High-Q Magnetic Levitation and Control of Superconducting Microspheres at Millikelvin Temperatures

We report the levitation of a superconducting lead-tin sphere with 100  μm diameter (corresponding to a mass of 5.6  μg) in a static magnetic trap formed by two coils in an anti-Helmholtz configuration, with adjustable resonance frequencies up to 240 Hz. The center-of-mass motion of the sphere is monitored magnetically using a dc superconducting quantum interference device as well as optically and exhibits quality factors of up to 2.6×10^{7}. We also demonstrate 3D magnetic feedback control of the motion of the sphere. The setup is housed in a dilution refrigerator operating at 15 mK. By implementing a cryogenic vibration isolation system, we can attenuate environmental vibrations at 200 Hz by approximately 7 orders of magnitude. The combination of low temperature, large mass, and high quality factor provides a promising platform for testing quantum physics in previously unexplored regimes with high mass and long coherence times.

Pharmacotherapy for depressed pregnant women: overcoming obstacles to gathering essential data

Approximately 3% of pregnant women take antidepressant medications. Information on the impact of antidepressants on short- and long-term maternal and offspring outcomes is highly desirable but neglected. The position that the dearth of treatment information is of greater concern than the risks to pregnant subjects involved in medical research is gaining support. Mandating the collection of reproductive outcome data in exposed childbearing women is an overdue step toward societal responsibility to our most vulnerable members.

Improving women's health through modernization of our bioinformatics infrastructure

Our nationwide bioinformatics infrastructure used to detect important sex differences associated with medical product use is antiquated. The Food and Drug Administration (FDA) has embarked on an ambitious bioinformatics modernization effort that will improve our ability to assess the safety and effectiveness of new medical products. This, in turn, will improve our ability to detect important sex differences.

Females in clinical studies: where are we going?

Historically females of all ages have been underrepresented in clinical research. Reasons for this exclusion are multifactorial and may possibly have their origins in regulation that forbid the participation of females of childbearing potential in the earliest phase clinical studies that support drug approval. Decades of female underrepresentation in clinical studies has resulted in inequality in the understanding, diagnosis, and treatment of disease between the sexes. Adequate numbers of both sexes is one approach which is likely to present overwhelming financial constraints. Advances in study design, statistical methodologies, and the promise of evolving technologies will lead to new tools that can foster a better understanding of the biology that governs sex and gender differences.

Advancing women's health via FDA Critical Path Initiative

Studying sex and gender differences is critical to understanding diseases that affect women solely, disproportionately or differently from men. Although inclusion of both sexes is essential in clinical research, advanced technology and analysis methods offer tools to define complex biological and physicochemical differences and improve prevention, diagnosis and treatments for diseases in women and men. This paper identifies the potential for biomarker development, pharmacogenetics and bioinformatics in research under the FDA Critical Path Initiative.:

Genomic structure and fine mapping of the two human filamin gene paralogues FLNB and FLNC and comparative analysis of the filamin gene family

The genomic structure of the filamin gene paralogues FLNB and FLNC was determined and related to FLNA. FLNB consists of 45 exons and 44 introns and spans approximately 80 kb of genomic DNA. FLNC is divided into 48 exons and 47 introns and covers approximately 29.5 kb of genomic DNA. A previously unknown intron was found in FLNA. The comparison of all three filamin gene paralogues revealed a highly conserved exon-intron structure with significant differences in the exons 32 of all paralogues encoding the hinge I region, as well as the insertion of a novel exon 40A in FLNC only. Gene organization does not correlate with the domain structures of the respective proteins. To improve candidate gene cloning approaches, FLNB was precisely mapped at 3p14 in an interval of 0.81 cM between WI3771 and WI6691 and FLNC at 7q32 in an interval of 2.07 cM between D7S530 and D7S649.

Delayed-type hypersensitivity skin reactions caused by subcutaneous unfractionated and low-molecular-weight heparins: tolerance of a new recombinant hirudin

BACKGROUND

Eczema-like infiltrated plaques at subcutaneous heparin injection sites are well-documented side effects of these anticoagulants. However, surgical interventions may be problematic if heparin is urgently needed in these patients.

OBJECTIVE

The aims of this study were to perform extensive allergy skin testing in 24 patients, including a pregnant woman in whom subcutaneous infiltrated plaques developed after subcutaneous heparin injections, and to find safe therapeutic alternatives for this group of patients.

METHODS

Patch, intradermal, and subcutaneous tests were performed with a panel of unfractionated heparins (UFHs), low-molecular-weight heparins (LMWHs), and heparinoids. Since 1997, we have also been performing allergy studies in 8 patients with lepirudin, a new recombinant heparinoid; tolerance of lepirudin was investigated by means of subcutaneous and intravenous injections. The allergy investigations in the pregnant woman were limited to patch tests with heparins and intradermal and subcutaneous tests with pentosanpolysulfate, which are not contraindicated during pregnancy.

RESULTS

In our study population 19 of 23 patients were sensitized to all the UFHs and LMWHs tested when intracutaneous and subcutaneous test results were read at up to 96 hours. LMWH was found to be a possible substitute in 4 patients. Five patients were also sensitized to the heparinoid pentosanpolysulfate. Sensitization to the heparinoid danaparoid was observed in 12 of the 13 patients who were tested with this substance. The administration of an intravenous bolus containing a therapeutic dose of lepirudin after negative subcutaneous provocation was tolerated without any side effects in all 8 patients. The pregnant woman was sensitized to LMWH but tolerated subcutaneous pentosanpolysulfate without any side effects.

CONCLUSION

Extensive allergy skin testing should be performed to find safe alternatives. With few exceptions, all patients react to both UFHs and LMWHs, as well as to danaparoid. The subcutaneous provocation test is the most reliable diagnostic measure. Intravenous lepirudin, and in some cases subcutaneous pentosanpolysulfate, appears to be a safe alternative in patients with eczema-like infiltrated plaques at subcutaneous heparin-injection sites.

A newly created splice donor site in exon 25 of the MyBP-C gene is responsible for inherited hypertrophic cardiomyopathy with incomplete disease penetrance

BACKGROUND

Hypertrophic cardiomyopathy is a myocardial disorder resulting from inherited sarcomeric dysfunction. We report a mutation in the myosin-binding protein-C (MyBP-C) gene, its clinical consequences in a large family, and myocardial tissue findings that may provide insight into the mechanism of disease.

METHODS AND RESULTS

History and clinical status (examination, ECG, and echocardiography) were assessed in 49 members of a multigeneration family. Linkage analysis implicated the MyBP-C gene on chromosome 11. Myocardial mRNA, genomic MyBP-C DNA, and the myocardial proteins of patients and healthy relatives were analyzed. A single guanine nucleotide insertion in exon 25 of the MyBP-C gene resulted in the loss of 40 bases in abnormally processed mRNA. A 30-kDa truncation at the C-terminus of the protein was predicted, but a polypeptide of the expected size ( approximately 95 kDa) was not detected by immunoblot testing. The disease phenotype in this family was characterized in detail: only 10 of 27 gene carriers fulfilled diagnostic criteria. Five carriers showed borderline hypertrophic cardiomyopathy, and 12 carriers were asymptomatic, with normal ECG and echocardiograms. The age of onset in symptomatic patients was late (29 to 68 years). In 2 patients, outflow obstruction required surgery. Two family members experienced premature sudden cardiac death, but survival at 50 years was 95%.

CONCLUSIONS

Penetrance of this mutation was incomplete and age-dependent. The large number of asymptomatic carriers and the good prognosis support the interpretation of benign disease.

S100-Beta, melanoma-inhibiting activity, and lactate dehydrogenase discriminate progressive from nonprogressive American Joint Committee on Cancer stage IV melanoma

PURPOSE

Monitoring advanced malignant melanoma, serum levels of S100-beta (S100beta) and melanoma-inhibiting activity (MIA) were assessed for the ability to discriminate progressive from nonprogressive disease. S100beta and MIA were supposed to be superior to conventional variables, such as lactate dehydrogenase (LDH) level.

PATIENTS AND METHODS

Seventy-one patients with stage IV malignant melanoma according to the criteria of the American Joint Committee on Cancer (AJCC) were included in the study. Results of restaging examinations were used as an independent reference standard for diagnosing progressive disease, and S100beta, MIA, LDH level, and erythrocyte sedimentation rate (ESR) were determined in venous blood just before restaging. Sensitivities and specificities of the parameters were calculated by logistic regression analysis. Discrimination ability was assessed by Somers' D(xy) rank correlation and the area under the receiver-operating characteristic curve (ROC-AUC).

RESULTS

All tested serum parameters were significantly elevated in patients with progressive disease. The highest sensitivities according to the established thresholds were found for S100beta and MIA (91% and 88%, respectively). LDH had the highest specificity (92%). ESR was dropped from the analysis because of low specificity. In calculating Somers' D(xy) and ROC-AUC values, S100beta, MIA, and LDH showed high discrimination ability. By multiple logistic regression, LDH was identified to be the only statistically significant marker for progressive disease. S100beta and MIA did not provide additional significant information because of their high correlation with LDH with respect to clinical outcome.

CONCLUSION

Elevated serum levels of S100beta, MIA, and LDH indicate current disease progression in AJCC stage IV melanoma. LDH was the most relevant overall parameter.

Effects of Plasmodium berghei infection on cytochromes P-450 2E1 and 3A2

Metabolism and disposition of most drugs used to treat malaria are substantially altered in malaria infection. Few data are available that specify effects of malaria infection on drug metabolism pathways in humans or animal model systems. In this report, studies were undertaken to determine the effect of Plasmodium berghei infection on cytochrome P-450 (CYP450) 2E1 and 3A2-mediated metabolism and enzyme expression in rat liver microsomes. Malaria infection (MAL) resulted in significant decreases in total cytochrome P-450 content (56%, P < 0.05) and NADPH cytochrome P-450 reductase activity (32%, P < 0.05) as compared to control (CON) rats. Chlorzoxazone 4-hydroxylase activity (CYP2E1-mediated) showed no significant difference between CON and MAL microsomes while testosterone 6-beta-hydroxylase activity (CYP3A2-mediated) was reduced by 41% (P < 0.05) in MAL. Enzyme kinetic studies and immunoblot analysis indicate that the loss of activity for CYP3A2 in malaria infection is due to significantly decreased CYP3A2 protein expression. The altered expression of CYP450s in malaria infection should be taken into account when treating patients with malaria in order to minimize drug-drug interactions or toxicity.

A high risk phenotype of hypertrophic cardiomyopathy associated with a compound genotype of two mutated beta-myosin heavy chain genes

Hypertrophic cardiomyopathy (HCM) is a genetically and clinically heterogeneous myocardial disease that is in most cases familial and transmitted in a dominant fashion. The most frequently affected gene codes for the cardiac (ventricular) beta-myosin heavy chain. We have investigated the genetic cause of an isolated case of HCM, which was marked by an extremely severe phenotype and a very early age of onset. HCM is normally not a disease of small children. The proband was a boy who had suffered cardiac arrest at the age of 6.5 years (resuscitation by cardioconversion). Upon screening of the beta-myosin heavy chain gene as a candidate, two missense mutations, one in exon 19 (Arg719Trp) and a second in exon 12 (Met349Thr), were identified. The Arg719Trp mutation was de novo, as it was not found in the parents. In contrast, the Met349Thr mutation was inherited through the maternal grandmother. Six family members were carriers of this mutation but only the proband was clinically affected. Segregation and molecular analysis allowed us to assign the Met349Thr mutation to the maternal and the Arg719Trp de novo mutation to the paternal beta-myosin allele. Thus, the patient has no normal myosin. We interpret these findings in terms of compound heterozygosity of a dominant (Arg719Trp) and a recessive (Met349Thr) mutation. Whereas a single mutated Arg719Trp allele would be sufficient to cause HCM, the concurrent Met349Thr mutation alone does not apparently induce the disease. Nevertheless, it conceivably contributes to the particularly severe phenotype.

Isolation of isoproteins from monoclonal antibodies and recombinant proteins by chromatofocusing

A fast protein liquid chromatographic method for the preparative separation of the various isoproteins is described. Highly purified human monoclonal antibodies, recombinant human superoxide dismutase and human superoxide dismutase from erythrocytes were used as starting material. The isoproteins were separated by chromatofocusing on Mono P columns. A very narrow pH gradient was applied to achieve complete separation of the isoproteins. The prepurification steps and the pretreatment of the samples to achieve optimum resolution are described in detail. The method is also applicable to extremely basic monoclonal antibodies (pI = 9). The successful separation was checked by isoelectric focusing in immobilized pH gradients (Immobilines). The future of these methods is discussed, because for many different biochemical and biophysical investigations pure and homogeneous isoproteins are necessary.

Pilot scale production of a human monoclonal antibody against human immunodeficiency virus HIV-1

Human monoclonal antibodies against the transmembrane protein gp41 of HIV-1 were isolated and purified on a pilot scale. A purification scheme was established for the production of human monoclonal antibodies on the gram scale. 50 1 of culture supernatant can be treated in one purification cycle. The hybridomas were mass cultured in an airlift fermenter. The culture broth was clarified by microfiltration and chromatographed on CM-Sepharose fast flow and protein A Superose. Scale up of the high performance affinity chromatography from 1 ml protein A Superose up to 40 ml is described. All desalting steps were performed by gel filtration on Sephadex G-25 coarse. The yield of the whole purification procedure is in the range of 50-60%. The purity is higher than 99.9%. DNA and reverse transcriptase could not be detected. The whole method is designed as a basis for scale up to industrial scale. Results from quality control assays have proven the validity of this approach.

[On the question of endocrine side effects in patients on medication for renal calcium stone disease (author's transl)]

In patients with recurrent idiopathic nephrolithiasis we studied whether treatment with sodium cellulose phosphate leading to decreased intestinal calcium absorption could induce secondary hyperparathyroidism and whether thiazides which diminish calciuria would impair glucose tolerance. After removal of a actual kidney stone, 74 patients were treated for one year as follows: 25 (group 1) received conventional therapy (Nieron), 22 (group 2) received sodium cellulose phosphate, and 27 (group 3) received sodium cellulose phosphate plus hydrochlorothiazide. The period of one year was too short to evaluate the effectiveness of treatment regarding stone recurrence, however, a significant decrease in calciuria only was seen in group 3. With respect to the possibility to develop secondary hyperparathyroidism, group 2 and group 3 did not reveal any hints. In group 3, the thiazide treatment did not worsen glucose tolerance. Therefore, longer lasting studies with these drugs could be performed without evident danger to develop the mentioned side effects.