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Biomedical subjects

W Becker

Publications and source records attributed to W Becker.

At least 253 records · Page 14Linked to original sources
PubMed1995

Replacement of maxillary and mandibular molars with single endosseous implant restorations: a retrospective study.

This retrospective report presents findings on 22 patients with 24 implants replacing single molars with implant-supported restorations. Patients with known bruxism habits were not considered for single-molar implant replacement. The patients underwent follow-up for an average of 24 months. The cumulative success rate was 95%, which reflects the loss of one 5 x 6 mm wide implant. Eleven implants were placed in edentulous ridges, and 13 were placed in extraction sockets. Most of the implants were placed in type B and C bone quantity and type 2 and 3 bone quality. All implants were restored on abutments with nonrotating gold cylinders. The occlusion for all restorations was developed to minimize centric contacts and lateral interferences. The frequency of gold retaining-screw loosening was obtained for 21 patients. The gold retaining screws loosened in eight implants between one and three times (38%). No incidence of crown or implant fracture occurred. Within the limits of this study, replacement of single-tooth molars by implant-supported restorations was predictable; however, a high incidence of gold screw loosening was seen.

Aged↗
PubMed1995

G-CSF-stimulated PMN in immunotherapy of breast cancer with a bispecific antibody to Fc gamma RI and to HER-2/neu (MDX-210).

Myeloid cells can mediate tumor cell cytotoxicity via certain receptors for immunoglobulins. Among the different Fc receptors, the high-affinity IgG receptor (Fc gamma RI, CD64) is a promising trigger molecule because it is selectively expressed on effector cells, including monocytes/macrophages and granulocyte colony-stimulating factor (G-CSF)-primed neutrophils. In vitro, a bispecific antibody (BsAb) (MDX-210, constructed by chemically cross-linking F(ab') fragments of monoclonal antibody (mAb) 520C9 to HER-2/neu and F(ab') fragments of mAb 22 to Fc gamma RI) mediated effective lysis of HER-2/neu overexpressing breast cancer cell lines. HER-2/neu (c-erbB2) is overexpressed in approximately 30% of breast and ovarian carcinomas and is a target for immunotherapy in clinical trials. In vitro assays showed Fc gamma RI-positive neutrophils to constitute a major effector cell population during G-CSF therapy. Based on these preclinical data and a preceding study at Dartmouth (New Hampshire) with a single dose of MDX-210 alone, a combination of G-CSF and MDX-210 is tested in a phase I study in breast cancer patients. In this study, patients receiving G-CSF are treated with escalating single doses of MDX-210. This therapy was generally well tolerated by the treated patients, some of whom reacted with fever and short periods of chills, which were temporally related to elevated plasma levels of IL-6 and TNF-alpha. After MDX-210 application, a transient decrease in the total white blood count and absolute neutrophil count (ANC) was observed. During G-CSF application, isolated neutrophils were highly cytotoxic in the presence of MDX-210 in vitro. These data indicate a potential role for G-CSF and BsAb in immunotherapy.

Antibodies, Bispecific↗
PubMed1995

Is there still a need for Tc-99m DMSA renal imaging?

Scintigraphy with Tc-99m MAG3 is, to date, the most commonly used technique for evaluating separate renal function (SRF). In this study, the performance of this technique is compared to Tc-99m DMSA. A total of 37 patients with various kidney disorders (12 children and 25 adults) underwent both Tc-99m DMSA and Tc-99m MAG 3 scintigraphy. In children and adults of normal weight the correlation coefficient between the two methods was 0.99 (P < 0.001), whereas in individuals who were more than 10% overweight according to Broca, or who had abnormal anatomical positions of the kidneys, the correlation coefficient was 0.82 (P < 0.05). Scintigraphy with Tc-99m DMSA was more accurate in renal parenchyma lesions. These results indicate that Tc-99m DMSA scintigraphy is preferable for the evaluation of SRF in patients who are more than 10% overweight, or have abnormal positions of the kidneys.

Adolescent↗
PubMed1995

Comparative assessment of saccadic eye movements, psychomotor and cognitive performance in schizophrenics, their first-degree relatives and control subjects.

This study is aimed at detecting biological markers for schizophrenia. For this purpose, a total of 70 subjects (21 schizophrenic patients, 27 first-degree relatives and 22 controls) performed a series of tests assessing various attentional, psychomotor and cognitive functions and saccadic eye movements. The schizophrenics performed significantly poorer than both high-risk and control subjects in most of the tests demanding attention, concentration and psychomotor speed (d2 concentration test, reaction times and Stroop test of perceptual interference) as well as cognition (Wechsler intelligence scales). On the other hand, these tests did not differentiate between the high-risk and control subjects. This distinction, however, could be made by two other parameters: hypometria score of saccadic eye movements and ratio of verbal to performance intelligence scores. Both parameters were significantly increased in both the schizophrenic and the high-risk group, distinguishing both from the control group. The relevance of these findings in indicating a schizophrenic disposition is discussed.

Adult↗
PubMed1995

Uptake and interconversion of plasma unesterified n-3 polyunsaturated fatty acids by the GI tract of rats.

The origin of the linoleic [18:2(n-6)], arachidonic [20:4(n-6)], and docosahexaenoic acid [22:6(n-3)] of the mucosal phospholipids in the gastrointestinal (GI) tract is not known. This study examines whether stomach, small intestine, and colon take up and desaturate-elongate unesterified polyunsaturated fatty acids (PUFA) from blood. Albumin-bound unesterified alpha-[14C]linolenate [18:3(n-3)] and [3H]eicosapentaenoate [20:5(n-3)] were injected intravenously. After 10 min, 1 h, and 18 h, radioactivity of tissue lipids and the degree of interconversion of the 3H-labeled and 14C-labeled fatty acids were determined. After 10 min, the lipids of the gastrointestinal tract contained 3.6% of the 14C (0.5% in stomach, 2.7% in small intestine, and 0.4% in colon) and 4.9% of the 3H (0.6% in stomach, 3.6% in small intestine, and 0.7% in colon). Both fatty acids were acylated mainly into phospholipids, both in liver and gastrointestinal tract. Although the proportions of radioactivity found in desaturation-elongation products increased with time, 15% of the 14C in the liver, 6% in the stomach, 8% in the small intestine, and 11% in the colon were in 20:5 already after 10 min. A rapid interconversion of 18:3 thus occurred both in the liver and in the gastrointestinal tract. In all tissues examined, interconversion of [3H]20:5 to [3H]22:5 also occurred. Interconversion of unesterified PUFA taken up from blood may be an important source of eicosanoid precursors in the gastrointestinal tract.

Animals↗
PubMed1995

Human demineralized freeze-dried bone: inadequate induced bone formation in athymic mice. A preliminary report.

The purpose of this study was to test the osteoinductive properties of demineralized freeze-dried bone (DFDBA) randomly purchased from four commercial bone banks. Twenty-five (25) milligrams of bone from each of the banks was implanted into the hindquarter muscles of athymic mice. Two samples from each of the banks were compared with samples from the other banks. A total of 16 implants were grafted into 8 mice. Two additional mice served as controls. One mouse received an implantation of deactived human cortical bone matrix (DBM) (negative control). The other mouse received an implant of human bone morphogenetic protein/non-collagenous proteins (hBMP/NCP) infused to surface demineralized human cortical bone (positive control). At 21 days the mice were killed, the hindquarters were photographed, and the tissues were prepared for histologic evaluation. Of the 16 commercial DFDBA implants, 12 were available for histologic evaluation. There was no radiographic evidence of bone formation for the DFDBA implanted mice or the DBM implants. Small bone ossicles were scarcely visible in the hindquarters of the mouse which received the hBMP/NCP infused bone. Histomorphometric analysis was used to determine the percentage of new and dead bone. The bone was measured in pixels. The predominant histologic feature of the DFDBA implants was non-vital bone chips with minimal amounts of new bone. The average amount of non-vital bone ranged from 78.4% to 92.5%. There was no evidence of bone formation for the DBM implants. The average amount of bone for the mouse which received hBMP/NCP was 96%. The results of this pilot study indicate that commercially-available DFDBA induced clinically insignificant amounts of bone.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Eye stabilization by vestibulo-ocular reflex (VOR) and optokinetic reflex (OKR) in macaque monkey: which helps which?

VOR-OKR interaction was studied in macaque monkey in the frequency domain, using various vestibular-visual stimulus combinations in the horizontal plane. At low stimulus frequencies (< 0.1 Hz), the eyes were always stabilized on the optokinetic pattern, irrespective of whether the head, the pattern, or both were rotated. At higher frequencies, the gain of the OKR attenuated, and concomitantly the eyes became increasingly stabilized in space. These findings show that the VOR becomes functionally relevant only at high frequencies. It compensates for the limited bandwidth of the OKR, thereby improving vision provided the pattern to be fixated is stationary in space.

Animals↗
PubMed1995

Prolactin-producing pituitary tumor: resistance to dopamine agonist therapy. Case report.

A 14-year-old girl presented with a rapidly growing, invasive prolactin-producing pituitary tumor that failed to respond to dopamine agonist medication. Histological, immunocytochemical, and ultrastructural studies of the surgically removed tissue revealed a pleomorphic, chromophobic, or slightly acidophilic pituitary tumor that was immunoreactive for prolactin and that, according to electron microscopy, consisted of atypical lactotrophs showing no evidence of cell shrinkage. In situ hybridization demonstrated large amounts of prolactin messenger ribonucleic acid (mRNA), moderate amounts of estrogen receptor mRNA and dopamine (D2) receptor mRNA, and an absence of growth hormone mRNA in the tumor cells. Because D2 receptor mRNA was present in the tumor, causes other than D2 receptor loss may have been responsible for the resistance of the lactotrophs to dopamine agonist administration.

Adenoma↗
PubMed1995

Somatostatin receptor expression in the thyroid demonstrated with 111In-octreotide scintigraphy.

Neuroendocrine tumors with somatostatin receptor expression may be localized by 111In-octreotide scintigraphy. This study examines those thyroid conditions where 111In-octreotide uptake could be observed also in the thyroid gland. 26 consecutive patients who underwent 111In-octreotide scintigraphy for tumor localization were additionally examined for thyroid disease by sonography and 99mTc-pertechnetate scintigraphy. 12 of these patients had no significant thyroid uptake and had an euthyroid normal-sized thyroid gland 14 patients with 111In thyroid uptakes had endemic goiters, two of them with thyroid autonomy and one with Graves' disease. Thus, 111In-octreotide thyroid uptake was predominantly seen in patients with endemic goiter with or without thyroid autonomy.

Adult↗
PubMed1995

[Complete nutrition and social assistance].

Additional supplementary benefits for nutrition are provided by social legislation; they are based on recommendations which have to be reconsidered in general as regards contents and quantities. The practice of assessment by Public Health Offices has no standardized regulations. Surveys have indicated that the recommendations are based on low-price calculations. The fundamental basis of supplementary benefits cannot guarantee healthy nutrition and therefore ignores the aim of prevention which had originally been included in social legislation.

Cost-Benefit Analysis↗
PubMed1995

Rat adjuvant arthritis: imaging with technetium-99m-anti-CD4 Fab' fragments.

UNLABELLED: The abundance of CD4 molecules on inflammatory cells in the synovial membrane renders anti-CD4 monoclonal antibodies (MAbs) or their fragments very promising for specific imaging of arthritic joints. METHODS: Joint uptake and body distribution of a 99mTc-labeled Fab', derived from the anti-rat CD4 MAb W3/25 (IgG1), were investigated following intravenous injection in normal and adjuvant arthritic rats. An isotype-matched Fab' (anti-human nonspecific crossreacting antigen-90) was used as control. RESULTS: A 14-hr sequential pinhole scan of the ankle joints revealed that both the anti-CD4 and the control Fab' accumulated to a higher degree in arthritic than in normal ankle joints; however, accumulation of the anti-CD4 Fab' in arthritic joints exceeded that of the control Fab' (approximate to 1.6 fold). Preferential joint accumulation of anti-CD4 Fab' was confirmed by whole-body scans at 14 hr and by direct well counter measurements of tissue samples at 16 hr following injection. Unlike the control Fab', the anti-CD4 Fab' preferentially accumulated in the liver and lymph nodes, organs rich in CD4-positive cells, as observed by direct tissue measurements. CONCLUSION: Despite its monovalency, the anti-CD4 Fab' retains the in vivo selectivity for CD4-positive cell-rich tissues, previously reported for the complete anti-CD4 MAb, and improves imaging of inflamed joints in experimental adjuvant arthritis.

Animals↗
PubMed1995

99mTc-trimethyl-BrIDA scintigraphy in HIV-related cholangiopathy.

A HIV-infected 37-year-old man with diffuse mid-abdominal pain and elevated liver enzymes was sequentially studied by sonography, computed tomography (CT), 99mTc-trimethyl-BrIDA scintigraphy and endoscopic retrograde cholangiopancreatography (ERCP). CT and sonography did not lead to a final diagnosis. Cholescintigraphy showed signs of cholecystitis and sclerosing cholangitis with intra- and extrahepatic bile duct dilatation. These findings could be confirmed by ERCP, rendering HIV-associated cholepathy probable. Cytomegalovirus infection was demonstrated by polymerase chain reaction from bile fluid and the presence of cryptosporidia infection in a histology specimen isolated by ERCP. Therefore, biliary scintigraphy seems promising for screening for HIV-associated cholangio- and cholecystopathy, being less invasive and less bothering for the patient than ERCP.

Adult↗
PubMed1994

[Neonatal hyperthyroidism in non-diagnosed Basedow's disease of the mother. Problems of diagnosis and therapy illustrated by a case history].

A male preterm infant (born at 34 weeks, birth weight 2130 g) developed jaundice (total bilirubin 7.4 mg/dl), hepatosplenomegaly, thrombocytopenia (82,000/microliters) and a raised C-reactive protein (1.2 mg/dl). Although sepsis was suspected, no organism was demonstrated. When the mother visited the child for the first time after 2 weeks, she had florid hyperthyroidism. This explained many of the child's clinical features (poor weight gain, tachycardia, exophthalmos). Both mother and child had raised TSH receptor antibodies (mother: 684.6 U/l; 54.1 U/l, normal < 15 U/l), an increased free T4 and a suppressed TSH. Because of the tachycardia, the child was treated with propranolol (1 mg/kg.d for 5 weeks). He was also initially given Lugol's solution (25 mg iodide/kg.d for 1 week) and then propylthiouracil (7 mg/kg.d) because of the increasing total T3. L-Thyroxine replacement was subsequently required for a period of 2.5 weeks because of treatment-related hypothyroidism. Since stopping treatment (at 12 weeks of age), the child has developed normally.--Neonatal hyperthyroidism due to transplacental transfer of TSH receptor antibodies associated with maternal Graves' disease is a rare self-limiting condition. However, it may pose considerable danger to the child both in utero and postnatally (with a mortality if untreated of up to 20%). Interdisciplinary cooperation is essential.

Adult↗