Multiple comparisons of diversity indices invaded by Lantana camara / Análises múltiplas de índices de diversidade da invasiva Lantana camara

Abstract Current study assessed the impact of Lantana camara invasion on native plant diversity in Pothohar region of Pakistan. The approach used for study was random samplings and comparisons of diversity indices [number of species (S), abundance (N), species richness (R), evenness (Jꞌ), Shannon diversity index (Hꞌ) and Simpson index of dominance (λ)] with two categorical factors i.e., invaded and non-invaded (control). Control plots harboured by an average of 1.74 more species/10m2. The control category was diverse (Hꞌ=2.56) than invaded category (Hꞌ=1.56). The higher value of species richness in control plots shows heterogeneous nature of communities and vice versa in invaded plots. At multivariate scale, ordination (nMDS) and ANOSIM showed significant magnitude of differences between invaded and control plots at all sites. The decrease in studied diversity indices in invaded over control sites indicated that plant communities become less productive due to Lantana invasion.

Resumo O presente estudo avaliou o impacto da invasão de Lantana camara na diversidade de plantas nativas na região de Pothohar, no Paquistão. A abordagem utilizada para o estudo foram a amostragem aleatória e a comparação de índices de diversidade, como número de espécies (S), abundância (N), riqueza de espécies (R), equitabilidade (Jꞌ), índice de diversidade de Shannon (Hꞌ) e índice de dominância de Simpson (λ), com dois fatores categóricos, ou seja, invadidos e não invadidos (controle). As parcelas não invadidas tinham, em média, 1,74 espécie a mais / 10 m2 que parcelas invadidas. A categoria controle foi mais diversa (Hꞌ = 2,56) do que a categoria invadida (Hꞌ = 1,56). O maior valor da riqueza de espécies em parcelas de controle mostra a natureza heterogênea das comunidades, e vice-versa, em parcelas invadidas. Na escala multivariada, ordenação (nMDS) e ANOSIM mostraram magnitude significativa das diferenças entre as parcelas invadidas e controle em todos os locais. A diminuição nos índices de diversidade estudados em locais invadidos por controle indicou que as comunidades de plantas se tornam menos produtivas por causa da invasão de Lantana.

Multiple comparisons of diversity indices invaded by Lantana camara.

Current study assessed the impact of Lantana camara invasion on native plant diversity in Pothohar region of Pakistan. The approach used for study was random samplings and comparisons of diversity indices [number of species (S), abundance (N), species richness (R), evenness (Jꞌ), Shannon diversity index (Hꞌ) and Simpson index of dominance (λ)] with two categorical factors i.e., invaded and non-invaded (control). Control plots harboured by an average of 1.74 more species/10m2. The control category was diverse (Hꞌ=2.56) than invaded category (Hꞌ=1.56). The higher value of species richness in control plots shows heterogeneous nature of communities and vice versa in invaded plots. At multivariate scale, ordination (nMDS) and ANOSIM showed significant magnitude of differences between invaded and control plots at all sites. The decrease in studied diversity indices in invaded over control sites indicated that plant communities become less productive due to Lantana invasion.

Multiple comparisons of diversity indices invaded by Lantana camara

Abstract Current study assessed the impact of Lantana camara invasion on native plant diversity in Pothohar region of Pakistan. The approach used for study was random samplings and comparisons of diversity indices [number of species (S), abundance (N), species richness (R), evenness (J), Shannon diversity index (H) and Simpson index of dominance ()] with two categorical factors i.e., invaded and non-invaded (control). Control plots harboured by an average of 1.74 more species/10m2. The control category was diverse (H=2.56) than invaded category (H=1.56). The higher value of species richness in control plots shows heterogeneous nature of communities and vice versa in invaded plots. At multivariate scale, ordination (nMDS) and ANOSIM showed significant magnitude of differences between invaded and control plots at all sites. The decrease in studied diversity indices in invaded over control sites indicated that plant communities become less productive due to Lantana invasion.

Resumo O presente estudo avaliou o impacto da invasão de Lantana camara na diversidade de plantas nativas na região de Pothohar, no Paquistão. A abordagem utilizada para o estudo foram a amostragem aleatória e a comparação de índices de diversidade, como número de espécies (S), abundância (N), riqueza de espécies (R), equitabilidade (J), índice de diversidade de Shannon (H) e índice de dominância de Simpson (), com dois fatores categóricos, ou seja, invadidos e não invadidos (controle). As parcelas não invadidas tinham, em média, 1,74 espécie a mais / 10 m2 que parcelas invadidas. A categoria controle foi mais diversa (H = 2,56) do que a categoria invadida (H = 1,56). O maior valor da riqueza de espécies em parcelas de controle mostra a natureza heterogênea das comunidades, e vice-versa, em parcelas invadidas. Na escala multivariada, ordenação (nMDS) e ANOSIM mostraram magnitude significativa das diferenças entre as parcelas invadidas e controle em todos os locais. A diminuição nos índices de diversidade estudados em locais invadidos por controle indicou que as comunidades de plantas se tornam menos produtivas por causa da invasão de Lantana.

A high risk critical mitral valve stenosis with emergency management at Apollo Hospitals Dhaka.

Heart valve surgery in high-risk patients with severe jaundice, congestive hepatomegaly and renal impairment is associated with considerable morbidity and mortality. Without operation the consequences are invariably grave. A 35 years old gentleman with congestive cardiac failure was initially treated in coronary care unit (CCU). Mitral valve area was 0.5cm², pulmonary arterial systolic pressure (PASP) was 110mmHg, serum bilirubin was 20mg/dl, SGPT & SGOT were 1024iu/l and 1027iu/l respectively. Serum creatinine was 3.35mmol/l. Serum bilirubin gradually diminished to 3.1mg/dl after 12 days treatment in Coronary Care Unit but next day it increased to 3.6mg/dl. Mitral valve was replaced on an emergency basis. Echocardiogram on the 5th post operative day showed well functioning prosthetic mitral valve in situ. Serum bilirubin decreased to 2.2mg/dl, SGPT, SGOT and serum creatinine to 43iu/l, 40iu/l and 1.34mmol/l respectively. After 8 weeks of postoperative follow up his serum bilirubin decreased to 0.8mg/dl.

Insulin-like growth factor-1 gene polymorphism in rheumatoid arthritis patients.

OBJECTIVES: Insulin-like growth factor-1 (IGF-1) regulates several biological functions, and low plasma levels of IGF-1 are known to contribute towards the pathogenesis of rheumatoid arthritis (RA). In view of the biological significance of IGF-1, we investigated the association of RA with the polymorphism of a 192-bp allele which is cytosine-adenosine repeat located 1 kb upstream from the IGF-1 gene transcription site and is known to regulate serum IGF-1 levels. METHODS: Blood samples were collected from 52 healthy controls (HC) and 68 RA patients to measure the levels of IGF-1 and to isolate genomic DNA. Polymorphism of the IGF-1 gene was examined using polymerase chain reaction (PCR). Disease severity, duration, and activity were recorded for all RA patients. RESULTS: We observed that 97% of all the subjects who participated in this study showed the presence of a 192-bp allele of the IGF-1 gene. All healthy controls exhibited the presence of 192-bp wild-type allele. All non-carriers of the 192-bp allele were Arabs and had RA. Gender correlated significantly with allele frequencies as 14% of the male and only 2% of the female RA patients were non-carriers of 192-bp allele. Plasma IGF-1 levels were significantly lower (p < 0.01) in RA patients compared to HC, and all RA patients who were non-carriers of the 192-bp allele had a significantly high disease activity score. No correlation was found between the duration of RA and the presence or absence of this allele. CONCLUSIONS: This study suggests a possible association of the IGF-1 gene polymorphism with developing RA, particularly in males as non-carriers of the 192-bp allele.

Haptoglobin gene polymorphisms in sickle cell disease patients with different ßS-globin gene haplotypes.

OBJECTIVE: To investigate the prevalence of haptoglobin (Hp) gene alleles in Kuwaiti sickle cell disease (SCD) patients, who generally have a mild phenotype, and compare the pattern to Nigerian SCD patients whose SCD phenotype is more severe. SUBJECTS AND METHODS: Hp genotyping was carried out in a group of 82 and 54 SCD patients from Kuwait and Nigeria, respectively, and appropriate Hb AA controls. The Hp genotyping was done using a PCR technique followed by agarose gel electrophoresis. RESULTS: The frequency of the Hp-2 allele was 73.8% among Kuwaiti SCD patients, while the Hp-1 allele predominated among Nigerian patients (60.7%). However, the differences were not significant (p > 0.05) when the allele distributions were compared between Kuwaiti SCD and their AA counterparts or between Nigerian SCD and their AA controls. There was no association of Hp-2 allele with frequent vaso-occlusive crisis among the Kuwaiti SCD patients. CONCLUSION: The distribution of Hp alleles appears to follow ethnic and geographical trends. Their role in the pathophysiology of pain crisis is not clear.

Prevalence of angiotensin-converting enzyme gene insertion-deletion polymorphism in patients with primary knee osteoarthritis.

OBJECTIVE: Angiotensin converting enzyme (ACE) plays an important role in a number of inflammatory and immune related disorders. This study was undertaken to investigate an association between Angiotensin converting enzyme (ACE) gene insertion- deletion (I/D) polymorphism and primary knee osteoarthritis (OA) in Kuwait and to explore a correlation between clinical subgroups of OA and ACE I/D polymorphism genotypes. PATIENTS AND METHODS: The prevalence of ACE gene I/D polymorphism was determined in 115 patients with primary knee OA and 111 ethnically matched healthy controls by using polymerase chain reaction (PCR) of the genomic DNA. The association of ACE gene I/D polymorphism genotypes was also studied with age of disease onset, function and radiological grading. RESULTS: No significant difference was detected in the frequency of ACE gene I/D polymorphism genotypes and alleles between knee OA patients and the controls. The frequency of ACE gene polymorphism genotypes was also studied in subgroups on the basis of clinical parameters of age of onset of disease, function and radiological grading and no significant difference was detected between subgroups of OA patients and the controls. This is in sharp contrast to a previous report from Korea in which a significant association has been reported between ACE gene polymorphism and knee OA. CONCLUSION: This study did not find an association between ACE gene I/D polymorphism genotypes in Kuwaiti patients with primary knee osteoarthritis and the onset or severity of the disease, which is very different from Korean knee OA patients in which an association has been reported.

Angiotensin-converting enzyme gene polymorphism in Kuwaiti patients with systemic lupus erythematosus.

OBJECTIVE: To investigate the frequency of angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism genotypes in patients with systemic lupus erythematosus (SLE), and to study the correlation between I/D polymorphism of the ACE gene and the clinical manifestations of SLE, especially vascular involvement, lupus nephritis and disease severity. METHODS: The frequency of ACE gene I/D polymorphism genotypes was determined in 92 patients with SLE from Kuwait, and compared to that in 100 ethnically matched healthy controls using the polymerase chain reaction. RESULTS: The distribution of ACE I/D polymorphism and allele frequencies in SLE patients was not significantly different from controls. Further analyses of SLE patients showed that there was a significant association between DD genotype and Raynaud's phenomenon (p=0.008, odd ratio=5.4, 95% confidence interval: 1.6-18.6). However, there was no significant association between the ACE genotype and lupus nephritis or disease severity. CONCLUSION: No difference was found between the distribution of the ACE genotype in SLE patients and the general pop-ulation in Kuwait. However, the presence of the DD genotype may confer susceptibility to the development of vascular morbidity.

The prevalence of human leukocyte antigen (HLA) DR/DQ/DP alleles in Kuwaiti children with oligoarticular juvenile idiopathic arthritis.

We have determined the prevalence of human leukocyte antigen (HLA)-DR, DQ and DP alleles in Kuwaiti children with oligoarticular juvenile idiopathic arthritis (OA-JIA) and healthy controls using the PCR-SSP (sequence specific primers) method. The analysis took into account the presence of antinuclear antibodies and chronic anterior uveitis. DRB1*03 (RR 2.20, P<0.001), DRB1*08 (RR 5.280, P<0.026), DQA1*0501 (RR 1.930, P<0.001), DQB1*0304 (RR 7.920, P<0.002), DQB1*0501 (RR 3.080, P<0.007) and DPB1*0101 (RR 8.8, P<0.001) were the main HLA alleles associated with OA-JIA in Kuwaiti Arabs in this study. DRB1*03 was detected in 71% of children with positive ANA, and in 50% of children with anterior uveitis. DQA1 alleles *0501, *0103 and *0105 (P<0.001; 0.029 and 0.024 respectively) were found to be associated with OA-JIA. In contrast, DQA1*0301 and DQA1*0302 alleles appear to be protective in Kuwaiti children (RR 0.153, P<0.001 and RR 0.278, P<0.016 respectively). The DQB1 alleles *0304 and *0501 were associated with OA-JIA (P<0.002 and P<0.007 respectively). In the case of DPB1, only one allele (*0101) was associated with OA-JIA (P<0.001). Most Kuwaiti Arab patients with OA-JIA who carried a DQ or DP susceptibility allele also had an accompanying DRB1*03 or *8 allele.

Lack of an association between candidate gene loci and idiopathic generalized epilepsy in Kuwaiti Arab children.

Idiopathic generalized epilepsies (IGEs) are the most common types of epilepsy in childhood and adolescence. A variety of data suggest that IGEs have a predominant genetic etiology. Recently, a number of gene mutations have been found to be associated with various types of epilepsy in mainly the Caucasian populations. The objective of this study was to investigate the association of three different candidate genes with IGE in Kuwaiti Arab children. This study includes 123 Kuwaiti patients with a confirmed diagnosis of epilepsy. Most of the patients have had a diagnostic EEG with generalized spike-wave discharges (GSWs). All patients were evaluated by using a validated seizure questionnaire. The clinical type of epilepsy was determined by a trained neurologist/pediatrician. The study also include 100 controls, the control subjects were children which did not have any history of neurological disorders. Blood samples were collected from all patients and control subjects after taking informed consent. DNA was isolated and analyzed by molecular methods. A FokI polymorphism in neuronal nicotinic acetylcholine receptor alpha-4 subunit (CHRNA4) gene was detected by PCR-RFLP method. A missense mutation (Ser248Phe) in CHRNA4 gene was analyzed by PCR-RFLP using HpaII. A C121W mutation in sodium-channel beta-1 subunit (SCN1B) gene was screened by a PCR-RFLP method using HinPI. A 2-bp deletion in Cystatin B gene was detected by PCR-RFLP using XcmI. The incidence of three FokI polymorphism genotypes in Kuwaiti IGE patients was 1,1 (85%), 1,2 (14%) and 2,2 (1%) respectively. The missense mutation Ser248Phe of CHRNA4 gene was not detected at all in Kuwaiti IGE patients. The C387G transversion resulting in C121W change in third exon of the SCN1B gene was detected in 3/123 patients (2%). The patients carrying this mutation also exhibited febrile seizures. The incidence of 2 bp deletion in the cystatin B gene was found to be 4% (5/123 IGE patients). The data obtained from molecular analysis show a lack of association between three candidate genes and clinical expression of IGE in Kuwaiti Arab children. This is completely different from the findings reported from Caucasian populations of France, Australia and USA in which case a strong association has been reported between IGE and these genes.

HLA-DRB1 alleles in Hb SS patients with avascular necrosis of the femoral head.

Strong associations have been established between various HLA alleles and different complications of sickle cell disease (SCD). Recently, the HLA-DRB1*03 allele was shown to be associated with susceptibility to stroke while the HLA-DRB1*02 allele may be protective. While stroke and silent brain infarcts (SBI) are unusual in Kuwaiti children with SCD, avascular necrosis of the femoral head (AVNFH) is quite common. The modulatory association factors must still be elucidated. An investigation of HLA-DRB1 alleles was carried out in a group of 68 Kuwaiti SS patients, of age 7-44 years, of whom 20 (29.4%) had AVNFH, confirmed by magnetic resonance imaging. A group of 167 apparently healthy age- and sex-matched individuals served as controls. Comparison of the HLA alleles between the whole SS group and the controls showed a significant over-representation of DRB1*01 (P < 0.01) and DRB1*10 (P < 0.05) in the patient group. No significant differences in the allele frequencies in the SS patients with or without AVNFH were observed. It therefore appears that the HLA-DRB1 locus does not play a significant role in the pathogenesis of AVNFH Kuwaiti patients.

Pulmonary function studies in Kuwaiti children with sickle cell disease and elevated Hb F.

Conflicting ventilatory defects have been reported in children with sickle cell disease (SCD). In Kuwait, the disease is relatively mild with a low incidence of acute chest syndrome and other complications, presumably due to the Arab-Indian haplotype chromosomal background and elevated Hb F levels. There have been no previous studies of pulmonary function in patients with this haplotype. Pulmonary function test (PFT) was carried out on 28 steady state children with SCD (21 homozygous sickle cell (SS), seven S beta(o) thal) and two group of controls: 17 age- and sex-matched healthy children and 10 children with HbH disease. The charts of the SCD patients were reviewed for frequency of acute chest syndrome and vaso-occlusive crisis. The mean values of forced vital capacity (FVC) (83.2 +/- 11.9 vs. 91.2 +/- 11.7) and vital capacity (VC) (81.5 +/- 11.8 vs. 90.5 +/- 10.9) were significantly lower in the SS patients compared with healthy controls (p < 0.05). Similarly, these values were significantly lower than in those of the HbH group (p < 0.001 for VC and p < 0.01 for FVC). The mean forced expiratory volume in 1 s (FEV1) was lower in SS patients (86.4 +/- 11.5) compared with healthy controls (94.2 +/- 14.2), but the difference was not significant (p = 0.07). Also, the FEV1 was significantly lower in SS patients than in the HbH group (p < 0.001). There was no significant difference in the PFT parameters between SS patients with acute chest syndrome and those without. Although patients with frequent vaso-occlusive crisis had lower PFT parameters, the differences were not significant in comparison to those with infrequent crisis. This study revealed an early restrictive and obstructive pulmonary function pattern in steady state children with SCD. The finding also indicates that the changes of PFT parameters in SS patients could not be attributed to anaemia per se as patients with HbH who also have chronic anaemia did not show similar changes. This observation underscores the early occurrence of pulmonary involvement, even in patients with an otherwise relatively mild SCD.

Systemic lupus erythematosus in Kuwaiti children: organ system involvement and serological findings.

The course and severity of systemic lupus erythematosus (SLE) in children is generally similar to the adult form with potential serious organ system involvement, there are, however, factors that influence the prevalence and clinical behavior of the disease. Our objective was to analyse the organ system involvement and immunological findings in Kuwaiti children with SLE in relation to gender and age of onset and compare these findings to that in published reports. Organ system involvement and serologic profiles were analysed in 35 children with SLE. The major organ systems studied were: renal, hematological, cardiac, pulmonary, hepatic and the central nervous system. The prevalence of ANA, anti-dsDNA, anti-Sm, SSA, SSB and anti-cardiolipin antibodies were studied in addition to complement C3 and C4 levels. The results showed that a high percentage of children had hematological involvement (34%); thrombocytopenia (23%) and hemolytic anemia (20%). Renal involvement was proven by biopsy in only 10 children (29%). Neuropsychiatric manifestations were seen in five (14%) of patients. Males had a tendency for major organ involvement relative to females. All patients had positive ANA tests. All males had positive anti-dsDNA tests compared to 86% of female patients. The most significant finding in this study is the high frequency of hematological manifestations and the relatively low incidence of renal disease and neuropsychiatric abnormalities in Kuwaiti children with SLE.

Angiotensin-converting enzyme gene polymorphism and lipid profiles in Kuwaiti children with type 1 diabetes.

METHODS: We studied angiotensin-converting enzyme (ACE) gene polymorphism and lipid profiles in Kuwaiti children with uncomplicated type 1 diabetes. A total of 125 children with type 1 diabetes were matched in a case-control study on age and gender to 125 non-diabetic children as controls. Serum lipids (total cholesterol, TC; high-density lipoprotein cholesterol, HDL; low-density lipoprotein cholesterol, LDL-c; triglycerides, TG; apolipoprotein A1 and B, apo A1 and B; lipoprotein(a), Lp(a)); and glycated hemoglobin, HbA1c were evaluated according to ACE genotypes. RESULTS: Genotype distributions were found to be similar in cases [ACE insertion/insertion (II) 9.6%, ACE insertion/deletion (ID) 38.4%, ACE deletion/deletion (DD) 52.0%], and controls (II 8.8%, ID 43.2%, DD 48.0%), and were characterized by higher frequencies of DD, ID, and lower frequencies of II. Diabetic children with DD genotype showed significantly higher levels of TC (p < 0.01), HDL (p < 0.001), and apo A1 (p < 0.001) than controls. There was a higher proportion of diabetic children with family history of cardiovascular disease (CVD) in the DD genotype group (51.9%) than those with II genotype group (11.1%) (p < 0.001). Also, there was a significant increase in the frequency of diabetic children with Lp(a) > 30 mg/dL in children with a family history of CVD (p = 0.008). Lp(a) levels were correlated with HbA1c in the diabetic group (r = 0.239, p = 0.019), but when patients with poor glycemic control (HbA1c > 9%) were excluded, the significant correlation disappeared (r = 0.127, p = 0.381). After adjusting confounding between variables, the logistic regression analysis showed that the two significantly related variables with the rise in Lp(a) were increasing TC level and poor glycemic control. CONCLUSIONS: In children with type 1 diabetes, the role of ACE polymorphism as a probable contributor to CVD seems to be partially mediated through other factors such as poor glycemic control, TC, and Lp(a) level. A longitudinal study is recommended with a larger number of patients in each ACE genotype group in order to assess such associations.

Avascular necrosis of the femoral head in adult Kuwaiti sickle cell disease patients.

While sickle cell disease (SCD) is generally mild in most Kuwaitis, because of their elevated fetal Hb levels, avascular necrosis of the femoral head (AVNFH) appears to be a common complication. It was recently documented in 26.7% of Kuwaiti children with SCD. There have, however, been no previous studies of adult patients. This is a 1-year study of consecutive, steady-state SCD patients seen in the hematology clinic of Mubarak Al-Kabeer Hospital. The patients' charts were reviewed for frequency of hospitalizations, any documented complications and steady-state complete blood count (CBC). MRI was performed using T1- and T2-weighted FATSAT sequences in coronal and axial planes with 4-mm-thick slices on a 1.5-tesla GE super-conducting magnet. Thirty-five patients were studied, consisting of 25 SS and 10 Sbeta(0)Thal patients aged between 17 and 44, with a mean age of 26.7 +/- 9.3 years. Seventeen (48.6%) had varying degrees of AVNFH; among the 70 hips examined, 29 (41.1%) were affected. Of the 17 patients affected, 11 (64.7%) were SS, while 6 (35.3%) were Sbeta(0)Thal. There were 14 (82.4%) males and 3 (17.6%) females (chi(2) = 8.6, p < 0.01). The mean age of those affected, 27.5 +/- 10.7 years, was not significantly higher than that of the unaffected (26.3 +/- 8.0 years). Eleven (64.7%) of those affected had a history of frequent vaso-occlusive crisis. No significant differences could be demonstrated in the mean CBC and Hb F values of the two groups; coexistent alpha-thal trait was not a factor in the SS group. Male gender was the only significant predisposing factor identified. While more patients with frequent vaso-occlusive crises were affected, the difference was not significant. AVNFH is, indeed, quite common among Kuwaiti SCD patients and there is a need for early institution of preventive and therapeutic protocols.

Role of human leukocyte antigen DRB1*0307 and DRB1*0308 in susceptibility to juvenile rheumatoid arthritis.

OBJECTIVE: To study the prevalence of Human Leukocyte Antigen (HLA) DR alleles in children with juvenile rheumatoid arthritis (JRA). METHODS: DNA samples from 64 children with oligoarticular and seronegative polyarticular JRA and 64 controls of the same ethnic background were analyzed using PCR-sequence specific primers (PCR-SSP) method. Analysis took into account the onset subtype, the presence of antinuclear antibodies (ANA) and the presence of chronic anterior uveitis, a recognised serious complication of JRA. RESULTS: A high prevalence of DR3 alleles were detected in children with oligoarticular JRA compared to controls (p < 0.05). DR3 alleles were the commonest also in patients with positive ANA as well as those with chronic anterior uveitis. The interesting finding in this study is the absence of two DR3 alleles, namely DRB1*0307 and DRB1 *0308 in the control group while present in significant proportion in children with JRA. DRB1*0307 was present in 16% of children with oligoarticular subtype and 15% of those with polyarticular JRA. DRB1*0308 was only detected in children with oligoarticular JRA, none of the children with polyarticular JRA or the controls had this allele. CONCLUSION: These findings support earlier observations linking these two DR3 alleles, namely 0307 and 0308, to the genetic susceptibility to JRA.

Silent brain infarcts in adult Kuwaiti sickle cell disease patients.

Although overt stroke is a common complication of sickle cell disease (SCD), its incidence is very low in Kuwaiti patients. On the other hand, the prevalence of silent brain infarcts, which is reported to be about 17-20% in American patients, has not been documented in adult Kuwaiti patients. This is a 1-year study of consecutive, asymptomatic SCD patients seen in the hematology clinic of Mubarak Al-Kabeer Hospital. Patients with a past history of seizure or any other neurological abnormality were excluded. The patients' charts were reviewed for frequency of hospitalizations, any documented complications, and steady-state CBC. MRI was done with a 1.5-Tesla unit with super-conducting magnet. T1- and T2-weighted sagittal and axial sections and proton-density axial images were obtained in 5-mm-thick sections. Thirty-five patients were studied, made up of 25 SS and 10 Sbeta(0)Thal, aged between 17 and 44 years, with a mean age of 26.9 +/- 9.3 years. MRI findings consistent with infarcts were found in 7 (20.0%) patients-6 SS and 1 Sbeta(0)thal-with a mean age of 31.8 +/- 8.2 years, which was significantly higher (P < 0.05) than the mean age of the unaffected group (25.1 - 9.0 years). There were also no differences in the mean Hb, Hb F, or any other hematological parameter in the two groups. Among the affected 6 SS, 2 had co-existent alpha-thal trait. It is interesting that, while silent infarcts are prevalent in young American patients, it is in the older age group that they occur in Kuwaiti patients. Further studies are needed to investigate the factors modulating this heterogeneity.

Angiotensin-converting enzyme gene insertion/deletion polymorphism in Kuwaiti children with retinopathy of prematurity.

Retinopathy of prematurity (ROP) is a disease characterized by neovascularization which occurs in infants with short gestational age and low birth weight and can lead to retinal detachment and blindness. In a proportion of ROP cases, the disease progresses to advanced stages despite rigorous intervention. The genotypes for angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism were determined in 181 premature Kuwaiti infants using a polymerase chain reaction (PCR) method. The incidence of different I/D genotypes was compared in ROP cases (n = 74) and non-ROP controls (n = 107) and within 2 subgroups of ROP patients: (1) in which ROP regressed spontaneously (stages 1-3, n = 53), and (2) in which ROP progressed to advanced stages (stages 4 and 5, n = 21). When the ROP cases were considered collectively as one group, the incidence of the DD genotype was almost identical to that of non-ROP controls. The incidence of heterozygous ID genotype was higher in non-ROP controls. The incidence of the II genotype was higher in ROP cases compared to non-ROP controls (p < 0.01). In contrast to this, when ROP cases were divided in 2 subgroups the incidence of the DD genotype was significantly higher in advanced stage ROP cases compared to spontaneously regressing ROP cases (p < 0.04). The incidences of ID and II genotypes were not significantly different amongst the 2 subgroups of ROP patients.

A C597-->A polymorphism in the Norrie disease gene is associated with advanced retinopathy of prematurity in premature Kuwaiti infants.

Retinopathy of prematurity (ROP) is a retinal vascular disease which occurs in infants with a short gestational age and low birth weight and may lead to retinal detachment and blindness. In some premature infants, ROP progresses to advanced stages despite rigorous intervention, but in the majority, it spontaneously regresses before the threshold stage. Genetic factors, e.g. mutations in the Norrie disease (ND) gene, have been implicated in determining the progression of ROP to advanced stages. We have identified a novel C597A polymorphism of the ND gene; we screened this and another mutation in the ND gene, C110G, in 210 premature Kuwaiti infants using PCR-RFLP, DNA sequence analysis and DNA enzyme immunoassay hybridization to investigate their association with advanced-stage ROP. In this cohort of premature Kuwaiti newborns, 115 of 210 babies had no eye problems and served as controls, while 95 were found to have ROP. In 71 of the 95 ROP cases, the disease spontaneously regressed at or before stage 3, while in 24 of 95 ROP cases, the disease progressed to advanced stages 4 or 5. The incidence of the AA genotype of the C597A polymorphism was considerably higher in advanced-stage ROP cases (83.3%) compared to spontaneously regressing ROP cases (0%) and the normal controls (10.4%) (p < 0.0001). For the other genotypes, no significant difference was detected between the controls and ROP cases. In the case of the C110G mutation in the ND gene, no significant differences were detected between the controls and ROP cases, and the majority of subjects had a CC genotype in all three groups.