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Biomedical subjects

J H Githens

Publications and source records attributed to J H Githens.

At least 19 recordsLinked to original sources
PubMed1992

Molecular genetic studies in black families with sickle cell anemia and unusually high levels of fetal hemoglobin.

Clinical, hematologic, and molecular genetic studies are reported for five families with SS patients having unusually high fetal hemoglobin (Hb F) levels (mean 28.3%, range 19-42%). Some of the individuals were symptom-free and one was not anemic. However, some were symptomatic despite a very high Hb F. Neither the Hb F level nor the F cell distribution entirely explained the variation in clinical severity. Molecular genetic studies identified the Senegal haplotype with the associated -158 G gamma (C----T) mutation in two of the five families. The -202 G gamma (C----G) mutation was not found in any of the individuals studied. Sequencing of the gamma-globin gene promoters to detect genetic high F determinants not detectable by restriction digestion was not performed. All AS parents and AS siblings demonstrated elevated F cells when the Senegal/-158 G gamma (C----T) mutation was present with either the beta S or beta A allele. Double heterozygosity for two different high F determinants in some SS patients is suggested by the studies in at least one family. Discordance among siblings in clinical and hematologic manifestations in two families provides additional evidence for loci regulating Hb F cell production which are not linked to the beta-globin gene clusters.

Adult↗
PubMed1990

Newborn screening for hemoglobinopathies in Colorado. The first 10 years.

In Colorado, newborn screening for hemoglobinopathies by cellulose acetate and citrate agar electrophoresis of dried capillary blood spots was established in 1979. We reviewed the results of screening 528,711 infants through 1988. Forty-seven infants with sickle cell diseases and 27 infants with other hemoglobin diseases were identified. The initial screening failed to detect sickle cell anemia in 4 infants, but the hemoglobinopathy in 3 of these infants was diagnosed correctly by routine retesting of those with suspected sickle cell trait. A total of 47 infants with sickle cell diseases were followed through September 1989. There was no mortality among these infants. The screening test identified 3779 infants (1:140 births) with a suspected hemoglobin trait; confirmatory retesting was obtained in 53%. The results of our experience confirm the value of newborn screening for hemoglobinopathies but suggest that a more sensitive test would improve the program.

Colorado↗
PubMed1989

Gallbladder function is altered in sickle hemoglobinopathy.

Despite comparable rates of hemolysis, only 50% of patients with sickle hemoglobinopathy (SH) develop pigment gallstones by age 20 yr. Thus, pathogenetic factors, other than hemolysis, may contribute to gallstone formation. In the present study we determined whether gallbladder function, measured by real-time ultrasonography or bile acid metabolism, determined by isotope dilution-mass spectrometry, were altered in adolescents and young adults with SH. Compared with healthy controls, SH subjects had larger fasting (27 +/- 16 vs. 15 +/- 5 ml, p less than 0.02), and residual (8 +/- 6 vs. 4 +/- 2 ml, p less than 0.03) volumes of the gallbladder, but similar rates of emptying (0.029 +/- 0.016 vs. 0.034 +/- 0.029 min-1) and percentage of fasting volume emptied (71% +/- 13% vs. 72% +/- 14%). In SH subjects, the volume and emptying of the gallbladder were similar between those with and without gallstones. Some SH subjects had stasis of bile within the gallbladder, as demonstrated by isotopic disequilibrium between the circulating bile acid pool and bile stored in the gallbladder. Subjects with SH with gallstones tended to have smaller bile acid pools than SH subjects without gallstones (81 +/- 11 vs 163 +/- 91 mumol/kg, p = 0.051). We conclude that adolescents and young adults with SH have enlarged gallbladders that retain an increased postprandial volume of bile. Bile retention within the gallbladder may lead to stasis and contribute to the pathogenesis of pigment gallstones.

Adolescent↗
PubMed1989

Normal vitamin E status in sickle hemoglobinopathies in Colorado.

Because previous studies of serum or plasma vitamin E (E) levels reported a high prevalence of E deficiency in patients with sickle cell anemia (SCA), we studied the E status in 101 patients with SCA in Colorado using both levels of serum E and ratios of serum E to total lipid (E:L). Compared with age-, sex-, and race-matched controls, 1 of 70 patients with homozygous SCA (SS), 1 of 7 with sickle beta+-thalassemia, and 0 of 24 with hemoglobin SC disease had E deficiency according to E:L and all were E-sufficient based on serum E levels. Serum cholesterol levels, lower in SS patients than in control subjects, correlated more strongly with serum E levels than did total serum lipid levels in control subjects and SS patients; hence, the ratio of serum E to cholesterol may be a useful indicator of E status in these patients. We conclude that vitamin E deficiency rarely occurs in SCA patients in Colorado.

Adolescent↗
PubMed1989

Intranasal administration of deferoxamine to iron overloaded patients.

We examined the effect of intranasal administration of deferoxamine on iron excretion in seven patients with iron overload secondary to chronic transfusion therapy. Deferoxamine was administered in doses of 0.75 to 3.0 gm given over 12 hours in a variety of dosing schedules. There was a probable, though not significant, dose response relationship between the amount of iron excreted and the dose administered. The amount of iron excreted was 10%-15% of that obtained using the same dosage of deferoxamine given by the subcutaneous route over the same time period. Hourly administration was more effective than less frequent administration. Addition of taurodeoxycholate to deferoxamine did not increase its absorption as measured by the levels of iron excretion. Side effects were few and consisted mainly of mild nasal irritation and a bad taste in the mouth. Nasal administration of deferoxamine may be a useful adjunct to iron chelation in patients receiving chronic transfusion therapy, particularly in those who are noncompliant with parenteral means of administration.

Administration, Intranasal↗
PubMed1988

Zinc status in children and young adults with sickle cell disease.

Previous studies have suggested an association of zinc deficiency and short stature in some children and adults with sickle cell disease (SCD). As a result, zinc supplementation has been recommended for these patients. The mechanism for zinc deficiency in certain patients with SCD is unknown, although renal loss of zinc has been suggested as a contributing factor. The zinc status of 29 subjects with SCD and 18 black controls was studied. No evidence of zinc deficiency in our population with SCD was found when plasma and cellular zinc levels were measured. Likewise, levels of two zinc-dependent enzymes, alkaline phosphatase and delta-aminolevulinic acid dehydratase, were normal in these subjects with SCD. Although adolescent subjects with SCD tended to be shorter than control subjects, there was no correlation between the height-forage z score and plasma zinc levels (r = -.31). It was concluded that zinc deficiency was not present in our population with SCD, and that there was no correlation between plasma zinc levels and the height-for-age z score in growing adolescent patients with SCD. These findings suggested that zinc supplementation may not be necessary in all patients with SCD.

Adolescent↗
PubMed1985

Splenic syndrome at mountain altitudes in sickle cell trait. Its occurrence in nonblack persons.

Six consecutive cases of splenic syndrome at mountain altitudes in persons with sickle cell trait are reported and the literature is reviewed. All six cases occurred in men who experienced the acute onset of severe left-upper-quadrant abdominal pain within 48 hours of arrival in Colorado from lower altitudes. All six patients were phenotypically nonblack. Three patients experienced their symptoms at moderate altitudes of 1,609 to 2,134 m (5,280 to 7,000 ft) above sea level. All recovered with medical management and none required splenectomy, although functional hyposplenia was a sequela in at least one patient. The possibility that nonblack persons with sickle cell trait may be at greater risk than black persons with sickle cell trait for the development of splenic syndrome at moderate altitude is discussed.

Adolescent↗
PubMed1979

Sickling crises and altitude. Occurrence in the Colorado patient population.

Seventy-five black patients with sickle hemoglobinopathies who are followed by the Colorado Sickle Cell Treatment and Research Center, and 172 of their family members were evaluated by retrospective interview for the occurrence of sickling crises when traveling in the Rocky Mountains or by aircraft. Twenty per cent of 39 patients with sickle cell anemia (Hgb SS) (Hgbs S/C and S/T) have developed crises when traveling in the mountains above 2000m. Vaso-occlusive crises predominated in the SS group and splenic crises occurred primarily in those with Hgbs S/C and S/T. Approximately 20 per cent of those with S/C and S/T, but none with SS, had crises when flying in pressurized aircraft. Among 103 family members with sickle cell trait (Hgb AS), no significant risk of developing crises could be identified with either mountain or pressurized aircraft travel.

Adolescent↗
PubMed1978

Remission of relapsed leukaemia during a graft-versus-host reaction. A "graft-versus-leukaemia reaction" in man?

Acute lymphoblastic leukaemic in two boys relapsed after engraftment of marrow from siblings identical at HLA A, B, and D loci but went into remission during subsequent graft-versus-host reactions without specific anti-leukaemia therapy. Later leukaemic relapse was primarily in extramedullary sites, with little or no involvement of bone-marrow, liver, or spleen. Cytogenetic studies in both cases showed that the relapsed leukaemic blasts were those of the recipients while marrow cells and blood lymphocytes detected during marrow remission originated from the female donors. Blood lymphocytes from one of the recepients kiled. 51Cr-labelled autologous lymphoblast. The prolonged bone-marrow remission in the face of active and even massive extramedullary leukaemia suggests a graft-versus-leukaemia reaction in these two patients.

Adolescent↗
PubMed1978

Recruitment and retention program for minority and disadvantaged students.

Attracting ethnic minority and disadvantaged students to health careers and facilitating their successful completion of training program requirements have been major activities of the University of Colorado Medical Center since 1969. As a result of extensive college campus recruitment efforts, high school and college level preprofessional programs, and the participation of ethnic minority faculty members in the medical school admissions process, the number of applicants to the medical school increased from 45 in 1971 to 265 in 1977. Concurrently, medical school matriculants increased from 12 in 1971 to 24 in 1977, with a maximum of 30 in 1975. However, significantly fewer minority students have shown interest in nursing, dentistry, or allied health professions careers. Because of support programs for matriculants (including preadmission and postadmissions personal, academic, study skills, and test-taking counseling and a prefreshman year summer orientation course), 71 percent of the minority students entering medical school in 1971-73 have received the M.D. degree.

Colorado↗
PubMed1977

Nine cases of sphingomyelin lipidosis, a new variant in Spanish-American Children. Juvenile variant of Niemann-Pick Disease with foamy and sea-blue histiocytes.

We describe nine Spanish-American children from five families with an unusual hereditary lipid storage disease. The family origins were in two small southern Colorado towns. The clinical course varied, but all of the children were found to bruise easily and to have splenomegaly, while most had hepatomegaly. Post-natal jaundice and hepatitis occurred in four. Impairment of vertical gaze and intellectual and neurologic deterioration occurred in most of the patients, with the onset of the disease, usually in childhood. The bone marrow in all patients examined contained both foamy and sea-blue histiocytes. Sphingomyelinase levels in skin fibroblast cultures were greatly decreased in seven of the eight cases evaluated. It is believed that these patients have a sphingomyelin lipidosis and represent a variant of the Niemann-Pick disease. Clinical and enzymatic findings are compared with those of other cases in the literature.

Adolescent↗
PubMed1977

Splenic sequestration syndrome at mountain altitudes in sickle/hemoglobin C disease.

The splenic sequestration syndrome was observed in five children with sickle/hemoglobin C (S/C) disease in association with a change in altitude. In four of them, it occurred during or immediately following a trip to mountain altitudes greater than 9,000 feet. In the fifth child, the crisis occurred in ten days after travel in a pressurized plane from sea level to Denver. No previous reports of this complication in S/C patients during mountain travel have been noted although the occurrence is known in association with aircraft flights.

Abdomen↗
PubMed1976

Establishment of erythropoiesis following bone marrow transplantation in a patient with congenital hypoplastic anemia (Diamond-Blackfan syndrome).

Marrow transplantation was attempted in a 13-yr-old boy with congenital hypoplastic anemia who had never responded to corticosteroid therapy. Prior to the transplant, he had received 238 transfusions, at least 12 of which were from his father. He was prepared for grafting with antilymphocyte globulin, procarbazine, and total body irradiation (1000 rads). The patient, whose red cells were Group B, then received marrow cells from his Group O, histocompatible, sister. Thereafter, reticulocytes, Group O erythrocytes, and female leukocytes appeared in the peripheral blood. Erythroid precursors were seen in the patient's marrow for the first time in his life, and all lacked fluorescent Y chromosomes. Dividing cells were all female. After initially progressing well, the patient developed interstitial pneumonia and died 55 days after the transplant. The successful erythroid graft suggested that this patient's failure to produce red blood cells was due to a defective stem cell rather than to a humoral defect, plasma inhibitor, or abnormal marrow microenvironment. It suggested further that sibling marrow may be engrafted in patients who have received multiple transfusions, even from a parent.

Adolescent↗