Examining the impact of a 9-component bundle and the INICC multidimensional approach on catheter-associated urinary tract infection rates in 32 countries across Asia, Eastern Europe, Latin America, and the Middle East

BACKGROUND

Catheter-Associated Urinary Tract Infections (CAUTIs) frequently occur in the intensive care unit (ICU) and are correlated with a significant burden.

METHODS

We implemented a strategy involving a 9-element bundle, education, surveillance of CAUTI rates and clinical outcomes, monitoring compliance with bundle components, feedback of CAUTI rates and performance feedback. This was executed in 299 ICUs across 32 low- and middle-income countries. The dependent variable was CAUTI per 1,000 UC days, assessed at baseline and throughout the intervention, in the second month, third month, 4 to 15 months, 16 to 27 months, and 28 to 39 months. Comparisons were made using a 2-sample t test, and the exposure-outcome relationship was explored using a generalized linear mixed model with a Poisson distribution.

RESULTS

Over the course of 978,364 patient days, 150,258 patients utilized 652,053 UC-days. The rates of CAUTI per 1,000 UC days were measured. The rates decreased from 14.89 during the baseline period to 5.51 in the second month (risk ratio [RR] = 0.37; 95% confidence interval [CI] = 0.34-0.39; P < .001), 3.79 in the third month (RR = 0.25; 95% CI = 0.23-0.28; P < .001), 2.98 in the 4 to 15 months (RR = 0.21; 95% CI = 0.18-0.22; P < .001), 1.86 in the 16 to 27 months (RR = 0.12; 95% CI = 0.11-0.14; P < .001), and 1.71 in the 28 to 39 months (RR = 0.11; 95% CI = 0.09-0.13; P < .001).

CONCLUSIONS

Our intervention, without substantial costs or additional staffing, achieved an 89% reduction in CAUTI incidence in ICUs across 32 countries, demonstrating feasibility in ICUs of low- and middle-income countries.

Validation study of AR Gynae endotrainer - a new mobile laparoscopic simulator

INTRODUCTION

In gynaecology, laparoscopy is the choice of treatment for a lot of procedures as it is considered safe and effective. However, laparoscopic surgery requires skills that are different from those required for open surgery. In order to acquire the skills, a surgeon needs specific training. The aim of this study was to validate the AR Gynae endotrainer, a new mobile laparoscopic simulator, as a comparable box trainer for gynaecology laparoscopic training, comparing it with the well-established Karl Storz SZABO-BERCISACKIER laparoscopic trainer.

MATERIALS AND METHODS

A randomised prospective crossover study was designed to compare the AR Gynae endotrainer versus Karl Storz SZABO-BERCI-SACKIER laparoscopic trainer as a tool for training gynaecology laparoscopic skills. Participants were assigned to perform two specially designed tasks used for laparoscopic training using both endotrainers. All subjects evaluated both simulators concerning their performance by the use of a questionnaire comparing: design, ports placement, visibility, ergonomics, triangulation of movement, fulcrum effect, depth perception, ambidexterity, resources for training, and resources for teaching. The overall score was defined as the median value obtained. The ability and time taken for participants to complete the tasks using both endotrainers were also compared. A total of 26 participants were enrolled in this study, including 13 Masters's students from the Department of Obstetrics & Gynaecology and 13 Masters's students from the Department of Surgery, Hospital Universiti Sains Malaysia (HUSM), Kelantan, Malaysia.

RESULTS

A better performance was observed with AR Gynae as compared to Karl Storz endotrainer in five out of ten items evaluated in the questionnaire. Additionally, the overall score of AR Gynae endotrainer (median of 3.98) was comparable to that of Karl Storz endotrainer (median of 3.91) with p=0.519. For the items design and resources for teaching, the evaluation for AR Gynae endotrainer was significantly higher with p-values of 0.003 and 0.032, respectively. All participants were able to complete both tasks using both endotrainers. The time taken to complete both tasks was comparable on both endotrainers. Also, the AR Gynae endotrainer was cheaper.

CONCLUSIONS

The AR Gynae endotrainer was found to be a convenient and cost-effective laparoscopic simulator for gynaecology laparoscopic training and was comparable to the established Karl Storz SZABO-BERCI-SACKIER laparoscopic trainer.

Effect of Saccharomyces cerevisiae Fortified with Selenium on the Hematological and Some Biochemical Traits of Local Iraqi Goat

Selenium (Se) is a mineral that is often used as a dietary supplement. Its deficiency has been associated with fertility disorders, as well as imbalances and inhibition of the immune system. This study aimed to estimate the role of organic selenium and Saccharomyces cerevisiae in improving kids' status, health, and physiological conditions. In total, 10 goat kids at seven days were used, with an average started life body weight (b.wt.) of 4±0.2 kg, and they were divided into two groups. Group 1 (G1) was treated with Se-fortified yeast (Saccharomyces cerevisiae+Se) with a dose (30 mg/kg) of body weight. On the other hand, group 2 (G2) was the control group and left untreated. The treatment was started from 7 days of age until three months of age. The kids were administered orally daily for three months of the experiment. The jugular vein was used to draw blood samples within 90 days of the experiment to measure RBC, Hb, PCV, and WBC. Blood serum was separated using a centrifuge to estimate ALT, AST, total protein, Albumin, and Globulin concentrations. The results revealed that Hb, PCV, and Globulin were increased significantly in the G1 (P≤0.05), compared to the control group. Moreover, AST was improved, compared to the control group. These results showed that using yeast fortified with organic Se has improved hematological and biochemical parameters' concentration.

Association Between Serum Bicarbonate Levels and Prediabetes and Subclinical Inflammation in Young Healthy Adults: A Cross-sectional Study

PURPOSE

Low bicarbonate, a hallmark of metabolic acidosis is associated with various diseases. This study investigated associations between bicarbonate levels with prediabetes and subclinical inflammation among healthy young adults in Qatar.

PATIENTS AND METHODS

A cross-sectional study was carried out with 825 participants aged 18-40 years, devoid of any known comorbidities, using data from the Qatar Biobank. For each participant, blood samples were taken for measurements of bicarbonate, prediabetes, and subclinical inflammation biomarkers. Prediabetes was defined using HbA1c between 5.7 and 6.4% and subclinical inflammation was defined using monocyte to high density lipoprotein (HDL) cholesterol ratio (MHR). Associations between bicarbonate levels and the outcomes were analyzed using multivariable linear and logistic regression and then stratified by gender.

RESULTS

A total of 825 participants with mean age 29.2 years (5.9) of which 365 (44.2%) were males. After multivariable logistic regression, each unit increase in serum bicarbonate was associated with a 17% decreased risk of prediabetes (OR: 0.83, 95%CI: 0.70-0.99, p=0.034), in males but no association was observed for females. Similarly, after multivariable linear regression, a unit increase in serum bicarbonate was associated with a 0.18 unit decrease in MHR (beta -0.18, 95%CI: -0.29, -0.07, p=0.002), again with no association observed in females.

CONCLUSION

In a healthy young adult population, higher serum bicarbonate levels were inversely associated with both prediabetes and subclinical inflammation in males, but not in females.

International Nosocomial Infection Control Consortium report, data summary of 50 countries for 2010-2015: Device-associated module

BACKGROUND

We report the results of International Nosocomial Infection Control Consortium (INICC) surveillance study from January 2010-December 2015 in 703 intensive care units (ICUs) in Latin America, Europe, Eastern Mediterranean, Southeast Asia, and Western Pacific.

METHODS

During the 6-year study period, using Centers for Disease Control and Prevention National Healthcare Safety Network (CDC-NHSN) definitions for device-associated health care-associated infection (DA-HAI), we collected prospective data from 861,284 patients hospitalized in INICC hospital ICUs for an aggregate of 3,506,562 days.

RESULTS

Although device use in INICC ICUs was similar to that reported from CDC-NHSN ICUs, DA-HAI rates were higher in the INICC ICUs: in the INICC medical-surgical ICUs, the pooled rate of central line-associated bloodstream infection, 4.1 per 1,000 central line-days, was nearly 5-fold higher than the 0.8 per 1,000 central line-days reported from comparable US ICUs, the overall rate of ventilator-associated pneumonia was also higher, 13.1 versus 0.9 per 1,000 ventilator-days, as was the rate of catheter-associated urinary tract infection, 5.07 versus 1.7 per 1,000 catheter-days. From blood cultures samples, frequencies of resistance of Pseudomonas isolates to amikacin (29.87% vs 10%) and to imipenem (44.3% vs 26.1%), and of Klebsiella pneumoniae isolates to ceftazidime (73.2% vs 28.8%) and to imipenem (43.27% vs 12.8%) were also higher in the INICC ICUs compared with CDC-NHSN ICUs.

CONCLUSIONS

Although DA-HAIs in INICC ICU patients continue to be higher than the rates reported in CDC-NSHN ICUs representing the developed world, we have observed a significant trend toward the reduction of DA-HAI rates in INICC ICUs as shown in each international report. It is INICC's main goal to continue facilitating education, training, and basic and cost-effective tools and resources, such as standardized forms and an online platform, to tackle this problem effectively and systematically.

Occupational injuries prone to infectious risks amongst healthcare personnel in Kuwait: a retrospective study

OBJECTIVE

The study aimed at determining the prevalence of incident occupational exposure to blood and other potentially infectious materials (OPIM) among healthcare personnel (HCP) during 2010 and at evaluating the factors associated with these incidents.

SUBJECTS AND METHODS

An epidemiological, retrospective, record-based study was conducted. All self-reported incidents of occupational exposure to blood and OPIM among HCP from all healthcare settings of the Kuwait Ministry of Health during 2010 were included.

RESULTS

The total number of the exposed HCP was 249. The prevalence of incident exposure was 0.7% of the HCP at risk. Their mean age was 32.31 ± 6.98 years. The majority were nurses: 166 (66.7%), followed by doctors: 35 (14.1%), technicians: 26 (10.4%) and housekeeping personnel: 22 (8.8%). Needle stick injury was the most common type of exposure, in 189 (75.9%), followed by sharp-object injury, mucous-membrane exposure and contact with nonintact skin. The majority of needle stick exposures, i.e. 177 (93.7%), were caused by hollow-bore needles. Exposure to blood represented 96.8%, mostly during drawing blood and the insertion or removal of needles from patients [88 (35.4%)] and when performing surgical interventions [56 (22.6%)]. Easily preventable exposures such as injuries related to 2-handed recapping of needles [24 (9.6%)] and garbage collection [21 (8.4%)] were reported. Exposures mainly occurred in the inpatient wards [75 (30.1%)] and operating theaters [56 (22.6%)]. Among the exposed HCP, 130 (52.2%) had been fully vaccinated against hepatitis B virus (HBV).

CONCLUSION

Needle stick injuries are the most common exposure among HCP in Kuwait, and nurses are the most frequently involved HCP category. A good proportion of exposures could be easily prevented. HBV vaccination coverage is incomplete.

Surgical site infection complicating breast cancer surgery in kuwait

Background and Objectives. Surgical site infection (SSI) is the most common postoperative complication associated with breast cancer surgery. The present investigation aimed to determine the SSI rate after breast cancer surgeries and the causative microorganisms. Patients and Methods. All patients who underwent breast surgery in Kuwait Cancer Control Center as a treatment for breast cancer from January 2009-December 2010 were prospectively followed for the development of SSI. Indirect detection was used to identify SSIs through medical record to review and discussion with the treating surgeons. Results. The number of operations was 438. Females represented 434 (99.1%) cases while males constituted only 4 (0.9%) cases. SSIs were diagnosed after 10 operations, all for female cases. Most of the SSIs (8 cases; 80%) were detected after patients were discharged, during outpatient followup. Out of those 5/8; (62.5%) were readmitted for management of SSI. Nine patients (90%) received systemic antibiotic therapy for management of their wound infection. The SSI rate was 2.3%. The main causative organism was Staphylococcus aureus (S. aureus) which was responsible for 40% of infections. Gram negative bacteria were isolated from 40% of the cases. Conclusion. SSI is an important complication following breast cancer surgery. Microbiological diagnosis is an essential tool for proper management of such patients.

Audit of physicians' adherence to the antibiotic policy guidelines in Kuwait

OBJECTIVE

To audit physicians' adherence to the local antibiotic policy guidelines in government hospitals in Kuwait.

MATERIALS AND METHODS

The study was a retrospective review of patient records in nine hospitals between July 1 and December 31, 2008. Clinical notes and medication charts of the latest hospital admissions were checked for antibiotic prescribing. On the audit form, aspects of the prescribed antibiotic were benchmarked to the hospital antibiotic policy guidelines to evaluate adherence.

RESULTS

Of 2,232 reviewed records, 1,112 (49.8%) patients had 1,528 antibiotic prescriptions. Patients who received antibiotics were significantly younger than those who did not (median age: 26.3 vs. 29.8 years, p < 0.001) and their hospital stay was significantly longer (median: 4 vs. 2 days, p < 0.001). The choice of an antibiotic was appropriate and matched the policy in 806 (52.7%) prescriptions. Of such appropriate antibiotics, adherence to route of administration was observed in 768/806 (95.3%), to dose in 758 (94%), to frequency in 746 (92.6%) and to duration in 608 (75.4%). Full adherence to all aspects of antibiotic choice, dose, route, frequency and duration was achieved in 464 (30.4%) prescriptions. In 382 (25%), the antibiotics administered were not indicated.

CONCLUSION

There was low adherence to the local antibiotic policy guidelines. Physicians' antibiotic prescribing practices should be optimized. Adherence to, and update of, the policy is recommended.

Phytochemical investigation and antimicrobial activity of Psidium guajava L. leaves

Psidium guajava L. leaves were subjected to extraction, fractionation and isolation of the flavonoidal compounds. Five flavonoidal compounds were isolated which are quercetin, quercetin-3-O-α-L-arabinofuranoside, quercetin-3-O-β-D-arabinopyranoside, quercetin-3-O-β-D-glucoside and quercetin-3-O-β-D-galactoside. Quercetin-3-O-β-D-arabinopyranoside was isolated for the first time from the leaves. Fractions together with the isolates were tested for their antimicrobial activity. The antimicrobial studies showed good activities for the extracts and the isolated compounds.

Treatment of venous leg ulcers with Dermagraft

BACKGROUND

A number of different treatment approaches have been recommended for the treatment of venous ulceration, including local ulcer treatment, compression and drug therapy. Recent advances in tissue engineering have resulted in living tissues being developed for cutaneous wound repair and skin replacement. The aim of this pilot study was to compare the rate of healing of venous ulcers in patients treated with Dermagraft (a human fibroblast-derived dermal replacement) and compression therapy or compression therapy alone.

METHODS

A total of 18 patients with venous ulceration of the leg were recruited into the pilot study. Ten patients were treated with Dermagraft and compression therapy, and eight patients were treated with compression therapy alone. Healing was assessed by ulcer tracing and computerised planimetry. Skin perfusion was measured by laser Doppler.

RESULTS

Five (50%) of the patients treated with Dermagraft and one (12.5%) control patient had healed by the end of the 12-week study period (NS). The total ulcer area rate of healing and linear rate of healing was significantly improved in patients treated with Dermagraft (P=0.001 and P=0.006, respectively, Mann-Whitney U-test). The number of capillaries increased in both the treatment and control group. Peri-ulcer skin perfusion increased by 20% in patients treated with Dermagraft, compared with 4.9% in the control group.

CONCLUSION

The data from this small pilot study suggests that Dermagraft is associated with improved healing of venous ulceration. Following this pilot study, further clinical studies are needed to confirm the validity of these results in 'hard to heal' venous leg ulcers.

Evaluation of dermagraft as an alternative to grafting for open fasciotomy wounds

Wounds produced following open fasciotomy can be healed by grafting but this requires a second operation. Is Dermagraft, a tissue-engineered human fibroblast-derived dermis that can be applied on an outpatient basis, a viable alternative?

Gram stain versus culture in the diagnosis of vulvovaginal candidiasis

We evaluated Gram stain as a rapid diagnostic method for vulvovaginal candidiasis (VVC). Vaginal swabs were taken from 100 pregnant women and subjected to Gram stain and culture; 39% were diagnosed as having VVC (29% had symptomatic VVC and 10% had asymptomatic VVC). Candida albicans was isolated from 94.9% of all cultures while other Candida species were isolated from 5.1% of cases. Multigravidae were significantly more affected than primigravidae. Gram stain is a valuable method in rapid accurate diagnosis of symptomatic VVC and even superior to culture as it demonstrates the invasive forms of the yeast. However, its low sensitivity could restrict its use in routine practice. A combination of culture and Gram stain is the ideal approach for the diagnosis of VVC.

Prevalence and possible risk factors of Helicobacter pylori infection among children attending Damanhour Teaching Hospital

Helicobacter pylori (H. pylori) is a major cause of gastrointestinal disease in children. The factors influencing the acquisition and prevalence of H. pylori infection remain incompletely understood. In the present study, the prevalence and possible risk factors of H. pylori infection were studied among children aged 1.5-16 years who were attending the pediatric outpatient clinic of Damanhour Teaching Hospital. Blood samples were drawn and IgG seroprevalence of H. pylori among the studied children was determined using ELISA kits. A specially designed questionnaire inquired about personal, socioeconomic, household characteristics, feeding history during infancy and the child's health data was completed for every child. Results revealed that the overall seroprevalence of H. pylori infection was 50.5 %. The prevalence was widely age dependent: it was 60.6% among those age > or = 5 years and only 25.9% among those < 5 years (OR = 4.4; 95% CI = 1.6-11.9). Increased crowding in bed was also an associated factor; the prevalence among children where > or = 3 share a bed was 59.7% compared to only 26.9% among those where < 3 persons share a bed (OR = 4.1; 95% CI = 1.5-10.9). The prevalence among children who were breast fed for < 1 year was 64.7% compared to only 42.4% among those who were fed for > or =1 year (OR = 2.5; 95% CI = 1.1-5.9). After controlling for possible confounding in a Stepwise Multiple Logistic Regression model, independent predictors for H. pylori infection were: increasing age (> or = 5 years), overcrowding in bed (> or = 3/ bed) and shorter duration of breast-feeding (< 1 year) during infancy. It could be concluded that, H. pylori was highly prevalent among the sampled children and the possible risk factors are related to the community. So, there is a need to early diagnose, treat and eradicate infection during childhood to prevent its complications during adulthood.

Ringworm of the scalp in primary-school children in Alexandria: infection and carriage

A total of 510 children from a primary school in Alexandria were examined for tinea capitis, and samples were taken from their scalps. Specimens were examined by direct microscopy and were cultured. Diagnosis was by clinical and mycological findings. Clinical evidence of pediculosis capitis was found in 54.1% of children, more commonly in girls. Dermatophytes were isolated from 7.4% of scalp samples (2.9% confirmed cases, 4.5% carriers). A further 2% were suspected cases as they were negative by mycology. Most of the children were under 10 years and none was aware of having the infection. All isolates were identified as Trichophyton violaceum.

Screening for hepatitis A virus antibodies among a disadvantaged group of preschool children in Alexandria

Hepatitis A virus (HAV) immunity in a group of socially and economically deficient preschool children in Alexandria has been investigated. A total of 228 randomly selected children were enrolled. Saliva was collected from every child using a cotton wool swab. Anti-HAV was investigated in the collected saliva by a competitive ELISA technique utilizing a commercially available kit. The results revealed that among the investigated children 60 (26.3%) were anti-HAV positive. The mean age of anti-HAV positive children was 4.43 years +/- 0.21 years. Ten (33.3%) couples were siblings, 2 (3.3%) children gave a positive history of jaundice. As regards housing conditions; 34 (56.7%) of anti-HAV positive children had indoor sources of water supply and 26 (43.3%) had outdoor ones. The mean crowding index was 3.35 +/- 1.72. Positive anti-HAV was significantly more prevalent among older (P < 0.05) and among female children (P < 0.02). In conclusion, the routine administration of hepatitis A vaccine, combined with improvements in sanitation should reduce the incidence of acute illness and complications associated with the disease thereby decreasing the spread of HAV in developing countries.

Erythroxan diterpenes from Fagonia glutinosa

Further investigation of the ether extract of the aerial parts of Fagonia glutinosa utilizing the brine shrimp bioassay resulted in the isolation of two new cytotoxic erythroxan diterpenes: 1 alpha, 10 alpha-epoxy-2-oxofagonene (1) and 1 beta, 10 beta-epoxy-2-oxofagonene (2). In addition, two inactive diterpenes, 2-oxofagonene (3) and its previously reported isomer 2-oxo-5-epi-fagonene (4), were also isolated.

Effect of CsA on the expression of renin and angiotensin type 1 receptor genes in the rat kidney

To determine whether Cyclosporine A (CsA) alters the intrarenal expression of the renin and type 1 angiotensin II receptor genes, male adult Sprague-Dawley rats were given 25 mg/kg/day CsA s.c. for three weeks (CsA, N = 20) and were compared to pair-fed vehicle treated rats (Con, N = 20). The intrarenal distribution of renin and its mRNA was assessed by immunocytochemistry and in situ hybridization. In addition, kidney renin and type 1 angiotensin II (AT1) receptor mRNA levels were determined by Northern blot analysis. The percentage of juxtaglomerular apparatuses containing renin was higher in the CsA (84 +/- 5.5%) than in the Con (61 +/- 6.7%) group, (P < 0.05). The length of renin immunostaining along afferent arterioles was higher in the CsA (74 +/- 4.5 microns) than in the Con (37 +/- 5.1 microns) group, (P < 0.05). In contrast, neither renin mRNA levels nor its intrarenal distribution were altered by chronic CsA administration. Kidney AT1 receptor mRNA levels were lower in the CsA group than in the Con group. We conclude that chronic CsA: (1) induces recruitment of renin containing cells along the afferent arteriole, (2) causes no changes in intrarenal renin mRNA levels or distribution, suggesting that post-transcriptional events may be responsible for the persistence and/or uptake of renin by the preglomerular vasculature, (3) promotes a downregulation of AT1 receptor gene in the kidney, suggesting that local angiotensin II may control AT1 receptor gene expression by a negative feedback.

Associations between subgingival plaque bacterial morphotypes and clinical indices?

The aim of the present study was to evaluate possible associations between subgingival plaque bacterial morphotypes, as assessed by darkground microscopy, and clinical indices of routine adult chronic periodontitis. Clinical indices were plaque index (PlI), gingival index (GI), sulcus bleeding index (SBI), papilla bleeding index (PBI), attachment loss (AL), pocket depth (PD) and probeable pocket depth (PPD). Apical border plaque was sampled in vivo and after extraction to test whether direct or indirect sampling affected any such associations. Similarly, pocket depth and attachment loss were also assessed directly and indirectly on the same teeth, in vivo or after extraction. The influence of the type of index used to record inflammation (GI, SBI, PBI) was also assessed, as were the effects of the numbers of sampled subjects and the method of analysis, which comprised the use of transformed and untransformed data and of parametric and non-parametric tests. Data were collected in relation to the approximal surfaces of 44 teeth extracted from 22 adults (2 teeth each) and from 1 pair of contralateral upper anterior or premolar teeth in each of 100 adults, all which untreated routine chronic periodontitis. Selected subjects had greater than or equal to 4 mm probeable pocket depth and/or attachment loss, and radiographic evidence of bone loss in relation to 1 approximal surface on each of 1 pair of contralateral anterior or premolar teeth, or to 2 teeth scheduled for extraction. Plaque preparation and darkground microscopy were as described previously. Insignificant associations (p greater than 0.05) were demonstrated between supragingival plaque (PlI) and periodontal inflammation (GI, SBI, PBI) or destruction (PPD and AL), as well as between inflammation and attachment level. In contrast, significant moderate associations (r = 0.5-0.77) were demonstrated between each of the 3 morphotype groups; spirochaetes, other motiles and cocci. Spirochaetes showed a significant moderate (r = 0.5) positive association with pocket depth with a 2.43% mean increase of spirochaetes for each 1 mm increase of PPD. Although highly significant associations (r = 0.9) were demonstrable between the 3 inflammation indices (GI, SBI, PBI) themselves, only PBI showed significant positive associations (r = 0.3) with spirochaetes and other motiles. Also, PlI showed significant associations with each of the 4 morphotypes (r = 0.3-0.5). The heterogeneity of spirochaetes and other motiles as well as the multiplicity of possible aetiological microbial agents in plaque may have resulted in underestimated associations between subjects as well as undetectable association within a given mouth using only 4 morphotype groups.(ABSTRACT TRUNCATED AT 400 WORDS)

Darkground microscopy of subgingival plaque from the top to the bottom of the periodontal pocket

Part of the results of a study of subgingival plaque by darkground microscopy was used to investigate morphotype distribution at different levels within the periodontal pocket. Subgingival plaque was sampled at coronal, middle and apical levels from each of 28 approximal surfaces on 28 teeth extracted from 28 adults with untreated moderate to advanced periodontitis. Sample preparation and darkground microscopy were as described previously. The data recorded only the subgingival level at which the maximum count occurred for a given morphotype and subject. It was found that the maximum count of spirochaetes occurred most frequently at the apical level (p less than 0.05) and the maximum count of 'others' at the coronal level (p less than 0.05). Also, coccal counts showed a trend to increase the more apical the sample. Standardised darkground microscopy was able to show that the sampled subgingival level had a significant influence on plaque bacterial morphotype distribution, indicating the importance of accurate sampling of subgingival plaque at the most apical level.

False results associated with darkground microscopy of subgingival plaque

This study considers false results which may arise due to problems in the preparation or examination of specimens for darkground microscopy of subgingival plaque. Subgingival plaque samples obtained with a sterile curette were placed in 0.1-0.3 ml sterile full or 1/4 strength Ringer's solution: 0.85% saline, 1% gelatin in 0.85% saline, formal saline or pyrogen-free water for injection. Test slides were prepared from the original dispersion, and control slides from the corresponding sterile solution. Optimal dispersion solution, syringe dispersion frequency and the effect on motility of delay in processing samples were tested. Slides were also prepared from dispersions of 11 representative subgingival "periodontopathic" organisms. Problems in sampling included variability in counts between sites with comparable pocket depths, contamination of the sample and reduction of the sample volume after scaling. Problems in dispersion included contamination, uneven distribution of the different morphotypes and destruction of delicate organisms. Problems in slide preparation included slide contamination, limitation in the number of samples that can be assessed by one examiner at a given time without loss of activity of motile cells, and preparation of a cell monolayer. Problems in identification and counting included confusion of Brownian movements with motility, coccoid particles with cocci, spirochetes with campylobacter, flagella with flagella-like structures, size of cocci, counting of fragmented spirochetes and non-motile flagellated organisms and motile cells, and also bias in counting. Problems in morphotype grouping included the observation that many (10 of the 11 representative) periodontitis-related organisms were in the non-motile groups and not all cells of the motile species (Campylobacter, Capnocytophaga) showed motility. The results indicate that each stage of subgingival plaque darkground microscopy, sampling, dispersion, slide preparation, counting, morphotype grouping and interpretation may lead to false results if not representative or reproducible. Procedures are suggested for the minimisation of problems in the preparation and examination of subgingival plaque specimens for darkground microscopy.

Difference spectrophotometric estimation of santonin

Santonin gives a characteristic alkaline vs acidic difference spectrum. This was used for its estimation in pharmaceuticals and in the crude drug. Santonin was first extracted and purified through a specific partition procedure; then the difference absorbance was measured either at the maximum, 285 nm, or the minimum, 242 nm. The percentage of santonin can be calculated either by reference to the difference absorbance of a reference santonin sample, treated similarly, or by making use of the determined absorptivity. Measurement at the maximum is advisable, especially when the crude drug is assayed, because natural contaminants may interfere with the difference absorbance at the minimum.

Biochemical genetics of Zea mays L. I. Isozymes and the linkage relationship between AP-1 and AP-2 loci

Following starch gel electrophoresis and a modified staining method, three distinct groups of acid phosphatase isozymes (AP-1, AP-2, and AP-3) have been identified in scutellum extracts of different inbred maize lines. The AP-2 group includes three electrophoretic variants: a fast (F), an intermediate (I), and a slow (S) type. Genetic analysis showed that AP-2 variants are under the control of three codominant alleles at the AP-2 locus. A linkage test between AP-1 and AP-2 indicated that a close linkage between these two loci is ruled out.

Alkaloids from Egyptian Papaver rhoeas

N-methylasimilobine was isolated as the major alkaloid from an Egyptian sample of P. RHOEAS L. Other alkaloids isolated from the same plant material were stylopine, coptisine, isocorydine and rhoeadine. Chromatography indicated the presence of at least nine other minor alkaloids.