Site-directed mutagenesis of highly conserved amino acids in the first cytoplasmic loop of Drosophila Rh1 opsin blocks rhodopsin synthesis in the nascent state

The cytoplasmic surface of Drosophila melanogaster Rh1 rhodopsin (ninaE) harbours amino acids which are highly conserved among G-protein-coupled receptors. Site-directed mutations which cause Leu81Gln or Asn86Ile amino acid substitutions in the first cytoplasmic loop of the Rh1 opsin protein, are shown to block rhodopsin synthesis in the nascent, glycosylated state from which the mutant opsin is degraded rapidly. In mutants Leu81Gln and Asn86Ile, only 20-30% and <2% respectively, of functional rhodopsins are synthesized and transported to the photoreceptive membrane. Thus, conserved amino acids in opsin's cytoplasmic surface are a critical factor in the interaction of opsin with proteins of the rhodopsin processing machinery. Photoreceptor cells expressing mutant rhodopsins undergo age-dependent degeneration in a recessive manner.

Outcome after traumatic brain injury in the U.S. military medical system

Personality and behavioral change after traumatic brain injury (TBI) are often the most significant concerns for the families of TBI patients. This report examines discharge from military service after TBI for medical and behavioral criteria. When compared with the total discharge population (n = 1,879,724), the relative risk for behavioral discharge was 1.8 times greater for those with mild TBI (n = 1,778), and no difference for those with moderate (n = 174) or severe TBI (n = 274). Discharge for alcoholism or drug use was 2.6 times for mild TBI, 5.4 times for moderate TBI, and no difference for severe TBI compared with the total discharge population. Discharge for criminal conviction was 2.7 times for those with mild head injury, and no difference for those with moderate or severe TBI when compared with the total discharge population. Discharge for medical disability ranged from 7.5 times to 40.4 times, and mortality ranged from 11.6 to 142.4 times the total discharge population. Total sick days defined as the time from admission to return to duty or separation from service increased with head injury severity. Mean Injury Severity Score for mild TBI was 5.5, and 20.9 for severe TBI. Patients who sustain TBI should be monitored after injury for development of behavioral problems. The most effective way to reduce the cost of TBI is primary prevention of these injuries and examining military practices to reduce exposure to risk of TBI. Secondary and tertiary prevention measures such as evaluation and rehabilitation, where indicated, should be undertaken on a routine basis after TBI.

Long-term treatment of malignant gliomas with intramuscularly administered polyinosinic-polycytidylic acid stabilized with polylysine and carboxymethylcellulose: an open pilot study

Polyinosinic-polycytidylic acid stabilized with polylysine and carboxymethylcellulose (poly-ICLC) (10-50 mcg/kg, administered intramuscularly one to three times weekly) was given for < or = 56 months to 38 patients with malignant gliomas. There was minimal or no toxicity. Twenty of 30 patients (66%) receiving at least twice weekly poly-ICLC showed regression or stabilization of gadolinium-enhancing tumor, as revealed by magnetic resonance imaging (median = 65% volume decrease). All but one patient with anaplastic astrocytomas who received continuous poly-ICLC remain alive, with a median progression-free survival of 54 months from diagnosis. Median Kaplan-Meier survival is 19 months for patients with glioblastomas who receive at least twice weekly poly-ICLC treatments. Tumor response was associated with 2',5' -oligoadenylate synthetase activation (P = 0.03) but not with serum interferon. We hypothesize clinical activation by poly-ICLC of a basic host tumor suppressor system. Prolonged, quality survival with tumor stabilization or regression confirmed by magnetic resonance imaging for most patients with anaplastic astrocytomas and glioblastomas suggests that more extensive laboratory and controlled clinical studies are warranted. The concept of long-term, broad spectrum stimulation of host defenses with nontoxic, inexpensive double-stranded ribonucleic acids, such as low-dose poly-ICLC, may be applicable to the treatment of other malignancies.

Frontal lobe injuries, violence, and aggression: a report of the Vietnam Head Injury Study

Knowledge stored in the human prefrontal cortex may exert control over more primitive behavioral reactions to environmental provocation. Therefore, following frontal lobe lesions, patients are more likely to use physical intimidation or verbal threats in potential or actual confrontational situations. To test this hypothesis, we examined the relationship between frontal lobe lesions and the presence of aggressive and violent behavior. Fifty-seven normal controls and 279 veterans, matched for age, education, and time in Vietnam, who had suffered penetrating head injuries during their service in Vietnam, were studied. Family observations and self-reports were collected using scales and questionnaires that assessed a range of aggressive and violent attitudes and behavior. Two Aggression/Violence Scale scores, based on observer ratings, were constructed. The results indicated that patients with frontal ventromedial lesions consistently demonstrated Aggression/Violence Scale scores significantly higher than controls and patients with lesions in other brain areas. Higher Aggression/Violence Scale scores were generally associated with verbal confrontations rather than physical assaults, which were less frequently reported. The presence of aggressive and violent behaviors was not associated with the total size of the lesion nor whether the patient had seizures, but was associated with a disruption of family activities. These findings support the hypothesis that ventromedial frontal lobe lesions increase the risk of aggressive and violent behavior.

Penetrating injuries in the Vietnam war. Traumatic unconsciousness, epilepsy, and psychosocial outcome

The WF Caveness Vietnam Head Injury Study includes over a thousand men who survived penetrating head injuries during the Vietnam War and on whom detailed medical and follow-up data are available. This population offers unique opportunities for the study of recovery from brain injury and of brain structure-function relationships. The authors briefly review long-term outcome in this cohort with respect to traumatic unconsciousness, post-traumatic epilepsy, and elements of psychologic and psychosocial function, including returning to work.

Prevalence and outcome of hepatitis C infection among heart transplant recipients

BACKGROUND

Hepatitis C virus infection is common in organ transplant recipients, and can be associated with significant morbidity and mortality. A unique feature of this infection among immunosuppressed patients is that it can progress without the development of hepatitis C virus antibodies.

METHODS

To define the prevalence of hepatitis C virus infection in patients undergoing heart transplantation and identify clinical syndromes associated with hepatitis C virus infection in heart transplant recipients, we collected sera from 59 consecutive heart transplant recipients and their donors. Samples were tested before and after transplantation for hepatitis C virus antibodies with the use of a second-generation recombinant immunoblot assay and for hepatitis C virus RNA by means of reverse transcriptase polymerase chain reaction.

RESULTS

Four of 59 patients (7%) had hepatitis C virus-RNA detected in posttransplantation serum samples; but only one of these was anti-hepatitis C virus antibody positive. Two of the four patients with hepatitis C virus RNA detected after transplantation received organs from donors who were positive for hepatitis C virus RNA/anti-hepatitis C virus. One of these two recipients tested positive for hepatitis C virus antibody and hepatitis C virus RNA before transplantation. The other two patients received organs from hepatitis C virus negative donors and possibly acquired infection after transplantation from blood or immunoglobulin preparations. One patient was anti-hepatitis C virus positive before transplantation but had no detectable hepatitis C virus RNA, and hepatitis C virus infection did not develop after transplantation. Progressive hepatitis C virus-induced cholestatic liver disease that led to hepatic failure and death after heart transplantation occurred in one of the four patients.

CONCLUSION

Hepatitis C virus infection may occur after heart transplantation in the absence of anti-hepatitis C virus antibodies, and a syndrome of severe cholestatic liver disease may complicate heart transplantation in the presence of hepatitis C virus infection.

Residual impairments and work status 15 years after penetrating head injury: report from the Vietnam Head Injury Study

We investigated the relationship of neurologic, neuropsychological, and social interaction impairments to the work status of a large sample of penetrating head-injured patients wounded some 15 years earlier during combat in Vietnam. Extensive standardized testing of neurologic, neuropsychological, and social functioning was done at follow-up on each head-injured patient (N = 520), as well as on a sample of uninjured controls (N = 85). Fifty-six percent of the head-injured patients were working at follow-up compared with 82% of the uninjured controls. Seven systematically defined impairments proved to be most correlated with work status. These were post-traumatic epilepsy, paresis, visual field loss, verbal memory loss, visual memory loss, psychological problems, and violent behavior. These disabilities had a cumulative and nearly equipotent effect upon the likelihood of work. We suggest that a simple summed score of the number of these seven disabilities can yield a residual "disability score" which may prove to be a practical tool for assessing the likelihood of return to work for patients in this population and perhaps in other brain-injured populations. These findings may also help to focus rehabilitation efforts on those disabilities most likely to affect return to work.

A national survey of neurosurgical care for penetrating head injury

We report results of a survey on the management patterns of penetrating head injury (PHI). American neurosurgeons (N = 2969) were asked to participate in a mail survey. One thousand one hundred twenty-eight responded, providing detailed information about their practices, their opinions concerning diagnostic testing, nonoperative therapy, and surgical debridement for PHI. Although there was agreement on some areas of management and care, including the use of computed tomography scanning, antibiotics, anticonvulsants, and a few surgical indications/contraindications, there was wide variation on a significant number of points. These included testing for coagulopathy; use of corticosteroids, intracranial pressure monitoring, and barbiturate coma; and surgical indications including debridement of contusions, removal of fragments, location of injury, and Glasgow Coma Score 5-8. Many nonoperative decisions were influenced by the presence of neurosurgical residents, whereas the decision to operate was based primarily on judgment of patient salvageability. This survey uncovered disagreement on several crucial issues in the care of patients with penetrating head injury and the need for continued research in this area of patient care.

The natural history of symptomatic arteriovenous malformations of the brain: a 24-year follow-up assessment

The authors have updated a series of 166 prospectively followed unoperated symptomatic patients with arteriovenous malformations (AVM's) of the brain. Follow-up data were obtained for 160 (96%) of the original population, with a mean follow-up period of 23.7 years. The rate of major rebleeding was 4.0% per year, and the mortality rate was 1.0% per year. At follow-up review, 23% of the series were dead from AVM hemorrhage. The combined rate of major morbidity and mortality was 2.7% per year. These annual rates remained essentially constant over the entire period of the study. There was no difference in the incidence of rebleeding or death regardless of presentation with or without evidence of hemorrhage. The mean interval between initial presentation and subsequent hemorrhage was 7.7 years.

Organ-specific hematopoietic changes induced by a recombinant human interferon-alpha in mice

Interferon-alpha (IFN-alpha) is a naturally occurring cytokine that mediates numerous biological activities and has demonstrated therapeutic potential in a variety of malignancies. Encouraging activity against HIV-1 replication has also been observed with IFN-alpha in the treatment of AIDS, although hematotoxicity has been a frequently observed side effect. In addition, in vitro studies have suggested that IFN-alpha may function as a down-regulator of myelopoiesis. A recombinant hybrid of subtypes of human IFN-alpha, rHuIFN-alpha A/D, has antiviral activity in murine cells in vitro and in vivo. This study examines the effect of acute and subchronic exposure to rHuIFN-alpha A/D on hemopoietic and immune parameters in C57Bl/6 mice. IFN-alpha was administered ip at 0, 1000, 10,000, and 100,000 units/day for either 1 or 10 consecutive days. Many of the known effects of IFN-alpha in humans such as anemia, leukopenia, and thrombocytopenia were observed in mice following subchronic exposure, with the latter two effects also manifested following acute exposure. Further analysis showed that this leukopenia was not selective. Both splenic and bone marrow cells were examined following 10 days of dosing with the high dose of IFN-alpha. Lymphocytes were reduced in both compartments, while granulocytes were increased in both compartments. Bone marrow cells programmed to differentiate into granulocytes (CFU-G) were suppressed, while macrophage progenitors (CFU-M) were stimulated. Erythroid cells decreased in the marrow but increased in the spleen, suggesting that the microenvironment may play a significant role in the effect of IFN-alpha. The proliferative capacity of both B and T splenic lymphocytes was significantly suppressed in a dose-related fashion following multiple exposure to IFN-alpha. Clinically, IFN-alpha is most often given in multiple doses and the present data suggest that such a regimen is toxic to both erythroid and myeloid cells, as well as being immunotoxic to splenic B and T lymphocytes.

[Results of a survey on periodontal prevention carried out in a test population in Bern]

In 1974 the authors carried out an inquiry about knowledge and behavior concerning periodontal prevention. Two-hundred persons from Berne and surroundings sampled by a random procedure were interviewed. It appeared that knowledge about the causes, consequences, prevention and therapy of periodontal disease was fragmentary. Accordingly prophylactic efforts of the interviewed persons were not very systematic. Often people believed in the effect of special remedies such as mouth-wash and special tooth-paste. They did not know that a perfect technique of oral hygiene is the basic requirement for periodontal prevention. It appeared that the advising function of the dentists was partially insufficient. Patients suffering from bleeding gums had not received adequate information regarding the seriousness of their situation, or they were referred to the special remedies mentioned in figure 3. Instruction of a perfect oral hygiene technique was therefore neglected.