Tales of diversity: Genomic and morphological characteristics of forty-six Arthrobacter phages

The vast bacteriophage population harbors an immense reservoir of genetic information. Almost 2000 phage genomes have been sequenced from phages infecting hosts in the phylum Actinobacteria, and analysis of these genomes reveals substantial diversity, pervasive mosaicism, and novel mechanisms for phage replication and lysogeny. Here, we describe the isolation and genomic characterization of 46 phages from environmental samples at various geographic locations in the U.S. infecting a single Arthrobacter sp. strain. These phages include representatives of all three virion morphologies, and Jasmine is the first sequenced podovirus of an actinobacterial host. The phages also span considerable sequence diversity, and can be grouped into 10 clusters according to their nucleotide diversity, and two singletons each with no close relatives. However, the clusters/singletons appear to be genomically well separated from each other, and relatively few genes are shared between clusters. Genome size varies from among the smallest of siphoviral phages (15,319 bp) to over 70 kbp, and G+C contents range from 45-68%, compared to 63.4% for the host genome. Although temperate phages are common among other actinobacterial hosts, these Arthrobacter phages are primarily lytic, and only the singleton Galaxy is likely temperate.

The Paf1 complex subunit Rtf1 buffers cells against the toxic effects of [PSI+] and defects in Rkr1-dependent protein quality control in Saccharomyces cerevisiae

The Rtf1 subunit of the Paf1 complex is required for specific histone modifications, including histone H2B lysine 123 monoubiquitylation. In Saccharomyces cerevisiae, deletion of RTF1 is lethal in the absence of Rkr1, a ubiquitin-protein ligase involved in the destruction of nonstop proteins, which arise from mRNAs lacking stop codons or translational readthrough into the poly(A) tail. We performed a transposon-based mutagenesis screen to identify suppressors of rtf1Δ rkr1Δ lethality and found that a mutation in the gene encoding the protein chaperone Hsp104 rescued viability. Hsp104 plays a role in prion propagation, including the maintenance of [PSI+], which contributes to the synthesis of nonstop proteins. We demonstrate that rtf1Δ and rkr1Δ are synthetically lethal only in the presence of [PSI+]. The deletion, inactivation, and overexpression of HSP104 or the overexpression of prion-encoding genes URE2 and LSM4 clear [PSI+] and rescue rtf1Δ rkr1Δ lethality. In addition, the presence of [PSI+] decreases the fitness of rkr1Δ strains. We investigated whether the loss of RTF1 exacerbates an overload in nonstop proteins in rkr1Δ [PSI+] strains but, using reporter plasmids, found that rtf1Δ decreases nonstop protein levels, indicating that excess nonstop proteins may not be the cause of synthetic lethality. Instead, our data suggest that the loss of Rtf1-dependent histone modifications increases the burden on quality control pathways in cells lacking Rkr1 and containing [PSI+].

Targeting of gp78 for ubiquitin-mediated proteasomal degradation by Hrd1: cross-talk between E3s in the endoplasmic reticulum

There are an increasing number of ubiquitin ligases (E3s) implicated in endoplasmic reticulum (ER)-associated degradation (ERAD) in mammals. The two for which the greatest amount of information exists are the RING finger proteins gp78 and Hrd1, which are the structural orthologs of the yeast ERAD E3 Hrd1p. We now report that Hrd1, also known as synoviolin, targets gp78 for proteasomal degradation independent of the ubiquitin ligase activity of gp78, without evidence of a reciprocal effect. This degradation is observed in mouse embryonic fibroblasts lacking Hrd1, as well as with acute manipulation of Hrd1. The significance of this is underscored by the diminished level of a gp78-specific substrate, Insig-1, when Hrd1 expression is decreased and gp78 levels are consequently increased. These finding demonstrate a previously unappreciated level of complexity of the ubiquitin system in ERAD and have potentially important ramifications for processes where gp78 is implicated including regulation of lipid metabolism, metastasis, cystic fibrosis and neurodegenerative disorders.

Identification of Rkr1, a nuclear RING domain protein with functional connections to chromatin modification in Saccharomyces cerevisiae

Proper transcription by RNA polymerase II is dependent on the modification state of the chromatin template. The Paf1 complex is associated with RNA polymerase II during transcription elongation and is required for several histone modifications that mark active genes. To uncover additional factors that regulate chromatin or transcription, we performed a genetic screen for mutations that cause lethality in the absence of the Paf1 complex component Rtf1. Our results have led to the discovery of a previously unstudied gene, RKR1. Strains lacking RKR1 exhibit phenotypes associated with defects in transcription and chromatin function. These phenotypes include inositol auxotrophy, impaired telomeric silencing, and synthetic lethality with mutations in SPT10, a gene that encodes a putative histone acetyltransferase. In addition, deletion of RKR1 causes severe genetic interactions with mutations that prevent histone H2B lysine 123 ubiquitylation or histone H3 lysine 4 methylation. RKR1 encodes a conserved nuclear protein with a functionally important RING domain at its carboxy terminus. In vitro experiments indicate that Rkr1 possesses ubiquitin-protein ligase activity. Taken together, our results identify a new participant in a protein ubiquitylation pathway within the nucleus that acts to modulate chromatin function and transcription.

Experimental Nipah virus infection in pigs and cats

A human isolate of Nipah virus from an outbreak of febrile encephalitis in Malaysia that coincided with a field outbreak of disease in pigs was used to infect eight 6-week-old pigs orally or subcutaneously and two cats oronasally. In pigs, the virus induced a respiratory and neurological syndrome consistent with that observed in the Malaysian pigs. Not all the pigs showed clinical signs, but Nipah virus was recovered from the nose and oropharynx of both clinically and sub-clinically infected animals. Natural infection of in-contact pigs, which was readily demonstrated, appeared to be acute and self-limiting. Subclinical infections occurred in both inoculated and in-contact pigs. Respiratory and neurological disease was also produced in the cats, with recovery of virus from urine as well as from the oropharynx. The clinical and pathological syndrome induced by Nipah virus in cats was comparable with that associated with Hendra virus infection in this species, except that in fatal infection with Nipah virus there was extensive inflammation of the respiratory epithelium, associated with the presence of viral antigen. Viral shedding via the nasopharynx, as observed in pigs and cats in the present study, was not a regular feature of earlier reports of experimental Hendra virus infection in cats and horses. The findings indicate the possibility of field transmission of Nipah virus between pigs via respiratory and oropharyngeal secretions.

Transverse momentum distributions and their forward-backward correlations in the percolating color string approach

The forward-backward correlations in the p(T) distributions at midrapidity, which present a clear signature of nonlinear effects in particle production, are studied in the model of percolating color strings. Quantitative predictions are given for these correlations at SPS, RHIC, and LHC energies. Interaction of strings also naturally explains the flattening of p(T) distributions and increase of <p(T)> with energy and atomic number for nuclear collisions.

Immunohistochemistry in the identification of a number of new diseases in Australia

Immunohistochemistry plays an important part in the diagnosis of some viral diseases. Demonstration of viral antigen in a lesion is an important contribution to diagnosis, either at the time of investigation or retrospectively. At the CSIRO Australian Animal Health Laboratory, the most frequent use of immunohistochemistry has been in the diagnosis of the important avian diseases, highly pathogenic avian influenza and Newcastle disease. The technology took key roles in the diagnoses of Hendra virus infections, and, later, an immunoperoxidase test gave the first indication of the existence of Australian bat lyssavirus. The test can often confirm that a virus isolated in an animal is the actual virus causing disease and not a coincidental isolation. Good examples of that in some more new diseases were the association of Wallal virus with blindness in kangaroos, and of the new porcine Menangle virus in natural and experimental cerebral disease in foetal piglets.

Phase II trial of chemoembolization for the treatment of metastatic colorectal carcinoma to the liver and review of the literature

BACKGROUND

Hepatic artery chemoembolization represents an alternative treatment for patients whose neoplastic lesions are not amenable or have become refractory to other treatment modalities. This project was designed to test the feasibility of regional chemoembolization for patients with colorectal carcinoma metastasis to the liver who had experienced failure with one or more systemic treatments.

METHODS

Thirty patients who met the study entry criteria underwent one to three hepatic artery chemoembolizations. The chemoembolization regimen consisted of an injection of a bovine collagen material with cisplatin (10 mg/mL), doxorubicin (3 mg/mL), and mitomycin C (3 mg/mL). Repeat treatments were performed at 6- to 8-week intervals.

RESULTS

Radiologic responses, as measured by a decrease in lesion density of at least 75% of the lesion or a 25% decrease in the size of the lesion, occurred in 63% of the cases. A decrease of at least 25% of the baseline carcinoembryonic antigen level occurred in 95% of the cases. All responses were transient. Median survival for all 30 patients was 8.6 months after the initiation of chemoembolization and 29 months after the initial diagnosis of metastasis to the liver. Common toxicities included a "postembolization syndrome," which consisted of fever > 101 degrees F (83%), pain in the right upper quadrant (100%), nausea, and vomiting. Lethargy was a common occurrence (in 60+% of cases) and lasted up to 6 weeks. Hematologic toxicities included leukocytosis, anemia, and thrombocytopenia.

CONCLUSIONS

Chemoembolization is a feasible treatment modality for patients with colorectal carcinoma metastasis to the liver who have experienced failure with other systemic treatments. It results in high response rates with transient mild-to-moderate toxicity. Responses are measured in months, however, and all patients have eventual progression of disease. Patients who are able to undergo three or more chemoembolization procedures may receive the most clinical benefit.

Phase II trial of chemoembolization for the treatment of metastatic colorectal carcinoma to the liver and review of the literature

BACKGROUND

Hepatic artery chemoembolization represents an alternative treatment for patients whose neoplastic lesions are not amenable or have become refractory to other treatment modalities. This project was designed to test the feasibility of regional chemoembolization for patients with colorectal carcinoma metastasis to the liver who had experienced failure with one or more systemic treatments.

METHODS

Thirty patients who met the study entry criteria underwent one to three hepatic artery chemoembolizations. The chemoembolization regimen consisted of an injection of a bovine collagen material with cisplatin (10 mg/mL), doxorubicin (3 mg/mL), and mitomycin C (3 mg/mL). Repeat treatments were performed at 6- to 8-week intervals.

RESULTS

Radiologic responses, as measured by a decrease in lesion density of at least 75% of the lesion or a 25% decrease in the size of the lesion, occurred in 63% of the cases. A decrease of at least 25% of the baseline carcinoembryonic antigen level occurred in 95% of the cases. All responses were transient. Median survival for all 30 patients was 8.6 months after the initiation of chemoembolization and 29 months after the initial diagnosis of metastasis to the liver. Common toxicities included a "postembolization syndrome," which consisted of fever > 101 degrees F (83%), pain in the right upper quadrant (100%), nausea, and vomiting. Lethargy was a common occurrence (in 60+% of cases) and lasted up to 6 weeks. Hematologic toxicities included leukocytosis, anemia, and thrombocytopenia.

CONCLUSIONS

Chemoembolization is a feasible treatment modality for patients with colorectal carcinoma metastasis to the liver who have experienced failure with other systemic treatments. It results in high response rates with transient mild-to-moderate toxicity. Responses are measured in months, however, and all patients have eventual progression of disease. Patients who are able to undergo three or more chemoembolization procedures may receive the most clinical benefit.

Phase II trial of chemoembolization for the treatment of metastatic colorectal carcinoma to the liver and review of the literature

BACKGROUND

Hepatic artery chemoembolization represents an alternative treatment for patients whose neoplastic lesions are not amenable or have become refractory to other treatment modalities. This project was designed to test the feasibility of regional chemoembolization for patients with colorectal carcinoma metastasis to the liver who had experienced failure with one or more systemic treatments.

METHODS

Thirty patients who met the study entry criteria underwent one to three hepatic artery chemoembolizations. The chemoembolization regimen consisted of an injection of a bovine collagen material with cisplatin (10 mg/mL), doxorubicin (3 mg/mL), and mitomycin C (3 mg/mL). Repeat treatments were performed at 6- to 8-week intervals.

RESULTS

Radiologic responses, as measured by a decrease in lesion density of at least 75% of the lesion or a 25% decrease in the size of the lesion, occurred in 63% of the cases. A decrease of at least 25% of the baseline carcinoembryonic antigen level occurred in 95% of the cases. All responses were transient. Median survival for all 30 patients was 8.6 months after the initiation of chemoembolization and 29 months after the initial diagnosis of metastasis to the liver. Common toxicities included a "postembolization syndrome," which consisted of fever > 101 degrees F (83%), pain in the right upper quadrant (100%), nausea, and vomiting. Lethargy was a common occurrence (in 60+% of cases) and lasted up to 6 weeks. Hematologic toxicities included leukocytosis, anemia, and thrombocytopenia.

CONCLUSIONS

Chemoembolization is a feasible treatment modality for patients with colorectal carcinoma metastasis to the liver who have experienced failure with other systemic treatments. It results in high response rates with transient mild-to-moderate toxicity. Responses are measured in months, however, and all patients have eventual progression of disease. Patients who are able to undergo three or more chemoembolization procedures may receive the most clinical benefit.

Phase II trial of chemoembolization for the treatment of metastatic colorectal carcinoma to the liver and review of the literature

BACKGROUND

Hepatic artery chemoembolization represents an alternative treatment for patients whose neoplastic lesions are not amenable or have become refractory to other treatment modalities. This project was designed to test the feasibility of regional chemoembolization for patients with colorectal carcinoma metastasis to the liver who had experienced failure with one or more systemic treatments.

METHODS

Thirty patients who met the study entry criteria underwent one to three hepatic artery chemoembolizations. The chemoembolization regimen consisted of an injection of a bovine collagen material with cisplatin (10 mg/mL), doxorubicin (3 mg/mL), and mitomycin C (3 mg/mL). Repeat treatments were performed at 6- to 8-week intervals.

RESULTS

Radiologic responses, as measured by a decrease in lesion density of at least 75% of the lesion or a 25% decrease in the size of the lesion, occurred in 63% of the cases. A decrease of at least 25% of the baseline carcinoembryonic antigen level occurred in 95% of the cases. All responses were transient. Median survival for all 30 patients was 8.6 months after the initiation of chemoembolization and 29 months after the initial diagnosis of metastasis to the liver. Common toxicities included a "postembolization syndrome," which consisted of fever > 101 degrees F (83%), pain in the right upper quadrant (100%), nausea, and vomiting. Lethargy was a common occurrence (in 60+% of cases) and lasted up to 6 weeks. Hematologic toxicities included leukocytosis, anemia, and thrombocytopenia.

CONCLUSIONS

Chemoembolization is a feasible treatment modality for patients with colorectal carcinoma metastasis to the liver who have experienced failure with other systemic treatments. It results in high response rates with transient mild-to-moderate toxicity. Responses are measured in months, however, and all patients have eventual progression of disease. Patients who are able to undergo three or more chemoembolization procedures may receive the most clinical benefit.

Radiographic appearance of intrathoracic complications of pregnancy

The authors reviewed all chest radiographs obtained for pregnant women at a university hospital over a 15-year period to determine the intrathoracic complications of pregnancy and diseases occurring during pregnancy. The characteristic physiologic changes seen on chest radiographs during normal pregnancy are reviewed. Examples of intrathoracic diseases that may occur in pregnant patients include pulmonary embolism, amniotic fluid embolism, beriberi, aspiration pneumonia, community-acquired pneumonia, viral pneumonia, asthma, systemic disease, trophoblastic disease and peripartum pulmonary edema. The authors discuss the radiation biology implications of performing chest radiography during pregnancy and conclude that the benefit that the fetus receives from diagnosis and treatment of the mother's disease may be greater than the risk of radiation exposure.

Contralateral loop snare removal of a ruptured and entrapped angioplasty balloon

We describe a technique that extracted a ruptured angioplasty balloon which had become entrapped by a calcified left common iliac artery stenosis. The balloon catheter had been advanced crossover from the right and could not be retracted directly into a sheath across the aortic bifurcation. Therefore, a guidewire was inserted through the balloon catheter and captured by a loop snare advanced from the left femoral artery. The loop snare was also used to free the balloon wings from the stenosis. The balloon was then pulled into a 10 Fr sheath and removed as a unit with the sheath.

Percutaneous cholecystostomy for the diagnosis and treatment of acute calculous and acalculous cholecystitis

PURPOSE

To determine the safety, efficacy, and diagnostic utility of percutaneous cholecystostomy in patients with suspected calculous or acalculous cholecystitis.

PATIENTS AND METHODS

Percutaneous cholecystostomy guided with ultrasound (US) was performed in 58 consecutive hospitalized patients with suspected acute cholecystitis (28 with calculous, 30 with acalculous disease) who were not surgical candidates.

RESULTS

The gallbladder was successfully catheterized in all 58 patients; 48 patients (83%) had a final diagnosis of acute cholecystitis. Clinical benefit was seen in 26 of 28 patients (93%) with calculous cholecystitis and in 16 of 20 patients (80%) with acalculous disease. The six patients who did not respond had pathologic evidence of transmural inflammation, and five had a gangrenous wall. The gallbladder was excluded as the source of sepsis in 10 patients with suspected acalculous cholecystitis. These patients' conditions did not improve after percutaneous cholecystostomy. Of the 48 patients with cholecystitis, 18 underwent cholecystectomy, 25 recovered and had their catheters removed, and five died of other causes with their catheters in place. There was one major complication, and seven minor complications.

CONCLUSION

Percutaneous cholecystostomy is efficacious in both calculous and acalculous cholecystitis, but it may be most useful in the diagnosis of acalculous cholecystitis.

Stimulation of human T cells by streptococcal "superantigen" erythrogenic toxins (scarlet fever toxins)

The pyrogenic (erythrogenic) exotoxins A and C (SPEA and SPEC) of Streptococcus pyogenes belong to the family of mitogenic toxins of which the staphylococcal enterotoxins are the prototypes. The erythrogenic toxin B (SPEB) is a proteinase precursor. All SPE have been reported to be superantigens. Here we have analyzed the human T cell response to these toxins. We used highly purified preparations of SPEA, SPEB, and SPEC from different S. pyogenes strains. These toxins were apparently homogenous in SDS-PAGE, IEF, and HPLC. In addition, recombinant SPEA and SPEC were produced in Escherichia coli. In cultures of PBMC, all three toxins expanded preferentially a fraction of T cells. Using mAb against V beta 2, -5, -6, -8, and -12, we investigated the phenotype of the stimulated cells. Natural SPEA, SPEB, and SPEC strongly stimulated V beta 8+ T cells, whereas recombinant SPEA and SPEC did not. Both natural and recombinant SPEA stimulated V beta 12+ cells and both natural and recombinant SPEC stimulated V beta 2+ cells. In accordance with these findings, a human V beta 8+ line responded to all three toxins derived from S. pyogenes but not to the recombinant proteins. An antiserum against natural SPEC neutralized specifically the V beta 2-stimulating activity of SPEC and the V beta 8-stimulating activity of all three toxins, but had no effect on the response to other superantigens. This shows that trace amounts of a potent novel V beta 8-stimulating activity not identical to SPEA and SPEC are responsible for the stimulation of V beta 8+ T cells by natural SPEA and SPEC reported previously. In a preliminary screening of S. pyogenes strains from patients, we found that this novel superantigen appears to be more widely distributed than SPEA and SPEC. Furthermore, we present evidence that also the superantigenic properties of SPEB are due to contaminations with this V beta 8 stimulator. The response to SPEB usually required 1000 times higher concentrations than to SPEA or SPEC. Antisera to SPEC but not to SPEB inhibited the response of PBMC and V beta 8+ Jurkat cells to SPEB. Furthermore, more stringent purification of SPEB yielded SPEB preparations devoid of mitogenic activity. These results indicate that the mitogenicity that is commonly attributed to SPEB is due to minute contaminations of the V beta 8 stimulator. These results raise two important caveats for the work with these highly potent T cell mitogens.(ABSTRACT TRUNCATED AT 400 WORDS)

Stimulation of human T cells by streptococcal "superantigen" erythrogenic toxins (scarlet fever toxins)

The pyrogenic (erythrogenic) exotoxins A and C (SPEA and SPEC) of Streptococcus pyogenes belong to the family of mitogenic toxins of which the staphylococcal enterotoxins are the prototypes. The erythrogenic toxin B (SPEB) is a proteinase precursor. All SPE have been reported to be superantigens. Here we have analyzed the human T cell response to these toxins. We used highly purified preparations of SPEA, SPEB, and SPEC from different S. pyogenes strains. These toxins were apparently homogenous in SDS-PAGE, IEF, and HPLC. In addition, recombinant SPEA and SPEC were produced in Escherichia coli. In cultures of PBMC, all three toxins expanded preferentially a fraction of T cells. Using mAb against V beta 2, -5, -6, -8, and -12, we investigated the phenotype of the stimulated cells. Natural SPEA, SPEB, and SPEC strongly stimulated V beta 8+ T cells, whereas recombinant SPEA and SPEC did not. Both natural and recombinant SPEA stimulated V beta 12+ cells and both natural and recombinant SPEC stimulated V beta 2+ cells. In accordance with these findings, a human V beta 8+ line responded to all three toxins derived from S. pyogenes but not to the recombinant proteins. An antiserum against natural SPEC neutralized specifically the V beta 2-stimulating activity of SPEC and the V beta 8-stimulating activity of all three toxins, but had no effect on the response to other superantigens. This shows that trace amounts of a potent novel V beta 8-stimulating activity not identical to SPEA and SPEC are responsible for the stimulation of V beta 8+ T cells by natural SPEA and SPEC reported previously. In a preliminary screening of S. pyogenes strains from patients, we found that this novel superantigen appears to be more widely distributed than SPEA and SPEC. Furthermore, we present evidence that also the superantigenic properties of SPEB are due to contaminations with this V beta 8 stimulator. The response to SPEB usually required 1000 times higher concentrations than to SPEA or SPEC. Antisera to SPEC but not to SPEB inhibited the response of PBMC and V beta 8+ Jurkat cells to SPEB. Furthermore, more stringent purification of SPEB yielded SPEB preparations devoid of mitogenic activity. These results indicate that the mitogenicity that is commonly attributed to SPEB is due to minute contaminations of the V beta 8 stimulator. These results raise two important caveats for the work with these highly potent T cell mitogens.(ABSTRACT TRUNCATED AT 400 WORDS)

An aberrant right hepatic artery from the right renal artery: anatomical vignette

The vascular supply of the liver is variable. An unusual aberrant right hepatic artery arising from the right renal artery is described. The embryologic derivation and clinical relevance are discussed.

A new DNA binding assay to study subclasses of SV40 large T antigen binding to individual binding sites on the SV40 DNA

SV40 large T antigen interacts specifically with three different sequences, termed sites I, II or III, within the control region of the SV40 DNA to regulate transcription as well as the initiation and progress of SV40 DNA replication. We have biotinylated three different DNAs containing either site I, II or III and immobilized these constructs on a streptavidin agarose matrix. All three immobilized DNAs were shown to bind T antigen from a total cell extract of SV40 infected monkey cells although with different affinities. Pulse chase experiments revealed that newly synthesized T antigen bound efficiently to all three binding sites whereas mature T antigen bound only to site I and site III DNA. The analysis of non-binding and DNA-bound T antigen on sucrose density gradients showed that only low molecular weight forms of T antigen were bound to all three immobilized DNAs. However, incubation of T antigen in the total cell extract with site I DNA resulted in high molecular weight forms of T antigen, indicating that the presence of site I DNA influences the quaternary structure of T antigen which might result in a detachment from the DNA.

Lung cancer in patients seropositive for human immunodeficiency virus

The authors describe the clinical and radiographic findings of lung carcinoma in six patients infected with the human immunodeficiency virus (HIV). These patients were in a younger age group than is commonly associated with lung cancer. The radiographic findings included mediastinal adenopathy (n = 5), hilar masses with distal atelectasis (n = 3), parenchymal masses (n = 3), pleural effusions (n = 2), and pleural thickening (n = 1). Recognition of any of these findings should raise the diagnostic possibility of lung cancer in this group of younger patients.

Pyriformis syndrome in a 10-year-old boy as a complication of operation with the patient in the sitting position

We present a case of sciatic neuropathy due to the pyriformis syndrome after operation in the sitting position. Neither sciatic nerve injury nor the pyriformis syndrome has been reported after operation in the sitting position, although a low incidence of common peroneal nerve injury has been reported as a complication of operation on patients who are in the sitting position. The clinical findings of sciatic neuropathy, external rotation of the ipsilateral foot in the position of comfort, and a therapeutic response to local anesthetic injection into the pyriformis muscle are diagnostic of the syndrome. Nerve conduction studies should be performed to aid in the differentiation between a common peroneal and sciatic neuropathy. The syndrome may occur because of extreme flexion of the hips and prolonged pressure while in the sitting position, leading to pyriformis muscle trauma, resultant spasm, and sciatic compression. The prognosis is for complete recovery after symptomatic treatment with nonsteroidal antiinflammatory medication and physical therapy.

Cerebral perfusion pressure monitoring in premature newborns

Cerebral perfusion pressure (CPP), believed to be a major determinant of neurologic outcome, was monitored at the bedside of high-risk premature newborns during the first few days of life. Intraventricular hemorrhage was presumed to have occurred in only one of the seven infants and was associated with ventriculomegaly and early death. The other infants had good neurologic outcomes at age 18 months despite low mean CPPs (less than 30 mm Hg). These low CPPs were determined to be dependent on mean arterial blood pressures and not on intracranial pressures which were low in all infants (and even lower in more premature infants with apnea). Methylxanthine treatment of apnea of prematurity did not apparently change CPP, despite hypothetical effects on cerebral and peripheral vascular tone. Although fairly low CPP can be associated with good neurologic outcome, it may not be useful in monitoring newborn infants.

Occupational therapy management of the acute spinal cord-injured patient

This report describes an occupational therapy program for the patient with an acute spinal cord injury. The program includes guidelines for evaluation and treatment, criteria for early orthotic selection, and psychological considerations. The program was developed by the occupational therapy staff at Northwestern Memorial Hospital, Chicago, in conjunction with a medical team and occupational therapy staff from the Rehabilitation Institute of Chicago. The intent of the program is to implement rehabilitation in the acute care environment immediately.

The jittery newborn and infant: a review

Jitteriness is an involuntary movement that is particularly frequent in the newborn. Its hallmark is tremor. The pathogenesis is poorly understood. Jitteriness is often accompanied by other signs of central nervous system excitation, such as hypermotility, hypertonicity, and ease of startle. It must be differentiated from myoclonus and seizure, although they may coexist. Jitteriness can be caused by a variety of pre-, peri-, and postnatal insults, and it is the nature and treatability of these, rather than the tremor itself, that are the major determinants of the ultimate prognosis. "Coarse" tremor is probably more often abnormal than "fine" tremor, and appears to bear some relationship to the later development of a choreiform syndrome. The evaluation of the jittery infant must be individualized and management aimed at reversing any remediable causes.

[Effect of high doses of retinol acetate on the 3-beta-ol-steroid dehydrogenase and alkaline phosphatase content in mouse ovaries]

The author reports on the effects of different doses of retinol acetate on ovarian steroidogenesis. Two groups of CBA/C57BL mice with a mean body weight of 18-20 g received 3.44% oily retinol acetate per os in daily doses of 50 000 and 80 000 IU for 10 days. After completion of the experiments the quick-frozen sections of the ovaries were subjected to a histochemical assay for the content of 3-beta-ol-steroid dehydrogenase and alkaline phosphatase. Administration of 50 000 IU vitamin A was found to stimulate ovarian steroidogenesis. The effect of vitamin A was the most demonstrable in the interstitial tissue, atretic corpora, and, in the internal theca of the follicles. Administration of 80 000 IU retinol acetate inhibited ovarian steroidogenesis. The estrous cycle in animals ceased. Administration of vitamin A (80 000) primarily affected the follicular apparatus of the ovaries, namely the epithelium of the follicles and yellow bodies. At the same time secretory function of atretic corpora and interstitial tissue remained within normal, which was regarded as a compensatory-adaptive mechanism under toxic hypervitaminosis A.

[Effect of different doses of retinol acetate on the RNA and total protein content of rodent ovaries and endometrium]

The effects of different doses of retinol acetate (RA) on protein synthesis by the hamster ovaries and endometrium were studied. Two groups of CBA/C57BL mice aged 3-4 months were given 3.44% oily RA per os on a daily basis for 10 days. After completion of the experiments the paraffin sections 6 micron m thin were subjected to a histochemical assay for the content of RNA and total protein in the ovaries and endometrium. RA (50 000 IU) was found to stimulate RNA and protein synthesis in all the ovarian structures and endometrium. In the ovaries, vitamin primarily affected the follicular epithelium and internal the-ca of the follicles. Administration of RA in a dose of 80 000 IU inhibited protein synthesis in the ovaries and endometrium. As for the ovarian structures the greatest changes under toxic hypervitaminosis A (80 000 IU) were experienced by the follicular epithelium and ovocytes.

[Histofunctional state of mouse ovaries in normal conditions and during hypervitaminosis A]

Morphometry was used to analyze different histofunctional structures of mouse ovaries (follicles of varying maturation grades, yellow and atretic bodies, interstitial tissue) in health and hypervitaminosis A (80 000 IU). It was noticed that in the ovaries of female mice in health, there occurred consistent cyclic processes marked by the changes in the number and size of the morphofunctional structures during different stages of the estrous cycle. In hypervitaminosis A, female mice had no estrous cycle. The ovaries showed the impairment of the growth of the follicles and enhancement of atresia. As a result, the follicles did not reach the final stages of development, which led to the cessation of ovulation and formation of yellow bodies.