The association between lithium use and neurocognitive performance in patients with bipolar disorder

Lithium remains the gold standard for the treatment of bipolar disorder (BD); however, its use has declined over the years mainly due to the side effects and the subjective experience of cognitive numbness reported by patients. In the present study, we aim to methodically test the effects of lithium on neurocognitive functioning in the largest single cohort (n = 262) of BD patients reported to date by harnessing the power of a multi-site, ongoing clinical trial of lithium monotherapy. At the cross-sectional level, multivariate analysis of covariance (MANCOVA) was conducted to examine potential group differences across neurocognitive tests [California Verbal Learning Test (CVLT trials 1-5,CVLT delayed recall), Wechsler Digit Symbol, Trail-making Test parts A and B (TMT-A; TMT-B), and a global cognition index]. At the longitudinal level, on a subset of patients (n = 88) who achieved mood stabilization with lithium monotherapy, we explored the effect of lithium treatment across time on neurocognitive functioning. There were no differences at baseline between BD patients that were taking lithium compared with those that were not. At follow-up a significant neurocognitive improvement in the global cognitive index score [F = 31.69; p < 0.001], CVLT trials 1-5 [F = 29.81; p < 0.001], CVLT delayed recall [F = 15.27; p < 0.001], and TMT-B [F = 6.64, p = 0.012] was detected. The cross-sectional and longitudinal (on a subset of 88 patients) investigations suggest that lithium may be beneficial to neurocognitive functioning in patients with BD and that at the very least it does not seem to significantly impair cognition when used therapeutically.

Premorbid cannabis use is associated with more symptoms and poorer functioning in schizophrenia spectrum disorder

BACKGROUND

Cannabis use disorder is associated with an earlier age at onset and a more severe outcome of schizophrenia spectrum disorders. The role of cannabis use before the onset of illness (premorbid cannabis use) has not been fully investigated. We here examined how amount and type of premorbid cannabis use was associated with the later course of illness including current substance use, symptoms and level of functioning in schizophrenia spectrum disorder.

METHOD

We used a naturalistic sample of patients with DSM-IV schizophrenia spectrum disorders with a comprehensive history of illness and substance use. Data on premorbid substance use was obtained from comprehensive self-report. The relationship to outcome was investigated using regression models that included current substance use and premorbid functioning.

RESULTS

Pre-schizophrenia cannabis use was significantly associated with more severe psychotic symptoms and impaired functioning. Higher levels of premorbid cannabis use were associated with higher levels of current psychotic symptoms. These associations were independent of current substance use and premorbid functioning. Early use of cannabis (age <17 years) was associated with earlier age at onset of psychosis, independently of potential confounders.

CONCLUSIONS

Pre-psychosis cannabis use affects illness outcome in schizophrenia spectrum disorders, and is associated with lower age at onset of psychosis. These findings of independent negative effects of premorbid cannabis use in schizophrenia suggest that a limitation of the general use of cannabis may have beneficial health effects.

Mucinous ductal ectasia of the biliary tree secondary to mucous metaplasia: A case report

Mucinous ductal ectasia is an uncommon disorder, characterized by ductal dilatation and filling with thick, viscid mucus, described in the pancreas. We report a case of mucinous ductal ectasia of the biliary tree. The cause of the mucus production was mucous metaplasia in the biliary epithelium. The patient was followed for 16 years, treated with serial saline flushings of the biliary tree whenever he became symptomatic.

In situ deposition of complement in human acute brain ischaemia

Experimental animal models indicate that complement contributes to tissue damage during brain ischaemia and stroke, but limited data are available for a role of the complement in human stroke. We, therefore, evaluated whether acute ischaemia leads to complement activation in human brain. Indirect immunohistochemical staining was performed on paraffin-embedded, formalin-fixed human brain from 10 patients and 10 controls. Complement components C1q, C3c and C4d were detected in all ischaemic lesions, suggesting activation via the classical pathway. C9, C-reactive protein and IgM were detected in necrotic zones. Marked CD59 and weak CD55 expression were found in normal brains, but these complement regulators were virtually absent in ischaemic lesions. Modest amounts of mannose-binding lectin (MBL), MBL-associated serine protease-2 and factor B were found in both ischaemic lesions and controls. These data suggest that increased deposition of complement components combined with decreased expression of complement regulators is a possible mechanism of tissue damage during ischaemia in human brain.

Oats induced villous atrophy in coeliac disease

The current trend is to allow coeliac disease (CD) patients to introduce oats to their gluten free diet. We sought further data from the clinical setting with regards to oats consumption by coeliac patients. Several oat products were tested for wheat contamination using a commercial enzyme linked immunoassay (ELISA) kit, and six samples were examined by an ELISA using a cocktail of monoclonal antibodies, mass spectrometry, and western blot analysis. Nineteen adult CD patients on a gluten free diet were challenged with 50 g of oats per day for 12 weeks. Serological testing and gastroduodenoscopy was performed before and after the challenge. Biopsies were scored histologically and levels of mRNA specific for interferon gamma were determined by reverse transcription-polymerase chain reaction analysis. Oats were well tolerated by most patients but several reported initial abdominal discomfort and bloating. One of the patients developed partial villous atrophy and a rash during the first oats challenge. She subsequently improved on an oats free diet but developed subtotal villous atrophy and dramatic dermatitis during a second challenge. Five of the patients showed positive levels of interferon gamma mRNA after challenge. Some concerns therefore remain with respect to the safety of oats for coeliacs.

Effect of global hypoxia-ischaemia followed by 24 h of mild hypothermia on organ pathology and biochemistry in a newborn pig survival model

BACKGROUND

Perinatal asphyxia may lead to multiorgan damage as well as brain injury. Posthypoxic hypothermia (HT) may protect other organs in addition to the brain. The aim of this study was to assess the systemic effects of our global hypoxic-ischaemic (HI) insult and compare the effect of mild 24-hour HT with normothermia (NT) during unsedated recovery.

METHOD

Thirty-eight newborn pigs were subjected to 45 min of global HI by ventilating them with approximately 6% O2. On reoxygenation, pigs were randomised to NT or HT. The 18 NT piglets were maintained at rectal temperature 39.0 degrees C for 72 h. Twenty-three HT pigs (20 experimental HT and 3 sham controls) were cooled to rectal temperature 35 degrees C for 24 h before NT was resumed and the animals then survived a further 48 h.

RESULTS

All lesions were small with no apparent clinical effect. The incidence of any damage to the heart (6 HT vs. 9 NT), liver (9 HT vs. 7 NT), kidney (6 HT vs. 9 NT) or intestinal injury (8 HT vs. 2 NT, p = 0.07) was not different in the two groups. More HT piglets developed lung injury, 10 HT and 3 NT. Plasma [Na], [K], [Ca] and [Mg] increased significantly after the HI insult as compared to baseline values. For the 24-hour period plasma [K] and [Ca] were significantly higher in the HT group, the mean area under the curve (AUC) being for [K] AUC(HT) 4.4 mmol/l vs. AUC(NT) 3.9 mmol/l, p = 0.04 and for [Ca] AUC(HT) 2.7 mmol/l vs. AUC(NT) 2.5 mmol/l, p = 0.01, respectively. Aspartate aminotransferase peaked at 48 h in the HT group and at 24 h in the NT group. Creatinine peaked at >72 h in the HT pigs and at 48 h in the NT pigs. White blood cells (WBC) peaked at 12 h for the HT pigs and at 6 h for the NT animals. AUC of the WBC during the cooling was significantly lower in the HT pig (AUC(HT) 11.1 vs. AUC(NT) 15.3 10(3)/mm3, p = 0.04). The HT pigs needed more glucose to maintain normal glucose during the last 12 h of HT. Also HT animals needed more oxygen during cooling to maintain PaO2.

CONCLUSION

Twenty-four hours of mild HT did not reduce damage in any organ. There was a slight increase in lung damage in the HT group. None of the biochemical or pathological changes were of clinical significance. We conclude that mild HT for 24 h does not affect the organ systems adversely when compared to NT. Additional glucose and oxygen is needed during cooling to maintain normal values.

Evidence for intraaxonal spread of Listeria monocytogenes from the periphery to the central nervous system

Rhombencephalitis due to Listeria monocytogenes is characterized by progressive cranial nerve palsies and subacute inflammation in the brain stem. In this paper, we report observations made on mice infected with L. monocytogenes. Unilateral inoculation of bacteria into facial muscle, or peripheral parts of a cranial nerve, induced clinical and histological signs of mainly ipsilateral rhombencephalitis. Similarly, unilateral inoculation of bacteria into lower leg muscle or peripheral parts of sciatic nerve was followed by lumbar myelitis. In these animals, intraaxonal bacteria were seen in the sciatic nerve and its corresponding nerve roots ipsilateral to the bacterial application site. Development of myelitis was prevented by transsection of the sciatic nerve proximally to the hindleg inoculation site. Altogether, our results support the hypothesis that Listeria rhombencephalitis is caused by intraaxonal bacterial spread from peripheral sites to the central nervous system.

Twenty-four hours of mild hypothermia in unsedated newborn pigs starting after a severe global hypoxic-ischemic insult is not neuroprotective

Three to 12 h of mild hypothermia (HT) starting after hypoxia-ischemia is neuroprotective in piglets that are anesthetized during HT. Newborn infants suffering from neonatal encephalopathy often ventilate spontaneously and are not necessarily sedated. We aimed to test whether mild posthypoxic HT lasting 24 h was neuroprotective if the animals were not sedated. Thirty-nine piglets (median weight 1.6 kg, range 0.8-2.2 kg; median age 24 h, range 7-48 h) were anesthetized and ventilated and subjected to a 45-min hypoxic (FiO(2) approximately 6%) global insult (n = 36) or sham hypoxia (n = 3). On reoxygenation, 18 were maintained normothermic (NT, 39.0 degrees C) for 72 h, and 21 were cooled from 39 (NT) to 35 degrees C (HT) for the first 24 h before NT was resumed (18 experimental, three sham hypoxia). Cardiovascular parameters and intermittent EEG were documented throughout. The brain was perfusion fixed for neuropathology and five main areas examined using light microscopy. The insult severity (duration in minutes of EEG amplitude < 7 microV) was similar in the NT and HT groups, mean +/- SD (28 +/- 7.2 versus 27 +/- 8.6 min), as was the mean FiO(2) (5.9 +/- 0.7 versus 5.8 +/- 0.8%) during the insult. Six NT and seven HT piglets developed posthypoxic seizures that lasted 29 and 30% of the time, respectively. The distribution and degree of injury (0.0-4.0, normal-maximal damage) within the brain (hippocampus, cortex/white matter, cerebellum, basal ganglia, thalamus) were similar in the NT and HT groups (overall score, mean +/- SD, 2.3 +/- 1.5 versus 2.4 +/- 1.3) as was the EEG background amplitude at 3 h (13 +/- 3.5 versus 10 +/- 3.3 microV). The HT animals shivered and were more active. The sham control group (n = 3) shivered but had normal physiology and neuropathology. Plasma cortisol was significantly higher in the HT group during the HT period, 766 +/- 277 versus 244 +/- 144 microM at 24 h. Mild postinsult HT for 24 h was not neuroprotective in unsedated piglets and did not reduce the number of animals that developed posthypoxic seizures. Cortisol reached 3 times the NT value at the end of HT. We speculate that the stress of shivering and feeling cold interfered with the previously shown neuroprotective effect of HT. Research on the appropriateness of sedation during clinical HT is urgent.

Qualitative and quantitative relationship between dysplastic aberrant crypt foci and tumorigenesis in the Min/+ mouse colon

The multiple intestinal neoplasia (Min)/+ mouse, which harbors only one functional allele of the Apc gene, is susceptible to environmental factors that disrupt this gene and subsequently trigger Apc-driven tumorigenesis in the colon. Aberrant crypt foci (ACF) are assumed to be preneoplastic lesions in colon carcinogenesis. Recently, we reported the absence of "classical" ACF in the colon of untreated Min/+ mice. Instead we identified flat dysplastic lesions, which we denoted ACF(Min) (J. E. Paulsen et al., Scand. J. Gastroenterol., 35: 534-539, 2000). In contrast to the classical type, ACF(Min) are not elevated above the surrounding mucosa, and their detection is totally dependent on methylene blue staining and transillumination. In the present study, we treated Min/+ mice with 5 mg/kg body weight azoxymethane (AOM) at weeks 1 and 2 and demonstrated induction of both types of lesions. However, only ACF(Min) appeared to be associated with the development of adenomas. Monocryptal ACF(Min), large ACF(Min), and adenomas showed a uniform histopathological picture of dysplasia and cytoplasmic overexpression of beta-catenin, indicating a qualitative relationship between these lesions. Also a quantitative relationship was suggested because the dramatic decrease in ACF(Min) number from week 7 to 11 was paralleled by a reciprocal increase in tumor number, indicating fast-crypt multiplication of ACF(Min). In AOM-treated +/+ (wild-type) littermates, a low number of ACF(Min) and tumors with the same characteristics as in Min/+ mice was seen. In contrast to ACF(Min), histopathological and immunohistochemical examination of classical ACF showed normal or hyperplastic crypts with normal levels of beta-catenin expression. In AOM-treated Min/+ mice, the number of classical ACF was virtually constant from week 7 to 11, and only a modest increase of crypt multiplicity was observed. The number of AOM-induced classical ACF at week 11 was not different in Min/+ mice and +/+ mice. In conclusion, we identified two distinct populations of altered crypts in the colon of Min/+ mice after AOM treatment. The ACF(Min), which resemble the dysplastic ACF described previously, clearly showed a continuous development from the monocryptal stage to adenoma, and they were characterized by fast-growing crypts with altered control of beta-catenin. In contrast, the classical ACF, which resemble the hyperplastic ACF described previously, were characterized by slow-growing crypts with normal beta-catenin expression, and they were probably not related to tumorigenesis.

[Will the revolutionary knowledge of apoptosis play an important role in medicine?]

Apoptosis is a phenomenon of fundamental importance in embryonal development and the homeostatic regulation of mature tissue. We review the present knowledge on apoptosis and the evidence that apoptosis may play a role in the pathogenesis of human disease. As examples we discuss its role in cancer, ischemic diseases, heart failure and neurodegenerative diseases.

Granulocyte marker protein is increased in stools from rats with azoxymethane-induced colon cancer

BACKGROUND

We wanted to investigate the relationship between the fecal levels of granulocyte marker protein (GMP) and the presence of aberrant crypt foci (ACF) and colorectal cancer in rats given injections of azoxymethane (AOM) and fed either of two different diets, a basal diet plus 20% corn oil or 20% beef suet, respectively.

METHODS

The rats received intraperitoneal injections of AOM, 15 mg/kg, once weekly for 6 weeks and were killed after 22 weeks.

RESULTS

In the group fed beef suet 17 of 19 rats developed colon cancer, whereas in the group fed corn oil 4 of 14 rats developed cancer. None of the 20 control rats fed either the beef suet or corn oil diets developed cancer or aberrant crypts, and GMP remained unchanged. Surprisingly, the numbers of ACF were significantly higher (467 versus 295; P = 0.004) in the group fed corn oil than in the group fed beef suet. On the other hand, the size (crypts/focus) of the ACF was significantly higher (P = 0.03) in the beef suet group. Furthermore, fecal GMP was significantly higher in the beef suet group than in the corn oil group after 18 weeks, and this difference increased further toward the end of the study. GMP was greatly increased in all rats with colorectal cancer.

CONCLUSIONS

Fecal GMP may have provided us with a valuable tool for further studies of the induction and progression of neoplasia in rats and, possibly, in mice, since the anti-GMP antibody cross-reacts with feces extracts from mice.

[Brain stem infection caused by Listeria monocytogenes]

Rhombencephalitis due to Listeria monocytogenes is a serious form of brainstem inflammation. It is difficult to diagnose on the basis of clinical and laboratory findings alone. We describe a fatal case of Listeria monocytogenes rhombencephalitis in a previously healthy female teenager. Clinical and pathogenetic aspects of this condition are discussed.

[Listeria monocytogenes--the perfect parasite?]

The pathogen Listeria monocytogenes has an extraordinary intracellular life cycle, based on adaption to and exploitation of normal cellular mechanisms. Extracellular organisms induce their own phagocytosis, followed by destruction of the phagosomal membrane. Cytoplasmatic bacteria organize the intracellular protein actin into "comet tails", and thus gain motility. In contact with the plasma membrane, motile bacteria induce a pseudopodium, corresponding to an invagination of the plasma membrane of the neighbouring cell. Eventually, the pseudopodium is engulfed by the neighbouring cell, creating a double membrane vacuole. L. monocytogenes destroys the double membrane, and escapes into the cytoplasm. This article reviews the molecular biology of Listeria infection, and how research in this field has yielded increased insight into normal cellular processes. Finally, we propose that the neuroinvasive properties of L. monocytogenes is caused by actin-dependent transport within axons from the periphery to the central nervous system.

Hemispheric asymmetry in schizophrenia: a "dual deficits" model

BACKGROUND

The aim was 1) to investigate left hemisphere functional integrity for auditory language processing in schizophrenic patients; and 2) to investigate the interaction between brain laterality and attentional processing by having subjects shift attention to the left or right ear.

METHODS

The subjects were 33 schizophrenic inpatients, and 33 healthy comparison subjects with the same age, handedness, and gender distribution as the patient subjects. All subjects were tested with dichotic listening (DL) to consonant-vowel syllables, which is a measure of lateralized temporal lobe language processing. The subjects were tested under three different attentional conditions: a non-forced attention condition, attention focused to the right ear stimulus, and attention focused to the left ear stimulus.

RESULTS

The main findings were 1) an absence of the expected right ear advantage in the schizophrenic group during the non-forced attention condition; and 2) a failure to modify DL performance through shifting of attention to either the right or left ear. The comparison group showed a right ear advantage during the non-forced and forced-right attention conditions (increased right ear advantage during the forced-right condition), and a left ear advantage during the forced-left attention condition. There were no significant effects of handedness.

CONCLUSIONS

This pattern of results may indicate a "dual deficit" involving both automatic and controlled processing deficits in schizophrenia.

Lactate and pyruvate changes in the cerebral gray and white matter during posthypoxic seizures in newborn pigs

Cerebral lactate rises after chemically induced seizures, but it is not known if this occurs with posthypoxic seizures. We examined changes in lactate and pyruvate in gray and white matter in the newborn pig brain after a hypoxic insult known to produce seizures and permanent brain damage. Fourteen halothane-anesthetized piglets aged 24-49 h, were instrumented with a two-channel scalp EEG and microdialysis probes positioned in white and gray matter. Forty-five minutes of hypoxia were induced by reducing the fraction of inspired O2 to the maximum concentration at which EEG amplitude was < 7 microV. Postinsult EEG was classified as electroconvulsive activity (ECA) (n = 4) or burst suppression (n = 2), persistently low amplitude (n = 2), or intermittent spikes on normal background activity (n = 6). Six hours after the insult the brains were perfusion fixed for histologic probe localization. Plasma lactate and brain lactate had different time courses with brain having a persistently elevated lactate/pyruvate (L/P) ratio. The highest L/P ratios in gray and white matter were in the two pigs with persistently low amplitude EEG. There was no association between onset of electroconvulsive activity and an increase in lactate or L/P ratio. Posthypoxic energy metabolism is disturbed in both gray and white matter probably because of mitochondrial dysfunction. Seizure activity does not increase cerebral lactate or L/P ratio above the already raised levels found in posthypoxic encephalopathy. These findings cast further doubt on the hypothesis that such seizures are, in themselves, damaging.

[Cytomegalovirus as the cause of toxic dilatation of the colon]

Toxic dilatation of the colon is sometimes a complication which occurs during exacerbations of inflammatory bowel disease. It often requires immediate surgical intervention. We describe here a male patient with known ulcerative colitis who was investigated for fever of unknown cause, diarrhoea, and general illness. Upon admission he had only modest symptoms of colitis and received no immunosuppressive treatment. The condition worsened considerably, and subsequent colonoscopy demonstrated widespread lesions compatible with viral disease, but not with ulcerative colitis. Antiviral treatment for cytomegalovirus was started immediately, but progression of the condition with toxic dilatation called for a rapid colectomy. Histological examination showed widespread lesions compatible with cytomegalovirus infection. This clinical picture is rarely seen in immunocompetent patients.

Protective effects of moderate hypothermia after neonatal hypoxia-ischemia: short- and long-term outcome

We have previously shown that mild hypothermia applied after hypoxia-ischemia in newborn piglets and rats reduces brain injury evaluated 3-7 d after the insult. The aim of the present study was to assess the neuroprotective efficacy of hypothermia with respect to short- (neuropathology) and long-term (neuropathology and sensorimotor function) outcome after hypoxia-ischemia in 7-d-old rats. One hundred fourteen animals from 13 litters survived either 1 or 6 wk after a hypoxic-ischemic insult. The animals were randomized to either 1) normothermic recovery for the whole 1- or 6-wk period or 2) cooling to a rectal temperature of 32.0 degrees C for the first 6 h followed by normothermic recovery with the dam. Hypothermia offered a uniform protection of 27, 35, 28, and 25% in cerebral cortex, hippocampus, basal ganglia, and thalamus, respectively, in the 1-wk survivors (n = 32). The corresponding values for the 6-wk survivors (n = 61) were 22, 28, 37, and 35%. There was a significant correlation between sensorimotor performance and infarct volume (r = 0.66; p < 0.001). However, the sensorimotor function was not significantly improved by hypothermia if all animals were included, but in female pups the total functional score was higher in the hypothermia group (150 +/- 35 versus 100 +/- 34, p < 0.0007) which corresponded to a marked (51%) reduction of the neuropathology score in this subgroup. This is the first neonatal study to show a long-term histopathologic protection of the brain after posthypoxic hypothermia.

Post-hypoxic hypothermia reduces cerebrocortical release of NO and excitotoxins

Hypothermia applied after hypoxia offers neuroprotection in neonatal animals, but the mechanisms involved remain unknown. Hypoxia was induced in newborn piglets and changes in excitatory amino acids (EAAs) and the citrulline:arginine ratio (CAR) were followed by microdialysis for 5 h. After the 45 min hypoxic insult, the animals were randomized to receive normothermia (39 degrees C; n=7) or hypothermia (35 degrees C; n = 7). After reoxygenation, extracellular glutamate, aspartate and the excitotoxic index were significantly lower in the cerebral cortex of hypothermic animals than in normothermic animals. A progressive rise of the CAR occurred during reoxygenation in the normothermic group whereas the ratio tended to decrease in the hypothermic group. In conclusion, post-hypoxic hypothermia attenuated NO production and overflow of EAAs.

Posthypoxic hypothermia in newborn piglets

The purpose of this study was to determine whether mild hypothermia after a moderate hypoxic-ischemic insult reduces the extent of brain damage. Hypoxia was achieved in newborn piglets (n = 24; age, 14-72 h) by abrupt reduction of the inspired oxygen concentration (FiO2) to the maximum concentration (approximately 6%) giving low amplitude (< 7.0 microV) EEG. FiO2 was temporarily increased if heart rate, blood pressure, or end expiratory partial pressure of alveolar CO2 (PAco2) were markedly reduced. This intermittently resulted in EEG amplitude greater than 7 microV, the EEG traces were therefore later examined to determine the duration of low amplitude EEG. After 45 min of hypoxia, the animals were randomized to normothermia (39 degrees C) or hypothermia (35 degrees C) for 3 h. Hypothermia was achieved by applying packs containing ice water. Neurologic assessments and EEG recordings were performed regularly until 3 d when the brains were perfusion fixed. Histologic damage in cortex/white matter, cerebellum, hippocampus, basal ganglia, and thalamus was graded by a pathologist blind to treatment allocation. We found that the severity of brain damage (by histopathologic and neurologic evaluation) was not significantly different when the piglets were normothermic after hypoxia compared with the group made hypothermic. Increased duration of low amplitude EEG and seizure activity were associated with increased damage. When controlling for duration of hypoxia and excluding seizures, piglets undergoing hypothermia had approximately 50% less severe histopathologic damage in cortex/white matter, cerebellum, and hippocampus than those kept normothermic. Thalamus and basal ganglia had no or minor damage. It was concluded that there was no general beneficial effect of postinsult hypothermia. However, when controlling for the duration of the insult and occurrence of seizures, hypothermia reduced the severity of brain damage. This indicates a significant neuroprotective effect of 3 h of mild hypothermia on moderate, but not severe, hypoxic-ischemic insults.

A piglet survival model of posthypoxic encephalopathy

The aim of this study was to produce a neonatal piglet model which, avoiding vessel ligation, exposed the whole animal to hypoxia and produced dose-dependent clinical encephalopathy and neuropathologic damage similar to that seen after birth asphyxia. Twenty-three piglets were halothane-anesthetized. Hypoxia was induced in 19 piglets by reducing the fractional concentration of inspired oxygen (FiO2) to the maximum concentration at which the EEG amplitude was below 7 microV (low amplitude) for 17-55 min. There were transient increases in Fio2 to correct bradycardia and hypotension. Posthypoxia, the piglets were extubated when breathing was stable. Four were sham-treated controls. We aimed at 72-h survival; seven died prematurely due to posthypoxic complications. EEG and a videotaped itemized neurologic assessment were recorded regularly. We found that 95% of the animals showed neuropathologic damage. The duration of low amplitude EEG during the insult and the arterial pH at the end of the insult correlated with cortical/white matter damage; r = 0.75 and 0.81, respectively. Early postinsult EEG background amplitude (r = 0.86 at 3 h) and neurologic score (r = 0.79 at 8 h) correlated with neuropathology. Epileptic seizures in seven animals were always associated with severe neuropathologic damage. We conclude that EEG-controlled hypoxia and subsequent intensive care enabled the animals to survive with an encephalopathy which correlated with the cerebral hypoxic insult. The encephalopathy was clinically, electrophysiologically, and neuropathologically similar to that in the asphyxiated term infant. This model is suitable for examining mechanisms of damage and evaluation of potential protective therapies after birth asphyxia.

[Ischemic colitis in young patients]

Ischaemic colitis is an established clinical entity in the elderly, characterized by acute onset of abdominal pain, diarrhoea and rectal bleeding. Six women 20-49 years old have been admitted to our hospital with ischaemic colitis during the last seven years. One of the cases in described, followed by a discussion of associated factors and clinical aspects. We emphasize that ischaemic colitis is an important differential diagnosis of colitis even in younger patients.

The stress of being restrained reduces brain damage after a hypoxic-ischaemic insult in the 7-day-old rat

Experimental animals and patients are immobilized to allow continuous monitoring of physiological parameters. Restraint stress affects brain neurotransmitter levels and induces expression of immediate early genes. Whether immobilization stress affects outcomes in newborn animals which have suffered a hypoxic-ischaemic insult is unknown. Twenty 7-day-old rats subjected to unilateral carotid ligation followed by 2 h hypoxia were randomly assigned to carry a rectal probe or to move freely. The 10 restrained animals showed 50% reduction in damage in all brain regions (p < 0.0.3). Plasma lactate levels, a marker of stress, were three times higher in animals carrying a rectal probe (p < 0.0.02) than those moving freely. We conclude that the stress of being restrained reduced damage after a hypoxic-ischaemic insult in the immature rat.

Posthypoxic cooling of neonatal rats provides protection against brain injury

AIM

To determine whether moderate hypothermia, applied after a hypoxic-ischaemic insult in neonatal rats, reduces cerebral damage.

METHOD

Unilateral hypoxic-ischaemic brain damage was induced in 7 day old rats by left carotid ligation, followed by 120 minutes of normothermic exposure to 8% O2, followed by random selection to three hours of hypothermia (rectal temperature, mean (SD), 32.5 (0.4) degrees C) or normothermia (38.3 (0.4) degrees C). One hundred and one animals were used for brain temperature or blood chemistry studies and 24 for survival studies (7 days) with neuropathology, including cell counting as outcome measures.

RESULTS

Thirty sections from each brain were histologically examined with respect to distribution and pattern of damage and given a score from 0 to 4. Animals treated with hypothermia had significantly less damage than normothermic animals (score 0.5 (0.3) vs 1.8 (0.5)).

CONCLUSIONS

Posthypoxic hypothermia reduces brain damage in awake, unrestrained 7 day old rats.

Early entry of plasma proteins into damaged neurons in brain infarcts. An immunohistochemical study on experimental animals

Entry of plasma proteins into damaged neurons has previously been demonstrated in various pathological conditions, but little is known about brain infarcts in this respect. In the present study, focal ischemic lesions were produced in rats by permanent occlusion of the middle cerebral artery (MCA). The animals were killed from 1 to 48 h postlesion. Leakage of plasma proteins across the blood-brain barrier into the infarcted area was visualized with immunostaining 2-3 h after the occlusion. This is earlier than in most previous reports. Entry of plasma proteins into ischemic neurons was seen 3 h after permanent occlusion of the MCA, while reliable changes were not seen until 12-24 h in sections stained with hematoxylin and eosin (H & E). Ischemic neurons stained for plasma proteins irrespective of their morphological appearance. Even cells that appeared normal with H & E staining were positively labeled. The technique may be used to diagnose very early ischemic lesions.

Neuronal uptake of plasma proteins after transient cerebral ischemia/hypoxia. Immunohistochemical studies on experimental animals and human brains

Rapid uptake of plasma proteins into damaged neurons has been demonstrated previously after lesions which cause early breakdown of the blood-brain barrier (BBB). The present study was undertaken to see whether a similar uptake occurred after hypoxic/ischemic episodes in men and experimental animals. Forebrain ischemia was produced in rats by a combination of carotid clamping and hypotension for 15 min, followed by recirculation for 6 h, 24 h, 48 h and 5 d. Paraffin sections from the brains were incubated with antiserum against albumin, and parallel sections were stained with hematoxylin and eosin (H & E). Breakdown of the BBB with extravasation of albumin was seen after 6 h in the lateral reticular nucleus of the thalamus, the dorsolateral striatum, and in restricted areas of the cerebral cortex. Uptake of albumin into damaged neurons was seen in the same structures, and partly before reliable changes were observed in routinely stained sections. With longer survival periods, the staining of the neuropil became stronger and more neurons in the damaged areas were positively labeled. After 48 h and 5 d many neurons in the hippocampal sector CA1 had also taken up plasma proteins. A similar uptake of plasma proteins into damaged neurons was seen in brains from patients with histological evidence of hypoxic injury. Even the small leakage of proteins that occurs after hypoxic/ischemic lesions is thus sufficient to give a definite immunostaining of damaged neurons.

Distinction between artefactually shrunken and truly degenerated 'dark' neurons by in situ fixation with microwave irradiation

Dark, shrunken neurons frequently occur as artefacts in immersion fixed tissue. Perfusion fixation will prevent artefacts of this type. However, morphologically identical neurons have been described as truly degenerated cells in perfusion fixed brains in various pathological conditions. Since adequate perfusion is difficult to obtain in some pathological conditions, the question still remains whether the dark neurons found in some of these situations are true in vivo phenomena or artefacts caused by inadequate fixation. In the present study rat brains with cryogenic lesions were fixed in situ by microwave irradiation. With this method no artefactually changed dark neurons were observed in the normal parts of the brains. In the cryogenic lesions, however, a narrow rim of dark, shrunken neurons occurred adjacent to the normal cortex. This zone was identical to that observed in perfusion fixed tissue. Since inadequate fixation due to uneven perfusion of the damaged tissue is prevented with this method, we suggest that the neuronal changes represent true in vivo phenomena. Fixation with microwave irradiation can thus be used to differentiate between artefactually changed and truly degenerated dark neurons in various pathological conditions.

Neuronal uptake of plasma proteins in cryogenic brain lesions. An immunoelectron microscopic study

A previous light microscopic study on cryogenic brain lesions in rats demonstrated uptake of plasma proteins into damaged neurons within a few minutes after the lesion. The protein concentration was much higher inside the nerve cell bodies than in the surrounding neuropil. This is puzzling since the neuropil to a large extent consists of damaged neuronal processes. The present investigation describes the intracellular localization of albumin in this model using a post-embedding immunoelectron microscopic technique. The distribution of albumin in the lesions was studied after 1, 6 and 12 h survival periods. The intraneuronal albumin was mainly bound to the particulate elements of the cytoplasm and nuclei, while the watery parts of the cells showed no immunoreactivity. The intracellular organelles contained very little albumin, indicating that their membranes may be more resistant to freezing than those of the cells. Most of the neuronal and glial processes in the neuropil were swollen and contained almost no albumin. This explains the contrast between the strong immunoreactivity of the neurons and the vague reactivity of the neuropil in light microscopy.

Neuronal uptake of plasma proteins in brain contusions. An immunohistochemical study

Twenty-five cases of cerebral contusions of various age were examined immunohistochemically for neuronal uptake of albumin and fibrinogen. The neurons in the damaged areas were heavily stained in all cases, even in those of only a few minutes' survival, and they remained positive for serum proteins until they disappeared from the lesions. In hematoxylin and eosin-stained sections, neuronal changes were observed from the first minutes after the lesion but they were indistinguishable from the shrunken "dark" neurons that occur as artifacts in poorly fixed material. However, in contrast to the artificially changed cells, the truly damaged ones took up serum proteins. It is concluded that staining with antisera against serum proteins may serve as early markers for neuronal injury before reliable histological changes have developed.

Hypoxemia and reoxygenation with 21% or 100% oxygen in newborn pigs: changes in blood pressure, base deficit, and hypoxanthine and brain morphology

To study whether room air is as effective as 100% O2 in resuscitation after hypoxia, hypoxemia (PaO2 2.3-4.3 kPa) was induced in newborn pigs (2-5 d old) by ventilation with 8% O2 in nitrogen. When systolic blood pressure had fallen to 20 mm Hg, animals were randomly reoxygenated with either 21% O2 (group 1, n = 9) or 100% O2 (group 2, n = 11) for 20 min followed by 21% O2 in both groups. Controls (group 3, n = 5) were ventilated with 21% O2 throughout the experiment. Base deficit peaked at 31 +/- 5 mmol/L (mean +/- SD) for both hypoxic groups at 5 min of reoxygenation and then normalized over the following 3 h. There were no statistically significant differences between the two groups during reoxygenation concerning blood pressure, heart rate, base deficit, or plasma hypoxanthine. Hypoxanthine peaked at 165 +/- 40 and 143 +/- 42 mumol/L in group 1 and 2 (NS), respectively, and was eliminated monoexponentially in both groups with an initial half-life for excess hypoxanthine of 48 +/- 21 and 51 +/- 27 min (NS), respectively. Blinded pathologic examination of cerebral cortex, cerebellum, and hippocampus after 4 d showed no statistically significant differences with regard to brain damage. We conclude that 21% O2 is as effective as 100% O2 for normalizing blood pressure, heart rate, base deficit, and plasma hypoxanthine after severe neonatal hypoxemia in piglets and that the extent of the hypoxic brain damage is similar in the two groups.

Plasma proteins in normal neurons. Immunohistochemical studies on autopsy material and experimental animals

Previous observations have shown that plasma proteins are taken up by damaged neurons after trauma, cold injury and anoxic lesions. The present study was undertaken to test whether such uptake also can occur in normal neurons. Normal human brains at different intervals after death as well as normal rat brains after perfusion and immersion fixation were studied. During the first 24 h after death, the human cases showed practically no immunostaining with anti-fibrinogen and vague and inconstant staining with anti-albumin in the cortex and hippocampus, while certain brain stem nuclei were stained with both antisera even at the shortest postmortem intervals. At longer intervals, increased immunostaining of the neurons in the cortex and hippocampus was also demonstrated. Generally, more cells were positive for albumin than for fibrinogen. Perfusion-fixed rat brains showed no immunostaining, whereas rat brains that were immersion-fixed 24 h after death showed positive staining, mainly located in the brain stem. It is concluded that the staining of normal neurons demonstrated with the present method is due to postmortem leakage of proteins. Since practically no uptake of fibrinogen occurs in the cortex or hippocampus during the first 24 h, a definite neuronal staining with anti-fibrinogen at these intervals probably indicates true neuronal damage. In the brain stem, on the other hand, this phenomenon can not be used to demonstrate neuronal damage even at the shortest postmortem intervals.

[Is the increased frequency of sudden infant death caused by changed diagnostic criteria?]

According to the official statistics the incidence of sudden infant death syndrome has more than doubled in Norway during the last 15 years, while the total number of deaths in infants of the same age has changed little during the period. We have reviewed the autopsy protocols from the Department of Pathology, Ullevål Hospital, from 1975 to 1989, and re-examined the histologic lung sections from all children aged from one month to one year who died suddenly and unexpectedly. Of the cases reclassified as sudden infant death syndrome, more than half had been diagnosed as pneumonia during the first five-year period (1975-79). During the last five-year period none of the cases received this diagnosis. We conclude that some of the apparent increase in sudden infant death syndrome recorded in Norway probably reflects a change in diagnostic criteria.

Uptake of plasma proteins into damaged neurons. An experimental study on cryogenic lesions in rats

Preliminary observations on human autopsy material have indicated that damaged neurons may take up plasma proteins early after the injury. These observations prompted an experimental study under controlled conditions. Focal brain lesions were produced in rats by extracranial application of dry ice for 90 s. This caused an immediate disruption of the blood-brain barrier with leakage of plasma components into the tissue and sharply circumscribed areas of necrosis of the underlying cortex. Five minutes after the lesion, uptake of albumin, fibrinogen and fibronectin into damaged neurons was demonstrated by immunostains. These proteins were retained in the injured neurons until they were phagocytized 2-4 days later. In addition, normal neurons whose axons or axon collaterals passed through or terminated in the lesion were labeled. This labeling was generally weaker than in damaged neurons and no labeling of neuronal nuclei was observed in these cells in contrast to those of damaged cells. Apart from nerve cells labeled through retrograde axonal transport, no staining of normal neurons was observed. Intravenous injections of Evans blue, which binds to plasma proteins, confirmed that albumin was taken up into damaged neurons almost immediately after the injury and showed that this uptake continued for at least 20 h. It is concluded that uptake of plasma proteins into damaged neurons may serve as early (and late) markers of neuronal injury.

Wernicke's encephalopathy in non-alcoholics. An autopsy study

In a 5-year autopsy material constituting 6,964 autopsies, there were 52 cases of Wernicke's encephalopathy of which 12 (23%) occurred in non-alcoholics. Among 18 cases with active (acute) disease, 7 cases (39%) were found in non-alcoholics. Only 4 cases of active Wernicke's disease were diagnosed clinically, all of them in alcoholics. The predominant clinical symptoms were disorientation and depressed levels of consciousness, whereas eye symptoms were recorded in only 3 cases. None of the non-alcoholics were given specific thiamine therapy, whereas some alcoholics received large doses of the vitamin as a routine procedure. However, the thiamine therapy was often instituted too late. It is concluded that active Wernicke's encephalopathy should be considered in all patients with prolonged malnutrition and that disorientation and depressed levels of consciousness may be the predominating symptoms of the disease. Even the slightest suspicion of Wernicke's encephalopathy should prompt immediate administration of large doses of thiamine parenterally.

The frequency of alcoholism and alcohol related brain disorders in various regions of Oslo city. An autopsy study

The autopsy materials from the 5-year period 1983-1987 from Ullevål and Aker Hospitals in Oslo were reviewed. All cases with alcoholism were recorded and the histological sections were re-examined with regard to the presence of Wernicke's encephalopathy and alcoholic cerebellar atrophy. The two materials were compared statistically in order to see whether any difference in the frequency of alcoholism and alcohol related brain disorders could be demonstrated between the geographic areas served by these two hospitals. The study revealed a significantly higher percentage of alcoholics in the Aker material which also had a higher proportion of alcoholics with cerebellar atrophy and Wernicke's encephalopathy, although not significant for the latter condition. These results indicate that alcoholism is particularly frequent in the north-eastern part of Oslo city and that this region also has a relatively high proportion of heavy drinkers.

The frequency of brain lesions in alcoholics. Comparison between the 5-year periods 1975-1979 and 1983-1987

This is a follow-up study of a previous investigation of brain lesions in alcoholics during the 5-year period from 1975 through 1979 (Torvik et al. 1982). The autopsy material from the 5-year period 1983-1987 was examined in order to see whether improved clinical treatment had resulted in a reduced frequency of alcohol-related brain lesions, particularly of active Wernicke's encephalopathy. The percentage of alcoholics (8.2 vs. 8.7%), the male/female ratio (4.2/1) and their mean age (60.4 vs. 62.2 years) were similar in the two recording periods, as was the frequency of alcoholic cerebellar atrophy (26.8 vs. 27.6%). In both periods the brain weight in male alcoholics aged 40-70 years was significantly lower than in age-matched controls. This difference was not present after 70 years of age. The most important finding was a considerable but not significant reduction of the frequency of active and inactive Wernicke's encephalopathy in alcoholics. Review of the clinical records supports the hypothesis that this reduction reflects better diagnostic and therapeutic procedures in the clinical departments. However, even during the last period most cases of active Wernicke's encephalopathy were not recognized clinically and further improvement of the clinical management should therefore be possible.