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Biomedical subjects

C Hershko

Publications and source records attributed to C Hershko.

At least 127 records · Page 7Linked to original sources

Recurrent Neisseria meningitidis bacteremia. Association with deficiency of the eighth component of complement (C8) in a Sephardic Jewish family.

A 24-year-old man had repeated episodes of meningococcal meningitis. Selective deficiency of the eighth component of complement (C8) was demonstrated in the patient, his twin brother, and in one of five siblings. As the parents were first cousins of normal phenotype, this pattern is suggestive of an autosomal recessive heredity. The present report brings the total number of patients given the diagnosis of C8 deficiency to 14, and calls attention to the existence of this condition in Jews of Sephardic (Mediterranean) origin.

Adult↗

Causes of iron deficiency anemia in an adult inpatient population. Effect of diagnostic workup on etiologic distribution.

The causes of iron deficiency anemia in a population of adults admitted to two Jerusalem hospitals within a period of 7 years were examined. About one half of the 262 patients with iron deficiency anemia were over 70 years old. The ratio of males to females exclusive of young females with menorrhagia was 1:1.8. Despite the combined use of various diagnostic procedures, no definite cause of iron deficiency anemia could be established in 34% of patients. Benign gastrointestinal lesions were found in about one half of the cases in both hospitals. The prevalence of GI neoplasms in hospital B with a more intensive use of endoscopic procedures was significantly higher than in hospital A (18% vs 5%, p less than 0.001). The relative usefulness of barium contrast vs endoscopic studies is illustrated by the fact that 22 diagnoses established by endoscopy were missed by barium studies, whereas only 2 of those established by barium studies were not visualized by endoscopy. A particularly high risk group were anemic males aged 50 to 69 years in whom the prevalence of GI neoplasms was 30%. These data indicate that reliance on traditional contrast radioscopy may result in misdiagnosis of a high proportion of gastrointestinal neoplasms.

Adolescent↗

Development and evaluation of the improved iron chelating agents EHPG, HBED and their dimethyl esters.

The phenolic EDTA analogues ethylenediamine-N,N'-bis-(2- hydroxyphenylglycine ) ( EHPG ), N,N'-bis(2-hydroxybenzyl)-ethylenediamine diacetic acid ( HBED ), and their respective dimethyl esters ( dimethylEHPG and dimethylHBED ) were studied in hypertransfused rats. Radioiron bound to these compounds was cleared mainly by the liver and excreted in the bile. After a single 40 mg i.m. injection, the percentage of radioiron removed from 59Fe-ferritin-labelled hepatocytes and excreted in the bile was 4% in untreated controls, 24% for desferral , 42% for dimethylEHPG , 58% for EHPG , 63% for HBED , and 80% for dimethylHBED . DimethylHBED combines oral effectiveness with superior chelating ability, selective hepatocellular action, and low apparent toxicity. It may represent a significant advance in the development of new iron chelating drugs.

Administration, Oral↗

Lead poisoning in a West Bank Arab Village.

Eleven patients from the West Bank village of Es-Sawiyeh were admitted with lead poisoning to two Jerusalem hospitals between November 1982 and January 1983. They all belonged to several households of a single large family. Colicky abdominal pains were present in five patients, weakness in four, behavioral changes ranging from irritability to frank psychosis in four, and paralysis in one. Anemia of various degrees was seen in all patients. Basophilic stippling and reticulocytosis were encountered in all patients with moderate to severe anemia. Therapy with edetate disodium calcium and penicillamine resulted in clinical improvement in all patients. A preliminary survey of 270 subjects in the same village disclosed 84 subjects with abnormally elevated blood lead levels, 17 of whom had grade IV lead burden according to the Centers for Disease Control risk classification. Contamination of homemade flour by lead used for stabilizing the metal parts of stone mills was the source of poisoning. As the method of milling in many West Bank villages is similar, these findings may have important implications to the well being of a large section of the rural West Bank population.

Adolescent↗

Iron depletion and blood lead levels in a population with endemic lead poisoning.

The effect of iron depletion on blood lead levels was studied in a group of 558 schoolchildren aged 10 to 18 residing in two West Bank Arab villages with a high prevalence of excessive lead exposure and clinical lead poisoning. Thirty percent of the subjects studied had whole-blood lead levels greater than 30 micrograms/dl, and 45% had whole-blood zinc erythrocyte protoporphyrin greater than 50 micrograms/dl. The percentage of abnormal blood lead values in subjects with normal serum ferritin and transferrin saturation (31%) was similar to that in subjects with one (28%) or two (25%) abnormal iron parameters. Likewise, there was no correlation between serum ferritin and blood lead levels in individual patients (r = 0.059). Normal distribution plots and mean levels of blood lead (27.3 micrograms/dl) were identical in the iron-deficient and iron-replete groups. These findings indicate that iron depletion does not affect blood lead levels and suggest that in man, unlike in experimental animals, iron depletion may not have a significant effect on lead absorption.

Adolescent↗

Phenolic ethylenediamine derivatives: a study of orally effective iron chelators.

Of 35 potential iron chelators screened for in vivo activity in rats, a group of phenolic compounds with excellent chelating properties were identified. These included N,N'-ethylene-bis(o-hydroxyphenylglycine) (EHPG), N,N'-Bis(o-hydroxybenzyl)-ethylenediamine diacetic acid (HBED), and their respective dimethyl esters (dmEHPG and dmHBED). All four phenolic compounds produced a marked increase in the fecal excretion of hepatocellular radioiron. This amounted to 42% of total body radioactivity with dmEHPG, 58% with EHPG, 63% with HBED, and 80% with dmHBED after a single injection of 40 mg/animal. At a dose of 5 mg/animal, EHPG, HBED, and dmHBED were 9, 12, and 15 times more potent, respectively, than deferoxamine. Both dimethyl esters showed significant oral activity; oral dmEHPG retained 1/3 and dmHBED retained 2/3 of the effect of the same dose given by intramuscular injection. The ester dmHBED combines oral effectiveness with superior chelating ability, selective hepatocellular action, and low apparent toxicity. It may represent a significant advance in the development of new iron chelating drugs.

Administration, Oral↗

[Lead poisoning].

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Adolescent↗

Syntheses of iron bis(pyridoxal isonicotinoylhydrazone)s and the in vivo iron-removal properties of some pyridoxal derivatives.

Pyridoxal isonicotinoylhydrazone (PINH; 1) and its isomeric O-acetates (E and Z) were synthesized and complexed with ferrous ions to afford the hitherto unisolated chelates iron(II) bis(pyridoxal isonicotinoylhydrazone)s (11) and iron(II) bis(O-acetylpyridoxal isonicotinoylhydrazone)s (12). The analytical and spectroscopic data of the new coordination compounds are presented. In addition, a series of imino derivatives of pyridoxal of structures 2-3 and 5-10 have been prepared and tested in vivo as chelators of storage iron, and the cumulative net excretion of radioiron in urine and in feces was estimated. This study reestablishes that PINH is a potent iron chelator in vivo comparable in efficiency with parenteral desferrioxamine (DF) and indicates that it requires further attention.

Animals↗

The changing pattern of megaloblastic anemia: megaloblastic anemia in Israel.

The causes of megaloblastic anemia were studied in a survey of patients admitted to six Israeli hospitals over a period of 15 yr. Among the 203 patients identified, 69% had pernicious anemia, 12% had gastrointestinal disease, 9% had primary nutritional deficiency of whom only 1% were associated with pregnancy, and 7% had selective vitamin B12 malabsorption with albuminuria. Comparison with previously published surveys showed, that in contrast with earlier studies where primary nutritional deficiency was the cause of megaloblastic anemia in about 70% of cases and pernicious anemia in only 20%, in more recent studies the proportion of cases with primary nutritional anemia in general and those associated with pregnancy in particular was much lower. This is most probably the result of improved standards of living and a national program of preventive folate supplementation at maternity clinics. A potential hazard of such preventive programs is the aggravation of neurological complications in patients with undiagnosed vitamin B12 deficiency. Early recognition of pernicious anemia and other forms of selective B12 malabsorption is a new challenge created by the changing pattern of megaloblastic anemias.

Adolescent↗

Evaluation of iron status in patients on chronic hemodialysis: relative usefulness of bone marrow hemosiderin, serum ferritin, transferrin saturation, mean corpuscular volume and red cell protoporphyrin.

The diagnostic usefulness of bone marrow hemosiderin, serum ferritin, transferrin saturation, mean corpuscular volume (MCV) and red cell protoporphyrin (EPP) in the evaluation of iron status in patients on chronic hemodialysis was studied in 39 subjects. The correlation between serum ferritin and the number of transfusions received per month was slightly higher (r = 0.717; p less than 0.001) than the correlation between bone marrow hemosiderin and transfusions (r = 0.685; p less than 0.01). Serum ferritin was useful in identifying subjects with both increased or reduced iron stores. In contrast, transferrin saturation could only be used for indicating iron overload. MCV for indicating iron deficiency, and EPP was not useful in either case. The abnormal increase of EPP in chronic uremia has not been previously described. It is unrelated to iron deficiency and is most probably explained by the known reduction in red cell ferrochelatase activity associated with chronic uremia. Serum ferritin is clearly the most useful diagnostic aid for assessing iron stores in patients on chronic hemodialysis. Whether ferritin is also the best predictor of response to iron therapy, cannot be determined on the basis of the present data.

Adolescent↗

Transient methimazole-induced bone marrow aplasia: in vitro evidence for a humoral mechanism of bone marrow suppression.

A patient with methimazole-induced aplastic anemia is described. Despite severe pancytopenia and the complete disappearance of hemopoietic elements from the bone marrow, recovery of hemopoiesis has been observed within 14 days of discontinuing methimazole therapy. In vitro studies of CFU-C inhibition of peripheral mononuclear cells harvested in remission, were performed by incubation with autologous sera collected at earlier phases of the disease. These studies provide evidence in favor of a humoral, and most probably autoimmune mechanism as the cause of transient bone marrow aplasia.

Adult↗

Causes of agranulocytosis in a hospital population: identification of dipyrone as an important causative agent.

A population of patients with agranulocytosis admitted to a general hospital over a period of 12 yr was studied retrospectively in order to determine the causes of the disease. Of the 48 cases identified, 31 (65%) had drug-induced neutropenia, whereas 17 (35%) had chronic neutropenia unrelated to the use of drugs. Eight patients had an underlying hematological malignancy. Patients with agranulocytosis not induced by drugs more frequently had hepatomegaly, splenomegaly, enlarged lymph glands, or thrombocytopenia together with severe anemia. In contrast, drug-induced agranulocytosis was more severe, with a higher incidence of positive blood cultures, low cellularity of initial bone marrow aspirates, and a shorter duration of neutropenia. Dipyrone and methimazole were the drugs most commonly associated with agranulocytosis. Dipyrone was probably the causative agent in two of the seven drug-induced fatalities. In view of these findings, and those of several previous reports, it is proposed that the use of dipyrone in Israel be severely restricted or discontinued altogether.

Adolescent↗

A rapid and sensitive ELISA for serum ferritin employing a fluorogenic substrate.

A fluorescent enzyme-linked immunosorbent assay is described for the rapid measurement of serum ferritin. Increased sensitivity was achieved by using 4-methyl-umbelliferyl-beta-D-galactopyranoside as the substrate for beta-galactosidase coupled to the purified antiferritin antibody. Further enhancement of the specific antigen-antibody reaction was attained by the addition of 4% polyethylene glycol 6000 to the antiferritin-beta-galactosidase conjugate. The procedure is performed in microELISA plates. These modifications of the method permit the measurement of serum ferritin at concentrations ranging from 0.25 to 50 microgram/liter with a coefficient of variation of 8% or less. The entire procedure is performed at ambient temperature and is completed within one working day. The cost of the assay is less than 10% of the immunoradiometric assay for serum ferritin.

Animals↗

Reduced frequency of iron deficiency anaemia in sickle cell trait.

The prevalence and causes of anaemia among the inhabitants of a Southern Lebanese village were studied. Of the 317 patients examined 75, or 24% were found to be heterozygotes for Hb S. There was a reciprocal relation between the presence of sickle cell trait and of iron deficiency anaemia. The prevalence of iron deficiency anaemia defined as the coexistence of Hb below 13 g/dl in adult males and below 12 in adult females and children with two laboratory indicators of iron deficiency, was 10.3% in the normal population as against 1.3% in the sickle cell trait group (P less than 0.008). The reduced frequency of iron deficiency anaemia in sickle cell trait may be explained by increased iron absorption, or alternatively by reduced iron requirements and a lower risk of discrepancy between iron supply and demand. Because of the central role of iron in the function of a great number of enzymes and proteins, it is possible that protection against iron deficiency anaemia by the sickle cell trait may result in improved working capacity and a lower incidence of infections.

Adult↗