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Biomedical subjects

D Schmidt

Publications and source records attributed to D Schmidt.

At least 307 records · Page 17Linked to original sources

Motor development, infantile reactions and postural responses of preterm, at-risk infants.

Eighty-nine low-birthweight, preterm infants were enrolled in a longitudinal study to describe motor development, infantile reactions and postural responses during the first chronological year of life and to determine the relationship between these behaviors. There was a clear trend from prevalence of primitive patterns, such as the asymmetric tonic neck reflex, towards a prevalence of mature postural reactions such as the Landau, righting and protective extension reflexes. Statistical analysis suggested that a relationship exists between infantile patterns, automatic postural reactions and motor development that is similar to that accepted as normal in term infant development, when allowance is made for preterm birth. Correlations were also obtained between integration of the tonic labyrinthine response and the presence of the asymmetric tonic neck pattern at the time of hospital discharge and later achievement of motor milestones. These relationships warrant further investigation.

Female↗

Clobazam for treatment of intractable epilepsy: a critical assessment.

Clobazam (CLB), a 1,5-benzodiazepine, is a remarkably effective add-on drug for individual patients with refractory partial epilepsy. CLB has an excellent safety record. As with all benzodiazepines used for treating epilepsy, sedation and withdrawal effects, together with the development of tolerance, limit its usefulness. Recent efforts to prevent or reverse tolerance with intermittent administration of CLB or periodic injection of a benzodiazepine antagonist, flumazenil, are encouraging and justify further investigations.

Animals↗

Temporal arteritis. Comparison of histological and clinical findings.

The aim of this investigation was to correlate the clinical and histological findings in 85 consecutive patients with temporal arteritis. Particular attention was given to a possible correlation between optic nerve involvement and the presence of giant cells upon histological examination. Severe ischemia as in anterior ischemic optic neuropathy and central retinal arterial occlusion was presented in 37 patients (43%). Giant cells were definitely observed in 32 biopsy specimens (37.6%) and suspected in 11 additional specimens (13%): In 42 specimens (49.3%) no giant cells were present. Our study showed no correlation between the occurrence of severe optic nerve involvement and the histological findings with regard to giant cells. Statistical evaluation also failed to show a significant correlation between the frequency of pain and jaw claudication and the respective histological findings regarding giant cells. In the biopsy specimen of one patient, numerous eosinophilic granulocytes had infiltrated the vessel wall.

Aged↗

Progressive proliferative diabetic retinopathy after transplantation of the pancreas. A case and a review of the topic.

The unusual case history of the development of a progressive diabetic retinopathy despite normal blood glucose after transplantation of the pancreas and despite panretinal laser coagulations is described. A 26-year-old male with diabetic background retinopathy underwent a segmental transplantation of the pancreas in 1988. One year after surgery, a progressive proliferative retinopathy despite normoglycemia was found, which required an intensive panretinal photocoagulation during the following months. However, despite massive retinal coagulations, vitreous hemorrhages and retinal neovascularizations continuously occurred, thus requiring two vitrectomies. After these procedures, visual acuity recovered distinctly. It is suggested that the 'point of no return' for the development of proliferative changes in the retina had been passed at a time when a background retinopathy was still present. The effect of normoglycemia during follow-up of patients with diabetic retinopathy, described in the literature, is compared to this unusual case history.

Adult↗

Toxoplasma encephalitis in congenic B10 and BALB mice: impact of genetic factors on the immune response.

Factors which determine the pathogenesis and course of Toxoplasma encephalitis are poorly understood. In the present study, the influence of genetic factors in congenic B10 and BALB mice of H-2q, H-2k, and H-2b haplotypes was examined following oral infection with a low-virulence strain of Toxoplasma gondii (DX). There were striking differences among these strains. Whereas B10 mice were highly susceptible, BALB mice had a less severe and more protracted disease. In all animals with a fatal outcome, Toxoplasma encephalitis was the cause of death. Within the two congenic groups, the major histocompatibility complex haplotype had a strong impact on the disease. The H-2k haplotype was associated with early death in B10 mice but with a favorable outcome in BALB mice, whereas the reverse was observed for the H-2q haplotype. These findings indicate that genetically determined factors are critically involved in determining the intracerebral immune response and the course of murine toxoplasmosis. Some of these factors appear to be associated with the major histocompatibility complex haplotype, but significant differences between B10 and BALB mice point to a modulating role of additional genetic loci. Immunohistochemical studies and cytokine analyses of cerebrospinal fluid and serum revealed significant differences in the intracerebral immune response between susceptible and resistant strains. A poor outcome was associated with a large number of intracerebral parasites, significant tissue necrosis, a reduced number of intracerebral CD4+ T cells, low intrathecal tumor necrosis factor levels, and, to a lesser extent, a reduced number of intracerebral CD8+ T cells.

Animals↗

The new anticonvulsant drugs. Implications for avoidance of adverse effects.

Several new antiepileptic drugs offer a worthwhile alternative when standard antiepileptic drugs have failed. Suggestions have been made to improve the risk-benefit ratio of the new antiepileptic agents. More specifically, vigabatrin, which is a very useful and well tolerated new antiepileptic drug for refractory partial epilepsy, should be started at a low dosage of 0.5 g/day with increments of 0.5 g/day every week. Daily dosages exceeding 3 g/day should be restricted to patients with improvement. If necessary, the daily dosage of vigabatrin should be withdrawn slowly, i.e. by not more than 1 g/week. Lamotrigine is also a beneficial new drug for refractory partial and generalized seizures. However, the drug is associated with rash. In patients also receiving valproic acid (sodium valproate) [which inhibits the metabolism of lamotrigine], the incidence of rash can be reduced by slow titration of 25mg every other day for the first week and 25mg per day for the second week. Rare hypersensitivity reactions, e.g. Stevens-Johnson syndrome, remain a problem. The risk-benefit ratio of felbamate has recently been compromised by fatal aplastic anaemia and fatal liver disease in a number of patients. In general, patients should be withdrawn from felbamate, if possible, until further clarification of its definitive risk-benefit ratio. Finally, gabapentin is a very safe add-on medication. Its remarkably low potential to cause adverse effects makes it a welcome addition for the treatment of refractory partial epilepsy.

Abnormalities, Drug-Induced↗

Evaluation of antiepileptic drug efficacy. A review of clinical trial design.

Up to 30% of patients with epilepsy are not adequately treated with currently available antiepileptic drugs. Despite a need for new agents, few were developed after valproic acid (sodium valproate), which appeared in the 1970s. This picture has changed recently. A number of new antiepileptic drugs have been approved for marketing, and additional approvals are expected soon. The evidence in the form of adequate and well controlled studies supporting the efficacy of each of these new drugs has included (and in some cases been wholly composed of) placebo-controlled add-on trials, showing the viability of that design. Add-on trials, which compare a new drug with placebo in the presence of a stable regimen of antiepileptic drug therapy, can be conducted as parallel or cross-over designs. These designs have been considered insensitive because they are conducted in patients refractory to available antiepileptic drugs, but add-on trials have proved able to identify effective new drugs. They also permit long term evaluation and provide information, including drug interaction data, in one of the major clinical contexts where a new antiepileptic drug may be used. New designs now allow the evaluation of antiepileptic effectiveness in other clinical contexts, including monotherapy, and provide alternatives when drug interactions obscure add-on trial interpretation. The key feature of this class of monotherapy designs is basing patients' trial duration on their seizure activity rather than on a fixed time period. This is accomplished by defining 'therapeutic failure' criteria which serve to assess efficacy of the test agent while protecting patient safety.(ABSTRACT TRUNCATED AT 250 WORDS)

Anticonvulsants↗

[Tibiotalar arthrodesis under arthroscopy].

PURPOSE OF THE STUDY: The authors describe an arthroscopic technique of tibio-talar arthrodesis. They discuss the advantages, indications and results of this technique. MATERIAL: Seven arthroscopic tibio-talar arthrodeses (A.T.T.A.) were performed between may 1992 and september 1993 for post traumatic arthritis (five following bimalleolar fractures, two following talar fractures). METHOD: Traction by means of a transcalcaneus pin was applied to obtain articular distraction. Arthroscopic debridement was performed using two standard anterolateral and anteromedial portals. The arthrodesis was secured in neutral position by two percutaneous tibio talar cannulated cancellous screws. RESULTS: Fusion was obtained in all cases over an average period of 12 weeks. No infections or cutaneous complications were noted. In one case, however, screw positioning caused an injury to a branch of the superficial peroneal nerve. At last follow-up, according to the Duquennoy grading system, the results were good or very good. DISCUSSION: In this study, we noticed a particularly low rate of complications, a significantly lesser recovery time and a higher fusion rate compared to open ankle arthrodesis techniques. This is probably due to the careful handling of the periarticular soft tissues, possible with the arthroscopic procedure. The best indication for this procedure seems to be "centered" ankle arthritis. However, a significant deviation in one plane, or a tibial or talar bone loss needing an autogenous graft is considered to be a contra-indication for the procedure. CONCLUSION: A.T.T.A. seems to be a simple and reliable technique for centered ankle arthritis.

Adult↗

Pheochromocytomas, multiple endocrine neoplasia type 2, and von Hippel-Lindau disease.

BACKGROUND: Pheochromocytoma is a feature of two disorders with an autosomal dominant pattern of inheritance--multiple endocrine neoplasia type 2 (MEN-2) (with medullary thyroid carcinoma and hyperparathyroidism) and von Hippel-Lindau disease (with angioma of the retina, hemangioblastoma of the central nervous system, renal-cell carcinoma, pancreatic cysts, and epididymal cystadenoma). The frequency of these syndromes in patients with pheochromocytoma is not known. METHODS: In an unselected group of patients with pheochromocytoma, we performed pentagastrin tests, parathyroid hormone assays, computed tomography (CT) or magnetic resonance imaging (MRI) of the brain, ophthalmoscopy, CT imaging of the abdomen, and ultrasonography of the testes. We also screened members of families with MEN-2 or von Hippel-Lindau disease for pheochromocytoma by measuring plasma and urine catecholamines and plasma chromogranin A and by performing abdominal ultrasonography, CT and MRI, and metaiodobenzylguanidine scintigraphy. RESULTS: Nineteen of 82 unselected patients with pheochromocytomas (23 percent) were carriers of familial disorders; 19 percent had von Hippel-Lindau disease and 4 percent had MEN-2. Prospectively, in 36 of 79 subjects at risk for pheochromocytoma (46 percent), 42 unsuspected pheochromocytomas were found. Overall, there were 130 patients with 185 pheochromocytomas; 43 had von Hippel-Lindau disease, 24 had MEN-2, and 63 had sporadic tumors. The patients with familial and those with sporadic pheochromocytomas differed in mean age at diagnosis (32 vs. 46 years, P < 0.001), multifocal localization (55 vs. 8 percent, P < 0.001), and cancer (0 vs. 11 percent, P = 0.005); but not in the frequency of extraadrenal tumors (24 vs. 16 percent). Thirty-eight percent of carriers of von Hippel-Lindau disease and 24 percent of carriers of MEN-2 had pheochromocytoma as the only manifestation of their syndrome. CONCLUSIONS: All patients with pheochromocytomas should be screened for MEN-2 and von Hippel-Lindau disease to avert further morbidity and mortality in the patients and their families. All patients in families with MEN-2 or von Hippel-Lindau disease should be screened for pheochromocytoma, even if they are asymptomatic.

Adolescent↗

DNA analysis in hepatoblastoma by flow and image cytometry.

BACKGROUND: In several types of tumors, including hepatocellular carcinoma, prognosis could be correlated with DNA ploidy. Few studies have been performed on hepatoblastoma with contradictory results. METHODS: Twenty-nine cases of nonpretreated hepatoblastoma were studied with flow cytometry and image cytometry for DNA index and proliferation index using paraffin-embedded tissue. RESULTS: Twenty-three (79.9%) tumors were diploid, and 6 (20.7%) were aneuploid (hyperdiploid). Patients with diploid tumors were younger than those with aneuploid tumors. With regard to stage, diploid tumors were almost equally distributed among stages (tumor, lymph node metastases, distant metastases), whereas aneuploid tumors tended to occur in higher stages (tumor, lymph node metastases, distant metastases). Diploid tumors had clearly a better prognosis than aneuploid tumors, although the difference was not statistically significant (flow cytometry, P = 0.06; image cytometry, P = 0.16). A more favorable prognosis was also noted for hepatoblastomas with low-proliferation index (< or = 7%), but the difference from tumors with high-proliferation index (> 7%) again was not statistically significant (P = 0.16). CONCLUSIONS: Although no statistically significant differences in prognosis between hepatoblastomas with diploid and aneuploid DNA content, respectively, were found, there is a clear tendency that diploid hepatoblastomas behave more favorably. The same is true for hepatoblastomas with low-proliferation index.

Aneuploidy↗

Synovial sarcoma of childhood and adolescence. Report of the German CWS-81 study.

BACKGROUND: Synovial sarcoma is the third most common pediatric soft tissue tumor. It requires an aggressive approach to achieve a cure. However, optimal treatment modalities adapted to disease extension and histologic variants have not been determined because there is little information about prospectively treated patients. METHODS: A multicenter trial for soft tissue sarcomas (Protocol CWS 81) was conducted in West Germany between 1981-1985, and 31 patients with synovial sarcoma were registered. Treatment included multiagent chemotherapy and irradiation after initial tumor excision or biopsy. The male-female ratio in this group was 1:1.6 with a median age of 14 years (range, 1-19 years). The median follow-up time after diagnosis was 101 months (range, 77-131 months). RESULTS: The overall event-free survival (EFS) for patients with synovial sarcoma was 74.2% at 5 years. Group I-II tumors had a significantly better prognosis than those in Group III-IV (EFS at 5 years 84.4% and 58.3%, respectively; P = 0.024). Small tumors (< 5 cm) responded better than larger tumors (> or = 5 cm; EFS, 93% versus 58%; P = 0.029). Synovial sarcoma involved the extremities in 28 patients who had a better outcome compared with those with extremity rhabdomyosarcoma in this study (EFS for Group I-IV was 82% versus 24%, P = 0.001). CONCLUSIONS: The results appeared superior to previous experience using radical surgery alone and suggested that after initial, nonmutilating surgery, adjuvant chemotherapy, and irradiation contributed to the improved long-term survival.

Adolescent↗