Abrogation of betaglycan attenuates TGF-beta-mediated inhibition of embryonic murine lung branching morphogenesis in culture

Although betaglycan (TGF-beta type III receptor) is known to enhance TGF-beta ligand binding to its type II receptor in murine lung epithelial cell lines, the biological significance of this phenomenon in the process of lung organogenesis is not understood. Betaglycan gene expression was detected in embryonic murine lungs undergoing branching morphogenesis in ex vivo culture. Antisense betaglycan oligodeoxynucleotides (ODN) resulted in up to 56% stimulation of lung branching morphogenesis in culture, while betaglycan mRNA and protein expression levels were suppressed by 90 and 82%, respectively. Following abrogation of betaglycan expression with antisense oligodeoxynucleotide, embryonic lungs were relatively insensitive to TGF-beta: TGF-beta2 (0.5 ng/ml) and TGF-beta1 (20 ng/ml), respectively, down-regulated lung morphogenesis by 38 and 34% in control cultures, whereas TGF-beta-induced inhibition was attenuated to 13 and 26% respectively, in the presence of betaglycan antisense oligodeoxynucleotides. TGF-beta neutralizing antibodies also prevented TGF-beta-mediated inhibition of lung branching in culture, supporting the speculation that autocrine/paracrine TGF-beta signaling is minimal in the absence of betaglycan. Betaglycan was immunolocalized mainly to the epithelial cells in developing airways, a spatial distribution which overlaps with that of TGF-beta type II receptor. Furthermore, abrogation of endogenous betaglycan gene expression prevented the characteristic down-regulation of cyclin A and surfactant protein C (SP-C) mRNAs by exogenous TGF-beta ligands. These results show that betaglycan expression is essential for optimal TGF-beta signaling during embryonic lung development. We therefore conclude that the abrogation of endogenous betaglycan attenuates endogenous autocrine and/or paracrine TGF-beta-mediated negative regulation of lung organogenesis.

Abnormal oxygen uptake kinetic responses in women with type II diabetes mellitus

Persons with type II diabetes mellitus (DM), even without cardiovascular complications have a decreased maximal oxygen consumption (VO2 max) and submaximal oxygen consumption (VO2) during graded exercise compared with healthy controls. We evaluated the hypothesis that change in the rate of VO2 in response to the onset of constant-load exercise (measured by VO2-uptake kinetics) was slowed in persons with type II DM. Ten premenopausal women with uncomplicated type II DM, 10 overweight, nondiabetic women, and 10 lean, nondiabetic women had a VO2 max test. On two separate occasions, subjects performed 7-min bouts of constant-load bicycle exercise at workloads below and above the lactate threshold to enable measurements of VO2 kinetics and heart rate kinetics (measuring rate of heart rate rise). VO2 max was reduced in subjects with type II DM compared with both lean and overweight controls (P < 0.05). Subjects with type II DM had slower VO2 and heart rate kinetics than did controls at constant workloads below the lactate threshold. The data suggest a notable abnormality in the cardiopulmonary response at the onset of exercise in people with type II DM. The findings may reflect impaired cardiac responses to exercise, although an additional defect in skeletal muscle oxygen diffusion or mitochondrial oxygen utilization is also possible.

A phase I/II study of the protease inhibitor indinavir in children with HIV infection

BACKGROUND

Indinavir, an inhibitor of the human immunodeficiency virus type 1 (HIV-1) protease, is approved for the treatment of HIV infection in adults when antiretroviral therapy is indicated. We evaluated the safety and pharmacokinetic profile of the indinavir free-base liquid suspension and the sulfate salt dry-filled capsules in HIV-infected children, and studied its preliminary antiviral and clinical activity in this patient population. In addition, we evaluated the pharmacokinetic profile of a jet-milled suspension after a single dose.

METHODS

Previously untreated children or patients with progressive HIV disease despite antiretroviral therapy or with treatment-associated toxicity were eligible for this phase I/II study. Three dose levels (250 mg/m2, 350 mg/m2, and 500 mg/m2 per dose given orally every 8 h) were evaluated in 2 age groups (<12 years and >/=12 years). Indinavir was initially administered as monotherapy and then in combination with zidovudine and lamivudine after 16 weeks.

RESULTS

Fifty-four HIV-infected children (ages 3.1 to 18.9 years) were enrolled. The indinavir free-base suspension was less bioavailable than the dry-filled capsule formulation, and therapy was changed to capsules in all children. Hematuria was the most common side effect, occurring in 7 (13%) children, and associated with nephrolithiasis in 1 patient. The combination of indinavir, lamivudine, and zidovudine was well tolerated. The median CD4 cell count increased after 2 weeks of indinavir monotherapy by 64 cells/mm3, and this was sustained at all dose levels. Plasma ribonucleic acid levels decreased rapidly in a dose-dependent way, but increased toward baseline after a few weeks of indinavir monotherapy.

CONCLUSIONS

Indinavir dry-filled capsules are relatively well tolerated by children with HIV infection, although hematuria occurs at higher doses. Future studies need to evaluate the efficacy of indinavir when combined de novo with zidovudine and lamivudine.

Quantitation of the extracellular domain of epidermal growth factor receptor in the plasma of dioxin-exposed individuals

Animal models suggest that dioxins have a negative effect on the level of expression of the epidermal growth factor receptor in cells. In vivo the level of expression in tissue of the epidermal growth factor receptor can be monitored by assaying for the extracellular domain in blood using an enzyme linked immunosorbent assay. We have determined the levels of the extracellular domain of the epidermal growth factor receptor in the plasma of 30 individuals: 10 with high blood dioxin levels (TEQ range = 318-673 ppt), 10 with medium blood dioxin levels (TEQ range = 16-60 ppt), and 10 with low background blood dioxin levels (TEQ range = 3-10 ppt). The levels of the epidermal growth factor receptor extracellular domain were lower in the high blood dioxin group (mean +/- SD = 45 +/- 26 fmol/ml) and the medium blood dioxin group (mean +/- SD = 41 +/- 23 fmol/ml) compared with the low blood dioxin group (mean +/- SD = 73 +/- 43 fmol/ml). These results suggest that the extracellular domain of the epidermal growth factor receptor may be a marker of the biological effect of dioxin exposure.

Reinfusion of discard blood from venous access devices

PURPOSE/OBJECTIVES

To determine if clots are present in the initial 10 ml of blood routinely discarded from venous access devices (VADs) prior to blood sampling, and to determine if clots form in the discard blood specimen during the five minutes required to complete blood specimen sampling.

DESIGN

A pretest/post-test design.

SETTING

A large, mid-Atlantic research institution.

SAMPLE

A convenience sample of 50 adult patients with cancer (27 males and 23 females) with a median age of 60. A large sampling size variation existed among the different VADs.

METHOD

Two 5 ml discard specimens were drawn into separate syringes. Syringe #1 was filtered immediately, and syringe #2 was filtered after a five-minute dwell time. Both samples were filtered through a 40 micron filter.

MAIN RESEARCH VARIABLE

The presence or absence of clots.

FINDINGS

Fifty percent (n = 25) of the VADs had clots present on the filter from syringe #1. The clots varied in length, width, depth, and diameter, which precluded a consistent measurement. The investigators were able to measure either the diameter or length, depending on the shape of the clots. The majority of the clots (n = 17) appeared to be shaped like the lumen of a catheter and varied from 0.1 cm to 1.2 cm in length. Six clots were round and varied in diameter from 1.6 mm to 2.8 mm. Only 4% (n = 2) of the VADs had clots in syringe #2, but those clots were much larger, measuring 8.3 mm and 18.4 mm.

CONCLUSIONS

The study addresses concerns of the investigators regarding the clinical practice of reinfusing discard blood obtained from VADs. Whether the clots present in the catheter and their reinfusion represent a significant risk to patient outcome is unclear.

IMPLICATIONS FOR NURSING PRACTICE

Until further research is conducted and the degree of risk can be better defined, methods of drawing blood that require reinfusion of discard blood from VADs are not recommended.

Satisfaction with outpatient geriatric evaluation and management (GEM)

The purpose of this study was to evaluate high-risk older adults' satisfaction with outpatient geriatric evaluation and management (GEM). Community-dwelling Medicare beneficiaries (n = 522) age 70 years and older who had a high probability of repeated admission to hospitals (Pra > .40) were randomly assigned to receive either usual care or GEM for six months. Despite the stresses imposed by outpatient GEM (e.g., new relationships with providers, frequent office visits and changes in treatments), the mean satisfaction scores of the recipients of GEM were 9% higher than those of the recipients of usual care (4.31 vs 3.96, p < .001). The primary physicians of GEM recipients were also highly satisfied with GEM care.

Effects of 14 d of covert substitution of olestra for conventional fat on spontaneous food intake

We conducted a double-blind, placebo-controlled, within-subject crossover study to investigate the effects of covert substitution of olestra, a non-energy-containing fat replacer, for conventional fat on food selection and energy intake in lean and obese men and women. Fifty-one subjects [BMI (kg/m2): 19-36; age: 25-63 y] were studied during two 14-d treatment periods (olestra and placebo), with a 7-d washout between feeding periods. During the intervention periods all foods were provided to the subjects. The aim was to produce a 10% dilution of total energy intake by replacing conventional triacylglycerol with olestra. To accomplish this, subjects were required to consume core foods providing 20-35 g olestra (depending on estimated energy needs) or the same foods containing placebo triacylglycerol. Additional items could be selected from foods that varied in macronutrient composition. When the two treatment periods were compared, total energy intake was 8% lower and fat intake 11% lower during the olestra period than during the placebo treatment period (P < 0.0001). Overall, subjects compensated for 15% of the fat and 20% of the total energy replaced by olestra. In absolute terms, subjects consumed 32% of total energy from fat during the placebo period and 27% of total energy from fat during the olestra period. Neither carbohydrate nor protein intake (g/d) differed between periods. The results did not differ as a function of BMI (lean compared with obese) or sex. Over a 2-wk period, covert substitution of olestra for conventional fat led to reductions in dietary fat intake and total energy intake in all subjects.

ErbB-2 protein in sera and tumors of breast cancer patients

We compared levels of erbB-2 oncoprotein among three groups: Group I included 60 asymptomatic women; Group II had 51 women with benign breast biopsies; and Group III had 67 women with node-negative breast cancer. Serological levels of erbB-2 protein were measured in all participants; tumor levels were measured for Groups II and III. Forty-three percent of usable tumors (25/58), including three of seven lobular tumors, were erbB-2 positive. Tumor and blood oncoprotein levels were unrelated. Blood levels, however, were positively related to tumor volume, but only when the tumor had both a ductal carcinoma in situ (DCIS) component and an invasive component, suggesting a role for erbB-2 protein in progression of DCIS to invasive carcinoma. In Groups I and II serological levels of erbB-2 protein were directly related to age, and inversely related to having had a live birth. Therefore, a model that determined the threshold levels of serological erbB-2 positivity in Group III included age and nulliparity as independent variables. Only three of the 67 women (4.5%) in Group III were positive for serological erbB-2. In a multivariate model, with serological erbB-2 as the dependent variable, and in which the independent variables included Study Group, there was a statistical trend for younger women, in which Group III had the highest serological levels of erbB-2, followed by Group II, and then Group I. In women who were over the age of 50 years the trend was reversed; i.e., levels of erbB-2 tended to be lowest in Group III, followed by Group II, and finally Group I.

Parameters of protein delivery using hydroxyapatite in simulated body fluid

Various studies have been conducted using hydroxyapatite (HA) to deliver therapeutic drugs over a long period of time. However, the rate of drug release from ceramics varies tremendously. Thus a study was designed to observe the effect of particle size, pressure, drug ratio, and the addition of a zinc stearate binder on the release of BSA from ceramics. Samples were collected every two hours for a 12 hour period. Three particle sizes were used in the study (< 38, 45-63, and 63-75 microns). Variations in particle size did not influence the release of BSA. Ceramics compressed at a pressure of 150 Mpa delivered more protein than pressures of 300 MPa, 450 MPa, and 900 MPa. Drug to ceramic ratio had the most significant effect. A ratio of 1:25 BSA to HA delivered the protein quickly whereas the 1:100 BSA to HA delivered BSA to HA delivered BSA slowly and in zero order kinetics. The addition of the zinc binder improved the quality of the composite and decreased the release rate of protein delivery when present in 5% or less of the total ceramic weight. HA ceramics can be used to deliver proteins at different rates by varying compression pressure and drug to HA ratio.

Measurement of radiation dose delivered to breast tissue during mantle field irradiation for Hodgkin's disease

The treatment of Hodgkin's disease involves mantle field irradiation. Patients with early stage (I-II) Hodgkin's are often in their 20's or 30's and can expect to live for many decades after the successful management of their disease; however, complications, including second cancers in the treatment area, occur in some survivors. Breast cancer is among the leading second solid cancers that develop in patients who have undergone mantle field irradiation. This paper attempts to determine the dose that may be delivered to breast tissue from mantle field irradiation to treat Hodgkin's disease. Utilizing an anthropomorphic phantom, thermoluminescent dosimeters (TLDs) were placed into a breast phantom constructed of Superflab and TX-150, and were irradiated with 6 MV photons. Readings from 170 TLDs in five layers of breast phantom were analyzed. The results show considerable doses reaching portions of breast tissue. In measured points under the blocks, 8-15% of the prescribed isocenter dose was delivered. For points in the primary beam, readings of up to 91% of the isocentric dose were obtained. Points in the breast near block or collimator edges also received substantial doses; upwards of 70% of the prescribed dose. Several points in the breast outside the treatment field were also measured and readings ranged from 2 to 29% of the prescribed dose. Similar patterns of dose distribution were found on computer plans; however, point-by-point comparisons were not performed. These results are compared with published reports.

Reducing a peritoneal dialysis program's cost by changing from a vendor-provided to a program-provided system for general medical supplies: significant savings in CCPD

An examination of the costs associated with outpatient chronic peritoneal dialysis prompted us to investigate the charges for general medical supplies used by patients on continuous ambulatory peritoneal dialysis (CAPD) and continuous cycling peritoneal dialysis (CCPD) in our hospital-owned, not-for-profit peritoneal dialysis program. The items used by patients to perform their dialysis exchanges and daily exit site care included 4 x 3 and 2 x 2 sterile gauze pads, antibacterial soap, masks, tape, and betadine swabsticks. The charges for these supplies when purchased from the dialysis vendor were compared with charges for the same items if purchased directly from hospital stores by the peritoneal dialysis program and then distributed to the patients. This initial analysis suggested a considerable savings if the peritoneal dialysis program provided the supplies. Based on this estimated savings, in July 1995, the peritoneal dialysis program changed from a vendor-provided to a program-provided system for general supplies used by CAPD and CCPD patients. This study examined the differences in charges expressed as $/patient-month for two periods: July 1994 to June 1995 (when all general medical supplies were provided by dialysis vendors directly to the CAPD and CCPD patients) and July 1995 to May 1996 (when the peritoneal dialysis program purchased general medical supplies from hospital stores and distributed these supplies directly to the patients). The median vendor charges for CAPD patients (n = 21 during 1994 to 1995 and n = 18 during 1995 to 1996) were not significantly different between the two periods. In fact, the charges were slightly higher during the 1995 to 1996 period ($1,264/patient-month v $1,193/patient-month during the vendor-provided period of July 1994 to June 1995, P = 0.67). The median vendor charges for patients on CCPD were significantly lower during the 1995 to 1996 period when the peritoneal dialysis program provided the general medical supplies used for CCPD ($1,110/patient-month v $1,389/patient-month during 1994 to 1995, P = 0.003). There were 30 CCPD patients during the 1994 to 1995 period and 27 patients on CCPD during 1995 to 1996. The total charges for CAPD and CCPD patients combined included dialysis vendor charges (dialysis solution, tubing, cycler rental) and charges from hospital stores. These total charges were lower in the July 1995 to May 1996 period when general medical supplies were purchased directly from hospital stores rather than from the dialysis vendors: $1,201/patient-month versus $1,360/patient-month (P = 0.03). The median hospital store charges rose slightly during the July 1995 to May 1996 period when supplies were purchased by the peritoneal dialysis program from hospital stores ($31/patient-month v $21/patient-month, P = 0.37, during the July 1994 to June 1995 period when general medical supplies were purchased directly from dialysis vendors). However, despite the rise in charges from hospital stores, an overall savings of $149/patient-month was achieved when the peritoneal dialysis program purchased and provided general medical supplies used by the peritoneal dialysis patients. This $149/patient-month equals $1,788 savings per dialysis year for each patient on peritoneal dialysis for that year. Significant savings in the cost of a chronic peritoneal dialysis program may therefore occur if less expensive sources for the general medical supplies used by CAPD and, especially, CCPD patients are found.

The successful use of pronuclear embryo transfers the day following oocyte retrieval

A retrospective analysis of results from 114 initiated in-vitro fertilization cycles utilizing pronuclear embryo transfer is presented. Patients were unselected for age or infertility criteria, constituted a continuous series and were grouped according to response to stimulation (Group 1, ideal; Group 2, suboptimal) or ovarian reserve (Group 3, poor). At 16-18 h post-insemination, embryos were scored for alignment of pronuclei and nucleoli and the appearance of the cytoplasm, generating an embryo score (ES). Transfers were performed 24-26 h post-insemination using two to six embryos with the highest ES. A corrected score was calculated (total score/number of embryos; CS). A total of 114 initiated cycles resulted in 97 oocyte retrievals with 38 clinical pregnancies (39%; 15% implantation). Pregnancy rates were significantly different between the three groups; 37 pregnancies in Group 1 (55% clinical pregnancy; 20% implantation), none in Group 2 and one in Group 3 (6%; 2% implantation: P < 0.001). The ES of transferred embryos correlated with groups. There was a strong correlation between CS and implantation and delivery rates. CS >15 resulted in a 28% implantation; 65% delivery rate. CS <14 resulted in four pregnancies, one delivered. The data show that oocyte quality and pronuclear embryo morphology are related to implantation and that pronuclear embryos can be successfully selected for embryo transfer.

A twin and family study of the association between immune system dysfunction and dyslexia using blood serum immunoassay and survey data

We conducted a study of the association between developmental reading disability (DRD) and immune disorders (ID) using both survey and immunoassay data in two separate samples of families. One sample was made up of twins and their parents and was ascertained through a population-based sampling scheme. The other sample was a set of extended pedigrees selected for apparent autosomal dominant transmission of DRD. We failed to find an association between DRD and ID in either sample, regardless of the method used to assess immune system function. Even though our twin sample provided evidence that both DRD and immune conditions were significantly heritable, there was no evidence for a genetic correlation between ID and DRD nor was there any clear indication that a special subgroup of individuals may be comorbid for these conditions because of genetic reasons. How these negative findings can be reconciled with the developmental hypothesis of Geschwind, Behan, Galaburda, and colleagues, and how they may relate to the gene locus influencing DRD that has been recently located in the HLA region of the short arm of chromosome 6 is discussed.