Cerebral arterial spasm--a controlled trial of nimodipine in patients with subarachnoid hemorrhage

We enrolled 125 neurologically normal patients with intracranial aneurysms in a multi-institution, prospective, double-blind, randomized, placebo-controlled trial within 96 hours of their subarachnoid hemorrhage, to determine whether treatment with the calcium blocker nimodipine would prevent or reduce the severity of ischemic neurologic deficits from arterial spasm. A deficit from cerebral arterial spasm that persisted and was severe or caused death by the end of the 21-day treatment period occurred in 8 of 60 patients given placebo and in 1 of 56 given nimodipine (P = 0.03, Fisher's exact test). Analysis of the amount of basal subarachnoid blood on pre-entry CAT scans in patients with deficits from spasm showed that an increase in subarachnoid blood was not associated with a worse neurologic outcome among patients who received nimodipine, unlike the situation in patients given a placebo. There were no side effects from nimodipine. We conclude that nimodipine should be given to patients who are neurologically normal after subarachnoid hemorrhage in order to reduce the occurrence of severe neurologic deficits due to cerebral arterial spasm.

An analysis of the natural history of cavernous angiomas

The advent of magnetic resonance (MR) imaging has permitted the recognition of many angiographically occult vascular malformations before the development of complications and subsequent surgical removal. This study reviews all patients at one institution who had radiographically identifiable vascular malformations believed to represent cavernous angiomas in order to obtain information on the natural history of this particular lesion. All 8131 craniospinal MR images performed at our medical center from January 1, 1986, to November 30, 1989, were reviewed, and 32 patients were identified with 76 lesions meeting the MR imaging criteria for cavernous angioma. Medical histories, physical examination records, and other data from these patients were then reviewed to determine the frequency of complications. Their mean age at latest follow-up examination (or at surgical removal of the lesion) was 37.6 years (range 16 to 72 years). Sixteen patients (50%) had a history of seizures, seven (22%) had focal neurological deficits, and three (9%) had clinically significant hemorrhage attributable to the cavernous angioma; six patients (19%) were asymptomatic. The estimated risk of hemorrhage for this population is 0.25%/person-year of exposure; the estimated risk of seizure development is 1.51%/person-year. Eight patients underwent surgical procedures, resulting in improved seizure control and/or lessened neurological deficit. Although these lesions are often excised with relative ease and minimal morbidity, the potential risks and benefits of surgery must be weighed carefully before removal of these relatively benign malformations.

Velo-cardio-facial syndrome associated with chromosome 22 deletions encompassing the DiGeorge locus

The large clinical overlap between DiGeorge syndrome and velo-cardio-facial syndrome suggests an aetiological connection. DiGeorge syndrome is associated with microdeletions of chromosome 22q11 and is therefore likely to be caused by reduced dosage of genes within this region. We present preliminary data that velocardiofacial syndrome patients have similar chromosome deletions, a finding consistent with the hypothesis that these disorders represent part of a spectrum of abnormalities seen with monosomy for 22q11.

Natural history of arteriovenous malformations of the brain: a clinical study

The natural history of intracranial arteriovenous malformations (AVMs) was studied in 131 patients. The 83 patients managed nonsurgically and the 48 patients treated surgically were followed for an average of 8 years. Hemorrhage occurred in 61.8% of all patients. A second hemorrhage occurred in 67.4% of the survivors of the first hemorrhage. The mortality associated with recurrent hemorrhage did not increase significantly with successive episodes of hemorrhage. The rate of rebleeding was 17.9%/year initially, but declined to 3%/year after 5 years and then to 2%/year after 10 years. Among patients treated nonsurgically, the prognosis was more favorable for patients presenting with seizures than for patients presenting with hemorrhage. Patients in the seizure group had a 26.9% incidence of hemorrhage causing an 11.6% mortality; 40.5% of the patients in the hemorrhage group died. The prognosis was poor for patients with posterior fossa AVMs; the mortality was 66.7% with the first hemorrhage. Recurrent posterior fossa hemorrhage was the rule in survivors, and most of those hemorrhages were fatal. The prognosis for children with AVMs was no different from that for adults.

Examining the validity of pressure ulcer risk assessment scales: developing and using illustrated patient simulations to collect the data

Simulations are of particular advantage in research studies where large samples are necessary to achieve statistical power and the information must be collected under uniform conditions in order to aid interpretation. In the study reported below, simulation was achieved through the use of medical photography accompanied by case studies of the same patients. All information was collected on the same day. The purpose of the study was to determine the validity of the three pressure ulcer risk assessment scales most commonly used in clinical nursing practice in the UK. Each clinical nurse assessed the same four patients using three risk assessment scales and a visual analogue scale designed to capture their own clinical judgement. External validity was assessed by a panel of tissue viability experts who provided independent ratings. Data were obtained from 236 clinical nurses, yielding 941 risk assessments. Experience with this approach to data collection suggests that it requires careful planning. This should include measures to ensure that the simulated information is valid and that all data collectors have been adequately trained and are able to motivate the nurses participating in the study. Providing consideration is given to these issues, the use of simulation can help to collect data that would be difficult to obtain by more conventional means. It is also important to recognize that clinical decisions are de-contextualized in simulations because they are reduced to verbal and visual summaries. The decision to use simulations should thus be taken only if this is acknowledged.

Management of treatment resistance in schizophrenia

A systematic approach to the evaluation and characterization of treatment resistance in schizophrenia has become increasingly important since the introduction of the second-generation antipsychotics. The need for accurate evaluation will increase further as other new antipsychotic medications are developed. Patients with schizophrenia may manifest poor response to therapy because of intolerance to medication, poor adherence, inappropriate dosing, as well as true resistance of their illness to antipsychotic drug therapy. Criteria for treatment-resistance are presented to help in standardizing treatment and clinical trials. As clinicians face the decision of when to change or augment antipsychotic medications, a clear understanding of the appropriate length of a treatment trial and which target symptoms respond to antipsychotic therapy is critical for maximizing response in patients with treatment-resistant schizophrenia.

Predictors of successful extubation in neurosurgical patients

A respiratory therapist-driven weaning protocol incorporating daily screens, spontaneous breathing trials (SBT), and prompts to caregivers has been associated with superior outcomes in mechanically ventilated medical patients. To determine the effectiveness of this approach in neurosurgical (NSY) patients, we conducted a randomized controlled trial involving 100 patients over a 14-mo period. All had daily screens of weaning parameters. If these were passed, a 2-h SBT was performed in the Intervention group. Study physicians communicated positive SBT results, and the decision to extubate was made by the primary NSY team. Patients in the Intervention (n = 49) and Control (n = 51) groups had similar demographic characteristics, illness severity, and neurologic injuries. Among all patients, 87 (45 in the Control and 42 in the Intervention group) passed at least one daily screen. Forty (82%) patients in the Intervention group passed SBT, but a median of 2 d passed before attempted extubation, primarily because of concerns about the patient's sensorium (84%). Of 167 successful SBT, 126 (75%) did not lead to attempted extubation on the same day. The median time of mechanical ventilation was 6 d in both study groups, and there were no differences in outcomes. Overall complications included death (36%), reintubation (16%), and pneumonia (9%). Tracheostomies were created in 29% of patients. Multivariate analysis showed that Glasgow Coma Scale (GCS) score (p < 0.0001) and partial pressure of arterial oxygen/fraction of inspired oxygen ratio (p < 0.0001) were associated with extubation success. The odds of successful extubation increased by 39% with each GCS score increment. A GCS score > or = 8 at extubation was associated with success in 75% of cases, versus 33% for a GCS score < 8 (p < 0.0001). Implementation of a weaning protocol based on traditional respiratory physiologic parameters had practical limitations in NSY patients, owing to concerns about neurologic impairment. Whether protocols combining respiratory parameters with neurologic measures lead to superior outcomes in this population requires further investigation.

Distribution of factor VIII mRNA and antigen in human liver and other tissues

The cellular site of synthesis of factor VIII (FVIII:C; anti-haemophilic factor) has long been sought. Previous studies suggested the liver as a major site of synthesis, but extrahepatic sources such as spleen and lung have been implicated. Using an immunoradiometric assay (IRMA), we recently localized factor VIII antigen (FVIII:Ag, formerly FVIII:CAg), to whole perfused guinea pig liver and spleen, and to isolated hepatocytes, with lesser or trace amounts in other tissues. Using an immunohistological technique, Stel et al. detected FVIII:Ag in normal human liver sinusoidal endothelial cells, while Exner et al. detected FVIII:Ag by IRMA in extracts of human lymph nodes, lung, liver and spleen. The localization of antigen in tissues does not, however, distinguish sites of factor VIII synthesis from those of storage, and such experiments are subject to misinterpretation due to entrapment of plasma factor VIII in tissues. The recent cloning of the human factor VIII gene provides hybridization probes for the detection of factor VIII messenger RNA in cells, thus directly determining sites of synthesis. During complementary DNA cloning, we detected factor VIII mRNA in liver, and it has been localized by others in liver and placenta and in liver and kidney. In the present study, we detected factor VIII mRNA in isolated human hepatocytes, in spleen and in numerous tissues including lymph nodes and kidney, but not in white blood cells or cultured endothelial cells. We also found that the factor VIII, factor VII, factor IX and protein C antigens in liver are predominantly localized in hepatocytes, while very little von Willebrand factor antigen (vWF:Ag, formerly FVIIIR Ag) is detectable in this organ.

Gut and muscle tissue PO2 in endotoxemic dogs during shock and resuscitation

There is indirect evidence that tissue hypoxia occurs in human sepsis and surface measures of muscle tissue PO2 (PtiO2) in hypodynamic endotoxic animals are decreased. This study assessed systemic and regional tissue oxygenation in a more relevant model of hyperdynamic endotoxicosis. We isolated venous outflow from the left hindlimb and a segment of ileum in six anesthetized dogs to measure muscle and gut O2 delivery and uptake (VO2) and lactate flux, gut intramucosal pH (pHi) by tonometry, and PtiO2 by multi-point surface electrodes placed on mucosal and serosal surfaces of gut and on muscle. We then infused Escherichia coli lipopolysaccharide (LPS; 2 mg/kg) over 1 h followed by a 2-h infusion of dextran (0.5 ml.kg-1.min-1). LPS infusion significantly decreased systemic and gut VO2, cardiac output (Q), and blood pressure and increased arterial lactate and gut lactate flux. Resuscitation increased Q to above baseline and restored systemic VO2. In response to LPS and then resuscitation, muscle PtiO2 distribution did not change, suggesting little microcirculatory disturbance, although mean PtiO2 first decreased and then increased. In contrast, gut VO2 and pHi remained low and lactate output remained high, despite restoration of gut blood flow. Gut VO2, lactate flux, pHi, and PtiO2 histograms were consistent with a marked redistribution of blood flow within the gut wall, away from the mucosa and toward the muscularis. These data show that, in hyperdynamic acute endotoxemia, skeletal muscle PtiO2 and VO2 are well maintained, but blood flow within the gut is significantly disturbed with mucosal hypoxia.

The natural history of intracranial venous angiomas

Cerebral venous angiomas are congenital anomalies of the intracranial venous drainage. Many believe that they are associated with a high risk of hemorrhage and neurological dysfunction, but newer neurodiagnostic imaging techniques are showing not only that they are more common than previously known but also that many have no associated symptoms. In this retrospective study, the natural history of venous angiomas was examined in 100 patients (48 males and 52 females) with radiographically identifiable lesions treated over a 14-year period. Information on the natural history of the lesion was obtained from clinical records and follow-up data. Imaging studies included angiography, computerized tomography, and magnetic resonance imaging. Angioma locations were classified as frontal (42 cases), parietal (24 cases), occipital (4 cases), temporal (2 cases), basal or ventricular (11 cases), cerebellar (14 cases), or brain stem (3 cases); 47 lesions were on the left side. Headache as a presenting symptom was common (36 patients) and often led to other radiographic studies, but this appeared to be related to the vascular lesion in only four patients. Other possibly related complications were hemorrhage in one patient, seizures in five, and transient focal deficits in eight. Fifteen patients had no neurological signs or symptoms. The mean patient age at last contact was 45.3 years (range 3 to 94 years). All patients have been managed without surgery. It is concluded that significant complications secondary to venous angiomas are infrequent and that surgical resection of these lesions and of surrounding brain is rarely indicated.

Double-blind, placebo-controlled, crossover trial of glycine adjuvant therapy for treatment-resistant schizophrenia

BACKGROUND

It has been proposed that schizophrenia is associated with underactivity of brain glutamatergic neurotransmission, especially at the level of the N-methyl-D-aspartate (NMDA) subtype of glutamate receptor. Glycine potentiates NMDA receptor-mediated neurotransmission, indicating that it may serve as an effective therapeutic agent in the treatment of schizophrenia.

METHOD

Eleven treatment-resistant patients with chronic schizophrenia completed a double-blind, placebo-controlled, six-week, randomly assigned, crossover treatment trial of 0.8 g/kg body weight/day of glycine, added to their prior antipsychotic treatment.

RESULTS

Glycine was well tolerated, resulted in significantly increased serum glycine levels and induced a mean 36 (7%) reduction in negative symptoms (P < 0.0001). Significant improvements were also induced in depressive and cognitive symptoms. The greatest reduction in negative symptoms was registered in the patients who had the lowest baseline serum glycine levels.

CONCLUSIONS

These results extend previous findings and suggest an additional approach to the pharmacotherapy of negative symptoms and cognitive deficits in schizophrenia.

Left ventricular function in acute myocardial infarction evaluation by gated scintiphotography

Ten normal volunteers and 38 patients with acute myocardial infarction were evaluated by biplane gated blood pool scanning. The mean left ventricular end-diastolic volume in those with infarction was 125 ± 41 ml/m 2 compared to 82 ± 10 ml/m 2 in the normals. The left ventricular end-systolic volume was 82 ± 35 ml/m 2 compared to 35 ± 4 ml/m 2 , and the left ventricular ejection fraction 36 ± 8% compared to 56 ± 3% in the normals. Thirty-six of the 38 patients with infarction had an area of akinesis which ranged from 15 to 59% of the left ventricular wall. Patients with acute myocardial infarction were found to have a significant increase in left ventricular end-systolic volume and decrease in ejection fraction compared to normals. The end-diastolic volume was, however, increased only in those with an elevated left ventricular filling pressure or decreased cardiac index.

Follow-up studies obtained in 20 patients between one week and three months following infarction showed that in the 14 who improved clinically, left ventricular ejection fraction significantly increased from 38 to 45% ( P < 0.001) while in six who failed to show clinical improvement or worsened, left ventricular ejection fraction remained at 30%.

Left ventricular ejection fraction was significantly greater and the extent of akinesis significantly less in the patients who survived compared to those who died.

The neurochemical and metabolic cascade following brain injury: moving from animal models to man

Experimental traumatic brain injury produces a series of cellular events contributing to a neurochemical and neurometabolic cascade. This cascade is defined by the release of neurotransmitters resulting in a massive ionic flux, which, consequently, produces an increase in glycolysis. This increase in glycolysis is followed by a metabolic diaschisis, which is related to the degree and extent of behavioral deficits. Clinical efforts have now determined that a similar cascade occurs in human head injury, validating the animal model as well as providing new assessment strategies for the management and treatment of brain injury.

Targeted CNS expression of interferon-gamma in transgenic mice leads to hypomyelination, reactive gliosis, and abnormal cerebellar development

Circumstantial and experimental evidence has implicated the immune cytokine interferon-gamma (IFN-gamma) as a key mediator in the pathological changes that are observed in many demyelinating disorders, including the most common human demyelinating disease, multiple sclerosis. To produce an animal model with which to study the effects of IFN-gamma on the CNS, we have generated transgenic mice in which the expression of IFN-gamma has been placed under the transcriptional control of the myelin basic protein (MBP) gene. Transgenic mice generated with this construct have a shaking/shivering phenotype that is similar to that observed in naturally occurring mouse models of hypomyelination (e.g., shiverer, jimpy, quaking), and these transgenic animals have dramatically less CNS myelin than control animals. Reactive gliosis and increased macrophage/microglial F4/80 immunostaining were also observed. Additionally, major histocompatibility complex (MHC) class I and class II mRNA levels were increased in the CNS of MBP/IFN-gamma transgenic mice, and the increase in MHC class I mRNA expression was detected in both white and gray matter regions. Furthermore, cerebellar granule cell migration was abnormal in these animals. These results strongly support the hypothesis that IFN-gamma is a key effector molecule in immune-mediated demyelinating disorders and indicate that the presence of this cytokine in the CNS may also disrupt the developing nervous system.

Early nutrition and the development of immune function in the neonate

The present review will concentrate on the development of the gut-associated lymphoid tissue and the role of early nutrition in promoting immune function. The intestine is the largest immune organ in the body, and as such is the location for the majority of lymphocytes and other immune effector cells. The intestine is exposed to vast quantities of dietary and microbial antigens, and is the most common portal of entry for pathogens, some of which are potentially lethal. The development of normal immune function of the intestine is therefore vital for survival, and is dependent on appropriate antigen exposure and processing, and also an intact intestinal barrier. In early life innate mechanisms of defence are probably more important than active or adaptive mechanisms in responding to an infectious challenge, since the healthy neonate is immunologically naïve (has not seen antigen) and has not acquired immunological memory. During this period maternal colostrum and milk can significantly augment resistance to enteric infections. The mechanisms of enhancing disease resistance are thought to be passive, involving a direct supply of anti-microbial factors, and active, by promoting the development of specific immune function. A tolerance response to dietary and non-invasive antigens is generally induced in the gut. However, it must also be able to mount an adequate immune response to ensure clearance of foreign antigens. It is now recognized that regulation of tolerance and active immune responses is critical to health, and failure to regulate these responses can lead to recurrent infections, inflammatory diseases and allergies. The education of the immune system in early life is thought to be critical in minimizing the occurrence of these immune-based disorders. During this phase of development maternal milk provides signals to the immune system that generate appropriate response and memory. One factor that has been proposed to contribute to the increase in the incidence of immune-based disorders, e.g. atopic diseases in Western countries, is thought to be the increased prevalence of formula-feeding.

Treatment of phobic states with antidepressants. A retrospective study of 246 patients

The treatment of phobic states is one of the most challenging psychiatric problems that face doctors today. Many treatments have been advocated, including intensive psychotherapy (Friedman, 1959), behaviour therapy (Wolpe, 1958; Cooper, Gelder and Marks, 1965) and desensitization under drugs (Yorkston et al., 1968). None of these treatments has proved to be completely effective, and many patients still remain ill and incapacitated for many years. In the series to be reported here, some patients had been ill for as long as 40 years, despite many types of treatment.

Confirmation that the velo-cardio-facial syndrome is associated with haplo-insufficiency of genes at chromosome 22q11

The velo-cardio-facial syndrome (VCFS) and DiGeorge sequence (DGS) have many similar phenotypic characteristics, suggesting that in some cases they share a common cause. DGS is known to be associated with monosomy for a region of chromosome 22q11, and DNA probes have been shown to detect these deletions even in patients with apparently normal chromosomes. Twelve patients with VCFS were examined and monosomy for a region of 22q11 was found in all patients. The DNA probes used in this study could not distinguish the VCFS locus and the DGS locus, indicating that the genes involved in these haploinsufficiencies are closely linked, and may be identical. The phenotypic variation of expression in VCFS and DGS may indicate that patients without the full spectrum of VCFS abnormalities but with some manifestations of the disorder may also have 22q11 deletions.

A clinical inflammatory syndrome attributable to aerosolized lipid-DNA administration in cystic fibrosis

Immunologic reactivity to lipid-DNA conjugates has traditionally been viewed as less of an issue than with viral vectors. We performed a dose escalation safety trial of aerosolized cystic fibrosis transmembrane conductance regulator (CFTR) cDNA to the lower airways of eight adult cystic fibrosis patients, and monitored expression by RT-PCR. The cDNA was complexed to a cationic lipid amphiphile (GL-67) consisting of a cholesterol anchor linked to a spermine head group. CFTR transgene was detected in three patients at 2-7 days after gene administration. Four of the eight patients developed a pronounced clinical syndrome of fever (maximum of 103.3EF), myalgias, and arthralgia beginning within 6 hr of gene administration. Serum IL-6 but not levels of IL-8, IL-1, TNF-alpha, or IFN-gamma became elevated within 1-3 hr of gene administration. No antibodies to the cationic liposome or plasmid DNA were detected. We found that plasmid DNA by itself elicited minimal proliferation of peripheral blood mononuclear cells taken from study patients, but led to brisk immune cell proliferation when complexed to a cationic lipid. Lipid and DNA were synergistic in causing this response. Cellular proliferation was also seen with eukaryotic DNA, suggesting that at least part of the immunologic response to lipid-DNA conjugates is independent of unmethylated (E. coli-derived) CpG sequences that have previously been associated with innate inflammatory changes in the lung.

Effect of weight loss on cardiac chamber size, wall thickness and left ventricular function in morbid obesity

To determine cardiac chamber size, wall thickness and left ventricular (LV) systolic function in morbidly obese patients, M-mode and cross-sectional echocardiography was performed in 62 patients whose body weight was greater than or equal to twice their ideal weight but who were free from underlying organic heart disease and systemic hypertension. The initial clinical protocol consisted of a medical history, physical examination, electrocardiogram at rest, chest x-ray and echocardiogram. Thereafter, each patient underwent gastric restriction. Thirty-four patients returned for follow-up echocardiography 4.3 +/- 0.3 months after substantial weight loss was achieved. For the whole group (n = 62) and LV internal dimension in diastole was enlarged in 24 (39%), the right ventricular internal dimension was enlarged in 20 (32%), the left atrial dimension was enlarged in 25 (40%) and the ventricular septal and LV posterior wall thickness was increased in 35 (56%). In the 34 patients who returned for follow-up, mean body weight decreased significantly, from 135 +/- 8 to 79 +/- 6 kg (73 +/- 4% of the amount over ideal body weight). In the subgroup with low preoperative LV fractional shortening (n = 13), mean LV fractional shortening increased from 22 +/- 2% to 31 +/- 2% (p less than 0.01). This was accompanied by a significant decrease in the mean LV internal dimension in diastole and mean blood pressure. The results indicate that cardiac chamber enlargement, LV hypertrophy and LV systolic dysfunction occur frequently in morbidly obese patients and that LV systolic dysfunction in such persons may improve following substantial weight loss.

Genome sequencing of an extended series of NDM-producing Klebsiella pneumoniae isolates from neonatal infections in a Nepali hospital characterizes the extent of community- versus hospital-associated transmission in an endemic setting

NDM-producing Klebsiella pneumoniae strains represent major clinical and infection control challenges, particularly in resource-limited settings with high rates of antimicrobial resistance. Determining whether transmission occurs at a gene, plasmid, or bacterial strain level and within hospital and/or the community has implications for monitoring and controlling spread. Whole-genome sequencing (WGS) is the highest-resolution typing method available for transmission epidemiology. We sequenced carbapenem-resistant K. pneumoniae isolates from 26 individuals involved in several infection case clusters in a Nepali neonatal unit and 68 other clinical Gram-negative isolates from a similar time frame, using Illumina and PacBio technologies. Within-outbreak chromosomal and closed-plasmid structures were generated and used as data set-specific references. Three temporally separated case clusters were caused by a single NDM K. pneumoniae strain with a conserved set of four plasmids, one being a 304,526-bp plasmid carrying bla(NDM-1). The plasmids contained a large number of antimicrobial/heavy metal resistance and plasmid maintenance genes, which may have explained their persistence. No obvious environmental/human reservoir was found. There was no evidence of transmission of outbreak plasmids to other Gram-negative clinical isolates, although bla(NDM) variants were present in other isolates in different genetic contexts. WGS can effectively define complex antimicrobial resistance epidemiology. Wider sampling frames are required to contextualize outbreaks. Infection control may be effective in terminating outbreaks caused by particular strains, even in areas with widespread resistance, although this study could not demonstrate evidence supporting specific interventions. Larger, detailed studies are needed to characterize resistance genes, vectors, and host strains involved in disease, to enable effective intervention.

Anxiety and the effects of sodium lactate assessed clinically and physiologically

Anxiety neurosis has been the subject of intensive study during the past ten years. Renewed interest in this syndrome has arisen both from the stimulus of new methods of treatment and from attempts to classify anxiety more accurately. Recently Pitts and McClure (1967) reported that anxiety symptoms and anxiety attacks could be produced by a specific biochemical stimulus: sodium lactate. This work was prompted by the finding that 'standard exercise’ tends to produce an excess amount of lactic acid in patients with anxiety neurosis (Cohen and White, 1950; Jones and Mellersh, 1946; Linko, 1950; Holmgren and Strom, 1959). Pitts and McClure found that an intravenous infusion of 10 ml. of half-Molar sodium (DL) lactate per kilogram of body weight, given over a twenty minute period, produced an anxiety attack in patients suffering from anxiety neurosis. The symptoms began a minute or two after the infusion was started and developed rapidly, and some patients reported ‘exacerbations of their characteristic symptom profiles for two to five days after the sodium lactate infusion’. In their double-blind study, many fewer symptoms were produced when calcium ion was added to the lactate infusion, and almost no symptoms were produced by an infusion of glucose in saline of similar osmolarity. Many fewer and less severe symptoms were produced in normal controls than in the patient group, both in response to sodium lactate and to lactate with added calcium, and almost no symptoms during the glucose and saline infusion. Pitts and McClure postulated that anxiety symptoms may have a common determining biochemical end-mechanism, involving the complexing of ionized calcium at the surface of excitable membranes by lactate ion with resulting interference ‘with the normal functioning of calcium in transmitting nerve impulses' (Pitts, 1969). They concluded that ‘there may be something highly specific about lactate ion in producing the naturally occurring hypocalcaemic anxiety symptoms in human beings'.

Comparison of mannitol regimens in patients with severe head injury undergoing intracranial monitoring

Eighty patients sustaining head injuries and presenting with Glasgow Coma Scale scores of 8 or less were entered into a prospective randomized study to assess the benefit of intracranial pressure (ICP) monitoring with two regimens of mannitol administration. Group I was treated with mannitol for ICP elevations greater than 25 mm Hg, while Group II received empirical mannitol therapy irrespective of ICP readings. No statistically significant differences in mortality rate or neurological outcome were demonstrated between the two groups. These results are comparable to those of several published series of head-injured patients receiving similar treatment from 1977 to 1982. However, those series must be reassessed in light of recently published studies with treatment initiated at lower levels of ICP.

Surgical treatment of brain stem gliomas

✓ A long-term study has been made of a consecutive series of 37 patients with brain stem gliomas, 22 of whom were children and 15 adults. Surgical exploration was carried out in 34 of the 37 cases and only very rarely was a diagnosis made on clinical grounds or air study alone. In 10 cases a histological diagnosis was made at operation. In five patients a significantly large neoplastic cyst was found and evacuated, and four of these have had long-term useful survivals. There were nine postoperative deaths, most of them in the pre-Decadron era; 17 cases died during follow-up, with a mean survival of 33 months; and eight patients are living, with a mean survival of 3 months to 9 years. A plea is made for surgical exploration of these lesions in the hope of finding a surgically approachable cyst, and for the use of radiation therapy at a later time.

Inactivation of the FGF-4 gene in embryonic stem cells alters the growth and/or the survival of their early differentiated progeny

Previous studies have shown that early mouse embryos with both FGF-4 alleles inactivated are developmentally arrested shortly after implantation. To understand the roles of FGF-4 during early development, we prepared genetically engineered embryonic stem (ES) cells, which are unable to produce FGF-4. Specifically, we describe the isolation and characterization of ES cells with both FGF-4 alleles inactivated. The FGF-4-/- ES cells do not require FGF-4 to proliferate in vitro, and addition of FGF-4 to the medium has little or no effect on their growth. Thus, FGF-4 does not appear to act as an autocrine growth factor for cultured ES cells. We also demonstrate that FGF-4-/- ES cells, like their unmodified counterparts, are capable of forming highly complex tumors in syngeneic mice composed of a wide range of differentiated cells types, including neural tissue, glandular epithelium, and muscle. In addition, we demonstrate that the FGF-4-/- ES cells can differentiate in vitro after exposure to retinoic acid; however, the growth and/or survival of the differentiated cells is severely compromised. Importantly, addition of FGF-4 to the culture medium dramatically increases the number of differentiated cells derived from the FGF-4-/- ES cells, in particular cells with many of the properties of parietal extraembryonic endoderm. Finally, we demonstrate that there are differences in the RNA profiles expressed by the differentiated progeny formed in vitro from FGF-4-/- ES cells and FGF-4+/+ ES cells when they are cultured with FGF-4. Taken together, the studies described in this report indicate that certain lineages formed in vitro are affected by the inactivation of the FGF-4 gene, in particular specific cells that form during the initial stage of ES cell differentiation. Thus, ES cells with both FGF-4 alleles inactivated should shed light on the important roles of FGF-4 during the early stages of mammalian development and help determine why FGF-4-/- embryos die shortly after implantation.