Attaining freshwater and estuarine-water soil saturation in an ecosystem-scale coastal flooding experiment

Coastal upland forests are facing widespread mortality as sea-level rise accelerates and precipitation and storm regimes change. The loss of coastal forests has significant implications for the coastal carbon cycle; yet, predicting mortality likelihood is difficult due to our limited understanding of disturbance impacts on coastal forests. The manipulative, ecosystem-scale Terrestrial Ecosystem Manipulation to Probe the Effects of Storm Treatments (TEMPEST) experiment addresses the potential for freshwater and estuarine-water disturbance events to alter tree function, species composition, and ecosystem processes in a deciduous coastal forest in MD, USA. The experiment uses a large-unit (2000 m²), un-replicated experimental design, with three 50 m × 40 m plots serving as control, freshwater, and estuarine-water treatments. Transient saturation (5 h) of the entire soil rooting zone (0-30 cm) across a 2000 m² coastal forest was attained by delivering 300 m³ of water through a spatially distributed irrigation network at a rate just above the soil infiltration rate. Our water delivery approach also elevated the water table (typically ~ 2 m belowground) and achieved extensive, low-level inundation (~ 8 cm standing water). A TEMPEST simulation approximated a 15-cm rainfall event and based on historic records, was of comparable intensity to a 10-year storm for the area. This characterization was supported by showing that Hurricane Ida's (~ 5 cm rainfall) hydrologic impacts were shorter (40% lower duration) and less expansive (80% less coverage) than those generated through experimental manipulation. Future work will apply TEMPEST treatments to evaluate coastal forest resilience to changing hydrologic disturbance regimes and identify conditions that initiate ecosystem state transitions.

Hepatitis of unknown aetiology in children - epidemiological overview of cases reported in Europe, 1 January to 16 June 2022

Following the report of an excess in paediatric cases of severe acute hepatitis of unknown aetiology by the United Kingdom (UK) on 5 April 2022, 427 cases were reported from 20 countries in the World Health Organization European Region to the European Surveillance System TESSy from 1 January 2022 to 16 June 2022. Here, we analysed demographic, epidemiological, clinical and microbiological data available in TESSy. Of the reported cases, 77.3% were 5 years or younger and 53.5% had a positive test for adenovirus, 10.4% had a positive RT-PCR for SARS-CoV-2 and 10.3% were coinfected with both pathogens. Cases with adenovirus infections were significantly more likely to be admitted to intensive care or high-dependency units (OR = 2.11; 95% CI: 1.18–3.74) and transplanted (OR = 3.36; 95% CI: 1.19–9.55) than cases with a negative test result for adenovirus, but this was no longer observed when looking at this association separately between the UK and other countries. Aetiological studies are needed to ascertain if adenovirus plays a role in this possible emergence of hepatitis cases in children and, if confirmed, the mechanisms that could be involved.

Estimated number of deaths directly averted in people 60 years and older as a result of COVID-19 vaccination in the WHO European Region, December 2020 to November 2021

Since December 2019, over 1.5 million SARS-CoV-2-related fatalities have been recorded in the World Health Organization European Region - 90.2% in people ≥ 60 years. We calculated lives saved in this age group by COVID-19 vaccination in 33 countries from December 2020 to November 2021, using weekly reported deaths and vaccination coverage. We estimated that vaccination averted 469,186 deaths (51% of 911,302 expected deaths; sensitivity range: 129,851-733,744; 23-62%). Impact by country ranged 6-93%, largest when implementation was early.

Lessons from intensified surveillance of viral hepatitis A, Israel, 2017 and 2018

Introduction

Universal vaccination of toddlers has led to very low hepatitis A (HAV) endemicity in Israel. However, sporadic outbreaks still occur, necessitating better surveillance.

Aim

To implement a comprehensive HAV surveillance programme.

Methods

In 2017 and 2018, sera from suspected HAV cases that tested positive for anti-HAV IgM antibodies were transferred to the Central Virology Laboratory (CVL) for molecular confirmation and genotyping. Sewage samples were collected in Israel and Palestine* and were molecularly analysed. All molecular (CVL), epidemiological (District Health Offices and Epidemiological Division) and clinical (treating physicians) data were combined and concordantly assessed.

Results

Overall, 146 cases (78 in 2017 and 68 in 2018, median age 34 years, 102 male) and 240 sewage samples were studied. Most cases (96%) were unvaccinated. In 2017, 89% of cases were male, 45% of whom were men who have sex with men (MSM). In 2018, 49% were male, but only 3% of them were MSM (p < 0.01). In 2017, 82% of cases and 63% of sewage samples were genotype 1A, phylogenetically associated with a global MSM-HAV outbreak. In 2018, 80% of cases and 71% of sewage samples were genotype 1B, related to the endemic strain previously identified in Israel and Palestine*. Environmental analysis revealed clustering of sewage and cases’ sequences, and country-wide circulation of HAV.

Conclusions

Molecular confirmation of HAV infection in cases and analysis of environmental samples, combined with clinical and epidemiological investigation, may improve HAV surveillance. Sequence-based typing of both clinical and sewage-derived samples could assist in understanding viral circulation.

Ensuring HIV care to undocumented migrants in Israel: a public-private partnership case study

BACKGROUND

Undocumented migrants in Israel, mostly originating from HIV endemic countries, are not covered by Israel's universal healthcare coverage. We initiated a Public-Private Partnership (PPP) to handle this public health and humanitarian challenge. The PPP venture included the Ministry of Health (MoH), pharmaceutical companies, pharmacies, and specialized HIV clinics, the Israeli HIV Medical Society (from the Israel Medical Association), and non-governmental organizations. This study describes the national policy process in conceptualizing and implementing access to HIV services for undocumented migrants through a PPP, and analyzes the preliminary results.

METHODS

This case study describes the process of creating a temporary Public-Private Partnership to provide HIV care for undocumented migrants based on institutional records of the Department of Tuberculosis and AIDS (DTA) and memories and reflections from partners. This case was analyzed according to the OECD-DAC criteria for development assistance (relevance, effectiveness, efficiency, sustainability and impact). Demographic and serological data of patients referred between 2014 to 2018 were collected to monitor progress. and analyze preliminary medical and biological outcomes. Ethical approval was obtained from the Ministry of Health.

RESULTS

Creating a policy to extend HIV care to undocumented migrants was a 15 year process that confronted several challenges within Israeli and international discourse, particularly concerning governmental response to the migration crisis. The use of a PPP model involving numerous stakeholders provided a solid, local feasibility demonstration that extending HIV care as a matter of policy would have positive implications for public health in Israel. During the first 2 years of the program (2014-2015), the MoH funded medical follow-up and the pharmaceutical companies provided antiretroviral treatment (ART) free of charge for only 100 patients at any given time, in addition to ART provided by the MoH for pregnant women. Since 2016, the MoH has fully covered this service and integrated it within the Israeli health system; this constitutes the major success of the PPP program. As of December 2018, the national program has monitored 350 patients and treated 316 (90.3%). The most prevalent disease present upon referral was Tuberculosis.

CONCLUSIONS

To our knowledge, this study documents the first example of a successful PPP with government partnership in a high-income country to address undocumented migrants' lack of access to health services in general and HIV care in particular. In light of the intensification of North-South migration, this Israeli case study could be useful for other countries facing similar challenges. It also has lessons within Israel, as the country grapples with other health problems among uninsured communities.

Heterosexual men who purchase sex and attended an STI clinic in Israel: characteristics and sexual behavior

Background

Commercial sex shares a role in HIV and sexually transmitted infections (STI) transmission. Men who pay for sex (MPS) may transmit HIV/STI to other populations which are low-risk. This study aimed to test our hypothesis that MPS engage in high-risk sexual behaviors associated with HIV/STI transmission more so than non-MPS.

Methods

This cross-sectional study included heterosexual men who attended an STI clinic between 2003 and 2010. Demographic, clinical, behavioral and laboratory data were compared between MPS and non-MPS to identify factors associated with high-risk sexual behavior and STI-burden.

Results

Of the first visits of 6156 heterosexual men who attended the STI-clinic during the study period, 1649 (26.7%) were MPS. MPS were more commonly older, married and non-Israeli born compared with non-MPS. MPS were more likely to engage in risk-behaviors associated with HIV/STI-transmission, including a greater number of lifetime sexual partners, substance use and previous STI diagnoses.

Determinants associated with STI-diagnoses at the current visit included being non-Israeli born, presenting with STI symptoms, reporting a greater number of lifetime sexual partners and having sexual encounters with non-Israeli individuals.

Conclusions

Approximately 25% of all men who attended the clinic were MPS. They were more likely to engage in risk-behaviors associated with HIV/STI transmission compared to non-MPS. These findings highlight the need to establish interventions for MPS that both continue to encourage condom use and address the potential perils pertaining to risky sexual behaviors.

Two blinking mechanisms in highly confined AgInS2 and AgInS2/ZnS quantum dots evaluated by single particle spectroscopy

Ternary AgInS2 quantum dots (QDs) have been found as promising cadmium-free, red-shifted, and tunable luminescent bio-probes with efficient Stokes and anti-Stokes excitations and luminescence lifetimes (ca. 100 ns) convenient for time resolved techniques like fluorescence life-time imaging. Although the spectral properties of the AgInS2 QDs are encouraging, the complex recombination kinetics in the QDs being still far from understood, limits their full utility. In this paper we report on a model describing the recombination pathways responsible for large deviations from the first-order decay law observed commonly in the ternary chalcogenides. The presented results were evaluated by means of individual AgInS2 QD spectroscopy aided by first principles calculations including the electronic structure and structural reconstruction of the QDs. Special attention was devoted to study the impact of the surface charge state on the excited state relaxation and effect of its passivation by Zn(2+) ion alloying. Two different blinking mechanisms related to defect-assisted charge imbalance in the QD responsible for fast non-radiative relaxation of the excited states as well as surface recharging of the QD were found as the major causes of deviations from the first-order decay law. Careful optimization of the AgInS2 QDs would help to fabricate new red-shifted and tunable fluorescent bio-probes characterized by low-toxicity, high quantum yield, long luminescence lifetime, and time stability, leading to many novel in vitro and in vivo applications based on fluorescence lifetime imaging (FLIM) and time-gated detection.

Effect of a myosin regulatory light chain mutation K104E on actin-myosin interactions

Familial hypertrophic cardiomyopathy (FHC) is the most common cause of sudden cardiac death in young individuals. Molecular mechanisms underlying this disorder are largely unknown; this study aims at revealing how disruptions in actin-myosin interactions can play a role in this disorder. Cross-bridge (XB) kinetics and the degree of order were examined in contracting myofibrils from the ex vivo left ventricles of transgenic (Tg) mice expressing FHC regulatory light chain (RLC) mutation K104E. Because the degree of order and the kinetics are best studied when an individual XB makes a significant contribution to the overall signal, the number of observed XBs in an ex vivo ventricle was minimized to ∼20. Autofluorescence and photobleaching were minimized by labeling the myosin lever arm with a relatively long-lived red-emitting dye containing a chromophore system encapsulated in a cyclic macromolecule. Mutated XBs were significantly better ordered during steady-state contraction and during rigor, but the mutation had no effect on the degree of order in relaxed myofibrils. The K104E mutation increased the rate of XB binding to thin filaments and the rate of execution of the power stroke. The stopped-flow experiments revealed a significantly faster observed dissociation rate in Tg-K104E vs. Tg-wild-type (WT) myosin and a smaller second-order ATP-binding rate for the K104E compared with WT myosin. Collectively, our data indicate that the mutation-induced changes in the interaction of myosin with actin during the contraction-relaxation cycle may contribute to altered contractility and the development of FHC.

The spatial distribution of actin and mechanical cycle of myosin are different in right and left ventricles of healthy mouse hearts

The contraction of the right ventricle (RV) expels blood into the pulmonary circulation, and the contraction of the left ventricle (LV) pumps blood into the systemic circulation through the aorta. The respective afterloads imposed on the LV and RV by aortic and pulmonary artery pressures create very different mechanical requirements for the two ventricles. Indeed, differences have been observed in the contractile performance between left and right ventricular myocytes in dilated cardiomyopathy, in congestive heart failure, and in energy usage and speed of contraction at light loads in healthy hearts. In spite of these functional differences, it is commonly believed that the right and left ventricular muscles are identical because there were no differences in stress development, twitch duration, work performance, or power among the RV and LV in dogs. This report shows that on a mesoscopic scale [when only a few molecules are studied (here three to six molecules of actin) in ex vivo ventricular myofibrils], the two ventricles in rigor differ in the degree of orientational disorder of actin within in filaments and during contraction in the kinetics of the cross-bridge cycle.

Long lived BSA Au clusters as a time gated intensity imaging probe

The work presented here reports the use of long lifetime (>1 μs) BSA Au clusters as a cellular/tissue, time gated, intensity imaging probe. By collecting the emission signal 50 ns post excitation, one can off-gate the intense auto-fluorescence background, thereby greatly enhancing the clarity/specificity in fluorescence imaging.

Rationale and dose-finding studies of the combination of irinotecan and a taxane on a weekly schedule

Cisplatin (Platinol)-based chemotherapy has been the standard systemic therapy for both non-small-cell and small-cell lung cancer for the past 2 decades, though the efficacy and benefit remain modest. Recently, several novel agents have been introduced that have single-agent activity comparable to cisplatin and offer the possibility of improved therapy for lung cancer. Camptothecin and taxane derivatives are associated with both different mechanisms of action and nonhematologic toxicities, and have demonstrated additive or synergistic activity when used in combination in preclinical studies. We review pertinent clinical studies of these agents in lung cancer and present our experience in combining irinotecan (Camptosar, CPT-11) with taxanes on a weekly schedule in dose-finding and efficacy studies. When chemotherapy is delivered for 4 consecutive weeks followed by a 2-week rest, hematologic toxicity is dose limiting and most prominent during weeks 3 and 4. Dose intensification is feasible if the schedule is modified so the chemotherapy is given on days 1 and 8, with cycles repeated every 3 weeks. The most common nonhematologic toxicities remain asthenia, neuropathy, and diarrhea. Future studies will explore and better define the role of these drug combinations in the treatment of lung cancer.

Therapeutic uses of sexually explicit materials in the United States and the Czech and Slovak Republics: a qualitative study

This study investigates the reflections of 279 U.S. and Czech and Slovak mental health and health professionals about their use of sexually explicit materials. Professionals were 2.6 times as likely to cite specific instances when their use of sexually explicit materials was useful with their clients and students than they were to cite instances when such materials were not useful. In addition, no significant differences were observed between the ways in which U.S. and Czech and Slovak mental health and health professionals evaluated these materials. The article presents several suggestions for the judicious and efficacious use of sexually explicit materials in therapy or in the classroom in either Western or Central European settings.

Intraocular pressure-raising potential of 1.0% rimexolone in patients responding to corticosteroids

OBJECTIVE

To compare the intraocular pressure (IOP) elevating potential of 1.0% rimexolone and 0.1% fluorometholone alcohol ophthalmic suspensions in patients known to have responded to corticosteroids.

DESIGN

In a double-masked, randomized, single-eye, crossover protocol, corticosteroid responsiveness initially was verified in 40 asymptomatic known steroid responders by challenge with either 0.1% dexamethasone sodium phosphate or 1.0% prednisolone acetate for up to 6 weeks. After a 1-month medication washout, subjects randomly received either rimexolone or fluorometholone for 6 weeks. Medications were again discontinued for 1 month, and subjects then received the alternate drug for 6 weeks.

RESULTS

There was no significant difference between rimexolone and fluorometholone in the number of subjects demonstrating a 10-mm Hg increase in IOP or in the mean number of weeks required to achieve a 10-mm Hg response. Responses occurred in significantly more subjects receiving dexamethasone sodium phosphate (P = .001) or prednisolone acetate (P < .001) and in a significantly shorter interval than in subjects receiving rimexolone.

CONCLUSIONS

Rimexolone has a low IOP-elevating potential, comparable to that of fluorometholone and less than that of dexamethasone sodium phosphate and prednisolone acetate.

Povidone-iodine for ophthalmia neonatorum prophylaxis

PURPOSE

The agents currently used to prevent ophthalmia neonatorum are less than optimal, with reports indicating evidence of bacterial resistance, ineffectiveness, and toxicity. Povidone-iodine ophthalmic solution, which has been shown to be effective in the preoperative preparation of the eye, generates no resistance, is an effective antimicrobial agent, and has low toxicity. We evaluated the effectiveness and safety of povidone-iodine for ophthalmia neonatorum prophylaxis.

METHODS

A bacterial culture was taken from the conjunctiva of each eye of 100 infants within 30 minutes of birth. A drop of 2.5% povidone-iodine solution was then placed on one eye, while the other eye received either one drop of silver nitrate 1% ophthalmic solution or 0.5% erythromycin ointment. Conjunctival bacterial cultures were again taken two to four hours after birth. At each culture and at 24 hours after birth, the eyes were examined for toxic changes. To measure the effectiveness of the medications, the number of bacterial colony-forming units and species from each culture was compared.

RESULTS

All three agents significantly reduced the number of colony-forming units, but povidone-iodine caused the most significant decrease. The number of species was reduced significantly by povidone-iodine (P = .00051) and silver nitrate (P = .007), with povidone-iodine yielding the most significant decrease. Erythromycin did not significantly reduce the number of species. Silver nitrate demonstrated more ocular toxicity at the 24-hour determination point than did either of the other two medications (P < .001).

CONCLUSIONS

Povidone-iodine 2.5% ophthalmic solution is an effective antibacterial agent on the conjunctiva of newborns and causes less toxicity than silver nitrate.

Complete heart block in a child with varicella

A case of varicella myocarditis in a previously healthy 6-year-old child was reviewed. The patient presented with third-degree heart block and shock as the sole manifestation of her cardiac involvement. Bradyarrhythmias required temporary transvenous pacing. Intravenous acyclovir was used. The patient recovered without permanent sequelae. The natural history, clinical presentation, and treatment of varicella myocarditis are reviewed.

Comparative efficacies of ciprofloxacin, pefloxacin, and vancomycin in combination with rifampin in a rat model of methicillin-resistant Staphylococcus aureus chronic osteomyelitis

The efficacies of the quinolones ciprofloxacin and pefloxacin alone and in combination with rifampin were compared with those of vancomycin alone and in combination with rifampin in a rat model of chronic osteomyelitis caused by methicillin-resistant Staphylococcus aureus. Neither the quinolones nor vancomycin alone was effective in reducing titers of organisms in bone after therapy, while rifampin alone was effective. All combination regimens with rifampin were more effective than the regimen with rifampin alone was, although these differences did not achieve statistical significance. Rifampin-resistant isolates were detected rarely. Quinolone-rifampin combination regimens may offer a nonparenteral option for the treatment of chronic osteomyelitis caused by methicillin-resistant S. aureus.

Microbiological and clinical significance of a new property of defective lysis in clinical strains of pneumococci

A pneumococcal isolate that caused relapsing meningitis in a patient infected with human immunodeficiency virus (HIV) was found to display an unusual response to penicillin--rapid death but a striking lack of cellular lysis. This lytic defect was also detected in all four pneumococcal isolates from three additional HIV-infected patients and in more than half of the clinical isolates from patients with bacteremia. In a rabbit model of meningitis, the lysis-defective strain remained cryptic, with a delay of 5 h in the onset of leukocytosis in cerebrospinal fluid. A marked burst of leukocytosis was associated with ampicillin-induced lysis of a lysis-sensitive strain but not of a lysis-defective strain. Pneumococcal clinical isolates have different lytic responses to penicillin; defective lysis may adversely affect the course of meningitis, an observation suggesting that autolysins play a role in modulating infectious diseases.

Growth of the conjunctival fornix and orbital margin in term and premature infants

Knowledge of the growth of the neonatal conjunctival fornix and anterior orbit will aid development of neonatal prosthetic conformers and conjunctival sensors for oxygen determinations, as well as help define orbital malformation syndromes. These data are not available in any prospective series in the literature. The authors studied 55 premature and term neonates and determined horizontal and vertical dimensions of the conjunctival fornix and orbital margin and palpebral fissure width. Each of the ocular parameters had statistically significant correlation coefficients in relation to weight and gestational age (P less than 0.05). Linear regression analysis showed significant relationships which predict conjunctival fornix, orbital margin, and palpebral fissure dimensions from body weight (P less than 0.05). Statistically significant correlation coefficients and linear regression relationships were found for horizontal, but not vertical, diameter measurements of the conjunctival fornix in relation to orbital margin and palpebral fissure dimensions (P less than 0.01).

Nonsteroidal anti-inflammatory agents in the therapy for experimental pneumococcal meningitis

An increased inflammatory mass in the subarachnoid space during bacterial meningitis may correlate with a poor outcome of disease. Using a rabbit model of pneumococcal meningitis, we sought to reduce this inflammatory process. The ability of the pneumococcal cell wall to cause death and to generate leukocytosis and abnormal chemistry in cerebrospinal fluid was prevented when animals were treated with inhibitors of cyclooxygenase pathway of arachidonate metabolism. Bacterial lysis by ampicillin led to release of cell wall that caused a significant, transient increase in meningeal inflammation. This inflammatory burst was also prevented by administering cyclooxygenase inhibitors concurrently with the antibiotic.

Induction of pulmonary inflammation by components of the pneumococcal cell surface

Using a rabbit model of experimental pneumonitis, the components on the surface of the pneumococcus that incite pulmonary inflammation were identified. Rabbits were challenged intratracheally with live pneumococci, capsular polysaccharide, purified cell walls, or cell wall subcomponents. Leukocytosis and elevation of protein concentration was quantitated in bronchial lavage fluid during the first 24 h after challenge. Of the pneumococcal surface components tested, cell wall preparations had the highest specific activity in inducing inflammation; abnormalities in bronchial lavage fluid cytochemistry appeared rapidly and in a dose-dependent manner. Cell wall building blocks and the products of penicillin-induced hydrolysis of the cell wall were also highly inflammatory, indicating that inflammation can be generated by disruption of the cell wall during lysis of bacteria by beta-lactam antibiotics. Administration of inhibitors of arachidonic acid metabolism suggested that inhibition of the lipoxygenase pathway reduced inflammation associated with cell walls. We propose that pulmonary inflammation during pneumococcal pneumonia arises in large part from the interaction of the bacterial cell wall with complement and noncomplement-mediated host defenses.

Treatment of advanced non-Hodgkin's lymphoma with vincristine infusion

Twenty-five patients with a variety of histologic types of advanced non-Hodgkin's lymphoma refractory to previous chemotherapy were entered into a trial of vincristine infusion. Patients received 5-day courses of vincristine 0.25 mg/m2/day by continuous intravenous infusion after an initial 0.5 mg intravenous bolus injection. Courses were repeated every 3 weeks. Objective responses were observed in nine patients (36%), all of whom had previously received vincristine given by conventional bolus injection. A complete response occurred in a patient with diffuse mixed histiocytic lymphocytic lymphoma, and partial responses were observed in eight patients with the following histologic types: diffuse poorly differentiated lymphocytic (4); nodular poorly differentiated lymphocytic (2); diffuse mixed histiocytic lymphocytic (1); and diffuse histiocytic (1). Duration of response lasted from 1.2 to 16.2 months (mean, 4.4 months). The principal complication of therapy was mild-to-moderate neurotoxicity; this occurred in 12 patients (48%) who received a total of 54 courses of vincristine infusion. Hematologic toxicity was minimal and nausea/vomiting did not occur. Vincristine infusion may afford palliation for patients with advanced non-Hodgkin's lymphomas who have become refractory to standard chemotherapeutic regimens even if they have received prior vincristine by conventional bolus injection. These data suggest the possibility of enhancing the therapeutic efficacy of vincristine in the treatment of non-Hodgkin's lymphoma by use of an infusion technique.

Anticoagulation in urologic surgery

The present report describes a pilot project to apply the principle of minidose heparinization to patients undergoing prostatectomy, comparing a control group of 50 prostatectomies treated in conventional fashion to a study group of 43 prostatectomies treated with minidose heparinization. Results of the study indicate that perioperative minidose heparinization in patients undergoing prostatectomy is associated with longer hospitalization, greater need for blood transfusion, greater degree of immediate and delayed postoperative bleeding, and a higher incidence of "rebound" pulmonary embolization after cessation of heparin, than in patients treated in conventional fashion.

Enzyme-induced formation of spheres from cells and envelopes of Escherichia coli

Normal and filamentous whole cells and isolated envelopes of Escherichia coli B were exposed to various enzymatic treatments to remove surface layers and to characterize the component(s) conferring rigidity in this organism. Modification of cell rigidity was determined by sphere formation in both whole cells and isolated envelopes. Enzymes capable of converting trypsinized normal or untreated filamentous whole cells and untreated envelopes to spheres included: lysozyme plus ethylenediaminetetraacetic acid, clostridial phospholipase C, and phospholipase D from cabbage. These data suggest that there are at least two components essential for maintenance of cell rigidity in E. coli B. The first is the peptidoglycan (mucopeptide), which is susceptible to lysozyme. The second is a phospholipid which is either covalently linked to the mucopeptide or in close association with it. This phospholipase C-sensitive component is protected more completely in normal than in filamentous whole cells by a protein layer which is easily modified by trypsin treatment to allow enzymatically induced sphere formation to occur.