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Biomedical subjects

J Y Mok

Publications and source records attributed to J Y Mok.

At least 37 records · Page 2Linked to original sources
PubMed1991

Increased expression of the CD45RO (memory) antigen on T cells in HIV-infected children.

Expression of the CD45RO putative memory cell antigen on CD4 (helper) and CD8 (cytotoxic/suppressor) lymphocytes of children born to HIV-infected women was investigated using the UCHL1 antibody. Significantly raised numbers of CD45RO+ CD8 lymphocytes were found in all nine of the infected children compared with uninfected and control children. Expression of CD45RO on CD4 lymphocytes was variable; absolute numbers were not increased, although the percentage was increased in four out of nine infected children. All the infected children except two (who had comparatively low numbers of CD45RO+ CD8 cells) were clinically well, which suggests that an increase in CD45RO+ CD8 cells may be indicative of a functionally active immune response against HIV.

Antigens, CD↗
PubMed1990

Diagnosis of Pneumocystis carinii pneumonia from non-invasive sampling of respiratory secretions.

An infant infected with HIV presented with fever, tachypnoea, hypoxia, and radiological evidence of bilateral pneumonitis. Fluorescent antibody technique identified Pneumocystis carinii within 24 hours from secretions obtained by nasopharyngeal aspiration. This rapid, non-invasive method should be the first line investigation of suspected P carinii pneumonia in immunocompromised patients.

Exudates and Transudates↗
PubMed1989

The management of children born to human immunodeficiency virus seropositive women.

Increasing numbers of children born to human immunodeficiency virus (HIV) antibody-positive women are being identified, but guidelines as to their management are lacking. We have therefore established a paediatric counselling and screening clinic for managing such children in Edinburgh. During a period of 3 years, 49 infants and children of 43 HIV seropositive women have been seen. After a median follow-up period of 23 months, four children were found to have clinical evidence of HIV disease which was non-specific and could have been missed had they not been regularly monitored. Thus, close surveillance of infants born to seropositive women is important. Identifying a single clinic where this is done has allowed experience to accumulate on issues beyond the medical management of these infants as well as contributing to the clinical care of infants with symptoms. Based on this experience, we have developed guidelines for managing children born to HIV antibody-positive women.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Vertical transmission of HIV: a prospective study.

Forty nine infants of HIV seropositive women were followed up for a median of 24 months, together with 24 controls. The infection status of 11 index children under 18 months of age was indeterminate; 34 were presumed uninfected while four showed clinical and laboratory evidence of HIV disease. Based on current definitions of HIV infection and excluding children under 18 months old as well as those who had not been studied from birth, two out of 28 children were infected. The estimated rate of maternofetal transmission was therefore 7.1%. In children with proved infection, sequential laboratory data showed that hypergammaglobulinaemia was noted as early as 6 months and often predated clinical signs. This observation, in the presence of non-specific clinical findings, was helpful in alerting the paediatrician to a diagnosis of HIV infection.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Intravenous immunoglobulin in HIV infection: evidence for the efficacy of treatment.

Eight children with symptoms of HIV infection were treated for 12-26 months (median 14 months) with infusions of intravenous immunoglobulin (200 mg/kg) every three weeks. Significant improvement was noted in all children in terms of weight gain, number of infectious episodes, and days spent in hospital. This resulted in a 49% saving in cost on treatment compared with costs accrued previously during inpatient admissions. Immunoglobulin concentrations, which were raised at the start of treatment were not altered, and T4 counts continued to decline slowly. HIV core antigen was detected in four children before treatment, but all became core antigen negative after treatment was commenced, this effect being sustained in three. Intravenous immunoglobulin therefore has major clinical benefit, and by reducing viral activity may delay disease progression.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Transcutaneous monitoring of oxygenation: what is normal?

We examined 55 infants on 119 occasions, from birth to 6 months, to obtain normal data and to establish guidelines for the management of oxygen-dependent infants with chronic lung disease. Transcutaneous oxygen tension (tcPo2) and saturation (tcSao2) were monitored during four states: awake, feeding, quiet sleep, and active sleep. Lowest values (mean +/- SD) for tcSao2 were recorded in all states during the first week of life: awake 96.2% +/- 2.6%, feeding 91.2% +/- 3.7%, quiet sleep 93.2% +/- 2.9%, and active sleep 92.1% +/- 2.9%. After the first week the results were affected by state rather than age, with differences observed between awake and feeding (P less than 0.0001), awake and asleep (P less than 0.00001), and quiet sleep and active sleep (P less than 0.001). The findings for tcPo2 were less consistent and probably affected by the characteristics of skin. In the first week, values were as follows: awake 83.5 +/- 10.1 mm Hg, feeding 73.4 +/- 10.1 mm Hg, quiet sleep 78.5 +/- 10.9 mm Hg, and active sleep 73.4 +/- 11.4 mm Hg. Subsequently, only the state effect remained, and significant differences existed between awake and feeding (P less than 0.0001) and awake and asleep (P less than 0.00001). We conclude that transcutaneous blood gas measurements are affected by state of the infant.

Eating↗
PubMed1984

Young diabetics: memories, current lifestyles and attitudes.

Eighty-six subjects aged 22.3 +/- 2.3 years (mean +/- S.D.), who attended one clinic as diabetic children, filled in a questionnaire designed to evaluate their present health and lifestyles, as well as discover their childhood memories. About two-thirds (66.3%) had unhappy recollections particularly of such irritating routines as urine testing, injections, and special food programmes. Only 6% complained that future complications were not discussed with the child at the appropriate time, but with the exception of blindness, childhood knowledge of diabetic complications was poor. Around two-thirds (66.4%) left school with some examination result; 44.2% went into further education, while 19.8% entered into a trade. These attainments were comparable to those of local school leavers. As young diabetic adults, 62.8% were employed; 22.1% were students or housewives with no other occupations.

Adolescent↗
PubMed1984

Symptoms, atopy, and bronchial reactivity after lower respiratory infection in infancy.

We studied the prevalence of subsequent respiratory symptoms and the relation between atopic status and bronchial reactivity in 200 index children and their controls 7 years after acute lower respiratory tract infections in infancy. Index children with recurrent symptoms differed from controls in respect of social and family characteristics and atopic background. Ventilatory function was diminished and bronchial reactivity increased. Symptom free index children also came from poorer environmental backgrounds, but did not otherwise differ from controls. 'Atopic' index children differed significantly from controls in respect of subsequent symptoms and ventilatory function and similar adverse trends were observed in 'non-atopic' index children. A comparable proportion of 'atopic' and 'non-atopic' index children showed bronchial reactivity (33.5% and 38.9% respectively). Index subgroups with and without bronchial reactivity had increased cough and wheeziness compared with respective matched controls. The former included children with 'established' asthma and the latter those with 'established' bronchitis. Atopic backgrounds were similar in both subgroups, with no differences between cases and controls. These findings suggest that atopic background and bronchial reactivity are not closely related but may contribute independently to the persistence of symptoms after respiratory infections in infancy. Bronchial reactivity may be a more useful basis than atopic status on which to separate children with episodic cough or wheeze, or both, into 'asthmatic' and 'bronchitic' subgroups.

Cough↗
PubMed1984

Outcome for acute bronchitis, bronchiolitis, and pneumonia in infancy.

The clinical and respiratory function characteristics of 200 children 7 years after their admission to hospital with acute lower respiratory tract infection in infancy have been presented. Results were subsequently analysed according to disease category (bronchitis, bronchiolitis, or pneumonia) at initial presentation. Within each diagnostic category recurrent cough and wheeze, a tendency for colds 'to go to the chest', medication, absence from school, and family doctor consultations were significantly increased. Ventilatory function was diminished and bronchial reactivity increased when compared with matched controls. Studies of a different design are required to elucidate the mechanisms whereby symptoms are increased, ventilatory function impaired, and bronchial reactivity increased after severe lower respiratory infection in infancy.

Bronchiolitis, Viral↗
PubMed1983

Pulmonary function in severe chronic asthma in children during apparent clinical remission.

We have studied PEF, MEFV curves and the response to breathing He/O2 in 10 children (mean age 12 years) with severe steroid dependent asthma during a two year period. Abnormalities of ventilatory function were almost invariably present, with FEV1 and V50, breathing air or He/O2, the commonest indices of abnormality. FEV1 was comparable in sensitivity to V50 in detecting airflow obstruction. Clinical criteria of severity greatly underestimated the degree of functional impairment. The absolute, but not the relative response to inhalation of He/O2 was reduced at 50% VC and 25% VC. Following the inhalation of salbutamol, FEV1 V50 and V25 increased significantly in every case.

Adolescent↗
PubMed1982

Outcome of acute lower respiratory tract infection in infants: preliminary report of seven-year follow-up study.

Seven years after admission to hospital for acute lower respiratory tract infection in infancy 200 children and their matched controls were assessed for respiratory state and epidemiological characteristics. The index group comprised 100 cases where respiratory syncytial virus infection had been responsible for the index illness (group 1) and 100 cases in whom this organism had not been found (group 2). There were no differences between index and control groups in birth weight or gestational age but fewer index cases were breast fed. Social indices such as class distribution and family size were more favourable in controls, though housing standards and maternal smoking habits were similar in the two groups. The prevalence of subsequent respiratory symptoms--cough, wheeze, nasal discharge, and hearing difficulties--was greater in index cases as was absence from school and family doctor consultation for respiratory illness. Bronchitis and asthma were significantly more common in the index group. Impaired ventilatory function and bronchial hyperreactivity were found in index cases when compared with controls. No differences in clinical characteristics and outcome were found in the two groups of index cases. The question whether lung "damage" during lower respiratory tract infection predisposes to subsequent respiratory problems or whether certain infants are more vulnerable than others to respiratory illnesses (including lower respiratory tract infection) from the onset is unanswered.

Acute Disease↗
PubMed1979

Mycoplasma pneumoniae infection. A retrospective review of 103 hospitalised children.

The clinical aspects of Mycoplasma pneumoniae infection in 103 children under 12 years admitted to hospital over an eight-year period were reviewed retrospectively. Respiratory illnesses occurred in 87 (85%) cases. The prevalence of lower respiratory tract involvement was similar in both pre-school and school children. Cough was the commonest symptom at all ages. Coryzal symptoms and wheeze were common in pre-school children. Most infants had signs of pharyngitis or otitis media. Non-specific symptoms--fever, lethargy, malaise, anorexia and vomiting--were common accompaniments in children older than one year of age. Non-respiratory illnesses in 16 (15%) patients included gastroenteritis, convulsions, non-specific skin rashes and limb pains. The duration of stay in hospital ranged from two to 30 days (median five days) with apparent clinical recovery and resolution of chest X-ray abnormalities within three months in 78 (76%) patients seen for review.

Age Factors↗
PubMed1979

Mycoplasma pneuminia infection. A follow-up study of 50 children with respiratory illness.

Fifty children with a previous history of Mycoplasma pneumoniae respiratory tract infection were assessed clinically, and pulmonary function tests carried out after an interval ranging from 1 1/2 to 9 1/2 years (median 2 1/2). 23 suffered from recurrent wheezy bronchitis or asthma, and in 5 the index illness appeared to precipitate the wheezing tendency. All were symptom-free when respiratory function tests were performed. Simple tests of ventilatory function (PEFR, FEV, and FVC) were within normal limits. Increased bronchial reactivity after exercise (a fall in PEFR greater than 15% resting value) was demonstrated only in children known to have asthma. Maximum expiratory flow rates in air at 50% of vital capacity (V mas50) were within the normal range in all patients with the exception of two. The response in flow rate at 50% of vital capacity after inalation of an 80% helium and 20% oxygen mixture delta V max50) was reduced (P less than 0.001) in asymptomatic patients with a history of M. pneumoniae respiratory infection, when compared with normal data from 48 healthy schoolchildren without a background of significant respiratory illnesses. These findings indicate impairment of small airways function, even in totally symptom-free children in the study group.

Child↗
PubMedDate not supplied

Hyperviscosity in HIV infected children--a potential hazard during intravenous immunoglobulin therapy.

A four year old boy with symptoms of HIV infection and serum IgG of 53.2 g/l had been treated for 16 months with regular infusions of intravenous immunoglobulin (IV IgG). During one such infusion he developed temporary neurological symptoms and signs suggestive of the hyperviscosity syndrome. Serum relative viscosity was raised at 5.0 (normal range 0.42-2.78). Subsequent IV IgG infusions given at a slower rate have been without adverse reactions. In a study of eight HIV infected children including the index case, and 20 children not infected with HIV, serum relative viscosity was significantly raised in the HIV infected children (p less than 0.01; students t-test). Viscosity correlated with total serum IgG, which was raised in all HIV infected children, and with serum IgM. In HIV infected children with very high levels of serum IgG a slow rate of IV IgG infusion should therefore be chosen due to the possibility of hyperviscosity.

Blood Viscosity↗
PubMedDate not supplied

Maternal factors in HIV transmission.

In order to identify features associated with an increased risk of transmission of HIV from seropositive women to their offspring, 70 children of 58 HIV seropositive mothers were studied. Fifty-six children were followed prospectively from pregnancy; in 14 identified after the puerperium, obstetric notes were reviewed and stored serum was tested. Twelve infants of 10 mothers were HIV infected. Risk of transmission was increased in the first year after seroconversion; 5/9 infants born at this time were infected compared with 7/61 born subsequently (P < 0.001). Progression to stage IV in transmitters was more likely, occurring in the mothers of 9 infected children at a median of 3 years (range 0.5-6.5) and in mothers of 19 non-infected children at a median of 5 years (range 1-7) (P = 0.032). Maternal CD4+ counts < 400 x 10(6)/l were found in 7/12 transmitting and 7/49 non-transmitting pregnancies (P < 0.01). Differences in HIV antigenaemia did not reach significance. These factors may influence the counselling of mothers regarding their child's and their own prognosis.

Acquired Immunodeficiency Syndrome↗