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Biomedical subjects

M Shapiro

Publications and source records attributed to M Shapiro.

At least 163 records · Page 9Linked to original sources
PubMed1994

Successful passive and active immunization of cynomolgus monkeys against hepatitis E.

Virtually full protection against hepatitis E and partial or complete protection against infection with hepatitis E virus (HEV) were achieved in passively or actively immunized cynomolgus monkeys. Hepatitis, viremia, and shedding of the virus in feces were detected in all nonimmunized animals that were challenged with HEV. HEV titers detected by reverse transcriptase PCR were higher in feces than in serum of nonimmunized animals. Anti-HEV antibody titers at the time of challenge ranged between 1:40 and 1:200 in animals passively immunized with convalescent plasma from a cynomolgus monkey previously infected with HEV and between 1:100 and 1:10,000 in animals actively immunized with a recombinant 55-kDa open reading frame 2 protein. The estimated 50% protective titer of passively acquired anti-HEV antibodies was 1:40. Although only one of four passively immunized animals showed histopathologic evidence of hepatitis, all four were infected after challenge; however, the titers of HEV in serum and feces were lower in the passively immunized animals than in the nonimmunized group. The actively immunized animals developed neither hepatitis nor viremia when challenged with HEV and virus was either not detected or was present in low titer in feces. The protective response was a function of the ELISA anti-HEV antibody titer at the time of challenge and the immunization schedule.

Animals↗
PubMed1994

Prevention of hepatitis C virus infection in chimpanzees after antibody-mediated in vitro neutralization.

Hepatitis C virus (HCV) is the most important etiologic agent of non-A, non-B hepatitis and is a major cause of chronic liver disease and hepatocellular carcinoma. Development of an effective vaccine would be the most practical method for prevention of the infection, but whether infection with HCV elicits protective immunity in the host is unclear. Neutralization of HCV in vitro was attempted with plasma of a chronically infected patient, and the residual infectivity was evaluated by inoculation of eight seronegative chimpanzees. The source of HCV was plasma obtained from a patient during the acute phase of posttransfusion non-A, non-B hepatitis, which had previously been titered for infectivity in chimpanzees. Neutralization was achieved with plasma obtained from the same patient 2 yr after the onset of primary infection but not with plasma obtained 11 yr later, although both plasmas contained antibodies against nonstructural and structural (including envelope) HCV proteins. Analysis of sequential viral isolates from the same patient revealed significant genetic divergence as early as 2 yr after infection. However, the HCV recovered from the patient 2 yr after the infection had a striking sequence similarity with the HCV recovered from one of the chimpanzees inoculated with the acute-phase virus, suggesting that the progenitor of the new strain was already present 2 yr earlier. This evidence, together with the different sequences of HCV recovered from the chimpanzees that received the same inoculum, confirms that HCV is present in vivo as a quasispecies. These results provide experimental evidence in vivo that HCV infection elicits a neutralizing antibody response in humans but suggest that such antibodies are isolate-specific. This result raises concerns for the development of a broadly reactive vaccine against HCV.

Animals↗
PubMed1994

Triple approach in the diagnosis of dominant breast masses: combined physical examination, mammography, and fine-needle aspiration.

In an attempt to reduce the number of breast biopsies done for benign breast disease in patients with breast lumps, we evaluated prospectively the sensitivity and specificity of the combination of three diagnostic modalities: clinical examination, mammography, and fine-needle aspiration cytologic examination (FNA). A total of 234 patients with a breast mass had a physical examination, a mammogram, and FNA, and were listed as malignant/suspicious or benign. All patients underwent a subsequent biopsy: 110 were found to have breast cancer, and 124 had a benign lesion. The sensitivity and specificity of the individual tests were as follows: 89% and 73%, respectively, for mammographic examination; 93% and 97% for FNA cytologic examination; and 89% and 60% for physical examination. For the combined triad of tests, the sensitivity was 100% and specificity 57%. All patients who had breast cancer had positive findings for malignancy in one or more of the diagnostic tests, i.e., 100% sensitively. All patients who had negative findings for malignancy in all three diagnostic tests had benign lesions, i.e., a negative predictive value of 100%. We conclude that breast masses can be diagnosed with a high degree of accuracy by combined physical, mammographic, and fine-needle aspiration cytologic examination. Patients in whom physical examination, mammography, and FNA were negative for malignancy can be safely observed, obviating the need for an open biopsy.

Adult↗
PubMed1994

In vivo transfection by hepatitis A virus synthetic RNA.

Marmosets injected intrahepatically with nucleic acids (cDNA and RNA transcripts) representing the full-length genome of the wild-type HM-175 strain of hepatitis A virus experienced acute hepatitis and seroconversion to hepatitis A virus capsid proteins. The hepatitis was comparable in severity to that caused by infection with the wild-type virus. The viral cDNA and the hepatitis A virus recovered from the feces of an injected animal contained the same marker mutation. Therefore, intermediate cell culture steps can be omitted and the virulence of a hepatitis A virus encoded by a cDNA clone can be evaluated by direct transfection of marmosets.

Animals↗
PubMed1994

Computed tomography in the diagnosis of blunt thoracic injury.

BACKGROUND: Computed tomography (CT) is an important diagnostic modality in the evaluation of blunt head and abdominal injuries, but it has not been routinely used to evaluate blunt chest trauma. METHODS: One hundred seventy stable patients with blunt thoracic trauma were evaluated with chest x-ray (CXR), and subsequently by CT. RESULTS: Of a total of 131 fractures, 53% were identified on initial CXR, 39% on CT, and 26% were not seen on either study. Twenty-one pneumothoraces were seen on CT but not on CXR. Chest tubes were placed in 8 patients and 12 patients were observed without incident. One hemothorax identified by CT scan alone required treatment. Four of 6 diaphragmatic injuries were seen on CT and 2 on CXR. Parenchymal abnormalities were apparent in 189 lung fields on CT and in 66 lung fields on CXR. Most represented atelectasis and did not require treatment. Altogether, CT scanning resulted in changes in management for 11 patients (6%). CONCLUSIONS: Although CXR is less sensitive in detecting parenchymal and pleural injuries than CT, the majority of the injuries identified by CT alone are minor and require no treatment. CXR remains the primary modality for diagnostic evaluation of blunt thoracic trauma.

Adult↗
PubMed1994

Predictors of occult scleral rupture.

PURPOSE: To determine which signs are sensitive and specific in the setting of trauma to establish the diagnosis of an occult scleral rupture. METHODS: The charts of patients with presumed scleral rupture were identified retrospectively. The ocular findings among the patients who had a rupture based on findings at surgery were compared with those patients who were noted to have normal findings at surgery. RESULTS: Visual acuity worse than 20/400, decreased intraocular pressure, intraocular pressure less than that in the nontraumatized eye, and an afferent pupillary defect were all significant indicators of an open globe. CONCLUSION: Determining the likelihood of an occult rupture can be facilitated by noting the presence or absence of those indicators that are significant and carry a high specificity.

Adolescent↗
PubMed1994

Bacterial laryngotracheitis associated with toxic shock syndrome in an adult.

Nonmenstrual toxic shock syndrome (TSS) in adults has been associated with various staphylococcal respiratory tract infections, including pharyngitis, tonsillitis, pneumonia, and postinfluenza respiratory tract infections. In children, nonmenstrual TSS has also been described as a complication of bacterial tracheitis. We describe the case of a 40-year-old woman who presented with laryngotracheitis as well as clinical and laboratory evidence of TSS. Culture of her sputum samples yielded pure growth of Staphylococcus aureus, which was shown to produce TSS toxin 1 (TSST-1). The patient responded promptly to therapy with iv clindamycin. We discuss the association of TSS with staphylococcal laryngotracheitis and the role of clindamycin in the treatment of TSS. To our knowledge, there are no previous reports of TSS complicating laryngotracheitis in adults.

Adult↗
PubMed1994

The changing clinical spectrum of liver abscess: the Jerusalem experience.

A retrospective study was conducted of all 31 patients with liver abscess admitted to Shaare Zedek Medical Center between 1979, the year computed tomographic scan and ultrasound were introduced, and 1992. Fever and abdominal pain were the most common symptoms. Duration of symptoms was short: 81% of patients had symptoms for < or = 5 days and none had symptoms for more than 3 weeks. Amoebic abscess was found in one patient only, the remainder were pyogenic. Biliary tract pathology remains the most common cause of liver abscess (39%). The diagnosis was made by ultrasound in 22/31 (71%) and by computed tomographic scan in 9/31 (29%) of patients. Treatment consisted of intravenous antibiotics and percutaneous drainage under ultrasound guidance in 24/31 patients (77%). Four patients died (13%), three of whom had underlying malignancies. Clinical features were compared with those from a similar series of 36 cases with liver abscess reported from Jerusalem predating ultrasound and computed tomographic scan (1967-1977). Several major changes have occurred. First, the relative incidence of amoebic abscess has dramatically decreased. Second, ultrasound and computed tomographic scan have facilitated earlier diagnosis and percutaneous drainage, contributing to improved survival and lower morbidity.

Adolescent↗
PubMed1993

The challenge-phage assay reveals differences in the binding equilibria of mutant Escherichia coli Trp super-repressors in vivo.

The phenotypes of four mutant Escherichia coli Trp repressor proteins with increased activities have been examined in vivo using the challenge-phage assay, an assay based on a positive genetic selection for DNA binding. These proteins, which differ by single amino acid changes from the wild type (Glu13-->Lys, Glu18-->Lys, Glu49-->Lys and Ala77-->Val), require less L-tryptophan than wild-type repressor for activation in vivo, and are super-aporepressors. However, none of the four mutant repressors binds DNA in a corepressor-independent manner. Three of the four mutant repressors (with Glu-->Lys changes) are more active when complexed with tryptophan, and are superholorepressors. Challenge-phage assays with excess tryptophan rank the mutant holorepressors in the same order as determined by binding studies in vitro. Challenge-phage assays with limiting tryptophan reveal additional phenotypic differences among the mutant proteins. These results show that the challenge-phage assay is a robust assay for measuring the relative affinities of specific protein-DNA interactions in vivo.

Bacterial Proteins↗
PubMed1993

Tryptophan super-repressors with alanine 77 changes.

The binding of L-tryptophan to Escherichia coli tryptophan aporepressor enables the holorepressor complex to bind operator DNA tightly. The side chain of residue alanine 77 is located in one of the most flexible regions of Trp repressor, between residues critical for binding DNA. Codon-directed mutagenesis was used to make genes encoding mutant Trp repressors with each of the 19 naturally occurring amino acid changes of Ala77. The 19 mutant proteins are made at the same steady-state levels as wild type. Sensitive challenge phage assays show that 7 of the 19 mutant proteins (Cys, Ser, Val, Leu, Thr, Ile, and Lys) are more active than wild-type protein when tryptophan is limiting in vivo. Among these 7 mutant super-aporepressors, proteins with Cys and Ser changes also are super-holorepressors, because they repress better than wild-type holorepressor when tryptophan is in excess. These results and others suggest that super-aporepressors associate more poorly than wild-type aporepressor with nonspecific DNA. Consistent with this idea, these 7 changes are predicted to disrupt the tertiary structure of aporepressor, but have more limited effects on the structure of holorepressor.

Alanine↗
PubMed1993

Characterization of the role of individual protein binding motifs within the hepatitis B virus enhancer I on X promoter activity using linker scanning mutagenesis.

A combination of linker scanning mutagenesis and deletional analyses has been used to determine the role of individual DNA-protein binding sites on expression from the hepatitis B virus (HBV) enhancer I-X promoter (map position (mp) 1042-1354, HBV adw2). Linker scanning mutation of the EF-C site caused a 67.5% drop in X promoter activity in HuH7 cells, but had no effect in HepG2 or HepSK cells. Mutation of the E element resulted in an approximately 50% reduction in X promoter activity in HuH7, HepG2, and HepSK cells. Deletional analysis showed that sequences upstream of the EF-C site (mp 1163) were required for full X promoter activity and implicated the NF-1a site as being sufficient for basal X promoter activity. However, PCR-directed linker scanning mutation of the NF-1a site did not cause a reduction in X promoter activity, indicating that this site was not an essential component of the X promoter. Taken together, these results indicated that multiple, partially redundant protein:DNA interactions in the enhancer I are essential for full X promoter activity. The lack of an essential basal promoter element supports the suggestion that the two separate HBV enhancer elements (enhI and enhII) were created by integration of the X gene into a primordial enhancer element.

Base Sequence↗
PubMed1993

Biologic and physical characteristics of the non-peptidic, non-digitalis-like natriuretic hormone.

At least three independent groups of natriuretic hormones have been isolated over the past ten years. Two, atrial natriuretic factor (ANF) and brain natriuretic peptide (BNP), are proteins and the third is made up of digitalis-like substances (DLS). The present report concerns the isolation, substantial purification and biologic actions of an entirely different natriuretic hormone (NH) which appears to be steroidal in nature and an isomer of cortisone. The source of NH was uremic urine. Purification involved successive chromatographic steps including gel filtration and multiple HPLC runs through C-18 resins. A translucent crystal ultimately was obtained. The product was examined using mass spectroscopy with trimethylsilyl derivatization. Only one compound was identifiable. The characteristics of the molecule include: a molecular weight, 360.4; a molecular formula, C21H28O5; a steroidal nucleus; UV absorption at 220 and 290 nm; and intrinsic fluorescence. The onset of action occurs within minutes both in the rat and, as previously shown, in several in vitro systems including the frog skin, toad bladder, fibroblasts and renal tubular epithelial cells grown in culture and isolated perfused cortical collecting tubules. In contrast to DLS, NH has been previously shown not to cross react with digoxin antibodies. Moreover, when given to intact rats, it produces a profound natriuresis but little or no kaliuresis. In contrast to ANF and BNP the compound is active orally as well as intravenously. It is clearly different from cortisone, based both on its biologic and mass spectroscopic characteristics.

Administration, Oral↗
PubMed1993

Infections caused by Pseudomonas pickettii in association with permanent indwelling intravenous devices: four cases and a review.

Permanent indwelling intravenous devices (PIIDs) have become increasingly prevalent in the past decade. These devices offer the advantage of long-term and convenient venous access, but their not-infrequent colonization by bacterial or fungi can lead to bloodstream infection with or without sepsis. We describe a series of four patients with PIIDs who became infected with Pseudomonas pickettii, and we review the properties of this unusual organism and the clinical presentation of the infections it causes.

Adult↗
PubMed1993

Changes in semantic memory in early stage Alzheimer's disease patients.

The types and number of exemplars of categories that are retrieved from semantic memory differentiate elderly normal controls and early stage Alzheimer's disease (AD) patients. Elderly normal controls generated more uncommon exemplars from closed semantic categories (fruits and vegetables) than did AD patients 2 1/2 years prior to the presumed onset of AD. AD patients, however, were just as productive as elderly normal controls in generating associations to open categories (letters). The findings suggest that one of the early cognitive symptoms of AD is changes in availability of uncommon exemplars of semantic networks.

Aged↗
PubMed1993

Variation in course of hepatitis E in experimentally infected cynomolgus monkeys.

Five cynomolgus monkeys (Macaca fascicularis) developed hepatitis after inoculation with a prototype strain of hepatitis E virus (HEV) from Pakistan. Although all 5 monkeys displayed liver enzyme elevations, viremia, virus secretion in feces, and seroconversion, two different patterns of these parameters were observed. For 4 monkeys, increased alanine aminotransferase (ALT) activity was first observed on days 21-26, viremia occurred before and during enzyme elevation, and the animals seroconverted coincidentally with the end of viremia or shortly thereafter. One of these monkeys had a more severe hepatitis, with peak ALT values more than twice the peak levels of the other monkeys. The fifth monkey developed biphasic hepatitis with peaks of ALT activity on days 26 and 54. In this case, viremia and seroconversion were correlated only with the second peak of enzyme elevation and liver histopathology only with the first peak. Viral shedding in this fifth animal lasted two times longer than in other animals.

Alanine Transaminase↗