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Biomedical subjects

J Lane

Publications and source records attributed to J Lane.

At least 55 records · Page 3Linked to original sources
PubMed1996

Transforming growth factor-beta 1 in a guanidine-extracted demineralized bone matrix carrier rapidly closes a rabbit critical calvarial defect.

Transforming growth factor beta 1 (TGF-beta 1) is a polyfunctional regulatory cytokine that has been shown to have roles in extracellular matrix interactions, soft tissue healing, and osteogenesis. Twenty-five microL of recombinant human TGF-beta 1 was added to guanidine-extracted demineralized bone matrix carrier and the implants were used to fill a 14-mm osteoperiosteal critical calvarial defect in New Zealand white rabbit model. The defects were allowed to heal over 4 weeks and the degree of new bone formation was assess by radiodensitometry and undecalcified bone histomorphometry techniques. Implants with TGF-beta 1 showed complete bridging of the gap with new bone in all cases, while the controls showed fibrous tissue repair of the gap with little or no new bone formation. These results demonstrate the ability of TGF-beta 1 to induce new bone in a brief time period in an inactive carrier.

Animals↗
PubMed1995

Sampling lymph node content of human immunodeficiency virus type 1 nucleic acids and p24 antigen by fine-needle aspiration in early-stage patients.

The potential of lymph node fine-needle aspiration (LNFNA) for sampling viral load was evaluated in excised, peripheral lymph nodes from five patients with early-stage human immunodeficiency virus type 1 HIV-1 disease (asymptomatic, CD4 cells > 300/mm3). The preponderance (> 80%) of viral RNA was within follicular germinal centers as noted by in situ hybridization on lymph node frozen sections (LNFSs) as well as within cohesive groups of 10-20 lymphoid cells (microfragments) in LNFNA preparations. Quantification of cells expressing HIV-1 RNA by in situ hybridization, quantification of HIV-1 gag RNA and gag DNA per 10(5) cells by polymerase chain reaction, and measurement of p24 antigen per 10(5) cells yielded similar values for LNFNA, lymph node mononuclear cells (LNMCs) from tissue homogenates by Ficoll-Hypaque separation, and LNFS. Sampling of lymph node viral load by LNFNA appears to capture viral components associated with both individual expressing cells and follicular germinal centers. Due to the advantages in terms of patients' morbidity, repeatability, and cost, assessment of lymphoid tissue viral load by LNFNA warrants an in vivo feasibility trial as an alternative to lymph node biopsy.

Adult↗
PubMed1994

T cell receptor V beta gene usage in the recognition of myelin basic protein by cerebrospinal fluid- and blood-derived T cells from patients with multiple sclerosis.

Because of its proximity to the central nervous system, the cerebrospinal fluid (CSF) represents an important source of T cells that potentially could mediate putative autoimmune diseases such as multiple sclerosis (MS). To overcome the low CSF cellularity, we evaluated culture conditions that could expand CSF T cells, with a focus on the expression of T-cell receptor V beta genes utilized by T cells specific for the potentially encephalitogenic autoantigen myelin basic protein (BP). Expansion of "activated" CSF cells with IL-2/IL-4 plus accessory cells optimally retained BP-responsive T cells that over-expressed V beta 1, V beta 2, V beta 5, or V beta 18, compared to expansion using supernatants from PHA-stimulated blood cells, or anti-CD3 antibody that led to different V gene bias and rare reactivity to BP. Sequential evaluation of paired CSF and blood samples from a relapsing remitting MS patient indicated that BP-reactive T cells were present in CSF during the period of clinical activity, and the pattern of BP recognition in CSF was partially reflected in blood, even after CSF reactivity had dissipated during remission. Over-expressed V beta genes were not always constant, however, since in three sequential evaluations of a chronic progressive MS patient, V beta genes over-expressed in the first BP-reactive CSF switched to a different V beta gene bias that was present in the second and third CSF samples. Blood samples reflected each pattern of CSF V beta gene bias, but retained the initial bias for at least 4 months after its disappearance from CSF. These data indicate that selective expansion of IL-2/IL-4-responsive CSF cells favors growth of the BP-reactive subpopulation, and, in a limited number of patients studied, reflected clinical disease activity. In comparison, blood T cells provided a partial but longer lasting reflection of the CSF BP reactivity and V beta gene bias.

Adult↗
PubMed1994

In vitro susceptibility of clinical isolates of HIV-1 to XM323, a non-peptidyl HIV protease inhibitor.

OBJECTIVE: To determine the in vitro susceptibility of primary clinical isolates and laboratory strains of HIV-1 to XM323. METHODS: The AIDS Clinical Trials Group/US Department of Defense p24 antigen-based consensus assay was used to determine in vitro susceptibility of 57 primary clinical isolates and three laboratory strains of HIV-1 to XM323, zidovudine, zalcitabine (ddC), and didanosine (ddI). RESULTS: The concentrations of compound required to inhibit viral p24 antigen production by 50% [median inhibitory concentration (IC50)] for nucleosides were as follows: zidovudine, 0.001-->5 microM; ddC, < 0.01-0.23 microM; ddI, 0.2-->25 microM). Against both nucleoside susceptible and resistant isolates XM323 exhibited potent inhibition with IC50 values of < 0.02-0.27 microM and IC90 values of 0.03-1.17 microM. CONCLUSIONS: XM323 is a potent inhibitor of diverse clinical isolates of HIV-1 in vitro and represents a novel class of non-peptidyl inhibitors of HIV-1 protease.

Antiviral Agents↗
PubMed1994

Dideoxynucleoside resistance emerges with prolonged zidovudine monotherapy. The RV43 Study Group.

Human immunodeficiency virus type 1 (HIV-1) isolates resistant to zidovudine (ZDV) have previously been demonstrated to exhibit in vitro cross-resistance to other similar dideoxynucleoside agents which contain a 3'-azido group. However, cross-resistance to didanosine (ddI) or dideoxycytidine (ddC) has been less well documented. ZDV, ddI, and ddC susceptibility data have been collected from clinical HIV-1 isolates obtained by five clinical centers and their respective retrovirology laboratories. All subjects were treated only with ZDV. Clinical HIV-1 isolates were isolated, amplified, and assayed for drug susceptibility in standardized cultures of phytohemagglutinin-stimulated donor peripheral blood mononuclear cells obtained from healthy seronegative donors. All five cohorts showed a correlation between decreased in vitro susceptibility to ZDV and decreased susceptibility to ddI and ddC. For each 10-fold decrease in ZDV susceptibility, an average corresponding decrease of 2.2-fold in ddI susceptibility was observed (129 isolates studied; P < 0.001, Fisher's test of combined significance). Similarly, susceptibility to ddC decreased 2.0-fold for each 10-fold decrease in ZDV susceptibility (82 isolates studied; P < 0.001, Fisher's test of combined significance). These data indicate that a correlation exists between HIV-1 susceptibilities to ZDV and ddI or ddC for clinical HIV-1 isolates.

AIDS-Related Complex↗
PubMed1993

Case report 772. Stress fracture of the hip secondary to renal osteodystrophy and erosion of ischium due to amyloid deposition.

We have reported the case history of a 72-year-old woman who was on hemodialysis for 15 years. Her course was marked by many of the musculoskeletal complications of ESRD including CTS, stromal amyloid deposition of synovium, amyloid cystic degeneration of bone, and inflammation of the synovium due to the deposition of calcium oxalate and calcium pyrophosphate microcrystals. She also had evidence of metabolic bone disease: moderate osteoporosis related to secondary hyperparathyroidism and osteomalacia related to aluminum deposition at the mineralization front. The pathological and radiological findings associated with her bone disease are described.

Aged↗
PubMed1993

Anti-secretory effects and pharmacokinetics of low dose ranitidine.

The purpose of this study was to examine the anti-secretory effect of low doses of orally administered ranitidine on meal-stimulated gastric acid secretion and assess its pharmacokinetics. The effect of 20, 40, 60 and 80 mg of ranitidine p.o. and placebo were tested on 5 separate days (Latin square, double-blind) in 15 healthy males (mean age 35 years). Gastric acid secretion was measured prior to and for 8 h following two sequential mixed liquid meals administered at 4-h intervals. Venous blood samples were obtained at frequent intervals before and following each dose for determination of plasma ranitidine concentration by high pressure liquid chromatography. Each dose of ranitidine significantly (P < 0.01) decreased the peak and cumulative 4-h acid secretory responses to the first meal (range 58-93%), and the 60 and 80 mg doses significantly inhibited the response to the second meal by 31 and 43%, respectively. Total 8-h meal-stimulated acid outputs were decreased significantly in a dose-related manner (range 38-73%). Peak plasma ranitidine occurred approximately 1 h after dosing. Ranitidine tmax, t1/2 and clearances were independent of dose; however, AUC and Cmax were dose-related. Inhibition of acid secretion was related to plasma ranitidine concentration; the mean IC50 was 27 (+/- 6.4) ng/ml. We conclude that modest doses (equivalent to 7-27% of the daily therapeutic dose) of ranitidine effectively suppress meal-stimulated gastric acid secretion in a dose-related manner. If these doses are of clinical efficacy, it may be possible for substantial cost savings to occur.

Administration, Oral↗
PubMed1993

Postoperative vomiting factors in IVF patients.

Postoperative vomiting patterns were documented in 504 patients having general anaesthesia for oocyte retrieval for in vitro fertilization or related procedures and compared with patient preoperative history and expectations, response to ovarian hyperstimulation, and details of the anaesthesia. The results showed that the likelihood of vomiting was related to peak plasma oestradiol level and the patient's expectation based on previous experience of anaesthesia.

Anesthesia, General↗
PubMed1993

Safety, tolerance, and pharmacokinetics of systemic ribavirin in children with human immunodeficiency virus infection.

Eleven pediatric patients, aged 1 to 10 years and with symptomatic human immunodeficiency virus infection, were treated with 6 or 10 mg of oral ribavirin per kg of body weight daily for 60 days. Safety and pharmacokinetic parameters were monitored; five children had comprehensive pharmacokinetic evaluations. The children tolerated the drug well, and treatment was not associated with any clinically significant adverse effects. Peak concentrations in plasma of 2.5 and 3.0 microM were reached at 90 min after single oral doses of 6 and 10 mg/kg, respectively. The mean systemic availability of oral ribavirin was 42.3%. After 60 days of ribavirin administration, mean trough concentrations in plasma of 2.6 and 4.1 microM were obtained. Ribavirin penetrated well into the cerebrospinal fluid, achieving 70% of the concentration in plasma at steady state.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Standardized peripheral blood mononuclear cell culture assay for determination of drug susceptibilities of clinical human immunodeficiency virus type 1 isolates. The RV-43 Study Group, the AIDS Clinical Trials Group Virology Committee Resistance Working Group.

A standardized antiviral drug susceptibility assay for clinical human immunodeficiency virus type 1 (HIV-1) isolates has been developed for use in clinical trials. The protocol is a two-step procedure that first involves cocultivation of patient infected peripheral blood mononuclear cells (PBMC) with seronegative phytohemagglutinin-stimulated donor PBMC to obtain an HIV-1 stock. The virus stock is titrated for viral infectivity (50% tissue culture infective dose) by use of serial fourfold virus dilutions in donor PBMC. A standardized inoculum of 1,000 50% tissue culture infective doses per 10(6) cells is used in the second step of the procedure to acutely infect seronegative donor PBMC in a 7-day microtiter plate assay with triplicate wells containing zidovudine (ZDV) concentrations ranging from 0 to 5.0 microM. The ZDV 50% inhibitory concentrations (IC50) for reference ZDV-susceptible and ZDV-resistant HIV-1 isolates ranged from 0.002 to 0.113 microM and from 0.15 to > 5.0 microM, respectively. Use of this consensus protocol reduced interlaboratory variability for ZDV IC50 determinations with reference HIV-1 isolates. Among eight laboratories, the coefficient of variation ranged from 0.85 to 1.25 with different PBMC protocols and was reduced to 0.39 to 0.98 with the standardized assay. Among the clinical HIV-1 isolates assayed by the standardized drug susceptibility assay, the median ZDV IC50 increased gradually with more ZDV therapy. This protocol provides an efficient and reproducible means to assess the in vitro susceptibility to antiretroviral agents of virtually all clinical HIV-1 isolates.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Identification and enumeration of Listeria monocytogenes by nonradioactive DNA probe colony hybridization.

A plasmid containing the cloned listeriolysin gene of Listeria monocytogenes was used as a probe to identify Listeria strains by DNA colony hybridization. The probe DNA was labeled with horseradish peroxidase in the presence of glutaraldehyde. After the hybridization and wash procedures, the hybrid molecules were detected by luminescence, which resulted from the oxidation of luminol by a horseradish peroxidase-hydrogen peroxide-coupled reaction. Of the 150 Listeria strains and 16 non-Listeria strains examined, the probe hybridized only with L. monocytogenes. The technique was also used to enumerate L. monocytogenes in artificially contaminated foods.

Colony Count, Microbial↗