Ultrasonic assisted permanent pacing in a patient with severe pulmonary tuberculosis

A 67-year-old male patient with previous history of pulmonary tuberculosis presented with syncope due to complete heart block. Collapse of the right lung and deviation of the heart to the right chest had prevented visualization of the cardiac silhouette by fluoroscopy. Successful endocardial permanent pacing using a passive fixation electrode was achieved with the help of ultrasonic visualization of the cardiac chambers.

Myocardial involvement in Churg-Strauss syndrome: the role of endomyocardial biopsy

A Chinese adult with Churg-Strauss syndrome with prominent cardiac involvement is described. The myocardial impairment initially showed good response to corticosteroid and cyclophosphamide. However, the cardiac status deteriorated later despite the absence of disease activity elsewhere. Endomyocardial biopsy was performed to determine the possibility of isolated myocardial relapse in case additional immunosuppression would be beneficial. Histology of the endomyocardial biopsy revealed myocardial fibrosis. Since cardiac involvement is the major cause of mortality in this condition and delayed treatment can lead to intractable cardiac failure, we advocate that endomyocardial biopsy should be performed more liberally and possibly serially to assess the disease activity in the myocardium. Immunosuppression may then be adjusted. To our knowledge, the occurrence of Churg-Strauss syndrome in Chinese has not been reported in the English literature.

Total occlusion of the left main coronary artery in a Hong Kong Chinese

Total occlusion of the left main coronary artery (LMCA) is a rare finding in patients with stable angina pectoris. To the best of our knowledge, it has not been described in Hong Kong Chinese before. In this paper, we report the clinical and angiographic findings of a Hong Kong Chinese with this condition treated in our unit.

Persistant abnormal serum parathyroid hormone after renal transplantation: correlation between renal graft function

Secondary hyperparathyroidism in uremia renal transplantation. We studied the i-PTH (immunoactive parathyroid hormone) of nineteen immunoactive parathyroid hormone) of nineteen patients before and after renal transplantation with average of 20 months post transplantation. In group I patients with normal i-PTH serum level had an significant lower serum level of creatinine than Group II with elevated abnormal i-PTH. While the calcium and phosphorus showed no significant difference between group I and Group II patients. We suggested that abnormal serum i-PTH level after renal transplantation after one year was closely related to renal graft function. This group of abnormal serum i-PTH should be closely monitored for their renal graft function.

Myxomatous mitral valve degeneration complicating asymptomatic cor triatriatum

Cor triatriatum presenting in adulthood is extremely rare. This paper reports a case of cor triatriatum initially masquerading as mitral stenosis, which was later complicated by myxomatous mitral valve degeneration with severe regurgitation, which necessitated mitral valvular replacement. To the authors' knowledge, such a combination has not been reported in the literature.

Epidermal growth factor receptor tyrosine kinase phosphorylation of glucose-6-phosphate dehydrogenase in vitro

The specific tyrosine phosphorylation of glucose-6-phosphate dehydrogenase (G6PDH) by the epidermal growth factor (EGF) receptor in vitro is demonstrated. The Km values of the substrate G6PDH and of ATP for the receptor tyrosine kinase were ca. 1 and 10 microM, respectively. The rate of phosphorylation was EGF dependent, with a four-fold increase in Vmax in the presence of EGF. The phosphorylation was stimulated maximally by 0.2 microM or greater EGF, with an ED50 of ca. 20 nM which is consistent with the affinity of the solubilized receptor for EGF. Using conditions of 5 microM G6PDH, 100 microM ATP, 5 mM Mg2+, and 1 mM Mn2+, up to 0.3 mol phosphate was incorporated into 1 mol of the 55-kDa subunit of Baker's yeast G6PDH. Tryptic peptide mapping revealed several unique phosphopeptides for both Baker's yeast and bovine adrenal G6PDH. The patterns of phosphopeptides for a given enzyme were identical for basal and EGF-stimulated phosphorylation.

Primary and secondary structure of antifreeze peptides from arctic and antarctic zoarcid fishes

Antifreeze peptides were isolated from Rhigophila dearborni, an antarctic eel pout, and Lycodes polaris, an arctic eel pout (both from the family Zoarcidae). The primary structures of two peptides, one from each species, were determined using a combination of Edman degradation and mass spectrometric techniques. The two sequences show a high degree of homology with nearly 80% of the residues being identical. These peptides are also homologous to antifreeze peptides from a third eel pout which inhabits the north Atlantic Ocean. The CD spectra of all of these peptides are also very similar. Unlike the antifreeze peptides of cottid fishes, the structures of antifreeze peptides from zoarcid fishes appear to be highly conserved, despite the large geographic distances which separate the different species. The zoarcid peptides also appear to have structures very different from other fish antifreezes.

Evidence for the presence of adrenocorticotropic and opiate-like hormones in the brains of two sea snakes, Hydrophis cyanocinctus and Lapemis hardwickii

The brain acetone powders of the sea snakes Hydrophis cyanocinctus and Lapemis hardwickii were extracted with a mixture of acetone:water:hydrochloric acid (40:21:1 by volume) and the extracts were then added to a copious volume of acetone, in accordance with the method of C. H. Li (1952, J. Amer. Chem. Soc., 74, 2134) for preparing adrenocorticotropin and beta-endorphin from mammalian pituitaries. The resultant precipitate, designated acid acetone powder, possessed adrenocorticotropic activity as evidenced in its ability to stimulate corticosterone production in isolated rat adrenal decapsular cells and lipolysis in isolated hamster adipocytes, and in its cross-reactivity in an ACTH radioimmunoassay. The presence of opioid molecules was indicated by activity in opiate radioreceptor assay using either 3H-D-Ala2-D-Leu5 enkephalin or [3H]naloxone as ligand and rat brain membranes. The brain acetone powders possessed neither "lactogenic" nor "somatogenic" activity as evidenced by their inability to displace the primary ligand in the rat hepatic prolactin receptor- and growth hormone receptor-binding assays, respectively.

The role of neonatal and pubertal gonadal hormones in regulating the sex dependence of the hepatic microsomal testosterone 5-reductase activity in the rat

Heptic microsomal testosterone 5-reductase activity was approximately fourfold higher in adult female rats than in males. This discrepancy was only partly androgen-dependent since gonadectomy of male rats at 68 days of age resulted in only a partial increase of the enzyme activity. This increase was reversible by the administration of testosterone. Similar treatment, however, produced no effect in the female rat, indicating that there is a sex difference in testosterone responsivity. Castration of newborn male rats resulted in a marked increase in the basal enzyme activity. This increase was not affected by treating the adults with testosterone. Giving testosterone to male rats immediately after neonatal gonadectomy, or to newborn female rats, did not produce the male pattern of both the basal enzyme activity and the testosterone responsivity in adulthood. These results suggest that a brief exposure to neonatal androgen is not critical for the expression of the male type of enzyme activity, but that the continuous presence of the male gonads up to and including the pubertal period is essential. Exposure of pubescent female rats to testosterone during the period from 35 to 50 days of age resulted in a significant increase in testosterone sensitivity when tested at 90 days of age, suggesting that pubertal exposure to androgen is important for the expression of testosterone responsivity in adulthood. The sensitivity was potentiated when the animals were ovariectomized before puberty. Furthermore, the enzyme activity in prepubertally ovariectomized female rats was significantly lower than that in adult gonadectomized animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Prolactin receptor in rat liver: sex difference in estrogenic stimulation and imprinting of the responsiveness to estrogen by neonatal androgen in male rats

Rat hepatic prolactin receptor is regulated by sex steroids. A high level of the receptor was found in female rats but the level was nearly undetectable in males. Gonadectomy reduced the receptor level in females but increased the level in males. Administration of estradiol benzoate (0.05 mumoles/kg on alternate days subcutaneously for 9 days) to adult gonadectomized females increased the receptor level by 473% whereas the same treatment in adult gonadectomized males produced a more modest 276% increase. This sexually dimorphic pattern in the responsiveness to estrogen stimulation in adult rats appeared to be determined neonatally. Neonatal gonadectomy of male rats changed the hepatic response system to a more female pattern in adulthood. Replacement of testosterone (1.45 mumoles at days 1 and 3 after birth) to these neonatally gonadectomized male rats restored the male pattern. Diethylstilbestrol replacement (1.45 mumoles at days 1 and 3 after birth) to the neonatally gonadectomized male rats showed the same effect as neonatally administered testosterone. Scatchard analysis revealed that the observed changes in binding are related to changes in binding capacity but not affinity. Desaturation by 4 M MgCl2 indicated that the amount of endogenously bound hormone was negligible in our membrane preparations.

Evidence for the involvement of essential sulphydryl group in rat hepatic lactogenic receptor but not in somatogenic receptor

Incorporation of p-chloromercuribenzene sulphonate (PCMBS) (1mM) in the assay medium for rat hepatic lactogenic receptor produced complete inhibition of binding of [125I]oPRL to the membrane. However, the presence of the thiol-reactive agent produced no effect on the binding of [125I]bGH to rat hepatic somatogenic receptor. Pretreatment of rat hepatic membrane with PCMBS inhibited the binding of [125I]oPRL but not that of [125I]bGH. The lactogenic receptor binding inhibition by PCMBS pretreatment was both concentration- and time-dependent, with complete inhibition at 0.5 mM for 60 min at 0 degrees C. Scatchard analysis of [125I]oPRL binding to membrane at 50% inhibition by PCMBS (0.11 mM) revealed that the binding capacity was decreased rather than the binding affinity. Furthermore, the inhibition of lactogenic receptor binding by PCMBS could be reversed by dithioerythritol (DTE) treatment. Following 80% inhibition by 0.2 mM PCMBS, full recovery of receptor binding was achieved at 6 mM DTE for 60 min at 0 degrees C. The 'recovered' membrane showed no difference from the control membrane in terms of binding capacity and affinity.

Rat hepatic prolactin receptor: pubertal exposure to sex steroids alters responsivity to testosterone

Administration of testosterone enanthate to adult female rats lowered the level of hepatic prolactin receptor. Pubertal exposure of intact female rats to testosterone enanthate at the dose used did not affect the level of hepatic prolactin receptor in adults. However, the responsivity of such treated rats to testosterone challenge in adulthood was enhanced. Prepubertal ovariectomy of female rats lowered the level of hepatic prolactin receptor in adulthood. Exposure of the ovariectomized rats during puberty to mestranol (ethynylestradiol 3-methyl ether) at the dose used did not restore the normal adult female rat's level of hepatic prolactin receptor. However, they did become more resistant to subsequent testosterone challenge in adulthood. Exposure of prepubescent ovariectomized rats to testosterone enanthate during puberty reduced the already diminished level of hepatic prolactin receptor further. In addition, these rats were rendered more responsive to testosterone challenge in adulthood.

The cerebral metabolism of L-dihydroxyphenylalanine. An autoradiographic and biochemical study

The regional cerebral distribution of carbon-14 activity was studied using autoradiography following the intravenous administration of L-3,4-dihydroxyphenyl-(3-14C)-alanine (14C-L-dopa) to rats pretreated with carbidopa. 5 min after 14C-L-dopa administration, the regional cerebral distribution of carbon-14 varied with regional cerebral blood flow. From 45 min to 4 h after 14C-L-dopa administration, however, carbon-14 activity accumulated in a regionally selective manner which correlated (p less than 0.001) with the total endogenous catecholamine content of each region (n = 26). A prior unilateral lesion of the substantia nigra pars compacta markedly reduced the accumulation of carbon-14 in the ipsilateral, but not the contralateral, striatum at all times from 45 min to 4 h after 14C-L-dopa administration. Similarly, reserpine pretreatment selectively reduced the accumulation of carbon-14 in only those regions in which a marked accumulation occurred in controls after intravenous injections of 14C-L-dopa. Liquid chromatography with electrochemical detection was utilized to determine the tritium content of L-dopa and its metabolites in the striatum and cerebellum from 1 min to 4 h after the intravenous administration of 3H-L-dopa. 3H-dopamine, and subsequently 3H-dihydroxyphenylacetic acid and 3H-homovanillic acid, appeared only in the striatum. 3H-3-O-methyldopa levels rose simultaneously in the cerebellum and striatum. These results demonstrate a feasible approach for imaging dopamine neurons in man in vivo by positron emission tomography provided that L-dopa can be labeled with a positron-emitting isotope with sufficient specific activity. Furthermore, these results suggest that quantitative interpretation of the images is possible.

Pubertal gonadal hormones in modulating the testosterone dependency of hepatic aryl hydrocarbon hydroxylase in female rats

The responsiveness of the hepatic microsomal aryl hydrocarbon hydroxylase (AHH) to testosterone enanthate (TE; 2.5 mumol/kg/day for 9 days) was sex-dependent in adult rats, the enzyme being very resistant to TE in normal adult or ovariectomized females. Administration of testosterone propionate or diethylstilbestrol (1.45 mumol) to neonatal female rats at 1 and 3 days of age did not increase the responsivity to TE in adulthood. However, exposure of female rats to TE (5.0 mumol/kg/day) during the peripubertal period (35-50 days old) resulted in increased sensitivity to TE (+55.2%) when tested in adulthood. The responsivity was further potentiated (+109.3%) if the animals were ovariectomized at 28 days of age. Prepubescent ovariectomized females which received corn oil or estradiol benzoate (1.5 mumol/kg on alternate days) during puberty were not able to respond to TE significantly. These results suggest that the refractoriness of the hepatic AHH to testosterone in adult female rats is determined by the absence of testosterone, as well as the presence of estrogens, during puberty.

Radiation control through licensing and intensive training

Various types of intensive training courses to suit radiation workers in different fields were sponsored by both the Atomic Energy Council of Executive Yuan and the National Health Administration of Executive Yuan, Republic of China during the past seven years. During the years 1974-79, the number of radiation workers attending each training course, their age, sex and educational background are presented in detail. The typical course contents for both medical and non-medical radiation workers are given. A summary of the percentage of passes and failures of the final examination given at the end of each training course is also given. The present status of licensing for radiation facilities and workers is described, and its results are indicated. The successful control of ionizing radiation through this kind of intensive training and licensing is evidenced in the film badge records given by a centralized service laboratory located at the National Tsing Hua University.

Dopamine turnover estimated by simultaneous LCEC assay of dopamine and dopamine metabolites

The estimation of changes in tissue levels of dopamine (DA) and its metabolites has been employed to approximate the turnover rate or release of DA. We have developed an assay using high pressure liquid chromatography with electrochemical detection to quantify DA, dihydroxyphenylacetic acid (DOPAC), 3-methoxytyramine (3-MT), and homovanillic acid (HVA) simultaneously in brain homogenates. The assay is simple, inexpensive, rapid and accurate; the sensitivity of the assay for DA and DOPAC was 10 pg, for HVA 50 pg, and 200 pg for 3-MT. Apomorphine treatment resulted in a reduction in tissue levels of DOPAC and HVA, while haloperidol administration increased tissue levels of DOPAC and HVA. Neither drug treatment caused changes in DA levels. Administration of d-amphetamine 2.5 mg/kg S.C. resulted 1 hour later in increases in the striatal concentration of DA (57%) and 3-MT (44%) and decreases in DOPAC (40%) and HVA (39%). These data are consistent with the agonistic effect of apomorphine and antagonistic effect of haloperidol on DA autoreceptors and post-synaptic receptors. In the case of amphetamine, the increases in the levels of DA and 3-MT probably reflect the ability of d-amphetamine to induce DA release and block re-uptake. The reduction of DOPAC and HVA levels are consistent with the ability of d-amphetamine to competitively inhibit monoamine oxidase activity as well as the neuronal reuptake of DA. The simultaneous estimation of DA, DOPAC, 3-MT, and HVA should facilitate the understanding of dopaminergic drugs with complicated mechanisms of action.

Melanotropins: aldosterone- and corticosterone-stimulating activity in isolated rat adrenal cells

Stimulation of corticosterone and aldosterone production in rat adrenal decapsular and capsular cells respectively by alpha- and beta-melanotropins (alpha- and beta-MSH) have been investigated. Although they are considerably less potent than corticotropin (ACTH), the dose-response curves are parallel to those for ACTH except in the case of aldosterone stimulation by beta-MSH where the dose-response curve is biphasic. The steroidogenic actions of ACTH, beta-MSH and alpha-MSH are antagonized by corticotropin-inhibiting peptide in both capsular and decapsular cells. A synthetic analog of beta-MSH ([Gly10]-betac1-MSH) inhibits both beta-MSH and ACTH in aldosterone output in capsular cells, but it does not inhibit their corticosteroidogenic actions in decapsular cells.

Human somatotropin 61. A simple method to predict potential of somatotropin fragments for noncovalent recombination by radioreceptor assay

Different mixtures of reduced-alkylated thrombin fragments of human and sheep somatotropin have been tested for binding affinity to liver membranes. The bioassay data correlated well with the abilities of the fragments to form noncovalent recombinants as shown in separate biochemical studies.

Two contiguous thrombin fragments of human somatotropin form a functionally active recombinant, but the two homologous fragments from sheep hormone do not

Two thrombin fragments of reduced-carbamidomethylated human somatotropin representing the full primary structure of the native hormone (residues 1-134 and 135-191) have been found to form a recombinant molecule with properties similar to those of reduced-carbamidomethylated human somatotropin as shown by circular dichroism spectroscopy, two receptor-binding assays, and radioimmunoassay. In contrast, the homologous thrombin fragments of reduced-carbamidomethylated sheep hormone (residues 1-133 and 134-191) do not undergo recombination. Furthermore, neither the reduced-alkylated nor the reduced and nonalkylated C-terminal thrombin fragment of sheep hormone is able to interact with the reduced-carbamidomethylated N-terminal thrombin fragment of human hormone, under conditions which favor the recombination of the two human somatotropin fragments.

Ovine prolactin. Isoelectricfocusing and characterization of the separated components

Highly purified ovine prolactin was subjected to preparative isoelectricfocusing. Although complete separation of the isoelectrically different components was not achieved, four enriched fractions of these components were prepared by this method. Studies on the separated fractions revealed that these components of ovine prolactin, probably a result of deamidation processes, have rather different properties. The more acidic components appeared to be less active in both the radioreceptor assay on mammary gland membranes and the pigeon crop-sac assay. However, the more acidic forms appeared to be more immunoreactive as revealed by radioimmunoassay.

Simultaneous radioenzymatic assay of dopamine and dihydroxyphenylacetic acid: an index of in vivo dopamine release

The relative brain tissue concentrations of dopamine (DA) and its deaminated metabolite, dihydroxyphenylacetic acid (DOPAC), appears to be a reliable index of the functional activity of dopaminergic neurons. In order to apply this approach to the assessment of dopaminergic neuronal activity in small regions of brain, we have developed a sensitive radioenzymatic assay for simultaneous measurement of DA and DOPAC. The sensitivity of the assay for DA is approximately 10 pg and for DOPAC 100 pg. In addition, the assay is highly specific, simple, and relatively inexpensive. The concurrent estimation of tissue DA and DOPAC concentrations seems to be a reliable means of evaluating the rate of DA turnover or release in behavioral, electrical stimulation, and certain drug paradigms. However, the release or turnover of DA as induced by D-amphetamine (and perhaps other indirectly-acting dopaminemimetic drugs) cannot be meaningfully assessed by measurement of DA and DOPAC alone.