Does platelet-rich fibrin have a role in osseointegration of immediate implants? A randomized, single-blind, controlled clinical trial.

Immediate implants are a valuable treatment option to replace natural teeth in the aesthetic region. The hypothesis of this randomized controlled clinical trial was that immediate implants grafted with autologous platelet-rich fibrin (PRF) have better clinical and radiographic outcomes than non-grafted controls. Forty-one implants were placed in 31 subjects with one or more non-restorable single-rooted teeth. Autologous PRF was placed in the peri-implant region of the study group (n=21) and no augmentation was done in the control group (n=20). A staged protocol was followed for implant restoration. The patients received a definitive restoration after 3 months and were followed up for a period of 1year. The statistical analysis included 39 implants sites in 29 subjects. A significant increase in implant stability was noted in both groups over the 3-month period (implant stability quotient: study group 56.58±18.81 to 71.32±7.82; control group 60.61±11.49 to 70.06±8.96; P=0.01). No significant difference was observed between the groups in terms of implant stability. The hypothesis was thus rejected, as there was no significant effect of PRF on immediate implants with adequate primary stability.

Graphene as a transparent conducting and surface field layer in planar Si solar cells.

This work presents an experimental and finite difference time domain (FDTD) simulation-based study on the application of graphene as a transparent conducting layer on a planar and untextured crystalline p-n silicon solar cell. A high-quality monolayer graphene with 97% transparency and 350 Ω/□ sheet resistance grown by atmospheric pressure chemical vapor deposition method was transferred onto planar Si cells. An increase in efficiency from 5.38% to 7.85% was observed upon deposition of graphene onto Si cells, which further increases to 8.94% upon SiO2 deposition onto the graphene/Si structure. A large increase in photon conversion efficiency as a result of graphene deposition shows that the electronic interaction and the presence of an electric field at the graphene/Si interface together play an important role in this improvement and additionally lead to a reduction in series resistance due to the conducting nature of graphene.

Cefotaxime-heparin lock prophylaxis against hemodialysis catheter-related sepsis among Staphylococcus aureus nasal carriers.

Staphylococcus aureus nasal carriers undergoing hemodialysis (HD) through tunneled cuffed catheters (TCCs) form a high-risk group for the development of catheter-related bloodstream infections (CRBSI) and ensuing morbidity. The efficacy of antibiotic-locks on the outcomes of TCCs among S. aureus nasal carriers has not been studied earlier. Persistent nasal carriage was defined by two or more positive cultures for methicillin-susceptible (MSSA) or methicillin-resistant (MRSA) S. aureus of five standardized nasal swabs taken from all the participants dialyzed at a large out-patient HD center affiliated to a tertiary care hospital. Of 218 participants, 82 S. aureus nasal carriers dialyzed through TCCs (n = 88) were identified through April 2005 to March 2006 and randomized to two groups. Group I comprised of 39 nasal carriers who had TCCs (n = 41) "locked" with cefotaxime/heparin while group II included 43 patients with TCCs (n = 47) filled with standard heparin. The CRBSI incidence and TCC survival at 365 days were statistically compared between the two groups. A significantly lower CRBSI incidence (1.47 vs. 3.44/1000 catheter-days, P <0.001) and higher infection-free TCC survival rates at 365 days (80.5 vs. 40.4%, P <0.0001) were observed in the cefotaxime group compared with the standard heparin group. However, no significant difference in MRSA-associated CRBSI incidence was observed between the two groups. Cefotaxime-heparin "locks" effectively reduced CRBSI-incidence associated with gram-positive cocci, including MSSA, among S. aureus nasal carriers. There remains a compelling requirement for antibiotic-locks effective against MRSA.

Effects of plane of nutrition on slaughtering traits and meat characteristics in Murrah graded male buffalo (Bubalus bubalis) calves in Nepal.

An experiment was conducted using 17 male buffalo calves to assess the effects of plane of nutrition on slaughtering traits and meat characteristics. To attain 250 kg body weight (BW), the calves were allocated into three groups: high (H), low-high (L-H) and low (L) corresponding to concentrate levels receiving the concentrate at 1.50% of BW, 0.75% of BW until 190 kg BW and 1.50% thereafter, and 0.75% of BW, respectively. The animals had ad libitum access to urea-treated rice straw. No significant differences of hot carcass weight, dressing percentage and lean fat-bone yields were observed among the treatment groups. The L group had heavier brisket weight and lower percentage of round weight in the hot carcass than the H and L-H groups (P<0.05). The H group had heavier hearts than the L group, and the H and L-H groups had heavier livers and kidneys than the L group (P<0.05). There was no significant difference of rib eye area, pH and the contents of moisture, crude protein and fat in loin meat among the groups. The findings indicated that the effects of plane of nutrition affected the weight or percentages of some cut yields in the hot carcasses and internal organs.

Effects of plane of nutrition on growth, feed intake, digestibility and nitrogen balance in Murrah graded male buffalo (Bubalus bubalis) calves in Nepal.

An experiment was conducted using 17 male buffalo calves to assess the effects of plane of nutrition on dry matter intake (DMI), daily gain (DG), body size measurement, apparent digestibility and nitrogen (N) balance. To attain 250kg BW, the calves were allocated into three groups: H, L-H and L, receiving the concentrate at 1.50% of BW, 0.75% of BW until 190kg BW and 1.50% thereafter and 0.75% of BW, respectively. The animals had ad libitum access to urea-treated rice straw (UTRS). The DMI of UTRS through the experiment was higher in L and L-H than H, showing 3.52, 2.90 and 2.62kg/day, respectively (P<0.01), but the total DMI did not differ among the treatment groups. The DG throughout the experiment was high in the order of H, L-H and L, showing 0.72, 0.57 and 0.45kg, respectively (P<0.01). The digestibility of DM, organic matter, crude protein, neutral and acid detergent fiber and N retention were higher in H than in L (P<0.05). The findings of this study thus revealed the greater DG has an advantage of shortening the growing period around 3months, and consequently increasing benefit in fattening of buffalo calves in Nepal.

Enhancing the survival of tunneled haemodialysis catheters using an antibiotic lock in the elderly: a randomised, double-blind clinical trial.

BACKGROUND: Tunneled-cuffed catheters (TCC) are often used among the elderly to commence and carry out haemodialysis (HD). Complications like infection and thrombosis frequently reduce the lifespan of TCC. The role of an antibiotic heparin 'lock' in the prevention of thrombotic and infectious complications and enhancement of TCC survival in the elderly has not been investigated previously. METHODS: In this prospective, double-blind clinical trial, TCC (n = 119, placed among 113 elderly patients requiring HD during March 2002 - February 2003) were randomised to either group I having TCC (n = 59, placed in 58 elderly patients) locked with cefotaxime (10 mg/mL) and heparin (5000 U/mL), or group II with TCC (n = 60, placed in 55 elderly patients) having catheter-restricted filling of heparin (5000 U/mL) alone. Symptomatic catheter-related blood stream infections (CRBSI) and catheter thrombosis were the primary end points in this study. Thrombosis was defined as an inability to use the catheter at a blood flow of 200 mL/min that did not respond to catheter repositioning and/or intraluminal thrombolysis. The incidence of catheter thrombosis, CRBSI and percentage of catheter survival were estimated and statistically compared between the two groups. RESULTS: Kaplan-Meier survival analysis using log rank test showed higher thrombosis-free TCC survival (84.7%vs 63.3%, P = 0.021), infection-free survival (68.7%vs 31.3%, P < 0.001) and infection and thrombosis-free survival (65.0%vs 35.0%, P = 0.006) at 365 days in group I compared with group II. CONCLUSION: Cefotaxime and heparin locks safely and effectively enhance the lifespan of TCC by lowering the incidence of thrombotic and infectious complications among elderly end-stage renal failure (ESRD) patients.

The impact of catheter-restricted filling with cefotaxime and heparin on the lifespan of temporary hemodialysis catheters: a case controlled study.

BACKGROUND: Reduction in the rates of major complications such as infection and thrombosis that limit the lifespan of hemodialysis (HD) catheters could conceivably lead to improved survival of "temporary" non-tunneled HD catheters (NTCs). This study was designed to evaluate the impact of the "locking"' of a broad-spectrum antibiotic-cefotaxime with heparin, on the incidence of catheter thrombosis, catheter-related bloodstream infections (CRBSI) and the NTC lifespan. METHODS: This prospective study included 208 (109 males and 99 females) end-stage renal disease (ESRD) patients of diverse etiology enrolled for long-term HD from July 2002 to June 2003 at our tertiary care hospital. Those patients requiring NTC insertion for the maintenance or commencement of HD were eligible for the study. Cefotaxime-heparin "lock" solutions were freshly prepared by dissolving sterile cefotaxime sodium powder for injection directly in the heparin sodium to reach a concentration of 10 mg/mL for cefotaxime and 5000 U/mL for heparin. A final volume of 5 mL was prepared in a syringe using aseptic precautions to fill 1.3 mL in the venous and 1.2 mL in the arterial lumen of the catheter with a combined volume of approximately 2.5 mL. Blood samples were collected for culture and sensitivity, simultaneously, from the catheter hub and the peripheral vein, on clinical suspicion of CRBSI. Thrombosis was defined as the inability to use the catheter at a blood flow of 200 ml/min, which did not respond to catheter repositioning and/or intraluminal thrombolysis. RESULTS: An overall relative risk reduction (RRR) of 56.5% for catheter thrombosis and separately for all types of NTCs (femoral (FC) - 52.7%, subclavian (SC) - 55.9%, and internal jugular (IJC) - 53.7%), were observed in group II having a cefotaxime-heparin lock solution. A lower CRBSI incidence (1.65 vs. 3.13/1000 catheter days) compared with group I, leading to a RRR of 50.5% was also recorded in group II. Significantly higher percentage catheter survival rates at 7, 14 and at 28 days for FC and at 14, 28 and 56 days for SC and IJC were observed among patients in group II in comparison to group I. CONCLUSIONS: Cefotaxime-heparin locks led to a significant reduction in catheter thrombosis and CRBSI incidence. The enhanced NTC lifespan thus achieved could help physicians in better assessment of the patient's vasculature prior to the placement of permanent vascular access.

Prevalence of methicillin-resistant and methicillin-sensitive Staphylococcus aureus nasal colonization among patients at the time of admission to the hospital.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is an important agent of hospital-acquired infection. The mode of entry of MRSA in the hospital might be on admission of patients with MRSA infection or nasal colonization. The present study was undertaken to determine the prevalence of MRSA nasal colonization among patients on admission to hospital. METHODS: Six hundred patients were screened for nasal colonization of MRSA on admission to hospital. Nasal swabs were cultured on salt mannitol agar and blood agar. Age, sex, previous admission to hospital and antibiotic therapy were recorded. RESULTS: S. aureus was isolated from the nasal swabs of 122 patients (20.2%) on admission to hospital. MRSA was isolated from 7 patients (1.1%) and methicillin-sensitive S. aureus (MSSA) from 115 patients (19.1%). Nasal colonization of S. aureus was higher in younger and elderly patients and significantly higher colonization was observed among females. The MRSA strains isolated from nasal swabs had a different antibiotic susceptibility pattern than those isolated from patients having hospital-acquired MRSA infection. Previous admissions to hospital, underlying disease antibiotic therapy were not risk factors for MRSA nasal colonization. CONCLUSION: MRSA nasal colonization of patients on admission to hospital is low in this region. The screening of every new admission would not be cost effective, but patients transferred form other institutions should be screened for MRSA. Standard infection control precautions should be strictly implemented to prevent the spread and control of MRSA infections.

Contamination of patients' files in intensive care units: an indication of strict handwashing after entering case notes.

BACKGROUND: The extent to which bedside patients' files become contaminated and the range of bacterial flora attributable to contamination in high-risk areas of the hospital are not known with certainty. The aim of the present study was to determine the degree of contamination of the patient's files and also to analyze and compare the spectrum of contaminant bacterial flora between the intensive care unit (ICU) and surgical wards, the 2 most high-risk areas for nosocomial transmission of infection. METHODS: Microbiologic samples were collected from the exposed outer surface of the patients' files kept bedside in the ICU and surgical wards with sterile swabs moistened with sterile normal saline. Swabs were cultured within an hour of collection on blood agar and MacConkey's agar plates, which were incubated at 37 degrees C for 48 hours. Gram-negative bacilli were identified by Gram's stain, catalase, oxidase tests, and API 20E and API 20NE. Staphylococcus species were identified by Gram's stain, catalase test, and tube coagulase test. Antibiotic susceptibility of the isolated bacteria was determined by the disk diffusion technique according to the criteria of National Committee for Clinical Laboratory Standards (NCCLS). RESULTS: In ICU, 85.2% (87/102) and, in surgical wards, 24.7% (22/89) of patient's files were found to be contaminated with pathogenic and potentially pathogenic bacteria (OR, 17.664; 95% CI: 8.050-39.423; P < .0001). Pseudomonas aeruginosa was the most commonly isolated bacteria (32.3%, 33/102) in ICUs, whereas Staphylococcus aureus was the peak contaminant (11.2%, 10/89) of the files in surgical wards. Methicillin-resistant Staphylococcus aureus (MRSA) was isolated from 6.8% (7/102) of ICU patient's files, whereas only 1.1% (1/89) of patient's files in surgical wards were contaminated with MRSA (OR, 6.484; 95% CI: 3.215-13.463; P < .0001). The multidrug-resistant P aeruginosa, Acinetobacter baumannii, Klebsiella pneumoniae, and Serretia marcesens isolated from the patient's files had the same antibiotic resistance pattern as of these bacteria isolated from the patients. CONCLUSION: The majority of the patient's files in ICUs were contaminated often with multidrug-resistant bacteria and even MRSA. Contaminated files could be a source of transmission of infection. To prevent this, handwashing practice should be strictly followed after attending the patient and before entering the case notes in the patient's file. The maintenance of good hand hygiene by the health care workers (HCWs) after handling contaminated files should perhaps be the most prudent approach to prevent patient-patient transmission of infection in high-risk areas including ICU and surgical wards.

Prevention of catheter-related bloodstream infections: an appraisal of developments in designing an infection-resistant 'dream dialysis-catheter'.

With the increasing number of elderly, diabetics and debilitated patients being accepted for haemodialysis (HD), the use of central venous catheters (CVCs) as vascular access has become more widespread, with an inevitable inherent risk of catheter-related bloodstream infections (CRBSI) and ensuing mortality. No reliable plans for the effective management of CRBSI without actually sacrificing vascular access sites are presently available. Therefore, the onus really falls on renal physicians to make effective use of the established supportive guiding principles, practices, policies and programs to prevent CRBSI among HD patients. A huge body of research in polymer industry has aimed at alterations of physical, chemical, biological and immunological properties of CVCs to prevent the bacterial colonization of catheters. Developing an infection-resistant dialysis catheter has been an elusive dream. This article analyses the current state-of-the-art strategies aimed at preventing CRBSI and also reviews the progress made to date, in the direction of development of a 'bioactive' thrombosis and infection-resistant dialysis catheter.

Haemodialysis catheter-related bloodstream infections: current treatment options and strategies for prevention.

Regardless of the repeated reservations raised by countless researchers with reference to the use of catheters as vascular access for haemodialysis (HD), central venous catheters (CVCs) remain irreplaceable tools of the modern dialysis delivery system as a reliable option for the clinical situations requiring instant access to circulation, for various reasons. Patients on long-term haemodialysis are therefore at a significantly high risk for catheterrelated bloodstream infections (CRBSI) and ensuing serious complications. Although early systemic antibiotic treatment should include the coverage for Staphylococcus aureus, the pathogen with most devastating consequences including bacterial endocarditis; optimal treatment of CRBSI while preserving the catheter site, remains contentious. Nonetheless, catheter exchange over a guide wire and antimicrobial-anticoagulant "locks" have shown promising results as novel access salvage techniques. Despite the fact that a number of novel potentially useful strategies for the prevention of CRBSI are in the pipeline; equally essential however, remains the role of rigorous implementation of standard infection control measures for hygiene and aseptic handling of CVCs in long-term HD patients. The policy of increasing the AVF (arteriovenous fistula) prevalence beyond 50% while minimising the use of CVCs, dependent largely upon the timely referrals and prudently implemented pre-ESRD program - ought to have a positive impact on long-term HD outcomes.

Epidemiology of antibody to hepatitis B core antigen screening among blood donors in Eastern Saudi Arabia. Need to replace the test by HBV DNA testing.

OBJECTIVE: Prevention of the residual risk of transfusion transmitted hepatitis B virus (HBV) infection is mostly relied on serological screening of blood donors for antibody to hepatitis B core antigen (HBc), to detect donors in window period of HBV infection. This study was carried out to determine the prevalence of anti-HBc antibody among blood donors and its impact on rejection of collected blood units. METHODS: Blood bank records of all the blood donors who donated blood at blood bank of King Fahad Hospital, Al-Hofuf, Kingdom of Saudi Arabia, during the period of 2000 to 2003 were reviewed. All the collected blood units were screened for hepatitis B surface antigen (HBsAg), anti-HBc, hepatitis C virus (HCV), human immunodeficiency virus (HIV) 1 and 2, HIV p24, human T-cell lymphotropic virus (HTLV) I/II, venereal disease research laboratory (VDRL) and malaria. All the HBsAg negative with anti-HBc positive units were checked for anti-HBsAg antibodies. RESULTS: Of 26,606 blood donors screened, 514 (1.9%) were HBsAg positive, 853 (3.2%) were isolated anti-HBc positive and 2687 (10.1%) were both anti-HBc and anti-HBsAg positive. The blood units, which were anti-HBc and anti-HBsAg positive, were utilized and the isolated anti-HBc positive blood units were rejected. There was a significant (odds ratio of 1.653, 95% confidence interval 1.298-2.105, p<0.0001) decline in anti-HBc positivity during the study period. CONCLUSION: Isolated anti-HBc positivity as a marker for window period of HBV infection leads to high rejection rate of collected blood units without completely covering the residual risk of HBV transmission by transfusion. Policy for checking the collected blood unit by 3 tests for anti-HBc, anti-HBsAg and HBsAg should be reconsidered in favor of HBV-DNA testing by polymerase chain reaction, to possibly achieve the zero risk goal of transfusion transmitted HBV infection.

Subcutaneous dirofilariasis caused by Dirofilaria repens.

Human dirofilariasis caused by Dirofilaria repens D. repens is a common zoonosis in the Mediterranean countries and parts of South Asia. During the last decade, it has been reported from countries previously considered non-endemic. This is likely due to the increased awareness regarding Dirofilaria infection. In some such cases however, dirofilariasis correlated with the travel of the patient to the endemic areas. We present the case of a Saudi male who had D. repens infection in the subcutaneous tissues of the forearm. The patient had traveled to Iraq, Syria, United Arab Emirates and Kuwait in the last 2 years. However, the known Dirofilaria endemic countries were not visited. Any prior occurrence of the human dirofilariasis in the Kingdom of Saudi Arabia is not documented. Lack of epidemiological studies or incidence reports in the Arabian region precludes any factual evaluation of Dirofilaria prevalence, which requires increased awareness amongst health workers regarding its potential occurrence in the native population.

Prevalence of human T-lymphotropic virus type I and type II antibody among blood donors in Eastern Saudi Arabia.

OBJECTIVE: Human T-cell leukemia/lymphoma virus type I and type II (HTLV-I/II) infections can be transfusion associated, leading to tropical paraparesis, myelopathy and other neurological disorders. The aim of this study is to circumvent the risk of transmission through blood transfusion and to describe the prevalence of HTLV-I/II antibody among blood donors of Al-Hasa region and the cost effectiveness of screening blood donors. METHODS: The study was conducted at the Department of Laboratory and Blood Bank, King Fahad Hospital, Al-Hofuf, Al-Hasa, Kingdom of Saudi Arabia during the period of 1997 to 2003. A total of 47426 blood donors were screened for HTLV-I/II antibody by enzyme-linked immunosorbent assay test, during the 7 years of study period. The positive samples were confirmed by western blot analysis. RESULTS: Overall, HTLV-I antibody positivity (confirmed by western blot) was 3/47426 (0.006%). Out of 3 donors positive for HTLV-I antibody during 1997 to 1998, 2 were expatriates (Indian) and one was native Saudi donor. Human T-cell leukemia/lymphoma virus type I antibody positivity among the native Saudi donors was 1/47426 (0.002%) (2/100000 blood donors). None of the donor were positive for HTLV-II antibody. During the last 5 consecutive years of the study period (1999-2003), none of the donor was positive for HTLV-I/II antibody. CONCLUSION: Al-Hasa region is non-endemic for HTLV-I/II virus infections. Screening of native Saudi blood donors for these viruses does not appear to be cost effective.

The vulnerability of middle-aged and elderly patients to hepatitis C virus infection in a high-prevalence hospital-based hemodialysis setting.

OBJECTIVES: To determine the relationship between advancing age and the risk of acquiring hepatitis C virus (HCV) infection, through evaluation and statistical comparison of seroprevalence and seroconversion rates in different age groups of patients on long-term hemodialysis (HD). DESIGN: Retrospective cohort study. SETTING: Hemodialysis facility of King Fahad Hospital and Tertiary Care Center, Al-Hasa region of the eastern province of Saudi Arabia. PARTICIPANTS: One hundred ninety-eight patients with end-stage renal disease enrolled for long-term HD therapy from September 1995 to September 2000. MEASUREMENTS: HCV seroprevalence and seroconversion rates. RESULTS: The overall HCV seroprevalence of 43.4% (86/198) and seroconversion rate of 8.6% per year were recorded. Patients aged 55 to 64 had the highest anti-HCV prevalence (55.3% (26/47)) and annual seroconversion rates (11.0%). Those aged 65 to 74 had the next-highest prevalence (48.9% (24/49)) and seroconversion rate (9.7%), and patients aged 15 to 24 had the lowest prevalence (12.5% (1/8)) and seroconversion rate (2.5%) (reference group). CONCLUSION: Significantly higher annual seroconversion rates in those aged 55 to 64 and 65 to 74 during a shorter dialysis period (35.6 and 32.7 vs 58.0 months), suggest the greater susceptibility of the middle-aged and elderly patients to acquisition of HCV infection than the younger (15-24 years) group. This could be attributed to the combined effect of immunosuppression associated with advancing age, uremia, and undernutrition, but multicenter molecular follow-up studies with larger sample sizes would be needed to corroborate these findings and plan appropriate strategies for these high-risk groups.