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Biomedical subjects

A Wolter

Publications and source records attributed to A Wolter.

11 recordsLinked to original sources
PubMed2002

Bone marrow scintigraphy with 99m Tc labelled monoclonal anti-NCA 90 Fab' fragment: a feasibility study and comparison of bone marrow uptake with 99m Tc labelled monoclonal anti-NCA 95 antigranulocyte antibody.

The aim of this retrospective study was to evaluate the usefulness of 99mTc labelled monoclonal anti-NCA 90 antigranulocyte antibody Fab' fragment (MN3 Fab') as a bone marrow imaging agent. One hundred and ten planar scans (88 patients) of the lumbar and sacroiliac regions as well as whole-body scans were performed after 1, 5 and 24 h. All the scans were evaluated visually and bone marrow uptake was determined semiquantitatively as count density ratio from sacroiliac-minus-background to background area. Results were compared to 50 age-matched patients with normal bone marrow scans obtained with the intact 99mTc labelled monoclonal anti-NCA 95 antigranulocyte antibody (BW 250/183) in a previous study. Seventy-three patients showed a physiological activity distribution in the central bone marrow. Ten patients showed a bone marrow extension, while in two patients central bone marrow depression was observed. Evaluation of the ribs, lower thoracic and upper lumbar spine was hampered by soft-tissue activity. Bone marrow uptake was 1.36+/-0.56 after 1 h, decreased thereafter and was significantly lower than that of BW 250/183 (P < 0.001). In conclusion, MN3 Fab' cannot be recommended for bone marrow scintigraphy, because relevant parts of the haemopoietically active bone marrow are not accessible to visual evaluation. A significant role of the semiquantitative evaluation of MN3 Fab' bone marrow uptake in patients with potential marrow depression seems unlikely.

Adolescent↗
PubMed2001

Nonspecific bowel activity in imaging inflammation with Tc-99m labelled monoclonal anti-NCA-90 Fab' fragment MN3.

AIM: Since the Tc-99m labelled monoclonal anti-NCA 90 granulocyte antibody Fab' fragment MN3 (MN3 Fab') might be of interest for imaging abdominal inflammation which could be hampered by nonspecific bowel activity, we prospectively investigated the appearance of bowel activity in MN3 Fab' imaging. METHODS: Eighty consecutive patients (age range 12-85 years) referred for suspected nonabdominal, mostly musculoskeletal infection, were included. Abdominal inflammation was excluded clinically and there were no signs of inflammatory bowel disease in the patients' histories. One, 5, and 24 hours after intravenous injection of up to 1.1 GBq of MN3 Fab' planar images of the abdomen were performed. Bowel activity was graded visually using a 5-point scale. RESULTS: The one (N = 80), 5 (N = 79), and 24 (N = 52) hour images revealed 46 (10%), 162 (34%), and 173 (55%) accumulating bowel segments, respectively, in 37 (46%), 69 (87%), and 52 (100%) patients. The mean intensity score per accumulating segment was 1.1, 1.8 and 2.7 (p = 0), respectively. Relative frequencies of appearance of the small intestine were 38%, 57%, and 21%, ileocaecal region 6%, 53%, and 48%, ascending colon 5%, 67%, and 89%, transverse colon 1%, 9%, and 69%, descending colon 8%, 15%, and 67%, and rectosigmoid 0%, 4%, and 38%, respectively. Follow-up investigations in 13 patients revealed diverging uptake patterns. CONCLUSION: Nonspecific bowel activity is often present in the early and almost always and more intense, in the delayed images. Early imaging at one hour after administration seems feasible, but a loss in sensitivity has to be considered. Thus, nonspecific bowel activity can be anticipated to be a pitfall in imaging abdominal inflammation with MN3 Fab'.

Abdomen↗
PubMed2000

Intraindividual Comparison of F-18-Fluorodeoxyglucose and Tc-99m-Tetrofosmin in Planar Scintimammography and SPECT.

Since the comparative value of several nuclear medicine investigations for breast cancer has not been established, the rationale of this study was to examine the diagnostic performances of F-18-fluorodeoxyglucose (FDG) and Tc-99m-tetrofosmin both in single photon emission computed tomography (SPECT) and planar technique in an intraindividual comparative study.A total of 54 patients with suspected breast cancer (48 malignant and 9 benign lesions) was investigated by planar and SPECT imaging with both FDG and tetrofosmin within the last preoperative week. Pathohistological confirmation of the diagnosis was obtained in all patients.2 cm 81%/67%, 92%/67%, 75%/50%, and 75%/100%. Sensitivity was higher with FDG SPECT than with the other imaging modalities and significantly lower for tumors </=2 cm with all the techniques investigated. In 20 out of 21 patients with diverging scintigraphic findings, FDG SPECT was either true positive or true negative. In 15 patients with axillary lymph node metastases, sensitivities were 33%, 73%, 36%, and 50%, respectively.2 cm, if dedicated PET is not available.

Journal Article↗
PubMed1997

The prevalence and implications of ocular hypertension and glaucoma in thyroid-associated orbitopathy.

PURPOSE: The authors determined the prevalence of ocular hypertension and its association with progression to glaucomatous damage in patients with thyroid-associated orbitopathy (TAO). METHODS: The charts of 500 consecutive patients with TAO seen at the Allegheny General Hospital (Pittsburgh, PA) between 1985 and 1995 were analyzed. The amount of proptosis, degree and duration of myopathy, exposure to corticosteroids, prior glaucoma treatment, and family history of glaucoma were evaluated. RESULTS: One hundred twenty (24%) patients with TAO were noted to have an intraocular pressure (IOP) greater than 22 mmHg but less than 30 mmHg. This ocular hypertensive group was composed of 34 men and 86 women with a mean age of 55 years and mean follow-up of 4 years. Seven patients were defined as glaucoma suspects, based on increased but nonprogressive cup-to-disc ratios or nonprogressive, atypical visual field changes in the presence of increased IOP. Two patients demonstrated progressive visual field abnormalities and cupping. Of the factors evaluated, only the duration of active orbital involvement was statistically associated with progression to glaucomatous damage. The mean duration of TAO was 3, 8, and 12 years for ocular hypertensives, glaucoma suspects, and glaucomatous damage, respectively. CONCLUSIONS: Only a prolonged duration of active TAO in association with ocular hypertension correlated with progression to glaucomatous damage. These patients with chronic TAO deserve special attention and close follow-up to prevent optic nerve damage.

Adolescent↗
PubMed1993

Radial keratotomy in the soldier-aviator.

Radial keratotomy (RK) is an ophthalmological procedure that alters the shape of the cornea, making it "flatter," causing the desired shift to farsightedness. Complications can be minor and "normal" in the immediate post-operative period, or can include problems that occur in many eyes, that persist but do not decrease best corrected visual acuity, or may include events that potentially or actually threaten vision and may produce blindness. At best, only 50% of patients can expect to have 20/20 uncorrected vision 2-3 years after surgery. Diurnal fluctuations in vision (two-five Snellen lines) can persist years after RK. Perhaps 1% of patients may have a two-three Snellen line loss of best corrected vision or ghost images that interfere with clear vision. Disabling glare can disrupt daily activities. Eyes that have undergone RK are at increased risk of corneal rupture after blunt eye trauma. The visual demands of the active duty military, and more dramatically the military aviator, are incompatible with RK. Therefore, RK should not be performed on active duty soldiers, nor should enlistees be accepted if they have undergone the procedure.

Aerospace Medicine↗
PubMed1987

[Diagnosis of obliterating vascular processes in the supraaortic area].

For the diagnostics of obliterating vascular changes in the supraaortic area the invasive diagnostics of the vessels is not to be renounced now as before. The indication to the angiographic investigation results from clinical, perfusion-scintigraphic and Doppler-sonographic-findings. Of 390 patients 289 pathological angiographic findings in the supraaortic vascular area. In 101 patients normal findings were stated. Altogether 509 individual pathological findings were represented. In the comparison of the results of the investigations in the various diagnostic methods the clinical neurological investigation showed itself as particularly evident method. It should be decisive for the indication to the invasive diagnostics. The correspondence between the angiographic findings and the result of the perfusion-scintigraphic and Doppler-sonographic investigations, respectively, was the greater the more expressed the extracranial vascular findings represented themselves. In 127 patients with multiple obliterating vascular changes the size of the pathological changes and their localization could be established only angiographically.

Arterial Occlusive Diseases↗
PubMed1984

Preliminary electronmicroscopical observations on the ampulla caudalis and the discharge of the material of Reissner's fibre into the capillary system of the terminal part of the tail of Ammocoetes (Agnathi).

The discharge of the material of the Reissner's fibre (RF) and the massa caudalis (MC) into the "meningeal spaces" has until now not been studied in detail and with the aid of the electron-microscope. It was generally assumed that the material of the MC disintegrates in the "meningeal spaces", but the nature and function of those spaces have not been established. The CNS of Ammocoetes ist encompassed by the meninx primitiva, which is the meningeal tissue of the lower vertebrates; the meninx does not differentiate during ontogeny into the pia mater and the arachnoides. In contrast, the meninx primitiva of mammals is the anlage in the ontogenetical sense of the leptomeninges in adult individuals. The results presented in this paper are valid for Ammocoetes only; Petromyzon and Myxine must be studied anew from a perspective which may be the result of our study. Of particular interest would be an anatomical analysis of these caudalmost structures of the CNS (Ampulla caudalis [AC], MC, neuropori, lacunae etc.) in Branchiostoma. The diameter of the RF of Ammocoetes is approximately 1.7 micron; this is not different from the diameter of the RF in adult individuals. In the AC the RF divides into several smaller fibres which eventually disintegrate and form the amorphous MC. In sagittal sections, the fibrillary structure of the RF is distinct. In cross sections the small fibres may appear as globules. The terminal part of the RF is very often coiled. The ependyma of the caudal part of the canalis centralis (CC) ist not remarkable; liquor contacting neurons are frequently found with their dendrites touching the RF. Liquor contacting neurons are never found in the ependyma of the AC. The ependymal cells of the dorsal part of the AC possess neither kinocilia or microvilli. The disappearance of these organelles begins in the dorsal part of the caudalmost segment of the CC. Most surprising is the distribution of the attachment devices which are probably desmosomes. In the ependyma of the caudal part of the spinal cord the attachment devices are typically situated; in the ependyma of the AC these devices are absent. We use the general term "attachment devices" until the nature of these devices has been clearly determined. In the caudalmost part of the spinal cord as well as in the AC, the intercellular spaces between the ependymal cells communicate, forming a 3-dimensional labyrinth. If there are no attachment devices between the proximal parts of the ependymal cells, the intercellular spaces may provide a passageway between the CC and the loose tissue of the meninx primitiva.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗