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Biomedical subjects

John Hill

Publications and source records attributed to John Hill.

13 recordsLinked to original sources

Pseudomonas syringae effector avrB confers soybean cultivar-specific avirulence on Soybean mosaic virus adapted for transgene expression but effector avrPto does not.

Soybean mosaic virus (SMV) was adapted for transgene expression in soybean and used to examine the function of avirulence genes avrB and avrPto of Pseudomonas syringae pvs. glycinea and tomato, respectively. A cloning site was introduced between the P1 and HC-Pro genes in 35S-driven infectious cDNAs of strains SMV-N and SMV-G7. Insertion of the uidA gene or the green fluorescent protein gene into either modified cDNA and bombardment into primary leaves resulted in systemic expression that reflected the pattern of viral movement into uninoculated leaves. Insertion of avrB blocked symptom development and detectable viral movement in cv. Harosoy, which carries the Rpg1-b resistance gene corresponding to avrB, but not in cvs. Keburi or Hurrelbrink, which lack Rpg1-b. In Keburi and Hurrelbrink, symptoms caused by SMV carrying avrB appeared more quickly and were more severe than those caused by the virus without avrB. Insertion of avrPto enhanced symptoms in Harosoy, Hurrelbrink, and Keburi. This result was unexpected because avrPto was reported to confer avirulence on P. syringae pv. glycinea inoculated to Harosoy. We inoculated Harosoy with P syringae pv. glycinea expressing avrPto, but observed no hypersensitive reaction, avrPto-dependent induction of pathogenesis-related protein la, or limitation of bacterial population growth. In Hurrelbrink, avrPto enhanced bacterial multiplication and exacerbated symptoms. Our results establish SMV as an expression vector for soybean. They demonstrate that resistance triggered by avrB is effective against SMV, and that avrB and avrPto have general virulence effects in soybean. The results also led to a reevaluation of the reported avirulence activity of avrPto in this plant.

Bacterial Proteins↗

The financial requirements and time commitments of caregivers for autologous stem cell transplant recipients.

This study is a prospective evaluation of the time commitment and financial requirements of caregivers of autologous stem cell recipients during the period of inpatient hospitalization. Eligible patients identified one caregiver, and a one-page survey addressing the necessary time commitment and out-of-pocket expenses was completed by the caregiver at each visit. The caregivers of 40 patients participated (non-Hodgkin's lymphoma [n = 19], multiple myeloma [n = 18], Hodgkin's lymphoma [n = 2], or acute myelogenous leukemia [n = 1]). Caregivers included spouses (n = 35), partners/friends (n = 2), or family members (n = 3). Results were summarized for the patient's total length of stay. Each caregiver traveled a median of 829 miles over 17.8 hours. Out-of-pocket expenses varied greatly depending on whether a caregiver stayed in local accommodations (cohort 1; n = 11) or in the patient's hospital room (cohort 2; n = 29). Total expenses (median) for each caregiver in cohort 1 were dollar 849.35, including accommodations (dollar 560), gasoline (dollar 87.35), and food (dollar 202). Total expenses (median) for each caregiver in cohort 2 were dollar 181.15, including gasoline (dollar 70) and food (dollar 111.15). Each caregiver in cohort 1 lost a median of 43.5 hours of work compared with 8 hours for each caregiver in cohort 2. The results from this prospective study demonstrate that there is a significant financial and time requirement on the part of the caregiver when a family member or significant other is hospitalized for an autologous stem cell transplant.

Adult↗

Laparoscopic splenectomy for autoimmune hemolytic anemia in patients with chronic lymphocytic leukemia: a case series and review of the literature.

The purpose of this study was to evaluate the safety and efficacy of laparoscopic splenectomy in patients with chronic lymphocytic leukemia (CLL) complicated by autoimmune hemolytic anemia. A series of nine such patients who underwent this procedure at our institution between August 1997 and September 2001 were retrospectively reviewed. Seven of 9 patients who underwent laparoscopic splenectomy for CLL and autoimmune hemolytic anemia achieved a complete response. One patient who initially responded relapsed 12 weeks postoperatively. Therefore, six of 9 patients showed sustained responses with a mean follow-up of 2 years, consistent with other published series. Two patients had no response, one of whom died within 3 weeks of surgery from transformed Hodgkin's disease. The only other postoperative complication occurred in a patient who developed pneumonia. We conclude that laparoscopic splenectomy is a safe and effective treatment for autoimmune hemolytic anemia in patients with CLL who fail medical therapy.

Aged↗

A clinicopathologic evaluation of follicular lymphoma grade 3A versus grade 3B reveals no survival differences.

CONTEXT: The World Health Organization classification recommends categorizing grade 3 follicular lymphomas based on the presence of centrocytes (grade 3A) or of sheets of centroblasts (grade 3B). The clinical significance of this practice is not known. OBJECTIVE: To determine whether grade 3 follicular lymphoma subtype is associated with prognosis. DESIGN: Multi-institutional retrospective case series. MAIN OUTCOME MEASURE: Overall survival. RESULTS: Forty-five cases of grade 3 follicular lymphoma without diffuse large B-cell lymphoma were studied (35 cases of grade 3A, 10 cases of grade 3B) from 21 men and 24 women (median age, 67 years; mean age, 63.8 years; range, 26-86 years). Follow-up information from the time of diagnosis was available in all patients, with a median follow-up time of 24 months (mean, 34 months; range, 2- 115 months). Treatment information was available in 40 patients. There was no difference in age (P =.45, Wilcoxon test) or stage (P =.76, Fisher exact test) between patients with follicular lymphoma of grade 3A or grade 3B. Furthermore, the Cochran-Armitage test for trends showed no evidence that the proportion of patients with follicular lymphoma grade 3A or 3B increased or decreased with increasing stage at presentation. Kaplan-Meier analysis showed a median overall survival of 44 months from the time grade 3 follicular lymphoma was diagnosed, with no significant difference between cases diagnosed as grade 3A or grade 3B (P =.14, log-rank test). Univariable Cox proportional hazards modeling showed no evidence that an anthracycline-containing chemotherapy regimen or history of lower grade follicular lymphoma affected overall survival. CONCLUSIONS: In this retrospective series, subclassification of grade 3 follicular lymphoma into type 3A and 3B categories had limited clinical and prognostic significance. However, the study was limited by lack of statistical power. Since morphology often provides clues for progress in defining biologic differences, subtyping may still be useful, particularly in the setting of prospective clinical studies.

Adult↗

Imaging and quantitation of the hypoxic cell fraction of viable tumor in an animal model of intracerebral high grade glioma using [18F]fluoromisonidazole (FMISO).

We have demonstrated that FMISO uptake is significantly higher in tumor tissue in the C6 intracerebral glioma rat model compared to normal brain, and that there is persisting hypoxia in gliomas independent of tumor size. FMISO uptake was observed homogeneously throughout viable glioma tissue in tumor sizes ranging from 2mm to almost 1cm. Quantitation of uptake of FMISO showed a tumor/brain ratio of 1.9 and a tumor/blood ratio of 2.6 at 2 hours post injection.

Animals↗

Co-existing cholesteatoma and vestibular schwannoma.

A 69-year-old man presented with a cholesteatoma in the right mastoid process and a vestibular schwannoma at the left internal acoustic meatus. Cholesteatoma co-existing with a vestibular schwannoma has not been documented previously in the contemporary literature. The clinical dilemma in the management of his progressive bilateral hearing loss is discussed. He presented with dizziness and bilateral hearing loss worse on the right side. Pressure over the mastoid process elicited vertigo and nystagmus. He had no history of previous operation or infection in the ear canal. Audiograms confirmed high-tone hearing loss. Radiological investigations revealed a symptomatic cholesteatoma on the right side and an incidental vestibular schwannoma on the left. We have elected to manage both lesions conservatively. Bilateral cholesteatoma and bilateral vestibular schwannomas have been previously reported. Co-existing lesions, as in our patient have, however, not been reported previously. The management options of his hearing loss are discussed.

Aged↗