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Biomedical subjects

M Karp

Publications and source records attributed to M Karp.

At least 145 records · Page 8Linked to original sources
PubMedDate not supplied

Detection of tetracyclines with luminescent bacterial strains.

The performance of two bioluminescent Escherichia coli K-12 strains for the specific detection of the tetracycline family of antimicrobial agents was compared, and the analytical applicability of one of the strains was preliminarily evaluated. One sensor plasmid contained the bacterial luciferase operon of Photorhabdus luminescens under the control of the tetracycline-responsive element from transposon Tn10 (15). An analogous plasmid construction with firefly (Photinus pyralis) luciferase reporter gene was constructed, and these two divergent tetracycline-inducible light-emitting systems were compared for their suitability for the qualitative detection of tetracyclines. Both sensor strains behaved in a similar manner kinetically, and the most sensitive tetracycline response for both sensor strains was achieved in 90-120 min by performing the assay at 37 degrees C. The sensor strain containing the bacterial luciferase operon responded slightly more sensitively to different tetracyclines than the strain containing firefly luciferase gene. The sensor bacteria retained their inducibility in lyophilization, and freeze-dried cells detected tetracyclines as sensitively as freshly cultivated sensor cells. The preliminary results from the analysis of tetracycline-spiked pork serum samples indicated that these sensor bacteria could be used to screen veterinary samples for tetracycline residues in real-time.

Animals↗
PubMedDate not supplied

Comparison of one daily injection of NPH and crystalline PZI insulins on urinary glucose in diabetic children.

Two one-injection insulin regimens--a combination of intermediate-action NPH insulin with regular insulin and a combination of long-acting PZI insulin with regular insulin, all of porcine origin and manufactured by Nordisk Insulin Laboratories--were compared to a group of 10 juvenile diabetics, each child serving as his own control. The results of thrice daily urine tests were recorded for periods of 3 months during each regimen and the incidence of glucosuria of less than 1% constituted the index used for metabolic control. Although the total insulin dose was almost the same with both schemes, it was found that less glucose was excreted during the night and early morning with the PZI regimen than the NPH regimen, indicating that a single injection of NPH is insufficient for good diabetic control.

Adolescent↗
PubMedDate not supplied

Psycho-social aspects of children and adolescents with diabetes.

The diagnosis of diabetes mellitus, a life-long disease with many possible complications, has a dramatic impact upon the entire family, precipitating a state of "shock". The psychological problems in diabetes should be divided in 3 periods: at diagnosis (other diseases or tension existing in the family and not related to diabetes, socio-economic state); initial adaptation period (acceptance to be "different", adjustment to rules of control such as daily injection of insulin, self blood glucose monitoring or urine testing, changing of nutritional habits, etc.), and long term coping (self-image, family dynamics, social activities, school achievements, vocational rehabilitation and continuing compliance. Counselling of the psychological problems is an ongoing need and is best delivered when the treating team included psychologists and social workers.

Adolescent↗
PubMedDate not supplied

Short- and long-range complications in offspring of diabetic mothers.

The perinatal mortality rate of infants of diabetic mothers (IDMs) has declined dramatically from 250 per 1000 live births in the 1960s to a near-normal 20 per 1000 live births in the 1980s. Five to 8% of all IDMs suffer from major congenital malformations, and it is the latter that are responsible for 50% of these perinatal deaths. It has been shown that tight glycemic control prior to conception and during pregnancy can prevent an excess rate of congenital malformations, fetal macrosomia, birth trauma, and neonatal respiratory distress syndrome. We briefly review the short- and long-range complications that occur in offspring of diabetic mothers (ODMs) from gestation through young adulthood. Short-term neonatal complications, such as hypoglycemia, hypocalcemia, hypomagnesemia, hyperbilirubinemia, and polycythemia, are related mainly to fetal hyperinsulinemia, hypoxemia, and prematurity. They are readily controllable within the setup of modern neonatal intensive care units. Long-range complications include an increased rate of childhood and adolescent obesity, impaired glucose tolerance or diabetes mellitus, and subtle neuropsychological dysfunctions. These may be related to the severity of the maternal hyperglycemia during pregnancy, the consequent fetal hyperinsulinemia, and third trimester maternal lipid metabolism disturbances. Today we have at hand the knowledge and tools to properly treat both pregestational and gestational diabetes. Increased education of the general practitioner and the target population regarding early referral of pregestational diabetic mothers and the implementation of screening programs for gestational diabetes will further reduce diabetic pregnancy-related morbidity.

Adolescent↗
PubMedDate not supplied

In vitro enzymatic biotinylation of recombinant fab fragments through a peptide acceptor tail.

We describe the site-specific enzymatic biotinylation of recombinant anti-estradiol Fab fragments through a 13 amino acid acceptor peptide translationally fused to the C-terminus of the Fd chain. The Fab-peptide fusion proteins were secreted to the periplasm of Escherichia coli, purified, and biotinylated in vitro using biotin ligase, biotin, and ATP. The E. coli biotin ligase (the BirA protein) was produced as a novel N-terminal fusion protein with glutathione S-transferase (GST) and purified in one step from bacterial cell lysate using a Glutathione Sepharose affinity column. The purified fusion protein worked as such (without cleavage of the GST part) for the in vitro biotinylation of the Fab fragments. After the removal of nonbiotinylated Fab fragments by monomeric avidin chromatography, the overall yield of biotinylated Fab was 40%. The site-specifically biotinylated Fab fragments (BioFab) were tested in streptavidin-coated microtitration wells, to which they were shown to bind linearly with respect to the amount of BioFab added, specifically as indicated by biotin inhibition, and tightly with a half-life of several days. Moreover, the enzymatic BioFab exhibited uniform antigen binding affinity unlike the same recombinant Fab fragments biotinylated through random chemical conjugation to surface lysines. Finally, the BioFab demonstrated its potential as a well-behaving immunoassay reagent in a model competitive assay for estradiol.

Artificial Gene Fusion↗
PubMedDate not supplied

Cardiac denervation and other multisystem manifestations caused by isolated autonomic neuropathy in a young diabetic patient.

A young, diabetic woman suffering from fainting spells, vomiting, and diarrhea is described. Extensive investigations showed total cardiac denervation, orthostatic hypotension, and disturbances in the the pupillary and sudomotor functions, as well as impairment of glucagon secretion during hypoglycemia. These disturbances were found to be caused by autonomic neuropathy. No signs of peripheral neuropathy could be detected. To the best of our knowledge this is the second case of total cardiac denervation due to diabetic neuropathy described in the literature.

Adult↗
PubMedDate not supplied

A multidisciplinary, comprehensive, ambulatory treatment scheme for diabetes mellitus in children.

A study has been carried out on 262 children with juvenile diabetes and their parents, treated up to 10 yr on an ambulatory basis by a multidisciplinary team composed of pediatric endocrinologist, nurse, dietitian, psychologist, and social worker. Comparison of the findings with those of a study performed before inception of the Counselling Center for Juvenile Diabetics revealed the following positive influences: the degree of control attained was both higher and sustained with greater regularity; there were fewer complications with no episodes of coma, brittle diabetes, or severe ketoacidosis and almost no need for hospitalization; the attitude of the affected child, his parents, and his teachers was found to be considerably improved; there was better understanding of the nature of the disease and its requirements; the child's motivation to maintain the diabetic regimen was greater and conflicts within the family circle were markedly reduced; the child's self-concept was much higher; and both scholastic achievements and social adjustment were greater. We concluded that psychological stability is a basic factor in the control of diabetes, and the value of the multidisciplinary approach in the treatment of this chronic disease is indicated.

Ambulatory Care↗
PubMedDate not supplied

Crisis intervention program in newly diagnosed diabetic children.

A group of 223 insulin-dependent diabetic patients, aged 7-24 yr, who had been under the regular care of our clinic up to 15 yr, were rated by two independent judges on a two-level scale of adjustment and maladjustment. The patients were divided into two groups. Group A (N = 107) comprised those who had been under care from diagnosis of the disease and had been subjected to the special crisis intervention program offered to every family upon referral of a newly diagnosed patient. Group B (N = 116) comprised patients who were diagnosed and treated initially in a clinic that had no crisis intervention program. Significant differences between the two groups were found in respect to three of the four aspects studied, i.e., compliance, familial relationships, and sociability, with group A showing a better adjustment than group B. There was no significant difference in the fourth aspect studied, i.e., school achievement and work performance. It was found that it took three times the effort, i.e., the time invested in counseling and psychotherapeutic measures, to bring group B to a good level of adjustment than it did to achieve similar results with group A. It is suggested that the initial period after diagnosis of diabetes in a child should be considered a period of crisis, requiring special multidisciplinary services to reduce future psychosocial maladjustments and improve compliance.

Adolescent↗
PubMedDate not supplied

The incidence of insulin-dependent diabetes mellitus in Israeli children and adolescents 0-20 years of age: a retrospective study, 1975-1980.

A survey of the entire population of Israel revealed 392 newly diagnosed type I diabetic children and adolescents aged 0-20 for the period of 1975-80. The mean annual age specific incidence of type I (insulin-dependent) diabetes mellitus was 3.8/10(5) for the age group 0-14 yr and 4.2/10(5) for the age group 0-20 yr. The incidence among the Jews of Ashkenazi origin was 6.8 X 10(5) and that for Jews of non-Ashkenazi origin was 4.3 X 10(5), whereas that for the Arabs was 1.2 X 10(5). The overall incidence is lower than that reported for similar populations in most European countries, the USA, Canada, and New Zealand; similar to that reported for Arabs in Kuwait; and higher than only that found in Japan. The relative importance of environmental and genetic factors in the interpopulation differences in incidence of type I diabetes remains to be established.

Adolescent↗
PubMedDate not supplied

Studies on kininogen bioassay in human and rat plasma by means of trypsin and guinea pig ileum.

We studied further plasma kininogen bioassay, which is based on the cleavage of bradykinin from kininogen by trypsin and on bradykinin assay by guinea pig ileum. Bradykinin-like activities released from human and rat plasma in incubation did not reach constant levels at any trypsin concentrations from 200 to 2.500 micrograms/ml of plasma. With high trypsin concentrations bradykinin activity released, like the spontaneous formation of bioactivity when incubation is performed without trypsin, may be partly due to other bioactive materials than bradykinin. On the other hand, with trypsin concentration less than 500 micrograms/ml of plasma the formation of bradykinin from human plasma may be incomplete if the substrate concentration is increased. The sensitivity of guinea pig ileum to bradykinin in Tyrode medium is highest near the pH 7, while the response to unspecific bioactive material produced by trypsin rises when pH increases from 7 to 8. The temperature of Tyrode medium bath does not seem to be very critical. Though the method described here gives no absolute activities, in stable conditions we can obtain well comparable results on different kininogen concentrations in human and rat plasma.

Animals↗