[A dental CT study for preoperative assessment of maxillary atrophy]

According to a new technology in the planning of endo-osseous implantation, based on a new CT-software for evaluation of the bone structure of the jaws, anatomico-morphological changes after the loss of teeth are measured much more accurately than with conventional methods like the panoramic intraoral x-ray or conventional tomography. 30 mandibles and 22 maxillae of 36 patients were examined. Besides the topographic course of the mandibular canal and the location of the foramen mentale, the anatomic structures as the important aspects for planning endo-osseous implants are seen more accurately. It is now possible to recognise morphological changes with paraxial reconstructions in a very short time more clearly and precisely than with former techniques.

Adaptive responses of coronary circulation and myocardium to chronic reduction in perfusion pressure and flow

We tested the hypothesis that chronic reduction in perfusion pressure and flow in the coronary circulation induces a state of myocardial "hibernation" characterized not only by a steady-state reduction in myocardial O2 consumption (MVO2) but also by evidence of persistent dilator reserve of the distal vasculature. Biochemical and morphological changes in the coronary vasculature were also assessed. Experiments were conducted in swine with an extraluminal coronary stenosis placed 4-32 wk before study. Stenosis reduced lumen diameter by approximately 80% at the time of final experimentation. Baseline, regional myocardial blood flow distal to the stenosis in both endocardial and epicardial layers was reduced vs. that of the normal zone. Vasodilator reserve persisted in both endocardial and epicardial layers of the stenosis zone. Flow increased in each layer in response to adenosine plus phenylephrine and failed to decline despite a marked reduction in perfusion pressure in response to adenosine alone. Regional MVO2 at baseline was reduced vs. historical controls without coronary stenosis. Protein synthesis rate in coronary vessels of the stenosis zone was reduced vs. that of the normal zone. Morphological responses of stenosis zone vessel walls were heterogeneous. Smaller microvessels exhibited mild hypertrophy of their walls, whereas walls of larger microvessels tended to atrophy. Thus chronic reduction in perfusion pressure and flow induces a state of myocardial hibernation characterized by a steady-state reduction in MVO2 in association with persistent dilator capacity. Biochemical and morphological changes occur in microvessel walls and may contribute to observed physiological responses.

Value of magnetic resonance imaging in staging carcinomas of the oral cavity and oropharynx

The value of magnetic resonance imaging (MRI) in preoperative tumor (T) staging was assessed prospectively in 46 patients with malignant carcinomas of the oropharynx and oral cavity. In each case, the MRI findings were compared with the preoperative clinical and postoperative histopathologic findings. MRI showed an accuracy of 89% in identifying the T stage, as compared with the histopathologic result. The accuracy of the clinical examination was 78%. Compared with the clinical examination, MRI is particularly suited for differentiating T3/T4 and the larger T2 tumors. MRI tends to overinterpret the T stage when the neighboring tissues are inflamed or edematous, as it allows no demarcation between inflamed or edematous tissue and tumor. Moreover, normal oropharyngeal mucous membrane and intrinsic tongue muscle both absorb contrast medium. In the clinical examination, the T stage is often underestimated, as the depth of infiltration and bone involvement cannot always be determined with certainty. The ability of MRI to give an axial, coronal, and sagittal image allows an exact preoperative view of tumor spread and assessment of infiltration into adjacent structures.

A comparison of radical and conservative neck dissection

A review is presented of the confusing terminology applied to the various types of neck dissection. It is recommended that the terms "conservative" and "radical" be based on clear definitions. The fourth prospective, randomized DOSAK therapy study deals with the controversial issue of radical as compared with conservative neck dissection. Patients with squamous cell carcinoma (SCC) of the oral cavity who had not been treated before were randomized and stratified according to the DOSAK treatment-dependent prognostic index (TPI). At present, 104 patients have been evaluated, of whom 48 had radical neck dissection, and 56 conservative neck dissection. Tumor location and patient age and sex are equally divided in both therapy groups. After an average follow-up time of 460 days, the relative mortality for both therapy groups is 23%. At this stage, there is no difference between the two groups in the percentage of patients with complete remission or in the percentage of patients alive. At this stage, there appears to be no difference between the two groups with regard to patient survival or recurrent disease.

Origin of anterior interventricular vein blood in domestic swine

This study tested the hypothesis that anterior interventricular vein effluent of domestic swine is composed primarily of blood draining the perfusion territory of the left anterior descending coronary artery. As a corollary, the extent to which circumflex and right coronary inflow contributes to anterior interventricular vein outflow also was determined. Experiments were conducted in vitro with buffer-perfused swine hearts in which anterior interventricular vein flow was measured under various combinations of left anterior descending and circumflex coronary perfusion. Studies also were performed in vivo in different groups of intact swine with normal, stenosed, and occluded left anterior descending coronary artery. The results of the study confirm the hypothesis and demonstrate under a variety of conditions that at least 90% of anterior interventricular vein effluent is derived from blood originating from myocardium perfused by the left anterior descending coronary artery.

The serratus anterior osteocutaneous free flap

Microvascular transfer of the rib as an osteocutaneous or osseous free flap based on the thoracic branch of the thoracodorsal artery is described. A review of the literature revealed various patterns of rib vascularization in different areas of the body from the periosteum and the endosteal vessels. Reversing the blood flow in the transcortical vessels of the rib is reported to be possible. Injection studies showed a reliable connection between the thoracic branch of the thoracodorsal artery and the endosteal vessels of the sixth and seventh ribs at the origin of the anterior serratus muscle. This approach to free rib transfer has proved to be quick, easy, and reliable in various clinical applications.

Postoperative active-specific immunotherapy of lymph node micrometastasis in a guinea pig tumor model

Strain 2 guinea pigs bearing the transplanted intradermally growing line 10 tumor underwent surgical tumor excision at a time when the tumor had already metastasized to the first draining lymph node. Postoperative active-specific immunotherapy (ASI) consisted of two vaccinations with either Newcastle disease virus (NDV) modified or BCG-admixed line 10 tumor cells. 32% of the animals were cured of residual lymphatic micrometastasis by ASI with NDV-modified tumor cells while ASI with BCG was successful in 45%. No synergistic effect was observed when both ASI procedures were combined. Vaccine preparations with mitomycin C inactivated tumor cells proved to be less (NDV) or noneffective (BCG) compared to those with irradiated tumor cells.

Animal experiments on the role of T lymphocytes in the course of antineoplastic chemotherapy. I. Chemotherapy and tumor-specific immunity

Strain 2 guinea pigs bearing an intradermally growing already lymphogenetically metastasized line 10 tumor received intralesional chemotherapy with either cisplatin or vincristine. After successful treatment with cisplatin and low-dose vincristine, nearly all animals developed tumor-specific immunity. This phenomenon was not observed in animals treated with high-dose vincristine. Possible mechanisms of generation and alteration of primary T-cell-induced posttherapeutic tumor immunity are discussed.

The doubtful relevance of nonspecific immune reactivity in patients with squamous cell carcinoma of the head and neck region

Nonspecific immune reactivity (lymphocyte stimulation with PHA, PWM; % T-cells; absolute T-cell levels; skin reactivity to DNCB) was determined in 30 patients with squamous cell carcinoma of the head and neck region and in 30 age- and sex-matched healthy controls. The tests were carried out in each patient at 4-week intervals for at least 1 year. The tumor patients were regularly controlled over a period of 5 years. A reduced nonspecific immune reactivity was detected for tumor patients as compared with healthy controls. However, there was no correlation between the follow-up tests on unspecific immune reactivity and the clinical course of the disease. Moreover it was not possible--on the basis of pretherapeutic unspecific immune reactivity and 5 years' clinical follow-up--to make any prognostic statement for the tumor patients tested.

Correlation of intralesional in vivo chemotherapy of line 10 hepatoma with in vitro drug sensitivity

The effects of intralesional chemotherapy with 7 different drugs on line 10 hepatoma grown in strain 2 guinea pigs were compared with the sensitivity of line 10 tumor cells in vitro, using a micro modification of the tumor stem assay with capillary tubes. A modified method was used to evaluate the in vitro dose-response curves. The correlation for in vivo/in vitro resistance was found to be 100% and for in vivo/in sensitivity it was 80%.

Immunoprophylaxis of an ocular solid malignant tumor in cattle

Individual Hereford cows bearing benign precursor lesions of ocular squamous cell carcinoma were treated by intralesional injection of mycobacterial cell walls in an oil-in-water emulsion in an attempt to interrupt neoplastic progression. Thirty-one months after treatment, statistical analysis of data indicated that intralesional BCG cell wall vaccine can interrupt this process and provides effective immunoprophylactic prevention of malignant disease.

Kinetics of 57Co-bleomycin in sheep after intra-arterial injection in the head and neck region

Intra-arterial (i.a.) chemotherapy for the treatment of head and neck tumors is performed on the basis of clinical reports. The hypothetical aim of i.a. chemotherapy is to achieve higher drug concentrations in the tumor than are achieved by systemic intravenous (i.v.) administration. Therefore, it is postulated that i.a. chemotherapy leads to an increased therapeutic effect at the tumor site and to a decrease in systemic drug toxicity. The lack of adequate animal experiments and the absence of prospective randomized clinical trials comparing i.a. with i.v. chemotherapy led to the present kinetic study, concerned with various modes of administration of bleomycin with the aim of achieving high cytotoxic concentrations at the required site. Radioactive bleomycin (57Co-bleomycin) was injected locally (buccal plane, group I), intra-arterially (transverse facial artery, group II; superficial temporal artery, group III; external carotid artery, group IV), and intravenously (saphenous vein, group V) in five sheep per group. Between 1 and 360 min after injection of radioactive bleomycin the urine and the systemic blood activities were determined, and the activities in the hypothetical tumor area (buccal plane) were measured continuously. The animals were killed 360 min after injection and the activities in the hypothetical tumor area, in the lymph nodes draining this area (submandibular, parotic, lateral pharyngeal) and in different tissues and organs were determined. For all groups, 70%-80% of the injected bleomycin was eliminated by the kidneys, without any significant differences among the five groups tested. The systemic blood activities measured at 5-min intervals exhibited no differences for the groups injected i.a. (II-IV) and i.v. (V). Only animals which received local injections (group I) showed lower activities for 60 min after injection as compared with the other four groups. The activities of radioactively labeled bleomycin in the hypothetical tumor area during the entire experiment (360 min) were again similar for the groups injected i.a. (II-IV) and those injected i.v. (V). However, only animals injected locally (group I) showed significantly increased activities. After the death of the animals there was again no significant difference between i.a. and i.v. administration. Only local injection led to significantly increased tissue activities. Similar results also obtained for the lymph nodes draining the hypothetical tumor area.(ABSTRACT TRUNCATED AT 400 WORDS)

[Intratumor immunotherapy with BCG cell wall preparations: development of a new therapy approach for head-neck tumors]

The present study deals with the influence of intratumoral injections of BCG cell-wall preparations (CWP) on the development of malignant tumors in the head-neck region. Line 10 tumor cells in strain 2 guinea pigs were used in a first assay. It became evident that intratumoral BCG-CWP injection leads to total tumor regression, a situation which can also be achieved by radical surgery. In contrast to the radically operated animals, those injected intratumorally with BCG-CWP develop a tumor-specific immunity. A second animal system was used to examine the effect of intratumoral BCG-CWP treatment on the development of autochthonous squamous cell carcinomas in cows. In this model, radical surgery leads to a clinical cure in all cases, while intratumoral BCG-CWP therapy leads to a complete clinical cure in 50% of the animals (observation period: 1 year). On the basis of experiments performed with animals systems, a clinical study was initiated to examine the effect of preoperative BCG-CWP injection in patients with squamous cell carcinomas in the head-neck region. At present, the case study involves 24 patients. The cumulative percentage of patients in complete tumor remission is now 69% for BCG-CWP pretreated tumor patients and 39% for patients who underwent surgery only. The hitherto existing life-table analyses of both therapy groups and the small degree of side effects resulting from BCG-CWP seem to justify a continuation of the study until a statistically confirmed statement can be made about the curative effect of BCG-CWP within the framework of a combination therapy in patients with squamous cell carcinomas in the head-neck region.