Raman spectroscopy of oxidized and reduced nicotinamide adenine dinucleotides

We have measured the Raman spectra of oxidized nicotinamide adenine dinucleotide, NAD+, and its reduced form, NADH, as well as a series of fragments and analogues of NAD+ and NADH. In addition, we have studied the effects of pH as well as deuteration of the exchangeable protons on the Raman spectra of these molecules. In comparing the positions and intensities of the peaks in the fragment and analogue spectra with those of NADH and NAD+, we find that it is useful to consider these large molecules as consisting of component parts, namely, adenine, two ribose groups, two phosphate groups, and nicotinamide, for the purpose of assigning their spectral features. The Raman bands of NADH and NAD+ are found generally to arise from molecular motions in one or another of these molecular moieties, although some peaks are not quite so easily identified in this way. This type of assignment is the first step in a detailed understanding of the Raman spectra of NAD+ and NADH. This is needed to understand the binding properties of NADH and NAD+ acting as coenzymes with the NAD-linked dehydrogenases as deduced recently by using Raman spectroscopy.

Induction of sIg-negative B lymphocytes for differentiation by PWM

It has been reported in the literature that PWM-responsive B lymphocytes are sIgM+, sIgD-, lack receptors for mouse erythrocytes, and are larger than PWM-negative lymphocytes. This paper describes the observation of B cells among the thymocytes from a patient with myasthenia gravis. In the thymocytes, actually no sIg+ cell was found, and Staphylococcus aureus Cowen strain I could not induce the mononuclear cells in the thymus to differentiate. It was surprising that 6.9 per cent of the cells were BA-1 positive cells. At the same time, in the presence of PWM, 9680 +/- 555 cells out of 1 X 10(-6) thymocytes could be induced to differentiate to immunoglobulin-secreting cells (ISC) in culture. This result suggests that PWM might be able to induce sIg- B lymphocytes to differentiate as well.

Study on the effect of calf thymic peptides preparation (TP) on human B lymphocytes

Extensive experimental evidence has shown that thymic hormones (or factors) affect and regulate the differentiation and function of T lymphocytes. However, little is known about the action, if any, of thymic hormones on B lymphocytes. This paper reports the results of an investigation of the effect of a calf thymic peptide preparation (TP) prepared in our laboratory, on the proliferation and differentiation of human B lymphocytes. TP at concentrations higher than 1 micrograms (protein)/ml inhibited the proliferative responses of human B lymphocytes to the stimulation by Staphylococcus aureus Cowen strain I (SAC) and F(ab')2 fragments of goat anti-human IgM, mu chain specific antibody (anti-mu). TP itself had neither toxic nor mitogenic effect on B cells. TP at concentrations of 60 and 100 micrograms/ml did not affect the differentiation of B cells driven by SAC and PWM in a reverse PFC assay, but appeared to suppress the production in some individuals of total IgG and IgM in culture supernatants in a PWM system. Preculture of B cells with 60 micrograms/ml of TP for 40 hrs showed a suppression of the proliferative response to SAC and anti-mu stimulation, suggesting that TP might act on cells directly and persistently for some time. When TP was added to the culture on day 0 or on day 1, a similar decrease of inhibition of B cell proliferation was observed. A decrease in monocytes from 15-17% to 5% did not appreciably influence the suppression of SAC- or anti-mu-induced proliferation of B cells by TP. These preliminary results suggest that a calf thymic peptides preparation might have some direct effect on B lymphocytes.

A potent converting enzyme inhibitor CGS 13928C. Drug profile in normal volunteers

The converting enzyme inhibitor CGS 13928C was evaluated in 15 healthy male volunteers. First the efficacy of a single oral dose of 0.5, 1, 2 or 5 mg in antagonizing the pressor response to exogenous angiotensin I was tested with continuous monitoring of the blood pressure and heart rate by an intraarterial catheter. CGS 13928C 1, 2 and 5 mg consistently reduced the response to angiotensin within 2 to 3 h and for a period exceeding the 4 h of monitoring. The 2 mg dose was hardly more effective than 1 mg and 5 mg did not further enhance the blockade. Subsequently, plasma renin and converting enzyme activity, angiotensin I, angiotensin II and aldosterone were measured serially before and up to 72 h following oral administration of either 1 mg (n = 7) or 2 mg (n = 8) CGS 13928C. As expected, plasma renin activity and angiotensin I rose, while plasma converting enzyme activity, angiotensin II and aldosterone fell following both doses of the drug. No side-effects occurred. In normal volunteers CGS 13928C is an effective and extremely potent, orally active converting enzyme inhibitor.

Prosthetic auricular reconstruction

Large lesions may necessitate resection of critical amounts of auricle, such that surgical reconstructive efforts may prove to be futile. We favor the prosthetic rehabilitation of patients requiring near total auriculectomy. Fifteen patients seen for the treatment of auricular lesions from 1976 to the present were reviewed. Near total auriculectomy with postoperative prosthetic management provided satisfactory functional and aesthetic results. This presentation will highlight the significant technical features of the surgical ablation and subsequent prosthetic management of patients with tumors of the auricle, such that postoperative rehabilitation will be facilitated.

Kinetic characteristics of bicarbonate-chloride exchange across the neonatal human red cell membrane

The kinetics of HCO-3/Cl- exchange across red cell membrane of newborn infants was studied using a stopped-flow rapid reaction apparatus with a glass pH electrode attached. The measured apparent permeability P is (1.35 +/- 0.08 (S.E.)). 10(-4) cm/s (n = 30) for newborns, compared with (3.1 +/- 0.4) . 10(-4) cm/s (n = 15) for adults. These correspond to half-times of 0.2 s for newborns and 0.1 s for adults indicating that neonatal red cells exchange Cl- for HCO-3 only half as fast as do adult cells. The temperature dependence of the exchange rate was studied from 2 to 42 degrees C. From the Arrhenius plot the activation energy of the exchange process in neonatal red cells changes from 22.9 kcal/mol (low temperature) to 4.8 kcal/mol (physiological temperature) at a transition temperature of 17 degrees C. These values are lower than the corresponding values for adult red cells, 34.7 and 10.2 kcal/mol. HCO-3/Cl- exchanges in both adult and neonatal red cells are inhibited by phlorizin. Inhibition constants Ki are 0.8 mM and 2.5 mM for adults and newborns, respectively. The differences in the value of the HCO-3/Cl- exchange rate constant and the activation energy of the exchange process between neonatal and adult red cells indicate that there is a modification of HCO-3/Cl- transport system in the neonatal red cell membranes.

Current status of radionuclide scrotal imaging

Scrotal imaging with technetium-99m sodium pertechnetate consists of a radionuclide angiogram and static scrotal scans. Utilization of this study in patients presenting with an acute scrotum can dramatically reduce the number of surgical explorations for acute epididymitis. It can also aid in other aspects of differential diagnosis in patients presenting with either an acutely enlarged and/or painful scrotum or a scrotal mass. Ambiguities in previous descriptions of perfusion through the spermatic and extraspermatic cord vessels are described and distinguished from scrotal perfusion. The clinical and scintigraphic spectrum of testicular torsion, including spontaneous detorsion, early acute testicular torsion, midphase testicular torsion, and late phase or "missed testicular torsion," is discussed and illustrated. The variety of patterns seen in acute epididymitis, including lateral and medial epididymal location, and focal epididymitis are described, as is the appearance of hydrocele as both a primary and secondary entity. The relationship of scrotal imaging to the overall clinical presentation and evaluation of these patients is emphasized in testicular torsion, torsion of the testicular appendages, epididymitis, abscess, trauma, tumor, spermatocele, and varicocele. The techniques, clinical utility, and relationship to radionuclide imaging of Doppler ultrasound and gray scale ultrasound scanning are reviewed. Doppler ultrasound results in many false negative studies in testicular torsion. Gray scale ultrasound is useful in clarifying the nature of scrotal masses.

Inhibitor of peritoneal mononuclear phagocyte colony forming cells

We investigated an inhibitory factor present in mouse L-cell conditioned medium. This soluble factor, colony inhibitory factor (CIF), selectively inhibits the clonal growth of mouse peritoneal exudate (PE) macrophages in vitro. CIF appears to be a non-dialyzable macromolecule which was eluted by Sephadex G200 gel filtration at post-albumin fractions. It can be fractionated by ammonium sulfate precipitation within the range of 60%--70% saturated solution at room temperature. CIF is moderately heat labile and is destroyed by incubation at high pH. CIF is more effective on PE cells from C57 mice than on those from C3H or DBA mice. It also inhibits the clonal growth of committed stem cells for both granulocytes and macrophages present in bone marrow but to a much lesser degree. CIF is not interferon since no antiviral activity is demonstrable in the CIF preparation.

Neuromuscular block by antibiotics: polymyxin B

Characteristics of neuromuscular block produced by polymyxin B (PXB) were examined in 12 anesthetized cats, using sciatic nervetibialis anticus muscle preparations. The ED50 was 6.7 (+/- 1.4, SD) PXB base/kg body weight. The ED95 was 10.8 (+/- 2.4) mg/kg. Spontaneous recovery from 25 percent of control to 75 percent of control required 72 (+/- 16) minutes. During a 50 percent block, train-of-four twitches elicited at 2 Hz faded with a train-of-four ratio of 0.42 (+/- 0.13), but the tetanus did not fade. Edrophonium Cl, neostigmine methylsulfate, and pyridostigmine Br at sub-clinical dosages weakly antagonized the block but enhanced the block at anti-curare dosages. All 3 cholinesterase inhibitors were short acting, lasting 10 to 15 minutes, and noncumulative on repeated injection. The potency ratio was approximately 20:10:1 in the order of edrophonium, neostigmine, and pyridostigmine on a weight-for-weight basis. Calcium partially antagonized the block. The authors conclude that neuromuscular blocks produced by various antibiotics differ from each other and from that produced by other groups of neuromuscular blocking agents, including curare.

Characteristics of nondepolarizing neuromuscular block: (I) post-junctional block by alpha-bungarotoxin

The characteristics of neuromuscular block produced by alpha-bungarotoxin, a post-junctionally active polypeptide toxin purified from snake venoms, have been studied in vivo in 12 anaesthetized cats, using the sciatic nerve-tibialis anterior muscle preparation. The onset of the neuromuscular block was slow and without fasciculation. The block was persitently progressive. The time course of the block depended on the dosage. In general, 0.1 mg/kg of alpha-BuTX appeared to approximate the threshold dosage while 0.2 mg/kg completely eliminated the twitch response in 2-5 hours. No recovery was observed in 8-30 hours. Larger doses accelerated the progression of the block. During the block, tetanic contractions and train-of-four twitches did not fade. The post-tetanic twitches were markedly facilitated. The block was antagonized by edrophonium, neostigmine, pyridostigmine, and succinylcholine, but the antagonism was less effective and shorter-lasting than that observed on curare-block, and the block always resumed the projected progression. Attempts were made to explain the observed difference between alpha-BuTX- and dTc-induced neuromuscular blocks by the practically permanent nature of block and the purely post-junctional site of action of alpha-BuTX. It was concluded that a pure post-junctional block is not characterized by fade, which rather might be a pre-junctional effect of some nondepolarizing neuromuscular blocking agents like d-tubocurarine.

Neuromuscular block by neomycin in the cat

The neuromuscular block produced by neomycin is unique. Despite nearly complete blockade of the twitch the tetanus is not blocked and does not fade. The pathognomonic post-tetanic exhaustion has not been reported previously. Anticholinesterases and calcium antagonize the block, but the antagonism may not be complete. Germine antagonizes the block in the cat, but its clinical value has not been tested. These characteristics of neuromuscular block by neomycin strongly suggest respiratory support and sedation to decrease the respiratory drive, rather than attempts at antagonism, as the rational management of patients suffering from toxic paralysis due to neomycin.

Spontaneous recovery of the thumb twitch from neuromuscular block by suxamethonium in anaesthetized man

The neuromuscular blocking effect of repeated bolus administration of suxamethonium 1 mg/kg was observed in 10 healthy surgical patients under enflurane-nitrous oxide-oxygen anaesthesia. Tachyphylaxis and slow recovery of the thumb twitch occurred in close dose-relationships with transition of Phase I block to Phase II, using train-of-four fade as an indicator of the transition. Failure of the thumb twitch to recover to 75% of control, and subsequent step-wise depression from additional doses of suxamethonium had a sudden onset shortly after establishment of marked train-of-four fade.

De Novo Biosynthesis of Deoxyribonucleic Acid Polymerase during Wheat Embryo Germination

An 8-fold enhancement in the activity of a DNA-dependent DNA polymerase was found in extracts from germinating wheat (Triticum vulgare var. Florence) embryos, as compared to the activity found in extracts from ungerminated embryos. The enhancement of this activity during the first hours of germination is concomitant to the increase of a Dnase activity. The two activities could be separated and the increased level of the DNA polymerase upon germination was observed in an enzymatic fraction which contains very low DNase activity. Addition of the protein synthesis inhibitor, blasticidin S, to germinating wheat embryos, reduced the increase in DNA polymerase. Incorporation of radioactive amino acids into a phosphocellulose preparation, which contains the DNA polymerase starts during the first 6 hours of germination. The amount of radioactivity incorporated is doubled in the next 6 hours, and the incorporation is continued between 12 and 18 hours of germination.