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J Pedersen

Publications and source records attributed to J Pedersen.

At least 19 recordsLinked to original sources
PubMed1993

A new trichrome-blue stain for detection of microsporidial species in urine, stool, and nasopharyngeal specimens.

Detection of microsporidia in clinical specimens has relied on electron microscopy, histology, or staining. This article describes further alterations to the modified trichrome staining method which make it easier to identify microsporidial spores. The changes are a decrease in the phosphotungstic acid level and the substitution of a colorfast counterstain, aniline blue, for the fast green of the original stain. The modified stain provides good contrast between microsporidial spores and background material including human and fungal cells. Stool specimens from 139 human immunodeficiency virus-seropositive patients revealed that 5 patients were infected with Enterocytozoon bieneusi and 6 patients had larger spores. Thin-section electron microscopy of the larger spores showed a structure consistent with that of either Encephalitozoon or Septata species. Three of the patients with Encephalitozoon- or Septata-like species had disseminated infection, with spores detected in nasopharyngeal aspirates and urine samples.

AIDS-Related Opportunistic Infections↗
PubMed1992

Correlation of the conformation of a modified ribonuclease octapeptide, homologous to peptide T, with its ability to induce CD4-dependent monocyte chemotaxis.

Peptide T, from the human immunodeficiency virus (HIV), whose sequence is Ala-Ser-Thr-Thr-Thr-Asn-Tyr-Thr, has been shown to inhibit attachment of this virus to T cells and neural cells bearing the CD4 receptor. This peptide shares extensive homology with the 19-26 segment of ribonuclease A (RNase A), whose sequence is Ala-Ala-Ser-Ser-Ser-Asn-Tyr-Cys. Based on comparison of the structures of peptides occurring in proteins of known structure that are homologous to peptide T, viz, RNase A and endothiapepsin and on conformational energy calculations, we predicted that peptide T adopts a structure much like that for residues 19-26 in RNase A. A critical feature is a bend involving residues Thr 4-Asn 7 in peptide T corresponding to Ser 22-Tyr 25 in the RNase A peptide. Our proposed structure for peptide T has recently been confirmed by Cotelle et al. (Biochem. Biophys. Res. Commun. 171, 596-602). We now show directly that the RNase A peptide, with Met replacing Cys 26 to prevent disulfide exchange reactions, strongly induces monocyte-chemotaxis that is blocked by anti-CD4 monoclonal antibody. Both peptide T and RNase A fail to induce chemotaxis, however, in neutrophils which do not express surface CD4 receptors. These results suggest that both peptides interact with the CD4 receptor in inducing monocyte chemotaxis. We have also prepared cyclo-RNase A peptide with Met 26. Using molecular dynamics and conformational energy calculations, we find that the cyclic peptide cannot form a bend structure involving Ser 22-Tyr 25 that is superimposable on the RNase A bend.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1992

Do burn patients have a silver lining?

Silver-containing pharmacological preparations have been used for many years in the prophylaxis and management of burn wound sepsis and, more recently, 1 per cent silver sulphadiazine cream (SSD) has been the treatment of choice for such problems. A prospective clinical study has been undertaken to determine the absorption and effects of the silver ion from SSD, with particular reference to hepatic and renal function. Twenty-two patients were studied. The silver assay was done by atomic absorption spectrophotometry with an attached graphite furnace. The detection level was 0.5 micrograms/l. The precision at 3.5 micrograms/l was 4.8 per cent and at 8.5 micrograms/l was 2.8 per cent. Silver was rapidly absorbed through the burn wound and serum silver levels were elevated in 20 patients. Silver was found to be deposited biochemically and electronmicrographically in the liver and kidneys of the only patient who died in the study group. Early hepatic dysfunction was present in all burns greater than 10 per cent total body surface area. Liver and renal function tests did not correlate with serum silver levels. A urinary threshold to silver excretion was seen at a serum silver level of 100 micrograms/l. This study demonstrates that silver is rapidly absorbed through burn wounds, is deposited in large amounts throughout the body but appears safe when used in the treatment of moderate burns. Whether the very high levels recorded in the subject who died were inherently detrimental will remain a matter for speculation.

Absorption↗
PubMed1992

Autotransposition of vas in a 2-stage procedure. An experimental study in the rat.

The patency rate of vasovasostomy in autotransposed vas has been studied using a technique set up in a rat model. In a two-stage procedure, 1 cm of the vas deferens was transposed to the opposite side. The anastomoses were performed with a simplified microsurgical suturing technique. On final examination, 9 of 15 rats operated upon showed good sperm passage over the transposed vas segment. Sperm granulomas were recorded in four of fifteen cases. Sperm antibodies were demonstrated in eight of fifteen cases.

Anastomosis, Surgical↗
PubMed1991

Is minitracheotomy a simple and safe procedure? A prospective investigation in the intensive care unit.

Patients with imminent respiratory failure due to sputum retention were assessed for minitracheotomy (MT). MT was considered potentially useful in 79 patients but only attempted in 73, 54 men and 19 women, aged 23-81 years (median 65 years). Insertion of the cannula failed in 4 cases. Sputum retention and atelectasis were successfully treated in 87% (N = 60). Treatment by MT in medical and neurological patients seems as effective as in surgical patients (success rate 81% versus 90%). The frequency of complications was 16%. Most complications were insignificant and occurred during cannulation, but a few severe complications were seen. To minimize the number of these it is essential that MT is done only by doctors who are familiar with the procedure. MT can be recommended for treatment of sputum retention and atelectasis in surgical and medical/neurological intensive care patients with preserved cough function.

Adult↗
PubMed1991

Bladder carcinoma--a 20-year review of radical irradiation therapy.

Between 1967 and 1986, 319 patients, judged unsuitable for cystectomy, were scheduled to receive curative radiation treatment for transitional cell cancer of the urinary bladder. Crude and corrected 5-year survival for all stages were 18% and 28%, respectively. Corrected 5-year survival by stage was: T1-57%, T2-31%, T3-16% and T4-6%. Fifty-seven patients (18%) never completed the scheduled treatment and all but two of them died in a short time from tumour progression. Local response could be evaluated in 179 of the 262 patients, who completed the radiation treatment. In 130 patients (73%) complete local response was observed and 49 patients (27%) had persistent tumour. Corrected 5-year survival in the responder group was 53% compared to 8% in the non-responder group. Intestinal complications occurred in 51 patients, of whom 24 were operated upon and another four died before operation from radiation-induced intestinal complications. More than 80% of all intestinal and/or urinary tract complications were observed within 3 years after irradiation. During this period, special attention should be paid to detect and treat radiation complications to prevent fistula formation or perforation, with poor prognosis. The dose per radiation fraction and the radiation technique appeared to be the most important factors for the development of intestinal complications.

Female↗
PubMed1991

Aberrant expression of intestinal mucin antigens associated with colorectal carcinoma defined by a panel of monoclonal antibodies.

Small intestine mucin antigen (SIMA) is an oncofoetal antigen for the colon and is distinct from the normal large intestinal mucin antigen (LIMA). In the present study, a panel of anti-SIMA and anti-LIMA monoclonal antibodies (MAb) was used to charaterise altered mucin expression in colorectal adenocarcinomas, by immunohistochemistry and quantitative immunoassays of tissue extracts. These results are compared with CEA expression and correlated with various clinicopathological indices. All mucin MAb reacted with a high proportion of the 100 colon cancers of every stage, histological type (including non-mucinous cancers), differentiation, site, or size. Inappropriate SIMA production was detected by either anti-SIMA MAb 4D3 or 4A1, even in 85% of early stage cancers. MAb 4D3 reacted with a higher proportion of cancers of smaller size and better differentiation. At the subcellular level, both anti-SIMA MAb showed reactivity typical of normal mucin, i.e., goblet cell and extracellular mucin. The normal colonic antigen, LIMA, was also detectable in the majority of cases, but quantitatively overproduced in some cases and reduced in others. However, in contrast to SIMA, LIMA was detected in predominantly undifferentiated cancer cells but not in goblet cells. Heterogeneity of MAb reactivity between cases and complementarity within each cancer was frequently observed. Mucin reactive with at least one of the MAb was detected in all of the CEA-negative cancers. A high rate of inappropriate SIMA expression was also detected in the perineoplastic transitional mucosa (88%, c.f. CEA, 35%) and adjacent, morphologically normal mucosa (80% c.f. CEA, 24%), indicating biochemical changes similar to the cancer. This panel of anti-mucin MAb demonstrated altered mucin glycoprotein metabolism associated with the development and progression of most colorectal cancers, which emphasises their utility as indicators of neoplastic change in the colon, and their superiority to CEA.

Aged↗
PubMed1991

Anaesthetic equipment for a developing country.

A development aid project to Malawi is described. This involved the development of a suitable anaesthetic machine for use in under-developed countries and the selection of a suitable oxygen concentrator to provide it with air and oxygen. All government hospitals were provided with anaesthetic equipment and personnel were trained to keep it regularly serviced. Follow up testing of reliability was undertaken. The cost benefit to the country amounted to 234,084 pounds (sterling) per year. This is the first instance of widespread use of standardized anaesthetic equipment which includes oxygen concentrators.

Anesthesiology↗
PubMed1991

The effect of nasotracheal intubation on the paranasal sinuses. A prospective study of 434 intensive care patients.

A total of 434 patients admitted to the intensive care unit for mechanical ventilation were followed prospectively to investigate the influence of a nasotracheal tube on the paranasal sinuses. Twenty-five patients died before the examination was completed. The rest were examined for clinical symptoms of sinusitis. If sinusitis was suspected or the patients were intubated for 5 days or more, an x-ray of the sinuses was performed. In patients intubated for less than 5 days (N = 357), sinusitis was clinically suspected in three, but radiographically verified in only one. In patients intubated for 5 days or more (N = 47), 23 (49%) had affection of the paranasal sinuses. Patients needing a nasotracheal tube should be examined for sinusitis if they are intubated for more than 5 days or if unexplained fever, sepsis or purulent nasal secretion develops. If the suspicion is confirmed, the nasotracheal tube should be removed.

Adult↗
PubMed1991

Conflict and its resolution in small groups of one- and two-year-olds.

48 1- and 48 2-year-olds were observed in groups of 3 for 25 min on 2 consecutive days, once with ample resources and once with scarce resources. The triads were composed of either 2 girls and a boy or 2 boys and a girl, and duplicate copies of toys were available for half the groups. Their conflicts contained interpersonal features and were more affected by social influences than by the availability of resources. Contrary to expectations, scarcity of resources did not result in increased conflict. In fact, 2-year-olds were more likely to resolve conflict by sharing when toys were scarce. The provision of duplicates decreased the probability of conflict, but many conflicts occurred even when a duplicate was easily accessible. The form of conflict depended on the children's age and the gender composition of the group. Older children and groups dominated by boys, relative to younger children and groups dominated by girls, were less likely to use force and more likely to resolve disputes in prosocial ways. Taken together, these findings provide further evidence for the social nature of conflict in the first few years of life.

Child, Preschool↗
PubMed1990

In vivo processing of N-terminal methionine in E. coli.

The processing of amino-terminal methionine from cytosolic proteins in E. coli has been investigated in vivo, using amino-terminal-extended human growth hormone (hGH) as a model system. Twenty different hGH-genes with the sequence Met-Xxx-Glu-Glu-hGH where Xxx denotes each of the 20 different amino acids, were constructed and expressed in E. coli. Following purification of the products, the N-terminal amino acid sequences (10 cycles) were determined. The results demonstrate that the removal of methionine is dependent on the amino acid adjacent to methionine, and that the processing is strongly correlated to the radius of gyration of this amino acid. In addition, measurement of the hGH expression level from the 20 clones demonstrated that the small difference in the amino acid extension leads to a change in the specific hGH expression rate.

Amino Acid Sequence↗
PubMed1990

[Sinusitis caused by nasotracheal intubation].

Sinusitis following nasotracheal intubation (NTI) is an almost overlooked complication. The pathogenesis is believed to be development of oedema of the nasal mucosa due to irritation by the tube in the nasal cavity. The size of the tube is probably not important, whereas the duration of intubation is of major importance. The infection is often caused by Gram-negative microorganisms. The frequency is found to be 0.3% in short term intubation (less than 5 days) and 40.4% in long term intubation (greater than 5 days). In neurosurgical patients treated with NTI sinusitis is found in 52% and 100% of the patients. In adults the indications for prolonged NTI instead of orotracheal intubation and early tracheostomy should be considered carefully. If fever or sepsis develops in patients treated with NTI, investigations for sinusitis should be included in the search for focus. When sinusitis has developed, the tube should be removed, and the patient tracheostomised. If this treatment fails, surgical drainage should be performed.

Humans↗
PubMed1990

Isolation of transferrin from porcine gastric mucosa: comparison with porcine serum transferrin.

1. An iron-binding glycoprotein has been purified to homogeneity from porcine gastric mucosa. 2. The molecular weight (80,000), amino acid composition, carbohydrate content, N-terminal amino acid sequence, tryptic map, stoichiometry of iron binding (2 mol/mol), visible absorption spectrum of the ferric complex and chromatographic behaviour of the gastric protein are all strikingly similar to the corresponding properties of porcine serum transferrin. 3. The quantity of the gastric protein (1.3 mg/g wet weight) present in the gastric mucosa suggests that it is not serum transferrin (plasma concentration 1.8 mg/ml) contaminating the tissue. 4. A role for transferrin in the uptake of dietary iron by the gastrointestinal tract is proposed.

Amino Acid Sequence↗
PubMed1990

The model Malawi.

Explore the source record for details and available documents.

Anesthesiology↗
PubMed1990

Exaggerated reaction to insect bites in patients with chronic lymphocytic leukemia. Clinical and histological findings.

We report three patients with chronic lymphocytic leukemia with unusual vesiculo-bullous skin eruptions on exposed areas which were more commonly noted in spring and summer. The lesions appeared to be due to insect bites and could be differentiated from other causes on the basis of histological, immunohistological and clinical features. There was no correlation between the occurrence of the skin eruptions, disease status and treatment modalities. Exaggerated cutaneous reaction to insect bites should be considered as a cause of vesiculo-bullous lesions in patients with chronic lymphocytic leukemia.

Adult↗
PubMed1990

Antibody-combining sites: prediction and design.

For maximum value, a predicted model of an antibody-combining site should have an accuracy approaching that of an X-ray structure (1.6-2.7 A). In addition, the method by which the combining site is modelled should make no demands on the user of a sort that require arbitrary or subjective decisions to be made during the process. We have made substantial progress towards this objective and some recent results are reviewed. In addition, we describe how the modelling protocols developed can aid in the design of novel features within the antibody-combining site. The particular design example reported here suggests an approach for the introduction of metal-binding sites to create metallo-antibodies. This type of modification may be useful in the design of immunobiosensors, the induction of catalytic activity or simply as an alternative to metal chelates in the preparation of antibodies for imaging.

Algorithms↗
PubMed1989

Crystallization and X-ray data collection on human growth hormone.

Single crystals of natural sequence human growth hormone have been grown from media containing ethanol, acetone or paraldehyde. Recombinant growth hormone in its native and desamidated form and pituitary hormone have been crystallized. A full native set of diffraction data extending to 3.5 A resolution has been obtained with synchrotron radiation for crystals of recombinant human growth hormone grown from ethanol. The identity of the material in these crystals has been established by anion-exchange chromatography.

Chromatography, Ion Exchange↗