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Biomedical subjects

C Silva

Publications and source records attributed to C Silva.

At least 109 records · Page 6Linked to original sources
PubMed1990

Craniometrical variation among South American prehistoric populations: climatic, altitudinal, chronological, and geographic contributions.

The independent contributions of climate, altitude, chronology, and geographic location of archeological sites to craniometrical variation are analyzed in a sample of 1,119 skulls from South America. Geographic location is responsible for the highest proportion of craniometrical variation, followed by climate and altitude. It is concluded that geographic isolation has partially prevented gene flow from counterbalancing craniometrical microdifferentiation produced by founder effect.

Altitude↗
PubMed1990

[The rupture of surgical gloves in a general hospital].

We studied the incidence of rupture of surgical gloves used at a general hospital: A) new gloves (n = 114); B) gloves used at a major general, gynecological or urological operation (n = 258), and C) recirculating surgical gloves (n = 86). A special techniques based on transmission of an electrical signal through the rupture was used to identify rupture. Rupture was present in 8.8, 28 and 26% of surgical gloves in groups A, B and C, respectively. Type of surgery or surgeon involved did not influence rupture of gloves in group A. However, rupture increased in relation to the duration of surgery (40% incidence in operations lasting more than 90 min). Our results suggest the need for better quality control of new surgical gloves and glove change after 90 min of operation.

Chi-Square Distribution↗
PubMed1990

Human IgM monoclonal antibody 16.88: pharmacokinetics and distribution in mouse and man.

Human IgM monoclonal antibody (MAb) 16.88 recognizes an antigen strongly expressed by colon cancer tissue. We used 131I-labelled 16.88 for biodistribution and pharmacokinetic studies in nude mice bearing WiDr or NIH:OVCAR-3 xenografts. Serum half-life was 8 h. Maximum tumour uptake was between 1 and 8 h after administration and amounted to, respectively, 3% and 1% of the injected dose g-1 for WiDr and NIH:OVCAR-3 tumours. Half-lives in these tumours were approximately 24 h. Tumour to normal colon uptake ratios increased from 2.3 at 24 h to 17 at 5 days after injection. Simultaneously, pharmacokinetic studies were performed in patients with advanced colon cancer reactive with 16.88. They were injected with 5 mCi 131I-16.88 by intravenous infusion over 2 h. Serum half-life was 20 h with greater than 90% of the 131I bound to 16.88. Within 40 h 50% of the injected dose was excreted as free 131I in the urine. In one patient an accelerated clearance was found, possibly caused by pre-existing antibodies reacting with 16.88. None of the patients showed an immune response against 16.88 antibody. Immunoscintigraphy showed positive tumour localization in the majority of the patients, best visualized at later days. We conclude that 16.88 has tumour localization properties while its human origin accounts for the lack of immunogenicity.

Animals↗
PubMed1989

Peopling of Andean South America.

Archeological, craniometrical, and genetic information is utilized to reconstruct possible migration routes used in the peopling of Andean South America. Special emphasis is given to the elaboration of craniometrical isoline maps and its application in testing models of population displacement based on archeological data. A genetic distance analysis among linguistic groupings complements the conclusions based on archeological and craniometrical information.

Agriculture↗
PubMed1989

Effect of oestradiol delivered from a perioviducal device on ovum transport in mice.

Silastic devices impregnated with oestradiol and blank devices were placed around both oviducts and around skeletal muscle bundles in the forelegs to attain local and systematic delivery, respectively. Another group of mice received an oestradiol-impregnated device around one oviduct and a blank device in the contralateral oviduct. Implantation of blank devices around the oviducts and in the forelegs did not alter ovum transport. Devices impregnated with oestradiol placed around both oviducts produced a dose-dependent delay of ovum transport, which was more pronounced than the effect of devices located in the forelegs. Oviducts receiving an oestradiol-loaded device had a larger retention of ova than did the contralateral oviducts receiving a blank device. These results demonstrate a direct action of oestradiol upon the oviduct to delay ovum transport in the mouse.

Animals↗
PubMed1989

H2-antagonists: synthesis and activity of 2-amino-5-thiazolyl derivatives.

2-Amino- and 2-guanidinothiazole derivatives having in position 5 a methylthioalkyl side-chain with urea-equivalent moieties were prepared for comparison with H2-antagonists of cimetidine and tiotidine series. Examination of the pharmacological results obtained from experiments on guinea pig atria and in cat gastric fistula, suggests some general observations about the structure-activity relationship of the compounds synthesized. The activity trend of these products is different from that of H2-imidazole antagonists while it is similar to that of the tiotidine series. Unlike the tiotidine similar compounds, the 2-guanidino-5-thiazolyl derivatives are less potent than the corresponding 2-amino-5-thiazolyl products. The activity of the latter ones is reduced in comparison to that of tiotidine or cimetidine.

Amines↗
PubMed1989

[4-(3-Oxo-1,2-benzisothiazolin-2-yl)alkanoic, phenyl and phenoxyalkanoic acids: synthesis and anti-inflammatory, analgesic, and antipyretic properties].

Based on previous observations, the preparation, some physicochemical (partition coefficient, pKa) and pharmacological properties of 4-(3-oxo-1,2-benzisothiazolin-2-yl)alkanoic, benzoic, phenyl, phenoxyalkanoic acids and of some of their functional derivatives are reported. All new compounds were biologically examined for their antiphlogistic, analgesic and antipiretic actions, in comparison with those of 1,2-benzisothiazolin-2-one and with those of ibuprofen as the antiphlogistic, analgesic, antipyretic arylalkanoic prototype. Structure-activity relationships showed that the 1,2-benzisothiazolin-2-one and its new alkanoic and arylalkanoic derivatives have strong actions which are however specific for some of the tested pharmacological properties. From this point of view, the synthesized substances have a narrow spectrum of activity, if compared with ibuprofen which is at the same time an antiphlogistic, analgesic and antipiretic substance. The antiphlogistic and antipyretic activities of 4-(3-oxo-1,2-benzisothiazolin-2-yl)benzoic, phenylacetic and phenylmethylacetic acids and the antipyretic and analgesic actions of 3-oxo-1,2-benzisothiazolin-2-ylacetic acid, which are comparable or higher in "potency" than those of ibuprofen, are noteworthy.

Animals↗
PubMed1986

Antipyretic activity of new compounds 4-(3-oxo-1,2-benzisothiazolin-2-yl)phenylalkanoic acids, their esters, amides and 1,1-dioxide derivatives.

Antipyretic activity of new compounds, 4-(3-oxo-1,2-benzisothiazolin-2-yl)phenylalkanoic acids, their esters, amides and 1,1-dioxide derivatives has been studied. The acid compound of the benzoic series (I:a), tested at graded doses, exerted a noticeable antipyretic action; it had two times the "potency" of benzisothiazolone but an almost equal "efficacy". Its "potency" however was not proportional to the development of gastric lesions and to the acute toxicity. A decreased pharmacological activity has been observed in phenylalkanoic acids in the following order: R = COOH greater than CH2COOCH greater than CH(CH3)COOH greater than CH(C2H5)COOH, probably due to their increasing lipophilic character. By contrast among 1,1-dioxide derivatives the most effective in preventing pyrogen-induced fever was the ethyl ester (V:c) of benzoic series which appeared to be as active as paracetamol. The interest arising from these observations is here after discussed.

Amides↗
PubMed1984

[3-Benzyl-1,2-benzoisothiazoles: spasmolytic properties of the aminoalkyl derivatives].

The synthesis and chemical and pharmacological properties of 3-benzyl-1,2-benzisothiazoleaminoalkyl derivatives are reported. These compounds were studied because 4-dimethyl-2-phenyl-2-(1,2-benzisotiazol-3-yl)-butyramide and N,N-dimethyl-3-phenyl-3-(1,2-benzisothiazol-3-yl)propylamine were recently found to have antispasmodic properties. Most of the compounds studied aspecifically inhibited the contracturant effects of acetylcholine, histamine and BaCl2. Three of them showed mixed antagonism (competitive and non-competitive) versus acetylcholine and histamine, showing both antimuscarinic and antihistaminic properties. However the antimuscarinic action prevailed over the others, as shown by pA2 and pD'2 calculated values. On the basis of the results obtained, the structure-activity relationships is discussed.

Acetylcholine↗
PubMed1984

[Synthesis and analgesic activity of 4-(3-oxo-1,2-benzoisothiazoline-2-yl)phenylalkanoic derivatives].

The synthesis of a new series of 4-(3-oxo-1,2-benzisothiazolin-2-yl)phenylalkanoic compounds and some of their functional derivatives is described. The compounds, on the basis of data obtained from 1,2-benzisothiazolin-3-one derivatives, were biologically examined mainly for their antiphlogistic and analgesic actions. Results obtained, in analyzing the relationship between structure and pharmacological actions, suggest that both 4-(3-oxo-1,2-benzisothiazolin-2-yl)-phenyalkanoic acids and o-sulphobenzimido alkanoic esters are endowed with pain-killing effects comparable in potency and efficacy with phenylbutazone.

Analgesics↗
PubMedDate not supplied

Severity of abuse before and during pregnancy for African American, Hispanic, and Anglo women.

OBJECTIVE: To describe timing and severity of abuse before and during pregnancy for African American, Hispanic, and white Anglo American women. FINDINGS: Among 199 abused women, 18.1% of the women were abused during pregnancy but not the year before, 30.2% were abused the year before but not during pregnancy, and 51.8% were abused both the year before and during pregnancy. The timing of abuse did not vary by ethnicity. The three (ethnicity) by three (timing) factorial analysis of variance showed severity of abuse to vary by timing of abuse. Women reporting abuse both before and during pregnancy reported greater severity of abuse on each of the five measures than did women abused only before pregnancy or only during pregnancy. CONCLUSIONS: Over half (51.8%) of the women reported abuse before and during pregnancy with these women reporting greater severity of abuse on all five severity scores. Timing and severity of abuse did not vary by ethnic group. The majority of women abused during pregnancy were also abused prior to pregnancy, indicating the need for universal screening of all women during each health encounter.

Adolescent↗