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Biomedical subjects

I Kassis

Publications and source records attributed to I Kassis.

At least 19 recordsLinked to original sources
PubMed2006

Isolation of mesenchymal stem cells from G-CSF-mobilized human peripheral blood using fibrin microbeads.

Adult mesenchymal stem cells (MSC) that are able to differentiate into various mesenchymal cell types are typically isolated from bone marrow, but their significant presence in human peripheral blood (PB) is controversial. Fibrin microbeads (FMB) that bind matrix-dependent cells were used to isolate MSC from the mononuclear fraction of mobilized PB of adult healthy human donors treated with a granulocyte colony-stimulating factor. Isolation by plastic adherence resulted in a negligible number of MSC in all samples tested, whereas FMB-based isolation yielded spindle-shaped cell samples that could further expand on plastic or on FMB in eight out of the 11 samples. The yield of these cells at days 17-18 after the harvest was approximately 0.5% of the initial cell number. The isolated cells were grown on plastic and characterized by FACS analysis and immunohistochemistry for specific markers. Following culturing and first passage, the FMB-isolated cells stained positive for mesenchymal stromal cell markers CD90 and CD105, expressed vimentin and fibronectin and were negative for hematopoietic markers CD45 and CD34. These cells could differentiate into osteoblasts, adipocytes and chondrocytes. This study indicates that FMB may have special advantage in isolating MSC from sources such as mobilized PB, where the number of such cells is scarce.

Antigens, CD↗
PubMed2005

An outbreak of Q fever in an urban area in Israel.

Reported here is an outbreak of 21 cases of Q fever that were diagnosed during 5 months in the spring and summer of 2001 at Rambam Medical Center, Haifa, Israel. An epidemiological investigation and a case-control study were conducted to identify risk factors associated with acquisition of the disease in this outbreak. Patients were more likely than controls to live in Krayot (a large suburb of Haifa) (76.2% vs. 41.5%; p=0.005), to have more contact with animals (usually pets) (66.7% vs. 26.9%; p=0.007), and to consume more unpasteurized dairy products (23.8% vs. 0%; p=0.01). The Krayot suburb is an entirely urban area, but several livestock facilities are located in its close vicinity, and some of them have been reported to harbor Q fever. Although the patients did not recall having had direct contact with farm animals, the results suggest the presence of livestock facilities in such close proximity to a residential area may cause urban outbreaks of Q fever.

Adolescent↗
PubMed2002

Clinical and epidemiologic significance of coagulase-negative staphylococci bacteremia in a tertiary care university Israeli hospital.

OBJECTIVES: To characterize the clinical significance of coagulase-negative staphylococci (CNS) bacteremia. DESIGN: Prospective cohort study. SETTING: A 900-bed hospital in Haifa, Israel, from November 1996 to March 1997. RESULTS: Of 137 episodes of positive blood cultures for CNS, 41 (30%) were considered as true infection. Twenty-seven of 119 episodes associated with only 1 blood culture positive for CNS (23%) met the definition of infection as compared with 14 of 18 episodes (78%) associated with 2 or more blood cultures positive for CNS (P <.001). Methicillin resistance was significantly more frequent among Staphylococcus epidermidis isolates of episodes of true bacteremia than of episodes of contamination (15 of 22 [68%] vs. 11 of 33 [33%], respectively; P =.02). S hominis was isolated only in episodes considered as contamination (P =.01). It was estimated that CNS represents 24% of all nosocomial bloodstream pathogens. When CNS were isolated in the first 48 hours of hospitalization, an intravascular device was more frequently associated with episodes of true bacteremia than in those considered as contamination (7 of 7 [100%] vs. 10 of 57 [18%], respectively; P <.001). The mortality rate among patients with true CNS bacteremia was 16%. CONCLUSION: Some laboratory parameters may help identify episodes of true CNS bacteremia, which appears to be more common than previously considered.

Adult↗
PubMed2001

Review of 49 neonates with acquired fungal sepsis: further characterization.

BACKGROUND: Neonatal acquired fungal sepsis (AFS) is a risky condition that warrants every effort for early diagnosis and management. METHODS: We retrospectively reviewed the medical charts of all 4445 neonatal intensive care unit (NICU) admissions in the past 10 years and detected 49 neonates with AFS. We then compared their data with those of 49 matched control neonates who did not have AFS. The following details were collected: gestational, perinatal and neonatal courses; bacterial sepsis; antibacterial therapy; laboratory and imaging investigations; and antifungal therapy and its complications. RESULTS: The incidence of AFS was.4 to 2 cases per 1000 live-births and 3.8% to 12.9% of very low birth weight (VLBW) infants. Compared with 1989 through 1992, between 1993 and 1995 the rate of AFS in VLBW neonates significantly increased (3. 8%-5.6% --> 9.6%-12.9%), along with a significant increase of NICU admission rate (369-410 --> 496-510 admissions/year). Compared with controls, AFS neonates had significantly longer hospitalizations, higher rates of mechanical ventilation, umbilical vein catheterization, and previous treatment with broad-spectrum antibacterial agents (amikacin, vancomycin, ceftazidime, or imipenem). At the onset of AFS, 42.8% of patients had hyperthermia and 40.9% had normal white blood cell count. Causative fungi were as follows: Candida albicans-42.8% of cases, Candida parapsilosis-26.5%, and Candida tropicalis-20.4%. Fungal dissemination was rare, complications of antifungal therapy were infrequent, and no deaths occurred. CONCLUSIONS: First, non-albicans Candida have become more frequent in neonatal AFS. Second, mechanical ventilation and antibacterial agents are significant risk factors for AFS. Third, hyperthermia is a frequent presenting sign of AFS. Fourth, a normal white blood cell count does not rule out AFS. Fifth, meningeal involvement in neonatal AFS should be ruled out before initiation of antifungal therapy. Sixth, the policy of empiric antifungal therapy for AFS should be considered on an individual NICU basis.newborn infant, fungal sepsis, clinical signs, risk factors.

Abdomen↗
PubMed2001

Staphylococcal scalded-skin syndrome in a very low birth weight premature infant.

Exfoliative skin diseases are rare in neonates. When caused by coagulase-positive Staphylococcus aureus, scalded-skin diseases such as staphylococcal scalded-skin syndrome (SSSS), bullous impetigo, and staphylococcal scarlet fever may develop. These diseases might cause significant complications and mortality. SSSS is caused by staphylococcal exfoliative toxins A or B, which split the granular layer of the skin, induce proteolysis, and might exhibit superantigen activities, such as epidermolysis and lymphocyte mitogenicity. We describe a 1378-g premature male infant who was born at 29 weeks' gestation and developed SSSS on day 3 of life, with no clinical signs of neonatal sepsis. After cultures from the lesion and bloodstream were obtained, intravenous cloxacillin therapy was started. Infection control measures were implemented instantly and included isolation of the infected infant, personnel handwashing with hexachlorophene, and placement of exposed neonates into a cohort. The initial lesion expanded and additional lesions appeared, but 12 hours after initiation of antibacterial therapy, the lesions ceased to proliferate. Cultures from scalded-skin lesions grew coagulase-positive Staphylococcus aureus, whereas the bloodstream culture was sterile. The lesions resolved completely within 6 days, and the infant's subsequent course was uneventful. No similar skin lesions were noticed in other infants in the neonatal intensive care unit. We discuss recent advances in understanding the pathogenesis of neonatal SSSS, highlight the importance of early diagnosis and treatment, and stress the need for new adjunctive therapies for this disease.

Coagulase↗
PubMed2000

Device-associated, device-day infection rates in an Israeli adult general intensive care unit.

Surveillance is an essential element of hospital infection control programs. Previous studies have shown that interhospital comparison of intensive care unit (ICU) nosocomial infections (NI) may be best made by comparing ICU-type-specific, device-associated infection rates and that these adjusted rates vary by ICU type. The aim of this study was to evaluate whether significant structural improvements introduced in an adult general ICU were associated with changes in the NI rates in this unit. In addition, we compared these rates with those of ICUs reported by the National Nosocomial Infections Surveillance (NNIS) System of the Centers for Diseases Control and Prevention. During a 12-month period 337 patients were surveyed. There were 20 ventilator-associated pneumonias (VAP)/1000 ventilator (VEN)-days, 12 bloodstream infections (BSI)/1000 central vascular catheter (CVC)-days and 14 urinary tract infection (UTI)/1000 indwelling urinary catheter (IUC)-days. Structural changes and reduction in device utilization ratios were not followed by change in NI rates in this unit. VAP and BSI rates were comparable to those reported for neurosurgical and burn ICUs, respectively, in the NNIS System, despite a much higher device utilization ratios. The present study provides specific surveillance data for further interhospital comparison with similar types of ICUs.

Adult↗
PubMed1999

Effectiveness of a nationwide infant immunization program against Haemophilus influenzae b. The Israeli Pediatric Bacteremia and Meningitis Group.

An ongoing nationwide prospective surveillance program for invasive H. influenzae b (Hib) disease in Israel enabled us to study the effectiveness of a national infant Hib immunization program, which included all infants born since January 1994. The vaccine used was Hib polysaccharide conjugated to outer membrane protein complex of Neisseria meningitidis b (PRP-OMPC). For the cohort born during the 3 years since January 1994, the vaccine effectiveness was 94.9% for all invasive Hib diseases and 96.6% for meningitis. The efficacy in fully immunized subjects was 98.7 and 99.5%, respectively. A herd immunity effect could be observed, since a reduction in cases also occurred among infants too young to be immunized. No increase in invasive cases caused by S. pneumoniae and N. meningitidis was observed during the study period. This is the first report outside North America and Western Europe that demonstrates a nationwide extensive reduction of invasive Hib disease within a short time of the introduction of Hib conjugate vaccines to the infant immunization program.

Bacterial Outer Membrane Proteins↗
PubMed1998

Coexistence of acquired protein S and protein C deficiency and the Arg506Gln mutation in factor Va in a child with severe thromboembolic disease.

An 11-y-old girl who presented with cellulitis and clinical signs of deep vein thrombosis (DVT) is reported here. She developed staphylococcal sepsis, recurrent septic emboli and a large vegetation on the tricuspid valve. The patient was found to be heterozygous for the Arg506Gln mutation in factor Va and had low levels of protein C and protein S during the sepsis. The coexistence of the two thrombophilic states may explain the severe thromboembolic manifestations.

Alleles↗
PubMed1998

Early emergence of ganciclovir-resistant human cytomegalovirus strains in children with primary combined immunodeficiency.

Children with primary combined immunodeficiency (CID) and human cytomegalovirus (HCMV) infection often deteriorate despite antiviral therapy. In this study, the emergence of ganciclovir-resistant strains was examined in 6 children with CID and HCMV infection, using sequence analysis of the HCMV UL97 gene and virus susceptibility assays. Mutations in the proposed ATP binding site associated with ganciclovir resistance were found in 4 of the 6 children. In 1 patient with B severe CID, an unusual multiplicity of mutations was found in the UL97 substrate binding domain between aa 590-606. All mutations were detected within 10 days to 3 weeks from initiation of therapy. The emergence of resistant strains in children with CID appears earlier than in other groups of HCMV-infected patients. These findings may have relevance to the cellular pathways involved in viral DNA repair and mutagenesis, and they indicate the need for early and frequent genotypic monitoring and prompt therapeutic modification in this patient population.

Bone Marrow Transplantation↗
PubMed1997

Human toxicosis caused by the tick Ixodes redikorzevi in Israel.

The clinical symptoms of a tick toxicosis caused by Ixodes redikorzevi in northern Israel are described. The patient was a nine-year-old Arab boy from an agricultural village who was admitted to a local hospital and had been suffering for 4 days from fever and torticollis. A partially engorged female tick was removed from the nuchal area of the scalp, and the symptoms disappeared within 2 hours. Morphometrical measurements indicated that the tick was attached to the skin for 3-4 days.

Animals↗
PubMed1996

Safety and immunogenicity of a novel mammalian cell-derived recombinant hepatitis B vaccine containing Pre-S1 and Pre-S2 antigens in children.

We tested the safety and immunogenicity of the new recombinant hepatitis B virus (HBV) vaccine produced via expression of the Pre-S1, Pre-S2 and S protein components of the hepatitis B surface antigen (HBsAg). A reduced dose (2.5 micrograms) of the vaccine (Bio-Hep-B) was tested in children aged 4-9 years and was compared to a 10 microgram dose of a licensed vaccine (Engerix-B) in a randomized manner. Both vaccines were administered in 3 doses (0, 1 and 6 month intervals). Adverse events were collected 5 days following each vaccination by a diary card provided to the parents. Immunogenicity was tested by measuring anti-hepatitis B surface antibody (anti-HBs). A total of 217 children were enrolled (162 in the Bio-Hep-B group and 55 in the Engerix-B group). Total adverse events were observed in 35% of the Bio-Hep-B group and 33% of the Engerix-B group, with no differences when each of the potential adverse events was considered. Titers were within the expected range (geometric mean titers post dose 1, 2 and 3 were 45.8, 8360.2 and 1445.7, respectively, for Bio-Hep-B and 36.3, 10316.1 and 1898.7, respectively, for Engerix-B). A trend toward better immunogenicity with Bio-Hep-B was observed at early visits when measured by both seroconversion (anti-HBs > or = 2.1 mIU ml-1) rate and seroprotection (anti-HBs > or = 10 mIU ml-1) rate; however, statistical significance was not reached. We conclude that in children, Bio-Hep-B vaccine at a reduced dose was as safe and as immunogenic as Engerix-B given at the regular pediatric dosage.

Child↗
PubMed1995

Evaluation of an enzyme immunoassay for the detection of Cryptosporidium spp. in stool specimens from infants and young children in field studies.

Diagnosis of Cryptosporidium is made by the identification of oocysts in stool specimens. Screening in field studies relies mainly on acid-fast staining followed by microscopic examination. The more sensitive immunofluorescent antibody (IFA) staining method is time-consuming, may involve technical difficulties, and is extremely costly as a screening procedure in field studies. We evaluated the diagnostic utility of a commercially available enzyme immunoassay (EIA), which detects Cryptosporidium-specific antigen, in 204 unprocessed stool specimens obtained from patients less than three years of age from a field study in southern Israel. When compared with the routine screening procedure applied in this field study (screening by acid-fast staining and microscopy after concentration, and confirmation of positive results by IFA), both the sensitivity and specificity were 98%. Of 139 specimens negative by microscopy, 13 (9.3%) were positive by the EIA. Eleven of these were confirmed by inhibition with antibody to Cryptosporidia-specific antigen. The EIA is an important tool for identifying Cryptosporidium in fecal specimens in field studies since it is sensitive, specific, simple to use, and unaffected by the presence of a preservative.

Animals↗
PubMed1993

Cost benefit analysis of Haemophilus influenzae type b vaccination programme in Israel.

STUDY OBJECTIVE: The recent availability of Haemophilus influenzae type b (HIB) conjugate vaccines prompted an examination of the costs and benefits of four and three dose HIB prevention programmes targeting all newborns in Israel. MEASUREMENTS AND MAIN RESULTS: A four dose programme would reduce the number of childhood (aged 0-13) HIB cases from 184.2 to 31.3 per year, yielding a benefit ($1.03 million) to cost ($3.55 million) ratio of just 0.29/l for health services only, based on a vaccine price of $7.74 per dose. When benefits resulting from a reduction in mild handicaps and severe neurological sequelae are included, the benefit ($4.48 million) to cost ratio rises to 1.26/l and it reaches 1.45/l when the $0.66 million indirect benefits of reduced work absences and mortality are also included. Break even vaccine costs are $2.24 when health service benefits only are considered and $11.21 when all the benefits are included. CONCLUSION: In the absence of other projects with higher benefit to cost ratios, Israel should start to provide a nationwide HIB vaccination programme since the monetary benefits to society of such a programme will exceed the costs to society. A barrier to implementation may occur, however, because the costs of the programme exceed the benefits to the health services alone.

Adolescent↗
PubMed1993

Clinical features and epidemiology of invasive Kingella kingae infections in southern Israel.

OBJECTIVE: To characterize the clinical spectrum and epidemiology of invasive Kingella kingae infections in children living in southern Israel. DESIGN: Five-year observational, descriptive study. POPULATION: Children in whom K. kingae was isolated from blood or other normally sterile body fluid. RESULTS: Twenty-five patients with invasive K. kingae infection (13 male and 12 female) were identified. Twenty-four of these children were younger than 2 years. The annual incidence was 14.3, 27.4, and 31.9 cases per 100,000 children < or = 4 years, < or = 24 months, and < or = 12 months, respectively. Seventeen (68%) of 25 patients sought treatment between July and December. Concomitant upper respiratory tract infection or stomatitis was observed in 14 (56%) of the patients, suggesting a respiratory or buccal source for the infection. Four children were bacteremic: 2 of them suffered from a lower respiratory tract infection, and the remaining 2 had bacteremia with no evident focal infection. Twenty-one children had skeletal infections and none of them was bacteremic; 16 had septic arthritis, 3 had osteomyelitis, 1 had both osteomyelitis and septic arthritis of the adjacent joint, and 1 had dactylitis of the hand. Involvement of the ankle was unusually frequent among children with septic arthritis, whereas the calcaneus was involved in 3 of the 4 children with osteomyelitis. Antibiotic treatment resulted in full recovery in all cases, and only 2 patients with septic arthritis required surgical drainage. CONCLUSION: Kingella kingae is a much more common cause of invasive infection in young children than has been previously recognized. The disease has a clear seasonal pattern, usually affects the skeletal system, frequently involves unusual bones and joints, and follows a benign course.

Arthritis, Infectious↗