Pallidotomy increases cortical inhibition in Parkinson's disease

BACKGROUND

Pallidotomy helps parkinsonian symptoms. We tested the hypothesis that this might be due to changes in inhibition in the motor cortex.

METHODS

We examined 15 patients with parkinsonism before and after posteroventral pallidotomy. Magnetic stimuli were delivered over the motor cortex, while subjects maintained a 30% maximum voluntary contraction of the contralateral first dorsal interosseus (FDI).

RESULTS

Weak stimuli inhibited voluntary muscle activity, while slightly stronger stimuli caused short latency facilitation from activation of the corticospinal neurons. After pallidotomy magnetic stimulation, at the threshold for the short latency facilitation, resulted in more inhibition than before.

CONCLUSION

Pallidotomy increases cortical inhibition. This may be associated with improved control of movements.

Phospholipid biosynthetic enzymes in human brain

Growing evidence suggests an involvement of brain membrane phospholipid metabolism in a variety of neurodegenerative and psychiatric conditions. This has prompted the use of drugs (e.g., CDPcholine) aimed at elevating the rate of neural membrane synthesis. However, no information is available regarding the human brain enzymes of phospholipid synthesis which these drugs affect. Thus, the objective of our study was to characterize the enzymes involved, in particular, whether differences existed in the relative affinity of substrates for the enzymes of phosphatidylethanolamine (PE) compared to those of phosphatidylcholine (PC) synthesis. The concentration of choline in rapidly frozen human brain biopsies ranged from 32-186 nmol/g tissue, a concentration similar to that determined previously for ethanolamine. Since human brain ethanolamine kinase possessed a much lower affinity for ethanolamine (Km = 460 microM) than choline kinase did for choline (Km = 17 microM), the activity of ethanolamine kinase in vivo may be more dependent on substrate availability than that of choline kinase. In addition, whereas ethanolamine kinase was inhibited by choline, and to a lesser extent by phosphocholine, choline kinase activity was unaffected by the presence of ethanolamine, or phosphoethanolamine, and only weakly inhibited by phosphocholine. Phosphoethanolamine cytidylyltransferase (PECT) and phosphocholine cytidylyltransferase (PCCT) also displayed dissimilar characteristics, with PECT and PCCT being located predominantly in the cytosolic and particulate fractions, respectively. Both PECT and PCCT exhibited a low affinity for CTP (Km approximately 1.2 mM), suggesting that the activities of these enzymes, and by implication, the rate of phospholipid synthesis, are highly dependent upon the cellular concentration of CTP. In conclusion our data indicate different regulatory properties of PE and PC synthesis in human brain, and suggest that the rate of PE synthesis may be more dependent upon substrate (ethanolamine) availability than that of PC synthesis.

[CHOLEDOCHAL CYST: ENDOSCOPIC RETROGRADE CHOLANGIOPANCREATOGRAPHY(ERCP) DIAGNOSIS VALUE]

We presented six cases of choledochal cysts all of whichwere diagnosed by ERCP. Patients were 12,13,17,20,29 and 36 years old. Five were female and one was a male. The main symptom was abdominal pain.The Endoscopic Retrograde Cholangiopancreatography showed the anatomic details of the biliary tree and the pancreaticobiliary ductal junction and also allowed us to decide the adecuate management of the patient.

[PREGNANCY AND LIVER CIRRHOSIS: REPORT OF A CASE]

Pregnancy in women with liver cirrhosis is unusual, because of the metabolic alterations that the liver disease produces.We report a case of a cirrhotic alcoholic patient who was pregnant twice. The first pregnancy was successful delivering a baby of 2,500g. On the second one, the patient died because of digestive hemorrahage caused esophageal varices the fetus also died.

Abscess within a brain metastasis

BACKGROUND

Neoplastic metastases to the cerebellum are a frequent complication in patients with carcinoma. However, the co-existence of an abscess within a CNS metastasis is a rare event.

METHODS

We report the case of a 79-year-old woman with two cerebellar abscesses within metastatic lesions in the cerebellum. She presented with a rapidly progressing syndrome characterized by elevated intracranial pressure and cerebellar findings.

RESULTS

At surgery, a purulent exudate within discrete metastatic tumours was identified. Pathological and microbiological examinations confirmed the coexistence of an abscess within a metastatic carcinoma.

SIGNIFICANCE AND CONCLUSION

The radiological diagnosis o f intracranial abscesses and metastases can be non-specific and brain imaging may not reliably identify both processes when they coexist. Furthermore, brain metastases often contain liquefied material which can be mistaken for tissue necrosis rather than an infectious process. It is important to be aware that a brain metastasis can also be infected. Therefore, acquisition of lesional tissue for both pathological and microbiological examinations is essential for accurate diagnosis and to direct optimal therapy in situations where the intracranial lesion could be either an abscess or a metastatic deposit.

A parallel broadband real-time system for electrical impedance tomography

This paper deals with the design, implementation and performance of TIE-4sys, an electrical impedance tomograph. This instrument is a parallel broad-band real-time system. It measures impedance using an array of 16 electrodes and reconstructs the images using a weighted back-projection technique. The objective of this development is to enable multifrequency EIT clinical studies to be undertaken. The system is capable of acquiring 25 frames/s and makes multifrequency cardiac-gated images. The frequency range is from 10 kHz to 250 kHz and the signal to noise ratio for the real component is better than 60 dB.

[Endoscopic retrograde cholangiopancreatography and sphincterotomy in parasitic diseases]

We report six patients with billary duct obstruction due to parasites (Fasciola hepatica, ascariasis and hydatid cyst) that were diagnosed and managed with the endoscopic approach. This is the first national paper which highlights the importance of endoscopic retrograde cholangiopancreatography in the management of this parasitosis. Despite choledocholithiasis as the most common cause of extrahepatic jaundice, biliary tree parasitosis must be considered in the differential diagnosis.

[Nonbacterial thrombotic endocarditis related to hepatocarcinoma]

A case of a woman with nonbacterial thrombotic endocarditis (NBTE) associated with hepatocarcinoma is here presented. Epidemiologic and clinicopathologic aspects are reviewed, early clinical suspicion may prevent embolization. it represents the first case reported in the national literature.

Detection of both herpes simplex and varicella-zoster viruses in cerebrospinal fluid from patients with encephalitis

Cerebrospinal fluid (CSF) samples from 46 patients with encephalitis were studied for the presence of herpes simplex virus (HSV) types 1 and 2 and/or varicella zoster virus (VZV)-specific DNA sequences by the polymerase chain reaction (PCR) assay. Patients were studied because of detection of intrathecal production of IgG antibody to HSV alone (10 patients, Group A) or to both HSV and VZV (11 patients, Group B) or because of the presence of specific anti-HSV IgG in CSF without evidence of intrathecal antibody production (25 patients, Group C). CSF samples taken between days 1 and 10 from onset of encephalitis were available from all patients, and follow-up samples (taken after 10 days from onset) were obtained from some of them. Positive PCR results were obtained in a total of 13 patients. Four patients (three from Group A and one from Group B) gave amplification of HSV type 1 DNA alone, two patients (both from Group B) showed amplification of VZV DNA alone, and seven patients (all from Group B) gave dual amplification of both HSV type 1 and VZV DNA sequences in CSF. All CSF samples from patients in Group C were negative by PCR. Ten patients with CSF samples positive by PCR lacked a prior history of herpetic cutaneous lesions. In seven patients, serum antibody tests (specific IgM detection and specific IgG avidity assays) identified both primary and recurrent infections. The results suggest that the dual presence of IgG antibody to both HSV and VZV in CSF from patients with encephalitis may reflect in some cases a dual infection of the central nervous system caused by both agents.

The safety and effectiveness of stepwise and low-dose administration of follicle stimulating hormone in WHO group II anovulatory infertile women: evidence from a large multicenter study in Spain

PURPOSE

Our goal was to investigate the safety, effectiveness, and feasibility for the practicing physician of stepwise and low-dose administration of FSH in WHO group II anovulatory infertile women.

METHODS

Infertile female patients (n = 234) suffering from WHO group II anovulation, and who failed to became pregnant with clomiphene citrate, were included in a multicenter, prospective, clinical study of treatment with a protocol of chronic low-dose and small incremental rises with urinary purified or highly purified FSH. Follicular development was monitored with ultrasonographic scans.

RESULTS

The 234 patients received a total of 534 cycles of treatment, for a mean number of 2.3 treated cycles per patient. hCG was withheld in 65 (12.2%) cyles because of no response and in 28 (5.2%) cycles because of hyperresponse. Of the remaining 441 cycles, 419 (95%) were ovulatory, and in 198 (47.3%) of these cycles a single dominant follicle developed. There were 93 pregnancies (39.7% per patient), for a cycle fecundity rate of 17.4%. Cumulative conception rate after two treated cycles was 33.5%. There were 14 (15%) pairs of twins and 10 (10.8%) spontaneous miscarriages. The prevalence of complications was low with no cases of severe OHSS. Basal LH/FSH ratio was significantly higher in the pregnant group of patients than in nonpregnant women.

CONCLUSIONS

Stepwise and chronic low-dose administration of FSH is a safe and effective method for treatment of WHO group II anovulatory infertility, mainly in those patients having high LH/FSH ratios.

[A surveillance program for surgical wound infections at the National Institute of Cancerology of Mexico]

OBJECTIVES

To evaluate the results of a prospective wound infection surveillance program during its first semester of operation, and to analyse the risk factors associated to wound infection.

METHODS AND DESIGN

From January 01 to June 30 1993, 1103 surgeries were prospectively followed. The incidence rates of infection were calculated and a case control analysis was done to evaluate the associated risk factors to POWI (postoperative wound infection).

SETTING

An oncological tertiary-care center.

RESULTS

The POWI rate was 9.0 per 100 surgeries. By univariate analysis the associated risk factors were: obesity (OR = 2.07 CI95% = 1.19-3.64), one drainage (OR = 2.10 CI = 1.33-3.31), two drainages (OR = 3.14 CI = 1.85-5.26), length of stay of the drainage (patients with wound infection: 15.2 +/- 6.7 days vs. patients without wound infection: 8.2 +/- 6.6 days), duration of operation (patients with wound infection: 188 +/- 163 minutes vs. patients without wound infection: 122 +/- 127 minutes) and duration of preoperative hospitalization (patients with wound infection: 2.9 +/- 6.4 days vs. patients without wound infection 1.5 +/- 3.0 days). The associated risk factors by regression analysis were: obesity (OR = 1.93 CI = 1.08-3.43), two drainages (OR = 2.09 CI = 1.03-4.05) duration of operation > = 120 minutes (OR = 1.96 CI = 1.00-3.86) and duration of preoperative hospitalization (OR = 1.03 CI = 1.00-1.09).

CONCLUSIONS

The program showed a previous under-reporting of POWI from 4.2-4.8 per 100 surgeries in the previous seven years to 9.0 in the first semester of operation. It also identified the associated risk factors to POWI in our institution.

Human central nervous system myelin inhibits neurite outgrowth

In vitro and animal studies have identified molecules in mammalian CNS myelin which inhibit neuritic extension and which may be responsible, at least in part, for the lack of axonal regeneration after injury in the injured brain, optic nerve and spinal cord. To determine whether such inhibitory activity may be present in human CNS myelin, we used a bioassay to characterize neurite outgrowth on this substrate. Human CNS myelin strongly inhibited neuritic outgrowth from newborn rat dorsal root ganglion neurons and NG-108-15 cells, a neuroblastoma-glioma hybrid cell line. Similar but less potent inhibitory activity was identified in human gray matter. The CNS myelin inhibition of neuritic outgrowth appeared to be dependent on direct contact between the myelin substrate and neurites. The inhibitory activity in human CNS myelin closely resembled that described in adult rodents. Inhibition of neurite growth by human CNS myelin in this in vitro bioassay mirrors the lack of regeneration in vivo and can be used as a model to develop strategies designed to enhance axonal regeneration and neural recovery.

Myelin from MAG-deficient mice is a strong inhibitor of neurite outgrowth

Myelin-associated glycoprotein (MAG) has potent neurite outgrowth inhibitory activity in vitro. To assess the importance of MAG in the neurite outgrowth inhibitory activity in CNS myelin, we used an in vitro bioassay to characterize neurite growth on CNS myelin derived from mice carrying a null mutation of the MAG gene. Myelin proteins from MAG-deficient mice inhibited neurite outgrowth to a similar degree to the wild-type CNS myelin. These results suggest that CNS myelin molecules other than MAG exert strong inhibitory effects on the growth of neurites.

[Dysphagia as an unusual form of presentation of malignant pleural mesothelioma]

Dysphagia is an unusual presenting symptom as of extradigestive tumors. Malignant mesothelioma, is a rare tumor localized in the pleural cavity in 80% of all cases and it rarely appears with dysphagia as first symptom. We describe the case of a 74-year-old woman admitted with progressive dysphagia for solid and liquid food, atypical epigastric pain, with in conclusive endoscopic and radiologic studies. Nuclear Magnetic Resonance established the diagnostic suspicion of malignant mesothelioma which was confirmed by the histologic study of a biopsy taken by thoracotomy. We think of interest to report this case of paraesophageal mesothelioma because of its unusual localization and presentation.

Methods for microelectrode-guided posteroventral pallidotomy

Methods for localizing the posteroventral globus pallidus intermus are described. The authors' techniques include the use of microelectrodes to record single-unit activity and to microstimulate in human pallidum and its surrounding structures. This technique allows a precise determination of the locations of characteristic cell types in sequential trajectories through the external and internal segments of the pallidum. The location of the optic tract can be determined from microstimulation-evoked visual sensations and recordings of flash-evoked potentials. In addition, microstimulation-evoked motor and sensory responses allow the internal capsule to be identified. The data collected using this technique are an important adjunct to selecting optimum sites to place electrocoagulation lesions for stereotactic posteroventral pallidotomy for refractory Parkinson's disease.

[Peutz-Jeghers syndrome. Apropos a familial case at Hospital Arzobispo Loayza]

The Peutz-Jeghers syndrome is a rare dominant autosomic, entity characterized by hyperpigmented lesions on the lips, hands and feet; with presence of gastrointestinal polyps producing acute or chronic anemia, intestinal obstruction, and/or abdominal pain. This polyps histologically are hamartomas; recent studies indicate a real risk for transformations in the malignant neoplasia. The high and low endoscopies and the intraoperative enteroscopy with polypectomy are the election treatment, improving prognosis quality on these patients. We describe a familiar case of a female patient 24 years old showing a repeated picture of intestinal subocclusion; her brother presented a similar clinical picture, and her mother presented the same syndrome, dying of carcinoma in the colon; also her child, at one and a half year old presented hyperpigmented lesions on the lips.

A multifrequency multichannel electrical impedance data acquisition system for body fluid shift monitoring

This paper discusses some important issues for the design of electrical impedance measurement systems intended for body fluid shift monitoring, in particular during dialysis treatments. We have studied two common signal generation systems: digital synthesis and carrier recovery. We have found that in prolonged measurement applications, digital synthesis yields the best performance. On the demodulation side, we balance the demodulator errors between the real and imaginary parts by rotating the demodulation axes. We use segmental multifrequency impedance measurements to estimate the values of intracellular and extracellular impedance by adjusting the parameters of a Cole-Cole model for each segment measured. We stress the need to perform segmental measurements in order to accurately measure the segments of interest, in particular the trunk during dialysis treatments. Our results show that there is a sharp disequilibrium between the intracellular and extracellular compartments in the very first dialysis period. This fact generates the need to continuously measure segmental impedance instead of comparing initial and final values.

Multi-frequency static imaging in electrical impedance tomography: Part 1. Instrumentation requirements

Static images of the human body using electrical impedance tomography techniques can be obtained by measuring at two or more different frequencies. The frequencies used depend on the application, and their selection depends on the frequency behaviour of the impedance for the target tissue. An analysis using available data and theoretical models for tissue impedance yields the expected impedance and boundary voltage changes, therefore setting the measurement instrument specifications. The instrument errors produced by different sources are analysed, and, from this analysis it is possible to determine the feasibility of building the instrument, the limit values for some parameters (or components) and indications on the most suitable design of critical parts. This analysis also shows what kinds of error can be expected in the reconstructed images. It is concluded that it is possible to build an instrument with limited errors, allowing static images to be obtained. An instrument has been built that meets some of the design requirements and fails in others because of technological problems. In vivo images obtained with this instrument will be presented in Part 2 of this work.

[Myokimia induced by gold salts]

We report a 44 year old male suffering from rheumatoid arthritis that developed myokymias when treated with gold salts. Myokymia is a clinical phenomenon characterized by involuntary repetitive contractions of muscle fibres, which give an undulating appearance to the overlying skin, last a few seconds, and with a typical electromyographic activity described as myokymic discharges. The difference between the single twitch of the fasciculation and the tetanic contraction of myokymia may be evident only on electromyography in difficult cases. Neurological complications associated with gold are infrequent, and they include myokymia, peripheral neuropathy, Guillain-Barré syndrome, cranial nerves paralysis and encephalopathy.

Errors in prolonged electrical impedance measurements due to electrode repositioning and postural changes

Long-term electrical impedance measurements are affected by specific errors. Electrode failure, changes in its impedance due to aging, and postural changes are among the most important. We analyse errors due to electrode replacement and body postural changes. Electrode replacement errors can cause impedance changes up to 5% of basal value. This is one of the most important factors in data reproducibility. Body postural changes also contribute to impedance variations. We have proposed the use of a reference position to carry out impedance measurements as the one that shows the smallest impedance sensitivity to postural changes. In general, we observed that this is achieved with arms and legs slightly separated from the body. We propose the use of a ratio of impedance at two different frequencies to discern the origin of impedance changes, whether from physiological phenomena or postural errors.

Thalamotomy for essential and cerebellar tremor

Thalamotomy significantly suppressed essential tremor in 86% of patients and restored the ability to hold a glass to drink in 81% in the long term, but tremor recurred in 5/21 patients up to 5 years postoperatively, unlike parkinsonian patients whose tremor seldom recurs after 3 months. In multiple sclerosis (MS), 67% of those followed showed sustained significant suppression of tremor, 67% sustained improvement in dexterity, 50% in drinking; tremor recurred up to 5 years postoperatively. In other cerebellar tremors, 52% of those followed enjoyed lasting significant relief of tremor, 55% in dexterity, 45% in drinking, tremor relief being best in poststroke cases. Chronic thalamic stimulation may be the preferred therapy in MS and other cerebellar tremors.

[Epidemiologic study of an outbreak of echovirus type-9 meningitis]

BACKGROUND

Several agents are able to produce lymphocytic meningitis, but sometimes it's not possible their identification. The viruses are the etiological agents more frequently found, especially enteroviruses, mumps virus and herpes simplex virus, with different epidemiological patterns depending on time and geographic location. Most of the infections caused by enteroviruses are asymptomatics. In general the viral meningitis have a good prognostic with an acute benign course and serious signs of neurological affectation are infrequent. From 1991 it has been observed an increase of nonpolio enteroviral meningitis outbreaks in our Country. Echovirus-4 was isolated in most of the outbreaks notified during that year. Echovirus-9 was not isolated in any of them.

METHODS

We describe the epidemiological and clinical characteristics of a lymphocytic meningitis outbreak that took place from June to July of 1993 in Burgos.

RESULTS

Forty-eight patients, most of them children, were hospitalized with fever, headache, vomits and stiff neck with an increase in the total cell count in cerebospinal fluid (CSF). Echovirus-9 was isolated from fecal samples in eight patients.

CONCLUSIONS

The etiology was attributed to Echovirus-9 because of microbiologic and epidemiologic findings. The incubation period can fluctuate between four an five days and fecal-oral transmission is the most probable mechanism.

Combined therapy of coarctation and coronary heart disease in an adult

The association of aortic coarctation and ischaemic cardiopathy is rare. We present a case of such an association in a 58-year-old patient with established spinal-cord damage and describe a one-stage surgical approach for the correction of both pathologies. Coarctation is solved by means of a supracoeliac to thoracic aortic bypass, and then coronary bypass grafting is performed under CPB. In this case grafts were carried out using the left internal mammary artery (IMA) even though it was hypertrophied. There were no postoperative complications and at 10 months the patient was asymptomatic.

A serological survey and review of clinical Lyme borreliosis in Spain

A serosurvey for Lyme disease was conducted by the National Reference Center for Microbiology in Spain. All serum specimens received from patients with erythema migrans (EM), arthritis, and cardiac and neurological disorders were tested for antibodies to Borrelia burgdorferi. Sera from 499 patients were tested. Of these patients, 310 had neurological disease, 101 had carditis, 79 had arthropathies, and 9 had EM; for 35 patients, a diagnosis of Lyme disease was confirmed. Of these 35, 68% had neurological disease, 6% had carditis, and 26% had EM. Twelve probable cases of Lyme disease were noted. The male-to-female ratio of patients with confirmed or probable disease was 1.6; all age groups were represented, but 25% of patients were within the age group of 0-9 years. The number of cases of Lyme disease decreases from the north of Spain (41%) to the south (26%), a distribution that is in agreement with the known range of Ixodes ricinus. Borrelia burgdorferi is a frequent cause of infection in some areas of Spain. It is possible that relapsing fever accounts for some of the serological reactivity to B. burgdorferi in residents of the south of Spain.

A broadband system for multifrequency static imaging in electrical impedance tomography

A widely accepted method for static imaging in electrical impedance tomography (EIT) is to measure at two frequencies. The choice of measurement frequencies is application-dependent because some different tissues cannot be distinguished when using two fixed frequencies. We have developed a system that generates signals from 8-10(3) kHz and applies two of these signals simultaneously to the body through a broadband current mirror. Great care has been taken in the design of the current injection multiplexer in order to keep the current source output capacitance as low as possible. Furthermore design of the layout of the patient interface board, in order to reduce feedthrough capacitances, also needs great care. Other parameters for driving and detection sections have been designed according to our results from FEM and circuit simulations including skin and electrode effects. Simulations using FEM with available tissue impedance data and preliminary measurements in a discrete phantom show that static imaging is possible for both the real and imaginary parts of the impedance.

[Radial nerve injury caused by external compression during the dissection of the internal mammary artery in coronary surgery]

Injury of the radial nerve produced by external compression during dissection of the internal mammary artery during surgery of ischemic heart disease, is an infrequent event. The use of sternal retractors with only one rod may be the cause of these lesions. We report two cases of radial nerve paralysis produced as a consequence of external compression induced by a sternal retractor during dissection of the internal mammary artery. In the first case the patient showed loss of power of the external muscles of the left forearm and a clear flexion of the left hand. The second patient presented loss of power of the left hand and impossibility to extend the carpus and fingers. In both cases the lesion was reversible.

[Variation of bone density in relation to age: analysis of 259 necropsies]

In a previous study we reported a relatively low incidence of hip fracture in our population compared to figures reported elsewhere and speculated that this could be related to differences in bone density. Accordingly, we measured bone density in 259 subjects at necropsy. In 172 males we found that bone density decreased from 0.88 g/cc at age 21-30 to 0.80 at age 70 (NS). In women, density decreased from 1.0 at age 21-30 to 0.84 at age 50, 0.69 at age 60 and 0.64 in those older than 70 years (p less than 0.01). These figures are higher than those reported from USA at all ages and could explain the lower incidence of hip fractures in our population.

[Postmenopausal women: changes in plasma lipids with different estrogen replacement therapies]

We measured total, HDL and LDL cholesterol and triglycerides in 183 postmenopausal women before and 4 weeks after hormone therapy. Ethinyl estradiol or conjugated estrogens alone or in association with medroxyprogesterone, norethyndrone or norgestrel were used in different dosages either continuously or sequentially. Total cholesterol decreased from 206 to 196 mg/dl and HDL raised from 47 to 53 mg/dl (p less than 0.001) except in the group treated with estradiol-levonorgestrel in which HDL fell from 41 to 36 mg/dl (p less than 0.001). HDL cholesterol decreased from 133 to 113 mg/dl, overall. The total cholesterol/HDL ratio decreased from 4.8 to 4.2 in all groups except the group previously mentioned. Estrogen therapy, isolated or in association to medroxyprogesterone induced a moderate increase in serum triglyceride levels (132 to 149 mg/dl, p less than 0.001). Thus, the administration of estrogens in postmenopausal women is associated with a decrease in total, LDL and total/HDL cholesterol ratio and an increase in triglycerides. Norgestrel but not medroxyprogesterone partially revert these effects.

Two-frequency impedance plethysmograph: real and imaginary parts

A four-channel impedance plethysmograph has been designed. Impedance signals are obtained at two frequencies by measuring both real and imaginary parts. Particular attention has been paid to the sine wave generation circuits that provide system versatility. The required phase-sensitive demodulation is achieved by means of analogue multiplexers. Results show that there are significant variations in the thoracic equivalent capacitance related to respiration and that there is an increased sensitivity to cardiac activity at low frequencies.

Familial mixed oligodendrocytic-astrocytic gliomas

We present the first reported cases of mixed oligodendrocytic-astrocytic gliomas to occur in two members of the same family, a father and a son. These tumors had common biological and histological characteristics, and their occurrence supports the concept of genetic determination in some gliomas.

Effect of 7-methylguanosine-5'-phosphate on the translation of rat milk-protein mRNAs in the wheat-germ cell-free system

The translation of polyadenylated and of non-polyadenylated RNA obtained from lactating rat mammary gland was almost totally inhibited by 0.5 mM 7-methylguanosine-5'-phosphate in the wheat-germ cell-free system. This inhibition was maintained during the preparation of the 9S whey-protein mRNA and of the 12S and 15S casein mRNAs. Chemical decapping of these mRNAs caused a similar reduction of their activity. Although a large fraction of milk-protein mRNAs have been reported to lack 3'-polyadenylation, these results show that the mRNAs in the mammary gland do contain a 5'-terminal 7-methylguanosine cap.

Failed stereotactic biopsy in a series of 518 cases

Failed stereotactic biopsy is one in which a definitive histological or microbiological diagnosis is not achieved based on the tissue obtained. Of 518 consecutive CT-guided stereotactic biopsies of intra-axial mass lesions, 42 (8.1%) cases were failed biopsies. Inflammatory changes were seen in 10 cases (24%); gliosis was seen in 11 cases (26%); 9 cases (21%) yielded necrotic specimens; normal brain was retrieved in 7 cases (17%); blood/hemorrhagic brain was seen in 3 cases and in 2 cases, no tissue could be obtained. Variables that significantly influenced the diagnostic success included the immune status (HIV positive; p < 0.001). The complication rate in the failed biopsy group was significantly higher. The subsequent management and outcome of patients who suffered a failed stereotactic biopsy are discussed.