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Biomedical subjects

M Jones

Publications and source records attributed to M Jones.

At least 613 records · Page 34Linked to original sources
PubMed1991

A typology based on measures of substance abuse and mental disorder.

The data of this study were derived from comprehensive interviews of 311 women and 949 men residing in the New York City public shelters for homeless adults during the summer of 1987. Interviews, guided by a 57 page interview protocol, were conducted by thoroughly trained interviewers who had worked in agencies and service systems focused on mental disorders, child abuse, substance abuse and problems of homeless people. Included in the content of the interview were seven dichotomous measures of substance use, substance abuse and mental disorder. A typology of ten groups comprised of individuals with similar profiles on the seven measures served as the independent variable. Three pairs of dependent variables were suicide attempts and current thoughts of suicide, a need for medical services reported by shelter residents and by their interviewers, and disclosure of a drug problem and a need for help in treating it. Consistently meaningful associations between group memberships and the 3 pairs of dependent variables, and 16 measures of health status in previous work, were interpreted as evidence for predictive validity of the typology.

Comorbidity↗
PubMed1991

Factors influencing mortality from bleeding peptic ulcers.

The mortality, causes of death, and the factors that are influencing deaths from bleeding acute and chronic peptic ulcers were evaluated retrospectively. During a 2-year period (1986-87) 272 patients were endoscoped for acute gastrointestinal hemorrhage and were found to have bled from a peptic ulcer (chronic gastric ulcers, 90; chronic duodenal ulcers, 114; acute gastroduodenal ulcers, 66; stomal ulcers, 2). The overall mortality was 9.6% (n = 26) (gastric ulcers, 6.7%; duodenal ulcers, 11.4%; acute ulcers, 10.6%). Statistically significant factors adversely affecting prognosis for gastric ulcer were re-bleeding, need for operation and serious intercurrent illness; for duodenal ulcer were units of transfused blood, re-bleeding, signs of recent hemorrhage at endoscopy, need for operation, and serious intercurrent illness; and for acute ulcer were increasing age, shock, units of transfused blood, re-bleeding, and serious intercurrent illness. Multivariate analysis was only attempted for duodenal ulcers because of sample sizes; it suggested that active bleeding or visible vessel at endoscopy, re-bleeding, and serious intercurrent illness were independent factors for mortality. From this study it is apparent that the major determinants of a fatal outcome in bleeding peptic ulcer diseases were serious intercurrent illness and rebleeding. As it must be anticipated that patients with these particular problems are at high risk of a poor outcome, it follows that it is important they have access to skilled treatment as provided by a specialist team in an intensive care ward. It also follows that every effort should be made to keep ulcers in remission to free the ulcer patient of potentially lethal complications.

Adult↗
PubMed1991

Recurrent ovarian carcinoma: presentation as idiopathic thrombocytopenic purpura and a splenic mass.

We report a case of a 38 year old female who was treated for a Stage IIIb serous cystadenocarcinoma of the ovary with cytoreduction, combination chemotherapy, negative second look laparotomy, and adjuvant chemotherapy, who eight months later presented with Idiopathic Thrombocytopenic Purpura (ITP) and an isolated splenic recurrence. Review of the literature shows only four other cases of gynecologic malignancy which exhibited this pattern of recurrence. This case is the first where the primary lesion was an ovarian carcinoma and the patient presented with thrombocytopenia.

Adult↗
PubMed1991

Ovarian neoplasm mimicking rectal carcinoma. Report of a case and review of the literature.

We report a rare case of primary endometrioid carcinoma of the ovary which presented clinically with rectal bleeding mimicking a rectal cancer. The patient's pre-operative evaluation included radiographic and sero-immunologic findings which indicated a primary ovarian neoplasm. Only two other cases of ovarian carcinoma with this presentation have been reported in the literature. Gynecologic processes that can present as bleeding gastrointestinal lesions are reviewed.

Adult↗
PubMed1991

Primary total knee arthroplasty in patients with severe varus deformity. A comparative study.

Varus deformity is a common finding in candidates for total knee arthroplasty (TKA), but very little has been written concerning the problems encountered in correcting these deformities at the time of arthroplasty. Compared to patients without deformities, this group of patients require more attention to the technical aspects of the arthroplasty, especially bony alignment and ligament balancing. Specific operative techniques used to correct severe varus deformities at primary TKA were evaluated, and the clinical and roentgenographic results were compared with those of a control group of patients without preoperative angular deformity. Operative findings and clinical results in 27 knees (20 patients) with a minimum preoperative varus deformity of 20 degrees (average follow-up period, 58.7 months; range, 24-102 months) were compared with those of 40 knees (31 patients) with a preoperative angulatory deformity of less than 5 degrees varus or valgus (average follow-up period, 50.0 months; range, 24-90 months), in whom a minimally constrained, posterior-cruciate-ligament-sparing prosthesis was implanted. Operative time was an average of 30 minutes longer in the varus deformity group. The average knee evaluation score in the varus group was 89 points, and for the nondeformity group it was 92 points (p less than 0.02). There were no fair or poor results in the varus deformity group; there was one poor result in the nondeformity group. Postoperative knee are of motion was 98 degrees in the varus deformity group and 107 degrees in the nondeformity group. After arthroplasty, the average angle between the mechanical axis of the femur and the tibia was 3 degrees varus in the varus deformity group and 0 degree varus in the nondeformity group (p less than 0.006). Postoperative functional scores of patients in the varus deformity group approached, but were not equal to, the nondeformity group. Greater variability in results and longer operative times were needed in the varus deformity group. Postoperative alignment of the varus deformity group tended to be in residual varus.

Adult↗
PubMed1991

Maternal, uteroplacental, and fetoplacental hemodynamic and Doppler velocimetric changes during epidural anesthesia in normal labor.

Pulsed Doppler and M-mode maternal echocardiography were combined with uterine and umbilical artery Doppler velocimetry to characterize the hemodynamic changes associated with fluid preload and epidural anesthesia in 12 normal laboring gravidas at term. Fluid preload alone was associated with significant (P less than .05) increases in heart rate (11%), stroke volume (10%), and cardiac output (20%), and a decrease in systemic vascular resistance (19%). There were no changes in mean arterial pressure (MAP) or ejection fraction during any stage of the study. Following placement of the epidural block, stroke volume and cardiac output returned to values not significantly different from baseline, whereas heart rate remained elevated and systemic vascular resistance remained decreased. There were no changes in uterine or umbilical artery systolic-diastolic (S-D) ratios during any stage of the study. We conclude that fluid preload and epidural anesthesia cause significant changes in maternal cardiac output, heart rate, stroke volume, and systemic vascular resistance without affecting MAP. These maternal changes do not correlate with any changes in uterine or umbilical artery S-D ratios following epidural anesthesia in the normal laboring gravida.

Anesthesia, Epidural↗
PubMed1990

Isolated peripheral T cells from GvHR recipients exhibit defective IL-2R expression, IL-2 production, and proliferation in response to activation stimuli.

Graft-vs-host reactions (GvHR) following the injection of class I/II MHC disparate parental cells into unirradiated F1 recipient mice result in the development of marked immune dysfunction. Following negative selection using adherence and antibody and complement depletion, highly purified T cells were examined to determine their ability to undergo activation. Three weeks after GvHR initiation, unstimulated splenic T cells from GvHR mice displayed normal CD3 and IL-2R expression but elevated expression of class I MHC and Ly-6A/E antigens. Despite culture with normal F1 accessory cells, both CD4+ and CD8+ GvHR T cells exhibited low levels of proliferation to both Con A and anti-CD3 mAb. Although following exposure for 12 h to either of these stimuli, GvHR T cells expressed normal levels of IL-2R, expression was greatly decreased vs normal T cells between 24 and 48 h. In addition, at no timepoint was detectable IL-2 produced by GvHR T cells. Importantly, mixing experiments did not demonstrate detectable suppressive activity in the purified GvHR T cell subsets. GvHR T cells were also tested for their ability to respond to stimuli in the absence of any accessory cell population. These cells again did not proliferate to levels equivalent to normal T cells. Incubation with PMA and either cytokines (Con A supernatant, rIL-7) or anti-CD3 mAb resulted in only low levels of proliferation in GvHR T cells. Notably, at high ionomycin concentrations together with PMA, GvHR T cells did proliferate to equivalent levels as normal cells. However, with decreasing concentrations of ionophore, these cells failed to proliferate as well as normal cells. In total, these findings demonstrate that GvHR T cells are phenotypically and functionally distinct from normal T cells. The results suggest that GvHR T cells themselves may contribute to the well-characterized immune depression occurring in recipients undergoing GvHR.

Animals↗
PubMed1990

Delayed nephrotoxic effects of cadmium and their reversibility by chelation.

A single injection of CdCl2 (15 mumol/kg) together with 300 mumol/kg mercaptoethanol into adult male rats induced renal dysfunction only after a delay of at least 12 h; in contrast, the peak value of cadmium in renal cortex (34 +/- 3 micrograms/g) was reached within 2 h. The chelator methoxybenzylglucaminedithioate (MBGDT) rapidly reduced the renal Cd level by 2/3, primarily by extracting the metal from the sedimentable rather than the cytosolic fraction. MBGDT prevented the subsequent onset of malfunction, but only when given at an early stage after Cd administration (2 h). It follows that the renal damage seen after the initiation period is independent of the Cd concentration at that time. The changes occurring during initiation remain unexplained.

Animals↗
PubMed1990

Hepatotropin mRNA expression in human foetal liver development and in liver regeneration.

A 569 bp probe against the beta-chain of hepatotropin was used to examine expression of RNA for this growth factor in human adult and foetal liver, foetal kidney and pancreas, and rat liver after partial hepatectomy. Low level expression of a 6 kb RNA occurred in human adult and normal rat liver. 70% hepatectomy increased expression, peaking at 10 h and returning to near normal levels 24 h after resection. The 6 kb band was strongly expressed in human foetal liver, as compared with adult, but not in foetal kidney or pancreas, suggesting a major role for hepatotropin in both foetal development and regeneration of the liver.

Animals↗
PubMed1990

Different isoforms of human FcRII distinguished by CDw32 antibodies.

The Third and Fourth International Workshops on Leucocyte Differentiation Antigens identified six mAb, designated CDw32, reacting with human Ig FcR type II (FcRII). We have examined the immunohistochemical and immunocytologic reactivities of these antibodies and find that the antibodies could be divided into three classes of reactivity: 1) antibodies IV.3, CIKM3, and CIKM5 reacted with monocytes, macrophages and neutrophils; 2) antibodies KB61 and 41H.16 gave strong reactions with B lymphocytes, placental and hepatic endothelium, and weaker reactions with monocytes, macrophages, and neutrophils; 3) antibody 2E1 gave an intermediate reaction pattern. Immunoprecipitation from U937 cell lysates showed that antibodies KB61 and 41H.16 recognized Mr 41,000 and Mr 37,000 molecules whereas the other antibodies detected a Mr 42,000 molecule. Preclearing with antibody KB61 removed the Ag recognized by the other five antibodies confirming the identity of the Ag and demonstrating reactivity of KB61 with the Mr 42,000 molecule. Antibodies KB61 and 41H.16 precipitated a Mr 41,000 molecule from B lymphocytes. Flow cytometry and immunoprecipitation studies of cells transfected with cDNA clones coding for two isoforms of FcRII showed that all six of the antibodies react with both transfectants but the only immunoprecipitations were obtained using KB61 and 41H.16 and one of the transfectants. The protein sequence of KB61 Ag isolated from leukemic B cells showed close homology with the proteins encoded by the cDNA clones but diverged in the intracytoplasmic carboxyl-terminal region. It was concluded that preferential recognition of one or more of the numerous isoforms of FcRII underlies the differing reaction patterns of CDw32 antibodies.

Amino Acid Sequence↗
PubMed1990

The alpha and pi isoenzymes of glutathione S-transferase in human fetal lung: in utero ontogeny compared with differentiation in lung organ culture.

Polyclonal antisera to the alpha and pi isoenzymes of glutathione S-transferase have been used in immunohistochemical studies of developing human lung. In utero expression of the pi set was down-regulated in distal airway cells and the first appearance of pi-negative cells coincided with phenotypic differentiation. In contrast, in the early phase of fetal lung organ culture pi isoenzyme was detected in all differentiated epithelial cells and only as culture progressed did focal negativity develop. The alpha set showed no developmental changes in utero or in organ culture.

Down-Regulation↗
PubMed1990

T lymphocytes can recognize determinants unique to neuropeptides of guinea pig myelin basic protein containing a single D-isomer amino acid substitution.

The present studies were undertaken to examine how the substitution of racemized forms of selected amino acids in synthetic peptides of guinea pig myelin basic protein (GPMBP) would alter the host's immunological ability to recognize such molecules. Using peptides from the 69-84 sequence of GPMBP containing a D-serine at position 70 or 75 (69-84[D-ser70 or D-ser75]) or D-aspartate at position 82 (69-84[D-asp82]), the findings demonstrated that the position of the diastereomer substitution on these neuropeptides was critical with respect to the ability of the immune system to recognize the molecule. Thus substitution of D-asp at position 82 or D-ser at position 75 abrogated the ability of these peptides to induce experimental autoimmune encephalitis and proliferation of host T cells. In contrast, a peptide containing a D-ser70 residue was capable of inducing clinical disease in rats, as well as stimulating T lymphocytes from 69-84-(D-ser70)-injected animals. Moreover, although this D-peptide was shown to share at least some determinant(s) with the 69-84 peptide, the use of 69-84(D-ser70)-stimulated cell lines demonstrated that some epitope(s) unique to this molecule could stimulate CD4+ syngeneic T cells.

Animals↗
PubMed1990

Yeast-derived recombinant human insulin-like growth factor I: production, purification, and structural characterization.

Recombinant human insulin-like growth factor I (IGF-I) is efficiently expressed and secreted from Saccharomyces cerevisiae using a yeast alpha-factor leader to direct secretion. However, approximately 10-20% of the IGF-I was in a monomeric form, the remaining materials being disulfide-linked aggregates. When the purified material was subjected to reverse-phase high-performance liquid chromatography (rp-HPLC), it gave two doublet peaks, I and II. Upon reduction, doublet peaks I and II converged to one doublet peak. This suggests that peaks I and II result from different disulfide structures, and the doublet feature of each peak results from other causes. Different disulfide structures between peaks I and II were also suggested from the near UV circular dichroism of these proteins. Only the peak II was biologically active, indicating that peak II has the correct disulfide structure. Concanavalin A affinity chromatography of the purified peak II doublet showed binding of the subpeak with an earlier rp-HPLC retention time, indicating that it was glycosylated. Sequence analysis of tryptic peptides suggested that Thr29 was the site of glycosylation. Site-directed mutagenesis was used to convert Thr29 to Asn29. This substitution reduced, but did not eliminate IGF-I glycosylation, suggesting additional glycosylation sites. The site of carbohydrate addition was consistent with the model that O-glycosylations occur on hydroxyl amino acids near proline residues in beta-turns.

Amino Acid Sequence↗
PubMed1990

Photon correlation spectroscopy of the polarization signal from single muscle fibres.

Measurements of crossbridge dynamics have been obtained from the spectrum of diffracted light derived from single, skinned fibres of skeletal muscle. This technique combines optical ellipsometry with photon correlation spectroscopy of the intrinsic reporters from the muscle cell. The difference in the intensities of the two linearly polarized electric field components of diffracted light is autocorrelated in time, and the dynamics of optical anisotropy from the contributing units of the sarcomere are measured. In focusing on the fast-time dynamics, we detected two principal features: a rapidly relaxing temporal signal with a relaxation time of approximately 5 microseconds, and an oscillatory component which transforms into a broad but spectrally defined signal centred at around 370 kHz. Experiments were conducted to measure changes of these two signals upon relax-rigor transition and alpha-chymotrypsin degradation. These studies strongly suggest that the relaxational component of the signal is primarily due to myosin crossbridge motion; the 370 kHz spectral signal has as its likely source the myosin thick filament.

Animals↗
PubMed1990

Dietary treatment eliminates succinylacetone from the urine of a patient with tyrosinaemia type 1.

Over an 18-month period serial observations of plasma tyrosine, methionine and urinary tyrosine metabolites were made and compared with urinary succinylacetone excretion in an infant with tyrosinaemia type 1 treated by diet alone. Despite broadly similar profiles there were significant temporal and quantitative differences between each of these metabolic parameters. Only when plasma tyrosine was kept in the low-normal range by strict phenylalanine restriction (10-15 mg phenylalanine/kg body weight) was detectable succinylacetone consistently eliminated from the urine. Urinary succinylacetone is the only measure of metabolite accumulation immediately proximal to the enzyme defect and its routine measurement will allow more effective control of dietary treatment.

Amino Acid Metabolism, Inborn Errors↗
PubMed1990

HSV-1 enhances GvHR-associated parent anti-F1 alloreactivity in vivo and in vitro.

The present studies were performed to demonstrate whether concurrent HSV-1 infection could enhance the immune alterations and dysfunction associated with P----F1-induced graft-versus-host reactions. Examination of phenotypic and functional parameters revealed that Gv-HR-related immune abnormalities in the (C3H.SW X H-2bm1)F1 recipient were dependent on the parental donor inoculum. Together with HSV-1 infection, virus was found to exacerbate the phenotypic changes and functional abnormalities induced in this GvHR model. In addition, the presence of concurrent HSV-1 was shown to augment the level of specific in vivo donor anti-host reactivity present in F1 recipient spleen cells. Moreover, in vitro studies demonstrated that HSV-1 also enhanced the levels of parent anti-F1 allospecific cytotoxic activity. In total, these findings support the hypothesis that viral exacerbation of GvHR is mediated by its enhancement of donor anti-host alloreactive responses.

Animals↗