Neuroanatomical correlates of a lactate-induced anxiety attack

Positron emission tomographic measurements of regional blood flow were used to assess local neuronal activity in patients with panic disorder and in normal control subjects before and during the infusion of sodium lactate. A new technique for the analysis of positron emission tomographic data was employed to identify significant changes in regional blood flow associated with lactate infusion in the panicking patients, nonpanicking patients, and controls. Lactate-induced panic was associated with significant blood flow increases bilaterally in the temporal poles; bilaterally in insular cortex, claustrum, or lateral putamen; bilaterally in or near the superior colliculus; and in or near the left anterior cerebellar vermis. Lactate infusion was not associated with significant changes in regional blood flow in the nonpanicking patients or control subjects. Thus, the identified regions seemed to be involved in an anxiety attack.     

Stroke in the young. Part II

Evaluation of the young stroke patient often requires an interdisciplinary approach because of the complexity of the problems encountered. We discuss some of the less common causes of stroke and present an approach to the patient.     

Occurrence of stroke associated with use/abuse of drugs

Ischemic and hemorrhagic stroke frequently occur in temporal association with use or abuse of illicit and over-the-counter (OTC) sympathomimetic drugs. However, little information is available on the proportion of strokes associated with use/abuse of drugs in specific hospital populations. Between September 1, 1988, and August 1, 1989, 167 of 178 stroke patients entered into the Maryland Stroke Data Bank were asked for a history of drug use or abuse. Information was incomplete in 51 of 167 (31%) patients due to neurologic deficit or lack of inquiry. Eleven of the remaining 116 cases (9.5%) were historically associated with drug use. Age range was 25 to 56 years (mean, 41 years). Stroke associated with drug use occurred in four of 62 (6%) cerebral infarcts, two of 28 (7%) intracerebral hemorrhages, and five of 26 (19%) subarachnoid hemorrhages (p = ns). Drugs included cocaine in five (45%), OTC sympathomimetics in three (27%), phencyclidine in two (18%), and heroin in one (9%).     

Minority female dentists: a synopsis

This pilot study identified a group of minority female dentists who are relatively young to the dental profession. In general, these individuals are enthusiastic about a career in dentistry. Career contentment is evinced by the reported level of satisfaction with the dental profession, irrespective of educational indebtedness or annual income. Of those who are dissatisfied, it seems as if income and debt are not the primary areas of concern. These findings provide an impetus for a more comprehensive investigation of this emerging population of dentists.     

Melanoma tumor vaccine: five-year follow-up

For many years, various melanoma vaccines have been employed. This is a unique melanoma vaccine in that it is a subcellular tumor homogenate and no adjuvants have been added. This vaccine has been given to 129 stage I and 61 stage II melanoma patients. All were followed at least 5 years and had 87.5% and 63.9% 5-year survival rates, respectively. Sixty-four stage I males and 65 stage I females had 84% and 90% 5-year survival rates, respectively. We saw no difference between those with or without lymph node dissection. Thirty-six stage II males and 25 stage II females had 66.7% and 60% 5-year survival rates, respectively. Of stage II patients, 23 had only one positive node, 22 had two to four positive nodes, and 9 had five or more positive nodes with 69%, 63%, and 55% 5-year survival rates, respectively. Large published series were used as historical controls [6,27,28], and significant differences were noted when compared to our stage II patients (P = 0.001)--those with two to four positive nodes (P = 0.03), and those with five or more positive nodes (P = 0.04). We conclude that there is a significant increase in survival for these stage II patients, at high risk of recurrence, receiving a tumor homogenate vaccine. This vaccine warrants further analysis, development, and use in a phase III randomized clinical trial.     

Ultrastructure of cholinergic synaptic terminals in the thalamic anteroventral,ventroposterior, and dorsal lateral geniculate nuclei of the rat

The principal relay nuclei of the thalamus receive their cholinergic innervation from two midbrain cholinergic groups: the pedunculopontine tegmental nucleus and the laterodorsal tegmental nucleus. The different thalamic nuclei exhibit populations of cholinergic axons which vary in density and morphology when examined at the light microscopic level. However, the ultrastructure of the cholinergic terminals in different thalamic nuclei has not been described. This study was undertaken to confirm that synaptic contacts are formed by cholinergic axons in several principal thalamic relay nuclei, to describe their ultrastructural morphology, and to identify the types of postsynaptic elements contacted by cholinergic synaptic terminals. The thalamic nuclei examined in this study are the dorsal lateral geniculate nucleus, ventroposteromedial nucleus, ventroposterolateral nucleus, and anteroventral nucleus. Our results confirm that cholinergic axons form synaptic terminals in these thalamic nuclei. Cholinergic synaptic terminals contact structures outside the characteristic synaptic glomeruli, are never postsynaptic, and have morphologies and postsynaptic targets which differ among the thalamic nuclei. In the ventroposterior nuclei, cholinergic terminals form asymmetric synaptic contacts onto larger dendrites in the extraglomerular neuropil. In the anteroventral nucleus, cholinergic terminals form both symmetric and asymmetric synaptic contacts onto dendrites and somata. Cholinergic terminals in the anteroventral nucleus are larger than those in other nuclei. In the dorsal lateral geniculate nucleus, cholinergic terminals contact both somata and dendrites in the extraglomerular neuropil, but the synaptic contacts in this nucleus are symmetric in morphology.     

Technical developments for cerebral thermal treatment: water-cooled diffusing laser fibre tips and temperature-sensitive MRI using intersecting image planes.

The aim was to determine if water-cooled diffusing tips could produce larger and safer (better controlled) thermal lesions than non-cooled diffusing tips at 980 nm. Thermal lesions were induced in beef myocardium in vitro with and without water cooling using a 980 nm diode laser at various power levels. Seven intracerebral treatments were performed in six canines using water-cooled diffusing tips with four animals having intracerebral transmissible venereal tumours grown from inoculate. Magnetic resonance thermal imaging (MRTI)-based feedback software using a fast, radio frequency-spoiled gradient echo acquisition with two intersecting image planes was used for on-line monitoring and control of treatment and for the evaluation of in vivo laser lesion production. In cases where two-plane MRTI was employed, the maximum calculated temperature was compared in each plane. Using water-cooled tips and 400 micro m core diameter laser diffusing fibres in in vitro beef myocardium, power of up to 9.5 W was applied for 8 min without tip failure. Without cooling, tip failure occurred in under 4 min at 6 W, in under 2 min at 7 W and instantaneously at 8 W. Additionally, char accompanied lesions made with uncooled tips while cooled application resulted in only minimal char at only the highest thermal dose. Achieved lesion cross-sectional diameters in in vitro samples were up to 26.5 x 23.3 mm when water cooling was used. In canine brain and transmissible venereal tumours, up to 18.1 x 21.4 mm lesions were achieved. It is concluded that water cooling allows safe application of higher power to small core diameter diffusing tip fibres, which results in larger thermal lesions than can be achieved without cooling. Two-plane MRTI enhances on-line monitoring and feedback of thermal treatment.     

Anemia during adjuvant non-taxane chemotherapy for early breast cancer: Incidence and risk factors from two trials of the International Breast Cancer Study Group

Goal of the work Anemia is a common side effect of chemotherapy. Limited information exists about its incidence and risk factors. The objective of this study was to evaluate the incidence of anemia and risk factors for anemia occurrence in patients with early breast cancer who received adjuvant chemotherapy. Materials and methods We evaluated risk factors for anemia in pre- and post/perimenopausal patients with lymph node-positive early breast cancer treated with adjuvant chemotherapy in two randomized trials. All patients received four cycles of doxorubicin and cyclophosphamide (AC) followed by three cycles of cyclophosphamide, methotrexate, fluorouracil (CMF). Anemia incidence was related to baseline risk factors. Multivariable analysis used logistic and Cox regression. Main results Among the 2,215 available patients, anemia was recorded in 11% during adjuvant chemotherapy. Grade 2 and 3 anemia occurred in 4 and 1% of patients, respectively. Pretreatment hemoglobin and white blood cells (WBC) were significant predictors of anemia. Adjusted odds ratios (logistic regression) comparing highest versus lowest quartiles were 0.18 (P < 0.0001) for hemoglobin and 0.52 (P = 0.0045) for WBC. Age, surgery type, platelets, body mass index, and length of time from surgery to chemotherapy were not significant predictors. Cox regression results looking at time to anemia were similar. Conclusions Moderate or severe anemia is rare among patients treated with AC followed by CMF. Low baseline hemoglobin and WBC are associated with a higher risk of anemia. The authors represent the International Breast Cancer Study Group.     

The variable influence of an alpha component in pregnancy plasma on four different assay systems for the measurement of pregnancy-specific beta1 glycoprotein

Four methods (radioimmunoassay, electroimmunoassay, laser nephelometry and kinetic immunoturbidimetry) have been evaluated for the measurement of proteins with pregnancy-specific beta1 glycoprotein immunoreactivity. The influence of two maternal plasma proteins with different electrophoretic mobilities (alpha2 and beta1) but with similar antigenic determinants has been assessed in each assay system. The radioimmunoassay method, which utilises a homogeneous preparation of pregnancy-specific beta1 glycoprotein for the preparation of iodinated tracer, and the kinetic immunoturbidimetric assay which measures antigen-antibody complex formation over the first minute of the reaction, were both considerably more specific for the beta1 component of pregnancy specific beta1 glycoprotein immunoreactivity than the laser nephelometric or electroimmunoassay methods.