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Biomedical subjects

Steven Rubin

Publications and source records attributed to Steven Rubin.

12 recordsLinked to original sources
PubMed2006

Predictors of partner notification for C. trachomatis and N. gonorrhoeae: an examination of social cognitive and psychological factors.

Efforts to control chlamydial and gonococcal infections include notifying eligible sexual partners of possible infection, primarily by asking the diagnosed patient to notify their partners. This approach, known as patient referral, is widely used but poorly understood. The current study examined psychosocial and cognitive factors associated with patient referral among an urban, minority sample of 168 participants recently diagnosed with Chlamydia trachomatis or Neisseria gonorrhoeae. At a follow-up interview 1-month from diagnosis, participants were more likely to have notified all eligible partners if they had greater intention to notify at baseline (OR = 3.72; 95% CI = 1.34, 10.30) and if they had only one partner at baseline (OR = 4.08; 95% CI = 1.61, 10.31). There were also gender differences as well as differences based on type of partner (i.e., regular, casual, one-time). The implications of these findings for the design of programs to promote patient referral for sexually transmitted infections are discussed.

Adolescent↗
PubMed2006

Interval appendectomy: an old new operation.

A retrospective chart review of 32 patients who underwent laparoscopic interval appendectomy at the Children's Hospital of Eastern Ontario between May 1999 and December 2003 was performed. The age range was 0.5 to 18 years (mean, 11.8 years; median, 11.5 years). The interval time from the acute episode to the laparoscopic interval appendectomy ranged from 1 to 16 weeks (median, 6 weeks). The initial presentations were 11 patients with appendiceal abscess, 9 with appendiceal masses/phlegmons, and 12 patients with an acute but resolving clinical picture with ultrasonographic evidence of appendicitis. There were no wound infections or recurrent intra-abdominal abscesses. The average length of stay was 1.38 days, ranging from same-day discharge (1 patient) to a three-night stay (2 patients). There were no complications related to the laparoscopic technique, confirming reports that laparoscopic interval appendectomy is a technically safe procedure. Pathologic analysis of the appendices demonstrated acute or subacute changes in 14 patients (interval time = 7.9 weeks), chronic changes in 8 (interval time = 8.1 weeks), both acute and chronic changes in 5 (interval time = 8.2 weeks), and no pathologic diagnosis in 6 (interval time = 4.28 weeks). These findings support the need for interval appendectomy, and suggest that laparoscopy is a safe alternative to open appendectomy.

Adolescent↗
PubMed2005

Serological and phylogenetic evidence of monotypic immune responses to different mumps virus strains.

The recent resurgence of mumps epidemics in many countries with ongoing vaccination programs along with evidence of antigenic diversity among mumps virus strains have recently challenged the assumption that mumps virus is serologically monotypic. To address this controversy, we sought to identify two mumps virus strains that would best represent different serotypes, should multiple serotypes exist, and assess the ability of human sera to neutralize both strains. The virus strains, Enders and Lo1, were selected based upon a phylogenetic analysis of the major target of neutralizing antibody, the viral hemagglutinin-neuraminidase (HN) protein, along with data reported by others indicating that (1) these viruses are antigenically distinct and (2) genotypically similar strains have been implicated in cases of reinfection. Our results show that of sera capable of neutralizing one of the virus strains, 90% could neutralize the other, although significant differences in neutralization titers were noted. Though the latter confirms the existence of inter-strain antigenic variability, the fact that few sera were unable to neutralize both virus strains argues against the presence of multiple serotypes. Of those sera incapable of co-neutralization, all but one had low neutralization titers (1:8), suggesting that individuals possessing low levels of neutralizing antibody may be at risk for breakthrough infections, thereby providing an explanation for cases of infection in previously infected or vaccinated individuals.

Antibodies, Monoclonal↗
PubMed2005

Empyema management: twelve years' experience since the introduction of video-assisted thoracoscopic surgery.

We reviewed empyema management at our center since video-assisted thoracoscopic surgery (VATS) was introduced. Between 1991 and 2003, 58 patients (34 male, 24 female) ages 1 day to 17 years (median, 6 years) were identified. The median interval from the onset of symptoms to presentation was 7 days; 31% of patients received inpatient care at another hospital, and 24% were from northern communities, including the Arctic. Symptoms included fever (100%), cough (66%), shortness of breath (46%), chest pain (38%), and abdominal pain (17%). Most patients (96%) had pneumonia. The most common organisms were Streptococcus pneumoniae (22%), group A streptococcus (8%), and Mycobacterium tuberculosis (3%). No organisms were identified in 31% of patients. One empyema was trauma-related and one was due to complications of esophageal stricturoplasty. All patients received intravenous antibiotics (median, 17 days). Three patients had thoracentesis, 17 had chest tubes, 3 had thoracentesis and chest tubes, 26 had VATS, 6 had thoracotomy, and 3 had minithoracotomy. Median operative times were 86 minutes for VATS, 90 minutes for thoracotomy, and 75 minutes for minithoracotomy. Median total length of stay (LOS) was 15 days for VATS, 20.5 days for thoracotomy, and 21 days for minithoracotomy. The median preoperative LOS was longer for thoracotomy (10 days) than for VATS (5 days) or minithoracotomy (1 day). The median postoperative LOS was 14 days for VATS, 9.5 days for thoracotomy, and 8 days for minithoracotomy. Our experience shows that VATS is a safe and effective approach to managing children with empyema. The shorter preoperative LOS for VATS is likely due to earlier surgical referral and intervention using less invasive surgical procedures.

Adolescent↗
PubMed2005

Mumps virus-specific antibody titers from pre-vaccine era sera: comparison of the plaque reduction neutralization assay and enzyme immunoassays.

Mumps virus-neutralizing antibodies are believed to be the most predictable surrogate marker of protective immunity. However, assays used to detect neutralizing antibodies, such as the plaque reduction neutralization (PRN) assay, are labor- and time-intensive and consequently are often supplanted by the more rapid and inexpensive enzyme immunoassay (EIA) technique. For virus infections for which international antibody standards exist and are bridged to clinical studies of protection (e.g., measles and rubella), the EIA has been successfully used to determine immune surrogate endpoints, yet no such international reference exists for mumps serology. Since both virus-neutralizing and nonneutralizing antibodies are measured in the EIA, in the absence of a mumps serological standard, the EIA may be prone to yielding false-positive results when utilized for assessing surrogate markers of protective immunity. Moreover, since mumps virus-specific antibody titers are generally low in comparison to antibody levels induced by other viruses and EIA procedures often employ relatively high serum dilution factors, the EIA may be prone to yielding false-negative results. To examine these issues, a PRN assay and two commercially available EIA kits were used to evaluate wild-type mumps virus serological responses in human serum samples from the pre-mumps vaccine era. Our results indicate that the PRN assay is a more sensitive and specific method of measuring serological responses to wild-type mumps virus.

Adolescent↗
PubMed2004

Developmental alterations in serotoninergic neurotransmission in Borna disease virus (BDV)-infected rats: a multidisciplinary analysis.

Neonatal Borna disease virus (BDV) infection of the rat brain serves as a valuable model for studying the pathogenesis of neurodevelopmental abnormalities following early brain injury. Previous experiments have demonstrated significant alterations in regional tissue content of serotonin (5-HT) in neonatally BDV-infected Lewis rats. The present study sought to provide more insights into postnatal virus-associated alterations in 5-HT neurotransmission by evaluating the density of 5-HT1a receptors in the hippocampus and 5-HT2a receptors in the cortex, regional 5-HT tissue concentrations, behavioral responses to a 5-HT agonist, quipazine, and numbers of neurons in specific subfields of the hippocampus on days 7, 14, and 30 after neonatal BDV infection in Lewis rats. Neonatal BDV infection was found to be associated with a gradual increase in the density of 5-HT2a and 5-HT1a postsynaptic receptors followed by an elevation of 5-HT contents at both the levels of synaptic terminals (i.e., cortex and hippocampus) and cell bodies (i.e., raphe nuclei). In addition, there was an enhanced behavioral response to quipazine. Virus-associated neurochemical and behavioral changes were accompanied by a decline in the number of neurons in the dentate gyrus and in the CA1 field of the hippocampus. No change in the number of neurons in the CA3/2 field of the hippocampus was observed. The present pattern of BDV-associated alterations in 5-HT brain system along with available data from other laboratories suggest that BDV might compromise axonal transport and/or release of 5-HT, resulting in decreased 5-HT neurotransmission.

Animals↗
PubMed2004

Wild-type and attenuated influenza virus infection of the neonatal rat brain.

Although influenza virus infection of humans has been associated with a wide spectrum of clinical neurological syndromes, the pathogenesis of influenza virus associated central nervous system (CNS) disease in humans remains controversial. To better study influenza virus neuropathogenesis, an animal model of influenza-associated CNS disease using human virus isolates without adaptation to an animal host was developed. This neonatal rat model of influenza virus CNS infection was developed using low-passage human isolates and shows outcomes in specific brain regions, cell types infected, and neuropathological outcomes that parallel the available literature on cases of human CNS infection. The degree of virus replication and spread in the rat brain correlated with the strains' neurotoxicity potential for humans. In addition, using sensitive neurobehavioral test paradigms, changes in brain function were found to be associated with areas of virus replication in neurons. These data suggest that further evaluation of this pathogenesis model may provide important information regarding influenza virus neuropathogenesis, and that this model may have possible utility as a preclinical assay for evaluating the neurological safety of new live attenuated influenza virus vaccine strains.

Animals↗
PubMed2004

Long-term complications of congenital esophageal atresia and/or tracheoesophageal fistula.

Congenital esophageal atresia (EA) and/or tracheoesophageal fistula (TEF) are common congenital anomalies. Respiratory and GI complications occur frequently, and may persist lifelong. Late complications of EA/TEF include tracheomalacia, a recurrence of the TEF, esophageal stricture, and gastroesophageal reflux. These complications may lead to a brassy or honking-type cough, dysphagia, recurrent pneumonia, obstructive and restrictive ventilatory defects, and airway hyperreactivity. Aspiration should be excluded in children and adults with a history of EA/TEF who present with respiratory symptoms and/or recurrent lower respiratory infections, to prevent chronic pulmonary disease.

Adolescent↗
PubMed2004

Wilms' tumor at the Children's Hospital of Eastern Ontario: 1990-2001.

BACKGROUND: Wilms' Tumor is the most common malignant neoplasm of the urinary tract in children. Since 1969, the National Wilms' Tumor Study Group (NWTSG) has contributed to improving the clinical management and outcome of children affected by Wilms' Tumor. We have managed our patients according to NWTSG protocols and report our results herein. METHODS: Retrospective chart review of consecutive patients presenting at the Children's Hospital of Eastern Ontario (CHEO) with a diagnosis of Wilms' Tumor between April 1990 and March 2001. RESULTS: Forty patients with Wilms' Tumor (18 M/22 F) were diagnosed at CHEO during this interval. Mean age at diagnosis was 28.5 months. The most common presenting feature was a palpable abdominal mass in 85%. An overgrowth syndrome was noted in 10%. Metastatic disease was present at diagnosis in 20%, with the lungs (75%) the most common site of involvement. Distribution of clinical stage: I = 40%, II = 20%, III = 20%, IV = 15%, V = 5%. Favorable histology (FH) was diagnosed in 82.5%, anaplasia in 12.5% and clear cell sarcoma (CCSK) in 5%. Nephrogenic rests were present in 43% (perilobar (PL) = 20%, intralobar (IL) = 18%, PL + IL = 5%). Recurrence of disease occurred in 10%, with lungs (100%) the most frequent site of relapse. Survival was significantly greater in stage I disease and in those patients with FH. Patient 4-year survival data: stage I (FH), 100%; stage II (FH), 80%; stage III (FH), 100%, stage IV (FH), 67%; stages I-IV (CCSK), 100%; stage V, 0%. Overall 4-year survival rates of patients with FH were 92% and of all patients in the study was 86%. CONCLUSIONS: The presentation of Wilms' Tumor at our institution mirrors that described in the literature. Importantly, by following NWTSG protocols we have achieved an outcome of overall 4-year patient survival comparable to the "gold standard". This demonstrates the utility of the NWTSG protocols as regards patient management of this relatively uncommon disease.

Child↗
PubMed2003

Identification of a new genotype H wild-type mumps virus strain and its molecular relatedness to other virulent and attenuated strains.

A single clinical isolate of mumps virus designated 88-1961 was obtained from a patient hospitalized with a clinical history of upper respiratory tract infection, parotitis, severe headache, fever and lymphadenopathy. We have sequenced the full-length genome of 88-1961 and compared it against all available full-length sequences of mumps virus. Based upon its nucleotide sequence of the SH gene 88-1961 was identified as a genotype H mumps strain. The overall extent of nucleotide and amino acid differences between each individual gene and protein of 88-1961 and the full-length mumps samples showed that the missense to silent ratios were unevenly distributed. Upon evaluation of the consensus sequence of 88-1961, four positions were found to be clearly heterogeneous at the nucleotide level (NP 315C/T, NP 318C/T, F 271A/C, and HN 855C/T). Sequence analysis revealed that the amino acid sequences for the NP, M, and the L protein were the most conserved, whereas the SH protein exhibited the highest variability among the compared mumps genotypes A, B, and G. No identifying molecular patterns in the non-coding (intergenic) or coding regions of 88-1961 were found when we compared it against relatively virulent (Urabe AM9 B, Glouc1/UK96, 87-1004 and 87-1005) and non-virulent mumps strains (Jeryl Lynn and all Urabe Am9 A substrains).

Animals↗
PubMed2002

Sequence diversity of Jeryl Lynn strain of mumps virus: quantitative mutant analysis for vaccine quality control.

The Jeryl Lynn strain of mumps vaccine live (MVL) was developed in 1966 by Merck Co. and has been widely used in the U.S. and other countries since the early 1970s. Partial sequencing has recently shown that the vaccine contains a mixture of two substrains with substantially different nucleotide sequences. We have determined the complete genomic sequences of both substrains and identified 414 nucleotide differences (2.69%), leading to 87 amino acid substitutions (1.67%). We used this information to develop methods for quantification of the substrain components in vaccine samples based on PCR and restriction enzyme cleavage and oligonucleotide microarray hybridization and monitored their dynamics in viral populations propagated in different conditions. Passaging Jeryl Lynn strain in Vero or CEF cell cultures resulted in rapid selection of the major component JL1, while growth in embryonated chicken eggs (ECE) favored accumulation of the minor component JL2. Based on the findings presented here, it is proposed that the substrain composition of Jeryl Lynn vaccine can be monitored as a part of its quality control to ensure consistency of the vaccine.

Amino Acid Sequence↗