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Biomedical subjects

D Miron

Publications and source records attributed to D Miron.

At least 55 records · Page 3Linked to original sources
PubMed1995

The lysine-dependent stimulation of lysine catabolism in tobacco seed requires calcium and protein phosphorylation.

The accumulation of free lysine in tobacco seed triggers the stimulation of lysine-ketoglutarate reductase, an enzyme that acts in lysine catabolism. The mechanism of lysine-ketoglutarate reductase stimulation was studied in two different systems: (1) developing seeds of wild-type plants in which the low basal lysine-ketoglutarate reductase activity can be stimulated by the exogenous addition of lysine; and (2) developing seeds of transgenic tobacco plants expressing a bacterial dihydrodipicolinate synthase in which lysine-ketoglutarate reductase activity is stimulated by endogenous lysine overproduction. In both systems, the stimulation of lysine-ketoglutarate reductase activity was significantly reduced when treated with the Ca2+ chelator EGTA. Moreover, the inhibitory effect of EGTA was overcome by the addition of Ca2+ but not Mg2+, suggesting that the lysine-dependent activation of lysine-ketoglutarate reductase requires Ca2+. This was further confirmed by a significant stimulation of lysine-ketoglutarate reductase activity following the treatment of wild-type seeds with ionomycin (an ionophore that increases Ca2+ flow into the cytoplasm). In addition, treatment of wild-type seeds with the protein phosphatase inhibitor okadaic acid triggered a significant induction in lysine-ketoglutarate reductase activity, whereas treatment of the transgenic seeds with the protein kinase inhibitor K-252a caused a significant reduction in its activity. Thus, we conclude that the stimulation of lysine-ketoglutarate reductase activity by lysine in tobacco seed operates through an intracellular signaling cascade mediated by Ca2+ and protein phosphorylation.

Calcium↗
PubMed1993

[Aneurysmal bone cyst of a lumbar vertebra in a child].

An aneurysmal cyst of the 3rd lumbar vertebra was diagnosed in a 6-year-old girl. She presented with right loin pain and a palpable mass in the region of the second and third lumbar vertebrae. X-ray of the vertebrae, but not computerized tomography, was characteristic for the tumor. The diagnosis was confirmed by histologic examination. Aneurysmal cyst of the vertebra is rare in children.

Bone Cysts↗
PubMed1993

Infections following nail puncture wound of the foot: case reports and review of the literature.

Between July 1989 and August 1990, five children (four boys and one girl, age 10-14 years) were hospitalized due to foot infection following nail puncture wound. Symptoms and signs at presentation included cellulitis and deep tissue abscess in all five, fever in three, high erythrocyte sedimentation rate in four, and leukocytosis in two patients. Pseudomonas aeruginosa was grown in pus culture that was taken from all the children at presentation. In three children who were initially treated by local debridement and drainage followed by anti-pseudomonal agents, plantar Pseudomonas osteochondritis later developed. In two children extensive debridement of affected tissues and drainage of pus were performed followed by 2 weeks of parenteral anti-Pseudomonas antibiotics. No further complication occurred. The clinician should be aware that any complication of nail puncture wound of the foot may require surgery.

Abscess↗
PubMed1993

Seroprevalence of antibodies against Toxoplasma gondii among two rural populations in northern Israel.

The prevalence of antibodies against Toxoplasma gondii was measured in two rural populations in northern Israel--Jewish kibbutz members and Arab villagers. The respective prevalences in these two populations were 22.2% and 55.8% (P < 0.001). No correlation was found between the presence of antibodies and sex, occupation, contact with cats, a history of fever and/or lymphadenopathy, eye disease, abortions or delivery of children with congenital malformations. In contrast to Jewish children who were not found to have antibodies in the first decade of life, 20.5% of Arab children tested positive. A gradual increase in the prevalence of antibodies with age was seen in both groups, with the Jews reaching a prevalence of 42.6% at age 60+ and the Arabs reaching 74% at age 40. The difference between the two groups probably stems from different eating habits, namely ingestion of raw meat and unpasteurized milk and milk products.

Adolescent↗
PubMed1992

[Congenital rubella syndrome after maternal immunization].

A 2.5 year-old girl was found to have congenital rubella syndrome. She presented with microcephaly, mild developmental delay, partial sensorineural deafness and cerebellar atrophy. Blood titers of rubella hemagglutinin were 1/256 and 1/512 (exclusively IgG). She had not had rubella, nor had she been immunized against it. The mother had been immunized against rubella 4 years before her pregnancy with this girl and 2 years later blood hemagglutinin titers were 1/32 and 1/64. She was neither exposed to nor suffered from rubella during the pregnancy. Reinfection with rubella, extremely rare during pregnancy, may occur in women whose hemagglutinin titers are lower than 1/64. Rubella also occurs in women who have been immunized but whose titers, similarly, are lower than 1/64. In some of these women the disease is asymptomatic. In general, reinfection does not result in fetal injury, but cases have been described in which babies of mothers infected in pregnancy were born suffering from various degrees of congenital rubella syndrome.

Antibodies, Viral↗
PubMed1992

Once daily cefixime compared with twice daily trimethoprim/sulfamethoxazole for treatment of urinary tract infection in infants and children.

We conducted a randomized prospective multicenter study to compare the safety and efficacy of once daily oral cefixime (8 mg/kg) to twice daily oral trimethoprim/sulfamethoxazole (TMP/SMX) (8/40 mg/kg/day) for the treatment of acute urinary tract infection in children ages 6 months to 13 years. Seventy-six patients (38 in each group) were studied. Thirty-seven percent were younger than 3 years of age. Escherichia coli was the most common isolate in both groups (85%). Eighty-five percent of all Gram-negative organisms were susceptible to TMP/SMX and all were susceptible to cefixime. Seventy-two percent of all patients were febrile at the time of diagnosis. Both groups were treated for 7 to 10 days. Peripheral white blood cell counts, erythrocyte sedimentation rate, body temperature and urinalysis returned to normal at the same rate in both groups. No failures were observed and relapse occurred in 3 cases within the 4 weeks after treatment (2 in the cefixime group and one in the TMP/SMX group). Side effects were observed in 14% of the cefixime group and 16% of the TMP/SMX group and were all mild enough not to necessitate discontinuation of therapy. We conclude that the efficacy and safety of cefixime administered once daily compared favorably with TMP/SMX administered twice daily for acute uncomplicated urinary tract infection.

Administration, Oral↗
PubMed1991

Radionuclide blood pool scintigraphy in a child with intestinal arteriovenous malformation (juvenile angiodysplasia). A case report and review of the literature.

Arteriovenous (AV) malformation or angiodysplasia of the gastrointestinal tract is a very rare cause of bleeding in children. These lesions are congenital anomalies and thought to be of hamartomatous origin. We report on a 4-year-old child with an AV malformation of the distal ileum treated by local resection. A brief review of the relevant literature is included. The importance of radionuclide blood pool scanning in the evaluation of these patients is emphasized.

Arteriovenous Malformations↗
PubMed1991

Calves as a source of an outbreak of cryptosporidiosis among young children in an agricultural closed community.

Transmission of Cryptosporidium from animals to humans, originating mainly in calves, had been suggested previously but has remained unproved. An outbreak of cryptosporidiosis that started among calves was transmitted to multiple pediatric groups living in close contact through one family who had close contact with the calves. Eleven of 19 (58%) infants and young children ages 10 to 15 months had Cryptosporidium compared with 3 of 27 (11%) of those ages 36 to 60 months and none of those ages 16 to 35 months. None of the asymptomatic children was positive for Cryptosporidium. These data emphasize that an extensive human to human transmission does not rule out the zoonotic nature of cryptosporidiosis.

Adult↗
PubMed1991

Sucrose Phosphate Synthase, Sucrose Synthase, and Invertase Activities in Developing Fruit of Lycopersicon esculentum Mill. and the Sucrose Accumulating Lycopersicon hirsutum Humb. and Bonpl.

The green-fruited Lycopersicon hirsutum Humb. and Bonpl. accumulated sucrose to concentrations of about 118 micromoles per gram fresh weight during the final stages of development. In comparison, Lycopersicon esculentum Mill. cultivars contained less than 15 micromoles per gram fresh weight of sucrose at the ripe stage. Glucose and fructose levels remained relatively constant throughout development in L. hirsutum at 22 to 50 micromoles per gram fresh weight each. Starch content was low even at early stages of development, and declined further with development. Soluble acid invertase (EC 3.2. 1.26) activity declined concomitant with the rise in sucrose content. Acid invertase activity, which was solubilized in 1 molar NaCl (presumably cell-wall bound), remained constant throughout development (about 3 micromoles of reducing sugars (per gram fresh weight) per hour. Sucrose phosphate synthase (EC 2.4.1.14) activity was present at about 5 micromoles of sucrose (per gram fresh weight) per hour even at early stages of development, and increased sharply to about 40 micromoles of sucrose (per gram fresh weight) per hour at the final stages of development studied, parallel to the rise in sucrose content. In comparison, sucrose phosphate synthase activity in L. esculentum remained low throughout development. The possible roles of the sucrose metabolizing enzymes in determining sucrose accumulation are discussed.

Journal Article↗
PubMed1990

[Cryptosporidiosis in children].

During January through June 1988, oocysts of Cryptosporidium were identified in fecal samples of 83 (7.7%) of 1073 children who presented with acute gastroenteritis. Other intestinal pathogens were less common: Salmonella 4.2%, E. coli 1.9%, Shigella 2.6% and Campylobacter jejuni 5.0%. Cryptosporidiosis (C) was more common under the age of 5 years than over (8.4% vs 1.8%, respectively, p less than 0.01). In 6 (7.2%) children with C, another stool pathogen was found. Frequent signs of C were diarrhea (85.4%), vomiting (36.3%) and fever (32.7%). Although no anticryptosporidial treatment was given, most children recovered within 5-9 days, but 6 had to be hospitalized: 4 were dehydrated and 5 had electrolyte imbalance. Repeated examination showed persistence of oocysts in the stools for up to 19 days. We conclude that C is a significant cause of gastroenteritis in Israeli children under the age of 5 years which occasionally requires hospitalization. We therefore recommend routine examination for C in cases of acute gastroenteritis.

Animals↗
PubMed1987

Sensory perception during movement in man.

The ability of subjects to perceive innocuous stimuli in the presence and absence of movement was evaluated using electrical stimulation of the skin. The subjective intensity of suprathreshold stimuli was unchanged during movement. Discrimination of small differences in the intensity of suprathreshold stimuli (difference thresholds) was also not altered by movement while, in the same subjects, detection thresholds were increased during movement of the stimulated arm. These results suggest that the elevation of detection thresholds during movement can be explained by masking. Both active and passive movement of the stimulated limb increased detection thresholds, with active movement having a slightly greater and more consistent effect than passive movement. Thus, both central and peripheral feedback factors appear to play a role in diminishing one's ability to detect weak stimuli during movement. Attention was also shown to influence performance of the detection task.

Electric Stimulation↗
PubMed1987

Sacroiliitis as a sole manifestation of Brucella melitensis infection in a child.

A case of a 12-year-old boy with sacroiliitis documented by positive Tc-99m MDP and Ga-67 scans is described. Isolation of brucella melitensis from the blood and bone marrow established the diagnosis. He responded promptly to docycycline therapy. Throughout the course of his disease this boy had neither fever nor other signs of brucellosis, and x-ray was normal.

Arthritis, Infectious↗
PubMed1984

Whole-saliva secretion rates in old and young healthy subjects.

Resting and stimulated whole-saliva secretion rates were compared in old and young healthy volunteers. The stimulated secretion rate was similar in both age groups, while the resting flow rate was significantly lower in the old females and males as compared with rates in the young.

Adult↗