Biomedical subjects

D Rodriguez

Publications and source records attributed to D Rodriguez.

At least 73 records · Page 4Linked to original sources

PubMed1997

Vaccinia virus membrane proteins p8 and p16 are cotranslationally inserted into the rough endoplasmic reticulum and retained in the intermediate compartment.

The use of two-dimensional gel electrophoresis has identified the gene products A14L (p16) and A13L (p8) as abundant membrane proteins of the first infectious form of vaccinia virus, the intracellular mature virus (IMV; O. N. Jensen, T. Houthaeve, A. Shevchenko, S. Cudmore, T. Ashford, M. Mann, G. Griffiths, J. Krijnse Locker, J. Virol. 70:7485-7497, 1996). In this study, these two proteins were characterized in detail. In infected cells, both proteins localize not only to the viral membranes but also to tubular-cisternal membranes of the intermediate compartment, defined by the use of antibodies to either rab1A or p21, which colocalize with rab1A (J. Krijnse Locker, S. Schleich, D. Rodriguez, B. Goud, E. J. Snijder, and G. Griffiths, J. Biol. Chem. 271:14950-14958, 1996). Both proteins appear to reach this destination via cotranslational insertion into the rough endoplasmic reticulum, as shown by in vitro translation and translocation experiments. Whereas p16 probably spans the membrane twice, p8 is inserted into the membrane by means of its single NH2-terminal hydrophobic domain, adopting a topology which leaves the C terminus exposed to the cytoplasm. Combined immunocytochemical and biochemical data show that p16 is a member of the inner of the two IMV membrane layers, whereas p8 localizes to both the inner and the outer membrane. These findings are discussed with respect to our model of IMV membrane assembly.

Blotting, Western↗

PubMed1997

Identification of a Val 145 Ile substitution in the human myelin oligodendrocyte glycoprotein: lack of association with multiple sclerosis. The Réseau de Recherche Clinique INSERM sur la Susceptibilité Génétique à la Sclérose en Plaques.

Myelin/oligodendrocyte glycoprotein (MOG) is a major target antigen in experimental autoimmune encephalomyelitis and it has been suggested that it may as well play a key role in the demyelination process in multiple sclerosis (MS). As MOG variants could be pathogenic in autoimmune demyelinating diseases of the central nervous system, we analysed the coding sequence of MOG in MS patients and described a G-->A transition occurring in exon 3 of the human MOG gene. The mutation predicts that isoleucine substitutes for a valine at codon 145 (Val 145 Ile) in the transmembrane region of the protein. This is the first aminoacid substitution reported in human MOG. The polymorphism can be detected by restriction enzyme digestion of genomic DNA or reverse-transcribed PCR amplified products, making it a simple tool to detect a potential implication of MOG alleles in susceptibility to MS by association study. The analysis of 83 unrelated MS patients and 82 unrelated healthy controls showed that the polymorphism is found in similar proportions in MS patients (18%) and controls (14.6%). It is therefore unlikely that the MOG Val 145 Ile variant is responsible for genetic susceptibility to MS.

Amino Acid Sequence↗

PubMed1997

Nutritional management of patients with acute renal failure.

Patients with acute renal failure are at high risk for developing malnutrition. Provision of adequate nutrition support begins with an understanding of the metabolic alterations that occur due to the disease state and renal replacement therapies. Assessment of nutritional requirements and implementation of appropriate feeding modalities can lead to optimal nutritional status and positive patient outcomes. Building collaborative relationships with other health care professionals is crucial to overcoming the barriers that hinder implementation of appropriate nutritional management.

Acute Kidney Injury↗

PubMed1996

Trials of 9-amino-20(S)-camptothecin in Boston.

9-Amino-20(S)-camptothecin (9-AC) is an analog of camptothecin with limited water solubility which has shown significant preclinical activity in a variety of human solid tumor xenografts. A Phase I trial using a soluble formulation of 9-AC, given as a 72-hour continuous infusion, has been completed. Thirty-one patients with resistant cancers received 5-60 micrograms/M2/h at three week intervals. The Maximum Tolerated Dose (MTD) was 45 micrograms/M2/hour. Neutropenia was the dose limiting toxicity, with few significant non-myelosuppressive toxicities. Minor responses were seen in 3/31 patients. Pharmacokinetic studies of 9-AC lactone (closed ring) showed substantial interpatient variability with a predicted half-life of 36 hours. A phase I/II trial of the same formulation of 9-AC is ongoing in refractory leukemia. Stomatitis and diarrhea are the non-myelosuppressive dose limiting toxicities. Evidence of antineoplastic activity has been seen in 3/15 patients. A Phase II trial in previously untreated metastatic breast cancer is also underway. A Phase I trial of a colloidal dispersion formulation, not yet completed, is better tolerated with a MTD > 45 micrograms/M2/h as a 72-hour continuous infusion. Evidence of antineoplastic activity has also been demonstrated.

Adult↗

PubMed1996

Characterization of in vivo primary and secondary CD8+ T cell responses induced by recombinant influenza and vaccinia viruses.

We characterized the in vivo primary and secondary murine CD8+ T cell responses induced by immunization with influenza and vaccinia viruses, which were engineered to express the same H-2K(k)- and H-2K(d)-restricted epitopes. Our results show that the induction and magnitude of the primary CD8+ T cell response closely depends on the viral dose used for immunization, while it is not affected by the route of immunization. The induction of secondary CD8+ T cell responses appears to be highly restricted, as suggested by the lack of in vivo expansion of antigen-specific CD8+ T cells after repeated immunization with the same virus. In contrast, a 20- to 30-fold increase in the frequency of antigen-specific CD8+ T cells could be induced after combined immunization with recombinant influenza and vaccinia viruses. These findings may provide the basis for the development of new prophylactic and therapeutic strategies to prevent or control intracellular infections and certain malignancies.

Animals↗

PubMed1996

Predictors of resource utilization for hospitalized patients with Pneumocystis carinii pneumonia (PCP): a summary of effects from the multi-city study of quality of PCP care.

To determine whether patient and hospital characteristics were significantly associated with variations in Pneumocystis carinii (PCP) care and outcomes, we analyzed the use of diagnostic tests, intensive care units (ICUs), anti-PCP medications for persons hospitalized with human immunodeficiency virus (HIV)-related PCP, and hospital discharge status. We conducted retrospective chart reviews of a cohort of 2,174 patients with PCP hospitalized in 1987-1990. Outcomes included process of care for PCP and in-hospital mortality rates. Persons with PCP who were more severely ill at admission were more likely to have early medical care, to receive care in an intensive care unit, and to die in hospital. After we adjusted for differences in this severity of illness, we noted that Medicaid patients, injection drug users (IDUs), and patients treated at VA or county hospitals were significantly less likely than others to have diagnostic bronchoscopies and that persons covered by Medicaid, with a previous diagnosis of acquired immunodeficiency syndrome (AIDS), who did not receive prior zidovudine (AZT) or who received care in a VA hospital had the highest chances of in-hospital death. Insurance and risk group characteristics, severity of illness, and hospital characteristics appear to be the most important determinants of the intensity and timing of medical care and outcomes among patients hospitalized with PCP.

AIDS-Related Opportunistic Infections↗

PubMed1996

The role of a 21-kDa viral membrane protein in the assembly of vaccinia virus from the intermediate compartment.

We have recently provided morphological evidence that a key event in the assembly of vaccinia virus is the formation of a novel cisternal domain of the intermediate compartment (IC) between the endoplasmic reticulum and the Golgi complex (Sodeik, B., Doms, R. W., Ericsson, M., Hiller, G., Machamer, C. E., van't Hof, W., van Meer, G., Moss, B., and Griffiths, G. (1993) J. Cell Biol. 121, 521-541). This tightly apposed cisternal domain incompletely surrounds the spherical immature virus that matures into the first of the two distinct infectious forms of vaccinia, the intracellular mature virus (IMV). In this study we describe the characterization of an abundant membrane protein of the IMV, the gene product of A17L, a 21-kDa protein that has recently been shown to be essential for the formation of the viral membranes (Rodriguez, D., Esteban, M., and Rodriguez, J. R. (1995) J. Virol. 69, 4640-4648). Upon translation in vitro, p21 associated with rough microsomal membranes in a co-translational manner. Using NH2- and COOH-terminal specific antibodies, we show that both in vitro as well as in vivo, p21 adopts a topology where the NH2 and COOH termini are cytoplasmically orientated. Immunocytochemical experiments demonstrated that p21 is a component of the inner of the two cisternal membranes of the immature virus as well as of membranes of the IC, identified using antibodies against Rab1. Taken together, these data provide the first molecular evidence in support of our assembly model; they show that an essential membrane protein of the IMV inserts into the rough endoplasmic reticulum, but gets efficiently targeted to the IC and membranes of the viral factory.

Amino Acid Sequence↗

PubMed1996

Italian population data on the loci LDLR, GYPA, HBGG, D7S8 and GC.

Allele and genotype frequencies for the five loci LDLR, GYPA, HBGG, D7S8 and GC were determined for 374 unrelated Italians using a multiplex PCR-amplification and typing commercial kit. The distribution of the genotype frequencies showed no deviations from Hardy-Weinberg expectations. The combined power of discrimination and chance of exclusion for all five loci were 0.999 and 0.702, respectively. A test for homogeneity was performed and no significant differences were observed among the Caucasian population samples.

Alleles↗

PubMed1996

Patterns of recurrence following pelvic exenteration and external radiotherapy for locally advanced primary rectal adenocarcinoma.

BACKGROUND: Local recurrence remains the main site of failure after pelvic exenteration for locally advanced primary rectal adenocarcinoma. This is a report on the patterns of recurrence in a group of such patients treated with pelvic exenteration and radiotherapy. METHODS: Between 1980 and 1992, we treated 49 patients. Thirty-one received preoperative radiotherapy (pre-RT), 4,500 cGy. Six weeks later, we performed posterior pelvic exenteration (PPE) in 21 patients, and total pelvic exenteration (TPE) in 10. Nine patients received postoperative radiotherapy (post-RT), 5,000 cGy after a PPE. Nine patients had surgery only, PPE (n = 7) and TPE (n = 2). RESULTS: Surgical mortality occurred in 16% of those patients who received pre-RT. The median follow-up was 52 months. Recurrences occurred in 23% of those patients who received pre-RT (local, one; local/distant, one; distant, four); in 88% of those patients treated with surgery only (local/distant, four; distant, four); and in 11% of those treated with post-RT (distant, one). The 5-year survival for patients who received radiotherapy was 66 versus 44% for those treated with surgery only. CONCLUSION: Local control of locally advanced primary rectal adenocarcinoma requiring a pelvic exenteration is improved by the addition of radiotherapy. When recurrences do occur they are predominantly at extrapelvic sites.

Adenocarcinoma↗

PubMed1995

Quantification of antigen specific CD8+ T cells using an ELISPOT assay.

An ELISPOT assay to detect and determine the number of antigen specific CD8+ T cells was standardized using cloned murine CD8+ T cells specific for the epitope SYVPSAEQI of a rodent malaria antigen. This assay is based on the detection of IFN-gamma secretion by single cells after their stimulation with antigen. The interferon secretion is visualized as spots revealed by using enzyme labeled anti-IFN-gamma monoclonal antibodies. Using known numbers of cloned murine CD8+ T cells it was determined that the assay detects 80-95% of these CD8+ T cells. The optimal culture conditions for the stimulation of the CD8+ T cells were determined and the antigen concentration, number of antigen presenting cells and supplement of growth factors required to perform the assay were defined. This ELISPOT assay can be performed with spleen cells from immunized mice, and provide the precise number of antigen specific CD8+ T cells present in mixed lymphocyte populations. This method is more sensitive than the chromium-51 release assay, and much simpler than the conventional precursor frequency analysis, providing the number of antigen specific CD8+ T cells in 36-48 h.

Amino Acid Sequence↗

PubMed1995

Clinical, biochemical, and molecular analysis of a maternally inherited case of Leigh syndrome (MILS) associated with the mtDNA T8993G point mutation.

We report a new case of Leigh disease (subacute necrotizing encephalomyelopathy) in a girl with mitochondrial DNA (mtDNA) mutation in the ATPase6 gene at nucleotide position 8993. Sequence analysis of mtDNA revealed a T-to-G transversion at nucleotide position 8993 in the ATPase6 gene. Southern blot restriction analysis of patient muscle mtDNA showed only a mutant pattern for the mutation 8993. Molecular analysis of seven subjects from the family showed that except for the father they all carried the 8993 mtDNA mutation in all studied tissues, with high percentages in the two symptomatic children and even in one asymptomatic boy.

Brain↗

PubMed1995

[Use of intravenous midazolam in status epilepticus in children].

BACKGROUND: Status epilepticus is usually treated by benzodiazepines such as diazepam or clonazepam in association with phenytoin and phenobarbital. Midazolam (MDZ) is a recently developed short-elimination half-life benzodiazepine. CASE REPORTS: Four children, aged 3 days to 4 years, were hospitalized in the pediatric intensive care unit for life-threatening illness and developed status epilepticus. They were given an i.v. bolus dose of 300 to 500 micrograms/kg of MDZ immediately followed by a continuous i.v. infusion at the dose of 100 to 300 micrograms/kg/h. All seizures stopped within 1 hour after the bolus dose administration. No acute adverse events of MDZ were noted. Withdrawal symptoms in one patient were controlled by progressive reduction of MDZ doses. Neurologic sequelae were noted in three children, secondary to their primitive illness. CONCLUSIONS: High doses of MDZ are effective for treating refractory status epilepticus; optimal dosage and duration of treatment remains to be determined.

Anti-Anxiety Agents↗

PubMed1995

Sphincter-saving surgery with and without pre-operative radiation therapy as treatment for adenocarcinoma of the mid-rectum.

AIMS: To determine if pre-operative radiation therapy induces a local response in patients with complete tumour penetration into the rectal wall and allows for anal sphincter preservation, we compared the results from pathological specimens and local recurrences as measurable end-points in patients treated with pre-operative radiation therapy plus low anterior resection vs. those only treated with low anterior resection. METHODS: From January 1986 to December 1992, we treated 62 patients with mid-rectal adenocarcinoma (5-10 cm from the anal verge as determined by rigid proctosigmoidoscopy with the patient in the jackknife position). Pre-operative evaluation included: complete blood cell count, chemistry profile and the determination of carcinoembryonic antigen, chest X-ray, barium enema or colonoscopy and CT scan of the abdomen and pelvis. Only tumours potentially curative by resection in patients with performance status 0-2 (ECOG) were included. Twenty-one patients received pre-operative radiation therapy at a dose of 45 Gy delivered to the pelvis; 4-8 weeks later a low anterior resection was performed. Forty-one patients were treated with low anterior resection alone. Surgical specimens were classified according to the Astler-Coller modification of Dukes' classification. RESULTS: There were 36 males and 26 females, with a mean age of 56 years. The surgical specimens of those treated only with surgery were classified as: A, 5; B1, 4; B2, 15; C1, 2; and C2, 15. Postirradiated specimens: no residual tumour, 3; A, 4; B1, 4; B2, 7; C2, 3. One surgical death occurred in the group who underwent surgery alone. The median follow-up was 50 months in patients treated with surgery alone vs. 62 months in the combined approach group. Local recurrences occurred in 15/40 patients treated with surgery alone and in 2/21 of those treated with the combined approach (P = 0.043). Anal sphincter continence was classified as excellent by 24/40 patients treated with surgery only and by 18/21 patients treated with the combined approach. The 5-year survival period was 58% in the surgery only group and 82% in the group with combined treatment (P = 0.08). CONCLUSIONS: The use of pre-operative radiation therapy plus low anterior resection was associated with a lower rate of local recurrence and with a higher number of surgical specimens with no lymph node metastases. Thus, this combined treatment modality should be further evaluated as a possible treatment of mid-rectal cancers in good surgical candidates selected for sphincter-saving procedures.

Adenocarcinoma↗

PubMed1995

Enhanced proteolytic processing of the human immunodeficiency virus type 1 envelope protein in murine Ltk(-) cells.

Proteolytic processing of the human immunodeficiency virus type 1 (HIV-1) envelope (Env) precursor glycoprotein (gp160) to produce the mature gp120 and gp41 proteins is required for virus infection and virus-induced cell fusion. It has also been suggested that cleavage of gp120 at the immunodominant V3 loop region is required for virus-to-cell and cell-to-cell fusion. In this investigation we have studied the proteolytic processing of the HIV-1 Env in cells of various origins (human, monkey, and mouse) infected with a vaccinia virus recombinant expressing the entire gp160 protein (VV-env-1). We have observed that in murine Ltk(-) cells, in addition to the proteolytic cleavage of gp160 at the gp120/gp41 site, there is also extensive intracellular proteolytic processing of gp160 at the V3 loop and at a novel site located at the C terminus of gp41. Similar proteolytic processing of the Env precursor was observed after treatment of extracts of VV-env-1-infected monkey cells with thrombin, a trypsin-like protease that has been shown to cleave the gp120 at the V3 loop. Our findings suggest that murine Ltk(-) cells could be a good model system for structural studies of Env with different HIV isolates and in searches for proteinase inhibitors that could prevent HIV-1 infection of susceptible cells by blocking proteolysis of Env.

Animals↗

PubMed1995

Relationship between procedures and health insurance for critically ill patients with Pneumocystis carinii pneumonia.

The objective of the present study was to assess the association between type of health insurance coverage and use of diagnostic tests and therapies among patients with AIDS-related Pneumocystis carinii pneumonia (PCP). Fifty-six private, public, and community hospitals in Chicago, Los Angeles, and Miami were selected for the study, and the charts of 890 patients with empirically treated or cytologically confirmed PCP, hospitalized during 1987 to 1990 were retrospectively reviewed. Patients were classified by insurance status: self-pay (n = 56), Medicaid (n = 254), or private insurance, including health maintenance organizations and Medicare (n = 580). Primary outcomes were the use and timing of bronchoscopy, the type and timing of PCP therapy, and in-hospital mortality. The results indicate that Medicaid patients were less likely than privately insured patients to undergo bronchoscopy (relative odds = 0.61; 95% CI = 0.40, 0.93; p = 0.02) or to have their diagnosis of PCP confirmed (relative odds = 0.51; 95% CI = 0.33, 0.77), after adjusting for patient, severity of illness, and hospital characteristics. Medicaid patients were approximately three-fourths more likely than privately insured patients (relative odds = 1.73; 95% CI = 1.01, 2.96; p = 0.04) to die in-hospital, after adjusting for patient, severity of illness, and hospital characteristics. However, with further adjustment for confirmation of PCP, Medicaid patients no longer had a significantly higher likelihood of dying in-hospital. We conclude that Medicaid patients are less likely to receive diagnostic bronchoscopy than privately insured or self-insured patients, more likely to be empirically treated for PCP, and more likely to die in-hospital.(ABSTRACT TRUNCATED AT 250 WORDS)

AIDS-Related Opportunistic Infections↗

PubMed1995

United States Supreme Court rules against Medicare providers in cost reimbursement case. Shalala v. Guernsey Memorial Hospital.

In the long run, the impact of Guernsey will depend on the interpretation and application of the decision by HCFA, the Provider Reimbursement Review Board, and the courts. If HCFA interprets the decision as a signal that the Supreme Court is willing to grant federal agencies broad latitude to avoid the rulemaking requirements of the APA, providers may have fewer opportunities for formal input into payment policy issues under the Medicare program. The impact of the case may well go beyond cost-based reimbursement issues and affect all aspects of the Medicare program.

Accounting↗

PubMed1994

Influenza and vaccinia viruses expressing malaria CD8+ T and B cell epitopes. Comparison of their immunogenicity and capacity to induce protective immunity.

We compared the effectiveness of several recombinant influenza and vaccinia viruses to induce a malaria-specific immune response. The CD8+ T cell epitope of the circumsporozoite (CS) protein of Plasmodium yoelii, a rodent malaria parasite, was expressed in two distinct influenza virus proteins, the hemagglutinin and the neuraminidase. These recombinant viruses were found to be equally efficient at inducing CS-specific CD8+ T cells in mice. A third recombinant virus, which expresses a B cell epitope of the CS protein, induced neutralizing anti-sporozoite Abs. Expression in the same recombinant virus of the CD8+ T cell epitope and of the B cell epitope did not impair the capacity of this recombinant virus to induce malaria-specific CD8+ T cells and neutralizing Abs. The immunogenicity of a vaccinia virus, expressing the entire CS protein, was compared with that of a highly attenuated vaccinia strain expressing the same protein and with that of another vaccinia virus expressing only the CD8+ T cell epitope. All three vaccinia virus recombinants elicited CS-specific CD8+ cells and a potent inhibitory response against pre-erythrocytic stages of malaria parasites. Optimal levels of anti-sporozoite Abs, inhibition of liver stage development, and protection against malaria infection resulted from repeatedly immunizing the animals with recombinant influenza viruses followed by boosters with a recombinant vaccinia virus. These findings support the concept that live viral vectors expressing the appropriate proteins and/or epitopes can be used as promising vaccine candidates.

Amino Acid Sequence↗

PubMed1994

Human core temperature minimum can be modified by ambient thermal transients.

By using slow linear thermal transients (+/- 0.025 degree C/min) of reduced amplitude (+/- 3 degrees C around thermoneutrality), we were able to advance the minimum of human internal temperature (Ti) during nocturnal sleep. During experimental night the minimum of esophageal (Tes) and rectal (Tre) temperature were respectively advanced by 1.6 h (P < 0.01) and 2.6 h (P < 0.001) in comparison to reference night spent at thermoneutrality. It must be emphasized that the provoked advance of nocturnal Ti minimum was not accompanied by any change in sleep latency, efficiency, SWS and REM sleep percentages. The result shows that appropriate ambient temperature transient changes could be used to modify the course of human Ti one of the major biological rhythms usually considered as resistant to sleep-wake rhythm manipulation.

Adult↗