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J Martinson

Publications and source records attributed to J Martinson.

At least 19 recordsLinked to original sources
PubMed2001

The exon A (C77G) mutation is a common cause of abnormal CD45 splicing in humans.

The leukocyte common (CD45) Ag is essential for normal T lymphocyte function and alternative splicing at the N terminus of the gene is associated with changes in T cell maturation and differentiation. Recently, a statistically significant association was reported in a large series of human thymus samples between phenotypically abnormal CD45 splicing and the presence of the CC chemokine receptor 5 deletion 32 (CCR5del32) allele, which confers resistance to HIV infection in homozygotes. We show here that abnormal splicing in these thymus samples is associated with the presence of the only established cause of CD45 abnormal splicing, a C77G transversion in exon A. In addition we have examined 227 DNA samples from peripheral blood of healthy donors and find no association between the exon A (C77G) and CCR5del32 mutations. Among 135 PBMC samples, tested by flow cytometric analysis, all those exhibiting abnormal splicing of CD45 also showed the exon A C77G transversion. We conclude that the exon A (C77G) mutation is a common cause of abnormal CD45 splicing and that further disease association studies of this mutation are warranted.

Alternative Splicing↗
PubMed2000

Polynesian origins: insights from the Y chromosome.

The question surrounding the colonization of Polynesia has remained controversial. Two hypotheses, one postulating Taiwan as the putative homeland and the other asserting a Melanesian origin of the Polynesian people, have received considerable attention. In this work, we present haplotype data based on the distribution of 19 biallelic polymorphisms on the Y chromosome in a sample of 551 male individuals from 36 populations living in Southeast Asia, Taiwan, Micronesia, Melanesia, and Polynesia. Surprisingly, nearly none of the Taiwanese Y haplotypes were found in Micronesia and Polynesia. Likewise, a Melanesian-specific haplotype was not found among the Polynesians. However, all of the Polynesian, Micronesian, and Taiwanese haplotypes are present in the extant Southeast Asian populations. Evidently, the Y-chromosome data do not lend support to either of the prevailing hypotheses. Rather, we postulate that Southeast Asia provided a genetic source for two independent migrations, one toward Taiwan and the other toward Polynesia through island Southeast Asia.

Biological Evolution↗
PubMed1998

Genetic evidence for the proto-Austronesian homeland in Asia: mtDNA and nuclear DNA variation in Taiwanese aboriginal tribes.

Previous studies of mtDNA variation in indigenous Taiwanese populations have suggested that they held an ancestral position in the spread of mtDNAs throughout Southeast Asia and Oceania (Melton et al. 1995; Sykes et al. 1995), but the question of an absolute proto-Austronesian homeland remains. To search for Asian roots for indigenous Taiwanese populations, 28 mtDNAs representative of variation in four tribal groups (Ami, Atayal, Bunun, and Paiwan) were sequenced and were compared with each other and with mtDNAs from 25 other populations from Asia and Oceania. In addition, eight polymorphic Alu insertion loci were analyzed, to determine if the pattern of mtDNA variation is concordant with nuclear DNA variation. Tribal groups shared considerable mtDNA sequence identity (P>.90), where gene flow is believed to have been low, arguing for a common source or sources for the tribes. mtDNAs with a 9-bp deletion have considerable mainland-Asian diversity and have spread to Southeast Asia and Oceania through a Taiwanese bottleneck. Only four Taiwanese mtDNA haplotypes without the 9-bp deletion were shared with any other populations, but these shared types were widely dispersed geographically throughout mainland Asia. Phylogenetic and principal-component analyses of Alu loci were concordant with conclusions from the mtDNA analyses; overall, the results suggest that the Taiwanese have temporally deep roots, probably in central or south China, and have been isolated from other Asian populations in recent history.

Alleles↗
PubMed1998

Estimating African American admixture proportions by use of population-specific alleles.

We analyzed the European genetic contribution to 10 populations of African descent in the United States (Maywood, Illinois; Detroit; New York; Philadelphia; Pittsburgh; Baltimore; Charleston, South Carolina; New Orleans; and Houston) and in Jamaica, using nine autosomal DNA markers. These markers either are population-specific or show frequency differences >45% between the parental populations and are thus especially informative for admixture. European genetic ancestry ranged from 6.8% (Jamaica) to 22.5% (New Orleans). The unique utility of these markers is reflected in the low variance associated with these admixture estimates (SEM 1.3%-2.7%). We also estimated the male and female European contribution to African Americans, on the basis of informative mtDNA (haplogroups H and L) and Y Alu polymorphic markers. Results indicate a sex-biased gene flow from Europeans, the male contribution being substantially greater than the female contribution. mtDNA haplogroups analysis shows no evidence of a significant maternal Amerindian contribution to any of the 10 populations. We detected significant nonrandom association between two markers located 22 cM apart (FY-null and AT3), most likely due to admixture linkage disequilibrium created in the interbreeding of the two parental populations. The strength of this association and the substantial genetic distance between FY and AT3 emphasize the importance of admixed populations as a useful resource for mapping traits with different prevalence in two parental populations.

Africa↗
PubMed1997

Recognition of temporally structured activity in spontaneously discharging neurons in the somatosensory cortex in waking cats.

We describe a method to automate the detection and analysis of structured neuronal activity obtained in relatively non-restrictive experiments in awake animals. Several different, regularly occurring, discharge patterns consisting of groups of spikes were identified in extracellular recordings from the somatosensory cortex of awake cats. The introduction of an interspike interval threshold made it possible to segregate these bursts from single spikes. The threshold interval was obtained from the modal interval in high-resolution autocorrelograms (up to 0.1 ms/bin) of the spontaneous neural activity. Single spikes were those separated by intervals greater than the threshold, while those within the group were of less than threshold value. When intervals were arranged and averaged according to their order of occurrence within the burst, four distinctive burst patterns were observed. These four patterns occurred in both normal and deafferented cortex and we believe them to be characteristic of particular cell types, a feature that will be useful for studying such cells in intact cellular networks.

Action Potentials↗
PubMed1997

A distinct profile of six soluble adhesion molecules (ICAM-1, ICAM-3, VCAM-1, E-selectin, L-selectin and P-selectin) in rheumatoid arthritis.

Soluble forms of ICAM-1, VCAM-1, E-selectin, L-selectin, P-selectin and, more recently, ICAM-3 are known to exist in human serum and have elevated levels in numerous diseases. Previous studies have demonstrated that in rheumatoid arthritis (RA) the levels of circulating sICAM-1 and sE-selectin are elevated relative to healthy controls. We have compared the serum profiles of these six soluble adhesion molecules in patients with RA (n = 22) to those seen in healthy controls (n = 10) using sandwich ELISA. In the patients, there were significant elevations of serum sICAM-1 (P < 0.0001), sICAM-3 (P = 0.0327), sVCAM-1 (P = 0.0025), sL-selectin (P = 0.0194) and sP-selectin (P = 0.0025), but not E-selectin (P = 0.0672). However, only sP-selectin was found to correlate with disease activity in the patients (r = 0.461, P < 0.05). Thus, there is a distinct profile of soluble adhesion molecules in RA of which only sP-selectin correlates with disease activity.

Adult↗
PubMed1996

Immunocytochemistry and flow cytometry evaluation of human megakaryocytes in fresh samples and cultures of CD34+ cells.

Adhering platelets on the cell surface can give misleading results when doing flow cytometry analysis of platelet/megakaryocyte-specific glycoprotein (GP) antigens to enumerate megakaryocytes (MK) in mobilized peripheral blood (PB), apheresis products, or normal bone marrow (BM). For adequate quantification and characterization of human MK, we examined samples with parallel flow cytometry and immunocytochemistry. MK expression of GP IIb/IIIa (CD41a), GP Ib (CD42b), GP IIIa (CD61), CD45, CD33, and CD11b, and their light scatter properties were evaluated. Fresh samples of low density mononuclear cells (MNC) or purified CD34+ cells contained 10-45% of platelet-coated cells. Platelet-coated cells decreased dramatically after several days of incubation in a serum-free medium supplemented with stem cell factor, IL-3, IL-6, and/or GM-CSF. Between d 9-12, flow cytometry detected a distinct CD41a+ MK population, 8.3 +/- 1.3% in BM CD34 cell cultures (n = 7) and 13.1 +/- 2.1% in PB CD34 cell cultures (n = 14), comparable to immunocytochemistry data (7.8 +/- 1.9% and 16.4 +/- 2.6%, respectively). CD41a stained a higher proportion of MK than CD42b or CD61, while CD42b+ or CD61+ cells contained more morphologically mature MK than CD41a+ cells in cultures containing aplastic serum. When fluorescence emission of CD41a was plotted against forward-light scatter (FSC), subpopulations of small and large MK were observed. Such subpopulations overlapped in CD41a intensity and side-light scatter (SSC) property. Most MK co-expressed CD45 (98.8% positive) but not CD33 (80.7% negative) or CD11b (88.9% negative). Our data indicate that flow cytometry can be used effectively to identify MK. However, caution should be taken with samples containing adherent platelets.

Adult↗
PubMed1995

Polynesian genetic affinities with Southeast Asian populations as identified by mtDNA analysis.

Polynesian genetic affinities to populations of Asia were studied using mtDNA markers. A total of 1,037 individuals from 12 populations were screened for a 9-bp deletion in the intergenic region between the COII and tRNA(Lys) genes that approaches fixation in Polynesians. Sequence-specific oligonucleotide probes that identify specific mtDNA control region nucleotide substitutions were used to describe variation in individuals with the 9-bp deletion. The 9-bp deletion was not observed in northern Indians, Bangladeshis, or Pakistanis but was seen at low to moderate frequencies in the nine other Southeast Asian populations. Three substitutions in the control region at positions 16217, 16247, and 16261 have previously been observed at high frequency in Polynesian mtDNAs; this "Polynesian motif" was observed in 20% of east Indonesians with the 9-bp deletion but was observed in only one additional individual. mtDNA types related to the Polynesian motif are highest in frequency in the corridor from Taiwan south through the Philippines and east Indonesia, and the highest diversity for these types is in Taiwan. These results are consistent with linguistic evidence of a Taiwanese origin for the proto-Polynesian expansion, which spread throughout Oceania by way of Indonesia.

Asia, Southeastern↗
PubMed1991

Two and four weeks' treatment for duodenal ulcer. Symptom relief and clinical remission comparing omeprazole and ranitidine. Scandinavian Clinics for United Research.

In a Swedish-Norwegian multicentre study patients with endoscopically verified duodenal ulcers (greater than 5 mm) were randomized to 2 or 4 weeks of treatment with either 20 mg omeprazole once daily or 300 mg ranitidine once daily. The aim was to evaluate 2 and 4 weeks' treatment with regard to symptomatic improvement during treatment, relapse after treatment, and safety of the two drugs. Endoscopy was not performed to check healing at the end of treatment. Instead the patients were instructed to contact the investigator in the event of recurrence of symptoms for renewed endoscopy. Follow-up was ended 10 weeks after stopping active treatment. Altogether 450 patients were evaluated at 17 centres. The symptomatic improvement during treatment was good in all groups, with significantly better reductions of daytime pain and heartburn in omeprazole-treated patients. Symptomatic relapse was commonest in the 2-week ranitidine group (57%), significantly more than in the 2-week omeprazole group (31%) (p less than 0.003). In the 4-week groups relapse rates were 34% (ranitidine) and 39% (omeprazole) (NS). It is suggested that in the short-term treatment of acute duodenal ulcer 20 mg omeprazole once daily is most rationally used in a 2- to 4-week regimen, whereas 300 mg ranitidine once daily should not be used for less than 4 weeks.

Absenteeism↗
PubMed1977

Vagal gastric relaxation in the dog.

Experiments were performed on anaesthetized dogs. Vagotomy was followed by an increase of gastric tone. The phasic responses of gastric tone to efferent vagal electrical stimulation were not separable in these experiments as they are in cats. Oesophageal distension, however, produced a marked gastric relaxatory response, which, as in cats, was non-cholinergic and non-adrenergic but abolished by vagotomy. This response is suggested to be equivalent to physiological receptive relaxation of the stomach, occurring during food intake.

Animals↗
PubMed1977

Gastric relaxatory response to feeding before and after vagotomy.

Experiments were performed on 4 non-anaesthetized dogs with chronic gastric fistulae. Gastric tonus was studied by volume and inflow rate recording at low pressure heads. Gastric tonus was not affected by propranolol or phentolamine. It was markedly reduced by atropine, presumably by blocking excitatory cholinergic nervous activity. Guanethidine induced a marked increase of gastric tonus, presumably by inhibiting sympathetic modulating activity on intramural cholinergic ganglia. Feeding was accompanied by a marked gastric relaxation which was not blocked by any of the drugs mentioned. Vagotomy, however, entirely abolished the gastric relaxatory response to feeding. The findings suggest that gastric receptive relaxation accompanying feeding is mediated via specific relaxatory vagal nerve fibres, which are non-adrenergic and non-cholinergic.

Animals↗
PubMed1977

Gastric relaxatory response to insulin before and after vagotomy.

Experiments were performed on 4 non-anaesthetized dogs with chronic gastric fistulae, Gastric tonus was studied by volume recording at low pressure head. 0.5 IE insulin/kg bodyweight intravenously was followed by an immediate gastric relaxation, obvious before any marked decrease of blood glucose or plasma potassium occurred, and furthermore not affected by administration of glucose or potassium. This initial relaxation was still present after vagotomy and might be due to transmembraneal metabolic changes upon insulin administration or to direct effect of insulin on gastric smooth smooth muscles. During hypoglycaemia, a second relaxatory phase occurred, and glucose given during this phase temporarily increased gastric tonus, indicating this relaxation to be due to hypoglycaemia. The hypoglycaemic relaxation was markedly reduced but not abolished by vagotomy, indicating also extravagal factors in this response.

Animals↗
PubMed1975

Surgical treatment of thyrotoxicosis: results of 272 operations with special reference to preoperative treatment with anti-thyroid drugs and L-thyroxine.

From 1959 to 1970, 272 operations for thyrotoxicosis were performed. Most of the patients received anti-thyroid drugs and thyroid hormones preoperatively. The patients were continuously followed up. The primary results with low morbidity and no mortality as well as the long term results with a low rate of recurrence and a relatively high incidence of thyroid substitution are discussed. A safe and effective programme for surgical treatment of thyrotoxicosis is described. Anti-thyroid drugs and thyroid hormones should be administered as the method of choice in preparing these patients for surgery.

Adolescent↗
PubMed1975

Comparative studies on the effects of bradykinin and vagal stimulation on motility in the stomach and colon.

The effect of bradykinin on gastric and colonic motility was studied in anaesthetized cats with volume recording devices and compared with the effects of vagal nerve stimulation. When administered intrarterially bradykinin caused a profound and prolonged gastric relaxation. Stimultaneously there was a marked and likewise prolonged colonic contraction. The gastric relaxation closely mimicked the atropine resistant relaxation elicited by vagal nerve stimulation. These effects could not be blocked by antiadrenergic drugs and it is suggested that bradykinin and the unknown transmittor substance(s) released on vagal stimulation act in a similar way on the gastric smooth muscles and that a kinin mechanism may be involved in the vagal response. As regards the colonic motor response it was shown that bradykinin does not reproduce the vagal motility effects on colon smooth muscle but mimicks closely the atropine resistant expulsive contraction elicited by activation of the pelvic nerves.

Animals↗
PubMed1975

Dynamic gastric response to expansion before and after vagotomy.

The dynamic gastric pressure response to expansion by direct intragastric air insufflation, 30-50 ml/s, was studied in healthy volunteers, non-operated ulcer disease patients, and in patients operated upon with antrectomy, antrectomy and vagotomy, or proximal selective vagotomy. Non-operated individuals accepted gastric expansion without considerable increase of pressure. Antrectomized patients showed a higher basal pressure and a moderate increase of pressure during expansion. Vagotomized patients, including the ones operated upon with proximal selective vagotomy, demonstrated a marked increase of pressure during expansion. The results indicate that vagal denervation of the corpus-fundus part of the stomach is followed by an impairment of gastric resrvoir function.

Cholecystectomy↗