Protein/amino acid metabolism and nutrition in very low birth weight infants.

A large number of studies in recent years have described protein and nitrogen metabolism in the neonate. However, the majority of these data are difficult to interpret because of a number of confounding variables, particularly in very low birth weight (VLBW) infants. In contrast, application of state-of-the-art tracer isotopic and molecular biology methods in isolated cell system and whole animals has resulted in major advances in our understanding of the regulation of protein breakdown, synthesis, and protein accretion.

Brain SPECT imaging of neuropsychiatric disorders.

Brain imaging has become an integral part of the evaluation of neurological and psychiatric disorders. Functional imaging techniques, SPECT and PET, together with structural modalities, CT and MRI, are widely employed. Functional imaging studies are routinely used in the diagnostic workup of patients with well-characterized neurological disorders, such as epilepsy and brain tumors, and have a growing role in research on psychiatric disorders without known mechanisms such as depression and schizophrenia.

A measurement of pulmonary blood volume increase during systole in humans.

Pulmonary blood volume increase during systole was measured in patients by analysing chest images obtained during ECG gated radionuclide angiography examination. The difference in the total radiation counts between systole and diastole in regions of interest, which included the lungs and the left ventricle, was measured and the relative pulmonary systolic blood volume increase (SBVI)-the ratio between the pulmonary SBVI and the cardiac stroke volume-was calculated. The relative pulmonary SBVI, which is a measure for the compliance of the pulmonary blood vessels, was found to be 0.

Maternal and pediatric AIDS in the United States: the current situation and future research directions.

The epidemic of HIV infection and disease in women, adolescents and children represents a complexly intertwined biological and social challenge to health care workers and researchers alike. When considering various issues in confronting this epidemic, women must be viewed as individuals important in their own right, as the primary caretaker of their family members (both infected and uninfected), and as the sexual partners of men who may or may not be infected. Of the myriad of compelling biological questions facing AIDS researchers today, two of the most interesting involve the timing and determinants of vertical transmission and the natural history of HIV infection and disease in women.

Paediatric labelling requirements. Implications for pharmacokinetic studies.

The US Food and Drug Administration (FDA) has proposed new labelling regulations that describe alternative approaches for providing additional information to support labelling a drug, already approved for use in adults, for use in children. Therefore, the study of drugs in paediatric populations may now be encouraged. Paediatric pharmacokinetic studies are an important part of these trials.

Gallbladder visualization with In-111 labeled octreotide.

In-111 DTPA octreotide, a labeled somatostatin analog, was reported to be superior to I-123 octreotide for detection of somatostatin-receptor-bearing tumors because of longer half-life and better labeling characteristics. In addition, renal rather than hepatobiliary clearance decreases intestinal interference and greatly reduces accumulation of the tracer in the gallbladder. Using the In-111 labeled octreotide, the authors noted distinct gallbladder visualization in one patient with an insulinoma who was studied following an overnight fast.

Registration and display of multimodal images: applications in the extracranial head and neck region.

Image registration is a correlation procedure that allows the matching of images obtained by different imaging modalities, both structural and functional. Once registered, they can be combined in a single "fused" image. This technique can be used to improve the interpretation and the quantification of relatively low resolution images obtained in nuclear medicine or to achieve a better diagnosis and treatment planning when high resolution anatomical images are registered.

ECG gated radionuclide plethysmography--a method for the assessment of pulmonary systolic blood volume increase.

During cardiac systole the stroke volume of blood which is ejected from the right ventricle increases the pulmonary blood volume. This systolic pulmonary blood volume increase is measured by using ECG gated chest scintigrams obtained with 99Tcm-labelled red blood cells. The total radiation counts in a region of interest that includes either the right or the left lung increases during systole.

Brain SPECT imaging in temporal lobe epilepsy.

Temporal lobe epilepsy is diagnosed by clinical symptoms and signs and by localization of an epileptogenic focus. A brain SPECT study of two patients with temporal lobe epilepsy, using 99mTc-HMPAO, was used to demonstrate a perfusion abnormality in the temporal lobe, while brain CT and MRI were non-contributory. The electroencephalogram, though abnormal, did not localize the diseased area.

Critical periods of neuroendocrine development: effects of prenatal xenobiotics.

Phenobarbital, when administered prenatally in a small dose to animals, produced profound, and permanent effects on reproductive function in the offspring. Preliminary analysis of a unique cohort of adolescents who were exposed to phenobarbital in utero, suggests that long-term effects are also evident in the human. The precise nature of these effects is currently being determined and will be reported separately.

Effects of prenatal treatment with phenobarbital.

Phenobarbital, when administered prenatally to animals, produced profound and prominent effects on reproduction. Preliminary analysis of a unique cohort of adolescents who were exposed to phenobarbital in utero suggests that long-term effects may be evident in the human as well.

A comparison of planar and tomographic thallium scintigraphy in patients with coronary artery disease.

Planar and tomographic scans from 57 patients are compared and related to coronary arteriographic results. Tomography identified inferior and septal defects not seen on planar imaging. Planar imaging better identified apical defects.