Expression of NGFI-B mRNA in a rat focal cerebral ischemia-reperfusion model

Cerebral ischemia is known to induce the expression of several immediate early genes (IEGs), including c-fos and c-jun, which subsequently regulate a number of late effector genes. In this study, we examined the expression of NGFI-B (or nur 77) mRNA in a rat focal cerebral ischemia-reperfusion model. NGFI-B is a member of the IEGs which encodes for a nuclear receptor and is rapidly induced by nerve growth factor (NGF). Northern blot analysis showed a rapid but transient enhancement of NGFI-B mRNA, a peak level for which was observed at 30 min of reperfusion following 60 min ischemic insult. At the peak level, quantitative analysis of the blot indicated a 12-fold and 4-fold increase of NGFI-B mRNA in the ischemic cortex and ipsilateral hippocampus, respectively, as compared to the sham-operated control. No apparent changes in mRNA levels were observed within contralateral sites of the cortex. Results from in situ hybridization showed that severe ischemia (60 min) resulted in a marked increase of NGFI-B mRNA throughout the entire ischemic cerebral cortex. The increase was particularly notable in the frontal, occipital, perirhinal and piriform cortical regions and in the dentate gyrus and CAI-3 regions of the ipsilateral hippocampus. A marked induction was also noted in the ipsilateral caudate putamen. Unlike the induction profile of NGFI-B mRNA, severe ischemia resulted in bilateral increases of its family gene, NGFI-A mRNA. The spatial induction profile is similar to that of NGFI-B mRNA in both hemispheres, except within the region of the contralateral dentate gyrus which showed low levels of NGFI-A mRNA. The expression pattern of NGF and BDNF mRNA, upstream genes of NGFI-B, were also examined. Interestingly the temporal and spatial expression patterns of BDNF mRNA were very similar to that of NGFI-A mRNA under the same conditions, whereas increased NGF and NGFI-B mRNA were observed only in the ipsilateral hemisphere. It is likely that multiple and/or overlapping pathways are activated subsequent to ischemic challenge which in turn are crucial for cel survival and/or functional recovery following focal cerebral ischemia.

Partially hyperfractionated accelerated radiotherapy and concurrent chemotherapy for advanced nasopharyngeal carcinoma

PURPOSE

A newly designed concomitant chemoradiotherapy was undertaken to assess the feasibility and efficacy for advanced nasopharyngeal carcinoma (NPC).

METHODS AND MATERIALS

Sixty-three patients with biopsy-proven NPC were entered in this Phase II trial from March 1992 to November 1993. Most patients present with Stage IV disease (93.4%) and poorly differentiated epidermoid carcinoma or undifferentiated carcinoma were the major pathologic type. Radiotherapy was delivered using a telecobalt unit and 10 MV x-rays and by altered fractionation (72-74 Gy/45 fractions/6 weeks). Chemotherapy with cisplatin 75 mg/m2, 2 h infusion at day 1, followed by 5-FU 400 mg/m2/day, continously infused for 4 days was given concurrently during the first and fifth weeks of radiotherapy.

RESULTS

The major toxicity was mucositis (61% belong to Grade 3, 31% to Grade 2). Weight loss, leucopenia, and skin reaction were frequently encountered. Three patients withdrew from treatment at 15, 25, and 55.5 Gy, three patients interrupted the radiotherapy for 1-4.5 weeks, and two patients refused the second cycle of concomitant chemotherapy due to toxicities. The initial tumor response showed 100% overall response rate, with 90.5% complete response. After a median follow-up time of 38 months, five patients failed at the primary and/or neck (four recurrent and one persistent), and 14 patients developed distant metastases alone. The 3-year primary disease-free, regional disease-free, distant disease-free, and overall survival rates are 89.1, 92.8, 74.3, and 73.6%, respectively. The late complication rate is acceptable so far.

CONCLUSIONS

Our data indicates that concurrent chemoradiotherapy for advanced NPC is both feasible and effective, with acceptable toxicities. Distant metastases are the major site of treatment failure. Postradiation adjuvant chemotherapy to eradicate subclinical distant metastasis should be further studied.

Preliminary report of outpatient weekly adjuvant chemotherapy for high-risk nasopharyngeal carcinoma

Distant metastasis has become the most frequent failure site-more so than locoregional relapse-after adequate radiotherapy in nasopharyngeal carcinoma (NPC). A prospective study was initiated to test the role of postradiation adjuvant chemotherapy using a weekly schedule for selected patients with high-risk NPC (N3, T4N2b-2c, and N2b-2c, with one of nodal size > 4 cm, or residual disease after radiotherapy). Through July 1993 to August 1994, a total of 20 patients were entered into the study: 16 men and four women, with a median age of 49 years and age range of 27-75 years. Pathology showed WHO type I:II:III = 2:13:5. Previous treatment consisted of concurrent chemoradiotherapy (16 patients), radiotherapy alone (two), and neoadjuvant chemotherapy followed by radiotherapy (two). Postradiation adjuvant chemotherapy was usually started 2 months after radiotherapy, using a weekly FP schedule (5-fluorouracil 1,250 mg/m2 + cisplatin 25 mg/m2, mixed in 100 ml saline, 24 h continuous i.v. infusion) for 18 weeks. The treatment of five patients was at 5, 6, 10, 14, and 15 weeks because of leukopenia-induced mortality, sudden death unrelated to adjuvant chemotherapy, a patient's refusal, and distant metastasis (the last two cases) during adjuvant chemotherapy. The major toxicity was leukopenia (grade I, 20%; grade II, 45%; grade III, 15%; and grade IV, 10%). Ten patients (50%) developed distant metastasis after a median follow-up time of 20 months. Our preliminary data indicate that postradiation adjuvant chemotherapy with a weekly FP regimen at our dosage is not recommended for high-risk NPC.

Damage, repair, and mutagenesis in nuclear genes after mouse forebrain ischemia-reperfusion

To determine whether oxidative stress after cerebral ischemia-reperfusion affects genetic stability in the brain, we studied mutagenesis after forebrain ischemia-reperfusion in Big Blue transgenic mice (male C57BL/6 strain) containing a reporter lacI gene, which allows detection of mutation frequency. The frequency of mutation in this reporter lacI gene increased from 1.5 to 7.7 (per 100,000) in cortical DNA after 30 min of forebrain ischemia and 8 hr of reperfusion and remained elevated at 24 hr reperfusion. Eight DNA lesions that are characteristic of DNA damage mediated by free radicals were detected. Four mutagenic lesions (2,6-diamino-4-hydroxy-5-formamidopyrimidine, 8-hydroxyadenine, 5-hydroxycytosine, and 8-hydroxyguanine) examined by gas chromatography/mass spectrometry and one corresponding 8-hydroxy-2'-deoxyguanosine by a method of HPLC with electrochemical detection increased in cortical DNA two- to fourfold (p < 0.05) during 10-20 min of reperfusion. The damage to gamma-actin and DNA polymerase-beta genes was detected within 20 min of reperfusion based on the presence of formamidopyrimidine DNA N-glycosylase-sensitive sites. These genes became resistant to the glycosylase within 4-6 hr of reperfusion, suggesting a reduction in DNA damage and presence of DNA repair in nuclear genes. These results suggest that nuclear genes could be targets of free radicals.

Immediate early gene expression in response to cerebral ischemia. Friend or foe?

BACKGROUND

Cerebral ischemia is a potent modulator of gene expression. Immediate early genes undergo rapid induction after both global and focal cerebral ischemia. Many immediate early genes code for transcription factors. Additional genes, including those encoding for neurotrophic factors and neurotransmitter systems, are induced in a delayed fashion after cerebral ischemia. The functional significance of early and late gene regulation after cerebral ischemia requires further investigation. These changes may be beneficial (friend) or detrimental (foe). Many of the genes are likely neuroprotective and important for recovery, but others may be involved in ischemic cell death mediated by apoptosis.

SUMMARY OF REVIEW

We review evidence that supports the hypothesis that cell death after cerebral ischemia occurs through the dual pathways of ischemic necrosis and apoptosis.

CONCLUSIONS

Gene regulation, including immediate early genes, is required for programmed neuronal death after trophic factor deprivation and is predicted to be involved in apoptosis triggered by cerebral ischemia. Novel therapies following cerebral ischemia may be directed at genes mediating either recovery or apoptosis.

Poly-phosphoinositide-mediated messengers in focal cerebral ischemia and reperfusion

The receptor-mediated poly-phosphoinositide (PI) signalling pathway is known to play an important role in maintaining intracellular calcium homeostasis, which in turn, is critical for mediating neuronal function. In this study, we examined the effects of focal cerebral ischemia induced in rats by temporary occlusion of the middle cerebral artery (MCA) and both common carotid arteries (CCAs) on this signal transduction pathway. Results indicate that several parts of the pathway are altered, both during the early phase of focal cerebral ischemic insult and after recirculation. Cerebral ischemia induced a decrease in levels of phosphatidylinositol 4,5-bisphosphate (PIP2) in the ischemic MCA cortex, due partly to stimulated poly-PI hydrolysis and partly to the depletion of ATP required for resynthesis of this substrate. ATP depletion during ischemia was also attributed to a sustained decrease in inositol 1,4,5-trisphosphate (IP3) levels. On the other hand, the decline in IP3 3-kinase activity after 30 min of ischemic insult was not related to ATP depletion. During reperfusion upon prolonged ischemic insult, neither IP3 level nor IP3 3-kinase activity were able to show recovery after reperfusion, despite that ATP levels recovered by 80%. In situ hybridization studies indicated a decrease in mRNA expression of IP3 receptor but not IP3 3-kinase during the initial 4 h of reperfusion after a 45 min ischemic insult. Under this same condition, insulted cortical neurons started to show morphological changes between 4 and 8 h after reperfusion and extensive cell death could be observed by 16 h. Taken together, these results demonstrated early and delayed changes in the poly-PI signalling pathway due to focal cerebral ischemia. These effects are likely to cause impairment in neuronal function and underline the process of cerebral ischemic damage.

Acute diffuse phlegmonous esophagogastritis: report of a survived case

A 42-year-old man was admitted because of a persistent pain on swallowing together with epigastralgia, chest pain, fever, and shortness of breath for 5 days. An unbearable shortness of breath with a retrosternal pain was noted each time he tried to lie down. The patient also developed bilateral pleural effusion and pericardial effusion. Ten days after admission, he underwent an emergency laparotomy after an acute episode of severe epigastralgia with hematemesis and rebound tenderness limited to the epigastrium. Operative findings showed diffuse phlegmonous esophagogastritis. A near-total esophagectomy and a total gastrectomy were done. He lost 15 kilograms of body weight and was discharged 3 months later. The patient underwent reconstructive surgery 2 months after discharge, recovered well and regained his weight within one year.

Automated measurement of infarct size with scanned images of triphenyltetrazolium chloride-stained rat brains

BACKGROUND AND PURPOSE

The extent of brain infarction after local cerebral ischemia is frequently assessed with the mitochondrial activity indicator 2,3,5-triphenyltetrazolium chloride (TTC). We describe an automated procedure for analysis of infarct size in TTC-stained rat brains.

METHODS

Rats were subjected to middle cerebral artery occlusion and killed after 24 to 36 hours, and their brains were processed for TTC staining. Digital images of coronal sections from these brains (n > 50) were acquired with a desktop color scanner. The resulting images were divided into red, blue, and green component images. Total brain and infarct areas were automatically determined on the basis of total pixel intensity and area after segmentation of the red and green images, respectively. Automated measurements were compared with those made with a video camera-based image acquisition system that required manual tracing of lesion boundaries.

RESULTS

The spatial resolution of scanned brain images (approximately equal to 200 microns) was comparable to that of the camera-based system and provided sufficient detail to recognize infarct boundaries and neuroanatomical features. Scanner-based acquisition and analysis were faster than with the camera-based method. The green component image accurately distinguished infarcted from normal brain, and the red component image represented total brain dimensions. Infarct measurements obtained by the automated method correlated closely with those from conventional apparatus (R2 = .89, P < .001). Intraobserver reliability with the automated method (R2 = 1.00) was higher than with the conventional method (R2 = .77).

CONCLUSIONS

Infarct size after middle cerebral artery occlusion in the rat can be rapidly and reproducibly assessed with inexpensive scanning equipment and automated image analysis of TTC-stained brains.

MASCIS evaluation of open field locomotor scores: effects of experience and teamwork on reliability. Multicenter Animal Spinal Cord Injury Study

The Multicenter Animal Spinal Cord Injury Study (MASCIS) adopted a modified 21-point open field locomotor scale developed by Basso, Beattie, and Bresnahan (BBB) at Ohio State University (OSU) to measure motor recovery in spinal-injured rats. BBB scores categorize combinations of rat hindlimb movements, trunk position and stability, stepping, coordination, paw placement, toe clearance, and tail position, representing sequential recovery stages that rats attain after spinal cord injury. A total of 22 observers from 8 participating centers assessed 18 hindlimbs of 9 rats at 2-6 weeks after graded spinal cord injury. The observers were segregated into 10 teams. The teams were grouped into 3 cohorts (A, B, and C), consisting of one experienced team from OSU and two non-OSU teams. The cohorts evaluated the rats in three concurrent and sequential sessions. After viewing a rat for 4 min, individual observers first assigned scores without discussion. Members of each team then discussed and assigned a team score. Experience (OSU vs. non-OSU) and teamwork (individual vs. team) had no significant effect on mean scores although the mean scores of one cohort differed significantly from the others (p = 0.0002, ANOVA). However, experience and teamwork significantly influenced reliability of scoring. OSU team scores had a mean standard deviation or discordance of 0.59 points, significantly less than 1.31 points for non-OSU team scores (p = 0.003, ANOVA) and 1.30 points for non-OSU individual scores (p = 0.001, ANOVA). Discordances were greater at the upper and lower ends of the scale, exceeding 2.0 in the lower (< 5) and upper (> 15) ends of the scale but were < 1.0 for scores between 4 and 16. Comparisons of non-OSU and OSU team scores indicated a high reliability coefficient of 0.892 and a correlation index (r2) of 0.894. These results indicate that inexperienced observers can learn quickly to assign consistent BBB scores that approach those given by experienced teams, that the scores are most consistent between 4 and 16, and that experience improves consistency of team scores.

Responses to primary and a booster dose of acellular, component, and whole-cell pertussis vaccines initiated at 2 months of age

A second generation acellular pertussis vaccine (component pertussis vaccine) containing purified pertussis toxin (PT) and filamentous hemagglutinin (FHA) was tested for its immunogenicity and safety in 2-month-old infants in comparison with first-generation acellular and whole-cell pertussis vaccines. At the ages of 2, 4, 6, and 18 months, respectively, 350 subjects were inoculated one dose of pertussis vaccine, which was combined with diphtheria and tetanus toxoids. Both acellular and component vaccines elicited significantly much fewer local and systemic reactions than whole-cell vaccine did. Besides, although not reaching statistical significance, the component vaccine was less reactogenic than the acellular vaccine. After each dose of the primary immunization, antibodies against PT and FHA were much higher in acellular and component pertussis vaccinees than in whole-cell vaccinees. However, at 18 months of age, just before the booster dose, both anti-PT and anti-FHA declined very close to, or even lower than, the prevaccination levels in all three groups and then responded rapidly to a booster dose to attain high levels. The booster responses were also significantly higher (P < 0.01) in acellular and component groups than in whole-cell group. Component and acellular vaccines induced similar levels of anti-FHA but the former induced higher anti-PT than the latter (P < 0.01). Our results indicate that both in primary immunization and as a booster, acellular and component pertussis vaccines are much more immunogenic for PT and FHA and much less reactogenic than whole-cell vaccine. However, the persistence of anti-PT and anti-FHA was not as good as one can expect from other protein antigens without giving a booster dose. A long-term follow-up of the vaccinees has been underway to understand the persistence of these antibodies after the first booster.

Gonadal transformation in male Rana catesbeiana tadpoles intraperitoneally implanted with estradiol capsules

Tadpoles of Rana catesbeiana at TK stages X-XII, about 9 months old, were laparotomized, and the males were implanted intraperitoneally with silastic tubes containing estradiol (E2) for various periods. Male tadpoles implanted with empty tubes served as the controls. Histology, secretions of E2, and testosterone (T) in the gonads were investigated. A rough estimate of estradiol released from silastic tubes suggested that about 90 micrograms per tadpole in 6 months. Histological observation revealed various degrees of transformation from testes toward ovaries in E2-treated testes. Ten in thirteen (77%), the testes were transformed into ovaries 6 months after the treatment. The testes of the controls, however, displayed normal histology. Radioimmunoassay showed that E2 level was increased while T level was decreased in E2-treated testes. These results indicate that a low dose of exogenous E2 may induce transformation of the testes into ovaries.

Malignant soft tissue sarcoma of the hypopharynx successfully treated by radiotherapy alone

Sarcoma of the hypopharynx has been reported very rarely in the literature, only six cases having been found among all head and neck malignancies reported to SEER (Surveillance, Epidemiology, and End Results) during 1973-1987. We report a 14-year-old boy with a huge malignant soft tissue sarcoma arising from the hypopharynx. Tracheostomy and feeding gastrostomy were performed as emergency life-saving procedures. Surgical resection had been attempted, but abandoned. Because of the rapidity of tumor growth, we gave the patient a course of accelerated radiotherapy (170 cGy/fraction, two fractions per day) with a total dose of 7140 cGy within one month. A series of endoscopy and imaging studies demonstrated complete regression of the tumor, and the patient is currently alive without evidence of disease 3.5 years after treatment. We conclude that for an unresectable tumor without distant metastasis, radiation therapy may be tried. The time, dose, and fractionation of radiotherapy should be carefully designed and individualized.

Detection of human T lymphotropic virus type I proviral DNA in patients with diffuse panbronchiolitis

In Japan a number of reported cases of diffuse panbronchiolitis (DPB) have been associated with human T lymphotropic virus type I (HTLV-I) infection. In this study the hypothesis that HTLV-I proviral DNA may be prevalent in DPB was examined using polymerase chain reaction (PCR) for the region of env or the two-step PCR for the pX region of this virus. The presence of HTLV-I proviral DNA was studied in the peripheral blood mononuclear cells (PBMC) obtained from 10 patients with DPB. The presence of proviral DNA in PBMC in 12 patients with chronic obstructive pulmonary disease (COPD), eight patients with idiopathic interstitial pneumonia (IIP), four patients disease were also studied as relevant controls. The lung tissue obtained from 11 patients with DPB, 12 patients with diffuse aspiration bronchiolitis (DAB) at autopsy, and the surgical lung samples obtained from 12 patients with bronchogenic cancer were also studied. Peripheral blood mononuclear cells obtained from one DPB patient and one bronchogenic carcinoma patient were positive for the HTLV-I pX region. The presence of the pX region was also found in the lung tissue of three DPB patients (27.3%) and one DAB patient (8.3%). None of other subjects were positive for HTLV-I proviral DNA, In conclusion, HTLV-I is not the causative virus in the pathogenesis of COPD, IIP, bronchiectasis and bronchogenic carcinoma. There is a likelihood that HTLV-I infection is associated with some cases of DPB; however this association needs further verification.

The role of zinc in selective neuronal death after transient global cerebral ischemia

Zinc is present in presynaptic nerve terminals throughout the mammalian central nervous system and likely serves as an endogenous signaling substance. However, excessive exposure to extracellular zinc can damage central neurons. After transient forebrain ischemia in rats, chelatable zinc accumulated specifically in degenerating neurons in the hippocampal hilus and CA1, as well as in the cerebral cortex, thalamus, striatum, and amygdala. This accumulation preceded neurodegeneration, which could be prevented by the intraventricular injection of a zinc chelating agent. The toxic influx of zinc may be a key mechanism underlying selective neuronal death after transient global ischemic insults.

Adenosquamous carcinoma and schneiderian papilloma-like lesion in a mature cystic teratoma of the ovary: a case report

Malignant transformation is uncommon in the mature cystic teratoma of ovary, in which adenosquamous carcinoma is even rarer. It seldom combines with papillary lesion, like schneiderian papilloma of upper airway. We report such a rare case of mature cystic teratoma undergoing malignant change, with the pictures of both adenosquamous carcinoma and schneiderian papilloma.

High-resolution computed tomography in pulmonary lymphangio(leio)myomatosis and pulmonary tuberous sclerosis

We report two cases where high-resolution computed tomography (HRCT) assisted in the diagnosis of a patient with lymphangioleiomyomatosis and a patient with pulmonary tuberous sclerosis. HRCT was used in both cases where the chest radiographs and conventional computed tomographic scans appeared relatively normal but the conditions were strongly suspected.

Additive neuroprotective effects of dextrorphan and cycloheximide in rats subjected to transient focal cerebral ischemia

Previous studies have implicated both excitotoxicity and apoptosis in the pathogenesis of cerebral infarction induced by focal ischemic insults. Here we tested the possibility that the NMDA antagonist, dextrorphan, and the protein synthesis inhibitor, cycloheximide, would produce additive protective effects in a rodent model of focal ischemia-reperfusion. Transient focal cerebral ischemia was induced by a 90 min period of ligation of the right middle cerebral artery and both common carotid arteries. Administration of either 30 mg/kg dextrorphan or 0.5 mg/kg cycloheximide, given i.p. 15 min before ischemia, reduced infarct volume by about 65%. When optimal concentrations of each drug were given together, infarct volume was reduced by 87% as measured 14 days later. These observations support the idea that both excitotoxicity, and apoptosis dependent on new protein synthesis, contribute to cerebral infarction after transient focal ischemia in the rat.

Dextrorphan reduces infarct volume, vascular injury, and brain edema after ischemic brain injury

Focal cerebral ischemia confined to the cerebral cortex in the right middle cerebral artery (MCA) territory was induced by temporary ligation of the MCA and both common carotid arteries (CCAs). Reperfusion was initiated by releasing all three arterial occlusions after 90 min of ischemia. Infarct volume was morphometrically measured after triphenyltetrazolium chloride staining 24 h postischemia. Blood-brain barrier breakdown was assessed 4 h postischemia by measuring vascular permeability to fluorescein isothiocyanate-conjugated dextran (FITC-D), a macromolecule tracer. Ischemic brain edema was measured based on percent water content, 24 h postischemia. Dextrorphan (DX) 20-10 mg/kg given ip 15 min before ischemia reduced infarct volume in a dose-dependent manner with an apparent U-shaped dose-response curve; best protection was observed at 30 mg/kg. Posttreatment at 30 min, but not 60 min, was still effective. DX (30 mg/kg, given 15 min before ischemia) also reduced the postischemic increase in vascular permeability and brain edema in the right MCA cortex. Results from this study support the idea that NMDA receptor activation contributes to blood-brain barrier breakdown and brain edema after ischemic insults

Very delayed infarction after mild focal cerebral ischemia: a role for apoptosis?

The temporal evolution of cerebral infarction was examined in rats subjected to transient occlusion of both common carotid arteries and the right middle cerebral artery. After severe (90-min) ischemia, substantial right-sided cortical infarction was evident within 6 h and fully developed after 1 day. After mild (30-min) ischemia, no cortical infarction was present after 1 day. However, infarction developed after 3 days; by 2 weeks, infarction volume was as large as that induced by 90-min ischemia. These data suggest that infarction after mild focal ischemia can develop in a surprisingly delayed fashion. Some evidence of neuronal apoptosis was present after severe ischemia, but only to a limited degree. However, 3 days after mild ischemia, neurons bordering the maturing infarction exhibited prominent TUNEL staining, and DNA prepared from the periinfarct area of ischemic cortex showed internucleosomal fragmentation. Furthermore, pretreatment with 1 mg/kg cycloheximide markedly reduced infarction volume 2 weeks after mild ischemia. These data raise the possibility that apoptosis, dependent on active protein synthesis, contributes to the delayed infarction observed in rats subjected to mild transient focal cerebral ischemia.

DNA damage and repair in central nervous system injury: National Institute of Neurological Disorders and Stroke Workshop Summary

BACKGROUND AND PURPOSE

DNA damage and repair are areas of research with important implications for stroke and cerebral trauma. DNA damage is present in central nervous system (CNS) injury, and defects in repair mechanisms are associated with neurodegenerative disease.

METHODS

A workshop, DNA Damage and Repair in CNS Injury, was organized by the National Institute of Neurological Disorders and Stroke in Bethesda, Md, on September 11, 1995. The objective of this workshop was to promote inquiry and to foster application of research in DNA damage and repair after stroke and trauma.

RESULTS

The participants discussed the connection between the fields of DNA damage and repair and stroke and trauma and identified gaps in knowledge to be filled to expand research of DNA damage and repair in CNS injury. Specific recommendations were made targeting research opportunities in the areas of DNA repair and damage in stroke and trauma.

CONCLUSIONS

Research in the science of DNA injury and repair will likely provide new and important information on mechanisms of cell damage and provide opportunities for the development of novel and effective therapies to reduce CNS injury in stroke and trauma.

Cephalosporin and carbacephem nephrotoxicity. Roles of tubular cell uptake and acylating potential

Three beta-lactams, desacetylcephaloglycin, ampicillin, and loracarbef, were studied to test a hypothesis derived from retrospective analysis of previously studied cephalosporins: that beta-lactam nephrotoxicity develops in approximate proportion to tubular cell antibiotic concentrations and lactam ring reactivities. Concentrations of each beta-lactam (and insulin) in rabbit renal cortex and serum were measured at the end of 0.5-hr infusions of 100 mg antibiotic/kg body weight and 0.5 to 0.67 hr later. Total cortical AUCs (total areas under the curve of concentration and time in renal cortex) and transported cortical AUCs (total minus insulin-space beta lactam) were calculated from these measurements. Reactivities, determined by the rate constants of lactam-ring opening at pH 10, were taken from the literature. Nephrotoxicity was quantified by grades of proximal tubular cell necrosis and by serum creatinine concentrations 2 days after infusion of 100-1500 mg/kg of the antibiotics. Desacetylcephaloglycin was slightly less nephrotoxic than cephaloglycin; the AUCs reactivities, and toxicities of these two cephalosporins fit the proposed model, particularly when allowance is made for hepatic and renal deacetylation of cephaloglycin. The very low AUCs, limited reactivity, and absence of nephrotoxicity of ampicillin also fit the model. Loracarbef had a transported AUC less than three times, and reactivity one-thirtieth, those of cefaclor, respectively. Although only at 1500 mg/kg, loracarbef was significantly more nephrotic than cefaclor. If the relativity of loracarbef with its targeted bacterial proteins, which is essentially the same as that of cefaclor, is considered instead of the base hydrolysis rate constant, than loracarbef also fits the model. By the same analysis, the comparatively high in vitro stability of other carbacephems, although pharmaceutically convenient, may not limit their nephrotoxicity.

Antiarrhythmic and electrophysiologic effects of intravenous ibutilide and sotalol in the canine sterile pericarditis model

INTRODUCTION

Atrial arrhythmias are a frequent clinical complication following open heart surgery. We compared the Class III agents d,l-so-talol and ibutilide fumarate in an intravenous cross-over study using the canine atrial sterile pericarditis model.

METHODS AND RESULTS

We studied pacing-induced sustained atrial flutter over a 7-day post-surgical period in conscious dogs, alternating analysis of ibutilide (1.0 to 30.0 micrograms/kg) and d,l-sotalol (0.1 to 3.0 mg/kg). Ibutilide significantly increased atrial flutter cycle length (AFL CL) 11 +/- 2 msec and atrial effective refractory period (AERP) 13 +/- 2 msec, and terminated atrial flutter in all cases (n = 12) following a mean dose of 6 +/- 2 micrograms/kg. Plasma concentrations of ibutilide were 53 +/- 13 ng/mL. Ventricular effective refractory period (VERP) was not significantly affected (4 +/- 2 msec). Following termination with ibutilide, atrial flutter could be reinitiated in 1 of 12 trials, and was nonsustained (40-sec duration). Sotalol significantly increased AFL CL 23 +/- 3 msec and terminated atrial flutter in 8 of 12 trials following a mean dose of 1.5 +/- 0.4 mg/kg. AERP and VERP were significantly increased 20 +/- 6 and 12 +/- 2 msec, respectively. The incidence of reinduced atrial flutter was 9 of 12 trials (P < or = 0.05 vs ibutilide) (7 nonsustained 57 +/- 7 sec duration, and 2 sustained). Sotalol failed to terminate atrial flutter in two dogs on days 1 and 5, despite increases in AFL CL (21 +/- 8 msec) and AERP (16 +/- 9 msec), whereas on day 3, ibutilide (20 +/- 7 micrograms/kg) terminated atrial flutter in those two dogs while increasing AFL CL and AERP 18 +/- 6 and 15 +/- 0 msec, respectively.

CONCLUSION

Both sotalol and ibutilide terminate atrial flutter in this model. Ibutilide converted atrial flutter in dogs in which sotalol was not successful. Following atrial flutter termination, ibutilide had a lower incidence of reinduced arrhythmias compared to sotalol. Ibutilide produced atrial antiarrhythmic effects while having no significant electrophysiologic effects on the ventricle.

Pharmacokinetics of ibutilide and its enantiomers in dogs

Ibutilide fumarate, a new drug for the treatment of cardiac arrhythmias, contains a stereogenic center bearing a secondary alcohol group. Several single dose and multiple dose studies of racemic ibutilide or its enantiomers were performed by the oral and intravenous routes in dogs. A chiral assay was used to examine racemization and the individual enantiomer pharmacokinetics. Following low oral or intravenous doses (approximately 0.3 mg/kg), the pharmacokinetics of the enantiomers were nearly identical, with no substantial chiral conversion. Both enantiomers exhibited high clearance rates, large volumes of distribution, and low oral bioavailability. As the dose increased, pharmacokinetic differences between the enantiomers were observed. The greatest differences (3-fold) were seen after oral administration at 4 mg/kg, indicating that first-pass metabolism of ibutilide was highly enantioselective at high doses. The clearances of the enantiomers differed by up to 34% at 5 mg/kg followed intravenous administration of the racemate. At high doses, other non-linear pharmacokinetic behavior was also apparent. The intravenous clearance of ibutilide declined from 5.3 L/h/kg at 0.3 mg/kg to 3.7 L/h/kg at a dose of 5 mg/kg. The absolute oral bioavailability of the racemate increased from 2% at 0.3 mg/kg to as much as 84% at 5 mg/kg.

Use of recombinant Epstein-Barr virus early antigen for detection of antibody in patients with nasopharyngeal carcinoma

BACKGROUND

Nasopharyngeal carcinoma (NPC) is one of the most common cancers in southern China and Taiwan. Serological studies revealed the close-relationship between NPC and Epstein-Barr virus (EBV). Elevated serum and saliva levels of anti-EBV antibodies are detected in patients with NPC. Therefore, Development Center for Biotechnology prepared the EBV-early antigen (EA-D) by recombinant DNA technique for screening the serum and throat washing samples from patients with head and neck cancers.

METHODS

The BMRF1 gene for EBV early antigen (EA-D) was placed into the plasmid pDB18, then transformed into an Escherichia coli strain containing the lambda cI857 temperature-sensitive repressor. Heat treatment of the transformant, at exponential growth phase, inactivated the cI protein and induced an over-expression of the EA-D protein. Next, the EA-D was purified by chromatography and characterized as a protein of molecular weight 47 kDa, by sodium dodecyl sulfate-polyacry lamide gel electrophoresis (SDS-PAGE) and Western blot analysis using monoclonal anti-EA antibody and sera from patients with nasopharyngeal carcinoma (NPC). Enzyme-linked immunosorbent assay (ELISA) with the purified EA-D antigen was used to screen 129 serum and throat washing (TW) samples from patients with head and neck tumors, 24 from patients with a nonmalignant disease and 44 from normal donors.

RESULTS

Experimental results indicated significantly higher positive rates of EA-D IgA (69%) and EA-D IgG (91%) in NPC sera than in the sera of patients with other head and neck tumors and normal controls. TW samples from patients with NPC also showed a higher positive rate (34%) than the other groups (7-20%).

CONCLUSIONS

Results in this study demonstrate that the bacterially expressed EA-D antigen could be recognized by sera from patients with NPC and monoclonal anti-EA antibody. Thus, it has potential use in ELISA for screening EBV-related diseases such as NPC.

Cytology of metastatic leiomyosarcoma. A case report

BACKGROUND

Metastasis of leiomyosarcoma is not uncommon. Determination of the primary site may be confused with the presenting symptoms and even the known pathology.

CASE

A 62-year-old man presented with chest pain, a productive cough and a lung mass on radiography. Fine needle aspiration of the tumor showed pleomorphic tumor cells. The patient began to have abdominal symptoms one year after presentation. Jejunal leiomyosarcoma was proven after an emergency exploratory laparotomy for mechanical ileus. Sputum cytology disclosed tumor cells one month before death. Necropsy of the lung mass demonstrated findings similar to those of the intestinal tumor microscopically.

CONCLUSION

Without laparotomy, our patient would have been diagnosed as having a primary pulmonary leiomyosarcoma by the presenting symptoms and known pathology.

Neuronal apoptosis: current understanding of molecular mechanisms and potential role in ischemic brain injury

Apoptosis is a rediscovered mechanism of cell death crucial in normal development. Recent exploration of the genetic mechanisms of apoptosis has broadened our insight into the regulation of cell death in development as well as disease states. We present an overview on current understanding of the genetic molecular events in apoptosis in all, or most cell types, with emphasis on events observed in a well-characterized model of neuronal death in vitro. The second part of this article reviews recent studies in in vivo stroke models on the mechanism of cell death relevant to apoptosis after cerebral ischemia. Further delineation of the mechanisms of cell death, especially those that trigger apoptosis, is likely to redirect our approaches in the development of new therapeutic interventions for ischemic stroke.

Inositol trisphosphate, polyphosphoinositide turnover, and high-energy metabolites in focal cerebral ischemia and reperfusion

BACKGROUND AND PURPOSE

Although the signaling pathway involving polyphosphoinositide (poly-PI) hydrolysis and release of inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] is an important mechanism for regulation of neuronal calcium homeostasis, the effect of cerebral ischemia-reperfusion on this calcium signaling pathway is not well understood. Because activity of this pathway is dependent on availability of ATP, this study is aimed at examining the poly-PI signaling pathway and high-energy metabolites in a rat stroke model.

METHODS

Focal cerebral ischemia in rats was induced by temporary occlusion of the right middle cerebral artery and both common carotid arteries. Levels of Ins(1,4,5)P3 were determined by use of the radioreceptor binding assay. Poly-PI turnover in rat cortex was assessed with an in vivo protocol involving intracerebral injection of [3H] inositol and systemic administration of lithium. High-energy metabolites (ATP, ADP, and AMP) were analyzed by high-performance liquid chromatography.

RESULTS

Ischemia induced an increase in poly-PI turnover in the right middle cerebral artery cortex, but reperfusion led to a decline in this signaling activity. However, Ins(1,4,5)P3 levels decreased during ischemia, and these levels were not restored if ischemic insults were longer than 30 minutes. ATP levels decreased to 26% of control during ischemia and recovered to 80% of control during the initial 4 hours of reperfusion; these changes were followed by a second phase of decline.

CONCLUSIONS

Results show an important relationship between ischemia-induced depletion of high-energy metabolites and poly-PI signaling activity. However, the uncoupling between Ins(1,4,5)P3 and ATP during reperfusion after severe ischemia suggests that metabolism of Ins(1,4,5)P3 is more stringently regulated than ATP.

Comparison of TI-201 and Tc-99m MIBI SPECT imaging in nasopharyngeal carcinoma

Both TI-201 and Tc-99m MIBI uptake in nasopharyngeal carcinoma (NPC) have been reported, yet no comparative study of these two agents using SPECT images has been undertaken for NPC. This study compares the relative effectiveness of TI-201 and Tc-99m MIBI SPECT for detecting NPC. In the patients with NPC, 26 of 32 (81%) showed TI-201 tumor uptake, whereas 24 of 32 (75%) showed Tc-99m MIBI tumor uptake. This preliminary study suggests that both Tc-99m MIBI and TI-201 SPECT imaging can be helpful in detecting NPC, and that sensitivity is slightly higher in TI-201 SPECT imaging.

Determination of intracellular calcium in vivo via fluorine-19 nuclear magnetic resonance spectroscopy

Fluorine-19-nuclear magnetic resonance (19F-NMR) spectroscopic detection of the NMR-active Ca2+ indicator 5-fluoro-1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (5F-BAPTA) is one method for measuring cytosolic free Ca2+ concentration ([Ca2+]i) and has been used previously to measure [Ca2+]i in isolated cells and perfused organs. The aim of the present investigation was to demonstrate the feasibility of determining [Ca2+]i in vivo and in situ using 19F-NMR and 5F-BAPTA. Experiments were performed on male Sprague-Dawley rats with a surface-coil antenna employed for NMR interrogation. The Ca2+ indicator, 5F-BAPTA, was infused either intravenously (kidney, spleen) or intraventricularly (brain) as a 100 mg/ml solution of the cell-permeant acetoxymethyl ester (5F-BAPTA-AM) in dimethyl sulfoxide. Rats tolerated intravenous infusion without evident change in mean arterial blood pressure. In all tissues examined, kidney, spleen, and brain, [Ca2+]i was approximately 200 nM. To our knowledge, these results represent the first in vivo and in situ determinations of [Ca2+]i employing 19F-NMR.

Alteration of transcription factor binding activities in the ischemic rat brain

Transient focal ischemia-reperfusion in the cerebral cortex caused regional alteration of DNA-binding activities of transcription factors AP-1, CREB, Sp-1, and NF-kB. The changes were time-dependent. During the first 24 hr of reperfusion after 90 min ischemia, there was an increase in the binding activity of AP-1 only in the region surrounding the ischemic cortex. Five days after ischemia, an increase in the binding activities of CREB, Sp-1, and NF-kB, but not AP-1, was noted in the ischemic cortex, and to a lesser extent, Sp-1 and NF-kB, in the surrounding region. The binding activities of these transcription factors were reduced by hydrogen peroxide but could be restored by dithiothreitol and 2-mercaptoethanol. These results are the first demonstration of ischemia-induced differential regulation of transcription factor binding activities which are time-, region-, and redox state dependent.

Detection of free radicals by microdialysis/spin trapping EPR following focal cerebral ischemia-reperfusion and a cautionary note on the stability of 5,5-dimethyl-1-pyrroline N-oxide (DMPO)

We have examined free radical production in a rat model of focal cerebral ischemia using microdialysis coupled with EPR analysis. A microdialysis probe was inserted 2 mm into the cerebral cortex, supplied by the right middle cerebral artery (MCA), and after a 2-hour washout period with artificial cerebral spinal fluid (ACSF), the perfusate solution was changed to ACSF containing the spin trapping agent, 5,5-dimethyl-1-pyrroline N-oxide (DMPO). No free radicals were detected by DMPO during the pre-ischemia period. Both common carotid arteries and the right MCA were then ligated for 90 minutes. Microdialysate collected every 15 min during the ischemic period demonstrated predominantly superoxide or peroxyl radical production. After release of the occlusive sutures, hydroxyl radical became apparent initially, then thiyl and carbon centered radicals appeared later in samples collected every 15 min for two hours following cortical reperfusion. Careful studies on the purification and stability of DMPO solution were performed to circumvent artifacts and spurious signals.

Effects of nephrotoxic beta-lactam antibiotics on the mitochondrial metabolism of monocarboxylic substrates

The nephrotoxic beta-lactam antibiotics (beta-lactams) cephaloridine, cephaloglycin and imipenem are toxic to the mitochondrial transport and (secondarily) oxidation of succinate and other dicarboxylic substrates. However, compared to cephaloglycin, cephaloridine is minimally toxic to the mitochondrial uptake and uncoupled oxidation of the short-chain fatty anion butyrate. Further studies were therefore done to compare the early effects of nephrotoxic doses (300 mg/kg body weight) of imipenem, cephaloridine and cephaloglycin on the mitochondrial metabolism of three important monocarboxylic substrates, butyrate, valerate and pyruvate, in rabbit renal cortex. The following was found: 1) imipenen reduces the oxidation of all three monocarboxylates, within 0.5 to 1 hr after administration. 2) The respiratory toxicity of cephaloglycin is essentially the same as that of imipenem with all three substrates. 3) cephaloridine causes little or no toxicity to pyruvate or butyrate oxidation and is significantly less toxic than imipenem or cephaloglycin to valerate oxidation. 4) The effects of the three beta-lactams on butyrate and pyruvate uptake parallel their effects on butyrate and pyruvate oxidation.

CONCLUSIONS

Imipenem and cephaloglycin have essentially the same patterns of toxicity to the mitochondrial metabolism of all metabolic substrates that have been tested. Although cephaloridine has similar effects on dicarboxylic substrates, it is significantly less toxic to the mitochondrial metabolism of pyruvate and the short-chain fatty anions. It is proposed that cephaloridine's zwitterionic charge may restrict its ability to acylate monocarboxylic and other anionic carriers, resulting in less nephrotoxicity than might otherwise result from its uniquely high intracellular concentrations and singular ability among the toxic beta-lactams to produce oxidative injury.

Local massage after vaccination enhances the immunogenicity of diphtheria-tetanus-pertussis vaccine

The effect of local massage on adverse reactions and immunogenicity of diphtheria-tetanus-pertussis vaccine was investigated. After diphtheria-tetanus-pertussis vaccination 327 infants were either massaged or not, and adverse reactions were evaluated. Local pain and fever were more frequent in the massage group. The extra febrile episodes from massage were mild (38-39 degrees C). For evaluation of the antibody responses, 124 infants were recruited into massage or nonmassage cohorts and antibody production was measured at 2, 6, 7, 18 and 19 months of age, respectively. Subjects in the massage group developed significantly higher antibodies against filamentous hemagglutinin at 6 and 7 months of age, pertussis toxin at 6, 7, 18 and 19 months of age, pertussis agglutinogen at 18 and 19 months of age and those in the nonmassage group. Local massage after diphtheria-tetanus-pertussis vaccination was associated with better immunogenicity and more adverse reactions, including low grade fever and local pain, which were mild and not particularly disturbing.

Tc-99m DTPA aerosol lung clearance test in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) can affect every organ. Involvement of the lung in systemic lupus erythematosus may be a significant cause of morbidity and mortality. To evaluate alveolar epithelial damage in SLE, we studied lung epithelial permeability by measuring the clearance of inhaled Tc-99m DTPA aerosol. Twenty-three SLE patients without clinical pulmonary manifestations were studied. Of the 23 patients, 16 had normal clearance rates of Tc-99m DTPA (T1/2 > 60mins) and normal chest X-ray findings. A mild increase in the clearance rate was found in 5 cases (T1/2 between 40-60 min) and a significant increase in clearance rate in the remaining 2 (T1/2 < 40mins). Totally, 30% (7/23) of SLE patients have abnormal lung permeability. Of the 7 patients with abnormal clearance of Tc-99m DTPA, 3 had abnormal findings in chest X-rays and four had normal chest X-rays. Our study suggests that the clearance of Tc-99m DTPA aerosol may be a useful complementary study to assess pulmonary involvement in SLE.

Effects of inhalation of steroids on lung permeability in patients with asthma

This study evaluated the effect of inhalation of steroids on lung permeability in patients with asthma by measuring the clearance of Tc-99m DTPA aerosol from the alveolar to vascular space. Twenty patients with asthma were studied in the supine position with a gamma camera and the clearance half time (T 1/2) was calculated. The base line lung permeability study was performed before treatment with inhalation of 100 micrograms beclomethasone dipropionate four times daily for 1 week, then the study was repeated. After treatment with inhalation of steroid, there was a change in T 1/2 from 76.4 +/- 37.4 minutes to 86.6 +/- 48.2 minutes (P = 0.08). This preliminary study suggests that lung permeability is not altered by inhaled steroid therapy.

Evaluation of tissue perfusion by the Xe-133 washout method in lower limbs of patients with noninsulin-dependent diabetes mellitus

Ischemia is thought to be a major component in the pathogenesis of foot problems. The authors use the Xe-133 washout method to evaluate the blood perfusion of muscle tissue in the lower legs of patients with noninsulin-dependent diabetes mellitus (NIDDM). Eighty-five male patients with NIDDM ranging in age from 51 years to 79 years (mean, 66.5 years) and 47 nondiabetic control males with a matched age ranging from 52 years to 82 years (mean, 64.5 years) were included in this study. None of the diabetics had a history or presentation of peripheral vascular disease in the lower limbs. The patients were separated into groups according to the duration of the disease and condition of blood sugar control. The Xe-133 washout method was performed in the anterior tibial muscle of all the subjects. According to a Student's t-test, the tissue perfusion were of significant difference between 1) NIDDM and normal controls (1.98 +/- 1.39 ml/100 g/minute versus 2.85 +/- 1.35 ml/100 g/minute), 2) good and poor blood sugar control (2.36 +/- 1.58 versus 1.51 +/- 0.94), and 3) long and short disease durations (1.50 +/- 0.78 versus 2.35 +/- 1.63). It is concluded that the tissue perfusion in the lower legs of patients with NIDDM is significantly decreased and related to the duration of the disease and condition of blood sugar control. This may contribute to the high incidence of foot gangrene and limb loss in patients with NIDDM.(ABSTRACT TRUNCATED AT 250 WORDS)

Neoadjuvant chemotherapy for advanced nasopharyngeal carcinoma

Between October 1990 and November 1991, a total of 16 male patients with advanced nasopharyngeal carcinoma were treated by neoadjuvant chemotherapy before conventional radiotherapy. They belonged to the AJCC stage IV with multiple bulky neck nodes metastases. The chemotherapy consisted of bleomycin, epirubicin, and cisplatin. Six patients completed 3 cycles, 9 patients finished 2 cycles, and 1 patient received 1 cycle of chemotherapy. Seven of the 16 patients (44%) were in complete response, and 50% (8/16) achieved partial response. The overall response rate was 94%. The major toxicities consisted of leucopenia (12/37 cycles had grade III-IV), nausea/vomiting, alopecia. Aplastic marrow developed in 1 patient, and one died of bleomycin-induced pneumonitis. Subsequent radiation therapy was well tolerated. After a minimal follow-up time of 24 months, the 2-year actuarial survival rate was 56%. Although we confirmed the impressively high response rate of this regimen, the toxicities were high and most patients failed at distant site(s). The efficacy of neoadjuvant chemotherapy for advanced nasopharyngeal carcinoma is doubtful and should be further studied in prospective randomized trials.

Hepatopulmonary syndrome in liver cirrhosis: report of a case

A 52-year-old woman suffered from exertional dyspnea, 5 years after she was diagnosed with cirrhosis of the liver. Hypoxemia was suspected because of persistent exertional dyspnea and was confirmed by contiguous arterial blood gas tests. After excluding other cardiopulmonary factors, a series of studies including lung perfusion scan, echocardiography and cardiopulmonary cineangiography revealed the cause of hypoxemia to be the patient's liver disease. Hepatopulmonary syndrome was diagnosed. Despite supplemental oxygen therapy and oral garlic powder for 6 months, the patient still had exertional dyspnea and platypnea, and arterial blood gas results did not improve. We report this case to call attention to arterial oxygen desaturation in cases of cirrhosis of the liver, and to emphasize that deteriorating oxygenation in patients with chronic liver disease may be an indication for liver transplantation, as such functional microvascular abnormalities could be reversed by liver transplantation.

Gianotti-Crosti syndrome associated with cytomegalovirus infection: report of one case

A one and half a month-old infant, a female, was brought to this hospital with the chief problem of diarrhea lasting for more than one week. Four days after admission, symmetric and nonpruritic lichenoid papules developed over her face and limbs. Physical examination showed several small palpable lymph nodes over the bilateral inguinal areas, but without hepatosplenomegaly. Gianotti-Crosti syndrome was diagnosed. Latter on, cytomegalovirus (CMV) was isolated from urine and throat swab. It seemed that this case of Gianotti-Crosti syndrome was associated with CMV infection.

Toxicity of cephalosporins to fatty acid metabolism in rabbit renal cortical mitochondria

Cephaloglycin (Cgl) and cephaloridine (Cld) are acutely toxic to the proximal renal tubule, in part because of their cellular uptake by a contraluminal anionic secretory carrier and in part through their intracellular attack on the mitochondrial transport and oxidation of tricarboxylic acid (TCA) cycle anionic substrates. Preliminary studies with Cgl have provided evidence of a role of fatty acid (FA) metabolism in its nephrotoxicity, and work with Cld has shown it to be a potent inhibitor of renal tubular cell and mitochondrial carnitine (Carn) transport. Studies were therefore done to examine the effects of Cgl and Cld on the mitochondrial metabolism of butyrate, the anion of a short-chain FA that does not require the Carn shuttle to enter the inner matrix, and the effects of Cgl on the metabolism of palmitoylcarnitine (PCarn), the Carn conjugate of a long-chain FA that does enter the mitochondrion by the Carn shuttle. The following was found: (1) Cgl reduced the oxidation and uptake of butyrate after in vitro (2000 micrograms/mL, immediate effect) and after in vivo (300 mg/kg body weight, 1 hr before killing) exposure; (2) Cld caused milder in vitro toxicity, and no significant in vivo toxicity, to mitochondrial butyrate metabolism; (3) like Cld, Cgl reduced PCarn-mediated respiration after in vivo exposure, but, unlike Cld, it did not inhibit respiration with PCarn in vitro; (4) the Carn carrier was stimulated slightly by in vitro Cgl but was unaffected by in vivo Cgl; (5) in vivo Cgl had no effect on mitochondrial free Carn or long-chain acylCarn concentrations in the in situ kidney; (6) Cgl increased the excretion of Carn minimally compared with the effect of Cld; and (7) cephalexin, a nontoxic cephalosporin, caused mild reductions of respiration with butyrate and PCarn during in vitro exposure, but stimulated respiration with both substrates after in vivo exposure.

CONCLUSIONS

Cgl has essentially the same patterns of in vitro and in vivo toxicity against mitochondrial butyrate uptake and oxidation that both Cgl and Cld have against TCA-cycle substrates. Cld has little or no in vivo toxicity to mitochondrial butyrate metabolism, whereas in vivo Cgl is as toxic as Cld to respiration with PCarn. The greater overall in vivo toxicity of Cgl to mitochondrial FA metabolism, with lower cortical concentrations and AUCs than those of Cld, supports earlier evidence that Cld is less toxic than Cgl at the molecular level.

Experimental therapies to improve delivery of oxygen and substrate in acute stroke

The results of large-scale clinical trials of hemodilution therapy and vasodilators for acute stroke have been disappointing. However, interventions involving the manipulation of whole blood viscosity, blood oxygen-carrying capacity, cardiac output, and the resistance properties of cerebral vessels are viable therapeutic modalities currently being investigated. The central aim of all of these therapies is the timely improvement of perfusion and substrate delivery to ischemic brain regions. Better understanding of cerebrovascular flow regulation and the physiology of microvessels may give rise to more effective therapies. In the past, overemphasis on hematocrit reduction and cerebral vasodilators has obscured the potential risks of reducing blood oxygen content and vascular resistance during acute stroke and the importance of optimizing oxygen delivery by other means, in particular by cardiac output augmentation and manipulation of plasma properties. A broader approach to therapeutic strategies for acute stroke includes not only increasing cerebral blood flow, but also interventions that will create favorable changes in the humoral microenvironment and promote overall substrate delivery to the brain.

Papillary carcinoma of thyroglossal duct cyst: a case report

We report a papillary carcinoma of thyroglossal duct cyst. Thyroglossal duct carcinoma is rare: only about 160 cases have been reported. Preoperative diagnosis of malignancy is even rare, except for a few cases by fine needle aspiration cytology or biopsy. A primary lesion or metastasis from the thyroid gland is widely discussed. However, the prognosis is good.

Recurrent hypertensive intracerebral hemorrhage

Hypertensive intracerebral hemorrhage has been considered as a one-time event with rare recurrence. This observation is quite different from our experience in Taiwan. We, therefore, conducted a systematic review of our series of consecutive patients with recurrent bleeding. During a 2-year period, we encountered 47 patients with recurrent hypertensive intracerebral hemorrhage from a total of 892 consecutive patients with hypertensive hemorrhage (5.3%). There were 25 men and 22 women with a mean age of 59 +/- 10 (range: 36-78) years at the onset of the first hemorrhage and 62 +/- 9 (range: 39-80) years at the second hemorrhage. The median interval between 2 hemorrhages was 2 years and 4 months (range: 1 month to 8.5 years). All except one recurrent hemorrhages occurred at a site different from the previous one. Of the 38 patients admitted to our hospital for both hemorrhages only 5 were regularly treated with antihypertensive therapy. The outcome for the recurrent bleeding was grave: 26% died and 51% became totally dependent or vegetative. Recurrent hypertensive hemorrhage is not as rare as previously thought; it comprises 5.3% of our patients with hypertensive intracerebral hemorrhage. The recurrent hemorrhage, however, rarely occurs at the same location as the previous one. Uncontrolled hypertension appears to be an important risk factor for the recurrence. Control of blood pressure after the first bleeding should be attempted to prevent recurrent hemorrhage.

Cytology of pulmonary Fusobacterium nucleatum infection. A case report

A patient with pulmonary Fusobacterium nucleatum infection presenting as a solitary nodule is reported. The infectious nature of the lung nodule was disclosed by ultrasound-guided percutaneous transthoracic fine needle aspiration cytology (FNAC) with Liu's stain. The cytologic characteristics of F nucleatum infection are described. The usefulness of real-time ultrasound in fine needle aspiration diagnosis of a peripheral lung lesion is demonstrated, and the role of Liu's stain in FNAC is emphasized.

Bone scintigraphy in evaluation of heel pain in Reiter's disease: compared with radiography and clinical examination

Tc-99m MDP bone scans were used to evaluate the heel pain (talalgia) in 38 patients with Reiter's disease, and compared with clinical examination and radiologic findings. In our work, 58% (22/38) patients presented talalgia with a total of 35 lesions. Only two lesions of clinical talalgia were missed by the bone scan. The diagnostic sensitivity was as high as 94% (33/35). However, the diagnostic sensitivity of radiography was only 69% (11/16) when the disease duration was more than one year; furthermore, it declined to 33% (4/12) when the disease duration was less than one year. Based on the bone scans, the correlation between positive scintigraphic findings and clinical talalgia was extremely good. Clinical talalgia occurred in all the 33 lesions demonstrated by bone scan. However, three lesions demonstrated by radiography were not consistent with clinical talalgia and not visualized by radioscintigraphy. Our data show that the radionuclide scan is a more sensitive indicator and has better correlation with clinical talalgia than radiography. We consider that bone scintigraphy is superior to radiography in the evaluation of heel pain in Reiter's disease.

The normal values of the radionuclide esophageal transit test and the influence of age and gender in healthy Chinese

This study evaluates esophageal function in 55 healthy Chinese using a radionuclide esophageal transit test (RETT) of solid and liquid foods. A standard method modified from Klein et al. and Russell et al. was used to calculate: total mean transit time (MTT), residual fraction (RF), and retrograde index (RI) in the supine position. In Group 1, 30 cases accepted solid food RETT and in Group 2, 25 cases accepted liquid food RETT. Both groups were divided into different subgroups based on their ages: older and younger or according to their sex: male and female. The results show significant differences in MTT, RF and RI between the two groups, but no statistical differences were found in all of the parameters between the subgroups based on age or sex in both food types. In conclusion, the RETT is a simple and non-invasive method of evaluating the esophageal functions for both types of food and influences due to differences in age or sex were not significant in healthy Chinese.