Biomedical subjects
B Littman
Publications and source records attributed to B Littman.
A review of Maryland insurance law.
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Managed Care 2000: the year in review.
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Products of arachidonic acid metabolism and the effects of cyclooxygenase inhibition on ongoing cutaneous allergic reactions in human beings.
BACKGROUND: There have been conflicting reports about the effects of inhibition of arachidonic acid metabolism on early- and late-phase cutaneous reactions. We re-examined this question with a unique nonsteroidal antiinflammatory drug, tenidap sodium. Tenidap sodium has been demonstrated in in vitro studies to inhibit cyclooxygenase, lipoxygenase, and cytokine production (interleukin-1, interleukin-6, tumor necrosis factor-alpha). METHODS: In a double-blind, randomized, crossover study, seven pollen-sensitive subjects ingested tenidap (120 mg, by mouth, daily) and placebo for 9 days with a 3-week washout period between treatments. On the eighth day they underwent allergen skin testing, measurable for up to 12 hours, and on the ninth day they underwent 5-hour skin chamber exposures to allergen and buffer. Chamber fluids were analyzed for cellular content, neutrophil granule protein release, cyclooxygenase and lipoxygenase arachidonic acid metabolites, histamine, and tryptase. RESULTS: Tenidap did significantly inhibit cyclooxygenase metabolites at both antigen and buffer sites but had no effect on histamine, tryptase, lipoxygenase metabolites, or granulocyte infiltration. Neutrophil granule release of lactoferrin was lower at the antigen site during tenidap administration, but there was no reduction of elastase release. Prostaglandin E2 and leukotriene E4 increased significantly at antigen sites compared with buffer sites during placebo administration and were the most prominent arachidonic acid metabolites detected. CONCLUSION: Tenidap, despite inhibiting cyclooxygenase release at antigen sites, had no effect on skin test responses to antigen or on antigen-induced mediator release or granulocyte infiltration. We conclude that cyclooxygenase metabolites are not important in the development of an allergic cutaneous inflammatory response.
Elevated cerebrospinal fluid levels of substance P in patients with the fibromyalgia syndrome.
OBJECTIVE: To measure, and seek clinical correlates with, levels of substance P (SP) in the cerebrospinal fluid (CSF) of fibromyalgia syndrome (FMS) patients. METHODS: CSF from 32 FMS patients and 30 normal control subjects was tested for SP by radioimmunoassay. Clinical measures included tender point examination and standardized questionnaires. RESULTS: CSF SP levels were 3-fold higher in FMS patients than in normal controls (P < 0.001), but they correlated only weakly with tenderness found on examination. CONCLUSION: SP is significantly elevated in FMS CSF, but other abnormalities must exist in FMS to more fully explain the symptoms.
Malignant histiocytosis presenting with vasculitis and cutaneous erythrophagocytosis.
We report a case of malignant histiocytosis that presented initially as a cutaneous vasculitis without malignant features. A subsequent biopsy specimen of an erythematous skin lesion showed erythrophagocytosis by normal-appearing histiocytes within the subcutis. The recognition of erythrophagocytosis was followed by systemic symptoms and signs of malignant histiocytosis and a rapidly deteriorating clinical course. Possible mechanisms for erythrophagocytosis are discussed, and other diseases associated with this histologic finding are reviewed briefly.
Medical correlates of infant development.
Attempts to correlate developmental outcome with medical complications affecting the fetus and infant have focused on the prenatal, intrapartum, and postnatal periods. The time beyond the newborn stage has not been explored in detail. The aim of this study was to relate events occurring during the gestational and neonatal periods as well as the infancy periods to later performance by the use of four medical scales. A total of 126 preterm infants were followed up prospectively from birth to 2 years of age. Medical complications occurring during the prenatal, intrapartum, and postnatal periods as well as the first nine months of life were recovered. No relationship was found between obstetric and neonatal events and developmental outcome. Significant correlations were seen between medical events of later infancy and development at 2 years of age.
Immunosuppressive characteristics of human AFP: effect on tests of cell mediated immunity and induction of human suppressor cells.
Murine AFP has been reported to be immunosuppressive in a variety of systems. However, the extent and degree of inhibition has varied in different species and laboratories. Therefore, we have examined the potential suppressive effect of purified human AFP on several in vitro tests of cellular immunity and the potential mechanism of its action. AFP purified from fetal and liver cancer sera significantly inhibited mitogen and antigen-induced proliferative responses but had no effect on lymphocyte E rosetting, MIF production or mitogen induced T cell cytotoxicity to Chang target cells. Purified human AFP induced human suppressor cell activity, capable of suppressing a one-way mixed lymphocyte reaction (MLC). In contrast to Con A induced suppressor cells, AFP induced suppressor cell activity was overcome by mitogen augmentation of the proliferative response in MLC. These data suggest that the inhibition of lymphocyte proliferation by human AFP may be mediated by the induction of a subpopulation of human suppressor cells. Furthermore, mitogen induced cell mediated cytotoxicity was partially inhibited by primary liver cancer serum and completely inhibited by newborn cord serum, in contrast to purified fetal or tumor AFP which had no effect. These data suggest that there are other immunosuppressive factors in fetal and tumor serum which require further characterization. These other serum factors may be responsible for some of the immunosuppressive effects attributed to AFP. Although AFP is unlikely to play a major immunosuppressive role physiologically in vivo, its selective effect on proliferative responses, apparently mediated by suppressor cells, may prove to be a useful pharmacologic probe of the mechanism of these in vitro lymphocyte responses and biological interactions.
A neurologic comparison of pre-term and full-term infants at term conceptional age.
There are currently no neurologic examinations designed for pre-term infants with sufficient data to determine neurologic deviance at various gestational or conceptional ages (gestational age plus age from birth). In this study a neurologic examination standardized for full-term newborn infants was administered to 97 full-term newborn infants was administered to 97 full-term newborn infants and 97 pre-term infants at their expected date of birth, 40 weeks' conceptional age. The pre-term infants had more weak responses than did the full-term infants despite being at a higher level of activity state throughout the examination. The pre-term infants also had more asymmetric responses. There was no correlation between gestational age and the incidence of weak responses in the pre-term infants, but the pre-term infants of lowest birth weight at all gestational ages had the greatest number of weak responses. The latter may be because pregnancy and neonatal problems contribute more to the neurologic findings than does the length of gestation.
Caring for families of high-risk infants.
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Peripheral nerve maturation in premature infants.
The association of peripheral nerve conduction velocity and conceptional age in premature infants is well established. However, the impact of premature birth on the rate of maturation of peripheral nerves is unclear. In this study a group of 119 premature infants and 32 term infants had nerve conduction velocity determinations. The correlation of velocity and conceptional age is significant. There appears to be no effect upon nerve conduction velocity by the occurrence of prenatal or postnatal events. It is unclear whether extrauterine rates of increase of velocity in prematures are comparable to intrauterine rates, but testing of prematures after they have reached their expected date of birth shows them to have identical mean values to term infants tested at term.
Letter: A question for Dr. Dobbing.
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Phenylketonuria in the American Indian.
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