Silver nanoparticles as a therapeutic agent in experimental cyclosporiasis.

Cyclosporiasis is an emerging worldwide infection caused by an obligate intracellular protozoan parasite, Cyclospora cayetanensis. In immunocompetent patients, it is mainly manifested by self-limited diarrhea, which is persistent and may be fatal in immunocompromised patients. The standard treatment for cyclosporiasis is a combination of two antibiotics, trimethoprim and sulfamethoxazole. Gastrointestinal, haematologic and renal side effects were reported with this combination. Moreover, sulfa allergy, foetal anomalies and recurrence were recorded with no alternative drug treatment option. In this study, silver nanoparticles were chemically synthesized to be evaluated for the first time for their anti-cyclospora effects in both immunocompetent and immunosuppressed experimental mice in comparison to the standard treatment. The effect of silver nanoparticles was assessed through studying stool oocyst load, oocyst viability, ultrastructural changes in oocysts, and estimation of serum gamma interferon. Toxic effect of the therapeutic agents was evaluated by measuring liver enzymes, urea and creatinine in mouse sera. Results showed that silver nanoparticles had promising anti-cyclospora potentials. The animals that received these nanoparticles showed a statistically significant decrease in the oocyst burden and number of viable oocysts in stool and a statistically significant increase in serum gamma interferon in comparison to the corresponding group receiving the standard treatment and to the infected non-treated control group. Scanning electron microscopic examination revealed mutilated oocysts with irregularities, poring and perforations. Biochemical results showed no evidence of toxicity of silver nanoparticles, as the sera of the mice showed a statistically non-significant decrease in liver enzymes in immunocompetent subgroups, and a statistically significant decrease in immunosuppressed subgroups. Furthermore, a statistically non-significant decrease in urea and creatinine was recorded in all subgroups. Thus, silver nanoparticles proved their effectiveness against Cyclospora infection, and this will draw the attention to its use as an alternative to the standard therapy.

Code-time diversity for direct sequence spread spectrum systems.

Time diversity is achieved in direct sequence spread spectrum by receiving different faded delayed copies of the transmitted symbols from different uncorrelated channel paths when the transmission signal bandwidth is greater than the coherence bandwidth of the channel. In this paper, a new time diversity scheme is proposed for spread spectrum systems. It is called code-time diversity. In this new scheme, N spreading codes are used to transmit one data symbol over N successive symbols interval. The diversity order in the proposed scheme equals to the number of the used spreading codes N multiplied by the number of the uncorrelated paths of the channel L. The paper represents the transmitted signal model. Two demodulators structures will be proposed based on the received signal models from Rayleigh flat and frequency selective fading channels. Probability of error in the proposed diversity scheme is also calculated for the same two fading channels. Finally, simulation results are represented and compared with that of maximal ration combiner (MRC) and multiple-input and multiple-output (MIMO) systems.

Gastrointestinal stromal tumours (GISTs): case report and review of the literature.

Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors of the gastrointestinal tract, the majority of which is KIT (CD117) positive. In this case report, we describe a case of recurrent and metastatic GIST who presented with hepatic and brain metastases. Despite the patient's GISTs was negative for c-Kit (CD 117), he responded to imatinib mesylate (Glivec) treatment with complete resolution of his liver and brain lesions. The patient has been and still in complete remission for 18 months of follow-up.

Correlation of antigenic expression with progress in antibiotic therapy of acute human brucellosis.

Human brucellosis is a zoonotic disease which is endemic in Saudi Arabia. The aim of this study was to investigate the humoral immune responses and identify the target antigens that persist at different stages in human brucellosis during antibiotic therapy. To do this, an acute case of accidental nosocomial infection was studied experimentally. Blood was collected from the patient at the time of diagnosis, and at weekly intervals during therapy until remission. IgG and IgM immunoblotting was used to characterize specific antigenic determinants, and ELISA antibody titration was performed to quantify the circulating antibodies. Results indicated that protein bands of 12-13.5 kDa bound IgG in the patient's sera but did not bind IgM on immunoblots and are probably not specific for, or important in, early stage infections. However, an 18 kDa band persisted during infection through remission. The pivotal and most important findings were that the number of protein bands seen on immunoblots, the magnitude of ELISA antibody titres and the concomitant changes in the intensity of the polypeptide bands of 42-43 kDa were positively correlated with the stage of infection. High numbers of anti-IgG and -IgM immunoblot bands coupled with high ELISA antibody titres and a concomitant increase in intensity of the 42-43 kDa bands were positively correlated with acute and severe infection. Conversely, a reduction in the number of polypeptide bands as well as a decrease in the intensity, until the complete disappearance of the 42-43 kDa bands, coupled with low (baseline) ELISA antibody titration values indicated successful treatment and remission. The routine use of the methods described here to ascertain the stage of the disease, assess the progress of antimicrobial therapy and monitor cases of relapse in human brucellosis is suggested.

Empty sella syndrome: does it exist in children?

OBJECT: The empty sella syndrome (ESS) is well documented in adults, and although the same phenomenon of herniation of the arachnoid space into the enlarged sella turcica has been noted in children, it is not widely known that children suffer from this syndrome. Therefore, the aims of this paper are to increase neurosurgeons' awareness of the existence of this phenomenon in children and to add to the scant body of literature on the subject. METHODS: The authors treated 12 children, ranging in age between 2 and 8 years, in whom neuroradiological studies demonstrated an enlarged sella turcica filled with cerebrospinal fluid and herniation of suprasellar and arachnoid spaces. The causes of ESS in these children were high intracranial pressure, neglected or improperly treated hydrocephalus, and suprasellar arachnoid cyst. Primary ESS was found as well. Most of the children presented with headache, abnormal body weight (the majority being underweight), and short stature. The results of hormone assays were normal in all children. CONCLUSIONS: If undiagnosed and untreated, ESS in children may lead to serious consequences, including impairment of pituitary and hypothalamic function and damage to the optic chiasm. It is important to raise awareness in the neurosurgical community about the existence of ESS in children so that it can be diagnosed and treated at an early stage. A classification system for the diaphragma sellae is recapitulated.

Magnetic resonance imaging of tuberculous spondylitis.

STUDY DESIGN: This retrospective study analyzed the magnetic resonance imaging characteristics of tuberculous spondylitis. OBJECTIVE: To describe the magnetic resonance imaging characteristics of tuberculous spondylitis and compare the diagnostic yield of magnetic resonance imaging versus other modalities. SUMMARY OF BACKGROUND DATA: Tuberculous spondylitis is not an uncommon occurrence with extrapulmonary disease. It requires prompt diagnosis and management. In the pre-magnetic resonance imaging era, computed tomography was used to delineate the associated radiologic changes. Data are limited that describe the magnetic resonance imaging pattern of tuberculous spondylitis and the effect of post-contrast enhancement. METHODS: The magnetic resonance imaging characteristics of 28 vertebrae in 12 patients with tuberculous spondylitis were studied. RESULTS: The thoracic spine was the most commonly involved region, with involvement occurring in the thoracic spine alone in 12 vertebrae (43%) and with other areas of the spine in an additional five (18%). Partial involvement was detected in the majority of the vertebral lesions (24; 86%). Magnetic resonance imaging evidence of disc space involvement was apparent in only 46% of the lesions. Paraspinal abscess and epidural extension were documented by magnetic resonance imaging in 71% and 61% of lesions, respectively. Decreased signal intensity on T1-weighted images was demonstrated in 13 vertebrae (46%), with increased signal intensity on T2-weighted images seen only in five (18%). CONCLUSION: Magnetic resonance imaging is a useful diagnostic modality for patients with suspected tuberculous spondylitis. Partial vertebral involvement and paraspinal and epidural extension were delineated. Study of the signal intensity on T1- and T2-weighted images revealed a pattern that may be dissimilar to that commonly reported. Post-contrast enhancement adds more certainty to the diagnosis of tuberculous spondylitis.

Postmenopausal osteoporosis in Saudi women: A pilot screening.

One hundred and ten radiographs of calcaneum were reviewed for postmenopausal osteoporosis in Saudi women. These patients had presented to the emergency room with unrelated complaints. The mean (+/- SD) age of this group was 58 (+/-8.9) years with a range of 45 to 80 years. Of these eighty-six (76%) patients had osteoporosis; of these, 42 had mild osteoporosis, 31 had frank osteoporosis, and 11 were diagnosed to have sever osteoporosis. Women with severe osteoporosis were significantly older than those with mild (P=0.0417) as those who were normal (P=0.002). This study indicates a high prevalence of postmenopausal osteoporosis in Saudi women and multicenter, large scale screening should be instituted to determine the incidence of postmenopausal osteoporosis among Saudi women.

Fatty infiltration of the liver: analysis of prevalence, radiological and clinical features and influence on patient management.

Over a 6-year period, in 1425 adult computed tomographic studies, radiological evidence of fatty infiltration of the liver (FIL) was found in 138 patients (9.7%). Patients with FIL had a mean age +/- SD of 45.9 +/- 15.7 years and 57% were males; the majority were Saudis (73%). Most patients (95%) had one or more underlying aetiological causes. Haematological and non-haematological malignancies with or without liver involvement were the most frequently encountered aetiological factors (66% of patients). FIL contributed to hepatomegaly or was associated with abnormality in one or more of the liver function tests in 30% and 39% of patients, respectively. Assessment of the various radiological patterns showed diffuse fatty changes in 68% of patients and solitary or multiple focal changes in 9% and 22%, respectively. 13 patients (9%) showed sparing of the caudate lobe within a diffuse fatty process. Patients with diffuse FIL had significantly higher values for alkaline phosphatase (p = 0.0016) and serum asparate aminotransferase (p = 0.0251) than those who had the focal pattern. FIL in 20 patients (14%) imposed a difficulty in making an appropriate diagnosis, led to inaccurate impressions, or forced unnecessary invasive or non-invasive investigations. We conclude from our large series of patients that FIL is not uncommon in hospital practice and among those at risk should always be considered as an appropriate diagnosis.

Choanal atresia: How useful is computed tomography.

Computed tomography (CT) has recently been hailed as the most useful tool in the diagnosis and management of congenital posterior choanal atreasia. Our study of 11 patients with posterior choanal atresia by CT does not seem to confirm this claim. CT, which demonstrates very clearly all the anatomical details of the region, does not appear to play any major role in the diagnosis of the condition; nor in the planning of the management of patients in whom posterior choanal atreasia is the only major craniofacial abnormality.

The paratemporal segment of the maxillary sinus: a new sign for assessment of size.

The area of the maxillary antrum in Waters' view has been measured in 68 patients using a mechanical planimeter. The mean area was 6.04 +/- 0.25 cm2. The part of the antrum lateral to the innominate line (defined as the paratemporal segment) has a mean area of 0.72 +/- 0.07 cm2. The latter diminishes in small antra and approaches zero when the total antral area falls below 3.48 cm2. It is proposed that the innominate line (Stenvers), or its extension, descends lateral to the field of the small maxillary sinus and may be used as an additional sign of such abnormality.

Tuberculosis in patients with malignant disease.

Of 2,143 biopsy proven cancer patients seen at our hospital over a six year period, 4 (0.19%) patients developed active tuberculosis (TB) during anticancer therapy or shortly after its completion. The cancer diagnoses of those patients were non-Hodgkin's lymphoma, breast cancer, chronic myelogenous leukemia, and astrocytoma. Institution of antituberculous therapy was successful in three patients, however, the TB course was rapidly fatal in the fourth patient with non-Hodgkin's lymphoma despite therapy. The association between TB and neoplasia is emphasized. TB complicating malignant disorders represents complex problem regarding its early recognition and its managements.

Angiomyolipoma of the nasal cavity.

Vascular tumours of the nasal cavity are uncommon and are either hamartomas or true neoplasms, mostly benign. We present an unusual case of angiomyolipoma of the nasal cavity. This hamartomatous lesion is often described in the kidney and may be associated with tuberous sclerosis. To our knowledge, there is no previous report of the lesion in the nasal cavity, and no association with tuberous sclerosis has been demonstrated in this case.

Primary paranasal Aspergillus granuloma in Saudi Arabia.

Respiratory aspergillosis has been described in many parts of the world; but primary paranasal aspergillus granuloma (PPAG), a recognised, distinct entity, has been described almost exclusively in Africa--specifically in the Sudan. The first case of PPAG in Saudi Arabia with bilateral involvement of paranasal sinuses is described. In view of the geographical similarities between Northern Sudan and Saudi Arabia, it is suggested that some of the granulomatous inflammatory conditions occurring in Saudi Arabia for which no definite aetiological agent has been ascribed may fall into this category. Increased awareness of the condition, together with the use of serological methods currently in use in the Sudan may help in defining the condition properly in this locality.

Traditional remedies and lead intoxication.

Three Saudi children suffered from lead intoxication as a result of ingestion of a preparation prescribed by a traditional practitioner. Two of them showed no symptoms of lead intoxication while the third child gave a history of symptomatic intoxication in the form of convulsions. The blood lead levels were increased in all patients and radiographic lead bands were seen in the long bones of the three children. The blood lead concentration was decreased by Na-Ca-EDTA and BAL treatment in the three patients.