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J Hästbacka

Publications and source records attributed to J Hästbacka.

14 recordsLinked to original sources
PubMed1992

Linkage disequilibrium mapping in isolated founder populations: diastrophic dysplasia in Finland.

Linkage disequilibrium mapping in isolated populations provides a powerful tool for fine structure localization of disease genes. Here, Luria and Delbrück's classical methods for analysing bacterial cultures are adapted to the study of human isolated founder populations in order to estimate (i) the recombination fraction between a disease locus and a marker; (ii) the expected degree of allelic homogeneity in a population; and (iii) the mutation rate of marker loci. Using these methods, we report striking linkage disequilibrium for diastrophic dysplasia (DTD) in Finland indicating that the DTD gene should lie within 0.06 centimorgans (or about 60 kilobases) of the CSF1R gene. Predictions about allelic homogeneity in Finland and mutation rates in simple sequence repeats are confirmed by independent observations.

Base Sequence↗
PubMed1991

Localization of a gene for progressive myoclonus epilepsy to chromosome 21q22.

Progressive myoclonus epilepsy of Univerricht-Lundborg type is a clinically defined entity among the progressive myoclonus epilepsies. It is an autosomal recessive disorder. The underlying biochemical defect is unknown. We used linkage analysis to localize the gene in 12 families with the aid of polymorphic DNA markers. Close linkage was detected with three markers on distal chromosome 21. The loci BCEI and D21S154 gave the highest positive logarithm-of-odds (lod) scores of 5.49 and 4.25, respectively, at zero recombination. The third locus, D21S112, gave a lod score of 6.91 at a recombination fraction of 0.034. There was no evidence of heterogeneity. Multipoint lod scores calculated against a fixed map of the three marker loci gave a maximum four-point lod score of 10.08 at a location of the disease gene at 6.0 centimorgans distal to locus BCEI and 0.8 centimorgan proximal to locus D21S154. As markers BCEI and D21S154 have previously been localized to 21q22.3 by physical methods, our findings place the EMP1 gene locus (for progressive myoclonus epilepsy of the Unverricht-Lundborg type) in chromosome 21 band q22.3. This finding provides an opportunity to test several other epilepsy phenotypes, particularly the so-called Ramsay Hunt syndrome, for linkage to the same locus. It also is a starting point toward isolating and characterizing the gene and its protein product.

Chromosome Mapping↗
PubMed1991

A linkage map spanning the locus for diastrophic dysplasia (DTD).

Diastrophic dysplasia (DTD) is an autosomal recessive osteochondrodysplasia. Patients have short-limbed short stature and suffer from generalized joint dysplasia. We have recently mapped DTD to the distal long arm of chromosome 5. Here we report the localization of DTD in relation to 16 polymorphic markers on distal 5q. No recombinations occurred with two loci, D5S72 and D5S66. One presumptive candidate gene, osteonectin (SPARC), could be excluded on the basis of three recombinations with the DTD locus. Multipoint linkage analysis performed against a fixed order of markers placed DTD between glucocorticoid receptor (GRL) and SPARC favored by the odds of 33:1 over the next best location of DTD between D5S72 and D5S55. The sex-averaged distance between the definite flanking markers, GRL and D5S55, is 17.5 cM. From previously reported data on the physical localization of markers, we conclude that the DTD locus is in 5q31-q34.

Alleles↗
PubMed1990

The etiology of XX sex reversal.

The primary testis-determining function is exerted by a gene in the sex-determining region of the human Y chromosome. This gene is termed the sex-determining factor or TDF. A zinc finger gene, ZFY, residing in this region has been cloned and characterized. It is a candidate for TDF. A challenge to future molecular research is to clarify the function of a zinc finger gene on the X chromosome, ZFX, that shows high structural similarity to ZFY. Furthermore, the existence of other genes involved in sex determination is likely but so far unproven. Sex reversal leading to testes in apparently XX individuals (XX males) is most often due to the presence of TDF on the paternally derived X chromosome. The abnormality arises during meiosis in the father when an abnormal exchange leads to the transfer onto the X of the entire pseudoautosomal region plus a portion of the Y chromosome-specific region including TDF from the Y. An XX male resulting from such an exchange is described. 10-20% of XX males do not have Y DNA. Two major mechanisms to explain such Y(-) XX males are discussed. First, several published pedigrees show clear-cut dominant autosomal or X chromosomal inheritance of XX maleness. These patients are always Y(-) and usually have sexual ambiguity. This indicates the existence of other genes, obviously 'downstream' from TDF, that when mutated can trigger testis determination. Nothing concrete is presently known about these putative genes, but their phenotypic effect is slightly different from that of TDF. Second, mosaicism with a prevalent XX lineage and a hidden or scarce lineage containing a Y chromosome can explain some apparently Y(-) XX males. Two XX/XXY mosaic patients are described in detail. In one, only a combination of DNA hybridization and cytogenetic studies led to the discovery of the XXY cell line. In conclusion, XX sex reversal in man is caused by at least 3 mechanisms, viz. abnormal Y-X interchange, genes other than TDF, and mosaicism.

Adolescent↗
PubMed1990

Diastrophic dysplasia gene maps to the distal long arm of chromosome 5.

We have used polymorphic DNA markers to map the gene for a clinically well-characterized form of osteochondrodysplasia, diastrophic dysplasia (DD), an autosomal recessive disorder of unknown pathogenesis. Linkage was analyzed in 13 families with two or three affected sibs comprising a total of 84 individuals. Positive two-point logarithm-of-odds (lod) scores were obtained between the DD locus and three polymorphic markers on chromosome 5. The highest pairwise lod score estimate of 7.37 with zero recombination to locus D5S72 suggests very tight linkage. There was no evidence of heterogeneity. Multipoint linkage analysis against the published order of the three loci gave the result centromere-D5S84-(DD, D5S72)-D5S61-terminus with a four-point lod score of 9.11. The present findings place the DD locus distal to the gene for adenomatous polyposis coli on the distal part of the long arm of chromosome 5. Our results provide a basis for refining the map position of the DD locus followed by physical localization, isolation, and characterization of the gene.

Blotting, Southern↗
PubMed1979

[Splenic transposition for portal hypertension (author's transl)].

Operative techniques for splenic transposition are reviewed and operative indications discussed. Thoracic transposition of the spleen for treatment of oesophageal bleeding is indicated in children and in patients with portal thrombosis and, in addition, in cases of intractable ascites complicating posthepatic obstruction. Late results of 28 cirrhotics operated on after variceal bleedings are presented. Fatal bleeding recurrences were avoided in 83 per cent of the cases surviving six months and the mean survival is 7.5 years so far. In elective surgery of cirrhotics with well maintained portal flow the most rational operative procedures are distal spleno-renal shunt and thoracic transposition of the spleen.

Esophageal Diseases↗
PubMed1979

The treatment of acute cholecystitis. A series of 497 consecutive patients.

In a five-year series of 497 consecutive patients with acute cholecystitis an overall mortality of 3.2% was observed. There was no significant difference in mortality between patients undergoing early surgery and those managed initially conservatively. The total incidence of postoperative complications was also similar in the early and delayed surgery groups, although wound complications were slightly more frequent after early surgery. A special risk group was formed by patients with unsuccessful conservative treatment demanding emergency surgery later. These delayed emergency cases contributed half of the deaths; the mortality was 28% in this group. Conservative initial treatment was followed by a recurrence rate of 21% before delayed surgery undertaken on average four months after the acute episode. With early surgery for acute cholecystitis recurrence and later emergencies can be avoided and the time of treatment approximately halved without significant increase in operative risks compared with delayed surgery. The data obtained under routine clinical work support the results of the prospective trial carried out at the same department of surgery (Järvinen & Hästbacka, 1979).

Acute Disease↗
PubMed1978

[Intravenous cholegraphy in acute cholecystitis (author's transl)].

In this prospective study iv-cholegraphy was performed before surgery on 152 patients by whom acute cholecystitis could not be excluded. The examination was diagnostic in 85% of the cases. Most of the patients (20/23) with nonvisualization of the biliary tract by iv-cholegraphy suffered from acute cholecystitis, the others (3/23) from acute pancreatitis. In three false negative examinations the opacification of the gallbladder was weak and in three false positive cases the cystic duct obstruction was caused by a chronic gallbladder disease. Because the preliminary clinical suspicion of acute cholecystitis even when using rigid criteria proved to be false in 30% of the cases, we consider a radiologic clarification to be indicated. Iv-cholegraphy is found to be an important examination in acute cholecystitis, practicable even at small radiologic departments with conventional equipment, and a reliable indicator of cystic duct obstruction.

Acute Disease↗
PubMed1978

Treatment of idiopathic thrombocytopenic purpura in adults. Long-term results in a series of 41 patients.

The results of treatment of idiopathic thrombocytopenic purpura (ITP) were analysed in a series of 41 patients 2 to 10 years (median 4 years) after initial treatment. There was one spontaneous remission. A good or fair long-term result was obtained in 11 patients after prednisone treatment, in 20 of 24 patients after splenectomy, and in 3 of 4 patients after immunosuppressive treatment. Short duration of symptoms and rapid response to prednisone had some value in predicting a good long-term result of prednisone treatment. Young age, a good response to prednisone and splenic sequestration of platelets were associated with good results after splenectomy, as was rapid postoperative normalization of platelet counts. These factors were unable to disclose with certainty a refractoriness to splenectomy. Nevertheless splenectomy was regarded to be the treatment of choice in all patients not adequately controlled with corticosteroids.

Adult↗
PubMed1978

Ectopic liver.

Abnormally positioned liver tissue is rare but can occasionally cause clinical symptoms. The four main types are: 1. Accessory liver lobe that can reach a considerable size and is attached to the liver by a stalk. 2. Small accessory liver lobe which is attached to the liver but is usually small, about 10-30 g in weight. 3. Ectopic liver which is situated outside the liver without any connection with it. It is usually attached to the gallbladder or intra-abdominal ligaments. 4. Microscopic ectopic liver which is found occasionally in the wall of the gallbladder. The literature is reviewed and two cases of ectopic liver are described.

Adult↗