PubMed Health⌕ Search

Biomedical subjects

J L Meyer

Publications and source records attributed to J L Meyer.

At least 19 recordsLinked to original sources
PubMed2005

The psychosocial impact of serological herpes simplex type 2 testing in an urban HIV clinic.

BACKGROUND/OBJECTIVES: Herpes simplex virus type 2 (HSV-2) is a common infection among HIV infected people. HSV type specific serologies permit the diagnosis of previously unrecognised HSV-2 infection. While substantial psychosocial morbidity has been associated with a clinical diagnosis of genital herpes, the burden associated with a serological diagnosis of HSV-2 is unclear. This study prospectively measured the psychosocial response to a new serological HSV-2 diagnosis in patients receiving care at an urban HIV clinic. METHODS: At entry, sera were tested for HSV-1 and HSV-2 antibodies by western blot. Participants completed a 90 item psychosocial and life quality questionnaire at enrollment, and at 2 weeks, 3 months, and 6 months after receiving test results. RESULTS: Of 248 HIV infected participants, 172 (69.4%) were HSV-2 seropositive and 116 (67.4%) seropositive people did not have a previous history of genital herpes. After correction for multiple comparisons, no statistically significant differences were detected on the psychosocial and life quality scales between those who received a new HSV-2 serological diagnosis compared with those who were HSV-2 seropositive with a history of genital herpes, or those who tested HSV-2 seronegative. Additionally, no significant changes in scores were observed during follow up. CONCLUSIONS: HSV-2 was a common but often unrecognised infection in this urban HIV clinic and participants coped well with a positive HSV-2 result. Concerns about psychosocial burden should not deter serological testing for HSV-2. Given the epidemiological and clinical interaction between HSV-2 and HIV, these data support routine HSV-2 testing of HIV infected people.

Adaptation, Psychological↗
PubMed2004

One year comparison between two add-back therapies in patients treated with a GnRH agonist for symptomatic endometriosis: a randomized double-blind trial.

BACKGROUND: It has been proposed that hormonal supplementation during prolonged GnRH agonist therapy prevents hypoestrogenic side effects, including bone loss. The optimal combination for long-term treatments with safe metabolic profile remains questionable. A norprogesterone derivative, promegestone, was assessed for the first time in a double-blind trial. METHODS: Seventy-eight patients with endometriosis with rAFS (Revised American Society for Reproductive Medicine) scores of III-IV were randomly assigned to monthly leuprorelin 3.75 mg (1 year) which, after the third injection was used in combination with promegestone 0.5 mg (P) plus either estradiol placebo (PL) or estradiol 2 mg (E) per day. Bone mineral density (BMD) was determined at baseline, 6 and 12 months, and biological and clinical quarterly assessments were performed. Analysis was by the intention to treat method. RESULTS: At month 12, BMD changes from baseline were -6.1 +/- 3.7 and -4.9 +/- 4.0% in the PL-P group, at the spine and hip, respectively. This bone loss was prevented in the E-P group: -1.9 +/- 3.1 and -1.4 +/- 2.3%, respectively (P < 0.0001 inter-group comparisons). The BMD decrease in the E-P group was explained by the changes occurring during the first 6 months of treatment. There was no deleterious change in lipid parameters. Clinical improvement was observed without an inter-group difference. CONCLUSIONS: Estradiol 2 mg and promegestone 0.5 mg per day is an effective and safe add-back therapy, which can be proposed for prolonged leuprorelin treatment over 6 months in severe endometriosis.

Absorptiometry, Photon↗
PubMed2003

Gastroscopic removal of an adjustable gastric band after partial intragastric migration.

BACKGROUND: Laparoscopic implantation of an adjustable gastric band is being performed widely. One potential complication is the transgastric migration of the band, that should be extracted. METHODS: The authors report a series of 182 patients, followed prospectively, October 1996 - April 2002, who had undergone insertion of the Swedish adjustable gastric band. All implantations had been completed by laparoscopy alone. RESULTS: There were no deaths. 15 complications were detected, of which 7 were intragastric migrations of the band (3.8%) at an average follow-up of 40 months. 6 were treated successfully by gastroscopy only, with a new cutter device and without complications. CONCLUSION: The endoscopic technique is beneficial even when the intraluminal migration is partial.

Adolescent↗
PubMed2002

Carbon and nitrogen transfer from a desert stream to riparian predators.

Adult aquatic insects emerging from streams may be a significant source of energy for terrestrial predators inhabiting riparian zones. In this study, we use natural abundance delta(13)C and delta(15)N values and an isotopic (15)N tracer addition to quantify the flow of carbon and nitrogen from aquatic to terrestrial food webs via emerging aquatic insects. We continuously dripped labeled (15)N-NH(4) for 6 weeks into Sycamore Creek, a Sonoran desert stream in the Tonto National Forest (central Arizona) and traced the flow of tracer (15)N from the stream into spiders living in the riparian zone. After correcting for natural abundance delta(15)N, we used isotopic mixing models to calculate the proportion of (15)N from emerging aquatic insects incorporated into spider biomass. Natural abundance delta(13)C values indicate that orb-web weaving spiders inhabiting riparian vegetation along the stream channel obtain almost 100% of their carbon from instream sources, whereas ground-dwelling hunting spiders obtain on average 68% of their carbon from instream sources. During the 6-week period of the (15)N tracer addition, orb-web weaving spiders obtained on average 39% of their nitrogen from emerging aquatic insects, whereas spider species hunting on the ground obtained on average 25% of their nitrogen from emerging aquatic insects. To determine if stream subsidies might be influencing the spatial distribution of terrestrial predators, we measured the biomass, abundance and diversity of spiders along a gradient from the active stream channel to a distance of 50 m into the upland using pitfall traps and timed sweep net samples. Spider abundance, biomass and richness were highest within the active stream channel but decreased more than three-fold 25 m from the wetted stream margin. Changes in structural complexity of vegetation, ground cover or terrestrial prey abundance could not account for patterns in spider distributions, however nutrient and energy subsidies from the stream could explain elevated spider numbers and richness within the active stream channel and riparian zone of Sycamore Creek.

Animals↗
PubMed2001

Control of nitrogen export from watersheds by headwater streams.

A comparative (15)N-tracer study of nitrogen dynamics in headwater streams from biomes throughout North America demonstrates that streams exert control over nutrient exports to rivers, lakes, and estuaries. The most rapid uptake and transformation of inorganic nitrogen occurred in the smallest streams. Ammonium entering these streams was removed from the water within a few tens to hundreds of meters. Nitrate was also removed from stream water but traveled a distance 5 to 10 times as long, on average, as ammonium. Despite low ammonium concentration in stream water, nitrification rates were high, indicating that small streams are potentially important sources of atmospheric nitrous oxide. During seasons of high biological activity, the reaches of headwater streams typically export downstream less than half of the input of dissolved inorganic nitrogen from their watersheds.

Absorption↗
PubMed2001

Identification of the target of monoclonal antibody A6H as dipeptidyl peptidase IV/CD26 by LC MS\MS.

The monoclonal antibody (MAb) A6H, originally developed to fetal renal tissues, was found to be highly reactive to renal cell carcinoma and was subsequently demonstrated to co-stimulate a subpopulation of T cells. The A6H antigen had not been identified heretofore. Antigen from detergent extracts of renal cell carcinoma cells (7860) was immunoabsorbed with A6H-agarose, and the resin-bound proteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The antigen had a molecular weight of approximately 120 kDa as determined by Western blots. The 120-kDa protein band was excised and subjected to in-gel tryptic digestion, and the resulting peptides were separated and analyzed by liquid chromatography tandem mass spectrometry (LC MS\MS). The tandem mass spectra of the eluting peptides were used in combination with the SEQUEST computer program to search a human National Cancer Institute (NCI) protein database for the identity of the protein. The target antigen was shown to be dipeptidyl peptidase IV (DPP IV), which is also known as the cluster differentiation antigen CD26. Flow analysis of the expression of the A6H antigen and of CD26 on 7860 cells and on peripheral blood lymphocytes supported the identification of the A6H antigen as DPP IV. Recognition that the A6H antigen is DPP IV/CD26 afforded the opportunity to compare previous studies on A6H with those on other anti-CD26 antibodies in terms of expression in cancer cell lines and various tissues and as co-stimulators of T-cell activation.

Amino Acid Sequence↗
PubMed2000

Choledochocele demonstrated by computed tomographic cholangiography: report of a case.

Choledochocele is a rare cystic congenital malformation of the distal common bile duct, the precise pathogenesis of which remains unclear. It is usually diagnosed in adulthood after many examinations for unclear digestive symptoms, as in the patient whose case is described herein. Of all the diagnostic techniques available, endoscopic retrograde cholangiography (ERCP) seems to be the best; however, it is an invasive procedure associated with some morbidity. Spiral computed tomographic cholangiography with three-dimensional reconstruction is also an interesting screening technique. Malignant transformation of a choledochocele occurs very rarely, compared with other cystic malformations of the biliary tract. If a choledochocele is small and symptomatic, the lesion can be treated by endoscopic sphincterotomy, but larger cysts are more effectively removed by a surgical cystoduodenostomy. We present herein the case of a 25-year-old woman admitted to our hospital in March 1998 with upper right quadrant abdominal pain caused by a choledochocele, who was successfully treated by a cystoduodenostomy.

Abdominal Pain↗
PubMed1998

Histamine phase shifts the hamster circadian pacemaker via an NMDA dependent mechanism.

The SCN acts as the central pacemaker for circadian rhythms in mammals. Histamine has been shown to affect circadian rhythms both in vivo and in vitro. We investigated the mechanism by which histamine phase shifts circadian rhythms in vitro. Hypothalamic slices containing the SCN were prepared from golden hamsters, and spontaneous firing rates of individual cells were recorded on the second day in vitro. Application of histamine (1 microM-10 mM) at the extrapolated time of 2 h after lights off (ZT 14) on day 1 in vitro delayed the time of peak firing in a dose-dependent manner. Pre-exposure to the N-methyl-D-aspartate (NMDA) receptor antagonist (+/-)-2-amino-5-phosphonopentanoic acid (AP-5; 100 microM-1 mM) 5 min before histamine (1 microM) was applied to the slice blocked the phase-delaying effects of histamine. Application of the H1 blocker mepryamine (100 nM) or the H2 blocker cimetidine (10 microM) followed by histamine had no effect on the phase delay induced by histamine. In whole cell recordings from acutely dissociated neurons of hamster SCN, histamine (50 microM) was shown to potentiate NMDA-evoked currents by 52 +/- 12%. These experiments demonstrate that histamine phase shifts of the circadian clock are dependent on NMDA receptor activation and that histamine can directly potentiate NMDA currents in SCN neurons. Histamine may alter circadian clock function by acting directly on NMDA receptors, possibly via binding to the polyamine site.

Animals↗
PubMed1995

Nasopharyngeal carcinoma. A study examining Asian patients treated in the United States.

From 1972 to 1991, 126 Asian patients with nasopharyngeal carcinoma underwent definitive radiation therapy for locoregional disease: 86 men, 40 women. Median age was 50. All patients received external-beam irradiation with cobalt 60 or 4-18 MV x-rays. Local recurrence, regional recurrence, and distant metastases were 22%, 11%, and 23%, respectively. Local recurrence progressively increased with increasing T stage, but doses in those who recurred did not differ from the group as a whole. Regional recurrence was not associated with T or N stage or dose. Patients with N2 disease had the highest distant metastatic rate. The 5- and 10-year overall survival rates were 54% and 38%, respectively. Of age, gender, and histology, only age less than 50 was found to be favorably prognostic. No severe long-term complications were observed, and acute reactions were acceptable. Our survival results are comparable with results found both in Asia and North America. Nonetheless, altered fractionation techniques and/or other radiation modalities should be further explored to improve locoregional control.

Adult↗
PubMed1993

Whole-lung irradiation for Kaposi's sarcoma.

Twenty-five patients were treated with whole-lung irradiation for symptomatic pulmonary KS. Treatment was most often given four days per week, 150 cGy per fraction, to 1050-1500 cGy (mean 1224 cGy). No acute toxicity was observed. 89% of patients completing therapy reported improvement in dyspnea. All patients responding symptomatically could reduce (and 78% could eliminate) oxygen use. Chest x-rays showed concurrent improvement in 78% of cases, although this was > or = 50% clearance of infiltrate in only 28%. Symptomatic improvement was prompt, always occurring during the 2-2 1/2 week therapy course. Clinical response was transient in some patients, but 12 weeks after therapy 56% remained symptomatically improved. Pulmonary KS indicated an advanced stage of AIDS and survival was short (mean: 15.7 weeks after completion of therapy). Patients with poor performance status (Karnovsky: < or = 30%) and progression of disease despite chemotherapy had very short survival (mean: 3.2 weeks). For such patients, a supportive care only approach without radiotherapy is suggested. For others, whole-lung irradiation provides prompt symptomatic improvement for most patients, and offers a simple treatment approach with little toxicity for often debilitated patients.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Parameters predictive for complications of treatment with combined hyperthermia and radiation therapy.

Pretreatment and treatment related factors were reviewed for 996 hyperthermia sessions involving 268 separate treatment fields in 131 patients managed with hyperthermia for biopsy confirmed local-regionally advanced or recurrent malignancies to ascertain parameters associated with the development of complications. A subset of 249 fields were identified in which multipoint or mapped temperature data were available for at least one treatment session per field. A total of 198 fields involved superficially located tumors (less than or equal to 3 cm from the surface), whereas 51 fields involved more deeply located tumors. Most of these patients had received extensive prior therapy: 77% had surgery, 75% chemotherapy, 65% radiation therapy and 28% hormonal therapy. They were treated with hyperthermia in conjunction with radiation therapy (244 fields) or hyperthermia alone (5 fields). The hyperthermia treatment objectives were to elevate intratumoral temperatures to a minimum of 43.0 degrees C for 45 minutes while maintaining maximum normal tissue temperatures to less than or equal to 43 degrees C and maximum intratumoral temperatures to less than or equal to 50 degrees C. The hyperthermia was given within 30 to 60 minutes following radiation therapy without the administration of additional analgesics. Hyperthermia treatment regimens using radiative electromagnetic, ultrasound, or radiofrequency interstitial techniques were individualized, with 3 to 4 days between hyperthermia treatments and an average of 3.6 treatments (range 1-14; standard deviation 2.2) utilized per field. A total of 38 complications in 33 treatment fields were noted; an incidence of 27/198 (13.6%) for fields with superficially located tumors, and 6/51 (11.8%) in fields with more deeply located tumors. Univariate analyses demonstrated statistically significant correlations between the maximum tumor temperature (p = 0.0005), average of the maximum tumor temperatures (p = 0.0006), the average of the % tumor temperatures greater than 43.5 degrees C (p = 0.0071), and the average number of hyperthermia treatments (p = 0.033), with the development of complications. The average of the maximum measured tumor temperature for fields without complications was 44.6 degrees C compared with 45.9 degrees C for fields with complications. The complication rate increased from 7.5% (9/120) in fields that received one or two hyperthermia treatments to 18.6% (24/129) in fields that received greater than two hyperthermia treatments. Multivariate logistic regression analyses revealed the best bivariate model predictive of the development of complications included average of the maximum tumor temperature and the number of treatments per field (p = 0.00012 for the bivariate model).(ABSTRACT TRUNCATED AT 400 WORDS)

Combined Modality Therapy↗
PubMed1992

[History of the research on differentiating Hepatitis A and B].

The numerous researches devoted to 'jaundice' during the Second World War have brought to light the existence of an infectious type of hepatic jaundice or 'homologous serum jaundice' following parenteral injection of vaccines containing human serum and blood transfusions, which were carried out on a large scale at the time. This type of serum jaundice was then gradually differentiated from 'catarrhal', contagious or epidemic jaundice by clinical trials along with large series of animal studies. Finally, the epidemiological, clinical and biological data obtained made it possible to establish, between 1944 and 1954, the viral etiology of these two types of jaundice: the A virus, present in the patients' blood and stools, was considered to be the agent responsible for epidemic hepatitis; the B virus, present primarily in the blood, was held to be responsible for serum hepatitis.

Diagnosis, Differential↗
PubMed1990

Two or six hyperthermia treatments as an adjunct to radiation therapy yield similar tumor responses: results of a randomized trial.

From March 1984 to February 1988, 70 patients with 179 separate treatment fields containing superficially located (less than 3 cm from surface) recurrent or metastatic malignancies were stratified based on tumor size, histology, and prior radiation therapy and enrolled in prospective randomized trials comparing two versus six hyperthermia treatments as an adjunct to standardized courses of radiation therapy. A total of 165 fields completed the combined hyperthermia-radiation therapy protocols and were evaluable for response. No statistically significant differences were observed between the two treatment arms with respect to tumor location; histology; initial tumor volume; patient age and pretreatment performance status; extent of prior radiation therapy, chemotherapy, hormonal therapy, or immunotherapy; or concurrent radiation therapy. The means for all fields of the averaged minimum, maximum, and average measured intratumoral temperatures were 40.2 degrees C, 44.8 degrees C, 42.5 degrees C, respectively, and did not differ significantly between the fields randomized to two or six hyperthermia treatments. The treatment was well tolerated with an acceptable level of complications. At 3 weeks after completion of therapy, complete disappearance of all measurable tumor was noted in 52% of the fields, greater than or equal to 50% tumor reduction was noted in 7% of the fields, less than 50% tumor reduction was noted in 21% of the fields, and continuing regression (monotonic regression to less than 50% of initial volume) was noted in 20% of the fields. No significant differences were noted in tumor responses at 3 weeks for fields randomized to two versus six hyperthermia treatments (p = 0.89). Cox regression analyses were performed to identify pretreatment or treatment parameters that correlated with duration of local control. Tumor histology, concurrent radiation doses, and tumor volume all correlated with duration of local control. The mean of the minimum intratumoral temperatures (less than 41 degrees C vs. greater than or equal to 41 degrees C) was of borderline prognostic significance in the univariate analysis, and added to the power of the best three covariate model. Neither the actual number of hyperthermia treatments administered nor the hyperthermia protocol group (two versus six treatments) correlated with duration of local control. The development of thermotolerance is postulated to be, at least in part, responsible for limiting the effectiveness of multiple closely spaced hyperthermia treatments.

Adult↗