Evaluation of non-breath-hold, ultra-fast, low-dose high-pitch (flash) CT scan as a practical alternative to standard spiral scan for pre-TAVI patients: a real-world single-center experience

Introduction and aim

Aortic annulus dimensions change during the cardiac cycle. A retrospective ECG-gated (Spiral) scan is the default technique for pre TAVR evaluation since it includes systolic phases considered optimal for aortic annulus assessment. Ultra-fast, Low-Dose High-Pitch (FLASH) offers faster, potentially low radiation and low contrast dose scans. However, it lacks the ability to time data acquisition to the systole. Therefore, measurements derived from FLASH scan are considered suboptimal for reporting. The effect of this potential annular measurement difference on procedural success and safety was not evaluated. Therefore, we aimed to assess the feasibility and safety of FLASH vs. Spiral scan before TAVI.

Methods

We conducted a retrospective, single-center study. 409 patients underwent CT-TAVI scan with either FLASH or SPIRAL acquisition. Baseline characteristics, CT study, procedural and f/u data were acquired from the EMR. Outcomes defined by Valve Academic Research Consortium3 (VARC-2) endpoint definitions included in-hospital mortality, bleeding, vascular complications, acute kidney injury (AKI), conduction disorders, mechanical complications, and prosthetic aortic valve regurgitation. Composite endpoints such as device success were also examined.

Results

Of the 409 patients, 55.7% underwent FLASH scans. The median age was 80 years, and males accounted for 55%. The FLASH-protocol patients had higher rate of chronic kidney disease, their CT-measured aortic annulus area and diameter were smaller, and they were exposed to a smaller amount of contrast agent and radiation than the SPIRAL group. There was no statistically significant difference in primary clinical and safety endpoints between the two groups, including mechanical complications (such as annular rupture and valve malposition) and conduction disorders.

Conclusions

FLASH CT scan is a pragmatic and safe approach that potentially may replace spiral scan for the evaluation before TAVI procedure in the appropriate patients.

Funding Acknowledgement

Type of funding sources: None.

Outcomes of patients treated with blood transfusion in a contemporary tertiary intensive cardiac care unit

Background

Different trials showed that patients treated with blood transfusion (BT) have unfavorable prognosis regarding outcomes and mortality. Nevertheless, outcomes in patients treated with BT hospitalized in a contemporary tertiary intensive cardiac care unit (ICCU) is limited.

Objective

To determine mortality rate in patients treated with BT in a contemporary tertiary ICCU.

Methods

A prospective single center study to evaluate short- and long-term mortality rate of patients treated with BT between January 2020 and December 2021 in a tertiary ICCU.

Outcomes

During the study period 2132 consecutive patients were admitted with a mean age of 66.9±16 and 650 (30.5%) of them were women. Of the total population, 108 (5%) patients were treated with BT (BT-group) during their hospitalization. Patients were followed-up for 2 years with a median [IQR] follow up time of 82.5 [12.25–240.50] days in BT-group vs. 138.5 [34–325, 75] days in the non-BT (NBT) group. Mean age was 73.81±14 years in BT-group vs. 66.59±16 years in NBT-group, p<0.0001. There was a higher rate of female gender in the BT-group 48.1% vs. 29.5% in the NBT, p<0.0001. Crude mortality rate was 29.6% in BT-group and 9.2% in NBT-group, p<0.0001. Median [IQR] length of stay was 5 [2–6] days in BT-group vs. 3 [2–4] days in the NBT-group. Multivariate Cox analysis for (Female gender, prior trans-catheter aortic valve replacement, prior cardiac intervention, sepsis, history of congestive heart failure, pulmonary hypertension, pacemaker implantation and anemia) showed that BT was independently associated with more than two folds the mortality rate [HR=2.19 95% CI (1.47–3.62)] as compared with the NBT-group, p<0.0001. Receiver operating characteristic curve (ROC) was plotted for multivariable analysis and showed area under curve (AUC) of 0.8, 95% CI [0.760–0.852].

Conclusion

Even in contemporary tertiary ICCU, with advanced technology, equipment and delivery of care, BT remains a strong predictor for short- and long-term mortality.

Funding Acknowledgement

Type of funding sources: None.

The prevalence and characteristics of patients with ST-elevation myocardial infarction during the first two months of the COVID-19 pandemics

Background

ST-Segment elevation MI (STEMI) is one of the leading cause of mortality in the western world. The coronavirus disease-2019 (COVID-19) pandemic might have implications of the treatment of STEMI patients. Our aim was to evaluate the treatment of STEMI patients during 2 months of the COVID-19 pandemic as compared with the year before.

Methods

Data of 90 STEMI patients treated at the Shaare Zedek Medical Center intensive coronary care unit (ICCU) Between March-April 2019 and March-April 2020 were collected. Patients were divided into 2 groups: The pre COVID-19 group and the COVID-19 era group. Data regarding complications upon arrival and during hospitalization, door to balloon time and echocardiographic exams.

Results

Fifty one (56%) patients were admitted with STEMI in the pre COVID-19 group and only 39 (44%) in the COVID-19 era group. Of them 13.7% vs. 20.5% were female, p=0.392 with a mean age of 62.1 (±13.5) vs. 63.4 (±11) years old, p=0.635 in the pre vs. post COVID-19 era group, respectively. Interestingly, more Jewish vs. non-Jewish were admitted with STEMI in the COVID-19 era group. There were no differences regarding baseline characteristics, catheterization access, culprit vessel and percutaneous coronary intervention rate. Door to balloon time was also similar in both pre and post COVID-19 era groups 35.4 (±32) vs. 30.5 (±29.1) minutes (p=0.896). Moreover, there was no difference regarding infarct size. Complications including acute renal failure, cardiogenic shock, and the use of intra-aortic balloon pump were similar in both groups. 30-day mortality rate was low and similar in both pre and post COVID-19 era groups (5.9% vs. 2.6%, respectively, p=0.426).

Conclusions

During the beginning of COVID-19 era there was a reduction in STEMI admission rate, while no significant difference was found regarding baseline characteristics, door to balloon time, infarct size and mortality rate

Funding Acknowledgement

Type of funding sources: None.

D-dimer as a prognostic factor in patients admitted to a tertiary care intensive coronary care unit

Introduction

D-dimer is a small protein fragment and is a product of fibrinolysis. A high levels of D-dimer have been suggested as a prognostic factor in cancerous and other critically ill patients. We aimed to evaluate D-dimer levels and outcomes of critically ill patients admitted to a tertiary care intensive coronary care unit (ICCU).

Material and method

All patients admitted to the ICCU at our Medical Center between January 1, 2020 and December 31, 2020 were included in the study. Patients were divided into 2 groups according to their D-dimer level on admission. Low D-dimer level <500 ng/ml, and high D-dimer level ≥500 ng/ml. Survival, in-hospital interventions and complications were compared.

Results and discussion

Overall 1,082 consecutive patients were included, mean age was 67 (±16), 70% were males. Of them 296 (27.4%) had low D-dimer level and 663 (61.3%) had high D-dimer level. Patients with high D-dimer level were older as compared to patients with low D-dimer level (mean age 70.4±15 and 59±13 years respectively, p=0.004), had significantly higher rate of female gender (35.9% vs 15.9% respectively, p<0.0001) and significantly higher rate of any prior cardiac interventions prior to their admission (26.7% vs 4.4% respectively, p<0.0001). Interestingly, patients with high D-dimer level had significantly lower rate of any acute coronary syndrome (ACS) as compared with the low D-dimer group (25.7 vs 66.4% respectively, p<0.0001) and lower rate of smokers (22.5 vs 45.6% respectively, p<0.0001). All 11 post-COVID-19 patients had high D-dimer level on admission.

A multivariate Cox proportional hazards analysis for mortality, adjusted for age, gender, risk factors for cardiovascular disease, ejection fraction<40 found that high D-dimer level was independently associated with higher mortality rates (HR=5.8; 95% CI; 1.7–19.1; p=0.004) as shown in Figure 1.

Conclusion

Elevated D-dimer levels on admission in ICCU patients is a poor prognostic factor of in-hospital morbidity and mortality in the first year following hospitalization.

Funding Acknowledgement

Type of funding sources: None. Cumulative survival according to d-Dimer

Health Indicators for Renal Replacement Therapy in Saudi Arabia

The renal replacement therapy in Saudi Arabia has 3 main modalities: hemodialysis, peritoneal dialysis, and renal transplantation. Hemodialysis is one of the fastest growing industries of health care providers in Saudi Arabia.

OBJECTIVE

We aimed to review the health indicators of renal replacement therapy.

MATERIALS AND METHODS

We used the Saudi Center for Organ Transplantation Annual Report 2016.

RESULTS

Patients with end-stage renal disease on hemodialysis and peritoneal dialysis totaled 17,687. Saudi Arabia increased the numbers of dialysis centers and also added 2 more sectors. The Ministry of Health hospitals have 55% of the centers, government non-Ministry of Health has 9%, private and charitable hospitals have 21%, the King Abdullah Hemodialysis Project has 2%, and the outsourcing dialysis programs have 13%. There are 243 dialysis units in Saudi Arabia. Most dialysis centers are in the central region (30%); 27% are in the western region, 19% are in the southern region, 13% are in the eastern region, and 11% are in the northern region. The average net increase of dialysis patients is 6.2% annually and is projected to reach 22,000 by 2020. Causes of renal failure are mainly diabetic nephropathy (40%) and hypertensive nephropathy (38%). Hepatitis C virus positivity is at 12% and hepatitis B surface antigen positivity is at 4%. From the year 2000 renal transplantation from deceased and living donation has tripled in number, with a total of 798 kidneys transplanted.

CONCLUSION

Renal replacement therapy is increasing and dialysis center numbers are expected to increase. Renal transplantation numbers have improved both from living and deceased donors but further actions toward the promotion of the organ donation in Saudi Arabia is essential.

Characterization of a lung epithelium specific E-cadherin knock-out model: Implications for obstructive lung pathology

The airway epithelium regulates responses to aeroallergens, acting as a physical and immunological barrier. In asthma, epithelial barrier function and the expression of adherens junction protein E-cadherin is compromised, but it is unknown whether this is cause or consequence of the disease. We hypothesized that airway epithelial loss of E-cadherin is a critical step in the development of manifestations of asthma. We generated a transgenic mouse model with conditional loss of E-cadherin in lung epithelial cells at birth and onwards. We observed normal lung development at the time of birth in mice lacking E-cadherin in the lung epithelium. However, E-cadherin deficiency led to progressive epithelial damage in mice growing into adulthood, as evidenced by airway epithelial denudation, decreased zonula occludens (ZO)-1 expression, loss of ciliated cells, and enlarged alveolar spaces. In addition, spontaneous goblet cell metaplasia with mucus production was observed. These epithelial changes were accompanied by elevated levels of the epithelial-derived chemokine CCL17, infiltration of eosinophils and dendritic cells, and mucus production. In conclusion, loss of E-cadherin induces features in the lung reminiscent of those observed in asthma, indicating that the disruption of E-cadherin-mediated cell-cell contacts may play a key role in the development of asthma manifestations.

Erythropoietin monotherapy in perinatal asphyxia with moderate to severe encephalopathy: a randomized placebo-controlled trial

OBJECTIVE

Erythropoietin (EPO) is neuroprotective after asphyxia in animal studies. The efficacy and safety of EPO monotherapy in term neonates with hypoxic ischemic encephalopathy (HIE) is uncertain.

STUDY DESIGN

Hundred term neonates with moderate or severe HIE were randomized by random permuted block algorithm to receive either EPO 500 U kg^-1 per dose in 2 ml saline intravenously (50 neonates) on alternate days for a total of five doses with the first dose given by 6 h of age (treatment group) or 2 ml of normal saline (50 neonates) similarly for a total of five doses (placebo group) in a double-blind study. No hypothermia was given. The primary outcome was combined end point of death or moderate or severe disability at mean age of 19 months (s.d., 0.61).

RESULTS

Death or moderate or severe disability occurred in 40% of neonates in the treatment group vs 70% in the placebo group (risk ratio, 0.57; 95% confidence interval (CI) 0.38 to 0.85; P=0.003). Death occurred in 16% of patients in both the groups (risk ratio, 1.0; 95% CI 0.33 to 2.9; P=0.61). The risk of cerebral palsy was lower among survivors in the treatment group (risk ratio, 0.52; 95% CI 0.25 to 1.03; P=0.04) and lesser number of babies were on anticonvulsants at assessment (risk ratio, 0.47; 95% CI 0.20 to 1.01; P=0.03). Neonatal brain magnetic resonance imaging showed more abnormalities in the placebo group (relative risk, 0.66; 95% CI 0.42 to 1.03; P=0.04)). Improvement in other neurological outcomes was not significant.

CONCLUSION

EPO monotherapy reduces the risk of death or disability in term neonates with moderate or severe encephalopathy.

9: AN IN VIVO MODEL OF HUMAN AIRWAYS FOR INVESTIGATING FIBROSIS

Purpose of Study

Limited models exist to investigate the airway epithelium's role in repair, regeneration, and pathology of chronic obstructive lung diseases. We introduce a human asthmatic airway epithelial xenograft system integrating a proliferating and differentiating airway epithelium with an actively remodeling rodent mesenchyme in an immunocompromised murine host. We hypothesized that epithelial regeneration in asthma induces underlying matrix fibrosis.

Methods Used

Human airway epithelial cells from asthmatic and non-asthmatic donors (n=5 per group) were seeded into decellularized rat tracheas. Tracheas were ligated to a sterile tubing cassette and implanted subcutaneously in the flanks of athymic nude mice. Grafts were harvested at 2, 4, or 6 weeks for analysis of tissue histology, fibrillar collagen deposition, and TGFβ1 activation. Non-transplantable human lungs from asthmatic and non-asthmatic donor FFPE sections were analyzed using similar methods.

Summary of Results

Grafted epithelial cells generated a differentiated epithelium with basal, ciliated, and mucus cells. By 4 weeks post-engraftment, asthmatic-derived epithelia showed decreased numbers of ciliated cells and E-cadherin expression compared to non-asthmatic controls, similar to human lung biopsy tissue. While there was no evidence of matrix remodeling in acellular xenografts, grafts seeded with asthmatic-derived epithelial cells had 3 times as much fibrillar collagen at 6 weeks post-engraftment as non-asthmatic epithelial seeded grafts. This was accompanied by a >2-fold induction of matrix TGFβ1 [with evidence of pSMAD3 activity] in asthmatic grafts at 4 weeks (positive pixels/total field pixels=0.12±0.001 vs. 0.05±0.001; p=0.003) and 6 weeks (0.09±0.02 vs. 0.04±0.01; p=0.044) post-engraftment.

Conclusions

We show in this model that asthmatic epithelium alone is sufficient to drive aberrant mesenchymal remodeling, specifically with fibrillar collagen deposition in asthmatic-derived xenografts.These xenografts are a major advance over current animal models of asthma in that they permit direct assessment of the epithelial-mesenchymal trophic unit.

Pre-operative staging of rectal cancer using multi-detector row computed tomography with multiplanar reformations: single center experience

BACKGROUND

Technical advancement in imaging has helped to stage and plan treatment modality for carcinoma rectum with still some objectives controversial.

AIMS

The aim of our study was to evaluate the accuracy of multidetector row computed tomography (MDCT) with multiplanar reformations in the pre-operative staging of rectal carcinoma and correlation with intraoperative and histopathologic staging of retrieved specimen with respect to the depth of tumor invasion (T-staging), lymph node metastasis (N-staging) and mesorectal fascia (MRF) involvement.

MATERIALS AND METHODS

The study was a prospective one and consisted of 52 patients with biopsy proved rectal carcinoma. MDCT studies were performed on a 64-slice computed tomography system. Images were reconstructed in axial, coronal and sagittal planes. MDCT findings were compared with intraoperative and pathologic (reference standard) findings. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy were assessed.

RESULTS

The diagnostic accuracy of MDCT for T1/T2, T3 and T4 lesions was 77%, 86.5% and 100%, respectively. For perirectal lymph node metastasis (N+), the diagnostic accuracy of MDCT was 84.1%. The diagnostic accuracy of MDCT for MRF involvement was 91%.

CONCLUSION

MDCT is a reliable radiological tool for local staging of rectal cancer with excellent accuracy rates for T and N-staging of rectal cancer.

Pregnenolone derivatives as potential anticancer agents

Pregnenolone (1) was used as a template to develop new anticancer compounds. Ring-D modification of 1 resulted in the synthesis of benzylidenes 2-17, pyrazolines 18-76, pyrazoles 85-91, hydrazones 77-84, and oximes 92-107 derivatives. The structure of compound 107 was also deduced through single crystal X-ray diffraction studies. The inclusion of furanyl and pyridyl rings to pregnenolone skeleton increases the cytotoxicity of all compounds significantly. Among benzylidene derivatives, only heterocyclic enone 8 (IC50=0.74 μM/mL against HepG2), and 17 (IC50=4.49 μM/mL against HepG2, IC50=5.01 μM/mL against MDA-MB-230 cancer cell line) exhibited a significant activity. The cytotoxicity data of pyrazoline derivatives 18-76 revealed that only furanyl bearing pyrazolines 40, 42-44, 48, and 49 exhibited significant activities. While all (O-carboxymethyl) oximes, hydazones, and pyrazoles derivatives of pregnenolone did not show any significant activity against both the cell lines. Thus the furanyl bearing enone 8 (IC50=0.74 μM/mL against HepG2), and its pyrazoline derivative 48 (IC50=0.91 μM/mL against MDA-MB-230 cancer cell lines) were identified as the most active compounds in all derivatives of pregnenolone.

Color Doppler findings of post-biopsy arteriovenous fistula in renal transplant

Post biopsy arterio-venous fistula in renal transplant range in incidence from 15-16%. Spontaneous resolution of 75% A-V fistulas is seen within four weeks. We report a patient with post biopsy arterio-venous fistula who had developed unexplained hypertension with no definite feature of rejection on biopsy. Doppler application revealed an arterio-venous fistula which showed spontaneous resolution in six weeks.

The new rHuEPO alpha (epotin) in the management of anemia of end-stage renal disease in patients on maintenance hemodialysis

Recombinant human erythropoietin has proved to be effective to treat anemia of end-stage renal disease (ESRD). The aim of this study was to assess the efficacy and safety profile of Epotin, a rHuEPO produced in the Middle East. One hundred thirty patients with Hct </= 27%; Hb </= 9 g/dL maintained on hemodialysis thrice weekly from 19centers in eight countries in the Middle East were recruited into this 13-week study. Depleted iron stores (TSTAT <20% and/or Serum ferritin < 100 microg/dL) were replenished prior to initiation of Epotin therapy, which was delivered intravenously in a dose of 150 U/kg body weight/week in three equal doses postdialysis and titrated according to hemoglobin (Hb) and hematocrit (Hct) response. Efficacy was assessed in terms of Hb/Hct response. Epotin raised the mean Hb level from 7.7 (+/- 1.2) g/dL to 12.0 (+/- 1.7) g/dL and Hct from 22.7 (+/- 4.1) % to 36.2 (+/- 5.7) % by week 13. The increase started to show significance at week 3. Targeting an absolute increase in Hb of 2.5 g/dL (Hct 7.5%) over a 13-week period, the success rate was of <85.71%. Segregating patients into subgroups of men and women and chronic ESRD versus recent ESRD failed to reveal a significant differences in either the severity of the anemia or the response to Epotin. Side effects were similar to other erythropoietins; no dropouts were reported. In conclusion, Epotin is effective to treat anemia in patients on maintenance hemodialysis with an acceptable safety profile. No difference in response was observed between men and women, nor between patients with different levels of chronicity of ESRD.

Schwann cell-autonomous role of neuropilin-2

Neuropilins and group A plexins are components of receptor complexes for class 3 semaphorins, gradients of which help to guide migration of neural progenitor cells and axonal growth cones during development. We demonstrated previously that neuropilins and class 3 semaphorins are induced in sciatic nerve by crush or transection. We now report that in cultured rat Schwann cells, expression of mRNA encoding neuropilin-2 (NRP2) and plexin-A3 (PlexA3), proteins involved in semaphorin-3F (Sema3F) signal transduction, is diminished markedly by forskolin, an adenylate cyclase activator that, like axonal contact, induces Schwann cell synthesis of myelin lipids and proteins. Interestingly, Schwann cell expression of mRNA encoding NRP1, which participates in Sema3A signaling, is not downregulated by forskolin. Antibodies that recognize ectodomains of NRP2 but not control antibodies prevented cultured Schwann cells from aligning in parallel and forming columns. These results are consistent with the view that in nerves undergoing Wallerian degeneration, Schwann cell NRP2 facilitates assembly of Schwann cells into the tubular aggregates (bands of Büngner) that guide regenerating axons.

Pregnancies in renal transplant recipients--with a focus on the maternal issues

One hundred and thirteen pregnancies in 73 women who received a renal transplant were studied. The duration between the transplant operation and the conception averaged 19.9 months with a range of I month to 72 months. The mean age was 28 years. The majority (50 recipients had one pregnancy each, but two women had 5 children each and one had seven children). Only 12 (11.5%) out of the 113 pregnancies ended up with spontaneous abortions. The maternal medical problems encountered were reversible rejection in 11%, hypertension in 43%, UTI in 17% and gestational diabetes in 21%. It was noted that there was high incidence of preterm delivery in 64% of the pregnancies Caesarian section was required in 72% % of the cases. In conclusion we observed a high prevalence of successful pregnancies with no adverse effect on the allograft function and excellent fetal outcome (which is described in a separate paper focusing on the fetal outcome).

Single cell laser dissection with molecular beacon polymerase chain reaction identifies 2A as the predominant serotonin receptor subtype in hypoglossal motoneurons

We hypothesize that sleep state-dependent withdrawal of serotonin (5-hydroxytryptamine, 5-HT) at upper airway (UAW) dilator motoneurons contributes significantly to sleep-related suppression of dilator muscle activity in obstructive sleep apnea. Identification of 5-HT receptor subtypes involved in postsynaptic facilitation of UAW motoneuron activity may provide pharmacotherapies for this prevalent disorder. We have adapted two assays to provide semi-quantitative measurements of mRNA copy numbers for 5-HT receptor subtypes in single UAW motoneurons. Specifically, soma of 111 hypoglossal (XII) motoneurons in 10 adult male rats were captured using a laser dissection microscope, and then used individually in single round molecular beacon polymerase chain reaction (PCR) for real-time quantitation of 5-HT(2A), 5-HT(2C), 5-HT(3), 5-HT(4), 5-HT(5A), 5-HT(5B), 5-HT(6) or 5-HT(7) receptor. Receptor mRNA copy numbers from single XII motoneurons were compared to control samples from within the XII nucleus and lateral medulla. All 20 motoneuronal soma assayed for the 5-HT(2A) receptor had measurable copy numbers (7028+/-2656 copies/cell). In contrast, copy numbers for the 5-HT(2A) receptor in XII non-motoneuronal (n=17) and lateral medulla (n=15) samples were 81+/-51 copies and 83+/-35 copies, respectively, P<0.05. Seven of 13 XII motoneurons assayed had measurable 5-HT(2C) receptor copy numbers of mRNA (287+/-112 copies/cell). XII soma had minimal 5-HT(3), 5-HT(4), 5-HT(5A), 5-HT(5B), 5-HT(6) or 5-HT(7) receptor mRNA. 5-HT(2A) receptor mRNA presence within XII motoneurons was confirmed with digoxigenin-labeled in situ hybridization. In summary, combined use of laser dissection and molecular beacon PCR revealed 5-HT(2A) receptor as the predominant 5-HT receptor mRNA in XII motoneurons, and identified small quantities of 5-HT(2C) receptor. This information will allow a more complete understanding of serotonergic control of respiratory activity.

Suppression of CCR5- but not CXCR4-tropic HIV-1 in lymphoid tissue by human herpesvirus 6

HIV-1 infects target cells via a receptor complex formed by CD4 and a chemokine receptor, primarily CCR5 or CXCR4 (ref. 1). Commonly, HIV-1 transmission is mediated by CCR5-tropic variants, also designated slow/low, non-syncytia-inducer or macrophage-tropic, which dominate the early stages of HIV-1 infection and frequently persist during the entire course of the disease. In contrast, HIV-1 variants that use CXCR4 are typically detected at the later stages, and are associated with a rapid decline in CD4+ T cells and progression to AIDS (refs. 2,7-11). Disease progression is also associated with the emergence of concurrent infections that may affect the course of HIV disease by unknown mechanisms. A lymphotropic agent frequently reactivated in HIV-infected patients is human herpesvirus 6 (HHV-6), which has been proposed as a cofactor in AIDS progression. Here we show that in human lymphoid tissue ex vivo, HHV-6 affects HIV-1 infection in a coreceptor-dependent manner, suppressing CCR5-tropic but not CXCR4-tropic HIV-1 replication, as shown with both uncloned viral isolates and isogenic molecular chimeras. Furthermore, we demonstrate that HHV-6 increases the production of the CCR5 ligand RANTES ('regulated upon activation, normal T-cell expressed and secreted'), the most potent HIV-inhibitory CC chemokine, and that exogenous RANTES mimics the effects of HHV-6 on HIV-1, providing a mechanism for the selective blockade of CCR5-tropic HIV-1. Our data suggest that HHV-6 may profoundly influence the course of HIV-1 infection.

Anticonvulsant activities of ethanolic extract and aqueous fraction isolated from Delphinium denudatum

Dried roots of Delphinium denudatum Wall. are a popular folk remedy for the treatment of epilepsy in the traditional Unani system of medicine in the sub-continent. We carried out anticonvulsant screening of the ethanolic extract (EE) and aqueous fraction (AF) of this plant utilising the maximal electroshock (MEST) and subcutaneous pentylenetetrazole (scPTZ), bicuculline (scBIC), picrotoxin (scPTX) and strychnine (scSTN) tests for anticonvulsant activity. EE had weak dose-dependent anticonvulsant effects on seizures induced by PTZ and BIC. AF exhibited dose-dependent activity against hind limb tonic extension phase (HLTE) of MEST and comparatively stronger anticonvulsant activity against seizures induced by PTZ and BIC. The results suggest the presence of potent anticonvulsant compounds in AF of D. denudatum and deserve further investigation for isolation of active compounds and elucidation of the mechanism of anticonvulsant action.

Anticonvulsant activities of the FS-1 subfraction isolated from roots of Delphinium denudatum

Delphinium denudatum Wall. (Ranunculaceae) is a medicinal herb used for the treatment of epilepsy in the subcontinent. The present study reports the anticonvulsant activities in the maximal electroshock test (MEST) and subcutaneous pentylenetetrazole (PTZ), bicuculline (BIC), picrotoxin (PIC)-induced seizures of the FS-1 subfraction (FS-1) that was obtained by purification of an aqueous fraction isolated from the roots of D. denudatum. In CF 1 mice, FS-1 (600 mg/kg i.p.) exhibited very potent anticonvulsant activity that was comparable to the effects of the well-known antiepileptic drug phenytoin (20 mg/kg) in MEST and protected 100% animals from hind limb tonic extension phase of this model. FS-1 also suppressed PTZ-induced threshold seizure and the loss of the righting reflex with tonic fore and hind limb extension by 100%, similar to the antiepileptic drug valproic acid (350 mg/kg). BIC-induced seizures were suppressed in 80% of the animals. FS-1 exhibited weak anticonvulsant effect on PIC-induced seizures, however, it significantly reduced mortality and delayed the onset of seizures. FS-1 had no effect on strychnine (STN)-induced extensor seizures. The results demonstrate the broad and potent anticonvulsant activity of the compounds in FS-1 of D. denudatum.

Steroidal alkaloids from the leaves of Sarcococca coriacea of Nepalese origin

Two new steroidal alkaloids, (-)-vaganine D (1) [(20S)-20-(N,N-dimethylamino)-3 beta-(senecioylamino)-5 alpha-pregn-16-en-4 beta-yl acetate], and (+)-nepapakistamine A (2) [(20S)-20-(N-methylamino)-3 beta-(tigloylamino)-5 alpha-pregn-16-en-2 beta,4 beta-diacetate], were isolated from the leaves of Sarcococca coriacea. Their structures were elucidated on the basis of their spectral properties. Compounds 1 and 2 were found to be cholinesterase inhibitors.

Nonproliferating bystander CD4+ T cells lacking activation markers support HIV replication during immune activation

HIV replicates primarily in lymphoid tissue and immune activation is a major stimulus in vivo. To determine the cells responsible for HIV replication during Ag-driven T cell activation, we used a novel in vitro model employing dendritic cell presentation of superantigen to CD4(+) T cells. Dendritic cells and CD4(+) T cells are the major constituents of the paracortical region of lymphoid organs, the main site of Ag-specific activation and HIV replication. Unexpectedly, replication occurred in nonproliferating bystander CD4(+) T cells that lacked activation markers. In contrast, activated Ag-specific cells were relatively protected from infection, which was associated with CCR5 and CXC chemokine receptor 4 down-regulation. The finding that HIV replication is not restricted to highly activated Ag-specific CD4(+) T cells has implications for therapy, efforts to eradicate viral reservoirs, immune control of HIV, and Ag-specific immune defects.

Spasmolytic constituents from Eucalyptus camaldulensis var. obtusa leaves

Phytochemical studies on the leaves of Eucalyptus camaldulensis var. obtusa have resulted in the isolation of a new triterpenoid camaldulin (3beta-formyloxyurs-11-en-28,13beta-olide) (1) along with ursolic acid lactone acetate (2), ursolic acid lactone (3), betulinic acid (4), and beta-sitosterol 3-O-beta-D-glucopyranoside (5). The structures were assigned on the basis of 1D and 2D NMR studies. Compounds 1-3 were tested for spasmolytic activity and were found to possess calcium antagonist activity.

Effect of vitamin-E-modified dialysers on dialyser clotting, erythropoietin and heparin dosage: a comparative crossover study

We performed a crossover study to compare the effects of different dialysis membranes on 20 patients with frequent dialyser clotting and requiring > or = 5,000 units of heparin per dialysis session. Low-flux dialysers are C15NL (cellulose - Terumo) and E15NL (vitamin-E-coated - Terumo) while high-flux dialysers were F60 (polysulphone) and EE15NL (vitamin-E-coated - Terumo). Ten patients underwent dialysis for 2 months with C15NL then switched to E15NL for 2 months. Similarly, the other 10 patients were started on the high-flux dialyser F60 and then switched over to EE15NL for 2 months. The following parameters were measured at the beginning of the study, 2 weeks, 1 month and then at 2 months: hemoglobin, prothrombin time (PT), partial thromboplastin time (PTT), fibrinogen, protein C, protein S, antithrombin III (ATIII) and factor 12 activity. Dialyser clotting, heparin and erythropoietin requirements were assessed during each dialysis session. There was a significant reduction in clotting with E15NL in comparison to C15NL (22.8 +/- 17 and 44.1 +/- 22.8 (p = 0.0233), respectively). Similarly, heparin requirements were less in the vitamin-E-coated (E15NL) dialysers, 4, 754 +/- 1,427 vs. 6,011 +/- 856 units (p = 0.0281) and erythropoietin usage was also significantly reduced, 4,630 +/- 2,620 vs. 7,850 +/- 4,069 units (p = 0.049). There was a significant increase in hemoglobin with E15NL compared to C15NL, 115 +/- 10.4 vs. 108 +/- 13.1 (p = 0.0343). When the high-flux dialysers were compared there was a tendency towards less dialyser clotting with the EE15NL compared to F60, though this did not achieve statistical significance (p = 0.0561). We could not demonstrate any significant changes between the different dialysers with regards to PT, PTT, fibrinogen factor 12 activity, protein C, protein S and ATIII. In conclusion, we have shown that the use of vitamin-E-modified dialysers is associated with less clotting in patients with persistent clotting problems. In addition, this was associated with less heparin and erythropoietin requirements.

Ethnopharmacological evaluation of the anticonvulsant, sedative and antispasmodic activities of Lavandula stoechas L

Lavandula stoechas L. (Lamiaceae) has been used for a long time in traditional medicine as an anticonvulsant and antispasmodic. The aqueous-methanolic extract of L. stoechas flowers (LS) was studied for its possible anticonvulsant and antispasmodic activities. When tested in mice, LS (600 mg/kg) significantly reduced the severity and increased the latency of convulsions induced by pentylene tetrazole (PTZ). LS likewise reduced PTZ's lethality. LS up to a dose of 600 mg/kg was found devoid of any hypnotic effect in mice, however, animals were found to be dull, calm and relaxed. The sedative effect of the plant extract was confirmed, as it prolonged the pentobarbital sleeping time in mice similar to that of diazepam. In isolated rabbit jejunum preparations, LS caused a dose-dependent (0.1-1.0 mg/ml) relaxation of spontaneous contractions. LS also inhibited K(+)-induced contractions in a similar dose range, thereby suggesting calcium channel blockade. This effect was confirmed when pretreatment of the jejunum preparation with LS produced a dose-dependent shift of the Ca(2+) dose-response curve to the right, similar to the effect of verapamil, a standard calcium channel blocker. These data indicate that the plant extract exhibits anticonvulsant and antispasmodic activities. Its calcium channel blocking property may be mechanistically related to these activities. Its usefulness in folk medicine appears thus to be based on a sound mechanistic background.

Studies on antihypertensive and antispasmodic activities of methanol extract of Acacia nilotica pods

A methanol extract of Acacia nilotica pods (AN) caused a dose-dependent (3-30 mg/kg) fall in arterial blood pressure. Treatment of animals with atropine abolished the vasodilator response of acetylcholine (ACh), whereas the antihypertensive effect of the plant extract remained unaltered. Phentolamine (an alpha-adrenergic blocker) abolished the vasoconstrictor effect of norepinephrine (NE), whereas pretreatment of the animal with AN, did not modify the NE response. These results indicate that the antihypertensive effect of plant extract is independent of muscarinic receptor stimulation or adrenoceptor blockade. In the in vitro studies, AN produced a dose-dependent (0.3-3.0 mg/mL) inhibitory effect on force and rate of spontaneous contractions in guinea-pig paired atria. Similarly, it inhibited the spontaneous contraction of rabbit jejunum in a concentration-dependent (0.1-3.0 mg/mL) manner. AN also inhibited K(+)-induced contractions in rabbit jejunum at a similar concentration range, which suggests that the antispasmodic action of AN is mediated through calcium channel blockade, and this may also be responsible for the blood pressure lowering effect of AN, observed in the in vivo studies.

Analysis of HIV-1 in the cervicovaginal secretions and blood of pregnant and nonpregnant women

OBJECTIVES

To detect HIV-1 in cellular and acellular fractions of cervicovaginal secretions obtained by cervicovaginal lavage (CVL) and evaluate viral genotypes in the HIV-1-positive CVL samples.

STUDY DESIGN/METHODS

This study consists of 37 HIV-1-seropositive pregnant and nonpregnant women from the United States. A total of 63 paired CVL and blood samples were collected. HIV-1 DNA from cervical cells (CC) and virion RNA from cervical supernatant (CS) was detected by gag polymerase chain reaction (PCR) assays. The HIV-1 genotypes were determined by analyzing the nested PCR-amplified V3 region sequences of the HIV-1 gp120 envelope gene.

RESULTS

Within this cohort, 95% of the women were on single or combination antiretroviral therapy. Of the pregnant women, 63% of samples had HIV-1 viral DNA in the CC, and 29% of samples were positive for viral RNA in the CS. Among nonpregnant women, 71% of samples were positive for HIV-1 DNA in CC, and 46% of samples tested positive for virion RNA in CS. Plasma viral load ranged between 10,000 and 100,000 copies/mL and showed significant correlation with the detection of HIV-1 RNA in the CVL; this relation was less apparent with viral DNA in CC. The viral blood and CVL specimens were further analyzed by evaluating the genotypes of HIV-1 variants. In most patients, a high degree of similarity was observed between the viral sequences derived from blood and CVL samples. Two patients demonstrated closely related but somewhat distinct genotypic variants in CVL and blood. One subject showed clear compartmentalization in which distinct viral genotypes were observed in CVL and blood. Based on V3 loop analyses of gp120, with one exception, the cervicovaginal secretions harbored viral populations with a macrophage (CCR5)-tropic phenotype.

CONCLUSIONS

This study demonstrates the unique characteris tics of HIV-1 strains in the genital secretions of a relatively large cohort of HIV-1-infected women in the United States. These results are important for further analysis of HIV-1 transmission and pathogenesis in vivo and for rational vaccine design.

Microbial transformations of hypolipemic E-guggulsterone

Biotransformation of E-guggulsterone (pregna-4,17(20)-cis-diene-3,16-dione) (1) by Aspergillus niger resulted in the formation of four new hydroxyl derivatives identified as 7 beta-hydroxypregna- 4,17(20)-trans-diene-3,16-dione (2), 7 beta-hydroxypregna-4,17(20)-cis-diene-3,16-dione (3), 7 beta- hydroxypregn-4-ene-3,16-dione (4), and 7 beta,15 beta-dihydroxypregn-4-ene-3,16-dione (5). The biotransformation of 1 with Cephalosporium aphidicola also resulted in the formation of four new steroidal derivatives as 11 alpha-hydroxypregna-4,17(20)-trans-diene-3,16-dione (6), 11 alpha- -hydroxypregna-4,17(20)-cis-diene-3,16-dione (7), 11 alpha,15 beta-dihydroxypregna-4,17(20)-trans-diene- 3,16-dione (8), and 11 alpha,15 beta-dihydroxypregna-4,17(20)-cis-diene-3,16-dione (9). The structures of these compounds were elucidated on the basis of 1D and 2D NMR spectroscopic techniques.

Hypotensive constituents from the pods of Moringa oleifera

Hypotensive activity of the ethanolic and aqueous extracts of Moringa oleifera whole pods and their parts, namely, coat, pulp, and seed was investigated. The activity of the ethanolic extract of both the pods and the seeds was equivalent at the dose of 30 mg/kg. The ethyl acetate phase of the ethanolic extract of pods was found to be the most potent fraction at the same dose. Its bioassay-directed fractionation led to the isolation of thiocarbamate and isothiocyanate glycosides which were also the hypotensive principles of the pods as observed in case of Moringa leaves. Two new compounds, O-[2'-hydroxy-3'-(2"-heptenyloxy)]-propyl undecanoate (1) and O-ethyl-4-[(alpha-L-rhamnosyloxy)-benzyl] carbamate (2) along with the known substances methyl p-hydroxybenzoate (3) and beta-sitosterol have also been isolated in the present studies. The latter two compounds and p-hydroxybenzaldehyde showed promising hypotensive activity. Structures of all these compounds have been deduced by spectroscopy and chemical reactions.

Interaction of ebeinone, an alkaloid from Fritillaria imperialis, at two muscarinic acetylcholine receptor subtypes

The ability of the alkaloid, ebeinone, isolated from Fritillaria imperialis, to act at muscarinic M2 and M3 acetylcholine receptors was investigated. In functional studies with guinea-pig left atrium, ebeinone was found to be ca. 10-fold more active as an antagonist of responses to carbachol (CCh) than in either guinea-pig ileum or trachea. Estimates of dissociation constants (KB values) in the three tissues were 77.3, 931.1 and 547.0 nM, respectively. Inhibition binding studies in rat atria with the non-selective antagonist [3H]N-methylscopolamine ([3H]NMS) showed ebeinone to have a KI value of 80.9 nM. Comparison of ebeinone with pancuronium, another steroid-like compound with a similar KB value at the muscarinic M2 receptor, found both compounds able to retard the dissociation rate of [3H]NMS in atria, indicating an allosteric mode of interaction at the M2 receptor. It is concluded that ebeinone exhibited a higher affinity for muscarinic M2 receptors than for M3 receptors in the guinea-pig and that it interacted allosterically at rat atrial M2 receptors.

Targeting human immunodeficiency virus type 1 reverse transcriptase by intracellular expression of single-chain variable fragments to inhibit early stages of the viral life cycle

Novel molecular approaches to inhibit human immunodeficiency virus type 1 (HIV-1) infection have received increasing attention because of the lack of effective antiviral drug therapies in vivo. We now demonstrate that cells can be intracellularly immunized by cytoplasmic expression of single-chain variable antibody fragments (SFv) which bind to the HIV-1 reverse transcriptase (RT) enzyme. The expression of anti-RT SFv in T-lymphocytic cells specifically neutralizes the RT activity in the preintegration stage and affects the reverse transcription process, an early event of the HIV-1 life cycle. Blocking the virus at these early stages dramatically decreased HIV-1 propagation, as well as the HIV-1-induced cytopathic effects in susceptible human T lymphocytes, by impeding the formation of the proviral DNA. These data also demonstrate that intracellular, complete SFvs may gain access to viral proteins of the HIV-1 preintegration complex. These SFvs will provide a tool with which to better understand the molecular mechanisms involved in restricting viral replication in HIV-1-infected cells.

Attitudes of commercial renal transplant recipients toward renal transplantation in India

Renal transplantation offers patients with end-stage renal disease the best opportunity for rehabilitation and long-term survival. However, there is a critical shortage of transplantable kidneys worldwide. This plays well into the hands of transplanters and entrepreneurs involved in commercial renal transplantation, particularly in India. This practice has been condemned by all transplant societies. In our fight against rampant commercialism in renal transplantation, we sought to describe feelings of patients who had received transplants in India, and the difficulties they faced during their stay there. The results show that the two reasons that motivated patients to go to India were lack of living-related donors and the need for prompt transplant. More than half of the patients did not meet their donors. Their experience, however, has been largely positive except for some negative feelings toward the broker and the standard of hospital hygiene. The total cost of the transplant was far less than that in the West but, despite that, some patients felt financially exploited. Communication with them was poor, as most patients did not get adequate pretransplant education and were not informed of possible complications including rejection and graft loss. Furthermore, almost half of the patients were not given medical reports. These results substantiate the impression that CRT in India does not conform to the high standards of renal transplant medicine.