The effect of angiotensin II on myosin heavy chain expression in cultured myocardial cells

Angiotensin II (AII), the principal mediator of the renin-angiotensin system, is an important regulator of vascular and cardiac homeostasis. AII has also been shown to be a regulator of cardiac hypertrophy and of the corresponding changes in amount and composition of certain tissue proteins. We examined the trophic effects of AII on cultured myocytes derived from neonatal rat ventricles and followed, by Northern blot analysis and polyacrylamide gel electrophoresis, the expression of alpha- and beta-myosin heavy chain iso-mRNAs and isoproteins. Our findings show that a single administration of AII is sufficient to induce a trophic response in cultured beating myocytes and to enhance the expression of beta-myosin heavy chain iso-mRNA and isoprotein, having no effect on alpha-myosin heavy chain. Induction of alpha-myosin heavy chain expression by thyroid hormone before AII was administered showed that AII could not potentiate a shift from alpha- to beta-myosin heavy chain predominance. We suggest that the potency of AII to regulate the expression of myosin heavy chain isogenes is restricted to the beta isoform and is overridden by thyroid hormone.

Prognostic value of day 3 estradiol on in vitro fertilization outcome

OBJECTIVE

To evaluate the prognostic value of day 3 E2 levels, independent of day 3 FSH levels, on responses to ovulation induction and subsequent pregnancy rates (PRs) in IVF-ET patients.

DESIGN

Prospective, observational.

SETTING

University-based tertiary care and private reproductive endocrine-infertility units.

PATIENTS AND INTERVENTIONS

A total of 225 patients underwent 292 IVF cycles with luteal phase GnRH agonist suppression and hMG stimulation.

MAIN OUTCOME MEASURES

We evaluated response and outcome data including age, day 3 FSH and E2 levels from a menstrual cycle before IVF, ampules of hMG used, maximum E2 level, cancellation rates, and clinical PR.

RESULTS

Despite similar age, number of ampules of hMG, and peak E2 levels, patients with an elevated E2 level (E2 > or = 80 pg/mL) (conversion factor to SI unit, 3.671) on day 3 of a cycle before IVF-ET achieved a lower PR per initiated cycle (14.8% versus 37.0%) and had a higher cancellation rate (18.5% versus 0.4%) compared with those with E2 levels < 80 pg/mL. Even when patients with elevated FSH levels (FSH > or = 15 mIU/mL) (conversion factor to SI unit, 1.00) were excluded (leaving 279 cycles), those with an elevated day 3 E2 still had a lower PR per initiated cycle (14.8% versus 38.9%) and maintained a higher cancellation rate (18.5% versus 0.4%). When the day 3 E2 was > or = 100 pg/mL there was a 33.3% cancellation rate and no pregnancies were achieved.

CONCLUSION

Patients who presented with an elevated day 3 E2 (> or = 80 pg/mL) in a cycle before IVF-ET had a higher cancellation rate and achieved a lower PR independent of FSH level. A day 3 E2 level, in addition to a day 3 FSH level, appears very helpful in prospectively counseling patients regarding cancellation risk and ultimate IVF-ET success.

The predictive value of serum progesterone and 17-OH progesterone levels on in vitro fertilization outcome

PURPOSE

In order to identify parameters which predict prognosis for success with in vitro fertilization, 17-hydroxyprogesterone and progesterone levels were evaluated in 254 patients undergoing 296 in vitro fertilization cycles. Selected response and outcome data were recorded.

RESULTS

Patients with intermediate values of serum progesterone (0.7-0.8 ng/ml) at the time of human chorionic gonadotropin administration achieved significantly higher pregnancy rates than patients with lower (< 0.7 ng/ml) or higher (> 0.8 ng/ml) levels. The clinical pregnancy rates were 46%, 31%, and 27% respectively (P = 0.02). There was no change in 17-hydroxyprogesterone concentration which predicted a higher pregnancy rate.

CONCLUSION

Excellent clinical pregnancy rates were noted in cycles with a progesterone level of 0.7-0.8 ng/ml, as well as good results in cycles above 0.8 ng/ml. There is therefore no reason to administer human chorionic gonadotropin at a smaller follicle size to prevent a rise in serum progesterone.

Characterization of hapten binding to immunoconjugates by electrospray ionization mass spectrometry

Electrospray ionization mass spectrometry (ESI-MS) has been used to characterize the covalent binding of different haptens to the enzyme glucose 6-phosphate dehydrogenase. The technique allows one to directly observe the relative amounts of each conjugated species present in a mixture, as well as the average hapten number. These measurements are useful for optimizing reaction conditions to yield a more precisely defined product for use in immunoassays. The results obtained show that ESI-MS with a quadrupole analyzer can be successfully used to analyze mixtures of derivatized proteins in the molecular weight range of 50-60 kDa, where the modifying hapten has a molecular weight as low as 130 Da.

Late outcome of valve replacement with the Cross-Jones caged-lens prosthesis

A 58 year old woman underwent re-replacement of a Cross-Jones caged-lens mitral prosthesis 23 years after the first operation. She represented one of the 38 patients who received 42 Cross-Jones prostheses two decades earlier. Continued adequate performance for more than two decades in five patients bears a surprising testimony to the longevity of this historic low profile prosthesis.

Expression of the insulin-like growth factor (IGF)-I and -II and the IGF-I and -II receptor genes during postnatal development of the rat ovary

Solution hybridization/RNase protection assays were used to study the developmental expression of the insulin-like growth factor-I (IGF-I), IGF-II, IGF-I receptor, and IGF-II/mannose-6-phosphate receptor genes in the rat ovary between postnatal days 1-80. Maximal IGF-I mRNA levels occurred during the 15- to 25-day postnatal period, and the level on day 20 represented a 9-fold increase over the baseline at earlier and later stages. IGF-II mRNA levels were maximal during the 1- to 5-day postnatal period and subsequently declined to undetectable levels after day 10. IGF-I receptor mRNA levels increased 10-fold to a maximum in the 20- to 25-day postnatal period. This pattern was similar to the developmental pattern of [125I]IGF-I binding in the ovary. Two apparent peaks of IGF-II/mannose-6-phosphate receptor mRNA levels were seen, on day 20 and between days 50-80. These specific and significant changes in the expression of the genes encoding the IGFs and their receptors suggest a role for the IGF system in postnatal ovarian development.

Rapid percutaneous tracheostomy

We describe a new method of performing percutaneous tracheostomy rapidly and safely using a specialized instrument kit. The technique permits the safe insertion of a full-sized 7.0 (ID) or 7.5 mm (ID) cuffed cannula into the trachea within 1-2 min, through the membranous second intercartilagenous space. Animal studies have demonstrated a superior healing process compared to that seen after conventional tracheostomy techniques.

Percutaneous tracheostomy--a new method

A rapid method of definitive low tracheostomy utilizing an original instrument kit and percutaneous approach is described. Through a horizontal, shallow (1.5-cm) skin incision in the neck, a 12-ga needle is introduced into the tracheal lumen. A flexible metal guidewire is gently introduced through the needle, which is then removed. A specially designed percutaneous tracheostomy tool slides over the guidewire into the trachea; by squeezing its handles, the intercartilaginous space is enlarged, securing the placement of a cuffed tracheal cannula. After extensive and successful investigation in both cadaver and animal trials, the procedure was carried out in 80 patients who had a variety of underlying diseases, without serious complications. Of these 80 patients, 33 required airway control after neurosurgical interventions or after severe head trauma, 23 had percutaneous tracheostomy performed before radical excision for head and neck cancer, and the remaining 24 suffered from severe cardiorespiratory problems. Twenty-nine procedures were performed in the operating theater, and 51 procedures were carried out at the patient's bedside in the ICU, ED, or in the ward. There was no infection at the stoma site, and late healing was remarkable. It should be strongly emphasized that in the majority of our patients the procedure was carried out safely at the bedside. This resolved the logistic problem of moving very sick ICU patients (who are sometimes on high PEEP levels) to the OR. Although our experience is totally restricted to elective situations, we do postulate that it could be as effective in a variety of urgent situations.

Proton NMR study of the influence on iron oxidation/ligation/spin state on the heme orientational preference in myoglobin

Proton nuclear magnetic resonance spectroscopy has been utilized to demonstrate that the degree of heme orientational disorder within a given myoglobin protein matrix can be a sensitive function of the oxidation/ligation/spin state of the heme iron. For sperm whale deuterohemin-reconstituted myoglobin, the equilibrium was found to strongly favor (5.7 to 7.8 kJ/mol) the X-ray characterized heme orientation in all six-coordinate states, but with a considerable reduction in preference (to 1.6 kJ/mol) in the five-coordinate deoxy state. In native yellow fin tuna myoglobin, changes in heme orientational preferences of approximately 3 kJ/mol occur even between two six-coordinate ferric states differing solely in spin states.

Dissecting aortic aneurysm in pregnant women without Marfan disease

Dissection of the young women without Marfan disease is related, in most instances, to pregnancy. The structural changes in the arterial wall that occur during pregnancy may predispose women to this complication of pregnancy. In this study, two young women, who had none of the characteristics of Marfan's syndrome, were operated upon for dissection of the ascending aorta. The first patient was in the 35th week of gestation and a cesarean section was performed prior to replacement of the ascending aorta. In the second patient, diagnosis of dissection and severe aortic regurgitation occurred in the postpartum period. Knowledge of this albeit relatively rare complication of pregnancy may assist the clinician in diagnosing and referring patients early for surgical treatment that, in most instances, may save the lives of both mother and fetus.

Safety precautions in the management of patients with pacemakers when electrocautery operations are performed

The hazards related to ten patients who underwent 11 urologic surgical procedures during a 36 month period were taken into consideration. Electrocautery was used in all instances and there were no complications. All of the pacemakers were preset for ventricular pacing and sensing inhibited or multiprogrammable and were reprogrammed during the operation to ventricular pacing fixed rate mode or magnet mode, with very satisfactory outcome. To avoid life-threatening situations arising from pacemaker inhibition or ventricular fibrillation during cautery for transuretheral resection, three basic factors were considered: 1, appropriate type of pacemaker; 2, the proper grounding of all medical electronic equipment used during the procedure, and 3, the directing of the complete flow of the electrocautery circuits substantially below the level of the pacemaker unit.

Surgical removal of a mobile, pedunculated left ventricular thrombus: report of 4 cases

During an 11-month period, 4 patients underwent surgical removal of a mobile, pedunculated left ventricular thrombus. All 4 patients had a history of myocardial infarction. Two of the 4 patients had systemic emboli, and in the 2 others, the ventricular thrombi were removed to prevent emboli. The thrombus was removed during the acute phase of myocardial infarction in 2 patients and one and two years, respectively, following the infarct in the remaining 2 patients. Concomitant coronary artery bypass grafting was performed in 3 patients. There were no early or late deaths, and none of the patients had clinical or echocardiographic evidence of recurrent thrombi or emboli at follow-up 3 to 15 months later. These results indicate that left ventricular thrombectomy might be an effective treatment for patients with mobile, pedunculated, left ventricular thrombi. However, additional experience is required to compare surgical and medical treatment.

Oligonucleotide N-alkylphosphoramidates: synthesis and binding to polynucleotides

A few different methods for the preparation of oligonucleotide N-alkylphosphoramidates were compared directly. One of these, involving the use of protected nucleoside phosphites as building blocks, provided the requisite N-alkylphosphoramidates via oxidation of the intermediate dinucleoside methyl phosphites with iodine in the presence of the appropriate alkylamine. This method was found to have several attractive features, including the use of building blocks identical with those employed for the synthesis of DNA and compatibility with procedures and instruments employed for the stepwise synthesis of oligonucleotides by solution and solid-phase methods. This procedure was used to make several di-, tri-, and tetranucleotide N-alkylphosphoramidates derived from deoxyadenosine and thymidine; alkyl substituents included N,N-dimethyl, N-butyl, N-octyl, N-dodecyl, and N-(5-aminopentyl). The aminoalkyl derivative of d(TpT) (24) was used to demonstrate the feasibility of introducing an intercalative agent to the alkylphosphoramidate moiety of such derivatives. The oligonucleotide N-alkylphosphoramidates were separated into their component diastereomers and characterized structurally by a number of techniques including circular dichroism, high-field 1H NMR spectroscopy, FAB mass spectrometry, and enzymatic digestion to authentic nucleosides and nucleotides. Physicochemical characterization of several di- and trinucleotide alkyl-phosphoramidates revealed that the adenine nucleotide analogues formed stable complexes with poly-(thymidylic acid). The stabilities of these complexes were found to increase with increasing chain length of the N-alkylphosphoramidate substituents. The finding that N-alkylphosphoramidate substituents can enhance the binding of certain oligonucleotides to their complementary polynucleotides suggests the existence of a novel source of polynucleotide affinity.

A safe and rapid method for the mobilization of the internal mammary pedicle

A simple method is described for the safe and rapid dissection of the internal mammary pedicle. The essential feature of this technique is the use of Silicone Rubber devices, for the identification and retraction of the internal mammary pedicle during its preparation.

Massive hemoptysis complicating Behçet's syndrome: the importance of early pulmonary angiography and operation

A 16-year-old patient with Behçet's syndrome had massive hemoptysis due to a ruptured aneurysm of a segmental artery of the left lung. Emergency left lower lobectomy was performed. The patient is well 12 months after operation. There have been no further episodes of hemoptysis.

Copper(II) facilitates bleomycin-mediated unwinding of plasmid DNA

The unwinding of plasmid DNA by bleomycin A2 (BLM A2) was investigated by use of two-dimensional gel electrophoresis. It was found that Cu2+ ions greatly facilitated the unwinding of topoisomers of plasmid DNA by BLM A2 at concentrations where cupric ions alone had no effect on DNA supercoiling. The concentration of BLM A2 required for observable unwinding was reduced at least 100-fold in the presence of equimolar Cu2+. A plot of [Cu2+] vs extent of DNA unwinding in the presence of 10(-4) M BLM A2 gave a curve consistent with the action of cupric ions on BLM in an allosteric fashion, possibly rearranging the drug into a conformation that facilitates DNA unwinding. The participation of the metal center in enhancing DNA unwinding via direct ionic interaction with one or more negatively charged groups on the DNA duplex also seems possible. Further analysis of the structural factors required for BLM-mediated DNA unwinding was carried out with Cu2+ + BLM demethyl A2, the latter of which differs from BLM A2 only in that it lacks a methyl group, and associated positive charge, at the C-terminus. Cu(II).BLM demethyl A2 was found to be much less effective than Cu(II).BLM A2 as a DNA unwinding agent, emphasizing the strong dependence of this process on the presence of positively charged groups within the BLM molecule. These findings constitute the first direct evidence that the metal center of BLM can participate in DNA interaction, as well as in the previously recognized role of oxygen binding and activation.

Total excision of a giant angiolipoma of chest wall with A-V malformation and with the use of an autotransfusion system

An 18 year old girl suffering from a giant angiolipoma of back and chest wall with A-V malformation underwent total excision of the tumor in 4 stages. The first two stages included surgical ligation of the arterial blood supply to the tumor. In the third and fourth stages the tumor was resected with the use of an autotransfusion system. The last stage was complicated with massive bleeding and disseminated intravascular clotting. Control of bleeding was achieved by the use of autotransfusion system, right thoracotomy and massive transfusion of blood and its components. After long convalescence period associated with renal and respiratory failure the patient recovered completely without sequellae. This case demonstrates the complexity associated with the treatment of these rare tumors.