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Biomedical subjects

D Jacobs

Publications and source records attributed to D Jacobs.

At least 127 records · Page 7Linked to original sources
PubMed1989

Differentiating Alzheimer's disease from Huntington's disease with the Wechsler Memory Scale-Revised.

The WMS-R represents a significant improvement over the original version of the WMS. Patterns of performance on the five WMS-R indices successfully differentiated patients with a "cortical" (that is, DAT) from patients with a "subcortical" (that is, HD) dementia. The differences between ACI and GMI also indicated that DAT patients' attention and concentration were better preserved than those of equally demented HD patients. Analyses of the differences between GMI and DMI indicated that rapid forgetting was more apparent for DAT than for HD patients in the early stages of these disorders. When savings scores for the Logical Memory and Visual Reproduction tests were used to examine retention over a 30-minute period, both mildly and moderately demented DAT patients demonstrated more rapid forgetting than did HD patients with similar levels of cognitive decline. Discriminant analyses performed with these indices of forgetting showed 95 per cent accurate classification of DAT and elderly controls, and 79 per cent correct classification of DAT and HD patients. Assessment of the patients' tendencies to make prior-item intrusion errors on the Visual Reproduction tests of the WMS and WMS-R yielded significant differences between patient groups and the two versions of the test. Patients with DAT made significantly more prior-figure intrusion errors than did HD patients on both versions of the VRT, but the original WMS form of this figural memory test was more likely to elicit such errors than was the revised version. Despite many improvements in the revised scale, a number of limitations still exist including standardization and a lack of norms for elderly individuals, as well as failures to include tests of verbal recognition and adequate measures of nonverbal memory.

Alzheimer Disease↗
PubMed1988

Liposarcoma of spermatic cord.

Liposarcoma of the spermatic cord is a rare tumor. Most are of a low-grade malignancy, and treatment is wide local excision with radical orchiectomy. At present there is no clear indication for chemotherapy. Because recurrence, especially local recurrence, is a possibility, periodic followup is necessary. Local recurrences are treated with repeat wide local excision and radiotherapy.

Adult↗
PubMed1988

Redox reactivity of bacterial and mammalian ferritin: is reductant entry into the ferritin interior a necessary step for iron release?

Both mammalian and bacterial ferritin undergo rapid reaction with small-molecule reductants, in the absence of Fe2+ chelators, to form ferritins with reduced (Fe2+) mineral cores. Large, low-potential reductants (flavoproteins and ferredoxins) similarly react anaerobically with both ferritin types to quantitatively produce Fe2+ in the ferritin cores. The oxidation of Fe2+ ferritin by large protein oxidants [cytochrome c and Cu(II) proteins] also occurs readily, yielding reduced heme and Cu(I) proteins and ferritins with Fe3+ in their cores. These latter oxidants also convert enthetically added Fe2+, bound in mammalian or bacterial apo- or holoferritin, to the corresponding Fe3+ state in the core of each ferritin type. Because the protein reductants and oxidants are much larger than the channels leading into the mineral core attached to the ferritin interior, we conclude that redox reactions involving the Fe2+/Fe3+ components of the ferritin core can occur without direct interaction of the redox reagent at the mineral core surface. Our results also suggest that the oxo, hydroxy species of the core, composed essentially of Fe(O)OH, arise exclusively from solvent deprotonation. The long-distance ferritin-protein electron transfer observed in this study may occur by electron tunneling.

Anaerobiosis↗
PubMed1988

Biochemical and serological characteristics of children with membranous nephropathy due to hepatitis B virus infection: correlation with hepatitis B e antigen, hepatitis B DNA and hepatitis D.

Fourteen children with biopsy-proven membranous nephropathy associated with hepatitis B virus (HBV-MN) were evaluated biochemically and serologically and compared to 45 children with idiopathic nephrotic syndrome (INS). The mean ages of the two groups were similar (4.9 +/- 1.6 vs. 4.6 +/- 2.6 years). Serum albumin levels were similar in both groups, but serum cholesterol was significantly reduced in children with HBV-MN compared to INS. Serum C3 was also significantly depressed in children with HBV-MN compared to INS, but no differences in C4 levels were noted. Serum alanine transaminase as well as aspartate transaminase concentrations were significantly elevated in children with HBV-MN compared to those with INS, suggesting the presence of chronic hepatitis in children with HBV-MN. Hepatitis B surface and e antigens were present in serum of all children with HBV-MN, but only 54% had circulating HBV-DNA particles demonstrable in their serum. Serum C3 levels were higher in children with HBV-MN and circulating HBV-DNA, compared to those without circulating HBV-DNA. No other serological or biochemical differences occurred between these two groups. Glomerular deposition of IgG and C3 occurred in 91% of children with HBV-MN; but IgM deposition appeared to occur more frequently and with greater intensity in those children positive for circulating HBV-DNA. Antibody to delta antigen was negative in all children with HBV-MN. We conclude that biochemical and serological differences can be identified between HBV-MN and INS.(ABSTRACT TRUNCATED AT 250 WORDS)

Antigens, Viral↗
PubMed1987

Penicillin resistant pneumococcal peritonitis in nephrotic syndrome.

Two infants with nephrotic syndrome who developed penicillin resistant pneumococcal peritonitis while receiving penicillin chemoprophylaxis are reported and the problems associated with prophylaxis against pneumococcal infection discussed. It is suggested that penicillin prophylaxis may be hazardous in an environment in which penicillin resistant pneumococci are prevalent.

Female↗
PubMed1987

Prostatic carcinoma: staging by clinical assessment, CT, and MR imaging.

The sensitivity, specificity, accuracy, and positive and negative predictive values of clinical assessment, computed tomography (CT), and magnetic resonance (MR) imaging were compared in the differentiation of stage B from stage C prostatic carcinoma. Forty-six patients who had undergone radical prostatectomy were included in the study. Surgical-pathologic staging was considered the "truth measure." Clinical staging had an accuracy of 61%, and CT, 65%. Accuracy for MR imaging depended on the instrument parameters and plane of section used. When only transverse T1-weighted images were analyzed, MR accuracy was 61%. However, when transverse T1- and T2-weighted images supplemented by additional T2-weighted coronal or sagittal images were studied, accuracy increased to 83%. At present, MR imaging is the most accurate diagnostic modality for the local staging of carcinoma of the prostate, but for optimal results, multiple sequences and two orthogonal planes of imaging are needed.

Aged↗
PubMed1987

The latex condom, an efficient barrier against sexual transmission of AIDS-related viruses.

Using a mechanical model, we studied human immunodeficiency virus (HIV) leakage through six different trademark condoms. The presence of the recovered virus was determined after passage to MT-2 cells and to cultured mitogen-stimulated normal human peripheral blood mononuclear cells (PMC). Only the natural membrane condom showed virus leakage after inside pressure. In addition, the kinetics of virus inactivation at 37 degrees C were followed inside and outside the condom. The virus was partially inactivated after 10 min at 37 degrees C inside the condom, but the degree of inactivation seemed higher in some of the trademark condoms.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Restriction endonucleases from Herpetosiphon giganteus: an example of the evolution of DNA recognition specificity?

We describe the partial purification and characterisation of five Type II restriction endonucleases from two strains of Herpetosiphon giganteus. One of the activities, HgiJII, was the first enzyme found that cleaves DNA at the family of related sequences 5'-G-R-G-C-Y/C-3'. This enzyme may be related to the enzyme HgiAI from a different strain of the same species, and which cleaves at the sites 5'-G-W-G-C-W/C-3'. We have shown that DNAs from the strains producing HgiAI and HgiJII are resistant to both of these restriction endonucleases. The remaining four enzymes described here share recognition and cleavage specificities with other restriction endonucleases. The evolution of Type II restriction-modification systems and their role in vivo are discussed.

Bacteroidetes↗
PubMed1986

Isolation and characterization of the M.EaeI modification methylase.

The modification enzyme (M.EaeI) corresponding to the restriction endonuclease EaeI was partially purified from Enterobacter aerogenes PW201. The M.EaeI enzyme methylates the innermost cytosine residue in each strand of the family of related sequences that constitute the EaeI recognition site to give: 5'-Y-G-G-5mC-C-R-3' where 5mC is 5-methylcytosine. M.EaeI protects these sites against cleavage by HaeIII, and protects overlapping 5'-C-C-G-G-3' sites against cleavage by both HpaII and MspI.

Binding Sites↗
PubMed1986

Urothelial injury to the rabbit bladder from various alkaline and acidic solutions used to dissolve kidney stones.

Different irrigating solutions are used clinically to dissolve uric acid, cystine and struvite stones. These studies were undertaken to assess the toxicity to the rabbit bladder epithelium of several commonly used formulations. Test solutions were infused antegrade through a left ureterotomy overnight. Bladders were removed and routine histological sections made. A pH 7.6 solution of NaHCO3 appeared harmless. The same solution with two per cent acetylcysteine produced slight injury. All pH 4 solutions caused significant damage to the urothelium. Hemiacidrin, which contains magnesium, produced less damage than did other pH 4 solutions without that cation. Our data tend to support Suby's conclusions that addition of magnesium reduces urothelial injury even though the presence of magnesium will slow dissolution of struvite.

Acetylcysteine↗
PubMed1986

Emergency psychopharmacology: a review and update.

The emergency area is a difficult site for the practice of careful psychopharmacology. The detailed history taking and collaborative treatment relationship often found in the consultant's office is rarely present. Instead, rapid decisions are made under a variety of pressures, with patients who may be uncooperative and unwilling to be treated. Many emergency patients are concurrently in treatment with a psychotherapist or psychopharmacologist who is available for consultation to the emergency service. When this is possible it is of great potential value, both in arriving more quickly at an appropriate treatment and in preventing a harmful opposition of the patient's treatment resources. For patients who are not currently in another treatment, additional helpful information often may be obtained from friends or family members. This is especially useful in treating patients who are acutely psychotic, unable to communicate, or uncooperative with the emergency interview. Although psychopharmacological approaches properly chosen often yield rapid results, medications are only a part of most emergency treatment plans. Medications are ineffective in a variety of crises and cannot replace careful interviewing of patients and others aimed at understanding the exogenous stress, change in interpersonal relationships, intrapsychic conflict, or biological disorder that precipitated an emergency visit. Furthermore, the decision to treat with medications must include a consideration of the adverse effects that may occur. With these limitations in mind, the area of emergency psychopharmacology can provide powerful assistance to emergency clinicians.

Acute Disease↗
PubMed1986

Dextroamphetamine-induced arousal in human subjects as a model for mania.

Because of the practical difficulties which arise in studying manic patients, a reproducible model for mania using human subjects would be a valuable adjunct to research in this condition. Dextroamphetamine, given as a single oral 20 mg dose, fulfils the criteria for such a model in that there are very close similarities between the changes which occur after dextroamphetamine and those which have been observed in mania in terms of subjective experience, physiological and endocrine changes, and response to pharmacological agents.

Administration, Oral↗
PubMed1986

Noradrenergic mechanisms in the response to dextroamphetamine in humans.

The effect of oral thymoxamine, an alpha-noradrenergic antagonist, on the arousal and anorectic action of oral dextroamphetamine was measured in order to investigate the role of the alpha-noradrenergic pathways in these responses. Thymoxamine appeared to accentuate the alerting action and reduce the anorectic action of dextroamphetamine. The implications of these findings on the role of the alpha-noradrenergic pathways in these responses is discussed in the light of previous findings.

Adult↗