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Biomedical subjects

A Holmberg

Publications and source records attributed to A Holmberg.

At least 37 records · Page 2Linked to original sources
PubMed1997

Sequence analysis of domestic dog mitochondrial DNA for forensic use.

A method has been developed for the direct sequencing of hypervariable region 1 (HV1) of domestic dog (Canis familiaris) and wolf (Canis lupus) mitochondrial DNA (mtDNA) using single hairs as template. The method uses a robotic work-station and an automated sequencer to allow for robust routine analysis. A population data base was created in order to investigate the forensic and population-genetic informativeness of domestic dog HV1. Sequence variation, partitioning of dog breeds among sequence variants and phylogenetic relations between the variants were determined. Samples from 102 domestic dogs of 52 different breeds and two captive wolves were analyzed. Nineteen dog-sequence variants were found and the frequencies of the variants ranged from 1 to 21%. The calculated discrimination power of the region, i.e., the exclusion capacity, implied that nine out of ten disputed individuals can be excluded by this analysis. The sequence variants were found to cluster into four phylogenetic groups.

Animals↗
PubMed1996

The sequence of a 30 kb fragment on the left arm of chromosome XV from Saccharomyces cerevisiae reveals 15 open reading frames, five of which correspond to previously identified genes.

We report the sequence of a 30,469 bp long DNA fragment on the left arm of chromosome XV of Saccharomyces cerevisiae. The fragment contains 15 open reading frames (ORFs) of at least 300 bp. Five previously sequenced yeast genes, PHO80, TIR2, SLG1, the gene encoding the subtilisin-like protease III precursor and the gene coding for ATP-dependent permease, are found among these ORFs. By DNA sequence comparison, two ORFs identified previously reported expressed sequence tags from yeast. Of the proteins encoded by the remaining eight ORFs, six show similarities to proteins from different organisms and two lack detectable similarity with any amino acid sequence described in public data banks.

Chromosomes, Fungal↗
PubMed1996

Long-term results of anterior levatorplasty for fecal incontinence. A retrospective study.

PURPOSE: To review the long-term results of anterior levatorplasty for fecal incontinence. METHODS: Fifty-four women with obstetric trauma and 31 with idiopathic incontinence responded to a questionnaire 1.5 to 18.5 (median, 8.5) years after anterior levatorplasty. Results were classified as excellent, good, fair, or poor. RESULTS: An excellent or good result was reported in 40 of 54 (74 percent) patients with an obstetric injury and in 14 of 31 (45 percent) patients in the idiopathic group (P < 0.01). The presence of a cloaca (P < 0.05) and a young age (P < 0.05) were associated with a favorable outcome in the obstetric and idiopathic group, respectively. Length of follow-up and preoperative severity of incontinence were not significantly related to outcome. CONCLUSIONS: This study suggests that every second patient undergoing anterior levatorplasty for fecal incontinence has a successful result that is sustained in the long term. Obstetric trauma, presence of a cloaca, and young age are associated with a successful outcome.

Adult↗
PubMed1996

Composite polytetrafluroethylene/vein bypass grafts: conventional distal vein segment or vein cuff?

OBJECTIVES: To determine the current status of PTFE vein composite grafts, we reviewed our experience with 205 composite reconstructions and compared the results of conventional distal vein segment to that of distal vein cuff. DESIGN: Retrospective review. SETTING: Department of Surgery, University Hospital. PATIENTS AND METHODS: The series included 85 women and 102 men with a median age of 70. The indications for surgery were claudication in 30, rest pain in 71 and ulcer/gangrene in 103. The site of the distal anastomosis was the popliteal artery in 111 and crural artery in 94. The graft consisted of a proximal PTFE graft anastomosed to a distal segment of reversed saphenous vein in 169 or to a modified distal Miller cuff in 36 operations after 1992. RESULTS: Cumulative life table primary patency rates for the whole series at 12, 24 and 36 months were 39%, 32% and 25% respectively. Limbs with good run-off demonstrated significantly better patency rates compared to limbs with poor run-off (55% and 17% at 12 months, 35% and 11% at 36 months, p = 0.04). The patency rate of femorocrural grafts with poor run-off was only 4% at 12 months. The overall limb salvage rates at 12 and 36 months were 63% and 55%, respectively. Similar results were obtained in limbs with distal reversed vein segment and distal vein cuff. CONCLUSION: The results of this study suggest that for infrainguinal bypass grafting where the saphenous vein is unavailable, a composite PTFE-vein graft might be an acceptable alternative in limbs with good run-off. Although not a randomised study, the results using a distal reversed vein segment of a cuff were similar.

Adult↗
PubMed1996

Arterial complications after knee arthroplasty: 4 cases and a review of the literature.

We reviewed 40 cases of arterial complications after total knee replacement from the literature and report 4 of our own cases. The incidence is low (0.03%-0.2%), but the prognosis is poor, with death or amputation in one fourth of the cases. Preexisting arterial insufficiency, absent pedal pulses, arterial calcification on plane radiographs, femoro- popliteal/distal grafts are all predisposing factors. Therefore, preoperative risk factor evaluation as well as rapid and adequate handling in case of bleeding and/or ischemic complications pre- and postoperatively are crucial. Cooperation with a vascular surgeon is also essential.

Aged↗
PubMed1995

Labeling of polypeptides with technetium-99m using a dextran spacer.

Radioimmunoscintigraphy and other forms of scintigraphy are becoming increasingly important as tools in detection and evaluation of cancer diseases. Several radionuclides can be considered as radiolabel; however, 99mTc may be the most suitable because of easy availability and near ideal physical properties. This study describes how dextran is coupled to a monoclonal anticytokeratin antibody, epidermal growth factor, and somatostatin through stable amine bonds. The dextran moiety could then be labeled with 40-62 MBq of 99mTc. The labeling efficiency was 60-94%, determined by gel filtration or TLC. The specific binding could be considerably preserved after the dextranation, the antibody retained > 90% of its activity, epidermal growth factor bound with > 90% specificity to receptor-expressing tumor cells, and somatostatin showed approximately 40% specific binding to rat adrenal homogenates. Because somatostatin only has a transient half-like in vivo, the in vivo plasma half-life of somatostatin-dextran was tested in normal female Sprague-Dawley rats. The result showed a strong enhancement of the plasma half-life that was dependent on two compartments, 4 and 8 h.

Animals↗
PubMed1995

Anorectal manovolumetry in the diagnosis of fecal incontinence.

PURPOSE: This study was designed to investigate rectal reservoir function and anal pressures in patients with fecal incontinence using anorectal manovolumetry and to evaluate the reproducibility of the investigation. METHODS: Forty-eight patients with fecal incontinence were investigated with respect to anal pressures and rectal volume changes and sensibility in response to stepwise increased rectal pressures (5-60 cm of H2O). Patients with known rectal wall diseases were excluded. Results were compared with those of 25 control subjects investigated in a similar manner. In ten individuals in the latter group, investigation was repeated after 5 minutes and 24 hours. RESULTS: Resting pressure (RP), squeezing pressure (SP), and the difference between SP and RP was lower in patients than in controls (P < 0.0001). There was no significant difference between patients and controls concerning rectal sensibility or compliance (P > 0.05), but there was a correlation between RP and rectal compliance (r = 0.25; P < 0.05) and between SP and rectal compliance (r = 0.30; P < 0.01). There was good reproducibility of RP and SP after five minutes (r = 0.88-0.92; P < 0.001). The day-to-day variation was larger for RP (r = 0.52; P > 0.05) compared with SP (r = 0.89; P < 0.001). Rectal compliance at 40 cm of H2O was reproducible after 5 minutes (r = 0.98; P < 0.0001) and 24 hours (r = 0.88; P < 0.01). CONCLUSIONS: These results indicate that the primary defect in incontinent patients is a sphincter dysfunction. Any reduction in rectal compliance is likely to be a secondary phenomenon.

Adult↗
PubMed1995

Direct solid-phase sequence analysis of the human p53 gene by use of multiplex polymerase chain reaction and alpha-thiotriphosphate nucleotides.

Among the candidate cancer-prognostic genes is the p53 tumor suppressor gene, which, when mutated, plays an important role in the development of many types of cancers. To facilitate robust large-scale DNA analysis of microdissected tumor biopsies, we describe a multiplex/nested PCR approach for a simultaneous outer amplification of exons 4-9 of the human p53 gene with parallel amplification of the HLA-DQB1 locus, involving a total of 14 primers. This approach reduces the required number of cells for analysis and avoids any variation in the amplifications of the individual p53 exons during the common outer amplification step. The HLA sequencing allows sample identification because the DQB1 locus is highly polymorphic and is thereby patient-specific. The p53 and HLA amplicons are analyzed by solid-phase sequencing in a semiautomated format. To improve the DNA sequence quality, we used 2'-deoxyribonucleoside 5'-O-1-thiotriphosphates in the sequencing reactions.

Autoanalysis↗
PubMed1992

Automated magnetic preparation of DNA templates for solid phase sequencing.

An integrated protocol for solid-phase DNA sequencing using a robotic work station is described involving magnetic separation of DNA and analysis of the sequencing product by electrophoresis with automated detection of the fluorescently labeled fragments. The method, which is based on magnetic beads in combination with streptavidin-biotin technology, can be used for sequencing both genomic and plasmid DNA. The DNA template is obtained by the polymerase chain reaction (PCR). Protocols to prepare five and ten immobilized samples is described, giving 10 and 20 single-stranded templates, respectively. The magnetic purification steps are performed in a microtiter plate and this allows for an integrated scheme involving a subsequent procedure for automated primer annealing and sequencing reactions. Here, the procedure is examplified by direct genomic sequencing of DNA in blood sample from a human immunodeficiency virus (HIV)-infected patient and a cloned human antibody DNA fragment using fluorescently labeled sequencing primers.

Automation↗
PubMed1992

Intraperitoneal 5-fluorouracil in the management of colorectal liver cancer.

Twenty-five patients with colorectal liver metastases had a subcutaneous portal connection with a peritoneal catheter implanted for the intraperitoneal (i.p.) administration of 5-fluorouracil (5-FU). In five patients, the malignant disease rapidly progressed and the implanted catheter system was never used. Among the remaining 20 patients, seven patients had i.p. 5-FU as adjuvant treatment following liver resection and 13 patients received palliative chemotherapy (5-FU) owing to unresectable liver metastases. 5-FU was administered on a regular basis every 4 to 6 weeks by continuous infusion of 1000 mg/day (approximately 15 mg/kg/day) for 5 days. In seven patients, i.p. chemotherapy was managed on an outpatient basis. In general, i.p. 5-FU treatment was well tolerated with only minor abdominal complaints during the initial treatments. No definite effect on survival has been noted. All patients (n = 13) receiving palliative i.p. 5-FU died after a median of 4 (range 1.5-18) months. Two patients receiving adjuvant chemotherapy died owing to recurrence after 20 and 23 months, while five patients are alive, two with recurrent disease and three without, after 14-35 months.

Adult↗
PubMed1991

Electrochemical detection of proteins in high-performance liquid chromatography using on-line, postcolumn photolysis.

Direct detection of proteins in high-performance liquid chromatography electrochemistry (LCEC) is difficult. By using on-line, postcolumn photolysis, proteins now can be detected by LCEC at microgram per milliliter levels. The compatibilities of size exclusion chromatography (SEC), reversed-phase chromatography (RPC), ion-exchange chromatography (IEC), and hydrophobic interaction chromatography (HIC) with photolysis-electrochemical detection is described for proteins together with the analytical figures of merit. Inherent from the advantages of electrochemical detection, the method is sensitive and selective.

Chromatography, High Pressure Liquid↗
PubMed1991

Binding of epidermal growth factor-dextran conjugates to cultured glioma cells.

Some gliomas, melanomas and squamous carcinomas have large numbers of EGF receptors which could, in these cases, be used for targeting with toxic agents. We investigated whether EGF could be conjugated to dextran, which is a suitable carrier for toxic agents, without losing its ability to bind to the receptor. Dextran of 20 kDa molecular weight was activated with I-cyano-4-dimethylamino pyridinium tetrafluoroborate (CDAP) yielding highly active pyridinium-isourea derivatives. EGF was coupled to the activated dextran through the amino terminus and glycine was added to block residual activity. The EGF-dextran conjugate was, after purification on Sephadex G25 and Sephacryl 200 columns, tested for its receptor binding properties on human malignant glioma, U343MGaC12:6, cells. The conjugate inhibited binding of 125I-EGF in a competitive assay, showing that the binding was receptor-specific. Dextran conjugated with glycine, without EGF, had no inhibitory effect. The conjugate was radio-labelled either on the EGF part with 125I or on the dextran part with 3H-glycine, and the internalization patterns were compared to the internalization of 125I-EGF. The radioactivity of the conjugates remained cell-associated for more than 20 hr, regardless of whether the radioactivity was on the EGF or on the dextran part, while the radioactivity of unconjugated EGF rapidly disappeared from the cells. Most of the cell-associated radioactivity was, at all analysed time intervals, located intracellularly. Thus, it seems promising to use dextran, conjugated with EGF, as a carrier of, for example, toxic radioactive nuclides.

Dextrans↗
PubMed1991

Ultrastructural changes in the gracile nucleus of the rat after sciatic nerve transection.

Ultrastructural changes in the gracile nucleus of the rat have been examined after peripheral nerve injury. The sciatic nerve of adult rats was transected at mid-thigh level, and after survival times ranging from 1 day to 32 weeks sections from the gracile nucleus were prepared for electron microscopic examination. Unoperated animals served as controls. Atypical profiles were regularly observed in the experimental cases at post-operative survival times from 3 days up to 32 weeks. It was sometimes not possible to classify these as preterminal axons or terminals, because synaptic contacts could not be identified. The two most common changes throughout the entire post-operative period were greatly expanded myelinated axons, or unmyelinated profiles containing numerous mitochondria, osmiophilic dense bodies and vacuoles. Atypical profiles were occasionally observed in unoperated control animals. The results clearly show that various types of degenerative changes occur in the gracile nucleus after peripheral nerve injury. These changes differ markedly from previously described transganglionic changes in other systems. It cannot be excluded that some of the changes reflect growth-related reactions, although the typical features of axon regeneration could not be found.

Animals↗
PubMed1990

A superficial corneal lesion of unknown origin.

Three patients are described showing corneal changes of unknown origin previously not described. The changes consist of discrete opacities mostly located in the epithelium of the cornea. The opacities are arranged in a continuous are originating from the limbus with the vertex extending towards the optic zone. The cornea inside and outside the arc was normal during the early stages of the disease. In two of the cases a progress of the changes were recorded and a stromal opacity developed inside the arc. The three cases were all unilateral. Bacterial and fungal cultures, virus isolation, several blood tests, serology and immunological tests have been negative. Light- and electron microscopy of biopsied material show intracellular specific epithelial cell changes in the form of perinuclear vacuoles. None of the treatments tried were successful.

Adult↗
PubMed1990

Implantable drainage after major abdominal surgery in compromised patients.

The risk of superinfection following routine abdominal drainage after major surgery is debated. Especially in patients with malignant diseases and a compromised host defense, this might be a factor increasing morbidity and mortality. During a 3-year period (1986-1988) 41 patients operated on for malignant abdominal conditions received a peritoneal catheter connected to a subcutaneous portal inserted in order to participate in a trial on postoperative intraperitoneal chemotherapy using 5-Fluorouracil. No abdominal drains were inserted. In 15 patients, the subcutaneous portal was used for evacuation of postoperative fluid accumulation within the abdomen. The mean age was 53 (range 41-70) years. Inserted catheters were used for drainage up to 14 days postoperatively. The daily amount of fluid drained varied from 20 to 2,000 ml with a mean of 610 ml/patient and day. One patient required removal of the catheter due to infection around the subcutaneous chamber. Otherwise, the catheter system was not associated with any other complications or complaints. One patient developed a postoperative left subphrenic abscess drained percutaneously by the guidance of ultrasonography, a complication that could not be attributed to the catheter system but merely to the major operation per se. An implantable device for peritoneal access thus also seem useful for drainage of postoperative fluid collection, as evaluated in this preliminary report.

Abdominal Neoplasms↗
PubMed1989

Heparin surface modified intraocular lenses implanted in the monkey eye.

The biocompatibility of heparin surface modified poly(methyl methacrylate) intraocular lenses (IOLs) was evaluated in two experiments following implantation in the anterior and posterior eye chambers of adult cynomolgus monkeys. Throughout the study, large inflammatory cells and prominent pigment deposits were seen on the unmodified lenses, whereas the heparin surface modified IOLs remained almost free of precipitates. Similarly, fewer posterior synechias were observed in eyes implanted with surface modified IOLs in the posterior chamber than in eyes implanted with control lenses. Histopathological examination of enucleated eyes confirmed the clinical findings. These experiments strongly support the idea that surface modification with heparin is a useful way to reduce clinical complications following cataract surgery with IOL implantation.

Animals↗
PubMed1985

The effect of sciatic nerve transection on myelinated fibers in the L5 dorsal root and lumbar dorsal column. A Marchi study in the rat.

The occurrence of Marchi-positive structures (MPS) in the L5 dorsal root and lumbar dorsal column was examined 1-18 weeks after unilateral sciatic nerve transection in rats, and compared to the occurrence of MPS during Wallerian degeneration seen after transection of L4 and L5 dorsal roots. There was an increasing number of MPS centrally to the junction between the peripheral (PNS) and central nervous system (CNS) and in the lumbar dorsal column ipsilateral to sciatic nerve transection throughout the examined time period. In the portion of the root distal to the PNS-CNS junction MPS were rare before 12 weeks postoperatively after which time small groups of MPS appeared. At all stages the incidence of MPS was just a fraction of that seen during Wallerian degeneration. From these observations it is inferred that few ganglion cells with myelinated central processes undergo complete disintegration after peripheral nerve transection. In addition, some of the myelinated central ganglion cell processes appear to be more severely affected proximal to the PNS-CNS junction than distally to it.

Animals↗