Biomedical subjects
Publications and source records attributed to A Rodriguez.
Thirty 6- to 16-year-old subjects were gradually tapered from their maintenance dose of nortriptyline while being monitored for withdrawal effects. Five subjects had brief gastrointestinal distress that did not require the administration of an extra dose. The results of this open study suggest that scheduled tapering of nortriptyline will preclude withdrawal symptoms in most pediatric patients.
Autogenous rib cartilage grafts are used to correct enophthalmos. The grafts are introduced through two small tunnels into the posterior quadrant of the orbit. The procedure leaves almost no scar and final results are satisfactory.
Fatty acid reduction in Photobacterium phosphoreum is catalyzed in a coupled reaction by two enzymes: acyl-protein synthetase, which activates fatty acids (+ATP), and a reductase, which reduces activated fatty acids (+NADPH) to aldehyde. Although the synthetase and reductase can be acylated with fatty acid (+ATP) and acyl-CoA, respectively, evidence for acyl transfer between these proteins has not yet been obtained. Experimental conditions have now been developed to increase significantly (5-30-fold) the level of protein acylation so that 0.4-0.8 mol of fatty acyl groups are incorporated per mole of the synthetase or reductase subunit. The acylated reductase polypeptide migrated faster on sodium dodecyl sulfate-polyacrylamide gel electrophoresis than the unlabeled polypeptide, with a direct 1 to 1 correspondence between the moles of acyl group incorporated and the moles of polypeptide migrating at this new position. The presence of 2-mercaptoethanol or NADPH, but not NADP, substantially decreased labeling of the reductase enzyme, and kinetic studies demonstrated that the rate of covalent incorporation of the acyl group was 3-5 times slower than its subsequent reduction with NADPH to aldehyde. When mixtures of the synthetase and reductase polypeptides were incubated with [3H] tetradecanoic acid (+ATP) or [3H]tetradecanoyl-CoA, both polypeptides were acylated to high levels, with the labeling again being decreased by 2-mercaptoethanol or NADPH. These results have demonstrated that acylation of the reductase represents an intermediate and rate-limiting step in fatty acid reduction. Moreover, the activated acyl groups are transferred in a reversible reaction between the synthetase and reductase proteins in the enzyme mechanism.
A Western Venezuelan indigenous Yukpa(Irapa) family with moderate bleeding and discrepancy in the prothrombin values by biological and immunological methods is described. The propositus presented biological activity of 2% by the methods in one-stage including Staphylocoagulase and Echis carinatus. Electrophoretic migration of the prothrombin in plasma was normal, while the serum only showed one precipitation arc instead of the three of normal serum. The propositus appeared to be homozygous for the abnormal prothrombin which we have denominated Prothrombin Perijá.
Xanthine, hypoxanthine, and total oxypurine levels were determined in the cerebrospinal fluid of 18 hydrocephalic patients and 8 healthy controls by high-performance liquid chromatography (HPLC). Eight of the hydrocephalic patients were self-compensated and 10 had shunts implanted during the course of the study. The mean xanthine, hypoxanthine, and total oxypurine levels in the normal children were 5.20, 5.94 and 11.29 mumol/l, respectively. In self-compensated hydrocephalics these levels were respectively 6.06, 6.50 and 12.57 mumol/l. In noncompensated hydrocephalics, they were 11.40, 10.79 and 22.19 mumol/l. The differences between the latter group and the first two are statistically significant (P less than 0.001). Fifteen days after implantation of shunts in the noncompensated hydrocephalics, the mean xanthine levels had fallen to 4.61 mumol/l, the mean hypoxanthine levels to 5.03 mumol/l, and the mean total oxypurine levels to 9.64 mumol/l. The change is statistically significant (P less than 0.001). In light of these findings we propose that xanthine, hypoxanthine, and total oxypurine levels be used in cases of hydrocephalus as guides for therapeutic action and to monitor progress.
A case of epidermoid carcinoma of the colon is described--the 25th such case reported in the literature. The pathogenesis, natural history, and treatment of the disease are reviewed.
The clinical findings in 13 drug abusers and one homosexual man with tuberculosis and the acquired immunodeficiency syndrome (AIDS) from New York City are described. Tuberculosis preceded the diagnosis of AIDS in nine of the 14 patients by a mean of 7 months and occurred within the same month in the remaining five. The presence of thrush, generalised lymphadenopathy, lymphopenia, cutaneous anergy and chest radiographs showing hilar adenopathy and/or lower lobe infiltrates was common among the patients in whom tuberculosis preceded AIDS. Eight of our patients had extra-pulmonary tuberculosis, six had disseminated tuberculosis and five had tuberculous lymphadenitis. Cultures of tissue biopsies may be positive for Mycobacterium tuberculosis despite the absence of acid fast bacilli or granulomas on microscopic examination. Tuberculosis generally responded to chemotherapy, but the majority of patients died from opportunist infections.
During a 9-year period, 60 patients with acutely ruptured diaphragms following blunt trauma were treated in our institution. Diaphragmatic injury was detected within 24 hours of hospital admission in all but two patients. The diagnosis was suggested by upright chest X-ray in 40% of the patients. Diaphragmatic tears were discovered at laparotomy for hemoperitoneum in the remaining patients. At initial evaluation hypotension was present in 67% of the patients, and respiratory distress was evident in 52%. In contrast to traditional teaching, there was a 30% incidence of right hemidiaphragmatic disruption. One patient experienced bilateral diaphragmatic rupture, and two had isolated tears of the pericardial diaphragm. Intra-abdominal organs were herniated through the diaphragmatic defect in only 32% of the patients. There was a 90% incidence of associated intra-abdominal injuries. The diaphragmatic tear was repaired via the abdomen in 53 patients, through a thoracoabdominal incision in five patients, and through the chest in only two cases. All defects were closed primarily. Twelve patients also required thoracotomy for resuscitation and/or correction of intrathoracic injury. Atelectasis was the most frequent postoperative complication, occurring in 65% of the patients. The mortality was 26.7% and was related to associated injuries in all cases.
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.
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.
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.
Explore the source record for details and available documents.
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.
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.).
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.
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.
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.
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.