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Biomedical subjects

C Ramirez

Publications and source records attributed to C Ramirez.

At least 37 records · Page 2Linked to original sources
PubMed1997

Photoperiod-temperature and neuroblast proliferation-migration in the adult lizard cortex.

The lizard medial cortex (a zone homologous to the mammalian fascia dentata) shows delayed postnatal neurogenesis throughout the lifetime of these animals. Experimental lesioning of this area is followed by neuronal regeneration, a unique phenomenon in the adult amniote telencephalon. The differential effects of temperature and photoperiod on postnatal neurogenetic activity were studied using tritiated thymidine pulses and posterior autoradiography as well as proliferating cell nuclear antigen (PCNA) immunostaining. Long (summer) photoperiods increased the number of proliferating neuroblasts in the ependymal neuroepithelium. Cold (winter) temperature prevented migration of the newly generated immature neurones.

Animals↗
PubMed1996

Ontogeny of somatostatin immunoreactive neurons in the medial cerebral cortex and other cortical areas of the lizard Podarcis hispanica.

The ontogeny of somatostatin immunoreactive interneurons in the cerebral cortex of the lizard Podarcis hispanica has been studied in histological series of embryos, perinatal specimens, and adults. Somatostatin immunoreactive interneurons appear in the early stages of lizard cerebral cortex ontogeny, their number increases during embryonary development, reaches a peak in early postnatal life, and decreases in adult lizards. The first somatostatin immunoreactive somata in the lizard forebrain appeared on E36, and they were located in non cortical areas. Then, on E39 and later, somatostatin immunoreactive neurons were seen in the lizard cortex in a rostral-to-caudal spatial gradient, which parallels that of the normal histogenesis of the lizard cerebral cortex. On E39, labelled somata were seen in the medial and dorsal cortex inner plexiform layers; immunoreactive puncta and dendritic processes were detectable in the inner plexiform layer of the medial cortex. On E40, labelled neurons were observed in the inner plexiform layer of the lateral cortex; labelled processes were found in the inner plexiform layers (dorsomedial, dorsal, and lateral cortices) and the outer plexiform layers (medial and dorsomedial cortices). At hatching (P0), some somatostatin immunoreactive neurons populated the external plexiform layer of the dorsomedial cortex. On P28, groups of labelled neurons appeared in the cell layer of dorsal and lateral cortices, reaching the adult-mature pattern of somatostatin immunoreactivity in the lizard cerebral cortex, i.e., labelled somata and dendritic processes populating the inner plexiform layers in addition to an axonic labelled plexus in the outermost part of the outer plexiform layers. Immunoreactive somata and processes occupied all the cortical areas, but they were especially abundant in the dorsomedial cortex. Proliferating Cell Nuclear Antigen (PCNA) immunostaining in the same histological series revealed that the number of PCNA immunoreactive nuclei in the subjacent proliferative neuroepithelium followed an inverse-complementary evolution to somatostatin, suggesting some temporal relationship between somatostatin immunoreactive cells and neurogenesis in the lizard cerebral cortex.

Animals↗
PubMed1996

The influence of women on the health care-seeking behavior of men.

BACKGROUND: Gender and social relationships are believed to have a strong influence on health care attitudes and behavior. This study was designed to determine the effect of the gender of closely associated persons on the health care-seeking behavior of persons of the opposite sex. METHODS: We developed a 14-item questionnaire that requested information on social and demographic characteristics, health status, and influences on the decision to seek health care, and administered it to 314 consecutive patients seen at two family medicine clinics in San Diego, California. Data were analyzed by means of one way analysis of variance for continuous variables and the chi-square test for categorical variables. Additionally, data were analyzed by means of a multivariant logistic regression model that calculated odds ratios and 95% confidence intervals. RESULTS: Men were 2.7 times more likely than women to be influenced to seek health care by a member of the opposite sex (95% CI, 1.6 to 4.6). Married patients were 2.4 times more likely than unmarried patients to be influenced to seek health care by a member of the opposite sex (95% CI, 1.4 to 4.3). CONCLUSIONS: Women exert an important influence on the decisions of men to seek health care.

Adult↗
PubMed1995

Experience with liver and kidney allografts from non-heart-beating donors.

Given the shortage of cadaveric organs, we began a study utilizing NHBD for OLTx and KTx. There were 24 NHBD between January 1989 and September 1993. These donors were divided into 2 groups: uncontrolled NHBD (G1) (n = 14) were patients whose organs were recovered following a period of CPR; and controlled NHBD (G2) (n = 10) were patients whose organs were procured after sustaining cardiopulmonary arrest (CA) following extubation in an operating room setting. Eight kidneys and 5 livers were discarded because of macroscopic or biopsy findings. In G1, 22/27 (81.5%) kidneys were transplanted; 14/22 (64%) developed ATN; 20/22 (95%) recipients were off dialysis at the time of discharge. With a mean follow-up of 32.7 +/- 21.1 months, sixteen (73%) kidneys are still functioning, with a mean serum creatinine of 1.7 +/- 0.6 mg/dl. The one-year actuarial patient and graft survivals are 95% and 86%. In G2, 17/20 (85%) kidneys were transplanted; 13/17 (76%) kidneys experienced ATN. All patients were off dialysis by the time of discharge. With a mean follow-up of 17.6 +/- 15.4 months, twelve (70%) kidneys are still functioning, with a mean serum creatinine of 2.5 +/- 2.1 mg/dl. The one-year actuarial patient and graft survivals are 94% and 82%, respectively. In G1, 6/10 (60%) livers were transplanted; 3/6 (50%) livers functioned, the other 3 patients required ReOLTx in the first week postoperatively because of PNF (n = 2) and inadequate portal flow (n = 1). Two functioning livers were lost due to HAT (n = 1) and CMV hepatitis (n = 1). In G2, 6/7 (85.7%) livers were transplanted. All the livers (100%) functioned. 2 patients required ReOLTx for HAT at 0.9 and 1.0 months. Both patients eventually died. One patient with a functioning liver died 2 months post OLTx. The remaining 3 patients are alive and well at 27 months of follow-up. This study shows that the procurement of kidneys from both uncontrolled and controlled NHBD leads to acceptable graft function despite a high incidence of ATN. The function of liver allografts is adequate in the controlled NHBD but suboptimal in the uncontrolled NHBD, with a high rate of PNF.

Adolescent↗
PubMed1995

Effect of prostacyclin on microvascular pressures in a patient with pulmonary veno-occlusive disease.

Continuous-infusion prostacyclin improves symptom scores and decreases mortality in patients with primary pulmonary hypertension, but use of prostacyclin in patients with pulmonary veno-occlusive disease may precipitate pulmonary edema. A patient with pulmonary veno-occlusive disease received a graduated intravenous infusion of prostacyclin and pulmonary capillary pressures were calculated during prostacyclin dose ranging. Calculated capillary pressure increased with low-dose prostacyclin (< or = 6 ng/kg/min) but decreased with higher doses. These data suggest that the post-capillary pulmonary venules in our patient had reversible vasomotor tone, but required a higher dose of prostacyclin to vasodilate than did the precapillary arterioles.

Blood Pressure↗
PubMed1993

Restriction endonuclease analysis of the vp7 genes of human and animal rotaviruses.

The vp7 genes of 194 strains of group A rotaviruses representing all known G types were analyzed with three restriction enzymes by direct digestion of amplified cDNA copies or by deduction of the restriction patterns from known sequences. Mammalian rotavirus strains were classified into 28 restriction patterns consisting of combinations of the 6 profiles (s1 to s6) obtained by digestion with Sau96I endonuclease, 9 profiles (h1 to h9) obtained with HaeIII, and 15 profiles (b1 to b15) obtained with BstYI. Digestion with Sau96I and HaeIII identified restriction sites common to all, or almost all, rotavirus strains studied, whereas BstYI was the most discriminating among rotavirus strains. A clear correlation between some restriction patterns or individual profiles and G type and/or host species of origin was found. Several discriminatory restriction sites consisted of type-specific nucleic acid sequences that encoded conserved amino acid residues. Although not directly involved in antigenic diversity, these sites appear to indicate the G type of the isolate. The technique permits rapid comparison of a large number of virus isolates directly from fecal specimens and provides useful markers for investigating the evolution of rotavirus vp7 genes and tracing vaccine virus and interspecies transmission.

Animals↗
PubMed1992

Temperature-dependent effects of cholesterol on sodium transport through lipid membranes by an ionizable mobile carrier.

Temperature-jump relaxation experiments on Na+ transport by (221)C10-cryptand were carried out in order to study the influence of cholesterol and its temperature-dependence on ion transport through thin lipid membranes. The experiments were performed on large, negatively charged unilamellar vesicles (LUV) prepared from mixtures of dioleoylphosphatidylcholine, phosphatidic acid and cholesterol (mole fractions 0-0.43), at various temperatures and carrier concentrations. The initial rates of Na+ transport and the apparent rate constants of its translocation by (221)C10 increased with the carrier concentration and the temperature. The incorporation of cholesterol into the membranes significantly reduced the carrier concentration- and temperature-dependence of these two parameters. The apparent energy required to activate the transport decreased significantly with increasing carrier concentrations at any given cholesterol molar fraction, and increased significantly with the cholesterol molar fraction at any given carrier concentration. Our interpretation of the action of cholesterol on this transport system is based on the assumption that the binding cavity of cryptands is likely to be located towards the aqueous side of the dipole layer. The results are discussed in terms of the structural, physico-chemical and electrical characteristics of carriers and complexes, and of the interactions occurring between an ionizable mobile carrier and the membrane.

Algorithms↗
PubMed1992

A randomized trial of adjuvant chemotherapy after radical hysterectomy in stage Ib-IIa cervical cancer patients with pelvic lymph node metastases.

Seventy-one patients with Stage Ib-IIa cervical cancer treated by radical hysterectomy and found to have pelvic lymph node metastases were entered on a randomized trial comparing standard pelvic radiotherapy versus three cycles of combination chemotherapy with cisplatin, vinblastine, and bleomycin followed by pelvic radiotherapy. After a median follow-up of 2.5 years, 24 patients have relapsed. In 12 patients, the first evidence of relapse was in the pelvis, in 11 patients the first relapse was evident at a distant site, and in 1 patient the local recurrence and distant metastases were documented simultaneously. No difference in disease-free or overall survival has emerged between the two treatment groups. Relapse was more common in patients with non-squamous tumors (44%) and in those with metastases in several pelvic lymph nodes. We conclude that patients with pelvic lymph node metastases have a rather poor prognosis, but it remains to be determined how they should best be treated after radical surgery.

Adult↗
PubMed1992

Respiratory failure revealing mitochondrial myopathy in adults.

Two patients, a 70-yr-old black woman and a 56-yr-old black man, presented with respiratory failure unexplained by intrinsic lung disease. Both had been dependent on a respirator for several weeks. No abnormalities of the central or peripheral nervous system or long-standing muscle weakness was noted. The findings from ophthalmologic and cardiac evaluations were normal. The serum creatinine kinase concentration was mildly elevated in case 1, and needle electromyography showed myopathic potentials in case 2. In both instances, muscle biopsy established the diagnosis of mitochondrial myopathy. Biochemical studies of muscle extracts showed partial deficiency of complex 3 in patient 2 and of complex 4 in patient 1. Both patients were weaned from the ventilator after long periods of ventilatory assistance. These observations document a hitherto undescribed presentation of adult-onset mitochondrial myopathy.

Aged↗
PubMed1991

A small basic ribosomal protein from the extreme thermophilic archaebacterium Sulfolobus solfataricus that has no equivalent in Escherichia coli.

The structure of the gene for a small, very basic ribosomal protein in Sulfolobus solfataricus has been determined and the structure of the protein coded by this gene has been confirmed by partial amino acid sequencing. The protein shows no sequence similarity to any of the ribosomal proteins from eubacteria (Escherichia coli) or to those that have been reported from eukaryotes.

Amino Acid Sequence↗
PubMed1991

Percutaneous urinary diversion in gynecologic oncology.

During the 10-year period after 1979, percutaneous urinary diversion (PCUD) was performed on 35 patients whose mean age was 53.5 years (30-80 years). Twenty-one patients (60%) had Stage IIB-IV cervical cancer, 11 (31%) Stage IB-IIA cervical cancer, 2 (6%) Stage IB-II endometrial cancer, and 1 (3%) Stage IB vaginal cancer. All had radiological evidence of ureteric obstruction and 8 patients also had urinary tract fistulae. Serum creatinine levels were elevated in 24. Following diversion there was a significant fall in mean pretreatment creatinine levels from 482 mumol/liter (range, 70-1703 mumol/liter) to 131 mumol/liter (range, 60-290 mumol/liter; P less than 0.0001); those patients with normal creatinine levels prior to diversion also had a reduction in their levels. A significant fall in mean serum urea levels from 22.0 mmol/liter pre- to 11.9 mmol/liter post-PCUD (P less than 0.001) was also noted. Minor complications occurred and included hemorrhage, replacement/reinsertion, infection, and blockage. Median survival of the 35 patients after PCUD was 6 months (mean, 16.5 months). For the 11 with normal pretreatment renal function median survival was 16 months (mean, 41 months) compared to 2.5 months (mean, 5.1 months) for those with elevated pretreatment serum creatinine levels. Median survival with untreated malignancy was 7 months (mean, 19.6 months) and 6 months (mean, 12.3 months) in patients with previously treated cancer. PCUD is indicated in previously untreated patients with gynecologic cancer so that primary therapy can be instituted. The role of urinary diversion in patients with previously treated cancer must be individualized. Palliative diversion is appropriate in selected patients where additional therapy is expected to prolong life, where symptom control is needed, or to allow the patient to return home for a significant proportion of the remainder of life.

Adult↗
PubMed1991

Comparison of the structure of archaebacterial ribosomal proteins equivalent to proteins L11 and L1 from Escherichia coli ribosomes.

The sequences of two ribosomal proteins from two widely divergent species of archaebacteria, Halobacterium cutirubrum and Sulfolobus solfataricus, have been deduced from the structure of their respective genes. These two proteins were found to be equivalent to the L11 and L1 ribosomal proteins of the eubacterium Escherichia coli. Sequence comparison revealed that the archaebacterial L11e (equivalent to E. coli L11) proteins are longer than the eubacterial protein due to a C-terminal extension of about 30 residues. The archaebacterial L11e proteins, like the E. coli L11, are rich in proline residues; most of these are conserved. L11 is the most highly methylated protein in the E. coli ribosome. However, sites of methylation are generally not conserved in the archaebacterial L11e proteins. The region of highest sequence similarity between L11 and the archaebacterial L11e proteins is the N-terminal domain. This domain is believed to interact with release factor 1 during termination of translation. The amino acid sequences of the archaebacterial L1e proteins were compared to the eubacterial E. coli L1 and Bacillus stearothermophilus L1e sequences. The archaebacterial L1e proteins are slightly shorter at both their N- and C-termini. A region of high sequence similarity (7 of 14 residues) occurs near the center of the proteins.

Amino Acid Sequence↗
PubMed1990

A new species of Penicillium isolated from soil at the Kruger National Park in South Africa.

A new species of Penicillium Link ex Fries is described and illustrated. It is represented by twenty six isolates recovered from soil at twenty six different locations at the southern part of the Paul Kruger National Park in South Africa. It clearly differs from all species of the genus described so far among the Biverticillata-Symmetrica Section, and it is therefore described and proposed as a new taxon: Penicillium krugerii sp. nov.

Penicillium↗