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Biomedical subjects

J Jackson

Publications and source records attributed to J Jackson.

At least 253 records · Page 14Linked to original sources
PubMed1986

Chronic pulmonary emboli. Sparing of affected regions of lung from noncardiogenic pulmonary edema.

In chronic pulmonary emboli, lung perfusion may be maintained by either recanalization of occluded pulmonary artery segments or collateral bronchial circulation. We present a case of noncardiogenic pulmonary edema superimposed on chronic pulmonary emboli, in which the occluded segments of lung were spared from pulmonary edema, but not from neutrophil infiltration. This case demonstrates that chronic emboli may lead to roentgenographic sparing in noncardiogenic pulmonary edema, similar to that previously reported in acute pulmonary emboli superimposed on noncardiogenic edema.

Chronic Disease↗
PubMed1986

Clinical and biologic features predict a poor prognosis in acute lymphoid leukemias in infants: a Pediatric Oncology Group Study.

Analysis of remission induction rates for 1,117 children 18 months to 10 years of age (group 1) and 90 infants less than 18 months of age (group 2) with acute lymphoid leukemia (ALL) and of duration of continuous complete remission (CCR) for 454 in group 1 and 33 in group 2 revealed that infants fared significantly worse in both measures of outcome (P = .03 and P less than .0001). To examine potential reasons for the poor prognosis of affected infants, clinical and biologic features of their ALL were compared. Infants had higher WBC counts (P less than .001), a higher incidence of massive splenomegaly (P less than .001), massive hepatomegaly (P less than .001), more central nervous system (CNS) disease at diagnosis (P less than .01), and lower platelet counts (P less than .001). Also, their blasts were less often PAS+ (P = .02). The incidence of non(T, B, pre-B), T and pre-B immunophenotypes of ALL did not differ significantly between the two groups. However, in patients with non(T, B, pre-B) ALL, the majority (51%) of infants had common ALL antigen (CALLA)-negative blasts, as compared with only 7% in group 1 (P less than .001). Furthermore, infants with non(T, B, pre-B) cell ALL who were less than 12 months of age were almost always CALLA- (18 of 21). The blasts of children from both groups usually expressed Ia-like antigens. These data illustrate that infants with ALL have extensive and bulky disease more often than do older children and are more often affected with a prognostically unfavorable phenotype of acute leukemia (AL) which expresses Ia-like antigens but is more often PAS- and CALLA-. We believe that these clinical and biological differences predict and explain in part the observed poor response to treatment of infants with ALL.

Age Factors↗
PubMed1985

Treatment of Aspergillus fumigatus keratitis in rabbits with oral and topical ketoconazole.

Aspergillus fumigatus keratitis was established in rabbits by intrastromal injection of a suspension containing 5,000 spores. After a 48-hour incubation period, the animals were treated with oral and topical ketoconazole alone and in combination with topical natamycin for five days. Colony counts per cornea were obtained at the conclusion of the treatment period. Based on these colony counts, neither oral nor topical ketoconazole was effective despite moderate in vitro sensitivity of the fungus to ketoconazole. Oral and topical ketoconazole used in conjunction with natamycin, however, appeared to augment sterilization of A. fumigatus in this model of fungal keratitis.

Administration, Oral↗
PubMed1985

HLA gene frequencies in children and adults with systemic onset juvenile rheumatoid arthritis.

The HLA genetic region was studied in 51 patients with systemic onset juvenile rheumatoid arthritis: 35 with childhood onset and 16 with adult onset (adult Still's disease). HLA genotypes were established by including family members, 261 of whom were also typed in the study. The most marked difference between patients and controls involved the HLA-DR4 gene, which occurred with a frequency of 0.348 in the childhood onset patients and 0.170 in the controls (chi 2 = 8.97, P = 0.0028, adjusted P = 0.017). In contrast, the adult onset patients showed a marginal increase in HLA-DR7, but were similar to controls with respect to HLA-DR4. HLA-Bw35 was increased in children with systemic onset disease, in accordance with earlier findings. The results suggest that patients with systemic onset juvenile rheumatoid arthritis have complex HLA associations which are different in childhood onset and adult onset disease.

Adolescent↗
PubMed1985

Ocular tolerance assessment--integrated tier policy.

A tier scheme is proposed for the assessment of ocular tolerance as part of the safety evaluation of materials. The scheme has four stages: (1) physico-chemical characterization, (2) an in vitro cytotoxicity study, (3) a dermal tolerance study in rabbits and (4) initial and confirmatory ocular tolerance studies in rabbits. The assessment may be terminated at any of the stages, including during the course of the final stage. This tier system appears to provide a considered and careful approach to the requirement to assess the ocular tolerance of those materials for which conventional animal tests are not essential.

Animals↗
PubMed1984

Does indomethacin attenuate the coronary vasodilatory effect of nitroglycerin?

Although previous studies have shown that indomethacin attenuates the dilative effects of nitroglycerin on human peripheral veins and canine coronary arteries, its ability to alter the influence of nitroglycerin on coronary blood flow in human beings is unknown. In 22 patients (16 men and 6 women, aged 47 +/- 10 years [mean +/- standard deviation]) referred for the evaluation of chest pain, heart rate, systemic arterial pressure, coronary sinus blood flow (by thermodilution) and coronary vascular resistance (mean arterial pressure/coronary sinus blood flow) were measured before and during the administration of intracoronary saline solution (n = 6, [control subjects]) or intracoronary nitroglycerin, 100 micrograms (n = 16). Of these 16 patients, 8 had no pretreatment and the other 8 received 50 mg of indomethacin orally, 10 and 2 to 3 hours before study. In the six control subjects, no variable changed with saline injection. In the eight patients given nitroglycerin without indomethacin pretreatment, heart rate and mean systemic arterial pressure were changed modestly (72 +/- 15 to 74 +/- 15 beats/min and 93 +/- 9 to 87 +/- 13 mm Hg, respectively, p less than 0.05), coronary sinus blood flow increased by 56 +/- 43% (107 +/- 72 to 155 +/- 78 ml/min, p less than 0.001) and coronary vascular resistance decreased (1.12 +/- 0.50 to 0.66 +/- 0.26 mm Hg/ml per min, p = 0.004).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Incidence of bite marks in a selected juvenile population: a preliminary report.

A study of the frequency of bite marks among sheltered children was conducted for a period of three months in the juvenile care facilities in Las Vegas, NV. The study demonstrated an incidence of 1 545 bite marks per 100 000 population. Analysis of the age, sex, and location of bite marks is presented. The study demonstrated an incidence comparable to diseases such as gonorrhea.

Adolescent↗
PubMed1983

A comparison of pre-operative bathing with chlorhexidine-detergent and non-medicated soap in the prevention of wound infection.

In a 60-week cross-over study on 5536 patients in 20 wards of three city hospitals (two general and one orthopaedic), pre-operative bathing with chlorhexidine-detergent failed to influence the incidence of postoperative infection, in spite of the relatively high incidence of infection with skin organisms. Of the patients bathing pre-operatively with chlorhexidine-detergent, 5.4 per cent subsequently became infected (4.0 per cent of clean wounds) and of those bathing with unmedicated soap 4.9 per cent (3.5 per cent of clean wounds). A single pre-operative bath with chlorhexidine-detergent would, therefore, appear to be of dubious value in preventing postoperative wound infection.

Baths↗
PubMed1983

Linkage analysis of myotonic dystrophy and sequences on chromosome 19 using a cloned complement 3 gene probe.

Variations in DNA sequence generate polymorphisms which can be followed through families. A cloned gene specific probe for human complement 3 (C3) was hybridised to DNA samples digested with restriction endonucleases. The C3 probe detects several restriction fragment length polymorphisms (RFLPs) that occur frequently in the general population. These DNA alleles can be readily used in linkage analyses of loci on chromosome 19, since most families studied are informative. The inheritance of one such polymorphism was followed through myotonic dystrophy families. The segregation data for both the C3 protein polymorphism and the C3 RFLP support the linkage of myotonic dystrophy (DM) and C3.

Chromosome Mapping↗
PubMed1983

Transmission of tuberculosis by flexible fiberbronchoscopes.

The development of flexible fiberoptic bronchoscopy was an important technologic advance in the diagnosis and management of patients with pulmonary disease. However, reliable decontamination and sterilization of these delicate instruments have been difficult. Many physicians routinely use a solution of povidone-iodine diluted in 70% ethyl alcohol and water to decontaminate fiberbronchoscopes, despite the fact that these iodophor compounds were developed as skin antiseptics and not as germicidal disinfectants for decontaminating instruments. We isolated a strain of Mycobacterium tuberculosis on a surveillance culture from a bronchoscope after it had been cleaned and disinfected with an iodophor solution. In another hospital, we documented the transmission of M. tuberculosis from one patient to another by a bronchoscope that had been disinfected with a commonly recommended iodophor solution. We then studied the tuberculocidal efficacy of various iodophor preparations used with exposure times from 10 to 30 min. In several experiments these iodophors failed to kill M. tuberculosis. Because iodophors do not reliably kill M. tuberculosis, they should not be used to disinfect fiberoptic bronchoscopes.

Adult↗