Residual human immunodeficiency virus (HIV) Type 1 RNA and DNA in lymph nodes and HIV RNA in genital secretions and in cerebrospinal fluid after suppression of viremia for 2 years

Residual viral replication persists in a significant proportion of human immunodeficiency virus (HIV)-infected patients receiving potent antiretroviral therapy. To determine the source of this virus, levels of HIV RNA and DNA from lymphoid tissues and levels of viral RNA in serum, cerebrospinal fluid (CSF), and genital secretions in 28 patients treated for < or =2.5 years with indinavir, zidovudine, and lamivudine were examined. Both HIV RNA and DNA remained detectable in all lymph nodes. In contrast, HIV RNA was not detected in 20 of 23 genital secretions or in any of 13 CSF samples after 2 years of treatment. HIV envelope sequence data from plasma and lymph nodes from 4 patients demonstrated sequence divergence, which suggests varying degrees of residual viral replication in 3 and absence in 1 patient. In patients receiving potent antiretroviral therapy, the greatest virus burden may continue to be in lymphoid tissues rather than in central nervous system or genitourinary compartments.

Local anesthesia does not block mustard-oil-induced temporomandibular inflammation

Temporomandibular joint (TMJ) disorders and rheumatoid arthritis are two conditions in which neurogenic mechanisms may play a critical role. We investigated the neurogenic contribution underlying acute TMJ inflammation by evaluating effects of local anesthetic blockade of afferent innervation on the development of mustard oil (MO)-induced edema in the rat TMJ area. Groups of eight adult male Sprague-Dawley rats were anesthetized by intraperitoneal alpha-chloralose and urethane. A saline injection into the right TMJ followed by MO (1% to 60%) 6 min later elicited dose-dependent edema development (P < 0.05, repeated measures analysis of variance). Lidocaine (5%) or bupivacaine (0.5%) followed by MO (1% or 40%) did not produce edema development different from saline controls (P > 0.05, repeated measures analysis of variance). The failure of local anesthetic blockade to prevent MO-induced edema is not consistent with MO acting through a neurogenic mechanism, as traditionally perceived.

IMPLICATIONS

Inflammation found in temporomandibular disorders and rheumatoid arthritis may result from mediators released by pain-sensing neurons. Local anesthesia failed to block simulated neurogenic temporomandibular inflammation in a rat model, suggesting that functional neuronal input may not be necessary for the promotion of inflammation.

Productive infection of T cells in lymphoid tissues during primary and early human immunodeficiency virus infection

Current models suggest that during human immunodeficiency virus type 1 (HIV-1) transmission virions are selected that use the CCR5 chemokine receptor on macrophages and/or dendritic cells. A gradual evolution to CXCR4 chemokine receptor use causes a shift in the proportion of productively infected cells to the CD4 cell population. Productively infected cells during acute and early infection in lymphoid tissue were assessed, as well as the impact of productive infection on the T cell population in 21 persons who had biopsies performed on days 2-280 after symptoms of acute HIV-1 seroconversion. Even in the earliest stages of infection, most productively infected cells were T lymphocytes. There were sufficient infected cells in lymphoid tissue (LT) to account for virus production and virus load in plasma. Despite the relatively high frequency of productively infected cells in LT, the impact on the size of the T cell population in LT at this stage was minor.

Estrogen receptor beta immunoreactivity in differentiating cells of the developing rat cerebellum

Estrogen receptors (ER) play a significant role in the development of some regions of the mammalian brain. Recently, ER-beta (ERbeta) mRNA and protein were shown to be expressed in the rat cerebellum. In the present study, the ontogeny of ERbeta protein expression was examined in the rat cerebellum during postnatal development. Western blot analysis indicated that a single ERbeta-like immunoreactive species of approximately 55 kDa was present in protein lysates prepared from the cerebella of female and male Sprague-Dawley rat pups. Immunocytochemical analysis of cerebellar sections from the midline vermis revealed that during development, the expression of ERbeta varied with age and cell-type, but not sex. In the developing cerebellum, highest levels of ERbeta-immunoreactivity (IR) were detected in neurons during neurite growth, and in some glia during migration. Throughout the first postnatal week, ERbeta-IR was localized to differentiating granule cells in the external germinal layer and to migrating glia. Differentiating granule cells expressed detectable levels of ERbeta throughout development. In Purkinje cells, ERbeta-IR was first detected on postnatal day 6 (P6), with peak intensities of immunostaining coinciding with the initiation of axonal and dendritic growth that occurs between P7 and P8. Expression of ERbeta-IR remained high during maturation of Purkinje cell dendrites, and then decreased to a lower level maintained in the adult. From the third postnatal week, ERbeta-IR was also detected in the later developing Golgi, stellate, and basket neurons. These results suggest that ERbeta may play a role in growth-related mechanisms during differentiation of cerebellar neurons and glia.

Reduced susceptibility of human immunodeficiency virus type 1 (HIV-1) from patients with primary HIV infection to nonnucleoside reverse transcriptase inhibitors is associated with variation at novel amino acid sites

Recently, significant numbers of individuals with primary human immunodeficiency virus (HIV) infection have been found to harbor viral strains with reduced susceptibility to antiretroviral drugs. In one study, HIV from 16% of such antiretroviral-naive individuals was shown to have a susceptibility to nonnucleoside reverse transcriptase (RT) inhibitors (NNRTIs) between 2.5- and 10-fold lower than that of a wild-type control. Mutations in the RT domain that had previously been associated with antiretroviral resistance were not shared by these strains. We have analyzed by logistic regression 46 variable amino acid sites in RT for their effect on susceptibility and have identified two novel sites influencing susceptibility to NNRTIs: amino acids 135 and 283 in RT. Eight different combinations of amino acids at these sites were observed among these patients. These combinations showed a 14-fold range in mean susceptibility to both nevirapine and delavirdine. In vitro mutagenesis of the control strain combined with a phenotypic assay confirmed the significance of amino acid variation at these sites for susceptibility to NNRTIs.

Effect of influenza vaccination on viral replication and immune response in persons infected with human immunodeficiency virus receiving potent antiretroviral therapy

Nineteen patients infected with human immunodeficiency virus (HIV) with varying levels of viral suppression achieved with antiretroviral therapy were evaluated to determine whether trivalent influenza vaccine activated HIV replication. Humoral immune responses and CD4+ lymphocyte subsets were compared in 5 HIV-uninfected vaccinated subjects. Transient elevations of plasma HIV RNA levels (76-89 copies/mL) appeared within 2 weeks in 3 of 11 patients with <50 copies/mL at baseline. Sustained elevation in HIV plasma RNA was observed in 7 of 8 patients with baseline HIV RNA of >50 copies/mL. HIV DNA decreased in patients with <400 RNA copies/mL at baseline and showed an HIV RNA increase after vaccination (n=8) when compared with 8 patients with <50 copies/mL at baseline who lacked viral response to vaccination. Concurrent decreases in proviral DNA and memory phenotype CD4+ cells in association with increased plasma HIV RNA after vaccination in patients with <400 RNA copies/mL at baseline suggest that in vivo mobilization of the latently infected cell reservoir may occur during potent antiretroviral therapy.

Multiple sites in HIV-1 reverse transcriptase associated with virological response to combination therapy

OBJECTIVE

To determine whether analysis of sequence variation in reverse transcriptase at baseline can explain differences in response to combination antiretroviral therapy.

METHODS

Amino acid sequences of reverse transcriptase obtained from baseline isolates from 55 patients included in a trial of zidovudine and didanosine versus zidovudine/didanosine/nevirapine (ACTG241) were analysed. Simple and multiple linear regression were used to determine the relationship between numbers and identity of mutations at baseline and virological response after 8 and 48 weeks.

RESULTS

Numbers of baseline zidovudine resistance mutations were predictive of short-term response (week 8). Amino acid identity at position 215 explained > 20% of the variation in response at week 8, but less at week 48. Multiple regression identified the combinations: 215 + 44 and 41 + 202, each of which explained about 30% of the variation in week 8 response. A model incorporating amino acids 214 + 215 + 60 + 202 + baseline viral load explained > 40% of the variation in response at week 48. Unexpectedly, the mutant combination 601 + 215Y/F responded threefold better than 60V + 215Y/F over 48 weeks.

CONCLUSIONS

Use of clinical data to analyse virological response to combination therapy has revealed effects of baseline amino acid mutations at sites not previously identified as being important in antiretroviral resistance. Predictors of long-term responses were different from those involved in the short term and may require more complex analysis.

Rapid accumulation of human immunodeficiency virus (HIV) in lymphatic tissue reservoirs during acute and early HIV infection: implications for timing of antiretroviral therapy

The follicular dendritic cell network (FDC) in lymphoid tissues (LTs) is the major site of human immunodeficiency virus (HIV) storage in presymptomatic and late stages of disease. However, little is known about the rate of virus accumulation during the acute and early stages. In situ hybridization and quantitative image analysis were used to determine the amount of virus bound to the FDC network during the first year of infection. The FDC pool was already >7.0 log10 copies of HIV RNA/g LT in the first year, and 2 patients biopsied within 2-4 days of symptom onset had 7.3 and 8.2 log10 copies of HIV RNA/g LT, respectively. There was no correlation between duration of infection and accumulation of HIV into the FDC network. These data suggest that a large pool of infectious virus is established soon after infection and that initiation of antiretroviral therapy when symptoms of primary HIV infection are recognized is unlikely to prevent substantial accumulation of virus in the FDC network.

Synthesis of C-11 methyl-substituted benzocycloheptapyridine inhibitors of farnesyl protein transferase

[formula: see text] Synthesis of C-11 methyl-substituted benzocycloheptylpyridine tricyclic compounds has been achieved via two different methods. Methylation of C-11 has been effected by treatment of amine 4 with BuLi followed by Mel quenching. In a similar procedure, introduction of a C-11 substituent with concomitant rearrangement of the exocyclic double bond has been carried out. Potent farnesyl protein transferase inhibitors have been synthesized using the above methodologies.

Evolution of envelope sequences of human immunodeficiency virus type 1 in cellular reservoirs in the setting of potent antiviral therapy

In human immunodeficiency virus (HIV)-infected patients treated with potent antiretroviral therapy, the persistence of latently infected cells may reflect the long decay half-life of this cellular reservoir or ongoing viral replication at low levels with continuous replenishment of the population or both. To address these possibilities, sequences encompassing the C2 and V3 domains of HIV-1 env were analyzed from virus present in baseline plasma and from viral isolates obtained after 2 years of suppressive therapy in six patients. The presence of sequence changes consistent with evolution was demonstrated for three subjects and correlated with less complete suppression of viral replication, as indicated by the rapidity of the initial virus load decline or the intermittent reappearance of even low levels of detectable viremia. Together, these results provide evidence for ongoing replication. In the remaining three patients, virus recovered after 2 years of therapy was either genotypically contemporary with or ancestral to virus present in plasma 2 years before, indicating that virus recovery had indeed resulted from activation of latently infected cells.

Sequence clusters in human immunodeficiency virus type 1 reverse transcriptase are associated with subsequent virological response to antiretroviral therapy

Many amino acid (aa) sites in reverse transcriptase (RT) have been implicated in resistance to nucleoside (NRTI) and nonnucleoside antiretrovirals. Interactions between these in response to combination therapy remain poorly understood. In a trial (ACTG 241) of zidovudine/didanosine (ddI) versus zidovudine/ddI/nevirapine in nucleoside-experienced patients, baseline sequence data from the RT coding region was analyzed from 55 individuals. Sequences were clustered by use of a parsimony method and the virological responses (ratio of baseline viral load to viral load after of therapy) for each cluster were analyzed at week 8 and week 48. Both clusters and genotype at aa 215 were significantly associated with virological response at both time points, whereas viral load showed a stronger association with sequence clusters. Sequence clusters identified one group of patients who never developed high-level resistance to NRTIs despite prior nucleoside exposure and poor suppression of viral replication.

Higher selection pressure from antiretroviral drugs in vivo results in increased evolutionary distance in HIV-1 pol

We investigated the effect of selection pressures on evolution of HIV-1 pol in 51 patients after switching to a new antiretroviral combination reverse transcriptase (RT) inhibitor therapy. Evolution of the protease (PR) and RT reading frames were analysed separately. Pairwise evolutionary distances (ED) were calculated between sequences from baseline and week 8 and between baseline and week 48 of protocol therapy. ED were calculated for all substitutions and for synonymous and nonsynonymous substitutions separately. At week 8 when HIV RNA reduction (selection pressure) was high, significantly more divergence in pol in both synonymous and nonsynonymous substitutions was found in patients with substantial RNA reduction (strong responders). Separate analyses of PR and RT revealed significantly greater ED in the RT (under selection pressure) of strong compared with nonresponders, whereas divergence between PR genes (not under selection pressure) did not differ in those two groups. Such differential evolution indicates that PR and RT were genetically unlinked and suggests recombination. The rapid increase of ED over the first 8 weeks was followed by only a minimal further rise by week 48, suggesting that selection of preexisting quasispecies accounted for the early changes. A disproportionally high number of synonymous substitutions accounted for the observed divergence and indicated that such genetic changes may not be completely silent.

A comparison of bitemark injuries between fatal wolf and domestic dog attacks

Bitemark patterns in adult human victims following a fatal wolf pack attack and a domestic dog pack attack are compared. Both victims exhibited a concentration of wounds to the extremities, left and right torso, but not to the groin or internal organs. The neck and face of the domestic dog attack victim were primary sites of attack while the feral wolf pack victim was spared damage to the neck, but had facial tissue destroyed postmortem. Most punctures were found on the ventral aspect of the domestic victim and dorsal aspect of the feral victim. It is speculated that most wounds were attributable to dominant animals of both packs and in both victims and this suggests a co-ordination of activity between. Differences in bitemark patterns may well have been caused in part by differences in genetics, training, breeding, socialization and impetus of attack between wolves and dogs. Distinct differences in bitemark patterns were found in these two human victims of a wolf and domestic dog attacks.

Use of the intubating laryngeal mask airway to facilitate awake orotracheal intubation in patients with cervical spine disorders

Airway management in patients with unstable cervical spines remains a challenge for anesthesia providers. Because neurologic evaluations may be required following tracheal intubation and positioning for the surgical procedure, an awake intubation technique is desirable in this patient population. In this report, we describe the use of an intubating laryngeal mask airway (ILMA) to facilitate awake tracheal intubation in two patients with cervical spine disorders. After topical local analgesia, the ILMA was inserted easily, and a tracheal tube was passed through the glottic opening without complications. Thus, the ILMA may be an acceptable alternative to the fiberoptic bronchoscope for awake tracheal intubation.

Comparison of two Doppler ultrasound criteria for grading cervical internal carotid artery stenosis

In a review of 49 carotid arteries that had been assessed by ultrasound and angiography, two Doppler criteria were compared for accuracy in grading internal carotid artery (ICA) stenosis. The Seattle criteria for Doppler spectral analysis and the internal-to-common carotid artery peak systolic velocity ratio were of similar accuracy. When used in combination, there was an increase in sensitivity compared with the use of a single criterion. The velocity ratio had a higher sensitivity for detection of high-grade stenosis, but it tended to overestimate the grade of stenosis more than the Seattle criteria. To increase the sensitivity for detection of severe stenosis, the criteria should be used together and the higher grade of stenosis should be taken if there is a mismatch in assessment.

Reversibility of the pathological changes in the follicular dendritic cell network with treatment of HIV-1 infection

Over the course of HIV-1 infection, the lymphoid follicles where the humoral immune response is generated initially increase in size and number and then progressively involute. In advanced disease, the network of the processes of follicular dendritic cells (FDCs) that serve as antigen repositories and anatomical substrate for B and T cells and antigen to interact is destroyed, contributing to the breakdown of the immune system. Because destruction of FDCs is associated with deposition of HIV-1, and much of the virus can be cleared from the network with antiretroviral therapy, we investigated the reversibility of damage. We measured the immunohistochemically stainable FDC compartment by quantitative image analysis, and we documented changes in this compartment at different stages of disease. We show that treatment, initiated even at advanced stages of HIV-1 disease, can slowly reverse pathological changes in the FDC network.

Predicting infection in localized intraabdominal fluid collections: value of pH and pO2 measurements

PURPOSE

To evaluate the use of pH, pO2, and the subjective opinion of the radiologist compared with bacterial culture in accurate diagnoses of bacterial infection in intraabdominal fluid collections.

MATERIALS AND METHODS

Prospectively, 79 patients who were suspected of having an intraabdominal fluid collection underwent diagnostic fluid aspiration. The aspirate was cultured and measured for pH and pO2. A pH < or = 7.1 and a PO2 < or = 49 mm Hg were threshold values used to separate infected from sterile fluid collections.

RESULTS

pH alone had a 92% sensitivity and 79% specificity, whereas PO2 alone had a 51% sensitivity and 79% specificity. pH or pO2 combined yielded a 92% sensitivity and 60% specificity. The radiologist's opinion produced a 83% sensitivity and 92% specificity. pH and the radiologist's opinion combined produced a 78% sensitivity and 96% specificity. pH or the radiologist's opinion combined had a 95% sensitivity and a 63% specificity.

CONCLUSION

pH is the most sensitive indicator of infection and the radiologist's opinion is the most specific. We recommend proceeding to drainage if the radiologist believes the collection to be infected and performing pH analysis if not. If the pH < or = 7.04, proceed to drainage. If neither of the above criteria are met, drainage could be delayed, pending the results of culture.

Role of actin in EGF-induced alterations in enterocyte SGLT1 expression

Na+-glucose cotransporter (SGLT1) expression and the role of actin in epidermal growth factor (EGF)-induced alterations in glucose transport and brush-border surface area were examined in New Zealand White rabbit jejunal loops. In separate experiments, EGF or EGF concurrent with cytochalasin D, an inhibitor of actin polymerization, was administered to the experimental loop and compared with its vehicle control. SGLT1 expression was measured by Western blot in brush-border membrane vesicles (BBMV) after 5-min and 1-h exposure. Glucose kinetics were determined by a rapid filtration technique, and brush-border surface area was examined by electron microscopy after 1-h exposure. The effect of cytochalasin D alone on BBMV glucose kinetics and brush-border surface area was also assessed. EGF resulted in a significant increase in BBMV SGLT1 expression (P < 0.05), glucose maximal uptake (Vmax; P < 0.001), and absorptive brush-border surface area (P < 0.001). These effects were abolished with concurrent cytochalasin D treatment. Cytochalasin D alone had no effect on glucose transport or brush-border surface area. The findings suggest that EGF acutely upregulates jejunal brush-border surface area and the Vmax for jejunal glucose uptake via the recruitment and insertion of SGLT1 from an internal pool into the brush border by a mechanism that is dependent on actin polymerization.

Dual antagonists of platelet activating factor and histamine. 3. Synthesis, biological activity and conformational implications of substituted N-acyl-bis-arylcycloheptapiperazines

A series of N-acyl-4-(5,6-dihydro-11H-benzo[5,6]cyclohepta[1,2-b]pyridin- 11-ylidene)piperazines is described that are dual antagonists of PAF and histamine. The structural requirements for activity in this series parallel those of their previously reported piperidinylidene counterparts. Whereas their global minimum energy conformations are different for both series of compounds, computer assisted molecular modeling suggests that a common bioactive conformation is possible.

Pain preceding recurrent head and neck cancer

Over a 7-year period, 12 patients experienced recurrence of primary head and neck cancers preceded by severe orofacial pain. Pain began within 6 months following treatment in 10 of 12 patients and was progressive in 11 of 12 patients. Six patients died from recurrence, five within 2 years following onset of pain. No clear indication of malignant disease was evident despite clinical examination, plain radiography, magnetic resonance imaging, and computed tomography. Pain was often mistaken for denture irritation. Frequently, no area of irritation was apparent.