Multiple emulsion-based systems carrying insulin: development and characterization

An insulin delivery system based on liquid surfactant membranes has been developed. The formulation was based on a w/o/w emulsion where an organic membrane separated two aqueous phases and the internal aqueous phase contained insulin. Sesame and cotton seed oils were used as organic membranes. In order to facilitate the transportation of glucose across the organic membrane various additives such as calcium stearate, lecithin, cholesterol, hexamine, stearic acid and glyceryl tristearate were used. The additives were found to be successful carriers for the transportation of glucose to the internal aqueous phase. Similarly, viscosity enhancers, e.g. cetostearyl alcohol, in the organic phase enhanced the immobilization of insulin. Various parameters affecting the stability of the emulsions were established. The developed system was characterized for insulin activity and insulin efflux profile.     

Activation of the human estrogen receptor by estrogenic and antiestrogenic compounds in Saccharomyces cerevisiae: a positive selection system

OBJECTIVE: To develop a slow-release carboplatin formulation for intratumoral administration to cats. DESIGN: Preliminary study to analyze pharmacokinetic effects of purified sesame oil in the carboplatin formulation for intratumoral administration, and a second study to evaluate the efficacy and toxicosis of intratumoral administration of carboplatin in purified sesame oil. ANIMALS: 23 cats with squamous cell carcinomas of the nasal plane. PROCEDURE: Eight cats with advanced-stage tumors were submitted to intratumoral administration of 100 mg of carboplatin/m2 of body surface area, with or without purified sesame oil, using a two-period, cross-over design. Fifteen additional cats were treated by intratumoral administration of carboplatin in purified sesame oil. Four weekly intratumoral chemotherapy injections of carboplatin in purified sesame oil at a dosage of 1.5 mg/cm3 of tissue were given. RESULTS: Purified sesame oil in the formulation significantly reduced systemic exposure to carboplatin and drug leakage from the sites of injection. Cumulative effects of repeated intratumoral administrations on plasma concentrations of carboplatin were not observed. Systemic toxicosis was not observed, and local toxicosis was minimal. Healing of ulcerated lesions was not compromised. Rates of complete clinical tumor clearance and complete response were 67 and 73.3%, respectively. Product-limit estimates of mean progression-free survival times was 16 +/- 3.3 months. The 1-year progression-free survival rate was 55.1 +/- 13%. Local recurrence was observed in 7 cats; 4 had marginal tumor recurrence, and 3 had in-field and marginal tumor recurrence. CONCLUSIONS: Intratumoral carboplatin chemotherapy is safe and effective for cats with squamous cell carcinoma of the nasal plane. Future studies to improve treatment efficacy could include evaluation of increased dose-intensity as well as combination of this modality with radiotherapy. CLINICAL RELEVANCE: Intratumoral administration of carboplatin in a water-sesame-oil emulsion was found to be a practical and effective new treatment for facial squamous cell carcinomas in cats.     

Thermodynamic stability of immunoglobulins and allosteric interactions with ferritin and protein A: distinct properties of the two antibodies of IgG2a subclass

The two anti-ferritin monoclonal antibodies of mouse IgG2a subclass, G10 and F11, are described that have similar affinity to human spleen ferritin and identical protein A-binding affinity. Antigen binding was shown to change significantly the protein A-binding parameters of the IgG2a antibodies. Antigen-induced conformational changes result in enhanced protein A-binding affinity of the G10 antibody while reduced affinity of the F11 antibody. Antigen binding does not change inherently low affinity of the anti-ferritin IgG1 antibody C5 to protein A. Differential scanning calorimetry revealed that the enthalpy and Gibbs free energy of denaturation for G10 was respectively by 19 and 29% higher than the corresponding parameters for F11. The lower structural energetics of F11 is associated with the lack of a calorimetrically revealed folding unit that may be responsible for distinct interaction between the antigen-binding and protein A-binding sites. This work provides experimental demonstration of the fact that functionally significant interactions between the two spatially remote recognition sites in antibodies of the same heavy chain isotype can be modulated by relatively small structural variations that also result in different thermodynamic stability.     

Tumor necrosis factor-alpha, interleukin-6, and interleukin-8 secretion and the acute-phase response in patients with bacterial and tuberculous osteomyelitis

Osteomyelitis, or bone infection, is a major worldwide cause of morbidity. Treatment is frequently unsatisfactory, yet little is known about pathogenesis of infection. Plasma tumor necrosis factor (TNF), interleukin (IL)-6, and IL-8 concentrations were measured before and after lipopolysaccharide stimulation of whole blood from patients with bacterial and tuberculous osteomyelitis and from controls. Patients with bacterial and tuberculous osteomyelitis mounted an acute-phase response and were anemic and febrile. However, plasma IL-6 concentrations were significantly elevated in only tuberculous osteomyelitis patients (vs. controls, P < .05). IL-6 concentrations correlated with erythrocyte sedimentation rate, C-reactive protein level, and plasma albumin concentration, all acute-phase markers. There were no other correlations between cytokine concentrations and clinical data. Following ex vivo stimulation, TNF, IL-6, and IL-8 were secreted equally by patients and controls. In summary, tuberculous osteomyelitis is characterized by elevated systemic IL-6 concentrations associated with an acute-phase response. For further insight into immunopathology of osteomyelitis, studies on infected bone are required.     

Detection of sight-threatening diabetic eye disease

Blindness due to diabetes mellitus is potentially preventable in the majority of patient. Early detection of sight-threatening changes is associated with a better outcome, indicating the need to screen for retinopathy. At least 50% of diabetic patients do not attend a hospital, so that diabetologists and ophthalmologists are unable to screen the diabetic population comprehensively. Although in theory all patients has access to general practitioners, these may lack training or confidence to screen for retinopathy. Hospital based or community optometrists using direct ophthalmoscopy or slit lamps and technicians performing fundus photography are alternatives which may be more effective. Further studies are required to examine the effectiveness of optometry screening. Initial studies using fundus photography raised concerns about the sensitivity of the technique, but these have been partially addressed by improvements in methodology and technology. As well as technicological effectiveness, factors affecting patient uptake of screening services still need to be addressed.     

Interbacterial binding among strains of pathogenic and commensal oral bacterial species

OBJECTIVE: Family resources and coping skills are important to adaptation to pediatric chronic illness. Psychological and educational interventions have been found to enhance the coping skills of children with juvenile rheumatic disease (JRD) and their families. We examined the efficacy of a 3-day family retreat as a multidisciplinary, comprehensive treatment. METHODS: Children with JRD and their caregivers completed questionnaires assessing the children's behavioral and emotional functioning, pain, strain on caregivers' work and leisure activities, and caregivers' psychological distress before and 6 months after the family retreat. Principal caregivers were both parents for 16 children, mothers only for 10 children, and an aunt for 1 child. RESULTS: Improvements were found in children's emotional functioning, strain on caregivers' work, and strain on caregivers' leisure activities. Reductions in reported pain were not consistently revealed. CONCLUSIONS: Family retreats are an efficacious, multidisciplinary approach to helping families of children with JRD cope with the disease and its manifestations. Importantly, retreats offer a comprehensive intervention package that might not be available to families on an individual basis.     

Localization and characterization of the human ADP-ribosylation factor 5 (ARF5) gene

ADP-ribosylation factor 5 (ARF5) is a member of the ARF gene family. The ARF proteins stimulate the in vitro ADP-ribosyltransferase activity of cholera toxin and appear to play a role in vesicular trafficking in vivo. We have mapped ARF5, one of the six known mammalian ARF genes, to a well-defined yeast artificial chromosome contig on human chromosome 7q31.3. In addition, we have isolated and sequenced an approximately 3.2-kb genomic segment that contains the entire ARF5 coding region, revealing the complete intron-exon structure of the gene. With six coding exons and five introns, the genomic structure of ARF5 is unique among the mammalian ARF genes and provides insight about the evolutionary history of this ancient gene family.