Hemodynamic performance evaluation of neonatal ECMO double lumen cannula using fluid-structure interaction

Extra corporeal membrane oxygenation (ECMO) is an artificial oxygenation facility, employed in situations of cardio-pulmonary failure. Some diseases i.e., acute respiratory distress syndrome, pulmonary hypertension, corona virus disease (COVID-19) etc. affect oxygenation performance of the lungs thus requiring the need of artificial oxygenation. Critical care teams used ECMO technique during the COVID-19 pandemic to support the heart and lungs of COVID-19 patients who had an acute respiratory or cardiac failure. Double Lumen Cannula (DLC) is one of the most critical components of ECMO as it resides inside the patient and, connects patient with external oxygenation circuit. DLC facilitates delivery and drainage of blood from the patient's body. DLC is characterized by delicate balance of internal and external flows inside a limited space of the right atrium (RA). An optimal performance of the DLC necessitates structural stability under biological and hemodynamic loads, a fact that has been overlooked by previously published studies. In the past, many researchers experimentally and computationally investigated the hemodynamic performance of DLC by employing Eulerian approach, which evaluate instantaneous blood damage without considering blood shear exposure history (qualitative assessment only). The present study is an attempt to address the aforementioned limitations of the previous studies by employing Lagrangian (quantitative assessment) and incorporating the effect of fluid-structure interaction (FSI) to study the hemodynamic performance of neonatal DLC. The study was performed by solving three-dimensional continuity, momentum, and structural mechanics equation(s) by numerical methods for the blood flow through neonatal DLC. A two-way coupled FSI analysis was performed to analyze the effect of DLC structural deformation on its hemodynamic performance. Results show that the return lumen was the most critical section with maximum pressure drop, velocity, shear stresses, and blood damage. Recirculation and residence time of blood in the right atrium (RA) increases with increasing blood flow rates. Considering the structural deformation has led to higher blood damage inside the DLC-atrium system. Maximum Von-Mises stress was present on the side edges of the return lumen that showed direct proportionality with the blood flow rate.

Sediment yield estimation and evaluating the best management practices in Nashe watershed, Blue Nile Basin, Ethiopia

Sediment yield estimation along with identification of soil erosion mechanisms is essential for developing sophisticated management approaches, assessing, and balancing different management scenarios and prioritizing better soil and water conservation planning and management. At the watershed scale, land management practices are commonly utilized to minimize sediment loads. The goal of this research was to estimate sediment yield and prioritize the spatial dispersion of sediment-producing hotspot areas in the Nashe catchment using the Soil and Water Assessment Tool (SWAT). Moreover, to reduce catchment sediment output, this study also aims to assess the effectiveness of certain management practices. For calibration and validation of the model, monthly stream flow and sediment data were utilized. The model performance indicators show good agreement between measured and simulated stream flow and sediment yields. The study examined four best management practice (BMP) scenarios for the catchment's designated sub-watersheds: S0 (baseline scenario), S1 (filter strip), S2 (stone/soil bunds), S3 (contouring), and S4 (terracing). According to the SWAT model result, the watershed's mean yearly sediment output was 25.96 t/ha. yr. under baseline circumstances. The model also revealed areas producing the maximum sediment quantities indicating the model's effectiveness for implementing and evaluating the sensitivity of sediment yield to various management strategies. At the watershed scale, treating the watershed with various management scenarios S1, S2, S3, and S4 decreased average annual sediment yield by 34.88%, 57.98%, 39.55%, and 54.77%, respectively. The implementations of the soil/stone bund and terracing scenarios resulted in the maximum sediment yield reduction. The findings of this study will help policymakers to make better and well-informed decisions regarding suitable land use activities and best management strategies.

Health-related quality of life after maxillectomy: obturator rehabilitation compared with flap reconstruction

Health-related quality of life (QoL) reported by patients has the potential to improve care after ablative surgery of the midface, as existing treatment algorithms still generally revolve around outcomes assessed traditionally only by clinicians. Decisions in particular relate to reconstruction with a flap compared with rehabilitation with an obturator, the need for adjuvant treatment, and morbidity related to the size of the defect. We prospectively collected health-related QoL assessments for 39 consecutive patients treated by maxillectomy between 01 January 2010 and 31 December 2014 using the University of Washington Quality of Life Questionnaire, and who had a mean (SD) duration of follow-up of 14 (4). We made sub-group analyses using paired t tests and analysis of variance (ANOVA) to compare reconstruction with a flap with rehabilitation with obturators, size of the vertical defect, and whether adjuvant treatment with radiotherapy or chemoradiotherapy adversely affected it. Overall there was a significant decrease in health-related QoL after treatment compared with before (p<0.001), but there was no significant difference in the effects of any of the paired reconstructive and rehabilitation treatments on it. Obturators remain an important option for rehabilitation in selected patients in addition to reconstruction with a flap. We found that neither increasing the size of the vertical defect (in an attempt to ensure clear margins) nor the use of postoperative radiotherapy seemed to have any adverse effect on QoL. More patients are required before we can conclude that the potential survival benefits of such measures may outweigh any adverse effects.

The use of foam sclerotherapy to treat low-flow vascular malformations of the head and neck

Liquid sclerotherapy, laser and surgery have been used in the treatment of head and neck vascular anomalies with variable success for many years. A multidisciplinary team consisting of plastic surgery, maxillofacial surgery and interventional radiology currently treats such lesions by converting liquid sclerosant into foam. Foam sclerotherapy is currently used successfully to treat varicosities of the lower limbs and in this study, we present four cases in which 3% sodium tetradecyl sulfate has been used to treat low-flow vascular malformations in the head and neck.

Development and in-vitro characterization of fish oil oleogels containing benzoyl peroxide and salicylic acid as keratolytic agents

Topical keratolytic agents such as benzoyl peroxide (BP) and salicylic acid (SA) are one of the common treatments for inflammatory skin diseases. However, the amount of drug delivery through the skin is limited due to the stratum corneum. The purposes of this study were to investigate the ability of fish oil to act as penetration enhancer for topical keratolytic agents and to determine the suitable gelator for formulating stable fish oil oleogels. 2 types of gelling agents, beeswax and sorbitan monostearate (Span 60), were used to formulate oleogels. To investigate the efficacy of fish oil oleogel permeation, commercial hydrogels of benzoyl peroxide (BP) and salicylic acid (SA) were used as control, and comparative analysis was performed using Franz diffusion cell. Stability of oleogels was determined by physical assessments at 20°C and 40°C storage. Benzoyl peroxide (BP) fish oil oleogels containing beeswax were considered as better formulations in terms of drug permeation and cumulative drug release. All the results were found to be statistically significant (p<0.05, ANOVA) and it was concluded that the beeswax-fish oil combination in oleogel can prove to be beneficial in terms of permeation across the skin and stability.

Influence of beta-cyclodextrin and chitosan in the formulation of a colon-specific drug delivery system

The increase in diseases of the colon underscores the need to develop cost-effective site-directed therapies. We formulated a polysaccharide-based matrix system that could release ibuprofen under conditions simulating those in the colon by employing a wet granulation method. Tablets were prepared in a series of formulations containing a polysaccharide (beta-cyclodextrin and chitosan) matrix system along with ethylcellulose. We characterized physicochemical properties and performed an in vitro drug release assay in the absence and presence of digestive enzymes to assess the ability of the polysaccharides to function as a protective barrier against the upper gastrointestinal environment. Fourier transform infrared spectroscopy studies revealed no chemical interaction between ibuprofen and polysaccharides; however, spectrum analysis suggested the formation of an inclusion complex of beta-cyclodextrin with ibuprofen. The formulations contained 50% ethylcellulose and 50% beta-cyclodextrins (1:1) were proven to be the better formulation that slowly released the drug until 24 h (101.04 ± 0.65% maximum drug release in which 83.08 ± 0.89% drug was released in colonic medium) showed better drug release profiles than the formulations containing chitosan. We conclude that a beta-cyclodextrin drug carrier system may represent an effective approach for treatment of diseases of the colon.

A biochemical and histopathologic study showing protection and treatment of gentamicin-induced nephrotoxicity in rabbits using vitamin C

Gentamicin and vitamin C have been proposed as nephrotoxic and antioxidant, respectively. This study involved biochemical and histopathologic investigation showing protection and treatment of gentamicin-induced nephrotoxicity in rabbits using vitamin C for 26 days hypothesizing that whether vitamin C would inhibit or decrease the raised serum urea and creatinine levels. This study was conducted on 25 healthy male albino rabbits (average weight 1.5±0.2 kg), classified into 5 groups: group A, B, C, D and E for nephrocurative (study-I) and nephroprotective (study-II) studies. Control group of rabbits (group A) received only the vehicle of gentamicin ampoule. In study-I, gentamicin sulphate (GS 80 mg/kg, i.m.) was administered to group B and C rabbits for ten days, then group C rabbits received vitamin C 250 mg/Kg for remaining 16 days. Group D and E received GS 80 mg/kg and GS 80 mg/kg i.m.-vitamin C 250 mg/kg orally, respectively during whole period (26 days) of study-II. After 26 days, various biochemical parameters, i.e. serum creatinine, blood urea nitrogen (BUN), and serum antioxidant activity, and histopathologic investigations were made. Nephrotoxicity was observed in rabbit groups B, C and D as evident from significant (p<0.05) high levels of serum creatinine and BUN and low serum antioxidant levels as compared to the levels of control group. Decrease in the levels of serum creatinine and BUN along with the increase in serum antioxidant activity was observed after vitamin C treatment in group C. While, renal-protective role of vitamin C was seen in group E as compared to the control. In conclusion, Gentamicin induced nephrotoxicity can be attenuated or treated using vitamin C.

Non-Hodgkins Lymphoma presenting as Garcin’s Syndrome

An 80 year old man presented with a twelve month history of progressive multiple unilateral cranial nerve palsies. A gadolinium enhanced MRI scan of his head and neck was performed. This showed an extra-axial enhancing lesion, which enveloped the hemi-mandible at the level of the left inferior alveolar nerve, and a dumbbell shaped lesion within the cerebellopontine angle. An incisional biopsy was performed to gain a tissue diagnosis, which demonstrated a Non-Hodgkin’s Lymphoma. The combination of signs, symptoms and radiological findings enabled a diagnosis of Garcin’s Syndrome secondary to Non-Hodgkin’s Lymphoma.

Traumatic pseudolipoma: herniation of buccal fat pad, a report of two cases

Traumatic pseudolipoma is a term used to describe intra-oral herniation of the buccal fat pad. A tear of the buccinator muscle and buccal mucosa allows the buccal fat pad to extrude into the oral cavity. Initially, the lesion can suggest a more sinister cause, but a history of trauma, an absence of mass before the accident, anatomical site and fatty appearance should suggest a diagnosis of traumatic herniation of buccal fat pad. This injury is rare, but two cases presented to the authors' hospital over a period of 3 months.

Function preservation with multimodality treatment in locally advanced oral tongue cancer

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Background: Total or near total glossectomy with postoperative radiation is a standard treatment option for locally advanced squamous cell carcinoma oral tongue (LASCCOT). However, the procedure is controversial due to dismal cure rates and major functional deficits that impact on speech, deglutition and quality of life. We evaluated function preservation and survival outcome in LASCCOT treated with induction chemotherapy, limited surgery, and postoperative radiation/chemoradiation. Methods: We retrospectively identified 15 patients with LASCCOT treated with induction chemotherapy, limited surgery and postoperative radiation/chemoradiation at our institution between 04/07 - 04–08. M67%:F33% median age 50 years. Pretreatment AJCC stage as assessed on MRI was T2N+ (tumour crossing midline) 13%, T3N0 20%, T3N+ 47%, and T4N+ 20%. Prior to surgery induction chemotherapy, consisting of cisplatin 75 mg/m2 day 1 and gemcitabine 1 mg/m2 day 1 and 8 every three weeks for 2 cycles was given. Four to six weeks following second cycle of chemotherapy local excision of residual primary tumor with ipsilateral modified neck dissection was performed. Postoperative radiation dose was 60Gy/30 fractions. Post therapy pathological stage was ypT0N0 20%, ypT1N0 20%, ypT1N+ 40%, ypT2N+ 13%, and ypT3N+ 7%. Patients with ypN+ disease received concomitant 3 weekly cisplatin 75 mg/m2 with radiation. Results: Overall and disease free survival at 20 months was 60%. Twelve patients (80%) are alive and 3 patients (20%) have died of disease at 9, 14 and 14 months (locoregional failure 1 and distant metastasis 2 patients). In patients alive without disease assessment of deglutition and speech at the time of last follow up showed all patients on full oral diet with spontaneous intelligible speech. Conclusions: Multimodality treatment with induction chemotherapy, limited surgery and post operative radiation/chemoradiation may allow selected LASCCOT patients to avoid morbid surgery and preserve tongue function without compromising survival. This approach merits further investigation in clinical trials.

No significant financial relationships to disclose.

Primary squamous cell carcinoma of the oral cavity at presentation in Pakistan

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Background: Squamous cell carcinoma of oral cavity (SCCOC) is characterized by marked geographical differences in frequency and site distribution. Pakistan is situated within the high risk zone on the global oral cancer map. However, no reliable data exists on oral cancer in this area. Our aim was to determine clinicopathological features and patterns at presentation of primary SCCOC in a comprehensive cancer centre in Pakistan. Methods: Demographic, risk factors, pathological and AJCC staging data for SCCOC treated at Shaukat Khanum Memorial Hospital for the period November 2003-October 2008 were obtained from the head and neck unit database. Results: The database identified 666 patients with biopsy proven primary SCCOC. Mean age was 53 years (range 12 - 90 years). Male (428): Female (238) ratio was M64%:F36%. The occurrence of major risk factors for oral cancer specifically smoking, betel quid chewing, naswar (smokeless tobacco) and alcohol use in males (428) was 45% (193), 28% (118), 29% (126), 3% (13), and in females (238) was 8% (20), 29% (68), 13% (30), 0% (0), respectively. Thirty-eight percent (411/666) had no association with tobacco, betel quid or alcohol use. Subsite within oral cavity; anterior tongue 41.1% (274), buccal mucosa 26.6% (177), lower gingival and alveolus 19.5% (130), upper gingival and alveolus 4.1% (27), lips 3.6% (24), retromolar trigone 2.9% (19), hard palate 1.7% (11), and floor mouth 0.6 (4). Broder's/World Health Organization histological grade; grade I 52% (334), grade II 34% (226), grade III 7% (49), and unknown 5% (36). According to AJCC 2002 system 0.2% (1), 10.8% (72), 12.2% (81), 13.2% (88), and 63.7% (420) had stage 0, I, II, III, and IV, respectively. Conclusions: Approximately 80% of patients with primary SCCOC present with stage III or IV disease with anterior tongue as the most common subsite in our hospital. While tobacco and betel quid chewing can be attributed to development of SCCOC in a significant proportion of patients, nearly 38% are unlinked to typical risks factors suggesting other environmental and genetic agents as etiological factors in this region.

No significant financial relationships to disclose.

Trimodality treatment (TMT) for locally advanced esophageal cancer in Pakistan; Analysis of prognostic factors influencing survival

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Background: The prognosis of patients with locally advanced esophageal cancer is poor. TMT for locally advanced esophageal cancer is being utilized with increasing frequency. In this study, we investigate the prognostic factors influencing survival in patients with locally advanced esophageal cancer following TMT. Methods: The study included 22 patients with esophageal carcinoma treated between January 2003 and December 2005 at Shaukat Khanum Memorial Hospital and Research Centre. Median age was 49 years (range 26 - 68). There were 15 (68%) males and 7 (32%) females. All patients had EGD with biopsy and CT chest. Twelve (54.5%) had squamous cell carcinoma and 10 (45.5%) patients had adenocarcinoma. Five patients (23%) had tumour in the middle third and 17 (77%) had lower/gastroesophageal lesions. Preoperative radiation consisted of 50.4 Gy / 28 fractions with concomitant chemotherapy day 1 and 29 (Cisplatin 75 mg/m2 day 1 and infusional 5FU 1000 mg/m2 day 1–5). Esophagectomy was done at 6 - 12 weeks following chemoradiation. The pathologic down-staging was evaluated by the 5-score tumor regression grade (TRG) of Mandard. Results: Post TMT pathologic TNM stage was; Stage 0 in 8 pts (36%), stage II in 5 pts (23%) and stage III in 9 pts (41%). 13 (59%) pts had R0 and 9 (41%) pts had R1 resection. The 4-year disease free survival was 29% with a median survival of 19 months. The number of patients with TRG score 1, 2, 3, 4 and 5 were 7 (32%), 4 (18%), 5 (23%), 2 (9%) and 4 (18%) respectively. Tumor regression grade 1–2 (p=.0016) and negative circumferential margins >2 mm (p=.0019) had a positive influence on DFS. Age (< 50 vs ≥ 50 years), sex, hemoglobin at presentation (≤ 12 vs > 12 gm/dl), tumor site (middle vs lower/GE junction), pathological nodal status (node positive vs node negative) and histological subtype (squamous cell vs adenocarcinoma) did not influence survival (p= 0.92, p= 0.82, p= 0.69, p= 0.79, p= 0.41 and p= 0.32 respectively). Conclusions: TMT results in prolonged disease free survival in patients with complete response or microscopic residual foci (TRG 1–2). Positive or circumferential margins <2mm is associated with poor prognosis.

No significant financial relationships to disclose.

Cisplatin plus gemcitabine (GC) as induction chemotherapy in locally advanced head and neck cancer (HANC)

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Background: Cisplatin/infusional 5-fluorouracil chemotherapy is routinely administered as standard induction chemotherapy in advanced HANC. However, the optimum treatment remains to be defined. Gemcitabine is an active agent in HANC and few studies have evaluated induction GC in HANC. We have explored the activity and toxicity of GC as induction treatment in HANC and report the results. Methods: From August 2005 to September 2006, 55 patients with locally advanced HANC had induction chemotherapy with GC at Shaukat Khanum Memorial Cancer Hospital and Research Centre. We reviewed the medical records and prospectively collected data to determine activity and toxicity of induction GC. M:F ratio was 64%:36% with a median age of 50 years (range 19–80). All patients had histologically confirmed squamous cell carcinoma. The site of disease was nasopharynx, paranasal sinuses, oral cavity, oropharynx, larynx and hyopharynx in 4% (2), 11% (6), 51% (21), 2% (1), 11% (6) and 22% (11) respectively. According to AJCC staging 7% (4) had stage III and 93% (51) had stage IVa/IVb disease (T3N0 7%, T3N+ 2%, T4N0 38% and T4N+ 53%). Induction chemotherapy consisted of 2 cycles of cisplatin 75 mg/m2 day 1 and gemcitabine 1000 mg/m2 day 1 and 8 with treatment repeated three weekly. Fifty-three (94%) patients received 2 cycles as planned. Toxicity was scored after each cycle according to the NCI.CTC criteria. Response was assessed following completion of induction chemotherapy by clinical examination/MRI scan. Results: All patients were available for assessment of toxicity and response. A total of 111 cycles were delivered. The response rates are: complete 24% (13), partial 62% (34), no response 7% (4) and progression 7% (4). The overall response rate was 86% (complete 24%, partial 62%). No treatment related deaths occurred. Haematological G3/G4 toxicity included neutropenia (13%/7%) and thrombocytopenia (5%/0%). The non-haematological toxicity observed (nausea, vomiting and diarrhoea) was only G1/G2. Conclusions: GC is well tolerated with low toxicity and high anti tumour activity as neoadjuvant chemotherapy treatment in squamous cell head and neck cancer. Combination GC arm should be included in future trials.

No significant financial relationships to disclose.

Links between anaesthetic modality and nerve damage during lower third molar surgery

OBJECTIVE

To investigate the relationships between eruption status, gender, social class, grade of operator, anaesthetic modality and nerve damage during third molar surgery.

DESIGN

Two centre prospective longitudinal study.

SETTING

The department of oral and maxillofacial surgery, University Hospital Birmingham NHS Trust and oral surgery outpatient clinics at Birmingham Dental Hospital.

SUBJECTS

A total of 391 patients had surgical removal of lower third molars. Sensory disturbance was recorded at one week post operatively. Patients with altered sensation were followed up at one month, three months and six months following surgery.

RESULTS

614 lower third molars in 391 patients were removed. Forty-six procedures (7.5%) were associated with altered sensation at one week with three procedures (0.49%) showing persistent symptoms at six months. Of these 46 nerve injuries, 26 (4.23%) involved the lingual nerve and 20 (3.25%) the inferior dental nerve (IDN). All three persistent sensations were IDN related. A logistic regression model found that the use ofa lingual retractor chi2 = 11.559, p = 0.003 was more significant than eruption status chi2 = 12.935, p = 0.007. There was no significant relationship between anaesthetic modality, age, social class, sex and seniority of operator.

CONCLUSIONS

There was no link between the choices of local or general anaesthesia and nerve damage during lower third molar removal when difficulty of surgery was taken into account.

The causes and consequences of maxillofacial injuries in elderly people

OBJECTIVE

The occurrence of trauma in older people is well-documented; however the incidence of maxillofacial trauma is scarcely reported. Therefore, the objective of this study is to determine the causes and consequences of maxillofacial trauma in older people.

DESIGN

A five-year (March 95 - March 2000) retrospective study was carried out of all patients over the age of 65 years with facial trauma presenting to Accident and Emergency Department (A&E). The information was collected using the medical notes and discharge summaries.

SETTING

The Departments of A&E and Maxillofacial Surgery.

SUBJECTS

A total of 42 patients' records were examined for study related data.

RESULTS

A total of 42 patients were seen during the study period. Thirty-six gave a history of a fall, of which 15 had tripped, 5 had slipped, 3 resulted from a Transient Ischaemic Attack (TIA), 1 as a result of alcohol abuse, in 1 a prosthetic knee gave way and 11 gave no cause for the fall. Of the remaining 6 patients, 5 were assaulted and 1 had a wardrobe fall on top of him. The majority of the falls occurred during the winter months. Maxillofacial injuries were noted in 27 of the 42 patients. Sixteen patients had cheekbone fractures, 8 mandibular fractures, 2 midface and 1 orbital complex fracture. Twenty-five percent of cheekbone fractures and 50% of mandibular fractures were treated surgically. Medical history was noted in 27 patients.

CONCLUSIONS

This study clearly demonstrates the majority of the facial trauma in the older people can be treated conservatively unless the patients complain of functional problems.

Proabsorptive action of gum arabic: regulation of nitric oxide metabolism in the basolateral potassium channel of the small intestine

BACKGROUND

Gum arabic, a high-molecular-weight natural polysaccharide, has been shown to have proabsorptive properties in animal models of gastrointestinal disease that involve nitric oxide (NO). Gum arabic may indirectly regulate NO metabolism by creating an outward NO gradient, thus altering other intracellular NO-dependent mechanisms such as gating of the potassium (K+) channel. This hypothesis was further investigated using the K+ channel blocker, glybenclamide.

METHODS

Following intraperitoneal injection of 4.5 mg/kg glybenclamide or saline, the jejunum of anesthetized rats was perfused with a standard oral rehydration solution in the presence or absence of 2.5 g/L gum arabic, as well as 1 mmol/L l-arginine to enhance NO production. Sodium, net water, and glucose absorption and unidirectional water movement were determined.

RESULTS

Gum arabic showed regulatory capacity for NO-dependent metabolism by reducing net water absorption in the absence of arginine, and sodium absorption after arginine stimulation, in the absence of glybenclamide. Addition of gum arabic to oral rehydration solution, in glybenclamide pretreated animals, and in the absence of arginine, normalized sodium absorption, but was less effective in restoring net water transport. Injection of glybenclamide sharply decreased all absorption markers in arginine supplemented oral rehydration solution, which were at least partially restored by addition of gum arabic to the oral rehydration solution. In the presence of glybenclamide, the effects of arginine became antiabsorptive, as had those observed in preceding studies with high arginine concentration. Gum arabic partially or fully reversed alterations produced by perfused 1 mmol/L arginine.

CONCLUSIONS

Some of the effects of gum arabic on the small intestine are likely caused by its ability to remove NO as it diffuses into the lumen, thus reducing NO concentration in the enterocyte and indirectly affecting the absorptive/secretory response of the gut, which leads to normalization of absorptive function. These findings are consistent with the previously shown gum arabic-scavenging properties of NO and support a potential therapeutic role for this product.

Calcium ion diffusion from calcium hydroxide-containing materials in endodontically-treated teeth: an in vitro study

The aim of this in vitro study was to determine the amount and duration of diffusion of calcium ions from both a calcium hydroxide-containing root canal sealer and an intracanal medicament, through the apical foramen and the dentinal tubules of endodontically-treated teeth. The root canals of 88 freshly extracted single-rooted teeth were prepared using the modified double flared, balanced force technique with patency filing. The teeth were divided into four test groups of 20 teeth each and a control group of eight teeth. One group was dressed with a non-setting calcium hydroxide while the other was obturated using cold lateral condensation of gutta-percha with a calcium hydroxide-containing sealer. An artificial root defect was created in the apical third of the root of the teeth in the other two groups and the root canals were either dressed or obturated in the same way as the first two groups. All groups were incubated at 37 degrees C and were sampled for calcium diffusion after 1, 2 and 3 days and 1, 2, 3, 4 and 8 weeks. There was statistically significantly more calcium diffusion with the non-setting groups compared with the sealer groups (P < 0.05). There was more calcium ion diffusion from teeth with a patent apical foramen than those with an artificial resorptive root defect (P < 0.05).

Prevalence of seromarkers of HBV and HCV in health care personnel and apparently healthy blood donors

Ninety-five health care workers and 91 controls were screened for seromarkers of both HBV (HBsAg, HBeAg, Anti-HBc) and HCV (anti-HCV) by ELISA. The control group showed a much higher frequency of seromarkers for both the viruses. HBsAg was positive in 5% of study group (health care personnel) and 14% of controls. Anti-HBc as a marker of past HBV-exposure was positive in 28% of study group as compared to 36% of controls. Overall, 33% of study group and 48% of control showed one or the other marker of HBV Anti-HCV was positive in 4% of study group and 14% of controls. This study suggests that health care workers are not particularly a high risk group as compared to rest of the population.

Sero-diagnosis for viral hepatitis in 93 patients admitted with acute hepatitis in three different teaching hospitals in Lahore

Serodiagnosis was done in 93 patients admitted with acute viral hepatitis (AVH) to three teaching hospitals in Lahore. Five (5.4%) had hepatitis A, 39 (41.9%) hepatitis B (2 of these were anti delta positive) [see erratum notice], 44 (47.3%) probable hepatitis E and 3(3.2%) had HAV/HBV co-infection. Antibody to hepatitis C (anti HCV) was detected in 6 patients (6.4%); 2 with HBV and 4 with probable HEV infection. Excluding 39 patients with hepatitis B and 3 with HBV as part of co-infection, there was evidence of previous HBV infection in 39 out of the remaining 51 patients. In the subset of 6 children, 3 had hepatitis A and 3 hepatitis E. Of these, 5 had evidence of previous exposure to HBV and one was also positive for anti HCV. Our results are suggestive of a strong background of HBV infection raising concern about its chronic sequelae in the community.