Factors influencing vitamin B6 status in domestic cats: age, disease, and body condition score

Limited studies are available on vitamin B6 status in domestic cats. To this end, we evaluated glutamate-oxaloacetate transaminase (GOT) activity in hemolysates with and without pyridoxal 5'-phosphate addition in two feline populations: a cohort of 60 healthy, domestic (sexually intact and specific pathogen-free) cats maintained under strictly controlled conditions with appropriate diets housed at the Feline Nutrition and Pet Care Center, and a cohort of 57 cats randomly selected between December 2022 to January 2023 that visited the Veterinary Medicine Teaching Hospital to seek care under different circumstances. The GOT activity expressed as the ratio with and without pyridoxal 5'-phosphate addition (primary activation ratio; PAR) decreased significantly with age in the healthy cohort. The PAR values normalized to age established a cut-off for vitamin B6 deficiency in both cohorts, identifying 17 of 101 animals as vitamin B6 deficient. Using machine learning, a partition-based model (decision tree) was built to identify the most important factors that predicted vitamin B6 deficiency while using the resulting tree to make predictions for new observations. This analysis, performed with all 101 cats, revealed that the diagnosis of an infectious, chronic or acute condition (0.55) was the main contributor, followed by age (0.26), and body condition score (optimal-overweight; 0.19). Thus, our study supports that vitamin B6 supplementation may be indicated in junior to adult animals diagnosed with an infectious, chronic, or acute conditions or healthy cats with body weight ranging from optimal to overweight. In older cats, even if healthy, underweight to optimal cats appear to be at risk of vitamin B6 deficiency.

Bow Hunter's Syndrome: A rare cause of vertebrobasilar insufficiency

Bow Hunter's syndrome, also referred to as rotational occlusion of the vertebral artery, is caused by dynamic compression of a patient's dominant vertebral artery. We reported a case of successful clinical and imaging work up of Bow Hunter's Syndrome that occurred in a 79-year-old female patient. We discussed the clinical presentation, imaging findings, and subsequent management options of this rare syndrome. The gold standard for diagnosis is dynamic cerebral angiography, which allows the reproduction of symptoms with head turn greater than 30-45 degrees. Subsequent management is based on the underlying etiology causing rotational compression.

Cardiac magnetic resonance longitudinal strain analysis in acute ST-segment elevation myocardial infarction: A comparison with speckle-tracking echocardiography

BACKGROUND

Strain analysis with speckle-tracking echocardiography (STE) is considered superior to ejection fraction for ventricular function assessment in different clinical scenarios. Feature tracking (FT) permits cardiac magnetic resonance (CMR) strain analysis in routinely acquired cine images. This study evaluated the feasibility of CMR-FT and its agreement with STE in patients with acute ST-segment elevation myocardial infarction (STEMI).

METHODS

An echocardiogram and CMR were performed in 128 patients who underwent primary percutaneous revascularisation after a STEMI. Adequate strain analysis was obtained by both techniques in 98 patients and peak systolic longitudinal strain (LS) was assessed with STE and CMR-FT.

RESULTS

Of 1568 myocardial segments, 97.2% were correctly tracked with STE and 97.7% with CMR-FT. For global LS, STE showed a mean of -14.8 ± 3.3% and CMR-FT -13.7 ± 3.0%, with good agreement between modalities [intraclass correlation coefficient (ICC) 0.826; bias -1.09%; limits of agreement (LOA) ± 4.2%]. On the other hand, segmental LS agreement was only moderate, with an ICC of 0.678 (bias -1.14%; LOA ± 11.76%) and the ICC ranged from 0.538 at the basal antero-lateral segment to 0.815 at the apical lateral segment. Finally, both STE and CMR-FT showed excellent intra- and inter-observer reproducibility (ICC > 0.9).

CONCLUSIONS

CMR-FT provides LS with similar feasibility to STE and both techniques showed good agreement for global LS, although agreement at segmental level was only moderate. CMR-FT showed excellent reproducibility, strengthening its robustness and potential for both research and clinical applications.

Aneurysms with persistent filling after failed treatment with the Pipeline embolization device

OBJECTIVEThe Pipeline embolization device (PED) has become a valuable tool in the treatment of cerebral aneurysms. Although failures with PED treatment have been reported, the characteristics and course of these aneurysms remain a topic of uncertainty.METHODSElectronic medical records and imaging studies were reviewed for all patients treated with the PED between July 2010 and March 2015 to identify characteristics of patients and aneurysms with residual filling after PED treatment.RESULTSOf 316 cases treated at a single institution, 281 patients had a long-term follow-up. A total of 52 (16.4%) aneurysms with residual filling were identified and constituted the study population. The mean patient age in this population was 58.8 years. The mean aneurysm size was 10.1 mm ± 7.15 mm. Twelve aneurysms were fusiform (23%). Of the aneurysms with residual filling, there were 20 carotid ophthalmic (CO) aneurysms (20% of all CO aneurysms treated), 10 other paraclinoid aneurysms (16.4% of all paraclinoid aneurysms), 7 posterior communicating artery (PCoA) aneurysms (21.9% of all PCoA aneurysms), 7 cavernous internal carotid artery (ICA) aneurysms (14.9% of all cavernous ICA aneurysms), 4 vertebrobasilar (VB) junction aneurysms (14.8% of all VB junction aneurysms), and 3 middle cerebral artery (MCA) aneurysms (25% of all MCA aneurysms). Eleven patients underwent placement of more than one PED (21.2%), with a mean number of devices of 1.28 per case. Eight of 12 aneurysms were previously treated with a stent (15.4%). Nineteen patients underwent re-treatment (36.5%); the 33 patients who did not undergo re-treatment (63.5%) were monitored by angiography or noninvasive imaging. In multivariate analysis, age older than 65 years (OR 2.65, 95% CI 1.33-5.28; p = 0.05), prior stent placement across the target aneurysm (OR 2.94, 95% CI 1.15-7.51; p = 0.02), aneurysm location in the distal anterior circulation (MCA, PCoA, and anterior choroidal artery: OR 2.72, 95% CI 1.19-6.18; p = 0.017), and longer follow-up duration (OR 1.06, 95% CI 1.03-1.09; p < 0.001) were associated with incomplete aneurysm occlusion.CONCLUSIONSWhile the PED can allow for treatment of large, broad-necked aneurysms with high efficacy, treatment failures do occur (16.4%). Aneurysm size, shape, and previous treatment may influence treatment outcome.

Decompressive hemicraniectomy: predictors of functional outcome in patients with ischemic stroke

OBJECT

Patients presenting with large-territory ischemic strokes may develop intractable cerebral edema that puts them at risk of death unless intervention is performed. The purpose of this study was to identify predictors of outcome for decompressive hemicraniectomy (DH) in ischemic stroke.

METHODS

The authors conducted a retrospective electronic medical record review of 1624 patients from 2006 to 2014. Subjects were screened for DH secondary to ischemic stroke involving the middle cerebral artery, internal carotid artery, or both. Ninety-five individuals were identified. Univariate and multivariate analyses were performed for an array of clinical variables in relationship to functional outcome according to the modified Rankin Scale (mRS). Clinical outcome was assessed at 90 days and at the latest follow-up (mean duration 16.5 months).

RESULTS

The mean mRS score at 90 days and at the latest follow-up post-DH was 4. Good functional outcome was observed in 40% of patients at 90 days and in 48% of patient at the latest follow-up. The mortality rate at 90 days was 18% and at the last follow-up 20%. Univariate analysis identified a greater likelihood of poor functional outcome (mRS scores of 4–6) in patients with a history of stroke (OR 6.54 [95% CI1.39–30.66]; p = 0.017), peak midline shift (MLS) > 10 mm (OR 3.35 [95% CI 1.33–8.47]; p = 0.011), or a history of myocardial infarction (OR 8.95 [95% CI1.10–72.76]; p = 0.04). Multivariate analysis demonstrated elevated odds of poor functional outcome associated with a history of stroke (OR 9.14 [95% CI 1.78–47.05]; p = 0.008), MLS > 10 mm (OR 5.15 [95% CI 1.58–16.79; p = 0.007), a history of diabetes (OR 5.63 [95% CI 1.52–20.88]; p = 0.01), delayed time from onset of stroke to DH (OR 1.32 [95% CI 1.02–1.72]; p = 0.037), and evidence of pupillary dilation prior to DH (OR 4.19 [95% CI 1.06–16.51]; p = 0.04). Patients with infarction involving the dominant hemisphere had higher odds of unfavorable functional outcome at 90 days (OR 4.73 [95% CI 1.36–16.44]; p = 0.014), but at the latest follow-up, cerebral dominance was not significantly related to outcome (OR 1.63 [95% CI 0.61–4.34]; p = 0.328).

CONCLUSIONS

History of stroke, diabetes, myocardial infarction, peak MLS > 10 mm, increasing duration from onset of stroke to DH, and presence of pupillary dilation prior to intervention are associated with a worse functional outcome.

Genotypic testing on HIV-1 DNA as a tool to assess HIV-1 co-receptor usage in clinical practice: results from the DIVA study group

PURPOSE

We have developed a sequencing assay for determining the usage of the genotypic HIV-1 co-receptor using peripheral blood mononuclear cell (PBMC) DNA in virologically suppressed HIV-1 infected patients. Our specific aims were to (1) evaluate the efficiency of V3 sequences in B versus non-B subtypes, (2) compare the efficiency of V3 sequences and tropism prediction using whole blood and PBMCs for DNA extraction, (3) compare the efficiency of V3 sequences and tropism prediction using a single versus a triplicate round of amplification.

RESULTS

The overall rate of successful V3 sequences ranged from 100 % in samples with >3,000 copies HIV-1 DNA/10(6) PBMCs to 60 % in samples with <100 copies total HIV-1 DNA /10(6) PBMCs. Analysis of 143 paired PBMCs and whole-blood samples showed successful V3 sequences rates of 77.6 % for PBMCs and 83.9 % for whole blood. These rates are in agreement with the tropism prediction obtained using the geno2pheno co-receptor algorithm, namely, 92.1 % with a false-positive rate (FPR) of 10 or 20 % and of 96.5 % with an FPR of 5.75 %. The agreement between tropism prediction values using single versus triplicate amplification was 98.2 % (56/57) of patients using an FPR of 20 % and 92.9 % (53/57) using an FPR of 10 or 5.75 %. For 63.0 % (36/57) of patients, the FPR obtained via the single amplification procedure was superimposable to all three FPRs obtained by triplicate amplification.

CONCLUSIONS

Our results show the feasibility and consistency of genotypic testing on HIV-1 DNA tropism, supporting its possible use for selecting patients with suppressed plasma HIV-1 RNA as candidates for CCR5-antagonist treatment. The high agreement between tropism prediction by single and triple amplification does not support the use of triplicate amplification in clinical practice.

Feeding value of dried shredded sugarbeets as a partial replacement for steam-flaked corn in finishing diets for feedlot cattle

Two experiments were conducted to evaluate the comparative feeding value of dried shredded sugarbeets (DSSB; 0, 20, and 40% of diet DM) as a replacement for steam-flaked corn (SFC) in finishing diets for feedlot cattle. In Exp. 1, 60 calf-fed Holstein steers (476 ± 6.3 kg) were used in a 97-d finishing trial. Substitution of SFC with DSSB did not affect ADG or DMI (P > 0.20). Increasing DSSB decreased gain efficiency (ADG:DMI; linear effect, P = 0.04) and dietary NE (linear effect, P = 0.03). Given that SFC has a NE(m) value of 2.38 Mcal/kg, the replacement NE(m) and NE(g) values for DSSB were 1.94 and 1.29 Mcal/kg, respectively. There were no treatment effects (P > 0.20) on carcass characteristics. In Exp. 2, 6 cannulated Holstein steers (205 kg) were used in a replicated 3 × 3 Latin square design to evaluate treatment effects on digestion. Ruminal digestion of starch, NDF, and feed N were not affected (P > 0.10) by DSSB, although ruminal OM digestion tended to increase (linear effect, P < 0.08). Replacing SFC with DSSB decreased flow of starch to the small intestine, but it increased flow of microbial N (linear effect, P = 0.05). There were no treatment effects (P > 0.14) on postruminal digestion of OM, NDF, starch, or feed N or total tract digestion of OM, starch, and N. Substitution of DSSB increased (linear effect, P = 0.05) total tract NDF digestion and decreased (linear effect, P = 0.05) dietary DE (Mcal/kg). Given that SFC has a DE value of 4.19 Mcal/kg, the replacement DE value of DSSB was 3.68 Mcal/kg. There were no treatment effects (P > 0.12) on ruminal pH or total VFA; however, DSSB decreased propionate (linear effect, P = 0.05) and increased acetate (linear effect, P = 0.07), butyrate (linear effect, P = 0.05), valerate (linear effect, P = 0.04), and estimated methane production (linear effect, P = 0.05). We concluded that DSSB may replace SFC in finishing diets at levels of up to 40% without detrimental effects on ADG and carcass characteristics. The NE value of DSSB is 82% that of SFC (DM basis). Partial replacement of SFC with DSSB alters ruminal VFA patterns, increasing estimated methane energy loss and slightly decreasing the efficiency of DE utilization.

Prognostic factors of long-term CD4+count-guided interruption of antiretroviral treatment

Aim of the study was to determine predictors of the duration of antiretroviral treatment interruption in patients infected with HIV. This pilot prospective, open-label, multicenter trial comprised 62 HIV-seropositive subjects who decided voluntarily to interrupt therapy after two or more years of successful HAART. The primary end-point was the time to patients being free of therapy before reaching a CD4+ cell count < or =350/microl. Fifteen of 62 patients remained in treatment interruption for more than 180 days. Patients restarting therapy had higher HIV-DNA levels (P = 0.05), were treated more frequently with NNRTI-drugs (P = 0.02), had a shorter period of HAART (P = 0.046), and lower CD4+ cell counts after day 14 of interruption of treatment (P = 0.04). Multivariate regression analysis showed that less than 323 baseline proviral HIV-DNA cp/10(6) PBMCs and more than 564 CD4 cells/microl at day 14 after interruption were associated independently with a reduced risk of restarting treatment (P = 0.041 and P = 0.012, respectively). A score based on CD4+ cell counts at nadir, at baseline, at week 2 of treatment interruption, and on baseline HIV-DNA values can identify patients with a prolonged period free safely of treatment.

Influence of dry-rolling and tempering agent addition during the steam-flaking of sorghum grain on its feeding value for feedlot cattle

Two experiments were conducted to evaluate the influence of dry-rolling (DRS) and tempering agent (TA) addition during the steam-flaking of grain sorghum (SFS) for feedlot cattle. Five dietary treatments were compared: 1) DRS; 2) SFS, no TA; 3) SFS, 0.275 mg/kg of TA; 4) SFS, 1.375 mg/kg of TA; and 5) SFS, 2.750 mg/kg of TA. Bulk densities of DRS and SFS were 0.48 and 0.36 kg/L, respectively. Diets contained 70.6% grain sorghum (DM basis). One hundred fifty crossbred steers (336 kg of BW) were used in a 115-d finishing experiment to evaluate treatment effects on feedlot performance. Body weight gain averaged 1.49 kg/d and was not affected (P = 0.47) by treatments. The SFS reduced (P < 0.01) DMI (9%) and enhanced (P < 0.01) G:F (13%) and the NE(m) and NE(g) value of the diet (9 and 11%, respectively). Use of a TA before flaking sorghum did not influence (P > 0.20) cattle growth performance or NE(m) or NE(g) value of the diet. Given that the NE(m) and NE(g) values of DRS are 2.00 and 1.35 Mcal/kg, respectively (NRC, 1996), the corresponding values for SFS were 2.28 and 1.59 Mcal/kg. Five steers (397 kg of BW) with ruminal and duodenal cannulas were used in a 5 x 5 Latin square design to evaluate treatment effects on digestive function. Ruminal digestion of OM and starch was greater (14 and 16%, respectively; P < 0.01) for SFS vs. DRS. Steam-flaking sorghum increased (P < 0.01) postruminal digestion of OM (11%), N (10%), and starch (25%) and total tract digestion (P < 0.01) of OM (8.3%), N (8.2%), and starch (8.9%). Grain processing did not affect (P > 0.20) ruminal pH or VFA molar proportions. There was a cubic component (P < 0.10) to level of TA on ruminal pH and VFA molar proportions, with values being optimal at 1.375 mg/kg of tempering agent. It is concluded that steam-flaking grain sorghum will increase its NE value for maintenance and gain (14 and 18%, respectively) and enhance the MP value of the diet due to greater intestinal N digestion. The use of a TA to enhance the mechanical efficiency of the flaking process may not otherwise benefit the feeding value of sorghum.

Side effects of sunitinib malate (SM) treatment for patients (pts) with metastatic renal cell carcinoma (mRCC)

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Background: SM is a tyrosine kinase inhibitor recently approved for treatment of mRCC. Side effects of treatment have been investigated in 51 pts with mRCC and 35 out 51 enrolled pts resulted evaluable for response. Methods: Pts were clinically evaluated before therapy and each month during SM treatment; haematological and biochemical parameters were measured after each cycle. Thyroid function was also evaluated measuring thyroid-stimulating-hormone (TSH), serum free thyroxine (FT4) and triiodothyronine (FT3), before the start and after 6 months of treatment. Results: Toxicity was evaluated according to NCI-CTC. Neutropenia grade 3 was observed in 7 pts (13,7%), grade 2 in 13 (25%); anemia grade 3 was found in 3 pts (5,8%) and grade 2 in 6 (11,7%); thrombocytopenia grade 3 was found in 6 pts (11,7%), grade 2 in 5 (9,8%). Mucositis resulted a frequent side effect. In fact, 4 (7,8%) pts showed a grade 3 toxicity, 16 (31,3%) grade 2 and 10 (19,8%) grade 1 Among 29 out 35 (82,8%) pts who responded to therapy, 3 had mucositis grade 3, 15 grade 2, 9 grade 1. Conversely, among 6 out 35 (17,1%) pts who had progressive disease during treatment, mucositis was observed in only 2 pts. 24 pts out 35 who received 6 months SM treatment were reevalueted for thyroid function. No patient had thyroid dysfunction before treatment. Conversely, 8 pts showed severe ipothyroidism (TSH, FT3 and FT4 out of the normal range) and 6 others intermediate ipothyroidism (only TSH increased over 20 μU/ml) after at least 6 cycles of therapy. Conclusions: SM therapy represents a new interesting approach to the treatment of mRCC, but shows noteworthy side effects. Regular monitoring of thyroid function with administration of levothyroxin substitutive treatment at the appearance of the thyroid disfunction is required. A direct correlation between grade 2–3 mucositis and clinical response to treatment could be postulated on the basis of our data, although a statistical analysis on a greater cohort of subjects is required to confirm this observation.

No significant financial relationships to disclose.

Gene-expression profiling of HIV-1 infection and perinatal transmission in Botswana

Perinatal transmission of human immunodeficiency virus (HIV)-1 represents a major problem in many regions of the world, especially Southern Africa. With the exception of viral and proviral load, the role for maternal cofactors in perinatal transmission outcome is largely unknown. In this study, an assessment was made of peripheral blood mononuclear cells (PBMC) gene-expression profiles to better understand transcriptional changes associated with HIV-1 infection and perinatal transmission among young adult mothers with infants in Botswana. Peripheral blood mononuclear cells specimens were used from 25 HIV+ drug naive and 20 HIV- healthy mothers, similar in age and location, collected in 1999-2000 and 2003, and processed with the exact same methods, as previously described. Expression profiling of 22 277 microarray gene probes implicated a broad initiation of innate response gene-sets, including toll-like receptor, interferon-stimulated and antiviral RNA response pathways in association with maternal HIV-1 infection. Maternal transmission status was further associated with host genes that influence RNA processing and splicing patterns. In addition to real-time polymerase chain reaction validation of specific genes, enriched category validation of PBMC profiles was conducted using two independent data sets for either HIV-1 infection or an unrelated RNA virus, severe acute respiratory virus infection. HIV-1 pathogen-specific host profiles should prove a useful tool in infection and transmission intervention efforts worldwide.

Discordant response to HAART: reduction of viremia and replicative capacity of HIV strains in patients after genotype guided change of therapy

The aim of this study was to evaluate outcome after a genotype guided change of therapy in 18 patients failing HAART. Patients were divided into two groups according to the response to therapy: immune responders (12 patients with immune recovery defined as having more than 100 CD4 cells compared to baseline value), and 6 failing patients (without immune recovery). At month 12 after genotype change of therapy a significant difference in the decrease of HIV-RNA viral load between the two groups of patients was detected (mean -1.95 and +0.04 log HIV-RNA copies/ml, p=0.04). One year after the change of therapy, all but one patients experienced a decrease in the replication capacity of HIV strains. Particularly, the HIV replication capacity of HIV strains decreased from 52% (range 14-98%) to 15.2% (range 0.1-74.5%). The HIV strains of patients failing HAART showed a progressive impaired replication capacity. In patients failing HAART the impaired replication capacity of HIV strains could justify the persistence of an immune recovery.

Decrease of replicative capacity of HIV isolates after genotypic guided change of therapy

A longitudinal study of the replication capacity of HIV strains isolated from 18 patients failing highly active antiretroviral therapy (HAART) was undertaken at the time of genotypic guided change of therapy and after 12 months. Patients were divided in two groups according to the response to therapy: immune responders (12 patients with immune recovery defined as having more than 100 CD4 cells compared to baseline value), and failing patients (six patients without immune recovery). At enrollment no significant difference in terms of CD4 cell count and HIV plasma viremia was detected between the two groups. One year after change of therapy, all patients experienced a decrease in the replication capacity of HIV strains. The HIV replication capacity of the failing and of immune-responder patients decreased from 60% (range 14-96%) to 26.4% (range 0.4-74.5) and from 46.8% (range 15-98%) to 3.6% (range 0.1-26.8%), respectively. At month 12, the difference of HIV replication capacity between the two groups reached a statistical significance (P<0.03). After the change of therapy, an increase in the number of drug resistance mutations in the protease gene was detected in both groups with a higher prevalence of M36I mutation in immune responders. The HIV strains of patients failing HAART showed a progressive impaired replication capacity. The degree of the impairment in viral replication correlated with the viro-immunological discordant response to HAART and with the acquisition of new drug resistant mutations in the protease gene. In patients failing HAART, the impaired replication capacity of HIV strains could justify the persistence of an immune recovery.

Influence of dietary urea level on digestive function and growth performance of cattle fed steam-flaked barley-based finishing diets

Four Holstein steers (282 kg) with cannulas in the rumen and proximal duodenum were used in a 4 x 4 Latin square experiment to evaluate the influence of dietary urea level (0, 0.4, 0.8, and 1.2%, DM basis) in a steam-flaked barley-based finishing diet on digestive function. There were no treatment effects (P > 0.20) on ruminal digestion of OM and ADF. Increasing dietary urea level increased (linear, P < 0.01) ruminal starch digestion. Ruminal degradability of protein in the basal diet (no supplemental urea) was 60%. Increasing dietary urea level did not increase (P > 0.20) ruminal microbial protein synthesis or nonammonia N flow to the small intestine. There were no treatment effects (P > 0.20) on total-tract ADF digestion. Total tract digestion of OM (quadratic, P < 0.01) and starch (linear, P < 0.05) increased slightly with increasing urea level. Urea supplementation increased (linear, P < 0.01) ruminal pH 1 h after feeding; however, by 3 h after feeding, ruminal pH was lower (cubic, P < 0.05) with urea-supplemented diets. Urea supplementation did not affect (P > 0.20) ruminal molar proportions of acetate and propionate. One hundred twenty crossbred steers (252 kg; approximately 25% Brahman breeding) were used in an 84-d feeding trial (five pens per treatment) to evaluate treatment effects on growth performance. Daily weight gain increased (linear, P = 0.01) with increasing urea level, tending to be maximal (1.53 kg/d; quadratic, P = 0.13) at the 0.8% level of urea supplementation. Improvements in ADG were due to treatment effects (linear, P < 0.01) on DMI. Urea supplementation did not affect (P > 0.20) the NE value of the diet for maintenance and gain. Observed dietary NE values, based on growth performance, were in close agreement with expected based on tabular values for individual feed ingredients, averaging 100.4%. We conclude that with steam-flaked barely-based finishing diets, ruminal and total-tract digestion of OM and ruminal microbial protein synthesis may not be increased by urea supplementation. In contrast, ADG was optimized by dietary inclusion of 0.8% urea. Urea supplementation may not enhance the net energy value of steam-flaked barely-based finishing diets when degradable intake protein is greater than 85% of microbial protein synthesis.

Correlates of human herpes virus-8 and herpes simplex virus type 2 infections in Northern Cameroon

The association between sexual activity and human herpes virus-8 (HHV-8) infection has been established, but the mode of acquisition is still unclear. Blood samples from 238 individuals from Northern Cameroon were tested to evaluate the incidence of herpes simplex virus-2 (HSV-2), human immunodeficiency virus (HIV), Treponema pallidum, and HHV-8 infections and to identify their possible association. The presence of HSV-2 antibodies was associated significantly with gender, age, and HIV, HHV-8 antilatent, and T. pallidum antibodies, but not with HHV-8 antilytic antibodies. In a multivariate model older age, female gender, seropositivity for HIV, for HHV-8 latent antigens and for T. pallidum were associated independently with seropositivity for HSV-2. HSV-2-seropositive individuals had significantly higher titers of antibodies to both lytic (P = 0.019) and latent (P = 0.021) HHV-8 antigens. These results suggest that HSV-2 infection can contribute to sexual transmission of HHV-8 infection.

Human GLI-2 is a tat activation response element-independent Tat cofactor

Zinc finger-containing GLI proteins are involved in the development of Caenorhabditis elegans, Xenopus, Drosophila, zebrafish, mice, and humans. In this study, we show that an isoform of human GLI-2 strongly synergizes with the Tat transactivating proteins of human immunodeficiency virus types 1 and 2 (HIV-1 and -2) and markedly stimulates viral replication. GLI-2 also synergizes with the previously described Tat cofactor cyclin T1 to stimulate Tat function. Surprisingly, GLI-2/Tat synergy is not dependent on either a typical GLI DNA binding site or an intact Tat activation response element but does require an intact TATA box. Thus, GLI-2/Tat synergy results from a mechanism of action which is novel both for a GLI protein and for a Tat cofactor. These findings link the GLI family of transcriptional and developmental regulatory proteins to Tat function and HIV replication.

Molecular mechanisms of estrogen action: selective ligands and receptor pharmacology

Estrogens exert profound effects on the physiology of diverse target cells and these effects appear to be mediated by two estrogen receptor (ER) subtypes, ERalpha and ERbeta. We have investigated how ER ligands, ranging from pure agonists to antagonists, interact with ERalpha and ERbeta, and regulate their transcriptional activity on different genes. Mutational mapping-structure activity studies indicate that different residues of the ER ligand binding domain are involved in the recognition of structurally distinct estrogens and antiestrogens. We have identified from ligands of diverse structure, several particularly interesting ones that are high potency selective agonists via ERalpha and others that are full agonists through ERalpha while being full antagonists through ERbeta. Antiestrogens such as hydroxytamoxifen, which are mixed agonist/antagonists through ERalpha, are pure antagonists through ERbeta at estrogen response element-containing gene sites. Studies with ERalpha/beta chimeric proteins reveal that tamoxifen agonism requires the activation function 1 region of ERalpha. Through two-hybrid assays, we have isolated an ER-specific coregulator that potentiates antiestrogen antagonist effectiveness and represses ER transcriptional activity. We have also focused on understanding the distinct pharmacologies of antiestrogen- and estrogen-regulated genes. Although antiestrogens are thought to largely act by antagonizing the actions of estrogens, we have found among several new ER-regulated genes, quinone reductase (QR), a detoxifying phase II antioxidant enzyme, that has its activity up-regulated by antiestrogens in an ER-dependent manner in breast cancer cells. This response is antagonized by estrogens, thus showing 'reversed pharmacology'. Increased QR activity by antiestrogens requires a functional ER (ERalpha or ERbeta) and is, interestingly, mediated via the electrophile response element in the QR gene 5' regulatory region. The up-regulation of QR may contribute to the beneficial effects of tamoxifen, raloxifene, and other antiestrogens in breast cancer prevention and treatment. Estrogens rapidly up-regulate expression of several genes associated with cell cytoarchitectural changes including NHE-RF, the sodium hydrogen exchanger regulatory factor, also known as EBP50. NHE-RF/EBP50 is enriched in microvilli, and may serve as a scaffold adaptor protein in regulating early changes in cell architecture and signal transduction events induced by estrogen. Analyses of the regulatory regions of these primary response genes, and the antioxidant and other signaling pathways involved, are providing considerable insight into the mechanisms by which ligands, that function as selective estrogen receptor modulators or SERMs, exert their marked effects on the activities and properties of target cells. The intriguing biology of estrogens in its diverse target cells is thus determined by the structure of the ligand, the ER subtype involved, the nature of the hormone-responsive gene promoter, and the character and balance of coactivators and corepressors that modulate the cellular response to the ER-ligand complex. The continuing development of ligands that function as selective estrogens or antiestrogens for ERalpha or ERbeta should allow optimized tissue selectivity of these agents for menopausal hormone replacement therapy and the treatment and prevention of breast cancer.

Human immunodeficiency virus type 1 subtypes differ in disease progression

At least 10 different genetic human immunodeficiency virus type 1 (HIV-1) subtypes (A-J) are responsible for the AIDS pandemic. Much of the understanding of HIV-1 disease progression derives from studies in the developed world where HIV infection is almost exclusively subtype B. This has led many to question whether the properties and consequences of HIV-1 infection can be generalized across subtypes that afflict the majority of infected persons in the developing world. From 1985 to 1997, a prospective study of registered female sex workers in Senegal tracked the introduction and spread of HIV-1 subtypes A, C, D, and G. In clinical follow-up, the AIDS-free survival curves differed by HIV-1 subtype. Women infected with a non-A subtype were 8 times more likely to develop AIDS than were those infected with subtype A (hazard ratio=8.23; P=. 009), the predominant subtype in the study. These data suggest that HIV-1 subtypes may differ in rates of progression to AIDS.

Five human immunodeficiency virus type 1 phenotypic variants with different MT-2 cell tropisms correlate with prognostic markers of disease

OBJECTIVES

We correlated virologic and immunologic parameters of disease progression with cytopathogenicity of HIV isolates.

STUDY DESIGN/METHODS

Human immunodeficiency virus type 1 (HIV-1) isolates from 207 patients with CD4+ cell counts < 500/mm3 were examined for biologic phenotype in MT-2 cells. We used a cross-sectional study design.

RESULTS

Three subtypes of syncytium-inducing (SI) strains with different times of appearance of syncytia formation in cell culture and two subtypes of non-syncytium-inducing (NSI) isolates, with (NSI/MT2+) or without (NSI/MT2-) replicative capacity in MT-2 cells, were identified. Early SI strains were associated with the lowest CD4+ cell counts and the highest levels of viral load, and NSI/MT2- isolates correlated with the highest CD4+ cell counts and the lowest viral loads. Patients with late SI and NSI/MT2+ strains showed minimal differences in immunologic and virologic markers.

CONCLUSIONS

Five HIV phenotypic variants that correlate significantly (P < 0.001) with markers of disease progression were identified.

Effect of lung T lymphocytes on fibroblasts in idiopathic pulmonary fibrosis and extrinsic allergic alveolitis

Increased fibroblast replication and interstitial collagen accumulation occur commonly in the interstitial lung disease that progress to fibrosis. The processes controlling lung fibrogenesis are not completely understood, however. This study was designed to analyse the influence of T lymphocytes from lung tissue obtained at open lung biopsy from four patients with idiopathic pulmonary fibrosis and four patients with extrinsic allergic alveolitis on fibroblast proliferation and collagen synthesis in vitro. Lung T cell supernatants from patients with both diseases induced a moderate but significant inhibition of human lung fibroblast cell line growth. In contrast, there was a clear difference in the effect of T cells from the two groups of patients in relation to collagen production. Lung T lymphocytes from all four patients with idiopathic pulmonary fibrosis produced a substantial increase in collagen synthesis (from 371% to 514% of control values), whereas T cells from three of the four patients with extrinsic allergic alveolitis induced a significant decrease in collagen production (to 35%, 36%, and 43% of control values); in the fourth case there was an increase in collagen synthesis but this was lower than that seen with T cells from any of the patients with idiopathic pulmonary fibrosis. Peripheral T cells from six patients and control subjects caused a small increase in fibroblast proliferation and no change in collagen synthesis. The findings suggest that at least two types of interaction occur between lung T cells and fibroblasts in these disorders. A variable degree of inhibition of cell proliferation is observed in response to lung T cell supernatants from patients with both idiopathic pulmonary fibrosis and extrinsic allergic alveolitis; a substantial increase in collagen synthesis is triggered by lymphokines from patients with idiopathic pulmonary fibrosis.

Molecular evidence of genetic heterogeneity in Wistar-Kyoto rats: implications for research with the spontaneously hypertensive rat

Spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto ("WKY") rats are frequently employed in experimental studies of hypertension. Although both SHR and WKY rat strains have been presumed to be fully inbred, recent studies have revealed important biologic variability in WKY rats from different commercial sources. Genealogic evidence suggests that, in the United States, breeding stocks of WKY rats may have been distributed to major commercial suppliers as early as the F10 generation. To test the hypothesis that commercially available WKY rats are genetically heterogeneous, we performed deoxyribonucleic acid (DNA) "fingerprint" analysis on genomic DNA of WKY rats from two of the largest vendors in the United States, Taconic Farms and Charles River Laboratories. We found molecular evidence of genetic variability not only among WKY rats from two different breeding facilities, but also among WKY rats within a single breeding facility (Taconic Farms). Although some studies have suggested the possibility of biologic variability in SHR from different sources, preliminary studies have not revealed molecular evidence of genetic heterogeneity in SHR from these vendors. In demonstrating genetic variability in WKY rats from different sources, the current study provides compelling evidence that rats designated WKY do not constitute an inbred strain. Accordingly, the results of studies in which SHR and WKY rats are compared might vary because of genetic heterogeneity in "the WKY rat control strain."

Prenatal diagnosis and carrier detection of Duchenne muscular dystrophy by restriction fragment length polymorphism analysis with pERT 87 deoxyribonucleic acid probes

New methods of prenatal diagnosis based on recombinant deoxyribonucleic acid techniques are assuming increased importance in obstetrics practice. Carrier detection and prenatal diagnosis of Duchenne muscular dystrophy were performed with the use of three intragenic probes and four restriction enzymes to test six polymorphic sites. Twenty-seven families at risk for Duchenne muscular dystrophy were studied. Eleven at-risk pregnancies were studied; two affected males and four carrier females were predicted. Some families with a single affected individual were shown to have had a spontaneous mutation and were therefore at a much lower risk in future pregnancies.