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S Gonzalez

Publications and source records attributed to S Gonzalez.

At least 91 records · Page 5Linked to original sources
PubMed1991

Frozen-section analysis of allograft renal biopsy specimens. Reliable histopathologic data for rapid decision making.

Rapid tissue diagnosis during acute events associated with renal transplantation is often necessary to permit immediate decisions regarding initiation or modification of therapy. To achieve this, we performed frozen section analyses with cryoprotected alcoholic Bouin's-fixed tissue, which permits evaluation within 2.5 hours. During a 30-month period, 200 allograft biopsies were performed; 68 frozen sections were obtained when deemed necessary by the clinical team. We compared frozen-section diagnoses with those following regular evaluation of the biopsy specimen. Agreement in diagnoses occurred in 61 (88.4%) of 69 specimens. Acute rejection was the dominant diagnosis (n = 39); others were acute tubular necrosis, cyclosporine toxicity, chronic rejection, and infection. Major misdiagnoses included acute vascular processes (three capillary and/or venous thromboses and one vascular inflammation); acute cellular rejection was missed in two cases, reflecting a sampling error. Secondary diagnoses not of immediate therapeutic importance were detected in seven frozen sections and missed in nine. These included chronic glomerulopathies, nephrosclerosis, and mild chronic rejection. Although acute vascular phenomena may be difficult to recognize in frozen sections, we conclude that allograft biopsy frozen-section analysis is a valuable part of the care of transplant recipients.

Biopsy↗
PubMed1990

Evaluation of renal transplant dysfunction by duplex Doppler sonography: a prospective study and review of the literature.

A disconcertingly wide variation exists in the literature as to the accuracy of duplex Doppler sonography in the detection of acute renal transplant rejection. Sensitivities range from 9% to 76%. In an attempt to explain the disparity of results, we undertook a double-blind prospective study of the accuracy of duplex Doppler ultrasound in the detection of acute rejection in renal transplants. We scanned 49 consecutive patients with a total of 65 biopsies; 46 biopsies in 33 consecutive patients were included in our study. In our population, the prevalence of acute rejection was 61% (28/46). Using a resistive index (RI) cutoff of greater than 0.90 based on the main renal artery flow pattern, the sensitivity of our test was 43%, with a 67% specificity. The positive predictive value was 67%. Our results are contrasted and compared with the published data from other groups in a critical survey of the literature. We conclude that duplex Doppler sonography alone is inadequate to evaluate acute rejection in renal transplants.

Adult↗
PubMed1990

Eosinophilic globules in pigmented spindle cell nevus.

Reed's pigmented spindle cell nevus is often misdiagnosed as malignant melanoma despite reliable clinical and histopathologic diagnostic features. In the present report, 10 cases of pigmented spindle cell nevus were studied with step sections to identify Kamino's eosinophilic globules. Eighty percent of the cases disclosed numerous eosinophilic globules, supporting the hypothesis that this nevus is a variant of Spitz's nevus. Kamino's eosinophilic globules could be considered another important sign for the differential diagnosis between pigmented spindle cell nevus and malignant melanoma.

Adolescent↗
PubMed1990

Genome rearrangements in porcine rotaviruses: biochemical and biological comparisons between a supershort strain and its standard counterpart.

Two porcine rotavirus strains (CN86 and CC86) isolated during an epidemiological survey of diarrhoea in swine in Argentina were studied because of several unique characteristics. Both these strains were isolated and cloned from the same faecal sample and the electrophoretic migration of 10 of their 11 genomic dsRNA genomic segments in polyacrylamide gels was identical, but strain CC86 had a supershort electropherotype. We analysed biochemical, serological and biological properties of both viruses. In vitro translation of genome segment 11 RNAs showed that both viruses produced a polypeptide with an apparent Mr of 26K. No differences in any of the other virus-induced proteins made in infected MA104 cells were found on one- and two-dimensional gels for either strain. In addition, the serotype and the subgroup specificities of both viruses were identical (group A, subgroup I, serotype 5). These results suggest that the rearranged strain was probably generated from the standard one and that the coding capacity of the rearranged segment was conserved. Consistent with this hypothesis, primer extension analysis revealed that the supershort strain had a rearrangement involving partial duplication of genomic segment 11. Biological studies showed differences between these viruses. The rearranged strain (CC86) produced larger plaques in monolayers of MA104 cells and outgrew the standard strain (CN86) when cells were coinfected with both viruses at different relative concentrations and different m.o.i. The possibility that large plaque formation and efficient virus replication can be influenced by the products of genomic segment 11, in addition to segment 4, is discussed.

Animals↗
PubMed1990

Problems in the long-term renal allograft recipient.

Despite great improvement in patient and graft survival, the long-term morbidity and mortality in renal transplant recipients are still significant. Cardiovascular disease accounts for much of the mortality in long-term survivors; screening before the transplant procedure and adequate control of hypertension should help improve patient survival. Many of the gastrointestinal complications are due to overimmunosuppression and sepsis. Adequate management must include withdrawal of all immunosuppressive medications in order to save the patient's life. Liver disease is usually of viral origin; patients with chronic active hepatitis or cirrhosis should remain on dialysis. Chronic rejection is the major cause of graft loss in long-term survivors; it is unresponsive to antirejection treatment and its progression may be mediated by nonimmunologic mechanisms. Correctable problems such as renal artery stenosis and ureteral obstruction should be ruled out before a late deterioration in graft function is disregarded as chronic rejection. Post-transplant diabetes, osteonecrosis, cataracts, and nephrotoxicity are directly related to the various immunosuppressive drugs currently used. The lowest dose compatible with graft acceptance should help reduce the incidence of these nonfatal but significant complications. Recurrence of disease is a common histologic finding in many transplant recipients but, except for a few diseases such as HUS, FSGS, and oxalosis, it usually does not lead to graft failure. Successful transplantation restores fertility in many uremic patients. Adequate counseling on contraception is imperative in order to avoid unwanted pregnancies and to delay parenthood for at least 1 year. Current immunosuppressive agents are not teratogenic, no dose adjustments are necessary, and an ill-advised decrease in medication may precipitate a rejection episode. Premature delivery is the major problem in these patients and can be avoided by maintaining adequate graft function and controlling hypertension and infections. It is evident from this review that most of the long-term morbidity and mortality seen in renal allograft recipients are due to overimmunosuppression with sepsis or to side effects of the individual drugs, steroids being a common denominator in almost all cases. New immunosuppressive protocols must aim not only to improve patient and graft survival but also to avoid the many complications that limit the full rehabilitation of these patients.

Graft Survival↗
PubMed1989

Sequence of bacteriophage T3 DNA from gene 2.5 through gene 9.

The nucleotide sequence of bacteriophage T3 DNA, from gene 2.5 through gene 9 has been determined. In addition to regulatory sites, the sequence predicts 19 close-packed genes plus two genes that overlap, in a different reading frame, another gene. The majority of these genes are highly homologous to those in the corresponding region of bacteriophage T7. However, there are some genes that are present in one, but not the other, phage. These apparent deletions are almost exactly gene size and thus the close-packed organization of genes remains the same in T3 as in T7. The varying levels of homology between T3 and T7 DNAs, first noted by Davis and Hyman in their study of DNA heteroduplexes, are also demonstrated here by a comparison of T3 and T7 nucleotide sequences. Many regions of extremely high homology immediately abut sequences that have no apparent homology. These data suggest that bacteriophages T3 and T7 have recombined, both with each other and with other members of a pool of T7-like phages, during their co-evolution.

Amino Acid Sequence↗
PubMed1989

Putting the illness in its place: discussion groups for families with chronic medical illnesses.

A new psychosocial intervention for families and patients experiencing the chronic phase of a disabling medical illness is described. The intervention, a short-term, highly structured, psychoeducationally oriented, multiple-family discussion group (MFDG), was developed within the context of a clinical research program and has been successfully applied to a heterogeneous range of disabling medical illnesses. This report includes a detailed description of the treatment model, the format and content of group meetings, and initial clinical impressions regarding MFDG efficacy.

Adaptation, Psychological↗
PubMed1989

Rhinomanometric evaluation of two nasal steroid sprays in rhinitis.

A prospective, randomized study comparing the effectiveness of two nasal steroid sprays, flunisolide and beclomethasone dipropionate, in the treatment of nasal obstruction associated with allergic or vasomotor rhinitis has been conducted at New York University Medical Center-Bellevue Hospital. All patients underwent routine history and physical examinations and a modified radioallergosorbent test. Paranasal sinus films were used to exclude patients with sinusitis. The Rhinotest microprocessor rhinomanometer was used to quantify pretreatment and posttreatment total nasal air flow and resistance during a period of 2 months. These findings were assessed in conjunction with the patients' subjective complaints. Results demonstrated that anterior rhinomanometric assessment of the nasal airway during inhalant therapy correlated well with the patients' own subjective impressions of nasal air flow. Both steroid inhalants were effective; however, flunisolide provided for earlier and more substantial symptomatic relief. Beclomethasone dipropionate had milder side effects.

Adult↗
PubMed1989

Mesocolic myxoid hamartoma showing neural differentiation: an ultrastructural and immunohistochemical study.

A myxoid mesocolic tumor in a 4-month-old female infant is described. The tumor weighed 190 g and measured 8 cm in diameter and presented as a single mass composed of stellate and round cells with vesicular nuclei and prominent nucleoli in a myxoid, well-vascularized stroma. Electron microscopy showed mesenchymal cells with dilated rough endoplasmic reticulum, cell projections with primitive and desmosome-like cell junctions, and basal membrane-like material. Immunohistochemical studies demonstrated immunoreactivity with antibodies against vimentin and S-100 protein. The infant is well and without evidence of disease 3 years after surgery. This is an example of a peripheral myxoid hamartoma with neural differentiation, and the tumor is expected to have a benign clinical course.

Female↗
PubMed1989

Treatment of resistant schizophrenia with valproate and neuroleptic drugs.

Four cases of resistant Schizophrenia treated with valproate association with different neuroleptic drugs (thioridazine in three cases and loxapine in one) are presented. After a mean period of three months with this treatment, clinical improvement, consisting in a reduction of positive symptoms, as measured by the BPRS, and a normalization of hostile/disruptive behavior, was observed, and hospital discharge was possible. Reduction of symptoms was still present after a follow-up of 4 to 24 months. As valproate is a drug with gabaergic properties, a GABA involvement in the pathogenesis of schizophrenia is discussed. The association of valproate to neuroleptic drugs should be considered in the treatment of resistant Schizophrenia.

Adult↗
PubMed1987

Industrial pollution with copper and other heavy metals in a beef cattle ranch.

Experimental evidence of air borne heavy metal pollution as the cause of a disease of unknown etiology in beef cattle was obtained. Analysis of metals in natural grasses and leaves of tree defined Cu, Zn and Pb as the major pollutants, with Cd being a minor one. Emissions from a Cu smelter were traced as the main source of metallic pollution. No evidence of metal accumulation in the soil was found, mainly because of the short duration and intermittent pattern of pollution. A progressive intake of the several heavy metals contained in dusts deposited on the grasses was considered the cause of the sickness; this was associated with the grazing of cattle on contaminated grasses. The most severe cases were found in the most polluted pastures. Excepting Cd, the concentrations of the metals in the livers and kidneys of affected cattle were high. No overlapping of the respective ranges between test and control samples from both organs was found. Mean hepatic levels of Cu (925.7 mg/kg DM), Zn (491.2 mg/kg) and Pb (26.7 mg/kg) reflected the decreasing order of the concentrations of these elements in the polluted grasses. The main clinical and pathological features of this disease were discussed in light of the organic levels of the investigated metals. Disease could not be ascribed to a pure chronic toxicosis with any one of these.

Animals↗
PubMed1986

Family process, chronic illness, and death. On the weakness of strong bonds.

Newer techniques for directly measuring social interaction in families permit more informative studies of the family's role in the course of chronic illness. We used laboratory techniques for measuring problem-solving strategies in family groups, supplemented by measures of the family's intelligence and accomplishments as well as its intactness, the latter indicated by measures of duration of marriage and the survival of grandparents. We studied 23 families, each containing an adult patient with end-stage renal disease who was being treated by center-based hemodialysis. In sharp contrast to expectations based on previous data, high scores on the problem-solving variables, as well as the measures of accomplishment and intactness, predicted early death rather than survival. Equally surprising was the finding that noncompliance accounted for most of the association between the family variables and survival.

Adult↗
PubMed1986

Cylindrical irradiator fiber tip for photodynamic therapy.

In photodynamic therapy (PDT) the uniform distribution of intratumor or externally applied light is desirable but often difficult to achieve. An optical fiber tip producing cylindrical or lateral light emission can facilitate the application of laser energy by direct implantation of the tip into solid tumors or within tubular cavities of the body such as the bronchus or esophagus. A procedure is described for fabricating such a fiber tip, the main component of which is a hollow glass cylinder containing a light-scattering material. Light distributions emitted from the tip in air are documented. Useful properties of the tip include good light distribution, durability, heat resistance, and simplicity of construction.

Adenocarcinoma↗
PubMed1986

Effects of estradiol and environmental temperature changes on rat liver delta 6 microsomal desaturase activity.

The regulation of delta 6 desaturase activity by environmental temperature changes was studied in the microsomal membranes from female and ovariectomized female rat liver. Female rats adapted at 30-32 C for 20-25 days and then shifted to 13-15 C for 5 days showed an increased delta 6 desaturase system. Ovariectomized rats adapted under the same conditions did not show significant changes in this enzyme. The fatty acid compositions of microsomal phosphatidylcholine showed a decrease in arachidonic acid in female rats at 30 C compared to females at 15 C and ovariectomized rats at both temperatures. These results suggest that a modification of ovaric sex hormone levels might be responsible for the different delta 6 desaturase activity in female rats acclimated at both temperatures. In this regard, serum estradiol radioimmunoassay yielded slight differences between the two groups of female rats, suggesting that estradiol could play a role in the regulation of the delta 6 desaturase. The administration of a pharmacological dose of 17-beta estradiol to female and ovariectomized rats kept at 30 and 15 C decreased the delta 6 microsomal desaturase activity. These data suggest that estradiol levels are involved in the regulation of the delta 6 desaturase during cold adaptation.

Acclimatization↗
PubMed1986

The ultrastructural heterogeneity of potentially preneoplastic lesions in the human bronchial mucosa.

170 consecutive biopsies from the bronchial tree were subjected to ultrastructural analysis. 62 were identified as preneoplastic lesions: of these, 7 as goblet cell hyperplasia, 20 as basal cell hyperplasia, 17 as combined goblet and basal cell hyperplasia, 10 as epidermoid metaplasia, and 8 as dysplasia. The ultrastructural features of these lesions are described. According to these results, preneoplastic lesions of the human bronchial mucosa are composed of heterogeneous populations that display mixed or combined morphologic features signaling abnormal differentiation patterns at this stage. The findings are tentatively correlated with bronchial carcinoma cell heterogeneity and histogenesis.

Adult↗