Axonal and myelin lesions inβ-mannosidosis: Ultrastructural characteristics

Summary Ultrastructural changes in central nervous system (CNS) white matter of three goats affected with-mannosidosis were analyzed to further define characteristics and pathogenesis of axonal and myelin abnormalities. The variations in myelin association and contents of axonal spheroids were delineated. The occurrence of spheroids in a 96/150-day fetus documented the early development of these axonal lesions. In regions of severe myelin deficits, the presence of apparently normal axons and a reduction in the number of oligodendrocytes were confirmed. Many remaining cells in myelin-deficient regions were characterized by dark, vacuolated cytoplasm. The occurrence of internodes with myelin sheaths adjacent to internodes without myelin sheaths suggested that an axonal defect is not primarily responsible for the absence of myelin sheaths. A mild myelin deficit in the spinal cord was indicated by the presence of unmyelinated axons. Except for occasional mild cytoplasmic vacuolation, the spinal cord glial cells appeared relatively normal. The findings presented here are consistent with the hypothesis that an oligodendrocyte defect, expressed by regional differences, is a major factor in the pathogenesis of myelin deficiency in-mannosidosis.Supported by NIH grant NS-16886 to MZJ and BRSG funds from the College of Osteopathic Medicine, Michigan State University, to KLL     

Third-dimension sweep: new scanning method in diagnostic ultrasound

The inability to image the 3rd dimension has meant a loss of valuable information, e.g., examination of an IUD in the uterine cavity. Whatever plane is examined longitudinal, transverse, or oblique the image always is a 2-dimensional tomograph producing either bars or dots. Even when the transducer lies perpendicular to the long axis of the IUD, the IUD cannot be visualized as a whole because the 1st bar produces an acoustic shadow that covers all the other bars. A technique now exists for obtaining the 3rd dimension by moving a linear array transducer over the area to be examined, which produces an endless number of images on the screen. Since the commonly used real-time scanners are not equipped with storage capacity, these images immediately fade away. This problem can be resolved by using a Polaroid camera as a storage device. The shutter is opened for the longest exposure possible, i.e., 1 second, while the diaphragm is closed. During this 1 second of exposure, the linear array transducer is "swept" over the area for examination using the compound movement technique. A second is a relatively long time, but some training is necessary before the operator can easily perform the "sweep." If the whole movement cannot be carried out in 1 second, an additional second can be used. This will rusult in a slightly overexposed picture, but these are sometimes even easier to interpret. It is important that the area be well lubricated, and the patient stop breathing for the duration of the scan. The equipment used in the study included a Picker 2000 and a Unirad real-time scanner. Both scanners were handled in the same way, and the same technique was used. Different kinds of IUDs were visualized and recorded.     

In vivo measurement of brain tumor pH using [11C]DMO and positron emission tomography

In vivo measurements of regional brain tissue/tumor pH (rpH) have been accomplished in 9 patients with primary or metastatic brain tumors using [11C]dimethyloxazolidinedione [( 11C]DMO) and positron emission tomography. Tumor rpH values ranged from 6.88 to 7.26, whereas gray matter and white matter rpH values ranged from 6.74 to 7.09 and from 6.77 to 7.03, respectively. Our results, which are consistent with reported [14C]DMO autoradiographic measurements of brain and tumor pH, suggest that the pH microenvironment of brain tumors is not more "acidic" than that of normal gray or white matter.     

Diagnosis and taxonomy of periodical psychosis

The concept and taxonomy of periodic psychosis still remains in controversy for the past 100 years. In China, it was first reported by Ji, and thereafter various rinds of terminology and views were given by different authors. In the presentation, clinical investigation and follow up were carried out in 62 cases. In many of these cases, the so-called "periodic psychosis" or "phasophrenia" was early clinical features of schizophrenia or manic-depression. In those cases with apparent symptoms and signs of diencephalic function, differential diagnosis should be carried out from organic brain syndrome. In a small number of cases, their clinical manifestations, conforming to previous diagnostic criteria, might be an uncommon syndrome. It was concluded by the authors that until now periodic could be considered only as a clinical syndrome rather than a disease entity.     

Carbamazepine dosage and its blood serum level in children

Evaluating in 62 children aged from 4 months to 14 years (mean age 3 years 7 months) the correlation between the carbamazepine dosage (carbamazepine was given as the only drug in 21 cases, and as one of several drugs in 41) the authors failed to find a simple correlation. Nevertheless, most children receiving the "proper" doses had therapeutic plasma carbamazepine levels. Moreover, it was found that carbamazepine dose increase over 25 mg/kg daily caused on further rise of its plasma level.     

Factors affecting the decision to admit mental patients in a community hospital

Analysis of consecutive emergency referrals to a community mental hospital over a 2-month period indicates that admissions are affected by a combination of demographic, clinical, and time factors. Both referrals and admissions were slightly higher in men. The mean age at referral was 44 years and of admitted patients was 30 years. Although married subjects constituted the largest group of applicants, widowers and divorced people were hospitalized more often. Both referral and admission rates were inversely correlated with education and employment. Most of the applicants came to the emergency ward accompanied by an escort. A lower rate of admissions was observed among those who came unescorted. The main indications for admission were acute psychosis and a nonspecific clinical state when the patient was defined as "dangerous to himself or to others." The family constituted the main source of referral. Peak referrals were during the morning hours, but admission rates were highest at night. Referrals decreased gradually from Sunday to Saturday, but the rate of admission was practically steady throughout the week. We conclude that the decisions for admitting a patient to a mental institute are based not only on pure psychiatric criteria, but also on an intuitive approach, in which the admitting physician's personal and emotional factors may play a role.     

Muscle energy metabolism in human phosphofructokinase deficiency as recorded by 31P nuclear magnetic resonance spectroscopy

31P nuclear magnetic resonance studies of a patient with phosphofructokinase deficiency in muscle provided the following new findings: First, ATP metabolism is disturbed at rest and during exercise. At rest, ATP levels are lower than normal and continue to decline during exercise. Second, exercise kinetics are normal, suggesting a normal mitochondrial fuel supply although glycolysis is blocked. Third, no "phosphate trapping" is observed during prolonged low-level exercise. Fourth, postexercise recovery is abnormally prolonged by the slow dephosphorylation of sugar phosphates, which has an in vivo half-life of about nine minutes. These findings demonstrate how muscle tissue adapts to a block in a major bioenergetic pathway.     

Potential placenta previa: definition, frequency, and significance

Sixty-three (5%) of 1239 women studied by sonography during the second trimester of their pregnancies had a diagnosis of placenta previa. Follow-up was available for 51 of the 63 patients; in three of these, the original diagnosis was complete placenta previa, and in the other 48, the first diagnosis was partial or marginal placenta previa. At term, placenta previa was seen in only four patients for an overall frequency of 0.3% (4/1227). In all three of the patients with complete placenta previa, the condition persisted from the second trimester to term; previa persisted in only one of 48 patients with marginal/partial previa. Because of the infrequent persistence of marginal or partial placenta previa to term, we recommend using the term "potential placenta previa" in the second trimester, with follow-up sonography indicated only for vaginal bleeding.     

Corynebacterium endocarditis. Difficult diagnosis in an elderly woman

Physicians have been reminded repeatedly of the many faces of bacterial endocarditis. In this case, Corynebacterium endocarditis presented as an occult malignancy and eluded diagnosis for six months. The coryneform isolates found in cultures are often considered to be contaminants because of their ubiquitous nature, sometimes causing a delay in diagnosis. Patients with culture-negative endocarditis or Corynebacterium "contamination" should be treated as having Corynebacterium endocarditis pending results of microbiologic isolation tests.