Perinatal outcome in prenatally diagnosed cardiac rhabdomyoma case series

OBJECTIVE

This study aims to determine the characteristics and outcome of prenatally diagnosed cardiac rhabdomyomas.

STUDY DESIGN

This retrospective descriptive study includes cases referred to our university hospital. We studied sonographic characteristics of rhabdomyoma along with the neonatal outcome.

RESULTS

Eight cases were included, with a mean gestational age at diagnosis at 31 weeks of gestation and five patients diagnosed after 32 weeks. We noted a male gender in 75%, multiple rhabdomyoma in 50%, mostly situated in the interventricular septum (41%) and valvular regurgitation in 25%. Most patients delivered at term, including five cesareans (62.5%). Six babies survived (75%); three of them were later diagnosed with tuberous sclerosis (50%).

CONCLUSION

Cardiac rhabdomyoma have variable ultrasound features. The usual favorable outcome can however be complicated by neonatal death (12%), valvular regurgitation and cerebral tuber.

Perspectives of Dental Practitioners Regarding Their Readiness for Medical Emergencies: A Study in Saudi Arabia

Background:

Training dental practitioners on emergency preparedness and response is essential for the successful management of medical emergencies.

Objectives:

To assess the perceptions of dental practitioners in Saudi Arabia about their readiness to manage medical emergencies in the dental practices.

Methods:

This cross-sectional survey was conducted among dental practitioners working in 52 dental centers in Saudi Arabia. Questionnaires mainly gathered data on the measures taken by dental practitioners to prevent medical emergencies, BLS certification, availability of essential drugs and equipment, and perceptions of dental practitioners regarding the adequacy of their training for medical emergencies.

Results:

Of the total 270 participants, the majority reported that they take medical history (94%), perform visual inspection (90%), consult with patients’ physician when needed (89%), and modify treatment plan as necessary (94%). However, only 19% of them routinely take baseline vital signs for their patients and 52.6% have valid BLS certification. Only 29.6% and 16.3% of dental practitioners have reported that they have all essential drugs and equipment, respectively.

Conclusion:

The preventive measures for medical emergency appears to be deficient because most dental practitioners are not routinely taking baseline vital signs for their patients. This important issue is combined with shortage of BLS certification among dental practitioners and inadequate availability of all medical emergency drugs and equipment in dental practices.

Absence of human papillomavirus in oral cavity squamous cell carcinomas among Saudi patients

This study aimed to examine the possible association of human papillomavirus (HPV) with oral cavity squamous cell carcinomas (OCSCCs) in Saudi Arabia. Forty-five paraffin-embedded tumor blocks that represent different subsets of OCSCCs between 2010 and 2014 were retrieved and histologically evaluated. The presence of high-risk HPV (16, 18, 31, and 33) was assessed by p16-immunohistochemistry followed by DNA detection using in situ hybridization technique. Twenty-four patients were male with the mean age of 59.3 years, and 21 patients were female with the mean age of 61.2 years. Forty-one cases were positive for p16 immunostaining, and the remaining four cases were negative. However, none of the 45 cases showed DNA-expression for any HPV subtypes (16, 18, 31, and 33). High-risk HPV appears not to be involved in the etiology of OCSCCs in older Saudi patients, but further studies with cross section of a younger age group are still required.

Mutations in ERGIC1 cause Arthrogryposis multiplex congenita, neuropathic type

Arthrogryposis multiplex congenita (AMC) is heterogeneous group of disorders characterized by non-progressive joint contractures from birth that involve more than 1 part of the body. There are various etiologies for AMC including genetic and environmental depends on the specific type, however, for most types, the cause is not fully understood. We previously reported large Israeli Arab kindred consisting of 16 patients affected with AMC neuropathic type, and mapped the locus to a 5.5 cM interval on chromosome 5qter. Using whole exome sequencing, we have now identified homozygous pathogenic variant in the ERGIC1 gene within the previously defined linked region. ERGIC1 encodes a cycling membrane protein which has a possible role in transport between endoplasmic reticulum and Golgi. We further show that this mutation was absent in more than 200 samples of healthy unrelated individuals of the Israeli Arab population. Thus, our findings expand the spectrum of hereditary AMC and suggest that abnormalities in protein trafficking may underlie AMC-related disorders.

A novel mutation in the GAN gene causes an intermediate form of giant axonal neuropathy in an Arab-Israeli family

Giant axonal neuropathy is a severe autosomal recessive neurodegenerative disorder of childhood that affects both the peripheral and central nervous systems. It is caused by mutations in the GAN gene linked to chromosome 16q24.1 At least 45 distinct disease-causing mutations have been identified throughout the gene in families of various ethnic origins, with different symptomatologies and different clinical courses. To date, no characteristic mutation or phenotype-genotype correlation has been established. We describe a novel missense mutation in four siblings born to consanguineous parents of Arab original with clinical and molecular features compatible with giant axonal neuropathy. The phenotype was characterized by a predominant motor and sensory peripheral neuropathies and severe skeletal deformities.

Oral cancer prevention and early detection: knowledge and practice among Saudi Arabian healthcare practitioners

PURPOSE

Despite the crucial role that healthcare practitioners (HCPs) have in preventing and detecting oral cancer (OC), studies suggest that dentists and physicians do not adequately detect early stage OC which is attributed to their attitude and knowledge. This Saudi Arabian study aims to assess HCP's knowledge and practice vis-à-vis OC's risk factors and patient evaluation.

DESIGN/METHODOLOGY/APPROACH

A questionnaire was distributed to HCPs in six different Saudi Arabian settings. A total of 16 items representing a mixture of OC's risk and non-risk factors were measured.

FINDINGS

The study found that only 20.9 percent of HCPs could distinguish 11 items or more correctly. Additionally, when HCPs obtained the patient's medical history, no more than 32.3 percent routinely assessed ten important OC issues. Almost 36 percent of HCPs thought that attending to too many patients prevented them from taking proper medical histories, and 37.6 percent admitted that more training in preventing and detecting OC is needed.

RESEARCH LIMITATIONS/IMPLICATIONS

Since there is no effective automated system to reach Saudi Arabian practitioners, the number of practitioners involved in this study is limited.

PRACTICAL IMPLICATIONS

The knowledge and practice of HCPs with relation to OC do not appear to be sufficient and HCPs should have better and more training in OC prevention and early detection.

ORIGINALITY/VALUE

It appears that Saudi Arabian HCPs do not adequately participate in OC's prevention and early detection. It is suggested that continuous education strategies in Saudi Arabia should be reassessed and emphasis given to OC diagnosis.

Bone strength in children with growing pains: long-term follow-up

OBJECTIVES

To examine the changes in bone strength in a cohort of children with 'growing pains' (GP) after 5 years follow-up and the correlation with pain outcome.

METHODS

Bone strength was measured by quantitative ultrasound. Subjects were 39 children with GP previously studied. Controls were normograms based on the measurement of bone speed of sound in 1085 healthy children. Current GP status was assessed by parental questionnaires. Bone strength was compared with pain outcome.

RESULTS

We examined 30/39 (77%) patients after 5 years. Bone strength was significantly increased when compared to the first study (Z score 0.65±1.77 vs. -0.62±0.90, p<0.001). While overall there was no significant difference in the bone strength between the 16 (53%) patients whose GP resolved and the 14 (47%) who continued to have GP episodes (p=0.71), all 6 (20%) patients with a speed of sound Z-score <-1 continued to have GP (p=0.003).

CONCLUSIONS

Our findings that pain improves in most patients parallel to the increase in bone strength may support the hypothesis of GP representing in some patients a local overuse syndrome.

Characterization of the expression pattern of adrenergic receptors in rat taste buds

Taste buds signal the presence of chemical stimuli in the oral cavity to the central nervous system using both early transduction mechanisms, which allow single cells to be depolarized via receptor-mediated signaling pathways, and late transduction mechanisms, which involve extensive cell-to-cell communication among the cells in the bud. The latter mechanisms, which involve a large number of neurotransmitters and neuropeptides, are less well understood. Among neurotransmitters, multiple lines of evidence suggest that norepinephrine plays a yet unknown role in the taste bud. This study investigated the expression pattern of adrenergic receptors in the rat posterior taste bud. Expression of alpha1A, alpha1B, alpha1D, alpha2A, alpha2B, alpha2C, beta1, and the beta2 adrenoceptor subtypes was observed in taste buds using RT-PCR and immunocytochemical techniques. Taste buds also expressed the biosynthetic enzyme for norepinephrine, dopamine beta-hydroxylase (DbetaH), as well as the norepinephrine transporter. Further, expression of the epinephrine synthetic enzyme, phenylethanolamine N-methyltransferase (PNMT), was observed suggesting a possible role for this transmitter in the bud. Phenotyping adrenoceptor expression patterns with double labeling experiments to gustducin, synaptosomal-associated protein 25 (SNAP-25), and neural cell adhesion molecule (NCAM) suggests they are prominently expressed in subsets of cells known to express taste receptor molecules but segregated from cells known to have synapses with the afferent nerve fiber. Alpha and beta adrenoceptors co-express with one another in unique patterns as observed with immunocytochemistry and single cell reverse transcription polymerase chain reaction (RT-PCR). These data suggest that single cells express multiple adrenergic receptors and that adrenergic signaling may be particularly important in bitter, sweet, and umami taste qualities. In summary, adrenergic signaling in the taste bud occurs through complex pathways that include presynaptic and postsynaptic receptors and likely play modulatory roles in processing of gustatory information similar to other peripheral sensory systems such as the retina, cochlea, and olfactory bulb.

A new mutation in the growth hormone-releasing hormone receptor gene in two Israeli Arab families

BACKGROUND

Mutations in the GHRH receptor gene (GHRH-R) are emerging as a common cause of familial isolated GH deficiency (IGHD).

DESIGN

We searched for GHRH-R mutations in 10 patients with IGHD of Israeli-Arab origin, belonging to two highly consanguineous families.

METHODS

Analysis of the 13 coding exons, the intron-exon boundaries, and the proximal promoter of the GHRH-R was performed by denaturing gradient gel electrophoresis. Abnormally migrating bands were sequenced. The newly found mutation was inserted into GHRH-R cDNA. Wild type and mutant receptor were expressed in Chinese hamster ovary (CHO) cells, and the cAMP response to GHRH was measured.

RESULTS

All patients were homozygous for a novel GHRH-R missense mutation in exon 11 that replaces arginine with cysteine (R357C). Functional assay demonstrated complete inactivity of the mutant receptor in vitro. The prevalence of the mutant allele in the Israeli-Arab population was found to be 2%. All the patients had low but detectable GH reserve, proportionate short stature, and growth retardation since early childhood, with good growth response to GH treatment. Magnetic resonance imaging, performed in 3 patients, revealed a normal sized anterior pituitary in one patient evaluated at early childhood, and a borderline hypoplastic gland in the 2 patients evaluated at puberty.

CONCLUSIONS

We describe a novel missense mutation in the GHRH-R. The high incidence of the mutant allele in Israeli Arabs suggests that the mutation may be a common cause of familial IGHD in this population.

Comparison of immunosuppression in dry and lactating Awassi ewes due to water deprivation stress

In seminomadic farming practice, dry and lactating ewes are exposed to different degrees of water deprivation, leading to stress followed by various disease outbreaks. This study compares quantitatively the immunosuppression to Salmonella Enteritidis (SE) fimbriae (14 and 21 kDa) and other major polypeptides (28.9, 37.7, 42.9, 68.0, 92.6 and 96.8 kDa) in water-deprived dry and lactating ewes. Sixteen dry and lactating multiparous Awassi ewes were divided into four treatment groups (A, A', B and B'). Ewes in groups A and B were lactating, whereas ewes in groups A' and B' were dry. All ewes were administered a killed SE vaccine, subcutaneously in the neck, at the initiation of the experiment. The water availability for ewes in groups B (lactating) and B' (dry) was ad libitum, while that for ewes in groups A (lactating) and A' (dry) was once every 4 days. A serum sample was collected from the jugular vein of each ewe at zero time (initiation of the experiment, when SE bacterin was delivered) and at 2, 9, 12, 15 and 18 days post SE vaccination. The percentage reduction in the level of humoral antibody response to polypeptides of > or = 21 kDa was more apparent in water-deprived lactating ewes of group A between 9 and 18 days post initiation of thirst. In this period, immunosuppression to polypeptides > or = 21 kDa was present in 14 out of 16 observations in group A (water-deprived lactating), with significant immunosuppression in 9 observations in relation to the respective control (p<0.05), while it was present in only 4 out of 16 observations in group A' (water-deprived dry), with significant immunosuppression in 2 observations (p <0.05). In conclusion, immunosuppression to polypeptides of > or =21 kDa is more significant in lactating water-deprived ewes in the period 9-18 days post initiation of thirst, a result that will influence our future sheep welfare awareness programmes targeting an elimination of the practice of water deprivation in seminomadic sheep farming.

The impact of consanguinity worldwide

Consanguineous marriages have been practiced for hundreds of years in many parts of the world. The rate of congenital malformations among the offspring is 2.5 times higher than that among the offspring of unrelated parents, mainly due to the expression of autosomal-recessive disorders, and hospitalization for these reasons causes a major financial burden. An increase in sterility and in the rates of abortion, stillbirths, perinatal losses and neonatal deaths has been reported by some authors but not by others. It is generally accepted that the advantages of consanguinity outweigh the disadvantages; however, strategies for reducing the burden require a unique approach as discussed in this article.

Immunohistochemical localization of mu-opioid receptors in human dental pulp

Studies in both animal and clinical models suggest that opioids exert their analgesic effects not only through activation of receptors in the CNS but also through interaction with peripheral opioid receptors. This study evaluated the presence and distribution of mu-opioid receptors in human dental pulp. Human third molars indicated for extraction were removed, fixed in 4% paraformaldehyde and 0.2% picric acid, and decalcified in 10% EDTA and 7.5% polyvinylpyrrolidone. The teeth were cut using a cryostat, and the avidin-biotin peroxidase immunohistochemistry technique was used. Immunostaining for mu-opioid receptors was detected along the nerve bundle of the radicular as well as coronal dental pulp. Positive immunostaining was also observed in the individual nerve fibers in the coronal region. This demonstration of opiate receptors on pulpal nerve fibers suggests a peripheral site in the dental pulp where endogenous or exogenous opioids can interact with mu-opioid receptors.

Facial clefting in an Arab town in Israel

To study the prevalence of cleft palate and cleft lip with or without cleft palate in an Israeli Arab town, questionnaires were sent to the parents of 1375 pupils in grades 1 and 2 in all seven primary schools in the town of Taibe, and 1281 responded. The information requested included data about siblings and members of the parental generation to give a total of 16 174, and the presence of consanguinity and history of exposure to medication, radiation, smoking or alcohol during pregnancy. There were four affected individuals among the index cases, of whom two had cleft palate only and two cleft lip with cleft palate, giving prevalence rates for each of these of 1.56/1000. Adding to these the number of affected siblings gave a total of 10 affected individuals; two with cleft palate only (0.39/1000) and eight with cleft lip with or without cleft palate (1.56/1000). Among the parental generation, of 16 reported affected individuals, two had cleft palate only (0.18/1000) and 14 cleft lip with or without cleft palate (1.26/1000). The overall prevalence rate for all 26 affected individuals was 1.6/1000; four of these had cleft palate only (0.24/1000) and 22 had cleft lip with or without cleft palate (1.36/1000). There were no cases whose mothers had been exposed to medication, radiation, smoking or alcohol during pregnancy. The effect of consanguinity was not significant (P < 0.92). This study shows that the prevalence of facial clefting in an Israeli Arab community is consistent with that in the general population worldwide.

Prevalence of Behçet's disease in an Arab community in Israel

OBJECTIVE

To evaluate the prevalence of Behçet's disease (BD) in an Israeli Arab town (Taibe).

METHODS

Questionnaires about the occurrence and prevalence of aphthous ulcers were distributed randomly to the parents of children attending a paediatric centre in Taibe. The parents were asked whether they or any of their children aged between 10 and 20 years had recurrent aphthous stomatitis. Any who had had more than four aphthous episodes (each episode lasting more than seven days) during the previous year were invited for an extensive interview and examination by a rheumatologist or a paediatrician.

RESULTS

A total of 4876 subjects were included in this survey, of whom six (one male, five female) were diagnosed as having BD. Of these six, two were siblings (a brother and a sister). Five had skin lesions, four had visual involvement, and all had genital ulcers and joint symptoms; one in two patients had a positive pathergy test. Five of the six carried HLA-B5 antigens. The results showed a prevalence of 12/10,000 in Taibe.

CONCLUSION

The prevalence of BD found in our survey is high and concurs with that found in other Mediterranean and Asian countries.

Fine mapping places the gene for arthrogryposis multiplex congenita neuropathic type between D5S394 and D5S2069 on chromosome 5qter

Arthrogryposis multiplex congenita (AMC) is a heterogeneous symptom complex characterized by non-progressive joint contractures from birth that involve more than one part of the body. In 1997, our group investigated a large Israeli Arab inbred kindred that showed autosomal recessive inheritance of AMC neuropathic type, and we mapped the gene to 5qter between markers D5S1456 and D5S498. Haplotype sharing studies revealed complete homozygosity in all affected individuals with marker D5S394, thus providing significant statistical evidence in favor of linkage. In this study, we have undertaken further fine mapping of this region of chromosome 5qter, and have examined several additional markers. All the affected individuals showed complete homozygosity for the marker D5S394, and also for three additional markers that are telomeric to marker D5S394 and situated 31766 bp, 58016 bp, and 58516 bp, respectively, from it. Analysis of the recombinant individuals has enabled us to narrow down the critical region to a distance of.442 Mb between markers D5S394 and D5S2069.

Analgesic effects of peripherally administered opioids in clinical models of acute and chronic inflammation

A series of double-blind, placebo-controlled clinical trials demonstrated that low doses of morphine (0.4, 1.2, and 3.6 mg) administered into the intraligamentary space of a chronically inflamed hyperalgesic tooth produced a dose-related naloxone-reversible analgesia. This analgesic effect is mediated by a local mechanism in the inflamed tissue, because subcutaneous administration of a 1.2 mg dose of morphine failed to elicit an analgesic response. In contrast, submucosal administration of 1.2 mg morphine or 50 microg fentanyl to the site of extraction of an impacted third molar after the onset of acute pain failed to elicit an analgesic response despite demonstration of a sensitive bioassay. These data indicate that peripheral opioid analgesia can be evoked in a model of chronic, but not acute, inflammatory pain, suggesting a temporal dependent mechanism needed for the expression of peripheral opiate analgesia during inflammation in humans.

Close association of HLA-B52 and HLA-B44 antigens in Israeli Arab adolescents with recurrent aphthous stomatitis

OBJECTIVES

To investigate the incidence and clinical features of recurrent aphthous stomatitis (RAS) among Israeli Arab adolescents and to determine the HLA typing profile in affected subjects.

STUDY DESIGN

Cross-sectional study.

SETTING

Junior high school in the largest Arab town in Israel.

PARTICIPANTS

Four hundred seventy-seven Israeli Arab junior high school students filled out a questionnaire. Students who reported more than 4 episodes of RAS during the previous year were interviewed by telephone. Those whose responses were confirmed were invited to the clinic. Of these, 22 were chosen at random for HLA typing. Findings were compared with those in 117 healthy Israeli Arabs who were candidate donors of bone marrow to patients at the Institute of Hematology-Oncology, Schneider Children's Medical Center of Israel, Petah Tiqva.

RESULTS

Recurrent aphthous stomatitis was confirmed in 80 subjects (16.7%). Of the 22 patients who underwent HLA typing, 7 (31.4%) had HLA-B52 antigens and 8 (36.4%) had HLA-B44 antigens; corresponding figures for the control group were 10 subjects (8.5%) (P = .007) and 9 subjects (7.7%) (P = .001), respectively.

CONCLUSIONS

There is a close association of HLA-B52 and HLA-B44 in Israeli Arab youths with RAS. Long-term follow-up is needed to determine the relationship between RAS and Behçet disease.

Trends in the frequencies of consanguineous marriages in the Israeli Arab community

To assess the trends in the frequency of consanguineous marriages in the Israeli Arab population in the last 40 years, we conducted a two-part study. For the first part, we re-analyzed data from a nationwide study carried out in 1992, and for the second part, we undertook a new survey in 1998 in four locations: Taibe, Tira, Kalansuwa and Kafr Bara. Data regarding the frequency of consanguineous marriage in these four locations for the years 1961-1985 was extracted from the original survey, and for the years 1986-1998, from new questionnaires. The frequency of consanguineous marriage was highest in the period 1961 1965 (50.6%), but by the period 1981-1985 it had decreased to 40.6%. Over the whole time span of the 1992 study, a significant decrease was observed between the periods 1961-1975 and 1976-1985 (p < 0.0001). In the four-location study, there was a significant decrease in the frequency of consanguineous marriage from 52.9%, in the period 1961-1970 to 32.8% in the period 1991-1998 (p = 0.0006). We conclude that the custom of consanguineous marriage in the studied population is still extremely high, and preventive measures should be taken to decrease its frequency and associated complications.

Molecular basis of heat labile hexosaminidase B among Jews and Arabs

Genotyping individuals for Tay-Sachs disease (TSD) is mainly based on the heat lability of beta-hexosaminidase (Hex) A (alphabeta) and the heat stability of Hex B (betabeta). Mutations in the HEXB gene encoding the beta-subunits of Hex that result in heat-labile Hex B thus may lead to erroneous enzymatic genotyping regarding TSD. Utilizing single strand conformation polymorphism (SSCP) analysis for all 14 exons of HEXB followed by direct sequencing of aberrant fragments, we screened individuals whose Hex B was heat labile. A novel heat labile mutation, previously concluded to exist in the HEXB gene, was identified among Jews and Arabs as 1627 G-->A. One individual with heat labile Hex B (HLB) was negative for this novel mutation and for the known 1514 G-->A HLB mutation, proving that there exists at least one other unidentified HLB mutation. Based on these results, it is advisable to perform DNA tests for 1627 G-->A mutation in suspected HLB individuals.

Prenatal diagnosis for detecting congenital malformations: acceptance among Israeli Arab women

BACKGROUND

A high rate of consanguineous marriages exists within the Israeli Arab community, with approximately half occurring between first cousins. This contributes towards a high incidence of congenital malformations and autosomal recessive diseases, many of which are detectable at prenatal diagnosis.

OBJECTIVES

To assess the levels of both awareness and acceptance regarding prenatal diagnosis and termination of pregnancy among a group of Arab women in order to devise the optimal means of providing genetic counseling and general health services.

METHODS

A total of 231 Arab women of childbearing age were interviewed 3 days postpartum to assess their knowledge of prenatal diagnosis and termination of pregnancy, their willingness to undergo prenatal diagnosis, and their opinions on termination of pregnancy in the event of a severely affected fetus.

RESULTS

Half the women believed that prenatal testing is not an effective (or accurate) tool for diagnosing an affected fetus. A quarter had poor knowledge on prenatal diagnosis, and a quarter believed that prenatal diagnosis does provide the correct diagnosis. Ninety-five percent said they would agree to undergo prenatal diagnosis; and in the event of a severely affected fetus, 36% said they would agree to a termination of pregnancy, 57% said they would not, and 7% were undecided.

CONCLUSIONS

There is a need for special intervention programs, with guidance by health professionals, geneticists and religious authorities, that will inform this population on the increased risk associated with consanguinity, stress the importance and effectiveness of prenatal testing to identify severe congenital malformations, and help them to accept prenatal diagnosis and termination of pregnancy if indicated.

Cytochemical demonstration of modification of carbohydrates in the mouse zona pellucida during folliculogenesis

In the present study, lectin-gold cytochemistry and antibodies against ZP2 and ZP3 glycoproteins were used to investigate the oligosaccharide content of mouse ovarian zona pellucida (ZP) during follicular development. The entire thickness of the ZP and several organelles of the oocyte (cortical granules, Golgi apparatus, and vesicular aggregates) were reactive to RCA-I, DSA, AAA, WGA, MAA, and LFA throughout follicular development. HPA labeling was not detected at the earliest stages of follicular folliculogenesis. HPA reactivity was first observed in the ZP, Golgi apparatus, and the vesicles of oocytes at the trilaminar primary follicle stage. HPA labeling in the ZP was always restricted to the inner region of the zona matrix. After neuraminidase treatment, HPA reacted with the entire ZP in ovarian follicles at different stages of development. Immunolabeling with specific antibodies showed that, although ZP2 and ZP3 glycoproteins were uniformly distributed in the zona matrix of ovarian oocytes, there was a progressive increase in thickness of the ZP in parallel with the proliferation of follicular cells. ZP3 glycoprotein was also localized to the Golgi apparatus and vesicular aggregate. The present results suggest: (1) a difference in composition of carbohydrate content between the inner and outer region of the fully developed ZP generated probably by a modification in the biosynthetic pathway of oligosaccharides in the oocyte during folliculogenesis, (2) that newly synthesized ZP glycoproteins displace previously synthesized ZP components in a direction toward the follicular cells and, therefore, no redistribution of the ZP matrix occurs during folliculogenesis, and (3) that the vesicular aggregates in the ooplasm constitute an intermediate step in the secretory pathway of ZP glycoproteins.

Blood pressure measurements in Israeli Arab children and adolescents

BACKGROUND

Hypertension is one of the most prevalent vascular diseases in the adult population. It is an important determinant of atherosclerosis in adolescents and young adults. There is to date no information on blood pressure in children of the Israeli Arab population.

OBJECTIVES

To study blood pressure in Israeli Arab children and adolescents.

METHODS

Blood pressure measurements were taken in the supine position in 4,488 Israeli Arab children and adolescents of both sexes aged 6-17 years. Height and weight were also determined. Correlation was investigated between systolic and diastolic blood pressure, body mass index, gender, and age.

RESULTS

The systolic and diastolic blood pressures were similar in both sexes for all age groups up to 14 years of age. Systolic blood pressure was significantly (P < 0.001) higher in males aged 15-17 years (120 +/- 13 vs. 111 +/- 12 mmHg, 123 +/- 13 vs. 113 +/- 14.0 mmHg, and 123 +/- 18 vs. 111 +/- 14 mmHg, respectively). Diastolic blood pressure was higher in males aged 15-17, with a statistically significant difference for age 17 only (75 +/- 12 vs. 69 +/- 13 mmHg). Blood pressure was elevated in 322 students in the initial screening (7.17%), with a decrease to 2.18% when this group was rescreened 2 weeks later. The systolic blood pressure in our group is higher than that in Jewish Israeli children of Asian and North African origin, and in American children. It is similar to the systolic blood pressure of European children and Jewish children born in Israel. The diastolic blood pressure in our group is higher than that in all groups of Israeli Jewish children and American children of different ethnic groups.

CONCLUSIONS

Israeli Arab children and adolescents have higher blood pressure levels than their Israeli Jewish counterparts. Further studies are required to confirm this observation.

[Control of brucellosis in Taibe: multi-central collaboration]

Brucellosis is contracted from domestic animals. Poor hygiene, primitive animal breeding methods and traditional food preparation are the main contributory factors. We describe an intersectoral program for controlling brucellosis in Taibe, an Arab town in Israel, which had a particularly high incidence of the disease in 1992 and 1993. At the beginning of 1994 the Israel Ministry of Health and the Community Pediatric Center of Taibe established a community-based program for controlling brucellosis in Taibe. It included an intensive public health education campaign and periodic examination and vaccination of animals. Physicians, veterinarians, nurses, school officials and health inspectors were recruited for this purpose. Residents' awareness of brucellosis was determined before and after the study. After intervention, the incidence of the disease sharply declined from 176.6 and 175.0/100,000 in 1992 and 1993 respectively, to 5.7, 10.4 and 2.5/100,000 in 1994, 1995 and 1996, respectively, (odds-ratio 24.44; p < 00000). Residents' awareness of brucellosis and preventive measures were significantly increased by the end of the study. We conclude that intersectoral collaboration is an important tool for controlling brucellosis.

Non-identical distribution pattern of epidermal growth factor and platelet-derived growth factor in the mouse uterus during the oestrous cycle and early pregnancy

In the present study, we examined by immunohistochemistry the cell-specific distribution of epidermal growth factor (EGF) and platelet-derived growth factor (PDGF) in the mouse uterus during the oestrous cycle and throughout the first 7 days of pregnancy. Paraffin-embedded tissue samples were immunostained using the avidin-biotin peroxidase technique and then examined by light microscopy. Our results showed that immunostaining for EGF was detected in the stroma but not in the luminal or glandular epithelium. A high concentration of EGF was detected in the stroma around the time of embryo implantation at days 3, 4 and 5 of pregnancy. The implanted embryo at day 7 of gestation showed immunostaining for EGF between the ectoderm and endoderm layers. The cell distribution pattern for PDGF was found to be different from that observed with EGF. Luminal and glandular epithelia displayed PDGF immunostaining throughout the first 7 days of pregnancy, with the highest intensity at days 4 and 5 of gestation. In contrast, no immunostaining was observed in the luminal and glandular epithelia at post-oestrus, dioestrus and pro-oestrus stages. However, a weak reaction started to appear at oestrus. The embryo at the blastocyst stage displayed a strong immunoreaction for antibody against PDGF. In addition, the decidual boundary zone surrounding the implanted embryo at days 5, 6 and 7 of gestation also showed an immunostaining for PDGF. The present observations demonstrate clearly the presence of EGF and PDGF in the mouse uterus in high concentrations at the peri-implantation period. Thus, our results, together with what is known about the effect of EGF and PDGF in controlling the growth, differentiation and activation of a variety of cell types, suggest a possible role for these growth factors during the preparation of the endometrium for implantation in controlling the proliferation activity of stromal and/or epithelial cells.

Evidence for complex nuclear inheritance in a pedigree with nonsyndromic deafness due to a homoplasmic mitochondrial mutation

The relationship between mitochondrial genotype and clinical phenotype is complicated in most instances by the heteroplasmic nature of pathogenic mitochondrial mutations. We have previously shown that maternally inherited hearing loss in a large Arab-Israeli kindred is due to the homoplasmic A1555G mutation in the mitochondrial 12S ribosomal RNA gene [Prezant et al., 1993: Nat Genet 4:289-294]. Family members with this mutation have phenotypes ranging from profound hearing loss to completely normal hearing, and we have shown that there is genetic and biochemical evidence for nuclear gene involvement in this family [Bu et al., 1993: Genet Epidemiol 9:27-44; Guan et al., 1996: Hum Mol Genet 5:963-971]. To identify such a nuclear locus, two candidate genes were excluded through linkage analysis and sequencing, and a genome-wide linkage search in family members who all have the identical homoplasmic mitochondrial mutation, but differ in their hearing status, was performed. In two stages a total of 560 polymorphic genetic markers was genotyped, and the data were analyzed under model-dependent and model-free assumptions. No chromosomal region was identified as a major contributor to the phenotypic expression of the mitochondrial mutation. Thus, in this simplified paradigm of a homoplasmic mitochondrial mutation in a single kindred who all live in the similar environment of a small village, the penetrance of the mitochondrial mutation appears to depend on the interaction of multiple nuclear genes.

Effects of consanguineous marriage on reproductive outcome in an Arab community in Israel

Intrafamilial marriage is favoured by the Arab community in Israel, almost all of whom live in villages populated by a few (< 20) founding families. A previous study in Taibe, a large Arab village located 30 km from Tel Aviv, showed a significantly high malformation rate among infants of consanguineous parents. The present study examines the reproductive consequences of parental consanguinity in 610 families from the same village, selected retrospectively through infants routinely seen in the local well baby clinic. All mothers were interviewed with regard to previous pregnancy outcomes, including abortions, stillbirths, and neonatal or infant deaths, as well as the degree of consanguinity. In addition, we analysed the anthropometric measurements of the probands. The incidence of infant deaths was significantly higher in the inbred group (p < 0.001). No significant increase in fetal loss between the inbred and outbred groups was observed. There were no differences in anthropometric features, except for a lower birth weight in the consanguineous group (p < 0.035). This study, combined with our previous studies of the same population, indicates a prominent public health problem associated with consanguineous marriage in the Arab community and a need for specific genetic counselling.

[Consanguinity among Arabs in Israel]

In a previous nationwide study, we examined the rate of consanguineous matings in the Israeli Arab community. The average inbreeding coefficient was 0.0192, much higher than that reported for the general population of Israel, 0.0038 in 1956-7. The inbreeding coefficients of 69 Arab villages, towns and cities (excluding the Bedouin in the South) were determined. Knowledge of the inbreeding coefficients of the various local populations is of value for geneticists, pediatricians and gynecologists and for planning suitable health programs.

Modifications of carbohydrate residues and ZP2 and ZP3 glycoproteins in the mouse zona pellucida after fertilization

Oligosaccharide side chains of zona pellucida (ZP) glycoproteins play a key role in the sperm-egg interaction phenomena during fertilization. In the present study, modifications of the ZP glycoproteins during the fertilization process in the mouse were studied by the lectin-gold technique and immunocytochemistry in conjunction with quantitative analysis. Binding of PNA, RCA I, DSA, LFA, MAA, AAA, and anti-ZP2 and anti-ZP3 antibodies was observed throughout the ZP of both unfertilized and fertilized eggs. However, HPA and BSAIB4 labeling was found only in the inner region of the ZP. After neuraminidase treatment (Neu), HPA showed an affinity for the entire ZP. Labeling by LFA, WGA, MAA, PNA, BSAIB4, and AAA decreased in the ZP of fertilized eggs; however, there was an increase in the binding of RCA I. HPA and Neu-HPA increased only in the inner region of the ZP. Immunoreactivity to antibodies against ZP2 and ZP3 also decreased after fertilization. The present results demonstrate that 1) terminal carbohydrate residues contained in the ZP glycoproteins are modified after fertilization and 2) inner and outer regions of the ZP contain different oligosaccharide side chains.

A gene for arthrogryposis multiplex congenita neuropathic type is linked to D5S394 on chromosome 5qter

Arthrogryposis multiplex congenita (AMC) is a heterogeneous-symptom complex characterized by joint contractures at birth that involve more than one part of the body. We performed a genetic-linkage study of one large Israeli-Arab inbred kindred showing autosomal recessive inheritance of AMC neuropathic type that had been recently investigated by our group. After analysis of approximately 80% of the genome, D5S1456, which showed no increased homozygosity, showed increased genotype sharing in affected individuals. Linkage analysis in all family members revealed linkage between AMC and D5S1456 on chromosome 5qter (maximum LOD score 5.3 at recombination fraction .001). Analysis of additional markers in this region places the gene causing AMC in this family between D5S1456 and D5S498.

Intramuscular ceftriaxone compared with oral amoxicillin-clavulanate for treatment of acute otitis media in children

Two hundred and fifteen children aged 4 months 6 years with acute otitis media (AOM) were randomized to be treated either by a single i.m. injection of ceftriaxone, 50 mg/kg, with a second dose in the event of unsatisfactory response after 48 h or a history of recurrent AOM (109 patients) or amoxicillin clavulanate 12.5 mg tid (106 patients). The failure rate was similar in children treated by ceftriaxone and amoxicillin clavulanate, 4.6% and 4.7%, respectively (standard error for intergroup difference -2.87%, 95% confidence interval -5.62% to 5.87%). No significant differences between the groups were found in the dynamics of the resolution of the acute symptomatology, otoscopy findings, relapse rate at 30 days or tympanographic evidence of middle ear effusion at the scheduled visits on days 30, 60 and 90. Recurrence of AOM between days 31 and 90 was observed significantly in more children treated with amoxicillin clavulanate than with ceftriaxone--25 out of 84 (29.4%) versus 11 out of 81 (13.6%) (P = 0.012).

CONCLUSION

Ceftriaxone injection(s) is as efficient at least as 10-day oral amoxicillin clavulanate for treatment of acute otitis media in children. Although not recommended as routine, ceftriaxone can be considered in the management of acute otitis media under special circumstances, particularly in cases when the ability to tolerate or absorb oral drugs is compromised, in children refusing or unable to take oral therapy or when the compliance is questionable.

Speech disorders in Israeli Arab children

The aim of this work was to study the frequency of speech disorders in Israeli Arab children and its association with parental consanguinity. A questionnaire was sent to the parents of 1,495 Arab children attending kindergarten and the first two grades of the seven primary schools in the town of Taibe. Eight-six percent (1,282 parents) responded. The answers to the questionnaire revealed that 25% of the children reportedly had a speech and language disorder. Of the children identified by their parents as having a speech disorder, 44 were selected randomly for examination by a speech specialist. The disorders noted in this subgroup included errors in articulation (48.0%), poor language (18%), poor voice quality (15.9%); stuttering (13.6%), and other problems (4.5%). Rates of affected children of consanguineous and non-consanguineous marriages were 31% and 22.4%, respectively (p < 0.01). We conclude that speech disorders are an important problem among Israeli Arab schoolchildren. More comprehensive programs are needed to facilitate diagnosis and treatment.

Consanguinity and common adult diseases in Israeli Arab communities

Consanguinity has a deleterious effect with regard to congenital malformation and rare autosomal recessive diseases; however, little information exists on its role in multifactorial common adult morbidity. We investigated the effects of consanguinity on the prevalence of common diseases in adulthood, including diabetes mellitus, myocardial infarction, bronchial asthma, and duodenal ulcer. As part of a larger study investigating the inbreeding coefficient in the Israeli-Arab community, we distributed questionnaires to parents of 4,100 second-grade students in 158 randomly chosen schools. Among the 3,772 responders (92%), 34.8% of the students' fathers and 31% of their mothers were found to be born to consanguineous matings. There was no difference in the prevalence (males, females) between the offspring of consanguineous versus non-consanguineous matings for diabetes mellitus (consanguinity: 4.3%, 1.5% vs. non-consanguinity: 2.9%, 1.6%) myocardial infarction (2.7%, 0.03% vs. 2.3%, 0.03%), bronchial asthma (2.4%, 2.0% vs. 3.7%, 2.3%), or duodenal ulcer (7.0%, 3.0% vs. 7.8%, 2.9%), respectively. The study suggests that even in a population with a high rate of consanguinity, there is no significant increase in the prevalence of these common adult diseases.

Demographic characteristics of the Israeli Arab community in connection with consanguinity

In a previous nationwide survey of the Israeli Arab community we showed that 44% of all marriages are consanguineous. Further analysis of the data from this previous survey was undertaken, and we defined six demographic characteristics that may be associated with consanguinity or non-consanguinity in the marriages. Of these, we found a significant correlation (P <0.001) with religion (for Moslems, odds ratio 1.7), consanguinity in parents' marriages, and the respondent's attitude towards consanguineous marriage. The educational level achieved was not a major factor in the type of marriage chosen. These findings should enable us to plan specifically designed educational and counseling programs with a view to reducing the overall incidence of consanguineous marriage.

Audiovestibular findings in patients with deafness caused by a mitochondrial susceptibility mutation and precipitated by an inherited nuclear mutation or aminoglycosides

OBJECTIVE

To characterize the audiological and vestibular changes associated with a mitochondrial DNA mutation in an Arab-Israeli family and in other families with mitochondrial predisposition to aminoglycoside-induced hearing loss.

DESIGN

Evaluation of audiological (pure tone thresholds, speech reception thresholds, speech discrimination, tympanometry, acoustic reflex thresholds, tone decay, and auditory brain-stem evoked response recording) and vestibular (complete history, physical examination, and 2-channel electronystagmography) systems. In 5 patients, structural evaluation of the inner ear was done by magnetic resonance imaging.

PATIENTS

Fifteen members of an Arab-Israeli family, and 1 Chinese woman with the same mitochondrial DNA mutation who experienced hearing loss after short-term exposure to streptomycin.

RESULTS

Most of the patients had a profound hearing loss due to cochlear involvement. The hearing loss usually was not accompanied by notable peripheral vestibular dysfunction. In the patient with severe hearing loss after exposure to aminoglycoside, the vestibular function was completely normal.

CONCLUSIONS

In most of the Arab-Israeli patients with congenital deafness, the vestibular system function was normal, in contrast to the frequency of vestibular abnormality among deaf children, which was described in the literature. This may be related to genetic predisposition to aminoglycoside-induced deafness.

Modifications of the lectin binding pattern in the rat zona pellucida after in vivo fertilization

The zona pellucida (ZP) is an extracellular matrix surrounding the mammalian oocyte. It is involved in the sperm-egg adhesion phenomenon, induces the acrosome reaction, and participates in the late blockage to polyspermy. Thus, during the process of fertilization the cortical reaction is induced and the biochemical and biological properties of the ZP are modified. Some of these changes have been suggested to prevent the polyspermy. However, the mechanisms behind most of these changes are not well understood. Carbohydrate residues of the ZP glycoproteins have been shown to play a key role in the early step of fertilization. In the present study, the changes produced in the terminal oligosaccharide sequences of the rat ZP glycoproteins after in vivo fertilization were investigated by means of lectin-gold cytochemistry. A comparative quantitative analysis of the density of labeling in the ZP before and after fertilization was carried out by automatic counting of gold particles. The ZP of fertilized and unfertilized eggs were labeled by a battery of lectins including PNA, LFA, MAA, AAA, DSA, RCA I, and WGA. For all lectin studied in both fertilized and unfertilized eggs the labeling was preferentially located in the inner region of the ZP. After fertilization, binding of PNA, LFA, MAA, AAA, and DSA decreased in both inner and outer regions of the ZP. Labeling of RCA I-binding sites only decreased in the inner ZP, whereas reactivity to WGA was increased in the inner ZP, whereas reactivity to WGA was increased in the inner area of the ZP. Digestion of the thin-sections with neuraminidase prior to labeling with WGA resulted in a decrease of labeling for WGA binding sites. However, the labeling density of WGA binding sites was similar in both unfertilized and fertilized eggs upon treatment with neuraminidase. The present results demonstrate that the oligosaccharide chains contained in the rat ZP are modified after fertilization of the oocyte. Cortical granules of the oocytes might be involved in these modifications by two mechanisms: 1) by hydrolysis of terminal carbohydrate residues of ZP glycoproteins by specific glycosidases contained in the granules; and 2) by addition of new glycoproteins to the ZP after the exocytosis of the cortical granules (cortical reaction).

Arthrogryposis multiplex congenita in an Arab kindred: update

We have restudied the genetic and clinical characteristics of a large Arab kindred previously reported in 1970 by Lebenthal et al. [Pediatrics 46:891-899]. At total of 40 affected individuals was identified; all, except one, were products of 22 different consanguineous matings between the parents. The syndrome, which is present at birth, is expressed mainly by flexion contractures at the knees and elbows, with muscle hypotrophy/weakness around the involved joints. Five of the 6 individuals who were originally reported as having congenital and lethal heart defects were limited to one sibship. None of the new cases had heart defect or any associated malformation. Neurologic examination and electrophysiological studies demonstrated a neuropathic (non-myopathic) type of arthrogryposis. This is an autosomal recessive trait with wide variability in expression and possibly incomplete penetrance in the females. Because of the high consanguinity rate, it allows the use of homozygosity linkage studies to map the gene for this disorder.

Hb Taybe (alpha 38 or 39 THR deleted): an alpha-globin defect, silent in the heterozygous state and producing severe hemolytic anemia in the homozygous

Several alpha-chain hemoglobin variants have been described as responsible, in homozygous or compound heterozygous patients, for a chronic hemolytic disease that overlaps thalassemia and Heinz bodies hemolytic anemia phenotypes. These variants are present in trace amounts together with some Hb H in the lysate of the patients. In the asymptomatic heterozygous carriers, they are usually not detected by electrophoretic methods. Hb Taybe is an example of such an unstable and thalassemic alpha-hemoglobin variant. This hemoglobin was observed in a young Israeli Arab woman having suffered since birth from a severe and highly regenerative hemolytic anemia for which she was splenectomized at age sixteen. The structural abnormality was characterized by protein chemistry as the deletion of a threonine residue at position alpha 38 or 39 and assigned to the alpha 1 gene by selective DNA sequencing. This structural modification is localized in helix C, which is a highly conserved 3(10) helix participating in the alpha 1 beta 2 contact and close to the alpha 1 beta 1 interface. The propositus and two siblings, who were also anemic, were found to be homozygous for the molecular defect, although the abnormal Hb was not detected in the latters. Consanguinity in this family demonstrated the threshold effect in the clinical manifestations of such alpha-gene disorders since heterozygotes were clinically and biologically normal.

Consanguineous matings in an Israeli-Arab community

OBJECTIVE

To determine the frequency of consanguineous marriages and the inbreeding coefficient in Israeli Arabs.

DESIGN

Cohort survey.

SETTING

General community in 70 settlements in Israel.

PARTICIPANTS

Nine thousand three hundred Israeli-Arab students in the second grade were sent questionnaires to be filled out by their fathers, with 8521 completed questionnaires returned.

INTERVENTIONS

None.

MEASUREMENTS/MAIN RESULTS

Of the 8521 completed questionnaires, 1156 (14%) were from urban areas, 2267 (27%) were from suburban areas, and 5098 (60%) were from rural areas. The prevalence of consanguineous matings in the studied group was 44.3%, with a mean inbreeding coefficient of .0192. This prevalence is high and was highest in the rural areas. Marriages between first cousins occurred more often than marriages between other relatives in all locations.

CONCLUSION

The frequency of consanguineous marriages is quite high among Israeli Arabs, approaching 50%.

High incidence of central nervous system malformations associated with marked parental consanguinity in an Israeli Arab community

It is common among Israeli Arabs who live in villages to prefer consanguineous marriages, particularly among first cousins. In addition, such villages are populated by a few (< 20) original families, and inter-family/inter-village marriages are infrequent. The purpose of this study was to examine the incidence of congenital malformation of the central nervous system associated with such "consanguinity" in Taibe, a large Arab village, 30 km from Tel Aviv. Six hundred and ten families were prospectively ascertained through infants who were routinely seen in the local "Well Baby Clinics". A significant increase in the incidence of major malformations was noted in relation to the closeness of the parental relationship. For the index cases group, the prevalence of individuals with major malformations was 5.8% in the product of inter-village marriages, 8.3% in the intra-village non-related matings, 15.1% in the distant consanguineous group, and up to 15.8% in the progeny of first-cousin marriages (P < 0.001). Malformations of the central nervous system consisted of 1/3 to 1/2 of the total malformations in the consanguineous group versus less than 1/5 in the non-consanguineous groups. The study demonstrates a marked high rate of consanguineous marriages, the effect of which leads to a marked increase in major malformations and especially those of the central nervous system. This requires a unique genetic counseling approach.

Mitochondrial ribosomal RNA mutation associated with both antibiotic-induced and non-syndromic deafness

Maternally transmitted non-syndromic deafness was described recently both in pedigrees with susceptibility to aminoglycoside ototoxicity and in a large Arab-Israeli pedigree. Because of the known action of aminoglycosides on bacterial ribosomes, we analysed the sequence of the mitochondrial rRNA genes of three unrelated patients with familial aminoglycoside-induced deafness. We also sequenced the complete mitochondrial genome of the Arab-Israeli pedigree. All four families shared a nucleotide 1555 A to G substitution in the 12S rRNA gene, a site implicated in aminoglycoside activity. Our study offers the first description of a mitochondrial rRNA mutation leading to disease, the first cases of non-syndromic deafness caused by a mitochondrial DNA mutation and the first molecular genetic study of antibiotic-induced ototoxicity.

Meconium aspiration and otitis media in children

Meconium-stained amniotic fluid was recently reported to be significantly correlated with a higher incidence of otitis media during infancy. In order to verify this connection, a case-control study was performed on 71 pairs of infants, with and without meconium aspiration, matched for gestational age, birth weight and sex. Data were collected by questionnaire or telephone, the response rate being 88.7%. No significant difference in incidence of otitis media between the two groups was observed. This study demonstrated that newborns with meconium aspiration are not at greater risk for otitis media in the 1st year of life.

A form of sensorineural deafness is determined by a mitochondrial and an autosomal locus: evidence from pedigree segregation analysis

We have previously reported a large Israeli-Arab pedigree with sensorineural deafness possibly determined simultaneously by two loci--one mitochondrial, and one autosomal recessive. This was analyzed by extending classic segregation analysis methods to the many nuclear families derived from the maternal line pedigree. Here we expand this pedigree and extend our analysis by using the regressive models for segregation analysis on the entire pedigree. The corresponding REGD computer program was utilized and the marrying-in males' and paternal line members' affection statuses were assigned as unknown to accommodate the exclusive maternal transmission pattern. For the autosomal locus, a simple autosomal recessive (q = 0.52) model with a nearly complete penetrance (0.93) was found to be the best-fitting model. Equally importantly, we were also able to use the power of the regressive models to test the hypothesis of mitochondrial heteroplasmy as an alternative for the proposed autosomal locus. We found no evidence for the heteroplasmy hypothesis as an explanation for the incomplete maternal transmission of deafness in this pedigree. Thus, even if the mitochondrial mutation occurred in a heteroplasmic distribution in the family members, this could not explain the familial aggregation in this pedigree, and an autosomal recessive locus is still required. These results provide further support for the concept that the sensorineural deafness occurring in this large Israeli-Arab pedigree results from simultaneous involvement of two genes at two different loci, one mitochondrial and likely homoplasmic, and the other autosomal and recessive.

Biochemical characterization of a pedigree with mitochondrially inherited deafness

A large kindred with a predicted 2-locus inheritance of sensorineural deafness, caused by the combination of a mitochondrial and an autosomal recessive mutation, was examined at the biochemical level. Because of the mitochondrial inheritance of this disease, we looked for defects in the oxidative phosphorylation Complexes I, III, IV, and V, the 4 enzymes that include all of the 13 mitochondrially encoded polypeptides. Biosynthetic labelling of lymphoblastoid cells from deaf patients, unaffected siblings, and an unrelated control showed no difference in size, abundance, rate of synthesis, or chloramphenicol-sensitivity of the mitochondrially encoded subunits. Since overall mitochondrial protein synthesis appears normal, these results suggest that the mitochondrial mutation is unlikely to be in a tRNA or rRNA gene. No change in enzymatic levels was seen in lymphoblastoid mitochondria of the deaf patients, compared to unaffected sibs and controls, for Complexes I and IV. Both affected and unaffected family members showed an increase in Complex III activity compared to controls, which may reflect the mitochondrial DNA shared by maternal relatives, or be due to other genetic differences. Complex V activity was increased in deaf individuals compared to their unaffected sibs. Since the family members share the presumptive mitochondrial mutation, differences between deaf and unaffected individuals likely reflect the nuclear background and suggest that the autosomal recessive mutation may be related to the increase in Complex V activity. These biochemical studies provide a guide for sequence analysis of the patients' mitochondrial DNA and for linkage studies in this kindred.

Prevalence of asthma in Israeli schoolchildren. A comparative study of Jewish and Arab populations

The prevalence of asthma in 2,160 schoolchildren from Arab and Jewish rural and urban communities in central Israel, was determined by means of questionnaire. For the purposes of the study, asthmatic children were defined as those suffering from two or more asthmatic episodes which had been diagnosed by their physicians and had necessitated anti-asthmatic therapy. Doubtful cases were classified after personal interviewing and physical examination. The overall prevalence of asthma was 6.38%. In the Arab rural sample, it was 2.86%, significantly lower than the other groups studied: Arab urban 6.63% (P < 0.001), Jewish urban 9.2% and Jewish rural 8.66% (P < 0.001). The relatively low prevalence in the Arab rural sample is in accordance with the rarity of asthma reported from less advanced societies in other countries. The reasoning for the low asthmatic morbidity found in this group is not clear.