Identification of a novel HLA-C allele, Cw*0406, in a Singapore Malay

A novel allele, C*0406, has been identified and is characterised by a single nucleotide substitution at position 196 of exon 3 when compared with its closest related allele, C*0403. The latter is found in 4/69 Chinese and 7/80 Malays while Cw*0406 was found in only one Malay individual within the study populations. The data suggest that Cw*0406 may have arisen as a relatively recent genetic event either by gene conversion or as a simple point mutation variant of Cw*0403.

The role of bcl-2 in the progression of the colorectal adenoma-carcinoma sequence

BACKGROUND

The bcl-2 proto-oncogene is a known inhibitor of apoptosis that may allow the accumulation and propagation of cells containing genetic alterations.

METHODS

An immunohistochemical study was performed to examine the role of BCL-2 protein expression in normal colonic mucosa, adenoma, and adenocarcinoma.

RESULTS

BCL-2 was present in the crypt base of normal mucosal glands, while diffuse expression of protein product was observed in 69 cases (65.1%) of adenoma and 29 cases (60%) of adenocarcinoma (p > 0.5). A diffuse expression pattern was often noted in adenomas of the tubular type, solitary lesions, small lesions (< 1 cm), and those with mild glandular dysplasia (p < 0.05, respectively). There was, however, no apparent difference as to location, Yamada type of gross appearance, and gender of patients (p > 0.05, respectively). Patterns of BCL-2 expression did not correlate with the biologic indicators of adenocarcinoma (p > 0.1, respectively).

CONCLUSIONS

Our results support that bcl-2 may play an important role in the early stage of the adenoma-carcinoma sequence. Down-regulation of bcl-2 is associated with the risk of malignant transformation for colorectal adenoma.

Elevated Fos expression in the nucleus tractus solitarii is associated with reduced baroreflex response in spontaneously hypertensive rats

We delineated the functional role of Fos protein at the nucleus tractus solitarii in the manifestation of reduced baroreceptor reflex control of heart rate during hypertension, using spontaneously hypertensive rats (SHR), stroke-prone SHR, Wistar-Kyoto rats, or Sprague-Dawley rats. Microinjection into the bilateral nucleus tractus solitarii of an antisense oligonucleotide that targets against the initiation codon of c-fos mRNA significantly potentiated the baroreceptor reflex in response to 30 minutes of sustained increase in blood pressure. Of particular note was the restoration of both the impaired sensitivity and capacity of baroreceptor reflex in SHR and stroke-prone SHR to levels comparable to those in normotensive rats. Likewise, the number of Fos-immunoreactive nuclei evoked by the sustained increase in blood pressure in the caudal nucleus tractus solitarii of SHR and stroke-prone SHR was reduced, after this antisense c-fos treatment, to the basal level exhibited by the normotensive animals. Control treatment with the corresponding sense oligonucleotide, an antisense oligonucleotide that targets against a different portion of the coding sequence of the c-fos mRNA or artificial cerebrospinal fluid, on the other hand, elicited no discernible effect on either the baroreceptor reflex response or the induced expression of Fos protein in the nucleus tractus solitarii by baroreceptor activation. We also found that the basal level of Fos expression in the caudal nucleus tractus solitarii was significantly elevated in the SHR and stroke-prone SHR. Together, these novel findings suggest that an elevated expression of basal Fos protein in the NTS during hypertension may be associated with the dysfunction in baroreceptor reflex control of heart rate.

Differential participation of hippocampal formation in cocaine-induced cortical electroencephalographic desynchronization and penile erection in the rat

We evaluated the role of the hippocampal formation in cocaine-induced cortical electroencephalographic (EEG) desynchronization and penile erection. Adult, male Sprague-Dawley rats anesthetized and maintained by chloral hydrate were used. Intravenous (1.5 or 3.0 mg/kg) administration of cocaine dose-dependently increased intracavernous pressure (ICP), our experimental index for penile erection. This was accompanied by desynchronization of EEG activity recorded from the somatosensory cortex (cEEG), as represented by a decrease in root mean square (RMS) and an increase in mean power frequency (MPF) values. There was a simultaneous increase in the RMS values, without significant changes in the MPF values of EEG signals recorded from the hippocampal formation (hEEG). In animals that received prior application of 10% xylocaine either intrathecally (i.t.) at the L6-S1 spinal levels or directly into the bilateral hippocampal formation, the RMS values of both cEEG and hEEG signals induced by cocaine (1.5 or 3.0 mg/kg, i.v.) were appreciably reduced, along with a further increase in ICP. Unilateral microinjection of cocaine (15 or 30 microg) into the hippocampal formation elicited discernible excitation of both cEEG and hEEG signals. Intriguingly, the ICP underwent a significant and dose-dependent reduction, which was discernibly antagonized by i.t. application of xylocaine. We conclude that cocaine may effect cortical EEG desynchronization but cause a reduction in ICP via an action on the hippocampal formation.

Expression of fibroblast growth factor-1 and fibroblast growth factor-2 in normal liver and hepatocellular carcinoma

This study was performed to examine the immunohistochemical expression of fibroblast growth factor-1 and fibroblast growth factor-2 in normal liver and a total of 31 cases of hepatocellular carcinoma (HCC). Reactivity for both types of angiogenic factor did not exist in any cellular component of normal liver. For HCC, variable amounts of fibroblast growth factor-1 were detected in 6 of 31 cases (19.4%). There was no apparent relationship between the expression pattern and clinicopathologic factors (P > 0.1, respectively), except a positive correlation with histologic grading (P = 0.04). No tumor showed reactivity for fibroblast growth factor-2 in their cancer cells. However, both types of peptide could be demonstrated in the pericellular stroma of HCC. With a mean follow-up at 60 months, fibroblast growth factor-1 expression did not correlate with patients' outcome (P > 0.1). Our study suggested that fibroblast growth factor-1 appears to play a certain role in hepatocarcinogenesis.

Induction of an ATPase inhibitor protein by propylthiouracil and protection against paracetamol (acetaminophen) hepatotoxicity in the rat

1. The purpose of the present study was to test the following hypothesis: propylthiouracil (PTU) treatments of rats induces an increase in the concentration and activity of the mitochondrial ATPase (m-ATPase) inhibitor protein (IF1). The PTU-induced elevated baseline levels of this inhibitor protein inactivated m-ATPase, and prevented hepatotoxicity by a toxic dose of acetaminophen (AAP) (paracetamol), by maintaining hepatic adenosine 5'-triphosphate (ATP) levels. 2. Male Wistar rats were either gavaged with a toxic dose of AAP alone, or after pretreatment with PTU for periods of 3 and 12 days. 3. Twenty four hours after acetaminophen treatment alone, toxicity was manifested by: an approximately 10 fold increase in serum transaminase levels (serum glutamic oxaloacetic transaminase and serum glutamic pyruvic transaminase); depletion of hepatic reduced glutathione (GSH) and ATP levels; loss of inhibitor protein activity, and extensive pericentral necrosis of the hepatocytes. Propylthiouracil pretreatment for 12 days enhanced the concentration of the following metabolites in the liver: ATP (1.5 fold), ATPase inhibitor protein (IF1) (4.5 fold), and reduced glutathione (1.3 fold), while the activity of the inhibitor protein increased 2 fold. When the PTU treated rats were challenged with AAP, transaminases were not elevated, and only sporadic areas of necrosis were detected by histological examination of the liver tissue. In contrast to the 12 day treatment with PTU the 3 day treatment had no protection against AAP. No histological evidence of protection was manifested and the transaminases were not different from AAP treated controls. Most of the protective metabolites were depleted. 4. Our findings suggest that PTU-induced increased concentration of inhibitor protein and GSH, are contributing factors in the prevention of hepatotoxicity by maintaining hepatic m-ATP levels and reducing the harmful effect of the toxic metabolite of AAP.

Epstein Barr virus (EBV) antibodies in the diagnosis of NPC--comparison between IFA and two commercial ELISA kits

BACKGROUND

Antibodies to Epstein Barr Virus (EBV) antigens have been used for the diagnosis of nasopharyngeal carcinoma (NPC). While immunofluorescence assays (IFA) of IgA antiviral capsid and early antigens have been the mainstay of this diagnosis, enzyme immunoassays (ELISA) of various EBV antigens are now available. However in almost all of these assays, the sensitivities and specificities have been calculated using blood donors and normal hospital staff as controls, who may not be the most appropriate controls. We wanted to evaluate the usefulness of IFA and ELISA of various EBV antigens in a clinical setting to distinguish between patients with NPC and those suspected of NPC but being biopsy negative.

METHODS

Between January 1987 and June 1988, 322 consecutive patients suspected of NPC and who had a post-nasal biopsy were studied. Blood was taken for EBV tests before diagnosis. Tests included IFA and ELISA IgA anti-VCA and anti-EA and ELISA IgA and IgG anti-ribonucleotide reductase, a cloned EA antigen.

RESULTS

IFA IgA anti-VCA together with IFA IgA anti-EA both at a cut-off of 1:10 gave the best discrimination between patients with NPC and those suspected of NPC but were biopsy negative.

CONCLUSION

The ELISA IgG anti-ribonucleotide reductase test is convenient to perform and looks very promising. An ELISA using a cocktail of cloned EA peptides may be even better.

Noradrenergic neurotransmission at PVN in locus ceruleus-induced baroreflex suppression in rats

We investigated the role of ascending noradrenergic projections from the locus ceruleus (LC) to the paraventricular nucleus (PVN) of the hypothalamus in LC-induced suppression of the baroreceptor reflex (BRR) response in adult Sprague-Dawley rats maintained under pentobarbital anesthesia. On the basis of in vivo microdialysis and high-performance liquid chromatography-electrochemical detection, microinjection of L-glutamate (5 nmol) into the LC resulted in a site-specific increase in norepinephrine (NE) concentration in the dialysate collected from the parvocellular subnucleus of the PVN. The temporal course of this increase in extracellular NE concentration in the PVN coincided with the time course of inhibition elicited by the LC on the BRR response. Microinfusion of NE (10, 50, or 100 nM) into the parvocellular subnucleus of the PVN by reverse microdialysis also promoted a parallel increase in NE at the PVN and a reduction in the BRR response. Inhibition of the BRR response induced by microinjection into the PVN of the alpha 1-adrenoceptor agonist phenylephrine (10 nmol) or chemical activation of the LC was reversed by bilateral PVN microinjection of prazosin (100 pmol). However, local application to the PVN of the alpha 2- or beta-adrenoceptor agonist guanabenz (10 nmol) or isoproterenol (10 nmol) was ineffective. Our results suggest that NE released from the LC-PVN noradrenergic projection may participate in LC-induced suppression of the BRR response by activating the alpha 1-adrenoceptors at the parvocellular subnucleus of the PVN.

Participation of hippocampal formation in negative feedback inhibition of penile erection in the rat

Detailed information on how the central nervous system regulates penile erection, particularly the inhibitory aspect, is sparse. We observed in Sprague-Dawley rats anesthetized and maintained with chloral hydrate that administration of papaverine (400 microg) directly into the corpora cavernosum of the penis produced an increase in intracavernous pressure (ICP). This elicited experimental index for penile erection was accompanied by a transient increase in the root mean square values, concurrent with a shift in the contribution of Theta (increase) and delta (decrease) power to the hippocampal electroencephalographic (hEEG) activity. Reversal blockade of these hEEG responses with xylocaine, given either intrathecally at the L6-S1 spinal levels or unilaterally to the hippocampal formation, significantly heightened and prolonged the ICP response. Pretreatment with xylocaine by itself, however, did not alter appreciably the baseline ICP or hEEG activity. These results suggest the presence of a novel negative feedback inhibitory mechanism in the hippocampal formation, which is triggered by ascending sensory inputs initiated by tumescence of the penis during normal erectile processes.

Power spectral analysis of arterial blood pressure after spinal anesthesia

BACKGROUND

The continuous, on-line and real-time analysis of the power spectrum (CORAPS) of systemic arterial pressure (SAP) and heart rate (HR) signals is one of the current progresses in the development of non-invasive indexes for autonomic nervous system. It might be a useful clinical tool to monitor the progress of preganglionic block of sympathetic nervous system and the homeostatsis of cardiac neuroregulation after spinal anesthesia. The purpose of this study is to examine the relationship between the hypotensive response and the changes of components in CORAPS throughout the course of spinal anesthesia.

METHODS

In 10 ASA class I-II patients (aged from 17 to 75 years) scheduled for elective surgery, we analyzed the changes of spectrum of systemic arterial blood pressure signals during spinal anesthesia. Spinal anesthesia was performed with 0.5% bupivacaine (dosage at 13-15 mg). For CORAPS, SAP signals were simultaneously relayed to an analog-digital converter connected to a computer. Power spectral density of the data was computed using a fast Fourier transform. The areas of the spectral peaks within each measurement were calculated as the follows: very low (BVLF, 0.01-0.08 Hz), low (BLF, 0.09-0.15 Hz), and high (BHF, 0.16-0.25 Hz).

RESULTS

During the time interval (S2 period) when spinal anesthesia was initiated and 15 min thereafter the power density of low frequency (BLF), (1.2 vs. 2.3), and very low frequency (BVLF) components decreased, (3.4 vs. 7.8), in comparison with that at the baseline level (S1 period). We also found the shift of dominance between low frequency (BLF) and high frequency (BHF) in S2 period. The effects of intrathoracic pressure on the venous return may contribute to the increase of power density of BHF components (1.7 vs. 1.1). We also found that even in patients with stable hemodynamic variability, the decrease of BLF and BVLF components, and the shift of dominance were the same as in patients with unstable hemodynamic variability.

CONCLUSIONS

It might prove that the cephalic spread of spinal block abolished the sympathetic tone of the autonomic nervous system. These results validated previous speculations of a sympathetic block during spinal anesthesia. More importantly, patients with stable hemodynamic variability still have profoundly sympathetic block with decreased power density of BLF and BVLF. The CORAPS is a good clinical monitoring tool to evaluate the homeostatsis of cardiac neuroregulation after spinal anesthesia.

Participation of AT1 and AT2 receptor subtypes in the tonic inhibitory modulation of baroreceptor reflex response by endogenous angiotensins at the nucleus tractus solitarii in the rat

We evaluated the endogenous action of angiotensin II (AII) and its active metabolite, angiotensin III (AIII), at the nucleus tractus solitarii (NTS) in the modulation of baroreceptor reflex (BRR) response, and the subtype(s) of angiotensin receptors involved in this process. Adult, male Sprague-Dawley rats that were anesthetized and maintained with pentobarbital sodium were used. Bilateral microinjection of AII or AIII (10, 20 or 40 pmol) into the NTS significantly and dose-dependently suppressed the BRR response, which was evoked by transient hypertension induced by phenylephrine (5 micrograms/kg, i.v.). The suppressive effect of AII (40 pmol) was reversed by co-administration of the non-peptide AT1 receptor antagonist, losartan (1.6 nmol), but only partially by the non-peptide AT2 receptor antagonist, PD-123319. On the other hand, both angiotensin receptor antagonists appreciably reversed the depressive action of AIII (40 pmol). Blocking the endogenous activity of the angiotensins by microinjection into the bilateral NTS of losartan (1.6 nmol) or PD-123319 (1.6 nmol) elicited a significant enhancement of the BRR response. An interruption of the conversion of AII to AIII with the aminopeptidase A inhibitor, amastatin (3.3 nmol), attenuated, but did not eliminate, the AII-induced inhibition of the BRR response. We conclude that whereas the endogenous AIII may exert a tonic inhibitory modulation on the BRR response by acting on both the AT1 and AT2 receptor subtypes, the same action of the endogenous AII engaged only the AT1 receptor subtype at the NTS. Furthermore, at least part of the suppressive action of AII may result from its metabolic conversion to AIII.

Mediation by N-methyl- d-aspartate and non- N-methyl- d-aspartate receptors in the expression of fos protein at the nucleus tractus solitarii in response to baroreceptor activation in the rat

We investigated the role of glutamatergic synapses in the expression of Fos protein at the nucleus tractus solitarii following baroreceptor activation in rats anaesthetized with pentobarbital sodium. Microinjection of L-glutamate (1 nmol) bilaterally into the nucleus tractus solitarii elicited significant hypotension and bradycardia. There was a concurrent increase, as determined immunohistochemically, in the expression of Fos protein at the commissural, medial and dorsomedial subnuclei of the caudal nucleus tractus solitarii. These effects were blunted when L-glutamate was co-administered with either the selective N-methyl-D-aspartate or non-N-methyl-D-aspartate glutamate receptor antagonist, dizocilpine maleate (200 pmol) or 6-cyano-7-nitroquinoxaline-2,3-dione (8 pmol), into the caudal nucleus tractus solitarii. Repeated and scheduled transient hypertension evoked by phenylephrine (2.5, 5.0 or 10.0 microg/kg, i.v.) also appreciably increased the number of Fos-immunoreactive neurons at the commissural, medial and dorsomedial subnuclei of the caudal nucleus tractus solitarii. The expression of Fos protein in this fashion was reduced, simultaneous with a discernible depression in baroreceptor reflex response, when baroreceptor activation was coupled with microinjection bilaterally of dizocilpine maleate (200 pmol) or 6-cyano-7-nitroquinoxaline-2,3-dione (8 pmol) into the nucleus tractus solitarii. Regression analysis showed that the depressive action on the baroreceptor reflex response by both glutamate receptor antagonists correlated positively to the reduction in Fos-immunoreactivity in the nucleus tractus solitarii after baroreceptor activation. Double immunohistochemical staining revealed that nucleus tractus solitarii neurons that showed Fos immunoreactivity were generally also immunoreactive to alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate receptor subunit 1. On the other hand, Fos immunoreactivity was usually absent from neurons in the nucleus tractus solitarii that were immunoreactive to N-methyl-D-aspartate receptor subunit 1. These results suggest that glutamatergic neurotransmission plays an active role, via comparable contributions from both N-methyl-D-aspartate and non-N-methyl-D-aspartate receptors, in the expression of Fos protein at the caudal nucleus tractus solitarii in response to baroreceptor activation.

Quantification of hepatitis B virus DNA using competitive PCR and a scintillation proximity assay

A rapid assay for the quantification of hepatitis B virus DNA in human serum was developed. The principle of the method combines competitive polymerase chain reaction (cPCR) (for the controlled amplification of hepatitis B virus DNA) and scintillation proximity assay (SPA) technology (for rapid detection and quantitation of PCR products). It also incorporates a reproducible and simple method for the preparation of serum DNA suitable for PCR amplification. The assay has a better linear dynamic range than traditional methods that use 32P to detect PCR products. It was applied to a range of hepatitis B virus (HBV) surface antigen positive (HBsAg + ) sera, and shown to be more sensitive than a commercially available HBV DNA kit.

Involvement of cerulospinal glutamatergic neurotransmission in fentanyl-induced muscular rigidity in the rat

BACKGROUND

Investigators in the authors' laboratory previously established the critical participation of the cerulospinal noradrenergic pathway in muscular rigidity elicited by fentanyl. The identification of colocalization of glutamate with tyrosine hydroxylase in most locus ceruleus neurons suggests a role for cerulospinal glutamatergic neurotransmission in fentanyl-induced muscular rigidity. This suggestion and the subtype(s) of glutamate receptors involved were investigated here.

METHODS

Electromyographic signals activated by bilateral microinjection of 2.5 microg fentanyl into the locus ceruleus were recorded differentially from the left sacrococcygeus dorsi lateralis muscle of adult male Sprague-Dawley rats. The effect of intrathecal administration at the lower lumbar spinal cord of various N-methyl-D-aspartate (NMDA) and non-NMDA receptor antagonists or agonists on this index of muscular rigidity was studied. Rats were under mechanical ventilation, and intravenous infusion of ketamine (30 mg x kg(-1) x h(-1)) was maintained until 10 min before fentanyl was administered.

RESULTS

Microinjection of fentanyl bilaterally into the locus ceruleus increased the root mean square and decreased the mean power frequency values of electromyographic signals. The efficacy of fentanyl to elicit muscular rigidity in this manner was significantly reduced by previous intrathecal administration of either 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine maleate (MK-801), D-(-)-2-amino-5-phosphonovaleric acid (AP5), or (+/-)-3-(2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP). Intrathecal administration of kainic acid or NMDA also resulted in significant electromyographic activation.

CONCLUSIONS

In addition to the cerulospinal noradrenergic mechanism, the cerulospinal glutamatergic pathway and both NMDA and non-NMDA receptors in the spinal cord may mediate fentanyl-induced muscular rigidity in the rat.

Enhancement of spontaneous baroreflex by antisense c-fos oligonucleotide treatment in the NTS of the rat

We evaluated the hypothesis that basal Fos protein at the nucleus tractus solitarii (NTS), the primary terminal site for baroreceptor afferents, exerts a tonic inhibitory modulation on the spontaneous baroreceptor reflex (BRR) control machinery, which is responsible for beat-to-beat regulation of resting systemic arterial pressure (SAP). In adult male Sprague-Dawley rats anesthetized and maintained with pentobarbital sodium, microinjection bilaterally into the caudal NTS of a 15-mer antisense oligonucleotide that targets against the initiation codon of c-fos mRNA (5'-129 to 143-3') significantly enhanced the spontaneous BRR response, as determined by transfer function analysis of SAP and heart rate signals. The same treatment also diminished baseline Fos-like immunoreactivity in the absence of acute cardiovascular perturbation. Control treatments with artificial cerebrospinal fluid, sense cDNA, or antisense oligonucleotides that either target against a different site of the c-fos mRNA (5'-135 to 149-3') or with three mismatched nucleotides in the antisense sequence, were ineffective. These observations support the notion that, under minimal cardiovascular perturbation, basal expression of Fos protein in the NTS may represent an early step in the cascade of intracellular events that leads to long-term inhibitory modulation of beat-to-beat baroreflex control of blood pressure.

Interchangeable discharge patterns of neurons in caudal nucleus tractus solitarii in rat slices: role of GABA and NMDA

1. We characterized in rat brain slices the discharge patterns of spontaneously active neurons in the caudal region of the nucleus tractus solitarii (cNTS) and the neuromodulatory role of GABA and glutamate, via GABAA and NMDA receptors. 2. Spontaneous action potentials recorded intracellularly from cNTS neurons manifested either a regular or an irregular discharge pattern, alongside characteristic waveforms of the action potentials. These discharge patterns were interchangeable, and were highly sensitive to fluctuations in membrane potentials. In addition, the repolarizing rate of the after-hyperpolarization (AHP) in cNTS neurons that exhibited a regular discharge pattern was significantly higher than that of neurons that displayed irregular discharges. 3. cNTS neurons that manifested a regular discharge pattern were converted to irregular discharges upon superfusion with GABA (200 microM). This was accompanied by a reduction in the repolarizing rate of the AHP of both spontaneous and evoked action potentials. Conversion of discharge patterns in the opposite direction was elicited by superfusion with NMDA (6.8 microM). 4. The irregular discharges of spontaneous or evoked cNTS neurons were converted to a regular discharge pattern by bicuculline (200 microM). Subsequent application of D(-)-2-amino-5-phosphonopentanoic acid (250 microM) essentially led the neuronal discharges to revert to an irregular pattern. 5. Our results support the presence of two interchangeable modes of electrophysiological manifestations from the same cNTS neuronal population. They also showed that GABA and glutamate, via GABAA and NMDA receptors, may provide a novel form of neuromodulation at the cNTS by switching the patterns of neuronal discharges.

Diminished vasomotor component of systemic arterial pressure signals and baroreflex in brain death

We compared the cardiovascular autonomic regulatory mechanisms between patients with brain death or under a persistent vegetative state and healthy volunteers, based on auto- and cross-spectral analysis of systolic blood pressure (SBP) and interpulse interval (PPI) signals. Brain-dead patients exhibited a significant reduction in the absolute and relative power of the low-frequency (LF; 0.04-0.15 Hz) component in both SBP and PPI spectra, along with appreciable decrease in the very low frequency (VLF; 0.004-0.04 Hz), LF, and high-frequency (HF; 0.15-0.4 Hz) power of the PPI signals. Patients in a persistent vegetative state exhibited a power of the VLF and LF component in the SBP spectrum that was comparable to that in healthy subjects, although a discernible reduction in the VLF, LF, and HF power of the PPI spectrum was manifested by the former group. Assessments with the magnitude of SBP-PPI transfer function and linear regression analysis of beat-to-beat fluctuations in SBP and PPI revealed a progressive decline in spontaneous baroreflex sensitivity from healthy subjects to patients in a persistent vegetative state or with brain death. We conclude that the vasomotor component of systemic arterial pressure signals and spontaneous baroreflex are highly correlated with the functional integrity of the brain stem.

Relationship between mesial temporal seizure focus and elevated serum prolactin in temporal lobe epilepsy

We evaluated the relationship between mesial temporal seizure focus and serum prolactin (PRL) in patients before and after they underwent anterior temporal lobectomy (ATL) for medically intractable temporal lobe epilepsy (TLE). These patients had a confirmed unilateral epileptogenic focus in mesial temporal structures, a postictal rise in serum PRL 15 to 20 minutes after onset of complex partial seizures, and were refractory for more than 2 years to antiepileptic drugs. Presurgical interictal serum PRL levels were significantly elevated (16.47 +/- 0.85 ng/mL, n = 62) and declined after ATL to normal values (patients, 9.63 +/- 0.55 ng/mL, n = 54; normal subjects, 8.99 +/- 0.57 ng/mL, n = 52). Serial evaluations indicated that normalization was seen 3 months after surgery (9.42 +/- 1.22 ng/mL, n = 9). The postsurgical reduction in serum PRL was similar in men and women, in patients with epileptogenic focus on either side of mesial temporal structures, and was unaffected by antiepileptic medication. We conclude that PRL is elevated following seizures and that a seizure focus in mesial temporal structures may exert a sustained excitatory influence on PRL release in patients with medically intractable TLE.

Prognostic significance of proliferating cell nuclear antigen expression in transitional cell carcinoma of the upper urinary tract

BACKGROUND

Haphazard cell proliferation is a fundamental biologic defect in cancer. Thus, assessment of the growth fraction provides a valuable index of biological property for human neoplasm. Proliferating cell nuclear antigen (PCNA) expression has been used to estimate the growth fraction of human cancer, and its prognostic value. Information in transitional cell carcinoma (TCC) of the upper urinary tract, however, is very few.

MATERIALS AND METHODS

A total of 73 patients with TCC of the upper urinary tract was collected between July 1988 and December 1995 for this study. The labeling index of PCNA immunostaining was correlated with clinicopathologic factors and compared for its prognostic value with a median follow-up of 54 months.

RESULTS

The PCNA index was positively associated with histological grading, tumor stage and patient prognosis (P = 0.00, respectively). Multivariate analysis demonstrated that significant factors in relation to patient survival were tumor stage (P = 0.01), followed by PCNA index (P = 0.04) and gender of patients (P = 0.04). Multiple comparison revealed that PCNA index set at 0.30 had prognostic value in terms of patient survival (P = 0.00), and the risk of metachronous bladder recurrence (P = 0.02).

CONCLUSION

Our data suggested that assessment of PCNA index may be used as an adjuvant prognostic factor for patients with TCC of the upper urinary tract.

Participation of paraventricular nucleus of hypothalamus in central regulation of penile erection in the rat

PURPOSE

To investigate the possible participation of the paraventricular nucleus of hypothalamus in central regulation of penile erection.

MATERIALS AND METHODS

Male adult Sprague-Dawley rats were anesthetized and maintained with pentobarbital sodium. The intracavernous pressure (ICP) was used as an experimental index for penile erection, and was recorded alongside systemic arterial pressure and heart rate. The effect on ICP of electrical (30-s train of 30-120 microA, 40-160 Hz, 1-ms rectangular pulses) or chemical (L-glutamate, 0.5 nmol/50 nl.) activation of the paraventricular nucleus of hypothalamus (PVN) or hippocampal formation was evaluated.

RESULTS

Electrical activation of the PVN elicited both multiple and single episodes of elevation in ICP, along with visible erection and ejaculation. The former pattern exhibited an increase in ICP that was more sustained, with higher peak amplitude and longer latency. Chemical stimulation of neuronal perikarya in the PVN also resulted in similar patterns of rise in ICP and visible erection. These effects were, nonetheless, not accompanied by significant alterations in systemic arterial pressure and heart rate. Activation of the hippocampal formation, as we reported previously, similarly elicited multiple and single episodes of increase in ICP. These erectile responses, however, were substantially reduced or eliminated upon electrolytic lesion of the ipsilateral PVN.

CONCLUSION

These observations suggest that the PVN may be an important nucleus that participates in central neural regulation of penile erection in the rat. Furthermore, an efferent pathway(s) from the hippocampal formation to PVN may constitute part of the neural circuitry in the forebrain in the regulation of erectile functions.

Implications of serum basic fibroblast growth factor levels in chronic liver diseases and hepatocellular carcinoma

Angiogenesis occurs in response to tissue damage, and is of vital importance for tumor growth and metastasis. Basic fibroblast growth factor (bFGF), a well-known angiogenic factor, has been suggested to be a useful diagnostic marker in certain hypervascular tumors. However, the relevance of its detection has not been well evaluated in patients with hepatocellular carcinoma (HCC) and benign chronic liver diseases. In the current study, immunoassay of bFGF was performed on serum samples from 39 patients with HCC, 21 with liver cirrhosis, 22 with chronic hepatitis and 40 normal subjects. The serum bFGF level was significantly increased in patients with liver cirrhosis and HCC when compared with those with chronic hepatitis or normal subjects (all p-values < 0.001). However, no difference was observed between the groups with liver cirrhosis and HCC (p > 0.05). If we set 9.6 pg/ml (mean + 3 standard deviations of bFGF in the control group) as the upper limit of normal serum level of bFGF, elevated bFGF concentrations were noted in 9.1%, 42.9% and 51.3% of patients with chronic hepatitis, liver cirrhosis and HCC respectively. In non-cancer patients, the coexistence of acute illness (p = 0.000) was an independent factor related to the elevation of serum bFGF. On the other hand, a multivariate analysis demonstrated that both advanced stage of cancer (p = 0.026) and coexistence of acute illness (p = 0.000) influence the serum level of bFGF in patients with HCC. We conclude that serum bFGF levels are significantly higher in patients with HCC and are positively correlated with advanced tumor stage. Nevertheless, elevation of serum bFGF may also be observed in a significant number of patients with liver cirrhosis. Therefore, measurement of serum bFGF alone cannot be satisfactory as a tumor marker for diagnosis of HCC. In addition, it is important to point out that coexistence of acute illness may be a crucial confounding factor in the diagnosis or monitoring of any cancer by the estimation of serum bFGF.

Expression patterns of erbB receptor family in normal urothelium and transitional cell carcinoma. An immunohistochemical study

The class I tyrosine kinase growth-factor receptors include epidermal growth factor receptor (EGFR), ErbB2 (c-erbB-2, HER-2/neu), ErbB3 and ErbB4. To elucidate their role in the regulation of homeostasis and carcinogenesis, we examined the expression of the receptors in normal urothelium and in urothelial carcinoma by immunohistochemistry. EGFR was expressed in the basal cells of normal urothelium, while ErbB2, ErbB3 and ErbB4 were present mainly in the superficial layer. A distinct reciprocal distribution was observed between the EGFR and the remaining members of the subclass (P = 0.0001). Both BCL-2 protein and Ki-67 antigen (MIB-1) showed a strong positive association with EGFR (P = 0.002) and an inverse correlation with ErbB2, ErbB3 or ErbB4 (P = 0.0004, 0.0000, and 0.001, respectively). With regard to carcinoma, there was no important relationship between receptor overexpression and tumour grading (P > 0.1), while only EGFR overexpression was correlated with muscular invasion (P = 0.02). Coexpression of EGFR-ErbB3 and ErbB3-ErbB4 was more often detected in high-grade tumours and correlated with the extent of tumour invasion. Our data indicate that class I receptors are differentially expressed in normal urothelium in vivo, but an orchestrated expression pattern does not exist during tumorigenesis.

Expression of vascular endothelial growth factor in normal liver and hepatocellular carcinoma: an immunohistochemical study

Angiogenesis is of vital importance during the development and progression of solid tumors. To examine the role of vascular endothelial growth factor (VEGF) in hepatocarcinogenesis, we evaluated the expression of peptide in normal human liver (n = 6) and in 36 cases of hepatocellular carcinoma (HCC). Immunoreactivity for VEGF was present in the extracellular matrix of the portal tracts in the normal and nontumor part of liver, but not in hepatocytes and bile duct epithelium. For HCC, variable amounts of VEGF were expressed in 13 cases (36.1%) of tumor cells. Using a logistic regression model, expression of VEGF was significantly associated with a higher proliferative index (P = .01) and sonographic portal vein thrombosis (P = .05). However, VEGF expression did not correlate with a biochemical liver profile, alpha-fetoprotein levels, histological grading, gender, or clinical stage of cirrhosis (P > 0.1, respectively). Log-rank test showed that evaluation of VEGF did not provide more prognostic information (P > .5) than that from tumor volume and portal vein thrombosis (P < .01, respectively). In addition, VEGF was always present in the fibrovascular stroma or pericellular matrix of HCC, although no strong relationship was observed with the expression of VEGF in tumor cells (P > .5). Our data suggested that expression of VEGF may characterize a progression toward higher proliferation in hepatocarcinogenesis in vivo. The relevance of VEGF existing in the extracellular matrix of the normal liver and HCC remains to be clarified.

Involvement of AT2 receptors at NRVL in tonic baroreflex suppression by endogenous angiotensins

We evaluated the role of endogenous angiotensin II and III (ANG II and ANG III) at the rostral nucleus reticularis ventrolateralis (NRVL) in the modulation of baroreceptor reflex (BRR) response and the subtype of angiotensin receptors involved in this process. Adult male Sprague-Dawley rats anesthetized and maintained with pentobarbital sodium were used. Exogenous application of ANG II or ANG III (10, 20, or 40 pmol) by bilateral microinjection into the NRVL significantly suppressed the BRR response to transient hypertension induced by phenylephrine (5 micrograms/kg i.v.). The suppressive effect of ANG II (20 pmol) was reversed by an equimolar dose (1.6 nmol) of its peptide antagonist, [Sar1, Ile8]ANG II, and the nonpeptide antagonists for AT1 and AT2 receptors, losartan and PD-123319, respectively. On the other hand, the inhibitory action of ANG III (20 pmol) was blunted by its peptide antagonist. [Ile7]ANG III or PD-123319, but not by losartan. Blocking the endogenous activity of the angiotensins by microinjection into the bilateral NRVL of [Sar1, Ile8]ANG II, [Ile7]ANG III, or PD-123319 elicited an appreciable enhancement of the BRR response, whereas losartan produced minimal effect. These results suggest that, under physiological conditions, both endogenous ANG II and ANG III may exert a tonic inhibitory modulation on the BRR response by acting selectively on the AT2 receptors at the NRVL.