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Biomedical subjects

C Miller

Publications and source records attributed to C Miller.

At least 289 records · Page 16Linked to original sources
PubMed1995

Dibutyryl cAMP reduces nonparenchymal cell damage during cold preservation of rat livers.

Sinusoidal lining cells are the main target for cold preservation injury and are further damaged with reperfusion. Different agents known to increase intracellular cAMP levels have been shown beneficial. This study was designed to assess the possible protective effect of a cAMP analogue on nonparenchymal cells of rat livers, during cold storage and during reperfusion. Parameters reflecting the status of the liver microvasculature were analyzed. The initial effluent collected after preservation reflects release during the cold storage period; therefore we measured interleukin-1 (IL-1) and endothelin-1 (ET-1) levels in these samples in order to detect and quantitate the degree of activation and/or disruption of Kupffer and sinusoidal endothelial lining cells. Rat livers were harvested after in situ flush with Ringer's lactate with or without 2 mM dibutyryl cAMP, excised, and stored in the same solution at 4 degrees C. After 6 hr, livers were perfused with Krebs-Henseleit buffer for 90 min. Physiological parameters were monitored throughout the perfusion. Perfusate samples were collected every 30 min for RIA measurements of IL-1 and ET-1. Treatment resulted in a significant decrease in release of ET-1 and IL-1 during storage. Likewise, livers treated with cAMP had a significantly improved bile output and decreased portal vein resistance during reperfusion. The beneficial effect granted by the analogue during cold storage and reperfusion was evident on parenchymal and nonparenchymal cells. Levels of ET-1 and IL-1 in the caval effluent confirm and quantitate preservation damage.

Animals↗
PubMed1995

Loss of speech after orthotopic liver transplantation.

Alteration of speech is a rare but distressing complication of orthotopic liver transplantation (OLT). We describe a characteristic speech disorder identified in a large series of consecutive patients undergoing OLT. Between 1988 and 1993, 525 adults underwent OLT. For all recipients with neurologic complications, we reviewed clinical findings, imaging and electrophysiologic test results, and perioperative laboratory data. Five patients (ages 23-52; UNOS status 3-4) exhibited a characteristic pattern of stuttering dysarthria, leading to complete loss of speech production, occasionally with elements of aphasia. In four of the five patients, right-sided focal seizures were subsequently noted. All cases presented within the first 10 postoperative days and improved with 1 month of cessation of cyclosporin (CyA), although halting, monotonous speech was evident to some degree in all five for up to 1 year. There was no correlation between onset of symptoms and CyA levels. None of the patients has clinical or radiologic findings suggestive of central pontine myelinolysis or akinetic mutism. EEGs and Spect scan results were consistent with dysfunction in the left frontotemporoparietal regions of the brain. A characteristic speech disorder, which may be described as cortical dysarthria or speech apraxia, occurs in approximately 1% of adults undergoing OLT. Prompt recognition of this syndrome and temporary cessation of CyA therapy may favorable affect the course.

Adult↗
PubMed1995

Effect of subzero incubation on fluoride binding by laccase.

We have refined a useful incubation method for preparing adducts of tree laccase with inhibitor anions; however, the technique should have wider application. The procedure involves incubating a previously frozen aqueous solution at subzero temperature. Factors influencing the amount of adduct that forms include the nature of the buffer, pH changes that occur at subzero temperatures and the presence of glycerol. In the absence of a glassing agent like glycerol, the phase separation and solute pooling that occur with ice formation help drive adduct formation. The results reveal several important factors to consider in designing or interpreting low-temperature spectroscopic investigations.

Journal Article↗
PubMed1995

Endobutton button endoscopic fixation technique in anterior cruciate ligament reconstruction.

The surgical technique of Endobutton (Acufex Microsurgical, Inc, Mansfield, MA) button fixation for anterior cruciate ligament reconstruction is described. This technique avoids the potential pitfalls of interference screw fixation, avoids a second incision, and is adaptable to a variety of graft materials (autograft or allograft bone-patellar tendon-bond and hamstring).

Anterior Cruciate Ligament↗
PubMed1995

Laboratory and bedside evaluation of portable glucose meters.

A two-phase, laboratory and bedside, evaluation of blood glucose meters was conducted in this study. Four meters, the AccuData Easy (Boehringer-Mannheim, Indianapolis, IN), HemoCue Glucose (HemoCue, Mission Viejo, CA), LifeScan One Touch II (LifeScan, Milpitas, CA), and Miles Encore QA (Miles, Elkhart, IN) systems, were compared to the Nova Stat Profile 5 (Nova, Waltham, MA) as the laboratory reference. Precision, linearity, correlation to the laboratory method, interference from hematocrit, data management, and operator preference were examined. None of the meters were found to satisfy all of the study's evaluation criteria. Therefore, institutions must weigh which criteria are most important to their individual settings. Although the HemoCue Glucose was found to be technically superior, this meter had no data management capabilities. The Encore QA had greater variance and low bias, whereas the AccuData Easy had bias affected by hematocrit and glucose concentration, and the One Touch II had a negative hematocrit bias and limited linear range when compared to the Nova. Only meters meeting both minimal analytical performance and computerization requirements, the One Touch II and AccuData Easy, were selected for further evaluation. At the bedside, the One Touch II demonstrated performance consistent with the lab evaluation, whereas the AccuData Easy showed greater imprecision in the low glucose range and a correlation that varied with sample type: capillary, venous, or arterial blood. This evaluation indicates that the clinician must interpret near-patient glucose results with respect to meter limitations. FDA approval and marketing statistics, alone, are insufficient to judge the performance of the meters in routine institutional use. Independent method validation, under actual operating conditions, is a better means of predicting future performance of the meters.

Blood Glucose↗
PubMed1995

Detection of hepatitis B and hepatitis C viral sequences in fulminant hepatic failure of unknown etiology.

In a significant number of patients, the etiology of fulminant hepatic failure (FHF) is unknown. To determine whether hepatitis B virus (HBV) and hepatitis C virus (HCV) play a role in patients without serologic markers of HBV and HCV infection, the authors examined tissue samples from 15 liver explants with massive hepatic necrosis for the presence of viral sequences by the polymerase chain reaction (PCR). The specimens were derived from nine patients with FHF of unknown etiology; two with serum hepatitis B surface antigen (HBsAg); two with antibodies to HCV; one with antibodies to hepatitis A virus (HAV) and anti-HBc of the IgM class; and one with isoniazid toxicity. Nucleic acids were extracted from frozen liver samples. RNA was used as a template for reverse transcription, followed by double PCR with nested primers for the 5'-untranslated region of HCV. DNA was tested by single PCR for S gene sequences of HBV. Hepatitis B virus sequences were detected in the specimens of the two HBsAg positive patients, the anti-HAV/anti-HBc positive patient, and three of nine patients with FHF of unknown etiology. Hepatitis C virus sequences were present in the explant of one patient with FHF of unknown etiology, but not in the two patients with antibodies to HCV. In two specimens with molecular findings of HBV infection (1 from a patient with serum HBsAg and 1 without), there was immunohistochemical evidence of coinfection or superinfection with hepatitis delta virus (HDV). In conclusion, in this patient population, HBV, alone or with HDV or HAV, causes fulminant hepatic failure more often than HCV infection. However, in the majority of patients, the etiology of fulminant hepatic failure remains unknown.

Adult↗
PubMed1995

Macroregenerative nodules in cirrhosis are not associated with elevated serum or stainable tissue alpha-fetoprotein.

We have explored the relationship of serum alpha-fetoprotein and macroregenerative nodules (MRNs), possible precursor lesions of hepatocellular carcinoma (HCC), and sought to demonstrate alpha-fetoprotein (AFP) expression in these nodules. One hundred and sixty-eight sequential adult cirrhotic resected livers were examined and MRNs were identified by standard criteria. Pretransplant serum AFP was available for 158 of these patients (normal < 20 ng/ml). One hundred and seventy-two randomly selected lesions, including ordinary and atypical MRNs, some containing microfoci of HCC, and HCCs were stained for AFP by immunohistochemistry. In the series, 12 cases had grossly apparent HCCs, four associated with high serum alpha-fetoprotein (p < 0.006). Forty-four cases had MRNs, 32 without grossly apparent HCC. Five of these 32 cases were associated with high serum AFP (not significant). Immuno-staining for AFP was seen in three specimens of HCC and in a cirrhotic nodule from a patient without HCC, but not in MRNs. 1) Neither the presence of MRNs--whether ordinary, atypical, or containing micro-foci of HCC--nor that of gross HCC is ruled out by a normal serum AFP. 2) Elevated serum AFP is not associated with the presence of MRNs. 3) MRNs rarely stain for tissue AFP.

Adenoma, Liver Cell↗
PubMed1995

Epstein-Barr virus nuclear protein 3C modulates transcription through interaction with the sequence-specific DNA-binding protein J kappa.

The Epstein-Barr virus (EBV) nuclear protein 3C (EBNA 3C) is essential for EBV-mediated transformation of primary B lymphocytes, is turned on by EBNA 2, and regulates transcription of some of the viral and cellular genes which are regulated by EBNA 2. EBNA 2 is targeted to response elements by binding to the DNA sequence-specific, transcriptional repressor protein J kappa. We now show that EBNA 3C also binds to J kappa. EBNA 3C causes J kappa to not bind DNA or EBNA 2. J kappa DNA binding activity in EBV-transformed lymphoblastoid cells is consequently reduced. More than 10% of the EBNA 3C coimmunoprecipitated with J kappa from extracts of non-EBV-infected B lymphoblasts that had been stably converted to EBNA 3C expression. EBNA 3C in nuclear extracts from these cells (or in vitro-translated EBNA 3C) prevented J kappa from interacting with a high-affinity DNA binding site. Under conditions of transient overexpression in B lymphoblasts, EBNA 2 and EBNA 3C associated with J kappa and less EBNA 2 associated with J kappa when EBNA 3C was coexpressed in the same cell. EBNA 3C had no effect on the activity of a -512/+40 LMP1 promoter-CAT reporter construct that has two upstream J kappa sites, but it did inhibit EBNA 2 transactivation of this promoter. These data are compatible with a role for EBNA 3C as a "feedback" down modulator of EBNA 2-mediated transactivation. EBNA 3C could, in theory, also activate transcription by inhibiting the interaction of the J kappa repressor with its cognate DNA. The interaction of two viral transcriptional regulators with the same cell protein may reflect an unusually high level of complexity or stringency in target gene regulation.

Antigens, Viral↗
PubMed1995

Two-stage tuberculin skin testing in individuals with human immunodeficiency virus infection. Community Programs for Clinical Research on AIDS.

In this study we estimated occurrence of the booster effect in a population infected with the human immunodeficiency virus (HIV) and assessed the relation between the booster effect, T-lymphocyte CD4 cell counts, tuberculosis risk categories, and HIV exposure categories. Patients were recruited from 13 participating sites of the Terry Beirn Community Programs for Clinical Research on AIDS (CPCRA). A two-stage tuberculin skin test was applied to 709 HIV-infected patients using the Mantoux method. An induration reading < 5 mm on the first test and > or = 5 on the second skin test defined the booster effect. Overall, 18 patients, or 2.7% (95% confidence interval, 1.6 to 4.2) experienced the booster effect. Boosted responses were seen in eight (2.1%) anergic patients, six (4.5%) nonanergic patients, and four (2.5%) with anergy status unknown. Boosting was noted in 1 of the 131 women enrolled. Age, race, CD4 cell count, injection drug use, anergy status, tuberculosis risk categories, and HIV exposure categories were not predictive of boosting. The booster effect occurs in a small percentage of HIV-infected patients tested, thus identifying small numbers of patients with latent tuberculosis infection. The two-stage procedure is probably of limited value in the diagnosis of latent tuberculosis in HIV-infected persons.

AIDS-Related Opportunistic Infections↗