Characteristics and outcomes of patients with heart failure discharged from different speciality units in Australia: an observational study

BACKGROUND

Previous studies have reported differing clinical outcomes among hospitalized heart failure (HF) patients admitted under cardiology and general medicine (GM) without consideration of patients' frailty.

AIMS

To explore outcomes in patients admitted under the two specialities after taking into account their frailty and other characteristics.

METHODS

This retrospective study included all HF patients ≥18 years admitted between 1 January 2013 and 31 December 2019 at two Australian tertiary hospitals. Frailty was determined by use of the Hospital Frailty Risk Score (HFRS) and patients with HFRS ≥ 5 were classified as frail. Propensity score matching (PSM) was used to match 11 variables between the two specialities. The primary outcomes included the days-alive-and-out-of-hospital (DAOH90) at 90 days of discharge, 30-day mortality and readmissions.

RESULTS

Of 4913 HF patients, mean age 76.2 (14.1) years, 51% males, 2653 (54%) were admitted under cardiology compared to 2260 (46%) under GM. Patients admitted under GM were more likely to be older females, with a higher Charlson index and poor renal function than those admitted under cardiology. Overall, 23.8% patients were frail and frail patients were more likely to be admitted under GM than cardiology (33.6% vs. 15.3%, P < 0.001). PSM created 1532 well-matched patients in each group. After PSM, the DAOH90 was not significantly different among patients admitted in GM when compared to cardiology (coefficient -5.36, 95% confidence interval -11.73 to 1.01, P = 0.099). Other clinical outcomes were also similar between the two specialities.

CONCLUSIONS

Clinical characteristics of HF patients differ between GM and cardiology; however, clinical outcomes were not significantly different after taking into account frailty and other variables.

A WC/WO star exploding within an expanding carbon-oxygen-neon nebula

The final fate of massive stars, and the nature of the compact remnants they leave behind (black holes and neutron stars), are open questions in astrophysics. Many massive stars are stripped of their outer hydrogen envelopes as they evolve. Such Wolf-Rayet stars¹ emit strong and rapidly expanding winds with speeds greater than 1,000 kilometres per second. A fraction of this population is also helium-depleted, with spectra dominated by highly ionized emission lines of carbon and oxygen (types WC/WO). Evidence indicates that the most commonly observed supernova explosions that lack hydrogen and helium (types Ib/Ic) cannot result from massive WC/WO stars^2,3, leading some to suggest that most such stars collapse directly into black holes without a visible supernova explosion⁴. Here we report observations of SN 2019hgp, beginning about a day after the explosion. Its short rise time and rapid decline place it among an emerging population of rapidly evolving transients^5-8. Spectroscopy reveals a rich set of emission lines indicating that the explosion occurred within a nebula composed of carbon, oxygen and neon. Narrow absorption features show that this material is expanding at high velocities (greater than 1,500 kilometres per second), requiring a compact progenitor. Our observations are consistent with an explosion of a massive WC/WO star, and suggest that massive Wolf-Rayet stars may be the progenitors of some rapidly evolving transients.

Use of the Patient-Generated Subjective Global Assessment to Identify Pre-Frailty and Frailty in Hospitalized Older Adults

OBJECTIVES

The Scored Patient-Generated Subjective Global Assessment (PG-SGA) and Edmonton Frail Scale (EFS) are widely used in acute care settings to assess nutritional and frailty status, respectively. We aimed to determine whether the scored PG-SGA can identify pre-frailty and frailty status, to simultaneously evaluate malnutrition and frailty in clinical practice.

DESIGN

Cross-sectional study.

SETTINGS AND PARTICIPANTS

A convenience sample of 329 consecutive patients admitted to an acute medical unit in South Australia.

MEASUREMENTS

Nutritional and frailty status were ascertained with scored PG-SGA and EFS, respectively. Optimal cut-off scores to identify pre-frailty and frailty were determined by calculating the Scored PG-SGA's sensitivity, specificity, positive and negative predictive values, Youden Index (YI), Liu index, Receiver Operator Curves (ROC) and Area Under Curve (AUC). Nutritional status and patient characteristics were analysed according to frailty categories.

RESULTS

The optimal cut-off PG-SGA score as determined by the highest YI, to identify both pre-frailty and frailty was >3, with a sensitivity of 0.711 and specificity of 0.746. The AUC was 0.782 (95% CI 0.731-0.833). In this cohort, 64% of the patients were well-nourished, 26% were moderately malnourished and 10% were severely malnourished. Forty-three percent, 24% and 33% of the patients were classified as robust, pre-frail and frail, respectively. Bivariate analysis showed that those robust were significantly younger than those who were pre-frail (-2.8, 95% CI -5.5 to -0.1, p=0.036) or frail (-3.4, 95% CI -5.9 to -1.0, p=0.002). Robust patients had significantly lower Scored PG-SGA than those who were pre-frail (-2.5, 95%CI -3.8 to -1.1, p<0.001) or frail (-4.9, 95% CI -6.1 to -3.7, p<0.001).

CONCLUSION

The Scored PG-SGA is moderately sensitive in identifying pre-frailty/frailty in older hospitalized adults and can be useful in identifying both conditions concurrently.

STUDY OF INDOOR RADON, THORON AND THEIR PROGENY IN SOUTH WEST KHASI HILLS DISTRICT OF MEGHALAYA, INDIA

A survey of indoor radon/thoron and their progeny concentrations was carried out in dwellings in the South West Khasi Hills district of Meghalaya, India. The survey was carried out using solid-state nuclear track detectors based on single-entry pinhole dosimeter and direct radon/thoron progeny sensors. The results are subjected to statistical analysis and discussed in the manuscript. The mean value of annual effective dose of the study region is estimated at 1.8 mSv.y -1. Seasonal variability and role of different indoor parameters are also discussed.

Patient experiences and health system responsiveness among internal migrants: A nationwide study in 13 Indian cities

OBJECTIVE

To report various components of health system responsiveness among poor internal migrants who availed the government health facilities in 13 Indian cities.

MATERIALS AND METHODS

Cluster random sampling was used to select 50,806 migrant households, of which 14,263 households avail the government health facility in last six months. In addition, 5072 women, who sought antenatal care and 3946 women who had delivery in government health facility during last six months were also included. Data on different domains of health system responsiveness were collected using an interviewer-administered questionnaire, developed based on the World Health Survey of WHO.

RESULTS

Of the eight domains of responsiveness, namely, autonomy, communication, confidentiality, dignity, choice, quality of basic facilities, prompt attention and access to family and community, seven domains, except the 'choice', are assessed, and they are moderate. Only about 30% of participants said that doctor discussed on treatment options (autonomy). And 50-60% of participants said positively for questions of clarity of communication. About 59% of participants acknowledged the confidentiality. Not more than 40% of participants said they were treated with dignity, and privacy is respected (dignity). The responses to quality basic amenities, prompt attention and access to family and community domains are fairly satisfactory.

CONCLUSIONS

This study has implications as many urban poor, including migrants do not utilize the services of public healthcare facilities. Hence, a responsive health system is required. There should be a policy in place to train and orient healthcare workers on some of the domains of health system responsiveness.

A three dimensional (3D) musculoskeletal finite element analysis of DARSN temporomandibular joint (TMJ) prosthesis for total unilateral alloplastic joint replacement

PURPOSE

The purpose of this study was to evaluate the strain and stress distribution for DARSN alloplastic unilateral temporomandibular joint (TMJ) prosthesis and the effects on contralateral natural joint using a finite element analysis (FEA).

METHODS

The replacement of the TMJ may have complications like infection, failure of hardware, facial paralysis and perforation. The understanding of the mechanical forces exerted by muscles of mastication and jaw movement on the joint helps in identifying the regions on alloplastic TMJ with various maximum forces, which makes that area more prone for failure of hardware. A three dimensional structural FEA was applied using a validated finite element model (FEM) where the areas of stress and strain were evaluated in the alloplastic joint and the contralateral natural joint. As the pattern of stress and strain can be influenced by the materials used for alloplastic joint and geometry of the design, mechanical property of bone and the attached musculature were also considered while construction the FEM analysis.

RESULTS

The forces of the muscles of mastication has a vital role on the amount of stress and strain present across the alloplastic joint. Masseter and temporalis exhibited the greatest resultant force on the alloplastic as well as the natural condyle with a magnitude of 272 N and 329 N. This study assessed the maximum stress and strain on the condyle-ramus unit and fossa.

CONCLUSION

FEA shows that alloplastic DARSN TMJ prosthesis distributes stress and strain equally between the alloplastic joint site and the contralateral natural joint causing minimal adverse effects to the natural joint. FEA also evaluated the stress and strain on alloplastic component and resulted in drawing clinical implications for operating surgical team.

Partial thickness temporalis rotation for alloplastic temporomandibular joint - how I do it

With increasing clinical evidence, the replacement of the temporomandibular joint with alloplastic joints is being increasingly accepted in severe degenerative diseases. There remains a risk of infection and a possibility of a failure of not just these prostheses but any alloplastic joint prosthesis post-operatively. Therefore, an extra precaution and additional coverage to the joint using partial thickness myo-temporalis rotation flap could be a useful option to minimize post-operative joint failure.

Identifying characteristics of an effective fracture liaison service: systematic literature review

Fracture liaison services (FLS) have been demonstrated to improve outcomes following osteoporotic fracture. The aim of this systematic literature review (SLR) was to determine the characteristics of an FLS that lead to improved patient outcomes. We conducted a SLR, including articles published between 2000 and February 2017, using global (Medline, EMBASE, PubMed and Cochrane Library) and local databases. Studies including patients aged ≥ 50 years with osteoporotic fractures enrolled in an FLS were assessed. Information extracted from each article included key person coordinating the FLS (physician, nurse or other healthcare professional), setting (hospital vs community), intensity (single vs multiple), duration (long vs short term), fracture type and gender. A meta-analysis of randomised controlled trials was conducted based on the key person coordinating the FLS. Out of 7236 articles, 57 were considered to be high quality and identified for further analysis. The SLR identified several components which contributed to FLS success, including multidisciplinary involvement, driven by a dedicated case manager, regular assessment and follow-up, multifaceted interventions and patient education. Meta-analytic data confirm the effectiveness of an FLS following an osteoporotic fracture: approximate 27% increase in the likelihood of BMD testing and up to 21% increase in the likelihood of treatment initiation compared with usual care. The balance of evidence indicates that the multifaceted FLS and dedicated coordination are important success factors that contribute to effective FLS interventions which reduce fracture-related morbidity and mortality.

Investigation of the benefits of early malnutrition screening with telehealth follow up in elderly acute medical admissions

BACKGROUND

The benefit of providing early nutrition intervention and its continuation post-discharge in older hospitalized patients is unclear. This study examined efficacy of such an intervention in older patients discharged from acute care.

METHODS

In this randomized controlled trial, 148 malnourished patients were randomized to receive either a nutrition intervention for 3 months or usual care. Intervention included an individualized nutrition care plan plus monthly post-discharge telehealth follow-up whereas control patients received intervention only upon referral by their treating clinicians. Nutrition status was determined by the Patient Generated Subjective Global Assessment (PG-SGA) tool. Clinical outcomes included changes in length of hospital stay, complications during hospitalization, Quality of life (QoL), mortality and re-admission rate.

RESULTS

Fifty-four males and 94 females (mean age, 81.8 years) were included. Both groups significantly improved PG-SGA scores from baseline. There was no between-group differences in the change in PG-SGA scores and final PG-SGA scores were similar at 3 months 6.9 (95% CI 5.6-8.3) vs. 5.8 (95% CI 4.8-6.9) (P = 0.09), in control and intervention groups, respectively. Median total length of hospital stay was 6 days shorter in the intervention group (11.4 (IQR 16.6) vs. 5.4 (IQR 8.1) (P = 0.01). There was no significant difference in complication rate during hospitalization, QoL and mortality at 3-months or readmission rate at 1, 3 or 6 months following hospital discharge.

CONCLUSION

In older malnourished inpatients, an early and extended nutrition intervention showed a trend towards improved nutrition status and significantly reduced length of hospital stay.

Malnutrition in Acutely Unwell Hospitalized Elderly - "The Skeletons Are Still Rattling in the Hospital Closet"

INTRODUCTION

Malnutrition is common in hospitalized patients with prevalence rates of up to 30% in Australian hospitals with adverse consequences for both the patients and health care services. Despite formulation of nutritional screening protocols, not all hospitalized patients get nutritional screening. Real life screening rates of hospitalized elderly patients are unknown.

AIM

The present study explored nutrition screening rate in acutely unwell elderly patients admitted in a large tertiary hospital and how these patients fared depending upon their nutrition status.

METHODS

A prospective cross-sectional study involving 205 general medical patients ≥60years recruited between November 2014 and November 2015. The number of patients who missed nutrition screening were noted and all patients underwent nutritional assessment by a qualified dietitian using PG-SGA and quality of life was measured using EQ-5D 5L. A survival curve was plotted and multivariate cox proportional hazard model was used to adjust for confounders.

RESULTS

Only 99 (49.7%) patients underwent nutritional screening. One hundred and six (53.5%) patients were confirmed as malnourished by PG-SGA. Malnourished patients had significantly longer length of hospital stay and had worse quality of life. Mortality was significantly higher in malnourished patients at one year (23 (21.7%) vs 4 (4.3%); p<0.001) and cox proportional hazard model suggests that malnutrition significantly affects survival even after adjustment for confounders like age, sex, Charlson index and polypharmacy.

CONCLUSION

This study confirms that nutrition screening is still suboptimal in elderly hospitalized patients with adverse consequences and suggests need for review of policies to improve screening practices.

Continuous flow telescopic oxidation of alcohols via generation of chlorine and hypochlorite

A 3-step continuous flow oxidation of alcohols is demonstrated with continuous generation of chlorine as the first step followed by its use for the flow synthesis of high strength sodium hypochlorite.

A protein-truncating R179X variant in RNF186 confers protection against ulcerative colitis

Protein-truncating variants protective against human disease provide in vivo validation of therapeutic targets. Here we used targeted sequencing to conduct a search for protein-truncating variants conferring protection against inflammatory bowel disease exploiting knowledge of common variants associated with the same disease. Through replication genotyping and imputation we found that a predicted protein-truncating variant (rs36095412, p.R179X, genotyped in 11,148 ulcerative colitis patients and 295,446 controls, MAF=up to 0.78%) in RNF186, a single-exon ring finger E3 ligase with strong colonic expression, protects against ulcerative colitis (overall P=6.89 × 10(-7), odds ratio=0.30). We further demonstrate that the truncated protein exhibits reduced expression and altered subcellular localization, suggesting the protective mechanism may reside in the loss of an interaction or function via mislocalization and/or loss of an essential transmembrane domain.

Automated segmentation of wood fibres in micro-CT images of paper

A novel algorithm has been developed and validated to isolate individual papermaking fibres in micro-computed tomographic images of paper handsheets as a first step to characterize the structure of the paper. The three-step fibre segmentation algorithm segments the papermaking fibres by (i) tracking the hollow inside the fibres via a modified connected component methodology, (ii) extracting the fibre walls using a distance transform and (iii) labelling the fibres through collapsed sections by a final refinement step. Furthermore, postprocessing algorithms have been developed to calculate the length and coarseness of the segmented fibres. The fibre segmentation algorithm is the first ever reported method for the automated segmentation of the tortuous three-dimensional morphology of papermaking fibres within microstructural images of paper handsheets. The method is not limited to papermaking fibres, but can be applied to any material consisting of tortuous and hollow fibres.

Assessment of use of complementary alternative medicine and its impact on quality of life in the patients attending rheumatology clinic, in a tertiary care centre in India

PURPOSE

Complementary and alternative medicine (CAM) has witnessed an increase in use in recent times in rheumatological conditions and is expected to have impact on the quality of life (QOL). We had planned to conduct this study to investigate the extent of use of CAM and its effect on QOL of patients at a tertiary care center.

MATERIALS AND METHODS

Ethics committee approval was obtained. Sixty patients suffering from osteoarthritis (OA) and rheumatoid arthritis (RA) were enrolled as per the selection criteria, after obtaining their informed consent. Each patient was interviewed for CAM use/non-use, and Western Ontario and McMaster Universities (WOMAC) (modified) index for QOL was recorded by the study personnel.

STATISTICAL ANALYSIS

The normality was checked by using Kolmogorov-Smirnov test. Descriptive statistics was performed and Mann-Whitney U-test was used to compare the QOL of CAM users and non-users.

RESULTS

Of the 60 patients enrolled with OA (10) and RA (50), 58% (35/60) used CAM. Ayurveda and massage therapy were the commonest [80% (28/35)], followed by yoga asana [34% (12/35)] and homoeopathy [20% (7/35)]. It was observed that combinations of therapies were used too. Nearly half [49% (17/35)] of the CAM users were on self-prescribed medication and 71% (25/35) of them did not inform the physician of CAM use. The QOL of CAM users (WOMAC score: 56.31 ± 6.82) was better than that of CAM non-users (WOMAC score: 60.16 ± 4.02) (P value 0.01).

CONCLUSION

Patients with RA frequently used CAM and QOL improvised with CAM use. We observed that self-administration of CAM was common and this was not informed to the treating physician.

Emerging extra-intestinal infections with Aeromonas hydrophila in coastal region of southern Karnataka

BACKGROUND

Aeromonas species are gram-negative rods usually isolated from the gastrointestinal tract. They have been occasionally reported as a cause of extra-intestinal infections such as cellulitis, cholangitis, necrotizing fascitis, meningitis, bacteremia, or peritonitis in both immunocompetent and immunocompromised patients.

AIM

To determine the role and possible pathogenesis of Aeromonas in extra-intestinal infections.

SETTINGS AND DESIGN

Retrospective analysis carried out at Kasturba Hospital Manipal, Karnataka in the months of January and February 2007.

MATERIALS AND METHODS

Clinical manifestations and management of eight cases of extra-intestinal infections caused by A. hydrophila , from the south Karnataka coastal region were reviewed. The isolates were identified with the help of biochemical tests using standard guidelines.

RESULTS

All patients acquired Aeromonas infections in the community. Five (62.5%) had underlying illnesses, such as liver disease, diabetes mellitus or malignancy. Five (62.5%) had polymicrobial infections, and three (37.5%) were complicated with bacteremia. These included three patients with ulcers or abscess over the lower leg, two with cellulitis due to snake bite and one each with pelvic inflammatory disease, spontaneous bacterial peritonitis and pneumonia. A. hydrophila was found to be a causative agent of pelvic inflammatory disease or cellulitis following sea snake bite, and such a clinical scenario has not been previously described. Seven patients survived the illness.

CONCLUSIONS

Isolation of A. hydrophila from extra-intestinal specimens demands utmost clinical and microbiological vigilance in diagnosis, since the organism can cause serious infections among immunocompromised as well as immunocompetent individuals.

Transfusion transmitted virus: A review on its molecular characteristics and role in medicine

The present review gives an updated overview of transfusion transmitted virus (TTV), a novel agent, in relation to its molecular characteristics, epidemiological features, modes of transmission, tissue tropism, pathogenesis, role in various diseases and its eradication from the body. TTV, a DNA virus, is a single stranded, non-enveloped, 3.8 kb long DNA virus with a small and covalently closed circular genome comprising 3852 bases. It was tentatively designated Circinoviridae virus. TTV genome sequence is heterogeneous and reveals the existence of six different genotypes and several subtypes. TTV has been reported to transmit not only via parenteral routes, but also via alternate routes. This virus has been detected in different non-human primates as well. At present, TTV is detected by polymerase chain reaction (PCR) with no other available diagnostic assays. It shows its presence globally and was detected in high percent populations of healthy persons as well as in various disease groups. Initially it was supposed to have strong association with liver disease; however, there is little evidence to show its liver tropism and contribution in causing liver diseases. It shows high prevalence in hemodialysis patients, pointing towards its significance in renal diseases. In addition, TTV is associated with several infectious and non-infectious diseases. Although its exact pathogenesis is not yet clear, TTV virus possibly resides and multiplies in bone marrow cells and peripheral blood mononuclear cells (PBMCs). Recently, attempts have been made to eradicate this virus with interferon treatment. More information is still needed to extricate various mysteries related to TTV.

Transfusion-transmitted virus in association with hepatitis A-E viral infections in various forms of liver diseases in India

AIM: To describe the prevalence of transfusion-transmitted virus (TTV) infection in association with hepatitis A-E viral infections in different forms of liver diseases in North India.

METHODS: Sera from a total number of 137 patients, including 37 patients with acute viral hepatitis (AVH), 37 patients with chronic viral hepatitis (CVH), 31 patients with cirrhosis of liver and 32 patients with fulminant hepatic failure (FHF), were analyzed both for TTV-DNA and hepatitis A-E viral markers. Presence of hepatitis B virus (HBV), hepatitis C virus (HCV) and hepatitis E virus (HEV) infections was detected in different proportions in different groups. Moreover, TTV-DNA was simultaneously tested in 100 healthy blood donors also.

RESULTS: None of the patients had hepatitis A virus (HAV) and hepatitis D virus (HDV) infections. Overall prevalence of TTV-DNA was detected in 27.1% cases with AVH, 18.9% cases with CVH, 48.4% cases with cirrhosis and 9.4% cases with FHF. TTV-DNA simultaneously tested in 100 healthy blood donors showed 27% positivity. On establishing a relation between TTV infection with other hepatitis viral infections, TTV demonstrated co-infection with HBV, HCV and HEV in these disease groups. Correlation of TTV with ALT level in sera did not demonstrate high ALT level in TTV-infected patients, suggesting that TTV does not cause severe liver damage.

CONCLUSION: TTV infection is prevalent both in patients and healthy individuals in India. However, it does not have any significant correlation with other hepatitis viral infections, nor does it produce an evidence of severe liver damage in patients with liver diseases.

Prevalence of Helicobacter pylori in Dhulikhel Hospital, Kathmandu University Teaching Hospital: a retrospective histopathologic study

OBJECTIVE

The main objective of this study was to determine prevalence of Helicobacter pylori infection in Dhulikhel Hospital, Kathmandu University Teaching Hospital.

METHODOLOGY

Endoscopic antral biopsies from January 1, 2004 to August 31, 2005 were studied retrospectively. Hematoxylin and eosin and Giemsa stained histological sections were examined.

RESULTS

Out of 224 patients (Male 125 and female 99) who underwent endoscopic biopsy and included in the study, a total of 76 (33.9%) patients (Male 50 and female 26) were infected by H. pylori. The mean age of the H. pylori infected patients was 40.2 years (SD 16.0). The infection by H. pylori was significantly higher in males than females (p<0.05) with male to female ratio of 1.9:1. The most common (31.3%) histopathologic finding was chronic superficial gastritis followed by normal histology (30.8%). A total of 10 cases (4.5%) of adenocarcinoma and 16 cases (7.1%) of intestinal metaplasia were detected and neither of them showed presence of H. pylori. Two cases (0.9%) were diagnosed as suspected malignancy and both were negative for H. pylori infection. Among gastritis, H. pylori was most frequently observed in chronic active gastritis (86.1%). Two of 69 cases (2.9%) of normal gastric mucosa showed H. pylori.

A randomized comparison of sublingual and vaginal misoprostol for cervical priming before suction termination of first-trimester pregnancy

This randomized trial compares the efficacy and side effects of sublingual and vaginal misoprostol for cervical priming before first-trimester pregnancy termination. One-hundred pregnant women between 6 and 12 weeks of gestation opting for termination of pregnancy by suction evacuation were included in this study. The women were randomly allocated into two groups. Group 1 received 400 microg of sublingual misoprostol and group 2 received 400 microg of vaginal misoprostol 2 h prior to suction evacuation. The abortion was carried out by suction evacuation using a Karman's cannula attached to an electrically operated suction machine under intravenous analgesia. Baseline cervical dilatation, duration of the procedure, operative blood loss, side effects and complications were noted in both groups. There was a significant difference between the sublingual and vaginal misoprostol groups with respect to mean cervical dilatation (8.6 mm vs. 6.8 mm, p < 0.05). However, the duration of the procedure (3.03 min vs. 3.16 min) and the amount of blood loss (29 mL vs. 31.2 mL) were not significantly different between the two groups. The women in the sublingual group experienced significantly more shivering and preoperative vaginal bleeding (68% vs. 56%, p < 0.05). None of the women in the two groups had either uterine perforation or excessive hemorrhage. In our study, sublingual misoprostol (400 microg) was significantly more effective in facilitating cervical dilation prior to surgical abortion than vaginal misoprostol.

Maternal and perinatal outcome in rheumatic heart disease

OBJECTIVES

To study the maternal and perinatal outcome of pregnancies complicated by rheumatic heart disease.

METHODS

A retrospective study was carried out in the cardio-obstetric clinic of the Postgraduate Institute of Medical Education and Research, Chandigarh (India) over a period of 13 years (1987-1999) involving 486 pregnant patients with rheumatic heart disease. Maternal and perinatal outcome was reviewed.

RESULTS

Three hundred and four patients (63.3%) had single valve involvement and mitral stenosis was the most predominant lesion (89.2%). One hundred and seventy one (38.6%) patients had undergone surgical correction prior to the onset of pregnancy. One hundred and thirteen patients (22.6%) were identified as NYHA class III-IV. Mitral valvotomy was performed during pregnancy in 48 patients. The incidence of preterm birth and small for gestational age newborns was 12% and 18.2%, respectively. There were 10 maternal deaths, of which eight patients were NYHA III and IV.

CONCLUSIONS

Rheumatic heart disease in pregnancy is associated with significant maternal and perinatal morbidity in NYHA class III-IV patients.

Calcium binding properties of gamma-crystallin: calcium ion binds at the Greek key beta gamma-crystallin fold

The beta- and gamma-crystallins are closely related lens proteins that are members of the betagamma-crystallin superfamily, which also include many non-lens members. Although beta-crystallin is known to be a calcium-binding protein, this property has not been reported in gamma-crystallin. We have studied the calcium binding properties of gamma-crystallin, and we show that it binds 4 mol eq of calcium with a dissociation constant of 90 microm. It also binds the calcium-mimic spectral probes, terbium and Stains-all. Calcium binding does not significantly influence protein secondary and tertiary structures. We present evidence that the Greek key crystallin fold is the site for calcium ion binding in gamma-crystallin. Peptides corresponding to Greek key motif of gamma-crystallin (42 residues) and their mutants were synthesized and studied for calcium binding. These peptides adopt beta-sheet conformation and form aggregates producing beta-sandwich. Our results with peptides show that, in Greek key motif, the amino acid adjacent to the conserved aromatic corner in the "a" strand and three amino acids of the "d" strand participate in calcium binding. We suggest that the betagamma superfamily represents a novel class of calcium-binding proteins with the Greek key betagamma-crystallin fold as potential calcium-binding sites. These results are of significance in understanding the mechanism of calcium homeostasis in the lens.

Transglutaminase-mediated cross-linking of alpha-crystallin: structural and functional consequences

Aggregation and covalent cross-linking of the crystallins, the major structural proteins of the eye lens, increase light scattering by the lens leading to opacification and cataract. Disturbance of calcium homeostasis in the tissue is one of the factors implicated in cataractogenesis. Calcium-activated transglutaminase (TG)-catalyzed cross-linking of some lens proteins has been reported earlier. We show here that alpha-crystallin, a major structural protein in the lens and a member of the small heat shock protein family, is also a substrate for TG-mediated cross-linking, indicating the presence of donor Lys and acceptor Gln residues in the protein. Upon TG-catalyzed dimerization, the secondary and tertiary structures of the protein are altered, and its surface hydrophobicity reduced. The chaperone-like property of the protein, suspected to be one of its functions in situ, is substantially reduced upon such cross-linking. These results, taken together with earlier ones on lens beta-crystallins and vimentin, suggest that TG-mediated events might compromise lens function. Also, since alpha-crystallin occurs not only in the lens but in other tissues as well, such TG-catalyzed cross-linking and the associated alterations in its structure and activity would be of general pathological interest.

Inhibitory effect of silibinin on ligand binding to erbB1 and associated mitogenic signaling, growth, and DNA synthesis in advanced human prostate carcinoma cells

We recently showed the inhibitory effect of a flavonoid antioxidant, silymarin, on erbB1-Shc activation in prostate cancer (PCA) DU145 cells. In the present study, we performed more detailed mechanistic and molecular modeling studies with pure silibinin to assess and define its effect on membrane signaling related to erbB1 activation in human PCA LNCaP and DU145 cells. Studies also were performed to establish the biologic responses toward extracellular signal-regulated protein kinase 1/2 (ERK1/2) activation, cell growth, and DNA synthesis. Treatment of serum-starved cells with various doses of silibinin for 2 h followed by (125)I-epidermal growth factor (EGF) showed 30-75% inhibition in ligand binding and 55-95% inhibition in its internalization in LNCaP cells and 20-64% and 12-27% inhibition in these two events in DU145 cells. Time-response studies showed similar effects. In further studies, treatment of serum-starved cultures with silibinin followed by EGF showed strong inhibitory effects on membrane and cytoplasmic signaling molecules. In the case of erbB1 activation, silibinin showed a 58-75% decrease in LNCaP and a 40-100% decrease in DU145 cells at 50, 75, and 100-microg/mL doses. Inhibitory effects of silibinin also were evident on ERK1/2 activation (20-80% inhibition) in both cell lines. Treatment of serum-starved cultures with silibinin resulted in 20-40% and 30-55% inhibition of LNCaP and DU145 cell growth, respectively, at similar doses after 1-3 d of treatment, and 10-50% cell death in both cell lines. Under 10% serum conditions, identical silibinin treatments resulted in 20-65% inhibition of cell growth in LNCaP and DU145 cells but did not cause any cell death. Similar doses of silibinin treatments for 24 h also resulted in 25-60%, 35-40%, and 36-50% inhibition of DNA synthesis when cells were cultured in 10% serum, totally serum starved, and serum starved plus stimulated with EGF, respectively. Molecular modeling of silibinin showed that it is a highly lipophilic compound, suggesting that it interacts with lipid-rich plasma membrane, including binding with erbB1, thereby competing with the EGF-erbB1 interaction. Because the ligand-erbB1 autocrine-loop is causally involved in advanced and androgen-independent PCA, the observed effects of silibinin and its strong lipophilic nature could be useful in developing this agent for the prevention and therapy of PCA.

Purification of myristoylated and nonmyristoylated neuronal calcium sensor-1 using single-step hydrophobic interaction chromatography

Neuronal calcium sensors (NCSs) belong to a family of Ca(2+)-binding proteins, which serve important functions in neurotransmission, and are highly conserved from yeast to humans. Overexpression of the neuronal calcium sensor-1, called frequenin in the fruit fly and in frog, increases the release of neurotransmitters. Studying the functional role of frequenin in mammals and understanding its structural dynamics is critically dependent on the availability of active purified protein. Neuronal calcium sensors like other members of the family share common structural features: they contain four EF-hands as potential binding sites for Ca(2+) and an N-terminal consensus sequence for myristoylation. Previously, recoverin, distantly related to NCSs, has been expressed and purified from Escherichia coli, involving a combination of different chromatographic steps. NCS-1 has earlier been purified adopting a two-step procedure used for recoverin purification. We have overexpressed NCS-1 from rat in its myristoylated and nonmyristoylated form in E. coli and purified it from crude lysates using a single-step hydrophobic interaction chromatography. The purified protein was identified by Western blotting and mass spectrometry and assayed for its ability to bind Ca(2+) using a Ca(2+) shift assay, terbium fluorescence, and Stains-all binding. The present protocol provides a rapid, more efficient and simplified, single-step method for purifying NCS-1 for structural and functional studies. This method can also be applied to purify related proteins of the superfamily.

Anticarcinogenic effect of a polyphenolic fraction isolated from grape seeds in human prostate carcinoma DU145 cells: modulation of mitogenic signaling and cell-cycle regulators and induction of G1 arrest and apoptosis

There is an increasing interest in identifying potent cancer preventive and therapeutic agents against prostate cancer (PCA). In a recent study, we showed that a polyphenolic fraction isolated from grape seeds (hereafter referred to as GSP) that is substantially rich in antioxidant procyanidins exerts exceptionally high preventive effects against tumorigenesis in a murine skin model. In the present study, we investigated the anticarcinogenic effect of GSP against PCA by employing DU145 human prostate carcinoma cells. GSP treatment (10-100 microg/mL doses for 2-6 d) of cells resulted in a highly significant (P < 0.01-0.001) inhibition of cell growth in both dose- and time-dependent manner. Compared with the vehicle, 2 d of GSP treatment resulted in 27, 39, and 76% growth inhibition at 50, 75, and 100 microg/mL doses, respectively, whereas 28-97% and 12-98% inhibition was evident at 10-100 microg/mL doses of GSP after 4 and 6 d of treatment, respectively. These doses of GSP also resulted in dose- and time-dependent cell death (6-50%, P <0.1-0. 001) that was later characterized as apoptotic death. In molecular mechanistic studies, treatment of DU145 cells with GSP at 25-75 microg/mL doses for 24, 48, and 72 h resulted in 77-88%, 65-93%, and 38-98% reduction, respectively (P < 0.001), in phospho-extracellular signal-regulated protein kinase (ERK) 1 and 78%, 19-76%, and 63-71% reduction (P < 0.1-0.001) in phospho-ERK2 levels, respectively. In other studies, similar doses of GSP showed up to 1.9-fold increases in Cip1/p21 and a significant (P < 0.001) decrease in cyclin-dependent kinase (CDK) 4 (up to 90% decrease), CDK2 (up to 50% decrease), and cyclin E (up to 60% decrease). GSP treatment of DU145 cells also resulted in a significant (P < 0.001) G1 arrest in cell-cycle progression in a dose-dependent manner. The growth-inhibitory and cell-death effects of GSP were also observed in another human PCA line, LNCaP. Together, these results suggest that GSP may exert strong anticarcinogenic effect against PCA and that this effect possibly involves modulation of mitogenic signaling and cell-cycle regulators and induction of G1 arrest, cell-growth inhibition, and apoptotic death. Mol. Carcinog. 28:129-138, 2000.

A polyphenolic fraction from grape seeds causes irreversible growth inhibition of breast carcinoma MDA-MB468 cells by inhibiting mitogen-activated protein kinases activation and inducing G1 arrest and differentiation

In recent years, significant emphasis is being placed on identifying naturally occurring cancer preventive and interventive agents. In this regard, a polyphenolic fraction isolated from grape seeds (hereafter referred as GSP) has recently been shown by us and others to prevent tumorigenesis in mouse skin models. Chemical analysis of GSP has shown that it is largely constituted with procyanidins that are strong antioxidants. Breast cancer is the most common invasive malignancy and the second leading cause of cancer-related deaths in United States women. Accordingly, here we investigated the effect of GSP on mitogenic signaling and regulators of cell cycle and apoptosis as molecular targets for the growth arrest, apoptotic death, and/or differentiation of estrogen-independent MDA-MB468 human breast carcinoma cells. Treatment of cells with GSP (at 25-, 50-, and 75-microg/ml doses for 1-3 days) resulted in a highly significant inhibition (90% to complete, P < 0.001) of constitutive activation of mitogen-activated protein kinase (MAPK)/extracellular signal-regulated protein kinase1/2 in a dose-dependent manner after 72 h of treatment. Whereas GSP treatment of cells did not show a conclusive effect on MAPK/ JNK1 activation, a moderate to highly significant inhibition (15-70%, P < 0.1-0.001) of constitutive activation of MAPK/p38 was also observed in a dose-dependent manner as early as 24 h of GSP treatment. GSP-treated cells also showed a strong induction (1.7-2.7 fold, P < 0.001) of cyclin-dependent kinase inhibitor Cip1/p21 and a decrease (10-50%, P < 0.1-0.001) in cyclin-dependent kinase 4. Consistent with these findings, GSP-treated cells resulted in their accumulation in G1 phase of the cell cycle in a dose-dependent manner. An irreversible growth inhibition (44-88%, P < 0.001) was also observed in 50 and 75 microg/ml GSP-treated cells in a time-dependent manner. Additional studies assessing the biological fate of GSP-treated cells showed that they do not undergo apoptotic death, as evidenced by a lack of DNA fragmentation, poly (ADP ribose) polymerase cleavage, and apoptotic morphology of the cells. A morphological change suggestive of differentiation was observed in GSP-treated cells that was further confirmed by a significant induction (1.7-2.6 fold, P < 0.001), in both a dose- and time-dependent manner, in cytokeratin 8 protein level, a marker of differentiation. An irreversible growth-inhibitory effect of GSP possibly via terminal differentiation of human breast carcinoma cells suggests that GSP and the procyanidins present therein should be studied more extensively to be developed as preventive and/or interventive agents against breast cancer in humans.

Anticarcinogenic effect of a polyphenolic fraction isolated from grape seeds in human prostate carcinoma DU145 cells: modulation of mitogenic signaling and cell-cycle regulators and induction of G1 arrest and apoptosis

There is an increasing interest in identifying potent cancer preventive and therapeutic agents against prostate cancer (PCA). In a recent study, we showed that a polyphenolic fraction isolated from grape seeds (hereafter referred to as GSP) that is substantially rich in antioxidant procyanidins exerts exceptionally high preventive effects against tumorigenesis in a murine skin model. In the present study, we investigated the anticarcinogenic effect of GSP against PCA by employing DU145 human prostate carcinoma cells. GSP treatment (10-100 microg/mL doses for 2-6 d) of cells resulted in a highly significant (P < 0.01-0.001) inhibition of cell growth in both dose- and time-dependent manner. Compared with the vehicle, 2 d of GSP treatment resulted in 27, 39, and 76% growth inhibition at 50, 75, and 100 microg/mL doses, respectively, whereas 28-97% and 12-98% inhibition was evident at 10-100 microg/mL doses of GSP after 4 and 6 d of treatment, respectively. These doses of GSP also resulted in dose- and time-dependent cell death (6-50%, P <0.1-0. 001) that was later characterized as apoptotic death. In molecular mechanistic studies, treatment of DU145 cells with GSP at 25-75 microg/mL doses for 24, 48, and 72 h resulted in 77-88%, 65-93%, and 38-98% reduction, respectively (P < 0.001), in phospho-extracellular signal-regulated protein kinase (ERK) 1 and 78%, 19-76%, and 63-71% reduction (P < 0.1-0.001) in phospho-ERK2 levels, respectively. In other studies, similar doses of GSP showed up to 1.9-fold increases in Cip1/p21 and a significant (P < 0.001) decrease in cyclin-dependent kinase (CDK) 4 (up to 90% decrease), CDK2 (up to 50% decrease), and cyclin E (up to 60% decrease). GSP treatment of DU145 cells also resulted in a significant (P < 0.001) G1 arrest in cell-cycle progression in a dose-dependent manner. The growth-inhibitory and cell-death effects of GSP were also observed in another human PCA line, LNCaP. Together, these results suggest that GSP may exert strong anticarcinogenic effect against PCA and that this effect possibly involves modulation of mitogenic signaling and cell-cycle regulators and induction of G1 arrest, cell-growth inhibition, and apoptotic death. Mol. Carcinog. 28:129-138, 2000.

Inhibitory effect of a flavonoid antioxidant silymarin on benzoyl peroxide-induced tumor promotion, oxidative stress and inflammatory responses in SENCAR mouse skin

In this communication, we investigate the preventive effect of a flavonoid antioxidant, silymarin, on free radical-generating skin tumor promoting agent benzoyl peroxide (BPO)-induced tumor promotion, oxidative stress and inflammatory responses in SENCAR mouse skin. Topical application of silymarin at a dose of 6 mg prior to BPO resulted in a highly significant protection against BPO-induced tumor promotion in 7,12-dimethylbenz[a]anthracene-initiated SENCAR mouse skin. The preventive effect of silymarin was evident in terms of a 70% reduction (P < 0.001) in tumor incidence, a 67% reduction (P < 0.001) in tumor multiplicity and a 44% decrease (P < 0.001) in tumor volume/tumor. In oxidative stress studies, topical application of BPO resulted in 75, 87 and 61% depletion in superoxide dismutase (SOD), catalase and glutathione peroxidase (GPX) activities in mouse epidermis, respectively. These decreases in antioxidant enzyme activities were significantly (P < 0.005-0.001) reversed by pre-application of silymarin in a dose-dependent manner. The observed effects of silymarin were 18-66, 32-72 and 20-67% protection against BPO-induced depletion of SOD, catalase and GPX activity in mouse epidermis, respectively. Silymarin pre-treatment also resulted in a dose-dependent inhibition (35-87%, P < 0.05-0. 001) of BPO-induced lipid peroxidation in mouse epidermis. In inflammatory response studies, silymarin showed a strong inhibition of BPO-induced skin edema (62-85% inhibition, P < 0.001), myeloperoxidase activity (42-100% inhibition, P < 0.001) and interleukin-1alpha protein level in epidermis (36-81% inhibition, P < 0.001). These results, together with our other recent studies, suggest that silymarin could be useful in preventing a wide range of carcinogen and tumor promoter-induced cancers.

Significant inhibition by the flavonoid antioxidant silymarin against 12-O-tetradecanoylphorbol 13-acetate-caused modulation of antioxidant and inflammatory enzymes, and cyclooxygenase 2 and interleukin-1alpha expression in SENCAR mouse epidermis: implications in the prevention of stage I tumor promotion

The flavonoid antioxidant silymarin is used clinically in Europe and Asia for the treatment of liver diseases and is sold in the United States and Europe as a dietary supplement. Recently we showed that silymarin possesses exceptionally high cancer-preventive effects in different mouse skin carcinogenesis models and affords strong anticancer effects in human skin, cervical, prostate, and breast carcinoma cells. More recently, we showed that the anti-tumor-promoting effect of silymarin is primarily targeted against stage I tumor promotion in mouse skin (Cancer Res 1999;59:622-632). Based on this recent study, in this report, further investigations were made to identify and define the biochemical and molecular mechanisms of silymarin's effect during stage I tumor promotion in mouse skin. A single topical application of silymarin at 3-, 6-, and 9-mg doses onto SENCAR mouse skin followed 30 min later with 12-O-tetradecanoylphorbol 13-acetate (TPA) at a 3-microg dose resulted in a 76-95% inhibition (P < 0.001) of TPA-caused skin edema. Similarly, these doses of silymarin also showed 39-90%, 29-85%, and 15-67% protection (P < 0.05 or 0.001), against TPA-caused depletion of epidermal superoxide dismutase, catalase, and glutathione peroxidase activity, respectively. Pretreatment of mice with silymarin also produced highly significant inhibition of TPA-caused induction of epidermal lipid peroxidation (47-66% inhibition, P < 0.001) and myeloperoxidase activity (56-100% inhibition, P < 0.001). In additional studies assessing the effect of silymarin on arachidonic acid metabolism pathways involving lipoxygenase and cyclooxygenase (COX), similar doses of silymarin showed highly significant inhibition of TPA-caused induction of epidermal lipoxygenase (49-77% inhibition, P < 0.001) and COX (35-64% inhibition, P < 0.01 or 0.001) activity. Western immunoblot analysis showed that the observed effect of silymarin on COX activity was due to inhibition of TPA-inducible COX-2 with no change in constitutive COX-1 protein levels. In other studies, silymarin also showed dose-dependent inhibition of TPA-caused induction of epidermal interleukin 1alpha (IL-1alpha) protein (39-72% inhibition, P < 0.005 or 0.001) and mRNA expression. Taken together, the results from these biochemical and molecular studies further substantiate our recent observation of silymarin's anti-tumor-promoting effects primarily at stage I tumor promotion. Furthermore, the observed inhibitory effects of silymarin on COX-2 and IL-1alpha should be further explored to develop preventive strategies against those cancers in which these molecular targets play one of the causative roles, such as non-melanoma skin, colon, and breast cancers in humans.

A p53-dependent S-phase checkpoint helps to protect cells from DNA damage in response to starvation for pyrimidine nucleotides

Normal mammalian cells arrest primarily in G1 in response to N-(phosphonacetyl)-L-aspartate (PALA), which starves them for pyrimidine nucleotides, and do not generate or tolerate amplification of the CAD gene, which confers resistance to PALA. Loss of p53, accompanied by loss of G1 arrest, permits CAD gene amplification and the consequent formation of PALA-resistant colonies. We have found rat and human cell lines that retain wild-type p53 but have lost the ability to arrest in G1 in response to PALA. However, these cells still fail to give PALA-resistant colonies and are protected from DNA damage through the operation of a second checkpoint that arrests them reversibly within S-phase. This S-phase arrest, unmasked in the absence of the G1 checkpoint, is dependent on p53 and independent of p21/waf1.

Modified helix-loop-helix motifs of calmodulin--The influence of the exchange of helical regions on calcium-binding affinity

The four calcium-binding sites, called the helix-loop-helix, or the EF-hand motifs, of calmodulin differ in their ion-binding affinities; this has been thought to arise due to the variations in the sequences of the loop regions where the ion binds. We focus attention here on the role of the flanking helical regions on the calcium-binding affinities. Peptides were synthesized in a manner that simulates the E and F helical flanks of site 4 (the strongest calcium-binding site of the calmodulin) to sandwich the loop sequences of sites 1, 2, 3 and 4 so as to produce peptides named 414, 424, 434 and 444, as well as using the helical flanks of site 1 (the weakest site) to produce peptides 111, 121, 131 and 141. Calcium binding was monitored using the calcium-mimic dye Stains-all (4,4,4',5'-dibenzo-3,3'-diethyl-9-methyl-thiacarbocyanine bromide). Binding abilities were seen to increase several-fold when the E and F helices of site 1 were replaced by those of site 4 (i.e., 111-414). In contrast, the intensity of circular dichroism induced in the absorption bands of the bound achiral dye decreased significantly when the helical flanks of site 4 were replaced with those of site 1 (i.e., 444-141). The helical flanks of site 4 impart greater binding ability to a given loop region, while the helical flanks of site 1 tend to weaken it.

A conformational study of corneal dermatan sulfate proteoglycan using fluorescence spectroscopy

DSPG is a major proteoglycan of the corneal stroma and is thought to be important for the transparency of the tissue. We have studied its conformation by exploring the microenvironment and dynamics of its lone Tryptophan (Trp) residue using steady state and time resolved fluorescence spectroscopy. DSPG exhibits a doublet Trp fluorescence emission. Such a doublet emission has been observed earlier in the copper protein azurin and in avian lens delta-crystallin. Unlike the above cases where the doublet emission is thought to arise due to vibronic structure or the location of Trp at the interface of interacting subunits, fluorescence quenching, denaturation studies and ANS binding with DSPG indicate the location of Trp at two different environments. Such a situation could arise from the differential glycosylation of the core protein or due to duplexation and aggregation of the glycosaminoglycan chains.

Effect of UVB radiation on corneal aldehyde dehydrogenase

PURPOSE

A Class 3 aldehyde dehydrogenase happens to be a major soluble protein constituent of the cornea. Its role is conjectured to be manifold: to protect the tissue from oxidative damage by eliminating the toxic aldehydes produced upon lipid peroxidation under oxidative stress, to act as an UV-absorber, and to maintain the level of the coenzyme NADH in the cornea. We have studied the effect of UVB on the structure and enzyme activity of corneal aldehyde dehydrogenase.

METHODS

Aldehyde dehydrogenase was irradiated at 295 nm for varying periods of time and change in its enzyme activity assayed. The structural changes in the molecule accompanying irradiation were monitored using fluorescence and circular dichroism spectroscopy, and its hydrodynamic behavior and surface hydrophobicity studied using gel filtration chromatography and binding of the hydrophobic fluorophore ANS. The protective ability of aldehyde dehydrogenase in preventing aggregation of photolabile proteins, such as Gamma-crystallin of the eye lens, was studied by monitoring the scattering value of the test protein with irradiation by UVB.

RESULTS

Aldehyde dehydrogenase is seen to undergo photodamage with alterations in its quaternary structure, though no significant change is noticed in the peptide chain conformation. Under such conditions the molecule continues to act as a protectant by preventing aggregation of photolabile proteins such as the eye lens Gamma-crystallin.

CONCLUSIONS

Our earlier studies have shown that the free sulfhydryl groups are important for the antioxidant abilities of aldehyde dehydrogenase. Its protective ability towards photoaggregation of Gamma-crystallin seen here might arise both due to: (i) oxyradical quenching and (ii) the increased surface hydrophobicity of the molecule upon irradiation, which allows it to bind to, and thus inhibit the aggregation of interacting proteins.

Conformation, stability and interactions of corneal keratan sulfate proteoglycan

We have monitored the molecular conformation, stability, interaction and dynamics of keratan sulfate proteoglycan, the major structural protein component of the cornea, in solution, by studying the fluorescence spectral features of its tryptophan residues as component-specific intrinsic spectral probes (collagen, the other structural component of the cornea, has no tryptophans). Our study suggests that the Trp region of the molecule is in a motionally restricted environment as it exhibits a fluorescence red-edge effect and shows dipole relaxation. The extrinsic spectral probe 8-anilinonaphthalene 1-sulfonate reveals keratan sulfate proteoglycan to possess significant surface hydrophobicity. This dual character of keratan sulfate proteoglycan allows us to label it as an 'ambidextran' proteoglycan. The molecule is stable between pH 5-8 and has a Tm value of 72 degrees C. Disulfide bonds play a role in the stability of the molecule. KSPG is seen to interact with collagen and the model compound, poly(L-proline). Interaction of the proteoglycan with unilamellar vesicles appears to be more interfacial than penetrative. This dual interaction displayed by KSPG with collagen and with lipid assemblages suggests that it plays the role of a 'filler' in the extracellular matrix of the cornea.