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Biomedical subjects

F Frank

Publications and source records attributed to F Frank.

At least 73 records · Page 4Linked to original sources
PubMed1984

Interception of lymphatic drainage by Nd:YAG laser irradiation in rat urinary bladder.

Lymphatic drainage can be demonstrated by colloidal indian ink injection. A small intramural indian ink spot in the bladder dome is separated from the rest of the rat urinary bladder by encircling transmural Neodymium-YAG (Nd:YAG) laser irradiation. In untreated animals there is an ink flow via the lymphatic vessels to the regional lymph nodes within several hours. In treated animals, after laser irradiation, the indian ink remains in the bladder dome and a penetration of the irradiated area cannot be found by macroscopic and histologic examination. Indian ink will be found in the regional lymph nodes after the ninth day of absorption of the coagulation necrosis and recanalisation of the intercepted lymphatics. Evidence for the interception of the lymphatic drainage is demonstrated by the distinctly delayed ink flow and the injected ink's remaining in the irradiated area. From this, we conclude that Nd:YAG laser irradiation is especially suitable for tumor coagulation, since simultaneous interception of lymphatic drainage will inhibit the spreading of tumor cells.

Animals↗
PubMed1984

Eye-safety requirements for Nd:YAG laser application in gastroenterology, urology, and neurosurgery.

The preconditions relating to radiation safety for application of the Nd:YAG laser in the various fields of open and endoscopic surgery are studied. Potential eye hazards of clinical personnel using a Nd:YAG laser photocoagulator in surgical procedures are investigated and methods of eye protection are discussed. The amount of exposure of the eye to radiation back-scattered from stomach and bladder tissue, as can occur in clinical practice, has been determined for several commercially available rigid cystoscopes and flexible gastroscopes. In addition, the amount of back-scatter from brain and liver tissue has been established under the usual surgical working conditions. The International Electrotechnical Commission (IEC) and the American National Standard Institute (ANSI) provisions relating to laser safety are briefly explained in relation to the use of the Nd:YAG laser. The results of experimental investigations are compared with the maximum permissible exposure (MPE) limiting values as per the IEC and ANSI drafts. The precautions necessary for safe application of the Nd:YAG laser in the various medical spheres are described.

Accidents, Occupational↗
PubMed1984

Effect of ASTA Z 7557 (INN mafosfamide) a precursor of 4-hydroxy-cyclophosphamide on human T-lymphocytes' Fc-receptors and immunoregulatory functions.

The precursor ASTA Z 7557 of the in vivo active metabolite 4-hydroxy-cyclophosphamide (4OH-Cy) of cyclophosphamide (Cy) was tested for selective effects on human T-lymphocytes' Fc gamma-receptor expression and certain immunoregulatory functions. It has been found that ASTA Z 7557 does not alter the expression of Fc gamma-F- or Fc gamma-I-receptors on the T-cell membrane nor does it exhibit differential toxicity for either T-cell subpopulation. PWM-induced B-cell proliferation is inhibited by ASTA Z 7557, whereas B-cells' Ig-synthesis as well as ConA-driven T-cell proliferation is only blocked with higher doses of the reagent. Final concentrations above 1 microgram/ml may therefore abrogate ConA-induction of suppressor T-lymphocytes. Already ConA-activated suppressor cells of PWM-driven B-cell cultures, however, are not inhibited even with high doses of ASTA Z 7557.

B-Lymphocytes↗
PubMed1984

Biophysical basis and technical requisites for the use of Nd-YAG laser in neurosurgery.

The different interactions between laser light and biological tissue are demonstrated for the CO2- and the Nd-YAG-laser by histological examinations. For Neurosurgery the following results became significant: The CO2 laser has become an important tool in contactless cutting and vaporization. The Nd-YAG-laser is suitable as a coagulator whenever the site and vascularity make the removal of a tumour difficult. For the various surgical techniques in Neurosurgery using the Nd-YAG laser, special laser attachments have been developed including micro-surgical and endoscopic instruments.

Biophysical Phenomena↗
PubMed1984

Extraneural metastases from primary pineal tumors. Review of the literature.

Extraneural metastases from primary pineal tumors are extremely rare: only 15 such cases could be found in th literature. Another case is presented of a 10-year-old boy who developed multiple pulmonary and skeletal metastases from a presumed primary pineal germinoma. The incidence and pathogenesis of distant dissemination in the different types of pineal tumors are discussed, with special comment on the controversial role of the direct surgical approach and shunting of cerebrospinal fluid.

Bone Neoplasms↗
PubMed1983

[Destruction of ureteral tumors with the neodymium-YAG laser. A new, organ-preserving surgical procedure].

Only the neodymium-YAG laser is suitable for destroying tumors endoscopically, because it shows a very high transmission through water and a slight absorption in the tissue. It means scattering becomes important and leads to a homogeneous and uniform distribution of the radiation in the tissue producing a deep thermal effect. An examination of a section through a bladder wall under light microscope after neodymium-YAG laser irradiation shows a layered, sharply delimited coagulation necrosis that extends to all of the bladder wall layers and reaches the outermost zones. In this way it is possible to destroy not only the exophytic part of a tumor but also the tumor base in the tissue. Since 1976 we destroyed more than 4000 bladder tumors by laser application. For tumors on the ureter or kidney pelvis a special endoscope, described by Perez-Castro Ellendt and modified by us, can be used, if it is not possible to perform a conventional operation. It is reported about four cases of distal ureter tumors (GI-II) in patients who had refused an operation for removing the tumor bearing ureter segments. Now, for more than one and half a year all patients are free of tumors and the irradiated ureters show a good function. This novel procedure is not for routine, but for high risk patients or patients, who refuse an open operation.

Aged↗
PubMed1983

Transurethral laser coagulation for treatment of urinary bladder tumors.

Owing to the biophysical properties involved, the Nd:YAG laser is most suited for coagulation of even inhomogeneous tissue. We determined the optimal laser parameters for therapy of urinary bladder tumors. Deep homogeneous necroses can be obtained without perforation risk of the bladder wall, and the procedure does not cause dangerous damage to the intestinal loops. We have studied animal experiments by close examination and systematic inquiry, and thus we were able to determine sufficient laser parameters in dependence on tissue thickness. Clinical studies verified these results for living human tissue. After some years of clinical use of the Nd:YAG laser we can make the first statistical statements.

Fiber Optic Technology↗
PubMed1983

Percutaneous trigeminal thermorhizotomy in treatment of malignant facial pain.

Fifty-eight patients suffering from intractable pain in the trigeminal distribution due to neoplasms of the intracranial or facial regions underwent controlled percutaneous coagulation of the Gasserian ganglion (trigeminal thermorhizotomy). Of them, 35 were evaluated at varying time intervals from the intervention (mean: 7 months). While pain was completely relieved in 71 per cent of cases at discharge, the follow-up examination was consistent with 49 per cent of analgesias. The rationale of percutaneous thermocoagulation in malignant facial pain is given and the pertinent literature summarized.

Dermatologic Surgical Procedures↗
PubMed1983

Leptomeningeal angiomatosis and aplasia congenita of the scalp. Case report.

This 9-year-old boy had two circular areas of aplasia congenita of the scalp in the territory of the first division of the trigeminal nerve and an ipsilateral parieto-occipital leptomeningeal capillary venous angioma. He had an associated giant aneurysm of the distal posterior cerebral artery on the same side as the vascular malformation. The patient had a long history of seizures and presented with intracerebral bleeding. This case may be considered as a variant of Sturge-Weber syndrome. Further observations must be added to consider this entity as a separate neurocutaneous disease.

Angiomatosis↗
PubMed1982

Various effects of the CO2-, the neodymium-YAG-, and the argon-laser irradiation on bladder tissue.

Application of lasers as cutting or coagulation instruments is based on the conversion of light energy into heat in the irradiated tissue. The extent and degree of the thermal action depends on the beam geometry and the energy of the incident light, as well as on the optic and thermal properties of this tissue. The extinction behavior in the tissue differs for the various laser systems employed in medicine. A comparison of the effects on bladder tissue of rats and rabbits is made with Neodymium-YAG laser and the argon and CO2 lasers to demonstrate the advantages of the Neodymium-YAG laser, especially for the therapeutic irradiation of bladder tumors.

Animals↗
PubMed1982

CT scan and metrizamide CT cisternography in arachnoid cysts of the middle cranial fossa: classification and pathophysiological aspects.

Thirty-one cases of arachnoid cysts of the middle cranial fossa were investigated by CT scan, 7 of them undergoing additional metrizamide CT cisternography. In this paper we analyze and correlate the different findings from these two examinations and propose a classification of arachnoid cysts of the middle cranial fossa into three basic types. Pathophysiological and surgical implications are discussed.

Adolescent↗
PubMed1982

Stereotaxic rostral mesencephalotomy in treatment of malignant faciothoracobrachial pain syndromes. A survey of 14 treated patients.

Stereotaxic rostral mesencephalotomy was performed 19 times in 14 patients suffering from intractable pain syndromes due to malignant diseases. The satisfying results in terms of pain relief during a necessarily short follow-up period (mean 4.9 months) are outlined. Undesired side effects were mainly confined to oculomotor disorders, which partly subsided over the months following the operation. Some technical aspects of the procedure and the pertinent literature are briefly discussed.

Adult↗
PubMed1981

Natural and antibody-dependent cellular cytotoxicity in tumour-adherent T lymphocytes: expression of Fc receptors and of a human T-subgroup-specific antigen.

Adherence of human lymphocytes to allogeneic tumour cell monolayers was found to depend on the presence of monocytes. Adherent lymphocytes could be separated from tumour cells by treatment with lidocaine followed by nylon wool passage. Tumour-adherent cells (70% E-RFC, 45% Fc gamma-R, 23% Fc mu-R, 5% monocytes) exhibited enriched natural killer (NK) activity not only against the tumour cell line used for isolation but also against seven other targets. When T cells were isolated subsequently as E-rosettes by density gradient centrifugation through Percoll, the enrichment in cytotoxicity was even more pronounced. Tumour-adherent T cells were severalfold enriched in both NK and antibody-dependent cell-mediated cytotoxicity (ADCC) activity. However, this enrichment was not paralleled by a concomitant increase in the number of T gamma cells (tumour-adherent T cells: 17% T gamma, 40% T mu ; tumour-nonadherent T cells: 12% T gamma, 60% T mu). Marked differences could be observed by staining with a monoclonal antibody that was raised against human leukaemic T gamma cells of high NK and ADCC activity. This antibody (T 8-11) stained 60% of tumour-adherent T cells, 20% of nonadherent T cells and 29% of T-cell controls. These results indicate that the spontaneous cytotoxic activity of human T cells resides within a small population, most of which are characterized by a specific surface antigen but not by conventional Fc gamma receptors.

Antibody-Dependent Cell Cytotoxicity↗