US Guidelines for immune tolerance induction in patients with haemophilia a and inhibitors.

INTRODUCTION: The development of anti-factor VIII (FVIII) antibodies (inhibitors) is the most serious treatment-related complication in patients with hemophilia A, rendering standard replacement therapy ineffective, heightening the risk for uncontrollable bleeding and morbidity, decreasing quality of life, and increasing healthcare costs. AIM: Formulate evidence-based guidelines for optimizing immune tolerance induction (ITI) in patients with hemophilia A and inhibitors. METHODS: Results from the International ITI study and other available evidence were used to develop guidelines for ITI. RESULTS: Predictors of ITI success were identified and recommendations made for ITI with regard to candidates, timing, product, regimen, monitoring, defining success, concurrent immunomodulation, duration of treatment, and bleed management before and during ITI. CONCLUSION: Evidence-based recommendations to guide treatment decisions may increase the likelihood of successful inhibitor eradication and the induction of FVIII tolerance in patients with hemophilia A who develop inhibitory antibodies.

Peroxidation of subcellular organelles: formation of lipofuscinlike fluorescent pigments.

Lipid peroxidation of subcellular organelles gives fluorescent products which have fluorescence and excitation spectra similar to those of lipofuscin pigments. Fluorescence and excitation spectra and total fluorescence in the 460-nanometer region are useful for qualitative identification and quantitative measurement of the Schiff base product, a molecular damage site of lipid peroxidation which develops during some aging processes.

Alteration of kidney brush border membrane maltase in aging rats.

The specific activities of membrane-bound maltase (alpha-d-glucoside glucohydrolase, EC 3.2.1.20) in renal cortex homogenates and isolated brush border membranes of senescent rats decreased about 30% compared to the specific activities of the enzyme from young adult animals. The decline was gradual and concomitant with the aging process. When the enzymes from rats of 25 and 6 months of age were solubilized and purified to homogeneity the same decrement with age was found, 32.5 and 46.1 units/mg of protein, respectively. This finding suggests that the decrease in maltase activity with age results from an alteration in the enzyme per se, rather than from a change in the enzyme's membrane environment, which was reflected secondarily as a loss in activity. Recoveries of enzyme activity and protein and fold-purification were similar for young and old maltase, indicating that the age-related difference in specific activities of the pure enzymes was not due to the selective purification of an altered species of enzyme. The age-associated difference in activity was not attributable to the presence of proteolytic activity in the homogenate nor to the presence of an activator in the young or an inhibitor in the old kidney. The pure enzymes from young adult and aged animals did not differ in molecular weight, electrophoretic mobility, amino acid composition and Km value. Circular dichroism spectra revealed that both the young and old enzymes contained beta-structure. However, the old enzyme had more helical structure than did the young enzyme, suggesting a conformational alteration with age.

Veno-occlusive disease of the liver in children with solid tumors undergoing autologous hematopoietic progenitor cell transplantation: a high incidence in patients with neuroblastoma.

We retrospectively analyzed the incidence and risk factors for veno-occlusive disease (VOD) in 83 consecutive children with solid tumors, who underwent autologous blood or bone marrow (BM) transplantation at UCSF between 1992 and 2000. Forty-one patients were diagnosed with neuroblastoma and 42 had another solid tumor (Ewing's sarcoma, soft tissue sarcomas, germ cell tumors, etc). Patients with neuroblastoma were more likely than patients with other solid tumors (ST) to be < or =7 years of age, to have a decreased serum albumin level, and to have received abdominal radiation and surgery prior to transplant. Patients with neuroblastoma received a different conditioning regimen and a purged stem cell product. Twenty patients (24%) developed VOD. VOD was self-limited in 15 (75%) patients and severe in five (25%) patients. Univariate analysis identified the following risk factors for VOD: diagnosis of neuroblastoma (odds ratio 6.1, P < 0.01), abdominal radiation (odds ratio 4.1, P < 0.01), abdominal surgery (odds ratio 4.1, P < 0.01), and age < or =7 years of age (odds ratio 3.3, P = 0.02). Disease status at transplant, intensity of previous chemotherapy, conditioning regimen, progenitor cell source, ALT, AST, albumin level, renal function prior to transplant, or use of amphotericin, growth-factor or heparin during transplant, did not affect the incidence of VOD. On multivariate analysis, only the diagnosis of neuroblastoma remained significant (odds ratio 7.8, P = 0.03). Larger studies of patients with neuroblastoma are necessary in order to confirm our findings and better define the risk factors for VOD development in neuroblastoma patients.

Definition of a critical T cell threshold for prevention of GVHD after HLA non-identical PBPC transplantation in children.

The aim of this study was to reduce the rate of graft failure after HLA non-identical stem cell transplantation by using G-CSF mobilized CD34+ peripheral blood progenitor cells (PBPC), either in combination with bone marrow or as single grafts. To prevent GVHD, PBPC were highly purified, resulting in a 5 to 6 log T cell depletion. In additon to T cell depletion no further GVHD prophylaxis was used. We transplanted 23 pediatric patients with life-threatening malignant or non-malignant hematological disorders, who had no available matched donor. Engraftment was obtained in 18 of 21 evaluable patients. Five patients developed acute GVHD of grade II and III, which became chronic in four cases and was fatal in four. The use of highly purified PBPC allowed the exact quantification of residual T cells in the grafts and a strict correlation between the residual T cell load and the development of GVHD was observed: patients with GVHD had received numbers of T cells between 8 and 20 x 104/kg, whereas patients without GVHD were grafted with T cell numbers ranging from 0.7 to 6.0 x 104/kg. We therefore clearly demonstrate that a residual T cell content of <5 x 104/kg is safe for prevention of GVHD after HLA non-identical PBPC transplantation in children.

Prostaglandin F2alpha human blood during labor.

Plasma prostaglandin F2alpha (PGF2alpha) concentrations were determined by radioimmunoassay in serial samples during labor and the early postpartum period. PGF2alpha was also measured during and between contractions every 20 to 30 seconds. The highest levels of PGF2alpha were found during expulsion of the fetus and placenta with an additional rise half an hour after delivery and a decrease 2 hours after delivery to the levels of first stage of labor. PGF2alpha values from cord blood were higher than in maternal peripheral blood in labor. The maximum PGF2alpha concentration occurred between 100 to 120 seconds after the peak uterine contraction and between 40 and 60 seconds prior to peak of the next contraction. The possible explanation is that PGF2alpha initiates uterine contractions and plays a role in the maintenance of labor, in the expulsion of the fetus and the placenta, and in the involution after delivery.

The effect of indomethacin in labour at term.

The effect of indomethacin as an antagonist to prostaglandin was evaluated on a series of 16 women during spontaneous labour in the ninth month of pregnancy. The evaluation of the effect of indomethacin on the progression of labour was determined by the deviation from the normal curve of Friedman. In 8 cases there was complete cessation of labour from 3 to 192 hours and in 8 additional cases there was protraction of the active phase from 3 to 17 hours. In 2 cases there was no effect. Seven births terminated spontaneously and in 9 cases it was necessary to administer pitocin intravenously to strengthen or renew contractions in order to terminate the pregnancy. There is no correlation between the obstetric state (the degree of cervical dilation, or effacement or rupture of membranes) at the time of indomethacin administration and the uterine response, or the speed of return to the normal curve of Friedman. The effect of indomethacin, as an antagonist to prostaglandin, at the time of labour was studied.

[Is there a clinical indication for the determination of atrial natriuretic peptide?]. / Gibt es eine klinische Indikation für die Bestimmung des atrialen natriuretischen Peptids?

Atrial natriuretic peptide (ANP) is a hormone produced, stored and secreted by atrial muscle cells. By its natriuretic, diuretic and blood pressure lowering activities ANP is possibly an endogenic antagonist for the sodium-retaining, vasopressor renin-angiotensin-aldosterone system (RAAS). In diseases associated with increased intravascular volume ANP plasma concentrations have been found elevated, in those associated with decreased volume ANP has been found decreased. In essential hypertension and chronic heart or renal failure diagnostic conclusions may be drawn from the ANP plasma concentration. This review summarizes the present knowledge about physiology and pathophysiology of ANP and values in addition the diagnostic power of ANP measurements for clinical routine in hypertension, heart and renal failure.

Function of the sexually dimorphic ear of the American bullfrog, Rana catesbeiana: brief review and new insight.

The dimorphic ear of the bullfrog, Rana catesbeiana, has long been enigmatic. The male's tympanic membrane (TM) area approximates twice the area of the female's; however, similar size differences in the area of the columellar footplate were not observed between the sexes. Hence, the male's hearing is expected to be more sensitive than the female's but this is not the case. Asking what offsets the advantage of the large TM, we applied a series of experiments to the auditory system. Male and female audiograms based on stimulation with airborne sound and on both multi-unit responses from the brain and alternating cochlear potentials ('microphonics') showed equal sensitivity and a small difference in frequency response; at low frequencies the male was more sensitive than the female. Amputating the columella and stimulating the stump with mechanical vibration showed that for an equal microphonic response, the male's footplate vibrated with lower amplitude than the female's footplate. Mechanically stimulating the TM of the intact ear replicated this result, excluding the involvement of the mechanical lever. The TM of the male weighs five times the TM of the female, and artificial loading of the TM of either sex greatly reduced the ear's sensitivity. Hence, the male's excessive area ratio (TM to columellar footplate) is offset by the heavier cartilage cushion on the male's TM, damping the TM's response to sound. This is corroborated by experimentally artificially loading the TM. The product of area ratio and footplate vibration amplitude would result in similar stimulation of the inner ear in the two sexes.

Monoclonal antibodies to renal brush border membrane maltase: age-associated antigenic alterations.

Monoclonal antibodies to maltase (alpha-D-glucoside glucohydrolase, EC 3.2.1.20) from young adult and aged rats were prepared by the hybridoma technique. Four cell lines producing antibodies of the IgG1 subclass to maltase were established. Two, designated 1F12E1 and 8B1G6, produced monoclonal antibodies specific for the catalytically active form of the enzyme found predominantly in enzyme preparations from young animals. The other two clones designated 7G10H3 and 2E1C10 produced monoclonal antibodies that reacted exclusively with an enzymatically inactive form of maltase found mostly in enzyme preparations from aged rats. The increased prevalence of an inactive form of the enzyme in the old rat accounts for the decreased maltase-specific activity previously reported in the senescent rat. The active and inactive maltase species were separated by immunoaffinity chromatography by using the monoclonal antibodies as ligands. The separated forms of the enzyme were not distinguished by NaDodSO4/polyacrylamide gel electrophoresis, peptide mapping of the CNBr-cleaved proteins, and the NH2-terminal residues of these peptides. This study demonstrates the presence of an altered, antigenically distinct enzyme in senescent animals. Critical issues on the mechanism of the aging process may be addressed by application of these findings.

Age-related changes in isocitrate lyase from the free living nematode, Turbatrix aceti.

Isocitrate lyase from both young and old free living nematodes (Turbatrix aceti) has been purified and compared. The "old" enzyme consists of the same five isozymes as the "young" preparation, but with quantitative differences. The enzyme shows an age-related decline in specific activity. Use of antibodies has confirmed the accumulation of cross-reacting material in old organisms as found by Gershon and Gershon ((1970) Nature 227, 1214), using crude homogenates. Km, molecular weight, subunit size, and behavior toward the inhibitors oxalate, malonate, and tartronate all appear unchanged. Although the enzyme isolated from old organisms has a sharply reduced specific activity, it binds as well to an affinity column as does "young" enzyme. It is tentatively concluded that the loss of specific activity in the "old" enzyme is due to the presence of partially active molecules, rather than to a mixture of active and inactive molecules.

Rat-liver superoxide dismutase. Purification and age-related modifications.

Cytoplasmic superoxide dismutase has been purified from livers of young (6 months) and old (27 months) rats. The enzyme purified from old animals shows an age-related reduction in the specific activity, accumulation of antigenically cross-reacting material and increased sensitivity to temperature. No differences were found in the molecular weight, electrophoretic mobility, antigenicity and Ki between enzymes purified from young and old rats. This is the first demonstration of age-related alterations in a purified form of a non-metabolic enzyme, which can be related to reduced activity. The possible role of this reduced activity in age-dependent deterioration of cellular functions is discussed.

Mortality trends in pediatric patients with chronic renal failure.

Mortality trends were analyzed in 441 children and adolescents with chronic renal failure (CRF) observed over a 24-year period before and after institution of renal replacement therapy (RRT). A total of 93 patients died. Overall mortality rate (MR) per 100 patient years decreased from 6.6 in 1969-1978 to 2.5 in 1979-1988 and increased slightly to 2.9 in 1989-1992. The fall involved all four modes of treatment: conservative, hemodialysis (HD), continuous peritoneal dialysis (CPD), and transplantation (TX). From 1979-1988 to 1989-1992 MR on conservative and on dialysis treatment changed only slightly and was similar on HD and CPD. An alarming rise in MR was noted after TX in 1989-1992, mainly due to malignant tumors. In 44 patients who died on conservative treatment, the reasons for non-acceptance for RRT were analyzed: in 22 multi-morbidity was the main reason, usually because of a congenital neurological disorder. Some patients died from advanced uremia or unexpected events after the decision to institute RRT. Our experience demonstrates a persistent mortality in pediatric patients with CRF, which in recent years is primarily ascribed to congenital multi-morbid conditions which make RRT unfeasible, infections on dialysis treatment, and malignancies after TX.