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Biomedical subjects

H Bloch

Publications and source records attributed to H Bloch.

At least 19 recordsLinked to original sources
PubMed2000

Organisation of left and right hand movement in a prehension task: a longitudinal study from 20 to 32 weeks.

The organisation of reaching movements was studied longitudinally (every two weeks) in infants aged from 20 to 32 weeks, in order to detect possible differences between the two hands. An object was presented on a table, at a reachable distance, and four trials were retained. Analysis of left and right hand movements was performed, frame-by-frame, on video images obtained from two cameras. Three body points were considered: the elbow, the wrist, and the major finger for drawing the profile of the movement. Three parameters were considered: movement time (MT), straightness, and number of changes in direction. Data show that the right hand MT is always shorter than the left hand MT. Moreover, the right hand is also continuously more directly oriented towards the object and makes fewer corrective changes than the left hand. These data show that a different organisation of movement of the left and the right hand exists early in infancy.

Journal Article↗
PubMed1999

Barley coleoptile peroxidases. Purification, molecular cloning, and induction by pathogens.

A cDNA clone encoding the Prx7 peroxidase from barley (Hordeum vulgare L.) predicted a 341-amino acid protein with a molecular weight of 36,515. N- and C-terminal putative signal peptides were present, suggesting a vacuolar location of the peroxidase. Immunoblotting and reverse-transcriptase polymerase chain reaction showed that the Prx7 protein and mRNA accumulated abundantly in barley coleoptiles and in leaf epidermis inoculated with powdery mildew fungus (Blumeria graminis). Two isoperoxidases with isoelectric points of 9.3 and 7.3 (P9.3 and P7.3, respectively) were purified to homogeneity from barley coleoptiles. P9.3 and P7.3 had Reinheitszahl values of 3.31 and 2.85 and specific activities (with 2,2'-azino-di-[3-ethyl-benzothiazoline-6-sulfonic acid], pH 5.5, as the substrate) of 11 and 79 units/mg, respectively. N-terminal amino acid sequencing and matrix-assisted laser desorption/ionization time-of-flight mass-spectrometry peptide analysis identified the P9. 3 peroxidase activity as due to Prx7. Tissue and subcellular accumulation of Prx7 was studied using activity-stained isoelectric focusing gels and immunoblotting. The peroxidase activity due to Prx7 accumulated in barley leaves 24 h after inoculation with powdery mildew spores or by wounding of epidermal cells. Prx7 accumulated predominantly in the epidermis, apparently in the vacuole, and appeared to be the only pathogen-induced vacuolar peroxidase expressed in barley tissues. The data presented here suggest that Prx7 is responsible for the biosynthesis of antifungal compounds known as hordatines, which accumulate abundantly in barley coleoptiles.

Amino Acid Sequence↗
PubMed1995

Intravenous magnesium sulfate as an adjunct in the treatment of acute asthma.

STUDY OBJECTIVE: This study was conducted to determine whether intravenous magnesium sulfate (MgSO4), when used as part of a standardized treatment protocol, can improve pulmonary function and decrease admission rate in patients presenting to the emergency department with exacerbations of asthma. DESIGN: In this randomized double-blind placebo-controlled study, patients with acute asthma were treated with inhaled beta-agonists at regular intervals and intravenous (IV) steroids. At 30 min after entry, patients received either 2 g IV MgSO4 or IV placebo. Patients were monitored for up to 4 h with regular measurements of pulmonary function. Patients who were discharged from the emergency department were contacted at 1 day and 7 days for follow-up. SETTING: Emergency departments of a university-affiliated, voluntary hospital and municipal hospital. PARTICIPANTS: Asthmatics aged 18 to 65 years during acute exacerbation with FEV1 less than 75% predicted both before and after a single albuterol treatment. INTERVENTIONS: Patients were given 2 g of MgSO4 or placebo as an adjunct to standardized emergency department procedure for acute asthma. MEASUREMENTS AND RESULTS: One hundred thirty-five patients were studied. Hospital admission rates were 35.3% for placebo-treated group and 25.4% for the magnesium-treated group (p = 0.21). FEV1 measured at 120 min was 56% predicted for the placebo-treated group and 55% predicted for the magnesium-treated group. (p = 0.92) For subgroup analysis, patients were divided into "severe" (baseline FEV1 < 25% predicted on presentation) or "moderate" (baseline FEV1, 25 to 75% predicted on presentation). For the severe group, admission rates were 78.6% (11/14) for the placebo-treated group and 33.3% (7/21) for the magnesium-treated group (p = 0.009). For the moderate patients, admission rates were 22.4% (11/49) for the placebo-treated group and 22.2% (10/25) for the magnesium-treated group (p = 0.98). There was no significant improvement in FEV1 in the moderate group for magnesium-treated patients. However, in the severe group, there was a significant improvement in FEV1 at 120 min and 240 min (p = 0.014 and 0.026, respectively). CONCLUSION: Intravenous MgSO4 decreased admission rate and improved FEV1 in patients with acute severe asthma but did not cause significant improvement in patients with moderate asthma.

Acute Disease↗
PubMed1992

On the onset of eye-head coordination in infants.

Head movements have been studied in newborns, during a visual pursuit and in relation with ocular movements, in order to know whether head movements help the ocular activity or impede it. The infants were tested three times during the first month of life. They were placed in a seated position, with the head held upright, but free to move. The results provided evidence that eyes and head were directionally coupled at as early as 2 weeks and that the interval between eye and head rotation decreases from the age of 2-4 weeks. This suggests that the beginnings of ocular-motor coordination are present from the first month of life in human infants.

Aging↗
PubMed1992

Concurrent phenomena of science and history in the 17th century and their essential interdependence.

The explanation for the explosion of science in the 17th century lies in history and medical historiography. Without this approach, it becomes fantasy, accidents, or success stories. Sigerist grasped the essential interdependence of science and history, and had no need for devised reasons or speculation. He realized that once the dark night of the Middle Ages was over, the sciences arose with undreamt of force and accelerated development. The advances in astronomy, mathematics, mechanics, and experimental science benefitted a society developing in seafaring, manufacture, and trade in the 17th century. Sigerist's views make the scientific explosion understandable in human and social terms. He did not overlook the capabilities of some extraordinary individuals, such as Paracelsus (1493-1541), to shape the course of medicine, nor the importance of the mechanistic philosophy in the 17th century. Man makes history and science; hence, we find concurrent phenomena of history and science essentially interdependent. The spirit of experimental science of 17th century England was inspired by the new needs of commercial enterprise for more means of transportation and communication. Likewise, the interest in the mechanics of the pump for waterworks and for the drainage of swamps led Harvey to think of the heart as a pump, and to explain the circulation of the blood in terms of its functioning.

England↗