Transfusion malaria: treatment with exchange transfusion after delayed diagnosis.

A 65-year-old woman was rehospitalized for increasing mental confusion 16 days after open heart surgery for mitral stenosis. A diagnosis of transfusion-acquired falciparum malaria was made from a routine peripheral blood smear 24 hours after admission. Because progressive encephalopathy developed while she was receiving antimalarial drugs, a therapeutic exchange transfusion was performed. Clinical improvement occurred promptly during the exchange, and the patient went on to complete recovery from her malaria. The putative blood donor involved met the currently accepted standards for blood donors.

Characterization of a novel, high-molecular weight, acidic, endothelin-1 inactivating metalloendopeptidase from the rat kidney.

OBJECTIVE: To characterize endothelin-1 inactivating peptidase (ET-1 peptidase) recently isolated from rat kidney. METHODS: ET-1 peptidase was purified from the membranes of whole Wistar-Kyoto (WKY) rat kidneys using differential centrifugation, detergent solubilization, ion-exchange chromatography, ultrafiltration and preparative electrophoresis. The enzyme activity in the presence of increasing concentrations of unlabelled peptides, inhibitors and other substances was determined at pH 5.5 and 37 degrees C using fixed amounts of [125I]-ET-1 as the substrate. RESULTS: On non-denaturing gels, the purified enzyme migrated in the form of a compact, low-mobility (Rf 0.07), high relative molecular mass (approximately 250,000) protein band. During denaturing polyacrylamide gel electrophoresis this protein separated into three fractions with apparent relative molecular masses 158,000, 110,000 and 61,000. Using different buffers, the optimum pH for this enzyme was found to be 5.5. Zinc (3.7 mmol/l), nickel (4.0 mmol/l), citrate (0.6 mmol/l), phosphate (1.3 mmol/l) and barbital ions (2.5 mmol/l) inhibited ET-1 peptidase activity by 50%, whereas magnesium, calcium, cobalt, manganous, sodium and borate ions were without effect. The most powerful inhibitors of the enzyme included: phenanthroline [median inhibitory concentration (IC50) 28 mumol/l], phosphoramidon (IC50 8.0 nmol/l), thiorphan (IC50 32 nmol/l) and N-carboxymethyl-Phe-Leu (IC50 12 mumol/l). Also, bacitracin (25 mumol/l), cyclosporine A (20 mumol/l) and sodium dodecyl sulphate (0.5%) inhibited enzyme activity by 50%, whereas bestatin, puromycin, aprotinin, phenylmethylsulphonyl fluoride, amanitin (50-100 mumol/l) and cardiotoxin (25 micrograms/assay) had no effect. The Michaelis constant (Km) values of 70 and 66 nmol/l were found towards ET-1 and the ET(16-21) fragment, respectively, whereas the Km values in respect to big-ET-1, sarafotoxin S6b, sulphated cholecystokin octapeptide, gastrin, glucagon, insulin, gastric inhibitory peptide and growth hormone ranged from 1.5 to approximately 50 mumol/l. The enzyme showed no apparent affinity for enkephalins, bradykinin, angiotensins, cholecystokinin tetrapeptides and kyotorphin. CONCLUSIONS: The present data suggest that the ET-1 peptidase that we isolated from rat kidney displays inhibitory characteristics similar to that of other known metalloendopeptidases. However, this enzyme exhibits several unique properties such as high molecular mass, an apparent complex subunits structure, pH optimum at 5.5, and very high substrate specificity towards ET-1 and the ET(16-21) fragment compared with other peptides either related or unrelated to endothelin.

Endothelin-1 inactivating peptidase in the human kidney and urine.

OBJECTIVE: Recently, an apparently novel, specific endothelin-1 inactivating metalloendopeptidase (ET-1 peptidase) has been isolated from the rat kidney. In this study we attempted to determine whether the same or a similar peptidase is present in the human kidney, and whether the enzyme is excreted into the urine. The urinary ET-1 peptidase could serve as an indirect index of the renal endothelin system, both in physiology and pathophysiology. METHODS: Kidney specimens were obtained from part of nephrectomized kidneys unaffected by any neoplastic process from six adult patients. The enzyme was purified using differential centrifugation, detergent solubilization of the membrane proteins, ultrafiltration and nondenaturing gel electrophoresis. The enzyme activity assays were performed at pH 5.5 and 37 degrees C in the presence of increasing concentrations of unlabelled peptides and inhibitors using a fixed amount of [125I]ET-1 as substrate. The degradation extent was quantified with trichloroacetic acid precipitation and high performance liquid chromatography. The degrading activity of ET-1 was determined in urine samples from adult patients with hypertension, children with chronic renal failure and those with stable renal allograft RESULTS: ET-1 peptidase from the human kidney displays characteristics close to that of the rat ET-1 peptidase we have recently described (J. Hypertens 1994; 12:1155-1162). The enzyme, a membrane-bound metalloendopeptidase, exhibits low electro- phoretical mobility on nondenaturing gel (Rf 0.08); it is an apparently heterologous structure comprising three enzymatically inactive subunits, it has a pH optimum at 5.5, a nanomolar range affinity to the ET-1 (KM 180 nmol/l) that is hydrolysed to two main degradation products, and a 10-100-fold lower affinity to big ET-1 (KM 11.5 micromol/l), endothelin 11 21 fragment (KM 15.3 micromol/l), endothelin antagonist Trp-Leu-Asp-Ile-Ile-Trp (KM 3.1 micromol/I), gastrin (KM 2.2 micromol/l) and cholecystokinin (KM 4.0 micromol/l). Substance P, neuropeptide Y, atrial natriuretic peptide, bradykinin, angiotensin II and enkephalin were poor substrates for the enzyme. The most powerful inhibitors of the ET-1 peptidase included thiorphan (IC50 0.28 nmol/l), phosphoramidon (IC50 0.55 nmol/l), phenanthroline (IC50 11.5 micromol/l), cyclosporin (IC50 400 micromol/l), phosphate (IC50 1.2 mmol/l), citrate (IC50 0.6 mmol/l) and aniline naphthalene sulphonic acid (IC50 0.25 mmol/l). Our data suggest that three ET-1 degrading peptidases with optimal activity at pH 4.5, 5.5 and 7.0, respectively, are excreted into the urine. The enzyme with a pH optimum 4.5 is of lysosomal origin whereas the two other enzymes correspond by their pH optima to the renal ET-1 peptidase and neutral endopeptidase. We have found statistically significant increases (P < 0.001) in the activity of both lysosomal and ET-1 peptidase in the urine in patients with hypertension and in children with chronic renal failure compared with healthy subjects or children with stable renal allograft CONCLUSIONS: Human kidney contains an acidic, highly specific endothelin-1 inactivating metalloendopeptidase that may have a key role in the regulation of concentrations of renal and circulating endothelins. The enzyme is excreted into the urine where its activity seems to be increased in patients with hypertension and chronic renal failure; it may potentially serve as an indirect index of the renal endothelin system.

Purification of endothelin-1-inactivating peptidase from the rat kidney.

OBJECTIVE: To identify and purify endothelin-1-inactivating peptidase from rat tissues. METHODS: Subcellular fractions of rat kidney, aorta, heart, lung, liver and blood cells were prepared by differential centrifugation. Kidney membrane-bound peptidase was solubilized with Triton X-100, chromatographed on the diethylaminoethyl-cellulose, ultrafiltered through a membrane of relative molecular mass 100,000 cutoff and subjected to electrophoresis on a non-denaturing polyacrylamide gel. The enzyme activity assay was performed at pH 5.5 using [125I]-endothelin-1 as the substrate. The trichloroacetic acid precipitation test, an endothelin-1 immunoreactivity assay, reverse-phase high-performance liquid chromatography and a receptor-binding assay were applied for the detection of degradation products. RESULTS: High-activity endothelin-1-degrading peptidase coincided with the fraction from the kidney membranes of both Wistar-Kyoto and spontaneously hypertensive rats, but not with any other of the tissues that were studied. The membrane (0.5 microgram protein/assay) degraded [125I]-endothelin-1 (5-100 pmol/l) within a half-time of about 10 min at 37 degrees C. The enzyme was purified to an apparent homogeneity with non-denaturing gel electrophoresis, by which it was identified as a low-mobility (Rf 0.07) protein fraction of high relative molecular mass (> 250,000). The optimum pH was 5.5, with a little activity found outside the range 5.0-7.0. The activity of the peptidase was inhibited by 0.5 mmol/l 1,10 phenanthroline (half-maximal inhibitory concentration 0.03 mmol/l), and by 1 mmol/l EDTA, implicating a metalloenzyme. Bestatin, puromycin, phenylmethylsulphonyl fluoride and thiorphan were without effect. Unlabelled endothelin-1 inhibited the degradation of [125I]-endothelin-1 (half-maximal inhibitory concentration 100 nmol/l), whereas 100 mumol/l methionine enkephalin or angiotensin I did not. High-performance liquid chromatography analyses of the [125I]-endothelin-1 incubated with purified peptidase revealed a time-dependent accumulation of one major radioactive fraction that was soluble in trichloroacetic acid. This product (or products) was not further hydrolysed. It did not react with the endothelin antibodies or with the specific, myocardial membrane receptors. CONCLUSION: Our data suggest that the rat kidney contains an acidic metalloproteinase of high relative molecular mass that is able to hydrolyse endothelin-1 rapidly and efficiently in vitro. The enzyme may participate in the inactivation of circulating or tissue endothelins, or both.

Effects of knife-cut lesions of the medial forebrain bundle in self-stimulating rats.

Unilateral frontal-plane knife-cut lesions were made in the anterior medial forebrain bundle ipsilateral to a lateral hypothalamic self-stimulation electrode. Behavioral effects of the knife cut on self-stimulation reward and operant performance capacity were measured via the reward summation function method. Knife cuts placed at the level of the anterior commissure were ineffective in altering reward or motor/performance capacity, whereas knife cuts just posterior in the caudal lateral preoptic area degraded reward and sometimes impaired motor/performance capacity. In a second experiment, knife cuts placed posterior to the ventral tegmental area were ineffective unless they intruded on the ventral tegmental area itself. Several small knife cuts placed just anterior to the ventral tegmental were effective in reducing self-stimulation reward. The results are discussed in terms of the anatomical substrate of lateral hypothalamic self-stimulation reward and as a first step in a larger mapping study.

Avian cochlear hair cell regeneration: stereological analyses of damage and recovery from a single high dose of gentamicin.

Hair cell regeneration after acoustic trauma has been conclusively documented in birds. Previous studies of aminoglycoside ototoxicity have typically used 5-10 day courses of drug to damage the cochlea and trigger regeneration. This long-term lesion prevented analysis of the early events of regeneration. We set out to determine how much damage would occur and how recovery would proceed after a single high-dose injection of the aminoglycoside gentamicin. White Leghorn chicks were given a single high dose of gentamicin (100 mg/kg). Three post-injection survival groups with age-matched controls were studied: short-term (3-5 days), intermediate-term (2 weeks) and long-term (5 weeks). After sacrifice, cochleae were dissected and processed for scanning electron microscopy. Using stereological techniques, a quantitative analysis of cochlear hair cell counts along the proximal 50% of the cochlea was performed from scanning electron micrographs on 4-7 chicks from each group. Variable degrees of damage were seen 3-5 days after the drug injection. All hair cells were lost from the proximal 20% of the cochlea in all chicks. This complete hair cell loss could extend to 50% of the cochlea. Immature appearing hair cells could be first identified by their immature stereocilia at 3 days. Immature appearing hair cells were present in greatest number in regions which had been denuded of native hair cells and in regions where partial loss occurred. Interestingly, immature appearing hair cells also occasionally appeared in adjacent areas in which there was no apparent loss of native hair cells. Two-week survivors showed an elevation in hair cell number compared to controls in regions which had sustained damage and immediately adjacent regions. This elevation implies that an overproduction of hair cells might occur as part of the regeneration response. By 5 weeks after damage hair cell numbers approximated controls.

The sublabial transseptal transsphenoidal approach to sellar and parasellar lesions.

Multiple surgical approaches to the sella turcica have been described. The sublabial transseptal transsphenoidal approach provides a safe, cosmetically acceptable route to the sella with excellent exposure. Since 1976, we have employed this technique for the surgical treatment of pituitary neoplasms and parasellar tumors. The University of Washington experience with the sublabial transseptal transsphenoidal approach to the sella in a series of 253 patients is reported with respect to the otolaryngological aspects of the surgical technique, results, and complications of the procedure. In addition, a literature review of major studies that used this procedure is included, and the reported results and complications are compared to those of the present study.

Effect of thyroplasty on laryngeal airflow.

Thyroplasty has virtually replaced Teflon injection as the procedure of choice for treatment of the unilateral paralyzed vocal cord. Previous studies have shown that Teflon injection, by stiffening the vocal cord, decreases the extrathoracic airway obstruction occasionally measured by pulmonary function testing in patients with unilateral vocal cord paralysis. We became interested in the effect of thyroplasty on extrathoracic airflow. In this prospective study, patients underwent prethyroplasty and postthyroplasty pulmonary function testing. Flow volume loops combined with traditional spirometry were used. Postoperative pulmonary function tests were performed at least 2 months after surgery to allow resolution of surgical edema. Our study results support the previous finding that vocal cord paralysis alone causes some degree of extrathoracic obstruction. However, in contrast to Teflon injection, thyroplasty decreased extrathoracic airflow in all but 1 patient, and by criteria based on the ratio of the midexpiratory flow to the midinspiratory flow, caused new postoperative extrathoracic obstruction in 27% of patients. Symptomatic evidence of this obstruction may be more evident in those active patients with more ventilatory demand.

[Influence of nitrates on red blood cell deformability and clinical parameters in patients with silent ischemia]. / Wplyw azotanów na odksztalcalnosc krwinek czerwonych i parametry kliniczne chorych z niemym niedokrwieniem.

In 30 patients after myocardial infarctum with actual silent ischemia (no pain during last 12 months) mononitrate (Olicard 40) was administered and red blood cell deformability was determined. Clinical improvement and decrease of aforementioned deformability were observed after mononitrate therapy.

Muscular dystrophy.

Muscular dystrophy can be a devastating diagnosis for children and their families. Understanding the potential course, prognosis, and genetic implications for the child and his/her family is dependent on the diagnosis of the specific type of dystrophy. This article suggests a sequential evaluation of children with possible muscular dystrophy and reviews the more common types.

A randomized crossover trial of levodopa in congestive heart failure.

BACKGROUND: The short- and long-term effects of levodopa (L-dopa), an oral dopaminergic prodrug, were assessed in patients with severe left ventricular dysfunction. METHODS AND RESULTS: Initially, 26 patients were included in the study group. After clinical, radiographic, and radionuclide examination, each patient underwent right heart catheterization (Swan-Ganz thermodilution catheter). Plasma noradrenaline levels were measured. In two patients, a favorable hemodynamic response to L-dopa was not observed, another two required permanent pacemaker implantation. These four patients were excluded from the study. Two patients required permanent pacemaker implantation. The remaining 22 patients with favorable hemodynamic response to L-dopa (increase in cardiac index, stroke volume index, reduction in total systemic resistance) were randomized in a nonblinded fashion to the conventional (11 patients) or conventional plus L-dopa (11 patients) treatment groups. During the study period, two patients, one from each group, died. They were excluded from the analysis. The final analyzed study group consisted of 20 men, aged 33-69, in New York Heart Association functional class IV (9 patients) and III (11 patients). The cause of congestive heart failure was primary dilated cardiomyopathy in 11 patients and ischemic heart disease in 9 patients. After 3 months' treatment, all patients were crossed over. Clinical, radiographic, radionuclide, and hemodynamic evaluation was repeated at the end of the 3-month treatment period. After 3 months of therapy with L-dopa in each group (covariance analysis), there was improvement in clinical, radiographic (relative heart volume, -128 mL/m2), radionuclide (left ventricular ejection fraction, +4.6; right ventricular ejection fraction, +4.8%), hemodynamic (mean pulmonary wedge pressure, -8 mmHg; total systemic resistance, -1.8 Wu; total pulmonary resistance, -3.5 Wu), and neurohumoral (noradrenaline, -218 pg/mL) measures. CONCLUSIONS: The addition of L-dopa to conventional therapy has beneficial short- and long-term effects in patients with severe left ventricular dysfunction.

Enhancement of metabolic activity in the diencephalon of monkeys performing working memory task: a 2-deoxyglucose study in behaving rhesus monkeys.

The 2-deoxyglucose (2-DG) method was used to study the effect of working memory processing on local cerebral glucose utilization (LCGU) in the diencephalon of the rhesus monkey. Monkeys were given [(14)C]2-DG while performing either one of three tasks that engaged working memory (WORK group) or one of two control tasks (CONT group) that used associative or non associative processes. The tasks of the WORK group-spatial delayed response, spatial delayed alternation, and delayed object alternation-are alike in that the information guiding a correct response changes from trial to trial and only the accurate record of the preceding response (or cue) is relevant for each successive trial. The CONT group, in contrast, performed on either a visual pattern discrimination test, in which the correct stimulus-response association was invariant across all trials and all test sessions, or on a sensorimotor task in which there was no explicit memory requirement. LCGU was examined in five diencephalic regions: the mammillary bodies, the anteroventral and anteromedial thalamus, and the parvocellular and magnocellular components of the mediodorsal thalamic nucleus. Comparisons across the two groups showed that mean LCGU in the anterior and mediodorsal thalamic nuclei was significantly elevated (by 12-16%) in the WORK group relative to the CONT group. Mean LCGU in the mammillary bodies also was higher in the WORK group than in the CONT group, but this difference was not significant. The present findings suggest that the anterior and mediodorsal thalamic nuclei represent diecephalic components of a neural network processing working memory. Together with our previous report on the enhancement of metabolic activity in the hippocampus and dentate gyrus, these results show that working memory has a wide-ranging influence on cerebral metabolism and emphasize the cooperative, rather than dissociable, roles of the hippocampus and medial thalamus in this function.

Progression of follicular large cell lymphoma to Burkitt's lymphoma.

Histologic progression of lymphoma into more aggressive cell types is well documented. We describe a patient who had the histologic and cytogenetic features of Burkitt's lymphoma after 15 years of therapy for follicular large cell lymphoma. To the best of our knowledge, this clinical progression with histologic and cytogenetic confirmation has not been reported.

Uniparental disomy of the entire X chromosome in a female with Duchenne muscular dystrophy.

Duchenne muscular dystrophy (DMD) is a severe, progressive, X-linked muscle-wasting disorder with an incidence of approximately 1/3,500 male births. Females are also affected, in rare instances. The manifestation of mild to severe symptoms in female carriers of dystrophin mutations is often the result of the preferential inactivation of the X chromosome carrying the normal dystrophin gene. The severity of the symptoms is dependent on the proportion of cells that have inactivated the normal X chromosome. A skewed pattern of X inactivation is also responsible for the clinical manifestation of DMD in females carrying X;autosome translocations, which disrupt the dystrophin gene. DMD may also be observed in females with Turner syndrome (45,X), if the remaining X chromosome carries a DMD mutation. We report here the case of a karyotypically normal female affected with DMD as a result of homozygosity for a deletion of exon 50 of the dystrophin gene. PCR analysis of microsatellite markers spanning the length of the X chromosome demonstrated that homozygosity for the dystrophin gene mutation was caused by maternal isodisomy for the entire X chromosome. This finding demonstrates that uniparental isodisomy of the X chromosome is an additional mechanism for the expression of X-linked recessive disorders. The proband's clinical presentation is consistent with the absence of imprinted genes (i.e., genes that are selectively expressed based on the parent of origin) on the X chromosome.

Hematologic neoplasia and the central nervous system.

Central nervous system (CNS) involvement with malignant cells is a well recognized complication of hematologic neoplasms. A number of disorders such as acute lymphoblastic leukemia and high grade lymphoma frequently involve the CNS and prophylactic therapy is advised. Disorders such as acute myeloid leukemia (AML) and multiple myeloma are less likely to be associated with CNS involvement. This series describes three cases of CNS involvement by malignant hematologic disease: myelomatous meningitis, CNS chloromas complicating AML, and primary lymphomatous meningitis.