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Biomedical subjects

A Martijn

Publications and source records attributed to A Martijn.

32 records · Page 2Linked to original sources
PubMed1989

Determination of diisobutyl- and diisopropylnaphthalenesulphonates in pesticide wettable powders and dispersible granules by high-performance liquid chromatography.

Methods are presented for determining diisobutyl and diisopropylnaphthalenesulphonates in pesticides formulated as wettable powders or water dispersible granules. The dispersing agents were concentrated on anion-exchange cartridges and after removal of interfering substances eluted with methanol containing 5% hydrochloric acid. The various isomers were separated by reversed-phase high-performance liquid chromatography on an octyl-modified column using a water-methanol gradient or on a cyanoalkyl-modified column with water-methanol. Quantitative results were obtained by comparing the peaks with those of the standard technical material. Various groups of peaks were identified as mono-, di- and triisobutylnaphthalenesulphonates respectively.

Chromatography, High Pressure Liquid↗
PubMed1989

Survival and clinical outcome in patients with cystic fibrosis, with or without neonatal screening.

After an experimental neonatal screening program for cystic fibrosis had been carried out in the Netherlands during 1973 to 1979, a follow-up study to evaluate the effects of neonatal screening was started in 1980. Although before 1980 the management of patients with cystic fibrosis was partly left to local hospitals, from the start of the follow-up program all patients in the study received similar treatment. A cumulative survival rate, calculated with exclusion of the patients with meconium ileus, showed at the age of 11 years a significantly better survival rate (p less than 0.05) for the 19 patients from the screened population (88%) than for the 25 patients from the nonscreened population (60%). Clinical condition was assessed on entry and at the age of 9 years in 16 screened and 20 nonscreened patients. On entry, comparison showed significantly better chest radiograph scores for the screened patients but no other significant differences. At the age of 9 years, after several years of similar treatment for all patients in the study, significantly better clinical (p less than 0.02) and chest radiograph scores (p less than 0.01), lower IgG levels (p less than 0.05), and higher vitamin A levels (p less than 0.01) were observed in the screened patients. Our study results suggest that early diagnosis and appropriate treatment may prevent serious deterioration and death at a young age, and may reduce the extent of early irreversible lung damage in patients with cystic fibrosis.

Albumins↗
PubMed1988

Determination of dodecylbenzenesulphonates and ethoxylated alkylphenols in liquid pesticide formulations by high-performance liquid chromatography.

A method is presented for determining mixtures of calcium dodecylbenzene-sulphonate (CaDBS) and ethoxylated alkylphenols in pesticidal emulsifiable concentrates. The pesticide formulations are adsorbed on a pre-concentration column. The active ingredients, the solvents and the emulsifiers are eluted successively by using solvents with increasing polarities. The various homologues of CaDBS and the ethoxylated alkylphenols are separated by reversed-phase high performance liquid chromatography using methanol-water containing tetramethylammonium bromide. The oligomers of the ethoxylated phenols are separated on an aminopropyl-modified column using a solvent gradient (propan-2-ol-water and hexane-tetrahydrofuran). Quantitative results are given for synthetic samples. The degree of ethoxylation of the ethoxylated alkylphenols has been determined and the CaDBS components characterized.

Benzenesulfonates↗
PubMed1987

The missing pericallosal artery on sonography: a sign of agenesis of the corpus callosum in the neonatal brain?

The sonographic findings in five newborn infants with agenesis of the corpus callosum are reported. Besides abnormal shape and position of the lateral and third ventricles of the brain, it was noted that echoreflections from the pericallosal artery were missing in all infants. Normally the pericallosal artery, which follows the surface of the corpus callosum, can be easily detected in the midline sagittal scanplane on sonography through the anterior fontanelle. It is suggested that a missing pericallosal artery is an easily detectable sign of agenesis of the corpus callosum in newborn infants.

Agenesis of Corpus Callosum↗
PubMed1987

Screening for cystic fibrosis. A comparative study.

A neonatal screening program for CF by determination of albumin in meconium was performed in the north eastern part of the Netherlands from 1973 to 1979. In this period 94,043 newborns were screened and 116,953 were not. A follow-up study of CF patients in the above cohorts was started in 1980. The purposes of this study were to evaluate the effects of early diagnosis and treatment in CF patients by comparing the outcome in the two groups of patients. Although the results indicate that very early diagnosis and treatment have a beneficial effect on outcome, more studies are needed before a definite answer can be given as to whether or not mass neonatal screening should be started.

Albumins↗
PubMed1985

A comparison of the Shwachman, Chrispin-Norman and Brasfield methods for scoring of chest radiographs of patients with cystic fibrosis.

Three systems are described for chest radiograph scoring in cystic fibrosis patients: the Shwachman-Kulczycki, the Chrispin-Norman and the Brasfield method. Sixty chest radiographs of 39 patients of different ages have been independently scored by two radiologists according to the three methods. No statistical differences between the methods could be demonstrated. The Chrispin-Norman method is recommended as the best choice because differences in scoring appeared better interpretable. A significant increase in precision could be achieved by combining the scores of the three methods.

Child↗
PubMed1984

Radiologic findings in a hypothalamic hamartoma.

This report presents a case of a hypothalamic hamartoma in a 4-month-old boy. Ultrasound demonstrated the tumor and its effect on the ventricular system. Computed tomography and ventriculography confirmed these findings and were complementary in the diagnosis. To the author's best knowledge, this is the first ultrasound documentation of a hypothalamic hamartoma.

Cerebral Ventriculography↗
PubMed1982

Radiologic findings in primary hyperoxaluria.

Six out of seven patients with primary hyperoxaluria showed various degrees of oxalosis. The radiographic manifestations differ between patients younger than 15 years and those older than 45 years. The mild manifestations in children, only urolithiasis, can be explained by the, as yet, unimpaired renal function. The renal function in the older patients, with extensive pathologic changes like nephrocalcinosis, urolithiasis, soft-tissue calcification, and osseous changes, is very poor. The findings of extensive soft-tissue calcification and the bony changes are not in complete agreement with those in the literature.

Adolescent↗
PubMedDate not supplied

Preoperative assessment of the portal vein and hepatic artery in children with end-stage liver disease: is selective angiography still necessary?

BACKGROUND: Selective angiography involves increased risk for children and may cause vascular complications. The aim of this study was to determine whether selective angiography is still necessary for viewing the portal vein and hepatic artery. METHODS: Doppler ultrasound, abdominal aortography, and selective angiography were performed and interpreted independently in 62 children (median age = 1 year 3 months), with end-stage liver disease, who were candidates for orthotopic liver transplantation. RESULTS: Selective angiography agreed with the Doppler ultrasound findings of patency, flow direction, and diameter of the extrahepatic portal vein in 84%, 73%, and 79% of the children, respectively. Important additional information was obtained from selective angiography in only five of the 62 children (8%). Selective angiography showed an anomaly of the hepatic artery in 21 of the 62 children (33%). In 18 out of these 21 children (85%), an anomaly of the hepatic artery was already visible on the abdominal aortogram. CONCLUSION: Selective angiography did not play any significant role in the detection of an anomaly of the hepatic artery and should only be done if the Doppler ultrasound findings of the portal vein are inconclusive or if abdominal aortography cannot provide reliable information about the hepatic artery. For the evaluation of the portal vein and hepatic artery, we recommend Doppler ultrasound and abdominal aortography, a less invasive angiographic procedure.

Female↗
PubMedDate not supplied

Gas chromatographic methods for determination of gamma-BHC in technical emulsifiable concentrates and water-dispersible powder formulations and in lindane shampoo and lotion: collaborative study.

Although the gas chromatographic separation of the isomers of BHC was demonstrated two decades ago, the present AOAC method of analysis of BHC for gamma-isomer (lindane) content is based on a separation carried out on a liquid chromatographic partition column. A method of analysis has been developed that uses an OV-210 column for separation of the gamma-isomer from the other isomers and impurities in technical BHC. Di-n-propyl phthalate was chosen as an internal standard. The same system allows quantitation of lindane in lotion and shampoo after these products are extracted with ethyl acetate-isooctane (1 + 4). The analytical methods were subjected to a collaborative trial with 10 laboratories. The coefficient of variation for technical BHC was 2.83%. For the water-dispersible powder and emulsifiable concentrate, the coefficients of variation were 2.89% and 4.62%, respectively. Coefficients of variation for 1% lindane lotion and shampoo were 4.36% and 11.92%, respectively. The method has been adopted official first action.

Chromatography, Gas↗