Interdisciplinary approach to abdominal Burkitt’s lymphoma

Burkitt’s lymphoma is a high-grade, rapidly growing B-cell neoplasm. It is recognized by its aggressive course, brief median survival, and low rates of long-term survival. The authors discuss the case of a patient who acutely presented with intraabdominal complications from a new onset of Burkitt’s lymphoma. The clinical and pathological features, staging, treatment options, and survival data are reviewed. In addition, the role of surgical intervention is carefully analyzed.     

Quantifying how location and dose of botulinum toxin injections affect muscle paralysis

Despite the widespread use of botulinum toxin to treat muscle dystonias, no method exists to quantify muscle paralysis in either human or nonhuman models. In this study we examined how the location, dose, and volume of botulinum injection affects paralysis in the rat tibialis anterior muscle. Paralysis was quantified by electrically stimulating the nerve to the tibialis anterior and then staining sections of the muscle for glycogen. The areas of glycogen-containing fibers represented regions of botulinum action. The results showed that the most important injection technique is to inject botulinum directly into the motor endplate region of a muscle. Injections only 0.5 cm from the motor endplate resulted in a 50% decrease in paralysis. Increases in dose increased paralysis, however, some of that increase was simply due to the increased volume of injection. Thus, delivering toxin in small volumes near the MEP band of a muscle should produce the most effectiveparalysis. © 1993 John Wiley & Sons, Inc.     

Therapeutic Options for Chronic Hepatitis B: Considerations and Controversies

Five agents are currently approved for the treatment of chronic hepatitis B infection. This article will discuss the three agents for which the most extensive data are available; interferon (IFN), lamivudine, and adefovir, while the following article by Dr. Jules Dienstag will discuss the recently marketed agents, entecavir and peginterferon alfa-2a. The advantages of IFN are its finite duration of therapy (4–6 months), lack of emergence of resistance, and durability of response. On the negative side, response to IFN is less durable in patients with HBeAg-negative chronic hepatitis B virus (HBV). Also, use of IFN is limited by adverse effects and the mode of administration (daily to thrice-weekly subcutaneous injection). Lamivudine and adefovir are orally administered and have good tolerability and safety. Even in patients who experience a marked decrease in serum HBV DNA and loss of HBeAg, oral therapy needs to be continued for at least 6 months, to avoid the risk of reappearance of HBeAg and viremia. Rates of HBeAg seroconversion to anti-HBe-positivity increase with duration of lamivudine or adefovir therapy. The likelihood of development of resistance to lamivudine and associated viral breakthrough limits its long-term use. In patients with HBeAg-negative chronic hepatitis B, long-term therapy is usually required, as off-treatment relapse is common. The emergence of resistance to adefovir is delayed and infrequent, hence adefovir may be preferred in patients requiring long-term therapy.     

Usher syndrome: clinical findings and gene localization studies

The issue of genetic heterogeneity is a critical problem in the localization of the gene(s) for Usher syndrome. Based on the data obtained on families studied to date, the differences between type I and type II Usher syndrome appear quite distinct with regard to auditory and vestibular function. Although the majority of families can be confidently diagnosed as typical type I or type II, clinical investigations revealed four families with findings that did not fit into either of the two more common subtypes. These findings emphasize the critical importance of an in-depth clinical analysis concomitant with the linkage investigation to assure accurate subtyping of Usher syndrome. Based on an analysis of only those families with definite type I or type II Usher syndrome, approximately 17% of the genome can be excluded as a potential site of the gene for type I, and 14% can be excluded as the site for the type II gene. This study will continue until the Usher gene(s) is successfully localized.     

Risperidone and falls in ambulatory nursing home residents with dementia and psychosis or agitation: secondary analysis of a double-blind, placebo-controlled trial.

OBJECTIVE: Authors evaluated the association between use/dosage of risperidone (RIS) and falls in a residential-care dementia population. METHODS: Authors performed secondary analysis of data from ambulatory patients in a randomized, double-blind, placebo-controlled, 12-week trial of three RIS dosages (0.5 mg/day, 1 mg/day, 2 mg/day). Outcomes included number of fallers, rate of falls, and time until the first fall after randomization. Additional analyses evaluated wandering as a potential moderating or mediating variable. RESULTS: The ambulatory sample included 537 subjects. Of those, 22.3% on placebo, 18.0% on RIS 0.5 mg/day, 12.7% on 1 mg/day, and 27.3% on 2 mg/day, respectively, fell during the trial. The difference between the RIS 1 mg/day group and placebo was significant, with a significantly lower hazard ratio in the RIS 1-mg/day group than placebo. Wandering was associated with an increased risk of falls. Among 205 patients with the highest levels of wandering at baseline, RIS 1 mg/day was associated with approximately a 70% reduction in risk for falls versus placebo condition. However, in those with the lowest levels of wandering at baseline, RIS 2 mg/day may have increased the risk of falls. CONCLUSIONS: Evaluating the benefits versus risks of risperidone in patients with dementia is complex and must consider multiple outcomes as a function of dose. At 1 mg/day, RIS was associated with decreased falls, especially in patients who exhibit wandering. However, at 2 mg/day, it may increase the risk of falls in ambulatory individuals with low levels of wandering.     

Rural Radiology: Who is Producing Images and Who is Reading Them?

The purpose of this study is to identify the local availability and trends in local availability of imaging technology and interpretation services in rural hospitals in the northwestern United States during the period between 1991 to 1994. Another objective is to describe hospital and community factors associated with the diffusion of image production and interpretation services. The information for this study was gathered through telephone surveys of rural hospital administrators in eight northwestern states in 1991 and 1994. The availability of magnetic resonance imaging (MRI) equipment, computed tomography (CT) scanners, ultrasonography equipment, and dedicated mammography equipment increased between 1991 and 1994. The increases in MRI units were primarily in mobile equipment, while ultrasonography and mammography equipment increases were primarily fixed hospital-based units. In 1994, image interpretation in the rural hospitals was provided by both primary care and radiology physicians. Forty-six (11.5%) of the rural hospitals had no on-site radiology services and only 73 (18%) had daily radiology services. Between 1991 and 1994, 12 hospitals gained at least once-a-week radiology services, but 24 lost all radiology services. Teleradiology availability more than doubled during the three years. Radiology technology has diffused widely into rural communities in this region of the United States at differing rates for large and small hospitals. Radiologists are available to these hospitals only 46 percent of the days each year, with more days of availability in the larger hospitals and fewer days in the smaller hospitals. Teleradiology capability is increasing more rapidly in the larger hospitals that have radiologists more readily available.     

Cerebral blood flow changes in normal aging: Spect measurements

Global and regional cerebral blood flow (CBF) were evaluated with single photon emission computerized tomography (SPECT) utilizing both ¹³³Xenon (¹³³Xe) (47 subjects, 47–82 years old) and ⁹⁹Tc-hexamethylpropyleneamine oxime (⁹⁹Tc-HMPAO) (27 subjects, 47–80 years old). The ¹³³Xe results showed: among total subjects, no age-related decline in global CBF, but a significant regional decline in the occipital lobe (p < 0.05); among men, significant age-related declines in global, frontal, temporal, occipital and right hemisphere CBF (all p < 0.05); among women, no age-related decline in global or regional CBF. The ⁹⁹Tc-HMPAO results showed no age-related decline in either global or regional perfusion among total subjects, men or women. These results suggest that age-related global and regional (including frontal lobe) CBF declines do not occur in healthy control subjects after the age of 45 years. However, gender differences in age-related CBF changes warrant further study.     

Sequential occurrence of IgA nephropathy and Henoch-Schönlein purpura: support for common pathogenesis

We report a patient who developed Henoch-Schönlein purpura (HSP) 13 years after he presented with IgA nephropathy (IgAN). In both HSP and IgAN renal biopsy most commonly reveals focal proliferative glomerulonephritis on light microscopy and immunofluorescence displays mesangial IgA deposits. In addition, patients with HSP or IgAN have elevated serum IgA levels, circulating IgA immune complexes, IgA-bearing lymphocytes, immunoglobulin-producing cells, and binding of IgG to glomerular components of similar molecular weight. The occurrence of both diseases in the same patient or the same families and the presence of immune abnormalities compatible with HSP or IgAN in relatives of patients with these diseases suggest a common pathogenesis.