A web-based review of global health programs in U.S. allopathic and osteopathic medical schools.

PURPOSE: There is no current centralized database of structured global health programs at U.S. medical schools and no published review in the past decade. This study aims to describe the prevalence, characteristics, and requirements of non-degree, longitudinal, structured global health programs in U.S. allopathic and osteopathic medical schools. MATERIALS AND METHODS: In July 2021, the authors performed a web-based review of existing structured global health programs for the 154 U.S. allopathic medical schools and 35 U.S. osteopathic medical schools established prior to 2019. RESULTS: Of 189 institutions examined, 74 (39%) had online information about a structured global health program. Forty-three (53%) programs reported coursework requirements, 44 (54%) required a global health experience, and one program required demonstration of language or cultural knowledge. More internally administered programs required experiential work, while more externally administered programs required didactic work. There were few differences in program requirements between allopathic and osteopathic medical schools. CONCLUSIONS: There has been a 75% increase over the past ten years in the number of U.S. allopathic medical schools with websites for structured global health programs. There appeared to be little standardization in their structure and requirements. The findings support the need for a web-based central repository for updated information regarding medical school global health curricula.

Melanotic neuroectodermal tumor of infancy.

We present a case of malignant melanotic neuroectodermal tumor of infancy arising in the skull and secondarily invading brain. The central tumor was hyperintense to brain on T1-weighted images and hypointense to brain on T2-weighted images. This appearance corresponded to the surgical and histologic findings of melanin-containing tumor.

Girl with signs of Pelizaeus-Merzbacher disease heterozygous for a mutation in exon 2 of the proteolipid protein gene.

We studied a female infant with clinical signs of Pelizaeus-Merzbacher disease (PMD), who has a familial mutation (C41-->T) in exon 2 of the proteolipid protein gene (PLP), and selected relatives. While the carrier mother and grandmother of the proposita currently are neurologically normal and show normal T2 magnetic resonance imaging (MRI) of the brain, the infant has a neurological picture, MRIs, and brain auditory evoked response (BAER) consistent with that diagnosis. The data here presented show that PMD can occur in females carrying a mutation in the PLP gene. Our experience with the MRIs of this patient, her mother and grandmother, and those of a previously reported family [Pratt et al.: Am J Med Genet 38:136-139, 1991] show that molecular genetic analysis and not MRI is the appropriate means for carrier detection.

Caenorhabditis elegans sqt-3 mutants have mutations in the col-1 collagen gene.

sqt-3 mutants of Caenorhabditis elegans form dumpy larvae and adults and display allele-specific defects in locomotion, fertility, and viability. We have determined that the sqt-3 locus encodes COL-1 collagen. We physically mapped the col-1 gene to a cosmid on chromosome V whose position is consistent with the location of the sqt-3 gene. We also observed morphological defects in sqt-3 mutants at stages that correlate with the mRNA expression patterns of col-1. Sequence analysis of the col-1 gene in the three temperature-sensitive mutants revealed that each allele of sqt-3 has a unique missense mutation causing arginine or glutamic acid to replace glycine in a Gly-X-Y triple helical domain. These glycine substitutions may result in longer non-collagenous domains, which may decrease the thermal stability or impart additional flexibility to mutant trimers. In addition, we describe four corrections to the published sequence of col-1, including one fifteen nucleotide addition that completes a conserved domain in the amino terminal coding region.

MRI in acute disseminated encephalomyelitis.

A retrospective analysis of CT and MRI studies in 12 patients with a clinical diagnosis of acute disseminated encephalomyelitis (ADEM) was performed. MRI was the definitive modality for the assessment of the lesions of ADEM: all patients had abnormalities consistent with the clinical diagnosis. Ten had abnormalities in the brain, three spinal cord lesions, and three showed evidence of optic neuritis. CT was normal in 6 of the 7 patients in which it was performed.

MR of intracranial Langerhans cell histiocytosis.

Langerhans cell histiocytosis (LCH) is a disease of children characterized by idiopathic proliferation of histiocytes in the reticuloendothelial system. Intracranial LCH involving the brain is uncommon. We present a case of LCH involving the dural venous sinuses and choroid plexus. Contrast MRI provided an excellent means of identifying the extent of tumor involvement and showed that the patient was at risk for venous sinus thrombosis.

Langerhans cell histiocytosis of bone: MR imaging.

Magnetic resonance (MR) images of 12 pathologically proven lesions of Langerhans cell histiocytosis (LCH) of bone were reviewed retrospectively. MR identified all lesions, three of which were not identified on plain radiographs. In all cases, MR showed greater abnormality than did plain radiographs. With one exception, all lesions were hypointense on T1-weighted images and hyperintense on T2-weighted images. The lesions and associated soft tissue abnormalities were very conspicuous on short TI inversion sequences and T1-weighted post-contrast images. Follow-up MR studies in two patients after chemotherapy showed decreased size and enhancement of lesions compared with baseline studies.

Magnetic resonance imaging of the head and neck.

MR imaging of the head and neck region has become the modality of choice for evaluating both malignant and benign tumors, functional derangements such as in temporomandibular joint dysfunction, and many congenital lesions. With improved scanner design and with newer pulse sequences becoming available, one can expect increased use of MR imaging in the future.

MRI of Guillain-Barré syndrome.

We describe the results of MRI of the spine in a case of Guillain-Barré syndrome. The main finding was abnormal enhancement of the nerve roots in the region of the conus medullaris and cauda equina.

Metabolic and degenerative diseases of childhood.

The metabolic and degenerative diseases of childhood are a diverse group of disorders with varied imaging features. Some of the disease processes have characteristic findings and some have no findings at all, but most present with nonspecific abnormalities in white matter. These patchy lesions, seen best on magnetic resonance scanning with T2 weighting, require a good history and a dialogue with the referring physicians to help in narrowing the differential possibilities. The major disease processes involving white matter are the dysmyelinating diseases, in which the abnormal white matter is the result of an inherited enzyme deficiency, and the demyelinating diseases, in which an acquired process such as infection destroys white matter. Several diseases result in gray matter abnormalities, including central pontine myelinolysis, MELAS syndrome (mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like symptoms), Batten's disease, Leigh disease, and Wilson's disease.

Imaging of metabolic diseases of the brain.

Increasing interest in metabolic diseases of the brain has revealed more specific patterns of disease, permitting us to make more accurate diagnoses or to suggest a more limited differential list of considerations. MR imaging is also useful in monitoring the course of the disease in processes for which treatment is available.

Gadolinium enhancement in acute disseminated encephalomyelitis.

Acute disseminated encephalomyelitis (ADEM) is a widespread CNS inflammation that usually follows an infection or vaccination. We present a case of ADEM, which in addition to the typical MR findings, demonstrates gadolinium enhancement of several of the lesions. Since ADEM is usually a monophasic illness, it has been postulated that all lesions might enhance with paramagnetic contrast medium since they would all be expected to be active. Our case demonstrates enhancement of some of the lesions, without enhancement of others.

Assessment and prevention of osteoporosis through use of a client self-reporting tool.

Osteoporosis is an age-related process that affects one out of every four women above 65 years of age. This article focuses on the assessment of osteoporosis through use of an osteoporosis assessment tool that is filled out by the client. The tool requests information about the woman's demographic profile, chief complaint, related symptoms, pain profile, risk profile, past medical history, nutritional history, fitness profile, menopausal history and self-care practices. The tool also includes information for the health care provider to complete about the client's lab analysis. Assessment needs to be extensive in order to uncover the specific factors that place an individual at risk for the silent changes of osteoporosis. The health care provider can elicit the aid of the client in securing such a comprehensive assessment.

The role of MRI in cerebral infarction.

Although nuclear magnetic resonance has existed since the 1940s and was used extensively in chemistry labs for molecular structural determination, it was not until the 1970s that the possibility for magnetic resonance imaging (MRI) was realized. It is only in the last few years that the great potential of MRI to visualize the brain, joints and several other structures has been recognized. This article discusses some basic pathophysiology of cerebral ischemia as it relates to MRI and focuses on some of the advantages and disadvantages of MRI in visualizing and studying many of the resulting lesions.

Imaging of metabolic diseases of the brain.

Awareness is increasing regarding the utility of MR imaging in the diagnosis and characterization of a wide number of inherited and acquired metabolic diseases. Although the pattern of disease is not often specific, the distribution may suggest a differential diagnosis that may be pursued by increasingly specific enzyme analysis. An exciting potential exists for detecting asymptomatic carriers for these diseases. MR imaging is also of value in monitoring these diseases and in planning therapy for those few conditions for which intervention is possible.

Foci of increased T2 signal intensity in MR images of healthy elderly subjects. A follow-up study.

An 18-month follow-up study was conducted on 26 healthy elderly subjects with and without foci of increased T2 signal intensity on MR imaging. The subjects did not differ with respect to health status or cognitive performance as measured by the Cognitive Subscale of the Cambridge Mental Disorders of the Elderly Examination and the Mini Mental State Examination at follow-up. There was a significant decline in performance on the Digit Symbol Substitution Test in subjects who had evidence of T2 foci compared to the performance of subjects without T2 foci. This may indicate that the presence of T2 foci is correlated with subtle difficulties in learning and memory.

Unilateral duplication of the cerebellar hemisphere and internal, middle, and external ear: a clinical case study.

This article presents the unique congenital anomaly complex of ipsilateral cerebellar hemisphere duplication and internal, middle, and external ear duplication. Diagnostic techniques included a head CT scan, a three-dimensional head CT scan, and a head MRI. An aberrant notochordal split was proposed as the embryologic mechanism leading to the development of such anomalies.

Toxoplasmic myelitis in AIDS: gadolinium-enhanced MR.

An acquired immunodeficiency syndrome (AIDS) patient developed acute symptoms suggestive of a lower spinal cord lesion. Magnetic resonance imaging was performed and demonstrated an enhancing lesion of the conus medullaris. Surgical biopsy revealed Toxoplasma gondii. Disease processes involving the spinal cord in AIDS patients are reviewed and differential diagnosis for the lesion in this patient is discussed.

Neuroimaging of disseminated germ cell neoplasms.

The purpose of this study was to determine the role of neuroimaging in the management of patients with metastatic germ cell tumors. Retrospective evaluation of 299 patients treated in 1986 and 1987 for initial presentation or recurrence of testicular, retroperitoneal, and mediastinal germ cell tumors was performed to determine indications for neuroimaging, frequency and site of CNS metastases, and occurrence of other CNS abnormalities. Sixty-six patients required CNS imaging with myelography, CT, or MR. Studies were normal in 24 patients. Twenty patients had CNS metastases including 11 with intracranial metastases, eight with spine lesions, and one with both brain and spine involvement. Sixteen had cerebral or cerebellar atrophy of unclear origin and functional significance. Two patients had ventriculomegaly without symptoms of hydrocephalus. Four patients had questionable lesions that were never confirmed. None of the 25 asymptomatic patients with elevated serum tumor markers had brain metastases. Fifteen of 17 patients with focal neurologic deficits and three of six patients with seizures had CNS metastases. CNS imaging to detect germ cell tumor metastases is most useful in the presence of neurologic deficits or seizures but is not useful in patients with unexplained elevation of serum tumor markers in the absence of neurologic deficits.