Virologic and serologic markers of rapid progression to AIDS after HIV-1 seroconversion

The association between early virologic and immunologic events after human immunodeficiency virus type 1 (HIV-1) infection and progression of HIV-1 infection to acquired immunodeficiency syndrome (AIDS) was studied among 59 homosexual men with documented time of seroconversion. Epidemiologic factors, such as number of lifetime sexual partners, history of sexually transmitted diseases, and other factors, also were studied. All 17 seroconverters in the cohort who developed AIDS within 3 years (rapid progressors = RPs) were compared with 42 men without AIDS for at least 6 years seroconversion (nonrapid progressors = non-RPs). Plasma levels of HIV-1 RNA, p24 antigen, antibodies to HIV-1 structural genes, beta-2 microglobulin, neopterin, and interferon-alpha were measured at four time points: (a) the last seronegative visit, (b) the first seropositive visit, (c) the visit closest to AIDS (or the corresponding visit for the non-RPs) and (d) 6 years after seroconversion (for non-RPs). Up to seroconversion, the RPs had a significantly higher number of lifetime sexual partners than non-RPs (503 versus 171, respectively). At the first seropositive visit, RPs had significantly higher concentrations of plasma HIV-1 RNA (p < 0.01) and prevalence of p24 antigenemia (p < 0.001) and significantly lower levels of antibodies to the HIV-1 gag proteins p17 and p24 (p < 0.01-0.001) compared with non-RPs. These differences increased during follow-up visits. Antibodies to p66 and gp120 were significantly different only at the visit closet to AIDS (p < 0.001), as were beta-2 microglobulin and interferon alpha. These findings suggest that early virologic-immunologic events after HIV-1 infection may determine the rate of progression to AIDS. Anti-gag immune response may prevent rapid progression of HIV-1 disease and should be considered for future vaccine studies.

Separation and comorbidity of hyperactivity and conduct disturbance in Chinese schoolboys

In a two-stage community study of 3069 Chinese schoolboys in Hong Kong, those entering stage 2 were classified by scores on Rutter's teacher and parent questionnaires into: (1) a mixed hyperactive/conduct-disturbed (HA-CD) group; (2) a pure hyperactive (HA) group; (3) a pure conduct-disturbed (CD) group; and (4) a normal control group. The four groups of children were compared on a series of psychosocial, cognitive and neurodevelopmental measures. This was followed by a regression analysis to examine the specificity of the differential patterns of associations between HA and CD. There was a mix of negative and positive findings defying a simple, definitive conclusion. However, the positive findings that did emerge supported a growing body of recent literature which favoured a separation of HA from CD and their cross-cultural validity: the former was associated with neurodevelopmental impairments, the latter with family disharmony. The mixed condition, HA-CD, was a hybrid of its two constituent conditions, displaying the attributes of both.

Hyperactivity and conduct problems as risk factors for adolescent development

OBJECTIVE

To clarify the developmental risk associated with hyperactive behavior, especially the relationship between hyperactive and conduct problems, in a longitudinal epidemiological design.

METHOD

A follow-up study of children who were identified, by parent and teacher ratings in a large community survey of 6- and 7-year-olds, as showing pervasive hyperactivity or conduct problems or the comorbid mixture of both problems or neither problem. They were later investigated, at the age of 16 to 18 years, with detailed interview techniques as well as parental and self-report ratings and cognitive tests.

RESULTS

Hyperactivity was a risk factor for later development, even allowing for the coexistence of conduct problems. Its sequelae included a high likelihood of psychiatric diagnosis, persisting hyperactivity, violence and other antisocial behaviors, and social and peer problems.

CONCLUSIONS

The results suggested a developmental pathway through which hyperactivity raised the likelihood of impaired social adjustment, including the development of psychiatric disorders, independently of the existence of conduct problems.

Sex ratio and litter size in the guinea-pig

A significant relationship between sex ratio and litter size at birth was observed in the young of guinea-pigs caged singly from 8 weeks of age and during their first pregnancy; a male was present only at or around oestrus. Small litters (1-2 young) had significantly more males than did large litters (4-5 young). Such a relationship was not apparent in animals housed communally, whether young or older or in their second pregnancy. Litters in late pregnancy (day 63) or at delivery were significantly smaller than at mid-pregnancy (day 35). A significant negative relationship was found between litter size and bodymass at birth and to at least 63 days of age. Growth rates during the period of lactation were lower in animals born in large litters. The possible adaptive significance of a plastic relationship between litter size and sex ratio is considered together with the physiological mechanism that might be involved.

Establishing the constructs of childhood behavioral disturbances in a Chinese population: a questionnaire study

The behavioral problems of Chinese children were examined in a questionnaire study of a representative sample of 3,069 seven-year-old Chinese schoolboys in Hong Kong using Rutter's questionnaires for completion by parents and teachers. Separate robust dimensions of hyperactivity, antisocial, and neurotic behaviors were evident. The correlations among different dimensions were similar to those reported in the West. Short-term longitudinal analysis suggested that these dimensions were stable over time and that antisocial behaviors might develop in hyperactive children. The finding highlights the necessity of differentiating the hyperactive domain from the antisocial one. A significant source effect was found in all three dimensions. Chinese schoolboys had nearly two times the level of questionnaire-rated hyperactivity compared with school boys in the West; but it is premature to conclude that hyperactivity is more common in Chinese schoolboys in Hong Kong. Cross-cultural differences in adults' expectations and tolerance remain a plausible explanation.

Smoking and the sudden infant death syndrome: results from 1993-5 case-control study for confidential inquiry into stillbirths and deaths in infancy. Confidential Enquiry into Stillbirths and Deaths Regional Coordinators and Researchers

OBJECTIVE

To investigate the effects of exposure to tobacco smoke and of parental consumption of alcohol and illegal drugs as risk factors for the sudden infant death syndrome after a national risk reduction campaign which included advice on prenatal and postnatal avoidance of tobacco smoke.

DESIGN

Two year population based case-control study. Parental interviews were conducted for each infant who died and four controls matched for age and date of interview.

SETTING

Three regions in England with a total population of 17 million people.

SUBJECTS

195 babies who died and 780 matched controls.

RESULTS

More index than control mothers (62.6% v 25.1%) smoked during pregnancy (multivariate odds ratio = 2.10; 95% confidence interval 1.24 to 3.54). Paternal smoking had an additional independent effect when other factors were controlled for (2.50; 1.48 to 4.22). The risk of death rose with increasing postnatal exposure to tobacco smoke, which had an additive effect among those also exposed to maternal smoking during pregnancy (2.93; 1.56 to 5.48). The population attributable risk was over 61%, which implies that the numbers of deaths from the syndrome could be reduced by almost two third if parents did not smoke. Alcohol use was higher among index than control mothers but was strongly correlated with smoking and on multivariate analysis was not found to have any additional independent effect. Illegal drug use was more common among the index parents, and paternal use of illegal drugs remained significant in the multivariate model (4.68; 1.56 to 14.05).

CONCLUSIONS

This study confirms the increased risk of the sudden infant death syndrome associated with maternal smoking during pregnancy and shows evidence that household exposure to tobacco smoke has an independent additive effect. Parental drug misuse has an additional small but significant effect.

Environment of infants during sleep and risk of the sudden infant death syndrome: results of 1993-5 case-control study for confidential inquiry into stillbirths and deaths in infancy. Confidential Enquiry into Stillbirths and Deaths Regional Coordinators and Researchers

OBJECTIVE

To investigate the role of sleeping arrangements as risk factors for the sudden infant death syndrome after a national risk reduction campaign.

DESIGN

Two year population based case-control study. Parental interviews were conducted for each infant who died and for four controls matched for age and date of interview.

SETTING

Three regions in England with a total population of 17 million people.

SUBJECTS

195 babies who died and 780 matched controls.

RESULTS

Prone and side sleeping positions both carried increased risks of death compared with supine when adjusted for maternal age, parity, gestation, birth weight, exposure to smoke, and other relevant factors in the sleeping environment (multivariate odds ratio = 9.00 (95% confidence interval 2.84 to 28.47) and 1.84 (1.02 to 3.31), respectively). The higher incidence of side rather than prone sleeping led to a higher population attributable risk (side 18.4%, prone 14.2%). More of the infants who died were found with bed covers over their heads (21.58; 6.21 to 74.99). The use of a dummy had an apparent protective effect (0.38; 0.21 to 0.70). Bed sharing for the whole night was a significant risk factor for infants whose mothers smoked (9.25; 2.31 to 34.02). No protective effect of breast feeding could be identified on multivariate analysis.

CONCLUSIONS

This study confirms the importance of certain risk factors for the sudden infant death syndrome and identifies others-for example, covers over the head, side sleeping position-which may be amenable to change by educating and informing parents and health care professionals.

Development of a sensitive porcine granulosa cell bioassay for follicle-stimulating hormone (FSH)

PURPOSE

Our objective was to develop a sensitive in vitro bioassay for follicle-stimulating hormone (FSH) that does not require the housing of animals in a research facility.

MATERIALS AND METHODS

Porcine granulosa cells from 1- to 3-mm follicles were cultured on laminin for 48 hr in serum-free medium in the absence or presence of FSH or with other purified pituitary hormones, supplemented with 19-OH androstenedione. Estradiol accumulation in medium per microgram of DNA of cells was determined as a reflection of FSH-induced aromatase activity.

RESULTS

FSH (0.01-10 ng/ml) caused a dose-dependent increase in estradiol production per microgram of DNA, with 1, 10, and 100 ng/ml significantly higher than control. Porcine FSH was approximately two fold more biopotent than rat FSH in this system. Higher doses of FSH (100 ng/ml) caused less estradiol accumulation, presumably reflecting FSH receptor down regulation. No other pituitary hormone produced significant estradiol accumulation. Unextracted serum from a patient with premature ovarian failure (10-50 microliters) was tested in parallel to purified rat FSH (0-50 ng/ml) in this system, resulting in similar estradiol accumulation per microgram of DNA.

CONCLUSIONS

We have developed a porcine granulosa cell bioassay for FSH which is sensitive, is specific for FSH, and does not require the housing of animals on site. It can be completed by a technician within 4 working days and can detect FSH in a sample of human serum.

Rating child psychiatric caseness from detailed case histories

Novel operationalized criteria were used to rate detailed psychiatric case histories on 151 schoolchildren with hemiplegia. Ratings of psychiatric caseness or non-caseness were reliable and valid; the method may be widely applicable. Caseness was defined both narrowly (in terms of social incapacity for the child) and broadly (in terms of disruption to others and distress too). Both definitions could be applied reliably to children of normal intelligence but broadly defined caseness was more reliable for children with low intelligence. Barely half of the psychiatric cases met operationalized criteria for one or more DSM-IV or ICD-10 diagnosis. The others mostly had partial or mixed syndromes that could, with clinical judgement, be assigned to "not otherwise specified' diagnoses. Even with clinical judgement, however, a substantial minority of children with low intelligence had clinically significant but undiagnosable abnormalities in social relatedness.

Use of a directly conjugated monoclonal anti-D (BRAD-3) for quantification of fetomaternal hemorrhage by flow cytometry

BACKGROUND

Determination of the volume of fetal D-positive cells in the circulation of D-negative women after delivery is carried out to determine whether additional prophylactic anti-D should be given to the mother. Although the Kleihauer-Betke test is still widely used to calculate the fetomaternal hemorrhage, increasing use is being made of flow cytometry.

STUDY DESIGN AND METHODS

A conjugated monoclonal anti-D was prepared by labeling purified BRAD-3 (IgG3) with fluorescein isothiocyanate (FITC-BRAD-3). This reagent was used to label D-positive red cells by a one-step procedure: 5 microL of washed cells were incubated with 50 microL of FITC-BRAD-3 (50 micrograms/mL) at 37 degrees C for 30 minutes; then the cells were washed and 500,000 events were analyzed by flow cytometry.

RESULTS

The FITC-BRAD-3 reagent effectively labeled D-positive cells. The percentage of D-positive cells in mixtures containing more than 0.04 percent D-positive cells in D-negative cells was accurately determined by using this reagent and flow cytometry. Although the Kleihauer-Betke test was more accurate than this one-step flow cytometric method at quantifying fetomaternal hemorrhage of < 1 mL, the flow cytometric method was more accurate in the 1- to 7-mL fetomaternal hemorrhage range of 1 to 7 mL (whole-blood equivalents). Analysis of 175 clinical samples for fetomaternal hemorrhage gave consistent quantification results with the three methods used: the Kleihauer-Betke test, flow cytometry with FITC-BRAD-3, and flow cytometry with polyclonal anti-D followed by FITC-anti-IgG.

CONCLUSION

Labeling of samples with FITC-BRAD-3 was simple and rapid. By flow cytometric analysis, good separation of D-positive from D-negative cells was obtained, and fetomaternal hemorrhage of > 1 mL was quantified accurately.

The diagnosis and prevalence of hyperactivity in Chinese schoolboys

BACKGROUND

This study was undertaken to examine the validity of different diagnostic definitions of hyperactivity in a Chinese population. Estimates of the prevalence of hyperactivity were made according to these different diagnostic definitions.

METHOD

In a two-stage epidemiological study of hyperactivity in Hong Kong, 3069 Chinese schoolboys were screened by questionnaires; and a stratified sample of 611 of them entered a second stage for more detailed diagnostic assessment.

RESULTS

Children with hyperkinetic disorder (ICD-10) or ADDH (DSM-III) both displayed significant hyperactive symptoms, but with somewhat different external correlates; hyperkinetic disorder tended to show more neurodevelopmental impairments, ADDH more cognitive and educational difficulties. These findings raise the possibility of heterogeneity in the disorders present with hyperactivity. The DSM-III-R category of ADHD was more common, and those extra cases, that did not overlap with ADDH or hyperkinetic disorder, included children with no obvious behavioural, cognitive or neurodevelopmental impairments. Hence ADHD may be an over-inclusive category. Prevalence rates for hyperkinetic disorder, ADDH and ADHD were respectively 0.78%, 6.1% and 8.9%.

CONCLUSIONS

A disorder of hyperactivity does exist in the Chinese culture, displaying the same kinds of symptomatology and external correlates as in the West. The prevalence rates of hyperkinetic disorder and ADDH in Chinese schoolboys are on the low side when compared to those reported in Western studies.

Seasonal temperature acclimatisation of rainbow trout: cardiovascular and morphometric influences on maximal sustainable exercise level

Adult rainbow trout (mass 600-1500 g; length 40-44 cm) were held in the laboratory for up to 28 days at seasonally appropriate temperatures. The maximal sustainable aerobic exercise level (involving slow-twitch muscle activity alone) was determined by following muscle recruitment patterns using electromyography. The mean (&plusmn; s.e.m.) speeds recorded for maximal sustainable aerobic exercise were 0.52&plusmn;0.02, 0.81&plusmn;0.06 and 0.39&plusmn;0.02 BL s-1 (body lengths per second) for animals swimming at their acclimatisation temperatures of 4, 11 and 18 &deg;C, respectively. Thus, fish acclimatised to 11 &deg;C reached the highest maximal sustainable (purely aerobic) levels of exercise. They had similar stride lengths to the 4 &deg;C animals, but generated less thrust per stride, as indicated by increased tail-beat frequency. Acclimatisation to 4 &deg;C led to an increased mass of slow muscle and more effective tail beats (greater stride length at lower frequencies), relative to animals at higher temperatures. Fish acclimatised to 18 &deg;C had the lowest stride length and a reduced aerobic swimming capacity. Sustainable levels of aerobic exercise were reflected in unchanged values for mean heart rate and arterial blood pressure between rest and imposed, graded exercise. Radiolabelled microspheres were used to determine cardiac output (V.b) and regional blood flow distribution simultaneously in fish, both at rest and while swimming, for each acclimatisation temperature. Fish acclimatised to 11 &deg;C had the greatest scope for increasing V.b. This resulted in a significant hyperaemia in slow muscle upon exercise (10-fold increase), without an active redistribution of flow from other tissues. Maximum V.b at 18 &deg;C did not differ significantly from that at 11 &deg;C but, because resting V.b was higher, the scope was reduced and was similar to that found at 4 &deg;C. Specific blood flow to the active muscle was also reduced and this, together with decreased blood oxygen content and reduced slow muscle mass, may limit aerobic swimming performance at 18 &deg;C.

Outpatient laparoscopic cholecystectomy feasibility

One-hundred nineteen elective cholecystectomies were performed at Kern Medical Center over a 20-month period from October 1992 to May 1994 and were retrospectively reviewed. Eight males and 111 females ranged in age from 16 to 70. Laparoscopic cholecystectomy was attempted in 116 patients and converted to open in 8 (7%). Of the elective procedures, 108 (91%) were planned as outpatient procedures. Of the 108 planned outpatient procedures, 73 (68%) were successfully completed as outpatients. Of the 35 patients who required unplanned admission, 21 were discharged in less than 24 h. In total, 101 (87%) of the 116 elective cholecystectomies begun laparoscopically were discharged in less than 24 h. Subsequent to this data analysis, our institution is developing a 23.9 h "day hospital" for postanesthesia observation. With extended postoperative monitoring and observation, patients with short-term problems such as nausea, vomiting, pain, and even patients with medical conditions requiring close observation and control should be able to avoid admission. This retrospective study indicates that with development of a 23.9 h postanesthesia care unit, the majority of elective cholecystectomies can be attempted and completed laparoscopically on an outpatient basis.

Large vesicle formation within cells induced by treatment with a mixed surfactant

MDCK cells have been treated with a mixed surfactant at low concentrations to study the induced morphological changes. The most significant change at the light microscope level was the appearance of multiple large vesicles, which increased in size with time, up to approximately 40 microns in diameter. Vesicle formation was shown to be linked with the uptake of the fluid medium, as judged by the presence of FITC-dextran within the vesicles, but was not a result of pinocytosis because cytochalasin D treatment had no effect on their formation. Furthermore, nile red staining demonstrated that the vesicles did not represent fusion of pre-existing lipid droplets. Transmission electron microscopy (TEM) analysis indicated that the vesicles lacked any obvious structure. It is hypothesised that the vesicles are large mixed structures synthesised as a result of interactions between cell membranes and detergent components after saturation with the surfactants. This effect is contrasted with the diffuse uptake of dyes and fluorescently labelled proteins following simple anionic or ionic detergent treatment. The effect of vesicle formation was reversible if the cells were placed in fresh medium lacking detergent. Other effects of mixed detergent included the loss of rounded compact colonies, an increase in mean cell diameter and the almost complete loss of surface microvilli as seen with scanning electron microscopy (SEM). In the TEM the cell ultrastructure was seen to have changed markedly following detergent treatment, with a loss of rough endoplasmic reticulum and an apparent clumping of the cytoplasmic constituents.

Situational versus pervasive hyperactivity in a community sample

Groups of home and school situational hyperactive primary schoolboys identified from the community were compared with pervasive hyperactive and non-hyperactive controls on a wide range of measures. The hyperactive groups tended to persist in the same category over a half-year period. Both situational hyperactive groups had lower measured activity levels than the pervasive hyperactive group and only the latter differed from non-hyperactive controls. Home hyperactivity was characterized by poor family relationships and was not distinguishable from non-hyperactive home-antisocial controls. School hyperactive boys had specific correlates of low intelligence, motor clumsiness, poor reading and academic abilities. Pervasive hyperactive subjects differed from both situational groups in showing a higher percentage of delayed language development. While home hyperactivity has dubious identity, the distinct pattern of external correlates in school and pervasive hyperactivity speak for the need to regard these as separate entities.

The effects of relaxin on the response of intramammary pressure and mammary blood flow to exogenous oxytocin in the goat

Lactating goats were given relaxin (50 micrograms) by close-arterial infusion into one mammary gland. The increase in intramammary pressure and in mammary blood flow elicited by exogenous oxytocin i.v. was attenuated by relaxin in goats during pregnancy and early lactation but not in a group studied during the oestrous cycle. Intramammary pressure in both mammary glands was affected at the dose of relaxin used. It is concluded that a change in responsiveness of the mammary myoepithelium to oxytocin is one possible effect of relaxin, acting directly or indirectly, circulating systemically during pregnancy and produced locally by the mammary gland at the onset of and during lactation.

The impact of state approval requirements on elective cholecystectomy patients

A total of 215 cholecystectomies were performed at Kern Medical Center over a 20-month period from 10/92 to 5/94 and were retrospectively reviewed. Twenty-four males and 191 females ranged in age from 15-70 years. Of the total 215 cholecystectomies, 119 were performed electively and were separated into two groups. Group 1 (79) consisted of patients awaiting state authorization for cholecystectomy. Group 2 (40) consisted of patients who did not require state authorization. Date of diagnosis was defined as the date when the positive gallbladder ultrasound was completed which, in context with the clinical presentation, confirmed the need for cholecystectomy. The average number of days between diagnosis and cholecystectomy differed significantly between Group 1 and 2 (116 vs 23 respectively, P < .01). The average number of preoperative emergency room (ER) visits differed significantly between Group 1 and 2 (1.48 vs 0.76 respectively, P < .01). The average number of preoperative surgery clinic visits also differed between the two groups (2.88 vs 1.96 in Group 1 and 2 respectively, P < .01). Patients with symptomatic cholelithiasis requiring state approval for cholecystectomy had to wait longer for their operation, and preoperatively visited the ER and outpatient surgery clinic more often. Delay increases patient discomfort and adds additional strain to an already overcrowded ER and clinic. Finally, the economic impact is most likely significant as lost work hours, and additional ER and clinic visits cost taxpayers money.

Plasma ammonia concentration in brown trout in soft acidic water and its relationship to decreased swimming performance

Adult brown trout (300&shy;600 g) were acclimated for 2 weeks to an artificial soft water (Ca2+, 50 &micro;mol l-1) and maintained at either 5 &deg;C (October to March) or 15 &deg;C (May to August). Following insertion of a cannula into the dorsal aorta under MS-222 anaesthesia and a recovery period of 2 days, the fish were exposed to a 4 day episode of sub-lethal copper levels at pH 5 or kept at control conditions of pH 7 without copper. The copper concentrations had been predetermined by toxicity testing and were approximately 0.47 &micro;mol l-1 at 5 &deg;C and 0.08 &micro;mol l-1 at 15 &deg;C. At 5 &deg;C, a group of fish was also exposed to approximately 0.08 &micro;mol l-1 copper at pH 5. Plasma total ammonia (Tamm) concentration was significantly elevated by exposure to copper and pH 5. In resting trout exposed to the appropriate sub-lethal copper concentration at pH 5, Tamm was six and 7.5 times greater at 5 and 15 &deg;C, respectively, than those of control trout at the respective temperatures. Although unconfirmed, an elevation of ammonia production alone seems unlikely to account for such substantial increases. From previous studies, there is little evidence of impairment of respiratory gas exchange in trout exposed to these copper concentrations and yet, in the acidic test waters, the gradient of NH3 partial pressure between fish and water was 5.5&shy;6 times greater than that under control conditions. Swimming performance determined by the critical swimming speed (Ucrit) was reduced by copper and acid exposure, and a significant relationship existed between Ucrit and the plasma ammonia concentration of exercised trout. Ammonium ions influence several key enzymes involved in energy metabolism, and elevated ammonia levels might, therefore, reduce the capacity of muscle to exercise. Alternatively, ammonia may have affected the nervous coordination of exercise either centrally or by disrupting peripheral motor innervation.

Genetic risk of neuropsychological impairment in schizophrenia: a study of monozygotic twins discordant and concordant for the disorder

We used a paradigm involving monozygotic (MZ) twin pairs discordant for schizophrenia (n = 20) and concordant for schizophrenia (n = 8), as well as normal MZ twin pairs (n = 7) in order to study cognitive measures of genetic risk in schizophrenia. A comparison between the unaffected twins from the discordant sample and the normal twins indicated subtle attenuations in some aspects of memory and executive functioning in the unaffected group and thus provided evidence for cognitive markers of a genetic component in schizophrenia. A comparison of the affected twins from the discordant pairs and the concordant twins yielded virtually no differences, suggesting that a distinction between familial and sporadic cases is not valid in this sample. Large differences between unaffected and affected members of discordant pairs on a wide variety of variables, including IQ, attention, memory, and executive function, highlighted the magnitude of disease-specific factors.