Gram stain microbiological pattern of upper extremities suppuration at Baptist Medical Centre, Ogbomoso Nigeria: a fifteen month review.

Sixty-eight (68) patients with serious upper extremity suppurative infections, presenting within a period of fifteen (15) months, were prospectively studied clinically, Gram stain of aspirates/pus were performed, specimen cultured, planted, and where indicated glucose levels and haemoglobin genotype determined. Half of the patients had hand infections. Staphylococcus aureus was isolated from thirty-nine (39) patients. Gram Negative bacilli, including Salmonella were more isolated from patients with diabetes mellitus or Hgb SS or SC. The Gram stain results correlated with the culture result 90%. When Gram Positive cocci were demonstrated in the primary microscopic examination, cultures were not mandatory. When no organism was demonstrated on primary Gram stain or the patient was diabetic or a sickler, cultures of the specimens were done. The Gram stain, well performed, remains a useful, inexpensive, technologically appropriate laboratory test for abetting decision making in patients with upper extremity suppurative infections. Organisms encountered in this study included: Staphylococcus aureus, Streptococcus pyogenes, Salmonella typhi, Proteus mirabilis, Pseudomonas aeruginosa, and Coliforms.

Conditioned turning behavior: a Pavlovian fear response expressed during the post-encounter period following aversive stimulation.

Rats were trained to fear an auditory conditioned stimulus (CS) by pairing it with a mild electric shock (the unconditioned stimulus, or US) delivered to one eyelid. After training, the CS elicited two different conditioned fear responses from rats: a passive freezing response, and an active turning response. The balance between these two modes of conditioned responding depended upon the rat's recent history of encounters with the US. If rats had not recently encountered the US, then they responded to the CS by freezing. But after recently encountering the US, rats exhibited CS-evoked turning responses that were always directed away from the trained eyelid, even if the US had recently been delivered to the opposite (untrained) eyelid. This post-encounter turning behavior was not observed in rats that had been trained with unpaired presentations of the CS and US, indicating that even though CS-evoked turning was selectively expressed after recent encounters with the US, it was nonetheless a conditioned Pavlovian fear response that depended upon a learned association between the CS and US. Further supporting this conclusion, pharmacological inactivation experiments showed that expression of both freezing and turning behaviors depended upon lateralized circuits in the amygdala and periaqueductal gray (PAG) that are known to support expression of Pavlovian fear responses. These findings indicate that even though the ability of a CS to elicit Pavlovian fear responses depend upon the long-term history of CS-US pairings, the mode of conditioned responding (freezing versus turning in the present experiments) can be modulated by short-term factors, such as the recent history of US encounters. We discuss neural mechanisms that might mediate such short-term transitions between different modes of defensive responding, and consider how dysregulation of such mechanisms might contribute to clinical anxiety disorders.

Bilateral phosphorylation of ERK in the lateral and centrolateral amygdala during unilateral storage of fear memories.

We previously showed that when rats were trained to fear an auditory conditioned stimulus (CS) by pairing it with a mild unilateral shock to the eyelid (the unconditioned stimulus, or US), conditioned freezing depended upon the amygdala contralateral but not ipsilateral from the US. It was proposed that convergent activation of amygdala neurons by the CS and US occurred mainly in the amygdala contralateral from US delivery, causing memories of the CS-US association to be stored primarily by that hemisphere. In the present study, we further tested this interpretation by administering unilateral infusions of U0126 (in 50% dimethyl sulfoxide (DMSO) vehicle) to block phosphorylation of extracellular signal-responsive kinase (ERK) in the amygdala prior to CS-US pairings. Conditioned freezing was impaired 24 h after training when U0126 was infused contralaterally-but not ipsilaterally-from the US, suggesting that fear memories were consolidated mainly by the contralateral amygdala. However, immunostaining experiments revealed that ERK phosphorylation was elevated in both hemispheres of the amygdale's lateral (LA) and centrolateral (CeL) nuclei after paired (but not unpaired (UNP)) presentations of the CS and US. Thus, fear acquisition induced ERK phosphorylation bilaterally in the amygdala, even though the ipsilateral hemisphere did not appear to participate in conditioned freezing. These findings suggest that associative plasticity may occur in both amygdala hemispheres even when only one hemisphere is involved in freezing behavior. Conditioning-induced ERK phosphorylation was identical in both hemispheres of LA, but was slightly greater in the contralateral than ipsilateral hemisphere of CeL. Hence, asymmetric induction of plasticity in CeL might help to explain why conditioned freezing depends preferentially upon the amygdala contralateral from the US in our fear conditioning paradigm.

Novel erythropoiesis stimulating protein (darbepoetin alfa) alleviates anemia associated with chronic inflammatory disease in a rodent model.

OBJECTIVE: We developed a rodent model of noninfectious systemic inflammation to examine the pathogenesis of the associated anemia of chronic disorders (ACD), to evaluate the similarity of this ACD model to human ACD, and to evaluate the potential efficacy of novel erythropoiesis stimulating protein (darbepoetin alfa) as an ACD therapy. METHODS: Lewis rats were immunized with peptidoglycan-polysaccharide polymers (PG-APS), the chronic inflammation and associated ACD were characterized, and the effects of darbepoetin alfa treatment on complete blood counts (CBC), red blood cell (RBC) indices, and iron metabolism were analyzed weekly. RESULTS: Acutely inflamed rats had reduced peripheral blood (PB) RBC counts and hemoglobin (Hb) concentrations and increased reticulocyte counts. PB RBC numbers normalized during chronic inflammation, but RBC remained hypochromic and microcytic. Consequently, the rats remained chronically anemic. Anemic rats had fluctuating serum erythropoietin (EPO) concentrations, but mean EPO concentrations never varied significantly from baseline control levels. Histology of anemic rat spleen sections revealed reticuloendothelial siderosis. Total serum iron concentrations were chronically low. Peritoneal exudate cells (PEC) isolated from anemic rats and stimulated with PG-APS in vitro produced more interleukin (IL)-1alpha and interferon (IFN)-gamma, and significantly more tumor necrosis factor (TNF)-alpha and IL-10 than control cultures. Darbepoetin alfa restored Hb concentrations to baseline levels within 2 to 7 weeks, depending on dosage. A refined treatment strategy restored Hb to baseline and maintained those levels with reduced dosing. CONCLUSION: ACD in this rodent model closely replicates human ACD. Darbepoetin alfa treatment reversed ACD in this model by increasing RBC production and RBC hemoglobinization while reducing siderosis and hypoferremia.

Prospective randomized comparison of two preoperative skin preparation techniques in a developing world country.

Povidone-iodine (PI) is a scarce and expensive item for some hospitals in developing countries. This prospective, randomized study was performed at Baptist Medical Centre (BMCO) in Ogbomoso, Nigeria to determine if the use of PI for preoperative skin preparation would result in a lower postoperative wound infection rate and to identify other factors influencing the infection rate. Two hundred patients undergoing inguinal hernia repair were randomized to receive skin preparation with either: (1) locally available, inexpensive market soap and methylated spirit or (2) imported PI. The two groups were equally stratified. The overall postoperative wound infection rate was 5.5%, and there was no significant difference between the groups (5.1% vs. 5.9%). Factors that did not affect the infection rate included gender, age, type of anesthesia, type or duration of the operative procedure, and number of breaks in optimal technique. There were eight abscesses and three cases of cellulitis without suppuration diagnosed an average of 10 days postoperatively. Staphylococcus was the only bacterium identified on Gram stain or culture. The expense of procuring PI is not justified at BMCO. Available funds may better be used for preoperative antibiotics or for improvement in hospital infrastructure, which should result in fewer breaks in optimal operating room technique.

Incidence of umbilical hernia in African children: redefinition of "normal" and reevaluation of indications for repair.

This study was undertaken to assess the degree of ubiquity of umbilical hernias (UHs) in Nigerians and to determine if a laissez faire approach to the presence of UHs is justified. A prospective evaluation was conducted of the umbilical area of 4052 Nigerians living in the vicinity of the Baptist Medical Centre (BMCO) in Ogbomoso, Nigeria. The diameter of the fascial defect was measured with the subject supine and the protrusion of the umbilical skin with the subject erect. Subjects were divided into three groups: group 1 (1 month to 18 years old); group 2 (older than 18 years); and group 3 (pregnant women in an antenatal clinic). "Outies" (defined as any protrusion of the umbilical tip past the periumbilical skin) were present in 92% of group 1, 49% of group 2, and 90% of group 3 subjects. UHs (defined as protrusion of at least 5 mm and diameter of at least 10 mm) were present in 23% of group 1, 8% of group 2, and 15% of group 3 subjects. Spontaneous closure of UHs seems to occur until age 14. A retrospective analysis identified 11 patients undergoing emergency operations for UH-related problems during the past 15 years. With a low incidence and 0% mortality rate associated with management of these emergencies, a policy of prophylactic repair is not justified at BMCO. Because most of the children we examined had outies, repair for cosmetic reasons is rarely requested. The only logical indication for repair of UHs at BMCO is incarceration, and this rarely occurs.

Prolonged neutropenia in a novel mouse granulocyte colony-stimulating factor neutralizing auto-immunoglobulin G mouse model.

Therapeutic use of recombinant human cytokines in humans can result in the generation of drug-specific antibodies. To predetermine the maximum potential effects of a granulocyte colony-stimulating factor (G-CSF) neutralizing auto-immunoglobulin G (auto-IgG) response during recombinant human G-CSF therapy, we developed a mouse model of mouse G-CSF (mG-CSF) neutralizing auto-IgG response. Mice were immunized and boosted with mG-CSF chemically conjugated to either keyhole limpet hemocyanin or ovalbumin on an alternating schedule. Sera were analyzed for mG-CSF-specific titers and full blood counts were performed on a Technicon H-1E. On day 252, tissues were collected for histology. IgG was protein A affinity purified from pooled mG-CSF autoimmune sera. Mice immunized with mG-CSF conjugates produced mG-CSF-specific auto-IgG responses that lasted for the length of the study. Significant neutropenia (p(max) < 0.004) was concurrent with the rise in mG-CSF-specific IgG titers. However, neutrophil counts remained at approximately 20% of preimmunization levels through day 252. Endogenous mG-CSF neutralizing auto-IgG had no significant effect on hemoglobin, erythrocyte, lymphocyte, eosinophil, basophil, and platelet counts, and had minor, transient, or no effects on monocyte counts. Bone marrow colony assays from mG-CSF autoimmune mice demonstrated no significant effect of G-CSF neutralization on the numbers or proliferative capacity of preneutrophil lineage progenitors. Purified IgG from mG-CSF autoimmune mice neutralized mG-CSF in vitro. High-titer G-CSF neutralizing auto-IgG in adult mice partially inhibited steady-state granulopoiesis and had little or no effect on steady-state levels of other hematopoietic cells.

Operative management of thyroid abnormalities in a general medical practice hospital in sub-Saharan Africa.

This is a retrospective analysis of 82 patients undergoing thyroid operations in a general medical practice hospital in sub-Saharan Africa. All patients complained of neck swelling, and in 75% of patients this was the only symptom. Indications for operation included cosmesis in 74%, suspected malignancy in 13%, hyperthyroidism in 7% and pressure symptoms in 5%. Operative complications included recurrent laryngeal nerve injury in two (2.4%), wound haematoma in two (2.4%), wound infection in three (3.6%) and hypoparathyroidism in one (1.2%). There were no deaths and no instances of thyroid storm. Thyromegaly can be operatively managed in a hospital such as ours with a relatively low morbidity rate using conservative gland extirpation techniques. This conservative approach may result in under treatment for thyroid malignancies but should result in a lower incidence of recurrent nerve damage and hypoparathyroidism in the majority of people who undergo thyroidectomy solely for cosmetic indications.

RANK is the intrinsic hematopoietic cell surface receptor that controls osteoclastogenesis and regulation of bone mass and calcium metabolism.

We have generated RANK (receptor activator of NF-kappaB) nullizygous mice to determine the molecular genetic interactions between osteoprotegerin, osteoprotegerin ligand, and RANK during bone resorption and remodeling processes. RANK(-/-) mice lack osteoclasts and have a profound defect in bone resorption and remodeling and in the development of the cartilaginous growth plates of endochondral bone. The osteopetrosis observed in these mice can be reversed by transplantation of bone marrow from rag1(-/-) (recombinase activating gene 1) mice, indicating that RANK(-/-) mice have an intrinsic defect in osteoclast function. Calciotropic hormones and proresorptive cytokines that are known to induce bone resorption in mice and human were administered to RANK(-/-) mice without inducing hypercalcemia, although tumor necrosis factor alpha treatment leads to the rare appearance of osteoclast-like cells near the site of injection. Osteoclastogenesis can be initiated in RANK(-/-) mice by transfer of the RANK cDNA back into hematopoietic precursors, suggesting a means to critically evaluate RANK structural features required for bone resorption. Together these data indicate that RANK is the intrinsic cell surface determinant that mediates osteoprotegerin ligand effects on bone resorption and remodeling as well as the physiological and pathological effects of calciotropic hormones and proresorptive cytokines.

Adult rodent double skeletal stain.

Rodent embryo double skeletal staining has long played a role in toxicological studies and is now an important part of selected genetic studies involving knockout or transgenic animals. However, phenotypic changes are sometimes not seen until animals reach adulthood. This study expands a previously developed embryonic staining method for use with adult mice.

The prolonged hematologic effects of a single injection of PEG-rHuMGDF in normal and thrombocytopenic mice.

A single injection of > or =10 microg/kg PEG-rHuMGDF in mice causes a dose-dependent increase in circulating platelets beginning on day 3 and peaking on days 5-6. The mean platelet volume and platelet distribution width at doses > or =100 microg/kg initially increase in a dose-dependent fashion and later decrease. However, the mean platelet volume does not change when platelets are incubated with PEG-rHuMGDF in vitro. The number of marrow megakaryocytes increases in a dose-dependent fashion as early as day 1 and peaks on day 3. Marrow megakaryocyte colony-forming units (CFU-Meg) do not increase on days 1-3 at a dose of 100 microg/kg (a dose that increases platelet numbers two- to threefold and may be clinically relevant), but the relative frequency of high ploidy megakaryocytes and the proportion of large marrow megakaryocytes (29-50 microm in diameter) increases. After a dose of 1,000 microg/kg the percentage of megakaryocytes in mitosis peaks at 24-48 hours and the percentage of megakaryocytes incorporating BrdU is maximal at 48 hours, the relatively delayed peak of BrdU incorporation most likely representing endomitosis. The relative frequency of type II and III megakaryocytes peaks on days 3 and 4, respectively. Pharmacokinetic analysis of PEG-rHuMGDF shows peak serum concentrations at 2-4 hours and a terminal half-life of 11.4+/-2.5 hours. A single injection of PEG-rHuMGDF ameliorates carboplatin-induced megakaryocytopenia and thrombocytopenia in a dose-response dependent fashion. In conclusion, a single injection of PEG-rHuMGDF increases megakaryocyte and platelet production in normal and myelo-suppressed mice.

Fgf-10 is required for both limb and lung development and exhibits striking functional similarity to Drosophila branchless.

Fgf-10-deficient mice (Fgf-10(-/-)) were generated to determine the role(s) of Fgf-10 in vertebrate development. Limb bud initiation was abolished in Fgf-10(-/-) mice. Strikingly, Fgf-10(-/-) fetuses continued to develop until birth, despite the complete absence of both fore- and hindlimbs. Fgf-10 is necessary for apical ectodermal ridge (AER) formation and acts epistatically upstream of Fgf-8, the earliest known AER marker in mice. Fgf-10(-/-) mice exhibited perinatal lethality associated with complete absence of lungs. Although tracheal development was normal, main-stem bronchial formation, as well as all subsequent pulmonary branching morphogenesis, was completely disrupted. The pulmonary phenotype of Fgf-10(-/-) mice is strikingly similar to that of the Drosophila mutant branchless, an Fgf homolog.

A Neu differentiation factor (NDF) domain essential for proliferation and alterations in morphology of colonic epithelial cells in vitro.

The Neu Differentiation Factors (NDFs, also termed "heregulins") are a family of proteins that were first isolated as ligands for the HER2 (ergB2, or p185neu) receptor protein tyrosine kinase. Here we show that NDF acts to stimulate the proliferation and alter the cellular morphology of colonic epithelial cells in culture. Dramatic NDF-induced changes in cellular morphology were noted in the colonic epithelial cell line, LIM 1215. In addition, the expression of specific cell proteins, such as carcinoembryonic antigen and integrin beta 4, was induced in LIM 1215 cells by NDF. These effects were more pronounced with the beta isoform than with the alpha isoform of NDF. The EGF-homology domain of NDF beta was sufficient to stimulate the proliferation and alteration in cell morphology. The use of chemically synthesized chimeric NDF alpha and NDF beta proteins enabled use to identify a region of seven amino acids in the EGF-homology domain of NDF beta that is required for both activities. These in vitro experiments suggest that NDF may act as a regulator of growth and differentiation of colonic epithelial cells in vivo.

osteoprotegerin-deficient mice develop early onset osteoporosis and arterial calcification.

Osteoprotegerin (OPG) is a secreted protein that inhibits osteoclast formation. In this study the physiological role of OPG is investigated by generating OPG-deficient mice. Adolescent and adult OPG-/- mice exhibit a decrease in total bone density characterized by severe trabecular and cortical bone porosity, marked thinning of the parietal bones of the skull, and a high incidence of fractures. These findings demonstrate that OPG is a critical regulator of postnatal bone mass. Unexpectedly, OPG-deficient mice also exhibit medial calcification of the aorta and renal arteries, suggesting that regulation of OPG, its signaling pathway, or its ligand(s) may play a role in the long observed association between osteoporosis and vascular calcification.

Aortoiliac occlusive disease and gastrointestinal malignancy: changing therapeutic options.

Treatment of gastrointestinal malignancy encountered unexpectedly during procedures involving the abdominal aorta continues to be debated. Previously, simultaneous vascular procedures with intra-abdominal malignancy were rare. Most underwent vascular reconstruction followed by a delayed aortic procedure. With recent improvement in axillobifemoral graft patency, a one-stage procedure for aortoiliac disease should be entertained. We recently encountered a small bowel lymphoma while beginning an aortic replacement for aortic occlusion. Resection of a near-obstructing small bowel tumor immediately after axillofemoral reconstruction provided treatment of both entities at one time. Since the early description of axillofemoral bypass in 1963, varying success with extra-anatomic bypass has been reported. Early data for axillofemoral bypass were dismal, but with recent technical and graft improvements patency has been improved. Occult malignancy during aortic procedures is uncommon, about 2 to 4 per cent, but when met is usually dealt with after the patient recovers from the vascular procedure. With improvements in extra-anatomic bypass results, a single operative period can be entertained.

Typhoid intestinal perforations in Nigerian children.

This study was a retrospective analysis of 75 children with perforated typhoid enteritis treated at the Baptist Medical Centre in Ogbomoso, Nigeria over a 4-year period. The mean age was 11.4 years. The usual symptoms were fever and abdominal pain, with a mean duration of 10.5 days. The diagnosis of perforation was usually based on the history and physical examination alone. The time interval from hospital presentation to operation was 11 hours, during which intravenous crystalloid and antibiotics were administered. Among the 75 children, 53 (71%) had a single perforation, and 22 had multiple perforations. Débridement and two-layered closure was performed in 71 (95%) and resection with anastomosis in 4 (5%). Ileus resolution was usually not complete until the eighth postoperative day, and the mean time until the surviving children were afebrile was 10 days. Complications other than death occurred in 7 (9%) children, and there were 15 deaths (20% mortality). All deaths were attributed to overwhelming sepsis, and all but one of the deaths occurred during the first 72 postoperative hours. The only factor statistically significant as a predictor of mortality was the duration of abdominal pain. Improvement in perioperative management including intensive care nursing and more effective antibiotics, although expensive, could result in decreased mortality. A significant decrease in mortality can occur only when the prevention of typhoid fever becomes a higher priority than its treatment.

Dephosphorylation and deactivation of Ca2+/calmodulin-dependent protein kinase II in betaTC3-cells is mediated by Mg2+- and okadaic-acid-sensitive protein phosphatases.

The alpha-toxin-permeabilized betaTC3 cell has been utilized as an experimental model for the identification of protein phosphatases responsible for the dephosphorylation and deactivation of Ca2+/calmodulin-dependent protein kinase II (CaM kinase II) in situ. In this model, the elevation of Ca2+ from 0.05 to 10 microM induced the near-total conversion of CaM kinase II into a Ca2+/calmodulin-independent (autonomous) form characteristic of autophosphorylated, activated enzyme. On the removal of Ca2+, the activation state of CaM Kinase II rapidly returned to prestimulated levels. This reversal was slowed, but not prevented, by the inhibitors of protein phosphatase-1 (PP-1) and PP-2A, okadaic acid and calyculin A, and by the selective chelation of Mg2+ by the addition of EDTA. Near-complete prevention of enzyme deactivation, however, was observed in the combined presence of both okadaic acid and EDTA. Under these conditions, CaM kinase II phosphatase was more sensitive to calyculin A relative to okadaic acid, characteristic of the involvement of PP-1. CaM kinase II deactivation was not affected by FK-506, eliminating the involvement of PP-2B in this process. These data suggest that CaM kinase II dephosphorylation and deactivation in the pancreatic beta-cell is mediated by the combined action of an okadaic-acid-sensitive phosphatase and a Mg2+-dependent phosphatase, such as PP-2C.

Correlation of the activation of Ca2+/calmodulin-dependent protein kinase II with the initiation of insulin secretion from perifused pancreatic islets.

An experimental procedure has been designed to permit the simultaneous assessment of the activation status of the multifunctional Ca2+/calmodulin-dependent protein kinase II (CaM kinase II) with insulin secretion in perifused islets. By this procedure, the activation of CaM kinase II by glucose correlated closely with the initial and sustained phases of insulin secretion within a 30-min test period. By contrast, islets (160-200/tube) in static incubations neither supported second-phase insulin secretion nor CaM kinase II activation beyond 10-15 min. This was not the result of the accumulation of insulin, because the introduction of insulin (40-160 ng/ml) into the perifusion medium failed to mimic the suppression of glucose-induced insulin secretion or CaM kinase II activation. A similar addition of SRIF (0.01-1 microM) or epinephrine (1 microM) profoundly suppressed insulin secretion although failing to significantly influence CaM kinase II activation. Finally, on withdrawal of glucose from perifused islets, insulin secretion rapidly returned to basal rates, but CaM kinase II deactivation was significantly delayed. The correlation of kinase activation with the initiation of insulin secretion suggests that CaM kinase II may be important in the regulation of glucose-induced insulin secretion. The observed dissociation of these parameters in the presence of inhibitory hormones or after the withdrawal of a glucose stimulus, however, suggests that the kinase is not directly involved in the final steps of insulin exocytosis.

Osteoprotegerin: a novel secreted protein involved in the regulation of bone density.

A novel secreted glycoprotein that regulates bone resorption has been identified. The protein, termed Osteoprotegerin (OPG), is a novel member of the TNF receptor superfamily. In vivo, hepatic expression of OPG in transgenic mice results in a profound yet nonlethal osteopetrosis, coincident with a decrease in later stages of osteoclast differentiation. These same effects are observed upon administration of recombinant OPG into normal mice. In vitro, osteoclast differentiation from precursor cells is blocked in a dose-dependent manner by recombinant OPG. Furthermore, OPG blocks ovariectomy-associated bone loss in rats. These data show that OPG can act as a soluble factor in the regulation of bone mass and imply a utility for OPG in the treatment of osteoporosis associated with increased osteoclast activity.