No association between body mass index and beta(3)-adrenergic receptor variant (W64R) in children with premature pubarche and adolescent girls with hyperandrogenism

OBJECTIVE

To determine if the Trp(64)Arg (W64R) variant of the beta(3)-adrenergic receptor (ADRB3) could be used as a genetic marker to define risk for polycystic ovary syndrom (PCOS) and/or obesity in children and adolescents.

DESIGN

Association study.

SETTING

Academic research environment.

PATIENT(S)

Children referred for evaluation of premature pubic hair (n = 63), adolescent girls referred for evaluation of hirsutism and/or oligomenorrhea (n = 33), and healthy adult controls (n = 67).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Relationship of body mass index (BMI) to presence or absence of W64R variant and frequency of W64R variant in our patient population.

RESULT(S)

Body mass index (kg/m(2)) was determined for 63 children (55 girls and 8 boys) and 33 adolescent girls. Presence or absence of the W64R variant was assayed by polymerase chain reaction (PCR) amplification followed by allele-specific restriction fragment digest. Twelve subjects and 11 healthy controls were found to be heterozygous for the W64R variant. One subject was found to be homozygous for the W64R variant. Allele frequency for the W64R variant was comparable between patients and controls. Among the patients, mean BMI values were not different between carriers and noncarriers.

CONCLUSION(S)

Although other studies suggest that the W64R variant is associated with the development of obesity and insulin resistance, we cannot demonstrate that it has a major effect on BMI in children with premature pubarche or in adolescent girls with hyperandrogenism. Serial observations are necessary to determine if this variant predicts the development of obesity and/or PCOS in adulthood.

SHIP-mediated inhibition of K562 erythroid differentiation requires an intact catalytic domain and Shc binding site

Growing evidence supports a role for the SHIP inositol 5'-phosphatase in the negative regulation of a variety of receptor-mediated signaling pathways in hematopoietic cells. SHIP expression among cultured cell lines was examined and found to be restricted to cells of hematopoietic origin, with the exception of the K562 erythroleukemia cell line, in which SHIP protein and mRNA were undetectable. The absence of endogenous SHIP in K562 cells provided a useful system to study the role of SHIP in growth and differentiation. When stably expressed in K562 cells, SHIP was found to be constitutively tyrosine phosphorylated and associated with endogenous Shc and Grb-2. Stable expression of SHIP did not affect growth of the cells but resulted in decreased synthesis of hemoglobin protein and epsilon-globin mRNA in response to hemin, an inducer of erythroid differentiation. This effect was not due to increased cell death in the SHIP-expressing lines following hemin stimulation, but was likely the result of an impaired differentiation program in these cells. Mutational analysis indicated that SHIP must retain both an intact catalytic domain and Shc binding site to efficiently inhibit K562 erythroid differentiation.

Cross-reactivity of the monoclonal antibody 9E10 with murine c-MYC

The C-terminal regions of the human and the murine c-MYC consist of a common conserved sequence, the amino acids (a.a.) 418-439 with one terminal exchange (C438G). The pre-C-terminal region of both proteins, a.a. 408-417, exhibit four exchanges. A commercially available monoclonal antibody, 9E10, raised against the C-terminal a. a. 408-439 of human c-MYC, is declared to recognize specifically and exclusively human c-MYC. However, in an immunofluorescence assay we observed, in addition to the reaction with a human cell line (SV80), reactivity with the murine cell line L929. In analogy, a rabbit polyclonal antiserum raised against a peptide which corresponds to the murine pre-C-terminus of c-MYC, a.a. 408-417, showed also cross-reactivity in immunofluorescence. The immunostaining with both anti-bodies in the human and the murine cell line was competed by the peptide, corresponding to the murine pre-C-terminal a.a. 408-417, whereas the staining of both cell lines with an antiserum raised against the conserved N-terminal region of c-MYC was not competed by this peptide. The cross-reactivity of 9E10 with murine c-MYC was confirmed by Western blot using two additional cell lines. In conclusion, our findings indicate that 9E10 which is generally regarded as specific for human c-MYC cross-reacts with denaturated murine c-MYC.

Human immunodeficiency virus type 1 cDNA integration: new aromatic hydroxylated inhibitors and studies of the inhibition mechanism

Integration of the human immunodeficiency virus type 1 (HIV-1) cDNA is a required step for viral replication. Integrase, the virus-encoded enzyme important for integration, has not yet been exploited as a target for clinically useful inhibitors. Here we report on the identification of new polyhydroxylated aromatic inhibitors of integrase including ellagic acid, purpurogallin, 4,8, 12-trioxatricornan, and hypericin, the last of which is known to inhibit viral replication. These compounds and others were characterized in assays with subviral preintegration complexes (PICs) isolated from HIV-1-infected cells. Hypericin was found to inhibit PIC assays, while the other compounds tested were inactive. Counterscreening of these and other integrase inhibitors against additional DNA-modifying enzymes revealed that none of the polyhydroxylated aromatic compounds are active against enzymes that do not require metals (methylases, a pox virus topoisomerase). However, all were cross-reactive with metal-requiring enzymes (restriction enzymes, a reverse transcriptase), implicating metal atoms in the inhibitory mechanism. In mechanistic studies, we localized binding of some inhibitors to the catalytic domain of integrase by assaying competition of binding by labeled nucleotides. These findings help elucidate the mechanism of action of the polyhydroxylated aromatic inhibitors and provide practical guidance for further inhibitor development.

Doctor-patient relationship in oncological illness: the "talking medicine"

For any physician, sympathetic interaction with his/her patients should remain a central concern. It is his/her task to understand the patient's hopes, fears, anxieties and social situation, as well as to understand himself and his own motives and attitudes, which can often be identified as helplessness. Continually advancing technology, rationalization, time, and the pressure for success leave less and less room for such considerations in medical practice. While patients often consider their medical care as very good, they, however, complain that the emotional support is often insufficient. Thus, for the benefit of both the doctor and the patient, every physician has to assure compassion in his relationship with the patients. Medical doctors taking care of cancer patients do not need only thorough medical training but also additional training in psychosomatic medicine.

Heart transplantation in patients with heparin-induced thrombocytopenia on the Novacor left ventricular assist system

We report on two patients with development of heparin-induced thrombocytopenia with thrombosis while on the Novacor left ventricular assist system. Heart transplantation was successfully performed in both patients with heparin used for cardiopulmonary bypass after careful monitoring of heparin-associated antibodies. The approach to the patients' management and potential alternatives for anticoagulation are discussed.

Role of reactive oxygen intermediates in activation-induced CD95 (APO-1/Fas) ligand expression

Activation-induced cell death of T lymphocytes requires the inducible expression of CD95 (APO-1/Fas) ligand, which triggers apoptosis in CD95-bearing target cells by an autocrine or paracrine mechanism. Although execution of the CD95 death pathway is largely independent of reactive oxygen intermediates, activation-induced cell death is blocked by a variety of antioxidants. In the present study, we investigated the involvement of redox processes in the regulation of CD95 ligand (CD95L) expression in Jurkat T cells. We show that various antioxidants potently inhibited the transcriptional activation of CD95L following T cell receptor ligation or stimulation of cells with phorbol ester and ionomycin. Conversely, a prooxidant such as hydrogen peroxide alone was able to increase CD95L expression. As detected by Western blot and cytotoxicity assays, functional expression of CD95L protein was likewise diminished by antioxidants. Inhibition of CD95L expression was associated with a decreased DNA binding activity of nuclear factor (NF)-kappaB, an important redox-controlled transcription factor. Moreover, inhibition of NF-kappaB activity by a transdominant IkappaB mutant attenuated CD95L expression. Our data suggest that, although reactive oxygen intermediates do not act as mediators in the execution phase of CD95-mediated apoptosis, they are involved in the transcriptional regulation of CD95L expression.

Augmenting and reducing of visual evoked potentials in high- and low-sensation seeking humans, cats, and rats

High- and low-sensation seeking behaviors in human and cat are shown to be correlated with visual evoked potential (VEP) augmenting and reducing, respectively. Demonstration of this relationship in RHA/Verh and RLA/Verh rats provides a heuristic animal model with which to investigate the physiological and genetic basis of this relationship. Recent work is described which shows that VEP augmenting and reducing is a true cortical phenomenon and not merely a reflection of differences occurring at the thalamus. Recent evidence is discussed that suggests the role of diffuse subcortical monoaminergic projections to the cortex as the neurochemical basis for sensation seeking behaviors controlled by prefrontal and limbic cortex and perhaps the correlated VEP augmenting/reducing responses recorded from the posterior cortex.

Butyrate modulates DNA-damage-induced p53 response by induction of p53-independent differentiation and apoptosis

Butyrate, a physiologically occurring agent, has been reported to decrease constitutively high expressed p53 levels in transformed cells. To elucidate whether butyrate also inhibits DNA-damage-induced p53 response we investigated the effects of butyrate and the anticancer drug mitomycin C in normal C3H10T1/2 cells harbouring wild-type p53. In comparison with p53-deficient fibroblasts we examined p53 protein level, cell cycle arrest, differentiation, and apoptosis. Butyrate induced G1 phase arrest, differentiation, and p53-independent increase in p21(waf1/cip1) protein. Moreover, butyrate induced p53-independent apoptosis, which was, as well as p53-mediated apoptosis, associated with a dose-dependent increase in Bax and c-Myc protein. Pretreatment with butyrate repressed dose-dependently mitomycin-C-induced p53 accumulation and interfered with p53-dependent cell cycle arrest. Butyrate further partially inhibited p53-mediated apoptosis, but low doses of butyrate were more effective than higher concentrations. This was reflected in an enhanced decrease in c-Myc and Bax protein in response to mitomycin C with low concentrations of butyrate. Our data indicate that the differentiation stimulus of butyrate, in association with p21(waf1/cip1) induction, and apoptosis, may explain antineoplastic effects of butyrate. Co-carcinogenic features of butyrate may result from inhibition of p53-mediated DNA damage response.

Moclobemide in social phobia: a controlled dose-response trial

Although the monoamine oxidase inhibitor phenelzine has proven efficacious in social phobia, the risk of hypertensive crises has reduced its acceptability. The reversible monoamine oxidase inhibitor moclobemide has less potential for such reactions, but its efficacy in this disorder remains unproven. A double-blind, placebo-controlled study was undertaken to assess the efficacy and safety of fixed doses of moclobemide. After a 1-week placebo run-in, subjects with social phobia were randomly assigned to placebo or one of five doses (75 mg, 150 mg, 300 mg, 600 mg, or 900 mg daily) of moclobemide for 12 weeks. Although a trend toward greater efficacy of higher doses of moclobemide was observed at 8 weeks, no differences in response to various doses of the drug and placebo were observed at 12 weeks. At 12 weeks, 35% of subjects on 900 mg of moclobemide and 33% of those on placebo were at least much improved. Moclobemide was well tolerated, insomnia being the only dose-related adverse event observed with the drug. In this dose-response trial, moclobemide did not demonstrate efficacy at 12 weeks. Some other controlled studies have found moclobemide and brofaromine, another reversible monoamine oxidase inhibitor, efficacious in social phobia. Possible reasons for inconsistent findings are discussed.

Managing the care of the diabetic transplant patient

Care of the diabetic transplant patient presents many challenges for therapeutic management. Complications of diabetes such as retinopathy, neuropathy, hyperglycemia, and hypertension add to the already difficult management of nondiabetic transplant patients. The role of the pharmacist as an educator, counselor, and interaction and profile manager is an essential part of a successful transplant program. Understanding the purpose of the medications and their side effects is vital for the patient to comply with a demanding medication regimen. This depth of understanding cannot be conveyed without repetitive educational efforts that are reinforced by all of the health care practitioners and supportive family members. Although kidney transplantation offers freedom from dialysis, it does not offer freedom from insulin dependence. Kidney-pancreas, pancreas, or islet cell transplantation may provide insulin independence and are the only curative interventions available. Evaluation of the research literature compares the advantages and complications of these surgical modalities. Early intervention with transplantation may offer insulin-dependent diabetics a new opportunity to improve their quality of life; however, intensive educational efforts and assurance of compliance are essential for successful outcomes.

GABA release in the dorsal raphe nucleus: role in the control of REM sleep

The cessation of firing of serotonergic dorsal raphe neurons is a key controlling event of rapid eye movement (REM) sleep. We tested the hypothesis that this cessation of activity is due to gamma-aminobutyric acid (GABA) release using the in vivo microdialysis technique. We found that REM sleep is accompanied by a selective increase in GABA release, but not by a change in glutamate or glycine release in the dorsal raphe nucleus. Microinjection of the GABA agonist muscimol into the dorsal raphe increased REM sleep, although microperfusion of the GABA antagonist picrotoxin blocked REM sleep. These results implicate GABA release as a critical element in the production of the REM sleep state and in the control of discharge in serotonergic neurons across the sleep/wake cycle.

Modulation of cutaneous nociceptor activity by electrical stimulation in the brain stem does not inhibit the nociceptive excitation of dorsal horn neurons

In anesthetized cats, recordings were obtained from single lumbar dorsal horn neurons and from primary afferent fibers of the posterior tibial nerve excited by controlled noxious radiant heating of glabrous hindpaw skin. Electrical stimulation in four brain stem regions (periaqueductal gray and lateral reticular formation in the midbrain, raphe and reticular formation in the medulla) during noxious skin heating markedly reduced the nociceptive excitation of the dorsal horn neurons. In contrast, such brain stem stimulation had small and variable effects upon the noxious heat-evoked activity in the primary afferent fibers; both increases and decreases were observed. The brain stimulation also produced transient changes in blood pressure, suggesting that circulatory effects may underlie the mechanism of nociceptor modulation. It is concluded that brain stem stimulation can modulate cutaneous nociceptor activity, but that this modulatory effect on nociceptor inflow is too small and inconsistent to explain the marked descending inhibition of the nociceptive excitation of dorsal horn neurons.

Metabolic responses to interleukin-1: centrally and peripherally mediated

OBJECTIVE

The purpose of this study was to differentiate between the catabolic effects of interleukin-1 (IL-1) when infused into the central nervous system or into the periphery.

SUMMARY BACKGROUND DATA

After injury and infection, IL-1 has been found in the central nervous system. Chronic intracerebrovascular infusion of IL-1 produces protein catabolism, anorexia, and fever. However, IL-1 may act directly on liver and bone marrow to elicit metabolic responses. Although IL-1 is thought to be involved in a number of metabolic responses associated with injury-inflammation, the sites of action are unclear.

METHODS

Rats were implanted with chronic infusion pumps and received diluent or three doses of IL-1 infused subcutaneously for 6 days, and a variety of response variables were measured. In a second study, doses were adjusted so that similar systemic catabolic responses were obtained from peripheral and intracerebroventricular infusion of IL-1. The acute-phase responses then were compared in the two groups of animals receiving IL-1 by different routes.

RESULT

Subcutaneously infused IL-1 elicited catabolic responses in a dose-response manner. Similar catabolic responses were achieved by infusing one tenth of the dose of IL-1 given subcutaneously into the central nervous system. Although similar systemic responses (protein catabolism, anorexia, fever, and weight loss) were observed with both routes of infusion, the subcutaneous infusion produced a much greater lymphocytosis, elevation in acute-phase reactants, and fall in serum iron and albumin.

CONCLUSIONS

The IL-1 appears to have different effects depending on the site of production and site of action. Regionalization of signal proteins such as IL-1 should be taken into consideration when devising specific anticytokine treatment strategies.

The normal pediatric larynx on CT and MR

PURPOSE

To determine the MR and CT appearance of the normal pediatric larynx.

METHODS

Fifteen CT scans and 15 MR examinations of children with normal larynges and airways were reviewed retrospectively. Characteristics that were noted included the level of the hyoid bone, calcification and signal intensity within separate laryngeal components, amount of paraglottic fat, anteroposterior airway diameters, and airway contours. Two cadaveric larynges were imaged by CT and MR and were then sectioned at corresponding levels and section thicknesses.

RESULTS

The larynx is higher in children than in adults, with the hyoid bone found at the C2-3 level in the youngest children (newborn to 2 years). The subglottic airway was narrowest in the youngest children. The hyoid bone was the only laryngeal structure ossified in any of the children. A thin line of high density was seen in the expected location of the thyroid cartilage in some children. The featureless circumferential soft tissue seen around the airway represented the uncalcified laryngeal cartilaginous structures. This was confirmed on gross sectioning of cadaveric larynges. The supraglottic airway contour was triangular or oval, the glottis was shaped like a teardrop, and the subglottic contour was oval. Contours were confirmed on histologic examination of necropsy specimens.

CONCLUSIONS

This preliminary study suggests that the pediatric larynx differs from the adult larynx with respect to size, position, consistency, and shape, and these differences are reflected on CT and MR studies.

Apyrase administration prolongs discordant xenograft survival

Platelet thrombi and vascular inflammation are prominent features of discordant xenograft rejection. The purinergic nucleotides ATP and ADP, which are secreted from platelets and released by injured endothelial cells (EC), are important mediators of these reactions. Quiescent EC express the ectoenzyme ATP-diphosphohydrolase (ATPDase; an apyrase), which exerts an important thromboregulatory function by hydrolyzing both ATP and ADP. We have shown that ATPDase activity is rapidly lost from the surface of the EC following ischemia-reperfusion injury and during xenograft rejection. The aim of this study was to supplement ATPDase activity within xenografts by infusion of soluble apyrases, and thereby validate the importance of local ATPDase activity in the modulation of xenograft rejection. Lewis rats underwent heterotopic cardiac xenografting from guinea pigs and apyrase was administered intravenously (200 U/kg) as a single dose to evaluate effects on hyperacute rejection (HAR). This initial dose was followed by a continuous apyrase infusion (8.0 U/kg/hr) directly into the graft aorta in combination with systemic cobra venom factor (CVF) administration to deplete complement when delayed xenograft rejection (DXR) was studied. Functional apyrase levels in vivo were assessed by the capacity of blood samples taken at the time of surgery and rejection to inhibit platelet aggregation in vitro. Apyrase administration significantly prolonged graft survival in HAR and DXR. Functional assays showed inhibition of platelet aggregation suggesting effective systemic antiaggregatory effects of the administered apyrases. Histologic studies showed that apyrase administration abrogated local platelet aggregation and activation in HAR and DXR. Our data demonstrate that local administration of apyrase prolonged discordant xenograft survival. These observations emphasize the potential importance of purinergic mediators in platelet activation during xenograft rejection.

Laboratory findings in hypertensive disorders of pregnancy

This study sought to determine whether a normal platelet count is a reliable predictor of the absence of other coagulation abnormalities in patients with a hypertensive disorder of pregnancy. A retrospective review of laboratory data obtained from 80 patients with hypertensive disorders of pregnancy was carried out. Results of complete blood cell count, prothrombin time (PT), partial thromboplastin time (PTT), D-dimer, fibrin split products, and fibrinogen, bilirubin, and liver enzyme levels were reviewed. Minor abnormalities of PT, PTT, and fibrinogen level were frequent, even in the presence of a normal platelet count. These were found mostly in patients with severe pre-eclampsia. A baseline complete blood cell count including platelet count is probably sufficient in patients with a hypertensive disorder of pregnancy. Fibrinogen level and PT and PTT determinations are recommended in patients who have severe preeclampsia and for whom operative delivery or regional anesthesia is planned. This will detect minor abnormalities in a few patients despite a normal platelet count. This information may help prevent bleeding complications.

Loss of rat glomerular ATP diphosphohydrolase activity during reperfusion injury is associated with oxidative stress reactions

Endothelial cell ATP diphosphohydrolases or ATPDases degrade extracellular inflammatory mediators ATP and ADP, thus inhibiting the formation of platelet thrombi, but the modulation of these ecto-enzymes during vascular injury remains largely undetermined. Renal glomerular ATPDase levels were determined in the rat following ischemia-reperfusion or systemic complement activation, by direct biochemical methods and histochemistry. Ischemia followed by reperfusion times over 30 min were associated with loss of glomerular ATPDase activity. Cobra Venom Factor (CVF) inhibited ATPDase activity and potentiated the deleterious effects of reperfusion. Treatment with either soluble complement receptor type 1 (sCR1), an inhibitor of complement activation, or antioxidants prior to the ischemia-reperfusion was largely protective. Expression of rat glomerular ATPDase activity appears susceptible to the inflammatory injury associated with systemic complement activation and ischemia/reperfusion processes. Oxidative stress could, at least in part, result in the loss of ATPDase activity and thus thrombotic consequences of vascular injury.

Arthroscopic release of the posterior cruciate ligament for stiff total knee arthroplasty

Ten posterior cruciate ligament sparing total knee arthroplasties were studied in 9 patients who underwent arthroscopic posterior cruciate ligament release to improve intractable postoperative knee stiffness and pain. Mean patient age was 64 years. Before posterior cruciate ligament release, the mean knee extension was 4 degrees (0 degrees - 10 degrees); mean knee flexion was 73.9 degrees (40 degrees - 110 degrees). The mean interval to posterior cruciate ligament release after primary total knee arthroplasty was 29 months. After release, mean extension was 1.3 degrees (0 degrees - 10 degrees) and mean flexion was 112 degrees (range, 85 degrees - 135 degrees). The average increase in flexion observed in the immediate postoperative period was 40.1 degrees (25 degrees - 60 degrees). At a mean followup of 20 months, mean extension was 1.5 degrees (0 degrees - 10 degrees), and mean flexion was 104.5 degrees (70 degrees - 125 degrees). At followup, the average increase in knee flexion was 30.5 degrees (10 degrees - 50 degrees). Before arthroscopic posterior cruciate ligament release, the average Knee Society knee and function scores were 70.9 and 71, respectively. At followup, the average Knee Society knee and function scores were 86.4 and 88, respectively. The Knee Society pain score improved from 33.5 preoperatively to 42 postoperatively. All patients reported subjective improvements in pain and stiffness. Eight patients (88%) reported satisfaction with the procedure. Two patients (22%) eventually required revision total knee arthroplasty.

Radioimmunotherapy of patients with small-volume tumors using iodine-131-labeled anti-CEA monoclonal antibody NP-4 F(ab')2

The clinical feasibility of radioimmunotherapy (RIAIT) was assessed in patients with metastatic, carcinoembryonic antigen (CEA)-producing cancers who had minimal residual or small-volume disease (tumor lesions < or = 3 cm in diameter).

METHODS

Thirteen cancer patients (8 colorectal, 3 lung, 1 pancreatic and 1 medullary thyroid cancer) received RAIT with 131I-NP-4 F(ab')2 anti-CEA antibody. The radioactive dose given was based on a prescribed radiation dose to the red marrow. Ten of the 13 patients received initial therapeutic doses delivering 150-450 cGy to the red marrow (70-296 mCi) and six patients had more than one therapy infusion.

RESULTS

Targeting of all known tumor lesions < 0.5 cm [corrected] in diameter was possible in nine patients and at least one tumor lesion was evident in all patients. Disease stabilization ranging from 3.5 to 7 mo was seen in 6 of the 13 patients who previously had clear evidence of progressive disease. Four of the six patients with disease stabilization received the presumed maximum tolerated dose of 450 cGy to the red marrow. Red marrow suppression was the only observed toxicity and there was a good correlation between the red marrow dose and myelotoxicity. Red marrow doses < or = 250 cGy resulted in < or = grade 2 myelotoxicity and a red marrow dose of 450 cGy resulted in reversible grade 3 or 4 myelotoxicity in 3 of 6 patients. Human anti-mouse antibodies (HAMA) developed in all but one of the six patients who received multiple therapeutic infusions of the antibody.

CONCLUSION

RAIT of patients with small-volume disease is feasible and these patients should be considered for future dose-intensification trials because of their generally poor prognosis.