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L Petersen

Publications and source records attributed to L Petersen.

At least 19 recordsLinked to original sources
PubMed1995

The 1.6 A structure of Kunitz-type domain from the alpha 3 chain of human type VI collagen.

The C-terminal Kunitz-type domain from the alpha 3 chain of human type VI collagen (C5), a single 58 amino acid residue chain with three disulfide bridges, was cloned, expressed and crystallized in a monoclonic form, space group P2(1), with a = 25.7 A, b = 38.2 A, c = 28.8 A and beta = 109 degrees. The structure was resolved by molecular replacement, using Alzheimer's protein precursor inhibitor and bovine pancreatic trypsin inhibitor three-dimensional structures as search models. The molecule with one sulfate ion and 43 associated water molecules was refined by XPLOR to an R-factor of 18.9% at 1.6 A. The molecule was not degraded by trypsin and did not inhibit trypsin or tested serine proteases. As opposed to the other Kunitz family members, C5 demonstrates left-handed chirality of the Cys14-Cys38 disulfide bond. Inversion of the Thr13 carbonyl and bulky side-chains at the interface with trypsin in a model of the C5-trypsin complex may explain the lack of inhibition of trypsin.

Amino Acid Sequence↗
PubMed1995

Human immunodeficiency virus seroprevalence in community-based primary care practices, 1990-1992. A report from the Ambulatory Sentinel Practice Network.

OBJECTIVE: To estimate the seroprevalence of human immunodeficiency virus type 1 (HIV-1) infection in primary care practices. METHODS: Fifty-four practices in the United States participated in an anonymous, unlinked HIV seroprevalence study between January 1990 and December 1992. Residual blood samples drawn for routine clinical tests from patients 15 to 49 years of age were centrally tested for the HIV-1 antibody for 1 month of each quarter. Information about patient demographics, clinician-recognized risk factors, the known HIV status of the patient, and whether the blood was drawn for HIV testing was recorded with each specimen. RESULTS: Of 21,998 specimens collected, 99 (0.45%) were seropositive. Of these 99 seropositive persons, 31.3% (a seroprevalence of 0.15%) were not suspected by their clinicians of being infected with HIV. Seroprevalences in men (0.96%) exceeded those in women (0.22%), and rates in rural practices (0.18%) were lower than in urban practices (0.71%). Among patients with unsuspected HIV infection, however, the gender differences, especially in rural areas, were less pronounced. Risk factors for HIV infection were infrequently noted. There was an increase in the overall seroprevalence during the 1990 to 1992 study period (0.36% to 0.53%); however, this trend was not statistically significant. CONCLUSIONS: Within a 3-year period, clinicians in at least two of five primary care practices can expect to encounter patients infected with HIV, regardless of practice location. Also, nearly one third of the patients with HIV infection will not be suspected of having this condition by their clinician.

Adolescent↗
PubMed1994

apbA, a new genetic locus involved in thiamine biosynthesis in Salmonella typhimurium.

In Salmonella typhimurium, the synthesis of the pyrimidine moiety of thiamine can occur by utilization of the first five steps in de novo purine biosynthesis or independently of the pur genes through the alternative pyrimidine biosynthetic, or APB, pathway (D. M. Downs, J. Bacteriol. 174:1515-1521, 1992). We have isolated the first mutations defective in the APB pathway. These mutations define the apbA locus and map at 10.5 min on the S. typhimurium chromosome. We have cloned and sequenced the apbA gene and found it to encode a 32-kDa polypeptide whose sequence predicts an NAD/flavin adenine dinucleotide-binding pocket in the protein. The phenotypes of apbA mutants suggest that, under some conditions, the APB pathway is the sole source of the pyrimidine moiety of thiamine in wild-type S. typhimurium, and furthermore, the pur genetic background of the strain influences whether this pathway can function under aerobic and/or anaerobic growth conditions.

Amino Acid Sequence↗
PubMed1992

[Encrusted ureteral endoprosthesis].

The case of a patient with a ureter endoprosthesis is presented. The endoprosthesis became encrusted after remaining in position for three years. Ureter endoprosthesis in connection with renal or ureteric calculi should only remain in position for 6-8 weeks.

Catheters, Indwelling↗
PubMed1992

Assessing the needs and quality of life of patients with HIV infection: development of the HIV Overview of Problems-Evaluation System (HOPES).

OBJECTIVE: To develop and evaluate the psychometric properties (reliability, validity etc.) of a comprehensive Quality of Life (QOL) tool, for patients infected with the human immunodeficiency virus (HIV), that was adapted from a previously validated cancer tool. DESIGN: Cross-sectional, patient completed written surveys and interviews. SETTING: The Medical Centers serving HIV infected patients in the Los Angeles community including UCLA, community physicians, Veterans Affairs Medical Centers, and a County hospital: and additional data contributed from Johns Hopkins University Medical Center CMV Retinitis Clinic. PATIENTS: Patients (n = 318) with HIV infection including asymptomatic (37%), ARC (20%), AIDS (25%) and AIDS with Cancer (18%) receiving health services at one of the above sites. MEASUREMENTS: The patients self-administered the newly developed instrument, the HOPES (HIV Overview of Problems-Evaluation System), other QOL related tools including the Medical Outcomes Study instrument adapted for HIV (MOS-HIV) the Profile of Mood States (POMS), the Perceived Adjustment to Chronic Illness Scale (PACIS), and the Physical Activity Scale (PAS). Brief interview to assess the Karnofsky Performance Status Score (KPS). Measured sociodemographic characteristics included age, sex, race, HIV risk factor, education etc. Assessed medical history, current medications, HIV clinical classification. MAIN RESULTS: The sociodemographic and medical characteristics of the sample resemble those of the general population with HIV infection in this geographic area: 96% male, 28% nonwhite, 84% homosexual contact as risk factor, 75% receiving antiretroviral therapy. The adaptation of the cancer QOL instrument to HIV appears to have face and content validity according to patients and health professionals who care for HIV infected patients. Analyses of the psychometric properties found that the HOPES has a similar structure to its parent instrument following factor analyses which results in five summary scales representing the Physical, Psychosocial, Medical Interaction, Sexual and Significant Other/Partners domains in addition to a Global Score. Internal consistency of 35 subscales is high with a mean alpha coefficient of 0.82. Correlations of the HOPES summary scales with other QOL instruments are in the predicted directions. Comparing patients within the HIV clinical diagnostic categories on the HOPES Global, Physical, and Psychosocial Summary Scales indicates that Asymptomatic Patients have better QOL than symptomatic patients. This finding is also found in the other QOL instruments which provides evidence of construct validity. CONCLUSIONS: The HOPES is an excellent tool for identifying the problems and needs of patients with HIV infection and for assessing their quality of life. It is reliable, valid and acceptable to patients. The tool may be especially useful in developing a normative data base.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Germ cell neoplasms in three intersex patients with 46,XY karyotype.

This report presents 3 cases with gonadoblastoma mixed with other germ cell tumours in intersex patients, all with a 46,XY karyotype. One 11-year-old patient was a true hermaphrodite, the others, aged 13 and 18, respectively, had both gonadal dysgenesis. Different clinical courses have been noted. Two patients had gonadoblastoma combined with dysgerminoma; in one of them a teratoma was also found. In the third case gonadoblastoma was transformed into teratocarcinoma. The malignant degeneration was more serious in the 2 pubertal patients. Thus, we recommend early and prophylactic gonadectomy.

Adolescent↗
PubMed1992

Smoking habits in relapsed subjects from a smoking cessation trial after one year.

Reports of smoking cessation studies often claim that many relapsed subjects reduce their smoking. We investigated the smoking habits of relapsers 1 year after quitting in a smoking cessation trial using nicotine or placebo patches. All 289 participants in that study were summoned to a 1-year follow-up visit--148 (57%) of 259 relapsers attended, as did all 30 sustained abstainers. Fewer than 1% of the subjects had quit spontaneously after the primary relapse. Daily cigarette consumption, standard nicotine yield per cigarette, saliva cotinine concentration, expired carbon monoxide level and two nicotine dependency scales were assessed at entry and at the 1-year follow-up. In five of these six smoking-related characteristics, there was a small but significant mean reduction of 7%-27%. A significant weight gain of 0.5 +/- 2.9 kg (mean +/- SD) was recorded in the relapsers compared with 4.8 +/- 4.2 kg for abstainers (p less than 0.001). It is concluded that smoking habits in relapsers are relatively unchanged, and thus the most important outcome measure in smoking cessation trials is abstinent subjects.

Administration, Cutaneous↗
PubMed1992

Smoking reduction during pregnancy by a program of self-help and clinical support.

This study investigated the impact of a low-cost, pregnancy-specific self-help smoking-cessation program on patient smoking behavior both pre- and postpartum. The population consisted of 274 English-speaking women enrolled in a large health maintenance organization who reported smoking at the time of the baseline survey or had quit within the previous 3 months. A control group receiving standard obstetric care was compared with two experimental groups, one receiving the self-help materials and standard care and the other receiving the materials plus brief regular clinician interactions and counseling about smoking. Smoking data were obtained from two additional self-reported surveys conducted at 6 months' gestation and approximately 8 weeks postpartum. Self-reported smoking behavior was verified using a urine cotinine test, which revealed no significant differences between the groups. Among baseline smokers, although neither intervention yielded significantly higher 6-month nonsmoking rates compared with controls, both interventions significantly increased the proportion of women who were not smoking postpartum. Among those who had quit smoking at baseline, only the more intensive intervention significantly increased maintenance of non-smoking postpartum. Brief counseling, a simple charting system, and improved access to educational materials allowed the program to be integrated easily into routine prenatal care at a cost of $50-111 per patient.

Adolescent↗
PubMed1991

[Should athletic injuries be treated with non-steroidal anti-rheumatic agents (NSAID)? Tenoxicam, piroxicam and placebo in the treatment of acute stress-induced injuries].

A total of 212 patients with acute sports injuries were allotted at random to treatment with 20 mg tenoxicam daily, 20 piroxicam daily or a placebo for ten days. The injuries could be subdivided into six groups: Tendinitis, periostitis, sprains, tendovaginitis, epicondylitis and muscular ruptures. Treatment was well tolerated and analysis of the total material showed a slight but significantly better effect in the group treated with the active drugs. More detailed analysis revealed that this increased effect was produced by a definitely better therapeutic result in the group of patients with tendinitis treated with non-steroid anti-inflammatory drugs (NSAID) while, in the other types of injury, no definite effect could be observed. On the basis of these observations, the authors conclude that acute tendinitis may be treated with NSAID (tenoxicam) while the question is not yet solved where other acute stress-induced injuries are concerned.

Acute Disease↗
PubMed1990

Monitoring blood donors for HIV-2 infection by testing anti-HIV-1 reactive sera.

Anti-HIV-1 EIA tests currently used for screening blood donors in the United States are estimated to detect 55 to 91% of HIV-2 infections; Western blots for HIV-1 antibodies may be positive, negative or indeterminate with HIV-2-positive sera. We reasoned that we could exploit the cross-reactivity of the anti-HIV-1 EIA as a means to monitor the blood supply for the appearance of HIV-2 infected or co-infected persons, and thus decide if and when routine HIV-2 screening should be adopted. We tested 913 anti-HIV-1-reactive donor sera using an anti-HIV-2 screening EIA, with confirmation by an anti-HIV-2 env-peptide EIA and an anti-HIV-2 Western blot. These 913 sera were derived from anti-HIV-1 screening of approximately 242,000 donations over a three year period. No HIV-2 infections were identified. This approach may warrant adoption in blood centers serving populations with persons from countries where HIV-2 is prevalent.

Antigens, Viral↗
PubMed1989

A randomised double-blind multicentre trial comparing tenoxicam and ketoprofen in osteoarthritis.

A double-blind multicentre study was conducted to compare the efficacy and safety of tenoxicam and ketoprofen in the treatment of osteoarthritis (OA). The study comprised 307 patients and the treatment period was 12 weeks. One-hundred and fifty-five patients received 20 mg tenoxicam once-daily and 152 patients received 100 mg ketoprofen b.i.d. Seventy-seven patients were prematurely withdrawn; 32 patients in the tenoxicam group and 45 in the ketoprofen group (p less than 0.05). There were only small insignificant differences in the efficacy parameters with the exception that significantly more patients in the tenoxicam group took paracetamol tablets during treatment. Adverse events developed in 29.0% of the patients on tenoxicam and in 47.3% of the patients on ketoprofen, this difference was statistically significant (p less than 0.05). The adverse events were predominantly from the gastrointestinal tract and the central nervous system. No serious side-effects occurred and the laboratory parameters showed no clinically relevant changes. The investigator's overall impression of treatment showed no significant difference between groups. Excellent or good results were judged in 55.2% of the patients on tenoxicam and in 62.1% on ketoprofen (p greater than 0.05). Tenoxicam appears to have a reasonable balance between efficacy and side-effects in the treatment of OA.

Adult↗