Selective brain cooling during and after prolonged global ischemia reduces cortical damage in rats

BACKGROUND AND PURPOSE

Studies of the cerebroprotective effects of selective brain cooling have failed to show amelioration of ischemic injury in the cerebral cortex. This study was designed to test the hypothesis that mild-to-moderate selective brain cooling initiated after the onset of global brain ischemia in rats protects the cerebral cortex and improves neurological outcome.

METHODS

Global forebrain ischemia for 30 minutes in 27 fasted adult male Wistar rats was achieved by bilateral carotid occlusion and hypotension. In group 1, brain temperature, measured in the temporalis muscle, was maintained at 37-38 degrees C throughout the experiment. In group 2, brain temperature fell spontaneously during ischemia to 34.7 +/- 0.1 degrees C and rose spontaneously to 36-37 degrees C after 10 minutes of recirculation. In group 3, brain temperature was lowered with ice packs placed around the head after 15 minutes of ischemia to 24.1 +/- 0.9 degrees C by the end of ischemia, maintained at 30.0 +/- 1.0 degrees C for the first hour of recirculation, then allowed to rise to 36-37 degrees C.

RESULTS

Seven-day survival was 0% (0 of 6) in group 1, 73% (8 of 11) in group 2, and 100% (6 of 6) in group 3. Severity of neuronal damage was less in group 2 than in group 1 in the cortex (p < 0.05) and hippocampal CA1 (p < 0.05) and CA3 regions (p < 0.05). Group 3 had less neuronal damage than group 2 in both cortex (p < 0.02) and striatum (p < 0.02). Furthermore, postischemic weight loss was less and neurobehavioral scores were significantly higher in group 3.

CONCLUSIONS

This study shows that selective brain cooling increases survival from prolonged global ischemia and reduces neuronal injury in the cerebral cortex as well as the striatum and hippocampus.

Androgen receptor in cirrhotic liver, adenomatous hyperplastic nodule and hepatocellular carcinoma in the human

Androgen receptors (AR) were assayed for cirrhotic liver, adenomatous hyperplastic nodule (AHN), and hepatocellular carcinoma (HCC) which were removed by partial hepatic resection from five patients. There were three men and two women. Age ranged from 59 to 68 years. Underlying cirrhosis was macronodular in three and micronodular in two. AHN was present within HCC in two patients, but these two lesions were found in different lobes of the same liver in another two patients. Only AHN was seen in the last patient. ARs in the cytosol of cirrhotic liver ranged from nil to 12.8 fmol/mg of protein with the dissociation constant (Kd) of 3.2-20.3 x 10(-10) M. AHNs possessed ARs ranging from 4.0 to 27.6 fmol/mg of protein (Kd values, 7.4-21.0 x 10(-10) M. All HCC nodules had ARs ranging from 11.8 to 72.8 fml/mg of protein with Kd values of 5.3-27.1 x 10(-10) M. Thus, cytosolic AR concentrations were highest in HCC, lowest in cirrhotic liver, and intermediate in AHN. The present study seems to indicate that AHN may be a precancerous lesion and that androgen and its receptor play an important role in human hepatocarcinogenesis.

Successful management of perforating injury of right atrium by chest tube

Tube thoracostomy is an invasive procedure caring about 1% complication rate. Most confronted complications include diaphragm or lung laceration [1-3], damage to intrabdominal organ, intercostal artery bleeding and unilateral pulmonary edema. Here we present another rare complication of perforation of the right atrium which occurred in a patient with rheumatic heart disease (RHD) who had received mitral valve replacement (MVR) and tricuspid annuloplasty. Severe tricuspid regurgitation (TR) with huge right atrium was noted. Chest tube was inserted for pleural effusion drainage. The lesion was proved to be in the right atrium by echocardiography and computerized tomography three days later. The penetrated hole was repaired with bovine pericardium patch with minimal blood loss. This case attests to the extreme caution warranted when performing tube thoracostomy in patient with huge cardiomegaly.

Antitumor effects of new-type recombinant interleukin-2

Two new human recombinant interleukin-2 (rIL-2), 125-Ser-rIL-2, and 125-Ala-rIL-2, were generated by protein engineering technique. Both of them maintained the proliferation of natural killer (NK) cells, CTLL-2 cells and their long-term propagations. The mutated new rIL-2 also enhanced the bioactivity of NK cells and the cytotoxicity of tumor-infiltrating lymphocytes (TIL) against the target tumor cells. The above results were all compared with that of the native rIL-2 and a similarity between them was found, which indicates that new type rIL-2 could be used for adoptive immunotherapy of malignant diseases.

A new autoperfusion technique for aortic reconstruction of suprarenal aortic aneurysm

Visceral ischemia is a serious factor in the postoperative morbidity and mortality of suprarenal aortic reconstruction. We reported two patients of suprarenal aortic aneurysm involving visceral arteries, who received successful Dacron graft replacement by using Pruitt-Inahara balloon catheters as an autoperfusion for preservation of the visceral organs. No visceral organ ischemia occurred postoperatively except in patient 2 who had preoperative chronic renal failure and persistent renal failure after the operation. The renal function recovered gradually during the follow-up period. Both patients are doing well at the present time. The new autoperfusion technique can directly deliver normothermic blood from the arterial cannula at proximal aorta to the individual visceral arteries by using the balloon perfusion catheters. It is simple, safe, easily instituted and the used products are readily obtainable. It allows the surgeon to provide an effective protection of visceral organs for the suprarenal aortic reconstruction.

Effects of tryptophan mutation on the deprotonation and reprotonation kinetics of the Schiff base during the photocycle of bacteriorhodopsin

The rates of deprotonation and reprotonation of the protonated Schiff base (PSB) are determined during the photocycle of nine bacteriorhodopsin mutants in which Trp-10, 12, 80, 86, 137, 138, 182 and 189 are individually substituted by either phenylalanine or cysteine. Of all the mutants, the replacement of Trp-86, Trp-182, and Trp-189 by phenylalanine and Trp-137 by cysteine is found to significantly alter the rate of the deprotonation, but not that of the reprotonation process. As compared with ebR, the Trp-86 mutation dramatically increases the rate of deprotonation of the PSB while the Trp-182 mutation greatly decreases this rate. Temperature dependence studies on the rate constants of the deprotonation demonstrate that the different energetic and entropic effects of the mutation are responsible for the observed different kinetic behavior of the Trp-86 and Trp-182 mutants as compared with that of ebR. In the case of Trp-86 mutant, a large decrease in both energy and entropy of activation suggests that the mutation of this tryptophan residue opens up the protein structure as a result of eliminating the hydrogen-bonding group on its side chain by a phenylalanine substitution. A correlation is observed between the proton pumping yield and the relative amplitudes of the slow deprotonation component but not with rate constants of the rise or decay process at constant pH. These results are best discussed in terms of the heterogeneity model (with parallel cycle) rather than back reaction model.

Enumeration and characterization of DJH structures in mouse fetal liver

The primary immunoglobulin (Ig) repertoire in the mouse develops during fetal life in the liver. The first Ig gene rearrangement--the joining of a DH to a JH gene segment--contributes largely to the diversity found in CDR3, as well as potentially encoding the D mu protein which is believed to function in the development of a B cell. In this report, the number of DJH joins in two mouse strains, C57BL/6 and BALB/c, were enumerated from days 12 to 16 of fetal development. It was found that the number of DJH structures increased from less than 300 per liver on day 12 to greater than 700,000 (C57BL/6) and 300,000 (BALB/c) on day 16. Each JH gene segment was used approximately equally on each day examined. When the DJH structures were examined by cloning and sequencing it was found that the DJH reading frame (RF) usage (with respect to JH) was not random--RF1 was used 70% of the time. Moreover, a single D gene segment, DFL16.1, was used in greater than 50% of all joins reinforcing the notion that the fetal repertoire is restricted in its antigen binding potential.

Vibrio cholerae hemagglutinin/protease, colonial variation, virulence, and detachment

The structural gene, hap, for the secreted hemagglutinin/protease (HA/protease), a putative virulence factor of Vibrio cholerae, has recently been cloned and sequenced (C. C. Häse and R. A. Finkelstein, J. Bacteriol. 173:3311-3317, 1991). The availability of the null mutant, HAP-1, and HAP-1 complemented with pCH2 (which expresses HA/protease), enabled an examination of the role of HA/protease in the virulence of V. cholerae in an animal model. However, the mutants exhibited reversible colonial variation similar but not identical to that which was previously associated with dramatic changes in virulence of parental strain 3083. Regardless of colonial morphology, the mutants were found to be fully virulent in infant rabbits. Thus, the HA/protease is not a primary virulence factor (for infant rabbits). Observations using cultured human intestinal cells indicated, instead, that the HA/protease is responsible for detachment of the vibrios from the cultured cells by digestion of several putative receptors for V. cholerae adhesins.

Cranial hypertrophic interstitial neuropathy

The authors describe a patient with complex cranial neuropathy caused by pathologically proved hypertrophic interstitial neuropathy. Plain and contrast-enhanced MR studies were performed prior to surgical exploration. Surgical complications caused the patient's death and a complete pathology study was done. Though nonspecific, MR proved helpful in determining the extent of disease and areas of anatomic involvement.

Initial results of laser angioplasty under angioscopic guidance for salvage of an ischemic lower limb: preliminary report

From March to July 1989, nine patients at risk for peripheral artery disease underwent intraoperative Nd:YAG laser angioplasty using angioscopy at the Veterans General Hospital (Taipei, Taiwan, Republic of China). Following the laser angioplasty, balloon dilatation was performed in all cases. Eight men and one woman at an average age of 68 were included in the study (range: 58 to 78 years old). Ischemic symptoms included five patients with disabling claudication, four with pain at rest and one with gangrene on the toes. Eight of the nine patients had complete occlusions ranging from 2 to 19 cm in length. Two patients had high degree multiple segmental stenosis of the superficial femoral artery from 1 to 2 cm in length. Initial clinical success (indicated by relief of symptoms and increase in Doppler ankle pressure and index) and improvement in the angiographic luminal diameter was noted in 9 of 10 occluded vessels (90%) that underwent Nd:YAG laser treatment which was delivered at 10 to 12 watts through laser probes. Prelaser intraluminal diameter increased from 0.05 +/- 0.07 to 0.53 +/- 0.07 mm, Doppler ankle pressure index rose from 0.51 +/- 0.12 to 0.81 +/- 0.12, Doppler ankle pressure increased from 62.44 +/- 16.10 to 104 +/- 21.21 mmHg and the amplitude of pulse volume recorder at ankle level rose from 5.77 +/- 2.80 to 12.11 +/- 2.77 mm as compared with prelaser therapy (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of IL-3 on promoter usage, attenuation and antisense transcription of the c-myc oncogene in the IL-3-dependent Ba/F3 early pre-B cell line

The c-myc gene uses two major promoters, P1 and P2, for production of mRNA. In most proliferating normal cells, transcripts initiated from P2 predominate over the ones from P1. Furthermore, transcription of normal and translocated c-myc genes is bidirectional and overlapping. In this study, we have measured the effects of interleukin 3 (IL-3) deprivation and restimulation on c-myc promoter usage in the IL-3-dependent pre-B cell line Ba/F3. The rapid drop in c-myc mRNA expression observed in Ba/F3 cells upon IL-3 deprivation is reversible upon restimulation with interleukin. The use of P1 and P2 promoters, as judged by P1/P2 ratio, shifted from 0.2 in cells in exponential growth or in quiescence to 1.3 following IL-3 stimulation. This change was not due to selective instability of one of the two myc transcripts. In vitro nuclear run-on experiments indicated that IL-3 addition resulted in a large release of transcriptional attenuation, as well as a significant increase in transcriptional initiation. These results are consistent with the hypothesis that P1/P2 promoter usage is involved in the control of transcriptional elongation. Furthermore, deprivation of IL-3 resulted in a dramatic increase in antisense transcription, whereas little change was observed in the rate of initiation of elongation of c-myc mRNA precursors. This correlation suggests a negative role for antisense transcription in expression of c-myc mRNA levels in IL-3-deprived Ba/F3 cells.

Helicobacter pylori infection and the risk of gastric carcinoma

BACKGROUND

Infection with Helicobacter pylori has been linked with chronic atrophic gastritis, an inflammatory precursor of gastric adenocarcinoma. In a nested case-control study, we explored whether H. pylori infection increases the risk of gastric carcinoma.

METHODS

From a cohort of 128,992 persons followed since the mid-1960s at a health maintenance organization, 186 patients with gastric carcinoma were selected as case patients and were matched according to age, sex, and race with 186 control subjects without gastric carcinoma. Stored serum samples collected during the 1960s were tested for IgG antibodies to H. pylori by enzyme-linked immunosorbent assay. Data on cigarette use, blood group, ulcer disease, and gastric surgery were obtained from questionnaires administered at enrollment. Tissue sections and pathology reports were reviewed to confirm the histologic results.

RESULTS

The mean time between serum collection and the diagnosis of gastric carcinoma was 14.2 years. Of the 109 patients with confirmed gastric adenocarcinoma (excluding tumors of the gastroesophageal junction), 84 percent had been infected previously with H. pylori, as compared with 61 percent of the matched control subjects (odds ratio, 3.6; 95 percent confidence interval, 1.8 to 7.3). Tumors of the gastroesophageal junction were not linked to H. pylori infection, nor were tumors in the gastric cardia. H. pylori was a particularly strong risk factor for stomach cancer in women (odds ratio, 18) and blacks (odds ratio, 9). A history of gastric surgery was independently associated with the development of cancer (odds ratio, 17; P = 0.03), but a history of peptic ulcer disease was negatively associated with subsequent gastric carcinoma (odds ratio, 0.2; P = 0.02). Neither blood group nor smoking history affected risk.

CONCLUSIONS

Infection with H. pylori is associated with an increased risk of gastric adenocarcinoma and may be a cofactor in the pathogenesis of this malignant condition.

Progressive multifocal leukoencephalopathy in persons infected with human immunodeficiency virus, San Francisco, 1981-1989

Progressive multifocal leukoencephalopathy (PML), a rare neurological disease, has been sporadically reported in persons infected with human immunodeficiency virus (HIV), the causative agent of acquired immune deficiency syndrome (AIDS). From January 1981 through February 1989, in San Francisco, we identified 94 HIV-infected persons with PML, of whom 48 (51%) were pathologically confirmed (as required for AIDS case reporting). These 48 patients were significantly older when diagnosed with AIDS (20% older than 50 years) than patients with AIDS without PML. The remaining 46 (49%) patients, diagnosed clinically and by neuroimaging, did not differ significantly from definitive patients in demographic or survival characteristics after PML diagnosis. We detected antibodies to JC virus, the causative agent of PML, in 9 of 14 (64%) AIDS-related patients with PML, and in 9 of 14 (64%) matched control subjects, suggesting that determination of JC virus antibody status before AIDS diagnosis does not reliably indicate which patients will contract PML. Our study shows that the proportion of patients with AIDS who contracted PML remained stable between 1981 and 1988, but increased in the first 2 months of 1989. Our findings further indicate that PML in HIV-infected patients may be underestimated by as much as 50%.

Inflammatory pseudotumor of the choroid plexus in Sjögren's disease

We report an unusual case of inflammatory pseudotumor of the choroid plexus of the right lateral ventricle, manifesting as an intraventricular mass and causing unilateral hydrocephalus in a 48-year-old man who suffered from Sjögren's disease and subacute cutaneous lupus erythematosus. The lesion obliterated the normal choroidal architecture by a mixed chronic inflammatory process that was associated with reactive connective tissue changes. Immunohistochemical studies showed no light-chain restriction in the cells, and residual islands of transthyretin-positive epithelial cells were identified, implicating the choroid plexus origin of the mass.

Helicobacter pylori infection in intestinal- and diffuse-type gastric adenocarcinomas

Gastric cancer can be divided into two histologic types: intestinal and diffuse. To determine whether Helicobacter pylori, a bacterium linked with gastritis, was associated with either cancer type, we reviewed histologic sections from stomachs of patients who had undergone gastrectomy for gastric cancer. Of 37 of the sections with evidence of intestinal-type cancer, 33 (89.2%) contained H pylori in noncancerous tissue compared with 7 (31.8%) of 22 of the sections with evidence of diffuse-type cancer (odds ratio = 17.7; P less than .001). This association remained strong when controlled for age, sex, site, and number of sections reviewed. The prevalence of H pylori in intestinal-type gastric cancer far exceeded the prevalence of H pylori in diffuse disease and that described in the normal US population. This finding suggests that H pylori may be a cofactor in development of intestinal-type gastric cancer.

L-tryptophan and the eosinophilia-myalgia syndrome: pathologic findings in eight patients

Pathologic findings in eight patients with the eosinophilia-myalgia syndrome, secondary to L-tryptophan ingestion, are reported. Tissue was obtained by biopsy alone in six patients, by biopsy and autopsy in the seventh patient, and by autopsy alone in the eighth patient. Muscle biopsies in five patients demonstrated an inflammatory infiltrate composed predominantly of lymphocytes, histiocytes, plasma cells, and a few eosinophils. The inflammation involved the perimysial and epimysial connective tissue, the walls of some small blood vessels, the perineurium of small nerve twigs, muscle spindles, and fibrous septae of subcutaneous adipose tissue. In two patients with peripheral neuropathy and one patient without overt neuropathy, denervation atrophy of muscle and perimysial and epimysial fibrosis were present. Sural nerve biopsy tissue taken from two patients displayed prominent axonopathy in one, and minimal changes in the second. Pulmonary changes in the two autopsied patients included endothelial cell damage, endovasculitis and fibromyxoid intimal change im arteries and veins, and interstitial pneumonitis with fibrosis.

Primary cutaneous rhabdomyosarcoma

We report an unusual case of primary cutaneous embryonal rhabdomyosarcoma presenting as a solitary skin lesion on the anterior chest of a 20-month-old child. The tumor was characterized by small, round to oval, poorly differentiated cells. Immunohistochemically, the tumor was negative for NSE, S-100 protein, LCA, and keratin but positive for muscle-specific actin, myoglobin, desmin, and vimentin, thus indicating the presence of myogenous differentiation. Ultrastructural analysis demonstrated thick and thin filaments. Special studies showed no evidence of a primary rhabdomyosarcoma in the patient at a more typical location, nor was there any evidence of metastases.

Specificity of androgen receptors of hepatocellular carcinoma and liver in humans

The specificity of androgen receptor in hepatocellular carcinoma and the liver was investigated using auto-radiographic techniques. Partial hepatectomy was carried out on 11 patients with hepatocellular carcinoma and associated parenchymal disease of the liver. Androgen receptors were assayed biochemically for hepatocellular carcinoma and the surrounding liver in all cases. Estrogen receptor was also measured in five patients. In eight patients, fresh resected specimens as thick as 3 mm were first incubated for 15 minutes in a medium containing estradiol and hydrocortisone, and then radio-labeled testosterones were added to the medium. After another 60 minutes incubation, macro-autoradiographic studies were carried out. With the same medium and chemicals, and using the same principle, micro-autoradiographic studies were performed using fresh hepatocellular carcinoma and liver cell suspensions in six cases. The radio-labeled testosterones were incorporated into hepatocellular carcinoma and the liver to a parallel extent with the androgen receptor titers biochemically assayed. The current results seem to indicate that androgen receptors present in hepatocellular carcinoma and the liver of humans specifically bind androgens. Further studies are needed to elucidate the role of AR in hepatocarcinogenesis in humans.

Evolution of post-natal herpes simplex virus encephalitis to multicystic encephalopathy

A 3-week-old, previously healthy infant developed biopsy-proven Herpes virus type 2 (HSV-2) encephalitis. The encephalitis was characterized by cells having intranuclear inclusions and was without evidence of inflammation or hemorrhage. Neuroimaging studies did not show any destructive lesions in the brain. In spite of antiviral therapy, the infant's neurological conditions deteriorated, and the patient died at the age of 18 weeks. Post-mortem examination showed that most of the cerebral hemispheres were replaced by multiloculated cystic cavities of various sizes, typical of multicystic encephalopathy (MCE). The cystic lesions were randomly distributed and were not confined to any vascular territory. By light microscopy, there were no features of viral infection in the brain. Although in situ hybridization of the biopsy specimen taken during the acute phase of the disease demonstrated abundant HSV genome, this same method failed to detect HSV on the post-mortem specimen. These findings suggest that HSV-2 can induce MCE. Furthermore, the absence of histological features of viral encephalitis and the failure to demonstrate viral genome in the brain at autopsy does not exclude an infectious etiology in certain cases of MCE.

Evidence for the exchange of segments between genomes during the evolution of lambdoid bacteriophages

Heteroduplexes between the DNA molecules of 12 lambdoid phages were analysed by electron microscopy. The positions of the regions of base sequence homology between the DNA molecules divide them into 35 segments, most of which have a number of alternative forms (alleles), which in general must be functionally homologous but which differ in base sequence and length. The positions of the boundaries between segments in phage lambda show that each segment is probably a gene or a group of genes, and that each phage genome is a different combination of the alleles of the segments. The frequency of the occurrence of the different alleles indicates that the total number in the natural population may be small. The different combinations of alleles of separate segments, found among the phages, indicate the exchange of segments between the phages during their evolution.