Simultaneous adrenal and cervical pheochromocytomas in childhood.

Pheochromocytoma is an uncommon tumor in childhood. The simultaneous occurrence of adrenal and cervical pheochromocytomas is a rare phenomenon; to our knowledge, this combination has been reported in the literature only once. Cervical pheochromocytomas are more accurately termed "aorticosympathetic paragangliomas." In children, 50% of pheochromocytomas are bilateral, multiple, or extra-adrenal. An increased familial incidence in the form of simple mendelian dominance is also noted in the pediatric age group. Bolus nephrotomography is extremely effective in identifying adrenal pheochromocytomas in children. To prepare the patient for surgery, and alpha-adrenergic blocking agent is administered from 7 to 10 days before operation and a beta-blocking agent is administered 3 days before. A transabdominal approach is essential because of the frequent extra-adrenal sites and multicentricity of the tumor in children.     

Radiographic techniques to evaluate paintings

Radiographic techniques may be helpful in evaluation of the condition of paintings for their restoration, preservation, and occasionally to determine their authenticity. On the basis of experience with several of these procedures, the utility of each method is described in reference to specific "diagnoses" regarding paintings. Radiographic techniques have several advantages over other methods; they are nondestructive, they may be used to survey the entire painting, and they are subject to quantitative and serial analysis.     

The vasa vasorum and angioplasty

Interruption of flow in the vasa vasorum may lead to medial necrosis and aneurysm formation. The purpose of this study was to determine whether angioplasty produces significant alterations in the morphology or blood flow of the vasa vasorum of the dilated artery. The morphology of the canine vasa vasorum was studied before and after angioplasty; in a separate experiment vessel wall blood flow (VWBF) in canine carotid arteries was measured after angioplasty to determine whether physiologic regulation of the blood flow was disrupted by arterial dilation. No morphologic changes could be demonstrated in the vasa vasorum of the dilated artery; however, VWBF was increased by 1194 +/- 215% (mean +/- standard error, p less than 0.01) between 90 and 120 minutes after angioplasty. VWBF in the adjacent nondilated arterial segment was also increased (720 +/- 177% between 10-30 minutes, p less than 0.01) but returned toward normal after 60 minutes. Adenosine caused a "paradoxical" decrease in VWBF (p less than 0.05) of the dilated arterial segment while causing increased VWBF (p less than 0.05) in the thoracic aorta. Angioplasty appears to produce persistent hyperemia in the dilated arterial wall. A paradoxical response to adenosine suggests that vasa vasorum in the dilated arterial segment are maximally vasodilated. This may be due to mechanical disruption of vasomotor tone or to release of vasoactive substances.     

Turnip yellow mosaic virus variants produced from DNA clones encoding their genomes

Summary Full-length dsDNA clones that encode the genomes of two Australian turnip yellow mosaic isolates, TYMV-BL and TYMV-CL have been constructed. These clones were transcribed to give 6.3 kb capped ssRNA which infects Chinese cabbages to give symptoms indistinguishable from those produced by the parental viruses. Extensions of up to 26 nucleotides at the 3 end of the TYMV-BL clone delay infections, but virus particles isolated from these plants 4 weeks after inoculation contain RNA with the original TYMV-BL 3 terminus. A 90 nucleotide-long portion of the virion protein gene of TYMV-BL was replaced by a synthetic 90-mer primer with 16 nucleotide changes to decrease the large cytosine content (34–42%) characteristic of tymovirus genomic RNA. No reversion of any of the mutated nucleotides to cytosine occurred during 7 passages in Chinese cabbage. Hybrids between the TYMV-BL and TYMV-CL clones were also constructed, by exchanging various portions of the genome. However, it was not possible to determine definitively which part of the viral genome is responsible for the more severe symptoms caused by TYMV-BL as the hybrids gave intermediate symptoms.     

Low arylsulphatase A activity and choreoathetotic syndrome in three siblings: differentiation of pseudodeficiency from metachromatic leukodystrophy

We report on a family with a sibship of three children for whom the diagnosis of an unusual form of metachromatic leukodystrophy (MLD) had been suggested earlier. The patients had choreiform movements and dystomic posturing accompanied by dysarthria since childhood. The availability of the polymerase chain reaction enabled us to show that the three siblings have a pseudodeficiency genotype (ASA_p/ASA_p). There was no abnormal sulphatiduria, and we propose that the neurological disease and low arylsulphatase A activity are unrelated to one another in this family. A diagnosis of MLD carries very serious implications, and we recommend that gene amplification by polymerase chain reaction and hybridization with allele-specific oligonucleotide probes should be used to corroborate the diagnosis, especially when there is no abnormal sulphatiduria and when metachromatic material cannot be demonstrated in a sural nerve biopsy.     

Variability in organochlorine analysis in fish: An interlaboratory study and its implications for environmental monitoring and regulatory standards

Samples of muscle, from four types of fish, that had been spiked at 0.25 and 1.0 mg/kg with hexachlorobenzene (HCB), gamma BHC (lindane), technical chlordane, p,p-DDT, p,p-DDE and p,p-DDD were analyzed by eight laboratories. Some laboratories could not reliably detect organochlorine compounds even though they were registered as national testing laboratories. The analytical accuracies of laboratories that were able to reliably detect the spiked compounds were very variable and exceeded acceptable limits. Within-laboratory precision was generally acceptable. There was significant interlaboratory variability among the estimates of percent lipid for each fish type. This variability negated the use of percent lipid for standardization of organochlorine concentrations for comparison between studies.The results highlight the need for standard analytical protocols that are regularly tested by interlaboratory studies. They also indicate that interchangeability of data between studies is limited due to low analytical accuracy. Therefore, comparison of analytical data to absolute environmental and regulatory standards is difficult. The use of latitudinal confidence ranges when setting regulatory standards is recommended.     

Cholecystokinin and satiety in rats and rhesus monkeys.

When ingested food does not accumulate in the stomach or enter the small intestine, rats do not stop eating. Small amounts of food placed in the small intestine or intraperitoneal injections of the intestinal hormone cholecystokinin (CCK) elicit the full behavioral display of satiety in these sham-feeding rats. In rhesus monkeys, intravenous infusions of CCK produce large, dose-related reductions in meal size. In addition, gastric preloads of calorically trivial amounts of l-phenylalanine, but not d-phenylalanine, produce large reductions in meal size, suggesting that: 1) endogenous CCK acts as a "satiety signal," and 2) certain foods may be very efficient releasers of such a satiety signal. Whether the satiety effect of CCK is physiological in rats and monkeys or operates in humans has not been determined.     

Longitudinal neurological follow-up of a group of HIV-seropositive and HIV-seronegative hemophiliacs: results from the hemophilia growth and development study

BACKGROUND: Boys and young men with hemophilia treated with factor infusions before 1985 had a substantial risk of acquiring the human immunodeficiency virus (HIV) and the acquired immunodeficiency syndrome. This study was designed to assess the effects of HIV and hemophilia per se on neurological function in a large cohort of subjects with hemophilia, and to investigate the relationships between neurological disease and death during follow-up. METHODS: Three hundred thirty-three boys and young men (207 HIV seropositive and 126 HIV seronegative) were evaluated longitudinally in a multicenter, multidisciplinary study. Neurological history and examination were conducted at baseline and annually for 4 years. The relationship between neurological variables, HIV serostatus, CD4+ cell counts, and vital status at the conclusion of the study was examined using logistic regression models. RESULTS: The risks of nonhemophilia-associated muscle atrophy, behavior change, and gait disturbance increased with time in immune compromised HIV-seropositive subjects compared with HIV seronegative or immunologically stable HIV-seropositive subjects. The risk of behavior change in immune compromised HIV-seropositive hemophiliacs, for example, rose to 60% by year 4 versus 10% to 17% for the other study groups. Forty-five subjects (13.5%), all of whom were HIV seropositive, died by year 4. Subjects who died had had increased risks of hyperreflexia, nonhemophilia-associated muscle atrophy, and behavior change. CONCLUSIONS: These results indicate that immune compromised, HIV-seropositive hemophiliacs have high rates of neurological abnormalities over time and that neurological abnormalities were common among subjects who later died. By contrast, immunologically stable HIV-seropositive subjects did not differ from the HIV-seronegative participants. Hemophilia per se was associated with progressive abnormalities of gait, coordination, and motor function.