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Biomedical subjects

D Franke

Publications and source records attributed to D Franke.

At least 19 recordsLinked to original sources
PubMed1996

Ultrasonographic organometry: liver and spleen dimensions among children in Zimbabwe.

Attempts have been made to develop a staging system of sonographic Schistosoma mansoni morbidity for use in epidemiological studies and for evaluation of control programmes. Therefore, normal dimensions of livers and spleens in children in countries with endemic S. mansoni infections need to be established. Normal dimensions of livers and spleens are presented, based on examination of 144 Zimbabwean children between 8 and 16 years of age found to be S. mansoni egg negative 12 months after treatment with praziquantel. Based on the liver and spleen measurements, an index of liver size and the spleen volume were calculated. Height was employed as the independent variable in all multiple regression models. The organometric data are presented as prediction plots, with observed values and fitted regression line with 95% confidence and prediction intervals. The mean spleen volume was 30% larger for boys than for girls, whereas there was no consistent difference in liver size. No effect of growth Z-scores was seen. The measurements were compared with normal dimensions of livers of German children. For a given height, the mean index of liver size was lower in Zimbabwean than in German children, but inter-observer variation could be a possible explanation for this difference.

Adolescent↗
PubMed1996

Ultrasonographic assessment of Schistosoma mansoni and S haematobium morbidity in Zimbabwean schoolchildren.

Ultrasound examinations for Schistosoma haematobium - and S. mansoni-related morbidity were done in 174 schoolchildren from a subsistence farming community in southern Zimbabwe. The examinations were done according to the standardized protocol elaborated by the Cairo Working Group (the Cairo classification) and the Managil classification. Forty-six percent of the children had grade I periportal thickening (PPT) on ultrasound according to the Cairo classification, but none had grade II or higher. The significance of grade I PPT in the Cairo classification is questionable, since there were no differences between those without and those with grade I PPT with respect to intensity of S. mansoni infection or liver size. The prevalence of grade I PPT according to the Managil classification was 10%, and no association between the two classifications was seen. In multiple regression analysis, S. mansoni egg output was found to be a significant predictor of liver size, when controlling for height and sex. An interaction between S. haematobium and S. mansoni infection is suggested because the positive relationship between S. mansoni and liver size was seen in the presence but not in the absence of S. haematobium infection.

Adolescent↗
PubMed1995

[Desmodont remains after tooth extraction in digital image processing].

Breakage of the dentoalveolar gomphosis during tooth extraction results in varying amounts of desmodont remaining at the surface of the root. By dying the remnants of desmodont with toluidine blue, the surface of the root can be made accessible to computerized optical analysis. After clinically induced extraction of 102 human teeth, and after the loosening of 24 sheep teeth by mechanical vibration, the remaining area of desmodont was compared to that of the entire surface. Except in one case, no parameters were found to influence the amount of desmodont. However, tooth extraction in sheep previously treated with ultrasound or low-frequency vibrations demonstrate more desmodont-free areas.

Animals↗
PubMed1994

Lack of ultrasonographic evidence for severe hepatosplenic morbidity in schistosomiasis mansoni in Mali.

The inhabitants of four villages endemic for Schistosoma mansoni in central Mali (n = 1,106 of both sexes, age range 2-80 years) and of two nonendemic villages in another part of the country were examined parasitologically and ultrasonographically to establish the prevalence of periportal liver fibrosis (PF) and other features of hepatosplenic schistosomiasis. The prevalence of S. mansoni infection ranged from 36% to 93% in the endemic villages. A severe infection (> 400 eggs/g of stool) was found in 16% of the infected individuals. No case of grade III PF (echogenic bands usually > 10 mm in diameter around the central part and major branches of the portal vein and streak-like fibrous bands that extended into the periphery of the liver) and only eight cases of grade II PF (echogenic bands usually > 10 mm in diameter around the central part and major branches of the portal vein) were found; no other signs of severe hepatosplenic disease were encountered. However, grade I PF (echogenic bands usually > 4 mm in diameter that were best visible in the area of the portal vein bifurcation and gall bladder neck) was detected in 21% of all individuals, mainly in adults. In the nonendemic villages, the prevalence of grade I PF in adults was 9%. Generally, there was no significant correlation between the grade of PF and S. mansoni egg output. In one village with a high endemicity level, however, the prevalence of grade PF I increased with the intensity of infection. Morphometric data revealed no significant influence of S. mansoni infection on portal vein stem diameter and spleen size.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

PCBs have a predominantly neurotoxic effect on dissociated cultures of the nervous system.

Although their manufacture and use have been restricted or banned in Europe and the United States since the 1970s, polychlorinated biphenyls (PCBs) are still an ubiquitous environmental contaminant whose low-term effects are as yet not completely clear. Clinical case studies of patients with occupational exposure report cognitive impairment and peripheral neuropathy. In our defined nerve cell culture models in which we use pure neurons, pure glia and mixed cultures prepared from dorsal root ganglia of chick embryos we observed a neurotoxic effect after the application of a PCB compound (Clophen). It was only at higher concentrations that an additional gliatoxic effect could be observed.

Animals↗
PubMed1994

Sonographical morphometrical findings of the liver and spleen in Sudanese patients with Schistosoma mansoni induced periportal fibrosis.

Sonographic measurements of the liver, spleen and related blood vessels were performed in 87 healthy controls and in 50 patients with periportal fibrosis (pF) as well as in 52 patients with pF and at least one episode of gastro-oesophageal bleeding due to chronic Schistosoma mansoni infection. There was a progressing shrinkage of the liver paralleled by an increasing rate of patients with a larger left than right liver lobe as involvement of pF due to S. mansoni infection progressed. This was accompanied by an increasing percentage of pathological gallbladder wall enlargement, splenomegaly and an increasing portal vein diameter. It is suggested that organomorphometrical parameters of the liver and spleen can be used for sonographical evaluation of patients with S. mansoni infection as these may be useful for their clinical assessment of the progression of disease.

Adult↗
PubMed1993

Spectral editing in MAS NMR of aprotic solids. 31P-113Cd cross-polarization and heteronuclear double-quantum filtering studies in II-IV-V2 semiconductor alloys.

Magic-angle-spinning NMR spectra of aprotic solids, ceramics and glasses frequently suffer from poor site resolution due to wide chemical shift distribution effects. In such cases, cross-polarization and heteronuclear double-quantum filtering experiments involving nuclei other than 1H offer unique spectral editing capabilities. The utility of such assignment techniques for examining site populations in semiconductor alloys is demonstrated for the chalcopyrite systems CdGeAs2-xPx, CdSiAs2-xPx and ZnxCd1-xGeP2. The results permit a distinction between local and non-local effects on experimental chemical shift trends and reveal that compositional dependences observed in these alloys are dominated by non-local chemical shift contributions.

Alloys↗
PubMed1993

[Valine and branched-chain amino acids in the treatment of hepatic encephalopathy].

We studied the effects of infusion of a liver adapted amino acid solution (Amino-Mel hepa: Group A) versus a liver adapted amino acid solution plus L-valine (Amino-Mel hepa + L-valine: Group B) in 30 patients with decompensated liver cirrhosis with coma. Each 15 patients were randomly allocated to the group A and B, respectively. Both regimens included the infusion of glucose and fat, further supplementation of vitamins and trace elements in addition to the amino acid solution. The results of this study show that in patients with advanced stage of hepatic coma a valine increased supply of branched chain amino acids neither influences the course of the disease nor the death rate. The prognosis of patients with this disease is mainly determined by liver function and accompanying complications.

Amino Acids, Branched-Chain↗
PubMed1992

Inter-observer variance in ultrasonographical assessment of Schistosoma mansoni-related morbidity in young schoolchildren.

49 Sudanese schoolchildren aged 6-9 years with Schistosoma mansoni infection were ultrasonographically examined by two independent observers in a double-blind fashion. The first observer recorded normal appearance of the liver in 23 cases, whereas the second observer recorded the appearance as normal in 33 cases. There were 23 concordant observations. For Grade I periportal fibrosis (PF), 13 observations were concordant. PF Grade II was rarely observed (2 versus 3 cases), and Grade III was not recorded at all. In total, 38 out of 49 observations were concordant (77.5%). These preliminary data from two ultrasound observers, from observations on a limited number of patients, can be seen as an indication of a potential inter-observer variation of around 20% for the distinction between the absence of PF and a low level of PF.

Child↗
PubMed1992

Heteronuclear X-Y double quantum MAS NMR in crystalline inorganic solids. Applications for indirect detection and spectral editing of rare-spin resonances.

Heteronuclear double quantum MAS NMR experiments in the solid state, involving pairs of highly abundant 31P spins and the rare spins 113Cd, 77Se, and 29Si, are described for the three crystalline compounds CdSiP2, CdGeP2, and Ag7PSe6. These experiments offer the opportunity of indirectly detecting the rare-spin resonance via chemical shift evolution of heteronuclear double quantum coherence. For suitable cases, this method results in significantly enhanced detection sensitivities. Criteria for favorable indirect detection experiments are established. Besides offering high sensitivity, the pulse sequence also acts as a heteronuclear double quantum filter, hence providing heteronuclear correlation and useful spectral editing for peak assignments.

Cadmium↗
PubMed1992

Dipolar 31P NMR spectroscopy of crystalline inorganic phosphorus compounds.

The ability of the 90 degrees-t1-180 degrees pulse sequence to produce accurate dipole-dipole coupling information in solids is investigated. To this end, the experimental 31P spin echo decays are measured for eighteen crystalline phosphides and phosphorus chalcogenides and compared with simulations, based on the known internuclear distances in these compounds. The experimental results are generally found accurate in compounds where the dominant contribution to the dipole-dipole coupling arises from nuclei in structurally inequivalent sites with large chemical shift anisotropies. For this situation, the quantum mechanical "flip-flop" term in the dipolar Hamiltonian is suppressed and the dipole-dipole coupling is entirely heteronuclear in character. All of those compounds that do not obey this condition show accelerated spin echo decays due to a fractional contribution of the flip-flop term and possibly incomplete refocusing of chemical shift terms on the time scale of the experiment. The results confirm on an empirical basis that the spin echo NMR technique can provide accurate dipole-dipole coupling information (and thus distance distributions) in disordered solids and glasses.

Crystallization↗
PubMed1992

Ultrasonographical investigation of periportal fibrosis in children with Schistosoma mansoni infection: reversibility of morbidity twenty-three months after treatment with praziquantel.

In February 1987, 322 Sudanese school children were diagnosed for Schistosoma mansoni infection and treated randomly with praziquantel (either 20 mg/kg or 40 mg/kg body weight). A followup of these subjects was carried out in January 1989. This treatment resulted in a substantial reduction of egg output. Patients underwent complete abdominal ultrasonography and periportal fibrosis of the liver was graded into three degrees of severity. The proportion of patients with periportal fibrosis decreased from 36.6% in February 1987 to 21.7% in January 1989. At the time of followup, higher grades of periportal fibrosis (grades II and III) were encountered in only 4.3% and 0.3% of these patients, respectively, compared with 21.1% and 5.9%, respectively, before therapy. This was paralleled by a significant decrease in hepatomegaly from 10.9% to 7% of the patients. In contrast, the rate of splenomegaly showed a slight increase during the period of observation. The different dosage regimens of praziquantel did not result in a significantly different reversibility of periportal fibrosis or a decrease in egg excretion. The reversibility of specific liver lesions 23 months after antischistosomal therapy with praziquantel was substantial. The improvement was greater at 23 months than that obtained seven months after treatment.

Adolescent↗
PubMed1992

Ultrasonography as a diagnostic aid for a district hospital in the tropics.

To improve diagnostic capabilities, an ultrasound unit was installed at a major hospital in Wad Medani, Sudan. During the implementation period (October 1986 to March 1987) of ultrasound service, 863 patients were examined cooperatively by Sudanese and German physicians. The service covered internal medicine (47.5%), obstetrics and gynecology (31.6%), surgery (12.5%), and pediatrics (8.4%). Pathologic findings were seen in 75% of the patients. In obstetrics, the rate of pathologic findings was 40%. Five hundred eighty-three pathologic findings were detected in organ systems that constituted the primary indication for ultrasonography (of a total of 1,009 indications). The clinical benefit of ultrasonography was evaluated in 289 randomly selected patients in a standardized questionnaire completed by the attending physicians. The final clinical diagnosis was established or substantially revised in 21.5% of the patients, based on the ultrasonographic report. The previously reported diagnosis was supported in 69.5% of the patients. Medical management was directly influenced in 26% of the patients. We conclude that the clinical benefit of ultrasonography at a district hospital in the tropics is substantial, providing cost-effective, immediate therapeutic benefits in 25% of the patients examined. The technique thereby contributes to better and more rational patient management in institutions with limited resources.

Adolescent↗
PubMed1992

Ultrasound versus clinical examination as indication for Schistosoma mansoni associated morbidity in children.

In order to compare clinical versus ultrasound based diagnosis of Schistosoma mansoni induced periportal fibrosis (pF) 536 infected Sudanese schoolchildren underwent clinical and sonographical examination. A liver exceeding 3 cm in sternal line and a palpable spleen were considered pathological. Ultrasound criteria for age dependent organometry of a Central European cohort were used as reference. Based on clinical criteria 190 children (35.4%) had hepatomegaly, whereas according to ultrasound results the rate was only 11.4%. Splenomegaly was detected in 77 cases (14.4%) by clinical means, but in 196 by ultrasound (36.6%). The sensitivity of clinical parameters as indication of pF was around 50%. Results for ultrasound detected organomegaly were only slightly better. It was concluded that assessment of liver and spleen sizes was of limited value as an indication for pF and that a considerable discrepancy existed between clinical and ultrasound based assessment of hepato- and splenomegaly.

Adolescent↗
PubMed1992

[Malignant angioendotheliomatosis as a rare cause of cerebrovascular insufficiency].

Malignant angioendotheliomatosis, so called intravascular malignant lymphomatosis or angiotropic lymphoma, was found in cerebral hemispheres, spinal cord and nerve roots of a 50-year-old woman who died 4 months after onset of neurological symptoms. The pathological findings were characterised by neoplastic cells within the lumina and wall of small vessels as well as by multiple infarcts in the CNS. Vascular occlusions were caused by tumor cells and secondary changes of the wall. Positive reactions of Common Leucocyte Antigen and B-cell-markers support the idea of a lymphoid origin for the tumor cells. The differentiation to the angiocentric lymphoma as a T-cell tumor and the obscure pathogenesis of this neoplastic process must be clarified in the future.

B-Lymphocytes↗
PubMed1991

Ultrasonographical investigation of periportal fibrosis in children with Schistosoma mansoni infection: reversibility of morbidity seven months after treatment with praziquantel.

Five hundred thirty six Sudanese schoolchildren with Schistosoma mansoni infection were treated at random with either 20 mg or 40 mg/kg praziquantel. Seven months later 420 children could be reinvestigated by ultrasonography. Reduction of egg excretion and reversibility of sonographically-proven periportal fibrosis (PF) was not significantly different in the two groups. Schistosoma mansoni-induced PF grade II decreased from 22.9% to 6.7% and grade III from 5.2% to 1.6%. An increased prevalence of PF grade I, from 10% to 29.8% of the investigated patients, was observed. This increase was caused partly by a downshifting of patients who had PF II (n = 45) and PF III (n = 8) before therapy, but also by patients who developed PF I in the seven months after therapy (n = 56). The overall percentage of patients with PF before and after treatment was 38.1%. Of 420 children, 17.4% increased in their PF grade, 55% remained at the same level and 27.6% improved. Children younger than 11 years of age had a higher rate of complete reversibility than older ones. The percentage of patients with hepatomegaly decreased significantly (11.6% to 6.9%; p = 0.001). The rate of splenomegaly remained unchanged. It was concluded that within seven months therapy with praziquantel resulted in a considerable qualitative improvement of PF in Sudanese schoolchildren with S. mansoni infection.

Child↗
PubMed1990

Ultrasonographic evaluation of gallbladder function in patients with Schistosoma mansoni infection.

Gallbladder function was studied in 22 patients with portal hypertension due to advanced Schistosoma mansoni infection and in 17 healthy adults. The fasting volume of the gallbladder was significantly less in patients than in controls. The gallbladder wall was grossly thickened in the study group. There was a significant difference between the patients and controls in the reduction of gallbladder volume following a fatty meal. Although the portal vein diameter and the splenic volume were significantly larger in study patients, no significant correlation could be detected between the reduction in volume or wall thickness of the gallbladder and any of the relevant sonographic features of schistosomiasis-induced portal hypertension.

Gallbladder↗