Bacteriology of chronic sinusitis after ampicillin therapy

The bacteriologies of the maxillary and ethmoid sinuses were studied in 74 chronic sinusitis patients who took ampicillin (500 mg every 6 hours) for 2 weeks preoperatively. The specimens from one ipsilateral maxillary and ethmoid sinuses were obtained when undergoing functional endoscopic sinus surgery. In 74 specimens of the maxillary sinus, 38 bacterial isolates were recovered. The culture rate was 46.0%. On the other hand, 34 bacterial isolates were taken from the ethmoid sinus specimens. The culture rate was 41.9%. As compared with a previous group who did not take any antibiotic preoperatively, the culture rate significantly decreased in the maxillary as well as the ethmoid sinus specimens. Not surprisingly, a significantly decreased sensitivity to ampicillin was also found in the recovered bacteria from both the maxillary sinus (23.7%) and ethmoid sinus (5.9%) specimens. These results demonstrate that antibiotic therapy with ampicillin could eradicate most sensitive bacteria in chronic sinusitis. However, persistence of resistant bacteria was demonstrated.

Neuronal cell death in the ischemic spinal cord: the effect of methylprednisolone

BACKGROUND

Cell death occurs by either necrosis or apoptosis. The role of apoptosis in the neuronal degeneration after ischemia remains to be defined. We studied (1) the nature of neuronal death and (2) the neuroprotective action of methylprednisolone in a rat model of spinal cord ischemia.

METHODS

Spinal cord ischemia was induced in adult Long-Evans rats by occluding the aortic arch for 14 minutes and simultaneously equilibrating the femoral artery pressure to the atmospheric pressure. Twenty rats were subjected to ischemia without treatment and another twenty to ischemia after treatment with methylprednisolone (30 mg/kg, 4 hours before ischemia). The animals were sacrificed and the lumbar spinal cords were examined on postoperative days 1 and 2.

RESULTS

On day 1, neurons with morphology indicative of apoptosis were present in the gray matter. Their numbers increased from the ventral to the dorsal location. There were significantly fewer apoptotic neurons in the dorsal horn of the methylprednisolone-treated animals. DNA obtained from the spinal cord of untreated rats on days 1 and 2 showed laddering after electrophoresis, a feature of apoptosis. Pretreatment with methylprednisolone inhibited the development of DNA laddering. Methylprednisolone treatment was not associated with significantly improved neurologic function in the postoperative period.

CONCLUSIONS

Apoptotic neuronal death occurs in the rat spinal cord after transient ischemia and is attenuated by pretreatment with methylprednisolone.

Complications of shoulder arthroscopy

Shoulder arthroscopy can be a safe and effective tool to perform a variety of diagnostic and therapeutic procedures about the shoulder. Careful attention to positioning, fluid management, use of traction, and appreciation of shoulder anatomy to select portal placement will help decrease the common complications associated with shoulder arthroscopy. The awareness of uncommon complications, such as deep venous thrombosis, pneumothorax, and iatrogenic rotator cuff tears will help the orthopedic surgeon to promptly diagnose and treat these problems.

Anionic- and lipophilic-mediated surface binding inhibitors of human leukocyte elastase

We report the synthesis of a series of diphenylmethane-based oligomers containing anionic and lipophilic functionalities that are potent inhibitors of human leukocyte elastase (HLE). The enzyme inhibition is regulated by the size of the oligomer, as well as, the number of charges. Lipophilicity is an important element in determining potency and specificity against other basic enzymes. Compounds whose scaffolds contain three phenoxyacetic acid groups and three alkyl ethers are competitive and specific inhibitors of HLE with Ki = 20 nM. The mechanism of action of this class of compounds is believed to involve multidendate interactions with the surface of HLE near the active site which prevents substrate access to the catalytic site.

Induction of basic fibroblast growth factor (bFGF) expression following focal cerebral ischemia

Basic fibroblast growth factor (bFGF) is a biologically active polypeptide with mitogenic, angiogenic, and neurotrophic properties. In the present study, we examined the temporal and spatial expression profiles of bFGF mRNA and protein concentration in a focal cerebral ischemia model induced by transient occlusion of the right middle cerebral artery (MCA) and both common carotid arteries (CCAs). Results of Northern blot analysis shows a transient 2.5-fold increase in the 6.0 kb transcript of bFGF mRNA within the ischemic cortex of rats subjected to 60 min ischemic insult followed by 12 h of reperfusion. Although enhanced expression of bFGF mRNA was also noted in the ipsilateral hippocampus, the temporal induction profile appeared to be different from that of the ischemic cortex. A significant increase in bFGF mRNA was observed as early as 60 min following ischemia and remained elevated for up to 2 weeks after the onset of reperfusion. In situ hybridization studies revealed constitutive expression of bFGF mRNA in discrete brain regions of sham-operated animals. Following 60 min ischemia and 12 h reperfusion, increased expression of bFGF mRNA was observed in the ischemic cortex (both peri-infarct and infarct area). Increased expression of bFGF mRNA within the infarcted area is largely confined rostrally to the outer cortical layers of the infarct, an area with increased density of blood vessels. bFGF-like immunoreactivity was also detected in areas expressing bFGF mRNA. Furthermore, a striking increase in bFGF-like immunoreactivity was observed in the ipsilateral hippocampus. Double-staining with anti-GFAP antibody indicated that the majority of the bFGF-like immunoreactivity was localized in the astrocytes, however, not all astrocytes showed bFGF-like immunoreactivity. Some GFAP negative cell also showed bFGF-like immunoreactivity. In summary, increased expression of both bFGF mRNA and immunoreactivity following ischemia were located in the same brain regions. An increase in bFGF-like immunoreactivity after ischemic insult is likely due to an increase in the expression of its 6.0 kb bFGF mRNA transcripts. Although increased bFGF mRNA was observed in both ischemic cortex and ipsilateral hippocampus after ischemic insult, the temporal expression profiles differed. Results from the present study raise the possibility that increased expression of bFGF in the peri-infarcted area may limit the spread of ischemic injury.

Protection of rat spinal cord from ischemia with dextrorphan and cycloheximide: effects on necrosis and apoptosis

OBJECTIVE

We examined the characteristics of neuronal cell death after transient spinal cord ischemia in the rat and the effects of an N-methyl-D-aspartate antagonist, dextrorphan, and a protein synthesis inhibitor, cycloheximide.

METHODS

Spinal cord ischemia was induced for 15 minutes in Long-Evans rats with use of a 2F Fogarty catheter, which was passed through the left carotid artery and occluded the descending aorta, combined with a blood volume reduction distal to the occlusion. The rats were killed after 1, 2, and 7 days. Other groups of rats were pretreated with dextrorphan (30 mg/kg, intraperitoneally, n = 7), cycloheximide (30 mg, intrathecally, n = 7), or vehicle (saline solution, n = 12) and killed after 2 days.

RESULTS

This model reliably produced paraplegia and histopathologically distinct morphologic changes consistent with necrosis or apoptosis by light and electron microscopic criteria in different neuronal populations in the lumbar cord. Scattered necrotic neurons were seen in the intermediate gray matter (laminae 3 to 7) after 1, 2, and 7 days, whereas apoptotic neurons were seen in the dorsal horn laminae 1 to 3 after 1 and 2 days. Deoxyribonucleic acid extracted from lumbar cord showed internucleosomal fragmentation (laddering) on gel electrophoresis indicative of apoptosis. The severity of paraplegia in the rats treated with dextrorphan and cycloheximide was attenuated 1 day and 2 days after ischemia. The numbers of both necrotic and apoptotic neurons were markedly reduced in both dextrorphan- and cycloheximide-treated rats.

CONCLUSIONS

The results suggest that both N-methyl-D-aspartate receptor-mediated excitotoxicity and apoptosis contribute to spinal cord neuronal death after ischemia and that pharmacologic treatments directed at blocking both of these processes may have therapeutic utility in reducing spinal cord ischemic injury.

Cell death suggestive of apoptosis after spinal cord ischemia in rabbits

BACKGROUND AND PURPOSE

After spinal cord ischemia, some neurons remain viable after an ischemic insult but may be at risk of dying during reperfusion. We searched for morphological and biochemical features of apoptosis, which is a mechanism of delayed neuronal death, in a rabbit model of spinal cord ischemia.

METHODS

The infrarenal aorta of White New Zealand rabbits (n = 24) was occluded for 40 minutes using a loop tourniquet. Rabbits were killed after 12, 24, or 48 hours (n = 8 per group). The loop was placed but never tightened in sham-operated rabbits (n = 6). The lumbar segment of the spinal cord (L5 to L7) was used for morphological studies, including hematoxylin and eosin staining and a modified terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end-labeling (TUNEL) staining method. Electron microscopy was used to examine ultrastructural morphology. In addition, lumbar tissue was used for biochemical investigation of DNA laddering by agarose gel electrophoresis.

RESULTS

After ischemia, the affected areas contained neurons with positive TUNEL staining. Positive neurons were located in laminae III to IX, although most were concentrated in the intermediate and ventral areas. Adjacent sections stained with hematoxylin and eosin exhibited ischemic cell changes (red and ghost neurons), while apoptotic bodies were also apparent. In addition, electron microscopy of ischemic tissue samples exhibited ultrastructural characteristics of apoptosis, including nuclear condensation and relatively normal organelle morphology. Finally, isolated DNA revealed a ladder on agarose gel electrophoresis, indicating DNA fragmentation into approximately 180 multiples of base pairs.

CONCLUSIONS

Spinal cord ischemia in rabbits induces morphological and biochemical changes suggestive of apoptosis. These data raise the possibility that apoptosis contributes to neuronal cell death after spinal cord ischemia.

Quantitative measurements of regional cerebral blood volume using MRI in rats: effects of arterial carbon dioxide tension and mannitol

A three-dimensional (3D) T1-weighted sequence was used to acquire high spatial resolution whole brain images in rats before and after the injection of an intravascular contrast agent. These T1-weighted images were used to estimate regional cerebral blood volume (rCBV) as a percentage of blood volume in each voxel. Ventilation was manipulated to investigate the effects of altered arterial carbon dioxide tension (PaCO2) on rCBV. In addition, different doses of a hypertonic mannitol solution were used to investigate the sensitivity of the proposed method in a serial monitoring paradigm. An rCBV of 2.40% +/- 0.34% was obtained before any physiological manipulation, in good agreement with literature values using alternative techniques. Using this method, it was found that there exists a linear relationship between PaCO2 and rCBV (R2 = 0.77) and that rCBV increased in a dose and time dependent fashion in mannitol-treated rats. High signal-to-noise was available due to the substantial increase in blood signal from the intravascular contrast agent.

Quantitative regional brain water measurement with magnetic resonance imaging in a focal ischemia model

Therapeutic approaches to cerebral edema require an understanding of both the magnitude and location of changes in brain water content. It is desirable to have a sensitive, accurate means of measuring brain water noninvasively so that effective therapies for cerebral edema in stroke, head trauma, and other conditions can be investigated. In this work, a three-dimensional magnetic resonance imaging technique that is able to provide both spin density and T1 simultaneously is described. This method was used to quantitate regional changes in brain water content in a rat model of focal cerebral ischemia. Brain water contents estimated from both relative spin density and relative T1 measurements made in vivo were compared with ex vivo measurements of relative tissue water content based on the wet-dry technique. Correlation coefficients of 0.95 and 0.98 were obtained between the wet-dry measurements and magnetic resonance measurements of T1 and spin density, respectively. Notably, the slope of the relationship between T1 and tissue water content changed dramatically after the injection of a paramagnetic contrast agent while precontrast and postcontrast spin density measurements remained essentially invariant. In addition, a plot of absolute spin density (obtained by normalizing spin density from agar gelatin phantoms of different water contents to the spin density of a sample of 100% water) was linearly related to wet-dry measurements with a slope of 0.99 (R2 = 0.99).

The clinicopathological characteristics of gonadotroph cell adenoma: a study of 118 cases

Gonadotroph cell adenoma was the most common pituitary adenoma, constituting 35% of the pituitary adenomas in our series of 339 patients with surgically removed pituitary adenomas from June 1987 to December 1995. The average age of these patients was 53 years, with a male predominance (1.5:1). The most common neurological symptoms were visual symptoms and headache. Amenorrhea and galactorrhea were recorded in 41% and 14%, respectively, of the female patients of reproductive age. Oncocytic change of varying degrees was seen in 69% of the tumors, and the average age of these patients (56 years) was older than those who had no such change (47 years) (P < .005). Five types of gonadotroph cell adenomas were recognized; they were tumors that contained (1) betaFSH, betaLH, and alphaSU, (2) betaFSH and betaLH, (3) betaFSH and alphaSU, (4) betaFSH, and (5) alphaSU. The immunostaining of betaFSH-containing cells was usually diffuse, whereas staining of betaLH- or alphaSU-containing cells was usually focal. Double immunostaining showed the immunoreactive cells containing one or any combination of the gonadotropin subunits. Increases in serum gonadotropin levels were only seen in 35% of the patients with gonadotroph cell adenoma. There was no correlation between serum hormonal levels and immunostaining results. Of the 33 recurrent cases, significant decrease or total absence of immunoreactivity of one or more hormone subunits in subsequent biopsy specimens were seen in three cases.

Neuronal and glial apoptosis after traumatic spinal cord injury

Cell death was examined by studying the spinal cords of rats subjected to traumatic insults of mild to moderate severity. Within minutes after mild weight drop impact (a 10 gm weight falling 6.25 mm), neurons in the immediate impact area showed a loss of cytoplasmic Nissl substances. Over the next 7 d, this lesion area expanded and cavitated. Terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL)-positive neurons were noted primarily restricted to the gross lesion area 4-24 hr after injury, with a maximum presence at 8 hr after injury. TUNEL-positive glia were present at all stages studied between 4 hr and 14 d, with a maximum presence within the lesion area 24 hr after injury. However 7 d after injury, a second wave of TUNEL-positive glial cells was noted in the white matter peripheral to the lesion and extending at least several millimeters away from the lesion center. The suggestion of apoptosis was supported by electron microscopy, as well as by nuclear staining with Hoechst 33342 dye, and by examination of DNA prepared from the lesion site. Furthermore, repeated intraperitoneal injections of cycloheximide, beginning immediately after a 12.5 mm weight drop insult, produced a substantial reduction in histological evidence of cord damage and in motor dysfunction assessed 4 weeks later. Present data support the hypothesis that apoptosis dependent on active protein synthesis contributes to the neuronal and glial cell death, as well as to the neurological dysfunction, induced by mild-to-moderate severity traumatic insults to the rat spinal cord.

Melatonin protects bovine cerebral endothelial cells from hyperoxia-induced DNA damage and death

Hyperoxia leads to excessive formation of reactive oxygen species (ROS). ROS cause damage to many cellular components, including DNA. Exposure of bovine cerebral endothelial cells to 95 or 100% oxygen resulted in an increase in DNA fragmentation, the appearance of DNA ladders, and cell death with morphological features suggestive of apoptosis. Melatonin, an antioxidant, reduced hyperoxia-induced DNA fragmentation and cell death in a dose-dependent manner. Results from the present study support the contention that ROS play a major role in DNA damage and apoptotic death. Melatonin is an effective agent in reducing ROS-mediated DNA fragmentation and death in bovine cerebral endothelial cells.

Multiple-dose mannitol reduces brain water content in a rat model of cortical infarction

BACKGROUND AND PURPOSE

Repeated use of mannitol in the setting of ischemic infarction is a controversial and poorly defined therapeutic intervention. The purpose of this study was to examine the effects of repeated mannitol infusions on brain water content and tissue pressure in a well-defined rat model of focal ischemic stroke.

METHODS

Mannitol infusions (0.5, 1.5, or 2.5 g/kg) were given by intravenous bolus 4 or 24 hours after 90-minute transient cortical ischemia in the territory of the right middle cerebral artery in rats and every 4 hours thereafter for a total of 24 hours. Fluid replacement was limited to 0.5 mL i.v. isotonic saline administered immediately after each mannitol dose. Control rats received 0.5 mL i.v. saline at the same intervals and were otherwise under ad libitum conditions. Water contents (percent H2O) of whole hemispheres and of cortical biopsies were measured with the wet-dry method, and blood samples were analyzed for plasma osmolality and chemistries. In a subgroup of rats, tissue pressure was also measured within the hemisphere ipsilateral to the infarct.

RESULTS

Repeated mannitol infusions resulted in a dose-dependent increase in plasma osmolality and a dose-dependent decrease in the percent H2O of the ischemic middle cerebral artery cortex and ipsilateral hemisphere. In contrast, percent H2O of the contralateral cortex and hemisphere was significantly decreased only in the groups given the highest dose of mannitol (2.5 g/kg). Mannitol infusions at a dose of 1.5 g/kg begun 24 hours after reperfusion were also associated with a significant reduction of tissue pressure.

CONCLUSIONS

In a rat model of ischemic cortical infarction, repeated mannitol infusions resulted primarily in a decrease in the percent H2O of the infarct and ipsilateral hemisphere, as well as decreased tissue pressure.

Identification of a promoter for the latent membrane protein 1 gene of Epstein-Barr virus that is specifically activated in human epithelial cells

Latent membrane protein 1 (LMP 1) is one of two Epstein-Barr virus (EBV)-encoded proteins that expressed in nasopharyngeal carcinoma (NPC) cells. Previous studies showed that a 3.5-kb transcript of the LMP 1 gene, in addition to the 2.8-kb transcript, was detected in a B95-8-EBV-containing, nude mice-passaged NPC tumor, C15. This indicated that a transcript was initiated from a region 5' to the putative promoter, ED-L1. We have isolated an EBV variant from a NPC tissue, and this virus strain contained a more pathogenic LMP 1 gene. DNA sequence analysis of the 5'-upstream region showed distinct variations as compared to that of B95-8 strain. To test if the LMP 1 gene of the NPC strain also contained an upstream promoter, we generated a series of deletion plasmids encompassing positions -1,030 to +20 of the LMP 1 promoter and tested for their abilities to drive the expression of the reporter gene in human epithelial cell lines, C-33A and NPC-TW076. We found that the region between -643 and -496 contained a promoter activity that was approximately five-fold higher than the putative promoter, ED-L1. This region between -643 and -496 was designated as ED-L1E. C-33A cells containing the genomic clone pT7(E) or the clone that had deleted a 94-bp ED-L1 sequence (delta94) was used to determine the transcription initiation sites by RNase protection assay. Results showed that a transcription initiation site was located at nucleotide 170,099 ("A") of EBV genome. The transcript was expressed in NPC biopsies and in human primary normal epithelial cells transfected with pT7(E) and delta94, respectively, as examined by reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. Furthermore, the ED-L1E was not regulated by the EBV-encoded nuclear antigen 1-mediated transcriptional enhancer family of repeats (FR) in C-33A cells. Our results suggested that the ED-L1E was specifically activated in epithelial cells. The biological significance of the selective usage of the ED-L1E promoter was discussed.

Prospective comparison of laparoscopic and traditional colposuspensions in the treatment of genuine stress incontinence

OBJECTIVE

To compare prospectively the results of laparoscopic and traditional colposuspensions in the treatment of genuine stress incontinence and to evaluate the efficacy, technique, and functional and anatomical changes after these two procedures.

MATERIALS AND METHODS

Ninety-two patients with urodynamically proven genuine stress incontinence participated in this study, with 46 patients randomly allocated to laparoscopic colposuspension, and the other 46 patients to the traditional procedures. All patients had repeat studies at least 3 months after operation.

RESULTS

The bladder neck position was significantly elevated after operation either at rest or during straining in both groups (all p < 0.001), but it was higher in the traditional group than the laparoscopy group during straining (p < 0.05). Comparison of urodynamics before and after operation in both groups showed significantly increased minimal urethral resistance and improved pressure transmission ratios at the proximal urethra (Q2). The blood loss was less in the laparoscopy group. The duration of bladder drainage after laparoscopic colposuspension was shorter, and was not affected by subsequent laparotomy. The operative time was almost the same. The success rate of the laparoscopy group was lower than that of the traditional group (80.4% vs. 95.6%, p = 0.044). The complication rates were 10.8% and 17.4% respectively.

CONCLUSION

Laparoscopic colposuspension is an effective method for the treatment of GSI, as documented by anatomical and functional assessments. However, the success rate is still lower than for the traditional procedure.

Regulation of cytokine-induced iNOS expression by a hairpin oligonucleotide in murine cerebral endothelial cells

Inducible nitric oxide synthase (iNOS) is expressed in response to cytokines by a number of cell types participating in CNS inflammation, including brain cerebral endothelial cells. NF-kappaB, a transcription factor, mediates effector actions of pro-inflammatory cytokines. A combination of tumor necrosis factor alpha (TNF-alpha) and interferon gamma (IFN-gamma) enhanced the expression of iNOS in murine cerebral endothelial cells (MCECs). In an attempt to modulate TNF-alpha+IFN-gamma induced expression of iNOS in MCECs, we designed a double-strand hairpin (hp) oligonucleotide carrying the NF-kappaB motif. This hp oligonucleotide inhibited NF-kappaB binding activity and decreased both iNOS mRNA and protein expression induced by TNF-alpha+IFN-gamma. As a control, a mutant hp oligonucleotide was without effect. The present study confirms the role of transcription factor NF-kappaB in iNOS expression induced by TNF-alpha+IFN-gamma in MCECs. More importantly, it demonstrates that an appropriately designed hp oligonucleotide is an effective tool to modulate iNOS expression and may be of potential pharmacological use.

Adult embryonal rhabdomyosarcoma metastatic to the breast and diagnosed by fine needle aspiration. A case report

BACKGROUND

Metastasis to the breast from extra-mammary malignancies is rare, but its recognition is important. A solitary metastasis must be distinguished from the primary breast cancer because the treatment and prognosis are quite different.

CASE

A 30-year-old female presented with a 4.0-cm, solitary, nontender mass in the upper outer quadrant of the right breast 11 months after primary surgery for maxillary sinus embryonal rhabdomyosarcoma. The cytomorphology revealed features of small round cell tumor. Immunocytochemical staining disclosed a positive reaction to vimentin and desmin and negative reaction to cytokeratin, confirming the diagnosis of rhabdomyosarcoma.

CONCLUSION

Fine needle aspiration with ancillary studies is essential in the diagnosis of metastatic malignancy of the breast in order to avoid unnecessary mastectomy and to implement appropriate systemic therapy.

Squamous cell carcinoma of esophagus with diffuse mucin-secreting component: a clinicopathologic study

BACKGROUND

Primary esophageal squamous cell carcinomas with a diffuse mucin-secreting component are not common, and the cases reported are few. The nomenclature for this group of tumors is complex and the histogenesis of these tumors is confused. Therefore, further investigation is needed.

METHODS

Twelve cases have been collected from pathology files of Veterans General Hospital-Taipei from 1965 to 1995. Clinicopathologic relationship, histopathological and immunohistochemical features of these cases were analyzed and compared with the reported literature concerning this entity.

RESULTS

The age, sex and prognosis for patients of this group, and the size and site of the tumors were not different from that of pure squamous cell carcinoma. The tumors continuously connected with esophageal squamous epithelium, and intraepithelial dysplasia were present in 83% cases. Positive anticarcinoembryonic antigen staining was also demonstrated in squamous epithelium, dysplastic epithelium and tumor cells with either squamous or adenomatous differentiation.

CONCLUSIONS

It is believed that esophageal squamous cell carcinoma with diffuse mucin-secreting component is close to the squamous cell carcinoma.

Postoperative MRI of anorectal malformation

Twenty-five patients who had pull-through rectum (PTR) surgery, some of whom suffered from fecal incontinence, soiling or constipation were studied by magnetic resonance imaging (MRI) postoperatively. MRI demonstrated 14 patients with proper placement of the PTR between the puborectal muscle and external sphincter muscle; four patients with improper placement of the PTR outside the puborectal muscle and external sphincter muscle (one with excess perirectal fat); one patient with disruption of the puborectal muscle and external sphincter muscle; three with hypoplasia of the puborectal muscle and external sphincter muscle; three with asymmetric placement of PTR in the levator ani (one with excess perirectal fat). MRI also depicted seven patients with spine anomalies; five with tethered cord; and 10 with genitourinary tract anomalies. The patients with correct location of PTR all had good fecal continence except three patients (two with soiling and one with constipation) who had tethered cord and ganglion cell dysfunction at the PTR. The patients with improper placement of PTR or poorly developed pelvic muscles all had fecal incontinence. Our study emphasizes that MRI can depict the causes of postoperative incontinence, detect anomalies and help to plan further surgery.

Bacteriology of ethmoid sinus in chronic sinusitis

This study was designed to study the bacteriology of the ethmoid sinus in chronic sinusitis with a new sampling method to decrease nasal contamination. The anterior nose was disinfected with povidone-iodine solution. Then, the sample of ethmoid sinus was obtained with a cotton-tip stick through a cannula that was put into the ethmoid cavity after removing ethmoid bulla. Thirty-nine patients of chronic sinusitis were included with a total of 69 specimens. Fifty-eight bacterial isolates were recovered. The cultural rate was 60.9%. The most frequently isolated bacteria were Streptococcus viridans, Klebsiella pneumoniae, Proteus mirabilis, and Hemophilus parainfluenzae. Conversely, only three isolates of Staphylococcus epidermidis were obtained. The results show that the new sampling method used in this study could decrease the chance of nasal contamination and might, at the same time, make the study of the bacteriology of the ethmoid sinus more accurate.

Assay of bropirimine in rat plasma by means of robotic solid-phase extraction and high-performance liquid chromatography

A rapid and simple high-performance liquid chromatography (HPLC) method incorporating automated solid-phase extraction (SPE) is described for the determination of bropirimine, 2-amino-5-bromo-6-phenyl-4(3H)-pyrimidinone, in plasma samples from various species. Using an automated sample processor, plasma samples were loaded onto C18 SPE columns and the drug eluted with ethanol-methylene chloride (10:90, v/v). The extracts were analyzed by reversed-phase HPLC using a C8 column with a mobile phase consisting of acetonitrile-water-trifluoroacetic acid (20:80:0.1, v/v/v). The UV absorbance of the column effluent was monitored at a wavelength of 292 nm. Linear calibration curves were obtained in the range of 0.01 to 22 micrograms/ml. Precision (< or = 4% relative standard deviation) and accuracy (< or = 5% error) were acceptable at the concentrations evaluated. Application of this method to the quantitation of bropirimine in rat plasma for a toxicokinetic/bioavailability study is reported.

Pilot study of concurrent chemotherapy and radiotherapy for stage IV nasopharyngeal cancer

Nasopharyngeal carcinoma (NPC) is a more radio- and chemosensitive tumor than all other head and neck cancers. Between September 1991 and December 1992, a total of 19 patients (13 men and six women; median age, 44 years) with AJCC stage IV NPC were entered into a pilot study of concurrent chemoradiotherapy. Pathology showed either poorly differentiated epidermoid carcinoma or undifferentiated carcinoma. Radiotherapy was delivered using a telecobalt unit and 10-MV x-rays and by conventional fractionation (1.8-2.0 Gy/fraction, 5 fractions/week). The total doses delivered were 70-75 Gy to the primary tumor and neck positive region, and 50-55 Gy to the neck negative area. Chemotherapy with cisplatin (10 mg/m2/day, days 1-5) and 5-fluorouracil (500 mg/m2/day, continuously infused for 5 days) was administered concurrently during weeks 1 and 5 of radiotherapy. The major toxicities were mucositis (42% had grade III and 58% grade II) and leukopenia (nadir white blood cells <3,000/mm3 in eight of 19). Although four patients required a delay in their second cycle of concurrent chemotherapy or had their radiotherapy interrupted for 1 week, all 19 patients completed the planned treatment and achieved a 100% complete response rate. After a median follow-up period of 42 months, one patient suffered from neck recurrence plus distant metastasis, and three patients developed distant metastases alone. The 3-year overall and disease-free survival rates are 89.5% and 83.3%, respectively. Our data indicated that concurrent chemoradiotherapy for advanced NPC is both feasible and effective, with acceptable toxicities. A phase III randomized trial to compare the efficacy of concurrent chemoradiotherapy and radiotherapy alone deserves to be studied further.

Prolongation and enhancement of postischemic c-fos expression after fasting

BACKGROUND AND PURPOSE

A rapid but transient expression of c-fos after cerebral ischemia has been extensively documented. However, the mechanism of this induction and whether induction of c-fos is neuroprotective or detrimental to the brain after ischemia is presently not clear. Fasting before transient cerebral ischemia has been shown to reduce delayed neuronal necrosis and infarct volume. The purpose of the present study was to examine the effect of preischemic fasting for 24 hours on the expression of c-fos after transient focal cerebral ischemia.

METHODS

Focal cerebral ischemia was induced by temporary occlusion of the right middle cerebral artery and both common carotid arteries for 60 minutes. Male Long-Evans rats weighting 250 to 300 g were randomly divided into two groups: fed (control group) and food deprived for 24 hours (fasted group) before ischemic surgery. Infarct volumes were measured on the basis of triphenyltetrazolium chloride-delineated infarct areas, and plasma glucose levels were determined by the glucose oxidase method. Temporal and spatial expression of c-fos was assessed by Northern blot analysis, in situ hybridization, and immunohistochemistry.

RESULTS

Fasting for 24 hours before 60 minutes of ischemia resulted in a 26.6% decrease in preischemic plasma glucose levels and a 74.5% reduction in infarct volumes in the fasted group compared with the control group. A rapid but transient induction of c-fos mRNA was observed in the ischemic cortex in control animals after 60 minutes of ischemia. Fasting not only prolonged but also enhanced the intensity of c-fos expression in the ischemic cortex. Regional c-fos expression was also different between these two groups.

CONCLUSIONS

The results support the contention that c-fos expression may be compatible with its purported neuroprotective role in selected experimental paradigms. The signaling mechanisms underlying the effect of fasting and subsequent lowering of plasma glucose levels on postischemic c-fos expression remain to be explored.

Loss of expression of the p16 gene is frequent in malignant skin tumors

Expression of the p16 gene from 30 malignant skin tumors has been surveyed by immunohistochemical assay. Gene point mutations were detected by DNA direct sequencing and the mRNA level of gene expression was measured by RT-PCR. A silent point mutation of the p16 gene was found in only one patient. However, loss of expression of the p16 gene was noticed in 23 of 29 samples (79.3%). Correlation between loss of expression of the p16 gene and metastasis is significant (p = 0.0036). These findings suggest that loss of expression of the p16 gene may play a critical role in tumor progression of malignant skin tumors.

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.