of release. Although 90% of the cohort received some type of service post release, a higher proportion of non service receivers were rehospitalized than service receivers. Even those who received services had a high rate of rehospitalization. These findings raise questions as to the appropriateness of service provision during and following hospitalization.This study was funded by a grant from the Office of Program Evaluation and Research, Ohio Department of Mental Health.     

Evaluation and Treatment of Children with Primary Immune Deficiency in the Emergency Department

The potential for morbidity and mortality in patients who have PID with febrile and nonfebrile illness is extremely high. Familiarity with the clinical manifestations of PID and collaboration with a pediatric immunologist are prerequisites for optimal short-term care of these complex patients. Conservative management with empiric broad-spectrum antimicrobials, early and aggressive surgical debridement of abscesses, and admission at a tertiary pediatric care center are often indicated.     

Effects of MK-801 and Phenytoin on Flurothyl-Induced Seizures During Development

Summary We determined the effects of the N-methyl-Daspartate (NMDA) receptor blocker MK-801 (0.05, 0.1, and 0.5 mg/kg intraperitoneally, i.p.) and phenytoin (PHT, 5, 10, and 20 mg/kg i.p.) on flurothyl-induced clonic and tonic-clonic seizures in 9-, 1 5, 30-, and 60-day-old male rats. Both agents had seizure-, age-, and dose-specific effects. The highest dose of MK-801 was anticonvulsant against clonic flurothyl-induced seizures only in 9- and 60-day-old rats, but suppressed tonic-clonic seizures in all ages. The lowest dose of MK-801 (0.05 mg/kg) produced significant anticonvulsant effects only in 15 day old rats. PHT did not have any effect on clonic seizures throughout development. Both doses of PHT (10 and 20 mg/kg) were anticonvulsant against tonic-clonic seizures in adult rats but not in any other age group. The results indicate that NMDA receptors play an important role in tonic-clonic flurothyl-induced seizures throughout development (especially in 15-day-old rats) and that the anticonvulsant effects of PHT may vary at different stages of brain development.     

Positive and negative symptoms covary during clozapine treatment in schizophrenia

Although negative symptoms were traditionally considered to be unresponsive to neuroleptic medication, recent studies have demonstrated that negative symptoms do improve during neuroleptic treatment and that such improvement tends to occur concurrently with improvement in positive symptoms. Clozapine is an atypical neuroleptic that is effective in a significant proportion of otherwise neuroleptic-nonresponsive schizophrenic patients; in contrast to conventional neuroleptics, clozapine is also purported to possess unique efficacy in the amelioration of negative symptoms. How clozapine-associated reduction in negative symptoms relates to change in positive symptoms is not clear. To study the relationship between change in positive and negative symptoms during clozapine treatment, we monitored symptomatology in 40 DSM-III-R schizophrenic patients before and about 8 weeks after a trial of clozapine. Both positive and negative symptoms improved significantly. There was a significant correlation (r = .63,p <.01) between change in positive symptoms and change in negative symptoms; as with conventional neuroleptics, negative symptoms improved concomitantly with positive symptoms during clozapine treatment. Clozapine's apparent greater efficacy on negative symptoms may be related to its greater efficacy on positive symptoms in otherwise neuroleptic-refractory patients and its lesser propensity to cause extrapyramidal side-effects.     

Age-Specific Effects of Baclofen on Pentylenetetrazol-Induced Seizures in Developing Rats

Summary: Purpose : To determine whether seizures have age-specific features, we studied the role of γ-aminobutyric acid, (GABAB) transmission in rats of various ages (9, 15, 30, and 60 postnatal days). Methods: We used a GABA, receptor agonist baclofen (2 or 5 mg/kg intraperitoneally, i.p.) and a GABA_B receptor antagonist CGP 35348 (100 or 600 mg/kg i.p.) in the pentylenetetrazol (PTZ)-induced model of clonic and tonic-clonic seizures (100 mg/kg subcutaneously, s.c.).
Results : Whereas baclofen was anticonvulsant and CGP 35348 proconvulsant in most animals, there were distinct age-related differences in the effectiveness of these drugs and the antagonist had some anticonvulsant activity in adults. Furthermore, the two drugs acting at GABA_B receptors had a different profile of action in clonic seizures as compared with tonic-clonic seizures.
Conclusions : The differences in the age-specific action of the GABA_B agonist and antagonist suggest that different GABA_B receptor subsets may mediate the drug effects. The results indicate that putative antiepileptic drugs (AEDs) must be tested during development because it may not be possible to extrapolate age-specific anticonvulsant effects from studies in adult animals.