Biomedical subjects
Publications and source records attributed to V Daniels.
Management of hypertension requires a thorough knowledge of currently available antihypertensive drugs. This article reviews the mode of action of the major classes of antihypertensives, indications for their use, and adverse effects. The main emphasis is placed on their use, in physiatric practice.
When observers are asked to align two rectangular stimuli oriented at 45 degrees to the visual axis there is a slight tendency to set the more distant stimulus closer to the eye than its true coplanar position. However, when a large rectangular surface is interpolated between the two oblique stimuli and the observer, errors of alignment become relatively much larger. The displacement caused by the interpolated stimulus occurs both when the display is viewed monocularly and when it is viewed binocularly. Reducing the obliquity of the rectangles results in smaller judgment errors and increasing obliquity increases errors; this is true with and without occlusion. The addition of texture elements to the surfaces of the rectangles reduces judgment errors significantly, but only under conditions of occlusion. It is possible that misalignments recorded for three-dimensional displays have something in common with the two-dimensional Poggendorff illusion.
Results are reported of a study in which 547 general hospital medical in-patients were screened, using a computer-administered questionnaire, for alcohol consumption, problems and concerns. Of males, 22.5% were classified as 'risk drinkers', of women 6.5%. Rates of risk were particularly high amongst younger male patients. It was concluded that certain screening questionnaire items were more useful than others in the general hospital context, and that standard questionnaires developed for other populations should not automatically be used in general hospitals. Comparisons with items relating to other health behaviours suggested that the medical profession, the general public and the patients themselves might be relatively insensitive to the risks associated with heavy drinking in comparison to those associated with smoking, weight and lack of exercise. Data from initial screening and from 75% of patients who were asked to repeat the questionnaire six months later, were used to test certain assumptions of a model of change based in part upon that of Prochaska & DiClemente (1986). Results suggested that processes of change were more complex than the model supposed.
Organic artefacts degrade by a number of mechanisms. Autoxidation is one of the most important and involves free radicals. The importance of free radical reactions in the degradation of paper and other cellulosic materials, rubber and other organics is described. In the case of paper, treatment with calcium and magnesium compounds can inhibit oxidation, while transition metals increase the rate. Antioxidants have not been used a great deal due to unwanted side effects. The Russell effect, a technique for detecting oxidation using photographic materials, is described.
Normal subjects preserve tidal volume (VT) in the face of added inspiratory resistance by increasing maximal amplitude and duration of the rising phase of respiratory driving pressure (DP) and by changing the shape of this phase to one that is more concave to the time axis. To explore the possible role of chest wall afferents in mediating these responses, we determined averaged DP in eight quadriplegic subjects during steady-state unloaded breathing and while breathing through an inspiratory resistance (8.5 cmH2O X 1(-1) X s). As with normal subjects, quadriplegics preserved VT (loaded VT = 106% control) by utilizing all three mechanisms. However, prolongation of the inspiratory duration derived from the DP waveform (+22% vs. +42%) and shape response were significantly less in the quadriplegic subjects. Shape response was completely absent in subjects with C4 lesions. The results provide strong evidence that respiratory muscle spindles are responsible for shape response and that changes in afferent feedback from the chest wall play an important role in mediating inspiratory prolongation.
The interrelationship of pregnancy with Crohn's disease is as nebulous as aetiology and pathogenesis of this inflammatory bowel disease. In the years 1964-1981 we have operated upon 342 patients with Crohn's disease. 47 women suffering from this disease became pregnant. Whereas pregnancy appears to have little influence on the course of Crohn's disease, the incidence of miscarriages appears to rise with increasing activity and extent of bowel involvement. Only in case of exacerbation or complications is medical or even surgical therapy indicated in the course of pregnancy. Abortion does not appear to influence the course of Crohn's disease favourably.
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Between 1963 and 1979 a total of 357 patients with malignant systemic lymphatic disease underwent splenectomy in the course of exploratory laparotomy. There were three groups: 1. Hodgkin's disease (215 patients), 2. non-Hodgkin's lymphoma (93), and 3. chronic lymphoid leukaemia (49). Comparing pre- and postoperative findings, primary exploratory laparotomy remained the most exact foundation for the differentiated treatment of Hodgkin's disease in stages I-III. Systematic staging laparotomy was of less importance for non-Hodgkin's lymphoma and chronic lymphoid leukaemia because of the much more frequent invasion of bone marrow, spleen and liver. However, it should be considered more often in the management of such cases.
In healthy dogs the parameters (amplitude and frequency) of small intestinal motility of segmental and propulsive contractions demonstrate a pressure-gradient directed from oral to aboral. The frequency of segmental contractions in the colo-rectal region shows a vector in the opposite direction. One rarely finds propulsive activity in this area. Following on colectomy, proctomucosectomy and ileum pull-through a distinct increase in segmental small intestinal activity is noticed, while the frequency of propulsive movements simultaneously decrease. Thus it comes to a slowing of the passage of intestinal contents, and to increased water resorption. From these findings we conclude that the small intestine plays an essential part in the regaining of fecal continence in these animals.
Upper gastro-intestinal bleeding or other complications after operations on this tract can lead to grave additional risk for the patient, especially in the early postoperative phase. Because of its high degree of diagnostic accuracy, emergency endoscopy is in most cases of decisive importance in planning the type (conservative or surgical) and timing of any necessary treatment. Special investigative techniques as well as the early use of endoscopy in 97 patients achieved a high rate of success at a low risk to the patients. Indications, results and risks of emergency endoscopy of the upper gastro-intestinal tract in the late postoperative phase are similar to those for the non-operated patient.
The early appearance of "hard" and "soft" tumors should give cause to search regularly for intestinal polyposis. Once the diagnosis is made prophylactic total colectomy with ileorectal anastomosis is justified. With regard to a polyposis of the upper gastrointestinal tract, there is room for observation. The possibility of a peripapillary carcinoma with or without simultaneous involvement of stomach and duodenum must be reckoned with even years after a colectomy. Postoperative mesenteric fibroses and widespread adhesions are responsible for subileus and ileus. Because of their tendency to recur, desmoid tumors should only be treated operatively when this appears unavoidable by reason of local symptoms.
Based on our own cases (1964-1979) the indications for and the surgical technique of small intestine-plication (Noble-procedure) are discussed. The mean follow-up period was 10.3 years. Utilizing this surgical procedure 87% of 15 patients treated for chronically recurring adhesive ileus experienced good results. These statistics correlate with other publications that propose recurrent adhesive ileus as the 'indicatio causalis' for Noble-procedure. Possible major complications and the problem of symptoms from adhesions occurring or persisting after small intestine-plication are demonstrated with reference to our own cases.
Endoscopic sclerotization of esophageal wall has been performed in 48 patients with bleeding of esophageal varices. The mortality rate in the acute bleeding was 29,2%. There was no mortality, if sclerotherapy was done in the non hemorrhagic interval. Of the 48 patients 25 are still alive, 8 more than 2 years without bleeding. In 12 cases we performed transhepatic obliteration of the V. coronaria ventriculi. Only in 3 of them no further hemorrhage occurred within 6 months. Fibrosclerotization seems to be superior to the transhepatic obliteration, because the primary mortality and complications are lower and long term results better.
Of 4,058 patients who had had surgery in the years 1964-1977 because of disease of the extrahepatic biliary system 232 had to be operated upon again; in 9% of these the remaining stump of the cystic duct was found to be too long. In one third of these cases a causal relationship between long stump and clinical trouble could be suspected. From analysing these cases it became clear, that complications arising in the long stump e.g. inflammation or formation of new stones, involving in some cases extended parts of the hepatic biliary system,--caused the troubles. Reoperation should be performed early; a long stump should be shortened and the biliary duct system should be investigated intraoperatively in order to exclude other pathological conditions. Three fourths of our patients became symptom-free after the second operation; in the other patients secondary changes of the hepatic biliary system had already become autonomous and were responsible for the further course of the disease.
After a short discussion of primary retroperitoneal tumour characteristics, the effectiveness of surgical re-interventions in recurrences of these tumours with regard to our own cases (1964 to 1978: 97 primary retroperitoneal tumours) is analysed. Repeated aggressive surgical interventions combined with chemo-and radiotherapy, particularly in malignant mesenchymal primary retroperitoneal tumours with an average of 5.8 years (10 cases), show a distinct improvement in survival rates, while the same procedure in 3 malignant neurogenic and teratoid primary retroperitoneal tumours resulted in an insignificant average prolongation of life of 8.3 months since the first operation for malignant growth. In 6 patients malignant degeneration of the primary retroperitoneal tumour, as described in literature, occurred. Malignant metaplasia appeared on an average of 5 years after radical extirpation of the primary benign tumour, partly after repeated benign recurrences. Therefore the benign primary retroperitoneal tumour should principally be put on a level with the malignant form concerning surgical tactics and tumour aftercare.
Mean duration from symptoms to diagnosis in 87 patients with primary retroperitoneal tumour was 4.8 months for malignant tumour (67 patients), 18.1 months for benign tumour (20). The cardinal symptoms were palpable abdominal mass (68%), feeling of fullness and nausea (64%), as well as ill-defined abdominal pain (55%). Radiological diagnosis, especially selective angiography, provided important pointers to the global diagnosis of "retroperitoneal tumour". Small-needle biopsy, guided by ultrasound, has now become available in the pre-operative diagnosis of the type and malignancy of these tumours. After radical resection of 30 malignant tumours there was a mean survival time of, so far, 30.2 months. Results were worse with palliative malignant-tumour removal in 25 patients, at an average of 17.3 months. Survival time was only 4.8 months for 29 patients declared inoperable. In individual instances cytostatic treatment achieved an increase in survival time of up to 12 years.
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In the Surgical and Gynecological Departments of the University of Mainz, Medical School, 50 patients were operated between 1964-1976 for mechanical and paralytical ileus and intestinal bleeding caused by radiation injury of the bowel. Diagnosis depends on the history of radiation therapy. At operation we have seen a recurrence of gynecological and other malignant growths only two times. Intestinal resection with anastomosis is the preferred method for the management of such radiation injuries. The postoperative dehiscence of the intestine was noticed only five times. In order to prevent higher mortality rates, operation should be carried out as soon as possible.