Topical testosterone treatment for chronic allograft failure in liver transplant recipients with recurrent hepatitis C virus

INTRODUCTION: Liver transplant recipients with allograft failure due to recurrent hepatitis C virus (HCV) infection often develop marked muscle wasting and ascites prior to death and are denied repeat liver transplantation. We sought to determine whether topical testosterone therapy is associated with improved muscle mass and survival in patients with chronic allograft failure post-liver transplant. METHODS: We performed a retrospective review of liver transplant recipients with chronic allograft failure. Group 1 patients were treated for >6 months with testosterone gel 1%; group 2 patients were untreated. RESULTS: Fourteen patients were identified with stage 3 or 4 fibrosis, muscle wasting, and allograft failure due to recurrent HCV. Group 1 (n=9) patients had statistically significant improvement in albumin, testosterone, muscle strength, well-being, and MELD/CTP scores, while there was no improvement seen for any of these parameters in group 2 (n=5). There were no deaths in group 1, while four of five patients in group 2 died on average 84 days posttransplant. Adverse effects of testosterone treatment included lower extremity edema (which resolved upon dose adjustment), hypertension, and pruritus. CONCLUSIONS: Topical testosterone gel appears to increase muscle strength, stimulate albumin synthesis, and improve survival in patients with allograft failure post-liver transplant.     

Airway intervention in adult supraglottitis

Background The timing of aggressive airway intervention in adult epiglottitis is controversial. Aims To correlate Friedman’s staging of epiglottitis on admission with the airway interventions undertaken. Methods A retrospective study of 23 adult patients, mean age 51 years (range 29–81 years), who had been admitted with acute supraglottitis between March 1988 and December 2000 was undertaken. Results Three patients (13%) had airway interventions; two with tracheostomy and one with tracheal intubation. All were Friedman stage III and had rapid symptom progression during the 24 hours prior to admission. Three other stage III patients with symptom progression longer than 24 hours and all the remaining patients (stage II or less) were managed with observation and intravenous therapy. Conclusions Friedman originally advocated airway intervention in any patient stage II or worse, but this intubation threshold should probably be lowered to those patients with rapid-onset stage III (moderate respiratory distress, stridor, respiratory rate >30 per minute, pCO₂ >45mmHg) disease.     

Effects of race, ethnicity, gender, culture, literacy, and social marketing on public health

Societies globally have a long road ahead in eliminating health risks and discrepancies due to race and ethnicity, gender, culture, and illiteracy. In terms of race, for example, females and African-Americans are less likely to be referred for cardiac catheterization, and Caucasians are more likely than minorities to receive pain management in the emergency room. Regarding gender, physiologic differences certainly account for some divergent health outcomes, but they do not explain how women and men have different prevalences of diseases that are not obviously gender-specific. Cultural beliefs play a vital role in determining health choices, and health care professionals need a deeper understanding of these beliefs prior to promoting certain health interventions. Illiteracy may also prevent a person from following health instructions, and the strong association between illiteracy and poverty may exert powerful, negative influences on health outcomes. Employing the characteristics of social marketing (synchronous messages, reinforcement, and actionability) may help society to overcome some of the obstacles.     

Identification of multiple sources of charge heterogeneity in a recombinant antibody

Seven forms of a therapeutic recombinant antibody that binds to the her2/neu gene product were resolved by cation-exchange chromatography. Structural differences were assigned by peptide mapping and HIC after papain digestion. Deamidation of light chain asparagine 30 to aspartate in one or both light chains is responsible for two acidic forms. A low potency form is due to isomerization of heavy chain aspartate 102; the Asp102 succinimide is also present in a basic peak fraction. Forms with both Asn30 deamidation and Asp102 isomerization modifications were isolated. Deamidation of heavy chain Asn55 to isoaspartate was also detected. Isoelectric focusing in a polyacrylamide gel was used to verify the assignments. All modifications were found in complementarity determining regions.     

Effect of Moisture on the Stability of a Lyophilized Humanized Monoclonal Antibody Formulation

Purpose. To determine the effect of moisture and the role of the glass transition temperature (T_g) on the stability of a high concentration, lyophilized, monoclonal antibody. Methods. A humanized monoclonal antibody was lyophilized in a sucrose/histidine/polysorbate 20 formulation. Residual moistures were from 1 to 8%. T_g values were measured by modulated DSC. Vials were stored at temperatures from 5 to 50°C for 6 or 12 months. Aggregation was monitored by size exclusion chromatography and Asp isomerization by hydrophobic interaction chromatography. Changes in secondary structure were monitored by Fourier transform infrared (FTIR). Results. T_g values varied from 80°C at 1% moisture to 25°C at 8% moisture. There was no cake collapse and were no differences in the secondary structure by FTIR. All formulations were stable at 5°C. High moisture cakes had higher aggregation rates than drier samples if stored above their T_g values. Intermediate moisture vials were more stable to aggregation than dry vials. High moisture samples had increased rates of Asp isomerization at elevated temperatures both above and below their T_g values. Chemical and physical degradation pathways followed Arrhenius kinetics during storage in the glassy state. Only Asp isomerization followed the Arrhenius model above the T_g value. Both chemical and physical stability at T T_g were fitted to Williams-Landel-Ferry (WLF) kinetics. The WLF constants were dependent on the nature of the degradation system and were not characteristic of the solid system. Conclusion. High moisture levels decreased chemical stability of the formulation regardless of whether the protein was in a glassy or rubbery state. In contrast, physical stability was not compromised, and may even be enhanced, by increasing residual moisture if storage is below the T_g value.     

The Effect of Formulation Excipients on Protein Stability and Aerosol Performance of Spray-Dried Powders of a Recombinant Humanized Anti-IgE Monoclonal Antibody1

Purpose. To study the effect of trehalose, lactose, and mannitol on the biochemical stability and aerosol performance of spray-dried powders of an anti-IgE humanized monoclonal antibody. Methods. Protein aggregation of spray-dried powders stored at various temperature and relative humidity conditions was assayed by size exclusion chromatography and sodium dodecyl sulfate polyacrylamide gel electrophoresis. Protein glycation was determined by isoelectric focusing and affinity chromatography. Crystallization was examined by X-ray powder diffraction. Aerosol performance was assessed as the fine particle fraction (FPF) of the powders blended with coarse carrier lactose, and was determined using a multiple stage liquid impinger. Results. Soluble protein aggregation consisting of non-covalent and disulfide-linked covalent dimers and trimers occurred during storage. Aggregate was minimized by formulation with trehalose at or above a molar ratio in the range of 300:1 to 500:1 (excipient:protein). However, the powders were excessively cohesive and unsuitable for aerosol administration. Lactose had a similar stabilizing effect, and the powders exhibited acceptable aerosol performance, but protein glycation was observed during storage. The addition of mannitol also reduced aggregation, while maintaining the FPF, but only up to a molar ratio of 200:1. Further increased mannitol resulted in crystallization, which had a detrimental effect on protein stability and aerosol performance. Conclusions. Protein stability was improved by formulation with carbohydrate. However, a balance must be achieved between the addition of enough stabilizer to improve protein biochemical stability without compromising blended powder aerosol performance.     

The agonist SR 146131 and the antagonist SR 27897 occupy different sites on the human CCK(1) receptor

1-[2-(4-(2-Chlorophenyl)thiazol-2-yl) aminocarbonyl indoyl] acetic acid (SR 27897) is an effective CCK₁ receptor antagonist, while the structurally related molecule 2-[4-(4-chloro-2,5-dimethoxyphenyl)-5-(2-cyclohexyl-ethyl)-thiazol-2-ylcarbamoyl]-5,7-dimethyl-indol-1-yl-1-acetic acid (SR 146131) is a highly potent and specific agonist for the same receptor. To discover how the two molecules interact with the human cholecystokinin (CCK) CCK₁ receptor, we have carried out binding and activity studies with 33-point mutated receptors. Only six mutants showed altered [³H]SR 27897 binding properties, Lys¹¹⁵, Lys¹⁸⁷, Phe¹⁹⁸, Trp²⁰⁹, Leu²¹⁴ and Asn³³³. In contrast, numerous mutations throughout the receptor either reduced SR 146131 agonist potency, Phe⁹⁷, Gly¹²², Phe¹⁹⁸, Trp²⁰⁹, Ile²²⁹, Asn³³³, Arg³³⁶ and Leu³⁵⁶ or increased it, Tyr⁴⁸, Cys⁹⁴, Asn⁹⁸, Leu²¹⁷ and Ser³⁵⁹. Only mutations of Phe¹⁹⁸, Trp²⁰⁹ and Asn³³³ affected both SR 27897 and SR 146131 binding or activity. The collated information was used to construct molecular models of SR 27897 and SR 146131 bound to the human CCK₁ receptor. The clear difference in the binding sites of SR 27897 and SR 146131 offers a molecular explanation for their contrasting pharmacological characteristics.     

Detection of carbamyl phosphate synthetase 1 deficiency using duodenal biopsy samples

The activity of urea cycle enzymes was assayed in duodenal biopsy specimens obtained from a female infant who presented with neonatal hyperammonaemia. All enzyme levels were normal except N-acetyl glutamate-dependent carbamyl phosphate synthetase 1 (CPS1) which was half the mean activity in normal control specimens. A similar deficiency of CPS1 was also shown in duodenal specimens from the patient's mother who became slightly symptomatic after relatively high protein meals and during pregnancy, and had spontaneously modified her diet to one with protein restriction. The patient is growing normally on a dietary regimen similar to that spontaneously adopted by her mother. Urea cycle enzyme activity in the duodenal biopsy material from the controls was similar to that found in the normal human liver and appears to have distinct advantages as a means of assaying for urea cycle defects in patients with hyperammonaemia and their relatives.     

Controlled trial of continuous inflating pressure for hyaline membrane disease

A controlled trial of elective intervention with continuous inflating pressure (CIP) was performed in infants with severe hyaline membrane disease who weighed more than 1000 g at birth. Infants entered the trial if their arterial oxygen tension (PaO2) fell below 60 mmHg while breathing a fractional inspired oxygen concentration (F1O2) greater than 0-95. 11 out of 12 infants in the CIP-treated group and 10 out of 12 in the control group survived. 7 treated and 6 control infants required mechanical ventilation. When CIP was started the Pao2 of the treated infants increased, and they breathed high concentrations of oxygen for a significantly shorter period than the control infants. During the 31-month duration of the trial 107 other infants with severe hyaline membrane disease were admitted who did not meet the criteria for entry to the trial. 37 survived after breathing high concentrations of oxygen (F1O2 greater than 0-60) spontaneously without any ventilatory assistance, and the remaining 70 infants were already being ventilated on their arrival in the unit, usually because they had required mechanical ventilation during transfer from other hospitals. The neonatal survival rate for those infants born in this hospital during the study period was 88% (50 out of 57 infants) and for those referred from other hospitals it was 69% (51 out of 74 infants). The maximum further increase in overall survival rate that might have been achieved in our population of infants if CIP had been initiated very early in the course of the illness was 5%--i.e. from 77% (101/131) to 82% (107/131).