Evaluation of maternal plasma creatine kinase activity as a marker of abnormal early pregnancy

We have tested the value of maternal plasma creatine kinase activity for diagnosing ectopic pregnancies obtained after in-vitro fertilization and embryo transfer. Plasma creatine kinase was assayed in 57 patients: 20 normal, 23 miscarriages and 14 ectopic pregnancies, for a total of 240 samples. All values were in the lower part of the normal range except only one in a miscarrying patient. A statistically significant difference was observed for a cut-off value of 45 IU/l between normal and ectopic pregnancies. However, for this cut-off point, the measurement of plasma creatine kinase activity had a sensitivity of 0.50 and a specificity of 0.76 for the diagnosis of ectopic pregnancy. The positive predictive value was 0.69. Creatine kinase activity measurements are thus of no practical value in this particular population, in which an early and specific marker of ectopic implantation would be of paramount interest. The association of human chorionic gonadotrophin (HCG) determinations and ultrasound scanning of the pelvis still remain the best paraclinical support for an early diagnosis of ectopic implantation.      

Collagen type IV: major component of basement membranes. Current knowledge

The collagen family represents the most abundant protein in animals. Type IV collagen ([alpha 1 (IV)]2 alpha 2 (IV)) differs from the other types in several respects and particularly in its distribution, being strictly limited to the basement membranes. Alterations in the structure and functions of basement membranes are observed in a number of diseases, such as tumoral angiogenesis and diabetic nephropathy. This article reviews current structural and pathophysiological knowledge concerning type IV collagen.     

Beta-blockers for the treatment of problematic hemangiomas

OBJECTIVE:

To examine treatment indications, efficacy and side effects of oral beta-blockers for the treatment of problematic hemangiomas.

METHODS:

A retrospective review of patients with hemangiomas presenting to the Alberta Children’s Hospital Vascular Birthmark Clinic (Calgary, Alberta) between 2009 and 2011 was conducted. The subset of patients treated with oral beta-blockers was further characterized, investigating indication for treatment, response to treatment, time to resolution of indication, duration of treatment, occurrence of rebound growth and side effects of therapy.

RESULTS:

Between 2009 and 2011, 311 new patients with hemangiomas were seen, of whom 105 were treated with oral beta-blockers. Forty-five patients completed beta-blocker treatment while the remainder continue to receive therapy. Indications for treatment were either functional concerns (68.6%) or disfigurement (31.4%). Functional concerns included ulceration (29.5%), periocular location with potential for visual interference (28.6%), airway interference (4.8%), PHACES syndrome (3.8%), auditory interference (0.95%) and visceral location with congestive heart failure (0.95%). The median age at beta-blocker initiation was 3.3 months; median duration of therapy was 10.6 months; and median maximal treatment dose was 1.5 mg/kg/day for propranolol and 1.6 mg/kg/day for atenolol. Ninety-nine patients (94.3%) responded to therapy with size reduction, colour changes, softened texture and/or healing of ulceration. Rebound growth requiring an additional course of therapy was observed in 23 patients. Side effects from beta-blockers included cool extremities (26.7%), irritability (17.1%), lower gastrointestinal upset (14.3%), emesis (11.4%), hypotension (10.5%), poor feeding (7.6%), lethargy (4.8%), bronchospasm (0.95%) and rash (0.95%). Side effects did not result in complete discontinuation of beta-blocker treatment in any case; however, they prompted a switch to a different beta-blocker preparation in some cases. Resolution of the primary indication, requiring a median time of three months, occurred in 87 individuals (82.9%).

CONCLUSIONS:

Treatment of infantile hemangiomas with oral beta-blocker therapy is highly effective and well tolerated, with more than 94% of patients demonstrating a response to treatment and 90% showing resolution of the primary functional indication for treatment.     

N-nitroso compounds, nitrite and pH in human fasting gastric juice

Total N-nitroso compounds, ethyl acetate-extractable N-nitrosocompounds and nitrite were measured in 146 samples of fastinggastric juice to investigate their relationship with pH. A positivecorrelation was found between pH and extractable N-nitroso compounds(r = 0.206, P < 0.02), whereas total N-nitroso compoundswere pH-independent It was inferred that pre-cancerous conditionsassociated with high gastric pH may be produced by an increasein the extractable N-nitroso compounds, which constitue onlya small fraction of the total gastric N-nitroso compounds.     

Fate of enterally administered ornithine in healthy animals: interactions with alpha-ketoglutarate

In order to improve our understanding of the metabolic interactions between alpha-ketoglutarate (alpha KG) and ornithine (Orn), which constitute the two parts of ornithine alpha-ketoglutarate (OKG) used as an adjuvant in enteral nutrition, we have investigated the plasma appearance and tissue distribution (qualitative and quantitative) of enterally administered 14C-Orn and 14C-alpha KG in healthy mice and rats. The influence of unlabelled alpha KG or Orn on 14C-Orn or 14C-alpha KG metabolism, respectively, was also studied. Unlabelled alpha KG was able to reduce strongly the rate of intestinal absorption of 14C-Orn, whereas the inverse was not true. This alpha KG-induced loss in plasma radioactivity after a load of Orn was associated with a decrease of radioactivity in tissue with no modification of the qualitative distribution in organs. In this study, a direct interaction between alpha KG and Orn was demonstrated at the intestinal level. The mechanisms involved in this phenomenon probably involve the regulation of metabolic conversions among alpha KG, Glu, pyrroline-5-carboxylate, and Orn. This is of importance in the therapeutic use of ornithine salts in clinical nutrition.     

Modulation of insulin action on 2-deoxyglucose uptake by chloroquine in chick embryo fibroblasts

Blazar et al. recently found that chloroquine therapy decreased intravenous insulin requirements in a case of extreme insulin resistance. However, no relationship has been shown to exist between insulin degradation and the stimulation of glucose uptake. In this study we investigate the action of insulin on glucose uptake by the ability of this hormone to stimulate 2-deoxyglucose. The effect on alpha-aminoisobutyrate uptake, which is known to be insulin sensitive, is also investigated. Cell-associated 125I-labeled insulin and trichloroacetic acid-soluble and -precipitable substances were measured in parallel. Chloroquine increased insulin-stimulated uptake of 2-deoxyglucose and alpha-aminoisobutyrate. Three hours were required for this effect to appear, and it did not depend on DNA synthesis. Chloroquine also increased cell-associated insulin and slightly decreased the percentage of trichloroacetic acid-soluble products. Methylamine affected neither nutrient uptake processes nor insulin binding and degradation; however, it did abolish the effect of chloroquine on these parameters. These data suggest that in chick embryo fibroblasts a relationship may exist between the increase in undegraded cell-associated insulin and the ability of the hormone to stimulate sugar and amino acid uptake.     

Characteristics of a donor population in western Venezuela

To determine the characteristics of blood donors in western Venezuela, we collected data from 1983 to 1985 on 31,320 volunteer donors at the Blood Bank of the State of Zulia in Maracaibo. Fifty-nine percent of the donors were blood group O, 30 percent were group A, 9 percent were group B, and 2 percent were group AB. Most of the donors (93%) were Rh positive. One percent of donors had positive reactions to hepatitis B surface antigen, 3.15 percent for syphilis, 1.43 percent for antibodies to Trypanosoma cruzi, and 0.32 percent to human immunodeficiency virus antibodies. About one-half of the donors were between 18 and 30 years old, and only 10 percent were women. To determine if iron deficiency anemia was a cause for the small size of the female donor pool, we measured serum ferritin in 50 first-time female donors. Ten of these (20%) had serum ferritin values below normal, and the distribution of serum ferritin levels of all 50 was very similar to that reported for frequent donors in Europe and the United States, with a clustering of ferritin values between 10 and 70 ng per ml. The data indicate that blood donors in western Venezuela are markedly different from those in the United States and that iron supplementation may be indicated for female Venezuelan donors.     

Cultured fibroblasts as a suitable model for studying insulin action on glucose uptake

The action of insulin on glucose uptake in human or animal cultured fibroblasts has been subject of several studies. The results obtained vary greatly from one study to the next with regard to the response to the hormone but this should be related to the various and somewhat questionable experimental protocols. In general, it would appear that fibroblasts are less sensitive to insulin than adipocytes in the stimulation of sugar transport. This might be due to a smaller number of insulin receptors in fibroblasts or to a poor affinity for the hormone. In addition, as the response to insulin depends greatly on culture conditions (confluency, serum or glucose starvation ...) this cellular model must be used carefully in studies concerning insulin action on glucose uptake.