A cross-over study of three oral contraceptives containing ethinyloestradiol and either desogestrel or levonorgestrel

A randomised cross-over trial was performed to compare the pharmacodynamic actions of three low-dose oral contraceptives (OCs): Marvelon (150 micrograms desogestrel (DSG)+ 30 micrograms ethinyloestradiol (EE)), Mercilon (150 micrograms DSG + 20 micrograms EE) and Microgynon (150 micrograms levonorgestrel (LNG) + 30 micrograms EE). None of the OCs produced any significant changes in serum cholesterol, LDL-C and apoprotein B. Triglycerides were increased by the desogestrel OCs but not by Microgynon. The latter however increased the glucose and insulin responses to a glucose tolerance test whereas Marvelon and Mercilon had no effect. HDL-C increased with Marvelon, was unchanged with Mercilon and was decreased with Microgynon. Apoprotein AII was increased by all three OCs but only the DSG OCs increased apoprotein AI. All OCs produced similar increases in caeruloplasmin but the increase in SHBG was much greater with Marvelon and Mercilon than with Microgynon. Testosterone was reduced more with Microgynon than with the DSG OCs. Many of the changes reflect the strong anti-oestrogenic action of LNG on metabolic parameters compared to DSG. Except for the effect on HDL-C, there was little difference between Marvelon and Mercilon on metabolic parameters and this complements the findings from large-scale clinical trials of the two OCs. Mercilon, therefore provides a very satisfactory alternative to Marvelon.

Clinical Experience with an Activity Sensing DDDR Pacemaker Using an Accelerometer Sensor

The rate adaptive characteristics and pacemaker mediated tachycardia protection algorithm of an accelerometer based DDDR pacemaker were evaluated in 11 patients with bradycardia (seven atrioventricular block, four sick sinus syndrome). Rate adaptive programming was effected by collecting the acceleration level during a 3-minute moderate exercise ("tailoring" of sensor). In comparison with an externally attached piezoelectric sensor, the accelerometer sensor showed lower rate changes during external tapping of the pacemaker (16 +/- 3 vs 29 +/- 4 ppm, P less than 0.02) and applied direct pressure (1 +/- 1 vs 40 +/- 3 beats/min, P less than 0.001) on the pacemaker. At nominal setting, the accelerometer sensor showed improved rate stability and higher rate response to jogging and standing, although responses to other daily activities and treadmill exercise were similar. Apart from changing the rate responsive slope, rate response could be improved by repeat "tailoring" of the sensor at a lower exercise level, resulting in better overall rate response characteristics. The ability of the rate monitoring software to collect acceleration levels for an activity and profile the projected rate response at different rate responsive settings allowed programming to be effected with the minimum amount of exercise testing. The pacemaker also discriminated atrial tachyarrhythmias from normal sinus response using the sensor to judge the appropriateness of the atrial rate, which correctly identified and prevented rapid ventricular tracking in two patients during atrial flutter/fibrillation.

The Use of Implantable Sensors for the Control of Pacemaker Mediated Tachycardias: A Comparative Evaluation Between Minute Ventilation Sensing and Acceleration Sensing Dual Chamber Rate Adaptive Pacemakers

The role of implantable sensors to control pacemaker mediated tachycardias was investigated in 16 patients with two different dual chamber rate adaptive (DDDR) pacemakers, which sensed eiter minute ventilation (DDDR-Meta, nine patients) or body acceleration (Relay, seven patients). Successive atrial sensed events beyond a programmable rate occurring in the absence of detection of exercise by the sensors were considered to represent retrograde conduction or atrial arrhythmias, and the pacemakers responded by either a mode shift from DDDR to ventricular rate adaptive (VVIR) pacing (DDDR-Meta) or by tracking at an interim rate, the so-called conditional ventricular tracking limit (CVTL, Relay). In the unipolar atrial sensing mode, myopotential sensing (MPI) and external chest wall stimulations (CWS) at 250 beats/min were induced to be preferentially sensed by the atrial channel to simulate the conditions of atrial arrhythmias. In the DDD mode, these maneuvers resulted in ventricular responses of 88 +/- 3 beats/min and 110 +/- 3 beats/min for MPI and CWS, respectively. The pacing rate was significantly reduced in the DDDR mode with the sensors correctly detecting and responding to the sensed abnormal atrial signals (68 +/- 5 beats/min during MPI and 71 +/- 5 beats/min during CWS, P less than 0.005 compared with the corresponding DDD rate). One patient with a Relay pacemaker developed spontaneous atrial flutter and the ventricular tracking responses were 140 and 85 beats/min in the DDD and DDDR pacing modes, respectively. Thus MPI and CWS are useful bedside testing methods to assess pacemaker response during atrial arrhythmias. The use of implantable sensors to judge the appropriateness of atrial rate is a new approach to the management of pacemaker mediated tachycardias.

21-aminosteroids interact with the dopamine transporter to protect against 1-methyl-4-phenylpyridinium-induced neurotoxicity

U-78518F, a 21-aminosteroid from the novel family of lipid peroxidation inhibitors (lazaroids), increased survival of dopamine (DA) neurons in mesencephalic cell cultures incubated with the neurotoxin 1-methyl-4-phenylpyridinium (MPP+). Protection against DA neuron death occurred with increasing concentrations of U-78518F up to 30 microM. Non-specific toxicity produced with higher concentrations of MPP+ was not affected by the lazaroid. U-78518F inhibited cellular uptake of [3H]MPP+ and [3H]DA, but not that of gamma-[3H]aminobutyric acid. In human striatal membrane preparations, U-78518F competed with [3H]mazindol for binding to the DA transporter, with a calculated Ki value of 10 microM. Two of four lazaroids tested inhibited [3H]DA uptake in the cell culture system. The protective effects of 21-aminosteroids in MPP(+)-induced neurotoxicity are, in part, a function of the interaction of these agents with the DA transporter.

[Cerebral germinoma]

16 cases of cerebral germinoma are reported. This tumor is comparatively rare. Since it is usually located in pineal and easily be confused with pineloma or ectopic pinealoma, its terminology, source of the tumor tissue, histopathological characteristics, diagnosis and differential diagnosis are discussed by the authors. According to the high mortality of the operative treatment, the radiotherapy is suggested.

A pharmacodynamic and pharmacokinetic study of the Chinese No. 1 pill

A pharmacodynamic and pharmacokinetic study of the Chinese No. 1 pill, a combined oral contraceptive containing 35 micrograms ethynyloestradiol (EE) and 600 micrograms norethisterone (NET), was performed in 29 women over a period of six months. Blood samples for analysis were taken during a pretreatment cycle, the first and 6th treatment cycles and post-treatment. Minor changes in carbohydrate metabolism occurred and these were particularly noticeable when the incremental areas under the serum concentration-time curves for both glucose and insulin in response to a glucose tolerance test were calculated. No changes occurred in the serum glycosylated haemoglobin levels. The serum concentrations of all the lipids measured (total cholesterol, triglycerides, LDL-C, HDL-C and apolipoproteins AI, AII and B) were significantly increased on treatment as were levels of Factor X, SHBG and caeruloplasmin whereas antithrombin III decreased. In 38 of the 40 treatment cycles, ovulation was suppressed. In one cycle serum oestradiol and progesterone levels showed a typical ovulatory pattern and in another there was evidence of follicular activity without ovulation. Serum EE concentrations showed a similar pattern in both treatment cycles showing that co-administration of NET did not affect EE metabolism. Serum NET levels were higher in the 6th than in the first treatment cycles. On comparing pharmacodynamic and pharmacokinetic parameters, the only statistically significant correlations were between the percentage change in triglycerides and SHBG and serum NET, but not EE concentrations, and between apolipoproteins AI and serum EE.

Cat-P300 present after association cortex ablation

The cat-P300 is a positive endogenous potential, larger to a stimulus when rare than when frequent, with a latency of 200-500 msec. The role of polysensory association cortex, postulated to be important in human P300 generation, was assessed in the cat. EEG was recorded in 13 awake cats from a skull screw at the vertex. Stimuli included frequent (P = 0.80) 1 kHz and rare (P = 0.10) 2 kHz tone pulses with probabilities counterbalanced across 260-trial blocks. After 12 preoperative sessions, bilateral ablations were made of pericruciate cortex (4 cats), anterior lateral and medial suprasylvian gyri (4 cats) and all 3 areas (5 cats). Postoperatively, all 13 cats showed a P300 across 12 recording sessions. Thus polysensory association cortex is not essential for generation of the cat-P300.

Retinoic acid regulation of the expression of retinoic acid receptors in wild-type and mutant embryonal carcinoma cells

The embryonal carcinoma cell line P19 undergoes terminal differentiation upon induction by retinoic acid (RA). The effects of RA on the retinoic acid receptor (RAR) mRNA level were investigated in P19 cells and an RA non-responsive mutant RAC65. RA induced a rapid accumulation of RAR alpha within 2 h and this was followed by an increase in the RAR beta mRNA. RAC65 cells differed from P19 cells in that the accumulation of RAR alpha mRNA was delayed and that an aberrant pattern of RAR alpha transcript was observed.

Determination of the complete nucleotide sequence of HBV adr NC-1 DNA

On the basis of sequencing the large DNA-fragments which have been inserted into M13mp8, we design a simple strategy to determine the complete nucleotide sequence of HBV adr NC-1 DNA with chain termination method. The whole genome is 3195 nucleotides long. Five reading frames are observed. The gene location and organization are shown.

Molecular cloning and expression of salmon pituitary hormones

A cDNA library was prepared from chinook salmon pituitaries. Growth hormone (GH), prolactin (PRL) and the β subunit of gonadotropin (GTH) genes were screened using synthetic oligonucleotides as probes. Full size cDNA clones coding for these polypeptide hormones were isolated and characterized. The cDNA sequences for PRL and βGTH have been reported earlier from our laboratories. The cDNA clone for GH contains 1148 bp and codes for a preGH of 210 amino acids. The chinook salmon GH, reported in the present investigation, differs from chum salmon GH in only 1 amino acid, and from coho salmon GH in 5 amino acids. Plasmids containing modified nucleotide sequences coding for GH, PRL and βGTH were constructed individually into an expression vector using the heat-inducible λ pL promotor. Mature PRL, GH and unglycosylated βGTH were expressed in the bacteria at elevated temperature.

Effect of some oral contraceptives on serum concentrations of sex hormone binding globulin and ceruloplasmin

Serum SHBG and ceruloplasmin (CP) concentrations were measured in women throughout a cycle of treatment with four oral contraceptives. In women receiving 150 micrograms levonorgestrel (LNG) daily both SHBG and CP decreased. SHBG also decreased, but CP increased, in women receiving ethynyloestradiol (EE) 30 micrograms with LNG 150 micrograms. In women taking 35 micrograms EE with either 600 micrograms or 1000 micrograms norethisterone, increases in CP were similar but SHBG increased more with the lower dose. Serum concentrations had not returned to pretreatment levels by eight days after cessation of dosing. The findings are compared with similar results for women taking 30 micrograms or 50 micrograms EE or an EE,LNG triphasic formulation. Serum concentrations of the gestagens were also measured. Increases in these concentrations when the gestagen was administered with EE to levels higher than expected from administration of the gestagen alone cannot be explained by increased binding to SHBG but are more likely to be due to changes in their metabolism. Differences in the responses of ostensibly closely related proteins of hepatic origin such as SHBG and CP to the oral contraceptives demonstrate that neither can be extrapolated to other pharmacodynamic responses.

Molecular cloning and expression of salmon prolactin cDNA

Prolactin was purified from chum salmon pituitaries. It was resolved into two variants by reverse-phase high-performance liquid chromatography. A cDNA library was prepared from Pacific chinook salmon pituitaries. Salmon prolactin gene was screened using a synthetic oligonucleotide based on partial protein sequence. A positive clone (PRL-10) was identified and sequenced. It is a full-size clone containing 1.1 kb and coding for a preprolactin of 211 amino acids. A modified prolactin plasmid (PRL-10A), in which the 5' untranslated sequence and the nucleotide sequence coding for the signal peptide of prolactin were deleted, was reconstructed into an expression vector using the heat-inducible lambda pL promotor. Mature prolactin, a single polypeptide of 22 kDa, was efficiently expressed in the bacteria at an elevated temperature.

Effect of Anordrin on serum levels of sex hormone binding globulin, caeruloplasmin and ovarian function

Ten doses of 7.5 mg Anordrin were administered on alternate days from day 5 of the menstrual cycle to 20 women. Serum concentrations of both SHBG and CP were significantly increased after the fourth dose but the increases were minor compared to those produced by ethynyloestradiol. Two weeks after stopping Anordrin, serum concentrations of the proteins were still elevated in most women. Ovarian activity was studied in 8 women; serum oestradiol and progesterone concentrations indicated that ovulation occurred at the normal time in three women but was delayed for two weeks or more in the remaining five. The findings suggest that in humans, Anordrin acts as a weak oestrogen and may also have antioestrogenic activity.

A cavernous sinus cavernous hemangioma. Case report

The case of a Turner's syndrome patient with an intracavernous hemangioma is presented. The rarity of this lesion is stressed, as is surgical removal without postoperative deficit, the role of estrogens in the pathogenesis, and the clinical and radiological findings.

A pharmacokinetic and pharmacodynamic study of a 'visiting pill' containing norethisterone

The pharmacokinetics and pharmacodynamic effects of two doses of norethisterone (5mg and 3mg) used as a 'visiting pill' were investigated. There were no significant differences in the pharmacokinetics of the two doses except for the peak concentration achieved and the bioavailability as assessed by the area under the serum norethisterone concentration - time curve. Both doses were rapidly absorbed. Pharmacodynamic effects were minor. No change occurred in serum concentrations of total cholesterol, total triglycerides or HDL-cholesterol. The area under the serum glucose concentration--time curve and particularly the area under the serum insulin concentration--time curve were significantly increased as a result of treatment but no change occurred in the serum levels of glycosylated haemoglobin. SHBG concentrations in serum decreased on treatment whereas those of ceruloplasmin increased.

Sudden death in a patient with Von Recklinghausen's neurofibromatosis

Sudden death caused by tumors is uncommon. Death attributable to an unsuspected primary intracranial neoplasm is especially rare. An undiagnosed brain tumor is particularly unusual in a patient with Von Recklinghausen's neurofibromatosis (NF). A young man with known NF, with no manifest central nervous system involvement, died less than 24 hours after plastic surgery. A glioblastoma multiforme was discovered at autopsy.