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Biomedical subjects

M A Goldstein

Publications and source records attributed to M A Goldstein.

At least 19 recordsLinked to original sources
PubMed1999

A beneficial effect on mood in partial epilepsy patients treated with gabapentin.

PURPOSE: Antiepileptic drugs (AEDs) are frequently used for their beneficial psychoactive effects on affective disorders. We sought to demonstrate a psychoactive effect of gabapentin (GBP) when used as add-on AED therapy. METHODS: Forty adult patients with partial epilepsy were studied in a prospective, non-randomized fashion with interviewer-rated and self-rated scales of mood and anxiety: the Cornell Dysthymia Rating Scale (CDRS), Beck Depression Inventory (BDI), and Hamilton Depression (Ham-D) and Anxiety (Ham-A) Scales. After completion of baseline mood and anxiety scales (time 1), 20 of the 40 patients were prescribed add-on GBP (treated group). The remaining 20 patients served as a control group. Both groups were similar in age and sex distribution. Follow-up mood and anxiety scales were performed in all patients approximately 3 months later (time 2). The average GBP dose at time 2 was 1,615 mg/day. All patients were taking stable doses of one to four AEDs at baseline and throughout the study. Seizure frequency was monitored throughout. Statistical significance was assessed by analysis of variance (ANOVA) by using a two-factor repeated-measures model. RESULTS: The GBP-treated group had a significant decrease in CDRS score over time compared with the control group (p = 0.04). No significant differences between the control and the treated groups were found for any of the remaining mood scales (BDI, p = 0.58; Ham-D, p = 0.59; Ham-A, p = 0.93). There was no significant difference or change in seizure frequency between groups. CONCLUSIONS: GBP treatment is associated with mood improvement as measured by the CDRS. This improvement was not accounted for by seizure improvement.

Acetates↗
PubMed1998

The effects of increased gravity and microgravity on cardiac morphology.

BACKGROUND: Our previous study of rats exposed for 14 d to microgravity on Cosmos 2044 revealed morphological changes consistent with cardiac atrophy. METHODS: In the current comparison study, light and electron microscopic studies were performed on cardiac muscle from 10 rats exposed to hypergravity (continuous centrifugation at 2G) for 14 d. RESULTS: Myofiber area was significantly greater in the 2G papillary muscle as compared with muscle from 10 control rats of the same strain and size. This contrasts with the significant decrease in myofiber area previously seen in the rats exposed to microgravity. At the electron microscopic level, general morphological features were similar in both groups and resembled tissue from control rats from the previous Cosmos studies. However, mitochondria from papillary and ventricular muscle from the 2G rats revealed signs of fatigue typical of the early stage of hypertrophy. These results are consistent with a state of adaptive cardiac hypertrophy for the 2G group.

Adaptation, Physiological↗
PubMed1996

Three-dimensional structure of the Z band in a normal mammalian skeletal muscle.

The three-dimensional structure of the vertebrate skeletal muscle Z band reflects its function as the muscle component essential for tension transmission between successive sarcomeres. We have investigated this structure as well as that of the nearby I band in a normal, unstimulated mammalian skeletal muscle by tomographic three-dimensional reconstruction from electron micrograph tilt series of sectioned tissue. The three-dimensional Z band structure consists of interdigitating axial filaments from opposite sarcomeres connected every 18 +/- 12 nm (mean +/- SD) to one to four cross-connecting Z-filaments are observed to meet the axial filaments in a fourfold symmetric arrangement. The substantial variation in the spacing between cross-connecting Z-filament to axial filament connection points suggests that the structure of the Z band is not determined solely by the arrangement of alpha-actinin to actin-binding sites along the axial filament. The cross-connecting filaments bind to or form a "relaxed interconnecting body" halfway between the axial filaments. This filamentous body is parallel to the Z band axial filaments and is observed to play an essential role in generating the small square lattice pattern seen in electron micrographs of unstimulated muscle cross sections. This structure is absent in cross section of the Z band from muscles fixed in rigor or in tetanus, suggesting that the Z band lattice must undergo dynamic rearrangement concomitant with crossbridge binding in the A band.

Animals↗
PubMed1995

Hepatitis B immunization in adolescents.

This article reviews the epidemiology of hepatitis B in the United States, previous vaccination strategy, and reasons for its failure and issues leading to the recommendation to vaccinate all adolescents. A review of specific hepatitis B virus risk behaviors of adolescents and barriers to vaccinating adolescents is covered. Strategies that favor successful completion of the immunization series are also examined. Hepatitis B infection is an important public health concern for adolescents. The previous vaccine strategy to immunize only individuals though to be at high risk was unsuccessful, especially because providers of care could not identify these individuals. Furthermore, many individuals thought not to be at high risk for infection were exposed through contacts which could not be identified. Challenges to immunization of adolescents include logistical issues, patient education, cost of the vaccine, and patient compliance. Several of these issues can be addressed by a school-based hepatitis B immunization program. The body of evidence and national policy is rapidly changing to support the recommendation that all adolescents receive the hepatitis B immunization series. The series would be most effective if administered during the middle-school years. A universal adolescent hepatitis B vaccination program would result in the most immediate health benefits and acceleration toward the eradication of hepatitis B in the United States.

Adolescent↗
PubMed1995

Prokaryotic promoters in biotechnology.

The basic properties of prokaryotic promoters and the promotor region are described with special emphasis on promoters that are found in Escherichia coli and Bacillus subtilis. Promoters recognized by major and minor forms of RNA polymerase holoenzymes are compared for their specificities and differences. Both natural and hybrid promoters that have been constructed for purposes of efficient and regulated transcription are discussed in terms of their utility. Since promoter regions contain sequences that are recognized not only by RNA polymerase but by positive and negative regulatory factors that regulate expression from promoters, the functions and properties of these promoter regions are also described. The current utility and the future prospects of the prokaryotic promoters in expressing heterologous genes for biotechnology purposes are discussed.

Bacillus subtilis↗
PubMed1994

Cellulose promotes extracellular assembly of Clostridium cellulovorans cellulosomes.

Cellulosome synthesis by Clostridium cellulovorans was investigated by growing the cells in media containing different carbon sources. Supernatant from cells grown with cellobiose contained no cellulosomes and only the free forms of cellulosomal major subunits CbpA, P100, and P70 and the minor subunits with enzymatic activity. Supernatant from cells grown on pebble-milled cellulose and Avicel contained cellulosomes capable of degrading crystalline cellulose. Supernatants from cells grown with cellobiose, pebble-milled cellulose, and Avicel contained about the same amount of carboxymethyl cellulase activity. Although the supernatant from the medium containing cellobiose did not initially contain active cellulosomes, the addition of crystalline cellulose to the cell-free supernatant fraction converted the free major forms to cellulosomes with the ability to degrade crystalline cellulose. The binding of P100 and P70 to crystalline cellulose was dependent on their attachment to the endoglucanase-binding domains of CbpA. These data strongly indicate that crystalline cellulose promotes cellulosome assembly.

Bacterial Proteins↗
PubMed1994

Mutation analysis of the cellulose-binding domain of the Clostridium cellulovorans cellulose-binding protein A.

Cellulose-binding protein A (CbpA) has been previously shown to mediate the interaction between crystalline cellulose substrates and the cellulase enzyme complex of Clostridium cellulovorans. CbpA contains a family III cellulose-binding domain (CBD) which, when expressed independently, binds specifically to crystalline cellulose. A series of N- and C-terminal deletions and a series of small internal deletions of the CBD were created to determine whether the entire region previously described as a CBD is required for the cellulose-binding function. The N- and C-terminal deletions reduced binding affinity by 10- to 100-fold. Small internal deletions of the CBD resulted in substantial reduction of CBD function. Some, but not all, point mutations throughout the sequence had significant disruptive effects on the binding ability of the CBD. Thus, mutations in any region of the CBD had effects on the binding of the fragment to cellulose. The results indicate that the entire 163-amino-acid region of the CBD is required for maximal binding to crystalline cellulose.

Amino Acid Sequence↗
PubMed1993

Characterization of the cellulose-binding domain of the Clostridium cellulovorans cellulose-binding protein A.

Cellulose-binding protein A (CbpA), a component of the cellulase complex of Clostridium cellulovorans, contains a unique sequence which has been demonstrated to be a cellulose-binding domain (CBD). The DNA coding for this putative CBD was subcloned into pET-8c, an Escherichia coli expression vector. The protein produced under the direction of the recombinant plasmid, pET-CBD, had a high affinity for crystalline cellulose. Affinity-purified CBD protein was used in equilibrium binding experiments to characterize the interaction of the protein with various polysaccharides. It was found that the binding capacity of highly crystalline cellulose samples (e.g., cotton) was greater than that of samples of low crystallinity (e.g., fibrous cellulose). At saturating CBD concentration, about 6.4 mumol of protein was bound by 1 g of cotton. Under the same conditions, fibrous cellulose bound only 0.2 mumol of CBD per g. The measured dissociation constant was in the 1 microM range for all cellulose samples. The results suggest that the CBD binds specifically to crystalline cellulose. Chitin, which has a crystal structure similar to that of cellulose, also was bound by the CBD. The presence of high levels of cellobiose or carboxymethyl cellulose in the assay mixture had no effect on the binding of CBD protein to crystalline cellulose. This result suggests that the CBD recognition site is larger than a simple cellobiose unit or more complex than a repeating cellobiose moiety. This CBD is of particular interest because it is the first CBD from a completely sequenced nonenzymatic protein shown to be an independently functional domain.

Amino Acid Sequence↗
PubMed1993

The hydrophobic repeated domain of the Clostridium cellulovorans cellulose-binding protein (CbpA) has specific interactions with endoglucanases.

We overexpressed one of the hydrophobic repeated domains (HBDs) (110 amino acid residues) of the cellulose-binding protein (CbpA) from Clostridium cellulovorans by making a hybrid protein with the Escherichia coli maltose-binding protein (MalE). The HBD was purified to homogeneity, and interactions between the HBD and endoglucanases were analyzed by a novel interaction Western blotting (immunoblotting) method. The HBD had specific interactions with endoglucanases (EngB and EngD) from C. cellulovorans. These results indicated that the HBD was an endoglucanase binding site of CbpA.

ATP-Binding Cassette Transporters↗