Patterns of orthostatic intolerance: the orthostatic tachycardia syndrome and adolescent chronic fatigue

OBJECTIVES

To describe the orthostatic tachycardia syndrome (OTS) in adolescents, similarities to and differences from chronic fatigue syndrome (CFS), and patterns of orthostatic intolerance during head-up tilt (HUT).

STUDY DESIGN

Using electrocardiography and arterial tonometry, we investigated the heart rate and blood pressure responses during HUT in 20 adolescents with OTS compared with 25 adolescents with CFS, 13 healthy control subjects, and 20 patients with simple faint.

RESULTS

Of the control subjects, 4 of 13 experienced typical vasovagal faints with an abrupt fall in blood pressure and heart rate, and 14 of 20 patients with simple faint experienced similar HUT responses. All patients with CFS (25/25) experienced severe orthostatic symptoms with syncope in 2 of 25, early orthostatic tachycardia during HUT in 16 of 23 (13/16 hypotensive), and delayed orthostatic tachycardia in 7 of 23 (6/7 hypotensive). Acrocyanosis and edema occurred in 18 of 25. Early orthostatic tachycardia occurred in 10 of 20 patients with OTS. Of these, 9 of 10 were hypotensive, but hypotension was delayed in 4 of 9. Delayed tachycardia occurred in 10 of 20 (all hypotensive). Acrocyanosis and edema occurred in most patients with CFS, fewer patients with OTS, and in one patient with simple faint. Orthostatic symptoms were similar but more severe in patients with CFS compared with patients with OTS.

CONCLUSIONS

Symptoms and patterns of orthostatic heart rate and blood pressure change in OTS overlap strongly with those of CFS. Orthostatic intolerance in OTS may represent an attenuated form of chronic fatigue pathophysiology.

Intrastriatal dopamine injection induces apoptosis through oxidation-involved activation of transcription factors AP-1 and NF-kappaB in rats

ABSTRACT More and more evidence suggests that increases in dopamine (DA) in striata may participate in neurodegenerative processes during acute ischemia, hypoxia, and excitotoxicity. With a rat model of intrastriatal DA injection, we studied the molecular events involved in DA toxicity. Intrastriatal injections of DA in amounts from 1 to 2 micromol result in apoptotic cell death, as indicated by terminal deoxynucleotidyl transferase labeling of DNA strand breaks and Klenow polymerase-catalyzed [(32)P]deoxycytidine triphosphate-labeled DNA laddering. Injections of DA produce a strong and prolonged activated protein 1 (AP-1) activity that contains c-fos, c-jun, and phosphorylated c-jun protein. DA injections also stimulate the activity of nuclear factor-kappaB (NF-kappaB), an oxidative stress-responsive transcription factor. Injection of curcumin at a dose that selectively inhibits AP-1 activation without affecting NF-kappaB activity attenuates DNA laddering induced by DA. Preinjection with SN50, a specific permeable recombinant NF-kappaB translocation inhibitor peptide, reduces DA-induced NF-kappaB activation and apoptosis. Moreover, preinjection of the antioxidant GSH significantly inhibits both DA-induced activation of transcription factors AP-1 and NF-kappaB and subsequent apoptosis. Thus, our data suggest that DA-oxidative stress-induced apoptosis in vivo is mediated by activation of transcription factors AP-1 and NF-kappaB.

Orthostatic intolerance in adolescent chronic fatigue syndrome

OBJECTIVES

To demonstrate the association between orthostatic intolerance and the chronic fatigue syndrome (CFS) in adolescents and to delineate the form that orthostatic intolerance takes in these children.

STUDY DESIGN

We investigated the heart rate and blood pressure (BP) responses to head-up tilt (HUT) in 26 adolescents aged 11 to 19 years with CFS compared with responses in adolescents referred for the evaluation of simple faint and to responses in 13 normal healthy control children of similar age.

RESULTS

A total of 4/13 of the controls and 18/26 simple faint patients experienced typical faints with an abrupt decrease in BP and heart rate associated with loss of consciousness. One CFS patient had a normal HUT. A total of 25/26 CFS patients experienced severe orthostatic symptoms associated with syncope in 7/25, orthostatic tachycardia with hypotension in 15/25, and orthostatic tachycardia without significant hypotension in 3/25. Acrocyanosis, cool extremities, and edema indicated venous pooling in 18/25. None of the control or simple faint patients experienced comparable acral or tachycardic findings.

CONCLUSIONS

We conclude that chronic fatigue syndrome is highly related to orthostatic intolerance in adolescents. The orthostatic intolerance of CFS often has heart rate and BP responses similar to responses in the syndrome of orthostatic tachycardia suggesting that a partial autonomic defect may contribute to symptomatology in these patients.

Infections due to nontuberculous mycobacteria in children with leukemia

We reviewed the spectrum of infections due to nontuberculous mycobacteria (NTM) in children with leukemia. Three children acquired such infections. One patient developed pneumonia after the cessation of chemotherapy when Mycobacterium xenopi was identified in his lung biopsy specimen. He required 2 years of treatment with antituberculous agents and clarithromycin. Cultures of central and peripheral blood specimens from two patients yielded Mycobacterium fortuitum and Mycobacterium chelonae, respectively. Broviac catheters were likely the source of infection. Removal of the catheters and antibiotic treatment resulted in cure. Central venous catheters in leukemic children are potential sources of infection. For febrile neutropenic children with leukemia who do not respond to antibiotic therapy, cultures positive for diphtheroids or negative routine bacterial and fungal cultures should raise a suspicion for infections due to NTM. Systemic infections may require up to 2 years of therapy. Removal of the infected catheters during persistent or recurrent infections in necessary for control of the infection.

Intrastriatal injection of dopamine results in DNA damage and apoptosis in rats

Overflow of the neurotransmitter dopamine (DA) in striatum is implicated in the neurodegenerative processes in ischemia, hypoxia and local exposure to high concentrations of excitatory amino acids. However, how DA causes neurotoxicity is not understood. We report that intrastriatal injection of DA (0.5-1 micromol/microl) in Wistar rats produces a robust increase in apoptotic cell death as determined by both a terminal deoxynucleotidyl transferase catalyzed dUTP-biotin nick labeling (TUNEL) and Klenow polymerase catalyzed [32P]dCTP labeled DNA ladder. Cells in which apoptosis was induced by DA are characterized by condensed chromatin, DNA fragmentation, shrinkage and irregular shapes. The apoptotic cell death induced by DA is not due to the effect of hyperosmolar solution since intrastriatal injection of identical concentrations of NaCl on opposite sides of the same rat brains shows little TUNEL-positive labeling. The number of apoptotic cells is proportional to the amount of DA and length of exposure period. With DA concentrations from 0 to 1 micromol/microl, the maximal toxic effect appears at a concentration of 1 micromol/microl after 24 h exposure. Demonstration of DA-induced apoptosis in vivo may provide a potential molecular mechanism for DA neurotoxicity.

Neurally mediated hypotension and autonomic dysfunction measured by heart rate variability during head-up tilt testing in children with chronic fatigue syndrome

Recent investigations suggest a role for neurally mediated hypotension (NMH) in the symptomatology of chronic fatigue syndrome (CFS) in adults. Our previous observations in children with NMH and syncope (S) unrelated to CFS indicate that the modulation of sympathetic and parasympathetic tone measured by indices of heart rate variability (HRV) is abnormal in children who faint during head-up tilt (HUT). In order to determine the effects of autonomic tone on HUT in children with CFS we performed measurements of HRV during HUT in 16 patients aged 11-19 with CFS. Data were compared to 26 patients evaluated for syncope and with 13 normal control subjects. After 30 minutes supine, patients were tilted to 80 degrees for 40 minutes or until syncope occurred. Time domain indices included RR interval, SDNN, RMSSD, and pNN50. An autoregressive model was used to calculate power spectra. LFP (.04-.15 Hz), HFP (.15-.40Hz), and TP (.01-.40Hz). Data were obtained supine (baseline) and after HUT. Thirteen CFS patients fainted (CFS+, 5/13 pure vasodepressor syncope) and three patients did not (CFS-). Sixteen syncope patients fainted (S+, all mixed vasodepressor-cardioinhibitory) and 10 did not (S-). Four control patients fainted (Control+, all mixed vasodepressor-cardioinhibitory) and nine did not (Control-). Baseline indices of HRV were not different between Control+ and S+, and between Control- and S-, but were depressed in S+ compared to S-. HRV indices were strikingly decreased in CFS patients compared to all other groups. With tilt, SDNN, RMSSD, and pNN50 and spectral indices decreased in all groups, remaining much depressed in CFS compared to S or control subjects. With HUT, sympathovagal indices (LFP/HFP, nLFP, and nHFP) were relatively unchanged in CFS, which contrasts with the increase in nLFP with HUT in all other groups. With syncope RMSSD, SDNN, LFP, TP, and HFP increased in S+ (and Control+), suggesting enhanced vagal heart rate regulation. These increases were not observed in CFS+ patients. CFS is associated with NMH during HUT in children. All indices of HRV are markedly depressed in CFS patients, even when compared with already low HRV in S+ or Control+ patients. Sympathovagal balance does not shift toward enhanced sympathetic modulation of heart rate with HUT and there is blunting in the overall HRV response with syncope during HUT. Taken together these data may indicate autonomic impairment in patients with CFS.

Linear Viscoelasticity of the Direct Hexagonal Liquid Crystalline Phase for a Heptane/Nonionic Surfactant/Water System

A linear viscoelastic characterization by small amplitude oscillatory shear and creep compliance tests was carried out for heptane/polyoxyethylene glycol nonylphenyl ether (EOa = 10)/water systems exhibiting a direct hexagonal liquid-crystalline structure. The influence of composition and temperature on the dynamic functions was considered. By adding heptane to the binary system, an increase in the critical Ninham-Israelachvili ratio defining the appearance of the hexagonal mesophase is likely to occur. Heptane solubilization at 25degreesC gave rise to the appearance of a "plateau" region in the frequency dependence of the dynamic functions, which was wider as heptane concentration increased and as temperature decreased. The Generalized Maxwell model fits the frequency dependence of the dynamic functions fairly well. The BSW-CW does not describe, in most cases, the relaxation spectrum of the hexagonal phase, except for binary systems at 20-25degreesC. The steady-state limiting viscosity of the hexagonal phase shows an Arrhenius-like dependence on temperature.

Colorectal cancer presenting with a cutaneous metastatic lesion on the scalp

Cutaneous metastases occur rarely with colorectal adenocarcinoma, accounting for approximately 5 percent of all cutaneous metastases. Cutaneous metastases from colonic cancer are most often located on the abdominal skin. The case we describe here is unusual because colorectal adenocarcinoma rarely metastasizes to the scalp. A review of the English language literature revealed only six reported cases of cutaneous metastases from a colonic adenocarcinoma to the scalp.

Septicemia occurring after colonoscopic polypectomy in a splenectomized patient taking corticosteroids

Although a transient bacteremia may occur in approximately 4% of patients after colonoscopic procedures, clinically significant bacteremia or endocarditis is exceedingly rare. To our knowledge, the case we describe herein is the first reported case of septicemia due to Flavobacterium meningosepticum and Escherichia coli after colonoscopic polypectomy. Our patient was probably immunocompromised and, therefore, predisposed to bacteremia after the procedure, because she was asplenic, diabetic, and receiving long-term steroid therapy for her chronic autoimmune disorders. Several recent reports have suggested that immunocompromised patients are more likely to develop septicemia after endoscopic procedures.

Negative feedback regulation of the ileal bile acid transport system in rodents

BACKGROUND

Active transport of conjugated bile acids by ileal enterocytes is a key mechanism for conservation of the bile acid pool. Experiments were performed to determine whether such transport is regulated by substrate load.

METHODS

Using anesthetized biliary fistula guinea pigs or rats, the ileum was perfused with ursodeoxycholyltaurine at a concentration causing maximal ileal transport of this bile acid; absorption was assessed by biliary recovery. Before ileal perfusion, animals ingested one of three diets: chow, chow with added conjugated bile acid, or chow with added cholestyramine.

RESULTS

In the guinea pig, ingestion of a taurocholate-enriched diet resulted in a 75% decrease in the absorption rate of ursodeoxycholyltaurine. Similar results were obtained with cholylsarcosine (a deconjugation-dehydroxylation resistant analogue) or with chenodeoxycholylglycine, the endogenous bile acid of the guinea pig. In contrast, cholestyramine ingestion caused an increase in ursodeoxycholyltaurine absorption. In the rat, cholyltaurine or cholylsarcosine ingestion also caused decreased ileal transport. In the guinea pig, maximal down-regulation of active ileal bile acid transport occurred after 2-3 days of bile acid feeding; up-regulation required 3-4 days.

CONCLUSIONS

Bile acid metabolism is regulated by feedback inhibition of active ileal transport in addition to the well-established feedback inhibition of bile acid biosynthesis in the liver. Together, these two regulatory mechanisms ensure constancy of bile acid secretion.

A hospital-based prospective study of perinatal infection with human immunodeficiency virus type 1

Most infants with pediatric acquired immunodeficiency syndrome and infections with human immunodeficiency virus type 1 (HIV-1) are infected perinatally by their mothers. To determine the proportion of exposed infants who are infected, we conducted a hospital-based prospective study in HIV-1-infected women whose infants were delivered at a single metropolitan hospital in Miami, Fla. A population of uninfected women and their infants was also enrolled and followed longitudinally for 2 years to assess laboratory and clinical measurements. The median follow-up is now 18 months for 82 infants born to HIV-1-infected mothers. The proportion of infected infants in this group is 0.30 (25/82). None of the infants born to 110 HIV-1-seronegative mothers were seropositive. Infected infants were easily distinguished from noninfected infants by virus isolation. No single immunologic or hematologic measure was predictive of infection for all infants at risk for HIV-1 infection who were 6 months of age or younger. As a group, however, infected infants could be distinguished from uninfected index infants by a number of immunologic measures by 6 months of age; the absolute number of CD4+ lymphocytes and the CD4+/CD8+ lymphocyte ratio were the variables most predictive of infection. As in retrospective studies, clinical disease developed in 80% of infected infants within the first 24 months of life. This study provides documentation of HIV-1 perinatal transmission risk and early correlates of infection in young infants from a single hospital.

Inorganic-carbon transport in some marine eukaryotic microalgae

Inorganic-carbon transport was investigated in the eukaryotic marine microalgaeStichococcus minor, Nannochloropsis oculata and aMonallantus sp. Photosynthetic O2 evolution at constant inorganic-carbon concentration but varying pH showed thatS. minor had a greater capacity for CO2 rather than HCO 3 (-) utilization but forN. oculata andMonallantus HCO 3 (-) was the preferred source of inorganic carbon. All three microalgae had a low affinity for CO2 as shown by the measurement of inorganic-carbon-dependent photosynthetic O2 evolution at pH 5.0. At pH 8.3, where HCO 3 (-) is the predominant form of inorganic carbon, the concentration of inorganic carbon required for half-maximal rate of photosynthetic O2 evolution [K 0.5 (CO2)] was 53 μM forMonallantus sp. and 125 μM forN. oculata, values compatible with HCO 3 (-) transport. Neither extra- nor intracellular carbonic anhydrase was detected in these three microalgal species. It is concluded that these microalgae lack a specific transport system for CO2 but that HCO 3 (-) transport occurs inN. oculata andMonallantus, and in the absence of intracellular carbonic anhydrase the conversion of HCO 3 (-) to CO2 may be facilitated by the internal pH of the cell.

Production of acid and alkaline phosphatases by Myxococcus coralloides

Acid and alkaline phosphatase of Myxococcus coralloides were examined during vegetative growth in a liquid medium. Two extracellular phosphatases and two cell-bound phosphatases, acid and alkaline in both cases, were produced. The phosphatase production was unaltered by the presence of high concentrations of inorganic phosphate. Both enzymes were produced constitutively. These two hydrolases were released into the growth medium during the exponential growth phase (approximately 10% of total activity). The production of these enzymes was modified by the presence of organic acids and metal ions in the medium.

Fetal-neonatal passive immunization against Hemophilus influenzae, type b

Twenty-one pregnant women were vaccinated with the polyribophosphate capsular antigen of Hemophilus influenzae, type b, at 34 to 36 weeks of gestation. All women experienced a large boost in their own antibody levels of anti-polyribophosphate capsular antigen, and 30% was transferred to their newborn infants. The newborn serum anti-polyribophosphate capsular antigen level at birth was 100-fold greater than that of control newborn infants, and the antibody persisted at a protective level for 12 months. Since newborn infants lose significant antibody by 3 months of age, they are susceptible to infection by Hemophilus influenzae, type b, such that it is the leading cause of meningitis in infants. The passive levels of anti-polyribophosphate capsular antigen achieved in these fetuses-neonates by active immunization of their mothers should theoretically lead to less disease caused by Hemophilus influenzae, type b, during infancy.

Pertussis toxin inhibits fMet-Leu-Phe- but not phorbol ester-stimulated changes in rabbit neutrophils: role of G proteins in excitation response coupling

Addition of pertussis toxin to rabbit neutrophils inhibits the fMet-Leu-Phe- induced increases in Na+ influx and in intracellular pH. In addition, pretreatment of the cells with the toxin inhibits the decrease in the levels of phosphatidylinositol 4,5-bisphosphate and phosphatidylinositol 4-phosphate and the enhanced production of phosphatidic acid produced by the chemotactic factor fMet-Leu-Phe. Furthermore, the fMet-Leu-Phe-induced changes in the phosphorylation of a 46-kDa protein and of several other proteins are also inhibited by the toxin. On the other hand, the phorbol 12-myristate 13-acetate (PMA)-induced increases in the phosphorylation of several proteins are not inhibited by the toxin. PMA, but not its inactive analogue 4 alpha-phorbol 12,13-didecanoate, was also found to stimulate Na+ influx and to increase the intracellular pH in rabbit neutrophils. These ionic effects, like those produced by fMet-Leu-Phe, are inhibited by amiloride. The stimulated Na+ influx and H+ efflux produced by the phorbol ester, on the other hand, are not inhibited by pertussis toxin. The results reported here suggest that the activity of the Na+/H+ antiport in neutrophils is regulated by protein kinase C; that the G-protein system, either directly or indirectly, is involved in the stimulus-response coupling sequence in these cells; and that the toxin acts at, or prior to, the steps responsible for the activation of phospholipase C, and it does not affect the sequence of reactions initiated by the activation of the protein kinase C.

Twice daily ceftriaxone therapy for serious bacterial infections in children

The clinical efficacy and safety of ceftriaxone, a long half-life cephalosporin were evaluated in 48 children with a variety of serious bacterial infections. Clinical cure was achieved in 92% (44 of 48) of patients. Peak serum bactericidal titres for Haemophilus influenzae type b, Streptococcus pneumoniae, Str. pyogenes and Escherichia coli were greater than or equal to 1:1024. Mean peak and trough ceftriaxone levels were 173 and 42 mg/l, respectively. Mild and transient diarrhoea was observed in 10% of patients. Laboratory side effects encountered were eosinophilia, thrombocytosis and neutropenia in another 8%. Ceftriaxone is a useful antibiotic for common childhood infections. Its prolonged half-life allows twice daily administration which reduces problems related to intravenous therapy as well as the cost and personnel time.

Role of the ovary in the regulation of sex hormone binding globulin and its contribution to peripheral levels of androstenedione

In order to assess the role of the ovary in the regulation of the levels of the sex-hormone-binding-globulin (SHBG) and its contribution to peripheral levels of androstenedione, three subject groups were studied: 10 normally menstruating women, 8 postmenopausic women, and 8 postmenopausic ovariectomized women. A basal venous blood sample was drawn between 8:00 to 9:00 h from all subjects in the latter two groups. The blood samples were drawn from the normally menstruating women on days 7, 14, 21 and 28 of their cycles. The following determinations were made in each sample: oestradiol, progesterone, testosterone, androstenedione SHBG, FSH and LH. It was concluded that: 1) SHBG does not vary during the menstrual cycle, nor there are significant differences between postmenopausic and castrated women, and 2) androstenedione levels in castrated women are significantly different from both postmenopausic and normally menstruating women.

Immunoglobulin quantitation and enumeration of immunoglobulin-producing cells: comparison of two index of B-cell activation

Human lymphocytes were cultured under different conditions to determine the effects of technical variations on the response to pokeweed mitogen (PWM) and Staphylococcus aureus as measured by (a) quantitation of immunoglobulins (Ig) in the culture supernatants and (b) enumeration of Ig-secreting cells (ISC) by a reverse plaque technique. The highest numbers of ISC were measured when the cells were cultivated in standing tubes, without glutamine supplementation during the culture, and at a concentration of 1 x 10(6) cells/ml. The highest Ig concentrations were measured under similar conditions, except that somewhat higher values were obtained with cell cultivated at 1 x 10(6)/ml in 2 ml cultures with PWM stimulation and 2.5 x 10(6)/ml in 1 ml cultures with S. aureus stimulation. In time-course studies, peak ISC responses occurred on day 5 with each mitogen, whereas extracellular Ig levels kept rising until day 7, possibly owing to accumulation of secreted Ig. Measurements of the numbers of ISC and of secreted Ig levels in simultaneous cultures of lymphocytes from the same donors showed no correlation; however, co-stimulation of cultures with PWM and concanavalin A (to stimulate suppressor cells) depressed both Ig levels and ISC numbers. These results suggest heterogeneity in the plaque-forming cell population with respect to rate of Ig secretion, but indicate that these two techniques both reflect B-cell activation. They should not, however, be considered interchangeable, and the two probably should be used in conjunction for complete characterization of B-cell activation.