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Biomedical subjects

R Mora

Publications and source records attributed to R Mora.

At least 73 records · Page 4Linked to original sources
PubMed1986

Trauma serum suppresses superoxide production by normal neutrophils.

The effect of trauma serum on superoxide production by normal neutrophils was studied in 47 serum samples from 18 patients with multiple trauma. Ten patients became septic and eight patients remained nonseptic. Incubation in trauma serum significantly suppressed superoxide production by normal neutrophils compared with incubation in normal serum: 3.6 +/- 1.44 vs 4.04 +/- 1.64 nmole of superoxide produced by 10(6) neutrophils (mean +/- SD). There was no difference in the suppressive effect between septic and nonseptic trauma serum samples. The chemiluminescence response of normal neutrophils was likewise suppressed following incubation in trauma serum compared with incubation in normal serum. The chemiluminescence response correlated with superoxide reduction of cytochrome C. In addition, the chemiluminescence response was significantly less in septic-trauma serum than in nonseptic-trauma serum. Suppressive serum was found to inhibit the neutrophil-membrane depolarization response to latex particles, as measured by flow cytometry. We conclude that trauma serum suppresses superoxide production by normal neutrophils, and that such suppression can be detected reliably using the clinically applicable technique of chemiluminescence. A normal chemiluminescence response excludes serum-mediated suppression of neutrophil superoxide production. In addition, chemiluminescence may be of value in detecting altered resistance to sepsis following injury, while superoxide determinations do not seem to be helpful in this regard. The mechanism of action of the suppressor may involve reversible inhibition of membrane depolarization necessary for the production of bactericidal oxygen species.

Adolescent↗
PubMed1986

Neutrophil chemiluminescence and opsonic fibronectin levels following blunt trauma.

Trauma is known to result in depression of opsonic fibronectin levels as well as abnormalities in neutrophil function. Neutrophil oxidative metabolism, important for bactericidal activity, has not been investigated following injury. Since fibronectin has been reported to increase neutrophil chemiluminescence (CL), we examined the relationship between neutrophil oxidative metabolism (as measured by chemiluminescence) and opsonic fibronectin levels following blunt trauma. Sera from 11 nonseptic and 9 eventually septic-trauma patients were studied. Normal neutrophils incubated in septic-trauma serum had decreased CL responses compared to incubation in nonseptic serum (P less than 0.0001). This difference was apparent immediately after injury, prior to the onset of sepsis. This depression was due to the presence of a serum suppressor of neutrophil chemiluminescence and not to the absence of a serum factor. This suppressor has been partially characterized as a protein of greater than 30,000 Da. Opsonic fibronectin levels were also depressed in septic-trauma sera compared to nonseptic-trauma sera (P less than 0.0001). However, no correlation could be demonstrated between the CL response and opsonic fibronectin levels. Addition of fibronectin to buffer increased the CL response, while addition of fibronectin to nonseptic-trauma serum had no effect. In contrast, addition of fibronectin to septic-trauma sera actually decreased the CL response (P less than 0.05), perhaps by forming complexes with abnormal proteins and interfering with membrane-particle interaction.

Adult↗
PubMed1984

Prevalence of gastroduodenal lesions in uremic patients undergoing dialysis and after renal transplantation.

Upper gastrointestinal endoscopic examination showed lesions in 28 of 112 dialysis uremic patients and in 19 of 52 after renal transplantation. Most patients with and without lesions were symptom free. A significant increase in gastric acid secretion was found in patients with transplant as compared with dialysis uremic patients. The prevalence of ulcer in the dialysis group was not increased compared with the general population, whereas it was increased in the group with transplantation. An increase of duodenal and a decrease of gastric lesions (ulcers and erosions) in the group with transplantation compared with the dialysis group was found. The importance of a systematic upper gastrointestinal endoscopic survey in hemodialyzed and transplanted patients is stressed.

Adult↗
PubMed1984

[X-ray features of the long-term follow-up (l0-12 years) of the Charnley hip prosthesis fixed with acrylic cement].

A long term follow-up (10 divided by 12 years) of Charnley total hip arthroplasties fixed with radiopaque acrylic cement is reported. Clinical results and X-rays features have been correlated and discussed with reference to the bone reaction and to the diagnostic possibilities of standard radiographs. A radiographic diagnosis of loosening preceding relevant clinical symptom may allow revision arthroplasty before anatomical situation becomes too deteriorated.

Acrylates↗
PubMed1983

Reaction to methylmethacrylate in bone metastases treated by surgical curetting and filling with acrylic cement. Histological study of a case.

A femur bone metastasis from breast carcinoma was treated by curetting and filling with acrylic cement and osteosynthesis. The histological study of the resected proximal third of the femur five months after surgery shows a thin layer of connective tissue between bone and cement. There are no neoplastic cells in this connective tissue nor in the spongious bone of the proximal femur. Instead the diaphyseal channel is fully invaded with neoplastic cells. Pathogenesis and validity of surgical treatment by the emptying and filling with acrylic cement of bone metastases are discussed.

Aged↗
PubMed1983

Synchronous multicentric osteosarcoma.

A case of synchronous multicentric osteosarcoma is reported in an 11-year-old boy. This very rare condition is characterized by simultaneous involvement of multiple skeletal sites, and the prognosis is generally poor.

Bone Neoplasms↗
PubMed1982

Identification of the stereospecific hexose transporter from starved and fed chicken embryo fibroblasts.

When deprived of D-glucose for 24 hr, chicken embryo fibroblasts exhibit a marked increase in hexose transport activity compared with that of control cells. Scatchard analysis of [3H]cytochalasin B binding to starved cell plasma membranes (46 pmol/mg) indicated a six-fold increase compared with fed cell plasma membranes (7.5 pmol/mg). Irradiation of starved cell plasma membranes with high-intensity UV light in the presence of 0.5 microM [3H]cytochalasin B resulted in covalent labeling of polypeptides of Mr 52,000 and 46,000. In fed cell plasma membranes irradiated under the same conditions, both polypeptides were labeled but at greatly decreased levels. In fact, labeling of the Mr 52,000 polypeptide was barely detectable. The amount of D-glucose-sensitive [3H]cytochalasin B covalent insertion into these membrane components was increased 11 +/- 2 (n = 4)-fold in starved versus fed cell plasma membranes. Photoaffinity labeling of both polypeptides in starved cell plasma membranes was inhibited by D-glucose, 3-O-methylglucose, 2-deoxyglucose, cytochalasin B, and cytochalasin A but not by D-sorbitol, L-glucose, or cytochalasin E. Half-maximal inhibition of labeling of the Mr 52,000 polypeptide occurred at 8 mM D-glucose whereas, for the Mr 46,000 polypeptide, half-maximal inhibition occurred at 40 mM D-glucose. It is concluded that (i) two hexose transport proteins, one of Mr 46,000 and one of Mr 52,000, have been identified in chicken embryo fibroblasts and (ii) the increased affinity labeling of these transporter components after cell starvation may reflect increased numbers of transporters in the plasma membrane.

Affinity Labels↗
PubMed1980

Analgesia induced by nitrous oxide and oxygen as an adjunct to local anesthesia in dermatologic surgery. Results of clinical trials.

Clinical trials were carried out to determine if analgesia induced by nitrous oxide and oxygen could be useful as an adjunct to local anesthesia in dermatologic surgery. Patients readily accepted the procedure. The analgesia obtained reduced anxiety and pain, and no important adverse side effects were encountered. Overall, the agents and method are effective and have advantages over more commonly used agents and methods used as adjuncts to local anesthesia.

Adolescent↗
PubMed1978

Porphyrin-like compounds genesis under simulated abiotic conditions.

Experiments with gas mixtures intended to simulate the primaeval atmosphere of the Earth yielded many biologically important chemicals. Investigations into the synthesis of porphyrin-like compounds from methane, ammonia and water vapour were carried out by using high frequency discharges. Microanalyses of porphyrins showed that porphyrin-like pigments were formed in this way. The presence of divalent cations in the reaction system increased the yield of porphyrin-like pigments also involving the direct synthesis of their metal complexes. The ready formation of these compounds in abiotic conditions is significant, suggesting the possibility of their appearance during the early stage of chemical evolution.

Ammonia↗
PubMedDate not supplied

Placental effects of lead in mice.

Although a number of studies in animal models have shown embryolethal and teratogenic lead effects when this element is administered by a parenteral route, the mechanism of the embryonary changes is well not established. In this study, the embryonic effects of parenteral lead exposure on day 9 of gestation were assessed in the Swiss mouse. Lead acetate trihydrate was injected intraperitoneally at 14, 28, 56 and 112 mg/kg. There was no maternal toxicity evidenced by death, reduced body weight gain or reduced food consumption. However, absolute placental weight at 112 mg/kg and relative placental weight at 14, 56 and 112 mg/kg were diminished significantly. The number of total implants, live and dead fetuses, sex ratio and fetal body weight were unaffected by lead exposure. Most sections of placenta showed vascular congestion, an increase of intracellular spaces and deposits of hyaline material of perivascular predominance. Trophoblast hyperplasia was also observed, whereas there was a reinforcement of the fibrovascular network in the labyrinth. It is concluded that the trophoblast hyperplasia observed in the placenta of pregnant mice after parenteral lead exposure at doses that are not toxic for the dam could act as a repairing mechanism of the extraembryonary tissues.

Animals↗
PubMedDate not supplied

[Social characteristics and risk behaviors for HIV in a group of transvestites and male transsexuals engaging in street prostitution].

OBJECTIVE: To describe life and work conditions, practices associated with HIV transmission, self-informed HIV status and HIV test coverage in a group of male transgender street prostitutes. METHODS: Case descriptive study of male transgender street prostitutes who attended a mobile unit of a harm reduction programme in 1998 in Madrid, Spain Information on sociodemographic characteristics, work conditions, illegal drug use, sexual behaviours and self-informed HIV status was collected. RESULTS: 132 male transgenders were interviewed, of which 56% were Spanish. Median age was 30 years. 50% had primary school education or less. 11% had injected drugs sometime in their lives. Median time in prostitution was 8 years and 66% had worked only in the streets. In the last month, all of them said to use condoms in insertive anal sex with clients, 98% in receptive sex and 49% always used it with their partners in the previous year. 39% referred accidents with condoms within the previous month. 73% had had an HIV test, of which 22% said to be HIV positive (16% in those who had never injected drugs and 58% in the ones who had). CONCLUSIONS: HIV seroprevalence in male transgender street prostitutes is high, even in non-intravenous drug users. They nearly always use condoms with clients but have a high level of accidents. HIV prevention programmes in prostitution should be more specifically adapted to the different groups of commercial sex workers.

Adult↗