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S A Hoffman

Publications and source records attributed to S A Hoffman.

35 records · Page 2Linked to original sources
PubMed1987

Brain-reactive autoantibody levels in the sera of ageing autoimmune mice.

Brain-reactive autoantibodies are thought to play an important role in mediating central nervous system (CNS) disorders in systemic lupus erythematosus (SLE). In this paper the developmental occurrence of these antibodies in the sera of autoimmune mice, i.e. NZB, NZB/W, MRL/l and BXSB mice were examined. All murine strains tested, whether autoimmune or not, showed some degree of serum reactivity toward brain antigens. Autoimmune mice, however, displayed higher levels of serum brain-reactive antibodies, and at earlier ages, than non-autoimmune mice. Immunofluorescence assays against brain sections and adsorption assays, with both neural and non-neural tissue, indicated a heterogeneity in the specificity of the populations of brain-reactive antibodies present. These studies provide an important step in characterizing the appearance and diversity of brain-reactive autoantibodies, with the goal of better understanding their significance and potential role in mediating CNS dysfunction in SLE.

Aging↗
PubMed1987

Dream bizarreness and the activation-synthesis hypothesis.

The unusual aspect of dream consciousness which has been called "dream bizarreness" may be defined as impossibility or improbability in the domains of dream plot, cognition and affect. The bizarre features of dreams may be divided into three broad categories: discontinuities, incongruities and uncertainties. Discontinuities are interruptions in orientational stability; incongruities are inappropriate syntheses of mismatching plot elements; uncertainties are confusions of distinct conceptions. Dream bizarreness appears to be the manifestation of some state-dependent cognitive process which is probably rooted in REM sleep neurophysiology. In the waking state, our brain/minds are capable of remaining focused on the normal flow of ongoing information, and such features of life as plot and time unfold in a linear sequence. In REM sleep/dreaming, this function appears to be interfered with, and disparate elements of consciousness are suddenly interjected as the brain/mind cannot maintain its orientational focus in the usual way.

Arousal↗
PubMed1983

Permeability of the blood cerebrospinal fluid barrier during acute immune complex disease.

Changes in the permeability of the blood-brain barrier (BBB) and blood-cerebrospinal fluid (blood-CSF) barrier in rabbits were assessed by using a sensitive double isotope technique at different times after the induction of acute immune complex disease (AICD). Induction of AICD was done with a single large dose of bovine serum albumin, whereas controls received only saline. Animals were sacrificed 6, 9, 12, 15, and 18 days after induction. Extravasation of protein was measured by injecting rabbits i.v. with 131I-rabbit serum albumin (RSA) 24 hr before sacrifice. In order to correct for intravascular blood volume, 125I-RSA was injected 5 min before sacrifice. Extravascular blood equivalents (EVBE), a measure of barrier permeability, were elevated in the CSF of rabbits sacrificed on days 12 and 15. None of the brain regions from any of the animal groups showed any changes or significant differences from controls in EVBE values on these days. These results indicate that there was an increase in the permeability of the blood-CSF barrier to radiolabeled albumin but not in the BBB proper during the time that CSF IgG levels were elevated in AICD. The potential significance of these findings for the mechanisms mediating central nervous system involvement in systemic lupus erythematosus is discussed.

Acute Disease↗
PubMed1982

Suppression of water intake by immune complex formation in the hypothalamus. Implications for systemic lupus erythematosus.

Immune complex formation in the perifornical region of the hypothalamus resulted in depressed water consumption in rats, but did not consistently alter body temperature. The antibody with an unrelated antigen did not affect water consumption or body temperature. These results support the notion that immune complex reactions within the central nervous system can alter behavior.

Animals↗
PubMed1982

Prostatic acid phosphatase and sperm in the post-coital vagina.

Sperm and prostatic acid phosphatase identified in vaginal fluid after an alleged sexual assault constitute important physical evidence useful in courts of law during rape trials. The purpose of this study was to define a normal and abnormal range for acid phosphatase in the post-coital vagina for our emergency department and to compare the sensitivity of acid phosphatase versus sperm in determining recent coitus. Vaginal swabs obtained from 90 patients were analyzed for acid phosphatase activity by the Sigma p-nitrophenyl phosphate technique. Swabs were stored in a bovine albumin preservative broth. Pap smears for sperm identification were also performed. Acid phosphatase values greater than 50, especially those greater than 138 Sigma units/cc, correlated with intercourse within the preceding 24 hours (P .005). Values greater than 20 but less than 50 correlated with intercourse within 48 hours (P .005). The presence or absence of sperm was found to be less sensitive, and correlated poorly with the time since intercourse [of 12 cases less than or equal to 24 hours, 11 were acid phosphatase-positive (91.7%) while seven were sperm-positive (58.4%)].

Acid Phosphatase↗
PubMed1982

Ethanol-induced hypoglycemic coma in a child.

Reported is a case of ethanol-induced hypoglycemic coma in a 33-month-old boy after accidental ingestion of ethanol. Blood glucose was 10 mg% and blood ethanol was 71 mg%. He responded promptly to an IV bolus of 50% dextrose. The pathophysiology and clinical presentation of this not uncommon metabolic disorder are discussed. A plan for early recognition and management is presented.

Adult↗
PubMed1978

A naturally occurring antibody in New Zealand mice cytotoxic to dissociated cerebellar cells.

A spontaneously occurring antibody cytotoxic to dissociated cells of the neonate mouse cerebellum was found in the sera of some New Zealand (NZ) mice. No significant activity was found in the sera of six non-autoimmune mouse strains. The degree of cytotoxicity was similar towards both allogeneic and syngeneic cells. Absorption of the cytotoxic sera with brain and kidney homogenates removed the reactivity, while liver removed less reactivity. Absorptions with thymocytes and several other tissue homogenates and cells had no effect on the cytotoxicity levels, nor was there a correlation between the levels of thymocytotoxicity and cerebellar cell cytotoxicity. The antibody cytotoxic for cerebellar cells could not be demonstrated in the cerebrospinal fluid (CSF) of any mice examined, including a mouse with high serum cytotoxic levels. Gel filtration of reactive sera indicated that the antibody is of the IgM class.

Animals↗
PubMedDate not supplied

Simple apparatus for blocking small animal brains.

A modification of previously described devices for blocking small animal brains is presented. The apparatus is easily constructed and allows for blocking at varous angles of both fixed and unfixed tissue of most small laboratory animals.

Animals↗
PubMedDate not supplied

Chronic immune complex disease: behavioral and immunological correlates.

Using a fear avoidance paradigm, behavioral effects were seen in Sprague-Dawley rats in which chronic immune complex disease was induced. These effects were related to changes in urine protein that developed during the course of the experiment. Experimental animals also had glomerular deposits of rat gamma globulin and BSA as determined by immunofluorescence; C3 deposits were observed in half of these animals. BSA and/or rat gamma-globulin, but not C3, was seen in the choroid plexus of half of the experimental animals. This is the first study to report behavioral changes associated with the induction of chronic immune complex disease in experimental animals.

Animals↗