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Biomedical subjects

C Stern

Publications and source records attributed to C Stern.

At least 19 recordsLinked to original sources

Karyotype evolution in a case of uterine angioleiomyoma.

Clonal karyotypic alterations of a uterine angioleiomyoma of a 41-year-old woman are reported. Cytogenetically a stemline of the tumor and two related subclones with additional abnormalities due to karyotypic evolution were identified: 46,X,t(X;11)(p11.4;p15)/46, idem,inv(2)(p15q13)/46, idem,inv(2)(p15q13),t(5;20)(q13;q13.2). None of the aberrations observed in the present case has been reported in uterine smooth muscle tumors before.

Adult

A new filtering algorithm for medical magnetic resonance and computer tomography images.

Inner views of tubular structures based on computer tomography (CT) and magnetic resonance (MR) data sets may be created by virtual endoscopy. After a preliminary segmentation procedure for selecting the organ to be represented, the virtual endoscopy is a new postprocessing technique using surface or volume rendering of the data sets. In the case of surface rendering, the segmentation is based on a grey level thresholding technique. To avoid artifacts owing to the noise created in the imaging process, and to restore spurious resolution degradations, a robust Wiener filter was applied. This filter working in Fourier space approximates the noise spectrum by a simple function that is proportional to the square root of the signal amplitude. Thus, only points with tiny amplitudes consisting mostly of noise are suppressed. Further artifacts are avoided by the correct selection of the threshold range. Afterwards, the lumen and the inner walls of the tubular structures are well represented and allow one to distinguish between harmless fluctuations and medically significant structures.

Algorithms

[New European medical flight safety guidelines. Their significance for the ophthalmologists].

In 1996 the new European Flight Crew Medical Requirements were finalized. The ophthalmological changes compared to the existing German standards range from the organization of evaluations to the necessary frequency of examinations. They also cover different examination techniques and different criteria for fitness. The changes in the requirements for ophthalmological fitness primarily affect ametropia, anisometropia, color vision and phoria. Knowledge of the European requirements is very important to advise pilots and any patient interested in becoming a pilot.

Accidents, Aviation

Antibodies to beta2 glycoprotein I are associated with in vitro fertilization implantation failure as well as recurrent miscarriage: results of a prevalence study.

OBJECTIVE: To investigate whether antiphospholipid and related autoantibodies are associated with IVF implantation failure as well as with recurrent spontaneous miscarriage. DESIGN: Prevalence study. SETTING: University teaching hospital and associated IVF unit. PATIENT(S): Patients with at least three consecutive first-trimester miscarriages (n = 97), patients undergoing IVF who had at least 10 embryos transferred without any resulting clinical pregnancy (n = 105), fertile women (n = 106), and patients newly referred for IVF treatment (n = 52). INTERVENTION(S): Antibodies tested included lupus anticoagulant; immunoglobulin (Ig) G and IgM isotypes of each of anticardiolipin antibody, antiphosphatidylserine, antiphosphatidylethanolamine, and antiphosphatidylinositol; beta2 glycoprotein I antibodies; and antinuclear antibodies. Statistical analysis included chi2 and Fisher's exact tests for differences between groups, and multiple linear regression analysis and Spearman's nonparametric tests for relations between results. MAIN OUTCOME MEASURE(S): Seropositivity for autoantibodies tested. RESULT(S): Overall, 84 (23%) of the 360 samples tested positive for at least one autoantibody. Beta2 glycoprotein I IgM antibody and antinuclear antibody were significantly associated with both IVF implantation failure and recurrent miscarriage. CONCLUSION(S): Autoantibodies, particularly beta2 glycoprotein I antibodies and antinuclear antibodies, are associated with IVF implantation failure as well as with recurrent spontaneous abortion, although the mechanism is still unclear. The high seroprevalence of antibodies to beta2 glycoprotein I suggests that it may have an important role in autoimmune reproductive failure that needs to be explored further.

Abortion, Habitual

Spatial grouping activity in children with early cortical and subcortical lesions.

Spatial construction skills were examined in 3- to 5-year-old children with prenatal or perinatal focal brain injury. In earlier work, a dissociation was reported between children with injury to the right hemisphere and the left hemisphere, right-hemisphere injury resulting in significantly lower levels of performance. In the current paper, the effect of isolated unilateral subcortical injury was explored. Thirty-four children with early focal brain injury were tested in a task which required them to copy a series of simple block constructions. There were approximately equal numbers of children with right-hemisphere and left-hemisphere injury; within each of these groups approximately half of the children had injury involving only subcortical regions. Consistent with the earlier work, children with right-hemisphere injury performed significantly below children with left-hemisphere injury and the normal controls. Importantly, no differences were observed between the children with isolated subcortical injury and children with injury involving both cortical and subcortical brain areas.

Apraxias

Developmental change in spatial grouping activity among children with early focal brain injury: evidence from a modeling task.

Spatial construction skills were assessed in children with left (LH) or right (RH) hemisphere focal brain injury and control children. Children copied simple and complex block models which were rated on accuracy and spatial strategy. The accuracy of simple and complex constructions for 4- to 5-year-old children with LH injury was indistinguishable from 4-year-old controls. However, although they were able to produce accurate complex constructions, the processes used by children with LH injury differed from those of normal children. On both simple and complex constructions, 4- to 5-year-old children with RH injury showed evidence of developmental delay. For both accuracy and process measures, children with RH injury performed at a level comparable to normal children at 3 years. A second group of children with LH and RH injury were tested at 5 to 6 years of age. Both lesion groups were indistinguishable from 4-year-old controls in terms of accuracy. However, both children with LH and RH injury used different spatial processes than did controls. This study emphasizes the importance of distinguishing between products of behavior and the processes which underlie them. It is in the dissociation of products and process of behavior that the subtle spatial construction deficits in this population of brain-injured subjects is revealed.

Brain Injuries

Structural aberrations of chromosome 6 in three uterine smooth muscle tumors.

Clonal karyotypic alterations of chromosome 6 in three uterine smooth muscle tumors are reported. In all cases an apparently identical breakpoint on the short arm of chromosome 6 was found. Two cases displayed the histologic features of cell-rich myomas with severe nuclear atypia but no clear evidence for malignancy. The remaining case was a primary uterine leiomyosarcoma of an 80-year-old patient showing an apparently balanced reciprocal chromosomal translocation, t(1;6)(p32-33;p21.3), as the sole karyotypic abnormality. This type of aberration has not been reported before in leiomyosarcomas. Because of the nuclear atypia in the other myomas with a breakpoint involving the short arm of chromosome 6 we feel that this cytogenetically recognizable but rare subgroup of uterine smooth muscle tumors warrants a careful clinical follow-up.

Adult

Verbal learning and memory in children with fetal alcohol syndrome.

Children with fetal alcohol syndrome (FAS) were administered the California Verbal Learning Test-Children's Version, a word list learning task that assesses immediate and delayed recall and recognition memory. When compared with matched control children, the children with FAS had difficulty learning and recalling the words after a delay period and tended to make an increased number of intrusion and perseverative errors. In addition, they had difficulty discriminating target words from distracter words and made more false-positive errors on recognition testing. Some of these deficits persisted even when mental age was controlled. The results suggest that children with FAS have profound verbal learning and memory deficits, and that some of these deficits cannot be accounted for even when mental age is considered. Furthermore, the results are consistent with deficits in encoding verbal information and impairment in response inhibition capabilities.

Adolescent

[Glaucoma and aircraft pilot fitness].

Two completely different questions arise when considering glaucoma and fitness to fly: Firstly, what is the risk for a passenger with glaucoma? Secondly, what is the flight safety risk connected with pilots suffering from glaucoma? National requirements and international standards pay little regard to this disease. This is astonishing, given that the perception of flight information in the peripheral visual field is of great importance in the cockpit. On one hand, diagnostic glaucoma examinations for pilots are mainly insufficient, and on the other, progressive visual field deficiencies may go undetected because of long intervals between examinations. Intraocular pressure may increase while flying in aircraft, e.g. in the case of negative g-load. Frequent flights at high altitudes without pressurized cabin air and with decreased oxygen supply, and therefore decreased tissue oxygen saturation, may represent a risk, especially for patients with progressive nerve fibre loss.

Aircraft

A hamartoma of the breast with an aberration of 12q mapped to the MAR region by fluorescence in situ hybridization.

Cytogenetic studies of a breast adenolipoma (hamartoma) of a 58-year-old patient revealed a karyotype 46,XX,add(4)(?),add(6)(q?),der(7)t(7;12)(q11.1 or q11.2;q11 or q12),der(12). To our knowledge, this is the second report of an aberration involving 12q12-15 in a hamartoma of the breast. By FISH studies, we found this chromosome 12 translocation breakpoint to be mapping within the MAR (Multiple Aberration Region). MAR is known to be a major cluster region of chromosome 12 breakpoints of benign solid tumors such as uterine leiomyoma, lipoma, and pleomorphic salivary gland adenomas, therefore raising the possibility that the same gene is involved in hamartoma of the breast as in these three benign solid tumors.

Breast Neoplasms

One of the two common mutations causing factor XI deficiency in Ashkenazi Jews (type II) is also prevalent in Iraqi Jews, who represent the ancient gene pool of Jews.

In recent years four mutations causing factor XI deficiency have been identified in Jews of Ashkenazi (European) origin. Two of them, type II (a nonsense mutation) and type III (a missense mutation), were found to prevail among 125 unrelated Ashkenazi Jews with severe factor XI deficiency. A finding of type II mutation in four unrelated Iraqi-Jewish families raised the possibility that this mutation is also common in Iraqi Jews, who represent the ancient gene pool of the Jews. A molecular-based analysis performed in 1,040 consecutively hospitalized patients disclosed the following results: Among 531 Ashkenazi-Jewish patients, the type II allele frequency was 0.0217 and among 509 Iraqi-Jewish patients, 0.0167 (P = .50). The type III allele frequency in the Ashkenazi-Jewish patients was 0.0254, whereas none of 502 Iraqi-Jewish patients examined had this mutation. These data suggest that the type II mutation was present in Jews already 2.5 millenia ago. The data also indicate that the estimated risk for severe factor XI deficiency in Ashkenazi Jews (due to either genotype) is 0.22% and in Iraqi Jews, 0.03%, and that the estimated risk of heterozygosity in Ashkenazi Jews is 9.0% and in Iraqi Jews, 3.3%. As patients with severe factor XI deficiency are prone to bleeding after injury and patients with partial deficiency may have similar bleeding complications when an additional hemostatic derangement is present, the observed high frequencies should be borne in mind when surgery is planned for individuals belonging to these populations.

Aged

Non-random jumping translocations as a result of SV40 large T-antigen expression in benign human tumor cells.

In an attempt to analyse the cytogenetic effects caused by SV40 large T-antigen expression in cells of human benign tumors we transfected cells of an uterine leiomyoma characterized by a primary reciprocal translocation t(12;14) (q15;q24) and a pleomorphic adenoma of the salivary gland with an inversion inv(12) (q15q24.1) using a construct coding for SV40 large and small T-antigen. The most interesting finding was not a generally destabilized karyotype, but the strictly non-random involvement of two chromosomal breakpoints, i.e. 5p13 and 10q11 in jumping translocations, never described before as a result of SV40 transformation. In addition we were able to show by non-radioactive in situ hybridization that there was no direct relationship between the integration site of the construct and the pre-disposition of 5p13 and 10q11 to somatic recombination. The jumping translocations with consistent breakpoints observed closely resemble the cytogenetic situation seen in a variety of human tumors with specific translocations. Based on the findings described here it is tempting to assume that the expression of SV40 large T-antigen can induce specific karyotypic alterations following an unknown trans-acting mechanism.

Adenoma, Pleomorphic

Acute annular outer retinopathy as a variant of acute zonal occult outer retinopathy.

PURPOSE: A 23-year-old man developed a rapid-onset, large, dense scotoma that was associated with a peculiar gray intraretinal ring corresponding to the edge of the scotoma and normal fluorescein angiographic findings. This disorder may represent a variant of acute zonal occult outer retinopathy. METHODS: We studied one patient by ophthalmoscopic examination and fluorescein angiography. RESULTS: The patient experienced a short period of concentric enlargement of the scotoma and narrowing of the retinal vessels within the ring, followed by stabilization of the scotoma and slow progressive depigmentation and intraretinal migration of the retinal pigment epithelium within the zone of visual loss. The cause of this disorder, which affects primarily the outer retina, was not determined. CONCLUSIONS: We speculate that this disorder is part of the spectrum of acute zonal occult outer retinopathy and that the gray border, which separates the normal from the abnormal retina, represents an immune ring phenomenon.

Acute Disease

Paclitaxel plus estramustine in metastatic hormone-refractory prostate cancer.

Combination antimicrotubule therapy with estramustine phosphate (EMP) and vinblastine has reproducible activity in metastatic hormone-refractory prostate cancer (HRPC) with an objective response rate of 31%. Although paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) by 24-hour infusion was inactive in HRPC, 0.5 to 1.0 nmol/L concentrations of paclitaxel combined with EMP exerted synergistic cytotoxicity in DU-145 androgen-independent human prostate cancer cell lines. Based on these results, we treated 24 patients with HRPC using the combination of paclitaxel 120 to 140 mg/m2 by 96-hour intravenous infusion every 3 weeks plus daily oral EMP at 600 mg/m2/d. Of seven patients with measurable soft tissue metastases, three have attained partial responses and a fourth patient is nearing partial response status. Of 16 patients with bone-only disease evaluated by change in serum prostate-specific antigen levels, 11 patients (68.8%) have had decreases of > or = 50% from pretreatment baseline. The prostate-specific antigen decrease has exceeded 80% in six of 16 (37.5%) patients. For all 23 evaluable patients, the prostate-specific antigen has decreased by > or = 50% in 15 (65.2%) and by > or = 80% in eight (34.7%). Grade 4 leukopenia occurred in one of 21 patients treated at the paclitaxel dose of 120 mg/m2/96 hr and one of three patients treated at 140 mg/m2/96 hr. The incidence of nausea (50%) and peripheral edema (37.5%) was similar to that associated with single-agent EMP. These results demonstrate that 96-hour paclitaxel plus EMP is active in HRPC and provide further evidence that the rational combination of antimicrotubule agents leads to synergistic antitumor activity in HRPC.

Adenocarcinoma

Self-tonometry under microgravity conditions.

Microgravity leads to a "fluid shift" towards the upper parts of the body and, therefore, to a rise of the intraocular pressure. Parabolic flights have also demonstrated some rise of the intraocular pressure. During the first German Spacelab mission D1, changes of the intraocular pressure were investigated for the first time in space. The first pressure readings were obtained 44 min after entering microgravity and showed a pressure rise of 20 to 25% compared to the baseline data. To get earlier measurements in microgravity a fully automatic self-tonometer was developed which functioned independent of position and microgravity. It was used during an 8-d manned space mission in March 1992. Measurements of the intraocular pressure have been performed 16 min after reaching microgravity. The pressure readings revealed a 92% rise of the intraocular pressure compared to the daytime-correlated baseline data on Earth.

Fluid Shifts

Kangaroo mother method: randomised controlled trial of an alternative method of care for stabilised low-birthweight infants. Maternidad Isidro Ayora Study Team.

Because resources for care of low-birthweight (LBW) infants in developing countries are scarce, the Kangaroo mother method (KMM) was developed. The infant is kept upright in skin-to-skin contact with the mother's breast. Previous studies reported several benefits with the KMM but interpretation of their findings is limited by small size and design weaknesses. We have done a longitudinal, randomised, controlled trial at the Isidro Ayora Maternity Hospital in Quito, Ecuador. Infants with LBW (< 2000 g) who satisfied out-of-risk criteria of tolerance of food and weight stabilisation were randomly assigned to KMM and control (standard incubator care) groups (n = 128 and 147, respectively). During 6 months of follow-up the KMM group had a significantly lower rate than the control group of serious illness (lower-respiratory-tract disorders, apnoea, aspiration, pneumonia, septicaemia, general infections; 7 [5%] vs 27 [18%], p < 0.002), although differences between the groups in less severe morbidity were not significant. There was no significant difference in growth or in the proportion of women breastfeeding, perhaps because the proportion breastfeeding was high in both groups owing to strong promotion. Mortality was the same in both groups; most deaths occurred during the stabilisation period before randomisation. KMM mothers made more unscheduled clinic visits than control mothers but their infants had fewer re-admissions and so the cost of care was lower with the KMM. Since the eligibility criteria excluded nearly 50% of LBW infants from the study, the KMM is not universally applicable to these infants. The benefits might be greater in populations where breastfeeding is not so common.

Breast Feeding

[Self tonometry during the German 1993 Spacelab D2 mission].

Microgravity during space missions leads to a fluid shift from the lower to the upper parts of the body that also affects the intraocular pressure. In the early phase after reaching microgravity there is an intraocular pressure peak. In order to analyse the potential health risks for astronauts, a self-tonometer was developed to examine the early phase of microgravity. During the German-Russian MIR mission the equipment was tested for the first time in space. As one result we found an initial pressure increase of 92% compared to the baseline data values. In order to obtain more detailed information on the intraocular pressure alterations in space, similar equipment was used during the 10-day German Spacelab D2 mission. Two German scientists and one American astronaut obtained self-tonometric pressure profiles on 6 mission days (44 pressure values determined out of 144 measurements). The initial peak values 15 min after entering microgravity revealed pressure increase of 114% compared to the baseline data (average pressure: right eye 10.0 mmHg, left eye 9.9 mmHg; peak values: right eye 22.6 mmHg, left eye 22.2 mmHg). Pressure values exceeding the baseline data by more than 50% were registered up to the 3rd mission day. As to circadian rhythm, there was no difference between inflight data and baseline data before and after the mission.

Adult

[Evaluation of current guidelines for flying capacity and internationally proposed revisions].

Despite several modifications of medical requirements for German flight personnel, these requirements have often been criticized by ophthalmologists because of their margins of interpretation. In many controversial cases regarding pilot licences, the final decision has to be made by the national aeromedical review board. The progress in ophthalmologic microsurgery, e.g. intraocular lens implantation and refractive surgery, has led to a certain insecurity among surgeons as to how to deal with these developments within the requirements. Besides, new cockpit designs with multiple colour displays have changed the demands on the pilot's visual system, especially with regard to colour perception. New European requirements which will probably become effective in 1994 are compared to the existing German standards.

Aircraft