Mild thalassemia intermedia resulting from a new insertion/frameshift mutation in the beta-globin gene

Hematological investigation of an antenatal patient led to the identification of a new beta-thalassemia mutation involving the net insertion of eight nucleotides into exon 2 of the beta-globin gene. As a result of the shift in the protein reading frame, this gene codes for an elongated beta-globin chain (159 amino acids) with an abnormal amino acid sequence beyond residue beta 99. There is no evidence of any abnormal hemoglobin in the circulation. The patient has a mild form of beta-thalassemia intermedia with moderate anemia, evidence of iron overload, severe red cell morphological changes, a significant reticulocytosis, and a marked increase in the proportion of fetal hemoglobin.

Risk of venous thromboembolism associated with a G to A transition at position 20210 in the 3'-untranslated region of the prothrombin gene

The odds ratio for the FII 20210G/A mutation in 504 patients with venous thromboembolism compared to controls was 2.0 (95% CI 1.0-4.0) and, for factor V Leiden, 5.8 (95% CI 3.3-10.3). 3/504 patients were heterozygous for both mutations. None of the patients had combined natural anticoagulant deficiency and the FII 20210G/A mutation. We conclude that the FII 20210G/A mutation is present in 2.6% of the population and the relative risk of venous thromboembolism in carriers is 2.0.

MR imaging of soft tissues adjacent to orthopaedic hardware: techniques to minimize susceptibility artefact

This article demonstrates and compares imaging of orthopaedic hardware (fixation plates, screws, Kischner wire and prostheses) using gradient-echo, spin-echo and fast spin-echo sequences. It describes simple techniques which minimize susceptibility artefact induced by these components at magnetic resonance (MR) imaging, allowing visualization of adjacent soft tissues. The article emphasizes the importance of selecting the appropriate imaging plane in order to avoid hardware distortion of slice select gradients, emphasizes the importance of selecting frequency encoding gradient axes in order to orientate the long axis of the artefact away from the tissue of interest and, finally, compares the marked susceptibility artefact observed adjacent to hardware using gradient-echo with the artefact reduction achieved by using fast spin-echo sequences.

Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version (K-SADS-PL): initial reliability and validity data

OBJECTIVE

To describe the psychometric properties of the Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime version (K-SADS-PL) interview, which surveys additional disorders not assessed in prior K-SADS, contains improved probes and anchor points, includes diagnosis-specific impairment ratings, generates DSM-III-R and DSM-IV diagnoses, and divides symptoms surveyed into a screening interview and five diagnostic supplements.

METHOD

Subjects were 55 psychiatric outpatients and 11 normal controls (aged 7 through 17 years). Both parents and children were used as informants. Concurrent validity of the screen criteria and the K-SADS-PL diagnoses was assessed against standard self-report scales. Interrater (n = 15) and test-retest (n = 20) reliability data were also collected (mean retest interval: 18 days; range: 2 to 36 days).

RESULTS

Rating scale data support the concurrent validity of screens and K-SADS-PL diagnoses. Interrater agreement in scoring screens and diagnoses was high (range: 93% to 100%). Test-retest reliability kappa coefficients were in the excellent range for present and/or lifetime diagnoses of major depression, any bipolar, generalized anxiety, conduct, and oppositional defiant disorder (.77 to 1.00) and in the good range for present diagnoses of posttraumatic stress disorder and attention-deficit hyperactivity disorder (.63 to .67).

CONCLUSION

Results suggest the K-SADS-PL generates reliable and valid child psychiatric diagnoses.

Language as a barrier to the acquisition of anatomical knowledge

The language of instruction for medical students at the University of Hong Kong is English, which is their second language. This presents a potential barrier to their academic learning. We have studied the extent of this problem by looking at the amount of terminology students have to assimilate during their anatomy course and the way in which the terminology is structured and explained (this provides, more generally, an indication of the factual loading to which medical students are exposed). We have also investigated the effect of the quality of students' language skills on their examination results in anatomy class tests and MBBS exams. It was found that students' entrance levels in English correlated well with their final examination results and that the quality and quantity of their English also correlated highly with scores in class tests. On this basis, we conclude that language is one of the most important barriers to students' academic success in the department and that current teaching materials may not be appropriate.

Pain behavior, spouse responsiveness, and marital satisfaction in patients with rheumatoid arthritis

Although the pain behavior of some diagnostic groups has been shown to be reactive to social influences, the reactivity of pain behavior in a rheumatoid arthritis (RA) population remains an open question. The authors in this article combined laboratory and self-report assessment techniques to examine the extent to which the pain report and behavior of 52 RA patients was susceptible to influence of social factors within the marital unit. The authors' findings suggest that (a) different types of spouse responsiveness (e.g., solicitous, punishing) may be viewed differently by the RA population than more general chronic pain populations; (b) the patient's perception of spouse responsiveness is a significant predictor of the pain behavior, whereas the spouse's perception of these same behaviors is not; and (c) the patient's perception of the spouse's responsive behavior adds significantly to the prediction of pain behavior over a model based on "disease impact" variables alone.

Haemoglobin Hallamshire (beta146 HIS --> TYR): a new high oxygen affinity haemoglobin responsible for familial erythrocytosis

A new high oxygen affinity haemoglobin with the beta chain mutation beta146 HIS --> TYR is described. This variant was detected in a fit 34-year-old man with true erythrocytosis. The abnormal haemoglobin was identified as an extra band on cellulose acetate electrophoresis at pH 6.3 and was later confirmed by beta globin gene sequencing and oxygen dissociation studies. Whole blood containing Haemoglobin Hallamshire has a P50 of 18 mmHg. This newly described haemoglobin variant was also responsible for erythrocytosis in the mother and maternal half cousin of the index case. The identification of Haemoglobin Hallamshire provides confirmatory evidence of the important role of the C-terminal end of the chain in haemoglobin function.

Tendon shift in hallux valgus: observations at MR imaging

OBJECTIVE

This study was undertaken to demonstrate a shift in tendon alignment at the first metatarsophalangeal joint in patients with hallux valgus by means of magnetic resonance imaging.

DESIGN

Ten normal feet and 20 feet with the hallux valgus deformity conforming to conventional clinical and radiographic criteria were prospectively studied using magnetic resonance imaging. Correlation was made between tendon position at the first metatarsophalangeal joint and the severity of the hallux valgus deformity.

RESULTS

There is a significant shift in tendon position at the first metatarsophalangeal joint of patients with hallux valgus. The insertion of the abductor hallucis tendon is markedly plantarward and the flexor and extensor tendons bowstring at the first metatarsophalangeal joint compared with patients without the deformity. The severity of the tendon shift correlates with the hallux valgus angle and clinical severity of the hallux valgus deformity in each case.

CONCLUSION

Patients with hallux valgus have a significant tendon shift at the first metatarsophalangeal joint which appears to contribute to development of the deformity.

Multi-disciplinary clinical study of Smith-Magenis syndrome (deletion 17p11.2)

Smith-Magenis syndrome (SMS) is a multiple congenital anomaly, mental retardation (MCA/MR) syndrome associated with deletion of chromosome 17 band p11.2. As part of a multi-disciplinary clinical, cytogenetic, and molecular approach to SMS, detailed clinical studies including radiographic, neurologic, developmental, ophthalmologic, otolaryngologic, and audiologic evaluations were performed on 27 SMS patients. Significant findings include otolaryngologic abnormalities in 94%, eye abnormalities in 85%, sleep abnormalities (especially reduced REM sleep) in 75%, hearing impairment in 68% (approximately 65% conductive and 35% sensorineural), scoliosis in 65%, brain abnormalities (predominantly ventriculomegaly) in 52%, cardiac abnormalities in at least 37%, renal anomalies (especially duplication of the collecting system) in 35%, low thyroxine levels in 29%, low immunoglobulin levels in 23%, and forearm abnormalities in 16%. The measured IQ ranged between 20-78, most patients falling in the moderate range of mental retardation at 40-54, although several patients scored in the mild or borderline range. The frequency of these many abnormalities in SMS suggests that patients should be evaluated thoroughly for associated complications both at the time of diagnosis and at least annually thereafter.

Comparison of benzodiazepine (BZ) receptor agonists in two rodent activity tests

The effects of four BZ receptor ligands in an operant test were compared with a rotarod test. In the operant test, rats were trained to pull a chain on a schedule that regulates the probability of delivery of food pellets to maintain a steady chain-pulling rate across a 1 h test session. For the rotarod test, mice were trained to remain on a rotarod for 2 min. Diazepam (0.1-3.0 mg/kg, i.p.), FG 8205 (0.1-3.0 mg/kg, i.p.), quazepam (3.0-60.0 mg/kg, i.p.) and zolpidem (0.3-10.0 mg/kg, i.p.) each produced dose-related impairments of performance in both the chain- pulling test and the mouse rotarod test. Furthermore, the impairment in performance induced by FG 8205 (10.0 mg/kg, p.o.) was dose-dependently reversed by the BZ receptor antagonist, flumazenil (1.0-10.0 mg/kg, i.p.), indicating that the chain-pulling deficit was mediated via BZ receptor activation. Diazepam, FG 8205 and quazepam all had comparable potencies in both the rotarod assay and the chain-pulling test. However, zolpidem suppressed the chain-pulling rates at a dose 30-fold lower than that required to induce a significant deficit in the rotarod performance. As zolpidem is a preferentially sedative compound, this pattern of results is consistent with the hypothesis that the chain-pulling test is sensitive to sedation induced by BZ receptor agonists.

Childhood abuse as a factor in attrition from drug rehabilitation

The following factors were examined as possible influences of clients' attrition from inpatient and outpatient drug-rehabilitation programs: depression (Center of Epidemiological Studies-Depression test), attributional style (Attributional Style Questionnaire), primary drug of choice, family incidence of substance abuse, and history of childhood physical abuse. A step-wise regression analysis indicated that a history of childhood abuse was a statistically reliable predictor of program noncompletion for 92 substance abusers who entered a drug-rehabilitation program.

Haemoglobin Dhofar is linked to the codon 29 C-->T (IVS-1 nt-3) splice mutation which causes beta+ thalassaemia

Investigations of a young man with apparent thalassaemia minor showed that he was a heterozygote for a rare abnormal haemoglobin variant, Hb Dhofar. The amino acid replacement is in the beta-globin chain (beta 58 Pro-->Arg) and is therefore not consistent with the observed proportion of Hb Dhofar, as in both this and the original case, it constituted only 15% of the total haemoglobin. We have determined the basis of the low expression of this mutant, which is due to its linkage to a thalassaemic splicing mutation on the same beta-globin gene at codon 29 (C-->T). The finding of this thalassaemia mutation linked to Hb Dhofar not only explains the low level of Hb Dhofar, but also provides evidence that the codon 29 C-->T, IVS-1 splice junction mutation causes a beta+ form of thalassaemia.

Parent and student preferences for services in a school-based clinic

As a component of program planning for a school-based clinic in a suburban high school, a sample of 199 students and 196 parents were surveyed about preferences for health services. Parents and students were asked about health services desired and level of interest. Student overall interest in health services was less than parent interest, although both groups indicated at least a moderate level of interest. Both students and parents reported interest in availability of comprehensive services, including general health services, reproductive health services, and counseling services. The process of polling parents and students serves dual purposes of informing the population about school-based clinics, as well as gathering information to attempt to match the health services offered with needs identified.

Dermatophytic profile of jaipur (rajasthan)

Out of 410 clinically diagnosed cases of superficial mycoses encountered during 1985 - 87, direct KOH mounts were positive in 250 (62.19%) cases and the cultures were positive in 123 (30.00%) cases. The organisms isolated included Trichophyton rubrum (36.58%). T. simii (32.52%), T.mentagrophytes (12.19%), C.tropicum (8.13%), Microsporum gypseum (6.50%), Epidermophyton floccossum (2.43%), T. violaceum (0.81%) and Candida albicans (0.81%). Majority of cases occurred among the age group of 21 - 30 years. Tinea corporis and tinea cruris were the commonest clinical types encountered.

The chloride effect in human haemoglobin. A new kind of allosteric mechanism

Chloride reduces the oxygen affinity of mammalian haemoglobin by acting as an allosteric effector that stabilizes the quaternary deoxy (T) structure. Perutz and others showed evidence that it does so by neutralizing electrostatic repulsion by an excess of positive charges in the cavity that runs through the centre of the molecule, but without binding to any specific site. On the basis of this proposal, any amino acid substitutions in the central cavity that halve the number of excess positive charges should halve the chloride effect, neutralization of the excess positive charges should inhibit it and introduction of additional positive charges should enhance it. Charge changes on the surface of the molecule should leave it unaltered. We have tested this proposal by measuring the chloride effects in several abnormal human haemoglobins with replacements of polar residues in the central cavity or on the surface that we happened to come across. They all proved consistent with the proposal. It appears that diffusible electrolytes can modify allosteric equilibria without necessarily binding to any specific site. Our proposal also implies that amino acid substitutions that make the central cavity more electropositive should destabilize the T-structure and therefore increase the oxygen affinity, while substitutions that make it more electronegative should do the reverse. A survey of all substitutions reported in the literature shows that this is true, with a few exceptions due to special stereochemical effects.

Maternal inheritance of extrachromosomal DNA in malaria parasites

Plasmodium falciparum has two extrachromosomal genomes, the mitochondrial 6-kb DNA element and the 35-kb circular DNA. The mitochondrial gene cytochrome b on the 6-kb element has been shown to be inherited uniparentally. In order to ascertain whether the route is maternal or paternal we have examined preparations of male and female gametes of the closely related Plasmodium gallinaceum for the presence of extrachromosomal DNA. DNA from purified preparations of gametes was hybridised to probes for both the 6-kb and 35-kb extrachromosomal genomes. Both probes hybridised to the preparation of Plasmodium gallinaceum female gametes but not to that of the males. We conclude that the extrachromosomal DNAs of malaria parasites are transmitted maternally.