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Biomedical subjects

S Salem

Publications and source records attributed to S Salem.

At least 19 recordsLinked to original sources
PubMed2003

Bio-augmentation by nitrification with return sludge.

Bio-augmentation can be used to obtain nitrification in activated sludge processes that operate at sub-optimal solid retention times. In this study, we evaluated the potential of augmenting the endogenous nitrifying bacteria, by implementing a nitrification reactor in the sludge return line. This reactor can be fed with an internal N-rich flow (e.g. effluent from the sludge treatment) or with an external ammonium source. A mathematical model based on ASM1 was developed and used to evaluate the potential of this technique. The bio-augmentation studied here aimed to enhance the nitrification process of highly loaded activated sludge systems. A calibrated simulation model of a high loaded wastewater treatment plant in The Netherlands was used for this study. A side stream process (the named BABE process) was included in the simulation. This process was fed with the ammonia-rich water generated by sludge digestion and subsequent thickening by centrifugation (the so-called rejectwater). An external source (artificial) of ammonium was also considered to evaluate the differences between the two origins of ammonium. The results showed that with the augmentation process, high loaded activated sludge systems can achieve nitrification even at low winter temperatures. The best effect is obtained for systems operating at approximately 50% of the minimal SRT without augmentation. The use of an internal ammonia source is more effective than an external source. The results of this study give a quantitative basis for the design of process internal bio-augmentation processes and the effect on the N-removal capacity of the treatment plant.

Bioreactors↗
PubMed2003

The efficacy and safety of a topical alprostadil cream, Alprox-TD, for the treatment of erectile dysfunction: two phase 2 studies in mild-to-moderate and severe ED.

In two multicenter, placebo controlled, phase 2 studies, patients with mild-to-moderate (n=161, Study 1) or severe (n=142, Study 2) erectile dysfunction (ED) were randomized to receive placebo, 0.05, 0.1, or 0.2 mg (Study 1) or placebo, 0.1, 0.2, or 0.3 mg (Study 2) of topically applied alprostadil (containing a proprietary skin permeation enhancer). The primary efficacy end point in both studies was the change in erectile function (EF) score from baseline to final visit. The changes from baseline for EF scores were -0.8+/-1.1, 1.8+/-1.1, 0.7+/-1.2, and 3.7+/-1.2 (P<0.01; Study 1) and 2.7+/-1.3, 6.29+/-1.4, 6.49+/-1.5, and 9.44+/-1.5 (P<0.001; Study 2) for ascending dose groups in each study. Topical alprostadil was well tolerated with the most common adverse event being urogenital pain. These results suggest this topical alprostadil formulation may be a potentially useful agent for the treatment of ED.

Administration, Topical↗
PubMed2002

Model-based evaluation of a new upgrading concept for N-removal.

Mathematical modelling is considered a time and cost-saving tool for evaluation of new wastewater treatment concepts. Modelling can help to bridge the gap between lab and full-scale application. Bio-augmentation can be used to obtain nitrification in activated sludge systems with a limited aerobic sludge retention time. In the present study the potential for augmenting the endogenous nitrifying population is evaluated. Implementing a nitrification reactor in the sludge return line fed with sludge liquor with a high ammonia concentration leads to augmentation of the native nitrifying population. Since the behaviour of nitrifiers is relatively well known, a choice was made to evaluate this new concept mainly based on mathematical modelling. As an example an existing treatment plant (WWTP Walcheren, The Netherlands) that needed to be upgraded was used. A mathematical model, based on the TUDP model and implemented in AQUASIM was developed and used to evaluate the potential of this bioaugmentation in the return sludge line. A comparison was made between bio-augmentation and extending the existing aeration basins and anoxic tanks. The results of both modified systems were compared to give a quantitative basis for evaluation of benefits gained from such a system. If the plant is upgraded by conventional extension it needs an increase in volume of about 225%; using a bioaugmentation in the return sludge line the total volume of the tanks needs to be expanded by only 75% (including the side stream tanks). Based on the modelling results a decision was made to implement the bioaugmentation concept at full scale without further pilot scale testing, thereby strongly decreasing the scale-up period for this process.

Ammonia↗
PubMed2001

Role of repeated F-18 fluorodeoxyglucose imaging in management of patients with bone and soft tissue sarcoma.

AIM OF THE STUDY: To assess the impact of repeated F-18 FDG studies on the management of patients with bone and soft tissue (B&S) sarcomas. MATERIAL AND METHODS: Twenty patients with B&S tissue tumors (11 M and 9 F age 17-72 years) had 52 F-18 FDG Dual Head Coincidence Imaging (DHCI) studies. 7 patients were followed for 6 months to 2 years clinically after removal of the primary tumor. Thirteen patients were evaluated for suspected recurrences. Patient's preparation, F-18 FDG injection and imaging procedure were done according to department protocol. Attenuation corrected images were interpreted visually by 3 trained physicians. Tumor to background ratios were calculated for all lesions. RESULTS: In 13 patients having both studies, baseline FDG and CT/MRI were concordant in 8 patients, FDG detected more lesions in 3 patients but it did not detect 4 metastatic pulmonary nodules in 2 patients. Follow up studies showed stable disease in 10 patients while 6 patients who showed worsening disease needed to change their chemotherapy. Surgery was avoided in 2 patients and 2 patients showed improved response. CONCLUSION: Repeated F-18 FDG DHCI examinations proved to have an impact on the clinical management of patients with malignant bone and soft tissue sarcoma. It helps to differentiate postoperative changes from local recurrence.

Adolescent↗
PubMed2000

Bone mineral density of the Lebanese reference population.

We determined the bone mineral density (BMD) of normal Lebanese subjects and compared results with US/European reference data. The investigation was conducted at one center, and included 858 women and 165 men aged 20-79 years. Spine, femoral and radial BMD measurements were made using dual-energy X-ray absorptiometry. Age-related changes in BMD were similar in form to those of US/European reference data. However, BMD values of Lebanese were generally lower than US/European values. Spine BMD of Lebanese women was about 8% lower than US/European values between ages 20 and 59 years, and 5-6% lower for ages 60-79 years. Femoral neck BMD values for Lebanese women were 8% lower in the young adult years (age 20-39 years), but only 2-3% lower in the postmenopausal years, compared with US/European women. There were smaller postmenopausal decreases in femoral and radial BMD in Lebanese women compared with US/European women, which led to a convergence of BMD after age 70 years. The BMD of Lebanese men was 5-8% lower than US/European values throughout the age range (20-79 years). The effect of weight on BMD ranged from 0.2% to 0.4% per kilogram. Height was not significantly associated with BMD when both height and weight were entered in multiple regression analyses. The prevalence of osteoporosis appeared to be overestimated if the US/European reference data, rather than Lebanese reference data, were used to calculate T-scores.

Absorptiometry, Photon↗
PubMed2000

Antioxidant status in children with juvenile rheumatoid arthritis (JRA) living in Cairo, Egypt.

The aim of this study was to examine both enzymatic and non-enzymatic antioxidant status in a select group of children with juvenile rheumatoid arthritis (JRA), living in Cairo, Egypt. The plasma concentrations of albumin, ceruloplasmin, vitamin C, vitamin E as well as erythrocyte superoxide dismutase and whole blood glutathione peroxidase activities were all significantly decreased in the presence of JRA compared to those without JRA. Unlike these antioxidant factors, vitamin A and its carrier (e.g. retinol binding protein), which have very little or no antioxidant property, remained unaffected by JRA. These results suggest that the children with JRA are subject to oxidative stress.

Antioxidants↗
PubMed2000

Tc-99m MAG3 scintigraphy in unusually dilated bilateral extrarenal pelves.

The authors report the findings of a radionuclide diuretic renogram in a patient with markedly dilated pelves bilaterally that filled most of the abdominal cavity. With the patient in the sitting position, at the end of the furosemide injection, there was good delineation and filling of the dilated calyces. These findings are unusual because of the extensive pelvicaliceal dilatation, and they emphasize the importance of the sitting position.

Aged↗
PubMed1994

Ultrasonography and ultrasound-guided fine-needle aspiration biopsy of head and neck lesions: a surgical perspective.

A head and neck ultrasound-guided fine-needle aspiration clinic was set up to determine the role of ultrasound and ultrasound-guided fine-needle aspiration in the evaluation of patients with lesions in this region. One hundred ninety-five lesions were biopsied by ultrasound-guided fine-needle aspiration in 203 patients. Ultrasound detected 2 or more lesions in 14 (48%) of 29 patients with a clinically solitary thyroid nodule. Three (8.8%) of 34 lesions thought to be within the parotid gland were determined to be external. A pronounced learning curve was evident in the technique of ultrasound-guided fine-needle aspiration, particularly for nonpalpable disease. Adequacy of sampling for each 3-month period was 71%, 89%, and 94%, respectively. Seventy-four percent of central aspirations were satisfactory compared to 54% of peripheral aspirations. Ultrasound-guided fine-needle aspiration did not alter the clinical staging of metastatic neck disease in 8 patients having 10 neck dissections but proved useful in detecting nodal recurrence in 3 irradiated necks that did not proceed to surgery. The smallest node to harbor malignancy had 4-mm maximal axial diameter. We conclude that ultrasound and ultrasound-guided fine-needle aspiration are valuable adjuncts to the clinical examination.

Biopsy, Needle↗
PubMed1994

Doppler sonography of adnexal masses: the predictive value of the pulsatility index in benign and malignant disease.

OBJECTIVE: The purpose of this study was to determine whether pulsed Doppler sonography can be used to distinguish between benign and malignant adnexal masses on the basis of pulsatility index. SUBJECTS AND METHODS: In an 18-month period, all patients in whom an adnexal mass was detected at sonography had further evaluation of the mass by color and pulsed Doppler sonography. Ninety-nine patients with 102 masses that were surgically removed were included in the study. The pulsatility indexes were calculated from the reproducible spectral waveforms generated from flow centrally or peripherally within or immediately adjacent to the mass. Each lesion was categorized on the basis of its gray scale morphologic features as typically benign or indeterminate/malignant in appearance. RESULTS: Of the 102 adnexal masses, 89 were benign and 13 were malignant. In seven of the 89 benign lesions, no flow could be detected, and these were excluded from analysis. Of the remaining 82 benign lesions, 65 showed pulsatility indexes consistently equal to or greater than 1.0, and 17 showed pulsatility indexes of less than 1.0. Ten of the 13 malignant lesions had pulsatility indexes consistently less than 1.0, and three primary malignant tumors had their lowest pulsatility indexes ranging between 1.1 and 1.8. Sixty-five of the 68 masses with pulsatility indexes equal to or greater than 1.0 were benign, for a positive predictive value of 96% for benign disease. Ten of the 27 masses with pulsatility indexes of less than 1.0 were malignant, for a positive predictive value of 37% for malignant disease. Forty-five masses were detected in perimenopausal and postmenopausal patients. In this group, the pulsatility index had a positive predictive value of 88% for benign disease and 47% for malignant disease. In this study, 45 of 49 masses that had a typically benign sonographic appearance had pulsatility indexes equal to or greater than 1.0. All 49 masses had benign histology. In the remaining 46 masses with an indeterminate/malignant sonographic appearance, 20 of 23 with pulsatility indexes equal to or greater than 1.0 were benign, and 10 of 23 with pulsatility indexes of less than 1.0 were malignant. CONCLUSION: Our results show a high positive predictive value of high-impedance flow in benign adnexal disease and a predominance of low-impedance flow in malignant adnexal disease. However, the pulsatility indexes showed considerable overlap between benign and malignant lesions, indicating that Doppler sonography has severe limitations in the differentiation of benign from malignant adnexal disease on the basis of low-impedance flow (pulsatility index < 1.0).

Adenofibroma↗
PubMed1993

Ultrasound-guided fine-needle aspiration biopsy in the management of thyroid disease.

During a 23-month period, 59 patients were referred for ultrasound (US)-guided fine-needle aspiration biopsy (FNAB) of the thyroid gland because of inadequate orthodox (office) FNAB, a clinically small lesion, or an occult lesion. Seventy percent of the group (41 patients) was referred for surgery, which revealed cancer in 37% of patients, adenoma in 19%, and benign disease in 44%. US-guided FNAB yielded false-positive reports in 0% of patients, false-negative reports in 5% to 12%, and inadequate aspirates in 32%. The US-guided FNAB technique had a sensitivity of 60% to 90%, a specificity of 100%, a positive predictive value of 100%, a negative predictive value of 80%, and an accuracy of 85%. US-guided FNAB provides cytologic information in 60% of patients in whom a diagnosis cannot be established by orthodox (office) means, thus enhancing the diagnostic ability of clinicians who can recommend a treatment program with confidence.

Adenoma↗
PubMed1993

Incidence and types of non-palpable thyroid nodules in thyroids removed for palpable disease.

The purpose of this study was to determine the number, size and types of non-palpable and ultrasound undetected thyroid nodules in thyroid glands removed for a single palpable nodule. Twenty patients undergoing partial (hemi- and subtotal) thyroidectomy and 40 patients having a total thyroidectomy were analyzed. Patients had no more than one palpable nodule, no cervical adenopathy and no history of previous thyroid surgery. An ultrasound was performed routinely within four months of surgery. Forty-six nodules were detected by final pathology in the partial thyroidectomy group but only 42% were detected by palpation and 59% by ultrasound. The median diameter of non-palpable and ultrasound undetected partial thyroidectomy nodules was 0.5 cm and all were benign except for one case of lymphoma. Pathology detected 186 nodules in the total thyroidectomy group although palpation only detected 22% of these and ultrasound 42%. The median diameters of the benign and malignant non-palpable nodules were 0.4 cm and 0.25 cm respectively. Most of the undetected nodules in the total thyroidectomy group were benign but there were 20 non-palpable and 18 ultrasound undetected papillary carcinomas.

Adolescent↗
PubMed1993

Pre-operative localization of 25 consecutive parathyroid adenomas: a prospective imaging/surgical correlative study.

The successful diagnosis and surgical treatment of primary hyperparathyroidism due to parathyroid adenoma benefits significantly, in our experience, from a process of pre-operative imaging localization of the parathyroid adenoma. This prospective study evaluates a window of 25 consecutive patients who underwent pre-operative imaging localization prior to successful unilateral parathyroidectomy for parathyroid adenoma. All parathyroid adenomas were successfully localized by imaging, and subsequently documented photographically in surgical correlation, and pathologically confirmed. All patients were cured biochemically. Ultrasound accurately localized 92% of adenomas (100% in the neck and extrathyroidal) while radionuclide subtraction scanning identified 60% of a smaller subset. Both DSA and CT were successful in the two cases utilized, and MRI demonstrated four of five adenomas. The high yield of these pre-operative localization studies should make them an important consideration in the routine evaluation of patients undergoing surgery for possible parathyroid adenoma. Their usefulness in directing a conservative unilateral operation may result in time and cost savings, as well as reduced surgical exposure.

Adenoma↗
PubMed1991

Analysis of 105 patients admitted over a 2-year period to a modern burns unit in Saudi Arabia.

This is an epidemiological survey of 105 burned patients treated between May 1986 and May 1988 in a modern Burns Unit in Saudi Arabia. Hospitalization time ranged from 1 to 100 days with a mean of 17 days. The mean age of the patients was 9 years. Sixty (57 per cent) of the patients were males and 45 (43 per cent) were females. The main causes of injury were hot liquids (57.7 per cent) and fire (33 per cent). The mean extent of injury was 19 per cent TBSA. Burns covered less than 40 per cent TBSA in 91 out of 105 patients (87 per cent). Deep burns did not exceed 100 units of burned skin in 48 out of 55 patients (87 per cent). Urgent escharotomy was done in 14 patients. Early excision and skin grafting was carried out in 34 patients. Complications included six cases (5.7 per cent) with septicaemia, one (0.9 per cent) with disseminated intravascular coagulopathy, three (2.9 per cent) with amputation and one (0.9 per cent) with stress gastric ulcer. Seven patients discharged themselves against medical advice. Five patients died. The favourable results in this series were attributed mainly to the low severity of burns and partially to the short delay between injury and admission, early surgery and remarkably good facilities. Childhood scalds in this region of the world could possibly be reduced by changing the family habit of having tea at floor level and recommending wide-based tea-pots.

Adolescent↗
PubMed1990

[Pedal cutaneous island flap. Apropos of 6 case reports].

The authors report their experience using the dorsalis pedis island flap, described by MacCraw, for coverage of soft tissue defects of the heel, and both lateral and medial areas of ankle. The operative technique is recalled and six cases are presented. The authors analyse the several indications of the island flap. Its disadvantages are emphasized.

Adolescent↗
PubMed1990

Bibliometric aspects of medical information in Arab countries.

This paper discusses the current state and development of health and biomedical literature in Arab countries. The study concentrates on the Arabic sources of medical articles, and surveys and analyzes the size of the literature and its development in the past 100 years. Two aspects of these sources are covered: the Arab medical information sources published within the Arab region, and those published outside the region. This includes the quantity of material available within and outside the Arab region. The size of the Arab medical literature indicates that it is worthy of collection. Treatment of the Arab medical literature, a pressing and urgent issue, is needed to assist in the research and development of an Arab medical infrastructure.

Bibliometrics↗
PubMed1988

Psychoactive medication use in intermediate-care facility residents.

Despite the large number of elderly patients in nursing homes and the intensity of medication use there, few current data are available on patterns of medication use in this setting. We studied all medication use among 850 residents of 12 representative intermediate-care facilities in Massachusetts. Data on all prescriptions and patterns of actual use were recorded for all patients during one month. On average, residents were prescribed 8.1 medications during the month (interquartile range, 7.4 to 8.8) and actually received 4.7 (range, 4.2 to 5.4) medications during this period. More than half of all residents were receiving a psychoactive medication, with 26% receiving antipsychotic medication. Twenty-eight percent of patients were receiving sedative/hypnotics during the study month, primarily on a scheduled rather than an as-needed basis. Of patients receiving a sedative/hypnotic, 26% (range, 14% to 41%) were taking diphenhydramine hydrochloride, a strongly anticholinergic hypnotic. Of those receiving one of the benzodiazepines, 30% were receiving long-acting drugs, generally not recommended for elderly patients. The typical benzodiazepine dose was equivalent to 7.3 mg per patient per day of diazepam. The most commonly used antidepressant was amitriptyline hydrochloride, the most sedating and anticholinergic antidepressant in common use. These data indicate that despite growing evidence of the risks of psychoactive drug use in elderly patients, the nursing home population studied was exposed to high levels of sedative/hypnotic and antipsychotic drug use. Suboptimal choice of medication within a given class was common, and use of standing vs as-needed orders was often not in keeping with current concepts in geriatric psychopharmacology. Additional research is needed to assess the impact of such drug therapy on cognitive and physical functioning, as well as to determine how best to improve patterns of medication use in this vulnerable population.

Aged↗
PubMed1982

Social and contextual factors in the analysis of mortality in end-stage renal disease patients: implications for health policy.

A sample of medical records of decreased End-Stage Renal Disease (ESRD) patients was reviewed by a panel of experienced clinicians. The panel's determination of cause of death was compared to that reported for these patients in the Health Care Financing Administration Management Information System. There was concurrence in only 25 per cent of the cases. The difference is attributable to increased awareness of psychosocial and behavioral antecedent factors surrounding the occurrence of death.

Adult↗