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Biomedical subjects

A M Rodriguez

Publications and source records attributed to A M Rodriguez.

49 records · Page 3Linked to original sources
PubMed1992

A direct radioimmunoassay for 5 alpha-androstane-3 alpha,17 beta-diol 17-glucuronide.

Synthesis of the 11 alpha-hemiglutaryl derivative of 5 alpha-androstane-3 alpha,17 beta-diol 17-glucuronide (androstane-diol-17G) starting from androsta-4,9(11)-diene-3,17-dione through a 10-step sequence and the preparation of its bovine serum albumin conjugate is described. By using this conjugate, antiserum was raised in rabbits which proved to be very specific for androstanediol-17G. A direct radioimmunoassay using a double antibody procedure is described for the measurement of androstanediol-17G from plasma without prior chromatography.

Androstane-3,17-diol↗
PubMed1991

Metastasizing renal cell carcinoma and acquired renal cystic disease in a hemodialysis patient.

Acquired renal cystic disease is an entity which is characterized by the progressive substitution of the atrophic renal parenchyma by multiple cysts in patients with renal insufficiency. Its main complications are hemorrhage and tumorous degeneration. The case discussed is a 57-year-old patient with terminal renal insufficiency secondary to interstitial nephropathy, who, following 6 years of treatment with hemodialysis and renal transplantation, developed a state of persistent hematuria requiring nephrectomy of the left kidney. Histological study revealed multiple cysts of monostratified epithelium with intracavitary projections, multiform adenomas and multifocal malignant tumorous polymorphism. The patient died in a state of progressive cachexia with pleural and hepatic metastasis.

Adenoma↗
PubMed1991

Operating room satellite pharmacies: demographics, services and implementation.

OR (operating room) satellite pharmacies are still a relatively new addition to the system of pharmacy-coordinated drug distribution. For the last ten years, however, hospitals creating OR satellite pharmacies have found that they provide improved service, reduced inventory, better narcotic control and more efficient drug delivery. Hospital Pharmacy and the OR Satellite Pharmacy Bulletin published a questionnaire to obtain information about OR satellite pharmacies from those actively involved in their planning, implementation, and operation. The questionnaire covered three major areas: demographics, functions and services. This article summarizes the results.

Centralized Hospital Services↗
PubMed1990

Synthesis of new steroid haptens for radioimmunoassay--VIII. Development and validation of a specific radioimmunoassay for serum 5 alpha-androstane-3 alpha, 17 beta-diol 17-glucuronide.

5 alpha-Androstane-3 alpha, 17 beta-diol glucuronide (androstanediol-G) is a dihydrotestosterone metabolite whose serum levels are elevated in hirsute women. Current assay methods do not distinguish between the two androstanediol-G isomers, androstanediol 3-G and androstanediol 17-G. Since the production of these isomers may be influenced by different factors, we have developed a specific radioimmunoassay for androstanediol 17G. The antibody was raised against 5 alpha-androstane-3 alpha, 17 beta-diol 17-G conjugated to bovine serum albumin (BSA). [9,11(-3H]5 alpha-Androstane-3 alpha, 17 beta-diol 17-G was used for determination of procedural losses and as the labeled ligand in the assay. Unlabeled androstanediol 17-G was used as assay standard. Serum levels of total androstanediol-G, androstanediol 3-G and androstanediol 17-G were measured in 8 normal men. Total androstanediol-G levels were 16.5 +/- 5.2 nmol/l, androstanediol 17-G levels were 12.9 +/- 5 nmol/l, and androstanediol 3-G levels were 3.3 +/- 1.8 nmol/l. 77 +/- 13% of total androstanediol-G was androstanediol 17-G. These results confirm our previous findings that androstanediol 17-G is the predominant androstanediol-G isomer in human serum and suggests that 5 alpha-dihydrotestosterone (DHT) is preferentially metabolized to androstanediol 17-G.

Androstane-3,17-diol↗
PubMed1987

Elevated catecholamine levels and abnormal hypoxic arousal in apnea of infancy.

Arousal from quiet sleep in response to a hypoxic challenge fails to occur in many patients with apnea of infancy. It was hypothesized that catecholamine-mediated responses might be involved in the depressed hypoxic arousal response in apnea of infancy and that these differences would be reflected in serum catecholamine concentrations. Fifteen infants with a median age of 5.5 months and a history of unexplained apnea during sleep were studied. Two hypoxic challenges (PiO2 80 mm Hg) were given for three minutes or until arousal from quiet sleep occurred. Of the 15 patients with apnea of infancy 11 (73%) did not arouse to hypoxia. These infants had serum epinephrine levels that were elevated 4.1-fold while awake (P less than .05), 3.4-fold during quiet sleep (P less than .02), and 3.5-fold during hypoxia (P less than .05). They also had serum norepinephrine levels that were elevated threefold while awake (P less than .05), 5.3-fold during quiet sleep (P less than .001), 3.2-fold during hypoxia (P less than .02), and 12-fold during recovery from hypoxia (P less than .001) in comparison with the corresponding levels in the four (23%) infants who aroused normally to hypoxia. It is speculated that elevated circulating catecholamines are associated with abnormal hypoxic arousal responses in children with apnea of infancy.

Arousal↗
PubMed1986

Synthesis of 5 alpha-androstane-3 alpha,17 beta-diol 3- and 17-glucuronides.

The glucuronidation of 5 alpha-androstane-3 alpha,17 beta-diol (3 alpha-diol) was carried out by three different methods: The Koenigs-Knorr reaction using methyl-2,3,4-tri-O-acetyl-1 alpha-bromo-1-deoxy-beta-D-glucuronate, by employing methyl-2,3,4-tri-O-acetyl-1-O-(trichloroacetimidoyl)-alpha-D-gl ucopyranuronate (imidate procedure), and by the reaction of 2,3,4-tri-O-acetyl-alpha-D-glucopyranuronate catalyzed by trimethylsilyl trifluoromethanesulfonate (triflate method). The Koenigs-Knorr method gave the beta-anomers of both the 3- and 17-glucuronides. The imidate procedure also resulted in the beta-anomers of the 3- and 17-glucuronides, but in lower yield. The triflate method, however, yielded only the alpha-anomers of the 3- and 17-glucuronides. The structural assignments of these compounds were made from NMR spectral data obtained with a 500 mHz instrument.

Androstane-3,17-diol↗
PubMed1986

Absent hypoxic and hypercapneic arousal responses in children with myelomeningocele and apnea.

Hypoxic and hypercapneic arousal responses from quiet sleep were tested in seven infants with myelomeningocele and Arnold-Chiari malformation who were symptomatic with apnea and/or hypoventilation. All infants with myelomeningocele required tracheostomy and posterior fossa decompression. Responses were compared with those of nine healthy control infants. To assess hypoxic arousal, inspired PO2 was decreased until the end-tidal (alveolar) PO2 reached 45 mm Hg for a maximum of three minutes. Eleven studies were performed in seven infants with myelomeningocele, and arousal occurred in only two studies (18.2%). Eight of nine control infants aroused to hypoxia (89%). To test hypercapneic arousal, inspired PCO2 was increased until end-tidal PCO2 reached 60 mm Hg for a maximum of three minutes. Eight studies were performed on six infants with myelomeningocele, and arousal occurred in three studies (37.5%). All seven control infants studied aroused to hypercapnea (100%). Three infants with myelomeningocele subsequently died. Infants with myelomeningocele, Arnold-Chiari malformation, and apnea or hypoventilation have arousal deficits to respiratory stimuli.

Arnold-Chiari Malformation↗
PubMed1985

Hypoxic and hypercapneic arousal responses and prediction of subsequent apnea in apnea of infancy.

Hypoxic and hypercapneic arousal responses from quiet sleep were tested in 56 infants with apnea of infancy (one or more episodes of cyanosis, limpness, and apnea requiring vigorous stimulation or resuscitation with no treatable cause; age 6.8 +/- 1.1 [SEM] months). Responses were compared with those of nine control infants ranging from 1 to 25 months of age. To assess hypercapneic arousal, the inspired PCO2 was rapidly increased during quiet sleep to 60 mm Hg or until arousal (restlessness, agitation, eye opening) occurred. All control infants and those with apnea of infancy aroused to hypercapnea, but control infants aroused at a lower inspired PCO2 (inspired PCO2 40.1 +/- 2.6 mm Hg) than those with apnea of infancy (inspired PCO2 46.9 +/- 1.5 mm Hg, P less than .05). To assess hypoxic arousal, the inspired PO2 was rapidly decreased during quiet sleep to 80 mm Hg or until arousal occurred. All control infants aroused to hypoxia (inspired PO2 78.3 +/- 2.1 mm Hg). However, only 38% of those with apnea of infancy aroused (inspired PO2 78.1 +/- 0.8 mm Hg), indicating an abnormality in recognition of hypoxia, or central brainstem response to hypoxia. During the 10.4 +/- 1.2 months of follow-up, there was a high incidence of subsequent apneas (greater than 20 seconds) during sleep at home in 50 apneic infants. Infants with abnormal hypoxic arousal responses had more severe subsequent apneas than those with normal hypoxic arousal responses (P less than .05).

Arousal↗
PubMed1983

Parasitological and immunological aspects of Trypanosoma cruzi infection in nude rats.

The role of the thymus on immunity of rats against Trypanosoma cruzi infection was investigated in vivo. The athymic (nu/nu) rats were shown to be significantly more susceptible to the acute phase of the infection than the control nu/+ rats, as measured by increased parasitemia and mortality. Specific anti-T. cruzi antibodies, complement, IgM and IgG2a serum levels were determined. The results would indicate the essential role of antibodies in immunity to acute Chagas' disease through T-dependent immune response.

Animals↗
PubMed1983

Trypanosoma cruzi: variation in susceptibility of inbred strains of rats.

Eight strains of male rats (AUG, BN, LEW, LIS, WAG, F 344, LOU/M, DA) and 3 strains of female rats (LEW, F 344, KGH) were challenged with 15 X 10(4) trypomastigotes of the Tehuantepec strain of T. cruzi. Parasitemia and mortality were observed for 60 days. Varying degrees of susceptibility were demonstrated between strains: complete resistance (R), no parasitemia; low resistance (LR), mild parasitemia; and no resistance (NR), high parasitemia. The differences in susceptibility to T. cruzi, using inbred strains of rats, were unrelated to Rt-1 haplotype. However, the level of parasitemia and host survival are not necessarily related; both male and female F 344 hosts are susceptible (NR) to T. cruzi but only females survive.

Animals↗
PubMed1981

Trypanosoma cruzi infection in B-cell-deficient rats.

The effect of neonatally initiated injections of anti-mu rabbit antiserum on immunity of rats against Trypanosoma cruzi infection was investigated in vivo. Anti-mu treatment resulted in a loss of immunoglobulin M (IgM) and IgG2a synthesis and, subsequently, of antibody production. These rats so treated were shown to be significantly more susceptible to the acute phase of the infection than the control rats treated with normal rabbit serum, as measured by increased parasitemia and mortality. These results indicate the essential role of antibodies, probably in association with complement or effector cells or both, in immunity to acute Chagas' disease.

Animals↗