Biomedical subjects

L Roman

Publications and source records attributed to L Roman.

At least 37 records · Page 2Linked to original sources

PubMed1996

Preconcentration of Pb(II), Cd(II), Cu(II) and Hg(II) with 2-mercapto-5-phenylamino-1,3,4-thiadiazole impregnated on silica gel.

Silica gel modified by the addition of 2-mercapto-5-phenylamino-1,3,4-thiadiazole (MPATD) was developed for the preconcentration of Pb(II), Cd(II), Cu(II) and Hg(II) at trace levels. A "series" experimental procedure permitted the determination of the optimal working conditions (time and pH) and an "on-column" experimental method permitted the determination of the quantity of MPATD retained on silica gel, the uptake capacity, the most suitable eluent and the minimum volume of eluent for which the maximum quantity of metal cations is recovered. The maximal retention capacity on the impregnated silica gel columns was obtained at pH 7.5-8 and was 1500 micrograms g-1 for Pb(II) and about 1000 micrograms g-1 for Cd(II), Cu(II) and Hg(II). The effect of preconcentration is relevant; on passing 1 l of solution containing 1 microgram ml-1 of cation through a column containing 5 g of impregnated silicagel, after elution with 30-50 ml of the appropriate eluent the cation concentration increased about 15-20-fold. The determination of cations by flame AAS was statistically evaluated and showed recoveries higher than 96% for Pb(II), 98.5% for Cd(II) and 97.95% for Cu(II) after elution with 4 M HNO3 and about 99.15% for Hg(II) after elution with thiourea.

Cadmium↗

PubMed1996

A modified McLafferty rearrangement in the electron impact mass spectra of dansylated amino-acid methyl esters.

Electron impact mass spectra of dansylated amino-acids and their methyl esters show a very time intense peak at m/z 171. A systematic study failed to show the genesis and origin of this ion. The present work is devoted to the electron impact mass spectrometric (EIMS) analysis of the appearance of this ion m/z 171 in the spectra of dansylated amino-acid methyl esters and its diagnostic importance in the analysis of dansyl derivatives. A structural model for this study is offered by a series of N-alkylated aromatic sulphonamides. The EIMS spectra of these compounds indicate that the classic fragmentation is accompanied by hydrogen migration from aliphatic radicals to the aromatic ring in a manner analogous with dansylated amino-acids. A modified McLafferty rearrangement mechanism is proposed for this EI reaction. The metastable transitions and the deuterium-labelled compounds confirm this mechanism and the origin of the itinerant hydrogen.

Amino Acids↗

PubMed1996

Spectrophotometric determination of fluoride in dosage forms and dental preparations.

The method is based upon the reaction between fluoride ions and the coloured complex of Fe(III) with methyl salicylate to form the stable, colourless hexaflouride complex of iron. The conditions of the method (pH, time and combination ratio) were studied and a standard curve was obtained for 0.01-0.08 mg NaF ml-1, at 525 nm. A study was conducted on interference with complexing anions of Fe(III), cations that react with fluoride ions and with common ingredients of dosage forms and dental preparations. The method was validated and the results showed good precision (100.16 +/- = 2.33%) comparable with that of other analytical methods. Good results were obtained in the spectrophotometric determination of fluoride ions in a stomatological gel and in a toothpaste.

Dentifrices↗

PubMed1996

Home health visits using a cable television network: user satisfaction.

There are about 1.5 million home patients who receive home health care (nurses visiting patients in their homes) in the US each year. In a significant proportion of these visits, hands-on care is not needed. Rather, the nurse needs to verify compliance with medication regimes, assess mental or emotional status, or check blood sugar levels, blood pressure and the like. Many of these activities might be handled by a nursing visit using interactive video to the patient's home, saving the nurse's time wasted in driving, finding parking, etc. A system for delivering home health care using interactive video has been piloted in the state of Kansas. Using the local cable television infrastructure for audio and video transmission, this system permits a nurse to see patients in their homes for a fraction of the cost of an on-site visit. This new method of delivering home health care is being evaluated with an ongoing study of utilization and user satisfaction. We conducted a prospective survey administered to home health nurses (n = 2) and homebound patients (n = 3) using a cable TV-mediated interactive video system, to assess utilization and user satisfaction with televideo-mediated home health care visits. One hundred and eighty-one patient questionnaires and 193 nurses questionnaires were completed. The average length of a visit was 15 minutes (range 1-91). All mean scores tabulated for the questions indicated strong nurse and patient satisfaction with the system. Participating nurses and clients were satisfied with the televideo encounters. The mean score for all questions was better than neutral. Recognizing that this was a pilot study, hampered by small numbers and subject to the inherent biases of a single institution study, the results support further investigation and implementation of this modality for home health care.

Aged↗

PubMed1995

Intraperitoneal 5-fluoro-2'-deoxyuridine (FUDR) and (S)-leucovorin for disease predominantly confined to the peritoneal cavity: a pharmacokinetic and toxicity study.

Intraperitoneal (IP) administration of fluorinated pyrimidines has been evaluated for ovarian and gastrointestinal malignancies in phase I, II, and III trials. The tolerance and pharmacokinetic profile of IP 5-fluoro-2'-deoxyuridine(FUDR) alone and with (R,S)-leucovorin ((R,S)-LV) have each been evaluated in previous phase I studies. FUDR doses of 3 g per day with and without (R,S)-LV doses up to 640 mg per day given IP are well tolerated. The current phase I study was designed to determine the pharmacokinetic profiles and clinical tolerance of escalating doses of the pure biologically active S-isomer of leucovorin ((S)-LV) given IP with the same dosing schedule of FUDR. A group of 16 patients with disease confined to the abdominal cavity were treated in this study. Pharmacokinetic studies of blood and peritoneal fluid, toxicity profiles, and clinical response for the first three cycles are reported here. The toxicity profile did not significantly differ from the prior two studies. All non-hematologic toxicities, such as fatigue, nausea, vomiting, diarrhea, and abdominal discomfort were less than grade 4, and most were less than grade 3. Neutropenia and thrombocytopenia were uncommon and observed only in patients with compromised bone marrow reserve. The pharmacokinetic profiles were also congruent with the previous studies and indicate a three-log advantage for FUDR. The (S)-LV profiles in the peritoneal cavity paralleled those of FUDR. Antitumor effects or absence of progression until after cessation of therapy were documented in 11 patients. At a median follow-up of 18 months 44% of patients were alive. IP administration of 3-g of FUDR and up to 640 mg (S)-LV daily for three days was well tolerated. The tolerance and antitumor effects observed during IP FUDR and LV in these studies encourage further exploration of this regimen against ovarian and gastrointestinal malignancies. The actual role and optimal dose of LV as an enhancer of the antitumor actions of FUDR administered by this route remain unknown.

Adult↗

PubMed1994

Paclitaxel (Taxol) in heavily pretreated ovarian cancer: antitumor activity and complications.

OBJECTIVE: To analyze the efficacy and toxicity of Taxol in patients with ovarian cancer who had failed at least two previous chemotherapy treatment regimens. PATIENTS AND METHODS: Sixty-eight patients with advanced pretreated ovarian cancer, with either measurable or evaluable disease who were shown to have disease progression were entered on a National Cancer Institute sponsored 'compassionate' treatment referral center protocol and received intravenous infusion of Taxol over 24 hours 135 mg/m2, (after steroid-containing premedication) repeated every 3 weeks and continued while showing no evidence of progression. RESULTS: Of the 68 patients enrolled, 10 patients (15%) had a partial response and one assessable by marker only had improvement of disease. In addition, 27 others (40%) were stable on continued Taxol for a median time of 6.4 months and CA-125 decreased in 20 patients out of 59 patients with elevated baseline CA-125s. Twenty-seven patients progressed while receiving 1-6 cycles of treatment. Three patients were not evaluable for response. Neutropenia and its complications occurred primarily during the first two cycles of Taxol treatment. Febrile episodes requiring antibiotic treatment occurred in 44% of patients which is a higher incidence than in prior series. CONCLUSIONS: Taxol as a single agent has modest activity in heavily pretreated ovarian cancer patients but appears to be useful and is subjectively well tolerated by many. The high incidence of infection in comparison with other series of patients with ovarian cancer treated with chemotherapy suggests this pretreated patient population has enhanced susceptibility to develop complications from neutropenia. Safer treatment in this advanced setting should include more aggressive use of cytokines and/or less myelosuppressive regimens (e.g. shorter Taxol infusions).

Adult↗

PubMed1993

Creative caring in the NICU: parent-to-parent support.

When infants are admitted to a neonatal intensive care unit, the parents are immediately confronted with the crisis surrounding a critically ill newborn and often require additional support. Parents experience feelings of anxiety, fear, anger, and guilt over this unanticipated event. In addition, parents often describe the withdrawal of friends and the denial responses of well-meaning family members during their infant's illness. In an effort to address the NICU parents' need for support, Butterworth Hospital in collaboration with Michigan State University initiated a demonstration and research project focused on parent-to-parent support. The primary goal of the program is to improve parenting outcomes by providing emotional, informational, and role modeling support to parents of high-risk infants utilizing experienced volunteer parents. The program model includes professional program coordinators who recruit and train volunteer parents with past NICU experience. Volunteers are then matched to new NICU families based on infant's diagnosis, similar geographic location, and other characteristics. Volunteers provide support through hospital visits, phone contact, and home visits during the infant's hospitalization and throughout the infant's first year of life. The program was evaluated by analyzing the differences between a treatment group and a comparison group of parents. Significant differences between groups were found on measures of maternal mood states, maternal-infant relationships, and home environment. Services to over 900 families by 110 volunteer parents have convinced staff that the volunteer parents are a valuable and indispensable component of the services at Butterworth Hospital and that families of high-risk infants benefit from past experiences and ongoing support of volunteer parents.

Adult↗

PubMed1992

Effectiveness of curosurf for severe respiratory distress syndrome: a case-control study.

Randomized trials have proven that exogenous surfactant is effective in severe neonatal respiratory distress syndrome when strict entry criteria are applied. To evaluate efficacy of surfactant treatment in a clinical setting, we performed a case-control study. The outcome of the first 25 consecutive cases treated with porcine surfactant (Curosurf) was compared to that of 25 matched historical nontreated controls. Survival at discharge was significantly higher in surfactant-treated cases than among controls (76 vs. 48%; p less than 0.05). No differences were found in other outcome parameters.

Biological Products↗

PubMed1992

Xanthomatized atypical T cells in a patient with mycosis fungoides and hyperlipidemia.

BACKGROUND: Lipoprotein-T-cell interactions are being reported with increasing frequency, and there is evidence that lipoproteins play a role in immunoregulation. We describe a patient with mycosis fungoides and hyperlipidemia who developed xanthomatization in one preexisting plaque. The case is unique in that some of the lipidized cells were atypical T cells. In previously reported cases of mycosis fungoides with dystrophic xanthomatosis, the lipid-containing cells have been identified only as histiocytes. OBSERVATIONS: Immunopathologic features, electron microscopy, and lipid stains of the xanthomatized plaque demonstrated that some of the lipid-laden cells were atypical T cells. CONCLUSIONS: In mycosis fungoides, malignant T cells may be intimately involved in processing of tissue lipids. We suggest that low-density lipoprotein receptors on activated T cells facilitated the cytoplasmic lipidization in this case.

Aged↗

PubMed1987