Phenol poisoning in three dogs

Three adult dogs were evaluated following oral administration of phenol by the owner. All three dogs experienced severe oral and gastric ulceration. Hematological abnormalities included neutropenia with the presence of toxic neutrophils, thrombocytopenia, and increased muscle enzymes. Endoscopic examination was performed, and biopsies yielded a diagnosis of gastric mucosal necrosis in two of the dogs. Following supportive care, the dogs recovered completely. Phenol is a caustic, highly poisonous derivative of coal tar. The dogs of this report were poisoned inadvertently by their owner who received misinformation concerning the use of this chemical via the Internet.

Standardization of immunoglobulin M capture enzyme-linked immunosorbent assays for routine diagnosis of arboviral infections

Immunoglobulin M antibody-capture enzyme-linked immunosorbent assay (MAC-ELISA) is a rapid and versatile diagnostic method that readily permits the combination of multiple assays. Test consolidation is especially important for arthropod-borne viruses (arboviruses) which belong to at least three virus families: the Togaviridae, Flaviviridae, and Bunyaviridae. Using prototype viruses from each of these families and a panel of well-characterized human sera, we have evaluated and standardized a combined MAC-ELISA capable of identifying virus infections caused by members of each virus family. Furthermore, by grouping antigens geographically and utilizing known serological cross-reactivities, we have reduced the number of antigens necessary for testing, while maintaining adequate detection sensitivity. We have determined that a 1:400 serum dilution is most appropriate for screening antiviral antibody, using a positive-to-negative ratio of >/=2.0 as a positive cutoff value. With a blind-coded human serum panel, this combined MAC-ELISA was shown to have test sensitivity and specificity that correlated well with those of other serological techniques.

Detection of anti-arboviral immunoglobulin G by using a monoclonal antibody-based capture enzyme-linked immunosorbent assay

Monoclonal antibody (MAb)-based capture enzyme-linked immunosorbent assays (ELISAs) for the detection of anti-arboviral immunoglobulin G (IgG ELISAs) were developed for a comprehensive array of medically important arboviruses from the Alphavirus, Flavivirus, and Bunyavirus genera. Tests were optimized and standardized so that maximum homology could be maintained among working parameters for the different viral agents, enabling a wide range of viruses to be easily tested for at one time. MAbs were screened for suitability as capture vehicles for antigens from the three genera. The final test configuration utilized group-reactive MAbs eastern equine encephalitis virus 1A4B-6, dengue 2 virus 4G2, and La Crosse encephalitis virus 10G5.4 to capture the specific inactivated viral antigens. Serum IgG was detected by using alkaline phosphatase-conjugated anti-human IgG (Fc portion). A dilution of 1:400 was chosen as the universal screening serum dilution, with endpoint titrations of serum samples testing positive eliminating occasional false-positive results. IgG ELISA results correlated with those of the standard plaque-reduction neutralization assays. As expected, some test cross-reactivity was encountered within the individual genera, and tests were interpreted within the context of these reactions. The tests were standardized for laboratory diagnosis of arboviral infections, with the intent that they be used in tandem with the corresponding IgM antibody-capture ELISAs.

T cell receptor interactions with class I heavy-chain influence T cell selection

The interaction of the T cell receptor (TCR) with peptide in the binding site of the major histocompatibility complex molecule provides the basis for T cell recognition during immune surveillance, repertoire development, and tolerance. Little is known about the extent to which repertoire selection is influenced directly by variation of the structure of the class I heavy chain. We find that the 2C TCR, normally positively selected in the context of the K(b) molecule, is minimally selected into the CD8 lineage in the absence of antigen-processing genes. This finding underscores the importance of peptides in determining the positive-selecting class I ligands in the thymus. In contrast, K(bm3), a variant class I molecule that normally exerts a negative selection pressure on 2C-bearing T cells, positively selects 2C transgenic T cells into the CD8 lineage in an antigen-processing gene-deficient environment. These findings indicate that structural changes in the heavy chain can have direct influence in T cell recognition, from which we conclude that the nature of TCR interaction with class I heavy chain influences the array of TCRs selected during development of the functional adult repertoire.

Prevalent class I-restricted T-cell response to the Theiler's virus epitope Db:VP2121-130 in the absence of endogenous CD4 help, tumor necrosis factor alpha, gamma interferon, perforin, or costimulation through CD28

C57BL/6 mice mount a cytotoxic T-lymphocyte (CTL) response against the Daniel's strain of Theiler's murine encephalomyelitis virus (TMEV) 7 days after infection and do not develop persistent infection or the demyelinating syndrome similar to multiple sclerosis seen in susceptible mice. The TMEV capsid peptide VP2121-130 sensitizes H-2Db+ target cells for killing by central-nervous-system-infiltrating lymphocytes (CNS-ILs) isolated from C57BL/6 mice infected intracranially. Db:VP2121-130 peptide tetramers were used to stain CD8(+) CNS-ILs, revealing that 50 to 63% of these cells bear receptors specific for VP2121-130 presented in the context of Db. No T cells bearing this specificity were found in the cervical lymph nodes or spleens of TMEV-infected mice. H-2(b) mice lacking CD4, class II, gamma interferon, or CD28 expression are susceptible to persistent virus infection but surprisingly still generate high frequencies of CD8(+), Db:VP2121-130-specific T cells. However, CD4-negative mice generate a lower frequency of Db:VP2121-130-specific T cells than do class II negative or normal H-2(b) animals. Resistant tumor necrosis factor alpha receptor I knockout mice also generate a high frequency of CD8(+) CNS-ILs specific for Db:VP2121-130. Furthermore, normally susceptible FVB mice that express a Db transgene generate Db:VP2121-130-specific CD8(+) CNS-ILs at a frequency similar to that of C57BL/6 mice. These results demonstrate that VP2121-130 presented in the context of Db is an immunodominant epitope in TMEV infection and that the frequency of the VP2121-130-specific CTLs appears to be independent of several key inflammatory mediators and genetic background but is regulated in part by the expression of CD4.

Color vision deficits and laser eyewear protection for soft tissue laser applications

PURPOSE

Laser safety considerations require urologists to wear laser eye protection. Laser eye protection devices block transmittance of specific light wavelengths and may distort color perception. We tested whether urologists risk color confusion when wearing laser eye protection devices for laser soft tissue applications.

MATERIALS AND METHODS

Subjects were tested with the Farnsworth-Munsell 100-Hue Test without (controls) and with laser eye protection devices for carbon dioxide, potassium titanyl phosphate (KTP), neodymium (Nd):YAG and holmium:YAG lasers. Color deficits were characterized by error scores, polar graphs, confusion angles, confusion index, scatter index and color axes. Laser eye protection device spectral transmittance was tested with spectrophotometry.

RESULTS

Mean total error scores plus or minus standard deviation were 13+/-5 for controls, and 44+/-31 for carbon dioxide, 273+/-26 for KTP, 22+/-6 for Nd:YAG and 14+/-8 for holmium:YAG devices (p <0.001). The KTP laser eye protection polar graphs, and confusion and scatter indexes revealed moderate blue-yellow and red-green color confusion. Color axes indicated no significant deficits for controls, or carbon dioxide, Nd:YAG or holmium:YAG laser eye protection in any subject compared to blue-yellow color vision deficits in 8 of 8 tested with KTP laser eye protection (p <0.001). Spectrophotometry demonstrated that light was blocked with laser eye protection devices for carbon dioxide less than 380, holmium:YAG greater than 850, Nd:YAG less than 350 and greater than 950, and KTP less than 550 and greater than 750 nm.

CONCLUSIONS

The laser eye protection device for KTP causes significant blue-yellow and red-green color confusion. Laser eye protection devices for carbon dioxide, holmium:YAG and Nd:YAG cause no significant color confusion compared to controls. The differences are explained by laser eye protection spectrophotometry characteristics and visual physiology.

New mouse model for dengue virus vaccine testing

Several dengue (DEN) virus vaccines are in development; however, the lack of a reliable small animal model in which to test them is a major obstacle. Because evidence suggests that interferon (IFN) is involved in the human anti-DEN virus response, we tested mice deficient in their IFN functions as potential models. Intraperitoneally administered mouse-adapted DEN 2 virus was uniformly lethal in AG129 mice (which lack alpha/beta IFN and gamma IFN receptor genes), regardless of age. Immunized mice were protected from virus challenge, and survival times increased following passive transfer of anti-DEN polyclonal antibody. These results demonstrate that AG129 mice are a promising small animal model for DEN virus vaccine trials.

Echoplanar diffusion-weighted imaging in neonates and infants with suspected hypoxic-ischemic injury: correlation with patient outcome

OBJECTIVE

Our objective was to examine the effectiveness of echoplanar diffusion-weighted (DW) imaging in detecting CNS ischemia in neonates and infants and to determine how well the imaging findings using this technique correlate with short-term neurologic deficit.

MATERIALS AND METHODS

Echoplanar DW images, turbo T2-weighted images, and fluid-attenuated inversion recovery (FLAIR) sequences were obtained in a clinically defined cohort of 26 consecutive neonates and infants with suspected hypoxic-ischemic injury. Echoplanar DW imaging was performed with the diffusion gradient in the slice-select direction: b value, 1200 sec/mm2; matrix, 128 x 128, interpolated to 256 x 256. Four scans (4 sec per scan) were obtained and averaged to optimize the signal-to-noise ratio. Most patients were not sedated (n = 19). Abnormalities seen on DW imaging were correlated with clinical findings at short-term follow-up and compared with findings on FLAIR and turbo T2-weighted images.

RESULTS

Short-term clinical follow-up showed neurologic deficit in 10 (83%) of 12 patients with DW images with abnormal findings, and no neurologic sequelae in 12 (86%) of 14 patients with DW images with normal findings. Echoplanar DW images revealed a greater extent of and a larger number of abnormalities compared with FLAIR or turbo T2-weighted images in 11 (92%) of 12 patients with DW images with abnormal findings.

CONCLUSION

Echoplanar DW imaging reveals abnormalities poorly depicted on turbo T2-weighted and FLAIR images in neonates and infants with clinically suspected hypoxic-ischemic injury. DW imaging may be able to identify which patients are likely to develop at least short-term neurologic deficits and may afford the best early evaluation of short-term neurologic prognosis in these patients.

Characterization of mouse lines transgenic with the human poliovirus receptor gene

Two mouse lines transgenic with the human poliovirus receptor gene (PVR), TGM-PRG-1 and TGM-PRG-3, were characterized to determine whether transgene copy number and PVR expression levels influence susceptibility to poliovirus. The mouse lines have been bred for more than 10 generations and the transgene was stably transmitted to progeny as determined by Southern blot hybridization and restriction fragment length polymorphism. The transgene copy number is 10 in the TGM-PRG-3 mouse line and one in the TGM-PRG-1 mouse line. Abundance of PVR RNA is on average three-fold higher in TGM-PRG-3 relative to TGM-PRG-1 tissues, and the abundance of the receptor molecule is three-fold higher in TGM-PRG-3 central nervous system tissues compared to TGM-PRG-1 tissues as determined by Western blot analysis. When TGM-PRG-1 and TGM-PRG-3 mice were inoculated intracranially with a neurovirulent type III poliovirus strain, they developed clinical symptoms and CNS lesions characteristic of human poliomyelitis. These results indicate that the PVR gene is expressed as a functional receptor in the CNS of both mouse lines rendering the mice susceptible to poliovirus infection. Even though the two mouse lines have different copy numbers of the transgene and different levels of PVR RNA and protein, they are similar in their susceptibility to poliovirus.

Color vision deficits during laser lithotripsy using safety goggles for coumarin green or alexandrite but not with holmium:YAG laser safety goggles

PURPOSE

Laser lithotripsy requires urologists to wear laser eye protection. Laser eye protection devices screen out specific light wavelengths and may distort color perception. This study tests whether urologists risk color confusion when wearing laser eye protection devices for laser lithotripsy.

MATERIALS AND METHODS

Urologists were tested with the Farnsworth Dichotomous Test for Color Blindness (D-15) and the Farnsworth-Munsell 100-Hue Test (FM-100) without (control) and with laser eye protection devices for coumarin green, alexandrite and holmium:YAG lasers. Error scores were tabulated. The pattern of color deficits was characterized with confusion angles, confusion index (C-index), scatter index (S-index) and color axes. Laser eye protection devices were tested with spectrophotometry for spectral transmittance and optical density.

RESULTS

The D-15 transposition errors (mean plus or minus standard deviation) for control, holmium:YAG, alexandrite and coumarin green laser eye protection were 0 +/- 0, 0 +/- 0, 0.3 +/- 0.5 and 6.4 +/- 1.6, respectively (p = 0.0000001). The FM-100 error scores (mean plus or minus standard deviation) were 20 +/- 15, 20 +/- 14, 91 +/- 32 and 319 +/- 69, respectively (p = 0.0001). The confusion index scores indicated a mild color confusion for the alexandrite and pronounced color confusion for the coumarin green laser eye protection. The confusion angles and scatter indexes mimicked a congenital blue-yellow deficit for coumarin green laser eye protection. Color axes showed no significant deficits for control or holmium:YAG laser eye protection in any subject, red-green axis deficits in 3 of 6 tested with alexandrite and blue-yellow axis deficits in 12 of 12 tested with coumarin green (p < 0.001). Spectrophotometry showed that laser eye protection for coumarin green blocks light less than 550 nm., alexandrite blocks light greater than 650 nm. and holmium:YAG blocks light greater than 825 nm.

CONCLUSIONS

Laser eye protection for coumarin green causes pronounced blue-yellow color confusion, whereas alexandrite causes mild red-green color confusion among urologists, holmium:YAG causes no significant color confusion compared to controls. The differences are explained by laser eye protection spectrophotometry characteristics and visual physiology.

GAA instability in Friedreich's Ataxia shares a common, DNA-directed and intraallelic mechanism with other trinucleotide diseases

We show that GAA instability in Friedreich's Ataxia is a DNA-directed mutation caused by improper DNA structure at the repeat region. Unlike CAG or CGG repeats, which form hairpins, GAA repeats form a YRY triple helix containing non-Watson-Crick pairs. As with hairpins, triplex mediates intergenerational instability in 96% of transmissions. In families with Friedreich's Ataxia, the only recessive trinucleotide disease, GAA instability is not a function of the number of long alleles, ruling out homologous recombination or gene conversion as a major mechanism. The similarity of mutation pattern among triple repeat-related diseases indicates that all trinucleotide instability occurs by a common, intraallelic mechanism that depends on DNA structure. Secondary structure mediates instability by creating strong polymerase pause sites at or within the repeats, facilitating slippage or sister chromatid exchange.

Immediate responses of leukocytes, cytokines and glucocorticoid hormones in the blood circulation of monkeys following challenge with aerosolized staphylococcal enterotoxin B

The immediate responses to aerosolized staphylococcal enterotoxin B (SEB) in respiratory toxic shock were studied in the circulation of rhesus monkeys with low antibody levels following immunization with SEB toxoid-containing microspheres. Both the surviving and dying monkeys had toxic shock syndrome 4-48 h after SEB challenge and all showed three distinctive patterns of immediate responses. The first pattern, characterized by the responses of all T cells, HLA-DRlo cells, monocytes, IL-2R+ cells, IFN-gamma, and augmented lymphocyte mitotic responses to lipopolysaccharide (LPS) and SEB in culture, was a rapid increase at 20 min followed by a quick decrease at 90 min to approximately the original levels. The second pattern, which included responses of HLA-DRhi cells, NK cells, adrenocorticotropic hormone (ACTH) and cortisol, was characterized by a moderate decrease at 20 min and a further decrease at 90 min. The third pattern, the inverse of the second pattern, including responses of polymorphonuclear leukocytes (PMN), concanavalin A (Con A) mitogenesis, IL-6 and IL-2, was a moderate increase at 20 min and a further increase at 90 min. Between the surviving and dying monkeys, the responses of T cells, HLA-DRhi cells, PMN and cortisol did not differ significantly, suggesting that they are the basic causes that initiated toxic shock. However, significant differences were seen in the responses of HLA-DRlo cells, monocytes, IL-2R+ cells and lymphocyte mitogenesis in culture at 20 min, and of Con A mitogenesis, NK cells, IL-2, IL-6 and ACTH at 90 min. These different responses are apparently the exacerbating causes of death of the monkeys. All together, the immediate responses seem to be caused by the combined effects of SEB superantigenicity, activation of NK cells and non-lymphoid cells, and depression of the neuroimmune defense system.

Variations in oxidative enzyme type profiles among prenatal rat lumbar motoneurons

We have used cytochrome oxidase histochemical staining to evaluate whether immature rat lumbar motoneurons show intrinsic separation into high or low oxidative enzyme types. Relative oxidative enzyme levels are frequently used to help differentiate between muscle fibres of various types and to differentiate between mature neurons. Here we show a wide variation in motoneuron cytochrome oxidase levels from prenatal times, although the range of staining levels as measured densitometrically is greater for mature than for prenatal animals. We find variation in cytochrome oxidase levels among motoneurons prior to the formation of mature patterns of connectivity or electrical activity, and conclude therefore that this differentiation is unlikely to have arisen by differential usage and probably arose as a function of cell lineage.

Detection of Colorado tick fever virus by using reverse transcriptase PCR and application of the technique in laboratory diagnosis

Colorado tick fever (CTF) virus elicits an acute illness in humans, producing nonspecific flu-like symptoms and a biphasic fever in approximately 50% of patients. The disease is transmitted by the adult Rocky Mountain wood tick (Dermacentor andersoni), and therefore incidence is limited by the habitat and life cycle of that vector. The early symptoms of infection are difficult to distinguish from those of several other agents, especially Rickettsia rickettsii. Serologic testing is usually unable to provide evidence of CTF viral infection during the acute phase because of the late appearance of the various antibodies. Here we report the development and clinical application of a test to diagnose this disease during the acute stages. Oligonucleotide primers to the S2 segment of CTF (Florio) virus were made, and these were used in the amplification of a 528-bp fragment of DNA, transcribed from the double-stranded CTF virus RNA template by reverse transcriptase PCR. RNAs processed from 16 CTF virus isolates yielded similar results when analyzed on agarose gels. These were distinguishable from their antigenic relatives Eyach, S6-14-03, and T5-2092 and from other coltiviruses and an orbivirus but not from the antigenically distinct CTF virus-related isolate 720896. A mouse model demonstrated the utility of this method with whole-blood specimens, and CTF virus was successfully detected in human sera from the initial day of the onset of symptoms to 8 days later. The reverse transcriptase PCR method is a promising tool for the early diagnosis of CTF viral infection, or for ruling out CTF virus as the etiologic agent, in order to facilitate appropriate medical support.

Occupational asthma in greenhouse tomato growing

An employee working in a commercial tomato growing greenhouse developed asthma of increasing severity over a period of 8 years. She was diagnosed as having occupational asthma by a chest physician. The cause was obscure and initial allergy testing was negative. Further investigation of the workplace gave rise to suspicion of allergy to insects. Immunological testing confirmed sensitization to Red Spider Mite.

Humoral immunity to aerosolized staphylococcal enterotoxin B (SEB), a superantigen, in monkeys vaccinated with SEB toxoid-containing microspheres

Staphylococcal enterotoxin B (SEB) toxoid-containing microspheres were tested for efficacy in rhesus monkeys as a vaccine candidate for respiratory SEB toxicosis and toxic shock. Forty monkeys were randomly separated into 10 groups of four monkeys each: 9 groups were vaccinated with the microspheres via combinations of mucosal and nonmucosal routes, and 1 group served as nonvaccinated controls. Both vaccinated and nonvaccinated monkeys were then challenged with a high lethal dose of SEB aerosol. Monkeys primed with an intramuscular dose of the microspheres followed by an intratracheal booster all survived the SEB challenge. Overall, monkeys with an intratracheal booster generally had the highest antibody levels, which is consistent with their high survival rate and lower rate of illness. Protective immunity was correlated with antibody levels in both the circulation and the respiratory tract. The protection was not due to the depletion or anergy of SEB-reactive T cells, since SEB-induced proliferation in cultures of circulating lymphocytes was not significantly reduced after the microsphere vaccination. It is evident that the nonsurvivors did not die of systemic anaphylaxis or hypersensitivity because the monkeys did not die immediately after SEB challenge and there were no significant differences in histamine levels between the vaccinated and control monkeys before and after SEB challenge. The antibodies seemed to neutralize the SEB that got into the airway and the circulation.

Aerosolized staphylococcal enterotoxin B-induced pulmonary lesions in rhesus monkeys (Macaca mulatta)

The pathology of aerosolized staphylococcal enterotoxin B (SEB) was studied in the nonhuman primate. Six juvenile rhesus monkeys that received multiple lethal inhaled doses of SEB developed diarrhea and vomiting within 24 hr followed by depression, dyspnea, and shock. Three of 6 animals died by 52 hr. The most striking gross lesion in all 6 monkeys was diffuse severe pulmonary edema. Histologically, edema fluid was present within the peribronchiolar, peribronchial, and perivascular interstitium, alveolar septa, and alveoli. The adventitia of pulmonary vessels was infiltrated by lymphocytes, macrophages, and fewer neutrophils. Numerous large lymphocytes with occasional mitotic figures were within pulmonary vessels, often occluding alveolar capillaries. These cells were strongly immunoreactive with monoclonal antibodies against CD3, establishing them as T cells. Ultrastructurally, endothelial cell junctions were intact, and endothelial cells and type I pneumocytes contained numerous pinocytotic vesicles. Alveolar septal interstitial spaces were expanded by edema. The mechanism of these SEB-induced pulmonary lesions was not determined. We hypothesize that cytokine production by activated T cells may have caused vascular permeability changes leading to widespread pulmonary edema and shock.

The envelope glycoproteins of dengue 1 and dengue 2 viruses grown in mosquito cells differ in their utilization of potential glycosylation sites

We have previously isolated and characterized two dengue (DEN) 2 viruses mutant in their fusion-from-within (FFWI) phenotype in the insect cell line C6/36. Both viruses lost a potential glycosylation site (Asn-153) in the envelope (E) glycoprotein. To determine whether the change in FFWI phenotype was due to a change in E-glycoprotein glycosylation, we characterized the patterns of glycosylation on the E-glycoprotein of wild-type DEN 1 and DEN 2 viruses. The E-glycoproteins were isolated from purified virus grown in Aedes albopictus C6/36 cells, by use of high-performance size-exclusion chromatography. The tryptic maps of wild-type glycosylated and enzymatically (PNGase F) deglycosylated E-glycoproteins were compared by reverse-phase high-performance liquid chromatography. The DEN 1 virus E-glycoprotein was found to have two peaks in the tryptic map that exhibited shifts after deglycosylation, whereas the DEN 2 virus E-glycoprotein had only one. Besides the potential glycosylation site at Asn-153, both DEN 1 and DEN 2 virus E-glycoproteins have another potential site located at Asn-67. Amino-terminal sequencing of the shifted peaks revealed that DEN 2 virus E-glycoprotein is glycosylated only at Asn-67; however, DEN 1 virus E-glycoprotein is glycosylated at both Asn-67 and Asn-153. These DEN virus serotypes are thus heterogeneous in their use of glycosylation sites. We also determined by a lectin-binding assay that the attached carbohydrates for both viruses were likely to be of the high-mannose type.

Determination of fifty percent inhibitory concentrations (IC50) of antimalarial drugs against Plasmodium falciparum parasites in a serum-free medium

Plasmodium falciparum chemosensitivity to the various antimalarial drugs is presently determined in the laboratory by setting up multiple microcultures of the parasite and estimating the amount of growth inhibition caused by known concentrations of drug. Parasite growth inhibition is assessed either by microscopy, radiolabeled substrate uptake, or calorimetrically. The obligate requirement for serum in this assay presents difficulties in the direct comparison of results among laboratories. We now have evidence that antimalarial drug sensitivity assays can be reliably performed in a serum-free medium. The overall comparison of 50% inhibitory concentration (IC50) values obtained with serum-free media (bovine albumin, Cohn fraction V [BAM] and BAM combined with glucose and lipids-cholesterol-rich mixture) and those obtained in serum-supplemented medium was r = 0.56; n = 60; P < 0.01.

Cultivation of Plasmodium falciparum parasites in a serum-free medium

The elimination of serum from Plasmodium falciparum culture media could decrease costs, enhance procurement, and improve the feasibility of large-scale production of parasite material. We provide a semi-defined, serum-free formulation, of commercially available constituents that supports P. falciparum parasite growth at rates comparable with those obtained with serum-supplemented media. The medium is composed of RPMI 1640 to which HEPES, extra glucose, bicarbonate, and hypoxanthine have been added. Bovine albumin and serum-derived, lipids-cholesterol-rich mixture are then used in place of serum.

Fibrin glue in otology and neurotology

The recent development of simple, low-cost methods for producing autologous fibrin glue have given rise to a variety of uses in routine otologic and neurotologic procedures. Some of the current applications used by the authors are discussed, and a brief review of the literature is presented. Included are methods of positioning and securing implants, closure of wound edges, and application as an adjunct to achieving watertight dural closures with intracranial procedures. Representative cases are presented. No adverse reactions or specific problems related to the glue have been noted. A simple production method is included, as well as comparison with other commonly available tissue glue products.

Immunity and responses of circulating leukocytes and lymphocytes in monkeys to aerosolized staphylococcal enterotoxin B

Rhesus monkeys immunized intramuscularly or orally with staphylococcal enterotoxin B (SEB) toxoid or SEB toxoid incorporated in microspheres made of poly(DL-lactide-co-glycolide) were challenged with a lethal dose of aerosolized SEB to study their immunity and cellular responses in the circulation. It was found that circulating antibodies play a critical role in preventing SEB from triggering toxicosis. Monkeys with high levels of antibodies survived, while those with low levels underwent 2 to 3 days of toxicosis and died. Intramuscular immunization induced high levels and oral immunization induced low levels of antibodies. The circulating antibodies in surviving monkeys decreased dramatically within 20 min and started to rebound at 90 min after SEB challenge. At 90 min, the dying monkeys showed in the circulation a dramatic increase of polymorphonuclear leukocytes and decreases of NK cells and monocytes (CD16 and CD56 markers) as well as of lymphocytes with HLA-DR, CD2, CD8, and IL2R alpha (CD25) markers. The number of polymorphonuclear leukocytes showed an inverse correlation with the numbers of monocytes and various lymphocyte subpopulations which, except for IL-2R, CD16, and CD56(+) cells, showed a direct correlation with one another. The changes in the populations of leukocytes, monocytes, NK cells, and lymphocytes seem to be an indication of initial toxicosis; however, the roles of these cells in toxicosis and death remain to be defined.

Enhancement of the antibody response to flavivirus B-cell epitopes by using homologous or heterologous T-cell epitopes

We have been investigating the T-helper (Th)-cell response to the flavivirus envelope (E) glycoprotein. In our studies with Murray Valley encephalitis (MVE) virus, we previously identified synthetic peptides capable of priming Th lymphocytes for an in vitro antivirus proliferative response (J. H. Mathews, J. E. Allan, J. T. Roehrig, J. R. Brubaker, and A. R. Hunt, J. Virol. 65:5141-5148, 1991). We have now characterized in vivo Th-cell priming activity of one of these peptides (MVE 17, amino acids 356 to 376) and an analogous peptide derived from the E-glycoprotein sequence of the dengue (DEN) 2, Jamaica strain (DEN 17, amino acids 352 to 368). This DEN peptide also primed the Th-cell compartment in BALB/c mice, as measured by in vitro proliferation and interleukin production. The failure of some MVE and DEN virus synthetic peptides to elicit an antibody response in BALB/c mice could be overcome if a Th-cell epitope-containing peptide was included in the immunization mixture. A more detailed analysis of the structural interactions between Th-cell and B-cell epitope donor peptides revealed that the peptides must be linked to observe the enhanced antibody response. Blockage or deletion of the free cysteine residue on either peptide abrogated the antibody response. The most efficient T-B-cell epitope interaction occurred when the peptides were colinearly synthesized. These Th-cell-stimulating peptides were also functional with the heterologous B-cell epitope-containing peptides. The Th-cell epitope on DEN 17 was more potent than the Th-cell epitope on MVE 17.

Effect of acute inhibition of lipolysis on operation of the glucose-fatty acid cycle in hepatic cirrhosis

Hepatic cirrhosis is frequently associated with glucose intolerance and insulin resistance, but the mechanisms underlying the insulin insensitivity are unknown. Plasma concentrations of nonesterified fatty acids (NEFA) are typically elevated in cirrhosis, and the glucose-fatty acid cycle provides a mechanism by which fatty acids may play a role in regulating glucose metabolism. We have therefore investigated the effect of acute inhibition of lipolysis, using the nicotinic acid analogue, acipimox, in 10 male patients with cirrhosis. All subjects were studied in the postabsorptive state after a 10- to 12-hour fast and were given either acipimox 250 mg or a placebo orally 2 hours before a 75-g oral glucose tolerance test (OGTT) and an infusion of insulin (50 mU/kg/h) and glucose (6 mg/kg/min) (insulin sensitivity tests [IST]). The drug was taken in a double-blind crossover design for each test. During the 2 hours following acipimox, there were rapid decreases in plasma NEFA, glycerol, and 3-hydroxybutyrate, confirming inhibition of lipolysis, while there were significant decreases in glucose, insulin, and C-peptide (P less than .001) compared with patients receiving the placebo. Acipimox blunted the increase in glucose after oral glucose loading and decreased incremental glucose concentration (from 579 +/- 76 to 445 +/- 65 mmol/min/L, P less than .02) and incremental insulin concentration (from 13.4 +/- 2.5 to 9.0 +/- 1.4 U/min/L, P = .056) in the OGTT. Improvements in classification of glucose tolerance were seen in five subjects. During the IST, significant reductions occurred in steady-state blood glucose (to 8.8 +/- 1 mmol/L, P less than .02) and C-peptide (to 3.0 +/- 0.5 nmol/L, P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)