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F Graf

Publications and source records attributed to F Graf.

At least 37 records · Page 2Linked to original sources
PubMed1987

Ecdysteroid titers during the molt cycle of Orchestia cavimana (Crustacea, Amphipoda).

Ecdysteroids were analyzed during a molt cycle in adult males of the crustacean Orchestia cavimana; levels were determined in the hemolymph and in whole bodies, using radioimmunoassay. Results show a single and sharp peak at the end of D1 stage, reaching 810 pg eq/microliter in the hemolymph (a 230-fold increase compared to the middle of intermolt). From B stage to the beginning of D1, levels are very low but increase regularly and significantly. The amplitude and the temporal position of the peak are discussed in detail, in relation to the precision of the staging (17 different stages can be easily made in Orchestia) and to the cuticle cycle (the hormonal peak occurs ca. 10 hr before the beginning of cuticle synthesis at D2). Preliminary experiments, using monoclonal antibodies during the period of low ecdysteroid titers or high-performance liquid chromatography followed by polyclonal RIA during the peak period, suggest that the immunoreactive hormone in O. cavimana behaves like 20-hydroxyecdysone. However, other minor compounds have been detected (some unknown, others migrating like ecdysone and ponasterone A in HPLC).

Animals↗
PubMed1987

Prescription patterns and costs of antihypertensive drugs in two outpatient clinics: Zürich (Switzerland) and Münster (FRG), 1975-1985.

In the present study the prescription patterns and cost of antihypertensive drugs in two outpatient clinics located in two different countries (Zürich, Switzerland, and Münster, FRG), were analyzed from 1975 till 1985 by using representative random samples of hypertensive outpatients. Throughout the observed period the leading positions were held by diuretics and beta-blockers, whereas central sympatholytics and ganglion blockers nearly disappeared. A rapid increase in the use of calcium antagonists occurred within the last 2 analyzed years. Drugs in fixed combination containing reserpin showed a constant decrease during the observed period, whereas beta-blocker-containing combination drugs increased in both clinics. The comparison between the two clinics revealed only minor differences in the prescription pattern of the various known classes of antihypertensive drugs. However, marked differences were observed within given classes between the preferred products. Both in Zürich and Münster the mean annual drug cost per patient doubled from 1975 to 1985. Especially during the last few years these changes took place with a remarkable rapidity, obviously the result of a more intense promotion of new antihypertensive drugs.

Adrenergic beta-Antagonists↗
PubMed1986

Ultrahistochemical localization of Na+-K+ ATPase, Ca2+-ATPase and alkaline phosphatase activity in a calcium-transporting epithelium of a crustacean during moulting.

Periodical changes in Na+-K+-ATPase, Ca2+-ATPase and non-specific alkaline-phosphatase activity were observed using cytochemical techniques in the posterior caeca of the crustacean amphipod, Orchestia cavimana, during the moult cycle. These changes were considered in relation to the calcium transport mechanisms in the posterior caecal epithelium. For both ATPases as well as alkaline phosphatase, the specific reaction products were most intense during the pre-exuvial period, i.e. when calcium is slowly transported against a concentration gradient: the localization of Na+-K+-ATPase activity in microvilli and the upper extracellular channels strongly supports the hypothesis that this enzyme is involved in an indirect, sodium-dependent mechanism for the transport of calcium. The detection of Ca2+-ATPase activity in microvilli would seem to indicate that this enzyme plays a role in the direct, active extrusion of Ca2+ at this level. Although the role of alkaline phosphatase in the transport of calcium remains unclear, the histochemical detection of this enzymatic activity throughout the apical part of the caecal epithelium suggests that this enzyme may be involved in calcium secretion. In post-exuvial period, we found only weak specific reaction products, thus indicating a reduced active calcium transport as these ions are rapidly reabsorbed down the concentration gradient.

Alkaline Phosphatase↗
PubMed1986

CD-15 antigen detected by the VIM-D5 monoclonal antibody for prediction of ability to achieve complete remission in acute nonlymphocytic leukemia.

The prognostic value of cell differentiation antigens detected with the monoclonal antibodies of VI series was studied in 242 cases of acute nonlymphoblastic leukemia (ANLL) treated in 7 cooperating centers. A significantly higher complete remission rate was observed in patients with a higher expression of CD-15 antigen detected by VIM-D5 antibody than in those with lower values. These significant differences were proved when comparing subgroups with VIM-D5 positivity of blastic cells less than 15 and much greater than 15% (p less than 0.01) as well as in the subgroups with values less than 50% (median value) and greater than or equal to 50% (p less than 0.02). Our studies suggest the VIM-D5 positivity of ANLL cells to be favourable prognostic factor predicting the ability to achieve complete remission. Further studies are needed to establish whether the expression of the VIM-D5-defined antigen may serve as a prognostic factor related to survival.

Acute Disease↗
PubMed1986

[Pharmacokinetics and bioavailability of diphenhydramine in man].

By the presented study the relative bioavailabilities and some important pharmacokinetic parameters should be evaluated after oral application of a single-dose of three different diphenhydramine (DPH, 2-diphenylmethoxy-N,N-dimethylethylamine)preparations in a randomized, cross-over design to 12 healthy volunteers. Additionally, some simple pharmacodynamic measurements of the volunteer's vigilance were performed and the question whether a combination with 8-chlorotheophylline influences the pharmacokinetic and/or pharmacodynamic profile of DPH was investigated. As the test preparations (Benocten as a tablet = A, as a buffered solution = B) contained 50 mg of DPH-HCl, but the reference preparation (= C) only 31 mg of DPH-HCl (+ 23 mg 8-chlorotheophylline), the biometric-statistic calculations had to be done with and without dose correction. Bioequivalence of the preparations could only then be demonstrated when the calculations were done with dose corrections: without these corrections for the reference preparation significantly lower serum levels resulted which hardly can be considered sufficient for exerting a sleep-inducing effect. The addition of 8-chlorotheophylline recommended by some other authors for an enhanced sedative effect could not be substantiated by our results. Peak serum levels of 61 and 53 ng/ml, respectively, for the test preparations and 40 ng/ml for the reference preparation were reached after 2.0 to 2.5 h p.a.; elimination half-lives were between 4 and 6 h. A statistically significant positive correlation could be found for AUC (0-24 h) and the amount excreted in urine in the same period of time, as higher mean serum levels were correlated with higher amounts excreted renally.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Calcium pathway through a mineralizing epithelium in the crustacean Orchestia in pre-molt: ultrastructural cytochemistry and X-ray microanalysis.

During the pre-exuvial period of the terrestrial crustacean Orchestia, the calcium of the old cuticle is almost entirely reabsorbed and stored as calcareous concretions in the lumen of the midgut posterior caeca. The elaboration of these concretions is due to transport by the caecal epithelium. With ultrastructural cytochemistry controlled by X-ray microanalysis, it can be demonstrated that the main sites of ionized or ionizable calcium are the apical microvilli and an extracellular (lateral and basal) network of channels. Direct precipitating cytochemical methods, using potassium pyroantimonate or pyrophosphate, potassium oxalate or oxalic acid, sodium fluoride, sodium tungstate, and indirect substitution methods, using lead acetate or nitrate and cobalt nitrate were comparatively used. The results are interpreted in favour of the hypothesis of an extracellular transport pathway for calcium through the lateral smooth septate junctions, in conjunction with a more classical apical transport through the microvilli.

Animals↗
PubMed1984

Some effects of removal of external calcium on pig striated muscle.

Bundles of about 800 cells from the m. thyreopharyngicus of pigs were used to measure activation and inactivation during contracture by K+ depolarization. When [Ca2+] in the medium was lowered to less than 5 X 10(-10) M for 3 min (replacing Ca2+ by Mg2+) the activation occurred at the same [K+] in the medium as in normal solution (3 mM-Ca2+) but inactivation was shifted to lower external [K+]. The absolute value of this shift in terms of membrane potential is uncertain, because [K+] at the cell surface is unknown. Exposure for 4 min to Ca2+-free medium (Ca2+ being replaced by Mg2+) had no effect on contractility tested after a subsequent rest of 22-25 min in normal solution ( [Ca2+] = 2 mM). However, if the muscle underwent one maximal K+ contracture in Ca2+-free medium the response (tetanus or K+ contracture) after the same interval in normal solution was strongly reduced, although the membrane potential recovered fully. K+ contractures in normal solution could be repeated without loss of contractile force. A K+ contracture in Ca2+-free medium had very little effect on the response to caffeine, tested after 25 min in normal solution. It seems that Ca2+ is lost into Ca2+-free medium only during depolarization, from a site which is not accessible to Ca2+ from outside at the resting membrane potential, or from inside at any membrane potential. This site might be located inside the transverse-tubular membrane and, when loaded with Ca2+, might represent the positive group of the model of Chandler, Rakowski & Schneider ( 1976b ), the movement of which during depolarization activates and inactivates the Ca2+ release from the sarcoplasmic reticulum.

Animals↗
PubMed1981

[Histological findings following preoperative catheter embolization in hypernephroid renal carcinoma (author's transl)].

The authors investigated the histological findings in various embolization materials and at various interval before operation in 11 hypernephroid renal carcinoma patients who had been subjected to a preoperative transfemoral catheter embolization of the renal artery. The embolization materials used were fibrin-thrombin, pieces of gelatine sponge, collagen and GAW-spirals. The periods at which nephrectomy was carried out ranged from immediately after the embolization to six weeks later. From the histological point of view, total necrosis of the tumour did not occur in any case; only in three cases could a subtotal necrosis be achieved and in all the other cases the tumour-free parenchyma showed greater damage as a result of more pronounced ischemic infarction than did the tumour. A complete and lasting elimination of a tumourous kidney cannot be achieved by embolization of the renal artery. The obvious reasons for this are the tendency towards recurrence of canalization and the formation of collateral circulation.

Adenocarcinoma↗