Role of thrombospondin-1 in high-salt-induced mesenteric artery endothelial impairment in rats

The matrix glycoprotein thrombospondin-1 (THBS1) modulates nitric oxide (NO) signaling in endothelial cells. A high-salt diet induces deficiencies of NO production and bioavailability, thereby leading to endothelial dysfunction. In this study we investigated the changes of THBS1 expression and its pathological role in the dysfunction of mesenteric artery endothelial cells (MAECs) induced by a high-salt diet. Wild-type rats, and wild-type and Thbs1-/- mice were fed chow containing 8% w/w NaCl for 4 weeks. We showed that a high salt diet significantly increased THBS1 expression and secretion in plasma and MAECs, and damaged endothelium-dependent vasodilation of mesenteric resistance arteries in wild-type animals, but not in Thbs1-/- mice. In rat MAECs, we demonstrated that a high salt environment (10-40 mM) dose-dependently increased THBS1 expression accompanied by suppressed endothelial nitric oxide synthase (eNOS) and phospho-eNOS S1177 production as well as NO release. Blockade of transforming growth factor-β1 (TGF-β1) activity by a TGF-β1 inhibitor SB 431542 reversed THBS1 up-regulation, rescued the eNOS decrease, enhanced phospho-eNOS S1177 expression, and inhibited Smad4 translocation to the nucleus. By conducting dual-luciferase reporter experiments in HEK293T cells, we demonstrated that Smad4, a transcription promoter, upregulated Thbs1 transcription. We conclude that THBS1 contributes to endothelial dysfunction in a high-salt environment and may be a potential target for treatment of high-salt-induced endothelium dysfunction.

[Complete revascularization for multi-vessel coronary diseases through lower ministernotomy on beating heart off-pump surgery]

Objective: To discuss a novel method of complete revascularization for multi-vessel coronary diseases on beating heart off-pump surgery through lower ministernotomy. Methods: Clinical data of 79 patients underwent ministernotomy off-pump coronary artery bypass from January 2015 to May 2016 at Department of Cardiac Surgery, Heart Center, Beijing Friendship Hospital, Capital Medical University were analyzed retrospectively. There were 62 male and 17 female patients, with an average age of (65±9) years. All the patients were multi-vessel coronary diseases and planned to receive coronary artery bypass grafting. Left internal mammary artery, radial artery and great saphenous veins were harvested and prepared, respectively. The perioperative clinical data was observed and collected. Postoperative ventilator-assisted time, intensive care time, and 24-hour thoracic mediastinal drainage volume were recorded. Postoperative cardiac function was evaluated by echocardiography. The data were compared between pre- and post-operative using paired t test. Results: Cardiopulmonary bypass was used in 2 patients during operation because of unstable hemodynamic status, but the incision was not needed to extend for those 2 patients. The lower ministernotomy was converted to traditional full sternotomy in 2 patients due to limited space for proximal anastomosis. In total, 79 patients had an average of (2.8±0.6) grafts. One proximal anastomosis was performed in 75 patients and 2 anastomoses in 4 patients. Distal target vessels consisted of left descending arteries for 79 patients, posterior descending artery for 60 patients, obtuse marginal branch and intermediate branch for 56 patients and diagonal branches for 25 patients, respectively. Average postoperative ventilation time was (19.0±2.2) hours and ICU stay was (60±20) hours. One patient developed postoperative myocardial infarction and needed temporary intra-aortic balloon pump support. One patient was subjected to incision infection. None of patient died in this study. There were no significant differences in left ventricular end-diastolic diameter and left ventricular end-systolic diameter between pre- and post-operative. The post-operative ejection fraction was significantly higher than that pre-operative (66.5%±1.6% vs. 61.2%±2.3%, t=4.30, P=0.00). Conclusion: With lower ministernotomy, the various sites of distal target vessels could be reached and complete revascularization could be achieved for selected patients with triple vessel diseases, although the procedure is technical demanding.

Complete chloroplast genome sequence of cultivated Morus L. species

The complete chloroplast genome (cpDNA) sequences of two cultivated species of Morus L. (Morus atropurpurea and Morus multicaulis) are reported and reconstructed in this study, and were compared with that of wild Morus mongolica. In M. atropurpurea, the circular genome is 159,113 bp in size and comprises two identical inverted repeat (IR) regions of 25,707 bp each, separated by a large single-copy (LSC) region of 87,824 bp and a small single-copy (SSC) region of 19,875 bp. The cpDNA sequence of M. multicaulis is longer than that of M. atropurpurea (159,154 bp), and consists of two IRs (25,678 bp), a LSC region (87,763 bp), and a SSC region (20,035 bp). Each cpDNA contains 112 unique genes including 78 protein-coding genes, 30 transfer RNA genes, and 4 ribosomal RNA genes, with a GC content of 36.2%. There were 83 simple sequence repeats (SSRs) with mononucleotides being the most common (60) and di-, tri-, tetra-, and hexanucleotides appearing less frequently in M. atropurpurea. M. multicaulis contains 81 SSRs containing 63 mononucleotide repeats. The genes and SSRs identified in this study may enhance understanding of cpDNA evolution at both intra- and interspecific levels. MEGA 6.0 was used to construct a phylogenetic tree of 27 species, which revealed that M. atropurpurea and M. multicaulis are more related to their congeners than to others. The cpDNA of M. atropurpurea and M. multicaulis and its structural analysis are important for the chloroplast genome project, development of molecular markers for Morus species, and breeding of varieties.

Characteristics of synonymous codon usage bias in the beginning region of West Nile virus

Adaptation in the overall codon usage pattern of West Nile virus (WNV) to that of two hosts was estimated based on the synonymous codon usage value (RSCU). Synonymous codon usage biases for the beginning coding sequence of this virus were also analyzed by calculating the usage fluctuation for each synonymous codon along the target region (the first 270 codon sites of the whole coding sequence of WNV). Adaptation of WNV to Anopheles gambiae regarding the overall codon usage revealed a mixture of synonymous codon usage patterns between this virus and its vector. Regarding the adaptation of WNV to its dead-end host and codon usage, although a mixture of overall codon usage patterns exists, the number of codons with reversed tendency codon usage is lower than that between the virus and its vector. In addition, some codons with low RSCU values for this virus are highly selected in the beginning translation region of WNV, while codons with low RSCU values in this region tend to pair with tRNAs present in low abundance in the host, suggesting that highly selected codons in a specific region in the beginning region of WNV are, to some degree, influenced by the corresponding low tRNA abundance of hosts to regulate the translation speed of the WNV polyprotein.

Polymorphism in PGLYRP-2 gene by PCR-RFLP and its association with somatic cell score and percentage of fat in Chinese Holstein

Peptidoglycan recognition protein 2 (PGLYRP-2), which belongs to the PGRP family, is the only member that has no direct bactericidal activity but has N-acetylmuramoyl-l-alanine amidase activity. This feature of PGLYRP-2 indicates that it may play an important role in eliminating the pathogen associated molecular pattern (PAMP), such as peptidoglycan (PGN), which can reduce leukocytes in blood and lower somatic cell count (SCC) in milk. To investigate whether the PGLYRP-2 gene is associated with mastitis and milk production traits in dairy cattle, the polymorphism of this gene was analyzed by PCR-RFLP in a population of 546 Chinese Holstein cows. A total of five single nucleotide polymorphism (SNP) loci were identified. The association analysis of a single SNP locus showed that the C+4867T locus was significantly associated (P < 0.05) with somatic cell score (SCS). Surprisingly, all loci were significantly associated (P < 0.01 or P < 0.05) with percentage of fat. Association analysis between combined genotypes and SCS and milk production traits indicated that H2H2 was associated with higher percentage of fat (P < 0.05). These findings demonstrated that SNPs in PGLYRP-2 gene were related to mastitis resistance and percentage of fat, and that H2H2 would be a useful genetic marker of combined genotypes for breeding of Chinese Holstein.

Polymorphism in PGLYRP-1 gene by PCR-RFLP and its association with somatic cell score in Chinese Holstein

Bovine peptidoglycan recognition protein 1 (PGLYRP-1), an important pattern recognition molecule (PRM) of the innate immune system, is an effector molecule in killing different microorganisms directly. To investigate whether the PGLYRP-1 gene was associated with mastitis and milk production traits in dairy cattle, the polymorphism of this gene was analyzed by PCR-RFLP in a population of 524 Chinese Holstein. A total of ten single nucleotide polymorphism (SNP) loci were identified. The association analysis of single SNP locus showed that T-35A, T-12G and G+102C were significantly associated (P<0.05) with somatic cell score (SCS), while G+102C and G+649C were significantly associated (P<0.05) with 305-day milk yield. Association analysis between combined haplotypes and SCS, milk production traits indicated that H3H3 was associated with the lower SCS (P<0.01), and H2H2 was associated with the lower 305-day milk yield (P<0.01). These findings demonstrated that polymorphisms in PGLYRP-1 gene associated with mastitis resistance and 305-day milk yield, and the H3H3 would provide a useful genetic marker of combined haplotypes for mastitis resistance selection and breeding in Chinese Holstein.

Efficacy and safety of telmisartan vs. losartan in control of mild-to-moderate hypertension: a multicentre, randomised, double-blind study

This multicentre, randomised, double-blind, double-dummy, parallel-group study compared the efficacy and safety of telmisartan with those of losartan after 8 weeks' treatment. In total, 330 patients with mild-to-moderate hypertension (systolic blood pressure [SBP] <180 mmHg; diastolic blood pressure [DBP] 95-109 mmHg) were randomly assigned to receive once-daily treatment with telmisartan 40 mg (n = 164) or losartan 50 mg (n = 166). After 4 weeks' treatment, if a patient's DBP was > or = 90 mmHg, the dose was increased to telmisartan 80 mg or losartan 100 mg, respectively. The results show that mean trough seated blood pressure was reduced significantly more in the telmisartan group than that in the losartan group (SBP 12.5 mmHg vs. 9.4 mmHg, p = 0.037; DBP 10.9 mmHg vs. 9.3 mmHg, p = 0.030). The overall DBP response rate (reduction from baseline in mean seated DBP > or = 10 mmHg and/or a mean seated DBP <90 mmHg) at the end of the study in the telmisartan group was higher than that in losartan group (70.1% vs. 58.7%, p = 0.020). At both the low and high doses, the DBP response rates for telmisartan were significantly higher than those for losartan (telmisartan 40 mg vs. losartan 50 mg: 46.3% vs. 32.5%, p = 0.010; telmisartan 80 mg vs. losartan 100 mg: 79.3% vs. 65.3%, p = 0.008). Adverse events with the two treatments were comparable (telmisartan vs. losartan 23.2% vs. 22.9%, p = 0.952). Most events were mild in intensity and abated within 72 h. Thus, telmisartan 40 mg or 80 mg administered once daily can reduce SBP and DBP effectively and safely.

[A clinical intervention study among 463 essential hypertensive patients with metabolic syndrome]

OBJECTIVE

To study the role of baseline risk factors in predicting the onset of diabetes among essential hypertensive patients with metabolic syndrome (MS) and to evaluate an ideal therapeutic regime that could reduce the risk factors and risk of onset of diabetes.

METHODS

A randomized parallel clinical trial in essential hypertensive patients of grade 1 or 2 was conducted. Two of the three components (1) increased waist circumference and/or BMI; (2) increased triglycerides (TG) and/or decreased high-density lipoprotein cholesterol; (3) impaired glucose tolerance (IGT) were present define the MS. The three intervention therapy groups were: indapamide + fosinopril (I + F, n = 151); atenolol + nitrendipine (A + N, n = 160); atenolol + nitrendipine + metformin (A + N + M, n = 152). Each case was followed-up monthly and the dosage of medicine taken be adjusted according to their BP level. The plasma glucose during fasting and two hours after taking 75 g glucose orally was also measured every six months. The new onset of diabetes was diagnosed according to the criteria. OGTT, insulin release test, lipid analysis, body weight and waist circumference were measured again at the last follow-up.

RESULTS

(1) The lowering of BP was similar among the three groups (P > 0.05). 23 new diabetes onsets occurred, being 10 in group I + F and 8 in group A + N and 5 in group A + N + M, respectively (P > 0.05); (2) Proportions of patients' risk factors decreased significantly in group A + N or A + N + M, e.g. the proportions of high TG in each group reduced by 14.7% and 9.3% respectively (P < 0.05), the central fat distribution reduced by 16.7% and 15.9% respectively (P < 0.05) and the IGT reduced by 6.6% and 29.6% respectively (P < 0.05). However no changes were found in group I + F; (3) After 1 year and 5 months' follow-up, the proportions of main risk factors (high TG, central fat distribution and IGT) in the three groups were 91%, 96%, 83% and 90%, 88%, 47%, respectively. The difference of IGT was significant between two groups (P < 0.01) and the proportions of having three risk factors were 70% and 31% in the two groups (P < 0.01); (4) I + F group was better than A + N group in reduction of TG and central fat distribution. And A + N + M group improved in all risk factors.

CONCLUSIONS

IGT alone or combined with increased TG plus abdominal obesity are the most important risk factors in predicting a new onset of diabetes among essential hypertensive patients with MS. Metformin in combination with atenolol plus nitrendipine can significantly prevent the onset of diabetes as well as improve patients' metabolic abnormality.

Allitridum mimics effect of ischemic preconditioning by activation of protein kinase C

AIM

To investigate whether allitridum has the effect of pharmacological preconditioning and whether protein kinase C (PKC) plays a role in myocardial protection.

METHODS

Thirty-four isolated rabbit hearts which subjected to 30 min of regional myocardial ischemia and 2 h reperfusion, were randomly divided into 5 groups: control group, ischemic preconditioning (PC) group, allitridum (A) group, polymyxin B (Poly B) group, allitridum + polymyxin B (A + Poly B) group. Infarct size was determined by triphenyltetrazolium staining.

RESULTS

Pharmacological preconditioning in hearts with a 5 -min allitridum infusion 10 min before the prolonged regional ischemia resulted in significantly smaller infarcts (7 % +\- 6 % of risk area) than in control hearts (25 % +\- 7 %, P < 0.05). There is no significant difference in infarct size between (A+Poly B) group and control hearts (23 % +\- 5 % vs 25 % +\- 7 %, P > 0.05).

CONCLUSION

These data indicate that allitridum can precondition rabbit ischemic myocardium and this protection can be effectively blocked by administration of Poly B, an inhibitor of PKC, implying that PKC has an important role in preconditioning.

Speech evaluation of partially implantable piezoelectric middle ear implants in vivo

OBJECTIVE

Cochlear microphonic responses (CMs) were measured in a rabbit model in the intact ear (CM1) and in ears with a partially implantable piezoelectric middle ear implant (P-MEI) (CM2) to investigate the characteristics of speech transmission of the P-MEI in vivo.

DESIGN

The spectra of pure tones, voices, and elicited CM1 and CM2 obtained from the round window before and after the implantation of a P-MEI device were calculated by using fast Fourier transform. Frequency response functions of CM1 and CM2 were used to demonstrate the functional similarity between the implanted P-MEI and the normal ossicular chain. The coherence functions between the voices and CM1 and between CM1 and CM2 were evaluated to characterize speech transmission of the P-MEI in vivo. Ten rabbit ears were used in this study. Pure tones, six Chinese vowels, and six Chinese characters were the acoustic stimuli. The CMs elicited by a list of bisyllabic words were tape-recorded and then recognized by subjects with normal hearing.

RESULTS

Using pure tones at the same intensity of 90 dB SPL, frequency response functions of the CMs between the two states (the intact ear with normal hearing and ears with a P-MEI device at the medium volume) were calculated showing great resemblance in shape. Compared with that at 1 kHz, gain factors were 10 and 20 dB, respectively, at higher frequencies. The correlation and spectral analyses of the vocalizations, CM1 and CM2, demonstrated that the harmonics of CM1 were approximately identical as those of the voices between 0.5 and 5.0 kHz with coherence functions of about 0.7 to approximately 1 at the formants' frequencies, whereas the harmonics of CM2 between 0.5 and 2.5 kHz were enhanced with the coherences near to unity at the formants' frequencies, and others <0.5 kHz and >2.5 kHz were attenuated. The recognition score of the CMs elicited by a list of bisyllabic words was >90% using subjects with normal hearing.

CONCLUSIONS

Data from this study suggest that cochlear microphonic potentials can be used as an important tool to evaluate objectively whether the implantation of a P-MEI device is successful and whether the quality in speech transmission of the P-MEI is satisfactory. Thus, the method would be of significance to clinically ascertain the performance of the device in vivo.

Muscarinic receptors mediate enhancement of spontaneous GABA release in the chick brain

The functional role of muscarinic acetylcholine receptors in the lateral spiriform nucleus was studied in chick brain slices. Whole-cell patch-clamp recordings of neurons in the lateral spiriform nucleus revealed that carbachol enhanced GABAergic spontaneous inhibitory postsynaptic currents. The duration of the response to carbachol was significantly reduced after blockade of muscarinic receptors with atropine. In the presence of the nicotinic receptor antagonist dihydro-beta-erythroidine, carbachol produced a delayed but prolonged enhancement of spontaneous GABAergic inhibitory postsynaptic currents that was completely blocked by atropine. Muscarine also enhanced the frequency of spontaneous GABAergic inhibitory postsynaptic currents in a dose-dependent manner, but had no effect on inhibitory postsynaptic current amplitude. While 4-diphenylacetoxy-N-(2-chloroethyl)-piperidine hydrochloride, a M3 antagonist, completely blocked muscarine's effect, telenzepine, a M1 antagonist, and tropicamide, a M4 antagonist, only partially decreased the response to muscarine. Pirenzepine, a M1 antagonist, and methoctramine, a M2 antagonist, potentiated muscarine's enhancement of spontaneous GABAergic inhibitory postsynaptic currents. Muscarine's action was blocked by tetrodotoxin, cadmium chloride and omega-conotoxin GVIA, but was not affected by dihydro-beta-erythroidine, 6-cyano-7-nitroquinoxaline-2,3-dione, D(-)-2-amino-5-phosphonopentanoic acid, naloxone or fluphenazine. These results demonstrate that activation of both muscarinic and nicotinic acetylcholine receptors can enhance GABAergic inhibitory postsynaptic currents in the lateral spiriform nucleus. The muscarinic response has a slower onset but lasts longer than the nicotinic effect. The M3 receptor subtype is predominantly involved in enhancing spontaneous GABAergic inhibitory postsynaptic currents. These M3 receptors must be located some distance from GABA release sites, since activation of voltage-dependent sodium channels, and consequent activation of N-type voltage-dependent calcium channels, is required to trigger enhanced GABA release following activation of muscarinic receptors.

[Hemangioma of external ear: an analysis of 8 cases]

OBJECTIVE

To investigate approaches of diagnosis and therapy to hemangioma of external ear and improve the effects of diagnosis and therapy.

METHOD

Eight cases of hemangioma of external ear were analyzed retrospectively. All patients were unilateral hemangioma. 5 were performed digital subtraction angiography (DSA) before operation, of which 3 were performed embolization simultaneously. 7 were operated, 1 was not done. Racemose hemangioma was 5 and cavernous hemangioma was 2 according to pathologic diagnosis.

RESULT

All patients have followed up 1 to 5 years, 5 were healed, 2 were controlled, and 1 was not treated.

CONCLUSION

Surgery was effective approach to hemangioma of adults. It suggested that it was the key of controlling bleeding during operation that DSA and embolization before operation or ligating artery of blood supply during operation.

N-type voltage-dependent calcium channels mediate the nicotinic enhancement of GABA release in chick brain

The role of voltage-dependent calcium channels (VDCCs) in the nicotinic acetylcholine receptor (nAChR)-mediated enhancement of spontaneous GABAergic inhibitory postsynaptic currents (IPSCs) was investigated in chick brain slices. Whole cell recordings of neurons in the lateral spiriform (SpL) and ventral lateral geniculate (LGNv) nuclei showed that cadmium chloride (CdCl2) blocked the carbachol-induced increase of spontaneous GABAergic IPSCs, indicating that VDCCs might be involved. To conclusively show a role for VDCCs, the presynaptic effect of carbachol on SpL and LGNv neurons was examined in the presence of selective blockers of VDCC subtypes. omega-Conotoxin GVIA, a selective antagonist of N-type channels, significantly reduced the nAChR-mediated enhancement of gamma-aminobutyric acid (GABA) release in the SpL by 78% compared with control responses. Nifedipine, an L-type channel blocker, and omega-Agatoxin-TK, a P/Q-type channel blocker, did not inhibit the enhancement of GABAergic IPSCs. In the LGNv, omega-Conotoxin GVIA also significantly reduced the nAChR-mediated enhancement of GABA release by 71% from control values. Although omega-Agatoxin-TK did not block the nicotinic enhancement, L-type channel blockers showed complex effects on the nAChR-mediated enhancement. These results indicate that the nAChR-mediated enhancement of spontaneous GABAergic IPSCs requires activation of N-type channels in both the SpL and LGNv.

Differential effects of wortmannin on the release of substance P and amino acids from the isolated spinal cord of the neonatal rat

1. Effects of wortmannin, an inhibitor of myosin light chain kinase, on the release of substance P and amino acids, GABA and glutamate, were investigated in the isolated spinal cord preparation of the neonatal rat. 2. Wortmannin at 0.5 - 10 microM depressed the release of substance P evoked by high-K+ (90 mM) medium from the spinal cord (IC50 = 1.1 microM). Wortmannin also depressed the high-K+ (70 mM)-evoked release of substance P from cultured dorsal root ganglion neurons of neonatal rats. In contrast, the high-K+ (90 mM)-evoked release of GABA and glutamate from the spinal cord was not affected by wortmannin (0.1 - 10 microM). 3. Upon stimulation of a dorsal root, a monosynaptic reflex and a subsequent slow ventral root depolarization were evoked in the ipsilateral ventral root of the same segment in the isolated spinal cord preparation. The magnitude of the slow ventral root depolarization was depressed gradually to about 70% of the control during the course of 30 min under wortmannin (1 microM). In contrast, the monosynaptic reflex was unaffected by wortmannin. 4. Immunofluorescent staining revealed that immunoreactivities of substance P and myosin II were colocalized at presynaptic terminals in the dorsal horn of the neonatal rat spinal cord. 5. The present results suggest that myosin phosphorylation by myosin light chain kinase may play a crucial role in the release of substance P, but not in the release of GABA and glutamate in the neonatal rat spinal cord. This may reflect a difference in the exocytic mechanisms of substance P-containing large dense core vesicles and amino acid-containing small clear vesicles.

Effects of a tachykinin NK3 receptor antagonist, SR 142801, studied in isolated neonatal rat spinal cord

Effects of a nonpeptide tachykinin NK3 receptor antagonist, SR 142801, were studied in the isolated spinal cord preparation of the neonatal rat. Potential changes were recorded extracellularly from a lumbar ventral root. Bath-application of neurokinin B induced a dose-dependent depolarization of the ventral root. SR 142801 caused rightward shifts of the concentration-response curve for neurokinin B with pA2 of 6.57, but did not affect the depolarizing responses to other agonists. Stimulation of a dorsal root evoked in the ipsilateral ventral root of the same segment monosynaptic and polysynaptic reflexes of fast time course which were followed by a slow depolarization (ipsilateral slow ventral root potential). SR 142801 depressed the ipsilateral slow ventral root potential. The present results indicate that SR 142801 is a specific antagonist for tachykinin NK3 receptors in the spinal cord and suggest that NK3 receptors are involved in primary afferent-evoked nociceptive responses of spinal neurones.

Glutamate and GABA release are enhanced by different subtypes of presynaptic nicotinic receptors in the lateral geniculate nucleus

The functional role of nicotinic acetylcholine receptors (nAChRs) in the ventral lateral geniculate nucleus (LGNv) was examined in chick brain slices. Whole-cell patch-clamp recordings of neurons in the LGNv revealed the presence of bicuculline-resistant spontaneous postsynaptic currents (PSCs), which were subsequently blocked by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), an AMPA receptor antagonist. Carbachol and other nicotinic agonists produced marked increases in the frequency of the glutamatergic spontaneous PSCs in the presence of tetrodotoxin, whereas they had little or no effect on current amplitude. The nicotinic receptor antagonist dihydro-beta-erythroidine (DHbetaE) blocked the carbachol-induced enhancement of spontaneous glutamatergic PSCs. alpha-bungarotoxin (alpha-BgTx) selectively blocked the nAChR-mediated enhancement of spontaneous glutamatergic PSCs but did not prevent nAChR-mediated enhancement of spontaneous GABAergic PSCs in the LGNv. Methyllycaconitine and strychnine, other blockers of nAChRs containing the alpha7 subunit, failed to inhibit carbachol's increase of spontaneous glutamatergic and GABAergic PSCs. These results demonstrate that the LGNv neurons receive both glutamatergic and GABAergic inputs and that the release of these transmitters can be modulated by different presynaptic nAChRs. Thus, the regulation of synaptic efficacy in the brain by presynaptic nAChRs can be complex, involving multiple neurotransmitters acting on the same neuron.

Tachykinin receptors on motoneurons in the spinal cords of neonatal rats, gerbils and hamsters

As a step to clarify the profiles of tachykinin receptors in the mammalian central nervous system, we examined the effects of various tachykinin receptor agonists and antagonists on motoneurons in isolated spinal cord preparations from rats, gerbils and hamsters. After treatment with tetrodotoxin, potential changes were recorded extracellularly from lumbar ventral roots at 27 degrees C. Bath-application of tachykinin NK1, NK3 receptor agonists produced depolarizing responses of ventral roots. In contrast, selective NK2 agonists exerted no or only marginal depolarizing action. Neurokinin A (NKA), however, exerted a distinct depolarizing action on motoneurons. Tachykinin NK1 receptor antagonists antagonized the actions of SPOMe and NKA in a competitive manner. The present results suggest that tachykinin NK1 and NK3 receptors are present on spinal motoneurons of newborn rats, gerbils and hamsters, and that NKA acts on the NK1 receptors.

Tachykininergic synaptic transmission in the coeliac ganglion of the guinea-pig

1. The responses of coeliac ganglion neurones of the guinea-pig to electrical stimulation of the mesenteric nerves and applications of tachykinin receptor agonists were investigated by use of intracellular recording techniques. 2. Ganglion neurones were classified into three groups based on firing patterns in response to a depolarizing current pulse: phasic (38% of the population), tonic (39%) and atypical (23%). In the majority of phasic neurones (91%) a long after-hyperpolarization (LAH) lasting 5-8 s followed action potentials induced by a train of depolarizing current pulses. In contrast, LAH was rarely observed in tonic neurones (5%). 3. In most of tonic neurones (90%) slow excitatory post-synaptic potentials (e.p.s.ps) lasting 3-10 min were evoked by repetitive electrical stimulation of the mesenteric nerves. Prolonged depolarizations were also evoked in most tonic neurones by applications of substance P (SP), neurokinin A (NKA) or senktide, a tachykinin NK3 receptor agonist. 4. In most of phasic neurones (73%), mesenteric nerve stimulation did not induce an obvious depolarization but induced a prolonged inhibition of LAH lasting 3-10 min. Bath-applied tachykinin receptor agonists similarly induced an inhibition of LAH without causing depolarization in most of the phasic neurones. 5. GR 71251 (5 microM), a tachykinin NK1 receptor antagonist, partially depressed the nerve-evoked slow e.p.s.ps in tonic neurones and the nerve-evoked LAH inhibition in phasic neurones. 6. Capsaicin (0.1-5 microM) induced a prolonged depolarization in tonic neurones and an inhibition of LAH in phasic neurones. 7. A mixture of peptidase inhibitors potentiated the depolarization and the LAH inhibition evoked by nerve stimulation, SP and NKA, but not those evoked by senktide. 8. It is concluded that tonic neurones respond to repetitive mesenteric nerve stimulation preferentially with slow e.p.s.ps and that phasic neurones respond preferentially with LAH inhibition. The present study further suggests that SP and NKA, released from axon collaterals of primary afferent neurones, produce slow e.p.s.ps in tonic neurones and the LAH inhibition in phasic neurones via NK1 receptors.

The effect of specific hormones on fibrinolysis in pregnancy

OBJECTIVE

Plasminogen activator inhibitor-1, the major serum protease inhibitor of fibrinolysis, increases steadily during pregnancy. The study objective was to examine four hormones, namely, estradiol-17 beta, progesterone, prolactin, and hydrocortisone to determine their individual contributions in the production of tissue plasminogen activator antigen, plasminogen activator inhibitor-1 antigen, and plasminogen activator inhibitor-1 activity.

STUDY DESIGN

Human umbilical vein endothelial cells were grown with physiologic third-trimester concentrations of the above hormones, and fibrinolytic parameters were measured.

RESULTS

Of the four hormones evaluated, only hydrocortisone significantly increased plasminogen activator inhibitor-1 antigen and activity at both concentrations tested (p < 0.001). Estradiol-17 beta significantly increased tissue plasminogen activator antigen and progesterone significantly decreased tissue plasminogen activator antigen, but neither affected the overall fibrinolytic balance.

CONCLUSION

Hydrocortisone demonstrated antifibrinolytic properties at physiologic concentrations in pregnancy, suggesting that there may be a role for hydrocortisone in the prothrombotic tendency associated with pregnancy. The overall process of fibrinolysis was unaffected by estradiol-17 beta, progesterone, or prolactin.

Pharmacological characterization of GR82334, a tachykinin NK1 receptor antagonist, in the isolated spinal cord of the neonatal rat

Pharmacological characteristics of [D-Pro9,[spiro-gamma-lactam]Leu10,Trp11]physalaemin-(1-11) (GR82334), a tachykinin NK1 receptor antagonist, and its effects on slow depolarizing responses of lumbar ventral roots evoked by primary afferent stimulation were examined in isolated spinal cord preparations of neonatal rats. GR82334 (1-3 microM) caused dose-dependent rightward shifts of the concentration-response curves for substance P, substance P methyl ester, delta-aminovaleryl [Pro9,N-Me-Leu10]substance P-(7-11) (GR73632) and neurokinin A in normal artificial cerebrospinal fluid and those for substance P methyl ester, GR73632 and neurokinin A in the presence of tetrodotoxin. GR82334 (10 microM) did not evoke gamma-aminobutyric acid (GABA) release from spinal cords of neonatal rats, whereas [D-Pro9,[spiro-gamma-lactam] Leu10,Trp11]substance P (GR71251), another tachykinin NK1 receptor antagonist, induced a significant increase in GABA release. GR82334 (1-3 microM) markedly depressed the slow depolarizing response of ventral roots, referred to as slow ventral root potential, evoked by the stimulation of the contralateral dorsal root or the ipsilateral saphenous nerve. In contrast, cyclo[Gln,Trp,Phe,Gly,Leu,Met] (L-659,877, 1 microM), a selective tachykinin NK2 receptor antagonist, did not depress the saphenous nerve-evoked slow ventral root potential and did not antagonize the action of neurokinin A to induce ventral root depolarization. The present results provide further evidence for the involvement of substance P, neurokinin A and tachykinin NK1 receptors in the primary afferent-evoked slow ventral root potentials.

Use of NK1 receptor antagonists in the exploration of physiological functions of substance P and neurokinin A

Tachykinin NK1 receptor antagonists were used to explore the physiological functions of substance P (SP) and neurokinin A (NKA). Pharmacological profiles of three NK1 receptor antagonists, GR71251, GR82334, and RP 67580, were examined in the isolated spinal cord preparation of the neonatal rat. These tachykinin receptor antagonists exhibited considerable specificities and antagonized the actions of both SP and NKA to induce the depolarization of ventral roots. Electrical stimulation of the saphenous nerve with C-fiber strength evoked a depolarization lasting about 30 s of the ipsilateral L3 ventral root. This response, which is referred to as saphenous-nerve-evoked slow ventral root potential (VRP), was depressed by these NK1 receptor antagonists. In contrast, the saphenous-nerve-evoked slow VRP was potentiated by application of a mixture of peptidase inhibitors, including thiorphan, actinonin, and captopril in the presence of naloxone, but not after further addition of GR71251. Likewise, in the isolated coeliac ganglion of the guinea pig, electrical stimulation of the mesenteric nerves evoked in some ganglionic cells slow excitatory postsynaptic potentials (EPSPs), which were depressed by GR71251 and potentiated by peptidase inhibitors. These results further support the notion that SP and NKA serve as neurotransmitters producing slow EPSPs in the neonatal rat spinal cord and guinea pig prevertebral ganglia.

Subtypes of tachykinin receptors on tonic and phasic neurones in coeliac ganglion of the guinea-pig

1. Intracellular recording techniques were used to investigate the characteristics of tachykinin receptors and their subtypes in tonic and phasic neurones, which constituted two major neuronal populations in the coeliac ganglion of the guinea-pig. 2. In 95% of phasic neurones a long-lasting after-hyperpolarization (LAH), 5-8 s in duration and 10-20 mV in amplitude, was observed following action potentials evoked by passing a train of depolarizing current pulses into the neurones. In contrast, LAH was observed in only 4% of tonic neurones. 3. In most tonic neurones, substance P (SP), neurokinin A (NKA) and senktide induced depolarizations, whereas in phasic neurones they usually inhibited LAH but rarely induced depolarization. 4. Tonic and phasic neurones were further classified into three groups based on their responses (depolarization for tonic neurones and LAH inhibition for phasic neurones) to these tachykinin receptor agonists: (1) neurones responsive to SP, NKA and senktide (71-78%); (2) those responsive to senktide but not to SP and NKA (12-23%) and (3) those not responsive to any of the three agonists (7-11%). 5. GR71251 (5 microM), an NK1-selective tachykinin receptor antagonist, depressed the depolarization in tonic neurones and the LAH inhibition in phasic neurones induced by SP and NKA, but not those induced by senktide. 6. Selective NK2 receptor agonists, [Nle10]NKA4-10, [beta-Ala8]NKA4-10 and GR64349, were without effect in both tonic and phasic neurones. Furthermore, an NK2 receptor antagonist, L659,877, did not inhibit the depolarization induced by NKA, SP or senktide in tonic neurones. 7. It is suggested that NK1 and NK3 receptors are present on a large proportion of coeliac ganglion neurones. In tonic neurones both subtypes of tachykinin receptors are coupled to membrane depolarization,whereas in phasic neurones activation of these receptors leads to inhibition of LAH. The present study also suggests that NKA evokes the depolarization in tonic neurones and the LAH inhibition in phasic neurones via NK1, but not NK2 receptors.

Effects of RP 67580, a tachykinin NK1 receptor antagonist, on a primary afferent-evoked response of ventral roots in the neonatal rat spinal cord

1. The pharmacological characteristics of RP 67580, a non-peptide tachykinin NK1 receptor antagonist, and its effects on a reflex response evoked by stimulation of primary afferent fibres, were examined in isolated neonatal spinal cord preparations of the rat. Potentials were recorded extracellularly from a lumbar ventral root and drugs were bath-applied in normal artificial cerebrospinal fluid (CSF) or in the presence of tetrodotoxin (TTX). 2. In normal artificial CSF, RP 67580 (0.1-0.3 microM) caused rightward shifts of the concentration-response curves for substance P (SP), neurokinin A (NKA) and substance P methyl ester (SPOMe), an NK1-selective agonist, with pA2 values of 7.25, 7.47 and 7.49, respectively. 3. In the presence of TTX (0.3 microM), RP 67580 also caused rightward shifts of the concentration-response curves for SPOMe and NKA. The pA2 value of RP 67580 against SPOMe (6.75) was significantly lower than that against NKA (7.22). RP 67580 (0.3-1 microM) did not cause a clear parallel shift of the concentration-response curves for SP, and it depressed the depolarizations induced by low concentrations of SP, but slightly potentiated those induced by high concentrations of SP. 4. RP 67580 (1 microM) did not depress the depolarizing responses to bombesin, L--glutamate, gamma-aminobutyric acid (GABA), thyrotropin-releasing hormone and muscarine. RP 67580 (1 microM), however, depressed the response to acetylcholine in the presence of atropine and the response to nicotine. RP 68651 (1 microM), the enantiomer of RP 67580 devoid of activity at tachykinin NK1 receptors, also depressed the response to acetylcholine in the presence of atropine. 5. RP 67580 (1 gAM) did not induce GABA release from the rat spinal cord.6. In the neonatal gerbil spinal cord, the antagonist effects of RP 67580 (0.3-1 JAM) against SPOMe were much less potent than in the neonatal rat spinal cord.7. In the rat spinal cord-saphenous nerve preparation, electrical stimulation of the saphenous nerve atC-fibre strength evoked a prolonged depolarization of the ipsilateral L3 ventral root (slow VRP).RP 67580 (0.1-1 JM) depressed the saphenous nerve-evoked slow VRP. In contrast, RP 68651 (0.3 JAM)had no effect on the slow VRP.8. The results of the present study indicate that RP67580 acts as a high affinity NK, receptor antagonist in the neonatal rat spinal cord, although it also possesses an antinicotinic action. This study further suggests the existence of a subpopulation of tachykinin NK, receptors that are activated by NKA and SPOMe, as well as by low concentrations of SP, and are sensitive to the antagonist action of RP 67580 in the neonatal rat spinal cord. This study also provides further evidence for the involvement of SP and NKA in the slow VRP evoked by C-fibre stimulation in the neonatal rat spinal cord.

[Pharmacokinetics and pharmacodynamics of slow release tablet of diltiazem in hypertensive patients with various renal functions]

Twenty hypertensive patients were equally divided into 2 groups: A) with normal renal function (NRF) and B) with impaired renal function (IRF) according to creatinine clearance, blood urea nitrogen and creatinine levels. The pharmacokinetic and pharmacodynamic effects of diltiazem (Dil, 90 mg, bid x 7 d, p.o.) were studied. The pharmacokinetic parameters in IRF patients (Ka 0.7 +/- 0.2 h-1, T 1/2e 3.7 +/- 0.7 h, Cmax1 45 +/- 4 ng.ml-1, Tmax1 3.1 +/- 0.4 h) did not differ from those in NRF patients (0.7 +/- 0.5 h-1, 4.1 +/- 1.3 h, 41 +/- 5 ng.ml-1 and 3.4 +/- 0.4 h, P > 0.05). Antihypertensive efficacy of Dil in patients with IRF was similar to that in those with NRF, and the hypotensive effect lasted over 24 h. The plasma Dil concentrations were strongly correlated with a decrease in BP in both groups. It was concluded that IRF did not affect the disposition of slow release Dil tablet under a steady state. No dosage adjustment of Dil is necessary in hypertensive patients with IRF.

Review of pneumatic reduction of intussusception: evolution not revolution

Pneumatic insufflation of the colon for reduction of pediatric intussusception has recently been recognized in the United States as an alternative method for the more traditional hydrostatic reduction with contrast material. The experience with pneumatic reduction in China is extensive; more than 14,000 cases have been reported in the English language literature. In this review, the general technique used in China is summarized, and the international experience with air insufflation is included in a comparison of hydrostatic and pneumatic reduction techniques.

Electrophysiological identification of horizontal synaptic connections in rat visual cortex in vitro

The presence of intrinsic horizontal synaptic connections in rat visual cortex was explored electrophysiologically using in vitro slice preparations. Intracellular recordings were made from pyramidal neurons located in the superficial and deep layers. Electrical stimulation at the gray matter in the same or different layers but 0.8-2.7 mm apart from the recording site evoked compound synaptic potentials composed of excitatory and inhibitory postsynaptic potentials of fast and slow time courses. Glutamate blockers, DNQX (5 microM) and kynurenate (2 mM) reduced the excitatory postsynaptic potential (EPSP), and GABAB receptor antagonist, phaclofen (0.5 mM), abolished the inhibitory postsynaptic potential of the slow time course. EPSP of the fast time course followed 20 Hz repetitive stimulation in the medium of high Ca2+ (6.0 mM) and Mg2+ (4.0 mM) concentration, suggesting that this fast EPSP was monosynaptic. Conduction velocity of the fibers mediating the monosynaptic EPSP was estimated to be 0.15-0.55 m/s. These results provide physiological evidence for the horizontal synaptic connections in the rat visual cortex, which had been previously suggested by morphology.

Involvement of NK1 receptors in synaptic transmission in the guinea pig coeliac ganglion

Using intracellular recording techniques, we examined the effects of tachykinin receptor agonists and antagonists on electrophysiologically identified tonic neurons of the isolated guinea pig coeliac ganglion. In most of the tonic neurons, substance P (SP), neurokinin A (NKA) and/or senktide induced a depolarization. The effects of SP and NKA were blocked by the NK1-selective antagonist, GR71251 (5 microM), but not by the NK2-selective antagonist, L659,877 (10 microM), whereas the effect of senktide was not affected by these antagonists. The NK1-selective agonists, [Sar9,Met(O)2(11)]SP and SP methyl ester, and the NK3-selective agonist, [MePhe7]neurokinin B, also evoked depolarizations in tonic neurons. By contrast, the NK2-selective agonists, [Nle10]NKA4-10, [beta-Ala8]NKA4-10 and GR64349, at 1 microM each, did not evoke any significant depolarizing response. Repetitive electrical stimulation of the mesenteric nerves induced slow excitatory postsynaptic potentials (EPSPs) in the majority of tonic neurons, which were depressed by GR71251 (5 microM). These results suggest that NK1 and NK3 receptors but not NK2 receptors are involved in the tachykinin-induced depolarization of tonic neurons, and that the NKA-induced response is due to the activation of NK1 receptors. This study also suggests the involvement of NK1 receptors in the slow EPSPs in tonic neurons.

Depression of primary afferent-evoked responses by GR71251 in the isolated spinal cord of the neonatal rat

1. The pharmacological profile of GR71251, a new tachykinin receptor antagonist, and its effect on the responses evoked by stimulation of primary afferent fibres were studied in isolated spinal cord preparations of neonatal rats. Potential changes were recorded extracellularly from a lumbar ventral root (L3-L5). 2. Bath-application of substance P (SP), neurokinin A (NKA) and neurokinin B (NKB) at 0.01-3 microM to the spinal cord induced depolarization of the ventral root in normal artificial cerebrospinal fluid (CSF). The NK1 agonist, acetyl-Arg6-septide, and the NK3 agonist, senktide, at 0.01-3 microM, also had potent depolarizing actions whereas two NK2 agonists, beta-Ala8NKA4-10 and Nle10NKA4-10, showed little depolarizing effects at 1 microM. 3. GR71251 (0.3-3 microM) caused a rightward shift of the concentration-response curves for SP, acetyl-Arg6-septide and NKA with pA2 values of 6.14, 6.75 or 6.70, respectively. The effects of GR71251 were readily reversible within 15-30 min after its removal. By contrast, GR71251 (1-5 microM) had little effect on the depolarizing responses to NKB and senktide. 4. GR71251 (1-3 microM) did not depress the depolarizing responses to bombesin, neuromedin B and gastrin-releasing peptide in normal artificial CSF. 5. Application of capsaicin to the spinal cord induced a depolarizing response, which was partially depressed by GR71251 (3-10 microM). 6. In the isolated spinal cord preparation, intense electrical stimulation of a dorsal root evoked a slow depolarizing response of the contralateral ventral root of the same segment. A similar slow ventral root depolarization was evoked by electrical stimulation of the ipsilateral saphenous nerve in an isolated spinal cord-saphenous nerve preparation. GR71251 (0.3-10 microM) dose-dependently depressed these slow ventral root potentials.7. In the spinal cord-peripheral nerve preparation, conditioning stimulation of the saphenous nerve evoked an inhibition of the muscle nerve-evoked monosynaptic reflex lasting about 20 s. The late part of the inhibition was markedly depressed by GR71251 (1-3 microM).8. The present results indicate that GR71251 is a potent and specific antagonist for tachykinin receptors in the spinal cord. The present study further provides evidence for the involvement of SP and NKA in the slow ventral root depolarization and the prolonged inhibition of monosynaptic reflex that are evoked by primary afferent stimulation.

[Pharmacokinetics and pharmacodynamics of diltiazem floating tablets]

Floating tablet is a new type of delayed-action preparations. The present study was aimed at pharmacokinetic and hemodynamic effects of diltiazem floating tablet in 8 healthy volunteers. Each subject received po 90 mg diltiazem floating and normal tablets in a crossover design. For floating tablets the T1/2 (6.4 +/- 4.4 h) and Cmax (56 +/- 23 ng.ml-1) were longer and lower than those of normal tablets (2.3 +/- 1.1 h and 96 +/- 30 ng.ml-1, P < 0.01), respectively. AUC of the 2 forms were similar, suggesting that they had same bioavailability. Diltiazem lowered the blood pressure of the subjects. Although there was no significant difference between the 2 formulations in maximal decreases of systolic and diastolic blood pressures, the duration of hypotension was longer with floating tablets than that with normal ones. There was a positive correlation between diltiazem concentration and its hypotensive action. Thus, administration of floating tablets twice a day may be effective in controlling the blood pressure of hypertensive patients.

Differential expression of the alpha 2 and beta messenger RNAs of Na,K-ATPase in developing brine shrimp as measured by in situ hybridization

We used in situ hybridization histochemistry with synthetic oligonucleotide probes to localize the mRNAs encoding the alpha 2- and beta-mRNAs of Na,K-ATPase during development of the brine shrimp Artemia. The mRNAs of the alpha 2- and beta-subunit were of low abundance in the cysts; in addition, less mRNA of the beta-subunit was localized. During emergence (12 hr), there was an increase in alpha 2-subunit mRNA in the gut mucosa, but there was a burst in beta-subunit mRNA throughout. As development progressed, the mRNAs of both the alpha 2- and beta-subunits showed a distinct pattern of expression in which the mRNA in the salt gland was of greatest abundance, followed by epidermal cells and gut mucosa. After 36 hr the alpha 2-subunit mRNA began to decrease in all positive cells but still remained highest in the salt gland and the brain region, while the mRNA of the beta-subunit kept increasing in the gut mucosa. Finally, the greatest abundance of the beta-subunit mRNA shifted from the salt gland to the antenna gland and the epidermal cells in the tail region, but the alpha 2-subunit mRNA did not. The more widespread distribution of the beta-mRNA than alpha 2-mRNA at certain stages (e.g., there was no alpha 2-mRNA in the antenna gland at the adult stage) is in all likelihood due to the marked drop in the alpha 2-subunit and a rise in alpha 1-subunit previously seen by Peterson et al. on polyacrylamide gel electrophoresis, as development progresses.

Na,K-ATPase expression in the developing brine shrimp Artemia. Immunochemical localization of the alpha- and beta-subunits

Developing brine shrimp are a good experimental model for study of gene expression during development. Development is initiated on suspension of brine shrimp cysts in seawater. Only 48 hr are required for progression from cyst to the larval stage. We have localize the alpha- and beta-subunits in different cells by immunostaining as development progresses. Both alpha- and beta-subunits are first detected in epidermal cells in the trunk region at the emergence 2 stage (16-hr incubation). At the nauplius 1 stage (24 hr) the enzyme appears in the brain and epidermal regions, as well as in mesenchymal cells, with weaker staining in the salt gland. After further development (nauplius 2 stage, 36 hr) stronger staining appears in the salt gland and in the epidermal region. At the nauplius 3 stage (48 hr) the enzyme appears in the midgut mucosa. Co-localization of the alpha- and beta-subunits appears in all positive cells during development. In the epidermal and salt gland cells the enzyme is mainly localized on the basolateral membrane. The basolateral localization of the Na,K-ATPase in epidermal and salt gland cells suggests that Na+ is actively transported into the epidermal and salt gland cells and passively diffuses out from the apical region.

Messenger RNA stabilization accounts for elevated basic fibroblast growth factor transcript levels in a human astrocytoma cell line

Basic fibroblast growth factor (bFGF) is a potent autocrine and paracrine mitogen for cells of mesodermal origin. Although the protein is present in substantial amounts in a variety of tissues, the level of mRNA is undetectable in most normal tissues. This has led to speculation that bFGF mRNA is very unstable, but the half-life of this mRNA has not been described. A number of mRNAs encoding growth factors and growth-related proteins are known to be short-lived and posttranscriptionally regulated. In the present study we have examined the half-life of bFGF mRNA in two human tumor cell lines, which contain high (U87-MG) and low (T98-G) steady state bFGF mRNA levels. The half-life of bFGF mRNA, determined after transcriptional arrest with actinomycin-D, was approximately 10 min in T98-G cells, but was extended to 120 min in the presence of cycloheximide. In contrast, bFGF transcripts in U87-MG cells were very stable with a half-life considerably greater than 5 h. This was not attributable to a general stabilization of mRNA in the U87-MG line, since the half-life of c-myc mRNA in the two cell lines was similar (10 and 15 min in T98-G and U87-MG, respectively). Cycloheximide had no effect on the steady state level of bFGF in U87-MG cells. These findings suggest that posttranscriptional processes play an important role in the regulation of bFGF transcript levels and demonstrate that loss of posttranscriptional regulation could contribute to elevated bFGF expression in some tumors.

Molecular cloning of the Na,K-ATPase alpha-subunit in developing brine shrimp and sequence comparison with higher organisms

We report here the molecular cloning, nucleotide sequence, and predicted amino acid sequence of an alpha-subunit of the developmentally useful model, Artemia. The amino acid sequence shows divergence from that of mammals, birds, Torpedo, and Drosophila. However, regions in the putative ATP binding and transmembrane domains show absolute or high levels of conservation. Major differences occur in the amino-terminal domain and several other hypervariable regions. These differences are consistent with the suggestion that the brine shrimp is a 'fast clock' organism which diverged from the precursors of vertebrates 0.5-1 billion years ago.

Malignant pheochromocytoma: diagnosis and treatment in fifteen cases

This study reviews the diagnosis and treatment of 15 patients with malignant pheochromocytoma (MP) between 1958 and 1986 in Shanghai Rui-jin Hospital. The main clinical features consisted of sustained elevation of arterial blood pressure, obviously increased catecholamine secretion and a sustained positive phentolamine test. Out of 15 patients only seven survived, two of whom suffered from paraplegia due to metastatic cordal compression. Compared with some earlier results, the prognosis was unsatisfactory. There were several factors which may have been responsible: (1) late diagnosis; (2) incomplete operation, and (3) no regular post-operative assessment of urinary biochemical changes. Because MP is a tumour with a low degree of malignancy, noting the above three factors and using 131I-MIBG to obtain accurate diagnosis and effective treatment enables a better prognosis of this disease.

Estrogen effects on modifications of chromatin proteins in the rat uterus

ADP-ribosylation and phosphorylation of chromatin proteins was studied in rat uterine nuclei isolated after estrogen treatment and then incubated with [adenylate-32P]NAD or [gamma-32P]ATP. Histone acetylation was studied in uteri from immature rats treated with estradiol by incubating the whole uterus in a medium containing [14C]acetic acid. Chromatin proteins were isolated from uterine nuclei and separated by electrophoresis on SDS polyacrylamide gels followed by autoradiography or fluorography. Chromatin proteins H1, H2B, H3, HMG 14 and HMG 17 were almost exclusively ADP-ribosylated. Uterine histones H1, H3, H4, HMG 14 and HMG 17 were phosphorylated. There was a general increase in [32P]ADP-ribose uptake in chromatin proteins after estrogen stimulation, whereas [32P]phosphate incorporation into chromatin proteins showed a biphasic pattern. The [14C]acetate activity associated with all histone proteins increased gradually after estrogen treatment.

Estrogen effects on histone messenger ribonucleic acid levels in the rat uterus

RNA was isolated from uteri of immature rats before and after estrogen treatment. The concentration of histone mRNA was analyzed by Northern hybridization and compared with messenger RNA concentration of alpha-actin, beta-actin, and beta-tubulin. Steady state levels of common histone mRNAs did not change up to 9 h after hormone administration. After that time the histone mRNA levels increased significantly and reached a maximum at 18 h, several hours later than the time of maximal histone protein biosynthesis induced by estrogen. The concentration of control mRNAs (alpha- and beta-actin and beta-tubulins) increased shortly after estradiol injection and reached a peak at 9 h. These results show that the pattern of histone gene expression induced by estrogen has some features similar to those observed during embryogenesis.

Differential stimulation of histone and high mobility group chromatin protein synthesis in the rat uterus by estrogen

Uterine tissue isolated from immature rats at different times after estradiol injection was incubated with medium containing [3H]lysine. The acid-extractable protein from the uterine tissue was subjected to electrophoresis on sodium dodecyl sulfate and acid-urea-Triton X-100 polyacrylamide gels, and the rate of chromatin protein synthesis determined by densitometric analysis of the fluorographs of the gels. Synthesis of chromatin proteins (histones and high mobility group chromatin proteins) was stimulated by 3 h after estrogen treatment and reached a peak at 9 h, several hours before DNA synthesis was stimulated. Synthesis of chromatin proteins occurred at the same time as total cellular protein synthesis. Estrogen stimulated the synthesis of histone variants at different rates, but the accumulation of histone proteins remained coordinated such that equivalent amounts of histone proteins were being produced at any one time.

Salt and the action of calcium antagonists

Calcium antagonists are unique in that they combine vasodilating and natriuretic properties. Although the acute natriuretic response, and details on intrarenal mechanisms of action, have been documented in the past, recent evidence shows intrarenal actions even in the chronic steady state of antihypertensive medication. Chance observations led to recent systematic studies that clearly document (a) that the antihypertensive action of calcium antagonists is not antagonized by high sodium diet and (b) that there is negative interaction between diuretics and calcium antagonists with respect to their antihypertensive actions. Potential mechanisms for the salt/diuretic-calcium antagonist interactions include (i) intrinsic natriuretic property of calcium antagonists, (ii) interaction of volume control and hormonal calcium control systems, and (iii) modulation of--at least dihydropyridine--binding sites by dietary sodium.