Detection of antibody to avian influenza A (H5N1) virus in human serum by using a combination of serologic assays

It presents information on cells and viruses, laboratory facilities, serum samples, microneutralization assay, H5N1 Western blotting, ELISA with HA, HI assays, and results obtained.

Risk of influenza A (H5N1) infection among health care workers exposed to patients with influenza A (H5N1), Hong Kong.

The first outbreak of avian influenza A (H5N1) occurred among humans in Hong Kong in 1997. To estimate the risk of person-to-person transmission, a retrospective cohort study was conducted to compare the prevalence of H5N1 antibody among health care workers (HCWs) exposed to H5N1 case-patients with the prevalence among nonexposed HCWs. Information on H5N1 case-patient and poultry exposures and blood samples for H5N1-specific antibody testing were collected. Eight (3.7%) of 217 exposed and 2 (0.7%) of 309 nonexposed HCWs were H5N1 seropositive (P=.01). The difference remained significant after controlling for poultry exposure (P=.01). This study presents the first epidemiologic evidence that H5N1 viruses were transmitted from patients to HCWs. Human-to-human transmission of avian influenza may increase the chances for the emergence of a novel influenza virus with pandemic potential.

Antibody response in individuals infected with avian influenza A (H5N1) viruses and detection of anti-H5 antibody among household and social contacts.

The first documented outbreak of human respiratory disease caused by avian influenza A (H5N1) viruses occurred in Hong Kong in 1997. The kinetics of the antibody response to the avian virus in H5N1-infected persons was similar to that of a primary response to human influenza A viruses; serum neutralizing antibody was detected, in general, >/=14 days after symptom onset. Cohort studies were conducted to assess the risk of human-to-human transmission of the virus. By use of a combination of serologic assays, 6 of 51 household contacts, 1 of 26 tour group members, and none of 47 coworkers exposed to H5N1-infected persons were positive for H5 antibody. One H5 antibody-positive household contact, with no history of poultry exposure, provided evidence that human-to-human transmission of the avian virus may have occurred through close physical contact with H5N1-infected patients. In contrast, social exposure to case patients was not associated with H5N1 infection.

Detection of antibody to avian influenza A (H5N1) virus in human serum by using a combination of serologic assays.

From May to December 1997, 18 cases of mild to severe respiratory illness caused by avian influenza A (H5N1) viruses were identified in Hong Kong. The emergence of an avian virus in the human population prompted an epidemiological investigation to determine the extent of human-to-human transmission of the virus and risk factors associated with infection. The hemagglutination inhibition (HI) assay, the standard method for serologic detection of influenza virus infection in humans, has been shown to be less sensitive for the detection of antibodies induced by avian influenza viruses. Therefore, we developed a more sensitive microneutralization assay to detect antibodies to avian influenza in humans. Direct comparison of an HI assay and the microneutralization assay demonstrated that the latter was substantially more sensitive in detecting human antibodies to H5N1 virus in infected individuals. An H5-specific indirect enzyme-linked immunosorbent assay (ELISA) was also established to test children's sera. The sensitivity and specificity of the microneutralization assay were compared with those of an H5-specific indirect ELISA. When combined with a confirmatory H5-specific Western blot test, the specificities of both assays were improved. Maximum sensitivity (80%) and specificity (96%) for the detection of anti-H5 antibody in adults aged 18 to 59 years were achieved by using the microneutralization assay combined with Western blotting. Maximum sensitivity (100%) and specificity (100%) in detecting anti-H5 antibody in sera obtained from children less than 15 years of age were achieved by using ELISA combined with Western blotting. This new test algorithm is being used for the seroepidemiologic investigations of the avian H5N1 influenza outbreak.

Vertebral blastomycosis with paravertebral abscess: report of eight cases and review of the literature.

Bone is the third most frequent site of disease in patients with blastomycosis, and the vertebrae are among the bones affected most often. We describe the clinical features and treatment of eight patients with vertebral blastomycosis and review the literature regarding this disease. All eight patients had destructive vertebral lesions evident on radiographs, and all had clinical or radiographic evidence of a contiguous abscess. The lower thoracic or lumbar regions were affected most often. Fever and skin lesions typical of blastomycosis were variably present. All but one patient had an abnormal chest radiograph. Treatment included long-term antifungal therapy and drainage of large fluid collections. Five of the eight patients were cured of their disease. Of the other 3 patients, 1 is still receiving therapy and is probably cured, 1 died of blastomycosis, and the status of 1 is unknown. In areas of endemicity, blastomycosis should be a diagnostic consideration for any patient with a destructive vertebral lesion.

Antioxidant enzyme activity in murine hematopoietic bone marrow following treatment with interleukin 1 alpha: influence of tumor.

To determine whether non-hematologic tumors influence the bone marrow's antioxidant enzyme response to the radioprotective cytokine interleukin 1 alpha (IL-1), studies were undertaken using BDF1 and Balb/c mice bearing small, medium or large Lewis lung carcinoma (LLCa) or EMT6 mammary carcinoma tumors, respectively. Results demonstrated that, similar to nontumor-bearing mice, treatment of tumor-bearing animals with IL-1 was associated with a significant increase in marrow MnSOD activity. However, the duration of this elevated activity was reduced as tumor burden increased, and this reduction may have an impact on IL-1's ability to radioprotect tumor bearing animals, especially when tumor burden is large. In addition to cytokine-mediated responses, significant tumor-related influences on the marrow's antioxidant enzyme status were seen. Notably, it was observed that the presence of tumor was correlated with a marked suppression of antioxidant enzyme activity. Surprisingly, however, the pattern of enzyme suppression was found to differ between the two tumor models studied both in temporal onset and in the number of enzymes involved. In conclusion, the data obtained from these studies on tumor-bearing animals demonstrate that there are both cytokine-related and tumor-related influences which can effect the antioxidant enzyme status of the hematopoietic marrow-influences which may have the potential to alter the marrow's ability to tolerate free radical-generating events, both endogenous (i.e inflammation, infection) and exogenous (i.e. radiation, certain chemotherapeutic drugs) in origin.

Induction of pheromone production in a moth by topical application of a pseudopeptide mimic of a pheromonotropic neuropeptide.

An amphiphilic analog of Locusta myotropin II (Lom-MT-II), Glu-Gly-Asp-Phe-Thr-Pro-Arg-Leu-amide, was synthesized by addition of 6-phenylhexanoic acid (6-Pha) linked through alanine to the amino terminus. This pseudopeptide, [6-Pha-Ala0]Lom-MT-II, was found to have pheromonotropic activity equivalent to pheromone biosynthesis activating neuropeptide when injected into females of Heliothis virescens. Topical application of [6-Pha-Ala0]Lom-MT-II or Helicoverpa zea-pheromone biosynthesis activating neuropeptide (PBAN), dissolved in dimethyl sulfoxide, to the descaled abdomen of females induced production of pheromone, although more Hez-PBAN than [6-Pha-Ala0]Lom-MT-II was required to obtain significant production of pheromone. Application of [6-Pha-Ala0]Lom-MT-II, dissolved in water, to the abdomen induced production of pheromone, but neither Hez-PBAN nor Lom-MT-II dissolved in water stimulated production of significant amounts of pheromone. Dose- and time-response studies indicated that application of the amphiphilic mimetic in water induced pheromone production in as little as 15 min after application and that the effects were maintained for prolonged periods. These findings show that amphiphilic pseudopeptide mimics of insect neuropeptides will penetrate the insect cuticle when applied topically in water and induce an endogenous response.

Healthy body weights: an alternative perspective.

The primary purpose of this roundtable discussion of the American Health Foundation is to establish healthy weight standards for adults. In most large, long-term, well-designed studies, the lowest morbidity and mortality rates occurred in adults at weights that yielded BMIs (in kg/m2) between 19 and 25. Best body fat percentages averaged between 12% and 20% for men and 20% and 30% for women. However, statistical values are not applicable to everyone and their strict application may be counterproductive. We believe that most weight-associated health problems result from a cascade of events associated with abnormal blood concentrations of insulin, glucose, or lipids that occur when fat cells become full and insulin-insensitive, and lose their protective functions. Indexes associated with high risk in obese persons often return to normal with appropriate physical activities, dietary habits, and a small weight loss even when body weight and percentage body fat remain above recommended amounts. We believe that statistically derived standards for body weight and percentage body fat are appropriate for use as a screening test but should be downplayed as strict guidelines for all.

Pheromone biosynthesis activating neuropeptides: functions and chemistry.

Sex pheromones are critical for reproductive success in most species of Lepidoptera and their production is regulated by the action of pheromone biosynthesis activating neuropeptides (PBAN). These peptides, composed of 33-34 amino acids, have approximately 80% sequence homology and share the C-terminal sequence FSPRL-NH2, which has been shown to be the minimum sequence required for pheromonotropic activity. This pentamer is structurally similar to the active core (FXPRL-NH2, X = V, T or G) of the insect myotropic pyrokinins. Structure-activity studies have shown that all of the pyrokinins have various degrees of pheromonotropic activity and that some have a superagonistic effect. Peptides that only have sequence homology with PBAN in the C-terminal pentapeptide region, but that are pheromonotropic, also have been identified from months. These findings suggest that induction of pheromone biosynthesis may be regulated by more than one peptide, that PBAN may have a number of physiological functions, and that these peptides regulate induction of pheromone production in a variety of ways.

Potent pheromonotropic/myotropic activity of a carboranyl pseudotetrapeptide analogue of the insect pyrokinin/PBAN neuropeptide family administered via injection or topical application.

A pseudotetrapeptide analogue of the pyrokinin/PBAN or FXPRLamide family (Cbe-Thr-Pro-Agr-Leu-NH2; Cbe = 2-o-carboranylethanoyl-), in which the phenyl ring of the Phe side chain is replaced with the hydrophobic cage-like o-carborane moiety, was synthesized and found to be 10-fold more potent than cockroach leucopyrokinin on an isolated cockroach hindgut bioassay system. In contrast with the naturally occurring peptide, the myostimulatory activity could not be immediately reversed following a saline rinse, providing evidence that the pseudopeptide analogue binds very strongly to the receptor. Once the analogue reaches the receptor, strong receptor binding characteristics may allow it to avoid inactivation by hemolymph peptidases. Although it has an eightfold smaller sequence than the endogenous 33-membered pheromone biosynthesis activating neuropeptide (PBAN), the carboranyl analogue is 10-fold more potent in an in vivo pheromonotropic bioassay of the female tobacco budworm moth Heliothis virescens, demonstrating that the small, C-terminal pentapeptide pyrokinin core analogue contains all the structural information necessary to fully activate pyrokinin receptors. In contrast with PBAN, the amphiphylic carboranyl analogue elicits pheromone production following topical application in aqueous solution to the lateral abdominal surface of H. virescens, providing a noninvasive means of inducing pheromone production in moths. The analogue can potentially serve as a useful tool to insect researchers studying, and/or attempting to disrupt, physiological processes regulated by pyrokinin-like neuropeptides in insects. A possible role for this and related pyrokinin analogues in future pest insect management strategies is briefly discussed.

Temporal recovery of short-term repopulating HSC subpopulations in marrow following schedule-dependent administrations of IL-1 alpha and M-CSF.

Studies were carried out to establish the temporal effects of abbreviated administrations of IL-1 and IL-1 plus M-CSF as rescue agents on multipotential and short-term repopulating hematopoietic stem cell (HSC) subpopulations in murine marrow treated with a myelosuppressive dose of 150 mg/kg 5-FU. The recovery kinetics for high-proliferative-potential colony-forming cells (HPP-CFC), CFU-S8 and -S12, and both CFU-M and CFU-G compartments were monitored over a 14-day interval in 5-FU-treated bone marrow (FUBM) following daily cytokine injections over a 4-day interval. Both IL-1 and the coadministration of IL-1 and M-CSF rapidly enhanced the recovery of the HPP-CFC in FUBM to supranormal levels and maintained these levels for extended intervals. Moreover, since M-CSF was unable to influence the recovery of the HSC subpopulations in FUBM by itself, the results of the two cytokines amounted to a synergistic effect on the recovery of the HPP-CFC in FUBM and a reduction of severe neutropenia in the myelosuppressed animal. Scheduling studies demonstrated that these synergistic effects were restricted to those schedules in which M-CSF was coadministered with IL-1 during the first 2 days of cytokine rescue. Finally, the recovery curves generated for the HSC and CFU-M subpopulations in response to IL-1 (with or without M-CSF) also suggest that these cytokines may conceivably alter the normal balance between proliferation and differentiation within CFU-S8 and -S12 during the accelerated recovery of hematopoiesis in FUBM.

Pheromonotropic activity of naturally occurring pyrokinin insect neuropeptides (FXPRLamide) in Helicoverpa zea.

Insect neuropeptides, having the common C-terminal sequence FXPRLamide X = V, T, S, or G), were tested for phyeromonotropic activity in the moth, Helicoverpa zea. Dose-response studies indicated that locustamyotropin-II or locustapyrokinin-II induced production of more pheromone than was stimulated by the pheromone biosynthesis activating neuropeptide of this moth. Other peptides showed various degrees of pheromonotropic activity. The data indicated that substitution of the variable amino acid in the C-terminal pentapeptide sequence resulted in significant differences in pheromonotropic activity. However, the overall structure of the peptide was also found to be of importance.

Is adipose tissue oversold as a health risk?

A high percentage of body fat is considered to be the primary cause of risks associated with high body weight. Yet body fat content per se may not cause the risks. The contribution of obesity to risks may be because overfilled adipose tissue cannot remove offending substances from circulation. The ability to remove excess glucose, lipids, and offending materials from circulation, not the amount of body fat, may be the important factor. People with large, partially filled adipose depots may have less risk than people with small, but filled adipose depots. This concept is supported by many studies. Energy restriction in genetically obese animals greatly increases longevity and slows signs of aging even while the animals remain obese. Weight reduction often corrects weight-associated medical problems in obese persons without returning body-fat levels to normal. Statistically generated desirable body-fat contents or desirable height-weight tables may have little meaning for individuals and may cause more harm than good. Because these standards are not appropriate for some people, they should be discarded as a guide for all. More emphasis should be placed on healthy lifestyles and less on body-fat percentages.

Stem cell responses in myelosuppressed mice following sequential treatment with recombinant human interleukin 1 (rHuIL-1), recombinant murine interleukin 3 (rMuIL-3) and recombinant human macrophage colony-stimulating factor (rHuM-CSF).

In vivo, recombinant human interleukin 1 alpha (rHuIL-1 alpha) + recombinant human macrophage colony-stimulating factor (rHuM-CSF) (IL-1 + M-CSF) effectively serves as a rescue agent for myelosuppression by enhancing the recovery of hematopoietic stem cell (HSC) subpopulations following treatment with 5-fluorouracil (5-FU). Because in vitro studies have suggested that hematopoietic recovery in 5-FU-treated bone marrow (FUBM) may proceed from a 5-FU resistant, (IL-1 + IL-3 + M-CSF-responsive) high proliferative potential HSC subpopulation of colony forming cells (HPP-CFC), studies were carried out to determine whether the addition of recombinant murine interleukin 3 (rMuIL-3) (IL-3) to either IL-1 or IL-1 + M-CSF would further enhance the recovery of HSC subpopulations in myelosuppressed C57Bl/6 mice. With the exception of the HPP-CFC, IL-3 dampened, rather than enhanced, the accelerated recovery of 8 d and 12 d colony forming units-spleen (8 d and 12 d CFU-S) and the committed macrophage progenitor (CFU-M) associated with in vivo treatment with IL-1 alone. Similarly, IL-3 interfered with the enhanced recovery of those HSC subpopulations in FUBM influenced by the synergistic interaction of IL-1 + M-CSF. This interference, however, was observed only when the rMuIL-3 was administered on day 2 or 3 of a four-day treatment with IL-1 + M-CSF. There was, however, no evidence that IL-3 exerted a negative influence on the restoration of granulocytes in the myelosuppressed animals. Moreover, sequencing studies provided data suggesting that the dampening effects of IL-3 on the synergistic interaction of IL-1 + M-CSF resulted from both an enhanced differentiation of the more primitive HSC subpopulations and a significant, but preferential, mobilization of the more mature 8 d CFU-S and CFU-M to extramedullary organs and that the mobilization of these more mature HSC subpopulations was temporally linked to their generation from the recovering HPP-CFC and 12 d CFU-S subpopulations.