A serological study of Chikungunya virus transmission in Yogyakarta, Indonesia: evidence for the first outbreak since 1982

A study of epidemic transmission of Chikungunya virus (CHIK) was initiated in April 1999 in Yogyakarta, Indonesia. Three hundred seventeen volunteers from three kelurahans (sub-districts) were recruited. Anti-CHIK IgG antibodies were detected in 68% to 74% of cases and 28% to 32% of controls. In the kelurahan with no reported CHIK illness, 29% of cases and 28% of controls had anti-CHIK IgG antibodies. None of these cases demonstrated anti-CHIK IgM antibodies. In the two kelurahans with disease activity, anti-CHIK IgM antibodies were detected in 3% to 36% of cases, with the highest percentage from the kelurahan with recently reported cases. Ten percent of controls from Gowok had anti-CHIK IgM detected in their serum. Twelve acutely ill volunteers were later included from the kelurahan Pilahan for virus identification. Samples from two volunteers were culture- and RT-PCR-positive for CHIK. This is the first documentation of epidemic transmission of CHIK in Indonesia since 1982.

Hepatitis C among child transfusion and adult renal dialysis patients in Indonesia

Hepatitis C virus (HCV) prevalence among high-risk pediatric and adult patients was evaluated. The study included 269 adults and 150 children in a case-control research design. Risk factors of HCV exposure in Indonesia were assessed among adult renal dialysis patients and pediatric patients who received multiple blood transfusions. A high prevalence of anti-HCV was found among the adult renal dialysis patients, measured by second-generation electroimmunoassay tests. Family members of dialysis patients, who served as a comparison group for dialysis patients, were found to have a 9.0% seroprevalence. The prevalence of anti-HCV among pediatric patients with hematological disorders was found to be 39.0%. The comparison group seroprevalence (pediatric patients and family members) was 4.3% among sera available for confirmatory testing. Patients with history of hospitalization (odds ratio [OR] = 7.94, 95% confidence interval [CI]: 4.06-15.51, P = 0.0001), blood transfusion (OR = 6.85, 95% CI: 3.95-11.88, P = 0.0001), circumcision (OR = 2.39, 95% CI: 1.43-3.99, P = 0.0001), or marital partner/family member history of jaundice (OR = 3.62, 95% CI: 1.97-6.62, P = 0.0001) were found to have an increased odds of HCV exposure compared with individuals without similar histories.

Establishment and comprehensive analysis of a new human transformed follicular lymphoma B cell line, Tat-1

A spontaneously EBV transformed follicular lymphoma (FL) cell line, Tat-1, was established from the lymph node biopsy specimen of a patient with B cell FL, grade 1 in transformation to high grade disease. Tat-1 cells expressed lymphoid markers and developed tumor masses in immunodeficient mice. Bcl-2, Bcl-X(L), Bax and p53 protein expression was revealed by Western blotting. Flow cytometric analysis confirmed P-gp expression. Cytogenetically, the Tat-1 cell line showed identical chromosomal alterations to that of the initial biopsy specimen, among which the most notable were the t(14;18) typical of FL and additional abnormalities involving chromosomes 1, 8 and 13. Multicolor FISH analysis delineated all abnormalities, including a t(1p;8q), a der(8)(8q24::14q32::18q21) and a der(13)(13q32::8q24::14q32::18q21). Further FISH investigations using a locus-specific probe cocktail containing c-myc, IgH and bcl-2 revealed fusion of these three loci on the derivatives 8 and 13, in addition to the derivative 14 IgH/bcl-2 fusion and an extra copy of c-myc on derivative chromosome 1. These results demonstrate an additional example of the deregulation of bcl-2 and c-myc expression through recombination with a single IgH enhancer region. The unusual molecular features of the Tat-1 cell line render it a unique tool for studies focused on cytogenetic alterations, expression of multidrug resistance phenotype and expression of anti-apoptotic proteins in FL.

Detection of dengue viral RNA in Aedes aegypti (Diptera: Culicidae) exposed to sticky lures using reverse-transcriptase polymerase chain reaction

Active surveillance for dengue (DEN) virus infected mosquitoes can be an effective way to predict the risk of dengue infection in a given area. However, doing so may pose logistical problems if mosquitoes must be kept alive or frozen fresh to detect DEN virus. In an attempt to simplify mosquito processing, we evaluated the usefulness of a sticky lure and a seminested reverse-transcriptase polymerase chain reaction assay (RT-PCR) for detecting DEN virus RNA under laboratory conditions using experimentally infected Aedes aegypti (L.) mosquitoes. In the first experiment, 40 male mosquitoes were inoculated with 0.13 microl of a 10(4) pfu/ml DEN-2 stock solution. After a 7-d incubation period, the mosquitoes were applied to the sticky lure and kept at room temperatures of 23-30 degrees C. Following 7, 10, 14, and 28 d application, 10 mosquitoes each were removed from the lure, pooled, and assayed for virus. DEN virus nucleic acid was clearly detectable in all pools up to 28 d after death. A second study evaluated sensitivity and specificity using one, two, and five DEN-infected mosquitoes removed after 7,10, 14, 21, and 30 d application and tested by RT-PCR. All four DEN serotypes were individually inoculated in mosquitoes and evaluated using the same procedures as experiment 1. The four serotypes were detectable in as few as one mosquito 30 d after applications to the lure with no evidence of cross-reactivity. The combination of sticky lures and RT-PCR show promise for mosquito and dengue virus surveillance and warrant further evaluation.

Expansion of the antigenic repertoire of a single T cell receptor upon T cell activation

Activated T cells and their naive precursors display different functional avidities for peptide/MHC, but are thought to have identical antigenic repertoires. We show that, following activation with a cognate mimotope (NRP), diabetogenic CD8(+) T cells expressing a single TCR (8.3) respond vigorously to numerous peptide analogs of NRP that were unable to elicit any responses from naive 8.3-CD8(+) T cells, even at high concentrations. The NRP-reactive, in vivo activated CD8(+) cells arising in pancreatic islets of nonobese diabetic mice are similarly promiscuous for peptide/MHC, and paradoxically this promiscuity expands as the aviditiy of the T cell population for NRP/MHC increases with age. Thus, activation and avidity maturation of T lymphocyte populations can lead to dramatic expansions in the range of peptides that elicit functional T cell responses.

Synthesis of phakellistatin 11: a micronesia (Chuuk) marine sponge cyclooctapeptide

The cyclic octapeptide phakellistatin 11 (1), a constituent of The Federated States of Micronesia (Chuuk) marine sponge Phakellia sp., was synthesized using solid-phase techniques. An initial solution-phase synthesis proved to be inadequate owing to spontaneous deprotection of the Fmoc group at the heptapeptide stage. Using the PAL resin attachment and proceeding from Fmoc-Glu-alpha-allyl ester, linear elongation of the octapeptide was performed until the final unit Pro was added. The allyl ester was removed using Pd(0)[P(C(6)H(5))(3)](4). Cleavage of the final Fmoc group and cyclization with PyAOP provided phakellistatin 11 (1) in 17% overall yield. The synthetic specimen of phakellistatin 11 (1) was found to be chemically but not biologically (cancer cell lines) identical to the natural product. The result suggested a conformational difference or more likely the presence of a trace amount of a highly active antineoplastic agent that binds noncovalently to the natural cyclic octapeptide 1.

Cardiovascular effects of hydrocortisone in preterm infants with pressor-resistant hypotension

OBJECTIVE

To study the cardiovascular effects of hydrocortisone in preterm infants with hypotension unresponsive to volume and pressor administration.

STUDY DESIGN

Retrospective review of the cardiovascular response to 23 courses of hydrocortisone administration during the first day of treatment in 21 preterm infants (gestational age: 26.9 +/- 3.9 weeks; postnatal age: 11.3 +/- 13.1 days). Hydrocortisone (2 mg/kg/d in 16 patients and 3-6 mg/kg/d in 5 patients) was administered when dopamine (22.2 +/- 11 microg/kg/min, range: 8-60) alone (n = 16) or in combination with dobutamine (8.4 +/- 4.9 microg/kg/min, range: 5-20, n = 7) and/or epinephrine (0.38 +/- 0.56 microg/kg/min, range: 0.01-1.2, n = 4) failed to normalize blood pressure.

RESULTS

Mean blood pressure increased from 29.3 +/- 4.1 to 34.1 +/- 5.2, 38.0 +/- 8.0, and 41.8 +/- 6.6 mm Hg by 2, 4, and 6 hours of hydrocortisone administration, respectively, and remained stable thereafter. Urine output increased despite a decrease in fluid administration during the first day of hydrocortisone treatment. The dose of dopamine and the number of patients receiving dobutamine and/or epinephrine also decreased during the same period. Eighteen of the 21 patients survived.

CONCLUSIONS

Preterm infants with volume- and pressor-resistant hypotension respond to hydrocortisone with rapid normalization of the cardiovascular status and sustained decreases in volume and pressor requirement.

Utilization of herpes simplex PCR assays for cerebrospinal fluid in a pediatric health care setting

An assessment was made of the utilization and impact of a diagnostic polymerase chain reaction (PCR) assay for the diagnosis of herpes simplex viruses (HSV) 1 and 2 in cerebrospinal fluid of children who attended a Canadian pediatric referral centre. One hundred and three assays were performed on specimens from 103 patients during the period August 1997 to September 1998. Patient ages ranged from newborn to 16 years. Indications for HSV PCR included seizures with or without fever (56.3%), aseptic meningitis (16.5%), and encephalopathy with or without fever (10.7%). Only 2 of 103 (1.9%) assays were positive, including one each for HSV1 and HSV2. Control specimens that were seeded with virus indicated inhibition for 24.3, 8.8, and 6.8% of assays for HSV1, HSV2, and both HSV1 and HSV2, respectively. The mean turn-around time for HSV PCR was 2.5 days, and 90.3% were completed in less than 5 days. Acyclovir was administered to 78.6% of the patients overall; the results of the HSV PCR impacted on the treatment courses for 36 individuals. Nevertheless, 16.5% of patients continued to receive extended courses of antiviral therapy despite negative HSV PCR assays. Although it is desirable to decrease the frequency of PCR inhibitions and to further decrease the interval to assay completion, HSV PCR does have a significant impact on antiviral use in this setting.

Lymphocytic vasculitis in X-linked lymphoproliferative disease

Systemic vasculitis is an uncommon manifestation of X-linked lymphoproliferative disease (XLP), a disorder in which there is a selective immune deficiency to Epstein-Barr virus (EBV). The molecular basis for XLP has recently been ascribed to mutations within SLAM-associated protein (SAP), an SH2 domain-containing protein expressed primarily in T cells. The authors describe a patient who died as a result of chronic systemic vasculitis and fulfilled clinical criteria for the diagnosis of XLP. Sequencing of this patient's SAP gene uncovered a novel point mutation affecting the SH2 domain. The patient presented with virus-associated hemophagocytic syndrome (VAHS) and later had chorioretinitis, bronchiectasis, and hypogammaglobulinemia develop. He further developed mononeuritis and fatal respiratory failure. Evidence of widespread small and medium vessel vasculitis was noted at autopsy with involvement of retinal, cerebral, and coronary arteries as well as the segmental vessels of the kidneys, testes, and pancreas. Immunohistochemical analysis using antibodies to CD20, CD45RO, and CD8 revealed that the vessel wall infiltrates consisted primarily of CD8(+) T cells, implying a cytotoxic T-lymphocyte response to antigen. EBV DNA was detected by polymerase chain reaction (PCR) in arterial wall tissue microdissected from infiltrated vessels further suggesting that the CD8(+) T cells were targeting EBV antigens within the endothelium. The authors propose that functional inactivation of the SAP protein can impair the immunologic response to EBV, resulting in systemic vasculitis.

Preparation and evaluation of insulin-loaded polylactide microspheres using factorial design

The aim of this work was to study the influence of the concentration and molecular weight of poly(DL-lactide) (PLA) on the characteristics and in vivo biological activity of protein-loaded microspheres. At the same time, an attempt was made to achieve further optimization of the formulation. In the study, insulin was chosen as a model of protein drugs. Nine formulations of injectable insulin-loaded PLA microspheres were prepared using an emulsification and solvent evaporation process according to a factorial design. The trapping efficiency, drug loading, and the drop percentages of blood glucose levels at 24 hr and 72 hr in mice were used to evaluate the formulations. The results showed that PLA molecular weight and, especially, PLA concentration exerted influences on the characteristics and in vivo biological activity of insulin-loaded microspheres. The drug-trapping efficiency increased with the increase of the polymer concentration. The drug loading decreased with the increase of the polymer concentration and was not obviously affected by PLA molecular weight. The drop percentage of blood glucose level at 24 hr increased with the increase of polymer concentration and molecular weight. At 72 hr, the drop percentages of blood glucose levels were slightly increased with the increase of PLA concentration and then significantly decreased after the PLA concentration was above 150 mg/ml. An optimized formulation was prepared with PLA-10k at a concentration of 200 mg/ml. The experimental values of the response variables were close to the predicted values. The results suggest that the in vivo release behavior should be taken into consideration in the design of protein-loaded PLA microspheres.

Defective NK cell activation in X-linked lymphoproliferative disease

X-linked lymphoproliferative disease (XLP) is characterized by a selective immune deficiency to EBV. The molecular basis of XLP has been attributed to mutations of signaling lymphocytic activation molecule-associated protein, an intracellular molecule known to associate with the lymphocyte-activating surface receptors SLAM and 2B4. We have identified a single nucleotide mutation in SLAM-associated protein that affects the NK cell function of males carrying the mutated gene. In contrast to normal controls, both NK and lymphokine-activated killer cell cytotoxicity was significantly reduced in two XLP patients. In addition to decreased baseline cytotoxicity, ligation of 2B4 significantly augmented NK lytic function in normal controls but failed to enhance the cytotoxicity of NK cells from XLP patients. These findings suggest that association of SAP with 2B4 is necessary for optimal NK/lymphokine-activated killer cytotoxicity and imply that alterations in SAP/2B4 signaling contribute to the immune dysfunction observed in XLP.

Creating HIV-1 reverse transcriptase cytotoxic T lymphocyte target structures by HLA-A2 heavy chain modifications

Vigorous HIV-1-specific CD8(+) cytotoxic T lymphocyte (CTL) responses play an important role in the control of HIV-1 replication and the induction of a strong, broadly cross-reactive CTL response remains an important goal of HIV vaccine development. It is known that the display of high levels of class I MHC-viral peptide complexes at the cell surface of target cells is necessary to elicit a strong CTL response. We now report two strategies to enhance the presentation of defined HIV-1 epitope-specific CTL target structures, by incorporating subdominant HIV-1 reverse transcriptase (RT) CTL epitope sequences into the human class I MHC molecule HLA-A2. We show that either incorporation of HIV-1 CTL epitopes into the signal sequence of HLA or tethering of epitopes to the HLA-A2 heavy chain provide simple ways to create effective CTL target structures that can be recognized and lysed by human HLA-A2-restricted RT-specific CD8(+) CTL. Moreover, cells expressing these epitope-containing HLA-A2 constructs stimulated the generation of primary epitope-specific CTL in vitro. These strategies offer new options in the design of plasmid DNA-based vaccines or immunotherapeutics for the induction of CTL responses against subdominant HIV-1 epitopes.

Progression of autoimmune diabetes driven by avidity maturation of a T-cell population

For unknown reasons, autoimmune diseases such as type 1 diabetes develop after prolonged periods of inflammation of mononuclear cells in target tissues. Here we show that progression of pancreatic islet inflammation to overt diabetes in nonobese diabetic (NOD) mice is driven by the 'avidity maturation' of a prevailing, pancreatic beta-cell-specific T-lymphocyte population carrying the CD8 antigen. This T-lymphocyte population recognizes two related peptides (NRP and NRP-A7) in the context of H-2Kd class I molecules of the major histocompatibility complex (MHC). As pre-diabetic NOD mice age, their islet-associated CD8+ T lymphocytes contain increasing numbers of NRP-A7-reactive cells, and these cells bind NRP-A7/H-2Kd tetramers with increased specificity, increased avidity and longer half-lives. Repeated treatment of pre-diabetic NOD mice with soluble NRP-A7 peptide blunts the avidity maturation of the NRP-A7-reactive CD8+ T-cell population by selectively deleting those clonotypes expressing T-cell receptors with the highest affinity and lowest dissociation rates for peptide-MHC binding. This inhibits the local production of T cells that are cytotoxic to beta cells, and halts the progression from severe insulitis to diabetes. We conclude that avidity maturation of pathogenic T-cell populations may be the key event in the progression of benign inflammation to overt disease in autoimmunity.

Isotretinoin therapy for antibiotic-refractory acne in Apert's syndrome

Apert's syndrome is a congenital disorder characterized by the premature fusion of the cranial sutures and early epiphyseal closure. Severe pustular acne is a common feature. We report a case that failed to respond to conventional antibiotic treatment but resolved following isotretinoin therapy. The patient's permanent tracheostomy proved a management challenge during isotretinoin treatment. The role of androgen-sensitivity is discussed in relation to the skin and bones.

Evaluation of a commercially available immunoglobulin M capture enzyme-linked immunosorbent assay kit for diagnosing acute dengue infections

Recently, commercially available kits for the detection of anti-dengue virus (anti-DEN) immunoglobulin M (IgM) antibodies have been developed. These standardized assays have greatly enhanced our ability to effectively diagnose DEN infections. We conducted an evaluation of a test kit manufactured by MRL Diagnostics Inc. that is designed to detect anti-DEN IgM antibodies. Eighty paired samples from DEN-infected individuals were tested by the MRL DEN Fever Virus IgM Capture enzyme-linked immunosorbent assay (ELISA), the PanBio Duo ELISA, the PanBio Rapid Immunochromatographic Test (PRIT), and the IgM-IgG antibody capture (MAC/GAC) ELISA. All infections were confirmed by either PCR-assisted detection of DEN transcripts or by DEN isolation in C6/36 cells. Seventeen paired samples from individuals with no evidence of acute DEN infection were used as negative controls. The PRIT had the best sensitivity (100%), whereas the MAC/GAC ELISA and the PanBio Duo assay had the highest levels of specificity. The MRL ELISA and the PanBio Duo assay were the top performers when taking into consideration both sensitivity and specificity. All assays were able to detect DEN-specific antibodies in samples from patients with either primary or secondary infections, regardless of the infecting DEN serotype.

A prospective seroepidemiologic study on dengue in children four to nine years of age in Yogyakarta, Indonesia I. studies in 1995-1996

A prospective study on dengue (DEN) viruses was initiated in October 1995 in Gondokusuman kecamatan, Yogyakarta, Indonesia. This report presents data from the first year of the study. The studied cohort included all children 4-9 years of age living in the kecamatan. Blood samples for serology were collected from 1,837 children in October 1995 and again in October 1996. Blood samples for virus isolation and serology were collected from cohort children who were seen in municipal health clinics with febrile syndromes or admitted to hospitals with a provisional diagnosis of dengue hemorrhagic fever. Dengue serotype antibody prevalence and 1995-1996 infection rates were calculated using a single dilution (1:60) 70% plaque reduction endpoint neutralization test. Prevalence of dengue antibody at the beginning of the study was DEN 1 = 12%, DEN 2 = 16%, DEN 3 = 2%, DEN 4 = 4%, and two or more dengue infections = 22%. Total dengue antibody prevalence increased from 38% in 4-year-old children to 69% in 9-year-old children. During the observation period, primary dengue infection rates were DEN 1 = 4.8%, DEN 2 = 7.7%, DEN 3 = 4.2%, and DEN 4 = 3.4%, while two or more dengue infections occurred in 6.7% of the study population. The secondary dengue infection rate was 19.0%. From febrile cases, all four dengue viruses were isolated with DEN 3 predominating. Seven children were hospitalized, including one fatal case with a hospital diagnosis of dengue shock syndrome. Based upon presence of antibody in the initial cohort bleeding and the serologic response both weeks and several months following illness, all had secondary dengue infections. Neutralizing antibody patterns in the initial cohort bleeding and in late convalescent serum samples permitted recognition of dengue infection sequence in five patients: DEN 2-DEN 1 (3), DEN 2-DEN 4 (1), DEN 1-DEN 3 (1), and none in the sequence DEN 1-DEN 2. In the total cohort 6.5% of the observed secondary infections were of the sequence DEN 2-DEN 1, while 4.9% were DEN 1-DEN 2, a highly pathogenic sequence in previous studies. Reduced pathogenic expression of secondary DEN 2 with enhanced pathogenic expression of secondary DEN 1 infections was an unexpected finding. Further studies will be required to understand the respective contributions to pathogenicity of antibody from initial dengue infections versus the biological attributes of the second infecting dengue viruses.

Antineoplastic agents. Part 409: Isolation and structure of montanastatin from a terrestrial actinomycete

A Montana soil actinomycete, Streptomyces anulatus, produced (1 x 10(-2)% yield) a new cancer cell growth inhibitory cyclooctadepsipeptide named montanastatin (1) accompanied by the potent anticancer antibiotic valinomycin (2) in very high (5.1%) yields. Valinomycin but not montanastatin inhibited growth of a number of pathogenic bacteria and fungi. Interpretation of high-field (500 MHz) NMR and high-resolution FAB mass spectral data allowed assignment of the structure cyclo-(D-Val-L-Lac-L-Val-D-Hiv) to montanastatin. Valinomycin (2) was also isolated from actinomycetes cultured from a tree branch and animal feces collected in Malaysia. Streptomyces exfoliatus, isolated from the tree branch, was found to contain valinomycin in 1.6% yield, while the fecal isolate, S. anulatus, gave valinomycin in 0.9% yield.

Antineoplastic agents. 400. Synthesis of the Indian Ocean marine sponge cyclic heptapeptide phakellistatin 2

Solution-phase synthesis of the marine sponge constituent phakellistatin 2 (1), cyclo(Tyr-Pro-Phe-Pro-Ile-Ile-Pro), was completed using a combination of stepwise coupling and (4 + 3) segment condensation. Use of diethyl phosphorocyanidate for the peptide bond formations gave the linear heptapeptide in 54% yield. Cyclization was achieved in high yields utilizing TBTU (2), BOP-C1 (3), PyBroP (4), and HOAt (5), resulting in 50-65% yields of phakellistatin 2 (1) depending on the method employed. The synthetic cyclic peptide was chemically but not biologically identical with the natural product.

Rapid death of adoptively transferred T cells in acquired immunodeficiency syndrome

Human immunodeficiency virus (HIV)-specific cytotoxic T lymphocytes (CTL) probably play the major role in controlling HIV replication. However, the value of adoptive transfer of HIV-specific CTL expanded in vitro to HIV+ patients has been limited: this contrasts with the success of CTL therapy in treating or preventing Epstein-Barr virus and cytomegalovirus disease after bone marrow transplantation (BMT). We investigated the fate of expanded HIV-specific CTL clones in vivo following adoptive transfer to a patient with acquired immunodeficiency syndrome (AIDS). Two autologous CTL clones specific for HIV Gag and Pol were expanded to large numbers (>10(9)) in vitro and infused into an HIV-infected patient whose viral load was rising despite antiretroviral therapy. The fate of one clone was monitored by staining peripheral blood mononuclear cells (PBMCs) with T-cell receptor-specific tetrameric major histocompatibility complex (MHC)-peptide complexes. Although the CTL transfer was well tolerated, there were no significant changes in CD4 and CD8 lymphocyte counts and virus load. By tracking an infused clone using soluble MHC-peptide complexes, we show that cells bearing the Gag-specific T-cell receptors were rapidly eliminated within hours of infusion through apoptosis. Thus, the failure of adoptively transferred HIV-specific CTL to reduce virus load in AIDS may be due to rapid apoptosis of the infused cells, triggered by a number of potential mechanisms. Further trials of adoptive transfer of CTL should take into account the susceptibility of infused cells to in vivo apoptosis.

[Effects of matrine on telomerase activity and cell cycle in K562 cell]

OBJECTIVE

In order to search for new tumor differentiation inducer, the effects of matrine of Chinese herbal origin on differentiation of K562 cells and its mechanism were studied.

METHODS

Telomerase activity was determined by PCR-ELISA in untreated or treated K562 cells, cell cycle phases were analyzed by fluorescence-activated cell sorter analysis.

RESULTS

Telomerase activity of K562 cells was significantly inhibited when treated with matrine, and cell cycle of the treated K562 cells was changed with marked decrease in S phase.

CONCLUSION

Matrine can induce differentiation of K562 cells, the mechanism of which might be related to the inhibition of telomerase activity and cell cycle arrest.

Extravisceral masses in the peritoneal cavity: sonographically guided biopsies in 52 patients

OBJECTIVE

Our objective was to determine the effectiveness of sonographically guided biopsies of extravisceral masses (masses outside the solid organs) in the peritoneal cavity.

MATERIALS AND METHODS

We retrospectively reviewed the results of sonographically guided biopsies of extravisceral masses found in the peritoneal cavity of 52 patients (age range, 25-90 years old; mean age, 52 years) from June 1990 to December 1996. Fifty-one patients underwent biopsy through the abdominal wall, and one patient underwent transvaginal biopsy. Sonographic guidance was obtained using 3.5- to 7.0-MHz vector probes. The size, depth, and sonographic characteristics of the mass and the type of biopsy (aspirate versus core) were determined for all lesions. Pathology reports and clinical courses were reviewed.

RESULTS

Placement of the biopsy needle within the lesion was successful in all patients. The mean depth from skin surface to lesion was significantly less (p < .0001) when shown by sonography (2.4 cm) than when shown by CT (3.8 cm). Biopsy results were true-positive for malignancy in 37 patients (no false-positives), true-negative for benign masses in 10 patients, and false-negative for malignancy in three patients (sensitivity, 93%; specificity, 100%; accuracy, 94%). Nondiagnostic samples were obtained in two patients (4%). Treatment was based on diagnostic biopsy results in 43 patients (86%).

CONCLUSION

Sonography is an effective alternative to CT in guiding biopsy of extravisceral masses in the peritoneal cavity.

Antineoplastic agents. 397: Isolation and structure of sesterstatins 4 and 5 from Hyrtios erecta (the Republic of Maldives)

The wide ranging marine sponge Hyrtios erecta is the source of the spongistatins, a new class of macrocyclic lactone antineoplastic agents. Continuation of a detailed investigation of cancer cell growth inhibitory (P388 lymphocytic leukemia) fractions (trace) from H. erecta has revealed the presence (10(-5) to 10(-7)% yield) of cytotoxic pentacyclic sesterterpenes. Employing P388 leukemia and human tumor cell line-guided bioassay techniques, two new moderate inhibitors of cancer cells were isolated and named sesterstatins 4 (1a, P388 ED50 4.9 micrograms/mL) and 5 (1b, DU-145 prostate GI50 1.9 micrograms/mL). Similar to other sesterterpenes, sesterstatin 5 inhibited growth of a Gram-positive bacterium. High field (500 MHz) 2-D NMR techniques were primarily employed for initial structural assignments, and structural assignments were confirmed by X-ray crystal structure determination of sesterstatin 4 (1a) and 5 (1b).

Ethylmalonic and methylsuccinic aciduria in ethylmalonic encephalopathy arise from abnormal isoleucine metabolism

Ethylmalonic encephalopathy (EE), an organic aciduria of unknown etiology characterized by developmental delay, hypotonia, and vascular instability associated with lactic acidemia and urinary excretion of ethylmalonic acid (EMA) and methylsuccinic acid (MSA), has been described in 11 patients. To test the possibility that the underlying biochemical defect involves isoleucine catabolism, we determined the response to oral L-isoleucine (IIe) load (150 mg/kg) in a 5-year-old girl with EE and in three healthy, age- and sex-matched controls. Following IIe load in the patient, there was accumulation of 2-methylbutyrylglycine (2-MBG) and a delayed and lower peak urinary excretion of tiglylglycine (TGL), suggesting a partial defect in 2-methyl-branched chain acylcoenzyme A dehydrogenase (2M-BCAD). In vitro measurements 2M-BCAD activity in cultured skin fibroblasts from patients with EE have been reported to be normal. Our results show that isoleucine is a source for the elevated EMA and MSA in patients with EE, and suggest a functional, possibly secondary, deficiency of activity of 2M-BCAD in vivo.

Antineoplastic agents. 398. Isolation and structure elucidation of cephalostatins 18 and 19

Continued investigation of murine leukemia (P-388) active fractions from the African marine worm Cephalodiscus gilchristi has resulted in the discovery of cephalostatins 18 (1b) and 19 (1c). The structures were determined by interpretation of their highfield (500 MHz) 1H, 13C, and 2D NMR and HRMS. Both of these new methoxy steroidal alkaloids exhibited strong activity against the murine P-388 lymphocytic leukemia cell line (ED50 ca. 10(-3) microg/mL), a mini panel of human cancer cell lines (GI50 <10(-3) microg/mL), and the U.S. National Cancer Institute's 60 human cancer cell line panel (mean panel GI50 ca. 10(-9) M).

A high resolution ultrastructural comparison of isolated and in situ murine AA amyloid fibrils

There is an inconsistency between the ultrastructural organization of AA amyloid fibrils that have been isolated, which are composed of a slowly twisting set of two or more protofibrils, and those seen in situ, which are tubular entities with a tight helical substructure. In this study, the ultrastructure of fibrils isolated from experimental murine AA amyloid were observed at high resolution and compared with those seen in situ in the hope of clarifying the reason for this inconsistency. The fibrils in situ were composed of a microfibril-like 8-9 nm wide core covered by a layer of heparan sulfate proteoglycan (HSPG) to which 1 nm wide filaments, immunohistochemically identified as AA protein, were externally associated. Following isolation with the standard distilled water washing procedure, the HSPG layer and AA protein filaments detached from their core and dispersed into the water. The remaining denuded, variously loosened cores lost their typical appearance. In distilled water the detached 1 nm wide AA protein filaments became quite conspicuous and coiled themselves into 3 nm wide tight helices which in turn assembled into the characteristic slowly twisting sets of two parallel protofibrils similar to that previously reported as "isolated amyloid fibrils". The results emphasize that great caution must be taken in extrapolating amyloid fibril structure from isolated preparations to in situ tissue conditions.

[Seasonal and sexual variety of Ginkgo flavonol glycosides in the leaves of Ginkgo biloba L]

HPLC methods have been developed for the determination of Ginkgo flavonol glycosides in the Ginkgo biloba leaves obtained from May to November in the fallen leaves and in the leaves obtained from female and male trees. The method includes hydrolysis of the leaves and subsequent quantitative chromatographic assay of the aglycones, followed by calculation of Ginkgo flavonol glycosides content. The result shows that the leaves obtained in May have the highest content of 0.96%, and then the content decreases from May to August, and from August to November remains almost the same, that is 0.5% also. Fallen leaves have the lowest content of 0.44%. The content range is 0.96% to 0.44%. Male trees have higher content of glycosides than female trees.

A novel glutamine-RNA interaction identified by screening libraries in mammalian cells

The arginine-rich motif provides a versatile framework for RNA recognition in which few amino acids other than arginine are needed to mediate specific binding. Using a mammalian screening system based on transcriptional activation by HIV Tat, we identified novel arginine-rich peptides from combinatorial libraries that bind tightly to the Rev response element of HIV. Remarkably, a single glutamine, but not asparagine, within a stretch of polyarginine can mediate high-affinity binding. These results, together with the structure of a Rev peptide-Rev response element complex, suggest that the carboxamide groups of glutamine or asparagine are well-suited to hydrogen bond to G-A base pairs and begin to establish an RNA recognition code for the arginine-rich motif. The screening approach may provide a relatively general method for screening expression libraries in mammalian cells.

Antigen-specific release of beta-chemokines by anti-HIV-1 cytotoxic T lymphocytes

A major advance in understanding human immunodeficiency virus (HIV) biology was the discovery that the beta-chemokines MIP-1 alpha (macrophage inflammatory protein-1 alpha), MIP-1 beta (macrophage inflammatory protein-1 beta) and RANTES (regulated on activation, normal T-cell expressed and secreted) inhibit entry of HIV-1 into CD4+ cells by blocking the critical interaction between the CCR5 coreceptor and the V3 domain of the viral envelope glycoprotein gp120 [1,2]. CD8+ lymphocytes are a major source of beta-chemokines [3], but the stimulus for chemokine release has not been well defined. Here, we have shown that engagement of CD8+ cytotoxic T lymphocytes (CTLs) with HIV-1-encoded human leukocyte antigen (HLA) class I-restricted peptide antigens caused rapid and specific release of these beta-chemokines. This release paralleled cytolytic activity and could be attenuated by naturally occurring amino acid variation within the HLA class I-restricted peptide sequence. Epitope variants that bound to appropriate HLA class I molecules but failed to stimulate cytolytic activity in CTLs also failed to stimulate chemokine release. We conclude that signalling through the T-cell receptor (TCR) following binding of antigen results in beta-chemokine release from CTLs in addition to cytolytic activity, and that both responses can be abolished by epitope mutation. These results suggest that antigenic variation within HIV-1 might not only allow the host cell to escape lysis, but might also contribute to the propagation of infection by failing to activate beta-chemokine-mediated inhibition of HIV-1 entry.

Case-control study of primary human herpesvirus 6 infection in children with febrile seizures

RATIONALE

Human herpesvirus 6 (HHV-6) has been demonstrated to be the causative agent in roseola infantum. It has been suggested that HHV-6 may have neurotropic properties and be involved in the pathogenesis of febrile seizures in infants. We describe a case-control study to examine the hypothesis that acute HHV-6 infection occurs more commonly in children with febrile seizures than in controls.

METHODS

Patients presenting with a first or second febrile seizure between 6 months and 2 years of age were entered in the study. Control patients did not have a seizure but had similar inclusion and exclusion criteria. Specimens were obtained for HHV-6 viral serology and polymerase chain reaction in the acute stage and approximately 2 weeks later. A diagnosis of HHV-6 infection was based on HHV-6-specific IgM and IgG serology and HHV-6 polymerase chain reaction of peripheral blood mononuclear cells and saliva.

RESULTS

Eighty-six patients (45 with febrile seizures; 41 controls) were enrolled. The HHV-6 infection status could be determined in only 68 patients (35 with febrile seizures; 33 controls). Acute HHV-6 infection was identified in 15 of 35 febrile seizure patients and in 15 of 33 controls. Evidence of past HHV-6 infection was demonstrated in 13 febrile seizure patients and in 8 controls.

CONCLUSIONS

The incidence of primary HHV-6 infection is similar in patients with febrile seizures and age-matched controls. HHV-6 does not seem to be a major factor in the pathogenesis of first and second febrile seizures.

Immunogenicities of intravenous and intramuscular administrations of modified vaccinia virus Ankara-based multi-CTL epitope vaccine for human immunodeficiency virus type 1 in mice

A vaccine against human immunodeficiency virus (HIV) is still awaited. Although the correlates of protection remain elusive, it is likely that CD8+ T cells play an important role in the control of this infection. To firmly establish the importance of these cells in protective immunity, a means of efficient elicitation of CD8+ T cell responses in the absence of antibody is needed and, when available, might represent a crucial step towards a protective vaccine. Here, a novel vaccine candidate was constructed as a multi-cytotoxic T lymphocyte (CTL) epitope gene delivered and expressed using modified vaccinia virus Ankara (MVA). The immunogen consists of 20 human, one murine and three rhesus macaque epitopes. The non-human epitopes were included so that the vaccine can be tested for immunogenicity and optimal vaccination doses, routes and regimes in experimental animals. Mice were immunized intravenously (i.v.) or intramuscularly (i.m.) using a single dose of 10(6) p.f.u. of the recombinant MVA and the induction of CTL was assessed. It was demonstrated that both administration routes induced specific CTL responses and that the i.v. route was moderately more immunogenic than the i.m. route. The frequencies of ex vivo splenocytes producing interferon-y upon MHC class I-restricted peptide stimulation were determined using an ELISPOT assay. Also, the correct processing and presentation of some HLA-restricted epitopes in human cells was confirmed.

Antineoplastic agents. 386. Isolation of sesterstatins 1-3 from the marine sponge Hyrtios erecta

The Republic of Maldives' black marine sponge Hyrtios erecta has been found to contain three cancer cell-line inhibitory pentacyclic sesterterpenes designated sesterstatins 1-3 (2-4). One of the sesterterpenes, sesterstatin 2, specifically inhibited the Gram-positive opportunist Staphylococcus aureus. All three of the P-388 lymphocytic-leukemia-active (ED50 0.46 to 4.3 micrograms/mL) sesterstatins were obtained in trace quantities (3.0 x 10-7 to 5.4 x 10-7% yields) and represent structural variations on the more usual scalarin-type porifera sesterterpenes. The structures were elucidated by highfield (500 MHz) 2D NMR techniques augmented by HRMS results.

The role of chemoradiotherapy in maintaining quality of life for advanced esophageal cancer

From May 1996 to July 1996, three male patients with advanced esophageal cancer with complete obstruction were treated with concurrent chemoradiotherapy. The first two courses of chemotherapy using 5-Fluorouracil (500 mg/m2) and Leucovorin (200 mg/m2) on day one through day five were given concurrently with radiotherapy. After completion of radiotherapy, four more courses of chemotherapy using the same regimen were given every four weeks. The total dose of irradiation using six MV linear accelerator given to the primary tumor was 5,000 cGy in 28 fractions. All three patients had relief of their obstruction with complete regression of the tumor after the completion of their treatment. All patients improved clinically and were able to remain symptom-free until the time of their death. The first patient survived for 12 months and died of respiratory failure because of his chronic obstructive pulmonary disease. The second patient also survived 12 months but died of liver metastasis. The third patient lived for 10 months and died of aspiration pneumonia.

Molding a peptide into an RNA site by in vivo peptide evolution

Short peptides corresponding to the arginine-rich domains of several RNA-binding proteins are able to bind to their specific RNA sites with high affinities and specificities. In the case of the HIV-1 Rev-Rev response element (RRE) complex, the peptide forms a single alpha-helix that binds deeply in a widened, distorted RNA major groove and makes a substantial set of base-specific and backbone contacts. Using a reporter system based on antitermination by the bacteriophage lambda N protein, it has been possible to identify novel arginine-rich peptides from combinatorial libraries that recognize the RRE with affinities and specificities similar to Rev but that appear to bind in nonhelical conformations. Here we have used codon-based mutagenesis to evolve one of these peptides, RSG-1, into an even tighter binder. After two rounds of evolution, RSG-1.2 bound the RRE with 7-fold higher affinity and 15-fold higher specificity than the wild-type Rev peptide, and in vitro competition experiments show that RSG-1.2 completely displaces the intact Rev protein from the RRE at low peptide concentrations. By fusing RRE-binding peptides to the activation domain of HIV-1 Tat, we show that the peptides can deliver Tat to the RRE site and activate transcription in mammalian cells, and more importantly, that the fusion proteins can inhibit the activity of Rev in chloramphenicol acetyltransferase reporter assays. The evolved peptides contain proline and glutamic acid mutations near the middle of their sequences and, despite the presence of a proline, show partial alpha-helix formation in the absence of RNA. These directed evolution experiments illustrate how readily complex peptide structures can be evolved within the context of an RNA framework, perhaps reflecting how early protein structures evolved in an "RNA world."

Evasion of cytotoxic T lymphocyte (CTL) responses by nef-dependent induction of Fas ligand (CD95L) expression on simian immunodeficiency virus-infected cells

Inoculation of macaques with live attenuated SIV strains has been shown to protect against subsequent challenge with wild-type SIV. The protective mechanism(s) remain obscure. To study the effect in more detail, we have investigated the role of virus-specific CTL responses in macaques infected with an attenuated SIV strain (pC8), which has a four-amino acid deletion in the nef gene, as compared with the wild-type SIVmac32H clone (pJ5). Cynomolgus macaques infected with pC8 were protected against subsequent challenge with pJ5 and did not develop any AIDS-like symptoms in the 12 months after infection. The pC8-induced protection was associated with high levels of virus-specific CTL responses to a variety of viral antigens. In contrast, pJ5-infected macaques had little, if any, detectable CTL response to the viral proteins after three months. The latter group of macaques also showed increased Fas expression and apoptotic cell death in both the CD4(+) and CD8(+) populations. In vitro, pJ5 but not pC8 leads to an increase in FasL expression on infected cells. Thus the expression of FasL may protect infected cells from CTL attack, killing viral-specific CTLs in the process, and providing a route for escaping the immune response, leading to the increased pathogenicity of pJ5. pC8, on the other hand does not induce FasL expression, allowing the development of a protective CTL response. Furthermore, interruption of the Fas-FasL interaction allows the regeneration of viral-specific CTL responses in pJ5-infected animals. This observation suggests an additional therapeutic approach to the treatment of AIDS.

Epidemic and sporadic hepatitis E virus transmission in West Kalimantan (Borneo), Indonesia

A cross-sectional survey was conducted in West Kalimantan (Borneo), Indonesia to geographically profile hepatitis E virus (HEV) prevalence in the riverine areas recognized as the foci of epidemic HEV transmission in 1987. Additionally, a contiguous, although distinct, population with no identifiable historical exposure to epidemic HEV was surveyed downstream for comparative purposes. Eight hundred eighty-five sera were assayed by enzyme immunoabsorbent assay for anti-HEV IgG and anti-hepatitis A virus (HAV) IgG markers. A very high percent (90%) of both the outbreak and comparison populations was anti-HAV IgG positive by the age of nine years. In contrast, the prevalence of anti-HEV IgG in the outbreak area (50%) was significantly higher than in the comparison area (23%) (P < 0.0001). In both the outbreak and comparison areas, anti-HEV IgG prevalence increased with age ( < 0.0001), except for the group > or = 50 years of age. The prevalence (53%) of antibody to HEV in the population > or = seven years of age from the outbreak area (alive during the actual 1987 outbreak) was significantly (P < 0.0001) greater than among the children < seven years of age (born after the outbreak) (15%). However, anti-HEV IgG prevalence among the population from the comparison area did not differ significantly between the > or = seven- (23%) and < seven- (20%) year-old age groups. The percentage of anti-HEV IgG-positive individuals among males (47%) from the outbreak area was lower (P < 0.05) compared with females (55%). While overall usage of river water for drinking purposes was not universal, dependence on river water as a primary source was significantly higher (P < 0.001) in households from the outbreak area (60%) compared with the comparison area (30%). This study indicates persistence of an anti-HEV IgG response in a large percentage of the population seven years after an epidemic of HEV infections. Also, the relatively high prevalence (15%) of anti-HEV in children < seven years of age from the outbreak area reflects continuing, sporadic infections.

The first reported outbreak of dengue hemorrhagic fever in Irian Jaya, Indonesia

During the months of September 1993 through February 1994, an outbreak of hemorrhagic fever occurred in the city of Jayapura, the provincial capital of Irian Jaya, Indonesia. Seventy-two patients (age range = 1-41 years) with suspected dengue hemorrhagic fever (DHF) were enrolled into the outbreak investigation conducted during October-November 1993. The pediatric patient population consisted of 36 individuals ages 1-12 years of age with a similar male to female ratio. From clinical histories obtained from the children diagnosed with DHF (n = 23), the predominant complaints were fever (100%), headache (96.7%), vomiting (47.8%), abdominal pain (39.1%), back/bone pain (39.1%), cough (39.1%), sore throat (21.7%), convulsions (17.4%), and eye pain (13.0%). Clinical findings of the same pediatric patients included a positive tourniquet test result (100%), thrombocytopenia (100%), hemoconcentration (100%), skin petechiae (43.5%), epistaxis (39.1%), and maculopapular rash (26%). All four of the children diagnosed with DHF grade IV had hepatomegaly, pleural effusion, ascites, cold perspiration, and confusion. Serologic data demonstrated that a majority (46 of 70, 68.7%) of the individuals assessed did not have significant levels of IgM specific for dengue viruses at the time of their admission. However, the nine successful dengue virus isolations were only from these serononreactive cases (19.6%). From the other patients assessed, 11.4% had a primary (or first exposure) serologic response to dengue virus antigen (predominantly IgM); 17.1% had a secondary (or subsequent exposure) serologic response to the same dengue antigens (predominantly IgG response) and 5.7% (four adults) had indeterminate serologic data that could not differentiate between reactivity to dengue or Japanese encephalitis virus antigen preparations. Virus culture of blood samples produced nine dengue virus isolates: DEN- 1 (2), DEN-2 (1), and DEN-3 (6). Japanese encephalitis and influenza viruses were not isolated from blood and pharyngeal specimens, respectively, from any of the patients. Thus, this first reported outbreak of DHF in Irian Jaya, Indonesia was found to be attributed to dengue viruses types 1, 2, and 3.

LARD: a new lymphoid-specific death domain containing receptor regulated by alternative pre-mRNA splicing

Fas and TNF-R1 are cysteine-rich cell surface receptors related to the low-affinity nerve growth factor receptor family. Engagement of these receptors by their respective ligands, FasL and tumor necrosis factor, leads to apoptosis that is signaled through a conserved intracellular portion of the receptor termed the "death domain." We have cloned a new member of this family, lymphocyte-associated receptor of death (LARD), which leads to spontaneous apoptosis when expressed in 293T cells. The expression of LARD is more tightly regulated than that of either Fas or TNF-R1 as it is found predominantly on lymphocytes (T and B cells) but not on macrophages or a number of transformed lymphocyte cell lines. Alternative pre-mRNA splicing generates at least 11 distinct isoforms of LARD. The full-length isoform, LARD-1, extends to include the transmembrane and death domains, whereas the other isoforms encode potentially secreted molecules. Naive B and T cells express very little LARD-1 but express combinations of the other isoforms. Upon T cell activation, a programmed change in alternative splicing occurs so that the full-length, membrane-bound LARD-1 predominates. This may have implications for the control of lymphocyte proliferation following activation.

Alpha helix-RNA major groove recognition in an HIV-1 rev peptide-RRE RNA complex

The solution structure of a human immunodeficiency virus type-1 (HIV-1) Rev peptide bound to stem-loop IIB of the Rev response element (RRE) RNA was solved by nuclear magnetic resonance spectroscopy. The Rev peptide has an alpha-helical conformation and binds in the major groove of the RNA near a purine-rich internal loop. Several arginine side chains make base-specific contacts, and an asparagine residue contacts a G.A base pair. The phosphate backbone adjacent to a G.G base pair adopts an unusual structure that allows the peptide to access a widened major groove. The structure formed by the two purine-purine base pairs of the RRE creates a distinctive binding pocket that the peptide can use for specific recognition.

Assignment and modeling of the Rev Response Element RNA bound to a Rev peptide using 13C-heteronuclear NMR

The Rev Response Element (RRE) RNA-Rev protein interaction is important for regulation of gene expression in the human immunodeficiency virus. A model system for this interaction, which includes stem IIB of the RRE RNA and an arginine-rich peptide from the RNA-binding domain of Rev, was studied using multidimensional heteronuclear NMR. Assignment of the RNA when bound to the peptide was obtained from NMR experiments utilizing uniformly and specifically 13C-labeled RNA. Isotopic filtering experiments on the specifically labeled RNA enable unambiguous assignment of unusual nonsequential NOE patterns present in the internal loop of the RRE. A three-dimensional model of the RNA in the complex was obtained using restrained molecular dynamics calculations. The internal loop contains two purine-purine base pairs, which are stacked to form one continuous helix flanked by two A-form regions. The formation of a G-G base pair in the internal loop requires an unusual structure of the phosphate backbone. This structural feature is consistent with mutational data as being important for the binding of Rev to the RRE. The G-G base pair may play an important role in opening the normally narrow major groove of A-form RNA to permit binding of the Rev basic domain.