Treatment of Vitreomacular Traction with Intravitreal Injection of Perfluoropropane

PURPOSE

To evaluate the effect of one intravitreal injection of expansile gas in the treatment of vitreomacular traction (VMT).

METHODS

A retrospective review of eyes with VMT treated with singl injection of 0,3 ml of 100% C3F8 gas was performed. The procedure was performed on an outpatient basis under topical anesthesia.

RESULTS

Twelve consecutive patient (14 eyes) with symptomatic VMT underwent pneumatic vitreolysis. Mean extend of vitreomacular adhesion was 490,5 µm (408-751). A posterior vitreous detachment developed in 13 eyes (92,9 %) after a single gas injection, in 11 eyes (84,6 %) during the first month of follow-up, in 2 eyes within two month of injection. Mean baseline and last BCVA were 0,5 (0,16-0,18) and 0,67 (0,2-1,0) respectively (p.

Is pancreaticoduodenectomy justified in elderly patients?

BACKGROUND

Although mortality & morbidity for pancreaticoduodenectomy (PD) have improved significantly over the last two decades, the concern for elderly undergoing PD remains. This study examines the outcome of the elderly patients who had pancreaticoduodenectomy in our institution.

METHODS

A prospective database comprising 69 patients who underwent pancreaticoduodenectomy between 2001 and May 2008 was analyzed. Using WHO definition, elderly patient is defined as age 65 and above in this study. Two groups of patients were compared [Group 1: Age ≤65 & Group 2: Age >65].

RESULTS

The mean age of our patients was 62 ± 11 years. There were 37 (54%) patients in Group 1 and 32 (46%) patients in Group 2. There was no statistical difference between the two groups in terms of gender and race. However, there were more patients in the Group 2 with >2 comorbidities (p = 0.03). The median duration of operation was significantly longer in Group 2 (550 min vs 471 min, p = 0.04). Morbidity rate in Group 2 was higher (56% vs. 44%, p = 0.04). There was higher proportion of post-operative pancreatic fistula (POPF) in the elderly group (37.5% vs. 16.7%, p = 0.05). Majority of them are Grade A POPF according to the ISG definition. The median post-operative length-of-stay (LOS) in hospital was 9 days longer in Group 2 (p = 0.01). Mortality rate between the 2 groups of patients was comparable (0% vs. 3%, p = 0.28).

CONCLUSION

Elderly patients are at increased risk of morbidity in pancreatocoduodenectomy, in particular POPF. However, morbidity and mortality rates are acceptable. It is therefore justified to offer PD to elderly patients who do not have significant cardiopulmonary comorbidities.

Nutritional assessment in an Asian nursing home and its association with mortality

OBJECTIVE

To study the nutritional status of nursing home residents in a multi-racial Asian society and its role in predicting short-term mortality independent of functional status and comorbidities.

DESIGN

Cross-sectional study with prospective collection of mortality data.

SETTING

Nursing home facility in Singapore.

SUBJECTS

A total of 154 patients (mean age 77 +/- 12 years, 53.2% women).

METHODS

We evaluated the demographic details, Mini Nutritional Assessment (MNA) scores, body mass index (BMI) and anthropometric measurements of the participants. Functional status and comorbidities were characterized by the modified Barthel Index and Charlson's comorbidity index respectively.

RESULTS

Prevalence of undernutrition were 52% (n= 80) and 39% (n=60) when determined by BMI < 18.5 kg/m2 and MNA <17 respectively. Mortality was 25.3% (n= 39) over 2 years. Baseline factors associated with mortality include increased age, low Barthel's score, BMI < 18.5 kg/m2 and MNA < 17 (OR= 1.05, 1.01, 3.08 and 3.03 respectively, all p < 0.05). The association between low BMI and mortality remained significant (p=0.027) after adjustment for patient's age, gender, Barthel's and Charlson's scores, and prior nutritional intervention, but the association between MNA and mortality was diminished (p=0.106).

CONCLUSION

There was a high prevalence of undernutrition in this nursing home population, and the diagnosis is an important predictor of mortality. Formal nutritional screening and targeted interventions may improve important clinical outcomes.

Comparative toxicity of oil, dispersant, and oil plus dispersant to several marine species

Dispersants are a preapproved chemical response agent for oil spills off portions of the U.S. coastline, including the Texas-Louisiana coast. However, questions persist regarding potential environmental risks of dispersant applications in nearshore regions (within three nautical miles of the shoreline) that support dense populations of marine organisms and are prone to spills resulting from human activities. To address these questions, a study was conducted to evaluate the relative toxicity of test media prepared with dispersant, weathered crude oil, and weathered crude oil plus dispersant. Two fish species, Cyprinodon variegatus and Menidia beryllina, and one shrimp species, Americamysis bahia (formerly Mysidopsis bahia), were used to evaluate the relative toxicity of the different media under declining and continuous exposure regimes. Microbial toxicity was evaluated using the luminescent bacteria Vibrio fisheri. The data suggested that oil media prepared with a chemical dispersant was equal to or less toxic than the oil-only test medium. Data also indicated that continuous exposures to the test media were generally more toxic than declining exposures. The toxicity of unweathered crude oil with and without dispersant was also evaluated using Menidia beryllina under declining exposure conditions. Unweathered oil-only media were dominated by soluble hydrocarbon fractions and found to be more toxic than weathered oil-only media in which colloidal oil fractions dominated. Total concentrations of petroleum hydrocarbons in oil-plus-dispersant media prepared with weathered and unweathered crude oil were both dominated by colloidal oil and showed no significant difference in toxicity. Analysis of the toxicity data suggests that the observed toxicity was a function of the soluble crude oil components and not the colloidal oil.

Theoretical investigation of the role of choriocapillaris blood flow in treatment of subfoveal choroidal neovascularization associated with age-related macular degeneration

PURPOSE

To investigate the relationship between choriocapillaris blood flow and blood flow through an overlying choroidal neovascularization, as it relates to photocoagulation-induced changes in the choriocapillaris circulation.

METHODS

A theoretical model that simulates the blood flow in the choriocapillaris and choroidal neovascularization of the human eye was developed, based on histologically determined vascular geometry and experimentally measured blood pressure gradients. The choriocapillaris blood pressure and blood flow were examined before and after simulated photocoagulation of various Sattler layer vessels entering the choriocapillaris in the vicinity of the choroidal neovascularization. (The Sattler layer is the inner layer of medium-sized choroidal vessels that includes both arterioles and venules that supply the choriocapillaris.)

RESULTS

The theoretical model showed that both partial and complete occlusion of either Sattler arteriole or venous vessels in the vicinity of the capillary-like vessels connecting a choroidal neovascularization to the underlying choriocapillaris results in significant choroidal neovascularization blood flow reduction. These theoretical results are similar to clinically observed changes induced by laser photocoagulation of feeder vessels. (In this discussion, the term "feeder vessels" refers to those vessels in an indocyanine green angiogram image that appear to supply blood to a choroidal neovascularization; these vessels appear to be Sattler layer vessels, rather than the histologically demonstrated short, capillary-like vessels that form choriocapillaris-choroidal neovascularization communications.)

CONCLUSIONS

Reduction of choriocapillaris blood flow underlying a choroidal neovascularization may be sufficient to reduce the blood flow rate in the choroidal neovascularization and thereby reduce the associated retinal edema. The results also suggest that reduction of choriocapillaris blood flow may be the common hemodynamic event associated with the successful application of several currently practiced methods of choroidal neovascularization treatment, including feeder vessel photocoagulation, photodynamic therapy, transpupillary thermotherapy, and prophylactic drusen photocoagulation. Ultimately, this model may be useful in determining optimal placement of laser photocoagulation burns to achieve a desirable perturbation in choroidal blood flow distribution and thereby reduce choroidal neovascularization blood flow to the extent necessary to obliterate associated retinal edema.

Anatomical landmarks for femoral nerve block: a comparison of four needle insertion sites

The site for needle insertion in femoral nerve block varies significantly among various descriptions of the technique. To determine the site with the highest likelihood of needle-femoral nerve contact, femoral nerve block was simulated in a human cadaver model (17 femoral triangles from 9 adult cadavers). Four 20-gauge 50-mm-long styletted catheters were inserted at four frequently suggested insertion sites for femoral nerve block. At the levels of inguinal ligament and the inguinal crease, the catheters were inserted adjacent to the lateral border of the femoral artery and 2 cm lateral to the femoral artery. During anatomical dissection, we studied the number of catheter-nerve contacts for each of the four insertion sites, and relationships between the femoral nerve and other anatomical structures of relevance to femoral nerve block. Insertion of the needle at the level of the inguinal crease, next to the lateral border of the femoral artery resulted in the highest frequency of needle-femoral nerve contacts (71%). Of note, the femoral nerve was significantly wider (14.0 vs 9.8 mm) and closer to the fascia lata (6.8 vs 26.4 mm) at the inguinal crease than at the inguinal ligament level. We conclude that needle insertion at the inguinal crease level immediately adjacent to the femoral artery produced the highest rate of needle-femoral nerve contacts. The main factors influencing this result include the greater width of the femoral nerve and the more predictable femoral artery-femoral nerve relationship at the inguinal crease level, compared with the inguinal ligament level.

IMPLICATIONS

Insertion of a needle at the inguinal crease level and immediately adjacent to the lateral border of the femoral artery results in a high rate of needle-femoral nerve contact.

Human serum sensitivities of Trypanozoon isolates from naturally infected hosts in the Luangwa Valley, Zambia

Of 235 Trypanozoon stocks isolated from naturally infected hosts in northeastern Zambia and tested by the Blood Incubation Infectivity Test (BIIT), 176 came from man, 37 from wild-caught tsetse, 11 from wild animals and 11 from domestic livestock. Of those from man, 2 gave unexpected, human-serum-sensitive (HSS) reactions on first testing; all 15 stocks from tsetse in the northern area (Kampumbu) were strongly serum-resistant (HSR) while 22 other infections, from tsetse in the southern area (Kakumbi), gave 1 equivocal, 11 positive and 10 negative test responses. HSR Trypanozoon infections were found in a bushbuck, a warthog, in a giraffe (for the first time) and in a "sentinel" goat, used to monitor SS transmission in a small SS endemic village.

Evaluation of a phenylalanine-free product for treatment of phenylketonuria

Ten children with classic phenylketonuria (PKU) participated in a controlled study of a phenylalanine-free formula recently released in the United States (PKU-2). Control data were obtained in the clinic while the children were receiving their baseline formula. The children were given the study formula and returned to the clinic for follow-up after they had been receiving the new formula for 4, 8, and 12 months. Serum phenylalanine and tyrosine concentrations, other hematologic measurements, urine analysis, growth, electroencephalogram, and physical findings remained similar to baseline values throughout the study. Nutrient intakes were comparable with the exception of a decrease in several micronutrients relative to baseline levels. We found that PKU-2 is appropriate for children with PKU who are over 3 years of age and may prove beneficial for the overweight child with PKU.

Excited-state Quenching Phenomena in Weakly Ionised Nitrogen

A number of studies of the ionisation behaviour of molecular nitrogen have revealed the importance of N 2(A 3L ;;) metastable particles which are created by direct electron impact excitation or cascade processes. More recent studies using cleaner gas samples have indicated that the ionisation current may be affected by the presence of a second metastable particle. The possible identity of this second metastable particle and the sensitivity of the ionisation current to its presence have been investigated by observing the changes in the pre-breakdown ionisation current as a function of the purity of the N 2 gas samples. Both the spatial and temporal behaviour of the ionisation current were observed. Particular care was required in this study to ensure that stable electrode surface conditions were obtained and the procedures adopted are described in detail. The addition of CO and H2 to the N 2 samples at the parts per million level confirmed the dominant quenching action of CO. Further consideration of the spatial growth of ionisation has demonstrated that an ionisation mechanism involving both N2(A 3L ;;) and N2(a' 1 L;;-) particles provides a plausible explanation for the observations and should be further investigated.

Zinc status and growth of children undergoing treatment for phenylketonuria

Children with phenylketonuria (PKU) are treated with semi-synthetic diets restricted in phenylalanine. Low-phenylalanine or phenylalanine-free formulae provide the majority of protein and energy in the diet while phenylalanine requirements are met by low-protein natural foods. Because of the restriction of natural protein sources in this diet, the study assessed the zinc nutrition of 22 treated children with PKU (aged from 1 month to 8 1/2 years) and correlated linear growth with zinc status. The mean (+/- SE) plasma zinc concentration of the PKU population was 66.6 +/- 3.3 micrograms/dl. The mean (+/- SE) hair zinc concentration was 70.2 +/- 11.5 micrograms/g. The mean plasma and hair zinc concentrations of the PKU population were significantly different (p less than 0.05) when compared with mean (+/- SE) normal values of 84.2 +/- 2.9 micrograms/dl and 130.7 +/- 8.3 micrograms/g, respectively. The mean (+/- SD) dietary zinc intake of 10 PKU patients was 8.56 +/- 2.68 mg/day. No significant differences (p less than 0.123) were found when the mean zinc intake was compared with National Academy of Sciences Recommended Dietary Allowance for age of 10 mg/day. No significant correlations were found when plasma and hair zinc concentrations were plotted with height percentiles. Further studies are required to assess the effects of zinc supplementation and the bioavailability of zinc from low-phenylalanine diets.

Zinc and copper status of treated children with phenylketonuria

Children with phenylketonuria (PKU) are treated with semi-synthetic diets restricted in phenylalanine. Low or phenylalanine-free formulae provide the majority of protein and energy in the diet while phenylalanine requirements are met by low-protein natural foods. Because of the restriction of natural protein sources in this diet, the study assessed the zinc and copper nutriture of treated children with PKU and correlated linear growth with zinc status. The plasma zinc of the PKU population was 66.6 +/- 3.3 micrograms/dl (mean +/- SEM). The hair zinc was 70.2 +/- 11.5 micrograms/g (mean +/- SEM). The mean plasma and hair zinc of the PKU population were significantly different (p less than 0.05) when compared to normal values of 84.2 +/- 2.9 micrograms/dl and 130.7 +/- 8.3 micrograms/g (mean +/- SEM), respectively. The dietary zinc intake of 10 PKU patients was 8.56 +/- 2.68 mg/day (mean +/- SD). No significant differences (p less than 0.123) were found when the mean zinc intake was compared with recommended dietary allowances for age of 10 mg/day. No significant correlations were found when plasma and hair zinc were plotted with height percentiles. Plasma copper of the PKU subjects (87.6 +/- 6.6 micrograms/dl, mean +/- SEM) was significantly less than that of normal young children (121.5 +/- 3.1 micrograms/dl, mean +/- SEM) despite a copper intake a 1.45 +/- 0.35 mg/day (mean +/- SD).