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Biomedical subjects

R Lisker

Publications and source records attributed to R Lisker.

At least 55 records · Page 3Linked to original sources
PubMed1982

Kinship coefficients and genetic distance among 23 Mexican Indian tribes.

Genetic distances (d) and kinship coefficients (f) of 23 Mexican Indian groups were obtained, based on the results of ABO, Rh, MN, Duffy and Diego blood group systems and serum haptoglobins. The results obtained did not correlate well with linguistic classification or geographical location and we conclude that the method used is not sensitive enough to correctly separate relatively similar groups which have different degrees of external admixture (with blacks and caucasians) and internal admixture (among themselves).

Blood Group Antigens↗
PubMed1981

Constitutive heterochromatin polymorphisms in patients with malignant diseases.

The frequency of constitutive heterochromatin heteromorphisms was assessed in peripheral blood cultures of 23 patients with various malignant diseases and in their respective controls, formed by cancer-free same sex siblings of the propositi. The results showed no significant differences between the cancer and the control groups, except for chromosome 1 in breast cancer, where polymorphisms were more frequent in the controls than in the patients. Our results do not support previous data reported by others, and although there are differences in the type of malignancies studied by us and them, we believe that our control group is a more appropriate one for this particular type of study.

Adult↗
PubMed1981

Peripheral motor neuropathy associated with autonomic dysfunction in two sisters: new hereditary syndrome?

We describe two sisters with distal, slowly progressive muscular weakness and hypotrophy since childhood, autonomic dysfunction characterized by profuse sweating, distal cyanosis related to cold weather, orthostatic hypotension, and esophageal achalasia. Nerve conduction velocity of several motor nerves was slow, and although no sensory abnormalities were present, sural nerve biopsy revealed severe nonspecific demyelination. No similar patients could be found in the literature and we therefore suggest the possibility that these individuals have a newly recognized hereditary syndrome.

Adult↗
PubMed1981

Symmetrical replication patterns and sex chromatin bodies formation of an idic(X)(p22.3::p22.3) chromosome.

The morphologic and staining characteristics of the sex chromatin bodies and the DNA replication patterns were studied in a patient with a 45,X/46,X,idic(X)(p22.3::p22.3) karyotype and in a normal woman. The analysis showed a relatively high frequency of bipartite Barr bodies as well as some variation of the distance, staining intensity, and size relationship between their halves. Regarding the DNA replication studies, in 71% of the cells the abnormal X chromosome showed a synchronous pattern, and in the remaining 29%, in which a slight asynchrony was present, an almost equal proportion of early and late functional and nonfunctional centric halves was observed. Furthermore, the atypical chromosome had a quite similar replication pattern to the late replicating X chromosome of the normal woman, suggesting that its sequence of DNA sythesis was not altered.

Child↗
PubMed1981

Clinical and endocrine spectrum in patients with the 45,X/46,XY karyotype.

Cytogenetic and endocrine studies were performed in five unrelated 45,X/46,XY individuals in an attempt to correlate them with their clinical expression and gonadal morphology. A lack of a consistent pattern between cytogenetic findings and phenotype was observed. Endocrine studies revealed a wide spectrum of hypothalamic, pituitary, and gonadal hormone production as assessed by the base line levels of LH, FSH, T, and delta 4-A and their responses to appropriate exogenous stimulation (LH-RH and HCG). An adequate correlation between endocrine findings with gonadal morphology and phenotype could be established; thus demonstrating that patients with this particular chromosome complement have a functional integrity of the gonadotropin hypothalamic pituitary activity modulated accordingly with the gonadal function of each particular case.

Adolescent↗
PubMed1981

Frequency and types of induced and spontaneous chromosome aberrations in relation to cell kinetics.

Induced and spontaneous structural chromosome aberrations (SCA) were studied in a child accidentally radiated with a high dose of 192Ir, and in three sibs with Fanconi's anemia, analyzing by separate first division metaphases (FDM) and second division metaphases (SDM). The results showed that the number of SCA, number of cells with aberrations, and SCA per cell were markedly higher in FDM in all patients. Furthermore, for some type of structural changes like dicentric chromosomes and chromatid interchanges, the differences were particularly striking. The importance of ascertaining FDM identified with proper techniques, for the study of the clastogenic effect of environmental agents and some aspects related to the differences in cytogenetic features found in diverse tissues in Fanconi's anemia are discussed.

Anemia, Aplastic↗
PubMed1980

Treatment of chronic portal-systemic encephalopathy with lactose in lactase-deficient patients.

A controlled cross-over clinical comparison of lactose (50 g twice a day) versus neomycin (3 g/day) plus milk of magnesia, was carried out in ten cirrhotic patients with chronic portal-systemic encephalopathy and documented lactase deficiency. Serial semiquantitative assessments were done including: mental state, asterixis, number connection test, electroencephalogram, and blood ammonia levels. No patient developed deep coma while ingesting either lactose or neomycin plus milk of magnesia. However, a significant improvement of mental state, asterixis, number connection tests, and electroencephalograms was evident during lactose therapy. apart from mild diarrhea and bloating, no severe side effects were noticeable during lactose treatment. Based on these results, we propose lactose as a valuable alternate treatment of portal-systemic encephalopathy in lactase-deficient populations.

Chronic Disease↗
PubMed1980

Double blind study of milk lactose intolerance in a group of rural and urban children.

Two-hundred forty rural and 101 urban children were studied in a double blind fashion to determine their clinical response to three types of milk. Each participant received in three different days, 250 ml of lactose free milk, regular milk, and lactose enriched milk. In the urban girls a control period in which no milk was given was included. In both study groups, lactose free milk was highly significantly better tolerated than the others. However, the frequency of subjects asymptomatic after its ingestion was much lower, particularly in the rural group, to that found previously in a group of adults of high socioeconomic status. It is thought that in the rural children, part of this phenomenon can be explained by intercurrent gastrointestinal infections. There also appears to be a "background" of gastrointestinal symptoms present in the children, which wrongly classifies them as symptomatic to milk ingestion. It is concluded that probably no less than 15% of children have gastrointestinal complaints after the ingestion of 250 ml of regular milk and that lactose hydrolyzed milk is highly significantly better tolerated than the others.

Adolescent↗
PubMed1980

Late-appearing Philadelphia chromosome in two patients with chronic myelogenous leukemia.

We describe two patients with typical myelogenous leukemia, who at the beginning of the disease lacked the Philadelphia chromosome in bone marrow cells, and 90 and 42 days later, respectively, its presence was shown in all cells analyzed from that tissue. These findings are compatible with the possibility that at least occasionally Ph1 occurs secondarily in already leukemic cells. The rapid change form Ph1- to Ph1+ CML in one of the patients (42 days), suggests the possibility that in addition to Ph1+ cells enjoying marked selective advantage, this change is induced simultaneously in multiple bone marrow cells.

Adult↗
PubMed1979

Cytogenetic and endocrine studies in a 45,X female subject with spontaneous sexual development.

Cytogenetic and endocrine evaluation of a postpubertal 45,X female subject with Turner's stigmas and spontaneous sexual development was performed. A 45,X chromosomal complement was found in the peripheral blood lymphocytes, bone marrow, and fibroblasts derived from skin and ovaries. Menarche, pubarche, and thelarche occurred at age 12; at age 16 she developed menstrual irregularities, with endometrial bleeding occurring every 60 to 90 days. The ovaries were normal in size, and histologic examination revealed a marked paucity of primordial follicles, increased collagenization, and absence of corpora albicans. Anovulatory cycles with moderately elevated levels of luteinizing hormone (LH) and low follicle-stimulating hormone (FSH) levels were observed. LH-releasing hormone pituitary stimulation induced a normal LH release with a very slight FSH increase. Administration of clomiphene citrate successfully induced a normal-length ovulatory cycle. Similarities in the hormonal situation of this patient and that seen in the Stein-Leventhal syndrome are pointed out.

Adolescent↗
PubMed1979

Gerodermia osteodysplastica hereditaria: report of three affected brothers and literature review.

Gerodermia osteodysplastica hereditaria was diagnosed in three Mexican brothers 6, 7, and 8 years old, respectively, who had the distinct facial appearance with sagging cheeks, premature wrinkling of the skin of face, abdomen, and dorsum of hands and feet; malocclusion, span greater than height; hyperextensibility; winging of the scapulae; stooped posture with kyphoscoliosis; protuberant abdomen; and pes planus. Radiologically they had generalized osteoplorosis, platyspondily due to multiple compression fractures, pseudoepiphyses of second metacarpals, and dislocated hips. Three other families with a total of 14 affected individuals have been reported. Inter- and intrafamilial variability can be recognized, particularly regarding the tendency to fractures, upper:lower segment ratio abnormalities, and results of skin biopsies, which have shown fragmentation of the elastic fibers in some cases (including the present family) and not in others. Although inheritance was considered to be X-linked recessive in the first reported family, an analysis of that pedigree together with those of the other reported families, including the present one, suggests that gerodermia osteodrysplastica is inherited in an autosomal recessive manner.

Abnormalities, Multiple↗
PubMed1979

Serum atypical pseudocholinesterase and leprosy.

The frequency of the serum atypical pseudochloinesterase variant was significantly higher (p less than 0.005) in a group of 115 lepromatous leprosy patients than in a comparison group of 133 healthy individuals. This finding corroborates the results obtained in the group of patients from India, and supports the contention that the serum atypical pseudocholinesterase is one of the possible genetic factors involved in susceptibility to leprosy.

Butyrylcholinesterase↗
PubMed1979

Variability between and within laboratories in the analysis of structural chromosomal abnormalities.

The frequency of structural chromosomal aberrations in two samples (AM and PM of the same day) from each of nine normal subjects, cultured in two different laboratories, was studied by six observers. The results were analyzed in order to determine the relative importance of inter- and intralaboratory factors in the variability of chromosomal abnormalities. In addition to the difference in the frequency of the abnormalities between the subjects studied, there were differences due to observers from different laboratories (P less than 0.01), as well as between laboratories (P less than 0.01). These results could be explained in part by insufficient agreement between observers from different laboratories and by differences in the quality of the method used.

Adult↗
PubMed1979

Complex segregation analysis of diabetes mellitus.

Complex segregation analysis was applied to a sample of 12,293 nuclear families each with at least 1 diabetic patient. The families were divided into two groups depending on the proband's treatment: insulin-dependent (IDG) and insulin-independent (IIG). Heterogeneity analysis has revealed a highly significant difference in the IIG group when families were divided into different mating types. The higher recurrence risk was found in the group with affected mothers. Also evidence for a major recessive gene was found in the IGG group, while it was not possible to distinguish between the hypothesis for absence of a major locus and absence of polygenic inheritance in the IDG group. Risks to develop the disease were calculated for a few typical situations.

Adolescent↗
PubMed1979

Frequency of sister chromatid exchanges in severe protein calorie malnutrition.

Nine children with severe protein calorie malnutrition were studied regarding the frequency of sister chromatid exchanges (SCE's) in peripheral blood lymphocytes. The results showed that there was no significant difference between the number of SCE's in the malnourished children as compared to an adequate control group. An interesting finding was that the proportion of 3rd or subsequent division metaphases found in the malnourished children, was higher and significantly different from that seen in the control group.

Adult↗
PubMed1978

A variant glucose-6-phosphate dehydrogenase Gd(-) Chiapas associated with moderate enzyme deficiency and occasional hemolytic anemia.

Erythrocyte glucose-6-phosphate deficiency is an X-chromosomal-linked hereditary trait often associated with hemolytic anemia. This report defines a new variant designated as Gd(-) Chiapas, which was found in a subject with occasional hemolytic jaundice. The red cell enzyme activity of the subject is about 15% of normal. The variant enzyme is thermolabile in vitro and has faster-than-normal anodal electrophoretic mobility and stronger-than-normal substrate affinity. The patient's hemolytic problem might be correlated with instability of the variant enzyme under physiologic stress.

Adult↗