Relation between baseline and on-treatment lipid parameters and first acute major coronary events in the Air Force/Texas Coronary Atherosclerosis Prevention Study (AFCAPS/TexCAPS)

BACKGROUND

The Air Force/Texas Coronary Atherosclerosis Prevention Study (AFCAPS/TexCAPS) is the first primary-prevention study in a cohort with average total cholesterol (TC) and LDL cholesterol (LDL-C) and below-average HDL cholesterol (HDL-C). Treatment with lovastatin (20 to 40 mg/d) resulted in a 25% reduction in LDL-C and a 6% increase in HDL-C, as well as a 37% reduction in risk for first acute major coronary event (AMCE), defined as fatal or nonfatal myocardial infarction, unstable angina, or sudden cardiac death. This article describes the relation between baseline and on-treatment lipid and apolipoprotein (apo) parameters and subsequent risk for AMCEs.

METHODS AND RESULTS

With all available data from the entire 6605-patient cohort, a prespecified Cox backward stepwise regression model identified outcome predictors, and logistic regression models examined the relation between lipid variables and AMCE risk. Baseline LDL-C, HDL-C, and apoB were significant predictors of AMCE; only on-treatment apoB and the ratio of apoB to apoAI were predictive of subsequent risk; on-treatment LDL-C was not. When event rates were examined across tertiles of baseline lipids, a consistent benefit of treatment with lovastatin was observed.

CONCLUSIONS

Persons with average TC and LDL-C levels and below-average HDL-C may obtain significant clinical benefit from primary-prevention lipid modification. On-treatment apoB, especially when combined with apoAI to form the apoB/AI ratio, may be a more accurate predictor than LDL-C of risk for first AMCE.

Expression of metabotropic glutamate receptor subtype mRNA (mGluR1-8) in human cerebellum

The expression of metabotropic glutamate receptor (mGluR) mRNAs in the human cerebellar neocortex was investigated using in situ hybridization. mGluR1, 3 and 4 mRNAs were most abundant and widely distributed, whereas mGluR2, 5 and 7 mRNA expression was circumscript. mRNAs coding for mGluR1, 3, 4 and 7 were expressed in Purkinje cells. mGluR1 and 4 mRNAs detectable in granule cells and mGluR1, 2, 3, 4 and 7 mRNAs in Golgi cells. mGluR5 mRNA was detectable in putative Bergmann glia as well as mGluR3 mRNA, which was widely expressed in glial cells. mGluR8 mRNA expression was very low in a subset of stellate/basket cells of the molecular layer whereas mGluR6 mRNA was not detectable in the cerebellar cortex.

[Noninvasive protocol for surgical treatment of focal epilepsies]

We present a non-invasive epilepsy surgery protocol, which includes EEG-video-monitoring, magnetic resonance imaging (MRI), interictal positron emission tomography (PET) and ictal single photon emission computerized tomography (SPECT). According to this non-invasive protocol 50 of 173 patients with medically intractable focal epilepsy underwent resective surgery. The localization of the epileptogenic zone was based on the congruence of the localizing results of EEG-video-monitoring, MRI, interictal PET and ictal SPECT. 46 (92%) of the patients had temporal and 4 (8%) had extratemporal epilepsies. 78% (n = 39) of all patients operated according to our non-invasive protocol were postoperatively completely or almost seizure free. Extramesiotemporal resections could be carried out without invasive EEG-recording if the epileptogenic zone was not adjacent to the eloquent cortex. We conclude from our results that in a considerable number of patients with medically intractable particularly temporal focal epilepsies, resective epilepsy surgery can be based on non-invasive EEG-evaluations and the risk of invasive recordings can be avoided.

Streptolysin O: inhibition of the conformational change during membrane binding of the monomer prevents oligomerization and pore formation

Streptolysin O is a four-domain protein toxin that permeabilizes animal cell membranes. The toxin first binds as a monomer to membrane cholesterol and subsequently assembles into oligomeric transmembrane pores. Binding is mediated by a C-terminally located tryptophan-rich motif. In a previous study, conformational effects of membrane binding were characterized by introducing single mutant cysteine residues that were then thiol-specifically derivatized with the environmentally sensitive fluorophoracrylodan. Membrane binding of the labeled proteins was accompanied by spectral shifts of the probe fluorescence, suggesting that the toxin molecule had undergone a conformational change. Here we provide evidence that this change corresponds to an allosteric transition of the toxin monomer that is required for the subsequent oligomerization and pore formation. The conformational change is reversible with reversal of binding, and it is related to temperature in a fashion that closely parallels the temperature-dependency of oligomerization. Furthermore, we describe a point mutation (N402E) that, while compatible with membrane binding, abrogates the accompanying conformational change. At the same time, the N402E mutation also abolishes oligomerization. These findings corroborate the contention that the target membrane acts as an allosteric effector to activate the oligomerizing and pore-forming capability of streptolysin O.

Properties of a model of Ca++-dependent vesicle pool dynamics and short term synaptic depression

We explore the properties of models of synaptic vesicle dynamics, in which synaptic depression is attributed to depletion of a pool of release-ready vesicles. Two alternative formulations of the model allow for either recruitment of vesicles from an unlimited reserve pool (vesicle state model) or for recovery of a fixed number of release sites to a release-ready state (release-site model). It is assumed that, following transmitter release, the recovery of the release-ready pool of vesicles is regulated by the intracellular free Ca(++) concentration, [Ca(++)](i). Considering the kinetics of [Ca(++)](i) after single presynaptic action potentials, we show that pool recovery can be described by two distinct kinetic components. With such a model, complex kinetic and steady-state properties of synaptic depression as found in several types of synapses can be accurately described. However, the specific assumption that enhanced recovery is proportional to [Ca(++)](i), as measured with Ca(++) indicator dyes, is not confirmed by experiments at the calyx of Held, in which [Ca(++)](i)-homeostasis was altered by adding low concentrations of the exogenous Ca(++) buffer, fura-2, to the presynaptic terminal. We conclude that synaptic depression at the calyx of Held is governed by localized, near membrane [Ca(++)](i) signals not visible to the indicator dye, or else by an altogether different mechanism. We demonstrate that, in models in which a Ca(++)-dependent process is linearly related to [Ca(++)](i), the addition of buffers has only transient but not steady-state consequences.

Transcallosal approach to the third ventricle: normative morphometric data based on magnetic resonance imaging scans, with special reference to the fornix and forniceal insertion

OBJECTIVE

The ability to visualize median-sagittal brain structures by magnetic resonance imaging (MRI) improves the planning for surgical removal of lesions located in and around the third ventricle. The transcallosal approach is the most appropriate path to the anterior part of the third ventricle. The present study was undertaken to obtain normative morphometric data, derived from sagittal MRI scans, which are necessary for operation planning that takes into account the surgical microanatomy and landmarks encountered during this approach.

METHODS

The morphometric evaluation was performed on 72 median-sagittal MRI scans. The surface landmarks for the corridor were the two points, P5 and P7, located 5 and 7 cm anterior to the central sulcus, respectively. With these two points on the cortical surface as references, a variety of measurements were made to provide quantitative information about distances between brain structures encountered during the surgical approach. In addition, various parameters were determined to characterize the different shapes of the fornix and the different types of forniceal insertion.

RESULTS

The following measurements (means) were obtained: 1) the distance between P5/P7 and the cingulate sulcus was 25.76 mm (range, 17.113-42.73 mm) with reference to P5, and 25.41 mm (range, 12.91-36.29 mm) with reference to P7; 2) the distance between the cingulate sulcus and the corpus callosum was 12.91 mm (range, 7.19-22.60 mm) with reference to P5, and 12.92 mm (range, 6.75-23.37 mm) with reference to P7; 3) the height of the corpus callosum was 6.22 mm (range, 3.07-9.00 mm) with reference to P5, and 6.92 mm (range, 3.50-13.57 mm) with reference to P7; 4) the distance between the anterior commissure and the foramen of Monro was 6.78 mm (range, 1.86-14.57 mm), independent of P5 and P7; 5) the distance between the lower margin of the corpus callosum and the upper insertion point of the fornix was 12.44 mm (range, 2.71-26.13 mm) with reference to P5, and 13.34 mm (range, 3.74-27.58 mm) with reference to P7; 6) the distance between the lower margin of the corpus callosum and the lower insertion point of the fornix was 18.08 mm (range, 9.47-29.71 mm) with reference to P5, and 18.58 mm (range, 10.48-30.40 mm) with reference to P7; and 7) the distance between the lower margin of the corpus callosum and the anterior commissure was 23.46 mm (range, 11.98-32.70 mm) with reference to P5, and 22.89 mm (range, 11.05-33.04 mm) with reference to P7. Four different insertion types between the fornix and the corpus callosum were noted and classified.

CONCLUSION

Morphometric data concerning the surrounding structures of the third ventricle have received very little attention in the literature. This morphometric study permitted definition of the surgical corridor to the third ventricle by preserving important anatomic structures such as the motor strip, genu of the corpus callosum, forniceal commissure (hippocampal commissure), anterior commissure, and forniceal columns. The detailed morphometric data obtained on median-sagittal MRI scans of the brain structures involved in the transcallosal interforniceal and/or transcallosal transforaminal approach allow for exact planning of the surgical approach.

Rare occurrence of intracerebellar colloid cyst. Case report

Colloid cysts are rare intracerebral lesions that are preferentially encountered within the third ventricle. There are only a few reports in which colloid cysts are described in other locations such as the fourth ventricle. A symptomatic intracerebellar colloid cyst in a 45-year-old woman is described. The patient presented with headache, gait disturbance, and nausea. Neuroradiological imaging revealed compression of the fourth ventricle, hydrocephalus, and an intracerebellar cystic lesion measuring 4 x 5 cm that had a small peripheral solid portion. The cyst was successfully removed via a paramedian suboccipital approach. Postoperatively, the patient recovered quickly. The findings in the present report represent an additional example of the broad spectrum of cystic lesions encountered in the cerebellum.

Normative volumetric data of the developing hippocampus in children based on magnetic resonance imaging

PURPOSE

To acquire normative data of the hippocampus and its postnatal growth in 50 children (age, 1 month to 15 years) without epilepsy.

METHODS

Morphometry of the hippocampus was carried out by using a spoiled FLASH 3D sequence (sagittal orientation), whereas the volume of the brain was assessed with a T2-weighted spin-echo sequence (transverse orientation). The volume of the hippocampus and the brain was determined by following Cavalieri's principle. Growth curves of the brain and hippocampus were fitted to a nonlinear Boltzmann sigmoidal equation.

RESULTS

Intra-/interobserver coefficient of variation was 2.0/4.9% for hippocampal volume measurements and 2.0/2.1% for brain volumetry. A significant difference in volume was noted between the right and left hippocampus (p < 0.001), with the right side being larger on average by 0.10 cc. Correlation coefficients of growth curves ranged between 0.71 and 0.94. Growth curves demonstrated a faster development of the hippocampus in girls. A steeper slope of hippocampal growth as compared with brain growth was found in girls, whereas in boys, the slope of brain growth was steeper.

CONCLUSIONS

Our findings will be of help in evaluating vulnerable phases of the hippocampal formation with accelerated growth, thereby leading to a better understanding of the development of hippocampal sclerosis in early childhood.

Unexpected death in persons with symptomatic epilepsy due to glial brain tumors: a report of two cases and review of the literature

Two cases of unexpected death in persons with epileptic seizures due to a brain tumor are presented which encompassed an astrocytoma WHO grade II and an anaplastic astrocytoma WHO grade III. A 35-year-old man was found somnolent and disoriented at home. A computed tomography (CT) scan revealed a tumor of the right frontal lobe suggestive for an oligodendroglioma. During an angiographic examination the patient experienced an epileptic seizure. Some weeks later, the man was found dead in front of his house with a fresh bite mark of the tongue. Neuropathological examination revealed an astrocytoma WHO grade II of the right frontal lobe. A 47-year-old man plunged into a swimming-pool and was found submerged some minutes later. After resuscitation he survived comatose for 8 days but finally died due to severe hypoxic brain damage. He had been operated on a brain tumor of the temporal lobe 1 year before the accident. Neuropathological examination revealed residual tumor tissue at the operation site corresponding to an anaplastic astrocytoma WHO grade III. Although rare, death in persons with epileptic seizures due to brain tumors is an important mechanism of death encountered by the forensic pathologist.

Non-lymphomatous brain tumors in HIV-1 infection: a review

A broad spectrum of malignant tumors affecting various organ systems in HIV-1 infected patients have been described in larger series. Intracerebral mass lesions encountered in HIV-1 infection are mostly due to toxoplasmosis and central nervous system (CNS) lymphoma. Brain tumors (excluding lymphomas) occurring in HIV-1 infected patients have only occasionally been described. The present review summarizes these diverse tumor entities and reports on the controversial theories of a possible oncogenic potential of HIV-1. Although rare, intracerebral tumors must be considered in the differential diagnosis of an intracranial space-occupying lesion in an HIV-1 infected patient.

Gridded genomic libraries of different chordate species: a reference library system for basic and comparative genetic studies of chordate genomes

The use of genomic libraries maintained in arrayed format is becoming a more and more popular tool for the analysis of molecular evolution and comparative molecular development. Being able to use already existing reference libraries considerably reduces the work load, and if results are made publicly available, it will facilitate in silica experiments in the future. Here we describe the construction and preliminary characterization of six cosmid libraries of different chordate species, Ciona intestinalis (Hemichordate), Branchiostoma floridae (Cephalochordate), Lampetra fluviatilis (Cyclostoma), Xiphophorus maculatus, and Danio rerio (Osteichthyes) in Lawrist7 and Fugu rubripes in Lawrist4.

Dural cysts in the cervical region. Report of three cases and review of the literature

Dural spinal cysts are exceedingly rare lesions. The authors are aware of only seven cases reported in the literature. This report comprises three patients with dural cysts of the cervical spinal canal who presented with atypical neurological signs and symptoms, including a long history of dysesthesias and atrophic pareses in the proximal upper extremities. Surgical intervention disclosed two ventrally and one dorsally located cystic lesions of the spinal dura mater. The cystic wall was fenestrated and kept open by a silicone catheter in each case. Histological examination of the excised lesions revealed fibrous connective tissue consistent with dural tissue. No epithelial lining was detected. The lesions were classified as dural cysts. The patients' postoperative courses were uneventful. Although dural cysts are rare lesions, they must be considered in the differential diagnosis of spinal cystic lesions. Because they are nonaggressive and can be safely drained by microsurgical techniques, patients have a favorable prognosis. Early surgical intervention is mandatory to prevent severe neurological deficits.

The macromelanophore locus and the melanoma oncogene Xmrk are separate genetic entities in the genome of Xiphophorus

Fish of the genus Xiphophorus are polymorphic for black pigmentation patterns. Certain intra- or interspecific hybrids exhibit enhanced expression of these patterns, leading in many cases to malignant melanoma. Because no recombination was ever observed between the pattern information and the genetic predisposition to develop melanoma after hybridization, a "tumor gene" (Tu) was postulated that encodes both phenotypes. A dominant oncogene, ONC-Xmrk, was then found to be necessary and sufficient for the transforming function of Tu. Here we present molecular evidence that ONC-Xmrk and the pigment pattern information are encoded by separate, although intimately linked loci. No ONC-Xmrk gene was present in the 15 Xiphophorus strains investigated which exhibit no black pigmentation pattern. Five different patterns from Xiphophorus maculatus, X. evelynae, X. milleri, X. cortezi, and X. montezumae were associated with ONC-Xmrk and were melanomagenic, while fish of X. helleri, X. variatus, X. nezahualcoyotl, and X. montezumae with five other patterns had no ONC-Xmrk and consequently did not produce hybrid melanoma. These data provide evidence that ONC-Xmrk is sufficient for tumorigenesis in Xiphophorus hybrids, and that a separate, pigment pattern-encoding locus is closely linked to it.

Decrease in high density lipoprotein cholesterol (HDL-C) levels following gemfibrozil therapy

This report represents the continuation of our studies on the effects of gemfibrozil therapy on high density lipoprotein cholesterol levels. Previously, we reported that despite an impressive mean increase in high density lipoprotein cholesterol (20%), the response to 12 weeks of gemfibrozil therapy was highly variable. Accordingly, out of the 27 subjects studied, five actually had lower high density lipoprotein cholesterol at the conclusion of therapy compared to baseline values. The changes observed in plasma lipids, combined with correlational relationships suggest that the conversion of triglyceride rich lipoprotein components into high density lipoprotein may be impaired in those subjects that respond poorly or negatively to gemfibrozil therapy.

Primary prevention of acute coronary events with lovastatin in men and women with average cholesterol levels: results of AFCAPS/TexCAPS. Air Force/Texas Coronary Atherosclerosis Prevention Study

CONTEXT

Although cholesterol-reducing treatment has been shown to reduce fatal and nonfatal coronary disease in patients with coronary heart disease (CHD), it is unknown whether benefit from the reduction of low-density lipoprotein cholesterol (LDL-C) in patients without CHD extends to individuals with average serum cholesterol levels, women, and older persons.

OBJECTIVE

To compare lovastatin with placebo for prevention of the first acute major coronary event in men and women without clinically evident atherosclerotic cardiovascular disease with average total cholesterol (TC) and LDL-C levels and below-average high-density lipoprotein cholesterol (HDL-C) levels.

DESIGN

A randomized, double-blind, placebo-controlled trial.

SETTING

Outpatient clinics in Texas.

PARTICIPANTS

A total of 5608 men and 997 women with average TC and LDL-C and below-average HDL-C (as characterized by lipid percentiles for an age- and sex-matched cohort without cardiovascular disease from the National Health and Nutrition Examination Survey [NHANES] III). Mean (SD) TC level was 5.71 (0.54) mmol/L (221 [21] mg/dL) (51 st percentile), mean (SD) LDL-C level was 3.89 (0.43) mmol/L (150 [17] mg/dL) (60th percentile), mean (SD) HDL-C level was 0.94 (0.14) mmol/L (36 [5] mg/dL) for men and 1.03 (0.14) mmol/L (40 [5] mg/dL) for women (25th and 16th percentiles, respectively), and median (SD) triglyceride levels were 1.78 (0.86) mmol/L (158 [76] mg/dL) (63rd percentile).

INTERVENTION

Lovastatin (20-40 mg daily) or placebo in addition to a low-saturated fat, low-cholesterol diet.

MAIN OUTCOME MEASURES

First acute major coronary event defined as fatal or nonfatal myocardial infarction, unstable angina, or sudden cardiac death.

RESULTS

After an average follow-up of 5.2 years, lovastatin reduced the incidence of first acute major coronary events (1 83 vs 116 first events; relative risk [RR], 0.63; 95% confidence interval [CI], 0.50-0.79; P<.001), myocardial infarction (95 vs 57 myocardial infarctions; RR, 0.60; 95% CI, 0.43-0.83; P=.002), unstable angina (87 vs 60 first unstable angina events; RR, 0.68; 95% CI, 0.49-0.95; P=.02), coronary revascularization procedures (157 vs 106 procedures; RR, 0.67; 95% CI, 0.52-0.85; P=.001), coronary events (215 vs 163 coronary events; RR, 0.75; 95% CI, 0.61-0.92; P =.006), and cardiovascular events (255 vs 194 cardiovascular events; RR, 0.75; 95% CI, 0.62-0.91; P = .003). Lovastatin (20-40 mg daily) reduced LDL-C by 25% to 2.96 mmol/L (115 mg/dL) and increased HDL-C by 6% to 1.02 mmol/L (39 mg/dL). There were no clinically relevant differences in safety parameters between treatment groups.

CONCLUSIONS

Lovastatin reduces the risk for the first acute major coronary event in men and women with average TC and LDL-C levels and below-average HDL-C levels. These findings support the inclusion of HDL-C in risk-factor assessment, confirm the benefit of LDL-C reduction to a target goal, and suggest the need for reassessment of the National Cholesterol Education Program guidelines regarding pharmacological intervention.

Spinal epidural cavernous hemangiomas. Report of three cases and review of the literature

Epidural cavernous hemangiomas are increasingly identified as a cause of acute or chronic progressive spinal cord syndrome and local back pain or radiculopathy. The authors present three cases of spinal epidural cavernous hemangiomas manifesting as spinal cord syndrome, thoracic radiculopathy, and lumbar radiculopathy. Based on the imaging characteristics of these three cases and a review of the literature, the clinical signs and symptoms and their implications, the role of preoperative neuroradiological diagnosis, and the need for complete surgical resection are discussed. Epidural cavernous hemangiomas display consistent magnetic resonance imaging properties: T1-weighted images most commonly show a homogeneous signal intensity similar to those of spinal cord and muscle, and contrast enhancement is homogeneous or slightly heterogeneous. On T2-weighted images the signal of the lesion is consistently high and slightly less intense than that of cerebrospinal fluid. Frequently, the lesion is characterized by its extension through the intervertebral foramen. Awareness of these characteristics facilitates diagnosis and treatment of the lesions. Despite the risk of bleeding, in all three cases complete surgical excision was achieved.

The application of a biotin-anti-biotin gold technique providing a significant signal intensification in electron microscopic immunocytochemistry: a comparison with the ultrasmall immunogold silver staining procedure

A three-step biotin-anti-biotin gold-detection system (method A) has been applied for ultraimmunocytochemistry using ultrasmall colloidal gold (0.8 nm) linked to anti-biotin antibodies which were visualized and enhanced by silver reduction. The reactivity for glucagon in human pancreatic islets and for cytochrome-c oxidase in heart mitochondria has been compared to a two-step ultrasmall immunogold technique (method B). For both antigens, method A provided significantly higher labelling indices (P<0.001): the labelling density for cytochrome-c oxidase was 223/microm2 using method A and 78/microm2 using method B. For glucagon, the labelling density was 1455/microm2 with method A and 322/microm2 with method B. The results demonstrate that the silver-intensified biotin-anti-biotin gold-detection system is a valuable immunocytochemical method for signal enhancement. The method utilizes biotinylated antibodies from different species, allowing its broad application at the electron microscopic level.

Ganglioglioma of the spinal cord: report of two rare cases and review of the literature

OBJECTIVE AND IMPORTANCE

The goal of this article is to present the clinical and histopathological features of two rare cases of ganglioglioma occurring in the cervicothoracic and thoracolumbar spinal cord.

CLINICAL PRESENTATION

A 4-year-old female patient presented with tetraparesis, whereas a 54-year-old woman showed paraparesis of both feet.

INTERVENTION

Both tumors could be removed totally by microsurgical techniques. Light microscopically, the tumors in both cases showed basically identical histological features and were diagnosed as benign gangliogliomas. Postoperatively, the two patients did not show improvement. Tumor recurrence was not noted at follow-up examinations within 11 and 24 months after surgery, respectively.

CONCLUSION

Ganglioglioma must be considered in the differential diagnosis of tumors affecting the spinal cord. In cases of suspected spinal ganglioglioma showing no sharp delineation from the surrounding tissue, a subtotal tumor removal should be considered to prevent severe neurological deficits.

Presynaptic depression at a calyx synapse: the small contribution of metabotropic glutamate receptors

Synaptic depression of evoked EPSCs was quantified with stimulation frequencies ranging from 0.2 to 100 Hz at the single CNS synapse formed by the calyx of Held in the rat brainstem. Half-maximal depression occurred at approximately 1 Hz, with 10 and 100 Hz stimulation frequencies reducing EPSC amplitudes to approximately 30% and approximately 10% of their initial magnitude, respectively. The time constant of recovery from depression elicited by 10 Hz afferent fiber stimulation was 4.2 sec. AMPA and NMDA receptor-mediated EPSCs depressed in parallel at 1-5 Hz stimulation frequencies, suggesting that depression was induced by presynaptic mechanism(s) that reduced glutamate release. To determine the contribution of autoreceptors to depression, we studied the inhibitory effects of the metabotropic glutamate receptor (mGluR) agonists (1S, 3S)-ACPD and L-AP4 and found them to be reversed in a dose-dependent manner by (RS)-alpha-cyclopropyl-4-phosphonophenylglycine (CPPG), a novel and potent competitive antagonist of mGluRs. At 300 microM, CPPG completely reversed the effects of L-AP4 and (1S, 3S)-ACPD, but reduced 5-10 Hz elicited depression by only approximately 6%. CPPG-sensitive mGluRs, presumably activated by glutamate spillover during physiological synaptic transmission, thus contribute on the order of only 10% to short-term synaptic depression. We therefore suggest that the main mechanism contributing to the robust depression elicited by 5-10 Hz afferent fiber stimulation of the calyx of Held synapse is synaptic vesicle pool depletion.

Colloid cysts of the third ventricle with fatal outcome: a report of two cases and review of the literature

Two cases of sudden death due to colloid cysts of the third ventricle are presented with a review of the literature. In the first case, a 40-year-old woman suffered an acute onset of severe frontal headache after an intercontinental air flight. The next day, she was found comatous and died 7 h after admission to a hospital. In the second case, a 33-year-old man with a medical history of recurrent headaches was found dead in his car. Autopsy in both cases revealed a colloid cyst of the third ventricle and hydrocephalus involving the lateral ventricles. These cases demonstrate that fatal cases still occur. Nevertheless, prompt diagnosis using computed tomography (CT) or magnetic resonance imaging (MRI) is essential, since colloid cysts are histologically benign tumors that can be removed safely by neurosurgical intervention.

Evaluation of gemfibrozil therapy: predictive response from lipoprotein subfraction analysis

Subjects with high-density lipoprotein cholesterol (HDL-C) values of less than 47 mg/dL (mean 35.6 +/- 5.5 mg/dL) were selected for this study to examine relationships between plasma lipids, lipoprotein components, and the outcome of gemfibrozil therapy. Changes in plasma lipoprotein subfractions were determined to better understand the previously observed variability of the responses in both HDL-C and triglycerides to gemfibrozil. Based on the data collected, an attempt was made to identify pretreatment lipid parameters that may be predictive regarding the efficacy of gemfibrozil therapy. Serum samples were analyzed at the outset and after the conclusion of 12 weeks of gemfibrozil therapy. Because the HDL-C response to therapy was highly variable, the data from patients were separated into two groups, responders (>20% increase in HDL-C) and nonresponders (<20% increase in HDL-C). The lipid components of lipoprotein subfractions were evaluated using multiple regression analysis yielding predictive models that show the relationship between specific lipoprotein subfractions and the percentage change in HDL-C and posttreatment triglyceride levels. Group classification was then predicted with 78% accuracy using specific lipoprotein subfractions to estimate an individual's percentage change in HDL-C. The major difference between the responder and nonresponder groups was their respective correlations between triglyceride-lowering and changes in HDL-C. In the responder group, there was a significant correlation between the changes in HDL-C and the lowering of triglycerides (r = 0.61, p = 0.03), whereas the nonresponder group showed no such correlation (r = 0.17, p = 0.52). The predictive model also proved to be highly accurate in forecasting the effectiveness of the triglyceride-lowering action of gemfibrozil in this group of patients.

Design & rationale of the Air Force/Texas Coronary Atherosclerosis Prevention Study (AFCAPS/TexCAPS)

The Air Force/Texas Coronary Atherosclerosis Prevention Study (AFCAPS/TexCAPS) is a randomized, double-blind, placebo-controlled primary prevention trial. It is designed to test the hypothesis that in addition to a lipid-lowering diet, treatment with lovastatin is more effective than placebo in reducing acute major coronary events (i.e., sudden cardiac death, fatal and nonfatal myocardial infarction, and unstable angina) in a cohort with normal to mildly elevated total (180 to 264 mg/dl) and low-density lipoprotein (LDL) cholesterol (130 to 190 mg/dl) and low high-density lipoprotein (HDL) cholesterol (< or =45 mg/dl for men and < or =47 mg/dl for women). Two sites in Texas, Lackland Air Force Base in San Antonio and the University of North Texas Health Science Center in Fort Worth, will conduct the study. After at least 12 weeks of an American Heart Association Step 1 diet and 2 weeks placebo run-in, 6,605 men and women, ages 45 to 73 and 55 to 73 years, respectively, without clinical evidence of coronary heart disease, are randomized in equal numbers to either lovastatin (20 mg/day) or placebo. Study procedures maintain the blind, allowing titration of lovastatin from 20 to 40 mg/day to achieve an LDL cholesterol goal of < or = 110 mg/dl. All participants are followed until study completion, when 320 participants have had a primary end point or a minimum of 5 years after the last participant is randomized, whichever occurs last. All end points are adjudicated by an independent committee using prespecified criteria. Unique features of this trial are (1) the inclusion of unstable angina in the primary end point to reflect the increasing trend to treat coronary heart disease aggressively before a myocardial infarction has occurred, (2) aggressive pharmacologic intervention, with titration, to attain an LDL cholesterol goal less than the current National Cholesterol Education Panel guidelines for primary prevention, and (3) a cohort that includes women, the elderly, and those with mild to moderate hyperlipidemia and low HDL cholesterol. Compared with earlier studies, results will be applicable to a broader population and may help clarify the role of aggressive LDL cholesterol reduction measures in primary prevention. Treatment of this population is likely to realize the greatest cumulative long-term benefit in the prevention of acute major coronary events.

Kaposi's sarcoma in the cerebellum of a patient with AIDS

A case of Kaposi's sarcoma in the left cerebellar hemisphere of a patient with AIDS is presented. The lesion was not detected with imaging techniques in the patient who, during the clinical course, did not show neurological signs and symptoms. This small nodular lesion was only revealed at autopsy. This rare finding is an example of the broad spectrum of central nervous system involvement in HIV-1-infected individuals.

The transcallosal interforniceal approach to the third ventricle: anatomic and microsurgical aspects

OBJECTIVE

The ability to visualize median-sagittal brain structures by magnetic resonance imaging improves planning for surgery to treat lesions of the third ventricle. The most appropriate path to the third ventricle is the transcallosal approach. The present study was undertaken to describe the surgical anatomy and landmarks encountered during this approach.

METHODS

The transcallosal-interforniceal approach was undertaken in 30 formalin-fixed brains using an operating microscope. The surface landmarks for the approach pathway were the two points, P5 and P7, located 5 and 7 cm anterior to the central sulcus, respectively. Using these two points on the cortical surface as references, a variety of measurements were made to provide quantitative information about distances between brain structures that are encountered during the surgical approach. Measurements that were made include the following: 1) the distance between P5 and the cingulate sulcus, 2) the distance between the cingulate sulcus and the corpus callosum, 3) the height of the corpus callosum, 4) the distance between the anterior commissure and the foramen of Monro, and 5) the distance between the lower margin of the corpus callosum and the fornix.

RESULTS

Mean values for these key measurements were as follows: 1) 23.96 mm (range, 15.0-32.0 mm); 2) 13.50 mm (range, 8.0-20.0 mm) with reference to P5 and 12.73 mm (range, 16.0-18.0 mm) with reference to P7; 3) 6.12 mm (range, 4.0-8.0 mm) with reference to P5 and 6.60 mm (range, 4.0-9.0 mm) with reference to P7; 4) 4.96 mm (range, 2.5-10.0 mm), independent of P5 and P7; and 5) 8.46 mm (range, 3.0-16.0 mm) with reference to P5 and 11.04 mm (range, 6.0-22.0 mm) with reference to P7.

CONCLUSION

The detailed quantitative information obtained in this study about the interforniceal approach permitted definition of surgical approach pathways that preserve important anatomic structures, such as the motor strip, genu of the corpus callosum, fornical commissure (hippocampal commissure), anterior commissure, and fornical columns. The approach through this surgical corridor can easily be planned and performed in individual cases using median-sagittal magnetic resonance imaging scans.