Tissue Integration of Polyacrylamide Hydrogel: An Experimental Study of Periurethral, Perivesical, and Mammary Gland Tissue in the Pig

BACKGROUND Polyacrylamide hydrogel (PAAG) is a nondegradable water-based polymer with high viscoelasticity. The gel is used as a tissue filler, the only risk being prolonged infection with anaerobic, contaminating microorganisms if not treated early with broad-spectrum antibiotics.
OBJECTIVE With silicone gel as reference, PAAG tissue integration and migration was studied in a longitudinal study of the pig.
MATERIALS AND METHODS Forty-one pigs were used. PAAG and silicone gel were injected into mammary tissue, and PAAG was injected into urethral or bladder wall or the anal canal. Tissues and regional lymph nodes were examined at 1, 1 1/2, 3, 3 1/2, 6, 12, and 14 months, and other lymph nodes and organs were examined at 1, 6, 12, and 14 months.
RESULTS PAAG was invaded by macrophages and giant cells that were gradually replaced by a network of fibrous tissue. Silicone gel was seen inside these cells or as large vacuoles, surrounded by a fibrous capsule. Regional lymph nodes contained PAAG only at 1 1/2 months and silicone gel at 12 months.
CONCLUSION PAAG is a stable, viscoelastic bulking agent, which unlike silicone gel is slowly integrated within its host tissue via a thin fibrous network. Long-term risk of fibrosis and migration is minimal.     

EVALUATION OF THREE SPIROMETERS ON HEALTHY CHILDREN

ABSTRACT. Two electronic spirometers (Dräger Spirotron and Monaghan M403) and one wedge bellows spirometer (Vitalograph) were compared with a Bernstein spirometer. Healthy children, 30 girls and 31 boys, were investigated. The regression lines of VC and FEV_1.0 in relation to the body height to the third power are very close and the S.D. values around the lines are very similar. The correlation coefficients of the regression lines are high for all the spirometers. An analysis of the paired differences showed slight differences of the mean values. The S.D. of paired differences was for VC 4.6–6.6% and for FEV_1.0 4.8-6.2%. The PEFR values obtained by the two electronic spirometers deviated substantially and highly significantly from the values obtained by the Wright peak flow meter.     

SCREENING FOR HYPERLIPOPROTEINEMIA IN 10 000 DANISH NEWBORNS Follow-up Studies in 522 Children with Elevated Cord Serum VLDL-LDL-Cholesterol

Abstract. Among 10440 newborns, 522 with upper 5 percentile values for very low-low density lipoprotein cholesterol in cord serum were selected for follow-up studies. Follow-up was possible in 446 of these 522 families (85%) and familial hypercholesterolemia (FH) was diagnosed in 11. In 273 of the 522 children, serum lipids were determined between the ages of 1 and 2 years and were now found to be normal, except in the 11 children with FH. Furthermore the serum lipids were compared in subgroups of these 273 children divided according to obstetric complications (i.e. low birth-weight, perinatal asphyxia and antepartum betamethasone treatment), which may cause a rise in serum lipids at birth. No differences were found between these subgroups at the age of 1–2 years.     

HYPERLIPOPROTEINEMIA IN NEWBORN INFANTS

ABSTRACT. Andersen, G. E., Lous, P. and Friis-Hansen, B. (Neonatal Department, Rigshospitalet, and the Department of Clinical Chemistry, Bispebjerg Hospital, Copenhagen, Denmark). Hyperlipoproteinemia in newborn infants. A study of 1025 families. Acta Paediatr Scand, 68: 683, 1979.—As part of a screening study for the detection of hyperlipoproteinemia in 10000 newborns, cord serum lipids and lipoproteins were measured in detail in 1025 infants. Elevated cord serum VLDL-LDL-cholesterol could easily be identified by a rapid turbidimetric estimation of cord serum VLDL-LDL. Cord serum VLDL-LDL-cholesterol was found to be significantly higher than normal in premature, asphyxiated and betamethasone-phenobarbital-ritodrine treated infants. Other obstetric complications, however, were not associated with hyperlipoproteinemia. Furthermore all 2050 parents had their serum cholesterol determined. 3 parents had familial hypercholesterolemia (FH). One child also had FH, though her cord serum total cholesterol and VLDL-LDL-cholesterol were normal. The 2 other children of the 3 FH parents, had normal lipids and lipoproteins both at birth and follow-up.     

HORMONAL TREATMENT BEFORE RADICAL PROSTATECTOMY: A 3-YEAR FOLLOWUP

Purpose

Hormonal treatment administered before radical prostatectomy has been shown to decrease the rate of positive surgical margins. We determine whether preoperative hormonal treatment has any impact on the subsequent failure rate.

Materials and Methods

We prospectively evaluated 122 patients with stages T1bNxM0 to T3aNxM0, grades 1 to 3 prostate cancer, including 64 randomly assigned to immediate radical retropubic prostatectomy and 58 randomly assigned to radical retropubic prostatectomy preceded by 3 months of pretreatment with a gonadotropin-releasing hormone agonist. We performed intention to treat analysis on the data with failure defined as lymph node involvement, serum prostate specific antigen greater than 0.5 ng./ml., or the need for postoperative hormonal or radiation adjuvant treatment.

Results

The positive margin rate was 23.6 versus 45.5% in the pretreatment plus prostatectomy versus prostatectomy only groups (p = 0.016). There were 20 failures (34.5%) in the pretreatment plus prostatectomy subgroup and 26 (40.6%) in the prostatectomy only group (p = 0.48). A negative surgical margin was associated with a significantly lower risk of progression than a positive surgical margin (20.8 versus 50.0%, p = 0.0016), and progression was delayed by approximately 1 year after hormonal pretreatment. However, at a median followup of 38 months there was no difference in progression-free survival (p = 0.57).

Conclusions

Although hormonal pretreatment significantly decreased the positive margin rate, it did not result in any difference in progression-free survival when followup exceeded 3 years. Thus, our current results do not support the routine administration of hormonal treatment before radical prostatectomy.     

Skeletal muscle sympathetic activity at rest in trained and untrained subjects

The effect of physical training on muscle sympathetic activity (MSA) was studied by comparing resting levels of MSA in 8 well-trained racing cyclists and in 8 age-matched untrained subjects (mean age 22 yrs). In addition, MSA was determined for 5 untrained subjects before and after an 8-week training program on cycle erogmeters (training group). Recordings were made from the peroneal nerve at the knee with the subject in recumbent position. The well-trained cyclists were characterized by a clearly higher maximal oxygen uptake (VO₂ max) and lower heart rate at submaximal exercise (180 W) than their untrained counterparts. These variables were also significantly changed with training in the training group. In contrast, there were no training-related effects on MSA. Thus, MSA expressed as either the number of sympathetic bursts/100 heart beats (+2%, NS) or bursts/min (-10%, NS) did not differ between the well-trained cyclists and the untrained controls. Furthermore, no changes in MSA occurred with training in the training group (bursts/100 heart beats: +8%, NS; bursts/min -2%, NS). Individual variations in MSA were large and independent of training state. It is concluded that differences in physical conditioning do not account for the large inter-individual differences in MSA in resting man.