Assessment end points for inhaled drug delivery

There is no "best" outcome or "gold standard" in the assessment of inhaled drug delivery. All levels of inquiry are important in development of drug formulations and delivery devices, and culminate in optimal therapy for the patient. Some advantages and disadvantages of each approach are summarized in Table 3. Each level forms a framework for the next step in the process, with in vitro leading to in vivo, followed by clinical trials. For optimal design, predictions and measurements of inhaled drug delivery should be done prior to large, expensive clinical trials. Bench testing with in vitro models is essential to document the performance of the delivery device/drug combination, whereas in vivo studies examine the behavior of the aerosol in human subjects. Both scintigraphy and pharmacokinetic/pharmacodynamic studies can add insights into the relationship between drug delivery and clinical efficacy and toxicity. There is a need for continued investigation on the subject of inhaled drug delivery, including more trials that bridge the levels of testing. We need more trials comparing in vitro with in vivo outcomes, as well as trials that relate in vivo assessments to clinical outcomes. In the final analysis, however, there is no substitute for clinical trials in patients. There is a lack of published, well-designed, randomized, controlled clinical trials comparing delivery devices or drug formulations. For these, attention must be given to the definition of the population, the dose-response relationships, and the expression of the physiologic responses. It is also important that clinical trials monitor both objective and subjective outcomes, as symptoms and quality of life measures help quantify the impact of disease and therapy on daily life.

Modification of P-selectin glycoprotein ligand-1 with a natural killer cell-restricted sulfated lactosamine creates an alternate ligand for L-selectin

Natural killer (NK) cells are components of the innate immune system that can recognize and kill virally infected cells, tumor cells, and allogeneic cells without prior sensitization. NK cells also elaborate cytokines (e.g., interferon-gamma and tumor necrosis factor-alpha) and chemokines (e.g., macrophage inflammatory protein-1alpha) that promote the acquisition of antigen-specific immunity. NK cell differentiation is accompanied by the cell surface expression of a mucin-like glycoprotein bearing an NK cell-restricted keratan sulfate-related lactosamine carbohydrate, the PEN5 epitope. Here, we report that PEN5 is a post-translational modification of P-selectin glycoprotein ligand-1 (PSGL-1). The PEN5 epitope creates on PSGL-1 a unique binding site for L-selectin, which is independent of PSGL-1 tyrosine sulfation. On the surface of NK cells, the expression of PEN5 is coordinated with the disappearance of L-selectin and the up-regulation of Killer cell Ig-like Receptors (KIR). These results indicate that NK cell differentiation is accompanied by the acquisition of a unique carbohydrate, PEN5, that can serve as part of a combination code to deliver KIR(+) NK cells to specific tissues.

Obesity is the key determinant of cardiovascular risk factors in the Hong Kong Chinese population: cross-sectional clinic-based study

OBJECTIVES

To examine the interrelationships between obesity and various cardiovascular risk factors, and to investigate the relative importance of insulin and obesity in their associations with various pathophysiologies.

DESIGN

Cross-sectional clinic-based study.

SETTING

Medical clinics at a university teaching hospital, Shatin, Hong Kong.

PARTICIPANTS

A heterogeneous cohort of 767 Hong Kong Chinese subjects with a mean age of 43 (standard deviation, 14) years.

MAIN OUTCOME MEASURES

Body mass index, waist circumference, plasma insulin, insulin resistance index, fasting plasma glucose and lipid levels, blood pressure, and 24-hour urinary albumin excretion.

RESULTS

Pathophysiological abnormalities and risk factors are frequently clustered to varying degrees. Compared with the control subjects, patients with at least one component of the metabolic syndrome were more obese, hyperinsulinaemic, insulin resistant, hyperglycaemic, hypertensive, dyslipidaemic, and albuminuric (all variables, P<0.001). Increasing degrees of body mass index, waist circumference, plasma insulin level, and insulin resistance index were associated with an increasing number of risk factors after adjusting for age and sex (all variables, P<0.02). Multiple regression analysis showed that obesity, as reflected by either the body mass index or waist circumference, had a closer association than plasma insulin with the fasting plasma glucose concentration, blood pressure, and high-density lipoprotein-cholesterol and triglyceride concentrations. Using 19.0-20.9 kg/m(2) as the reference body mass index interval, the lowest cardiovascular risk was associated with a body mass index of <23.0 kg/m(2). There was an increased risk of 3.1 and 5 times when the body mass index was 23. 0-24.9 kg/m(2) and > or =25 kg/m(2), respectively.

CONCLUSIONS

Obesity, hyperinsulinaemia, and insulin resistance are characteristic features of Hong Kong Chinese patients who have various components of the metabolic syndrome. Obesity has a greater effect than plasma insulin on various pathophysiologies.

Reconstruction of the scalp and cranium using multiple free-tissue transfers following recurrent basal cell carcinoma

It is well-recognised that recurrent disease can occur following surgery for malignancy in the head and neck region. This is particularly true of basal cell carcinoma in which recurrences may occur over many years and despite the use of different treatment modalities. Reconstruction of large defects may become increasingly difficult and can be optimally managed by free tissue transfer. The authors report a case of basal cell carcinoma that has required treatment for over 20 years, unique in that on five different occasions, free flaps have been used for reconstruction.

A sibling-pair analysis of fasting lipids and anthropometric measurements and their relationship to hypertension

Fifty non-diabetic, young Chinese hypertensives were compared to their normotensive siblings with respect to body fat distribution and fasting lipid and glucose (FPG) profiles. Sitting BP in hypertensives met conventional hypertension criteria after a 4-week washout period on placebo. Hypertensives had greater body mass index (BMI), subscapular skin-fold thickness (SFT), waist circumference (W), waist-to-height (WHtR) and waist-to-hip ratio (WHR), p<0.0001 for all. Higher triglycerides (p=0.004) and lower HDL-cholesterol (p=0.015) concentrations were also observed. Weight, W, WHtR and BMI were higher in hypertensives in both male (n=9) and female gender-concordant sibling pairs (n=21). Higher WHR, hip circumference and subscapular SFT were only seen in the male hypertensives. Hypertension is associated with central adiposity and adverse lipid profiles in this group of young hypertensives, supporting the hypothesis that obesity, particularly central, is closely associated with hypertension in Chinese as in other ethnic groups.

Predictors of change in the neuropsychological profiles of children with type 1 diabetes 2 years after disease onset

OBJECTIVE

To identify type 1 diabetes-related predictors of change in the neuropsychological profiles of children over the first 2 years of the illness.

RESEARCH DESIGN AND METHODS

Children (n = 116) aged 3-14 years were assessed soon after diagnosis and re-evaluated 2 years later to examine relationships between illness variables, such as age of onset and metabolic control history, and changes in neuropsychological status over the first 2 years of type 1 diabetes.

RESULTS

Illness variables were significant predictors of change in neuropsychological test scores within 2 years of onset of type 1 diabetes. Age of onset of type 1 diabetes predicted negative change on Performance Intelligence Quotient, whereas both recurrent severe hypoglycemia and chronic hyperglycemia were associated with reduced memory and learning capacity.

CONCLUSIONS

These results suggest that the relationship between metabolic control and neuropsychological risk is nonlinear in that children with either recurrent severe hypoglycemia or chronically elevated blood sugars exhibit negative changes in their neuropsychological profiles. Onset of type 1 diabetes very early in life adds another dimension of risk, particularly affecting the acquisition of visuospatial skills.

The feet in Apert's syndrome

Apert's syndrome (acrocephalosyndactyly type 1) is characterised by anomalies of the cranium, hands, and feet. The cranial and hand anomalies have been investigated, and the management of these is well established. In contrast, the anomalies affecting the feet and their management has previously received little attention. Forty-three children with Apert's syndrome underwent investigation of the anomalies affecting their feet. This consisted of history, clinical examination, and where possible, radiographic examination to establish the anomalies present, how these altered during development, and their clinical significance. The conclusion of the study is that there are widespread anomalies of the feet, with defects including both predictable dysmorphic changes and progressive fusions of the skeletal components during skeletal maturity. These fusions and their effect on growth combine to produce increasing deformity during childhood. The clinical significance of the anomalies is that walking is often delayed, and the increasing deformity results in difficulty obtaining footwear. This is the most common reason for surgery to the feet being undertaken during childhood to improve the shape of the feet to facilitate the provision of footwear. The unexpectedly high incidence of surgery in this study suggests that the management of foot deformities may require surgery more frequently than current literature would suggest.

Management of a large pleomorphic adenoma of the parotid gland

The surgical management of an extensive pleomorphic adenoma arising within deep lobe of the parotid gland is presented.

Expression, folding, and characterization of small proteins with increasing disulfide complexity by a pT7-7-derived phagemid

The expression, folding, and characterization of a series of small proteins with increasingly complex disulfide bond patterns were characterized. A phagemid was prepared from the pT7-7 plasmid to facilitate mutagenic studies with these proteins. cDNAs coding for bovine, rat, and human prolactin; human growth hormone; and bovine alpha-lactalbumin were amplified by PCR using primers that inserted restriction sites at the 5' and 3' ends and reduced the coding sequence to the mature methionyl protein with bacterially preferred codons in the 5' region. The expressed proteins were folded and oxidized by methods that allowed disulfide bond formation to occur either during or following folding. The effectiveness of the folding procedures was determined for each protein by electrophoresis, absorption spectroscopy, and functional studies. The redox conditions required for folding functional proteins varied as the number of disulfide bonds per unit molecular weight increased. Human growth hormone, 22 kDa; human prolactin, 23 kDa; and bovine prolactin, 23 kDa, contain two, three, and three disulfides, respectively, and are folded correctly by air oxidation performed during renaturation under alkaline conditions. Proper disulfide bond formation of rat prolactin, 23 kDa, containing three disulfide bonds required the addition of a reducing agent at the initiation of renaturation. Bovine alpha-lactalbumin, 14 kDa with four disulfide bonds, required complete renaturation prior to the removal of a reducing agent. SDS-gel electrophoresis under nonreducing conditions provided information regarding the proper folding of these proteins. The absorption of 250-nm light by disulfide bonds also provided information regarding the proper folding of rat prolactin and bovine alpha-lactalbumin.

Assessment of various parameters in the estimation of differential renal function using technetium-99m mercaptoacetyltriglycine

Differential renal function (DRF) is an important parameter that should be assessed from virtually every dynamic renogram. With the introduction of technetium-99m mercaptoacetyltriglycine (99mTc-MAG3), a tracer with a high renal extraction, the estimation of DRF might hopefully become accurate and reproducible both between observers in the same institution and also between institutions. The aim of this study was to assess the effect of different parameters on the estimation of DRF. To this end we investigated two groups of children: group A, comprising 35 children with a single kidney (27 of whom had poor renal function), and group B, comprising 20 children with two kidneys and normal global function who also had an associated 99mTc-dimercaptosuccinic acid scan (99mTc-DMSA). The variables assessed for their effect on the estimation of DRF were: different operators, the choice of renal regions of interest (ROIs), the applied background subtraction, and six different techniques for analysis of the renogram. The six techniques were based on: linear regression of the slopes in the Rutland-Patlak plot, matrix deconvolution, differential method, integral method, linear regression of the slope of the renograms, and the area under the curve of the renogram. The estimation of DRF was less dependent upon both observer and method in patients with two normally functioning kidneys than in patients with a single kidney. The inter-observer comparison among children in either group was not dependent on either ROI or background subtraction. However, in patients with poor renal function the method of choice for the estimation of DRF was dependent on background subtraction, though not ROI. In children with two kidneys and normal renal function, the estimation of DRF from the 24 techniques gave similar results. Methods that produced DRF values closest to expected results, from either group of children, were the Rutland-Patlak plot and matrix deconvolution methods.

A dimeric form of prothrombin on membrane surfaces

Blood coagulation requires the conversion of zymogens to active enzymes. These reactions are facilitated by Ca2+-dependent protein binding to membrane surfaces containing anionic phospholipids. Here it is shown that only in the presence of both Ca2+ and phospholipid vesicles composed of phosphatidylcholine and phosphatidylserine can a prothrombin dimer be chemically cross-linked. A cross-linker containing evenly spaced reactive groups was prepared by activating the carboxy groups of a ten-residue glutamic acid peptide and allowed to react with physiological concentrations of prothrombin. When Ca2+ and anionic phospholipids were both present during exposure to the cross-linker, it was found that more than 50% of the prothrombin was trapped as a chemically defined dimer with reaction times of the order of 1 min. The dimer yield remained high even when reactions were performed at high phospholipid-to-protein ratios at protein concentrations an order of magnitude less than physiological. Amino acid sequencing of a CNBr peptide produced from the purified dimer localized the cross-link to residues Lys341 and Lys427 of prothrombin. The specificity and high yield under mild conditions of the cross-linking suggest that dimeric membrane bound prothrombin might be a physiologically relevant substrate for the formation of thrombin. Prothrombinase converts this modified protein to an enzyme that catalyses the hydrolysis of a thrombin chromogenic substrate as efficiently as thrombin and is inhibited by a thrombin active-site directed inhibitor, but is a thrombin dimer. The thrombin dimer has impaired activity compared with thrombin with respect to physiological functions requiring binding to exosite I. A model based on the known structure of thrombin is presented that can account for the prothrombin dimer and the properties of the dimeric thrombin formed from it.

Prostate disease patients: planning services to meet their coping needs

A committee comprising hospital and community-based urology and oncology nurses and social workers planned, organized, implemented, and evaluated an educational public seminar on prostate cancer (PC). Data relating to satisfaction with the seminar, reasons for attendance, perceived needs for further support/education, and demographics were collected using a feedback questionnaire. Results suggested a need for education and a significant interest in support groups and further educational forums for patients with PC or symptoms and their caregivers.

Sensitivity of aerosol bolus behavior to methacholine-induced bronchoconstriction

STUDY OBJECTIVES

Airway narrowing causes alterations in the shape of an exhaled aerosol bolus that can serve as indexes of airway changes during bronchoprovocation. We compared the sensitivities of aerosol bolus behavior and specific airway conductance (SGaw) during bronchoprovocation in normal subjects.

DESIGN AND PARTICIPANTS

Fifteen normal, nonsmoking subjects were studied. Doubling methacholine (MCh) concentrations were delivered during tidal breathing. After each dose, SGaw was determined followed by inhalation of narrow pulses of 1-microm particles introduced into 1-L breaths. Inhaled and exhaled particle concentrations were measured with light scattering photometry. Using plots of concentration vs volume, the exhaled bolus was compared with the inhaled bolus for measurements of volumetric change in mode location (modal shift), particle deposition, and dispersion. To determine baseline intrasubject variability, sham studies using buffer solution were performed on five subjects.

RESULTS

MCh caused a proximal modal shift, and increased dispersion and deposition of the exhaled bolus. At most doses, a greater percentage of subjects showed significant change (p<0.05) from baseline for modal shift and deposition than for SGaw. Aerosol bolus behavior displayed less intrasubject variability than did SGaw during sham studies.

CONCLUSION

Aerosol bolus behavior is at least as sensitive as SGaw in detecting MCh-induced airway constriction in normal subjects and exhibits less intrasubject variability.

Nasal dermoid cysts in siblings

Nasal dermoid cysts are congenital malformations which result from anomalous embryological development. Two cases occurring in siblings are presented. There have been several previous reports that the condition may be familial but in this report the initial suspicion of the milder anomaly in the younger child was raised primarily because of his older brother's history. This further report suggests that the incidence of familial occurrence of this anomaly may be greater than current literature suggests, and the possibility that other family members may be affected should be remembered by clinicians treating patients with this condition.

Pharmacokinetics of (R,S)-Albuterol after aerosol inhalation in healthy adult volunteers

The pharmacokinetics of inhaled (R,S)-albuterol following pulmonary absorption were studied in healthy human subjects. Ten subjects (5 females and 5 males) inhaled two puffs (180 microg) of albuterol via a metered-dose inhaler and spacer device. All subjects were nonsmoking and had normal pulmonary function. Charcoal slurries were ingested to block gastrointestinal absorption of drug. Venous samples were obtained from each subject at thirteen time points from 0 through 12 h post dose. (R,S)-Albuterol concentration in plasma was measured using a gas chromatography-mass spectrometry (GC-MS) assay. The plasma concentration-time profiles conformed to a two-compartment extravascular model with first-order absorption kinetics. The drug levels reached maximum in 12.6 +/- 2.2 (SD) minutes, which is in contrast with previous reports that maximum plasma concentrations occur within 2 to 4 h. The mean peak plasma level was 1469 +/- 410 pg/mL. The mean half-life of distribution was 17.9 +/- 8.2 min. The mean half-life of elimination was 4.4 +/- 1.5 h. Female subjects achieved peak concentration more rapidly than male subjects (10.4 vs 14.8 min, p = 0.01) and had a higher mean peak concentration (1778 vs 1159 pg/mL, p = 0.04).

The elbow in syndromic craniosynostosis

Craniosynostosis may occur in conjunction with limb and visceral anomalies in more than 100 syndromes and may include anomalies of the elbow. Apert's, Pfeiffer's, Crouzon's, and Saethre-Chotzen syndrome have been linked with anomalies of the elbow, but the incidence and severity of such anomalies is unknown. A prospective radiographic study was undertaken to establish the types, incidence, and severity of elbow anomalies in patients with either Apert's, Pfeiffer's, Crouzon's, or Saethre-Chotzen syndrome attending the Craniofacial Centre at Great Ormond Street Hospital during a 12-month period. This study showed that elbow anomalies were very common in Apert's and Pfeiffer's syndrome, but less so in Crouzon's syndrome. The elbows in all patients with Saethre-Chotzen syndrome were normal. A range of anomalies was seen, with overlap between the syndromes. The severest anomaly seen in children with Crouzon's, Pfeiffer's, and Apert's syndrome was complete synostosis, which may require surgical intervention in due course. The results of this study suggest that the incidence of elbow anomalies in Apert's, Pfeiffer's, and Crouzon's syndrome is higher than the current literature suggests. Synostosis can be so severe that orthopedic review as part of the management of these children may be beneficial and may become increasingly important as more of these children survive into adulthood.

Neuropsychological complications of IDDM in children 2 years after disease onset

OBJECTIVE

To compare the neuropsychological profiles of children with IDDM with a community control group at two time points: 3 months after disease onset and 2 years after the baseline assessment.

RESEARCH DESIGN AND METHODS

A total of 123 children (age 3-14 years) with recent IDDM onset were compared with 129 community control subjects, stratified for age and sex, on standardized measures of general intelligence, attention, speed of processing, memory, learning, executive skills, and behavioral adjustment soon after diagnosis and 2 years later. Exclusion criteria were premorbid evidence of central nervous system disease or trauma, or English not spoken in the home.

RESULTS

There were no differences between children with IDDM and control subjects on any measure at the initial assessment 3 months after disease onset. Two years later, children with IDDM tended to show a less positive change, relative to control subjects, in their standardized scores on measures of general intelligence, and significantly so on the vocabulary (P < 0.01) and block design (P < 0.05) subtests. Multivariate group differences were also apparent on speed of processing (P < 0.05) and learning (P < 0.01) subtests, reflecting smaller developmental gains in the children with IDDM when compared with control subjects.

CONCLUSIONS

The findings are consistent with previous reports, suggesting that IDDM is associated with an increased risk of mild neuropsychological dysfunction. The skills most affected in this cohort were information processing speed, acquisition of new knowledge, and conceptual reasoning abilities. Clinicians and educators should be made aware of the risk of specific neuropsychological deficits in children with IDDM.

The feet in Pfeiffer's syndrome

Broad toes are the classic clinical finding occurring in the feet in Pfeiffer's syndrome patients, but few cases undergo formal radiological assessment. However, the feet in other craniosynostosis syndromes resulting from mutations of the fibroblast growth factor receptor 2 gene have anomalies at many other sites within the feet, which raised the possibility that there may also be a wider range of anomalies other than broad big toes in the feet of those with Pfeiffer's syndrome. The object of this study was to assess prospectively the incidence and pattern of clinical and radiographic anomalies of the feet of patients with a confirmed diagnosis of Pfeiffer's syndrome. Twenty-two Pfeiffer's syndrome patients were examined both clinically and radiologically for anomalies of the feet. Clinical examination revealed broad big toes in 12 patients and syndactyly in 2. Radiographs of the feet were evaluated by a radiologist with an interest in skeletal dysplasia as well as by members of the Craniofacial team. A wider range of radiological than clinical anomalies involving the phalanges, metatarsals, and tarsals was seen. The severity of the anomalies observed ranged from normal to those resembling the feet of Apert's syndrome patients. Only 4 patients had radiologically normal feet. These radiographic findings suggest that there is a range of foot anomalies more extensive than the broad big toes, which are classically associated with Pfeiffer's syndrome.