The role of F-18 FDG PET/CT in evaluating the impact of HIV infection on tumor burden and therapy outcome in patients with Hodgkin lymphoma.

BACKGROUND: To evaluate the impact of HIV infection on tumor burden and therapy outcome following treatment with chemotherapy in patients with Hodgkin lymphoma. METHODS: A total of 136 patients with classical Hodgkin lymphoma were studied (mean age ± SD = 32.31 ± 1.39 years, male = 86, female = 50). Advanced disease (stage III and IV) was present in 64% of patients. HIV infection was present in 57 patients while 79 patients were HIV-negative. Baseline F-18 FDG PET/CT was obtained in all patients. SUVmax, MTV and TLG were determined on the baseline scan to evaluate for tumor burden. All patients completed a standard regimen of adriamycin, bleomycin, vinblastine and dacarbazine (ABVD). After a median period of 8 weeks (range = 6 to 17 weeks), a repeat F-18 FDG PET/CT scan was obtained to evaluate response to therapy using Deauville 5-point scoring system. RESULTS: The HIV-positive and HIV-negative groups were similar with regards to age and disease stage. The groups were heterogeneous with respect to gender (p = 0.029). The SUVmax, MTV and TLG of lesions were not significant different between the two groups. Complete response was seen in 72.8% of the study population. Presence of HIV infection was associated with higher rate of treatment failure with 40.4% of the HIV-positive patients having treatment failure while only 17.7% of the HIV-negative patients had treatment failure (p = 0.0034). HIV infection was a significant predictor of response to chemotherapy. Effects of SUVmax, MTV, TLG and Ann Arbor stage of the disease were not statistically significant as predictors of therapy outcome. In a multiple logistic regression, presence of HIV infection still remained an independent predictor of therapy outcome in the presence of other factors such as SUVmax, MTV, TLG and the Ann Arbor stage of the disease. CONCLUSIONS: HIV infection is not associated with a higher tumor burden in patients with Hodgkin lymphoma. HIV infection is, however, a strong predictor of poor therapy outcome in patients treated with standard regimen of ABVD.

95 GHz gyrotron with ferroelectric cathode.

Ferroelectric cathodes were reported as a feasible electron source for microwave tubes. However, due to the surface plasma emission characterizing this cathode, operation of millimeter wave tubes based on it remains questionable. Nevertheless, the interest in compact high power sources of millimeter waves and specifically 95 GHz is continually growing. In this experiment, a ferroelectric cathode is used as an electron source for a gyrotron with the output frequency extended up to 95 GHz. Power above a 5 kW peak and ~0.5 µs pulses are reported; a duty cycle of 10% is estimated to be achievable.

Morphometric study of the human lumbar spine for operation-workspace specifications.

STUDY DESIGN: The anatomy of the lumbar vertebrae of 55 patients was measured by use of data provided by computed tomography. On the basis of these measurements, the location of puncture points and the orientation of the surgical instruments for pedicle, vertebral body, and disc entry points were calculated for open as well as percutaneous surgery. OBJECTIVE: Normal anatomic variations of the lumbar spine were investigated to define the workspace for several spinal procedures and to define the workspace of a robot designed to guide the physician during those procedures. SUMMARY OF BACKGROUND: Several comprehensive studies of vertebrae dimensions have been conducted in the past, but they lack several dimensions that are needed to determine the exact location of the entry point and orientation of the tool, in particular when a computerized guidance system is used. METHODS: Fifty-five spinal columns (L1-L5, total 250 vertebrae) were measured by computed tomography. These data provide geometric relations that determine entry points and tool orientations for different spinal interventions. RESULTS: The workspace for spinal operations was defined on the basis of anatomic data taken from computed tomography scans. The data included 15 measurements for each vertebra that defined its shape. The processed data provided puncture points for several spinal procedures in both open and percutaneous surgery. CONCLUSIONS: This study provides additional information on vertebral structure needed to calculate accurately the entry point and tool orientation in various spinal procedures. These statistical data are also valuable for model and implant designs and for workspace specifications for a robot-assisted surgery system.

Hospitalizations due to falls in Jewish and Arab children in northern Israel.

In Israel, there are no epidemiological data regarding nonfatal childhood falls. A retrospective survey was conducted in order to find epidemiological characteristics of childhood falls among the different populations of northern Israel. During the years 1993 through 1995, 3082 children were hospitalized in Rambam Medical Center (RMC) due to injury. The children were subdivided into the four main populations: Jewish and Arab residents of Haifa region (the main metropolitan area) and Jewish and Arab residents of the Galilee region (the rural region). All of the children who suffered injury that required mechanical ventilation and careful assessment were admitted to the PICU. The charts of the children admitted to the PICU were then further studied. The demographic characteristics of all the cases of falls were statistically analyzed and the annual admission rates due to falls were calculated using the national statistical registrations of children in Israel. Falls were responsible for 1049 admissions due to injury, one third of the total number of children who were admitted due to an injury. Most of the children were five years of age or younger. Two thirds of the total childhood falls were of Arabs. The majority of the admissions were of two major sub-populations of northern Israel: Arab residents of Galilee region (66%) and Jewish residents of Haifa region (34%). Higher admission rate was found among Arab children of the Western Galilee district in comparison with Jewish children of the Haifa district. Most of the children who were admitted to the PICU were Arabs: nearly all of these children were from the rural region. More Arab than Jewish children who fell were admitted to the PICU and the majority of these cases were falls from buildings (private houses). Arab children of the rural region were responsible for 95% of the cases. These falls were mainly in staircases (46%) and from balconies (21%), roofs (11%) and windows (11%). The findings of the present study suggest that young Arab rural children in northern Israel are at high risk to a severe injury due to fall. Possible causes are discussed and a preventative intervention is suggested.

Gene expression of insulin-like growth factor-I, its receptor and binding proteins in retina under hypoxic conditions.

Hypoxia is the main stimulus for neovascularization in the retina. Insulin-like growth factor-I (IGF-I) is thought to be one of the mediators of this process. Severe persistent hypoxia, as occurs in central retinal artery occlusion, is associated with less retinal neovascularization than relative hypoxia. To study the influence of different types of hypoxia on the IGF system, we used a model of neonatal rat retina that responds with neovascularization to a relative hypoxic stimulus produced by alternating oxygen concentrations in the respired air. We studied the influence of 24-hour hypoxia (10% oxygen), 48-hour hyperoxia (75% oxygen), and relative hypoxia (shifting from 48 hours in 75% oxygen to 24 hours in room air) on the gene expression of IGF-I, IGF-I receptor (IGF-IR), and IGF binding protein-1 (IGFBP-1), IGFBP-2, and IGFBP-3 in retina using a solution hybridization RNase protection assay. Hypoxia induced a significant increase in retinal IGF-IR (178%), IGFBP-2 (227%), and IGFBP-3 (317%) mRNA; however, retinal IGF-I mRNA was reduced, as well as serum growth hormone (GH). Relative hypoxia caused a similar but less pronounced trend in the gene expression of IGF-IR and the binding proteins, whereas retinal IGF-I mRNA was unchanged and serum GH was elevated. Both hypoxia and relative hypoxia may cause IGF system stimulation in the retina through upregulation of IGF-IR and IGFBPs. This stimulation may result in neovascularization. However, during hypoxia, low levels of tissue oxygenation and reduced local production of IGF-I may impede the neovascularization process.

The endogenous insulin-like growth factor system in radiocontrast nephropathy.

The response of insulin-like growth factor (IGF) I in acute renal failure was evaluated in a model of radiocontrast nephropathy associated with selective necrosis of medullary thick ascending limbs. In brief, rats were administered radiocontrast medium or vehicle injections for controls after combined inhibition of prostanoids and nitric oxide. Twenty-four hours after the insult, tissue mRNAs for IGF-I, the IGF-I receptor, and IGF-binding proteins (IGFBP) 1 and 3 were assayed in cortex, medulla, and liver by solution hybridization-RNase protection assay, and IGFBPs were measured in serum and tissue by Western ligand blotting. Cortical IGF-1 increased, whereas medullary IGF-I mRNA decreased. Renal IGFBPs decreased, whereas IGFBP-1 mRNA increased. The IGF system in the liver was unchanged. We conclude that general changes in renal IGFBPs in this experimental model of acute renal failure might increase the level of cortical IGF-I in a way that could modulate medullary recovery.

The impact of Hymenoptera venom allergy on occupational activities.

The objective of this study was to investigate the impact of allergy to hymenoptera venom on the occupational activities of patients undergoing immunologic treatment for insect sting anaphylaxis. The design was a cross-sectional study conducted in a sample of 500 out of 1,500 patients undergoing venom immunotherapy for insect sting reaction in 13 allergy clinics in Israel. A self-administered questionnaire was used to collect data about demographic characteristics of patients, severity of the allergic reaction and adverse effects on occupational activities. Of the 204 respondents who were part of the labour force, 48.5% reported adverse effects on routine occupational activities. The factors with a significant influence on the probability of adverse occupational effects were: (1) patient's type of work (blue collar vs. white collar: OR = 3.22, p < 0.001: army vs. white collar: OR = 5.28, p = 0.001); (2) severity of the allergic reaction (severe reaction vs. mild/moderate reaction: OR = 2.34, p = 0.007). Our findings suggest that severe insect sting allergy has an adverse impact on patients' occupational activities. This factor requires special attention by the medical community. Social workers and occupational physicians should collaborate in the assessment and management of these patients.

Risk factors associated with the severity of systemic insect sting reactions.

To evaluate risk factors associated with the severity of systemic insect sting reaction and to determine the type of insect responsible for systemic anaphylaxis, we conducted a cross-sectional study of 498 patients undergoing venom immunotherapy for insect sting reaction in 13 allergy clinics in Israel. Data were collected by questionnaire and review of patient records. Eighty percent of the patients were treated with honeybee venom, which was used as a single therapy in 60% of the group. In a multivariate logistic model the major factors identified as significantly influencing the probability of a more severe systemic reaction were short time of onset of reaction after stinging (<30 min), high number of prior stings (> or = 4), and age (> or = 18 years). A total of 79.3% of the patients had been stung outdoors, and 50% had lived all their lives in rural areas as compared to 10% in the general Israeli population. This study reports clinically valuable risk factors for the severity of systemic sting reaction. A practical finding was that the honeybee is the insect mostly responsible for sting reactions in Israel, but the type of insect is not a significant predictor of the severity of the reaction.