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K M Hassanein

Publications and source records attributed to K M Hassanein.

At least 19 recordsLinked to original sources
PubMed2006

Quasi-empirical Bayes methodology for improving meta-analysis.

This article addresses the problem of heterogeneity among various studies to be combined in a meta-analysis. We adopt quasi-empirical Bayes methodology to predict the odds ratios for each study. As a result, the predicted odds ratios are pulled toward the estimated common odds ratio of the various studies under consideration. With strong heterogeneity among the studies, we jointly consider the display of the 95% CIs of the ORs and a Dixon's test (1950) for "outliers" to exclude the "extreme" estimated ORs. We demonstrate the effectiveness of our methodology based on the data analyzed by Thompson and Pocock (1987) demonstrating the power of the new approach to meta-analysis to find statistical agreement in what looks like great disagreement via a chi-squared test. We believe our technique (i.e., minimum mean-square sense) will go a long way toward increasing the trustworthiness of meta-analysis.

Bayes Theorem↗
PubMed2005

Association analysis of tissue inhibitor of metalloproteinase2 gene polymorphisms with COPD in Egyptians.

Proteinase/antiproteinase imbalance is recognized to play an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD). A relative increase in the activities of matrix metalloproteinases might be caused by mutations of tissue inhibitor of metalloproteinase2 (TIMP2). Recently, two polymorphisms of the TIMP2 gene, +853 G/A and -418 G/C (+551 and -720 from the translation initiation site), have been shown to be associated with the development of COPD in the Japanese population. In this study, a case-control association analysis for these polymorphisms was conducted in the Egyptian population using 106 COPD patients and 72 healthy controls. The genotype frequency of +853 G/A was significantly different between the patient and the control groups (P = 0.029), although no significant difference was detected in the allele frequency between the two groups. These results suggest that the +853 G/A polymorphism of the TIMP2 gene might be associated with COPD across ethnicities. In contrast, neither the distributions of genotype nor allele frequencies of -418 G/C were significantly different between the two groups, raising the possibility that a combination of different genetic factors contributes to the development of COPD in different ethnic groups.

Case-Control Studies↗
PubMed1999

Phototherapeutic keratectomy for recurrent erosion syndrome in anterior basement membrane dystrophy.

PURPOSE: To determine the outcome of patients who received phototherapeutic keratectomy (PTK) for recurrent erosion syndrome due to anterior basement membrane dystrophy (ABMD). DESIGN: A retrospective, noncomparative case series. PARTICIPANTS: Forty-eight eyes of 43 consecutive patients who underwent PTK for recurrent erosions occurring in ABMD at the Hunkeler Eye Center from 1991 to April 1995. All patients had previously failed at least one method of medical or surgical treatment for recurrent erosions and had slit-lamp findings of ABMD on initial evaluation. INTERVENTION: The eyes each underwent manual superficial keratectomy and PTK with the Summit Omnimed excimer laser. MAIN OUTCOME MEASURES: Data were analyzed by a retrospective chart review for 1, 3, 6, and 12 months for the 36 eyes with at least 12 months of follow-up data available. They were analyzed for preoperative and postoperative visual acuity, change in spherical equivalent, recurrence rate, and patient satisfaction. RESULTS: The preoperative mean visual acuity was not statistically significantly different at 1 month after PTK. Statistically significant improvement in mean visual acuity was present at 3, 6, and 12 months. Recurrence of symptoms of recurrent erosion was present in 5 (13.8%) of 36 eyes during the 12-month follow-up period, which was managed with repeat PTK over the area of the cornea initially treated with PTK; 1 of 5 required a third PTK treatment. All recurrences presented within 6 months of PTK or repeat PTK. The mean dioptric change in spherical equivalent was not statistically significant. Patient satisfaction levels after PTK for recurrent erosions in ABMD were assessed in 21 (58%) of 36 patients on a scale of 0 to 5 (5 = most satisfied); the mean response was 4.14 of 5. CONCLUSIONS: Phototherapeutic keratectomy is an effective treatment for recurrent erosions occurring in the setting of ABMD, is well tolerated, and may improve visual acuity. The rate of recurrence of erosions in ABMD treated with PTK is low during a 12-month follow-up period.

Anterior Chamber↗
PubMed1999

Very long survival in pediatric cancer between 1944 and 1993.

OBJECTIVE: To identify factors associated with very long survival among all cancer cases diagnosed at age 19 years or younger registered by the Cancer Data Service at the University of Kansas Medical Center in Kansas City, Kansas, U.S.A. in the 40-year period between 1944 and 1983, with follow-up to 1993. METHODS: There were 2720 pediatric patients with 2750 cancers who were studied. Forty-four types of cancer were grouped into 11 diagnostic categories. Diagnosis years spanned four eras: 1944-1953, 1954-1963, 1964-1973, and 1974-1983. Cases were compared using specific characteristics and were divided into short-term and long-term survivors with the division generously set at seven years. The proportions of the long-term survivors were compared by specific characteristics. RESULTS: Among the diagnostic categories, leukemias were the most common (29.8%), followed by CNS tumors (15.2%), and Hodgkin's disease (9.0%). Male to female ratio was 4:3; average age at diagnosis was 8.83 +/- 6.08 years. Long-term survivors totaled 1148 (41.7%). Prognosis was better in cases diagnosed in earlier stages and in later eras. Proportion of long-term survivors increased from 18.7% in era I to 52.6% in era IV. Improvement of survival was statistically significant in most diagnostic categories. CONCLUSIONS: This study shows continuing improvement of survival during four consecutive eras for childhood and adolescent cancer. Early diagnosis was associated with better survival. Unstaged cases decreased over time reflecting progress in diagnostic techniques. Many patients died before seven years after diagnosis. Those who survived more than seven years had excellent survival. Pediatricians can expect to participate in the care of these patients long after the original dianosis and treatment.

Child↗
PubMed1997

A simulation of hand impairments: effects on upper extremity function and implications toward medical impairment rating and disability determination.

OBJECTIVES: To determine whether simulation of significant impairment of the hand will have a predictable impact on degree of functional loss at the wrist and hand. DESIGN: Single subject repeat measures using before-after trial comparisons and healthy volunteer subjects. SETTING: Occupational therapy section of a large academic medical center. OTHER PARTICIPANTS: Twenty adult volunteer student subjects from an occupational therapy education (OTE) department were included. All were between ages 18 and 43 years, right hand dominant, and in excellent general health. There were 19 women and 1 man, reflecting gender distribution of the OTE student body. INTERVENTION: A simulated fusion of the carpometacarpal (CMC) joint of the thumb was achieved by immobilization in an individually fabricated splint designed to maximally restrict motion at the first CMC joint. Impairment ratings (baseline vs splinted) according to the AMA Guides were obtained by Greenleaf testing, and upper extremity function was quantitatively assessed before and after splinting. MAIN OUTCOME MEASURES: Measures of upper extremity function included grip and pinch strength, wrist torque, and speed of performance on the Valpar Small Tools test, Jebsen Hand Function test, and an exploratory measure, the Functional Life Activity Test (FLAT). RESULTS: Significant impairments were achieved for all subjects after splinting and according to Greenleaf testing. Splinting resulted in significant reductions in grip and pinch strength, wrist torque, and significant slowing of performance on the Valpar, Jebsen, and FLAT tests. Regressions of degree of impairment on degree of functional loss after splinting, and according to each of the above measures, were not significant. CONCLUSIONS: Impairment of the hand was simulated to a mild-to-moderate degree as measured according to the AMA Guides. This imposed significant reductions in motion at key joints of the wrist and hand as well as significant reductions in grip and pinch strength and wrist torque. A corresponding and significant slowing of performance on a variety of measures of upper extremity function of an industrial and nonindustrial nature was also seen. However, and for the first time, correlation and regression reveals that it is not possible to predict degree of functional loss attributable to degree of impairment for the hand. It thus appears that, for mild-to-moderate clinical impairments, the associated impairment rating is a poor estimator of functional loss at the hand and should be used cautiously, if at all, as a criterion for disability determination.

Activities of Daily Living↗
PubMed1996

Slit-lamp needle revision of failed filtering blebs using mitomycin C.

PURPOSE: The purpose of the study is to determine the efficacy and safety of Mitomycin C (MMC) augmented slit-lamp needle revision of failed filtration surgery. METHODS: The authors retrospectively reviewed the charts of 62 patients (62 eyes) (age, 72 +/- 15 years) with failed filtration surgery who underwent needle revision using MMC. A mixture of 0.01 ml of MMC (0.4 mg/ml) and 0.02 ml of bupivacaine with epinephrine was injected subconjunctivally. Twenty to 30 minutes later, a 30-gauge needle was used to perforate the area of subconjunctival fibrosis and re-establish flow. RESULTS: Overall, 118 needing procedures (mean, 1.9 +/- 1.4 revisions per eye; range, 1-7) were performed on 62 eyes (mean follow-up, 9.9 +/- 3.7 months; range, 4.5-20.1 months). Thirty-six patients (58.1%) were needled once and 26 patients (41.9%) underwent more than 1 needling procedure. Intraocular pressure decreased from 24.1 +/- 6.4 mmHg (range, 18-44) before surgery to 11.5 +/- 4.8 mmHg (range, 1-26) at last follow-up (P = 5.51 x 10(-21)). Antiglaucoma medications decreased from 1.6 +/- 1.0 to 0.3 +/- 0.6 (P = 3.8 x 10(-14)). Successful single-needling procedure was highly correlated with race (white) and past conventional glaucoma filtration surgery of more than 4 years. Complications included serous choroidal detachment (10 eyes), suprachoroidal hemorrhage (1 eye), bleb leak (5 eyes), iris blocking sclerostomy (2 eyes), hyphema (2 eyes), corneal abrasion (2 eyes), and hypotony (1 eye). CONCLUSION: Mitomycin needle revision appears to be an extremely effective way to revive failed filtration surgery. The incidence of complications compares favorably to trabeculectomy with MMC.

Adult↗
PubMed1995

Relation of visual symptoms to topographic ablation zone decentration after excimer laser photorefractive keratectomy.

BACKGROUND: The authors used computer-assisted videokeratoscopy to analyze the relation of photorefractive keratectomy ablation zone decentration to subjective patient assessments of disturbing visual symptoms. METHODS: Ablation zone decentration was measured 1 month postoperatively. The study population was divided into two groups: group 1, patients whose ablation zone decentrations were less than 0.50 mm; group 2, patients whose ablation zone decentrations were greater than 0.50 mm. Visual symptoms including glare, rings or halos around lights and problems with night driving were scored preoperatively and 6 months postoperatively. The Hotelling T-square and chi-square tests were used. RESULTS: The mean decentration from the center of the ablation zone to the pupillary center was 0.30 mm and 190 degrees for group 1 compared with 0.66 mm and 198 degrees for group 2. The Hotelling T-square test showed a significant statistical preoperative/postoperative difference in group 1 (P < 0.03) for the halo symptom category. No other symptom category showed a significant statistical difference in either group for the mean scores. The Hotelling T-square test did not show a statistically significant difference between the two groups preoperatively to postoperatively regarding the mean scores of the individual patient differences for the three symptoms. The only significant statistical difference for the individual patient ratings preoperatively to postoperatively was for the halo symptom category (chi-square = 7.756; P < 0.03). CONCLUSIONS: Multivariate analysis did not show a significant statistical difference preoperatively between the two groups or postoperatively except for group 1 with regard to the halo symptom category. It appears from this study that ablation zone decentrations less than 0.89 mm from the pupillary center do not necessarily produce unwanted visual symptoms 6 months postoperatively.

Cornea↗
PubMed1995

Transmission of Toxoplasma gondii in Panama City, Panama: a five-year prospective cohort study of children, cats, rodents, birds, and soil.

A cohort of more than 500 children from Panama City, Panama was studied prospectively over five years for acquisition of antibody to Toxoplasma gondii. The direct agglutination test showed that 72 of 571 children seroconverted between one and six years of age, for a cumulative incidence of 12.6%. Children were examined by pediatricians quarterly, and illnesses that had occurred in the interval and their activities were noted on questionnaires. Thirty-eight variables were examined for their role as risk factors for seroconversion. There was a higher correlation between children's seroconversion and contact with dogs than with cats. Combinations of significant predictors without dogs explained only 67% of the seroconversions, but the same factors with dogs explained 90%. On the other hand, ingestion of raw or rare meat or eggs appeared to play no role in transmission. Cats were examined and 110 (45.6%) of 241 had Toxoplasma antibody on the first bleeding. Only two (0.5%) of 383 cat fecal specimens, when tested in mice, resulted in seroconversion. Ten (1.1%) of 924 soil samples resulted in seroconversion in mice that had been injected. Antibody to Toxoplasma was found in 52 (23.3%) of 226 rats (Rattus norvegicus) and two (0.035%) of 571 mice (Mus musculus). Two hundred sixteen birds of 16 different species were bled. Antibody to Toxoplasma was found in 13.4% of these birds, mostly in grackles, blue-gray tanagers, and doves. The rate of isolation of Toxoplasma was low: one of 23 in rats and three of 201 in birds. High relative risks (RRs) of transmission to children were predicted by contact histories with nursing dogs (RR = 5.8), weaned dogs (RR = 4.7), many flies (RR = 3.6), 6-12-month-old dogs (RR = 3.4), weaned cats (RR = 3.0), 6-12-month-old cats (RR = 2.7), nursing cats (RR = 2.5), much garbage (RR = 2.4), and many roaches (RR = 2.2). The high statistical correlation of dog contact with seroconversion in children suggests the possibility that dogs, by eating and rolling in cat feces, are instrumental in mechanically transmitting Toxoplasma infection. In addition, flies, and to a lesser extent, cockroaches, may have practically important roles in transmission.

Animals↗
PubMed1994

Further studies on the electrodiagnosis of diabetic peripheral polyneuropathy using discriminant function analysis.

Discriminant function analysis can be useful when applied to multiple nerve conduction parameters for diabetic and nondiabetic subjects to reveal the essential dimension along which key neuropathic differences occur between these groups. In this study, 19 electrophysiologic parameters were used in a stepwise discriminant function analysis to reveal a highly significant dimension of intergroup differences between 67 diabetic and 75 normal adult Japanese-American males. The classification functions thereby derived are more sensitive and specific than those reported previously for this population. Furthermore, when 72 additional subjects with impaired glucose tolerance were examined, they showed considerable overlap with the normal and separation from the diabetic groups, respectively. Their intermediate position between normal and diabetics in the key discriminant dimension indicates that essential neuropathic change is, at most, incipient in this latter group.

Cross-Sectional Studies↗
PubMed1993

Comparison of rapid versus slow tissue expansion on skin-flap viability.

The effect of rapid versus slow tissue expansion on random-pattern skin-flap survival lengths was evaluated in two groups of pigs. Each group (group 1--slow; group 2--rapid) was further evaluated for the effect that delay (A), delay plus expansion (B), expansion only (C), and acute flap elevation (D) had on flap length viability. Intergroup and intragroup comparisons were made. In the slowly expanded group, significantly greater flap length viabilities were demonstrated in the slow expansion flaps as compared with the delay plus expander flaps and the delayed flaps, respectively. In the rapidly expanded group, the flap length viabilities of flaps C, B, and A were statistically equal. However, the flap length viability of the rapidly expanded flaps was statistically equal to that of the slowly expanded flaps (C1 = C2). The effect tissue expansion has on improving flap length viability as compared with the delay phenomenon may be related to the combination of a delay effect plus increased nutrient flow density that slow expansion produces. This combined metabolic enhancement is preserved with rapid tissue expansion.

Animals↗
PubMed1993

The effect of sulfinpyrazone on treadmill exercise-induced angina pectoris.

Suspecting that platelet thromboemboli could play a role in the pathogenesis of myocardial ischemia, we have done a random-order, double-blind, crossover study of the effect of the platelet-active drug sulfinpyrazone on treadmill exercise-induced angina pectoris in 30 men with coronary artery disease. The mean duration of exercise before onset of angina was 43 s longer after taking sulfinpyrazone than before and 11 s shorter after taking placebo than before. Analysis of variance for crossover design showed that the mean difference between the values obtained before and after sulfinpyrazone was significantly different (p < 0.01) from the mean difference between the values before and after placebo. Sulfinpyrazone had no effect on the mean heart rate-blood pressure product at onset of angina, change in ST segment during exercise, or preexercise platelet aggregate ratio and bleeding time. Exercise until angina occurred did not affect the platelet aggregate ratio.

Angina Pectoris↗
PubMed1989

Antiidiotypic antibodies against anti-DNA antibodies in sera of families of lupus patients.

We searched for antiidiotypes directed against anti-DNA in sera of healthy family members of lupus patients. Controls were healthy individuals without a personal or family history of lupus. No significant differences were noted between the family members' and the control group's sera with respect to binding to DNA or to non-anti-DNA F(ab')2 fragments. Family members' sera had higher binding to anti-DNA F(ab')2 and to normal IgG F(ab')2 fragments (P less than 0.01). Sera of the family members had significantly higher binding to anti-DNA F(ab')2 than to normal IgG F(ab')2 fragments (P less than 0.0036). Inhibition experiments have shown that the antiidiotype is directed against the framework determinants and not against the antigen binding sites of the idiotype. The antiidiotypic antibodies were directed against cross-reactive anti-DNA idiotypes and were not restricted to the idiotypes of the lupus proband. Age, sex, and blood relationship to the lupus patient did not influence the presence of antiidiotypes in the family members. The possible role of environmental factors in the induction of antiidiotypes and the role of the latter in regulating anti-DNA antibodies are discussed.

Adult↗
PubMed1988

Total lymphoid irradiation retards evolution of articular erosions in collagen induced arthritis.

Collagen induced arthritis was elicited in rats and monitored with serial magnification radiographs and serologic studies. Total lymphoid irradiation (TLI), 1050 rad in 3 fractions, was given at 1 of 2 days after primary immunization. Erosive arthritis and periostitis evolved more slowly in rats irradiated on Day 9 compared to nonirradiated control animals; in contrast, rats irradiated on Day 21 showed no significant differences. At Day 114 neither group receiving TLI differed from nonirradiated controls. Additional groups of rats were irradiated at varying times relative to collagen immunization. On Day 18 the mean IgM and IgG anticollagen antibody responses were transiently decreased in animals receiving TLI by Day 9, with no differences by Day 36.

Animals↗
PubMed1987

Midsagittal magnetic resonance imaging of autism.

Since recent reports suggest structural brain abnormalities in autistic patients, we analysed magnetic resonance imaging (MRI) scans of autistic children. Planimetric measurements were done on midsagittal MRI scans, produced with a 0.5 T superconducting magnet. Scans of 13 'high-level' autistic subjects were compared with 35 control MRI scans, read as anatomically normal by a neuroradiologist. Corpus callosal, fourth ventricular, cerebellar, cerebral, and cranial areas were measured. The fourth ventricle was found to be significantly larger in the autistic group. No other areas in the midsagittal scans differed statistically between groups. Results suggest that structures defining the fourth ventricle are anatomically altered in autistic patients.

Adolescent↗
PubMed1987

Anti-idiotypic antibody against anti-DNA in sera of laboratory personnel exposed to lupus sera or nucleic acids.

We tested for anti-DNA, anti-idiotypic, antinuclear, and lymphocytotoxic antibodies in the sera of three groups of normals: volunteers never exposed to lupus sera or nucleic acids (group I), research personnel handling nucleic acids (group II), and laboratory personnel handling lupus sera (group III). There was no significant differences among the groups with respect to levels of either single stranded or double stranded anti-DNA. Group I showed no significant differences in binding to F(ab')2 fragments of lupus anti-DNA, lupus non-anti-DNA or normal IgG. Compared to group I, groups II and III bound significantly higher to anti-DNA F(ab')2 fragments compared to non-anti-DNA F(ab')2 or normal F(ab')2 fragments. Sera from the three groups were negative for antibodies and all but one individual from group III had normal antinuclear antibody titres. These results indicate that sera of normals exposed to lupus sera or to nucleic acids contain an anti-idiotype directed against anti-DNA antibody. The possible role of these anti-idiotypes in regulating the anti-DNA antibody is discussed.

Antibodies, Anti-Idiotypic↗
PubMed1986

Starr-Edwards aortic prosthesis: a 20-year retrospective study.

Over the years the Starr Edwards prosthesis has demonstrated a high durability and improved survival in patients with severe aortic stenosis or insufficiency. While the ideal valve prosthesis is not yet available, the Starr-Edwards valve in most instances demonstrates an adequate hemodynamic performance, does not degenerate throughout the human life span, is biocompatible, and is inserted reliably without requiring unique technical dexterity. Despite occasional valve-related complications with early models, beneficial effects of valve replacement are clearly seen in patients with a reversible myocardial dysfunction, a lower level New York Heart Association functional class (II to III), and who survive the early postoperative period and the first year. Long-term complications seen with the Starr-Edwards valve are primarily thromboembolism, endocarditis, hemolysis, and anticoagulation related complications. Despite good operative results, the major cause of deaths in these patients remains cardiac.

Adult↗