Biomedical subjects
Publications and source records attributed to M Meyer.
Five members of one family had been operated on for primary hyperparathyroidism. One of them also had Cushing's disease (i.e. pituitary tumor). An association between familial hyperparathyroidism and Cushing's disease is quite unusual. Such a combination of rare diseases is not fortuitous though; it probably is but a special type of multiple endocrine neoplasia.
Five-day continuous intraperitoneal (ip) infusions of 5-fluorouracil (FU) were injected into five patients as part of a phase I clinical pharmacology study. They received 20 courses through a totally implanted catheter/injection port system. Six courses are evaluable for kinetic parameters and all courses are evaluable for toxicity. In each course a 2 to 3 log FU concentration differential in favor of the peritoneal cavity was achieved and maintained. Steady-state venous plasma FU concentrations averaged 0.34 microM, whereas steady-state ip FU concentrations averaged 697 microM. Mean total body clearance (TBC) in these patients was 18.4 l/min and mean permeability-area (PA) product for diffusion from the peritoneum was 13.7 ml/min. Mean TBC of 20 l/min with ip FU infusion was observed in one patient who also received a 24-hr IV FU infusion for comparison. The TBC during the later infusion was 5.9 l/min. In this patient, calculations indicate 75% extraction of drug during the passage from the peritoneum to the systemic circulation, presumably representing in large part hepatic extraction of FU taken into the portal venous circulation. Ip constant infusion and bolus kinetics were compared in one patient. TBC for the ip bolus was 14.3 l/min, which was approximately half of the TBC of 29.5 l/min determined during the 5-day constant ip infusion. Thus constant ip infusion of FU (l gm/day) can provide an improved regional advantage over bolus ip FU because of an increased TBC. Toxicity was acceptable in all courses. Dose limiting toxicity was regional, namely moderate chemical peritonitis seen in two of the five patients on repeated courses. There was no myelosuppression, alopecia, nausea, or vomiting.(ABSTRACT TRUNCATED AT 250 WORDS)
The authors describe the use of flexible bronchoscope in infants and children ranging in age from 20 hours to 17 years and in weight from 1.5 kg upwards. Bronchoscopy was carried out under local (17 cases) and general anesthesia (95 cases). Seventeen-six of the 95 examinations under general anesthesia were conducted using the jet-ventilation technique. The advantages and drawbacks of this technique are discussed. The authors list the indications which they regard as favoring the flexible tube rather than the rigid one, and emphasize the complementary nature of these 2 techniques in pediatrics.
Alcaligenes hydrogenophilus was found to contain a soluble and a particulate hydrogenase whose control and structure differed in part from that in Alcaligenes eutrophus. One of at least two plasmids indigenous to A. hydrogenophilus determines hydrogenase genes (Hox). The interspecific exchange of Hox-encoding plasmids generated transconjugants which expressed the structural and regulatory Hox phenotype of the donor.
By using an isolated constant current stimulator producing true square-wave pulses, sensory strength-duration curves were obtained at various sites by percutaneous electrical stimulation. Strength-duration curves derived from normal groups were compared to those of patients with peripheral neuropathy. Stimulus strength at sensory threshold was shown to be a reproducible measure of sensory deficit, increasing parallel to the degree of axonal failure found by conventional methods. This may be useful as a complementary method in assessing peripheral neuropathy.
The accuracy of muscle blood flow measurement by the 133Xe clearance method (QXe) was assessed against direct venous outflow (Qv) and microsphere trapping flow (Q mu) determinations in isolated perfused dog gastrocnemius both at rest and during graded stimulation [O2 consumption (VO2) up to 12 ml X 100 g-1 X min-1] and in the gastrocnemius, vastus lateralis, and triceps of intact dogs at rest and while running on a treadmill at varied speeds up to maximum VO2. In 29 measurements performed in 11 isolated muscles, Q mu was in good agreement with Qv at rest and at all stimulation levels (Q mu/Qv = 1.0; r = 0.98). 133Xe clearance yielded much lower blood flows than the venous outflow and the microsphere trapping methods. In 43 measurements in 11 muscles, the mean QXe/Qv ratio was 0.57 +/- 0.03 (SE), independent of blood flow. Similarly, in 65 measurements in 2 intact dogs, the mean QXe/Q mu ratio in all tested muscles was 0.49 +/- 0.02 (SE), independent of blood flow. These results show that the 133Xe clearance method considerably underestimates blood flow in dog muscles.
To reinvestigate the blood-gas CO2 equilibrium in lungs, rebreathing experiments were performed in five unanesthetized dogs prepared with a chronic tracheostomy and an exteriorized carotid loop. The rebreathing bag was initially filled with a gas mixture containing 6-8% CO2, 12, 21, or 39% O2, and 1% He in N2. During 4-6 min of rebreathing PO2 in the bag was kept constant by a controlled supply of O2 while PCO2 rose steadily from approximately 40 to 75 Torr. Spot samples of arterial blood were taken from the carotid loop; their PCO2 and PO2 were measured by electrodes and compared with the simultaneous values of end-tidal gas read from a mass spectrometer record. The mean end-tidal-to-arterial PO2 differences averaging 16, 4, and 0 Torr with bag PO2 about 260, 130, and 75 Torr, respectively, were in accordance with a venous admixture of about 1%. No substantial PCO2 differences between arterial blood and end-tidal gas (PaCO2 - PE'CO2) were found. The mean PaCO2 - PE'CO2 of 266 measurements in 70 rebreathing periods was -0.4 +/- 1.4 (SD) Torr. There was no correlation between PaCO2 - PE'CO2 and the level of arterial PCO2 or PO2. The mean PaCO2 - PE'CO2 became +0.1 Torr when the blood transit time from lungs to carotid artery (estimated at 6 s) and the rate of rise of bag PCO2 (4.5 Torr/min) were taken into account. These experimental results do not confirm the presence of significant PCO2 differences between arterial blood and alveolar gas in rebreathing equilibrium.
A needs assessment was conducted to determine the existence and extent of differences between Vietnam-era veterans and other veterans residing within the catchment area of the Northport Veterans Administration Medical Center. The results of a questionnaire completed by 486 veterans indicated that, compared with World War II and Korean War veterans, a greater percentage of Vietnam-era veterans reported experiencing the symptoms of posttraumatic stress disorder. They also reported more situational adjustment problems. A great number of Vietnam-era veterans expressed a need for psychotherapy and anger-control therapy, and they generally preferred to be treated with other Vietnam-era veterans who have had similar combat experience.
The relative and absolute configurations of naphthomycin A were elucidated by an X-ray structural analysis of a methylation product, 25-O-methylnaphthomycin A iminomethyl ether. The absolute configuration was confirmed by degradation (O3, NaBH4) to (S)-butane-1,2,4-triol.
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The concentration of the glycoprotein (GP) IIb-IIIa complex in thrombasthenic platelets of 8 patients of 6 families has been estimated. In the thrombasthenic platelets of 3 patients this complex is absent (thrombasthenia type I and subtype I). In 2 patients only traces are detectable and in 3 patients GP IIb-IIIa complex is strongly reduced (less than 5%). On the basis of the haemostatic data as well as the content of GP IIb-IIIa complex and platelet fibrinogen the classification of these types as subtypes of thrombasthenia type II is discussed. The diagnostic applicability of GP IIb-IIIa complex determination for heterozygote detection in types of thrombasthenia with absent or extremely reduced GP IIb-IIIa complex is shown.
Fluorophores processing a 6-acyl-2-dimethylaminonaphthalene moiety show fluorescence that is extremely sensitive to solvent polarity (Weber, G., and Farris, F. J. (1979) Biochemistry 18, 3075-3078). We have synthesized and characterized 6-acryloyl-2-dimethylaminonaphthalene (Acrylodan) which selectively labels thiol moieties in proteins. The quantum yield of this agent is markedly enhanced after reaction with thiols, and as expected, the fluorescent derivatives are very sensitive to dipolar perturbation from their environments. The usefulness of Acrylodan in the study of "hydrophobic" domains, conformational changes, and dipolar relaxation processes in proteins is demonstrated by measurements of fluorescence spectra and lifetimes of a mercaptoethanol adduct dissolved in different solvents and of adducts of this agent with parvalbumin, troponin C, papain, and carbonic anhydrase.
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Two patients developed a Guillain-Barre-like syndrome and a third suffered neuropathy and myokymia during therapy with sodium aurothiomalate. The cumulative dose at the time of development of neuropathy was different in all 3 cases. Evidence for gold toxicity was suggested by clinical, electromyographic, and histologic findings, as well as the disappearance of symptoms and signs on cessation of gold injections.
Plasmid pJP4 encoding the ability to degrade the herbicide 2,4-dichlorophenoxyacetic acid (Tfd+) was transferred by conjugation from Escherichia coli JMP397 to various lithoautotrophic strains of Alcaligenes eutrophus and to the autotrophic bacterium Pseudomonas oxalaticus. The herbicide-degrading function of the plasmid was phenotypically expressed in all of the recipients. The majority of Tfd+ transconjugants also exhibited additional plasmid-encoded properties such as 3-chlorobenzoate degradation, resistance to mercuric ions, and sensitivity to the male-specific bacteriophage PR11. Furthermore, Tfd+ transconjugants were able to act as donors of plasmid pJP4. Physical evidence is presented by agarose gel electrophoresis showing that plasmid pJP4 coexisted with the resident plasmids widely distributed in this group of bacteria. However, in some of the hosts plasmids pJP4 was not stably maintained, had a reduced size and tended to form multimers.
Steady-state gas exchange was studied in anesthetized paralyzed dogs subjected to high-frequency ventilation (HFV) to determine the effects of oscillation frequency (f 10-40 Hz) and stroke volume (Vs 20-40 ml) on gas exchange efficiency. Alveolar gas fractions were measured by rapid withdrawal of lung gas while oscillations and the bias flow circuit were interrupted. Alveolar ventilation (VA) calculated from steady-state CO2 elimination and FACO2 was found to exhibit a frequency-dependent maximum. Similarly, PaCO2 increased and PaO2 decreased again when f exceeded a critical level. VA was 13% of total ventilation (f . Vs) at 10 Hz (40 ml Vs) decreasing to about 4% at 40 Hz. Blood - gas differences for O2 (PA - Pa) were about 6 torr and close to zero for CO2 (Pa - PA). Lung volume assessed from He wash-out was increased with f and Vs. O2 uptake and CO2 elimination were significantly enhanced by HFV as a function of Vs. Because the effective VT was essentially unknown, the apparent gas exchange inefficiency at high f and Vs values may be due to the functional characteristics of the apparatus rather than a general feature of HFV.
1. The protein and glycoprotein composition of the blood platelets of six primate species have been compared by high resolution two-dimensional polyacrylamide gel electrophoresis. 2. Only minor differences have been observed in the protein patterns of all six species. 3. The glycopeptide patterns of the monkey platelets five species) were rather uniform, but clearly different from the human pattern.
STS 557 (17 alpha-cyanomethyl-17 beta-hydroxy-estra-4, 9-dien-3-one) was tested for progestagenic activity in rabbits and for ovulation-inhibiting activities in rabbits and rats in comparison with levonorgestrel and, in some cases, with norethisterone acetate or chlormadinone acetate. In the immature rabbit, the endometrium transformation-inducing activity of STS 557 was about 5 times higher than levonorgestrel for both oral and subcutaneous administration. The ovulation-inhibiting effect of STS 557 was 3.5 times higher than that of levonorgestrel in the rabbit after oral administration, and about 7 times higher in the rat. After subcutaneous injection, however, the antiovulatory activity of STS 557 in rats was only about 4% of that of levonorgestrel when the ED 50 were compared.