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Biomedical subjects

A Rodriguez

Publications and source records attributed to A Rodriguez.

At least 325 records · Page 18Linked to original sources
PubMed1986

A histological assessment of the initial healing response adjacent to porous-surfaced, titanium alloy dental implants in dogs.

We report here the results of a histological assessment of the initial healing response following implantation into the dog mandible of a porous-surfaced, titanium alloy endosseous dental implant. Two implants were placed in edentulous areas on each side of the mandible of each dog and covered with a full-thickness mucoperiosteal flap. The implant sites on one side of the mandible were allowed to head for four weeks, while those on the other side were allowed to head for eight weeks before the animals were killed. Histological specimens were obtained and assessed both qualitatively and by computer-assisted morphometry. All but one of the 24 implants were well-tolerated and healed with a variable ingrowth of bone into the porous-surface geometry. The histomorphometric measurements revealed that bone ingrowth had reached a plateau by four weeks of initial healing.

Alloys↗
PubMed1986

The diagnosis of acute acalculous cholecystitis: a comparison of sonography, scintigraphy, and CT.

The clinical and laboratory diagnosis of acute acalculous cholecystitis is difficult, and the reliability of various diagnostic imaging techniques has not been established. The results of several imaging procedures performed over a 6-year period on 56 patients with clinically suspected acute acalculous cholecystitis were evaluated retrospectively. Sonography and CT were both highly sensitive (92% and 100%, respectively) and specific (96% and 100%, respectively). Hepatobiliary scintigraphy was compromised by frequent false-positives; the result was a specificity of only 38%. Percutaneous bile aspiration was insufficiently sensitive (33%) for diagnosis. Sonography was as sensitive as hepatobiliary scintigraphy and was more specific in establishing the diagnosis. Because sonography is relatively inexpensive and can be performed at the bedside, it should be regarded as a satisfactory screening procedure. However, CT is a good alternative in an easily transported patient when other intraabdominal disease is suspected.

Accidents↗
PubMed1986

Two-year prospective study in Colombia of Norplant implants.

A clinical trial of levonorgestrel-releasing Norplant implants used for contraception was undertaken in two cities in Colombia. Through two years in which 389 women had accumulated 594 years of use, there were no pregnancies. In a comparison group of copper intrauterine device acceptors, the one-year pregnancy rate was 1.1 per 100. Menstrual disturbances associated with progestin-only administration were the principal side-effects, and the major reason for cessation of use. Continuation among users of the implants was at the same or at a higher rate than observed among users of the intrauterine device. Advantages and disadvantages of alternate sites for implant placement are discussed.

Adolescent↗
PubMed1985

Fatty acyl-AMP as an intermediate in fatty acid reduction to aldehyde in luminescent bacteria.

The acyl protein synthetase component (50K) of the fatty acid reductase complex from the luminescent system of Photobacterium phosphoreum has been found to catalyze the activation of fatty acid via formation of an enzyme bound acyl-AMP (carboxyphosphate mixed anhydride) immediately prior to the acylation of the enzyme. PPi-ATP exchange and nucleotide binding experiments are dependent on fatty acid and indicate that the fatty acyl-AMP is directly formed and that an adenylated enzyme intermediate is not part of the mechanism. The formation of acyl-AMP from fatty acid and ATP is reversible with a standard free energy of -2 kcal/mol, and is dependent on Mg2+. The fatty acyl-AMP intermediate has been isolated and shown to be part of the pathway of fatty acid reduction. The 34K component of the complex, which strongly stimulates the acylation of the 50K protein by fatty acyl-AMP or fatty acid and ATP, is not required for the formation of acyl-AMP showing that it differentially affects the fatty acid activation and acylation steps catalyzed by the 50K protein.

Acyltransferases↗
PubMed1985

Analysis of 3-indolylacetic acid and abscisic acid by high-performance liquid chromatography and gas-liquid chromatography.

A method of analysis of 3-indolylacetic acid (IAA) and abscisic acid (ABA), allowing the simultaneous extraction of both regulators from plant material, has been developed. The method involves extraction with methanol, isolation of the acid fraction, diazomethane methylation, separation of the hormones through reverse-phase preparative high-performance liquid chromatography, and quantification of both compounds by gas-liquid chromatography. The recovery percentage at each step was monitored with radioactive compounds added at the beginning of the process. The final recovery was 70% for IAA and 96% for ABA. The method was applied to the analysis of the IAA and ABA content of stems of hazel (Corylus avellana L.).

Abscisic Acid↗
PubMed1985

Basal prolactin and the behaviour of the gonadotrophins, testosterone, androstenedione, estradiol, and the sex-hormone-binding globulin during stimulation with clomiphene in subjects with spermatogenic disorders.

To clarify the significance of clomiphene test in spermatogenic disorders, it was performed on three groups of subjects: 10 with normozoospermia, 29 with oligozoospermia, and 11 with azoospermia. Two basal blood samples were drawn five days apart; prolactin, FSH, LH, estradiol, testosterone, androstenedione and sex-hormone-binding globulin were determined. 100 mg of clomiphene per day were administered for eleven consecutive days; another sample was drawn on the eleventh day and all the basal parameters, except prolactin, were determined. It may be concluded from the results: a) All the parameters studied increased significantly after clomiphene; and b) Testosterone levels obtained after clomiphene, as well as the increases in this hormone during the test and the ratio delta T/delta LH, were significantly lower in the oligozoospermic group. This finding suggests a decrease in the testicular androgenic function of this group.

Adult↗
PubMed1985

Operative technique for repair of tracheoinnominate artery fistula.

Tracheoinnominate artery fistula is a relatively rare but highly lethal complication for long-term tracheostomy patients that occurs with an estimated incidence of 1 out of every 150 tracheostomies performed. Appropriate operative technique during tracheostomy and meticulous postoperative care usually prevent this devastating lesion. When tracheoinnominate fistula is suspected, immediate evaluation under general anesthesia in the operating suite, followed by prompt thoracotomy and repair, is essential for the survival of these patients.

Brachiocephalic Trunk↗
PubMed1985

Lateral canthoplasty to change the eye slant.

A technique is described to modify eyelid slanting and correct excessive scleral show. The anatomic relations of the canthal ligament with the fibrous supporting structures of the eyelid are discussed. The procedure is indicated in aesthetic surgery, in congenital anomalies, and in sequelae of trauma.

Adolescent↗
PubMed1985

CT evaluation of thoracic infections after major trauma.

Thirty-seven septic patients with major multisystem trauma were evaluated by computed tomography (CT) to identify possible thoracic sources of infection. CT was 72% accurate in the diagnosis of empyema and 95% accurate in the diagnosis of lung abscess. While CT proved useful in demonstrating these sites of thoracic infections in septic trauma victims, the presence of concurrent thoracic pathology, particularly loculated hemothorax or hemopneumothorax and traumatic lung cysts with hemorrhage or surrounding parenchymal consolidation, introduced sources of diagnostic error. CT also proved helpful in guiding appropriate revisions of malpositioned and occluded thoracostomy tubes.

Abscess↗
PubMed1985

Acquired immunodeficiency syndrome (AIDS) in an economically disadvantaged population.

Forty patients with acquired immunodeficiency syndrome (AIDS), 70% of whom were intravenous drug abusers (IVDAs), were seen over a 20-month period (July 1, 1981, through Feb 28, 1983). Most of the patients came from two inner-city sections of New York City and from nearby correctional facilities. Eighty-five percent of the patients were black or Hispanic; only 15% were white. Unique features of AIDS in this mostly heterosexual population were the high incidence of opportunistic infections (90% of the patients), the low incidence of Kaposi's sarcoma (10%), and the high mortality rate (34% died during initial hospitalization, 74% after one year of follow-up). Tuberculosis occurred in 10% of cases, preceding other opportunistic infections by four to 24 months. We found that AIDS was a common disease among inpatient IVDAs, and in one of the participating hospitals, its incidence was similar to that of infective endocarditis. Acquired immunodeficiency syndrome should be considered as the underlying illness in all IVDAs with oral thrush, shortness of breath, pneumonia, or extra-pulmonary tuberculosis.

Acquired Immunodeficiency Syndrome↗
PubMed1984

In vitro acylation of the transferrin receptor.

In vitro fatty acylation of the transferrin receptor with [3H]tetradecanoate or [3H]tetradecanoyl-CoA has been demonstrated for isolated sheep reticulocyte plasma membranes. Although less than 5% of the receptor was labeled in vitro, the acylated protein could be readily observed after sodium dodecyl sulfate-gel electrophoresis. The acylated transferrin receptor in the reticulocyte membrane was specifically precipitated with a monoclonal antibody and was absent from mature red cell membranes. Incorporation of fatty acid was dependent on ATP, and fatty acid was 5-10 times less effective as an acyl donor than the acyl-CoA derivative, pointing out the strong potential of this reagent for in vitro acylation of membrane proteins. During in vitro maturation of reticulocytes, the receptor is released in vesicles into the incubation medium. Using reticulocytes labeled with [3H]tetradecanoate, it can be shown that the 3H-labeled receptor is transferred from the cells to the vesicles without loss of acyl groups, suggesting that the vesiculation process does not involve deacylation.

Acyl Coenzyme A↗
PubMed1984

Generation of fatty acids by an acyl esterase in the bioluminescent system of Photobacterium phosphoreum.

The fatty acid reductase complex from Photobacterium phosphoreum has been discovered to have a long chain ester hydrolase activity associated with the 34K protein component of the complex. This protein has been resolved from the other components (50K and 58K) of the fatty acid reductase complex with a purity of greater than 95% and found to catalyze the transfer of acyl groups from acyl-CoA primarily to thiol acceptors with a low level of transfer to glycerol and water. Addition of the 50K protein of the complex caused a dramatic change in specificity increasing the transfer to oxygen acceptors. The acyl-CoA hydrolase activity increased almost 10-fold, and hence free fatty acids can be generated by the 34K protein when it is present in the fatty acid reductase complex. Hydrolysis of acyl-S-mercaptoethanol and acyl-1-glycerol and the ATP-dependent reduction of the released fatty acids to aldehyde for the luminescent reaction were also demonstrated for the reconstituted fatty acid reductase complex, raising the possibility that the immediate source of fatty acids for this reaction in vivo could be the membrane lipids and/or the fatty acid synthetase system.

Aldehyde Oxidoreductases↗
PubMed1984

Empyema occurring in the multiply traumatized patient.

During an 11-month period 31 cases of nosocomial empyema were identified in 29 of 741 multiply traumatized patients who remained in our unit for more than 3 days. Nosocomial empyema was defined as purulent culture-positive material drained from the pleural space after five days' hospitalization. All patients had fever and leukocytosis. Possible risk factors included previous aspiration in five patients but none developing pneumonia, prior respiratory tract infection in nine but none with the same pathogen as their empyema, prior antibiotic use in over 50% of the patients, and severe head or chest injury in two thirds of the patients. Thirty-eight pathogens were recovered: S. aureus, 14; beta-streptococci, three; Pseudomonas, six; Klebsiella, two; Enterobacter, two; E. coli, two; other Gram-negative bacilli, six; and anaerobes, three. Fourteen infections were polymicrobic and bacteremia occurred in 42% of the patients. Of these 29 patients, 27 had chest tubes inserted for fluid in the pleural cavity before development of empyema; nine for hemo- or pneumothorax secondary to chest trauma, 11 for pneumothorax while on ventilators, and seven for unexplained sterile pleural effusion. If empyema complicated a prior hemothorax it was usually caused by Staphylococcus aureus and occurred about 10 days after draining blood from the pleural cavity. If empyema was a complication of pneumothorax or serothorax it was usually due to Gram-negative organisms colonizing the upper respiratory tract and occurred within 4 days of draining the fluid. Sixteen per cent of all patients who had chest tubes placed for fluid in their pleural cavity subsequently developed empyema.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1984

Leukapheresis in a patient with Sézary syndrome.

A patient with Sézary syndrome refractory to cytotoxic agents underwent leukapheresis on the Aminco continuous flow centrifuge. Five procedures were performed over a 15-day period. A total of 6.9 X 10(9) cells were removed. The patient's skin lesions and lymphadenopathy regressed. Repeated removal of the buffy coat by leukapheresis has not resulted in thrombocytopenia. It is concluded that cytapheresis may be effective in this clinical condition even when the peripheral leukocyte count is normal.

Hemoglobins↗
PubMed1983

Purification of the acyl coenzyme A reductase component from a complex responsible for the reduction of fatty acids in bioluminescent bacteria. Properties and acyltransferase activity.

The acyl-CoA reductase component of the fatty acid reductase complex responsible for synthesis of long chain aldehydes for the bioluminescent reaction in bacteria has been purified to homogeneity. The enzyme copurified as part of the complex through the initial steps and was then resolved and further purified to give a single band on sodium dodecyl sulfate-gel electrophoresis of molecular weight 58,000. The molecular weight of the native enzyme was 2 x 10(5), indicating it was an oligomeric enzyme containing identical subunits. The acyl-CoA reductase had a high specificity for NADPH with a Km value of 5 microM at optimal concentrations of tetradecanoyl-CoA (5-10 microM). The purified enzyme was discovered to have a high, intrinsic acyltransferase activity forming thioesters with a number of different thiol compounds (mercaptoethanol, dithiothreitol, 2-mercaptoethyl ether). The rates of the acyltransferase and acyl-CoA reductase reactions were similar to the rate of turnover of the fatty acid reductase complex suggesting that fatty acid reduction and not activation controls the rate of conversion of fatty acids to aldehydes.

Aldehyde Oxidoreductases↗
PubMed1983

DNA/protein ratio as an index of oestrogen receptor content in human breast cancer.

The nuclear DNA/cytoplasmic protein ratio was related to the oestradiol receptor content in both cytoplasmic (ERc) and nuclear (ERn) fractions in 165 cases of breast cancer. The patients under study were divided into groups according to whether their biopsies contained functional (ERc/ERn = +/+), abnormal (+/0) or non-detectable receptor (0/0). The mean microgram DNA/mg protein ratio was significantly decreased in both the abnormal and receptor-negative groups, with means of 30.4 and 30.2 respectively, when compared to the mean of 52.8 for the receptor-positive group. When the DNA/protein ratio for each patient was related to age, a discriminant line which clearly differentiated the ER +/+ group from the other two groups was obtained. It may be concluded that an increased DNA/protein ratio is related to the presence of ERn. Furthermore, since the DNA content per cell is higher in ER-negative tumours, an increase in cellularity must exist in ER-positive tumours.

Adult↗