Search PubMed⌕ Search

Biomedical subjects

A Holm

Publications and source records attributed to A Holm.

At least 109 records · Page 6Linked to original sources

The T-lymphocyte proliferative response to synthetic peptide antigens of defined secondary structure.

Immunodominant sites in proteins recognized by T lymphocytes are segments consisting of at least 7-8 amino acids. It has previously been proposed that these sites in proteins are alpha-helical and amphipatic structures. We synthesized and investigated the immunogenicity of three synthetic peptides (MP7, MP8, and MP9), each consisting of the same 15 amino acids, but differing with respect to sequence. Based on information analysis and circular dichroism measurements, MP7 was shown to have an alpha-helical secondary structure and, based on previously assigned hydrophilicity indices, was also strongly longitudinally amphipatic. MP8 also was conformed as an alpha-helix, but was amphipatic in the sense that the N-terminal half of the molecule was hydrophilic and the C-terminal half hydrophobic. MP9 had neither an amphipatic nor alpha-helical structure. All three peptides were immunogenic in some strains of mice but none was immunogenic in all strains. This supports other studies concluding that amphipaticity per se is neither a necessary nor sufficient requirement for immunogenicity of a peptide. On the other hand, the present experimental data suggest that longitudinally amphipatic alpha-helical peptides may function better as T-cell determinants than the other peptides investigated.

Amino Acid Sequence↗

In vivo chemotaxis evoked by Actinobacillus actinomycetemcomitans and Haemophilus aphrophilus.

The chemotaxis-evoking capacity of 5 Actinobacillus actinomycetemcomitans and 5 Haemophilus aphrophilus strains were studied in a tissue cage model in rabbits. A significant increase of the total number of polymorphonuclear leukocytes was induced in the tissue cage fluid by both viable and killed bacteria, reaching a maximum after 12-24 h. In parallel, the proportion of viable/non viable leukocytes increased. The leukocyte counts declined during the following 24-48 h in all chambers except in those inoculated with viable cells of H. aphrophilus. The H. aphrophilus strains survived the 72 h experiment while A. actinomycetemcomitans decreased to undetectable levels within 24-72 h. Lactate dehydrogenase and lysozyme activities in cage fluid increased in all but the uninoculated chambers. Viable bacteria induced higher activities of the enzymes than killed ones. It is concluded that both species of bacteria exhibit similar chemotaxis evoking properties. A strain dependent ability to induce release of leukocyte-associated enzymes exists.

Actinobacillus↗

Short- and long-term effectiveness, morbidity, and mortality of peritoneovenous shunt inserted to treat massive refractory ascites of nephrogenic origin analysis of 14 cases.

The experience with 14 patients with end-stage renal disease (ESRD), 13 of them maintained on chronic hemodialysis (x 20.4 months +/- 2.9 SEM) and one following successful renal transplantation, underwent placement of a peritoneovenous shunt (PVS) for refractory ascites that had been present before insertion from two to 15 months (x 5.3 +/- 0.8 SEM). A "specific" cause for the ascites could not be identified in any of the 14 patients. The ascites was an exudate in every patient (protein content greater than 3.5 gm/dl). Twelve patients (86%) obtained significant relief of the discomfort and all effects of the ascites, and objective clinical improvement persisted for at least six months. Nine patients (75%) survived one year and six (50%) survived three or more years. Three patients (21%) had recurrence of ascites because of shunt malfunction; however, two of them were successfully treated with placement of a second shunt. Eight (57%) patients have died since the onset of their ascites (x 14.1 months +/- 3.5 SEM); one death was attributable to PVS placement, while the other seven deaths were due to complications of their ESRD. Insertion of a PVS is an effective therapeutic alternative to palliate the discomfort and ill effects of massive nephrogenic ascites that is often refractory to hemodialysis with ultrafiltration.

Adult↗

Response of glucagonomas to surgical excision and chemotherapy. Report of two cases and review of the literature.

The glucagon-producing pancreatic tumors or glucagonomas are among the rarest forms of islet cell tumors; most are malignant and usually produce a definite clinical syndrome. Mild diabetes mellitus, weight loss, and anemia usually accompany the syndrome. However, only the presence of a peculiar cutaneous rash (necrolytic migratory erythema) and the finding of hyperglucagonemia on assay are reliable diagnostic features of the syndrome. Selective, celiac axis arteriography is the most valuable preoperative technique for localizing these neoplasms and their common liver metastases. Immunohistochemical and ultrastructural examinations are particularly helpful in defining the tumor cell nature (alpha-2 islet cell) and the peptide content (glucagon). When the tumor is benign (less than 30%), complete operative removal results in lasting cure; for malignant forms, surgical therapy is mainly palliative, and adjunctive chemotherapy should be administered. In this report, the importance of clinical recognition and operative and chemotherapeutic responses is illustrated in two patients. In each case, the characteristic dermatitis, diabetes mellitus, weight loss, anemia, and elevated plasmatic glucagon were present. Both patients had their tumors localized by selective angiography and underwent operative removal of the primary pancreatic lesion. In the case of benign glucagonoma, surgical excision was curative. In the malignant one, cytoreductive surgery plus adjunctive chemotherapy (dimethyltriazenomidazole-carboxamide resulted in prolonged survival and significant clinical improvement. Follow-up with serum glucagon assay has been useful in monitoring recurrence.

Adenoma, Islet Cell↗

Arthroscopic suture of peripheral meniscal tears.

Twenty-nine patients underwent meniscal repair using an inside-to-out technique and instruments developed in our department. The tears were more than 1.5 cm in length, vertical, and located in the outer third of the meniscus. The torn segment was mobile, the remainder of the meniscus stable. After six months, fourteen out of sixteen patients achieved a good or excellent Lysholm knee score. We conclude that the technique is safe and reliable and allows better access than an arthrotomy. Care must be taken to avoid neurovascular injury.

Adolescent↗

Diaphragmatic rupture due to blunt trauma: morbidity and mortality in 42 cases.

We present an analysis of 42 cases of acute rupture of the diaphragm by blunt trauma. There were 31 men (74%) and 11 women (26%); the mean age was 32.8 years +/- 2.4 SEM. At admission, hypovolemic shock was present in 45% of the cases, pelvic fracture in 36%, and severe respiratory distress in 21%. Diaphragmatic rupture was suggested before operation by unilateral elevation of the diaphragm, supradiaphragmatic densities, and displacement of abdominal organs into the thorax, as shown by chest films and GI series in 18 cases (43%). The left hemidiaphragm was injured in 24 cases (57%), the right in 15 (36%), and both sides in three (7%). Of the 17 patients (40%) found to have an abdominal organ in the thorax, 12 had had a left-sided rupture. Only four patients (10%) had solitary diaphragmatic injuries. Associated injuries (usually two or more) occurred in 38 cases (90%); they were abdominal in 34, musculoskeletal in 26, neurologic in 16, and thoracic in nine. The injuries were repaired through a celiotomy in 33 cases, by thoracotomy in six, and by separate celiotomy and thoracotomy in three. Postoperative complications occurred in 29 cases, the most common being pulmonary (18), systemic sepsis (six), and recurrent bleeding (three). There were 14 deaths, for a mortality of 33%. Seven were operative and due to massive hemorrhage; the late deaths were caused by systemic sepsis in five and neurologic trauma in two. We conclude that (1) diaphragmatic rupture after blunt trauma must be suspected when specific radiologic findings are present; (2) solitary diaphragmatic injuries seldom occur; (3) in most cases, morbidity or mortality is caused by the severity of the associated injuries; and (4) most diaphragmatic injuries can be repaired through a celiotomy, and all of them should be repaired to avoid the sequela of entrapment of abdominal organs in the thorax.

Accidents, Traffic↗

Improved selective culture media for Actinobacillus actinomycetemcomitans and Haemophilus aphrophilus.

By modifying the previously described media tryptic soy-serum-bacitracin-vancomycin (TSBV) agar and tryptic soy-serum-bacitracin-vancomycin-fluoride (TSBVF) agar, two improved selective culture media were developed for isolation and enumeration of Actinobacillus actinomycetemcomitans (A medium) and Haemophilus aphrophilus (H medium) in oral specimens. Both media were supplemented with fusidic acid and spiramycin, and carbenicillin was also added to A medium. The growth yields of pure cultures of A. actinomycetemcomitans on A medium and of H. aphrophilus on H medium were comparable with those on the reference media. Compared with blood agar, the selective media inhibited these species about 10-fold or less. In addition, A and H media suppressed the growth of pure cultures of Capnocytophaga spp. and Neisseria spp., commonly found as contaminants on TSBV and TSBVF, 10(5) times or more compared with that on blood agar. In samples from diseased periodontal pockets, the recoveries of A. actinomycetemcomitans on A medium and H. aphrophilus on H medium equaled those on TSBV and TSBVF, respectively. In about 50% of the cultures on the reference media, contaminating bacteria were detected at levels higher than 10(4) CFU/ml of sample. The corresponding value for both A and H media was about 2%.

Actinobacillus↗

Improvement of subcutaneous nutritional blood flow in the forefoot by hydroxyethylrutosides in patients with arterial insufficiency: case studies.

Four patients with bilateral arterial insufficiency were treated with i.v. hydroxyethylrutoside for three days (1.5 grs twice a day). All patients experienced relief of symptoms. By continuous registration of subcutaneous nutritional blood flow in the forefoot (by 133Xenon clearance technique) a significant increase in nutritional blood flow of 33% on the average during the second and third hour after medication could be demonstrated. The drug seems to be of use in treating subacute occlusions and thrombosis of arteries in the lower extremity.

Aged↗

Function after lower limb amputation.

Functional ability and social dependence were investigated by personal interview of 107 lower limb amputees surviving 1-5 years postoperatively. Among eight independent variables studied by multiple regression analysis, increased age was associated unfavorably with physical ability and social dependence. Independence from social provisions preoperatively showed favorable relationships with functional capacity and postoperative dependence. Above-knee or bilateral amputation and postoperative pain were associated with reduced functional ability, but not with social dependence. No significant association was found with cause of operation or sex of the amputees. The importance of proper prosthetic fitting and pain control is emphasized.

Activities of Daily Living↗