Progesterone alters biliary flow dynamics

OBJECTIVE: To test the hypothesis that progesterone alters sphincter of Oddi and gallbladder function and, therefore, bile flow dynamics. SUMMARY BACKGROUND DATA: Although the effects of progesterone on the biliary tract have been implicated in the increased incidence of gallstones among women, the specific effects of prolonged elevation of progesterone levels, such as occurs with contraceptive progesterone implants and during pregnancy, on the sphincter of Oddi and biliary flow dynamics are still incompletely understood. METHODS: Adult female prairie dogs were randomly assigned to receive subcutaneous implants containing either progesterone or inactive pellet matrix only. Hepatic bile partitioning and gallbladder emptying were determined 14 days later using 99mTc-Mebrofenin cholescintigraphy. RESULTS: Significantly less hepatic bile partitioned into the gallbladder in progesterone-treated than in control animals. The gallbladder ejection fraction was significantly reduced from 73+/-6% in controls to 59+/-3% in the progesterone-treated animals. The rate of gallbladder emptying was significantly reduced from 3.6+/-0.3%/minute to 2.9+/-0.1%/minute. CONCLUSIONS: Progesterone administered as subcutaneous implants alters partitioning of hepatic bile between gallbladder and small intestine and, therefore, gallbladder filling. Progesterone also significantly impairs gallbladder emptying in response to cholecystokinin. The effects of progesterone on the sphincter of Oddi and the gallbladder may contribute to the greater prevalence of gallstones and biliary motility disorders among women.     

Proceedings of the Symposium ‘Angiotensin AT1 Receptors: From Molecular Physiology to Therapeutics’: STRUCTURAL CHANGES IN THE RENAL VASCULATURE IN THE SPONTANEOUSLY HYPERTENSIVE RAT: NO EFFECT OF ANGIOTENSIN II BLOCKADE

• 1 There is strong evidence for a renal basis to the development of hypertension in the spontaneously hypertensive rat (SHR). Alterations of the SHR renal vasculature, including the glomerulus, may be involved in the initiation and maintenance of hypertension in this animal model.
• 2 The arterial walls of pre-glomerular vessels of the SHR are hypertrophied compared with WKY vessels. Unlike other vascular beds in the SHR, this hypertrophy is independent of angiotensin II (AngII).
• 3 Glomerular number and volume are similar between SHR and the normotensive Wistar-Kyoto (WKY) rats. These results provide no support for the theory that a reduced filtration surface area within the kidneys of the SHR contributes to the elevated blood pressure in these animals.
• 4 Intrarenal hypertrophy may have similar haemodynamic consequences to clipping of the main renal artery, as in Goldblatt hypertension. Further analysis of the role of pre-glomerular arterial hypertrophy is warranted to determine its involvement in the initiation and maintenance of hypertension in the SHR.

     

53 a. Notwendigkeit und Anwendungsgebiet retrospektiver Analysen in einer Zeit der prospektiven kontrollierten Studien

Zusammenfassung Prospektiv-kontrollierte Studien sind die verläßlichsten Hilfsmittel, mit denen klinische Fragestellungen entschieden werden können. Für ihre korrekte Handhabung gibt es eine Fülle strenger Voraussetzungen, die sich in der Praxis meist nicht verwirklichen lassen. In diesen Fällen auf Forschung ganz zu verzichten, hieße sich in fataler Weise von einer Methode abhängig machen. Das Anwendungsgebiet retrospektiver Analysen umfaßt daher vor allem diesen Bereich im Sinne einer zweitbesten Lösung. Darüber hinaus ist der retrospektiven Betrachtungsweise eine innere Notwendigkeit für die medizinische Forschung eigen, wenn man auf kritische Reflexion des eigenen Tuns und auf das Angehen neuer Probleme Wert legt.     

Experimental parasitization of eggs of Triatoma maculata (Erichson) by the oriental microhymenopteran,Gryon triatomae Masner and comment on the susceptibility of other neotropical triatomines

The oriental microhymenopteran wasp, Gryon triatomaeMasner, 1975 was reared in eggs of triatomine bugs, including vectors of Chagas' disease. In particular, G. triatomae was maintained for 31 generations in eggs of Triatoma maculata (Erichson). Only one parasite develops in each bug egg and 30 to 40 days are required for completion of development at 24 ± 1 °C. Mean parasitization rate of 7484 eggs of T. maculata, in 54 rearings, was 34·7% with a range from zero to the highest rate of 86·7%. Mated females produce predominantly female progeny (mean sex ratio, 1 male : 6·7 females). Unmated females produce parthenogenetic males. The wasp reproduces in fertile eggs, from those recently laid to those with well-advanced bug embryos. Infertile eggs are not usually parasitized. Both sexes survive for one to two weeks unfed, but for several weeks (up to 16 for females) if fed (on honey). Frequent ovipositions may reduce survival. Successful parasitization by females persisted for about three weeks but declined subsequently.Abortions of developing Gryon were usually 10% or less. Brief comparison with other neotropical triatomine species indicates that eggs of Triatoma spp. are susceptible to G. triatomae; Panstrongylus spp. seem relatively poor hosts, and there is little or no parasitization of Rhodnius spp.     

Aluminum, zinc and copper concentrations in plasma in chronic renal insufficiency.

Plasma aluminium, zinc and copper were determined in 68 patients with chronic renal insufficiency and in 20 healthy individuals. In the renal insufficiency group 16 patients had received aluminium containing substances particularly phosphate binding drugs (aluminium hydroxide) for a long time. We observed that only the patients taking aluminium hydroxide showed elevated aluminium levels in plasma (controls: 0.86 +/- 0.27 mumoles/l; renal insufficiency: 3.05 +/- 1.63 mumoles/l). In two of these patients with symptoms of "dialysis dementia", plasma aluminium concentrations were markedly increased. The zinc concentrations in plasma of patients with renal insufficiency were slightly decreased (controls: 14.48 +/- 2.65 mumoles/l; renal insufficiency: 11.77 +/- 2.35 mumoles/l); the plasma copper concentrations were slightly increased (controls: 17.3 +/- 2.83 mumoles/l; renal insufficiency: 22.98 +/- 4.7 mumoles/l). There was a distinct decrease of plasma zinc concentrations in patients with raised aluminium levels. The clinical aspects of these changes are discussed.     

The evaluation of continuing medical education: a literature review.

The literature of continuing medical education (CME) program evaluation was reviewed and analyzed. The "State-of-the-art" of CME evaluation is depicted in a series of tables which indicate evaluation methods and results. Evaluation designs providing strong assurances of valid results were not often found. The weakness of most published evaluations limit possible conclusions about the effectiveness of CME.     

The use of BRIAC for evaluating therapeutic effectiveness

Forty-six children in eight different psychotherapeutic settings were evaluated at the beginning and at the end of a 12-month period by means of the Behavior Rating Instrument for Autistic Children (BRIAC). The younger children (3 to 6 years of age) were initially more severely disturbed and improved significantly more than the older children (7 to 9 years of age). The large, bleak, custodial residential center produced significantly less improvement in the children than did the other settings. However, among good programs—i.e., those which were sensitive to the behaviors and needs of the children and which were skillfully implemented by a dedicated and attentive staff—there was little evidence of differences in therapeutic effectiveness regardless of whether the therapy was behavior modification, education, psychoanalytically oriented relationship therapy, or activity therapy.     

Median nerve compression in Proteus syndrome

Proteus syndrome is a multi–organ disorder, a prime feature of which is localized gigantism, usually clinically obvious. Symptoms secondary to hypertrophy of nerves has not been previously recognized as a part of the syndrome. Accepted: 16 May 1997