A theoretical model of biochemical control engineering based on the relation between oestrogens/progestagens and prostaglandins.

A biological complex organism is involuntarily guided from all sides by measure and regulation systems. The human being is such a complex organism. Many cyclical processes are simultaneously at work, making it unclear how and why which process takes place at which moment. Noticeable examples are the 28-day menstrual cycle and the 40-week pregnancy. The time of activation in the middle of the menstrual is fairly clear. Hormonal changes also occur in this period. Why the hormonal changes occur, and what their relationship is with the activation of the processes is unclear. That is also the case during pregnancies. What is it that determines that a pregnancy should last an average of 40 weeks? What causes the changes in a complicated pregnancy? What are those changes? Prostaglandin concentrations have been found to have some relationship with these changes, but the activation of these changes and how to examine them is unknown. Using an example from practical experience, this article illustrates what Horrobin and Manku already reported in 1977, namely, the properties of prostaglandin E1 and 6-keto pgF1α: reversal effect with elevated concentration. The properties described is exceptionally suitable for the time of activation in a biochemically regulated measure and regulation system. These properties can help explain the occurrence of physiological cycles. The known electronic saw-tooth wave has a biochemical analogue with this. This paper describes the presumed relationship between hormones and the accompanying prostaglandins with the hormone effects based on what is known regarding their concentrations progress. This relationship reveals the practical consequences of the experimentally found sensitivity of biochemical effects with regard to the accompanying prostaglandins. This paper shows how the theoretical relationship between effects of oestrogens and progestagens result in a curve that comprise observable aspects of the Basal Body Temperature Curve. The modulating and activating prostaglandins also affect local changes in blood circulation. These changes are visible on specific sites on the abdominal skin via viscerocutaneous reflex pathways. Changes in blood circulation at specific areas of the skin can be representative of pain. Pain that also frequently arises during activation processes. These changes can be seen and measured with non-contactual infrared thermography on the cutaneous surface, and moments of activation and pain can be determined.

Major depressive episodes over the course of 7 years and hippocampal subfield volumes at 7 tesla MRI: the PREDICT-MR study.

INTRODUCTION: Smaller hippocampal volumes have been associated with major depressive disorder (MDD). The hippocampus consists of several subfields that may be differentially related to MDD. We investigated the association of occurrence of major depressive episodes (MDEs), assessed five times over seven years, with hippocampal subfield and entorhinal cortex volumes at 7 tesla MRI. METHODS: In this prospective study of randomly selected general practice attendees, MDEs according to DSM-IV-R criteria were assessed at baseline and after 6, 12, 39 and 84 months follow-up. At the last follow-up, a T2 (0.7 mm(3)) 7 tesla MRI scan was obtained in 47 participants (60±10 years). The subiculum, cornu ammonis (CA) 1 to 3, dentate gyrus&CA4 and entorhinal cortex volumes were manually segmented according a published protocol. RESULTS: Of the 47 participants, 13 had one MDE and 5 had multiple MDEs. ANCOVAs, adjusted for age, sex, education and intracranial volume, revealed no significant differences in hippocampal subfield or entorhinal cortex volumes between participants with and without an MDE in the preceding 84 months. Multiple episodes were associated with smaller subiculum volumes (B=-0.03 mL/episode; 95% CI -0.06; -0.003), but not with the other hippocampal subfield volumes, entorhinal cortex, or total hippocampal volume. LIMITATIONS: A limitation of this study is the small sample size which makes replication necessary. CONCLUSIONS: In this exploratory study, we found that an increasing number of major depressive episodes was associated with smaller subiculum volumes in middle-aged and older persons, but not with smaller volumes in other hippocampal subfields or the entorhinal cortex.

Demonstration of tissue alterations by ultrasonography, magnetic resonance imaging and spectroscopy, and histology in breast cancer patients without lymphedema after axillary node dissection.

Estimates of the incidence of arm swelling after axillary lymph node dissection for breast cancer range from 10 to 37%. Yet the subjective sensation of edema is described in at least 54% of patients. The purpose of this research was to examine the structural changes occurring in the subcutaneous tissue that might explain these subjective complaints using multiple imaging modalities. Two female cadavers with unilateral breast amputation and axillary dissection were studied. The dermal and subcutaneous layers of both arms were visualized with high frequency ultrasonography, and magnetic resonance imaging and spectroscopy (MRS), and tissue biopsies were taken for histological evaluation. On the operated side, ultrasound imaging showed a hyperechogenic subcutis and the fat-to-water relationship in adipose cells was higher as measured by MRS. Dissection of the arms revealed structural adipose tissue changes, which were confirmed by microscopic evaluation.

Drainage pattern of the upper medial quadrant of the breast in young healthy women after subdermal injection: a lymphscintigraphic study.

This study examines the lymphatic drainage after injection of a radiotracer in the upper medial quadrant of the right breast in young healthy female subjects. Most studies concerning lymphatic drainage pathways have focused on the upper lateral quadrant of the breast because of the high incidence of carcinoma in this quadrant while the drainage pattern of the medial quadrant has been less studied. We injected radiotracer (Human Serum Albumin labeled with 99 technetium) subdermally into the upper medial quadrant of the right breast tissue of 33 young healthy female volunteers and obtained static images with a scintillation camera briefly after injection and approximately one hour after injection. We identified lymphatic pathways in 82.8% of our subjects, lymph nodes in 79.3% and in 3.4%, a sentinel lymph node was found in the internal mammary chain. In early images, lymph nodes were visualized in 65.5% of subjects while in 17.2% of subjects, lymphatic vessels only appeared on later images.

Lymphatic pathways of the upper medial quadrant of the breast in healthy women: radiotracer study of the sentinel lymph node.

This study examined the lymphatic drainage after injection of a radiotracer into the upper medial quadrant of the breast in healthy women. Most studies of lymphatic pathways of the breast have been performed in patients with breast cancer and concentrate on the upper lateral quadrant of the breast because of the high incidence of carcinoma at this site. The lymphatic drainage pathways of the medial half of the breast, however, has been less studied. A radiotracer (Tc-99m human serum albumin nanocolloid or HSA) was injected intradermally into the upper medial quadrant of the right breast in 12 healthy women. Dermal markers were placed at the middle of the clavicle, the axilla and at the jugular incisura. Three minutes after injection a static image of the injection site was made with a scintillation camera (Multispect 2 Gamma Camera System) over 20 seconds. After nine minutes, local soft massage was instituted at the injection site for 6 minutes. Fifteen minutes after injection, a graphic scintigraphic image was made of both breasts and axillae over 22 minutes. After this interval, three or four static images were made for a few seconds to locate the sentinel lymph node as related to the injection site. A sentinel lymph node (lymphatic pathway) in the axilla was visualized in 11 subjects (91.9%) and was undetected in one subject (8.3%). The radiotracer migrated in all patients (100% ) towards the ipsilateral axilla. In 9 subjects, the sentinel lymph node was visualized 15 minutes after injection, whereas in 2 subjects it appeared within an hour.

A key to understanding postoperative lymphoedema: a study on the evolution and consistency of oedema of the arm using ultrasound imaging.

Post-mastectomy oedema is a very serious complication that, in the course of time, will transform into fibrotic tissue. The aim of our study is to evaluate when and in which layer liquid oedema transforms into fibrotic tissue. To do so, ultrasonographic images were taken of 22 patients and 9 control women at the shoulder and 10 cm proximal and distal from the olecranon, with the images then being scanned and imported into a computer program to determine echogenicity of the dermis, subcutis, subcutis on dermal side and subcutis on fascial side. Statistical analyses were performed by means of the Wilcoxon test and a Student's t-test. No significant differences (P< or =0.05) were found for the different parameters in the control group. In the experimental group: significant differences in perimeter, skinfold, thickness of dermis and subcutis were found. Although not significant, subcutaneous tissue was more echogenic on the oedematous side, with significant hyperechogenicity at the fascial subcutaneous layer. This indicates that fibrotic tissue develops distally in the forearm.

Electromagnetic diathermia: a lymphoscintigraphic and light reflection rheographic study of leg lymphatic and venous dynamics in healthy subjects.

Because electromagnetic diathermia (ED) has been reported to reduce lymphedema, we opted to examine the effects of ED on leg venous and lymph dynamics in healthy subjects. To examine lymph flow, we performed lymphangioscintigraphy (LAS) in 10 subjects without leg edema and used static images at the injection site and at the inguinal region for "control data." Later, we applied ED (2450 MHz, 200W) and then repeated the LAS using the same dosage and volume. Differences between the first and second sessions were examined using two way ANOVA and the differences between the scores with or without ED were analyzed by a Student's t-test. To examine venous flow, we first tested the left lower leg of 15 healthy subjects on two occasions using light reflection rheography (LRR). Venous refill time was recorded after each individual performed 10 dorsiflexions with the left foot on three occasions with an interval of 3 minutes between each recording. Thereafter, 20 minutes ED (2450 MHz, 200 W) was applied and using the same protocol venous refill time was recorded and repeated after an interval of one week. The 20% level and the declination angle of the refill time was determined and differences between the experimental and control groups analyzed by ANOVA. The results between the first and second sessions were consistent and reproducible with or without the electromagnetic application, with no change of radiotracer transport from the injection site or arrival at the inguinal nodes. There was also a high correlation between the scores for the 50% level and declination angle (r = 0.97) after LRR. Thus, after ED there was an accelerated venous refill time. In conclusion, after ED there was no increase in lymph flow but there was accelerated venous return.

The influence of cold and compression on lymph flow at the ankle.

OBJECTIVE: To investigate the effects of cold application with different temperatures on lymph flow in healthy persons and to examine the effects of the combination of cold and compression on lymph vessels. PARTICIPANTS: Thirty-nine healthy persons were included in the study, and each served as his or her own control. INTERVENTION: Water bags (1 degree, 15 degrees, and 32 degrees) with or without 25 mm Hg pressure were applied to the experimental legs for 30 minutes. Cold, pressure, or both were administered by an Aircast-Cryo-cuff (Aircast Europe GMBH, Rosenheim, Germany). MAIN OUTCOME MEASURES: Skin temperature was measured with a TESTO 901 (Testoterm GMBH, Leuven, Belgium) precision thermometer. Lymph flow was recorded continuously using lymphoscintigraphy. MANOVA with repeated measures was used for data analysis. RESULTS: As expected, skin temperature dropped relative to the temperature of the water. The migration of the tracer was comparable in both ankles during the first 30 minutes of the experiment (rest). When the water bag was applied, lymph flow increased significantly (p < 0.01). The application of water of 1 degree C without pressure influenced lymph evacuation significantly differently from the other temperatures. The application of pressure of 25 mm Hg influenced lymph evacuation significantly at 1 degree C and 32 degrees C. CONCLUSION: These results indicate that lymph evacuation at the ankle is influenced significantly when cold water is applied with or without pressure. When pressure is added to the application of water of 32 degrees C, lymph flow will also increase significantly, indicating the importance of pressure in lymph evacuation.

An extreme creA mutation in Aspergillus nidulans has severe effects on D-glucose utilization.

Aspergillus nidulans wild-type and the extreme carbon catabolite derepressed mutant creAd-30 were characterized with respect to enzyme activities, metabolite concentrations and polyol pools all related to glycolysis, after growth on D-glucose. In the creAd-30 strain the enzymes hexokinase and fructose-6-phosphate reductase showed a two- and threefold increase in activity, respectively, whereas phosphofructokinase and pyruvate kinase activity decreased two- and threefold, respectively, in comparison with the wild-type strain. The most notable changes in metabolite concentrations were that fructose 2,6-bisphosphate and fructose 1,6-bisphosphate showed a 2.5-fold increase, whereas both pyruvate and citrate decreased in the creAd-30. Striking differences were found for the polyol concentrations measured for the two strains tested. Intracellular glycerol and arabitol concentrations were 10-fold higher and erythritol fivefold higher in creAd-30, whereas intracellular trehalose and mannitol were both decreased. The total internal polyol concentration appears to be constant at approximately 700 mumol (g dry wt)-1. All polyols were also detected in high amounts in the culture filtrate of the creAd-30 mutant strain but no extracellular trehalose was found. The overall production of polyols in this strain was therefore much higher than in the wild-type. The high level of polyols produced and the changes in metabolite concentrations in the creAd-30 strain suggest that the differences in enzyme activities result in an altered flow through glycolysis leading to a more rapid formation of polyols which are subsequently secreted.

Arabinase gene expression in Aspergillus niger: indications for coordinated regulation.

Aspergillus niger secretes three glycosylated glycosyl hydrolases which are involved in degradation of the plant cell wall polysaccharide L-arabinan: alpha-L-arabinofuranosidases (ABF) A and B, and endo-1,5-alpha-L-arabinase (ABN) A. The nucleotide sequence of the previously cloned gene encoding ABF A (abfA) from A. niger was determined. The coding region contains seven introns. Mature ABF A comprises 603 amino acids with a molecular mass of 65.4 kDa as deduced from the nucleotide sequence. The secreted enzyme is N-glycosylated. The primary structures of the three A. niger arabinases characterized lack similarity. Regulation of arabinase expression upon induction by sugar beet pulp and by L-arabitol was studied as a function of time. This was done in wild-type A. niger as well as in transformants carrying multiple copies of either one of the ABF-encoding genes. Each arabinase gene responded differently upon a mycelial transfer to L-arabitol-containing medium. Extra copies of abfA or abfB led to a decreased expression level of ABN A, though the repression elicited by abfB is stronger and more persistent than that effected by abfA. Multiple copies of both abf genes influence expression of the other ABF similarly, but to a far less pronounced degree than they affect ABN A synthesis. Four putative promoter elements, shared by all three arabinase genes, could be involved in coordination of L-arabinan degradation by A. niger.

Extracellular arabinases in Aspergillus nidulans: the effect of different cre mutations on enzyme levels.

The regulation of the syntheses of two arabinan-degrading extracellular enzymes and several intracellular L-arabinose catabolic enzymes was examined in wild-type and carbon catabolite derepressed mutants of Aspergillus nidulans. alpha-L-Arabinofuranosidase B, endoarabinase, L-arabinose reductase, L-arabitol dehydrogenase, xylitol dehydrogenase, and L-xylulose reductase were all inducible to varying degrees by L-arabinose and L-arabitol and subject to carbon catabolite repression by D-glucose. With the exception of L-xylulose reductase, all were clearly under the control of creA, a negative-acting wide domain regulatory gene mediating carbon catabolite repression. Measurements of intracellular enzyme activities and of intracellular concentrations of arabitol and xylitol in mycelia grown on D-glucose in the presence of inducer indicated that carbon catabolite repression diminishes, but does not prevent uptake of inducer. Mutations in creA resulted in an apparently, in some instances very marked, elevated inducibility, perhaps reflecting an element of "self" catabolite repression by the inducing substrate. creA mutations also resulted in carbon catabolite derepression to varying degrees. The regulatory effects of a mutation in creB and in creC, two genes whose roles are unclear, but likely to be indirect, were, when observable, more modest. As with previous data showing the effect of creA mutations on structural gene expression, there were striking instances of phenotypic variation amongst creA mutant alleles and this variation followed no discernible pattern, i.e. it was non-hierarchical. This further supports molecular data obtained elsewhere, indicating a direct role for creA in regulating structural gene expression, and extends the range of activities under creA control.

Cloning and characterization of the abfB gene coding for the major alpha-L-arabinofuranosidase (ABF B) of Aspergillus niger.

Based on amino-acid sequence data from Aspergillus niger alpha-L-arabinofuranosidase B (ABF B), and cyanogen bromide fragments derived thereof, deoxyoligonucleotide mixtures were designed to be employed as primers in a polymerase chain reaction (PCR) on A. niger genomic DNA. This resulted in amplification of three related PCR products. The abfB gene encoding ABF B was isolated from a genomic library using such an amplification product as a probe. A 5.1-kb BamHI fragment was subcloned to result in plasmid pIM991. Upon introduction by co-transformation into both A. niger and A. nidulans uridine auxotrophic strains, pIM991 was shown to contain the functional gene since prototrophic transformants overproduced ABF B upon growth on the inducing carbon source sugar beet pulp. A plate assay was developed enabling quick selection of ABF B-overproducing transformants. The sequence of a 4122-bp long BamHI/SstI fragment was determined. The abfB gene does not contain introns and codes for a protein of 499 amino acids. The mature ABF B, 481 amino acids in length, has a deduced molecular weight of 50.7 kDa. A. niger abfB is the first eukaryotic gene encoding an ABF to be characterized.

Molecular cloning, expression and structure of the endo-1,5-alpha-L-arabinase gene of Aspergillus niger.

Secretion of endo-1,5-alpha-L-arabinase A (ABN A) by an Aspergillus niger xylulose kinase mutant upon mycelium transfer to medium containing L-arabitol was immunochemically followed with time to monitor its induction profile. A cDNA expression library was made from polyA+ RNA isolated from the induced mycelium. This library was immunochemically screened and one ABN A specific clone emerged. The corresponding abnA gene was isolated from an A. niger genomic library. Upon Southern blot analysis, a 3.1-kb HindIII fragment was identified and subcloned to result in plasmid pIM950. By means of co-transformation using the A. niger pyrA gene as selection marker, the gene was introduced in both A. niger and A. nidulans uridine auxotrophic mutants. Prototrophic A. niger and A. nidulans transformants overproduced A. niger ABN A upon growth in medium containing sugar beet pulp as the sole carbon source, thereby establishing the identity and functionality of the cloned gene. The DNA sequence of the complete HindIII fragment was determined and the structure of the abnA gene as well as of its deduced gene product were analysed. Gene abnA contains three introns within its structural region and codes for a protein of 321 amino acids. Signal peptide processing results in a mature protein of 302 amino acids with a deduced molecular mass of 32.5 kDa. A. niger abnA is the first gene encoding an ABN to be isolated and characterized.

Cloning of the Aspergillus niger gene encoding alpha-L-arabinofuranosidase A.

Using L-arabitol as an inducer, simple induction conditions were established that resulted in high-level expression of alpha-L-arabinofuranosidase A by an Aspergillus niger D-xylulose kinase mutant strain. These conditions were adapted to construct a cDNA expression library from which an alpha-L-arabinofuranosidase A cDNA clone was isolated using specific antiserum. The corresponding gene encoding alpha-L-arabinofuranosidase A (abfA) was isolated from a genomic library and cloned into a high copy plasmid vector. By co-transformation of uridine auxotrophic mutants lacking orotidine-5-phosphate decarboxylase activity, the afbA gene was introduced both in A. niger and A. nidulans, using the A. niger pyrA gene as selection marker. The identity of the abfA gene was confirmed by overexpression of the gene product by A. niger and A. nidulans transformants, upon growth using sugar beet pulp as the carbon source.