In vivo measurement of the oxygen saturation of retinal vessels in healthy volunteers

A new method for the spatially resolved measurement of the oxygen saturation of retinal vessels is described. Imaging spectrometry was used for both measurements of transmission and reflectance spectra of whole blood in cuvettes as well as for fundus reflectance spectra. A model was developed for the calculation of the oxygen saturation, valid in the wavelength range between 510 nm and 586 nm, in that the internal reflectance is constant and only the transmitted light depends on layer thickness and hematocrit. Altogether 265 measurements were performed in different number at 30 eyes. In each measurement, the oxygen saturation was simultaneously determined for 193 locations along a line of 1.5 mm at the fundus. The mean oxygen saturation in retinal arteries was (92.2 +/- 4.1)% and (57.9 +/- 9.9)% in retinal veins. The mean retinal arterio-venous difference of the oxygen saturation was (35.1 +/- 9.5)%. The venous oxygen saturation depended on distance from the optic disc. The measured mean of the arterio-venous difference of the oxygen saturation corresponded well to the value of the brain (34%). The utilization of oxygen in the temporal quadrants (inferior: 39.4 +/- 10.4%) is significantly (p = 0.05) higher than in the nasal quadrants (inferior: 31.3 +/- 6.7%).

Environmetric modeling and interpretation of river water monitoring data

This environmetric study deals with modeling and interpretation of river water monitoring data from the basin of the Saale river and its tributaries the Ilm and the Unstrut. For a period of one year of observation between September 1993 and August 1994 a data set from twelve campaigns at twenty-nine sampling sites from the Saale river and six campaigns from the river Ilm at seven sampling sites and from river Unstrut at ten sampling sites was collected. Twenty-seven chemical and physicochemical properties were measured to estimate the water quality. The application of cluster analysis, principal components analysis, and apportioning modeling on absolute principal components scores revealed important information about the ecological status of the region of interest:identification of two separate patterns of pollution (upper and lower stream of the rivers);identification of six latent factors responsible for the data structure with different content for the two identified pollution patterns; anddetermination of the contribution of each latent factor (source of emission) to the formation of the total concentration of the chemical burden of the river water. As a result more objective ecological policy and decision making is possible.

ELISA detection of SARS-CoV-2 antibodies in saliva

To facilitate containment of the COVID-19 pandemic currently active in the United States and across the world, options for easy, non-invasive antibody testing are required. Here we have adapted a commercially available, serum-based enzyme-linked immunosorbent assay (ELISA) for use with saliva samples, achieving 84.2% sensitivity and 100% specificity in a set of 149 clinical samples. This strategy will enable widespread, affordable testing for patients who experienced this disease, whilst minimizing exposure risk for healthcare workers.

Magnetic resonance imaging and joint outcomes in boys with severe hemophilia A treated with tailored primary prophylaxis in Canada

BACKGROUND/OBJECTIVES

Tailored primary prophylaxis (TPP) is a reduced-intensity treatment program for hemophiliacs with the goal of preventing arthropathy. Our primary aim was to evaluate the joint outcomes of treated subjects using magnetic resonance imaging (MRI) and physical examination as outcome measures.

METHODS

Ankles, elbows and knees (index joints) of 24 subjects (median [range] age at start of therapy, 1.6 [1-2.5] years) with severe hemophilia A enrolled in the Canadian Hemophilia Primary Prophylaxis Study (CHPS) were examined by MRI at a median age of 8.8 years (range 6.2-11.5 years). Subjects were treated with TPP using a recombinant factor VIII concentrate, starting once weekly and escalating in frequency and dose according to frequency of bleeding.

RESULTS

Osteochondral changes (cartilage loss/subchondral bone damage) were detected in 9% (13/140) of the index joints and 50% (12/24) of study subjects. Osteochondral changes were restricted to joints with a history of clinically reported joint bleeding. Soft tissue changes were detected in 31% (20/65) of index joints with no history of clinically reported bleeding (ankles 75% (12/16); elbows 19% (6/32); and knees 12% (2/17)). In these apparently 'bleed free' index joints hemosiderin deposition was detected by MRI in 26% (17/65) of joints (ankles 63% (10/16); elbows 16% (5/32), and knees 12% (2/17)).

CONCLUSION

TPP did not completely avoid the development of MRI-detected structural joint changes in hemophilic boys in this prospective study. A longer period of follow-up is required for assessment of the longitudinal course of these early changes in hemophilic arthropathy, detected using a sensitive imaging technique (MRI).

Residual impairments and work status 15 years after penetrating head injury: report from the Vietnam Head Injury Study

We investigated the relationship of neurologic, neuropsychological, and social interaction impairments to the work status of a large sample of penetrating head-injured patients wounded some 15 years earlier during combat in Vietnam. Extensive standardized testing of neurologic, neuropsychological, and social functioning was done at follow-up on each head-injured patient (N = 520), as well as on a sample of uninjured controls (N = 85). Fifty-six percent of the head-injured patients were working at follow-up compared with 82% of the uninjured controls. Seven systematically defined impairments proved to be most correlated with work status. These were post-traumatic epilepsy, paresis, visual field loss, verbal memory loss, visual memory loss, psychological problems, and violent behavior. These disabilities had a cumulative and nearly equipotent effect upon the likelihood of work. We suggest that a simple summed score of the number of these seven disabilities can yield a residual "disability score" which may prove to be a practical tool for assessing the likelihood of return to work for patients in this population and perhaps in other brain-injured populations. These findings may also help to focus rehabilitation efforts on those disabilities most likely to affect return to work.

A new method for the measurement of oxygen saturation at the human ocular fundus

Measurements of the transmission and the reflectance spectra of whole blood exhibit a different dependence of the thickness of the blood layer. Whereas the transmission spectra decrease at all wavelengths, in the reflectance two ranges with different behaviour have to distinguish. In the absorption dominated range between about 500 and 600 nm, there is only a marginal influence of the thickness of the blood layer. In contrast, in the scattering dominated range higher than about 600 nm the reflectance increases if the thickness of the blood layer increases. Proofed by Monte Carlo simulation, the reflected light, which will be measured in ophthalmologic devices, consists both of light which penetrates a vessel once and will be reflected at the background and of light which is internally reflected at the blood column. Only in small vessels (diameter < 50 microm) the transmitted part dominates. With increasing diameter of the vessels the internally reflected light dominates. Especially under the conditions of a confocal laser scanner, the transmitted part of light is always small. As the measured light consists of both parts of light, a new model for the approximation of the measured reflected light is given, containing an expression for the transmitted and for the internally reflected light. The model was applied for the approximation of the reflectance of blood in a cuvette with an coloured background, delivering sufficient exact result. The oxygen saturation was determined in 256 measurements of 30 healthy persons using an ophthalmo imaging spectrometer. The mean arterial oxygen saturation was 91 +/- 5%, the mean venous oxygen saturation was 59 +/- 9% and the arterio-venous difference in the oxygen saturation was 35%, which is in good agreement with the arterio-venous difference known in the brain. First measurements of the oxygen saturation in age-related macular degeneration point to partly different pathological changes of the retinal microcirculation in dry and in wet AMD.

Aberrant expression of nitric oxide synthase III in Alzheimer's disease: relevance to cerebral vasculopathy and neurodegeneration

Alzheimer's disease (AD) has heterogeneous pathology, in part due to the large subset of cases (AD+CVD) with superimposed vascular lesions that are sufficient in number and distribution to accelerate the clinical course of dementia. Brains with AD+CVD have lower densities of neurofibrillary tangles and A beta-amyloid diffuse plaques, and increased numbers of cerebral vessels exhibiting p53-associated apoptosis relative to brains with uncomplicated AD. AD and AD+CVD both exhibit altered expression of the nitric oxide synthase 3 (NOS-III) gene; however, in AD+CVD, reduced NOS-III expression in cerebral vessels is associated with an increased frequency of vascular lesions, vascular smooth muscle cell apoptosis, and A beta-amyloid plaques. In contrast, experimental and spontaneous focal acute and subacute cerebral infarcts are associated with increased NOS-III expression in perifocal neurons, glial cells, cerebrovascular smooth muscle and endothelial cells, and diffuse A beta-amyloid plaque formation. This suggests that ischemic injury and oxidative stress can precipitate NOS-III-mediated cell loss and neurodegeneration. A role for aging-associated impaired mitochondrial function as a contributing factor in AD and CVD is suggested by the reduced levels of mitochondrial protein observed in AD and AD+CVD cortical neurons and vascular smooth muscle and endothelial cells. The aggregate findings suggest that cell loss and neurodegeneration may be mediated by somewhat distinct but overlapping mechanisms in AD and AD+CVD.

Fine structure of identified neurons in the primate hippocampus: a combined Golgi/EM study in the baboon

The hippocampi of two 1-year-old female baboons (Papio anubis) were used for a combined Golgi/electron microscope (EM) study of characteristic cell types in the hippocampus proper and fascia dentata. Results were compared with previous Golgi/EM studies of hippocampal neurons in small laboratory animals. Cell bodies of pyramidal neurons in CA1 were more loosely distributed than known from studies on the rat or guinea pig. Numerous basal and horizontal dendrites originating from the perikaryon filled in the space between neighboring cell bodies. Apical stem dendrites were varying in length, depending on the position of the parent cell body in outer or inner portions of the pyramidal layer. Dendrites were densely covered with spines which in the EM showed very complex synaptic contacts. In contrast to our observations in rats and guinea pigs, CA3 pyramidal cells in the monkey hippocampus exhibited numerous large spines or excrescences not only on apical dendrites but also on basal dendrites running through stratum oriens. These excrescences appeared to be more complex than in small rodents. They often branched, protruding deeply into presynaptic mossy fiber boutons, and formed multiple asymmetric synaptic contacts. Granule cells of the monkey fascia dentata, in contrast to those of the rodent, occasionally had basal dendrites extending into the hilar region. In the EM, granule cells either with or without basal dendrites exhibited fine structural characteristics that were very similar to those described in Golgi/EM studies of granule cells in the rat fascia dentata. Of the various types of nonpyramidal neurons the horizontal cells in stratum oriens with dendrites parallel to the alveus were analyzed. As seen in rats, these cells exhibited large amounts of rough endoplasmic reticulum, indentations of the nuclear membrane, and nuclear inclusions. Numerous terminals formed synaptic contacts on dendritic shafts. In contrast to rodents, numerous spines arose from dendrites and cell bodies of these neurons. In the EM, often single spines were found to establish synaptic contacts with several presynaptic boutons. In summary, our correlated light and EM study of four characteristic cell types, which are present in both nonprimates and primates, demonstrates a much more complex dendritic pattern and synaptic organization of these neurons in primates than in commonly studied small laboratory animals.

FDG PET versus CT radiomics to predict outcome in malignant pleural mesothelioma patients

BACKGROUND

Careful selection of malignant pleural mesothelioma (MPM) patients for curative treatment is of highest importance, as the multimodal treatment regimen is challenging for patients and harbors a high risk of substantial toxicity. Radiomics-a quantitative method for image analysis-has shown its prognostic ability in different tumor entities and could therefore play an important role in optimizing patient selection for radical cancer treatment. So far, radiomics as a prognostic tool in MPM was not investigated.

MATERIALS AND METHODS

This study is based on 72 MPM patients treated with surgery in a curative intent at our institution between 2009 and 2017. Pre-treatment Fluorine-18 fluorodeoxyglucose (FDG) PET and CT scans were used for radiomics outcome modeling. After extraction of 1404 CT and 1410 FDG PET features from each image, a preselection by principal component analysis was performed to include only robust, non-redundant features for the cox regression to predict the progression-free survival (PFS) and the overall survival (OS). Results were validated on a separate cohort. Additionally, SUVmax and SUVmean, and volume were tested for their prognostic ability for PFS and OS.

RESULTS

For the PFS a concordance index (c-index) of 0.67 (95% CI 0.52-0.82) and 0.66 (95% CI 0.57-0.78) for the training cohort (n = 36) and internal validation cohort (n = 36), respectively, were obtained for the PET radiomics model. The PFS advantage of the low-risk group translated also into an OS advantage. On CT images, no radiomics model could be trained. SUV max and SUV mean were also not prognostic in terms of PFS and OS.

CONCLUSION

We were able to build a successful FDG PET radiomics model for the prediction of PFS in MPM. Radiomics could serve as a tool to aid clinical decision support systems for treatment of MPM in future.

Incremental amounts of Ascophyllum nodosum meal do not improve animal performance but do increase milk iodine output in early lactation dairy cows fed high-forage diets

The objective of this study was to investigate the effects of incremental amounts of Ascophyllum nodosum meal (ANOD) on milk production, milk composition including fatty acids and I, blood metabolites, and nutrient intake and digestibility in early lactation dairy cows fed high-forage diets. Twelve multiparous Jersey cows averaging (mean±standard deviation) 40±21 d in milk and 464±35 kg of body weight and 4 primiparous Jersey cows averaging 75±37 d in milk and 384±17kg of body weight were randomly assigned to treatment sequences in a replicated 4×4 Latin square design. Each period lasted 21 d with 14 d for diet adaptation and 7 d for data and sample collection. Cows were fed a total mixed ration (64:36 forage-to-concentrate ratio) supplemented (as fed) with 0, 57, 113, or 170 g/d of ANOD. Milk yield as well as concentrations and yields of milk components (fat, protein, lactose, milk urea N) were not affected by increasing dietary amounts of ANOD. Concentration (from 178 to 1,370 µg/L) and yield (from 2.8 to 20.6 mg/d) of milk I increased linearly in cows fed incremental amounts of ANOD as a result of the high concentration of I (820 mg/kg of dry matter) in ANOD. Overall, only minor changes were observed in the proportion of milk fatty acids with ANOD supplementation. Quadratic trends were observed for dry matter intake and total-tract digestibilities of organic matter and neutral detergent fiber, whereas negative linear trends were observed for serum concentration of cortisol and crude protein digestibility with ANOD supplementation. Serum concentrations of triiodothyronine and thyroxine were not affected by ANOD supplementation and averaged 1.1 and 48.4 ng/mL, respectively. However, feeding increasing amounts of ANOD linearly reduced the plasma concentration of nonesterified fatty acids (from 164 to 132 mEq/L). Quadratic effects were found for the total-tract digestibility of ADF and urinary output of purine derivatives, suggesting that ANOD supplementation may stimulate growth of ruminal cellulolytic bacteria in a dose-dependent fashion. In general, feeding incremental amounts of ANOD to early lactation dairy cows dramatically increased milk I concentration and output with no effect on animal performance.

FDA Approval Summary: Selpercatinib for the Treatment of Advanced RET Fusion-Positive Solid Tumors

On September 21, 2022, the FDA granted accelerated approval to selpercatinib (Retevmo, Eli Lilly and Company) for the treatment of adult patients with locally advanced or metastatic solid tumors with a rearranged during transfection (RET) gene fusion that have progressed on or following prior systemic treatment or who have no satisfactory alternative treatment options. The approval was based on data from Study LOXO-RET-17001 (LIBRETTO-001; NCT03157128), an international, non-randomized, multi-cohort clinical trial that included patients with advanced solid tumors harboring RET alterations. The overall response rate in 41 patients with locally advanced or metastatic RET fusion-positive solid tumors other than non-small cell lung cancer (NSCLC) or thyroid cancer was 44% [95% confidence interval (CI), 28%-60%], with median duration of response 24.5 months (95% CI, 9.2-not evaluable). Patients with 10 of 14 tumor types with a variety of fusion partners had objective responses, including patients with the following tumors: pancreatic adenocarcinoma, colorectal, salivary, unknown primary, breast, soft-tissue sarcoma, bronchial carcinoid, ovarian, small intestine, and cholangiocarcinoma. The recommendation for approval was supported by results from LIBRETTO-001 in patients with RET fusion-positive NSCLC and thyroid cancer, which formed the basis of prior approvals in these tumor types. The most common adverse reactions (>25%) were edema, diarrhea, fatigue, dry mouth, hypertension, abdominal pain, constipation, rash, nausea, and headache. This is the first tissue-agnostic approval of a RET-directed targeted therapy.

Role of aberrant nitric oxide synthase-3 expression in cerebrovascular degeneration and vascular-mediated injury in Alzheimer's disease

Nitric oxide (NO) is an important signaling molecule that is generated through the catalytic activity of nitric oxide synthase (NOS). In the brain, NO mediates neuronal survival, synaptic plasticity, vascular smooth muscle relaxation, and endothelial cell permeability. Previous studies demonstrated aberrant expression of the NOS-III gene in neurons and glial cells in brains with Alzheimer's disease (AD). Since NOS-III is also expressed in vascular cells, and cerebrovascular disease (CVD) frequently complicates the pathology of AD, we investigated the role of NOS-III in relation to CVD in AD. Vasculopathy in AD + CVD was characterized by thickening and hyalinization of the media of small and medium-size vessels, variable degrees of beta-amyloid (A beta) deposition, and increased apoptosis of vascular smooth muscle and endothelial cells, particularly involving white matter vessels. These abnormalities were correlated with reduced levels of NOS-III expression in cerebral vessels. Double-labeling studies demonstrated that the low levels of cerebrovascular NOS-III were associated with increased levels of the pro-apoptosis gene product, p53 in smooth muscle and endothelial cells, suggesting a role for altered NOS-III expression in AD-associated vascular degeneration. Constitutively reduced cerebrovascular NOS-III expression and NO production could also lead to cerebral hypoperfusion due to impaired vasodilation responses, and diminished capacity to remove respiratory waste products and toxins from the extracellular space due to reduced capillary permeability. The role for phosphodiesterases as modulators of NOS activity is discussed, as these molecules represent potential therapeutic targets given their cell type and cyclic nucleotide specificities of action.

Ligneous conjunctivitis in a girl with severe type I plasminogen deficiency

BACKGROUND

Ligneous conjunctivitis is a rare form of chronic recurrent pseudomembranous disease and may be associated with systemic membranous pathological changes. Recently ligneous conjunctivitis has been linked to severe type I plasminogen deficiency. We report on a patient with plasminogen deficiency and severe bilateral ligneous conjunctivitis. A new treatment approach and its outcome in this patient are described.

CASE REPORT

We present the case of a 9-month-old Turkish girl with massive swelling of the eyelids and hard white pseudomembranes on both lids. The conjunctival smear was positive for Streptococcus pneumoniae. The clinical diagnosis was: ligneous conjunctivitis with superinfection. Histological investigation showed fibrin as major component of the pseudomembranes. The coagulation analyses revealed decreased plasminogen activity (<5%; normal 80-120%) and decreased plasminogen antigen (<0.4 mg/dl; normal 6-25 mg/dl). The failure of surgical therapy led to the attempt at treatment with intravenous lys-plasminogen. A significant improvement of the ocular symptoms occurred; stabilization with no recurrent pseudomembranes could be achieved for 6 months after treatment.

DISCUSSION

The initial amelioration of symptoms in our patient after systemic replacement therapy confirms the etiological importance of plasminogen deficiency in the development of ligneous conjunctivitis. Curative treatment of ligneous conjunctivitis is still not available. However, intravenous application of plasminogen offers new possibilities in therapy, although long-term treatment seems necessary.

FDA Approval Summary: Margetuximab plus Chemotherapy for Advanced or Metastatic HER2-Positive Breast Cancer

On December 16, 2020, the FDA granted regular approval to margetuximab-cmkb (MARGENZA), in combination with chemotherapy, for the treatment of adult patients with HER2-positive (HER2⁺) metastatic breast cancer who have received two or more prior anti-HER2 regimens, at least one of which was for metastatic disease. Approval was based on data from SOPHIA, a multicenter, randomized, open-label, active controlled study comparing margetuximab with trastuzumab, in combination with chemotherapy. The primary efficacy endpoint was progression-free survival (PFS) by blinded independent central review. SOPHIA demonstrated a 0.9-month difference in median PFS between the two treatment arms [5.8 vs. 4.9 months, respectively; stratified HR, 0.76 (95% confidence interval: 0.59-0.98; P = 0.0334)]. Overall survival (OS) was immature at the data cut-off date of September 10, 2019. Infusion-related reactions (IRR) are an important safety signal associated with margetuximab plus chemotherapy. In SOPHIA, 13% of patients treated with margetuximab plus chemotherapy reported IRRs, of which 1.5% were grade 3. The most commonly reported adverse drug reactions (>10%) with margetuximab in combination with chemotherapy were fatigue/asthenia, nausea, diarrhea, vomiting, constipation, headache, pyrexia, alopecia, abdominal pain, peripheral neuropathy, arthralgia/myalgia, cough, decreased appetite, dyspnea, IRR, palmar-plantar erythrodysesthesia, and extremity pain. Overall, the favorable risk-benefit profile for margetuximab when added to chemotherapy supported its approval for the intended indication.

Low-tube-voltage 80-kVp neck CT: evaluation of diagnostic accuracy and interobserver agreement

BACKGROUND AND PURPOSE

Low-tube-voltage acquisition has been shown to facilitate substantial dose savings for neck CT with similar image contrast compared with standard 120-kVp acquisition. However, its potential for the detection of neck pathologies is uncertain. Our aim was to evaluate the effects of low-tube-voltage 80-kV(peak) acquisitions for neck CT on diagnostic accuracy and interobserver agreement.

MATERIALS AND METHODS

Three radiologists individually analyzed 80-kVp and linearly blended 120-kVp image series of 170 patients with a variety of pathologies who underwent dual-energy neck CT. Reviewers were unblinded to the clinical indication for CT but were otherwise blinded to any other data or images and were asked to state a final main diagnosis. Findings were compared with medical record charts, CT reports, and pathology results. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated for each observer. Interobserver agreement was evaluated by using intraclass correlation coefficients.

RESULTS

Diagnoses were grouped as squamous cell carcinoma-related (n = 107, presence/absence of primary/recurrent squamous cell carcinoma), lymphoma-related (n = 40, presence/absence of primary/recurrent lymphoma), and benign (n = 23, eg, abscess). Cumulative sensitivity, specificity, positive predictive value, and negative predictive value for 80-kVp and blended 120-kVp images were 94.8%, 93.0%, 95.9%, and 91.1%, respectively. Results were also consistently high for squamous cell carcinoma-related (94.8%/95.3%, 89.1%/89.1%, 94.3%/94.4%, 90.1%/91.0%) and lymphoma-related (95.0%, 100.0%, 100.0%, 95.2%) 80-kVp/120-kVp image series. Global interobserver agreement was almost perfect (intraclass correlation coefficient, 0.82, 0.80; 95% CI, 0.76-0.74, 0.86-0.85). Calculated dose-length product was reduced by 48% with 80-kVp acquisitions compared with the standard 120-kVp scans (135.5 versus 282.2 mGy × cm).

CONCLUSIONS

Low-tube-voltage 80-kVp CT of the neck provides sufficient image quality with high diagnostic accuracy in routine clinical practice and has the potential to substantially decrease radiation exposure.

Active NaCl absorption across split lamellae of posterior gills of the chinese crab Eriocheir sinensis: stimulation by eyestalk extract

Split lamellae of the posterior gills of freshwater-adapted Chinese crabs (Eriocheir sinensis) were mounted in a modified Ussing-type chamber, and active and electrogenic absorption of Na(+) and Cl(−) were measured as positive (I(Na)) or negative (I(Cl)) short-circuit currents. Haemolymph-side addition of eyestalk extract stimulated I(Cl) by increasing both the transcellular Cl(−) conductance and the electromotive force for Cl(−) absorption. The effect was dose-dependent. Boiling the eyestalk extract did not change its effectiveness. The stimulating factor passed through dialysis tubing, indicating that it has a molecular mass of less than 2 kDa. R(p)cAMPS, a blocker of protein kinase A, reduced the stimulated I(Cl). Eyestalk extract stimulated I(Na) by increasing the transcellular Na(+) conductance at constant electromotive force. Amiloride-induced current-noise analysis revealed that stimulation of I(Na) was accompanied by an increase in the apparent number of open apical Na(+) channels at a slightly reduced single-channel current. In addition to the electrophysiological experiments, whole gills were perfused in the presence and in the absence of putative transport stimulators, and the specific activities of the V-ATPase and the Na(+)/K(+)-ATPase were measured. Eyestalk extract, theophylline or dibutyryl-cyclic AMP stimulated the activity of the V-ATPase, whereas the activity of the Na(+)/K(+)-ATPase was unaffected. The simultaneous presence of R(p)cAMPS prevented the stimulation of V-ATPase by eyestalk extract or theophylline.

Biological effects of the dihydroorotate dehydrogenase inhibitor polyporic acid, a toxic constituent of the mushroom Hapalopilus rutilans, in rats and humans

Inhibitors of dihydroorotate dehydrogenase (DHO-DH), such as brequinar or leflunomide, have been intensively tested for their antitumour and immunomodulating effects. Polyporic acid (PA) from the mushroom Hapalopilus rutilans (H. r.) also is a DHO-DH inhibitor (50% inhibitory concn., IC50, 10(-4)-10(-3) M). As three people had been poisoned following ingestion of H. r. we wanted to investigate the effects of PA in rats and in cell cultures. Rats given PA via probang (100-800 mg/ kg) within 24 h developed strongly reduced locomotor activity, depressed visual placing response and impaired wire manoeuvre. Laboratory investigation of blood revealed hepatorenal failure, metabolic acidosis as well as hypokalaemia and hypocalcaemia. All symptoms closely paralleled the effects seen in the poisoned people. Proliferation of cultured cells (including rat brain neurons and glia, fibroblasts, tumour cells) was depressed at 10(-4)-10(-3) M PA. We conclude that the intoxication of people poisoned with H. r. is due to the high content of the DHO-DH inhibitor PA.

The relationship between seizure subtype and interictal personality. Results from the Vietnam Head Injury Study

A wide variety of interictal personality traits has been associated with complex partial (CP) epilepsy. However, the specificity of these behavioural changes to CP epilepsy has been questioned in several controlled studies. To address this issue, we examined personality and behavioural characteristics in 467 Vietnam veterans 15 years post penetrating head injury. Of this sample, 238 (51%) had developed seizure disorders which were classified as follows: 39 simple partial (SP), 59 CP, 76 partial with secondary generalization (PG), and 64 generalized (G). Seizure patients were compared with two demographically matched control groups: 229 penetrating head-injured Veterans without seizures (PHI-C) and 84 uninjured veterans (UC). Dependent measures included self-report and examiner rating scales, and history of psychiatric treatment. Pre-injury intelligence, brain volume loss (CT scan), seizure frequency and duration of epilepsy served as covariates. We found statistically significant increases in interictal psychopathology in the CP, PG and G groups when compared with the two control groups (PHI-C and UC). No group differences were observed across seizure subtypes. These results suggest that interictal personality and behavioural abnormalities are not specific to individuals with CP seizures. Furthermore, the increased psychopathology in seizure groups when compared with the PHI-C group suggests that personality changes cannot be accounted for by structural brain damage alone.

Diagnostic value for acute myocardial infarction of creatine kinase and lactate dehydrogenase isoenzymes compared with total enzymes. Creatine kinase isoenzyme specificity for myocardial damage

The diagnostic value of creatine kinase (CK) and lactate dehydrogenase isoenzymes was investigated in a prospective study of 201 patients with suspected acute myocardial infarction (AMI). The isoenzymes were analyzed with a column chromatographic method. The patients' final diagnoses were made according to the WHO criteria without knowledge of the isoenzyme results. The prevalence of AMI was 50%. The diagnoses were predicted with significantly greater reliability with the isoenzyme than with the total enzyme determinations in most of the patients. However, the greater diagnostic reliability had sufficient therapeutic consequence to justify the extra analytical cost only in patients for whom the diagnosis must be based mainly on the enzyme results. The CK isoenzyme specificity for myocardial damage was studied in populations with low prevalence of heart disease. In a group of 39 patients who had elevated total CK due to noncardiac disease there were five with elevated isoenzyme values, but since among 69 young healthy persons none had elevated isoenzymes, this was taken to indicate that the isoenzymes may be leaked into the blood from other organs than the heart.