Overcoming complications of breast implants.

Having nice breasts is important to many women and their self-images. For those women who have had congenital deformities, were not blessed naturally with the shape they wanted, have had experiences that have adversely affected breast tissue, or have had a mastectomy as a result of breast cancer, breast implants can provide a boost in self-confidence. This article provides an overview of breast implant issues and treatments, and reviews breast implant complications, their potential causes and treatments.     

Differences between beige and bg/+ mice in the disruption of plasma proteinase regulation in the tumor-bearing state or following Corynebacterium parvum treatment. Evidence for the involvement of polymorphonuclear leukocyte proteinases

Mice bearing the B16 melanoma or treated with Corynebacterium parvum develop elevated levels of plasma neutral proteinase activity. Similar experiments carried out with C57BL/6-bg/bg (beige) mice, which are genetically deficient in polymorphonuclear neutrophil (PMN) proteinases, revealed that such mice develop significantly diminished elevation in plasma proteinase activity compared to C57BL/6-bg/+ mice. Lysates of C. parvum elicited PMN from beige mice contained approximately 80% less neutral proteinase activity as did lysates of PMN from bg/+ mice. These results indicate that host cells, such as PMN, may become activated during the tumor progression, or following C. parvum treatment, causing degranulation and a subsequent elevation in plasma proteinase levels. If such an interpretation is correct, then this phenomenon may be the murine corollary to what has been observed in patients with certain inflammatory diseases or tumors.     

Clinical MR imaging with a Helmholtz-type surface coil

Limited-field-of-view radio-frequency receiver antennas provide improved near-field sensitivity for magnetic resonance imaging by decreasing the antenna volume. The Helmholtz-type surface coil, consisting of two flat rings, is an organ-encompassing antenna that takes advantage of this principle to yield an improved signal-to-noise ratio (S/N). The coil was tested in a group of 50 patients and 16 healthy volunteers. Images obtained with the Helmholtz coil demonstrated quantitatively superior S/N of 2.2-fold or greater than that of comparison body coil images, as well as qualitatively superior anatomic resolution.     

Insulin-like growth-factor-binding protein 3 is decreased in early-stage operable pre-menopausal breast cancer

Insulin-like growth factor 1 (IGF-1) is a potent mitogen for human breast-cancer cells in vitro. In circulation, most of IGF-1 is bound to IGF-binding protein 3 (IGFBP-3). This high-affinity binding is thought to have an important limiting effect on the availability of IGF-1 for biological activity. To assess the availability of IGF-1 for receptor binding, we determined serum levels of IGF-1 and IGFBP-3 and IGF-1/IGFBP-3 ratios. In a case-control study, 150 women aged 38 to 75 years presenting with stage-l or-II breast cancer were investigated just prior to surgery (n = 76), or to irradiation one month after surgery (n = 74). The population-based control group consisted of 441 women of the same age having no breast cancer. Women reporting diabetes mellitus or other hormonal abnormalities were excluded. Premenopausal cases showed elevated IGF-1 serum concentrations, decreased IGFBP-3 levels and increased IGF-1/IGFBP-3 ratios. The IGF-1/IGFBP-3 ratio was a significant breast-cancer risk factor, also after adjustment for age, family history, height, body-mass index, body-fat distribution, and serum levels of C-peptide. The relative risk was 7.34 for the highest compared with the lowest quintile of IGF-1/IGFBP-3. The presence or absence of tumor had no influence on these results. Increased levels of available IGF-1 in the circulation of pre-menopausal women may contribute to the development of breast cancer. © 1995 Wiley-Liss Inc.     

Ribavirin disposition in high-risk patients for acquired immunodeficiency syndrome

Ribavirin is a broad-spectrum antiviral drug that has in vitro activity against human immunodeficiency virus. To determine the kinetics of ribavirin, 17 symptom-free homosexual men with lymphadenopathy were studied. Single doses of ribavirin, 600, 1200, or 2400 mg, were given orally or intravenously. The plasma ribavirin concentration-time profiles were well fitted by a three-compartment open model. Ribavirin followed linear kinetics over the dose range studied. The mean 1-hour postinfusion concentrations after intravenous ribavirin, 600, 1200, and 2400 mg, were 8.0, 19.7, and 37.1 mumol/L, respectively. The mean +/- SD plasma beta-phase half-life, terminal-phase (gamma) half-life, and volume of distribution at steady state were 2.0 +/- 1.1 hours, 35.5 +/- 14.0 hours, and 647 +/- 258 L, respectively. The mean ribavirin renal clearance and total body clearance were 99 +/- 30 and 283 +/- 37 ml/min, respectively. After an oral dose of 600, 1200, and 2400 mg, the mean peak plasma ribavirin concentrations (which occurred 1.5 hours after administration) were 5.1, 9.9, and 12.6 mumol/L, respectively. The mean absorption half-life and bioavailability of ribavirin were 0.5 hour and 45%. Ribavirin had no plasma protein binding and the drug accumulated within red blood cells. In conclusion, ribavirin is incompletely absorbed from the gastrointestinal tract, its renal excretion accounts for approximately one third of the drug's elimination, and drug accumulation (greater than threefold) will result with repetitive dosing at the 6- to 8-hour dosing interval currently used.