The treatment of retroperitoneal fibromatosis with medroxyprogesterone acetate

Wide excision is the recommended primary therapy for retroperitoneal fibromatosis. Radiation therapy and a variety of medications have been used to treat patients with recurrent tumors, but the response to these agents has not been uniform. The patient presented was successfully treated with medroxyprogesterone acetate for recurrent retroperitoneal fibromatosis that was refractory to multiple operative resections and radiation therapy.

DNA fingerprinting in birds

Several regions of the human genome are highly variable in populations because the number of repeats in these regions of a short 'minisatellite' sequence varies at high frequency. Different minisatellites have a core sequence in common, however, and probes made up of tandem repeats of this core sequence detect many highly variable DNA fragments in several species including humans, cats, dogs and mice. The hypervariable sequences detected in this way are dispersed in the genome and their variability means that they can be used as a DNA 'fingerprint', providing a novel method for the identification of individuals, confirmation of biological relationships and human genetic analysis. We show here that human minisatellite-derived probes also detect highly variable regions in bird DNAs. Segregation analysis in a house sparrow family confirms that these regions comprise many mostly heterozygous dispersed loci and we conclude that house sparrow DNA fingerprints are analogous to those of humans. Fingerprint analysis identified one nestling, with fingerprint bands not present in the parent pair's fingerprints, which we conclude resulted from an extrapair copulation. Extrabond copulations have been described in many wild bird species, but their success and hence adaptive significance have rarely been quantifiable. DNA fingerprinting will be of great significance to studies of the sociobiology, demography and ecology of wild birds.

Specific proteolytic modification of creatine kinase isoenzymes. Implication of C-terminal involvement in enzymic activity but not in subunit-subunit recognition

We are using the isoenzymes of creatine kinase (CK) to investigate the effect of specific proteolytic modification on the abilities of enzyme subunits to establish precise subunit-subunit recognition in vitro. Previous work by others has shown that treatment of the MM isoenzyme of rabbit CK with Proteinase K results in a specific proteolytic modification and inactivation of the enzyme. In the present work, we show that both the MM and BB isoenzymes of chicken CK are also specifically modified by Proteinase K, resulting in over 98% loss of catalytic activity and approx. 10% decreases in subunit molecular masses of the enzymes. Similar reactions appear to occur when the isoenzymes are treated with Pronase E. Limited amino acid sequence analysis of intact and Proteinase K-modified MM-CK suggests that the proteolytic modification results from a single peptide-bond cleavage occurring between alanine residues 328 and 329, about 50 amino acid residues from the C-terminal end; the active-site cysteine residue was recovered in the large protein fragment of modified M-CK subunits. Proteolytically modified M-CK and B-CK subunits were able to refold and reassociate into dimeric structures after treatment with high concentrations of LiCl and at low pH. Thus the proteolytically modified CK subunits retain their ability to refold and to establish precise subunit-subunit recognition in vitro.

Noncardiogenic pulmonary edema and invasive cardiovascular monitoring

When a parturient develops clinical and roentgenographic evidence of pulmonary edema during labor or delivery, the obstetric staff often concludes that iatrogenic overhydration or left ventricular failure is the cause. This impression may be reinforced by increased central venous pressure measurements. Although acute respiratory failure (ARF) (non-cardiogenic pulmonary edema) is well described in the medical and surgical literature, the diagnosis is rarely, if ever, made in the obstetric patient unless aspiration pneumonitis is suspected. Unfortunately the usual historic and clinical findings do not differentiate ARF from cardiogenic pulmonary edema. The diagnosis of ARF is based on the finding of pulmonary edema in the absence of an elevated pulmonary capillary wedge pressure. As invasive cardiovascular monitoring is not usually part of the obstetrician's armamentarium, many cases of ARF may be mislabeled and mistreated as cardiogenic pulmonary edema. Four illustrative cases are presented.

Hemodynamic monitoring of cardiogenic pulmonary edema complicating toxemia of pregnancy

Swan-Ganz catheters were used in the care of 3 toxemic parturients who developed pulmonary edema. Initial pulmonary capillary wedge pressures (PCWP) ranged from 22 to 33 torr, indicating decompensated left ventricular failure. Simultaneous central venous pressures were essentially normal. Isolated left ventricular dysfunction was primarily the result of increased afterload and responded to afterload reduction with arteriolar vasodilators. Continued measurement of PCWP permitted the titration of afterload reduction to the levels associated with normal ventricular filling pressures and volume. Since the relationship between right and left ventricular pressures may be disturbed in cardiogenic pulmonary edema, the Swan-Ganz catheter is the preferred method of hemodynamic monitoring in toxemic patients who develop cardiopulmonary dysfunction.

Role of solute excretion in prevention of norepinephrine-induced acute renal failure

Infusion of 0.75 μ g/kgbw/min norepinephrine (NE), for 40 minutes, into one renal artery in anesthetized dogs, induced acute renal failure (ARF). Subsequently there was nearly complete reversal of function within 8 weeks. Isotonic saline volume expansion, or renal vasodilation plus diuresis by acetylcholine (into renal artery: 20 μg/min) did not protect against this type of ARF. Volume expansion with either 5 or 20 percent mannitol partly prevented the fall of GFR 3 hours after NE, this protection being correlated with the magnitude of the osmolar clearance at the time of the insult. IV furosemide (10 mg/kg + 10 mg/kg/h; fluid losses replaced) afforded an even better protection. Proximal tubular necrosis in the "protected" kidneys was as severe as in non-protected kidneys. Glomerular cell morphology (scanning electron microscopy) was not altered by the 40-minute NE infusions. Functional "protection" appeared to depend on solute diuresis at the time of insult.