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Biomedical subjects

C Hammer

Publications and source records attributed to C Hammer.

At least 235 records · Page 13Linked to original sources
PubMed1984

Spleen transplantation in the dog as a model for studying immunological feedback reactions.

Modification of the immune response towards the generation of suppressor T cells can be attained using experimental designs promoting immunological feedback mechanisms. Those studies have been carried out in defined inbred animal systems. With respect to the great importance for organ transplantation, an in vivo model using larger outbred animals was developed in order to study such feedback reactions. The following experimental design was used: (1) allogeneic spleen transplantation in the dog; (2) autologous retransplantation of this spleen together with an allogeneic kidney transplantation to the former donor of the spleen after a period of 2-4 days. Although full immunological activity of the transplanted as well as the retransplanted spleen was demonstrated, rejection of the kidney occurred in a fashion identical to that observed in control animals.

Animals↗
PubMed1984

Analysis of in situ inflammation of allogeneic canine kidney grafts under antilymphocyte globulin treatment.

15 mongrel dogs receiving allografts were treated with antilymphocyte globulin (ALG; 20 mg/kg b.w. daily). The kinetics and distribution of inflammatory cells invading the transplant were analyzed by transplant aspiration cytology. Only transplant aspiration cytology enables one to observe the direct influence of ALG within the grafts themselves. Although a low-potency ALG was used, ALG-treated animals showed a significant long-term suppression of the in situ inflammation of lymphocytes (p less than 0.05) and lymphoblasts (p less than 0.05) during the entire experimental period. Other leucocyte populations were influenced to a lesser degree. This in situ reduction combined with a significant prolongation of graft function (p less than 0.001) establishes the beneficial effect of ALG in suppressing cell-mediated immune responses in renal allografts.

Animals↗
PubMed1984

Infrared contact coagulation: a new approach for local hyperthermic therapy of solid animal tumors.

Infrared contact coagulation (ICC) was evaluated in 3 different tumor models. 56-94% of all tumor-bearing rats, hamsters or mice were cured by ICC, whereas 100% of the controls died. The possibility that long-lasting immunological resistance might develop against the tumor after ICC was investigated by repeated tumor challenge. Cytotoxicity against tumor cells of host thymocytes and splenocytes following ICC was demonstrated in a Winn assay. The production of a mainly T-cell-dependent immune response could be due to ICC-induced antigenic changes in the tumor cells.

Animals↗
PubMed1984

Lung involvement in scleroderma.

Lung involvement (LI) was studied by lung function (LF) in 101 scleroderma patients (circumscribed scleroderma, n = 17; progressive systemic scleroderma [PSS], n = 84; with the subtypes I, acroscleroderma [n = 19]; 2, proximal ascending scleroderma [n = 61]; 3, trunk scleroderma [n = 4]). Eighteen percent of morphea, 32 percent of type 1, 56 percent of type 2, and 75 percent of type 3 patients had impaired LF. The LI was more frequent (57 percent vs 45 percent) and more severe (20 percent vs 3 percent) in PSS with systemic inflammation (form A) compared to those without (form B). Elevated lymphocytes/neutrophils in bronchoalveolar lavage (BAL) were found associated with form A and severe LI. The LF of patients showing an inflammatory cell pattern in initial BAL (n = 3) worsened, whereas those with normal BAL findings (n = 4) did not. Collagenase activity in BAL was significantly elevated in those with elevated lymphocytes/neutrophils in lavage. Patients with type 2 or 3 of PSS, especially form A, carry a higher risk of developing severe LI than circumscribed scleroderma, type 1, or form B patients. Differential cell count and collagenase activity in BAL is correlated with active disease and provides prognostic information.

Adolescent↗
PubMed1984

[What is new in plastic surgery of the head and neck for the practicing otorhinolaryngologist?].

On examples the plastic facial surgery is shown as an multidisciplinary territory, whereby main points are set. Most important for the oto-rhino-laryngology is the ear and nose correction as whereas the possibility to use collagen injections, the problems of secondary Rhinoplastics, the esthetic corrections in the area of the throat and head (dermabrasio, eye lid corrections, face lifting, hair transplantation) and considerations about education and advanced training. The maxillo facial surgery puts out the dento-alveolic dysgnathies, the ophthalmology the eye lid corrections. The experimental surgery can contribute to the still open questions, whether in the future in plastic operations allogene transplantates can fill the place of autogenous material or not.

Collagen↗
PubMed1983

[Immunologic reactions following heart transplantation and their detection].

Transplantation antigens of the major histocompatibility complex are able to stimulate the rejection of the graft. Class I and class II antigens presented by dendritic cells to the host macrophages are found on parenchymal cells (class I) or combined on all passenger leucocytes. Humoral factors like interleukin 1 produced by the macrophages activate the helper-lymphocyte subpopulation. The cytotoxic effector cells but also antibody producing B-cells receive their signal (interleukin 2) from the helper cells. Cellular and humoral mechanisms attack the vascular endothelium and the endocard first. Typical perivascular infiltrates or antibodies on the sarcolemm of myocard fibres and the intima herald the two types of rejection. The activated lymphocytes and their blast forms recirculate in various amounts in the peripheral blood, reflecting the severity of the event. Hematological evaluation including differentiation of lymphocyte subsets by monoclonal antibodies according to their phenotype seem to be a tool to recognize these mechanisms at an early stage. It is suggested that the optimal therapy and the necessary biopsy can be adjusted even more precisely using this immunological monitoring.

Antibody Formation↗
PubMed1983

Lysis of paroxysmal nocturnal hemoglobinuria erythrocytes by acid-activated serum.

Erythrocytes from paroxysmal nocturnal hemoglobinuria patients (PNH-E) are much more susceptible to lysis by acid-activated human serum than normal human erythrocytes. Acidification of normal human serum to pH 6.4 in the absence of erythrocytes generates this lytic activity independently of the alternative pathway of complement activation. A shift of pH of a mixture of purified human C5 and C6 to 6.4 at 0 degrees C generates a similar activity C(56)a that lyses PNH-E together with C7-C9 much more efficiently than normal erythrocytes. Since acid-activation of normal human serum occurs in the absence of C3, the acid-activated C56 appears to be the lytic principle in acidified human serum.

Animals↗
PubMed1983

Transplant aspiration cytology for monitoring of kidney xenograft (wolf-dog) under cyclosporin A treatment.

Mongrel dogs receiving wolf kidney grafts were treated with Cyclosporin A. The kinetics of the inflammatory response and the display of major histocompatibility (MHC) antigens on graft tubular cells were analyzed by transplant aspiration cytology. Tubular cells aspirated from grafts that underwent repeated rejection episodes showed a higher degree of MHC antigen expression than cells obtained from a well-functioning graft.

Animals↗
PubMed1983

Studies on the mechanism of bacterial resistance to complement-mediated killing. III. C5b-9 deposits stably on rough and type 7 S. pneumoniae without causing bacterial killing.

Gram-positive cocci resist direct killing by serum. The mechanism of resistance was studied by measuring consumption of terminal complement components from serum and uptake of purified, radiolabeled C7 and C9 on rough and encapsulated type 7 Streptococcus pneumoniae. Extensive consumption of C5, C7, and C9 occurred when 5 X 10(8) rough or type 7 pneumococci were incubated for 1 hr in 10% pooled normal human serum (PNHS). Approximately 10,000 molecules of C7 and C9 bound per organism during the same period of incubation. Twenty to 30% of C7 and C9 was released from rough organisms. Release was not due to autolysis since it occurred with glutaraldehyde-fixed organisms as well as in S. pneumoniae that were rendered resistant to autolysis by growth in ethanolamine. Between 10 and 30% of bound 125IC9 counts were eluted from the rough and type 7 organisms by incubation in 1 M NaCl or 0.01 M EDTA, which suggests that bound C5b-9 was not attached by predominantly ionic interactions. Elution of 44 to 74% of 125IC9 from live and glutaraldehyde-fixed organisms by 1% sodium deoxycholate suggests that hydrophobic bonds are involved in C5b-9 attachment. Trypsin cleaved 67 and 55% of 125IC9 counts from live rough and type 7 S. pneumoniae, respectively which indicates that the bound complex is not protected by the cell wall from proteolytic attack. Serum resistance in S. pneumoniae does not represent a failure to form C5b-9 on the bacterial cell wall but apparently reflects a failure of the bound complex to penetrate the thick peptidoglycan layer.

Blood Bactericidal Activity↗
PubMed1982

[Report on a successful orthotopic cardiac transplantation in Germany].

The first successful heart-transplantation carried out in the Department for Cardiovascular Surgery of the University of Munich, Klinikum Grosshadern is reported. The recipient, 32 years old at the time of operation, had sustained a large antero-lateral-septal myocardial infarction in June 1980; thereafter the left ventricular ejection fraction was severely impaired (e.f. = 19%). Yet, the operation was definitely planned some year later, after the patient had survived an embolus to the right lung, an acute left heart failure and a small ulcer of the stomach. The operation was performed on 8-19-1981. The donor was a 23 year old young man, who had met a fatal motorcycle accident 10 days ago. The man was pronounced dead in the afternoon of the preoperative day according to the criterions of the German Society for Surgery by means of a carotid angiogram. Donor and recipient were well matched in regard to blood group, HLA-A2-System and finally cross-match-test. Transplantation was carried out according to the technique of Lower and Shumway. Immediately p.o., immunosuppressive therapy was started using azathioprine, cortisone and antihuman thymocyte globulin. Two acute rejections were noted, the first from p.o. day 6 to 15, the second from p.o. day 22 to 34. The second acute rejection was complicated by a pneumatosis cystoides intestinii, which caused a change of the immunosuppressive therapy to Cyclosporin A. No further complications were registered in the following p.o. course, the patient is discharged since Christmas 1981.

Adrenal Cortex Hormones↗