Non-Mendelian transmission in a human developmental disorder: split hand/split foot

The study of Mendelian disorders that do not meet some Mendelian expectations has led to an increased understanding of such previously obscure genetic phenomena as anticipation. Split hand/split foot (SHSF), a human developmental malformation, demonstrates such distinctive genetic features as reduced penetrance and variable expressivity. In this study, new pedigrees with defined ascertainment confirm the existence of non-Mendelian transmission characterized by the overtransmission of SHSF from affected fathers to sons.

Relationship of endocrinopathy to iron chelation status in young patients with thalassaemia major

Disturbances of growth and development in patients with thalassaemia receiving hypertransfusion programmes are well recognised and are most likely to be due to iron overload. The extent of endocrine dysfunction was investigated in a group of 18 patients thought to have been treated by acceptable modern standards, 11 of whom could be considered as well chelated. Assessment of growth and puberty showed a wide variation in height SD scores with five patients having significantly short stature. Most patients are progressing through puberty normally with the exception of two boys with marked pubertal delay. The most prominent finding was that growth hormone responses to glucagon stimulation were significantly impaired in all of the patients with iron overload. Basal endocrine assessment showed primary hypothyroidism in two patients aged 16.8 and 12.9 years with plasma thyroxine-concentrations of 86 and 59 nmol/l (normal range 65-165 nmol/l) and plasma thyroid stimulating hormone 10.2 and 30.3 mU/l (normal range 0.5-5 mU/l). One patient had diabetes mellitus. These results show that even when ideal management is sought a significant amount of endocrine damage occurs; surveillance of these patients is thus essential.

Evidence for locus heterogeneity in human autosomal dominant split hand/split foot malformation

Split hand/split foot (SHSF; also known as ectrodactyly) is a human developmental disorder characterized by missing central digits and other distal limb malformations. An association between SHSF and cytogenetically visible rearrangements of chromosome 7 at bands q21-q22 provides compelling evidence for the location of a causative gene at this location, and the locus has been designated SHFD1. In the present study, marker loci were localized to the SHFD1 critical region through the analysis of somatic cell hybrids derived from individuals with SHSF and cytogenetic abnormalities involving the 7q21-q22 region. Combined genetic and physical data suggest that the order of markers in the SHFD1 critical region is cen-D7S492-D7S527-(D7S479-D7S491)-SHFD1-++ +D7S554-D7S518-qter. Dinucleotide repeat polymorphisms at three of these loci were used to test for linkage of SHSF to this region in a large pedigree that demonstrates autosomal dominant SHSF. Evidence against linkage of the SHSF gene to 7q21-q22 was obtained in this pedigree. Therefore, combined molecular and genetic data provide evidence for locus heterogeneity in autosomal dominant SHSF. We propose the name SHSF2 for this second locus.

Analysis of 222Rn concentration in North Carolina household water supplies derived from private wells

The objectives of this study were to characterize the concentrations of 222Rn in North Carolina household groundwater supplies and to investigate the relationship between indoor air and groundwater 222Rn concentrations. Measurements of 222Rn in groundwater supplies were performed in 400 North Carolina homes in which a state/Environmental Protection Agency survey had made measurements of indoor airborne 222Rn. The arithmetic mean 222Rn concentration measured in groundwater supplies statewide was 67 Bq L-1 (1,800 pCi L-1), and the geometric mean was 24 Bq L-1 (660 pCi L-1). Sixty-seven percent of the state's homes with wells had 222Rn water concentrations in excess of the Environmental Protection Agency's proposed limit for public drinking water supplies of 11 Bq L-1 (300 pCi L-1). The percentage of homes with water concentrations in excess of the proposed limit was 30% in the eastern region of the state, 75% in the central region, and 83% in the western region. No significant correlation was observed between measurements of indoor air and water 222Rn concentrations in these homes.

Comparison of immunodiffusion and enzyme linked immunosorbent assay in the detection of abnormal antibodies in pigeon breeder's disease

AIMS

To compare the sensitivity of two methods for the detection of serum antibodies to pigeon faecal antigens in patients with pigeon breeder's disease.

METHODS

Serum samples stored at -20 degrees C from 50 patients with pigeon breeder's disease, 50 control samples from patients with other respiratory diseases, and 50 healthy blood donors were examined for the precipitating antibodies and IgG antibodies to antigens present in extract of pigeon droppings by immunodiffusion and enzyme linked immunosorbent assay (ELISA), respectively.

RESULTS

Both antigen preparations of pigeon dropping extract were equally effective. A positive immunodiffusion reaction gave one or more precipitin lines and these antibodies were detected only in undiluted sera from 80% of the patients with pigeon breeder's disease. In the ELISA the sera were tested at a starting dilution of 1 in 100 because positive reactions were observed with sera from healthy blood donors at lower dilutions. All sera which gave optical density readings above 3 SD of the control value were considered to have IgG antibodies. These antibodies were detected in sera from all the patients with pigeon breeder's disease. The antibody titres were much higher in those patients who had precipitating antibodies (range 800-51,200) than those without (range 100-800). The antibodies were not detected in the sera of patients with respiratory diseases or healthy blood donors by either method.

CONCLUSIONS

Antibodies to pigeon dropping antigens were detected by immunodiffusion and ELISA in sera from patients with pigeon breeder's disease but not in control sera. ELISA was a more sensitive method for detecting antibodies and therefore seems to have considerable potential as a routine technique in the serological diagnosis of pigeon breeder's disease.

Retrotransposition of a mouse L1 element

Long interspersed elements (LINEs) of the L1 family represent a major class of mammalian repetitive DNA and are present at copy numbers of between 10(4) and 10(5) elements per genome. Structural similarities between L1 elements and known retrotransposons have led to the suggestion that a subset of L1 elements may function as mobile genetic elements and have thus gained their prominent place in the mammalian genome. We describe a consensus mouse L1 element that was tagged with a heterologous intron and shown to transpose by way of an RNA intermediate when transfected into baby hamster kidney cells, formally establishing L1 elements as retrotransposons. When the putative reverse transcriptase-encoding region of this L1 element was deleted, the element still underwent retrotransposition in hamster cells, suggesting that reverse transcriptase activity can be supplied by an endogenous enzyme.

Talin and vinculin in the oocytes, eggs, and early embryos of Xenopus laevis: a developmentally regulated change in distribution

We have investigated the expression and distribution of talin and vinculin in the oocytes, eggs, and embryos of Xenopus laevis. Antibodies to the previously characterized avian proteins stain several different Xenopus cell types identically by immunofluorescence: adhesion plaques of cultured kidney (A6) cells, the cell peripheries of oviduct cells, and the postsynaptic neuromuscular junctions of tadpole tail muscle fibers. These antibodies also identify cognate proteins of the appropriate sizes on immunoblots of A6 cell and oviduct lysates. Using these antibodies on ovarian tissue, we find talin to be highly localized at the cortices of oocytes and vinculin to be in the oocyte cytoplasm and absent from the oocyte cortex. In the cells of the ovarian layers that surround the oocytes, talin and vinculin can be detected as soluble and cytoskeletal components. Vinculin is first detectable as a cytoskeletal component in eggs, appearing some time during or between oocyte maturation and oviposition. During early embryo development, talin and vinculin are colocalized in the cortex of cleavage furrows and blastomeres. Thus, Xenopus oocytes and eggs display different distributions of talin and vinculin. The change from unlinked localization to colocalization appears to be developmentally regulated, occurring during the transition from oocyte to egg.

Binding of G-CSF, GM-CSF, tumor necrosis factor-alpha, and gamma-interferon to cell surface receptors on human myeloid leukemia cells triggers rapid tyrosine and serine phosphorylation of a 75-Kd protein

Granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), gamma-interferon (gamma-IFN), or tumor necrosis factor-alpha (TNF-alpha) triggered the rapid, stable phosphorylation of a 75-Kd protein (p75) when incubated with permeabilized HL60 human myeloid leukemia cells in the presence of [gamma-32P] ATP. Among several chemical inducers of HL60 cell differentiation, dimethyl sulfoxide also triggered p75 labeling, but retinoic acid or 12-O-tetradecanoylphorbol-13-acetate did not elicit this response. Pretreatment of cells with G-CSF or GM-CSF for more than 30 seconds before permeabilization rendered the p75 labeling undetectable, suggesting that ligand-stimulated labeling was rapidly completed within this time in intact cells. Phosphorylation of p75 occurred on serine and tyrosine residues. This conclusion was confirmed by direct phosphoamino acid analysis. Immunoblot analysis of lysates of intact HL60 cells that had been incubated with G-CSF, GM-CSF, IFN, or TNF confirmed that tyrosine phosphorylation of a p75 also occurred in response to these cytokines in intact cells. Pretreatment of intact HL60 cells with one biologic agent or dimethyl sulfoxide abolished p75 labeling in response to incubation of permeabilized cells with a second agent, strongly suggesting that the same protein was phosphorylated in response to these treatments. p75 labeling was strictly dependent on expression of the appropriate ligand receptor. Data suggest that activation of a tyrosine kinase system is an early response to the binding of G-CSF, GM-CSF, TNF, or IFN to their respective cell surface receptors, or to the addition of dimethyl sulfoxide, and that the resulting phosphorylation event(s) may play a role in securing common elements in the biologic responses to these agents.

Canine hemophilia B resulting from a point mutation with unusual consequences

We have used the polymerase chain reaction to amplify the entire coding region of canine factor IX from a hemophilia B animal. When the sequence was compared to that which codes for normal canine factor IX, a single missense mutation was identified. This mutation (G----A at nucleotide 1477) results in the substitution of glutamic acid for glycine-379 in the catalytic domain of the molecule. The mutation creates a new restriction site that allowed confirmation of the abnormal sequence in both hemophilic and carrier animals. Amino acid 379 in canine factor IX corresponds to position 381 in human factor IX, a location at which no human mutations have been described. Moreover, it occurs at one of the few amino acids that have been rigorously conserved among the trypsin-like serine proteases throughout evolution. The mutation responsible for canine hemophilia B results in a complete lack of circulating factor IX in the affected animals. As it is unusual for a missense mutation to result in a complete absence of protein product, structural modeling of the mutant and normal proteins was pursued. These studies suggest that the observed mutation would have major adverse effects on the tertiary structure of the aberrant factor IX molecule. The elucidation of this mutation sheds light on structure-function relationships in factor IX and should facilitate future experiments directed toward gene therapy of this disease.

Molecular cloning of a cDNA encoding canine factor IX

Factor IX (F.IX) is a vitamin K-dependent plasma protein, a deficiency of which results in hemophilia B. A canine model of hemophilia B exists; attempts to use this model for gene transfer experiments or characterization of the hemophilic defect require elucidation of normal canine F.IX structure. We report the isolation and characterization of the coding region for canine F.IX cDNA. Canine F.IX possesses 86% identity at the amino-acid level with human F.IX. The leader peptide, Gla domain, EGF domains, and the carboxy-terminal portion of the heavy chains show extensive sequence conservation between the canine and human. All Glu residues undergoing gamma-carboxylation in humans are conserved in canines. The complete coding sequence for canine F.IX has been determined, and the derived translation product has been analyzed. A similar approach should allow identification of the causative mutation in canine hemophilia B. Furthermore, this clone may prove a valuable resource in gene transfer experiments for this disease.

Bilaterality in anterior cruciate ligament injuries: associated intercondylar notch stenosis

Nonsimultaneous, bilateral ACL injuries are not uncommon. We studied a group of patients with these injuries to determine possible predisposing factors that could aid in early detection and prevention of contralateral ACL injury. Retrospective analysis of 1,120 patients with ACL ruptures who were treated between 1983 and 1987 revealed 45 patients with bilateral ruptures. Complete follow-up data were available for 41 of these patients. We examined age at initial injury, sex, interval between initial and contralateral ACL injury, mechanism of injury, activity at injury, medical and family histories, treatment of initial injury, and radiographic measurement of intercondylar notch width. The overall incidence of bilaterality was 4.01% in the 28 male and 13 female patients. Their average age was 19 years and 10 months. The average interval between initial and contralateral injury was 47 months. A noncontact cutting maneuver was the most common mechanism of injury. We devised a method to measure and compare intercondylar notch widths on plain radiographs. We compared the mean notch width index (NWI) of the bilateral group to the mean NWI of a group of 50 consecutive patients with "normal" knees and to the mean NWI of 50 consecutive patients with acute ACL ruptures. The mean NWI for the normal group was .2338, for the acute ACL group, .2248, and for the bilateral group, .1961. We noted a statistically significant difference when we compared the bilateral group to the normal and acute groups (P less than 0.0001, respectively). There was no statistically significant difference between the NWI of the normal and acute ACL groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Childhood monosomy 7 revisited

Monosomy 7 is found in acute myeloid leukaemia (AML) and myelodysplasia and is characteristic of a rare chronic myeloproliferative disease (MPD) of young children. We have seen 16 children with monosomy 7. Their clinical features and response to treatment are discussed. Monosomy 7 diseases appear to have a particularly poor prognosis. The AML is often resistant to treatment and relapse is common. Children with chronic MPD die of bone marrow failure or evolve to AML or myelofibrosis. We have treated these children intensively with combination chemotherapy and allogeneic bone marrow transplantation. Four children with MPD received supportive care and low dose chemotherapy alone. They all died, surviving between 4 months and 4 years. Six children with MPD received intensive chemotherapy: three remitted, one relapsing after 9 months, the others remaining in remission at 18 months and 3 years. One child with MPD has undergone successful BMT and survives 7 1/2 years after presentation. Remission was achieved in three of four cases of AML. They all relapsed within 9 months. Bone marrow transplantation was successful in one child with myelofibrosis. Intensive chemotherapy and early bone marrow transplantation is likely to offer these children their best chance of survival.

Detection of tyrosine protein kinase substrates in fresh leukemia cells and normal blood cells using an immunoblotting technique

Kinases which phosphorylate proteins on tyrosine residues are of importance in the control of both normal and malignant cell proliferation. The receptors for a number of growth factors have intracellular domains with tyrosine protein kinase activity and several viral oncogenes code for tyrosine protein kinases. An abnormal tyrosine protein kinase has been implicated in the pathogenesis of chronic granulocytic leukemia. Using an immunoblot method and an antiphosphotyrosine antibody, we have detected substrates of tyrosine protein kinases in fresh human leukemia cells and normal blood and bone marrow cells. These substrates were present in all types of cells examined. Cells from patients with acute lymphoblastic leukemia, acute myeloid leukemia, and chronic lymphocytic leukemia contain prominent phosphotyrosine-containing protein bands with molecular weights in excess of 95 kDa. By contrast, chronic granulocytic leukemia cells, as well as normal bone marrow cells, lymphocytes, and monocytes, contain predominantly low molecular weight (less than 95 kDa) tyrosine kinase substrates. When lymphocytes were stimulated to enter cell cycle, however, high molecular weight substrates of similar molecular weights to those detected in acute lymphoblastic leukemia, acute myeloid leukemia, and chronic lymphocytic leukemia became prominent. The implications of these findings in the control of normal and malignant cell proliferation and differentiation are discussed.

Operative treatment of Medial epicondyle fractures in children

Thirty-one patients with fractures of the medial epicondyle displaced more than 2 mm were evaluated an average of four years after their injury. Twenty-three patients had good results regardless of the degree of displacement or the presence of an elbow dislocation. One patient, had a poor result due to a technical error in pin placement. The remaining seven patients had the fracture fragment trapped in the joint and did worse, with three poor results. There was no correlation between range of motion and degree of displacement, length of immobilization, time from injury to surgery, presence of a dislocation, or open versus percutaneous treatment. Operative treatment of medial epicondyle fractures displaced greater than 2 mm gave consistently good results with a good range of motion, good stability, no ulnar nerve symptoms, and no deformity.

Tyrosine protein kinase substrates in Philadelphia-positive human chronic granulocytic leukemia derived cell lines (K562 and BV173): detection by using an immunoblotting technique

In chronic granulocytic leukemia (CGL) the Philadelphia translocation results in the production of a novel 210 kDa bcr-abl fusion protein which shows increased tyrosine protein kinase activity in comparison with its normal 145 kDa c-abl counterpart. Using an immunoblotting method and antiphosphotyrosine antibody, we have identified the tyrosine protein kinase substrates present in intact cells from two Philadelphia-positive CGL derived cell lines (K562 and BV173) and compared these with the substrates present in a Philadelphia-negative myeloid cell line (HL60). We have demonstrated an increased number of substrates, particularly of low (less than 110 kDa) molecular weight in the K562 or BV173 cells compared with the HL60 cells. There is virtual identity of the substrates present in the two CGL-derived lines. This work supports the hypothesis that the functional changes present in the bcr-abl 210 kDa protein of CGL results in altered tyrosine phosphorylation of intracellular proteins and that this is of importance in the pathogenesis of CGL.

Inosine monophosphate dehydrogenase activity in acute leukaemia

Inosine monophosphate dehydrogenase (IMPD) is an important enzyme in de-novo purine synthesis. The level of IMPD activity has been suggested to determine whether acute leukaemia cells proliferate (if the activity is high) or differentiate (if IMPD activity is low). IMPD activity measured by the conversion of inosine monophosphate to xanthine monophosphate ranged from 12.5 to 87.0 (mean 49.4) pmol/h/10(6) cells in normal bone marrow. The levels were significantly raised in AML (range 14-374, mean 184 pmol/h/10(6) cells) and ALL (range 65-228, mean 172 pmol/h/10(6) cells). Normal tonsillar (B) lymphocytes showed higher levels (range 78-159, mean 110 pmol/h/10(6) cells) than resting peripheral blood T lymphocytes (range 8.8-51.2, mean 28.1 pmol/h/10(6) cells). In CLL, the results (range 19-173, mean 64.3 pmol/h/10(6) cells) were comparable to those of normal tonsillar B lymphocytes. IMPD levels could be related to cell cycle in PHA-stimulated lymphocytes, since IMPD activity increased in parallel with increase in DNA synthesis measured by labelled thymidine incorporation. On the other hand, IMPD activity did not correlate with the proportion of proliferating cells measured on a FACS sorter in either AML or ALL or in normal tonsillar B cells. We conclude that IMPD levels are higher in B than T lymphocytes and in acute leukaemia blasts compared to more differentiated mixed bone marrow cells. The results do not suggest, however, that IMPD assay will be of value in differentiation of the various subtypes of acute leukaemia or of malignant haemopoietic cells from the equivalent normal cell at the same level of differentiation.

Non-Hodgkin's lymphoma: a survey from a district general hospital

We report a retrospective survey of 167 patients with non-Hodgkin's lymphoma (NHL) seen at a district general hospital between 1 August 1971 and 1 August 1983. Details of their clinical presentation, histology, therapy, response rates and survival are presented. The patient population reported is generally older than that seen at specialist centres and has a greater proportion of tumours with low-grade histology. Whereas specialist centres see a pre-selected population of patients, our data may be from a more representative group and this gives a truer incidence of this disease in the general population. The remission rates and overall survival of our patients are comparable to those achieved at specialist centres. We conclude that it is both feasible and desirable for patients with NHL to be assessed and treated in a district general hospital with a radiotherapy department.

A case of elliptocytosis associated with a truncated spectrin chain

A case of haemolytic anaemia with elliptocytosis is described, in which a large part of the smaller (beta) subunit of the spectrin is truncated, and has an apparent molecular weight of about 214 000 compared with about 230 000 for the normal chain. It is shown that this is not a product of adventitious proteolysis during lysis or extraction. At the same time about 35% of the total spectrin in the cells is liberated from the membrane as the dimer (which is present in normal cells to the extent of less than 10%). The truncated (beta') chain appears exclusively in this dimer fraction. The beta'-chain is incapable of phosphorylation by the endogenous cAMP-independent membrane kinase, and it may be inferred that the deleted segment of the chain contains both the spectrin self-association site and the residues normally phosphorylated. The alpha beta'-dimer is active with respect to participation in a ternary complex with its partnering proteins in the membrane cytoskeleton, F-actin and 4.1, confirming that the phosphorylation sites are not involved in the primary interaction with the other cytoskeletal proteins at the network junctions. The spectrin alpha-chain generates the terminal tryptic fragment of molecular weight 80 000 characteristic of normal spectrin, rather than the 74 000 molecular weight peptide derived from the alpha-chain in cases of hereditary elliptocytosis and pyropoikilocytosis, associated with anomalous self-association of spectrin dimer. Membrane cytoskeletons, extracted from the patient's red cells, undergo normal gelation on incubation with cAMP-independent kinase and ATP, and thus do not resemble those derived from hereditary spherocytosis cells. The properties of the anomalous spectrin resemble in most respects that described in a French family by Dhermy et al (1982).

Evaluation of Some High-Temperature Platinum Resistance Thermometers

Two sets of high-temperature platinum resistance thermometers of different design have been tested in the temperature range 0 to 1100 °C. One set was constructed at the National Institute of Metrology, in the People's Republic of China, and the other at the National Bureau of Standards. The results of the tests provide information on long- and short-time thermometer stability, and on other characteristics such as temperature coefficient, immersion, self-heating effect, electrical leakage, and durability. The results also show that the behavior of the two sets is similar enough to allow them to be considered as a single set of thermometers, and that the sets perform as well as, or better than, other sets of thermometers tested earlier. It is expected that this information will aid in the evaluation of the high-temperature platinum resistance thermometer as an interpolating instrument for a practical temperature scale up to the gold point.