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Biomedical subjects

K Abraham

Publications and source records attributed to K Abraham.

At least 37 records · Page 2Linked to original sources
PubMed1993

Transient renal medullary hyperechogenicity in ultrasound studies of neonates: is it a normal phenomenon and what are the causes?

A prospective ultrasound study of the renal morphology of 51 neonates with no clinical signs of renal impairment showed transient medullary hyperechogenicity of varying intensity in 37%. These findings were made in the first few postnatal days, were not accompanied by any other echographic changes, and disappeared again within the first week of life. They were encountered twice as often in full-term as in premature babies. In parallel with this phenomenon, the concentration of Tamm-Horsfall protein, calcium, and uric acid, and the osmolality were determined in the daily urine of 44 of these neonates. The analyses did not provide any definite clues as to the etiology of the ultrasound findings. It is therefore suggested that the term "Tamm-Horsfall nephropathy or proteinuria" should no longer be used for such sonographic phenomena in the neonatal kidney, but rather, they should be regarded as normal. Furthermore, the term "tubular stasis nephropathy" should be reserved for cases with clinically demonstrable impairment of renal function.

Calcium↗
PubMed1993

Retrospective statistical analysis of coagulation parameters after 250 liver transplantations.

Extensive transfusion of blood components as a typical feature of OLT has been described by many authors. The perioperative requirement for transfusion, however, follows a downward trend, although the indications for OLT have been extended. Functional disturbances such as hyperfibrinolysis or platelet dysfunction, demonstrated by laboratory tests, such as platelet counts, PT, aPTT, TT, fibrinogen, and ATIII are often used to direct the transfusion of blood components, although preoperative data give insight only into the insufficient function of the old liver, which will be explanted and replaced by the donor graft. We have described a retrospective statistical analysis of laboratory data, clinical data, and perioperative blood requirements from 250 liver transplantations performed in our hospital from 1988 to 1992. The OLT was performed according to the usual surgical methods using a venovenous bypass system. Intraoperatively, volume was restored with packed RBC and FFP according to hemodynamic data, hemoglobin, and diuresis; clotting data were not used as indications for blood replacement. This analysis demonstrated that neither preoperative nor intraoperative clotting parameters were able to allow a prediction of the intraoperative requirement for transfusion of blood components; these findings parallel those of previous reports. With respect to other studies showing that perioperative transfusion rates correlated with postoperative infections and mortality, we strongly suggest that perioperative clotting measures as indicators for transfusion requirement should be analyzed with caution. Whether other diagnostic methods such as TEG are useful alternatives has to be determined.

Adult↗
PubMed1991

[Non-invasive detection of left ventricular diastolic function in variously trained endurance athletes during a marathon run with pulsed Doppler sonography].

UNLABELLED: To evaluate left ventricular (LV) diastolic function in long distance runners LV filling parameters were assessed by Doppler echocardiography during marathon race in 23 male subjects. On the basis of their personal record the athletes were divided into two groups: 12 endurance athletes (END; 218 min over 42 km) aged 34 years (29/37, median and 25%/75%-percentiles) and 11 ultra endurance athletes (ULTRA; 152 min over 42 km) aged 32 years (28/37). At rest 21 healthy untrained subjects (UT) aged 33 years (28/37) served as control group. In long distance runners the values for LV mass and LV mass index were significantly higher in END with 210 (168/253) g rsp. 110 (87/135) g/m2 and in ULTRA with 225 (179/267) g rsp. 118 (93/142) g/m2 as compared to UT with 129 (105/162) g rsp. 68 (57/79) g/m2 (p less than 0.001 each). Doppler-derived mitral flow was characterized by the early passive (E wave) and late (A wave) diastolic inflow. In particular atrial filling fraction (AFF) as the relative atrial contribution to LV filling was measured. At rest and at km 21 we saw a normal filling behaviour (AFF = 27% bzw. 28%) in both groups of long distance runners with an AFF of 27 (26/29)% in END and an AFF of 28 (26/29) in ULTRA. In END AFF rose to 42 (38/47)% at km 42 (p less than 0.001) and remained significantly elevated with 37 (35/42)% until 30 min post marathon (p less than 0.05). Only 60 min post exercise AFF returned to baseline values with an AFF of 28 (25/39)% in END. In contrast at km 42 in ULTRA AFF was significantly lower and at baseline levels with 26 (25/29)% compared to END (p less than 0.001) and did not significantly change in the further course of the post running period. CONCLUSION: Long distance runners show a normal LV filling behaviour at rest despite significant LV hypertrophy. In contrast to top class athletes (ULTRA) there is a shift of LV filling from early (E wave) to late (A wave) diastole in less trained runners (END) during marathon. Thus, the results indicate an impairment of early diastolic LV filling in amateur endurance athletes (END) during extreme physical exercise.

Adult↗
PubMed1990

Persistence of various polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs and PCDFs) in hepatic and adipose tissue of marmoset monkeys.

A defined mixture of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs and PCDFs) was subcutaneously administered to marmoset monkeys (Callithrix jacchus). Tissue concentrations in hepatic and adipose tissue were measured at different times after treatment (1-28 weeks). One week after application high concentrations could be detected for the 2,3,7,8-substituted congeners only. The percent of the administered dose in whole liver differed for the various 2,3,7,8-substituted congeners, ranging from 24.5 +/- 4.5% for 2,3,7,8-TCDD to 74.1 +/- 4.9% for 2,3,4,6,7,8-H6CDF. Therefore, the concentration ratio (liver/adipose tissue) was also very different, ranging from about 1 (2,3,7,8-T4CDD or 2,3,7,8-T4CDF) to greater than 10 in the case of some higher chlorinated PCDDs and PCDFs. Half-lives of PCDDs and PCDFs were very different for the various 2,3,7,8-substituted congeners. For the most toxic compound (2,3,7,8-T4CDD) a t/2 of about 8 weeks in hepatic tissue and about 11 weeks in adipose tissue was found when calculated from data obtained later than 6 weeks after injection. For 2,3,7,8-T4CDD and 1,2,3,7,8-P5CDD the decreases in hepatic concentrations were much faster during the first 6 weeks after administration (t/2 of 4 weeks). This was apparently due to redistribution phenomena. Half-life increased with increasing degrees of chlorination. In some cases (e.g. OCDD, OCDF) no significant decrease in tissue concentrations could be observed after 28 weeks. The shortest t/2 was determined for 2,3,7,8-T4CDF: shorter than 6 days in hepatic tissue and about 10 days in adipose tissue. Calculation of the body burden of the non-2,3,7,8-substituted PCDDs/PCDFs 1 week after injection revealed that all groups of isomers were present at less than 5%. Consequences of these findings for the use of TCDD-toxic-equivalency factors are discussed and a change in strategy is suggested.

Absorption↗
PubMed1990

Synchronous adenocarcinomas of jejunum and cecum following transverse colon carcinoma. A case study.

A case of synchronous primary adenocarcinomas of the small and large bowel in a patient previously treated by transverse colectomy for cancerous polyps is presented. These new primaries were incidental findings during surgery for suspected recurrence of colonic carcinoma. Primary tumors of the small bowel are rare, and the diagnosis of primary adenocarcinoma of small bowel in the presence of primary adenocarcinoma of large bowel requires a high degree of suspicion and may well modify the prognostic outcome if detected early.

Adenocarcinoma↗
PubMed1989

Anti-laminin receptor antibody targeting of liposomes with encapsulated doxorubicin to human breast cancer cells in vitro.

The tumor cell laminin receptor is a cell-surface protein that binds laminin with high affinity (Kd = 1.0 nM). The putative ligand-binding domain of the laminin receptor has been molecularly cloned and sequenced. In the present study, we used the predicted amino acid sequence of the laminin receptor to generate synthetic peptide antigens and produced immunoglobulin M (IgM) anti-laminin receptor monoclonal antibodies. The disulfide bond group of the IgM molecule was used to couple the antibodies to the surface of liposomes encapsulating doxorubicin. The anti-laminin receptor monoclonal antibodies coupled to the liposomes bound avidly to the surface of MDA-MB-435S (MDA-435) human breast carcinoma cells, which have high numbers of laminin receptors. These antibody-coupled liposomes exhibited a low degree of binding to Hs 578Bst (Hs 578) normal human breast epithelial cells, which express a low number of laminin receptors. Excess liposomes competed for the binding of unbound laminin to the tumor cell surface, and excess laminin competed for binding with the liposomes. Antibody-coupled liposomes encapsulating doxorubicin were specifically more efficient in inhibiting colony formation by MDA-435 cells in vitro than unbound doxorubicin or liposomes without anti-laminin receptor monoclonal antibodies. Unbound doxorubicin inhibited thymidine uptake by 10%-20% in both Hs 578 and MDA-435 cells, whereas the antibody-coupled liposomes encapsulating doxorubicin inhibited thymidine uptake by 90% in MDA-435 cells but only 15% in Hs 578 cells. Thus, use of anti-laminin receptor monoclonal antibodies coupled with liposomes encapsulating doxorubicin represents a new strategy for selective targeting of doxorubicin to carcinoma cells with exposed laminin receptors.

Antibodies, Monoclonal↗
PubMed1989

Absorption and tissue distribution of various polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs and PCDFs) in the rat.

A defined mixture of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs and PCDFs) was parenterally administered to rats and absorption and tissue distribution were measured: 1) Toluene/DMSO (1 + 2; v/v) proved to be a convenient vehicle for the subcutaneous administration of the various PCDDs and PCDFs. Seven days after application the rate of absorption was 90% of the administered dose or even higher for almost all of the PCDDs/PCDFs in the mixture. In a few cases only (e.g. OCDD) the rate was found to be 84-89%; 2) Seven days after subcutaneous administration all 2378-substituted congeners were found in the liver, whereas only a few non-2378-substituted congeners could be measured in minor quantities. The 2378-substituted congeners also predominated in adipose tissue; however, most of the non-2378-substituted congeners were also detected; 3) The amount deposited within the liver as percentage of the administered dose differed for the various 2378-substituted PCDDs and PCDFs, ranging from less than 10% for OCDD or 2378-T4CDF, and between 60 and close to 100% for 12378-P5CDD or the H6CDDs. Therefore, the concentration ratio (liver/adipose tissue) was also found to be very different, ranging from less than 3 in the case of 2378-T4CDD or 2378-T4CDF to greater than 40 in the case of 1234678-H7CDD, 23478-P5CDF, 123678-H6CDF, or 1234678-H7CDF; 4) Studies performed at the time period of ongoing absorption (13-14 h after injection) provided the first evidence that some of the non-2378-substituted congeners do reach substantial concentrations in hepatic tissue shortly after administration; 5) Subsequent to intraperitoneal injection of the same PCDD/PCDF mixture the concentrations within the liver were found to be almost identical with that found after subcutaneous injection. In contrast, much higher concentrations of the congeners were found in (abdominal) adipose tissue; 6) In the liver of untreated rats of the same strain no T4CDDs/T4CDFs or P5CDDs/P5CDFs were detectable under our experimental conditions.

Animals↗
PubMed1989

Elimination of various polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs and PCDFs) in rat faeces.

A defined mixture (of a composition characteristic of that present in incinerator fly ash) of polychlorinated dibenzo-p-dioxins and -furans (PCDDs and PCDFs) was subcutaneously administered to rats and the elimination of the unchanged congeners via faeces was measured. 1) All congeners administered could be found in faeces. 2) The rates of elimination via faeces were rather different for the different congeners. 3) The most toxic congeners, 2378-T4CDD and 12378-P5CDD, were present in unmetabolized form in faeces to less than 4% and less than 8% of the administered dose within the first week. Thus, parenteral administration clearly minimizes contamination of the animal quarters when compared with corresponding oral dosing. 4) The rate of unchanged elimination was apparently especially pronounced for the higher chlorinated PCDDs and PCDFs. The highest excretion rate was found for 1234678-H7CDD (up to 30% of administered dose). 5) No obvious differences were observed in the rates of elimination of the unchanged substances via faeces of the 2378-substituted or the non-2378-substituted isomers.

Animals↗
PubMed1989

Synchronous adenocarcinoma and carcinoid of the uterine cervix: immunohistochemical study of a case and review of literature.

Mixed neoplasms, adenocarcinoma and carcinoid, have been reported to occur in several areas of the body, including gastrointestinal tract, breast, prostate, lung, skin, and kidney. Mixed tumors of the uterine cervix are very rare. Their histogenesis, immunohistochemical profile, and prognosis are not well established. Here, we report a case of a 49-year-old female with infiltrating adenocarcinoma of the cervix within which was found a separate nodule of small cell endocrine carcinoma.

Adenocarcinoma↗
PubMed1988

Pharmacokinetics and biological activity of 2,3,7,8-tetrachlorodibenzo-p-dioxin. 1. Dose-dependent tissue distribution and induction of hepatic ethoxyresorufin O-deethylase in rats following a single injection.

Concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in rat liver and adipose tissue, and hepatic ethoxyresorufin O-deethylase (EROD) activity were studied subsequent to a single subcutaneous injection of TCDD. Two types of experiments were performed to study: (a) time-dependent changes following a single injection of 300 ng TCDD/kg body wt (points 1-4), and (b) dose-dependent changes measurable after 7 days following a single injection (points 5-7). 1. Absorption of TCDD following a single subcutaneous injection was about 90% after 3 days and 98% after 5 days. 2. Following a single dose of 300 ng TCDD/kg body wt peak concentrations were: liver (after 3 days): 4.7 +/- 0.9 ng/g wet wt, and adipose tissue (after 7 days): 0.82 +/- 0.07 ng/g wet wt. 3. T1/2 of TCDD in liver was 13.6 days over the total experimental period (from day 10 to 91 of the study), apparently with an initial faster phase: 11.5 days (from day 10 to 49), and a slower period at the end of the experiment: 16.9 days (from day 49 to 91); in adipose tissue the t1/2 was 24.5 days (from day 14 to 91 of the study). 4. Maximum induction of EROD in the liver was observed (14-fold at 300 ng TCDD/kg body wt) 3-7 days following the injection; the activity was decreased to about one third of the maximum 3 weeks after the injection; increase in total cytochrome P-450 at this dose was only about 1.4-fold at the induction maximum. 5. The ratio of the TCDD concentrations in liver and adipose tissue increased considerably between doses of 3 ng TCDD/kg body wt (ratio: about 0.74) and 3000 ng TCDD/kg body wt (ratio: about 7.7). 6. The extent of EROD induction in the liver increased dose dependently. A significant effect was first observed with a dose of 3 ng TCDD/kg body wt (activity about +32% above control activity). The corresponding tissue concentration was about 10 pg TCDD/g liver wet wt. 7. An almost perfect linear relationship exists (when using a double-log plot) between the hepatic TCDD concentration and the EROD activity for tissue concentrations ranging from 40 to 30,000 pg TCDD/g wet wt.

Adipose Tissue↗
PubMed1982

The in vitro synthesis and secretion of alkaline phosphatase from first trimester human decidua.

We studied the in vitro synthesis and secretion of alkaline phosphatase by human first trimester decidual tissue incubated in organ culture. Decidua synthesizes two different alkaline phosphatase isoenzymes; heat stable and heat labile. decidual tissue maintains a constant pool of alkaline phosphatases. The synthesis of alkaline phosphatase may be the driving force for its secretion. The de novo synthesis and secretion rate of alkaline phosphatases were also investigated. The higher specific radioactivities of the secreted enzymes than those found in the tissue may suggest that newly synthesized alkaline phosphatase is preferentially released. The intracellular distribution of the alkaline phosphatase isoenzymes was compared as well. The characteristics of the two isoenzymes are different in human decidua of maternal origin from those previously reported in the human placenta originating from embryonic stem cells.

Alkaline Phosphatase↗
PubMed1982

[Quantitative determination of regional cerebral circulation with Xe-133: lst experiences using this method in the clinic].

After injection of the radioactive noble gas Xe133 into the A. carotis interna, the regional blood flow in the brain is determined with a 10-channel measuring unit. From the first clinical evaluation of the findings in 35 patients, the following conclusions can be drawn: 1. In epileptics, a localised hyperaemia very probary indicates a latent increased convulsive activity. 2. The measurement of the cerebral blood flow does not yield a contribution to the diagnosis of the type of cerebral tumours. 3. As a consequence of mass shifting of space occupying processes particularly endangered brain sections, also remote from the focus proper, show a localised pathological hyperaemia (morbid "luxus perfusion"). 4. Of greatest importance is the method for clearing up of pathophysiological relations, the clearing up of questions in connection with the blood/brain barrier function, and for the indications for and estimation of the results of vascular-surgical interventions.

Brain↗
PubMed1981

[Diagnosis of brain abscesses by angiography and nuclear medicine methods].

In most cases, abscesses are formed otogenically or rhinogenically. The clinical symptoms may be uncharacteristic. The diagnosis is made by employing nuclear-medical and angiographic procedures. In 40 patients suspected of having a cerebral abscess, transfemoral cerebral angiography and in 14 cases gammaencephalography or cerebral scintigraphy was carried out. Angiographically, cerebral abscesses mostly appear as avascular growths while nuclear-medical or localised increase in the activity concentration suggests a pathological finding. The symptoms are uncharacteristic and can only be attributed to an abscess process in connection with clinical and paraclinical findings.

Adolescent↗
PubMed1975

[Brain tumor diagnosis using 3-detector-gamma-encephalography].

The probability of diagnosis of brain tumours by means of 3-detector-gamma-encephalography (Hg 197-Neohydrin) is higher than that of the scintigraphic procedures so far available. Above all, the diagnostic accuracy of foci with low storage rates and space-occupying processes of the infratentorial region is improved. The short duration of the examination allows the method to be applied as a screening test.

Brain Neoplasms↗