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Biomedical subjects

S Frye

Publications and source records attributed to S Frye.

15 recordsLinked to original sources

Clinical implications of nucleic acid amplification methods for the diagnosis of viral infections of the nervous system.

Amplification of viral nucleic acids from the cerebrospinal fluid (CSF) has considerably improved the diagnosis of several acute, subacute and chronic viral infections of the nervous system. In herpes simplex virus (HSV) encephalitis (HSE) the polymerase chain reaction (PCR) has become the method of choice for the rapid, non invasive diagnosis. Other herpes virus associated diseases which can now be reliably diagnosed are encephalitis, ventriculoencephalitis, polymyeloradiculitis, myelitis and an inflammatory polyradiculoneuropathy caused by cytomegalovirus (CMV), HSV, varicella-zoster virus (VZV) or Epstein-Barr virus (EBV), EBV associated primary B-cell-lymphoma of the brain, acute aseptic meningitis in young adults allied with VZV, and meningoencephalitis with recurrent seizures due to human herpes virus type 6 (HHV-6). In AIDS patients, PCR has helped to differentiate lesions either due to the human immunodeficiency virus (HIV) itself or to opportunistic infections such as progressive multifocal leukoencephalopathy (PML) caused by JC virus (JCV) or CMV related complications. HIV can be detected early in the course of infection in the CSF and the amount of proviral DNA in CSF cells seems to be correlated with the severity and/or progression of neurological signs and symptoms. Acute epidemic aseptic meningitis caused by enterovirus infections can now be reliably diagnosed and typed by reverse transcriptase PCR (RT-PCR). Meningitis cases caused by vaccination with the Jeryl Lynn and Urabe vaccine strain of mumps virus have been identified using RT-PCR and sequencing of the amplified products (amplicon).

Central Nervous System

Decoupling spatial and temporal processes for clinical analyzers.

The separation of time and space in processing a sample greatly simplifies the design of automation for clinical testing. The efficient spatial arrangement of analytical units and sample manipulators has become a more complex task because of the degree of automation required on today's state-of-the-art analyzer. Minimization of sample volume and the reduction of overall analyzer size further complicate the design problem. We report the development of a proprietary method of decoupling the temporal and spatial elements required for analysis of samples. This process is based on number theory and can be used to optimize the distance between the physical processing stations while allowing these same stations to operate on samples over a substantial range of times. The technique is versatile and can also be used when it is desirable to sequentially move groups of items from location to location.

Autoanalysis

Inflammatory mediator profile in urine and bladder wash fluid of patients with interstitial cystitis.

Interstitial cystitis is a syndrome of urinary urgency, frequency and suprapubic pain. We investigated the role of inflammatory mediators in 96 patients with histories and symptoms consistent with interstitial cystitis, and 13 controls from The New York Hospital-Cornell Medical Center, University of Washington and University of California at San Diego. Patients were classified into either group A (meets all criteria of the National Institute of Arthritis, Diabetes, Digestive and Kidney Diseases for inclusion in research studies), group B (meets all of these criteria but without glomerulations) or an "other" group. A small number of group A patients had detectable interleukin-6 in the urine. Urinary concentrations of tumor necrosis factor, prostaglandins E2, D2 and F2 alpha, and thromboxane B2 were not different among either patient groups or controls. Urine specimens contained inhibitors of the bioactivity of interleukin-6 and tumor necrosis factors but no differences between patients or controls were found. No factors chemotactic for human neutrophils were detected in a small patient sample. Bladder wash fluid concentrations of prostaglandins E2, D2 and F2 alpha, and thromboxane were much lower than urinary levels. Bladder wash fluid interleukin-6 and tumor necrosis factor were not detectable. The results suggest that while a small subset of patients may have elevated levels of interleukin-6 the majority of patients do not appear to have elevated levels of inflammatory mediators in the urine or bladder wash fluid. Evaluation of patient bladder tissue may indicate changes not detectable in urine or bladder wash fluid. Alternatively, other etiologies must be considered in those patients.

Adult

Specific diagnosis of progressive multifocal leukoencephalopathy by polymerase chain reaction.

Using polymerase chain reaction (PCR), 34 cerebrospinal fluid (CSF) samples from 28 patients with progressive multifocal leukoencephalopathy (PML) were analyzed. As controls, 116 samples were evaluated from 82 human immunodeficiency virus type 1 (HIV-1)-infected patients and 1 HIV-1-negative patient. Of the HIV-1-positive patients, 23 had cerebral toxoplasmosis, 10 had HIV leukoencephalopathy, and 49 had other neurologic complications. Detection of JC virus (JCV) DNA in CSF was increased 10-fold by the addition of carrier DNA before phenol-chloroform-isoamyl alcohol extraction. The primer pair JC 26/29, from the VP1/large T region, had a limit of detection of 10(5) JCV DNA molecules/100 microL. The primer pair JC 36/39, located in the large T gene region, had a 100-fold lower limit of detection. With JC 26/29, the sensitivity was 43% (12/28) and specificity was 100%. Using JC 36/39, sensitivity increased to 82% (23/28), and false-positive results were not observed. Diagnosis of PML is greatly aided by PCR analysis of CSF.

Base Sequence

Progressive multifocal leukoencephalopathy diagnosed by amplification of JC virus-specific DNA from cerebrospinal fluid.

OBJECTIVE: To study the diagnostic sensitivity and specificity of polymerase chain reaction (PCR) for the non-invasive diagnosis of progressive multifocal leukoencephalopathy (PML) in HIV-1-infected individuals. DESIGN: Retrospective analysis of stored cerebrospinal fluid (CSF) samples by PCR of HIV-1-infected patients. METHODS: Results of the PCR analysis of the CSF of three AIDS patients with autopsy-proven PML were compared with the results in 15 neurologically asymptomatic HIV-1-infected patients and with 15 AIDS patients with other opportunistic infections of the central nervous system (CNS). A polyclonal antiserum to simian virus 40 (SV40) cross-reacting with JC virus (JCV) late antigens was used for immunocytochemical confirmation of the diagnosis. Two different primer pairs, one taken from the VP1/large T gene and the other from the large T gene, were used to amplify JCV-specific DNA sequences from CSF. RESULTS: Five CSF samples were analysed and JCV-specific DNA found in three patients with autopsy-proven PML. No JCV-specific DNA was detected in 47 CSF samples, including serial samples from 14 of the 30 non-PML patients. The diagnosis of PML was confirmed in all three cases by immunocytochemistry. CONCLUSION: PML can be diagnosed by PCR analysis of CSF. The sensitivity and specificity of the method depends on the sensitivity of the primers used for amplification. Using a primer pair from the large T gene, JCV-specific DNA was amplified in three cases with PML as early as the day of presentation with the first neurological symptom of PML.

AIDS-Related Opportunistic Infections

Influence of low density lipoproteins on cytosolic free Ca2+ concentration and dense tubular system in human platelets.

The cytosolic free Ca2+ concentration [Ca2+]i and dense tubular system (DTS) of washed human platelets were affected by low density lipoproteins (LDL) of 25 micrograms/ml at 37 degrees C for 10 minutes. After the incubation with LDL, the [Ca2+]i increased from 115 +/- 29 nM to 141 +/- 24 nM. LDL promoted the increase of [Ca2+]i (471 +/- 31 nM) induced by thrombin (0.03 U/ml) as compared to that which thrombin did alone (240 +/- 11 nM) (p < 0.05). The increased Ca2+ influx from the extracellular space is thought to be the reason of the increase in [Ca2+]i, since the effect of LDL was abolished by removal of external Ca2+ by EGTA. The DTS changed primarily from thin elongated forms to rounded vesicles. No evidence was noticed that LDL caused a mobilization of Ca2+ from the DTS.

Biological Transport

Remediation for subgroups of retarded readers using a modified oral spelling procedure.

The effectiveness of Bradley's modification of the method of Simultaneous Oral Spelling (SOS) remedial training for both spelling and reading was assessed in this study. Subgroups of disabled readers, 'Chinese' (dysphonetic) and 'Phonecians' (dyseidetic), received six remedial sessions and were assessed immediately after treatment and then two months later on spelling of the training words and on general reading measures. Compared with a non-treated group, the two experimental groups showed significant but different general gains in reading. SOS training appears to be more effective for the teaching of regular words, as opposed to exceptional ones.

Adolescent

Testicular needle biopsy in diagnosis of infertility.

Testicular needle biopsies were performed on 10 patients who at the same time underwent open testicular biopsy. The tracts and puncture sites were explored on each of these patients, and an open biopsy was obtained at the puncture site simultaneously. Both needle specimen and open tissue specimen were fixed in Bouin solution and sent for histologic examination. In none of the cases was there found to be bleeding or extrusion of the testis at the puncture site. In one of the needle specimens, however, insufficient tissue was obtained for diagnosis. In the other 19 specimens, diagnostic accuracy was not compromised by the technique. The main differences appear to be fewer tubules obtained by the needle technique as well as decreased preservation of the interstitial tissue. This is a rapid, simple, and inexpensive method for testes biopsy which has proved to be both safe and diagnostically accurate.

Biopsy, Needle